HomeMy WebLinkAboutAPA176SET tD.No.3 7
COpy No.OL
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Demeo,Inc.38·293
ARLIS
Alaska Resources
Libra~y &Information Services
Anchorage,AJaska
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-SUSITNA HYDROELECTRIC PROJECT
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FEASIBILITY REPORT
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VOLUME 2
ENVIRONMENTAL
REPORT
SECTIONS 1-4
FINAL DRAFT
Prepared by:
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Envi'onmentol
.pecialilt"Inc.
ARLIS
Alaska Resources
Library &Information SerVices
AnC)[a...:..:,/Jask~
Prepared for:
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TABLE OF CONTENTS
L1ST OF TABLES
LIST OF FIGURES
PREFACE
1 -GENERAL DESCRIPTION OF THE LOCALE
1.1 -Location ...•...•......••..•...•...•..••....•.......•.......
1.2 -Physiography and Topography ••.•..•....••••.•.•..•...•.••.••
1.3 -Geology and Soils ..•.............•........•................
1.4 -Hydrology .....•...•...•...•....•.....................•.....
1.5 -Cl imate ................•........••........•............•...
1.6 - Veg et at ion ...•...•................•........•.............•.
1.7 -Wildlife ....•.......•.............................•........
1.8 -Fish ...............•...•....................•...•....•.....
1.9 -Land Use .•........................................••...•...
1-1
1-1
1-1
1-1
1-2
1-2
1-3
1-3
1-3
2 -WATER USE AND QUALITY
2.1 -Water Use ••....•...•.......•.......................•......•2-1
2.2 -Water Quality •.................•.............•.....•.......2-5
3 -REPORT ON FISH,WILDLIFE,AND BOTANICAL RESOURCES
3.1 -Description of Botanical Resources •..••....•.........•.....
3.2 -Description of Wildlife Resources .•....•.................••
3.3 -Description of Fish Resources ...•..••....••.........•...••.
3.4 -Threatened or Endangered Species .......••...•......•...•...
3.5 -Anticipated Impacts on Botanical Resources ..•.•............
3.6 -Anticipated Impacts on Wildlife Resources .
3.7 -Anticipated Impacts on Fish Resources .•..........•...•.....
3.8 -Anticipated Impacts on Threatened or Endangered Species •..•
3.9 -Mitigation of Impa~ts on Fish,Wildlife and Botanical
Resources .••...•...•...•..................•...•....•...••
3-1
3-19
3-83
3-119
3-123
3-131
3-173
3-199
3-201
4 -REPORT ON HISTORIC AND ARCHEOLOGICAL RESOURCES
4.1 -Agency Consultation ..........•..............••...•.......•.4-1
4.2 -Survey Methods ...•.....•....•...•.........•.....•........••4-2
4.3 -Historical and Archeological Sites in the Project Area .....4-6
4.4 -Impacts on Historic and Archeological Sites .•...•..........4-8
4.5 -Mitigation of Impacts on Historic and Archeological Sites..4-10
TABLE OF CONTENTS (Cont'd)
5 -REPORT ON SOCIOECONOMIC IMPACTS
5.1 -Summary of Impacts •••••••.•••••••.•••••••••.••••••.••••••••
5.2 Identification of Impact Areas •••••••••••••.•••.••••.••.•••
5.3 -Baseline Description •••.••.•.••••.•••••••••••••••••••••••••
5.4 -Project Elements Influencing Change •.••.••••.••••••••••••••
5.5 -Socioeconomic and Sociocultural Project Impacts •••.••••••••
5.6 -Mitigation Process •••••••••••••••••••••••.•.••••.••••.••••.
Page
5-1
5-4
5-7
5-26
5-46
5-57
6 -GEOLOGY AND SOILS
6.1 -General Geology and Soils ••.••••••.••••.••••••.•••••••••.••6-1
6.2 -Devil Canyon Reservoir.....................................6-2
6.3 -Watana Reservoir ••••••..••.•••••.•..•••••••••••••.•••••••.•6-4
6.4 -Mitigation Measures •••••••••••.•••••••••••••••••••••.••••.•6-8
6.5 -Conclusions ••••••••.•.•.•••••.•.•••••••••••••.•••••••••••.•6-9
7 -REPORT ON RECREATIONAL RESOURCES
7.1 -Recreational Lands Designations ••.••••••••..••.••.•••••••••
7.2 -Existing and Proposed Recreational Facilities ••••••.•••••••
7.3 -Plan for Public Access •••••••••••••••••.•••.•••••••••••••.•
7.4 -Estimates of Existing and Future Recreational Use ••••••••••
7.5 -Schedule and Cost of Recreation Facility Development ••.••••
7-1
7-1
7-6
7-7
7-8
8 -REPORT ON AESTHETIC RESOURCES
8.1 -Aesthetic Character of Lands and Water to be Affected ••••..8-1
8.2 -Impacts on Aesthetic Resources .••.•••••••.•••••••••••••••••8-2
9 -REPORT ON LAND USE
9.1 -Existing Land Use in Project Area ••.•••••••••.•••.•.•••••••9-1
9.2 -Land Uses With the Project.................................9-10
10 -ALTERNATIVES TO THE SUSITNA PROJECT
10.1 -
10.2
10.3
10.4
10.5
10.6
Non-Susitna Hydroelectric Alternatives •..••.••••••••••••••.
Environmental Assessment of Selected Alternative Sites •••••
Upper Susitna Basin Hydroelectric Alternatives •••••••.•••.•
Coal-Fired Generation Alternative •••••••••.•.••••.••••••••.
Tidal Power Alternatives •••••••••.•••••••••••••••••••••••.•
Comparison of Alternatives •••.•••.•••••.••••••••••.••••••••
10-1
10-7
10-13
10-26
10-35
10-51
11 -LIST OF LITERATURE
11.1 -General Description of the Locale ••..••••.••..•••.•••.•••••
11.2 -Water Use and Quality •.••••••••••••••.••..•••••••••.•••••.•
11.3 -Fish,Wildlife and Botanical Resources ••.•••.•••••.••••••.•
11.4 -Historic and Archeological Resources •••.•••••••..•••.•...•.
11.5 -Socioeconomics ••..•••••.•.••..•..•..••.•••.••.••••••.•••••.
11.6 -Geological and Soil Resources •..••••...•••...•.••••.•.•.••.
11.7 -Recreational Resources .•••.•.•.•••••••••••.•.••••••.•••••••
11.8 -Aesthetic Resources .•••.••••••.••.•••.••.•••••..••••.••••••
11.9 -Land Use •.•••••••••.••..•.••••.•.•••.•..•••.•.••....•••••••
11.10 -Alternatives to the Susitna Project ••••..•••.••..•••••••••
Note:Sections 5 -11 under separate cover.
11-3
11-5
11-7
11-29
11-43
11-63
11-65
11-67
11-73
11-77
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ERRATA
Reference is made in various areas of Volume 2 to Appendix E3.The reader
should be referred instead to Reference Report R65.
LIST OF TABLES
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TABLE 2.1
TABLE 2.2
TABLE 2.3
TABLE 2.4
TABLE 2.5
TABLE 2.6
TABLE 3.1
TABLE 3.2
TABLE 3.3
TABLE 3.4
TABLE 3.5
TABLE 3.6
TABLE 3.7
TABLE 3.8
TABLE 3.9
TABLE 3.10
TABLE 3.11
TABLE 3.12
TABLE 3.13
TABLE 3.14
TABLE 3.15
TABLE 3.16
TABLE 3.17
TABLE 3.18
TABLE 3.19
TABLE 3.20
TABLE 3.21
-Susitna Township Grid
-Summary of Water Appropriations
-Water Appropriations Within One Mile of the Susitna River
-Basin and Runoff Characteristics
-Detection Limits for Water Quality Parameters
-Parameters Exceeding Criteria by Station and Season
Common and Scientific Names of Plant Species Appearing in the Text
-Hectares and Percentage of Total Area Covered by Vegetation/Habitat
Types in th~Upper Susitna River Basin
-Hectares and Percentage of Total Area Covered by Vegetation/Habitat
Types for the Area 16 km on Either Side of the Susitna River From
Gold Creek to the McLaren River
-Hectares and Percent of Total Area Covered by Vegetation/Habitat
Types Within the Healy to Fairbanks Transmission Corridor
-Hectares and Percent of Total Area Covered by Vegetation/Habitat
Types Within the Willow to Cook Inlet Transmission Corridor
-Vascular Plant Species Recorded in the Upper Susitna River Basin
Which are Outside of Their Range as Reported by Hulten (1968)
-Hectares of Different Wetland Types by Project Component
-Common and Scientific Names of Furbearer and Big Game Species
Mentioned in the Text
-Summary of Elevational Use by Approximately 200 Radio-Collared Moose
From October 1976 Through Mid-August 1981 in the Upper Susitna and
Nelchina River Basins of Southcentral Alaska
-Nelchina Caribou Herd Population Estimates,in Fall Unless Otherwise
Noted
-Reported Hunter Harvest of the Nelchina Caribou Herd,1972-1981
-Summary of Territory Sizes for Wolf Packs Studied as Part of the
Susitna Hydroelectric Project Studies During 1980 and 1981 in
Southcentral Alaska
-Estimate of Numbers of Wolves by Individual Pack Inhabiting the
Susitna Hydroelectric Study Area in Spring and Fall 1980 and 1981
-Summary of Wolf Den and Rendezvous Sites Discovered From 1975 Through
1981 Occurring Within an 80 Kilometer Radius of the Proposed
Susitna Hydroelectric Project in Southcentral Alaska
-Comparisons of Food Remains in Wolf Scats Collected at Den and
Rendezvous Sites in 1980 and 1981 from GMU-13 of Southcentral
Alaska
-Average Spring Ages of Susitna Area Brown Bear Subpopulations
-Reported Brown Bear Densities in North America
Comparisons of Mean Home Range Size of Brown Bears Radio-Collared in
1978, 1980,and 1981 Studies in GMU-13
-Comparison of Reported Home Range Sizes of Brown/Grizzly Bears in
North America
-Early Spring Use of Devil Canyon and Watana Impoundment Areas by
Radio-Collared Brown Bears
-Number of Aerial Brown Bear Observations by Month in Each of Five
Habitat Categories
TABLE 3.22
TABLE 3.23
TABLE 3.24
TABLE 3.25
TABLE 3.26
TABLE 3.27
TABLE 3.28
TABLE 3.29
TABLE 3.30
TABLE 3.31
TABLE 3.32
TABLE 3.33
TABLE 3.34
List of Tables - 2
Average Spring Ages of Black Bear Subpopulations in the Susitna Area
and Kenai Peninsula
Densities of Black Bears as Estimated in Studies Conducted in
Different Localities
-Comparisons of Mean Home Range of Black Bears Radio-Tracked in 1980
and 1981 Studies in GMU-13
-Number of Aerial Black Bear Observations by Month in Each of Five
Habitat Categories
-Tabulation of November,1980 Aerial Snow Transect Data,Indicating
the Number of Furbearer Tracks,by Species,Noted on Each Transect
-Background Information for Radio-Collared Marten,Tsusena Creek
Area,1980
-Occurrence of Beaver Signs Along Three Sections of the Lower Susitna
River
-Results of Otter and Mink Surveys,Susitna River,10 through 12
November,1980.Number of Tracks of Each Species Observed at North
and South Sides of 37 River Check Points
-Tabulations of November,1980 Aerial Snow Transect Data,Indicating
the Distribution of Furbearer Tracks,by Species,Noted in Various
Vegetation Types
-Common and Scientific Names of Birds Mentioned in the Text
-Relative Abundance of Loons,Grebes,and Waterfowl,Upper Susitna
River Basin,Alaska,Based Primarily on Total Number Observed on
1980 and 1981 Aerial Surveys and 1981 Ground Surveys
-Relative Abundance of Large Landbirds and Cranes,Upper Susitna
River Basin,Alaska,Based Primarily on Total Number Observed 17
April-23 October 1981,excluding Observations from Aircraft
-Relative Abundance of Shorebirds and Gulls,Upper Susitna River
Basin,Alaska,Based Primarily on Total Number Observed 17 April-23
October 1981,but Supplemented by Data from late Summer and Fall
1981 for Rare Species
TABLE 3.35 -Relative Abundance of Small Landbirds,Upper Susitna River Basin,
Alaska,Based Primarily on Total Number Observed 17 April-23
October 1981,Supplemented by Data from Late Summer and Fall 1980
for the Less Numerous Species
TABLE 3.36 -Avian Habitat Occupancy Levels,Upper Susitna River Basin,Breeding
Season,1981
TABLE 3.37 -Number of Territories of Each Bird Species on Each 10-Hectare Census
Plot,Upper Susitna River Basin,Alaska 1981
TABLE 3.38 -Number of Adult Waterbirds (or Independent Young)and Broods Found on
28 Waterbodies,Upper Susitna River Basin,Alaska,July 1981
TABLE 3.39 -Summary of Total Numbers and Species Composition of Waterbirds Seen
on Surveyed Waterbodies During Aerial Surveys of the Upper Susitna
River Basin,Fall 1980
TABLE 3.40 -Summary of Total Numbers and Species Composition of Waterbirds Seen
on Surveyed Waterbodies During Aerial Surveys of the Upper Susitna
River Basin,Fall 1981
TABLE 3.41 -Summary of Total Numbers and Species Composition of Waterbirds Seen
on Surveyed Waterbodies During Aerial Surveys of the Upper Susitna
River Basin,Spring 1981
TABLE 3.42 -Waterfowl Noted Along the Susitna River Between Devil Canyon and
Cook Inlet,7 May 1981
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TABLE 3.54
TABLE 3.62
TABLE 3.63
TABLE 3.64
TABLE 3.43
TABLE 3.44
TABLE 3.45
TABLE 3.46
TABLE 3.47
TABLE 3.48
TABLE 3.49
TABLE 3.50
TABLE 3.51
TABLE 3.52
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List of Tables - 3
-Location of Active Raptor and Raven Nest Sites,Upper Susitna River
Basin,Alaska,1980 and 1981
-Bald Eagle Observations Noted During the 26 June 1981 Flight Along
the Susitna River from Cook Inlet to Portage Creek
Breeding Chronologies of Eagles,Gyrfalcon,and Common Raven in
Interior Alaska
-Species of Small Mammals Found in the Upper Susitna River Basin,
Alaska,1980 and 1981
-Habitat Locations Between Cook Inlet and Devil Canyon Sampled During
the Juvenile Anadromous and Resident Fish Study
-Common and Scientific Names of Fish Species Appearing in the Text
-Unadjusted Sonar Counts of Chinook Salmon by Sampling Station,
Anadromous Adult Investigations,1981
-Apport i oned Sonar Counts and Petersen Popu 1at i on (Tag/Recapture)
Estimates by Species and Sampling Location,Adult Anadromous
Investigations,1981
-Summary of Fishwheel Catches by Species and Sampling Location,Adult
Anadromous Investigations,1981
-Petersen Population Estimates and Corresponding 95%Confidence
Intervals of Sockeye,Pink,Chum,and Coho Salmon Migrating to
Sunshine,Talkeetna,and Curry Stations,Adult Anadromous
Investigations,1981
TABLE 3.53 -Arctic Grayling Total Catch by Month in the Upper Susitna River
Drainage,1981
Ranges or Values Recorded for Parameters Measured at Study Sites in
the Susitna River and Its Tr'ibutaries During the Summer Field
Season,1981
TABLE 3.55 -List of Endangered and Threatened Plant Species Sought in the Upper
Susitna Basin Surveys
TABLE 3.56 -Hectares of Different Vegetation Types to be Impacted by the Watana
Facility Compared with Total Hectares of That Type in the Entire
Upper Basin and in the Area Within 16 km of the Susitna River
TABLE 3.57 -Hectares of Different Vegetation Types to be Impacted by the Devil
Canyon Facility Compared with Total Hectares of That Type in the
Entire Upper Basin and in the Area Within 16 km of the Susitna
River
TABLE 3.58 -Hectares of Different Vegetation Types to be Impacted by the Access
Road Compared with Total Hectares of That Type in the Upper Basin
and the Area Within 16 km of the Susitna River
TABLE 3.59 -Hectares of Different Vegetation Types to be Impacted by the Trans-
mission Facility Compared with Total Hectares of that Type in the
Transmission Corridors
TABLE 3.60 -Area of Overlap of Brown Bear Home Ranges and the Watana and Devil
Canyon Impoundments
TABLE 3.61 -Area of Overlap of Black Bear Home Ranges and the Watana and Devil
Canyon Impoundments
-General Types of Impacts to Raptors
-Disturbance of Raptors --Influence of Timing
-Linear Distances of Cliffs in Vicinity of Proposed Impoundments,and
Distances That Would be Inundated
List of Tables - 4
TABLE 3.65
TABLE 3.67
TABLE 3.68
TABLE 3.69
TABLE 5.1
TABLE 5.2
TABLE 5.3
TABLE 5.4
TABLE 5.5
TABLE 5.6
TABLE 5.7
TABLE 5.8
TABLE 5.9
TABLE 5.10
TABLE 5.11
TABLE 5.12
TABLE 5.13
TABLE 5.14
TABLE 5.15
TABLE 5.16
TABLE 5.17
TABLE 5.18
TABLE 5.19
TABLE 5.20
TABLE 5.21
TABLE 5.22
TABLE 5.23
TABLE 5.24
TABLE 5.25
-Number of Known Raptor or Raven Nest Sites in Upper Susitna River
Basin,Alaska,That Would be Inundated by Devil Canyon and Watana
Reservoirs
- A General Assessment of Potential Fish Ecology Impact Issues by
Project Stage for the Entire Susitna River Study Area Under Post-
Project Flows
-Priority Organization of Wildlife Mitigation Impact Issues
-Predicted Downstream Water Temperatures (OC)for an Average Year
with Project Flows
-Baseline Forecasting Techniques
-Impact Forecasting Techniques
-Total Resident Population and Components of Change by Impact Area:
1970-1980
-Civilian Labor Force Data and Percent Unemployed for Selected Areas
-Community Population:Matanuska-Susitna Borough Census Data 1939,
1950,1960,1970, 1976, 1980,1981
-Matanuska-Susitna Borough Annual Nonagricultural Employment by
Sector
Ratio of Population to Borough Employment in the Mat-Su Borough,
1966,1970-1980
Per Capita Personal Income in the Mat-Su Borough in Current and 1970
Dollars
-Population in the Anchorage Region,1966,1970-1980
-Population in the Anchorage,Kenai-Cook Inlet,Mat-Su,and Seward
Census Districts as a Percent of Total Anchorage Region Population
1966,and 1970-1980
-Railbelt Annual Nonagricultural Employment by Sector
-Anchorage Annual Nonagricultural Employment by Sector
-Employment in the Anchorage Region,By Place of Employment 1964-1980
-Employment in the Anchorage,Kenai-Cook Inlet,Mat-Su,and Seward
Census Districts as a Percent of Total Anchorage Region
Employment,By Place of Employment,1964-1980
-State Annual Nonagricultural Employment by Sector
-Total On-site Manpower Requirements,1983-2000
-On-site Manpower Requirements of Laborers,1983-2000
-On-site Manpower Requirements of Semi-skilled/Skilled Labor,1983-
2000
-On-site Manpower Requirements of Administrative/Engineering
Personnel,1983-2000
-Total Payroll for On-site Manpower,1983-2000
-Payroll for On-Site Manpower:Laborers,1983-2000
-Payroll for 8n-Site Manpower:Semi-skilled/Skilled Personnel,1983-
2000
-Payroll for On-site Manpower:Administrative/Engineering Personnel,
1983-2000
-On-site Construction Workforce:Local,Alaska Nonlocal,and Out-of-
State,1983-2000
-Recent Census Division Share of Total Impact Area 3 Construction Em-
ployment (Laborers,Semi-skilled/Skilled and
Engineering/Administrative
List of Tables - 5
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TABLE 5.26
TABLE 5.27
TABLE 5.28
TABLE 5.29
TABLE 5.30
TABLE 5.31
TABLE 5.32
TABLE 5.33
TABLE 5.34
TABLE 5.35
TABLE 5.36
TABLE 5.37
TABLE 5.38
TABLE 5.39
TABLE 5.40
TABLE 7.1
TABLE 7.2
TABLE 7.3
TABLE 7.4
TABLE·7.5
TABLE 7.6
TABLE 7.7
TABLE 7.8
TABLE 8.1
TABLE 8.2
TABLE 8.3
TABLE 9.1
TABLE 9.2
TABLE 9.3
TABLE 9.4
TABLE 9.5
TABLE 9.6
TABLE 9.7
TABLE 9.8
-Residence of Project Workers That Live in Impact Area 3,All Labor
Categories,by Year
-Cumulative Immigrants to Impact Area 3,all Labor Categories,
1983-2000
-Number of Dependents That Accompany Immigrants Into Parts of Impact
Area 3
-Total Population Influx Into Impact Area 3 Associated with the Direct
Construction Work Force
-Number of School-Age Children Accompanying Immigrant Workers,
1983-2000
-Number of Primary School-Age Children Accompanying Immigrants Into
Impact Area 3
-Secondary School-Age Children Accompanying Immigrants Into Impact
Area 3
-1981 Housing Stock Estimates and Vacancy Rates,by Areas of
Matanuska-Susitna Borough
-1980 Population,Households and Population per Household Ratios for
Selected Communities in the Matanuska-Susitna Borough
-Matanuska-Susitna Borough Percentage of Owner-Renter Distribution by
Housing Type
-1981 Civilian Housing Stock in the Municipality of Anchorage,by
Type
-Vacancy Rates in the Municipality of Anchorage,by Type of Housing
Unit,1978-1981
-Post Office Survey Vacancy Rates in the Anchorage Bowl,by Type of
Housing Unit 1975-1981
-Housing Stock in Fairbanks and the Fairbanks-North Star Borough by
Type,October 1978
-Vacancy Rates in Fairbanks-North Star Borough,1976-1980
-Regional Recreational Facilities
-Description of Opportunity Settings
-Description of Proposed Recreation Sites and Facilities
-Daily Traffic Count for the Denali and Parks Highway
-Visitor Counts for State Recreation Areas Adjacent to Parks Highway
-Capital Improvement Costs -Phase 1
-Capital Improvement Costs -Phase 2
-Estimated Annual Operating Cost
-Exceptional Natural Features
-Other Important Natural Features
-Potential Aesthetic Impacts of Borrow Areas and Housing Sites
-Zone 1 -Existing Structures
-Zone 2 -Existing Structures
-Zone 3 -Existing Structures
Use Information for Existing Structures in the Upper Susitna River
Basin
-Major Trails in the Upper Susitna River Basin
-Parcels by Land Status/Ownership Category
-Summary of Land Status/Ownership in Project Area
-Summary of Present and Future Land Management Activities in the
Proposed Susitna Hydroelectric Project Area
List of Tables - 6
TABLE 10.1 -Summary of Results of Screening Process
TABLE 10.2 -Sites Eliminated in Second Iteration
TABLE 10.3 -Evaluation Criteria
TABLE 10.4 -Sensitivity Scaling
TABLE 10.5 -Sensitivity Scaling of Evaluation Criteria (2)
TABLE 10.6 -Site Evaluations (3)
TABLE 10.7 -Site Evaluation Matrix
TABLE 10.8 -Criteria Weight Adjustments
TABLE 10.9 -Site Capacity Groups
TABLE 10.10 -Ranking Results
TABLE 10.11 -Shortlisted Sites
TABLE 10.12 -Alternative Hydro Development Plans
TABLE 10.13 Operating and Economic Parameters for Selected Hydroelectric Plants
TABLE 10.14 -Potential Hydroelectric Development
TABLE 10.15 -Results of Screening Model
TABLE 10.16 -Environmental Evaluation of Devil Canyon Dam and Tunnel Scheme
TABLE 10.17 -Social Evaluation of Susitna Basin Development Schemes/Plans
TABLE 10.18 -Overall Evaluation of Tunnel Scheme and Devil Canyon Dam Scheme
TABLE 10.19 -Environmental Evaluation of Watana/Devil Canyon and High Devil
Canyon/Vee Development Plans (2)
TABLE 10.20 -Overall Evaluation of the High Devil Canyon/Vee and Watana/Devil
Canyon Dam Plans
LIST OF FIGURES
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FIGURE 1.1
FIGURE 1.2
FIGURE 1.3
FIGURE 1.4
FIGURE 2.1
FIGURE 2.2
FIGURE 2.3
FIGURE 2.4
FIGURE 2.5
FIGURE 2.6
FIGURE 2.7
FIGURE 2.8
FIGURE 2.9
FIGURE 2.10
FIGURE 2.11
FIGURE 2.12
FIGURE 2.13
FIGURE 2.14
FIGURE 2.15
FIGURE 2.16
FIGURE 2.17
FIGURE 2.18
FIGURE 2.19
FIGURE 2.20
FIGURE 2.21
FIGURE 2.22
FIGURE 2.23
FIGURE 2.24
FIGURE 2.25
FIGURE 2.26
FIGURE 2.27
FIGURE 2.28
FIGURE 2.29
FIGURE 2.30
FIGURE 2.31
FIGURE 2.32
FIGURE 2.33
FIGURE 2.34
FIGURE 2.35
FIGURE 2.36
FIGURE 2.37
FIGURE 2.38
FIGURE 2.39
FIGURE 2.40
FIGURE 2.41
FIGURE 3.1
FIGURE 3.2
-Location of the Proposed Susitna Hydroelectric Project
-Vicinities of the ~roposed Dam Sites,Susitna Hydroelectric Project
-Upper Susitna River Basin
-Lower Susitna River Drainage
-Data Summary -Color
-Data Summary -Conductivity
-Data Summary -Hardness
-Data Summary -PH
-Data Summary -Temperature
-Data Summary -Total Dissolved Solids
-Data Summary -Total Suspended Solids
-Data Summary -Turbidity
-Data Summary -Alkalinity
-Data Summary -Chloride
-Data Summary -Ammonia Nitrogen
-Data Summary -Kjeldahl Nitrogen
-Data Summary -Nitrate Nitrogen
-Data Summary -Organic Nitrogen
-Data Summary -Total Nitrogen
Data Summary -Oxygen,Dissolved
-Data Summary -D.O.,%Saturation
-Data Summary -Ortho Phosphate
Data Summary -Phosphorus
-Data Summary -Sulfate
-Data Summary -Total Inorganic Carbon
-Data Summary -Free Carbon Dioxide
-Data Summary -Aluminum (d)
-Data Summary -Aluminum (t)
-Data Summary -Bismuth (d)
-Data Summary -Cadmium (d)
-Data Summary -Cadmium (t)
-Data Summary -Copper (d)
-Data Summary -Copper (t)
-Data Summary -Iron (d)
-Data Summary -Iron (t)
-Data Summary -Lead (t)
-Data Summary -Manganese (d)
-Data Summary -Manganese (t)
-Data Summary -Mercury (d)
-Data Summary -Mercury (t)
-Data Summary -Nickel (t)
.Data Summary -Zinc (d)
-Data Summary -Zinc (t)
-Data Summary -Chemical Oxygen Demand
-Data Summary -Total Organic Carbon
-Vegetation Map of the Upper Susitna River Basin
-Vegetation/Habitat Map of an Area Within 16 km of the Upper Susitna
River,Western Portion
List of Figures - 2
FIGURE 3.3
FIGURE 3.4
FIGURE 3.5
FIGURE 3.6
FIGURE 3.7
FIGURE 3.8
FIGURE 3.9
FIGURE 3.10
FIGURE 3.11
FIGURE 3.12
FIGURE 3.13
FIGURE 3.14
FIGURE 3.15
FIGURE 3.16
FIGURE 3.17
FIGURE 3.18
FIGURE 3.19
FIGURE 3.20
FIGURE 3.21
FIGURE 3.22
FIGURE 3.23
FIGURE 3.24
FIGURE 3.25
FIGURE 3.26
FIGURE 3.27
FIGURE 3.28
FIGURE 3.29
FIGURE 3.30
-Vegetation/Habitat Map of an Area Within 16 km of the Upper Susitna
River,Central Portion
-Vegetation/Habitat Map of an Area Within 16 km of the Upper Susitna
River,Eastern Portion
-Vegetation/Habitat Map of Healy to Fairbanks Transmission Corridor,
Northern Portion
-Vegetation/Habitat Map of Healy to Fairbanks Transmission Corridor,
Central Portion
-Vegetation/Habitat Map of Healy to Fairbanks Transmission Corridor,
Southern Portion
-Vegetation/Habitat Map of Willow to Point MacKenzie Transmission
Corridor,Northern Portion
-Vegetation/Habitat Map of Willow to Point MacKenzie Transmission
Corridor,Southern Portion
-Boundaries of the Susitna Moose Study Area -Upstream
-Boundaries of Established Moose Count Areas
-Relative Distribution of Moose Observed During a Winter
Distribution Survey Conducted from 4 through 25 March 1980
-Distribution of Main Nelchina Radio-Collared Caribou,
14 April 1980 Through 29 September 1981
Distribution of Nelchina Radio-Collared Caribou During the Calving
Period,15 May Through 10 June,1980 and 1981
-Location of Radio-Collared Caribou in Subherds,9 May 1980 Through
22 September,1981
-Suspected Locations and Territorial Boundaries of Wolf Packs
During 1980 and 1981
-General Location and Year of Use of Observed Wolf Den and Rendezvous
Sites Discovered in the Susitna Hydroelectric Project Area from
1975 Through 1981
-Wolverine Study Area
-Furbearer Study Area -Upstream
-Aerial Transects for Furbearers and Checkpoints for Signs of Otter
and Mink
-Tracking Locations for Four Radio-Collared Male Marten,1980
-Temporal Variation in Numbers of Small Mammal Captures at 12 Sites
in the Upper Susitna River Basin,Alaska
-Abundance Patterns of Eight Small Mammal Species Relative to Vege-
tation Types at 42 Sites in the Upper Susitna River Basin,
Alaska,29 July -30 August 1981
-Field Stations,Adult Anadromous Investigations,ADF&G Susitna
Hydroelectric Studies,1981
-Slough Locations and Primary Tributaries of the Susitna River From
Above the Chulitna River Confluence to Slough 4 (RKm 168)
-Slough Locations and Primary Tributaries of the Susitna River
Between Chase Creek and Slough 8
-Slough Locations and Primary Tributaries of the Susitna River
Between Lower McKenzie Creek and Slough 8B
-Slough Locations and Primary Tributaries of the Susitna River
Between Moose Slough and Fourth of July Creek
-Slough Locations and Primary Tributaries of the Susitna River
Between Slough 9A (RKm 214)and Slough 20 (RKm 225)
-Slough Locations and Primary Tributaries of the Susitna River
Between Slough 21 (RKm 227)and Devil Canyon
List of Figures - 3
-
.....
FIGURE 3.31
FIGURE 3.32
FIGURE 3.33
FIGURE 3.34
FIGURE 3.35
FIGURE 3.36
FIGURE 3.37
FIGURE 3.38
FIGURE 4.1
FIGURE 4.2
FIGURE 4.3
FIGURE 4.4
FIGURE 4.5
FIGURE 4.6
FIGURE 5.1
FIGURE 5.2
FIGURE 5.3
FIGURE 5.4
FIGURE 5.5
FIGURE 5.6
FIGURE 5.7
FIGURE 7.1
FIGURE 7.2
FIGURE 7.3
-Yentna Study Reach
-Sunshine Study Reach
-Talkeetna Study Reach
-Gold Creek Study Reach
-Impoundment Study Reach
Dissolved Gas Saturation in Vicinity of Devil Canyon,12 June 1981
-Fish and Wildlife Mitigation Plan Development and Implementation
-Option Analysis
-Known Cultural Resources Sites,Central Study Area-Map I
-Known Cultural Resources Sites,Central Study Area-Map II
-Known Cultural Resources Sites,Central Study Area-Map III
-Known Sites and Areas of High Potential for Cultural Resources,
Southern Study Area
-Known Sites and Areas of High Potential For Cultural Resources,
Northern Study Area-Map I
-Known Sites and Areas of High Potential for Cultural Resources,
Northern Study Area-Map II
-Socioeconomic Impact Areas
-Employment,Population and Per Capita Personal Income in the
Matanuska-Susitna Borough,1970-1980
Employment,Population and Per Capita Personal Income in the
Ra i1 be It Reg ion
Employment,Population and Per Capita Personal Income in the
Anchorage Municipality
-,Employment,Population and Per Capita Personal Income in the State
of Alaska,1970-1980
Total Population of Alaska (100 Years)1880-1980
-On-Site Construction Work Force Requirements,1983-2000 (Watana and
Devi 1 Canyon)~
~Recreational Opportunity Setting for the Susitna Area
-Recreation Facilities--Immediate Development
Recreation Facilities--Long-Term Development
FIGURE 8.1 -Exceptional Natural Features and Other Important Natural Features
,....
i
FIGURE 9.1
FIGURE 9.2
FIGURE 9.3
FIGURE 9.4
FIGURE 9.5
FIGURE 9.6
FIGURE 9.7
FIGURE 9.8
FIGURE 9.9
-Study Areas for Land Use Analysis
-Existing Structures
-Land Use Aggregations:Recreation,Mining,Residential
-Land Ownership/Stewardship,Devil Canyon Portion
-Land Ownership/Stewardship,Watana Portion
-Biophysical Coastal Boundary Matanuska-Susitna Borough
-Project Facilities
-Induced Land Use Activities -Devil Canyon Portion
-Induced Land Use Activities -Watana Portion
List of Figures - 4
FIGURE 10.1
FIGURE 10.2
FIGURE 10.3
FIGURE 10.4
FIGURE 10.5
FIGURE 10.6
-Susitna Basin Plan Formulation and Selection Process
-Selected Alternative Hydroelectric Sites
-Generation Scenario Incorporating Thermal and Alternative Hydropower
Developments -Medium Load Forecast -
-Formulation of Plans Incorporating Non-Susitna Hydro Generation
-Damsites Proposed by Others
-Potential Tidal Power Sites
""'"
I
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PREFACE
Terrestrial Environmental Specialists,Inc.(TES),on behalf of the Alaska Power
Authority (the Power Authority)and as a subcontractor to Acres American,Inc.
(Acres),is performing environmental studies as part of a feasibility study and,
depending on that study's outcome,a'license appl ication to the Federal Energy
Regul atory Commi ss i on (FERC)for the Sus itna Hydroel ect ric Project.The
environmental program consists of baseline studies,impact analyses,and mitigation
planninq,each of which is being conducted in two phases:preceding submission of
the Feasibility Report and License Application (Phase I)and following the License
Application (Phase II)(Acres American,Inc.1979,1980).This report is a summary
of the findings of the Phase I studies,which were performed over a two-year period
(1980-1981).
TES acknowledges the substantial input received from its subcontractors and
consultants.Principal investigators at the University of Alaska included:Dr.J.
McKendrick,Or.W.Collins,and Dr.D.Helm (Botanical Resources);Dr.P.Gipson,
Mr.S.Buskirk,and Mr.W.Hobgood (Furbearers);Dr.B.Kessel and Mr.S.MtDonald
(Birds and Small Mammals);Dr.E.J.Dixon and Mr.G.Smith (Archeological
Resources);and Dr.A.Jubenville,Ms.J.Feyhl,and Ms.P.Powell (Recreation,
Aesthetics,and Land Use).Frank Orth &Associates,Inc.(Mr.P.Rogers,Project
Manager)performed the socioeconomic study.Consultants to TES included Dr.R.
Taber (Big Game),Dr.F.Banfield (Caribou),and Mr.R.Williams,Mr.C.Atkinson
and Mr.M.Bell (Fish Resources).Ms.A.Fazekas served as editorial consultant;
Ms.C.Page and Mr.M.Goff prepared the graphics.Studies to describe the
existing fish and big game ecology were performed by the Alaska Department of Fish
and Game (ADF&G)under direct agreement with the Power Authority.
The environmental report sections on Water Use and Qual ity,Geological and Soil
Resources,and Alternatives were prepared by Acres to be combined with those
sections prepared by TES.Acres has also prepared Volume I,which describes
engineering aspects of the proposed project.In a separate appendix (E3)along
with Acres I engi neeri ng drawi ngs,are maps prepared by TES to ill ust rate
environmental considerations for the transmission route.
The environmental resources and impacts of transmission facilities between Willow
and Healy have been addressed in an independent study by the Power Authority.The
proposed route parallels the Alaska Railroad "in the vicinity of Gold Creek.
Therefore,the Susitna transmission line study,as presented in this feasibility
report,has been limited to those areas where additional corridors would be
required,namely,from the proposed dams to·Gold Creek as well as Willow to
Anchorage and Healy to Fairbanks.
1 GENERAL DESCRIPTION OF THE LOCALE
1.1 -Location
The location of the proposed Susitna Hydroelectric Project is the upper Susitna
River,Alaska,approximately 180 km north-northeast of Anchorage and 230 km
south-southwest of Fairbanks (Figure 1.1).Two proposed dams would generate
electrical power for the railbelt region of Alaska,that is,the corridor
surrounding the Alaska Railroad from Seward and Anchorage to Fairbanks.The two
proposed dam sites,Watana and Devil Canyon,are 266 and 216 km upstream of the
river's mouth at Cook Inlet.The nearest settlements (Gold Creek,Canyon,
Chulitna)are along the Alaska Railroad,approximately 18 km from Devil Canyon.
1.2 -Physiography and Topography
The Susitna River basin lies largely within the Coastal Trough province of
south-central Alaska,a belt of lowlands extending the length of the Pacific
Mountain System and interrupted by the Talkeetna,Clearwater,and Wrangell
Mountains (Wahrhaftig 1965).In the vicinity of the proposed impoundments (Figure
1.2),the river cuts a narrow,steep-walled gorge up to 300 m deep through the
Clarence Lake Upland and Fog Lakes Upland,areas of broad,rounded summits 900 to
1400 m in elevation.Between these uplands,the gorge cuts through an extension of
the Talkeetna Mountains,where rugged peaks are 1200-1900 m high.Downstream of
its confluence with the Chulitna and Talkeetna rivers,near Talkeetna,the Susitna
traverses the Cook Inlet-Susitna Lowland,a relatively flat region generally less
than 150 m in elevation.A portion of the proposed transmission facilities,
between Healy and Fairbanks,would follow the narrow valley of the Nenana River
through the Northern Foothills of the Alaska Range,traverse the Tanana-Kuskokwim
Lowland in a flat region generally less than 200 m in elevation (the Tanana Flats),
and then parallel a ridge on the edge of the Yukon-Tanana Upland.
1.3 -Geology and Soils
-;
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I
In its complex geologic history,the upper Susitna River region has undergone
uplifting and subsidence,marine deposition,volcanic intrusion,glacial planing
and erosion.The Susitna basin lies within the Talkeetna terrain,a zone of
moderate seismicity (see Volume I,Section 7).Continuing erosion has removed much
of the glacial debris at higher elevations,but very little alluvial deposition has
occurred here.The resulting landscape consists of barren bedrock mountains,
glacial till-covered plains,and exposed bedrock cliffs in canyons and along
streams.Climatic conditions have retarded the development of topsoil.sons are
typical of those formed in cold,wet climates and have developed from glacial till
and outwash.They include the acidic,saturated,peaty soils of poorly drained
areas;the acidic,relatively infertile soils of the forests;and raw gravels and
sands along the river.The upper basin is generally underlaid by discontinuous
permafrost.
1.4 -Hydro logy
The entire drainage area of the Susitna River is about 50,000 km 2 of which the
upper basin above Gold Creek comprises approximately 16,000 km Z (Figures 1.3
and 1.4).Three glaciers in the Alaska Range feed forks of the Susitna River,
which join after about 30 km to flow south through a broad valley for approximately
90 km.The river then flows westward about 140 km through a narrow valley,withr-the constriction at Devil Canyon creating violent rapids.Numerous small,
1-1
clear-water tributaries flow steeply to the Susitna in this middle section,several
of which cascade over waterfalls as they enter the gorge.As the Susitna curves
south past Gold Creek,its gradient gradually decreases.The river is joined about
60 km beyond Gold Creek in the vicinity of Ta"lkeetna by two major rivers,the
Chul itna and Talkeetna.From this confluence,the Susitna flows south through
braided channels about 130 km,until it empties into Cook Inlet near Anchorage,
approximately 450 km from its source.
Most of the annual flow occurs between May and September,when the Susitna is
heavily laden with glacial silt.Average summer flows at Gold Creek are 20,250
cubic feet per second (cfs);winter flows average only 2100 cfs.In the winter,
the river runs clear.The upper Susitna River (above the confluence with the
Chulitna)contributes about 20%of the mean annual flow measured near the river's
mouth.
The upper reaches of the Susitna start to freeze up in early October,and by the
end of November,the lower river is icebound.Breakup begins in late April or
early May,and occasional ice jams may cause the water level to rise as much as six
meters.
1.5 -C1 imate
As in most of Alaska,winters are long,summers are short,and there is
considerable variation in daylight between these seasons.Higher elevations in the
upper basin are characterized by a continental climate typical of interior Alaska.
The lower floodplain falls within a zone of transition between maritime and
continental climatic influences (Searby 1968,cited by Hartman and Johnson 1978).
From the uppe:to the lower basin,the cl imate becomes progressively wetter,with
increased cloudiness and more moderate temperatures.
At Talkeetna,which is representative of the lower basin,average annual
precipitation is'about 71 mm (28 in),of which 68%falls between May and October,
and annual snowfall is about 269 mm (106 in).Monthly average temperatures range
from _13°C (9°F)in December and January to 14°C (58°F)in July.
1.6 -Vegetation
The Susitna basin occurs within an ecoregion classified by Bailey (1976,1978)as
the Alaska Range Province of the Subarctic Division.The major vegetation types in
the upper basin are low mixed shrub,woodland and open black spruce,sedge-grass
tundra,mat and cushion tundra,and birch shrub.(Scientific names of plants are
listed in Table 3.1)These vegetation types are typical of vast areas of interior
Alaska and northern Canada,where plants exhibit slow or stunted growth in response
to cold,wet,and short growing seasons.Deciduous and mixed conifer-deciduous
forests occur at lower elevations in the upper basin,primarily along the Susitna
River,but comprise less than three percent of the upper basin area.These forest
types have more robust growth characteristics than the vegetation types at higher
elevations and are more comparable to vegetation types occurring on the floodplain
farther downstream.
The floodplain of the lower river is characterized by mature and
decadent balsam poplar forests,birch-spruce forest,alder thickets,and
willow-balsam poplar shrub communities.The willow-balsam poplar shrub and alder
communities are the earliest to establish on new gravel bars,followed by balsam
1-2
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......'I,
poplar forests and,eventually,by birch-spruce forest.The major vegetation types
within the proposed transmission corridor from Healy to Fairbanks are closed and
open deciduous forests,closed and open mixed forests,and mixed low shrub.
1.7 -Wildl ife
Big game in the upper basin include caribou,moose,brown bear,black bear,wolf,
and Dall sheep.(Scientific names of these and other wildlife species are listed
in Tables 3.8,3.31 and 3.46.)Caribou migrate through much of the open country in
the upper basin,and important calving grounds are present outside of the impound-
ment zone.Moose are fairly common in the vicinity of the proposed project,but
high quality habitat is rather l"imited.Moose also frequent the floodplain of the
lower river,especially in winter.Brown bear occur throughout the project
vicinity,while black bear are largely confined to the forested habitat along the
river;populations of both species are healthy and productive.Several wolf packs
have been noted using the area.Dall sheep generally inhabit areas higher than
900 m in elevation.
Furbearer species of the upper basin include red fox,wolverine,pine marten,mink,
river otter,short-tailed weasel,least weasel,lynx,muskrat,and beaver.Beavers
become increasingly more evident farther downstream.Sixteen species of small
mammals that are characteristic of interior Alaska are known to occur in the upper
basin.
Bird populations of the upper basin are typical of interior Alaska but sparse in
comparison to those of more temperate regions.Generally,the forest and woodl and
habitats support higher densities of birds than do other habitats.In regional
perspective,ponds and lakes in the vicinity of the proposed impoundments support
relatively few waterbirds.Ravens and raptors,including bald and golden eagles,
are conspicuous in the upper basin.Bald eagles also nest along the lower river.
1.8 -Fish
Anadromous fish in the Susitna basin include all five species of
Pacific salmon:pink (humpback);chum (dog);coho (silver);sockeye (red);and
chinook (king)!:ialmon.(Scientific names of fish are listed in Table 3.48.)
Salmon mi grate up the Susitna to spawn in tri butary streams,sloughs,and si de
channels below Devil Canyon.Surveys to date indicate that salmon are unable to
ascend the Devi 1 Canyon rapids and are thus prevented from mi grat i ng farther into
the upper basin.Anadromous smelt (eulachon)are known to migrate into the lower
Susitna River,and Bering cisco have recently been discovered.
Grayling abound in the clear-water tributaries of the upper basin;these
populations are relatively unexploited.Grayling as well as lake trout also
inhabit many lakes.The mainstem Susitna has populations of burbot and round
whitefi sh,often associ ated with the mouths of cl ear-water tr"j butari es.Dolly
Varden,humpback whitefish,sculpin,sticklebacks,and long-nosed suckers have also
.been found in the drainage.Rainbow trout,1 ike the anadromous species,have not
been found above Devil Canyon.
1.9 -Land Use
Because of limited access,the project area in the upper basin has retained a
wilderness character.There are no roads to the project vicinity,but there are
several off-road vehicle and sled trails.Although rough,dirt landing-strips for
light planes are not uncommon,floatplanes provide the principal means of access
via the many lakes in the upper basin..
1-3
Perhaps the most significant land use over the past three decades has been the
study of hydropower potential of the Susitna River.The area is also used by
hunters,white-water enthusiasts,fishermen,trappers,and miners.A few
wilderness recreation lodges and private cabins,single and in small clusters,are
scattered throughout the basin,especially on the larger lakes.
Most of the lands in the project area and on the south side of the river have been
selected by the Natives under the Alaska Native Claims Settlement Act.Lands to
the north are generally federal and are managed by the Bureau of Land Management.
The State has selected some lands on the north side of the river,and there are
many small,scattered private holdings in the upper basin.
The transmission corridors outside the dam and impoundment areas (Willow to
Anchorage and Healy to Fairbanks)traverse lands with a somewhat higher degree of
use.Most of the land within the corridors,however,is undeveloped.
1-4
J
.
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"·"'-11
u 40 Milp.s
SCALE i
o 60 Kllorneten
FIGURE ,.,.
-~]1
LEGEND
-PRIMARY PAVED UNDIVIDED HIGHWAY
----SECONDARY PAVED UNDIVIDED HIGHWAY
------SECONDARY GRAVEL HIGHWAY
++-++t+I-RAILROAD
---~•.-WATERWAY
...DAM SITES
-]-1-]------]
'"
.../
/
1-)
LOCATION OF THE PROPOSED
SUSITNA HYDROELECTRIC PROJECt
1]
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,,()\->f-\J I t/7 I~1-:;;::r ~IIV v-;]/
----'1
o
PREPARED BY TES/ACRES
.....
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Devil Canyon,View Upstream
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PREPARED BY TES
VICINITIES OF THE PROPOSED
DAM SITES,SUSITNA HYDROELECTRIC PROJECT
FIGURE 12.
~~~~1 "-~I '~~I "---'1 ~~~-l -J ]-----1 ---1 ]--)1 --,~,~J 1 -"~"J -------1
:.'~-
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Miles
10
10 20
Kilometers
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20
30
,":\"..
"i=
'"~;':i\::'(';,~'".".:.~~
R",.e".-',.v,'
Ii'"0'"iJ,7:-'~"<!1 "f.;r-~w::oDo.H.·"•
.,-:'.~."i<lSl\l '",'''·X'
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\.:!.;.~>,'\"0'0:/...,.:~..'.",
. .,,,,,e\J ......r'..,,,,,<,..,,,_I ~ilZ'""..:"~~~;;~-.....-"'i"
.\.-!~_,~:'.'.1:~.~'r r,c !
\-.1.
:/1°0 °'-
~:...
PREPARED BY TES
UPPER SUSITNA RIVER BASIN
FIGURE 1.3 [ii
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Miles
10 20
PREPARED BY TES
LOWER SUSITNA RIVER DRAINAGE
FIGURE 1.4 riJ
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!
(i)Mainstem Susitna Corridor
The mainstem Susitna corridor encompasses 30 townships,
from the proposed impoundment area at Devi 1 Canyon down-
stream to the Cook Inlet estuary.Existing surface and
ground water appropriations are primarily for singlefamily
and multi-family'homes (Table 2.1).A small amount of
water is used year-round for watering 1 ivestock.Only
0.153 cfs or 50 ac-ft/yr of surface water has been appro-
priated for all purposes (Table 2.2).Water appropriations
in other areas are even less significant.On a seasonal
bas is,the greatest usage occurs dur i ng summer months for
irrigating lawns,gardens,and crops.The largest single
use of surface water is for placer gold operations.
r
--
-
I"'"
I
As listed in Table 2.3,there are only five areas where
water appropriations are located within one mile of the
mainstem Susitna River.No surface water diversions are
recorded that draw water directly from the Susitna River or
its adjoining side channels and sloughs.Immediately down-
stream from the Delta Is 1ands,on the west bank of the
Susitna River,a single-family dwelling has a certificate
for 650 gpd of ground water from a well of unlisted depth.
The certificate includes 0.5 ac-ft/yr for crop irrigation
for three months.About six mi 1es below Ta lkeetna,and
0.25 miles inland from the west bank of the Susitna River,
a single-family dwelling has a certificate for 500 gpd of
ground water from a 90-foot-deep well.In Talkeetna,
ground water from three shallow (20-,27-,and 34-foot)
wells have been appropriated for a single-family dwelling
(500 gpd),the grade school (910 gpd),and the fire station
(500 gpd).In the vicinity of Chase,between miles 235 and
236 of the Alaska Railroad,several unnamed streams,lakes,
and creeks have been appropriated for single-family dwell-
ings (1,250 gpd),lawn and garden irrigation (100 gpd),and
crops (1 ac-ft/yr).In the vicinity of Sherman,at mile
258 of the Al aska Railroad,Sherman Creek and an unnamed
stream have been appropriated for two single-family dwell-
ings (325 gpd)and lawn and garden irrigation (50 gpd).
(ii)Other Areas
Data on existing water rights for the remalmng township
grids in the Susitna River basin are summarized in Table
2.2.The major uses of surface water occur in the Kahiltna
and W"illow Creek township grids.This water is used on a
seasonal basis for mining operations.Water appropriations
are 125 cfs,or 37,000 ac-ft/yr,in the Kahiltna area and
18.3 cfs,or 5,660 ac-ft/yr,in the Willow Creek area.
2-3
(c) Impacts of Susitna Project
Post-project water surface elevations for the mainstem river below
Talkeetna are expected to be approximately three feet hi gher dur-
ing winter months and from one half to one and one half feet lower
during the summer months (R&M Consultants).Such a moderate range
of fluctuation is not expected to adversely affect the ground
water zones being tapped by the two small-capacity domestic wells
in the Delta Is1 ands and Tapper Creek areas.The surface water
appropriations at Sherman are 50 to 100 feet above the present
elevation of the Susitna River and would not be influenced by
changes in water surface elevation of the Susitna River.
The three shallow wells (20 to 34-foot depth)recorded in Talkeet-
na are approximately 1.5 miles downstream from the confluence of
the Chulitna and Susitna rivers and 0.13 miles downstream from the
confluence of the Talkeetna River.From all visual indications
the Talkeetna River appears to be upgradient and the principal
recharge source for these well s.It appears that the water sur-
face elevation of the Susitna River could be influencing the
ground water level by providing the downgradient base elevation
for the water table.However,the anticipated maximum decrease in
average monthly water surface elevations of the Susitna River near
Ta 1keetna wi 11 be approxi mate ly three feet.At worst,the water
surface elevations of the local water table will be reduced one
foot (R&M Consultants).
In the vicinity of Chase,all surface water appropriations are
from small tributary streams and lakes at an elevation of 450 to
500.The Susitna River is apprOXimately 0.25 miles from the near-
est appropriation and is at an elevation of approximately 400.
The anticipated changes in water surface elevation for the main-
stern Susitna Ri ver near Chase are unl ikely to have any effect on
these surface water diversions from small streams or lakes located
50 to 100 feet above the river on the hillsides.
In summary,examination of state agency files indicated the major,
although small,users of surface water occur along the Kahiltna
and Willow Creek township grids.No surface water withdrawals
from the Susitna River are recorded.Ground water appropriations
along the mainstem Susitna River corridor are minimal,both in
terms of number of users and total amount of water withdrawn.The
analysis of topographic maps and overlays showing the specific
locations of the appropriations along the mainstem Susitna River
corridor indicated that neither surface water diversions from
small tributaries nor shallow wells in the corridor area are like-
ly to be affected by operation of the proposed project.
2-4
2.2 -Water Quality
This section presents a discussion of present water quality conditions
in the Susitna River and potential impact of the proposed project.
r
(a)Present Conditions
The Susitna River is characterized by wide seasonal fluctuations
in discharge.Breakup occurs in late April or early May.result-
i ng in an increase in ri ver fl ows wi th peak fl ows occurri ng in
June.Di schar ge var i es throughout the summer.dependi ng on tem-
perature and rainfall.Flows decline during the fall and winter
and are at minimulQ level in March.Basin and runoff characteris-
tics appear in Table 2.4.
The wide seasonal fluctuations in discharge.along with the glac-
ia1 character of the ri ver.have a s i gnifi cant effect on water
quality.Suspended sediment concentrations and turbidity levels
are low during late fall and winter.but sharply increase at
breakup and remain high throughout summer during the glacial melt
period.Dissolved solids concentrations and conductivity values
are high during low flow periods and low during the high summer
flows.
l"-
I
I
-
r
I
-I
(i)Availability of Data
Existing water quality data have been compiled for the
mainstem Susitna River from stations located at Denali,Vee
Canyon.Gol d Creek.Sunsh i ne,and Sus itna Stat i on.Data
from two Susitna River tributaries,Chulitna and Talkeetna
Rivers,have also been compiled.The periods of record for
each station are presented below:
Station Peri ad of Record Agency
Denali (D)4/9/57 -5/19/81 USGS
Vee Canyon (V)7/6/62 -5/11/81 USGS
6/19/80 -10/8/81 R&r~
Gold Creek (G)6/22/49 -7/21/81 USGS
8/8/80 -10/8/81 R&M
Chulitna (C)4/5/58 -3/25/81 USGS
Talkeetna (T)4/29/54 -10/4/77 USGS
Sunshine (S)7/2/71 -7/23/81 USGS
Susitna Station (SS)8/17/55 -8/12/81 USGS
Data have been compiled according to three seasons:break-
up,summer,and winter.Breakup is usually short and
extends from the time ice begins to break up until reces-
sion of spring runoff.Summer extends from the end of
break up unt i1 the water temperatur e drops to essent i ally
DoC in the fall.and winter is the period from the end of
2-5
2-6
Ava il-
Federal
EPA,1980.Water Quality Criteria Documents;
ability.Environmental Protection Agency,
Register,45,79318-79379 (November 28,1980).
A second priority system was used for selecting the guide-
lines or criteria presented for each parameter.This was
required because the various references presented above
cite levels of parameters that provide for the protection
of identified water uses,such as (1)the propagation of
fish and other aquatic organisms,(2)water supply for
drinking,food preparation,industrial processes,and agri-
culture,and (3)water recreation.The first priority,
therefore,was to present the gui de 1i nes or criter ia that
apply to the protection of freshwater aquatic organisms.
The second pri or ity was to present 1eve 1s of parameters
that are acceptable for water supply,and the third prior-
ity was to present other guidelines or criteria,if avail-
able.It should be noted that water quality standards set
Sitting,Marshall,1981.Handbook of Toxic and Hazar-
dous Chemicals.Noyes Publications,Park Ridge,New
Jersey,729 pp.
McNeely,R.N.,V.P.Neimanis,and L.Dwyer,1979.Water
Qual ity Sourcebook--~Gui de ~Water Wual ity
Parameters.Environment Canada,Inland Waters
Directorate,Water Quality Branch,Ottawa,Canada,88
pp.
ADEC,1979.Water Quality Standards.Alaska Department
of Environmental Conservation,Juneau,Alaska,334 pp.
EPA,1976.Quality Criteria For Water.U.S.Environ-
mental Protection Agency,Washington,D.C.,255 pp.
The guidel ines or criteria used for the parameters were
chosen based on a priority system.Alaska Water Quality
Standards were the first choice,followed by criteria pre-
sented in EPA's Quality Criteria for Water.If a criterion
expressed as a specific concentration was not presented in
the above two references,the other cited references were
consulted.
The water qual ity gui del i nes and criteri a used in thi s
evaluation were established from the following references:
summer to breakup.Detect i on 1i mits for vari ous water
quality perameters appear in Table 2.5.
(ii)Water Quality Standards
-
r
,....
I
r
r
I
r
r
I
(iii)
criteria which limit man-induced pollution to protect iden-
tified water uses.Although the Susitna Ri ver Hydroelec-
tric Project is a pristine area,some parameters exceeded
their respective criterion.
As noted in Table 2.6,criteria for three parameters are
suggested rather than legally mandated or have otherwise
been set at a level which natural waters usually do not
exceed.The criteria for aluminum and bismuth have been
suggested on the basis of human health effects.The cri-
terion for total organic carbon (TOC)was established at 3
mg/l because water containing less than this concentration
have been observed to be relatively clean.However,
streams in Al aska receiving tundra runoff commonly exceed
this level.The maximum TOC concentration reported herein,
20 mg/l,is likely the result of natural conditions.The
cr iteri on for manganese was estab 1i shed to protect water
supplies.The criteria presented in the rema-ining para-
meters appearing in Table 2.6 are established by law for
the protection of freshwater aquat ic organi sms.The water
qua 1 ity standards apply to man-made a1terat ions and const i-
tute the degree of degradat i on whi ch may not be exceeded.
Because there are no industries,no significant agricultur-
al areas,and no major cities adjacent to the Susitna,Tal-
keetna,and Chul itna Ri vers,the measured 1eve 1s of these
parameters are considered to be a natural condition.Also,
these rivers support diverse populations of fish and other
aquatic life.Consequently,it is concluded that the para-
meters exceeding their criteria have little,if any,detri-
mental effect on aquatic organisms.
Evaluation of Current Conditions
The results of the analyses indicate the Susitna River is a
fastflowing,cold-water stream of the calcium bicarbonate
type containing soft to moderately hard water during break-
up and in the summer and moderately hard water in the win-
ter.Nutrient concentrations,namely nitrate and ortho-
phosphate,exist in low-to-moderate concentrations.Dis-
solved oxygen concentrations typically remain high,averag-
ing about 12 mg/l during the summer and 13 mg/l during win-
ter.Percentage saturation of di ssol ved oxygen always
exceeds 80 percent but averages near 100 percent in the
summer,and in the winter saturation levels decline slight-
ly from the summer levels.Typically,pH values range
between 7 and 8 and exhi bi t a .wi der range in the summer
compared to the winter.During summer,pH occasionally
drops below 7,which is attributed to tundra runoff.True
color,also resulting from tundra runoff,displays a wider
range during summer than winter.
2-7
Color levels in the vicinity of the damsites have been mea-
sured as high as 40 color units.Temperature remains at or
near aoc during winter,and the summer maximum is 13°C.
Alkalinity concentrations,with bicarbonate as the dominant
anion,are low to moderate during summer and moderate to
high during winter.The buffering capacity of the river is
relatively low on occasion.
The concentrations of many trace elements monitored in the
river were low or within the range characteristics of nat-
ural waters.However,the concentrations of some trace
elements exceeded water quality guidelines for the protec-
tion of freshwater aquatic organisms.These concentrations
are the result of natural processes because there are no
man-induced sources of these elements in the Susitna River
Basin.
Concentrations of organic pesticides and herbicides,uran-
ium,and gross alpha radioactivity were either less than
their respective detection limits or were below levels con-
sidered to be potentially harmful.
It is worthy to note that the range di spl ayed in the
figures l pH and color are typical for streams in Alaska
recei vi ng tundra runoff.It is not uncommon for pH to be
6.5 (the criterion)or slightly less and color to be as
high as 100 color units (the maximum reported herein).It
should also be noted that the four highest levels of per-
centage saturation of dissolved oxygen are probably in
error.If these data are eliminated,all the dissolved
oxygen percentage saturation values are less than the cri-
terion of 110 percent.
Figures 2.1 through 2.41 depict the result of the analysis
for all physical parameters and inorganic and non-metallic
parameters.Data summaries for metals which exceeded their
criteria are also presented.
(b)Parameters Exceeding Criteria and Aberrant Data
This section presents a summary of the parameters that have
exceeded their criteria (Table 2.6),a discussion of aberrant
data,and a list of parameters that exhibited values less than
their respective detection limits.
A number of parameters listed in Table 2.6,exceeded their respec-
tive criteria.The implications of this to freshwater aquatic
organisms are related to the rationale behind the criteria and to
the fact that the Susitna River is largely unaffected by man's
act i vity.
2-8
The identification of aberrant data was considered because of the
extreme values manifested by some parameters.The following para-
meters were suspected of having aberrant data:
r
r
I
(i )
(i i)
(iii)
D.O.and Saturation
The high values measured at Gold Creek during summer
exceeded the cr iter i on.The four highest va 1 ues mea sured
by R&M (116,115,114,and 113 percent saturation)are pro-
bably in error because of a faulty barometer and should be
el iminated from the data set.R&W s fifth highest val ue
was similar to the USGSls highest values of 106,104,103,
and 102 percent saturation.
Free Carbon Dioxide
The five highest values measured by R&M at Gold Creek dur-
ing summer were 36,35,20,16,and 16 mg/l.The two high-
est values may be aberra nt,but there are no acceptab 1e
reasons to eliminate them.
Ortho-P hosphate
One high value,0.49 mgjl,measured at Vee Canyon during
summer appears unrealistic and should be eliminated.The
next highest value was 0.1 mgjl.The high value measured
at Talkeetna during breakup may also be unrealistic,but
there are no data with which to compare this value,so it
shoul d stand.
(i v)
""'"!'
,...
r
I
r
I
~
r
Phosphorus
The hi gh val ue of 0.49 mgjl measured at Vee Canyon during
summer is likely to be aberrant because the next highest is
0.1 mg/l.Likewise,a high value of 0.36 mgjl is signifi-
cant ly different from the next hi ghest va 1ue of 0.05 mgjl
measured at Susitna Station during winter.It is recom-
mended that both of the high values be eliminated.
(v)Turbidity
The five highest turbidity values measured at Susitna Sta-
tion during summer were 790,590,430,430,and 260 NTU.
There is no reason to eliminate any of these values.
(vi)Total Organic Carbon
The four concentrations measured at Gold Creek during win-
ter are 39,34,27,and 5.5 mgjl,and one measurement at
Vee Canyon duri ng wi nter was 23 mgjl.Al though the four
high values appear unrealistic,there is no apparent reason
to eliminate them.
2-9
(c)Impacts of Susitna Project
Construction of hydroelectric dams and their reservoirs has a pro-
found effect on the water regi me of downstream river reaches.
Since the rate of reservoir water outflow is controlled,the down-
stream reach is no longer subject to the fluctuations of a normal
river regime with the consequence that the flow generally becomes
less variable throughout the year (Turkheim 1975).Under current-
ly proposed operating conditions,the Watana and Devil Canyon dams
will significantly affect the average monthly flows at Gold Creek.
The minimum flow regime is significantly increased and peak flows
are decreased.The decrease in spring flood magnitude,especially
during the initial impoundment,may result in negative effects on
the downstream environment.It is reasonable to expect that the
interference with natural Susitna River flows will cause some
changes in streams and branches,adjacent wetlands,and ground
water levels for some distance downstream from the dams.
The number of upstream hydrologic effects are few compared to at-
reservoir and downstream effects.Due to an aggradation process
whereby reservoir waters are backlogged or increased in an up-
stream direction,the reservoir can increase the amount of evapor-
ation from a river (Turkheim 1975).However,the amount of evap-
oration from the river will be a small percentage of the total
evaporation from the Watana and Devil Canyon reservoirs which will
in itself be insignificant.
The principal impacts requiring consideration relate to sedimenta-
tion,temperature,dissolved oxygen,dissol ved sol ids,and dis-
solved nitrogen.
(i)Turbidity and Sedimentation
When a turbulent,sediment-laden stream such as the Susitna
River enters a reservoir,quiescent conditions will allow
much of the material to settle to the bottom.Weiss and
Love substantiate the reduction of turbidity by impoundment
of sediment-laden waters in reservoirs (Weiss,Francisco,
and Lenat 1973;Simmons 1972;Love 1961).According to
reservoir sedimentation studies,95-100 percent of sediment
entering Watana reservoir would settle,even shortly after
fill ing of the reservoir starts.The Devi 1 Canyon reser-
voir would have a slightly lower trap efficiency than
Watana due to its smaller volume.However,most sediment
will be deposited in Watana,the upstream reservoir.Tur-
bidity levels and suspended solids concentration downstream
from the reservoir will decrease sharply during the summer
months due to the sediment trapping characteristics of the
reservoirs.It is likely that the turbidity of water
released during winter will be substantially reduced from
summer conditions as suspended sediment in near-surface
2-10
-i
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r
(i i )
(i i i )
waters should rapidly settle once the reservoir ice cover
forms and essentially quiescent conditions occur.
Sed imentat i on affects other water qua 1 ity parameters
besides turbidity and suspended solids.Color (Drachev
1962),particulate phosphorus (Wright,Soltero 1973),dead
microorganisms such as plankton and algae (Erickson,
Reynolds 1969),and precipitated chemicals (Mortimer 1941;
Mortimer 1942)are removed in the sedimentation process.
Consequently,color levels and total phosphorus concentra-
tions ought to be reduced in and downstream from the reser-
voir.Metal concentrations,such as iron,manganese,and
some of the trace elements,will also be reduced as they
are precipitated and settled to the bottom.Leaching under
anaerobic conditions will cause some of these compounds to
redissolve into the water near the reservoir bottom.How-
ever,if the deposited material is inorganic,it can form a
mat on the reservoir bottom,thereby effectively blocking
leachate from entering the water column (Nech 1967).This
is expected to occur in the Watana reservoir but is likely
to be a minor factor in the Devil Canyon reservoir.
Temperature
The range and seasonal var i at ion in temperature of the
Sus itna Ri ver wi 11 change after impoundment.An i mpound-
ment study revea 1ed that the reservoi r not on ly reduced the
magnitude of variation in temperature but also changed the
time period of the high and low temperatures (Bolke and
Waddell 1975).This will also be the case for the Susitna
Ri ver,where pre-project temperatures generally range from
O°C to l3°C with the lows occurr i ng in October/November
thro~gh March/April and the highs in July or August.After
closure,the temperature range will be reduced and low tem-
peratures will occur in November through March.The period
of hi ghest temperature wi 11 be July and August,as is the
pre-project case.Reservoirs releasing water from the sur-
face are "heat exporter"reservoirs (Turkheim 1975),and
both Susitna River reservoirs fall into this category.
Dissolved Oxygen
Thermal stratification is not likely to occur in either
reservoir,but a temperature gradi ent wi 11 exi st.It is
expected that vertical mixing will occur in the spring as a
result of the large input of water,wind effects,and sur-
face water warming.This will result in the transport of
oxygen from the surface,where reaeration occurs,through-
out the top 60 to 100 feet of the reservoir,where biologic
and chemical processes use oxygen.
2-11
(iv)Dissolved Solids
Anaerobic bottom conditions can harm aquatic life and cause
the reduction and release of undesirable chemicals into the
water (Fish 1959).The leaching process which is more
efficient under anaerobic conditions,degrades bottom water
quality by releasing such chemicals as alkalinity,iron,
manganese (Symons 1969),hydrogen sulfide,and nutrients
(Turkheim 1975).Also,leaching problems become more
severe as the organic content in the soils increases.The
potential for leaching at the Watana reservoir should
decline in time as the inorganic,glacial sediment carried
in by the river settles and blankets the reservoir bottom.
The products of leaching are not anticipated to be abundant
enough to affect more than a small layer of water near the
reservoir bottoms.Also,leaching products will not
degrade downstream water quality over the long-term because
water will be released at or near the surface.A shortterm
increase in dissolved solids,conductivity,and most of the
major ions may be evident immediately after closure of the
dam.Other reservoir studies have shown that the highest
concentration of all major ions.except magnesium,occurred
immediately after impoundment (Bolke and Waddell 1975).
The increase in concentration was attributed to the initial
inundation and leaching of rocks and soils in the reservoir
area.
Although evaporation has been noted to cause the dissolved
solids concentrations to increase (Symons 1969;Love 1961),
this potential effect on water quality at the Watana and
Devil Canyon reservoirs is not significant.The average
annua 1 evaporat i on predi cted for May through September at
Watana is 10.0 inches;at Devil Canyon it is 11.1 inches.
There is no evaporation during the period of ice cover from
October through April.The percentage of the reservoirs
lost to evaporation during summer will be 0.3 percent at
Watana and 0.6 percent at Devil Canyon.A less than 1 per-
cent increase in concentration of most water quality para-
meters is not significant.Local effects may be noted from
evaporation and subl imation may cause some water loss
creating local effects.These are not anticipated to be
significant.
Both Watana and Devil Canyon reservoirs will release water
from at or near the surface and therefore have the poten-
tial to become nutrient traps.resulting in eutraphic con-
ditions.The major criteria for eutrophiation to occur
include nutrient concentrations,algae populations.solar
radiation and the effects of reservoir processes.
2-12
F--
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r
(v)
(vi)
Dissolved Nitrogen
The critical concentration of nitrogen ina 1 ake at the
begining of the growing season above which excessive algae
blooms may be expected to occur is 0.2 -0.3 mgjl when
phosphorus concentrations are from 0.01 to 0.02 mgjl
(Mackenthun 1960).Phosphorus is reported to be the con-
trolling nutrient and blooms could be expected if the level
exceeded 0.01 mgjl (Symons 1969).The pre-project concen-
trations of nitrogen and phosphorus measured at Vee Canyon,
upstream from the proposed reservoi r 1ocat ions,have
exceeded the critical concentration levels cited above.
These critical concentration levels were developed from
work done in temperate regions,and may not be applicable
in the subarctic.In a study of the nutrient chemistry of
a large,deep subarctic lake,nitrogen and phosphorus con-
centration were simil ar to those measured at Vee Canyon
(LaPerrerie,Tilsworth,and Casper 1978).The lake studied
was not eutrophic,and the peak algal biomass and produc-
tivity occurred under the spring ice rather than in the
summer.It was also predicted that a large number of cot-
tages coul d be added around the 1ake wi thout euthrophi c
conditions developing.Based on this work,it is likely
that Watana and Devil Canyon reservoirs w"i 11 be mesotrophic
to oligotrophic,providing sufficient nutrients for fish
life,but not so much as to become eutrophic.
Nitrogen supersaturation of water below a dam is poss"ible
at certain seasons,extending an unknown distance down-
stream (Turkheim 1975).This is certainly a possibility
below both dams.However,the ultimate impact of nitrogen
supersaturation is its effect on fish.Nitrogen supersat-
uration problems will be solved structurally through the
use of fixed-cone valves,to dispense discharged flows,
thereby eliminating plunging spills up to the 1:50-year
flood.Portage Creek is essentially the upstream limit for
spawni ng sal mono Consequently,water supersaturated wi th
nitrogen leaving the dams must travel through Devil Canyon
before reaching an important fisheries area.It is reason-
ab le to expect that post-project nitrogen s upersaturat i on
levels will be the same as the pre-project levels at the
downstream end of Devil Canyon.
Summary
Impoundment of the Susitna River will change its water
quality.The following parameters will exhibit reductions
in values in the reservoir and downstream reaches as com-
pared to the pre-project levels:suspended solids,turbid-
ity,color,nutrients,iron,manganese,and some trace
elements.Both reservoirs will be heat exporters and the
2-13
downstream reaches of the river will exhibit a reduced mag-
nitude of seasonal temperature vari at ion.Di sso 1ved oxygen
concentrations will remain high,at or near saturation,in
the upper levels of both reservoirs and downstream in the
river.Dissolved oxygen concentrations will likely be
reduced in the hypolimnion if a stable stratification
develops.The potential for eutrophication to develop -in
either reservoir is low.
Although water quality changes will be effected by the pro-
ject,none of these changes will be significantly adverse,
and many changes may be beneficial.A possible exception
to this is the downstream temperature change.
2-14
~~,-
.....
TABLE 2.1:SUSITNA TOWNSHIP GRID
TYPE
Cedi ficates
:iUHfACE WATER APPROPHIAIIUN:i
cfs opd ac-tt/yr
DAYS
OF USE
LiKUUNL WAlt-K AP.PKOPHIAllUN:i DAYS
cfs opd ac-tt/yr OF USE
.....,
.....
Single-family dwelling
2 to 4 unit housing
Grade Schools
F ire protection
Animals
Lawn and garden irrigation
General Crops
Total
Permit.s
Single-fami ly dwelling
Vegetables
Total
Pending
Single-family dwelling
Lawn and garden irrigation
Placer gold
Total
TOTAL
.1
.1
.1
4,500
75
63.5
20r]
100
4,938.5
250
250
75
50
125
5,313.5
12.5
12.5
13.5
365
214
365
184
153
153
365
153
365
183
184
5,440
1,200
910
500
94
8,144
1,000
250
1,250
9,394
.5
5.5
6.0
6.0
365
365
334
365
365
6fJ
91
365
214
TABLE 2.2:SUMMARY OF WATER APPRoPRIATIoN*
::JUM AU,-WA .IlK lqUI VALENI GROUND WA cK t.l.IUl VALt.N I
TOWNSHIP GRID cfs ac-tt/yr cts ac-tt/yr
Susitna .153 50.0 .0498 16.3
Fish Creek .000116 .021 .003 2.24
Willow Creek 18.3 5,660 .153 128
Little Wi 1101'<Creek .00613 1.42 .00190 1.37
Montana Creek .0196 7.85 .366 264
Chulina .00322 .797 .000831 .601
Susitna Reservoir .00465 3.36
Chulitna .00329 2.38
Kroto-Trapper Creek .0564 10.7
Kahiltna 125 37,000
Yentna .00155 .565
Skwentna .00551 1.90 .000775 5.60
*Figures from Table 2.1 all converted to cfs and ac-ft/yr equivalents as
follol'<s:
1 gpd =.00000155 cfs
1 cfs =1.98 ac-ft/day
r"'"
I
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i
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'I
TABLE 2.3:WATER APPROPRIATIONS WITHIN ONE MILE OF THE SUSITNA RIVER
ALJLJ 11 IONAL ~uURCE
LOCATION*NUMBER TYPE (DEPTH)AMOUNT DAYS OF USE
CERT IFICATE
T19N R5W 45156 Single-family dwelling well (7)650 gpd 365
general crops same source .5 ac-ft/yr 91
T25N R5W 43981 Single-family dwelling well (90 ft)500 gpd 365
T26N R5W 78895 Single-family dwelling well (20 ft)500 gpd 365
200540 Grade school well (27 ft)910 gpd 334
209233 Fire station well (34 ft)500 gpd 365
T27N R5W 200180 Single-family dwelling unnamed stream 200 gpd 365
Lawn &garden irrigation same source 100 gpd 153
200515 Single-family dwelling unnamed lake 500 gpd 365
206633 Single-family dwelling unnamed lake 75 gpd 365
206930 Single-family dwelling unnamed lake 250 gpd 365
206931 Single-family dwelling unnamed lake 250 gpd 365
PERMIT---
206929 General crops unnamed creek 1 ac-ft/yr 153
nON R3W 206735 Single-family dwelling unnamed stream 250 gpd 365
PENDING
209866 Single-family dwelling Sherman Creek 75 gpd 365
Lawn &garden irrigation same source 50 gpd 183
*All ·locations are within the Seward Meridian.
TABLE 2.4:BASIN AND RUNOFF CHARACTERISTICS
Watana*De\il Canyon*Gold Creek**
Drainage Area,Mi 2 5,180 5,810 6,160
A\erage Annual Flow,cfs 7,860 8,960 9,647
Maximum A\erage Monthly Flow,cfs 23,100 26,200 27,900
Minimum Average Monthly Flow,cfs 890 1,030 1,100
*Data supplied by Ste\e Bredthauer,R&M Consultants,Inc.
**USGS 1981
-
TABLE 2.5:DETECTION LIMITS FOR WATER QUALITY PARAMETERS
R&M
Detection
Limit (I)
U.S.G.S
Detection
Limit (5)
-
Field Parameters
Dissolved Oxygen
Percent Saturation
pH,pH Units
Conductivity,umhos/cm @ 25°C
Temperature,°c
Free Carbon Dioxide
Alkalinity,as CaC0 3SettleableSolids,mIll
Laboratory Parameters
Ammonia Nitrogen
Organic Nitrogen
Kjeldahl Nitrogen
Nitrate Nitrogen
Nitrite Nitrogen
Total Nitrogen
ortho-Phosphate
Total Phosphorus
Chemical Oxygen Demand
Chloride
Color
Hardness
Sulfate
Total Dissolved Solids(2)
Total Suspended Solids(3)
Turbidity
Uranium
Gross Alpha,picocurielliter
Total Organic Carbon
Total Inorganic Carbon
Organic Chemicals
-Endrin
-Lindane
-Methoxychlor
-Toxaphene
-2,4-D
-2,4,5-TP Silvex
ICAP Scan(4)
-Ag,Silver
-AI,Aluminum
-As,Arsenic
-Au,Gold
-B,Boron
-Ba,Barium
-Bi,Bismuth
-Ca,Calcium
-Cd,Cadmium
-Co,Cobalt
-Cr,Chromium
0.1
1
+0.01
-1
0.1
1
2
0.1
0.05
0.1
0.1
0.1
0.01
0.1
0.01
0.01
1
0.2
1
1
1
1
1
0.05
0.075
3
1.0
1.0
0.0002
0.004
0.1
0.005
0.1
0.01
0.05
0.05
0.10
0.05
0.05
0.05
0.05
0.05
0.01
0.05
0.05
.01
•1
.01
.01
.01
.01
.01
.01
1
.05
1
1
1
.00001
.00001
.00001
.001
.00001
.00001
.001
.01
.001
.01
.1
.01
.001
.001
.001
TABLE 2.5:DETECTION LIMITS FOR WATER QUALITY PARAMETERS (Cont'd)
Laboratory Parameters (Cont'd)
-Cu,Copper
-Fe,Iron
-Hg,Mercury
-K,Potassium
-Mg,Magnesium
-Mn,Manganese
-Mo,Molybdenum
-Na,Sodium
-Ni,Nickel
-Pb,Lead
-Pt,Platinum
-Sb,Antimony
-Se,Se lenium
-Si,Si licon
-Sn,Tin
-Sr,Stront ium
-Ti,Titanium
-W,Tungsten
-V,Vanadium
-Zn,Zinc
-Zr,Zirconium
R&M
Detection
Limit(l)
0.05
0.05
0.1
0.05
0.05
0.05
0.05
0.05
0.05
0.05
0.05
0.10
0.10
0.05
0.10
0.05
0.05
1.0
0.05
0.05
0.05
U.S.G.S
Detection
Limit (5)
.001
.01
.0001
•1
.1
.001
.001
.1
.001
.001
.001
.001
.1
.01
.01
(1 )
(2)
(4)
(5)
All values are expressed in mg/l unless otherwise noted.
TDS -(filterable)material that passes through a standard glass fiber
TITter and remains after evaporation (SM p 93).
TSS -(nonfilterable)material required on a standard glass fiber filter
aTfer filtration of a well-mixed sample.
ICAP SCAN -thirty two (32)element computerized scan in parts/million
(Ag,AI,As,Au,B,Ba,Bi,Ca,Cd,Co,Cr,Cu,Fe,Hg,K,Mg,Mn,Mo,
Na,Ni,Pb,Pt,Sb,Se,Si,Sn,Sr,Ti,V,W,Zn,Zr).
U.S.G.S detection limits are taken from "1982 Water Quality Laboratory
Services Catalog"U.S.G.S.Open-File Report 81-1016.The limits used are
the limits for the most precise test available.
TABLE 2.6:PARAMETERS EXCEEDING CRITERIA BY STATION AND SEASON
t"'AKAMt.It.K ~IAI1UN ~t.A~UN LKllt.K1A
D.O.~~Saturation G S L
pH T 5,W,B L
G B
Color T,S 5 L
Phosphorus,Total (d)V,G,T,5,55 5,W,B L
Total Organic Carbon G,55 5 5
V,G,55 W
55 B
Aluminum (d)V,G 5,W 5
Aluminum (t)G,5,55 5
Bismuth (d)V,G 5 5
G W
Cadmium (d)T,55 5,W L
55 B
Cadmium (t)G,T,5 55 5
T,SS W,B
Copper (d)T,55 5 A
T W
55 B
Copper (t)G,T,5,55 5
T,5,55 W
T,55
Iron (d)0,V,C 5 L
Iron (t)G,T,5,55 5
T B
Lead (t)G,T,5,55 5 A
T,55 W,B
Manganese (d)0,V,G,C 5 L
Manganese (t)G,T,5 S
T,55 B
Mercury (d)G,5 5 L
5 W
Mercury (t)G,T,5,55 5
T,5,55 W
T,55 B
Nickel (t)G,5,55 5 A
Zinc (d)V 5 A
Zinc (t)G,5,55 5
T,5,SS W
SS B
,...
r
-
-
-I
Stations
o -Denali
V -Vee Canyon
G -Gold Creek
C -Chulitna
T -Talkeetna
5 -Sunshine
SS -Susitna Station
Seasons
S -Summer
W -Winter
B -Breakup
Criteria
L -Established by law as per
Alaska Water Quality
Standards
S -Criteria that have been
suggested but are now law,
or levels which natural
waters usually do not
exceed
A -Alternate level to 0.02 of
the 96-hour LCSO
determined through bioassay
-J -----1 -~l I oJ 1 1 1 )---1 :---]-J -1 ---]I 1
PARAMETER I TRUE COLOR,PLATINUM COBALT UNIT
w-ttl=l=t=~1=b::w-+!::1--i::~::~trlmtti±t1tmaE=-Em8-!t1-JJ:11fl]I:F1::r::ltti~
150
H-t-t -++-+-H--t-t-
--l-
I I I I I ++-j-f-+++++-+-+++H+-+-t-+H~---
--'-.~-+--I-H-t--H I I I I I I I I-+-+---t-+-H I I t I I I / I I I I I +-+-+-+-+I I I j I-f---I-H-H-+---t+i-
100
-f--H++J....--.-.-_.-----
-f--+-t+H+-t--t+H=t
-t--.-
-+-~tt::t+t=t+I::ttt~t]UlllllIJimm1IEfI.-
..MAXIMUM
--,-f
+H+-f--H+H--f-H-J:t-t L _~_A.::;r---++----+~-:l-=tttltttt1-i-++++-H-
t -t-+----,---I---,-f-t-I+H-+-H+t I I I I I I-H---t--t-t-t-t---------I -t---J
•.MINIMUM
-MEAN
#=OBSERVAT/ON
--.--'--l-
-.-_.-.-.-.~-t-++~-t-t--
f--+t-H--j--+++H+-t-~-t-+--I-~-
t-H I I i I I f--t-++-tl:-tttttttl+j-j-f-
--~----~-.-++-.---'::1=++'+.+-+<--+-4-f)'~t
__'_'_''_l++--I~i+-i++_&-_.I_-+-+-+-_-:t.::>I~::::=1t --=:=:-;---::
___~:.._._L •..~r 1=11-:j)c-~tj~=::HEmRtj:100m~=f1~i.I®mi~Mffit_?,=1 .-.=Q =~/rn=lti~jl
o
~50
SUMMER WINTER BREAKUP
0-DENALI V-VEE CANYON G~GOLO CREEK C-CHULITNA T-TALKEETNA S -SUNSHINE:SS-SUSITNA STATION
Shall not exceed 50 units (ADEC,1979)
E5I~"""'~T?J.!~H'II DATA 'SUMMARY -COLOR
FIGURE 2.1
J J 1 <--I )-"-'--J 1 ---]----1 ~~]'--1 ...._..]"-1 -.".-].-]
PARAMETER'CONDUCTIVITY,~mhos/cm @ 25°C
--~-~-<-.j~++-+-.f
--.-.---··.--l-+--l-j~-j~+++++-H--j ..I---l-+..I---l-l~-
400
·-H-+-++-++++++-j-++-H-I-+-l.I.~---••_·-·...J.-l--..-
f~-'1---·-··..JTn'-d --H-I-._.-.-l-JT
-+++--+-1 1InTrL.~--~ttl-'_·_·
..--l-
300 H-H++++-~-+-I-+-++-+++I 1 I I I I 1-+-+-++•MAXIMUM
I~----
•MINIMUM
-MEAN
I-~-.-'-<_.-
roo-j-J.-.!--l---1-4-
H-H-.f-+-H-l---~-l-
-·~-··--+--f-
--.-l-I-~-I-+++~-+-I-+-f-l-~-+-+-++-.f-I---l++-H-I-
I--'~-'-
---H-W-I:::r.~t-t..-1-...
I_j_++_+-++[.1-1-'·1-1-I-H+l-~H-I-+
-.-+-+-I-l~.-
200
#:OBSERVATION
---+-.1-\..+-+++-1
,,--+--1-
-~-l-t-t--I-H-t--t-t-t-H--t--f.-++++-H
....~._._._f-__._.'"__+_-1 __+·~_""-'-""""'''-T---t-_"-"'l--"'-+-
~pat1nmtl1S-~~:!m~3~
_....-~-+-+++++H++++-I-+-++++-H-j-H+H-H
,12
-·_~H-I-++++I-
-~~iJ~~=~~~r~=
.•_--t-.
-+-++-++1-,.,.-
-~-_.-~-I-I-~-+-j-+++---~-.~_.-
~I I 1 I I 1 I I 1 I H-I-H I I T I I ++.J+l-I---I-l--I---l-I--.+-+.-I---H-+--l-+++--H-+-l-+-++-l-+++++-+I I I I I+I++-H+++++-++H
mt±~trf1~~=rfHttl1I~
100
SUMMER WINTER BREAKUP
D-DENALI v-VEE CANYON G~GOLD CREEK C-CHULITNA T-TALKEETNA S -SUNSHINE:SS-SUSITNA STATION
No criterion established
l ~-'~.C:~~.§~l::~!;J.T~..!~oc;:II DATA SUMMARY -CONDUCT IVI TY
FIGURE 2.2
'---'1 '~J --1 ~--,1 '---]~]1 "-'-~J J -1 '1 '~-J -1
PARAMETER:HARDNESS,as Ca CO],(mg./1.)
1-::::r::r::1::.11::t::t::+-H+H-+++++-l-+H-+.H++++++--l-+--+-++f--l--f--H--+-'j.-
__•.•_H+'I I I I \\ I I
III I II II f 11-+1'II I 1+---+-f--+++-+-++-!--I-++--l-f--J---j-H-H---+----
I-'."-'--~-".-~.--.~·,-~-·,+f·+++--t
170
_'_H_·_·_~I I I I I I I H+++++I--~=BflttH±tlttjjJi::t::tJ-
->-·-·-·-·-+1-++1-+++-
__0'__._h_._._~_.,I I I I I
---I-
--'.--'-1--"--.-0,-
__::::r±r::::t::r::f.~-+++l--l
+++H+H-1-H+H I I I I I H+++~
120
-l---~-,
·+--l-l--+-·j.---i-~-'-'---
----,+--f--+---l-
--+--.-f--.--l--,--"----_I-
•MAXIMUM
-I--H-+-+l I I I I I I I , ,1-+--1----1-+-+I I I I I I--J-+-l-+++I--++++-+-+++H--+--+++-l-+-++H-l I I , I I
·,·--H-++-t
-MEAN
---6-!---+--1--+---+-·-.•.~-•.-.~,-.---.--
-l---++-H-H-++--I-
,__.·-·--+··-·-·-l--H-l-+-H--l-++-H-l-
I-I-H·++H I I I I-!+-H I I I I 1
·.-·~~-.~-++++H--++--I-.!.+-H-H--
70
--.-1--+--1---1--+-+-+--+-+
--\--i-+--I--+-l-l---l--l-l--·H+-+--+-+--H-I
•MINIMUM
.._~-+~--.++-I--+-+-+-+-+++-+-+-!+H-++I-
--·-·-+-+':++-H-!-+--.+-H
--I-f++-H++I-I-++--H---l-'--_'_+--·
-I-+H-H-+H ,--I+-!--!-----t-ttiti::tttttt:tttl::r~::~=-H--H-H
1+llI-H-H-
t::l:--'-..--.+-..-
-1-
--·--+--~H-l-+--I-+-+-+-f---
I+++-H-I-H-I-'-'·~-~·_"
20
-~+l-++++-H-l-++--++--I-+-H-
,--61 -------5rqtt*~kt~H=l+M--::F:tt-1~tllH~d=rflJhH+ll~r+tlmtDjr --.---ttlHttlf\~mmf[flffi'r:lRIJ[IJBJI.lf8fHlEI~8.EEllHlfltl:JJ:8'11:UI js
#=OBSERVATION
SUMMER WINTER BREAKUP
D-DENALI V-VEe CANYON a~GOLD CREEK C-CHULITNA T-TALKEETNA S -SUNSHINE::SS-SUSITNA STATION
No criterion established
~~~~,s::11 DATA SUMMARY -HARDNESS
FIGU RE 2.3
'I "---1 '~l'----'-1 "J ',e'j -,"1 ,.._~,eel 1 ----..-l--~J ]1
PARAMETER:PH
..~_h·,.-j-+++++t-H-+++-\-\-+--'·_'··~·-'-H-+++-I---I-'-"~·-~'~-~'-·"H-t--\-t·
-'-'--'''''H~-I---I-t-W-~--+I I I II I I H-I--~--t-I--f-+-l.-I I I I I H-+H-+t-!-+-++-l+H-+-+-I+~
I++-+··j -1---1-+-+-+-~-
.-......-'-..e·-·-····-I--+-1..++-
-H-
-+-+--
H-,~JJTJJ:JTdj:.:~...._,...1--0 -r I-'-""'~-+-----_.
A 8
-1--+--1-1
-I--I-Ie I I I , I 1-+~"-+-J+-1--.\-I-
h:-I---+--~_H--t-++-.I ,I I I I 1-1 I I I I 1 I I I I I
•MAXiMUM
1--1-+1 I I I 1\-+-++--+-+-1 I I I I I I I I++-H+f--l-H+H-+-H-H-Hgr-#lIt~::r+Ut!=J:l..-...
7
H-l-f-+--I-+-_.)-I-+--+---I---!+++-1-1+-1-
1·-+·H-++-+-+
··I-I-I-l-j ,,1--++--+--1--1-
-MEAN
..,--+-
1-+-+-t-+-'~-+--j --J-,'_'_h ,_.,-,,,,-
..·'-·1 ..-
+-~-_.
Jjj I I I I I l-H-H+rl
•MINIMUM
~litttt~=tl++:;Ht+j;t!j~tFfft{l-t~±m4diJii~tijj~l,btt~=Q[t=t~wl~rl!lH~~r++++-J MttH~Jtltt=+rl11tl$l++lr$ll~+le$H¢ej-tttLtt1~[iuJ~jj~tliJtt1"ttT=tt~_l-=1~__
6
SUMMER
__1---',.
--H-+-I--H-I~-
--l-l-I-j-I-\-j--+-I-
WINTER
-b=U::ttLLL I I I I I ~~r:-t=t=t=m+-i--+++-l
BREAKUP
#=OBSERVATION
D-DENALI V-VEE CANYON G-GOLD CREEK C-CHULITNA T-TALKEETNA S -SUNSHINE S$-SUSITNA STATION
A,Not less than 6.5 or greater than 9,0,Shall not vary more than 0.5 pH unit
from natural condition (ADEC,1979).
~'I DATA SUMMA~V -PHR&M CONSULTANTS,INC.I
......Q g.D~Dt.ll.~•..1,.""v·v O"'.FIGURE 2.4
-I ~-J -l -~J e-I e-l '-1 --J ----]'I ----]--1 J ~-J
1 '-----.1
A
PARAMETER:
-1---'--
°TEMPERATURE.C
-+--
~15
~
10
5
+--
-+--1-1 I I I I I I I ,+-+-+-t-+-l--t-l-t,-J-+--+-t--J-W-J--1 I I I 1 1-+-
-.~-~-,-.-J-t--1-1--J-
J----,',-~--
'.-.---1-.-
1-1--I-H-\--I--I--1--1--++-+-+++
-f-.,'-
----'~-+++-I-++++-+++-H-H-+I
,···-·-t-+-i+H-++
-Hlillli-+~
-.-.--_.-1----I-e--++
•MAXIMUM
-MEAN
-+-
----I--I-I--!-+--I-t--+lH--!-I++I+-+--t--H--"--4-f-
-1--1++--+--·..·--·-·-~-~--.-~-.-._.-
-.-_•.-_.-1---1 f-H-+-+-+++--H--+++
•MINIMUM
o
l-J .--+-1-t-I--I-J-H+++-++!I I I I I I I t+-H
-~...--.--.-.-.--+++--1--1--.-.-~t-
I I I I "~,=FfE9~pn3I~~~::llr=m]Hl-1~p++±~1+11Prn+.QfJ=~~:t=13-q=f~_5-ttl±l?Rtttt:t!P-ttljj:..ttt~±tTjtttj?etttttttt:ttttlj-1ttTi=t-11tlilE
#=OBSERVATION
SUMMER WINTER BREAKUP
D-DENALI V-VEE CANYON G~GOLD CREEK C-CHULITNA T-TALKEETNA S -SUNSHINE SS-SUSITNA STATION
A.Shall not exceed 20°C at any time.The following maximum temperature shall not be
exceeded where applicable:nligration routes and rearing areas--1SoC,spawning areas
and egg and fry incubation--130 C (ADEC,1979)
~~.1\DATA SUMMARY -TEMPERATURE
~~~.C:~~';JQ~~l:T~~T~'.!~oC:~.1 FIGURE 2.5
<~I <~--l -1 '-'"~~1 --~l 0"1 '---1 '-1 .~-'"l <-]
P~RAMETERI TOTAL DISSOLVED SOLIDS,(mg.11.)
-.+
".1-
-"'-i+l-+-1-++1 II I I I I +-++++++-++-I-+·+-+++++-I-+I-+-I-++-I-I-H-+-f-H-
~·._._·<_.Jj:ttt:t=tt~
300
:1:trJ:I:H-H-l-H-H'+-
.._+-+..-..
~-···<-·-~-+-+++-I-f-+-H--+....
I-+-++'+~~~H-++++-+-+-+'+++H -I~H--~i+
200 . I I I I I I I I I I I +-._-e MAXIMUM
~'-~~~':tLU-~H-++I I I I I I I I I I I I I I--H-H I I I I I I I I I I I I t-++++-H-++-+++I I I I I I I I I I I I I I I !t++t
_.._~::rtt-+1=tt~tt:t=tt::ttt-ittlWj+t+t++--H
" " !1/I I !I I I t-H::.rr.::j..:.t .
.••.k /..+-+.-H-I-+--H--H--f-+-++-+--MEAN
+d-t~H+H~
•MINIMUM-+++=tJJ±1l
H-t-H-t-"
·_'--...··-·-..·I-l-!-t-t-.-l+H-l-f-+-'"~+IH+i-t'l H-t~.=t.ttt++tft=-lttt:::t:=t
LLLLtJ:~ij~·11 j '.L!111 IjJJ !±I j lJj U t tilt!i±ilti!!J t r l±l j i !i iJ jJ 11 i j ±J I jJ Ltil±J I100
+t-++...I I I I I +-H-'-'-~-'---'-.H_
o .+~~•.~.-f-j-H--++1...·1-
~+++t-+-1-++'4-'++-'..,./...
_.~:p~~~=16GrllEt~ctl~!l1%~~m~d=H~l~ttiH?fFffJ~tfT~Ef~lttm *1:OBSERVAT ION~-t-t++j:o/.t-=tt:I.Lpl.f \Fr Ef:IEl$FEEI~JItJli·fjlllJ1Il.EI~EEfB~~BJf[~-B§±llELtB~
SUMMER WINTER BREAKUP
Coo DENALI ..,..VEe CANYON a-GOLD CREEK Coo CHULITNA Too TALKEETNA S -SUNSHINE::SS-SUSITNA STATION
A.1,500 mg/l (ADEC,1979)
~--'-JIDATA SUMMARY -TOTAL DISSOLVED SOLIDS
R&M CONSULTAN"S,INC.
•""111 "_0 0 ,.1 \,U"'10 ..FIGURE 2.6
--~-1 I ]----1 1 ---J 1 1 1 1 --J 1 1 1
PARAMETER I TOTAL SUSEENDED SOLIDS,(mg./1.)
+++++-1-t-l+ITlj=:1TJT..._-
-H I Itt 1--1---1--+-t--+--t--l--+-H-l-l-j-.j-l-H-l-t~~~-l--I-+j
-t---l--..-.Io-."-
-.-~.-...--<-.-.-1--
----.-.--!-
----.-,-,-,--,-+-++H-
f-~-'--
H-1-H+tttttttt1~tt1.=rl-+-H-+-I -I--
-_.-<-+_++H-+++-4++++-H+++H -++--++-I--+-
4000
++++-l-t--l--t+++H-~-I--f-•MAXIMUM
·+..H ..-t-
.,.,.MEAN
•MINIMUM
--0 j Ij...+-.
-~...j~..-I-,
_.__-t__-'~1'__·f I __f--f -"'l"'"f--+--+~
-+-H-I +I--t--I-'·
__.._~.._.._.._~_.~_-+-_.~f --'1'--t--t'--t--+-..
-\"++-H-I++++..+++-l-l-H-·-·-·-~-
t-~_.~-
---,-+-·..~·-I-+"d,,+-+=
-H I I I I H--J-H+1-t-H-\~l__.I-t_---rul~=I-~_~=._~..--~m-,=+-4=1-+;+-+=+-+-+-1-.._...._..__..p1 U::U-l-l-l r I I::J+j::; ___:__:tI1 H .'-1-1-H++
o ......-ltttttr-.l
I++-f-!-_+-+-+-+H-+-H+<I+H-f-f-I+-+-l-j.-+++..f-f-j-+-I++-l--I-H-+-+~-+·H+
2000
*OBSERVATION
_...__...-...._+-l-..l.......l_1_1_.l_J._l .....l __I._l .._!_J._J_J_.--L---f,.__l l_.l__a.-~·l_,""_.-...-r -t ...,..._.f.._.•_,__t--+-----.1-"
--H-H++-f-H+H-mFttli1I:I411[fl:ff~lffl~~I_imi~E=m~~t.OO1111Iflm~~T
BREAlCUPWINTERSUMMER
D-DENALI V-VEE CANYON G~GOLD CREEK C-CHULITNA T-TALKEETNA S -SUNSHINE::SS-SuslTNA STATION
No measurable increase above natural conditions (ADEC,1979).
~~..JI DATA SUMMARY -TOTAL SUSPENDED SOLIDS
RG.M CONSULTANTS,INC.
......'......'"".O ..CQI''''.......IV .........1.1 ......1'0 ..."
----~--'---_.-.~
FIGURE 2.7
-'J ---J ---1 ~l ?-]1 1 ·----1 J 1 ~I c--,-J 1
PARAMETER I .>.TURBIDITY~NTU
_+=tttaMmmat8tttlJl~MH-++-+--+-t-t III II ++1 II II I+H-
600 I
-I--
400 ITI1lTTIII !I TTnl rrrRTITrl R 1II111I1111111111 \I\111\1 !i 1111 t IllJ If \II LLLLti
-+-+++J-t-+++I-+++-l-+-+-+++-I-++H--I-J-+-+-t--H-+-+-I I I I I I I I +.1.-1-1-
•MAXIMUM
I-++-+++-li !I I I I I I++++H-+-+-f-.I-I-
-MEAN
•MINIMUM-I~
mtE~ttEBIfIi~--j--P-\--J--W+-W--l-
-I--H--I+-H-t--++-HJ=:JJ.:.._
--.--.-.-1---1--1 ~-
--.--.-.--.--.-l--!-+-+-+
-I---!--I--I-
-I--
1+1 I I I I H-+++++--H---\--1-1--l-l--f-.-
~i=t:t:t:t:t-i:ttt:tt1~tt-t++++-1-+-+-I-I-H-I-I-+'-+-+-!--!--++!-H-I=m-t-H+-l-+++-t+.t
o m rTT1'l rfll r 1=rrrrrrrrrT jIll j i III t 11+11111111+I J+IIIIIIIIIII t II i !j j LitU±J±J
200 II I \1111
#:OBSERVATION-+++--l--++-I-l--l-l--+--l--H-l-++++--I-I I I I I I I I I I I I I I I-'-~-'-'--ttttttItimllillitt-±lli~EtJffft1131lBIlltfftB~mlltftt!tlllt1mtmnt=1
SUMMER WINTER BREAKUP
D-DENALI V-VEE CANYON G~GOLD CREEK C-CHUUTNA T-TALKEETNA S -SUNSHINe SS-SUSITNA STATION
Shall not exceed 25 NTU above natural conditions (ADEC,1979)
5~DATA SUMMARY -TURBIDITY
FIGURE 2.8
i J ,....~'1 ..~.~]"J "'1 )'1 .....~).'1 1 -~l 1 1 1
PARAMETER:ALKALINITY,as CAC03'(mg./l.)
.•tittr±tEmtntE8mttl18trW~iltElEtltt1=tattEa~
175
1-1-,..\.+·I-I···-I-I.+-1-1-\.·I-\....+--+-H-1++...H+-I I I I I I j I I I I I
1-++++-1-+...+...\-I-H I I I \ I 1-+1-1+-1 ++t-+++-H-1 ...I-H-
H ...++++-I++-1-1-+I I I I I I f -I...-H++++++-f-f-++-+-+t-+++t-I-+~_····...··Trn..r=l=:-•••\·....;..1..,·\...+-
.......................1--++++....+-j-
·H-H
H-
125 ~++++++I...+++...+-++H I I I I I j I I I I H-t.:ttl...tttttttJ=ttttttltttll:ttjj::+++H"....J.....l-l...t-t-•MAXIMUM
l-H-+·-I-+-+....H+++1-+-1-!--
-MEAN
_..L.--+__~-+-+--f --+_.-t--.J.-.t-+-----+--J..--
",Jt:tUt:Tttll~tIfftmJmmM~mtl~glfmnWlisgL-,
.J..-i -I ....j.l-H-1...J..-H-+.....J-.J-1-.J..-H+
1"-...•MINIMUM
*OBSERVATION
....-.....+-1--+-+..
..._~-.-.f...+-+....t-t-1-1
t-
..•-1-
+_·f-j.....!-+-I-+++.J++-I ...j ..++-
-+-.--1-H+r\~EFtft111tifrt1TLt+~H...j
...++--t-.l-....~...
.....i:p......j I I I I I H'+f+
jj..li:t:.U~F++T·"'··-~-~~
..tli...ttt+..~.
1-j·-f-l-1-l-!-i_1++.J-l-+-jitTtt·++~+1-+--·_·"·"'"
.....l-
-+++-+-+-T .t+t+j-I ...f-.j-++j++-Jjj~·l-j~
I I I I I +-++f·++H±tl±±ttt!=tt·-
75
~25
SUMMER WINTER BREAKUP
D-DENALI V-VEE CANYON G~GOLD CREEK C-CHULITNA T-TALKEETNA S -SUNSHINE SS-SUSITNA STATION
20mg/l or more except where natural conditions are less.(EPA,1976).
~---II DATA SUMMARY -ALKALINITY
R&M CONSULTANTS.INC.
.......0'...........O.OI.DO'.".~L"''''''''''••••u ..v ....O ...FIGURE 2.9
1 1 ···1 --1 1 1 ~'1-1 '1 1 ~)]1
_._~_'-'~-'-H++++--+-H--+++-H-l-H I I I I I I +--+-+--+-++-+-i--H--+-+-H++-H-+-+I I I I I
-l--J I I I I ++++++++~+--H---+-H-H~H+H-+--+--t---+---I-+-H-H--
PARAMETER:CHLORIDE,(mg-,-L:L.,J
-.-.~-.-.l--\---i-+-+--++++t-+++-t-l-f-'+'-H-I--H-'+++t-'-+++--H+tttttt:tt_ttt::tti::ttJ±ttljj±~tU-.:~-I-H---1--l-I-l-t+H-t
A 30
+++-H I I I I I I I I I+H++~+-H--j-l--!-I-j~I-H-H-+-H-+-H+H-l-I-H-1-
---'~m>-+-!--l-+11-l--l---~--.-~-~--.-.-~-~
t-+-++++++--+I I I If I I I I I I I H-+-t+H-+~=t:ttt:tttt:1 •MAXIMUM
~-t1ttt:ttttttt:l=t:tt~+-1I I I I I I I I I I I I -/I---l----l I I I iif-·
-..:::rjjjjJlt±tttut-,I I I I I Ittttmltlt11Ittiltl:lli·j··llfJ Jr
20 -~
-I--·-·-H-
-j r+-+-+--+-++++-+---H-+-H--+~-J-+--·-
+-++-1+1 I I I I H+H++\i ilJttttt±tj±tttttii_',I I I
•MINIMUM
-MEAN
-··=ti T [
-~-~--+~_.~-j-
=1 Ttttt±t:t±t
++-':Ljj=tttj=tttl=~'
i---ll-++-l-l-!--+-+-+--H--I-I-H--+-l
-.-H-I--ttttttrJ=~:J-.:l___~1=-+=+__++-_H-l-+----l---l---l-t---l-
-I---+-~-~-._-
-··l··-··-~_·---
-l---+-I-+----l-++-++++t--+++=b·--'---•.--1--++I-+-I-I-+--+-H-HtD~
1-+-1-+-+-1--1- 1--1 -1---+--1----1-1--1 ++"'l'++--
t--t-+-t--t±tEEEfl£EEElffiE---l-t--I-t-H-,-l--l--l---++++++-H--++
Ittttttt:ttltltt.tJj~jj:i~tlttt:tittttttttt:1-j-
o
10
-1---+--1-+--+--.~~-.--.-.----
>-+-
-'~~d~~~·Onrn~T~NH-+-H-I I I I I----t-+·-·-~--
SUMMER WINTER BREAKUP
D-DENALI V-VEE CANYON G~GOLD CREEK C-CHULITNA T-TALKEETNA S -SUNSHINE::SS-SUSITNA STATION
Less than 200 mg/lx (ADEC,1979)
~~.~~l;T.e[:J'-[~~!~aC::JI DATA SUMMARY -CHLOR I DE
FIGURE 2.10
~~~~J ~]-1 ---1 ··-1 -1
PARAMETER:AMMONIA NITROGEN,as N,(mg./l.)
__L----.1._.J.._L__.J._LJ__~.j._....__t--l------t-..~
tA
0.3
·-H~-
_....._-...-.....--+---+-1"-t-t--t--H--+-~-_...-~-·--·--·-...-
II ....c.,.~
I-..1_r-+++=n:tt=wttttttttti=Uj:t:Jj=++++f-I-+-t-+-H-~
_.._,_.,-.-~-<-.-·,-I-+-~t-1--1-+
_.__•.<_.·_._.1-1--1-1-1_.,_.~~._<.~_.-."-"-.-1--+-+-++.-1-1--1--+-+-+-+--+-1--
•MAXIMUM
-~I--I-j-l-1-+++-H
--11-'-
-H+++H-+++-l I I I I H-I.._._'-H++++-+:ljj=ttt--t=ttl.ttr~+-
=rn~ff~~l~~l~~r~unlnu~",,~~~
I--+-I-I-I-I-H-'-'-
0.2
-MEAN
1--1
=C:U-LJ-l---l-J-l-J-l-J-+-+++-+-l
I--t~_.-
+-+-1--+-1-1-+++-1-1-1-1-..
-I-++-+-H-i++-I-H I I I \ I \ \ I I I \ \-+++-+-H-t-l--l-.+-I I I I I 1
__.__._...._..........._t-t_L-~__'-1-'-·-'---.._,_..
-~t·+
-t++-l-+-H-H--l--H--+++I-+--+-~-++++-+-I-I I I I I I I I I I I I I I •I I--+-+-H-+-+-+---I-I-+-_.+++-I ++~-++-+-++-litl1.1=1 =jJ=1 =t.=t
l-l-I-j.-...j-j-
0.1
•MINIMUM
-.-.-~-.-~-~--+-+-l-
--._._~_t_J-.--t-l-+-+---l----+--l--j
-.-.-'-'JJJ=ttl l -
_._.~_,_~__~I-1-+-j.-
-'-'-'--~-w='---J---'--I--t--.--.-~.-
++_I-+~_j_H __I-f=-l=1.:Llr:t:::l:-l1-=r=H-++j···1 -J-H-l-1--H--l +l--++-H-++.-.-~.+---.-+.
.•-·1----+--1-+++++++--++++
I-+--I·t~
-.--.---I--j
0.0
-1----+--1--1-1--.---.--._.•-
5U][-'--fH_Ll~r~t
#:OBSERVAT/ON
BREAI(UPWINTERSUMMER
D-DENALI v-VEE CANYON,G~aOLD CREEK C-CHULITNA T-TALKEETNA S -SUNSHINE SS-SUSITNA STATION
A.Less than O.02mg/l as un-ionized ammonia (EPA,1976).Data appearing above are total
dissolved ammonia.The concentration of un-ionized ammonia is pH and temperature
dependant.The maximwn ammonia nitrogen concentration appearing in this figure is
less than the stated criterion.
~;;:~.C:~~.~~l;T~~"T~'"~~oC:::II OATA SUMMARY -AMfviON IA NITROGEN FIGURE 2.11
·1 1 1 1 .~..._J 1 1 -1 --1 ~l .~l -]1 1 --J
f~·
PARAMETER:KJELDAHL NITROGEN,as N,(mg./1.)
-I+++++~'-'-'-'--.f-+--
!-t.
..'-f-
0.80
+.+-++++.I-/··+-H--+-+-+.,..~•.•..~.-•.•..~-
-..t-
+·+-+-+++-+-t-H~+-
-+-+-H-+-!--+-H-I-·-·-·~·-.-.-
+~-
-H--I--++++-I -t-I-H·+-+-t-t-+--I--t-+-H
•MAXIMUM
H-+--+-I--I--+--+--+--+
0.40 -•.I-+-+~--t-.-.-.~.-
.f-+-4-+-+-++++++-+I I I I I
-MEAN
-f-f-
......-t--._-.......•..-•......-.
t-f-t-++---·...f-l++I--t-+--H-+-+-+·•MINIMUM
-~-f-+H-H'H--j-t++H++-1 I I I I I I I
~-tt-ti"i-rt-t:f.Tt'tpqrllIlrlJ:::frj>:mrt:ttttrtt:~tUttJli1mQ.·tJwttttt(j)·fj::1::t=ptt!J!It:t:qrf::tlfj+~.
ttt:tt1:w_trlc .lfjjJttt ~.$.1-=1$1·+::l:iLlJ>.tJ1::tt<J1-H.4JiJ_t+tti~t±±±±.~±ttttti<f:ttl-i=t!~p-
0.00
-t-t-+-H++H-+--t-+-+-t-++-t-+-t-H-+-++++H-H-H-+-H--I-+--t-H I I I I I !
-._-.-j-
--l·H·+H-·f-H-t·++-H++--t-H·---+··-
..~.+.
-_··_-~·_··t I I I I 1+
1++-1-+-+-+-H--j-
*OBSERVATION
SUMMER WINTER BREAKUP
D-DENALI V-VEE CANYON G~GOLD CREEK C-CHULITNA T-TALKEETNA ~-SUNSHINE::SS-SUSITNA STATION
No criterion established
~.II DATA SUMMARY -KJELDAHL NITROGEN
R&M CONSULTANTS,INc~l
•..,0.""....'"d.n ...O<Jl'.''''.......",,,,.IIl"••u_..._..-o·'"J FIGURE 2.12
_.'-]~-l --1 -'-1 --1 .--1 )1 1 )-I )1
PARAMETER:NITRATE NITROGEN I as N,(mg.j 1.)
+++-'~HfiI!:rlllm:§JffiflIrHtll±11t=tl}Eilll±Etlllljtl±l±l~±lmUlf"---.--1-
3
-I--f-l+-I-t -1--+-+-1-1--+-1-j-t-I-l-I--+-+-t-t
+-+++++++1--'----.--.-.-"-+-1--+--1++++\-++++-H-
-.-.-.-1-~_~._+_.++I~[t -1-1-1 1-+-111-1-+-1--,-"_··_··_~-t.-
-W+-I-I--I-
l-l-i--H--l-4--+~-
•MAXIMUM
-1--+-.-
-+-l-"-
++-+-+-1-1----
-I-H-I-+I I I I I I I 1-I-1-+-I-l-+-1--t---\--\--t--I-+-+-I-l--l-l-H-I-L~-
W-l-t-i-i-I-I-I-
·-I-l-i-'H-t-t-t+++-H-
H-+++I-I-I I I I I 1 I I-++-I t I II I ti1-i-j±t±HtttttttttttttttJjjjj=tt:W=tttnnnf=t=q=rrrl='-
2
-MEAN+++H 1 I I I I 1 I +-t-I--I-H-
-_._l-+-!_t_+--t_l_l__I_t-----+--+-i-++-++++-+++H-+++++-+I--+-H--+-+--I--i-I-I+-+-+-+-+-+-+--I-I-+~~-'-
---.-_.•-+-•MINIMUMtt~tJJtF'_1-+4-+-+-j±ttl~EtfE8mmimfl£DJ·EItl1H£8-·-tllr-tJr-I-I-H-+++-H-++H-++H I I I I I
+--1--I-+-I--!--+-I--
++-+-I--l--'-'-'-·~-·-,~_.-.-~~-
-+--1-1--+-"-1--1--
o 1--j-.-
--T j-!-t--+-!-I-+-++-j I I I 1 I i
-1--+1-4---+-++-H-+-H-+-H-f--l--i-1
#=OBSERVATION-+-1-\-+-1-+-1
-++--1-1--+--+-1-1-+-l-I--H-+-I-H-+-+++-I+'-~-
-+-+-+-H-++-i-+-+--::t:!jjitltl=J-=-tjtH=e~[-ltj~Lmlrn~=j:m~m1E~Jlll1i[#ErHtliOOlUJIl-lImlf~~m~
SUMMER WINTER BREAKUP
D-DENALI V-VEe CANYON G~GOLD CREEK C-CHULITNA T-TALKEETNA S -SUNSHINE:SS-SUSITNA STATION
Less than 10 mgjl (water supply).(EPA,1976).
R&M CONSULTANTS,INC.
.."'G,..........aWOl-ug .•,....I.......,.,..JIl ••u_"'."0".
DATA SUMMARY -NITRATE NITROGEN
FIGURE 2.13
-~l ~'--l )-1 1 1 -)J 1 1
PARAMETER:ORGANIC NITROGE~as N,(mg./1.)
-+--_..._~_._._.~TIttlttttl :It-l=ttJ=ljjJ:tttt±i±t±l±1=tJ±L-tlt:+-l++-
1.5
--~-1----j-+-·-·--·-·-~-w--+--+++++·H-
-_.•-.-.~~.•--....-..,~.~j --+++--1-+-+--+-+-+-
,~-++1-f-~I~-I+H1r-f-r-JI·ttii1-r-I=-r:rl L ]Xr::l+U+~j .+--,-,-~l----W--l -11-1-1 j +++H·+-·~-
H-Hlllllllllil
1.0
-I I I I I-H++H-++++H-
-1-.--•MAXIMUM
-l-+++-I-f+-f-.-._....
~--I-f+++++-'l'·H-I·I~+-I-·I-+-·-~-·~-I-l---t---l---!-l--t-++++H--H+H-++
•MINIMUM
-MEAN
tttttttttt1
-+~-.-.-.•--
-._.-._.]::rlJt-r-rt+H-+++~
H-H-H-I-+-tTL,....-
!-+++I=t=1=·-
I-t--+++-+-+-·-~·_~··-~~·--
!-+~+-H-++-I~+++++-++++-I-
+~_.-
-.-.-.--~~~.·~I-!-+-!-l-+++-+--+--+-f-
~...-,,-,"-,~-+--'"_.'-:-1-·H-···--....~-··-
-+-1-++--1--'--•.-.---.-
t--~.-.-~~.-
_,_._,~I-...J~t.::tH+-W I--I-I~·-
!-~-I-I-H-+-+H-+-l~-··
-·-I-~-
-1-++1·++++.-
...._='1::-t1 __~-
1++++1-1 ~tTtttttttttttitttJtttt=
0.0
0.5
+-I---l+-l---t---t---J-----1-1----'--'--.l.,-~--~~.~..~.--.-.-.-.~--
t ~_.l~"'_._~_"~""'_~"_
tfUlbJj=<P:ttijj:a-ttr?:G~ttolJttltt$-I~lwl1tF~~'--
-'Tttl\lJ+V H$H¢-t-+tH$j-:I$I-:tttL~J=tltt<p +<h
-u-rh+-+-~aJi8--~-.~fft-F1tttt+-+-11-1-1 '1'-++~~-.-,".-{~;~~~~~,.~~.-~-----~~.-~,~"--~
#:OBSERVATION
SUMMER WINTER BREAKUP
D-DENALI V-VEE CANYON a-GOLD CREEK C-CHULITNA T-TALKEETNA S -SUNSHINE:SS-SUSITNA STATION
No criterion established
~~»:0f\V;1.11DATA SUMMARY -ORGAN Ie NI TROGEN
R&M CONSULTANTS,INC .
•"'(J."'11 ....U_Ol.oo,.,.,",L""""'.""••u·v ...u ....
----~
FIGURE 2.14
]"""--_1 '----1 ---------1 -"--'1 ----1 -]~)-1 .-]1 ']-)-1
PARAMETER I TOTAL NITROGEN,as N,(rug./1.)
+---+---I-·!-t-t---l+l--t-I-.j~~·-/--++++-1 -1-1-1-1--1-1-+-+-++H++++H--H--1-H-H-H-H--t-H-+++---+--I---l--H --1--1 -I-I-~<--'-
-~-_l--_~-<-.-<--I--~-
-!---
3
-'-<--l---I--+-+--f+l--H-H-H-l
-tt~=I=t=~Ef.-~_~<_,_._~
.j--"-~jltttt-tlttEt~~~~--~+-l-.
2
-·J=ttlttttttt1tttJj~1 ~tt1=--.~_.
.t--+-.J--I--+----i-t-\-I---I--I--I-t---l-1--+---t---+-I-j--/--+++t++
+---.--
•MAXIMUM
-MEAN!---
-+---+~---.-<'--H'--
-+--J ++-I-J--t-l-++-l---,I I I I 1-"-<,,-<,,--+---
!---
_-+++I I I I I--t--t--t-++-I--e.-H----+-++!+++++++++++++I I I I I I I I I t++H j I I I H I I I I I I I I I I I I ,I !-+-H
-H++-++H-H++-+-+++++=l=tI-ttl:tttttt:t+'J--t
__~_.._o--.~•-f------i_t-_{__t --i-----t --t-..---+-~-+-t-+-·.f
--••••!---
•MINIMUM
~ttH.!
--<••---l--
---I-+-t-I ++-t-'H-t±
-.-+-
I--
-.·.;I~mllmmjmnlmli1itm3Bmf:nJiW:l±tJ1tl=ftf
o
ttttt~~f~tBl¥1~ttn1BJll~1JiffitlJf~I1fl1mlfl~EEfEfHlW "',{JLUJji+--t--1
#=OBSERVATION
SUMMER WINTER BREAKUP
D-DENALI V-VEE CANYON G~GOLD (;REEK C-CHULITNA T-TALKEETNA S -SUNSHINE::SS-SUSITNA STATION
No criterion established
[3f~~~~.T_~,~JiDATA SUMMARY·TOTAL NITROGEN
FIGURE 2.15
-~"]--1 --1 ~-.-J ~-']')--1 -J -J ----1 1
17
t
A
PARAMETER I DISSOLVED OXYGEN,(mg./1.)
-H-+-+-+-J-l---l-l--l--I-l-l-J---I--.t-t-I-I--I--l--t--l--l---l--l---I-l-
_·_·_·--_·--·-~-I I I I I++-I-++H-
~+++-+-H-I I I I I I H-+++-++-H I I I 1 1-++I I I I I I I"I I I I 1-++-1--+-1--11 I I I I I -++-J.-j..-H-
14
+++-++++-
--,.-.--.----~...-'--tj-=:
l--l--l-+-+-+-++-+H+-H-+-+-++-H-l -I+-I--I-+-+-+--+-+-+--l-+~~H-+--I-+-+--+--h..J..-l-
12
10
r--r
.-.-~-l~------~'-'-H--I-++++I 1 I I +
~MAXIMUM
-MEAN
j--H++++-H-l-H-H-H-+++H+-f++-I I I I I H+++++++++++l
-I--1--"-1-J.-+--l--1-j-j~-1-----•MINIMUM
8
I-H--+-+-H-+-+-+-+-+--l---t-l--l---H-l++-+-+--1-+-+-.-.-.--/---.-.-.-..
-.-j--
~++-+-+-H-+--+--+-++-H-+--l-I I 1 I I I +--+++--+-+-H-l--l-++-+-+--+--+-+-+-+-·-···.....•···.-
-+--+--++-+-H -H-H-
I--!--/--I I 1 1 I +-+1-++-1-+-
~+++-+-+'!'+-+-.l?--H]IIUWU4~UIlr -l-l-+tml-~·;-H~m1~W~mH~Jit1i§IEfI=Ll*~~·#=OBSERVATION
SUMMER WINTER BREAKUP
D-DENALI V-VEE CANYON G~GOLD CREEK C-CHULITNA T-TALKEETNA S -SUNSHINE SS-SUSITNA STATION
A.Greater than 7mg/l,but 1n no case shall D.O.exceed 17mg/1 (ADEe,1979).
R&M CONSULTANTS,INC.
..""GIl,...••"'.aIOLQO'll ••L ..NN ....","'."""'0 ..011 DATA SUMMARY -OXYGEN)DISSOLVED
FIGURE 2.16
~1 •...•.)-~l --J ~"1 -1 -1 -'1 -J .~-]1 ~l 'j
PARAMETER:D.O.,PERCENT SATURATION
..l-t---
..I-...._.f--..
-
.---._...~....
120
---....·....
-.---._----
A :>=-.- --------~----..-..-_.·-_.----~---.,---..._..-....~.....
.--....---------.-...~_.--.1--...
-----~_.--
..
100
_..
-..•MAXIMUM
.---.--_.-.--_._-....•
I
.
-~----......-..-.
..
..-MEAN_...-.
~.-.--"-_.--..._.-~--.-'-...
80 -.--e-...-.~-.•-'-._-
-I-......-.--
--.----·--
-_.~......-...1--
..-._..------_.--.--..~--•MINIMUM
._.--~....
----._.-.•-
~-----'-----.-..
60
---..-.----"-
- -
-~.--.-.-
- --'-_..---_.-....--_.-----_.
~.._•....J ...-..._.....-------~-
e.----
..-..--_._.'--,-.----#:OBSERVATION(~~n J~~--~21 )-..~..=-~.--J _.
JI ~...,...\U .
)~.---j ~---).-l oj-5131·r-t-.;;>p I -'f~-F .
.-1 -r ---,._-.......~.-4 t--
SUMMER WINTER BREAKUP
D-DENALI.V-VEE CANYON G-GOLD CREEK C-CHUl.ITNA T-TALKEETNA S -SUNSHINE SS-SU$ITNA STATION
A.The concentration of total disolved gas shall not exceed 110%saturation at
any point.(ADEC,1979).
~DATA SUMMARY -D,O '.I %SATURATION~a~!Y1.C:~~a~~l:Tf:,!;I.:!"~'''~~DC:;FIGURE 2.17
--]1 -]'1 -~-J --J 1 1 ·--1 --"]-_..]-1 -1 J 1
PARAMETER:ORTHO PHOSPHATE,as P,(mfj ./1.)
0.6
-l--J--l--l-t--!--H-+-l-
ttttjittttttttjjtl.+-l-H.-H-W-!-H-++f I I I I -J-i-++--+-t I I I I j
0.4
.l--+-~
.-H-j.--+-l---\--~
.1--t-
,-H 't I I I j \."._-.~-
.._.-~_._.J=j-l--+--1-1--1~-
•MAXIMUM
-'-"-'-'-.-~+-+--+-j.++++-t-+-H
I-+H-H-l-l-
+-+-+++++-l--t-l -MEAN
..--•..•-.~-+-t-l-+-l--1
•MINIMUM
-H-.·-+--+--t-l--1-+-l
.._.__•..•..•_,_I-j._+--t-_j._j.·_j_j_j._+-·+-·H~
-++-1-+++,,_:tttlj:-i±ii::ljjjjJ:ttt:l:tt=ttttttt=t::ttl=l
_·tijt::r:r:::~rj-.ji-+-1-1 I I I I I ~l-P--l--l-
-14\
~tJ~~.L---l-.._J.-+__·t._l ~l_"._·
+f-H H H-H +mtml=mmmm=-~I+l-H-j."titt:ttti1:::!=
0.2
0.0
*OBSERVATION
I-+-+-+t-·H·-+-++-t--f-·-
-'-•.-l-~-_.•-.~-.-t-~-.->-.-+-
-++-+-H+-+-+-H-++·~-+-.j..I-I-I-+--._.<-.-
Ttr-tttttt-tl-+-'ltRI~fit§;f[falt~Jlr.m~tlfIDiim~wmt:J-
SUMMER WINTER BREAKUP
D-DENALI y-VEE CANYON G~GOLD CREEK C-CHULITNA T-TALKEETNA S -SUNSHINE SS-SUSITNA STATION
No criterion established
L9~~.1~~.C:~'~Q~~l:~~!:""T~ul"~~a~.jDATA SUMMARY -ORTHO PHOSPHATE
L.:--_~----.--FIGURE 2.18
~~-l 1 e'l .~J -----1 I 1 -~I --1 -~l --~·l J ~--1 ---"1 ")J 1
PARAMETER:DIS.PHOSPHORUS (P),(mg./l.)
--.--.-..•-~-~-.~.,-+-+++-I-+--1
-+-,-!--I--
-+.._~.-.-.+-+-!--+-+--H
_i-+-H-+_H--+-tt:t::r~
-__•.-.-.-.-I-l--1-+-J-.+--l-J---l--l-l--f-l-·'·,.•-.--~._.---"'-'--'--'-1--J--,-1 i -1--~--,-_..-
_,,,__0_"'_-+_.....~._.•_._~._._.•_•..._>-_..__._,O-_~_""'__•.._".~_"__:L "'__'__'__.'~.~""'_..o--......';o.__....__•__
I-+I++-H-H-++H-++-+++H I II II II l--tTtt-11 (II Ltti±ttttttttttt±ttttttti-J-+H-I I I I I !+++~
--+++-+-+-+-+I--+++-+-t-t-I I I I I
0.4
-.--'--~'.-.-+-+-j -l-+'-,-
~"-'_h_....._+--I_4-_~_.0-_..._..0-__--1--1-!-+-+-+--"--'~-'-
f--I-+++I'-.-~-.-
_'_~'_'_._-L.j---t-+-I-1-
•MAXIMUM
-I I I I I I 1-~-'-'-'-
-~.....:tl1J:1=+-+-I-I-lt+-I-++-+-+-1----.-.-.-+-t~-~-
H~-·-
--I-.~----
-MEAN
-.---I-.-.-+--:--=-.--:_1--.:::.>::1'.-_t.··:.·.1.-=-_..-_1-.._:.-'--'.-_'.....••._..~:..-."-'._-'_'-'.--.•..~"•.'--~I..-_·..!.·.:.~=...•-..-.··..·f..·..·..-..-·m.--.·.·. -.•.~-.~.•t ttt:.-.--.1 --.r.-.t t r.:.•.LtT.J.=+.-t.~.._h_._.}+..- -~t 1 lrHTI-I-I-'!1Et~lllr
-3=;-1 ~"__:~--i!;:-h JHf +~>-....-1 -~tttlliJ-r{lffi'
~jij\~\ffi{~f J:1 ••~~~:'-:•••~--~-~=~•..]~!11~~i~tl=~~;H ~:s ~LLLlml~J~~Httf ..........---...1 ..·1 j~J;gntt11ITilht ;~I:
0.2
A-----=;.-OO.
"'11'::CC!=tt-I++I-+-"~-'-'-'-"-'-'-"-I--~-'-..--.-•.~.-.-I--I:tttcrl-I-I-"-.---+-~....-.--
•MINIMUM
*OBSERVATION
SUMMER WINTER BREAKUP
D-DENALI V-VEE CANYON G-GOLD CREEK C-CHULITNA T-TALKEETNA S -SUNSHINE:SS-SUSITNA STATION
A.Less than 0.01 mg/l for elemental phosphorus (EPA,1976)
R&M C~NSULTANTSIINC.II DATA SUMMARY -PHOSPHORUS
......a,""••••[Jl'o ..b~'..'._l.""",,,,.-'t ••uAv ....O ....FIGURE 2.19
'--1 ~~]""-"-1 'J "1 ······-1 --l --1 ----1 ----1 -J "---1 ~l
-I-++-++++++-H-+-+-+-t-I--t
A
PARAMETER:SULFATE,(mg./1.)
+-+·i-f-I-H..·-.-.-._-
++-+-1 I I I 1 I I I t-+++-+-1 1 I I I 1 I+_·_·~_H_._~_
-+-+-+-+-+-f-··-·-·-·-~··-
..-.-.---·I-H +t
+-++++-t-
-+-+-t-t-++---.-.....-.-~-
·-t+-+-+-N-······-...~-.--.-~.•-
w~++-I-I-H-+-I--H
~=tD=1JTLI-H---H-1+
40
--1-++++++I I 1 I I I I 1 I 1 I l-++t-+-H I I I I I I I I I I I I I 11-1-1-1 I I I I H++H+++I I I I I I I I t-H-I---I--+-j
---I--
•MAXIMUM
-MEAN
20
o
-I~-
I--H-+",-++I I III I +
-t:tt~tttl-H-!·-H-++H-t-+-l++-T-+
H-l-+-+-H-+l+--j-H-
+1-+-1-++++++1-1 -I-++H-I-+H-
"p-+-I-H-1
-'-++-I-I-I-H-1+-
H---~-
----·..+-f-·-·..·•-.~--
t+-
•MINIMUM
I-+-++-+-H-H-j-j--H -f--H-·H++-H+H
1~-tm=+7\~i$+159W-~t~~~ttt:~tlt=f=$t!21~t1Wcti'*t:j~lj=t=tll~-~m-...i=4:t~Ult=tlj¢i:~+tflmto/tit=1=t -~tt~ttf-rt~-tl?pj=tj=tt~t-rtt:~ttjJtttt~ii-~jiti-tP--t itt~t<tt:tlttjj~*OBSERVATION
SUMMER WINTER BREAKUP
D-DENALI V-VEE CANYON G~GOLD CREEK C-CHULITNA T-TALKEETNA S -SUNSHINE SS-SUSITNA STATION
A.Shall not exceed 200 mg/I.(ADEC,1979).
o~[J'}-"'c..::::J'01l-_~.~.r::.c:~,~"~~l.;T~~"T~I"~~oc;::IDATA SUMMARY -SULFATE
FIGURE 2.20
-]"·-"~l -~l ~-"~J '~~l 1 -_.."1 )-1 "]~-1 ..J -j
PARAMETER:TOTAL INORGANIC CARBON,(mg./1.)
~++++_+++_+H_+__+++-J-_H_++_+_I-+++__j--l_l-i_J..-+..+...j_·I--l--I-1 I I I I I ,j
~~~··-H-
100
HI--j--l-··I I 1 I 11-+-++-1--1-1-
-.\-J-I--l--l-+l-l--l+J-I-H-I-'-
+H++-++t--I I \ I I+-I-+-I-H--+-+-,-+-+++++t-+'~l=·_·_·_..--.-•.-l--1---1--1-+-1-', ,1 I
75
--J--I-I--J-I-+-I--I-H-t-++I-+++t-++I-+-H·-l--I--I-+-+++-I-
•MAXIMUM
--·-·-~--l-H-+++-H--I
-.-+-+-+-~----MEAN
1--
H-I-I-I •MINIMUM
1-1-1--1··1-+---1-.-
m-
=1
-·~--·-l-+-H-++'++H-
+--1--1--1-++++-
>-j-+-++-H-'-~-..-
H+++H-H-H I I I I ~I , I I 1--
--I.+-+-1-+-1-I --I-+-+-+-I-H=t±tttt:t£8~++I-H-++++-+
50
--~-_.I-'-
-~~-~.-.-
25
+-1-+++-1 I I I I I-+-!-++I~-J-++-'-~...-.~.-
-j-+T...j--~--I-I--I-+--J-+-I-
-1--1-1-1--I--I-I-I-+---I-j ·j-++--I-+·-
l:ttqt~I'~lj~Htt-1-#fi¥it{ldmmJj1-jwt_fltfm1=I-¥H&*OBSERVATION
SUMMER WINTER BREAKUP
0-DENALI v-VEE CANYON G-GOLD CREEK C-CHULITNA T-TALKEETNA S -SUNSHINE:SS-SUSITNA STATION
No criterion established.
L--------II DATA SUMMARY -TOTAL I NORGAN IC CARBON
R&M CONSULTANTS,INC.
....."......."'.OICH.C11J1",lt_.."..............•\.1"'V.~O"'.FIGURE 2.21
C-~~l -)'~'C']~'-l -~'l -'-1 '---~-,-')--j ''''Cl ~-----]1 I ]
PARAMETER I FREE CARBON j)I_9xIDE,(mg ./1.)
+-I-++++-H-t+H--H-++!I II I I
+--I+++-
+++!++++-i_H__W++1--m1+t+J:+t~~+~=~=l=tj~~~n=tt:ttT~tt~:t=lttt~++:+l±ttj±tttH-J
_.._~_._i-.,__
-1-+-+-1-++-+-1-+-1-1-1-+--
30
•MAXIMUM
~---l---l-H-+J-H-f I I I I I I f+J-h
~,-~--~-.-,-·-.-J-l-f-i
-1-+-
,+++-l -++-1-+...1-+-+I--I-I-+-I-I-H-J -l---!-+--J -++-1-+-1
~--~-+--
,1-tt:,tJ=E:8JI1F11ml1:E1JlTUXI::
-.-+--t-t-+-+-I-±ttttttttlJi-ttti=:ttttttt-1-l---l---l-20
tfnEPIEftRfLf~ftfimrilJItJH~tffft=l4=i±lli$m1LfHtJ±fRilt1t~H1ttm]
•MINIMUM
-MEAN
#:OBSERVATION
_,J::"
--I---I-H++-H-L
tlT--
...:Jili::tJ::f-f-f-H-J+--
,+-I+I-l-'-,·....-....._--
Jl:!fuItitllj.i:J t ~I}nl
--.--.--.-.-.,.-.--l---!-+-+-+-1-
+-
I-+-H·-+-J-f-+-H---!-f-I...'-l-
-I-+-I--l--+-H-+···-·~.-.~
-~·-H--+--4-+-H-+-I-
-1-.-
~I---!-+-I-I-·I·~+-+I !---'c_'-
--+--J---+--l--I--+-'~~~-.-.--.-'.-
,.-l-+--+-+I·I~..H-+-l+1-+-l
+-,~
-I---
-+--+--H....l-t:(=lttt=ttttttttH_tt~1--~-+-I~-++-l-1.-1...1-I-H--l-H-+-H-+-
--.f-
-~i-I-I I I I I +-+-H \I I I I i I I I I I +-1--+-t-++-f--(--1-~-t--1-l-(+++H--H++++t I I I I I J-H+i-
~1111111+-H++-1-
~++++~+_II._LLLJ~_l_LL ~L]=[.£·~-
~m-f-t-rttttl'-I-tii-trtttittl-I-:I:titttt~jj=iJttl·Ju=L...Tm=W=+=l=!=!=l=l:r:++++++++-t=tfttt=tt:±tttt~tl~-l---!-l
1-+--l-I---!-+-T+-I-J~.j-+=rT):Pl+P++r-r~EEe__T.::tnl.::r=r:-I--+-I-+--+-+-...j-l--+-I-
o
10
SUMMER WINTER BREAKUP
D-DENALI V-VEe CANYON G~GOLD CREEK C-CHuLITNA T-TALKEETNA S -SUNSHINE S$-SUSITNA STATION
No criterion established
[P~II DATA SUMMARY -FREE CARBON DIOXIDE
R&M CONSULTANTS,INC.
.....0'.........0_00.001''''.JII""~N••••UJIIV."Olll.FIGURE 2.22
"-1 '--'j .,._]r--].......)·~·····'·l c-'--J 1 '-'-1 "-1 J '''--'1 '--1 1 J I
1111tttEtft111lfBftf!lUTLtllEtftf1fEffiffttJfiffiftlB £litt
3
PARAMETER I ALUM~NUH CAl)DISSOLVED,(mg./1.)
t-
..H-·~-·
-J--[TI'=l-U-
--<----+-H-+-+'-
_'_._H _H _H I I I I I , I I I
-....-~._-.--··++H--+++++-++1-+-++-_I+}-mfJ#JmffHUtttttt l.j -I++4 ++-+-~-~-
·-·--,--t~-·-
2 •MAXIMUM
,-t+l--}-t++·+·-·-_·~-·..
--..._-1-
-t-+-.-
. I , I I I +-+--1-
1-
-W--+.++-+-+-+++++
t--~-"""""'_...I-.---"'--+---~'-.-.
-MEAN
•MINIMUM
-\-~~.-
-,.-l-~.
-.-.---1...+-1-+-1-+-.-+-.-1-1--1
++++-+++-t-!--+--+-t~r:tttt
-H-f-+-+-+-t-t-
-!-o •.
-~t-H--·H+++++f++-.j+I-I--++H--+-·_·'-_·_-
.~]]xtt:~..--._,......-~
......+--1-1 ..1-1--+·+++-f-+--~-_1++-.-+--~-l--+-+-I-+-+++-J-+-J--I-t-··H+++H·.l...H-.,I,-j-t·++-f--j-++
~mi~mffiltmMttmllfil-llliitJHI~itilljJ *OBSERVATION
=OOl~=rnntllljltlttIl1}lI~t::lJtli::I:l-I±I::l::l:ttlttLlI,t:jjj-l::ttl::tt
.+--+-+--J.-..f-I-I-I--+-~...t-
-.-.--.--1-
B~O
SUMMER WINTER BREAKUP
D-DENALI V-VEE CANYON G-GOLD CREEK C-CHULITNA T-TALKEETNA S -SUNSHINE:SS-SUSITNA STATION
A.No criterion established
B.A limit of 0.073 mg/1 has been suggested by EPA (Sittig,1981).
~.2J01 J~..~~.C:~L~o~~L;T~~,.T~LJ'.~~oC::------------_._----
DATA SUMMARY -ALUMINUM (el)
FIGURE 2.23
1 "1 "'--'----1 e"l -"']~-1 -----1 ---~J '~J ~-I --~1 ,---1 "1 --~l '1 I -1 "1
RecoverClb le (mg./1.)
-+-1-4-+,++-1--
Tt=~+=R=Rl=FR=I=rrF=n=r-n=F-lttIEE
}-1_'_U'..'__'"_H'H_t-+_+-t±E]!t=ti=w~=l=tl~:r+f-t=+itr=n=t=r-t=f-f~~tt±=ffq±:TJ]]JjTJ=._~....--.
PARAMETER I ALUMINUM (AU~otal
-·-i-
e MAXIMUM
•MINIMUM
-MEAN
#:OBSERVATION
..+~--
-H-
-1-1
-+~.-
-I-+-+-+H--H-
-.-.-i-
-,0 _..__._.._.~__I-
+H--~++i-~--l-I--l--
'"'~]Ttjj:"tLtt1:::1::r~-t-++l+~
-Tr-Trt-tlrf-r1--H-+--t--H+-\--!-I--t---H-H-++-.,.+I-
-H-+-Hj=tj_~-
H-++-H-H-\-l-+-I--!-+-+-+-+-I-++-+-h-,
-·_"-·--·-H--
I-I--J-+-H-t-+-+-I-l-l-l-LLJ _LL 1-._1_1-,1_\__
+-+-I++--+--+-l-
+-1-\-\-\-t-~-
-t:::tttttttttt:.tttH ++
-+-1-
-.-._--~-~--++-I-+I-
-l--•
t -l--l--l--.-.-
+-1-'~-'-
--t--+_.J-.--f---...-_1-t.--
I I I I I H+H--H I I j I H H_++H+-i-++++--H-l--!-++H-I+-l+-+-+++-+-l-+H-+-l--I-+-H----t-l-+-H-I-
l-~.-~.-
!--.-
.!--I -W-l--
T133tt:tt-...lH.-f-
t1:::ttttLtttti.-ttttttttttt+--H I I I I I I I I I I I I I I I ;--1-++-++
+-.-.-
-EII[3J=[EE8l!-li=~t=~~=G8,~~I~I~'IJ~'tI11I~"I'~jj-=--1-;_.~=~H=I~=ffi=~I--=:~1 ~I rIJFR~EfIl±FHffifffBJEi~-it "--,-''"-----fB3fE1JB±Ef+-+++H--i
__,__"___..___.._.~~..f.---t-_~_f_·'._~_
-J+H-l I I I I I-+++f-+++-+H-+++--H-!-+-++I I I I I f I I I I t--I-l-++J-H--I-J--J-H-.f-..l-+.4-J--+-,+-
-.+.~--
,·,+,~j.i.-I[mM~i.l.Blll~lwmm~f~t~j~j·j
10
20
~o
WINTERSUMMER
0-DENALI V-VEE CANYON 0-GOLD CREEK C-CHULITNA T-TALKEETNA S -SUNSHINE SS-SUSITNA STATION
A.No criterion established
B.A limit of 0.073 mg/lhas been suggested by EPA (Sittig,1981)
~)lJ~·1
~.~.I'f.!.C;:~~.~!-!l::::'::.T~I.!~oC:~I-----,--_.-~-_.----
DATA SUMMARY -ALUMINUM (t)FIGURE 2.24
I 1--j ---I ---1 '-1 --~1 -.--~)1 '--J---~I
PARAMETER:BISMU~H (Bi)DISSOLVED,(mg./l.)
--1~=H~J-t=q=T--I-I-I-H-j+H-t-+-H+t+-+-H-t-+-t=l-r~=+tt:::t--LJ=~---·-tlT-lJ1ICI--H++++I--I-++-+-+
---·-1-
'-'-'TtllIf~~-.-
1---
1--
-+-l-I-t-H-l-I-I-"
-.·-·-·-·-H-I--I+I-
•MAXIMUM
-MEAN
j +-1-1-1-+-1 I I I 1 I
_._•<._,,--\--1-+-++-+-1
+l-tttttjj-:1JJT
.•,--~-+--~--.,I.-"--
+-t-~-
I~-~-
-1--t-++-H-H-H-f-H-1-++-H-+-+-I-+-+
jlWt+:::,I I III
_..-.-~-r-1~·--\....1-++1ttt±~~lIttt-~
1-+-1-+-
~t-j_-l-J.----
-1-'-
1---
-.+-
-1-I--t-++++_+--+-4-~-'-'-'-
,--'-
__1-1-1-1 T[[[Ctt
+-+-++++H-\-t-'H +H+H-f-H I \ \ I H+\-j -t--t-tt
1----l-l--I-+--J..-++-1--l---1-1-~-~~J~jj::::,_<_
+--t--+--+---+-+-t-~~j~"--I -'.•-
--.-.--~-'-'-1-H-t-1-
-1-
-t--+-H--H-H-+i-I-J-++I-H-I---t-+-+-+-
-t--t-J+I-l++-+-+-i-
I-H-\++++--+--+-
--~-H++-H-1-I I I I I I \ I I I I,I I 1-++--++++--1-++--+-+-+-
.H-.-H-H-I--+-+-I--i-H-H 1 I I I H-f-+-l-H I I I I I I I I I I I I I I t-1-f-l--+-+-
0.20
•MINIMUM
-#=OBSERVATION
--1-1-1--+-1-1-1-\--+-+--1 -1-I -I--I-H--..-•.-<.,_.~-~~--+_.-.-.-H++-+-H-'--
lEEliJ*J-!tt~~~~~--:"~~t :~-~:tl~~I---.~-I-3~~-j.-.~.~..~.~I:::;f~-I-::::~j--i"·~'-=-'~'~';~-
--_c.---..'.--.- - --j---.---.-.--.-.~--....---··f-....-.J_--f-I-____-------------_t ..-.--
-----.-.~_.._-~-~----~------'.'-,.~.-,-.--'.-..__..._--~-
1-~1-J±llttl±~:'::t'+'.H J:_"1-._-.._.-..__:--=:-+1 :T iltm
J--+-l-.-
-.-f----
-...~-t--t-~--t-------'o.--1--1----&-~-
0.10
~'--1----.---I--•-.--.--.---------1 ~1-·_t~f-----~j-----1--H-+-'-~~-__-__-:::::L --f-----•-.~-1__~-I::::--_~~- -:::::::-::::---.-::::::::::::1 __~_.__::::;-i~-~.:+=--:-.::=--f::::t J-
f..--_~___------1--.-- --f~---1--1--
+-+-\--+-l-~--l--'-___ _1-____-------.-----------..--f--.-.-----1------I-I-
I I -F11'<{-(. -~-.--((---r -c.--..---.--h ---,Jr-.,--r~-"~__~__~J:-i"::::"_:L _J::::{;~::::=::::::::~~-:~-:::\-:~--:=------f-t;._=:i'-:::::J::::1\-s-::.'-I*Rt --,--l ·-1 - - . .-··1 --------------+-----of ..-.---~-.--=]----
SUMMER WINTER BREAKUP
0-DENALI V-VEE CANYON G-GOLD CREEK C-CHULITNA T-TALKEETNA S -SUNSHINE SS-SUSITNA STATION
B----:;;-O.00
A.No criterion established
B.EPA has suggested an ambient limit of 0.0035 mglI.(Sittig,1981).
R&M CONSULTANTS,INC .
•"'100'''....O.Ol OP'.'._1..."'''''••••u·,,·.0".
DATA SUMMARY -BISMUTH (d)
FIGURE 2.25
1 ~-~~J ~~l 1 ~l ~---l -~-J ~)I J
PARAMETER:CADHIUH (Cd)DISSOLVED,(mg./1.)
-._.__.--t-t-+-!-J-!-+-+--l-J.-J-l-+-I-l-I H-
+-4--
~-H-J-·-
-.-,_.~_+-1 I I I I I-+-l-I++-!-H-J-l-'-+-'-'_L_'_-'-'_'_'_'_"_~_
-H++-H-+-l--'-l-+-1-:tJ=t111m±rj±+-~I~+H
0.003 111!lillt-++1
+I I ! I I I I I I I I \ \ I +-.f-l-H-H+t-+-+--H-t-I-t,-'-'-~-~'-·-~·
i--l-~-i--+-+--+-J-J-I-+-+.•-.-.-.----
I_+-+++-++++++-H-H-~-k-'."-.-.-
--.-.-.-'-'-+-:e-,-t-++-t-+-H--+--+-I--l--J.-W-~j=tt1P~-·-·-ttjj±ttttttj:-ttJJ-~~~
-+--+-+_.i-~--I--+-I--+-l-I-+-+-1-+--+--i---+-+--j
-l-i--l-+--+-i--I-I---+---I-+-i--
1-+-1--!-
..-.~_.-.,-I--J-i-I-+-
•MAXIMUM
t r I !I I--I+i-++!--++-H--
-1.-j.-j-ljj:ttt1--+~·_·--.-~--l-"-'~-
o .002 -t---'-
•MINIMUM
-MEAN
:I-t'OBSERVATION
+-t-
-l~--.-.-
----.-~-I---1-+-+-+--1-+-1-+-H-H-H~-'-~-
-l-I++I·~---·-·-
-I-+-+-W
_•.__+-_-4_',_..-".--1 ..__-t._."f-·__l---.l-·--l-··__•_~__f---+.-_-"_·.--->--
-H-+-t-+H-ttttttt:t=t1j~tti:j::tt:::l=1~1
I I I I I 1 I !!!I !+.-J++I-+-++-ttt+=tt:l=t=I
-1-+-1+1--1 -+--l-J--+.-~-
_+-+--l--l_H-++++_t+I+f--I_--I+!-I_+j_.-j-l-l_~rxr:'j=J=~t.-J+H
+-1-1-+-+--1---1 -.--+-1-+--1--1---1-
-~-.-.-.-.~--.-f-f-f-t--t--t-
=r:L1=w--J:J::.r::
-+---J.-i-.--.-._-
-1-++++++-1 I I 1I t I I I I I 1-++H-1--l-i--
A ---7-
B ~~lt=H-:::.::.:.-I--,I-----+-1---- - - - - ---1---I---1=1-=l-------=f.=-I--+]-l-+-I-.+--l--J-+-+-
0.000 I---_1 __~_'r__' _ __:=_.-l--f --_~::---t::.::=T=~=~
'tJl,lJ:'-n ::,~~:~:~~~-_>-;-1/:_-==_j;~-:>i~J
f--l-t-f-+t-..j:~J::1'~,~---~~-:::Iss -:::::::-:-i -_:----..-_..,(:1--:t~:::'.-:-I~~:=~,==t ---t .~~t--t-:{--:£tft:r-J:''''>-
A >-
0.001 1 11111+1111111
SUMMER WINTER BREAKUP
D-DENALI V-VEe CANYON G~GOLD CREEK C-CHULITNA T-TALKEETNA S -SUNSHINE:SS-SUSITNA STATION
A.0.0012 mg/l in hard water and 0.0004 in soft water.(EPA,1976)
B.Less than 0.0002 mg/l.(HcNeely,1979)
~--jl DATA SUMMARY -CADMIUM Cd)
R&M CONSULTANTS,1f\.IC.~~~_~~~_::.~.~_::_':.-"-:~,~~..v.y~~~FIGURE 2.26
1 1 -1 -1 -1 '.')~-~J J ]----)---1
-+-I-H-ttt-tmtttttm=!tl=tttu=t~m+l++=rU=~t=:t=~,,:tii:l=t=---}j:ttt=ttttt~Jl-b:::iit-+l
1]1=[.~-
PARAMETER:CADlHUM (Cd)Total Recoverable (mg ./1.)
=1-1-1~t-1i"tt--l--t-t-1~---"1--fi~I-'~JT'--r --,--,---.--------'--r-
~-~-~~:_=--_.=-~:=-=-~--~=~,~=--==--=~.-
_'-'~_H--.-i_t_H-+-+--+-+-I-+-+-t--j I I I ,f
.-.~-l-'-"
•MINIMUM
-MEAN
•MAXIMUM
:U=OBSERVATION
----l-+~--·~-.j.._··-
-1-1--
_0 ._.-.=tJj=,_,__.~_._.__
~_...-+-__i_+~""__+-H--"-+--1.-__~!_..l._.J.~_.._-Io __...----<~
1--,..
-II'TII---t'-~--~----rr-~l·-~#111-!1-J.-)-;-~--1f~-f:t t~-~-l'-~·-li~1-t-~l--l-i~1J'j--
:..~,_____________.~.______~,____._______---.------',.----.------ ----------- -----------'---'-t _.----,---____ _ _ ___.__._______________________.___ _ ____----+·1
~.------- - -,~-------~- -~----~----~-.._..---..-
-.~-'~---,-._.-"",----~-.._.---",-------~~.---'--_.--_.-----.-----~--_._.- - -"-'._-
.j='::·l~·I¢t :llr1:=J .•.............::=!AJ·.-=-~i~:J!l
--I-I t -_1.1--1_-1--~---+-+--f-+-j-I--I---1--r-f-.---t-+--I--I-H--+-t---+---f---+-+-~fj'-m--I--t -----I--t---------1-+--1--1------ --+1--f-.----t-+----..-It-±_-l--..- -l-- -I----------.-
-fill--rf-jl$t-I-------"::=------~---j------I--~;='::1 -;=-1---~-i'~,----:::.r~-J:.r---::-=-=f----=--~----I=--------j-I-----1----3 =-1-::.-
------1---,------tl-,,..j ____, - - ----------c-___-r--'- - ------w-.ttj
=ftlult!lli~f~f:tlm~~I=I=HHtmj#nfiBJr:1l1Brl-··
1-'-1",-,-a'[----t---',"_+-+'_t:.
H !_-,-I----I-+-+--LI--1--1-'-1-,·-----I~'[i,~--'-~-~-,11--_t-I'~-'-'-t
'-----------1--1--1--------l-I--l---H +-1--I-- --I-,--_.--,-----,-
•__--__--I---':=,----1-1-'-------I---1-1-----1-/-,------------------- -1~::==:=~,:~1~::-;~~,:=-::=,::::c~=~~-=•~~(L -~:~JJ:;L.
L ___,~_~j~,~I ~.--~~-Jl Itlt1
0.01.
0.02
~o
BREAICUPWINTERSUMMER
D-DENALI V-VEE CANYON G~GOLD CREEK C-CHULITNA T-TALKEETNA S -SUNSHINE SS-SUSITNA STATION
A.0.0012 in hard water and 0.0004 mg/l in soft water (EPA~,1976).
B.Less than 0.0002 mg/l (McNeely et al,1979).
[J22r~J]\11 -;
,~!:!:':!.(~S;1,~~~L;T~~.T~".•~~g:I__,...~,_:"J.J DATA SUMMARY -CADMIUM (t)FIGURE 2.27
-~~1 -I ]1--1 -]J -)-,]1 )
PARAMETER I COPPER (Cu)DISSOLVED (mg./1.)
--
--.
---..--
.----.---
.-.--
---_.-_.---.-----
.- ----~-----..-
.-_.-
0.02 •MAXIMUM-.--
-
-MEAN
---'-
0.01 -------_.-.-.
---
B--?--------------.-~>..~------- - -•MINIMUM
-
--'----
--
-.--
0.00
,
--f------
- - - ---
-.-
-*OBSERVATIONrIIJ--if '-'{...-"-'][)----'-.
-;-
-_.----...--------...------_.-------
SUMMER WINTER BREAKUP
D-DENALI V-VEE CANYON O~GOLD CREEK C-CHULITNA T-TALKEETNA S -SUNSHINE:SS-SUSITNA STATION
A.0.01 of the 96-hour LC SO determined through bioassay (EPA,1976).
B.0.005 mg/1,(McNeely et aI,1979)
~DATA SUMMARY -COPPER (d)
R&M CONSUL.TANTS,INC.
•1'\1 ••"".......O"OD'.T ••L .....~••••u •..,....o ....FIGURE 2.28
~1 ')'--')J ]---]1 "'~l 1 '1 -"J J 1 '-]1 )
PARAMETER I COPPER (Cu)(m~./l.)Total Recoverable
1-------,.- ---I-
-1---.----..-f---
-
-----------~
.
..-I-----.-----'
~-.,1-"
.
--
----~--,------------..--_.---
---.--1--,..
,--"--
0.2 ----'
--
.•MAXIMUM
,,
---~--
.---.-
-MEAN
.--I-
-
0.1
~
.-~.--
-
.---
-.
-'------~--------.-------.---------'•MINIMUM
--f-.-
----~-..----
---,--
B.--;-O ---.-----..--1----.
I-
-.---.-.-.-
.----,--
.-----,---~.-"--
..'--------.-----~-------'---.'-#=OBSERVATION
-V-
.-_.-tJ 11 iJ ' J
___i1.--~~.l =--tt It -tI =_II JL f)
--I~.-I--._-----I-----
5f---~-~Ie ~i?~--I[}:.,-r..'.-
----..I-f--------
SUMMER WINTER BREAICUP
D-DENALI V-VEE CANYON G-GOLD CREEK C-CHULITNA T-TALKEETNA S -SUNSHINE SS-SUSITNA STATION
A.0.01 of the 96 ~hour LCSO determined through bioassay (EPA,1976).
B.0.005 ing/l (McNeely et aI,1979).
~~
R&M CDNSULTANTS,INC.DATA SUMMARY -COPPER (t)
.....,,..••,..O.(h.OIl .....•"...............u-...•..,,",,-
FIGURE 2.29
,]--J ''···'1 )--1 1 ]1 J --1 '1 1 ]1 J
PARAMETER I IRON (Fe)DISSOLVED,(mg./1.)
=1:±1tUt4illlltii14±t±t=lli:tlU~tt:t~i±ttttt:ttttj±l=t:tt!:=t±t±lii~
--.-.-<-.-.-.--j+-f-f-I-f--~-".-~-3 I
~I I I I I I I I I I I I I I I I I I I I I I I +++H-H-I I 1 I 1 I I I I I I I I I .-
-~--_.~-·+~-H-I I I 1 I 1++++++_.-W--t-i-I-I-++-I I I I I I I I I I I I 1I I +....J.-+i
-+/-++++++-+-+-t--+-+-+--I--·-~~-
I++++++H++++++I--I I I I I I 1 I I 1++-1-\-+++++-1 I I I I I I I -I-+H-H--t-+--l-I-I-I+++H-l-+l-I-+-+--J~--I-f-+--l--+++-+II I I I 11++1 I I I I -I-I-++I--~H+--
II--+-H--H+++-I I I I I H I I , I I I +I I I I ++4+1 I I I I H--I-I-+-l--l--I I I , I I I , I I 1
•MAXIMUM
1--1--+++1+1--1-++++++I I I I I t-+-t+H-·-·-
I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 1 I I I I I I I I I I I I I I I I I I I 1-1-++--1-1++++-1 I I I I I I l+H++++2
-MEAN
~I -I+++-+-l~--I-+-~-+-++-I-
c-l-l-l-I--+--+-I--l+I-I++-I-+-I-++!--I+H-+-'-'-'-~""---.-.....-~.-+-.+-1'-+--+-+++•MINIMUM
-.-+--I-I-H I I I I I T~I I I I 1--1-+1++'1
_.-I--H-+-t+I--l::-+-I-Hi:i.-+-f--1
1-+f-I+H-++J-++T++-f+I-=F-++:1:+-hJ.-I·-·-·-
I I I I I I \ I I I I I I+++~', I ,I I I , , I I I I I l-t-l I I I I I I I I I I-J--+-~-I-I-l-I-I-H+H-H+1+1 I I I I I I I I j I I-++H I I I I I I 11--+-1 I I I I I I I I I I I +-+++-H-~+++I I 1 I I I I-++f-l-I I I I I I +-+++I I I I I I
o
I 1 I I I I 1+-+++1++-1-+1 I I I I I I +--1-,--
lm±rmr1!Jttlttfttttt~t1WlImfm±m$mt±t±LtfflmBIfRE1Emf~
*OBSERVATION
SUMMER WINTER BREAKUP
D-DENALI V-VEE CANYON G~GOLD CREEK C-CHULITNA T-TALKEETNA S -SUNSHINE::SS-SUSITNA STATION
A.Less than 1.0 mg/1 (EPA,1976;Sittig,1981).
~,II DATA SUMMARY -IRON Cd)
R&M CONSULTANTS,INC.
...................Da'.T.PL ...fIIl"'.....U"Ivw·...••FIGURE 2.30
1 1 "-'--1 "-"--"1 "-)"-1 -1 -J -1 -]1 1 1 --J J
PARAMETER'IRON (E~l Total Recoverable (mg./l.)
t-H-f-t--t-tmlfl£EEUma{£I~rlrm----±tt--tt-+-t+~+
H-
-_.-.~-.-t---t---H--H-I I I I I I I I I .-.-.-.-_...
-.-1---.~-~-
•MAXIMUM
t---.-40 lfrttlmmW=H=-mmmm=t+RfmfRm-rrCi±llitt±±tt:::l±1t±ttttmtt::+:tHH=!
•MINIMUM
-MEAN
---.-t----
f-_•
rJ":
~ttttitl:ttJtttt~~~1--+-+-1
-+-t-H-++++-H-
20~•
.-~I-~-l-+-{.-+--l-t-
tj~tttti±tl~+A .-----:;;.-0 1-"i-t--'-H-IH-JH-IH-J~~~
#:OBSERVATION
'H-H-Ai-f-fffttFFgmft1EWW~*fffl=t1l=tt1tfl~tff~WJJltt~1:'j~t+~-$-j~~~1
BREAKUPWINTERSUMMER
D-DENALI v-VEE CANYON G~GOLD CREEK C-CHULITNA T-TALKEETNA S -SUNSHINE::SS-SUSITNA STATION
A.Less than 1.0 mg/l (EPA,1976;Sittig,1981)
~~
RSM CONSULTANTS,INC.
.........."••"O_CH.U"".-'''......""'......".ullt~.'n ••
DATA SUMMARY -IRON (t)FIGURE 2.3/
..~---]-~~l .'~-J 1 -~.]~-l 1 ~-l 1 1 ---1 ~-l -]...._.~
PARAMETER r LEAD (Pb)(mg./l.)Total Recoverable
----.-.~-
••0 ----.--f--..--~
---
0.3
_.
~.--_._~--~--
.----
-
--~.
---.-~~- -.••0 .-.~._.---.---- -
.• 0 -.~
-~..---.--.--f---
---
0.2
-•MAXIMUM
.-0-
-
--MEAN
0.1
--_.-.
--..
~--
----.----"----------- -•MINIMUMA-......----
--.
a --..t-----~----.-
,
- -
_.-.--
..--_.--------------
--
.0 _--_.
*OBSERVATIONl-.J .1 _l _II.~I -.l L l.- --o._--.~o ---.Go -.-.-,-}-..(;1 ~)(
------_.---.-_..-._.--I---..
SUMMER WINTER BREAKUP
D-DENALI V-VEE CANYON G-GOLD CREEK C-CHULITNA T-TALKEETNA S -SUNSHINE:SS-SUSITNA STATION
A.Less than 0.03 mg/l (McNeely et al,1979).
B.0.01 of the 96 -hour LC SO determined through bioass~y (EPA,1976).
~o
R&M CONSULTANTS,INC.DATA SUMMARY -LEAD (t)...........""•••g_D\,O<l"'.''"_\..,..,...,,,..........,."0".FIGURE 2.32
~--l --1 -1 -------)-]i -1 1 1 J --1 -----)-----1 --~l 1 1
PARAMETER I MANGANESE (Mn)DISSOLVED,(mg./1.)
--
-----
--
--_.-._.
0.3
----
--
------_..---f--
---------!---
----
0.2 •MAXIMUM
--
-
-MEAN
-
0.1
--
----->--.-...----------------"--_.----•MINIMUM
--~'-+
---
0.0
,
-
-
--#OBSERVATION
11 ~'1 -iT H-'-I l-f;!-I-
I~h -It}!---1-1 li-1-~J _I--
~-,....IJ 1"-P
--1---I----.---1---1-
SUMMER WINTER BREAKUP
D-DENALI Y-VEE CANYON G~GOLD CREEK C-CHULITNA T-TALKEETNA S -SUNSHINe SS-SUSITNA STATION
A.Less than 0.05 mg/l for water supply.(EPA,1976).
~DATA SUMMARY -~1ANGANESE (d)
R&M CONSULTANTS,INC.
................O_DI.D ....1 ••".............",fI",.YO"'.FIGURE 2.33
-1 -1 I --'']J 1 1 1 1 -]-1 I
--t!-~-
PARAMETER',MANGANESE (Mu)(mg./l.)Total Recoverable
~t811~8=i=E811El1MtB3~r~rJ_rtttLtttl=tm1=t-1jjj:ttLtttte-
1.5 ~H---++-+-H-+++-H-++-H-1f-++++-H-+++-H-+++-H-t-++-~++t-+-1--t++-H--t++-H--t++-H-+-+
_.__._~~_~H-+-+-I--+-H-H+++++++++-+++I I 1 I I I +-++++-1 I I I I I I 1-1--+--\-1-+-
_•..L..-...._I_,"_I_~'__~__'.__'''_''•.•,....._"'-.-.-•.-.....-0-
I-+-+-..J.-..--t-..+-__J __4._~_.._~,,",-..__-o _
•MAXIMUM
-I---I--\--I-I-~I-+-\-H-H--+---l I I I I I+++-H++-H--j
,-I-1-t-l-t-J--+-H-'-A-'-'-'-'-'--~--'-'-._.-
-I-
-I-l--+--l--I--!--+-t--•.-.-.-.--.-____._.._~_~_~__,-~l-+-++-I-I --1--+-+-+_1--<__._._1.-1-1_~-~--J..-.+-..I-+-+-I-H-IA-1---1---1
f---l'-"~+-,
-MEAN
+-1--\-+-1-1-+++-1-1-+-
-.--I~~-,l--l----f-l--!--\-I-·I-·l--\·-1-1-1-\-1--\-
0.:1 1111/1111
+-H+++'-'-~-
-++f-tttljjj::ttt·-
•MINIMUM
*OBSERVAT JON
_.__I--I_I--l-_+_I_I_I-I-j-H-++++-++--l--J-I-.-I-I--f--\~-·-~.---_.-~-.-1-+-+--+-1-
_-._-,-+-1---1--+-1-+--1-l--f-l--I-J-++l+t·-·-~-·_·-_~._.---.-+-+-I-H-H-H+H "I I I I H-H++++H-H-H-
1~]lmlltfffl.l~1Hlm~ttlf£Ritjl~lfi~~l:[{t~~~gflf~
A·----;.-O
BREAICUPWINTERSUMMER
D-DENALI V-VEE CANYON G~GOLD CREEK C-CHULITNA T-TALKEETNA S -SUNSHINE SS-SUSITNA STATION
A.Less than 0.05 mg/1 for water supply (EPA,1976)
BD@....J01-J-J".....~
~..f~":'2.~~.r;:~~I;:~!:'.T ~u0i:'Qs::DATA SUMMARY -MANGANESE (t)FIGURE 2.34
-"-----1 "--1 --1 1 _.-1 1 -1 --]--1 _~1 1 ]
PARAMETER'MERCURY __(Hg)DISSOLVED,(mg./1.)
-~H-H-+-H+-4 '-+I--+++-H I I I I I ~-_J-.-I--I--+-I-~-l---W-W-I-I-f-l
-H-i-++H++++H++I I I I I I I f-~-l-
--.-.--'--0 --.•-~-.-t-.-.-
_+--J-+-+~_+_o_o~_,_._.-
0.0002 I I I I I I j I I I lIt I I •MAXIMUM
I-H+++t-++-\--t-+-l-l--\-l-H-,.'.-._.-
-MEAN
--.-~+-+-~_.~---
0.000/I ~_.__._._4_.~--.•-+-
•MINIMUM
-~-I-+-I-l--l--~-f-----
_0 __>__'_'-1-++++H--I+l-++++++++-1
A ~I-~-+-t-+I-I-l-
-H-
1-1-+++-+'-++1---\--\I I I I I I-H-H++--+-f+-H-f-H-I-I+H-+++H-H-++H--i++-+++j--1-l-I-I-I-I---H-I-I-I-H-H+
0.0000 Ulllrn::+++I=m=++:++mM-t+-H-I-H+J-H-l++++-m#++t+t-++++t+t-tttt-tiiTttttt1:tltt
_W_W-.l--t_~.I __-1_I_IJtt:tjjTIt::tti~-+--i-l--
I I I I I I I H-H I I I !I +-I-l--I-I--H--+-~-+-++~-
I I I I I rh~-t-m'----.JEfFJili41=t:"-r.::r =tt-81TImltLtf~mELmfEfmilfm1lm *OBSERVATION
SUMMER WINTER BREAKUP
0-DENALI V-VEE CANYON G-GOLD CREEK C-CHULITNA T-TALKEETNA S -SUNSHINE SS-SUSITNA STATION
A.Less than 0.00005 mg/1.(EPA,1976).
~11 DATA SUMMARY -MERCURY (d)
~&M CONSULTANTS,INC.
.....(11,......"'.O'OLDr:J'.'.~"A""""••••u"v.·OFll.FIGURE 2.35
C~~l cc.,~]~l _.c.c ~'1 '~-1 ~J .-''~1 -·'1 ~""l '1 --_.)·-1 ....)-1 J
PARAMETER:MERCURY (Hg)Total Recoverable (llg/1 )
.1=tttttjj=l:tj:=ttJj::ttttttttttljj=l:tttttttttt-tt:ttttt+t=ttJ=tt=tjj=tttjj±ttttttttt1=~-
++-1-1-1-./-1++-1-1-1+1 I , I I I I I I1-+++-+-1·+1--1 I I I I j ,.~-~.~''''.
O.6 t+tt+t-mmW=ilitttlli±±tlli:±±J±+:H+mffim=R=r++mmW+:l=1~ttltt±±ti±J
-+-I++I-I-I··-·-~·~
-.~I-+·I·-l-I·-l·I-++··-·--..•-t-t~--.......~t.~
o.411TrrrnTnllT11 !III \IIIIIIII I III III I I II l+rll unTIl IIIIIIII II,IIIII !IIIIII t •MAXIMUM
-MEAN
-1-1-.......f-+-l-++-+....h.'.a.2 r++:mmw=tttttttt±Dd±H±llii+Hft-fffR=RJR=t=mm=t+t+tww=t±llit±±±tU
+~-•MINIMUM
.•~1-1 I I .-f-H
A.---->
a -+++++-1-1-1--+++-1-1-+-
I I I I I I·++'~t-t I I I I I I I I I H-I--.-.•..I-~.-
1-l-++-l-I-H-14-h-'.~-.-.-
11mtr-J:tf11fljmWrm-Tm1fltt~lBm~mt~mtlmi1IijlttHn:fi:#:OBSERVATION
BREAKUPWINTERSUMMER
D-DENALI V-VEE CANYON G-GOLD CREEK C-CHULtTNA T-TALKEETNA S -SUNSHINE SS-SUSITNA STATION
A.Less than 0.05 Ilg/1 (EPA,1976)
L.....--il
R&M CONSULTANTS.INC.
....0 .......,...D.OI..IJIO'.""..l .............R.mu_",.yO_..
DATA SUMMARY -MERCURY (t)FIGURE 2.36
-'J "-'1 _e~ee'-l 0,e1 e~,e-J '--1 ]'~-l ---J --]J e '1 e·._........)~~-l ~l
PARAMETER:NICKEL (Ni)Total Recoverable (mg./l.)
t--l--1--J.-t--+-I-t--l-++-!-I-I--l-I~J-+-~!-H-++++~-'-'-,--
-f--I-~~I-+-J--+.+-.J-~-
··.-1-----.~-._-!++-!-i-++++++-
1_+_1_++1-++I I I I I I I I I I I !-H+'~-'-U-
-_.._~.-~-.--1.--!-j-!-+
0.1 •MAXIMUM
I-H--H+++I I I I I 1 I I I I I I II I ! I I I I I I I I I -l--H-t-H-I--1-H I I \ I H+l I I I I I !I \ I I +++-1-+-++-+I I I I I --MEAN
..•-~-.-.-•·+-+-++1O.OSITTTITTTrmTlffi 11111 !I !I11111l!\II III 1\II !I ±11111 !IIII i I LUiI i iJ j Ii tlitlU
A_---=;;::-_l:ttItttttttl-H I I I I I I H-++++
14-·!-l-l-H-+
--··__··-·-·--+-+-++-+-++-i
H··
•MINIMUM
H++++++--l--H-H-H-H+t-H-L":"r"LL I I
o
-~~-._-.-.-l-H--I-+++++++-++-+++
#:OBSERVATION
,(
'-'-~~-'-'-'-'-~':::=[J:]~§~L...!-\11-+-+<1i-l--~+..-~$f1B~[~l±tJ3Jdl{frl1jIEtSf31::--<5t t\l--'-"-'-
SUMMER WINTER BREAKUP
D-DENALI V-VEE CANYON G-GOLD CREEK C-CHULITNA T-TALKEETNA S -SUNSHIN~SS-SUSITNA STATION
A.Less than 0.025 mg/l (McNeely et al,1979).
B.0.01 of the 96 -hour LC 50 determined through bioassay (EPA,1976)
~I~~~.c:~r~G~~l;T~~.T~ul..!r'!~~.DATA SUMMARY -NICKEL (t)FIGURE 2.37
"1 '--~J '---1 "--1 ~']_·········1 c<'J -)]"-1 1 .--]"."'-J P --"1 ··----1 ]"''1
PARAMETER'ZINC (Zn)DISSOLVED,(rng./l.)
-+'_M-~+-++++++I-'I'<I+t-l-++-l+-t-+llI I I I H-t-J-+-I-+-I-+-l-+l+-t-l
l'-f-H I I I I I +!--+-I I I 1 I I I-++++++~f-'~-'-
+--.-~-'...-'-.-j-+-+-++++-I-\.-._.-~~-
0.2
0.1
-J++++++-I-++I-J I I I , I I +--I-++-f-J-++++-j.-I-+J I , I I I , I I I
.~-+-.-
-.1-1--1-.14-·!-++-1--+-+-+++-1·-I--
•MAXIMUM
-MEAN
A----:-
-.•-I--f~.-•...•..
-1-f-I-H-H-+-H-++-I-f:=\=U±ttl::tt'--~-l~---
-·..·-.-.-+-1-+-+·+•MINIMUM
o '·-<-rJ-+++·j++-J-+-+-J+1++--H-
[1JD~Hlbtt.Srtt<P-t1Jtttm\tttl1:1Jlrtt~lnTI'.1rTI.(+-+-t-RihT.::r-\V~l=l $H tHt-H$j-I$I+I-HIb++~++Grt-l-+~
I-l-I-l-t--l---I-+-l-l--·-'_.-.-.~-
~~iIfEl;tr+l-[ffi~llff±f~~t~~#:OBSERVATION
SUMMER WINTER BREAKUP
D-DENALI V-VEE CANYON G-GOLD CREEK C-CHULITNA T-TALKEETNA S -SUNSHINE:SS-SUSITNA STATION
A.Less than 0.03 rng/l (McNeely,1979)
B.0.01 of the 96-hour LC SO determined through bioassay (EPA,1976).
~II DATA SUMMARY -ZINC (d)
R&M CONSULTANTS,INC.."",a,"oI.""'....O ..CDl.T._t-...""N.IIl ••u""v.,.o ....j FIGURE 2.38
--'1 .~~"--1 -~---1
--]-)1--)J )1
PARAMETER I ZINC (Zn)Total Recoverable (mg./1.)
+-+-+-+++-1+I I I I I I I I I I I I I I I I I I I t-+-I-++++-+-+-l-l-t-l-t-t-I-H--l-1
______H_._H+._T-.-.-+++I I I I I I I ~+++++I I I I I I 1+++-1 I I I I I I I I--t-I-t I , I I I 1H--'''''-'-'._.__~._~~_,~_·I-1+++-j-l---l-+-l-I-l--l--l-
....._..__.f.-+--+--t---i--....--H·,--l-_.l-_.1,_•.1 .-..-•••-A_.
•MAXIMUM
-·-·-++-f-+++++-t+t-
._.__~._."'~__I_t~-t~
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BREAJ(UPWINTERSUMMER
D-DENALI V-VEE CANYON G~GOLD CREEK C-CHULITNA T-TALKEETNA S -SUNSHINE:SS-SUSITNA STATION
A.Less than 0.03 mg/1 (McNeely,1979)
B.0.01 of the 96 -hour LC SO determined through bioassay (EPA,1976)
~..J0\II
~&M CONSULTANTS,INC•
.....,""0,-00 ••1.~"u~"0".
DATA SUMMARY -ZINC (t)FIGURE Z.39
----~]]--1 J -J ]1
PARAMETER:CHEMICAL OXYGEN DEMAND,(mg./1.)
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SUMMER WINTER BREAKUP
D-DENALI V-VEE CANYON G-GOLD CREEK C-CHULITNA T-TALKEETNA S -SUNSHINE SS-SUSITNA STATION
No criterion established
~11 DATA SUMMARY -CHEMICAL OXYGEN DEMAND
R&M CONSULTANTS,INC•
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D-DENALI V-VEE CANYON G~GOLD CREEK C-CHULITNA T-TALKEETNA S -SUNSHINE SS-SUSITNA STATION
A.No criterion established
B.Waters containing less than 3.0 mg/l have been obseryed to be relatively-
clean,(McNe,ely et al,1979).
RII~1\'1l DATA SUMMARY TOTAL ORGAN,I C CARBON~
R&M CONSULTANTS,INC.
........".....D_O ..OO'.'.__"'...""""...._4-"....D".FIGURE 2.41
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3 -REPORT ON FISH,WILDLIFE,AND BOTANICAL RESOURCES
3.1 -Description of Botanical Resources
Descriptions of vegetation/habitat types in the upper basin and transmission
corridors were based on aerial photograph interpretation and on air and ground
reconnaissance.Ocular estimates of the cover of dominant species were used to
classify the vegetation according to the system developed by Viereck and Dyrness
(1980).High altitude (U-2)color infrared photographs and LANDSAT imagery were
used to map the vegetation cover types.Vegetation of the entire upper Susitna
River drainage (upstream of Gold Creek)was mapped at a scale of 1:250,000.
Vegetation adjacent to and within 16 km of the upper Susitna River and within the
transmission corridors was mapped at a scale of 1:63,360.The vegetation within
the proposed impact areas (that is,impoundments,areas with in 0.8 km of
impoundments,floodpl ain from Devi 1 Canyon to Talkeetna,and borrow sites)was
mapped at a scale of 1:24,000.Delineation of wetlands was based on the
classification of Cowardin et al.(1979).
Reconnaissance-level surveys were made of each major vegetation type.During these
ground surveys,information was obtained on species composition,community
structure,wildlife habitat,and physical characteristics of the site.
Descriptions of downstream floodplain plant communities were based on
quantitative descriptions of 29 stands between the Deshka River and a location
.11 km north of Talkeetna.Vegetation cover was estimated on four to eight
randomly located 30-meter transects within each stand.Density,age,height,and
diameter breast height (dbh)of trees and tall shrubs were measured along each
transect;density,age,height,and width of low shrubs were also measured.
(a)Regional Botanical Setting
The upper Susitna River basin is located in the Pacific Mountain
physiographic divi sion in southcentral Al aska (Joint Federal-State Land
Use Planning Commission for Alaska 1973).The Susitna basin occurs
within an ecoregion classified by Bailey (1976,1978)as the Alaska Range
Province of the Subarctic Division.
The Sus itna River system drai ns parts of the Alaska Range on the north
and parts of the Ta"lkeetna Mountai ns on the south (Figure 1.3).Many
areas along the east-west portion of the river between the confluences of
Portage Creek and the Oshetna River are steep and covered with conifer,
deciduous,and mixed conifer and deciduous forests.Flat benches occur
at the tops of these banks and usually contain low shrub or woodland
conifer communities.Risinq from these benches are low mountains covered
by sedge-grass tundra and mat and cushion tundra.
The southeastern portion of the study area between the Susitna River and
Lake ~ou i se is characteri zed by extensive fl at areas covered with low
shrubland and woodland conifer communities,which,because of
intergradations,are often intermixed and difficult to distinguish in the
field or on aerial photographs.To the northeast,the area along the
Susitna River between the Maclaren River and the Denali Highway is
covered with woodl and and open spruce st ands.Farther east,the area
3-1
has more low shrub 1and cover.The Cl earwater Mount ai ns north of the
Denali Highway have extensive tundra vegetation.The floodplain of the
Susitna River north of the Denali Highway has woodland spruce and willow
stands,while the Alaska Range contains most of the permanent snowfields
and glaciers in the study area.
The steep sections and some adjacent areas along the east-west portions
of the river are considered in the closed spruce-hardwood forest type of
Viereck and Little (1972),the moderately high mixed evergreen and
deciduous forest map unit of Spetzman (1963),or the upland spruce
hardwood forest of the Joint Federal-State Land Use Planning Commission
of Alaska (1973).Whichever label one chooses,this type of vegetation
is found mainly along rivers in the southcentral and interior regions of
the state.
Both the benches bordering this same east-west portion of the river and
the area around tne Maclaren River are classified as moist tundra in all
three of the previously mentioned references.This classification
includes herbaceous meadows as well as shrub-dominated areas,both of
which also occur around the Brooks Range,on the Seward Peninsula,and
near the Killuck Mountains.
The extensive fl ats in the lower Oshetna River and Lake Louise areas,in
the southeastern portion of the study area,are considered open,low
growing spruce forests by Viereck and Little (1972),low mixed evergreen
and deciduous forest s by Spetzman (1963),and lowl and spruce-hardwood
forests by the Joint Federal-State Land Use Planning Commission of Alaska
(1973).Viereck and Little's (1972)description appears most
appropriate,since the area is covered primarily by spruce stands with
treeless bogs.
The vegetation along the lower mountains,and the lower slopes of the
higher mountains,was classified as alpine tundra by Viereck and Little
(1972)and the Joint Federal-State Land Use Planning Commission (1973)
and as barren and sparse dry tundra by Spetzman (1963).In the current
study,some of these areas were mapped separately as rock,whi le other
areas were mapped as sedge-grass tundra or mat and cushion tundra,
whereas the previous maps included the rock in the alpine tundra.Some
areas mapped as rock do have some important pioneering species growing in
crevices,but the plants provided negligible ground cover.Alpine
tundra grows on mountains throughout the state.
The downstream floodplain is a part of the Cook Inlet-Susitna Lowlands,a
portion of the trough which forms a major bifurcation in the Pacific
Mountain System (Joint Federal-State Land Use Planning Commission for
Alaska 1973).This region is generally flat,occurs mostly below 150 m
in elevation,and experiences a climate that is transitional between
marit ime and cont i nental .The growi ng season is at 1east one month
longer than that in the upper basin.The vegetation of this region is
considered closed spruce-hardwood forest by Viereck and Little (1972),
moderately mixed evergreen and deciduous forest or high evergreen spruce
forested by Spetzman (1963),and the upland spruce-hardwood or bottomland
spruce-poplar forest by the Joint Federal-State Land Use Planning
3-2
f"'C'T 0••'
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Commission (1973).White spruce,balsam poplar,paper birch,and alder
(see Table 3.1 for scientific names of plants)are all important species
in the floodplain vegetation.Additionally,willows and horsetails are
dominant aspects of pioneer,non-forested communities.
(b)Vegetation/Habitat Types
The vegetation/habitat types described in this section include those in
the upper basin (upstream of Gold Creek),the downstream floodplain
(Devil Canyon to Delta Islands),and the transmission line corridors.
Additional description information is presented in the Plant Ecology
Studies -First Annual Report (APA 1980b).Vegetation cover maps for the
entire upper basin and an area 16 km on either side of the river from
Gold Creek to the mouth of the Maclaren River are presented in Figure 3.1
and in Figurei 3.2 through 3.4,respectively.
The area covered by each veget at i on/h abitat cover type is presented in
Tables 3.2 and 3.3.Vegetation/habitat cover maps for the transmission
1 ine corridors are presented in Figures 3.5 through 3.9;corresponding
area measurements are provided in Tables 3.4 and 3.5.
(i)Upper Basin
-General Description of Forest Types
Forest vegetation/habitat types were located at the lower
elevations of the upper basin (Figures 3.1 through 3.4).The
average elevation of sampled areas was 523 m.These forest types
were divided according to their dominant tree types (conifer,
deciduous,or mixed)and then by tree crown cover percentage.
Deciduous and conifer types had at least 75%of the tree cover
provided by deciduous or conifer trees,respectively.The
wood 1and type had between 10%and 25%tree cover and was on ly
observed for conifer stands.Open stands contai ned 25-50%tree
cover,while closed stands had over 50%tree cover.The boundary
percentage between open and closed types was set at 50%rather
than the 60%that Viereck and Dyrness (1980)used,since the
former percentage was easier to est"imate both on the aeri al
photographs and in the field.
Conifer,deciduous,and mixed stands with open canopies were
observed in the field,while the only stands with closed canopies
located in the field were deciduous and mixed.One closed
conifer area that appeared on the aerial photographs near Lake
Louise was not field checked.All forested stands had almost
complete vegetation cover with 80-95%ground layer cover.
-Spruce Forests
Spruce stands were dominated either by white spruce (see Table
3.1 for list of scientific names)or black spruce and contained a
well-developed ground layer,which itself accounted for most of
the vegetat i on cover.The 1ayer structure of open black and
white spruce stands was simil ar,except that white spruce stands
3-3
contained more overstory,a reflection of the generally larger
size of white spruce trees.These units were mapped only at the
1:24,000 and 1:63,360 (Figures 3.2 through 3.4)scales.Another
difference was that the overstory in open white spruce stands was
less variable in height among stands than was the overstory in
black spruce stands.Open spruce stands were usually found on
slopes or flatlands along the rivers at elevations averaging
487 m.Overstory provided almost one-fourth cover in open
stands which contained trees several meters tall.
Whi 1e the white spruce cover was concentrated in the overstory
1 ayer,most of the bl ack spruce tree cover was contained in the
shrub layer.Black spruce stands contained low shrubs,such as
crowberry,northern Labrador tea,bog blueberry,and mountain
cranberry in the ground layer,while prickly rose and bluejoint
were the most important ground layer species in open white
spruce.Twin-flower was important in the white spruce stands but
was not observed in the black spruce stands,possibly reflecting
that ground species I preference for better-drained soi 1s.In
each of these mapping units,30 to 35 identified species were
encountered.In these open white and black spruce stands,
feather mosses covered as much ground as trees did.Low shrubs,
such as crowberry,northern Labrador tea,bog bl ueberry,and
mountain cranberry accounted for much of the woody ground layer.
Important herbaceous species included bluejoint and horsetails.
Northern Labrador tea,Labrador tea,bog blueberry,mountain
cranberry,and sphagnum and feather mosses were found in bl ack
spruce forests in the upper Susitna River basin.Crowberry,
nagoonberry,and woodland horsetail were also important in black
spruce stands;however,these varieties were not reported along
the Chenan River by Virecek (1970).
Meadow horsetail and feather mosses provided significant amounts
of cover in white spruce stands along the Chena River (Viereck
1970)and in the upper Susitna River basin,but bluejoint,
twinflower,and the moss Ptilium crista-castrensis were
apparently more important along the Susitna River than along the
Chena.
All woodland spruce stands visited were black spruce.Here,it
was observed th at,un 1i ke open spruce stands,woodl and stands
were composed of scattered,stunted trees,and the overstory was
almost negligible.One reason for this pattern is that this
vegetation/habitat type was usually found on the relatively level
benches where soils were poorly drained.Average elevation of
sampled areas was 620 m.The resulting trees were usually too
small to qualify for the overstory layer because trunks were
<10 cm dbh.Maximum heights were less than two meters in some
areas.
In these woodland stands,sphagnum mosses,not feather mosses,
were the most important cover spec i es;important ground 1ayer
species included sedges,woodland horsetail,and low shrubs
3-4
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similar to those found in the open spruce stands.Slightly over
30 i dent ifi ed speci es were encountered in the woodl and spruce
vegetation/habitat type.
Woodl and spruce sites graded into boggy areas where tree cover
might be less than 10%and where the vegetation resembled
muskegs.Low birch shrub stands and woodland spruce were
frequently difficult to distinguish in the field because birch
stands sometimes had scattered trees which.on occasion.produced
almost 10%cover.On aerial photographs.the overall pattern
created by small trees produced simi 1ar textures for woodl and
spruce and for low birch shrub sites.This phenomenon.along
with the fact that these areas took on a simi 1 ar color when
photographed (dark gray).made distinguishing between them
d iffi cult.
Among black spruce stands.those occupying significant slopes
(8-10°)appeared to be more productive of browse species and.in
fact.received noticeably greater use by moose than did other
black spruce areas.Compared to other vegetation types.browse
production was low.but since the browse had incurred heavy use.
such stands appeared to provi de important cover areas duri ng
severe weather.Open black spruce stands on the flats were
generally very poor in terms of forage production.but some
caribou sign was present.Skoog (1968)considered this forest
type to represent a good supply of terrestrial forage lichens for
caribou in winter.
-Deciduous Forests
Deciduous forest vegetation usually had a greater overstory cover
than had spruce stands because individual trees had more foliage
cover.These types were restricted mostly to the steep banks and
floodplain along the river (Figures 3.2 through 3.4).Eleva-
t ions averaged 582 m,with closed stands occurring at average
elevations of 560 m and open stands at 625 m.They had almost
complete vegetation cover,with an especially well-developed
ground layer.While the overstory layer in closed stands covered
almost three-fourths of the area,it only covered about
three-ei ghths in open stands.Overstory was somet imes 15 m tall
and.in the balsam poplar stands.even taller.Paper birch.
trembling aspen or balsam poplar dominated the overstory.
Neither the shrub 1ayer nor the understory 1ayer was of major
importance.Important woody species in the ground layer in both
types incl uded crowberry,northern Labrador tea,bog blueberry.
and mountain cranberry.Open stands appeared to have more woody
cover in the ground layer than did the closed stands,while
closed stands had more herbaceous components.such as bunchberry.
bluejoint,and oak fern.Sixteen identified species were
encountered in open deciduous forest types;in closed forest.
31 were found.
Closed deciduous stands were separated on the 1:63.360-scale map
(Figures 3.2 through 3.4)according to the dominant species:
3-5
either balsam poplar or paper birch.Minor amounts of trembling
aspen were also found but were barely large enough to sample and
not large enough to map.
Closed balsam poplar generally occurred on islands in the river
or on flat areas alongside the river.Balsam poplar was usually
the first tree in the successional stage of vegetation
development on alluvial deposits.The trees themselves provided
about three-fourths cover.The ground 1 ayer was well developed
and included bunchberry.crowberry.northern Labrador tea.bog
blueberry.and mountain cranberry.About 14 species were
encountered and identified in these areas.
Closed paper birch stands occurred on steep.usually south-facing
slopes.The vertical layer structure is similar to the closed
balsam poplar stands:three-fourths overstory.a well-developed
ground layer.and relatively unimportant shrub and understory
layers.The most important ground layer species were bunchberry.
bog blueberry,bluejoint.and oak fern.Twenty five species were
identified in the birch stands.
~-l
The minor.closed trembling aspen stands were usually found on
the upper portions of dry.south-facing slopes.Their general
structure was similar to other closed deciduous stands in that ,C'
there were well-developed overstory and ground layers but
insignificant shrub and understory layers.
-Mixed Conifer-Deciduous Forests
Mixed conifer-deciduous forests were usually dominated by white
spruce and paper birch.Elevations for mixed conifer-deciduous
forests averaged 466 m,with closed stands having a mean
elevation near 425 m and open stands occurring around 482 m.
Most of the 1 arger stands occurred on slopes downstream from
Tsusena Creek (Figures 3.2 through 3.4).These were probably
successional stands,which developed as spruce replaced deciduous
trees.
Cover in these vegetation/habitat types was almost complete with
a well-developed ground layer containing important amounts of
bluejoint.bunchberry.woodland horsetail,and Ptilium.The
extent of overstory cover for the mixed conifer deciduous
vegetation/habitat types fell between that for spruce stands and
that for deciduous stands.Overstory cover in closed mixed
stands was about 60%,while that in open mixed stands was 38%.
The height of the overstory was sometimes up to 20 m.The shrub
layer was more important in the open stands.mostly as a result
of tall blueberry willow.Bog blueberry was an important ground
species in the open mixed stands.Forty identified vascular
pl ant species were encountered in open mixed stands;29 were
found in closed mixed stands.
3-6
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General Discussion of Forest Types
Forested communities in the upper Susitna River basin were
similar to those described by Viereck (1975).Black spruce
generally occurred in wetter sites than white spruce did,whi le
deciduous or mixed forests as well as all closed forests occurred
on warmer sites than those supporting spruce.The drier of these
closed sites were usually deciduous,while the moister ones
either were mi xed or were domi nated by spruce.Dec i duous and
mixed forest stands were considered earlier successional stages
of the conifer stands (Viereck 1970,1975 and Hett inger and Janz
1974).
In general,the deciduous and the mixed conifer-deciduous
forests,particularly in the closed stands,appeared to represent
a relatively poor forage resource for moose and caribou.Steep
slopes often associated with these types might also be partially
responsible for the low preference by ungulates.Natural records
of browsing intensity,as indicated by the structure of paper
birch suckers,suggested that these forest types may incur heavy
use in severe winters.Skoog (1968)stated that these types were
little used by caribou at any time of the year.The frequency of
berry-filled bear scats in these types in spring suggested that
these areas mi ght be an important food resource for bl ack bears
as they come out of wi nter torpor.The open nature of the
understory vegetation,however,made sighting of fecal piles
easier in these forest types and,therefore,positively biased
any comparison with other types.
-Tundra Types
Tundra commun it i es usuall y occurring above the present 1 imit of
tree growth (Figure 3.1)exhibited approximately 70 identified
vascular plant species.Most of the well-vegetated tundra
communities occurred on flat to gently sloping areas,while
sparser vegetat i on occurred on steep or rocky terrain .Although
aspects of tundra vegetation/habitat types were variable,four
di st inct subtypes occurred in areas 1arge enough to map:wet
sedge-grass tundra,mesic sedge-grass tundra,herbaceous alpine
tundra,and closed mat and cushion communities.
Wet sedge-grass tundra communities occurred at an average
elevation of 587 m in wet,depressed areas with poor drainage.
They had almost total vegetation cover,with most of it occurring
in the ground layer.Nineteen species were identified.The most
important herbaceous species were sedges,especially water sedge;
bluejoint;and sphagnum as well as several other unidentified
mosses.Th~shrub layer,when it was present,contained
scattered individual willows.Wet sedge-grass corrmunities could
potentially contain up to 10%cover of erect shrubs.There was
usually a large amount of organic matter in these soils,and
there was sometimes a thick organic layer on top of mineral
soil .
3-7
Mesic sedge-grass tundra generally occurred at an average
elevation of 1372 m on rolling uplands with well-drained soils.
The soils were well-developed in some areas,but in others,the
soil occurred as patches alternating with rocks.Nine identified
species were identified,with total vegetation cover between half
and three-fourths of the area.All vegetation was low in the
ground layer,usually less than 30 cm tall.Bigelow sedge was
the most common species and accounted for almost half of the
total vegetation cover.
Two types of herbaceous alpine tundra occurred in the upper
Susitna River basin,although only one herb-sedge occurred in
areas large enough to map.Herb-sedge communities occurred at
elevations of around 1295 m near the glaciers,particularly the
West Fork Glacier,where there existed gentle slopes of fairly
well-drained and relatively well-developed soils.These were
basically mineral soils but contained about 5%organic matter.
Some of the soil may also have developed from loess.Vegetation
cover was almost complete,but cover was dispersed evenly among
the many species present so that no group of species dominated
the area.Because of both time constraints and the complexity of
the vegetation,no estimates were made of cover.All vegetation
occurred in the ground layer,and approximately 42 identified
species were encountered in the one area of herb-sedge tundra
vis ited.
The other type of herbaceous alpine community was found in small,
isolated rocky areas that were too small to map or to sample.
Small forbs and,sometimes,shrubs grew in the pockets of mineral
soil imbedded between the rocks.
The fourth major type of tundra community was the mat and cushion
tundra,which was found at high elevations (1013 m)on dry,windy
ridges.Vegetation covered about three-fourths of the area and
was usually less than 20 to 30 cm tall.Lichens and low
mat-forming shrubs,such as dwarf arctic birch,crowberry,
bearberry,and bog blueberry,dominated these areas,and soils
were shallow and coarse.
Diverse wildlife occupied the high elevation tundra communities
in summer.Most obvious were whimbre1,caribou,black and brown
bears,ptarmigan,hoary marmots,and arctic ground squirrels.
Whimbrel s were frequently spotted here in early summer.Bear
scat indicated over wintered berries were the major attraction
for bears in June,although many squirrel dens were also found
which had been excavated by bears.Caribou were more frequently
sighted in the sedge-grass tundra than in any other type.In
fact,Skoog (1968)considered sedge-grass tundra to be important
year-round range for caribou in this region.On the other hand,
he considered mat and cushion tundra to be a more important
winter forage supply,since its wind-swept condition generally
meant it was relatively snow-free.
Wet sedge-grass communities,more common below tree line,showed
use by moose where browse was available.Otherwise,these types
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were more important to wading birds and,where topography
allowed dam building,to beaver.In many cases,in fact,the wet
sedge-grass vegetation was likely the result of beaver activity.
-General Description of Shrub Types
Shrubland vegetation/habitat types were the most prevalent types
in the upper Susitna River basin (Figure 3.1 and Table 3.2).They
generally occurred at higher el evat ions than forest communities
but at lower elevations than tundra types.Most areas,particu-
larly the low shrub,were found on extensive,fairly level
benches at mid-elevations throughout the upper basin.Less
extensive areas,usually tall shrub,were found on steep slopes
above the river.While aspects of the shrubland vegetation/
habitat types were variable,two main types,tall and low,were
found,with each being further divided by the percentage shrub
cover into closed and open types.Approximately 65 identified
species were encountered in this overall type.
-Tall Shrub Types
Tall shrub communities were dominated by Sitka alder and were
found mostly on steep slopes above the river or sometimes above
the flat benches at an average elevation of 573 m.Many of these
stands were two to four meters tall.Approximately 25 identified
speci es were encountered "in the al der stands,whether closed or
open.
Along the slopes by the river,these stands frequently occurred
as stri ngers through other vegetation/habitat types.Many areas
also contained alder as a ring around a mountain at a certain
elevation or in a strip along a river drainage,as at Portage
Creek.The closed stands had almost complete vegetation cover,
with the ground 1ayer and understory accounti ng for most of the
cover.Portions of some stands were like thickets.Again,alder
provided the most cover,with bluejoint and woodl and horsetail
making up most of the ground layer cover.
Only one open alder stand was visited.It had less vegetation
cover than the closed alder sites,and most of the vegetation was
in the understory layer.Bluejoint was the most important ground
layer species;white spruce was present in both the overstory and
understory.This mixture of alder with white spruce indicated
that this was probably a successional stand.
Hanson's (1953)description of alder types was similar to those
found in the upper Susitna basin in that these thickets occurred
on well-drained slopes and varied from one to four meters tall.
In many cases,bluejoint was the dominant ground layer species.
Hanson (1953)al so menti oned Beauverd spiraea and bog bl ueberry
as important speci es,whi ch was consi stent with the fi ndi ngs of
the present study.Hanson (1953)also observed birch shrubs as
an important species in alder stands,but the alder stands
encountered in the upper Susitna River basin did not contain
3-9
birch shrubs.In contrast,the Susitna stands contained
important quantities of woodland horsetai 1.As in the Susitna
study,Hettinger and Janz (1974)likewise observed that alder
stands occurred on steeper slopes and older riparian sites.
One alder stand located on a slope of the Susitna canyon
(RIlE,T29N)was very heavi 1y used by moose.Currant appeared to
be highly preferred browse in this stand.Willow was important
browse in all stands,and certain individuals of American green
alder were heavily browsed.
-Low Shrub Types
As in earlier studies in northwestern (Hanson 1953)and
northeastern Alaska (Hettinger and Janz 1974),low shrub
vegetation/habitat types were common in the upper Susitna River
basin.Low shrub communities were found on the extensive,
relatively flat benches where soils were frequently wet and
gleyed but,except for those supporting willow types,usually
lacking standing water.Average elevation was about 781 m.Over
40 identified species were encountered in this vegetation/habitat
type.Subtypes included birch,willow,and a mixture of the two.
(Because of the gradations between them,descriptions of the
subtypes are very general).
Birch shrub stands were usually dominated by resin birch about
1.0 m tall and contained several other species of low shrubs,
especially northern Labrador tea.The most important associated
species in these stands was bog blueberry,while mosses and
1 ichens contributed an important amount of cover.In some
stands,there was a buildup of soil and debris around the base of
each birch shrub clump,creating a large amount of microrelief.
Sometimes,the stands were dense,like a thicket,while others
had large openings between individual birch shrubs.Scattered
black spruce occurred in some stands contributing almost 10%
cover.Hence,low shrub and woodland black spruce stands were
difficult to distinguish on the ground and on the aerial
photographs.The two species of birch shrub,resin and dwarf
arctic birch,were sometimes difficult to distinguish based on
leaf shape and plant height.Viereck (1966)also commented on
this problem.
Willow stands were usually found in wetter areas,frequently with
standing water.Diamond willow sometimes formed thickets along
small streams at high elevations.Water sedge was the important
herbaceous species in these stands.Because of the wetness,
these communities were usually less diverse than birch shrub
stands.Willows frequently also had soil and debris built up at
their bases,with standing or running water in the troughs.
The birch and willow types were further divided into open and
closed stands.Both open and closed stands had almost complete
vegetation cover.The ground and shrub layers contributed
similar amounts of cover in closed stands,while the ground layer
alone provided most of the cover in the open communities.
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Moreover,shrub 1ayer cover estimates mi ght be hi gh because of
prob 1ems in est imat i ng cover from the ground,the same problem
encountered in the forest types.
Associated species similar to those noted by Hanson (1953)and
Hettinger and Janz (1974)were observed in the Susitna area and
included northern Labrador tea and bog blueberry.Mountain
cranberry,however,while not important in the northwestern part
of the state,was important in both northeastern Al aska and in
the Susitna region.
Birch shrub communities apparently received moderate use by moose
most of the year.It was obvious,however,that stands with more
wi 11 ow were preferred.Indeed,wi 11 ow stands recei ved greater
use than any other vegetation type.Feltleaf willow and
diamond willow were heavily utilized in most areas.
Caribou sign,too,were frequent in birch communities.Skoog
(1968)found that leaves of resin birch were important food for
caribou in summer,and in winter,lichens were important.He
found that caribou feed on willows in both spr-ing and fall,and
he considered willow stands important to the ecology of caribou.
The present study's findings agree with this conclusion,with the
exception that,in the Susitna area,apparently only those stands
above the rim of the river canyon are important to caribou.
-Herbaceous Types
Two herbaceous types were found in the upper basin.Grass 1ands
dominated by bluejoint were present on level to sloping areas at
lower elevations along the river and along the Portage Creek
drainage (Figure 3.2).Herbaceous pioneer communities were
present on gravel and sand bars that had recently become
vegetated.Soils here had little organic matt.er and often had a
large number of cobbles.Pioneer species included horsetails,
lupines,and alpine sweetvetch.
-Unvegetated Areas
Three cl asses of unvegetated areas are depi cted on the maps:
(Figures 3.1 to 3.4)water,rock,and snow and ice.Lakes and
streams were included in the water category.Lakes were
generally found along fl at benches and ranged in si ze from small
ponds to large lakes,such as Big Lake (approximately 450 ha).
Rock incorporated those areas of bedrock or deposited geologic
materials supporting little or no vascular vegetation.Rock
occurred as outcroppings,either at high elevations or along
steep cliffs along the river,or as unconsolidated gravel in
newl y depos ited river bars.The category snow and ice incl udes
permanent snowfields and glaciers.Glaciers and permanent
snowfields were most common at the northern end of the study area
in the Al aska Range,although some did occur near the southern
boundary in the Talkeetna Mountains.
3-11
(ii)Downstream Floodplain
An intensive study of the vegetation on the downstream floodplain
(Devil Canyon to Delta Isl ands)was conducted duri ng summer 1981.
Tabul ar presentation of summari zed data is not practi cal;conse-
quently,a general description of each vegetation type encountered
is provided below.
-Early Successional Stages
Early successional communities commonly found on the floodplain
were dominated by horsetail,horsetail-willow,horsetail-balsam
poplar,balsam poplar,or dryas vegetation.Horsetail was
generally the first to invade silty or sandy sites.Established
horsetai 1 communities had approximately 40%cover by horsetai 1,
2%by balsam poplar seedlings,and 4%by willow.Bare grolJnd was
47%.Willow and balsam poplar sometimes occurred on newly formed
bars but usually did not become established until after the
horsetail.The mean density of willow was 22,333 stems/ha,while
balsam poplar density was 13,000 stems/ha.Rockier or more
gravelly sites tended to have less horsetail cover.
In most cases,alder (thin1eaf and Sitka)did not appear until
two or three years after the willows and balsam poplar.Its
rapid growth,however,made it the highest shrub after two to
four years of growth.The average ages of willow,balsam poplar,
and alder in early successional stands was 4.5,6.5,and 3.2
years,respectively.
Dryas was visually dominant on gravelly sites having little silt.
Living dryas,however,accounted for only 4%cover.Balsam
poplar and dead dryas covered 6%and 7.5%respectively.Dryas is
a nitrogen-fixing pl ant and benefits other species by adding
nitrogen to the soil.Even so,vegetation on these sites is of
poor form and is slow-growing until sufficient soil is deposited
by wind and water,at which point dryas is important for
stabilizing these soil deposits.Bare ground equaled 76%of
cover;of that percentage,one-third was cobbles.
-Mid-Successional Stages
Deposition of sands and silts,elevating sites above the level of
frequent fl oodi ng and freei ng them from di sturbance by ice and
fast water,appeared to be necessary for transition of early
successional vegetation to mid-successional stages.Mid-
successional vegetation was characterized by immature balsam
poplar or by thinleaf alder which had developed into tall shrubs
or trees.
Total vegetation cover in alder stands averaged 87%.Trees and
tall shrubs provided 29%and 46%cover,respectively.Bluejoint
grass gave 44%cover;wormwood,5%.Thinleaf alder dominated the
overstory cover (59%),with balsam poplar providing 13%.Age and
dimension data indicated that,initially,balsam poplar either
lagged behind or was suppressed by alder until late in the mid-
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successional stage.Alder canopies were typically seven meters
high,with protruding balsam poplar averaging eight meters.When
balsam poplar did emerge through the alder canopy,it quickly
doubled its height to approximately 17 m.Thinleaf alder and
balsam poplar averaged 20 and 19 years,respectively.Density of
alder >4 m high was 3,557 stems/ha,whereas there were only 414
stems/ha of balsam poplar.Density of browsable willow (>0.4 m
high)was 3,333 stems/ha.Highbush cranberry (>0.4 m high)
averaged 466 stems/ha.Browsable balsam poplar (>0.4 m,<4 cm
dbh)had a density of 1,332 stems/ha.
Balsam poplar dominated the overstory of immature balsam poplar
stands,giving 62%cover;thinleaf alder provided 40%cover.
Bluejoint provided 23%of the ground cover;perennial forbs gave
9%cover.Total vegetation cover was 91%.
Balsam poplar tree (>4 m height)density was 620 stems/ha.
Thinleaf alder density (all sizes)was 5,049 stems/ha.
Browsable balsam poplar,willow,and highbush cranberry densities
were 433,400,and 633 stems/ha,respectively.
The average height of immature balsam poplar trees was 17.7 m
with an average age of 44 years.Thinleaf alder averaged 6.6 m
and 22.3 years.Compared with the ages of trees and tall shrubs
in alder stands,immature balsam poplar stands appeared to
represent a later phase of the mid-successional stage.
Late (Mature)Successional Stages
As the balsam popl ar stands mature,white spruce may appear in
the canopy (a few may become evident as early as the alder
stage).Eventually,the balsam poplar becomes decadent,leaving
space for development of more balsam popl ar or of spruce and
birch.The factors responsible for development of the birch-
spruce stands versus continuation of the balsam poplar are still
unclear.Geographic locations and continuity of stands suggest,
however,that birch-spruce forests occur on more stabl e sites
than do mature or decadent balsam poplar forests.
Mature and decadent balsam poplar stands,collectively,averaged
90%total vegetal cover.Trees provided 50%cover,tall shrubs
43%,low shrubs 36%,perennial forbs 23%,and perennial grasses
12%.The average height of balsam poplar trees was 26.4 m,with
an average age of 98 years.White spruce growing in these stands
averaged 12.6 m and 100 years;thinleaf alder was 7.3 m and 28
years.
The density of balsam poplar trees was 293/ha.White spruce
density was less than seven per hectare.Density of thinleaf
alder (all sizes)was 4,801 stems/ha.Browsable highbush
cranberry density was 21,831 stems/ha.No browsable balsam
popl ar or wi 11 ow were present in the understory of mature or
decadent bal sam popl ar stands.Pri ckly rose,wild currant,and
American red raspberry,however,occurred at densities of 12,365;
6,566;and 6,133 stems/ha,respectively.
3-13
Bi rch-spruce communities were characteri zed in the overstory by
42%cover by paper birch and 12%cover by white spruce.Tall
shrubs,predominantly thinleaf alder,accounted for 14%cover.
Low shrubs,forbs,and grasses provided 40%,44%,and 18%cover,
respectively.Horsetail,highbush cranberry,prickly rose,and
bluejoint were the dominant understory species,providing 30%,
19%,20%,and 18%cover,respectively.
The average height and apparent age of paper birch trees was
15.3 m and 70 years;70 years is a low estimate,since unrotted
tree trunks were difficult to find.White spruce average 16.2 m
and 90 years.Thinleaf alder (>4 m)averaged 5.6 m and 28
years.
The density of paper birch trees was 227/ha.There were 147
white spruce/ha and 1,525 alder (all sizes)/ha.Browsable
willow,paper birch,highbush cranberry,and prickly rose had
densities of -200;39;17,065;and 16,932 stems/ha,respectively.
Birch-spruce stands were the most diverse of vegetation types
found on the fl oodpl ai n.There was some evi dence that these
stands are self-perpetuat i ng.That is,upon overmaturity,the
birch overstory falls,making the spruce more susceptible to wind
throw and,thereby,allowing a paper birch shrub-alder/highbush
cranberry-prickly rose community to become established.The
shrub community then advances agai n to the bi rch-spruce forest
condition.The woody species composition and density of the
seral brush phase makes it ideal moose habitat,especially as it
is interspersed with the more mature forest.
(iii)Healy to Fairbanks Transmission Corridor
The mapping units presented on Figures 3.5 through 3.7 and in Table
3.4 are based on vegetation characteristics and are named according
to Viereck and Dyrness (1980).Since the same classification
system was used,transmission corridor mapping units are similar to
those used in the upper basin.Deciduous mapping units consist of
aspen and/or birch and contain broadleaf vegetation.Complexes of
types were used where individual types existed in the field but
were too small to separate on the map.Some cover cl asses may be
under estimated,since trees had started losing their leaves when
the corridors were flown for field-checking.
The northern transmission corridor consists of three basic
sections:Healy to Nenana River,Nenana River to Tanana River,and
Tanana River to Fairbanks.The Healy to Nenana River section
contains a dissected plateau on the west side,a relatively flat
area in the middle,and the Parks Highway and Nenana River to the
east.Vegetation along the ridges leading from the plateau is
predominantly open spruce,open mixed spruce/deciduous,and open
deciduous forest.The flat area is predominantly low shrub with
sedge-grass and open and closed spruce types.Except along the
streams,most of the spruce trees were relatively short.
The Tanana Fl ats area extends from just beyond the Nenana River
crossing to the Tanana River.This section is characterized by a
mosaic of wet vegetation types,including open spruce (usually with
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larch),low shrub,and wet sedge-grass.Locations of many types
appear to be controlled by old stream meanders and drainage
patterns.Some patches of deciduous forests also occur.Some
portions of the mosaic could be delimited on the map,while others
were too intermi ngl ed to separate.Simi 1arly,dry streambeds have
stringers of other vegetation,such as low shrub,through them,and
frequently these could not be delimited on the map.
The section from the Tanana River to Fairbanks passes through
rolling hills covered predominantly by open deciduous forest with
small areas of spruce,usually in drainages.Some low areas of
spruce contained larch (tamarack)but not as much as in the
previous section.The woodland mixed patches in this section are
generally cutover areas.Many of the closed spruce areas have very
short,scrub-like individuals and appear more like a low shrub
type.
Species of spruce were not checked on the ground,but stands in
low,poorly drained areas were assumed to be black spruce.
Individuals in better drained locations may be either species.
These species could not be separated confidently without
ground-checking many stands.Therefore,this vegetation was mapped
spruce.
Most spruce areas between the Tanana River and Fairbanks contain
only spruce and little larch,while about half the areas in the
Tanana Flats section contain larch as well.Larch was not observed
between Healy and the Nenana River.The spruce-larch mixture was
easily visible from the air but could not be distinguished on the
aerial imagery.The black spruce-larch type,which is confined in
Alaska to the interior,is generally found only on wet lowland
sites with shallow permafrost (Viereck and Dyrness 1980).
(iv)Willow-Cook Inlet Transmission Corridor
The Willow-Cook Inlet transmission corridor passes through an area
dominated,first,by closed birch and mixed conifer-deciduous
forests,next,by large wet sedge-grass marshes,and,finally,by
open and closed spruce stands (Figures 3.8 and 3.9 and Table 3.5).
Forested stands in th is part i cul ar area of the Sus itna vall ey are
characterized by generally good stocking of relatively good quality
birch,white spruce,aspen,and balsam poplar.Many of the stands,
however,have poor regenerat i on and have deve loped a woodl and/
shrubland or woodland/grassland aspect.Birch is the predominant
deciduous species.Localized stands of balsam poplar and aspen are
associated with active river floodplain (Willow vicinity)and drier
south slopes,respectively.
Wet sedge-grass is the second most dominant vegetation type in this
area.Most stands are quite extensive and associated with diverse
network s of ponds,1akes,and meander ing streams.These areas are
generally thought to be unsupportive of other types of vegetation
except for scattered islands of black spruce and low shrub along
drier margins..
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White spruce is dominant in stand composition for most of interior
Alaska but occupies a minority position in this part of the Susitna
valley.The vegetation map of this corridor is not specific as to
spruce species.Most of those areas identified,however,as closed
and open spruce and occurring in areas dominated by mixed conifer-
deciduous forest are likely white spruce.Spruce stands skirting
wet sedge-grass or low shrub areas may be either white or bl ack
spruce,whi 1e most woodl and spruce stands are bl ack spruce.
(c)Floristics
In the upper Susitna River basin and downstream floodplain combined,254
vascular plant species,occurring in 130 genera in 55 families,were
identified.Some collected specimens have yet to be identified,and
others need to be verified by experts in the field.This situation is
particularly true for the Carex and Salix genera.The families
containing the most species were Asteraceae (Compositae),Salicaceae,
Rosaceae,Poaceae (Grami neae),Cyperaceae,and Ericaceae.The Sal icaceae
family was important from the standpoint of canopy cover,wildlife usage,
and pioneering on gravel bars,whereas the Asteraceae contributed
relatively minor cover.The genus Salix contained 17 species,
tentatively,while Carex had 10 species and Saxifraga had nine species.
Seven genera of lichen,which included at least 11 species,were
identified,while five taxa of mosses were identified.More extensive
work on lichens and mosses would undoubtedly reveal many more species.
The major floristic and botanical feature observed in the study of the
upper Sus itna Ri ver bas in was a tendency for lowl and and al pi ne spec i es
of the Cook Inlet and coastal region to extend into the Susitna River
drainage farther than botanical records indicate.Actually,this finding
is to be expected because of the paucity of collections in the upper
Susitna River basin previous to this study.A list of those species
discovered in the upper basin which are outside of the range reported by
Hulten (1968)are listed in Table 3.6.
(d)Wetlands and Aquatic Vegetation
Apparent wetl ands within the direct impact areas were cl assified and
mapped according to that system (Cowardin et al.1979)recently adopted by
the U.S.Fish and Wildlife Service (USDI 1980a).Lakes,ponds,rivers,
and streams were not specifically classified.This study's estimates of
total palustrine wetland acreages (Table 3.7)were extremely liberal,
since the wetl ands were highly integrated with non-wetl ands and because
no supporting soil data were available for each of the types.Also,
although the mapping was performed using the U.S.Fish and Wildlife
Service system,which is acceptable to the U.S.Army Corps of Engineers
for permit applications,there are several wetlands mapped under this
systan which are outside of the Corps'jurisdiction.Isolated wetlands,
for example,with an outflow of less than five cubic feet per second are
included in Table 3.7 but are not within the Corps'jurisdiction.
Most of the water bodies in the upper basin occur on the upland plateau
between the edge of the river canyon and the surrounding mountains.
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There are virtually countless numbers of lakes in the large flats of the
upper Susitna basin,such as those in the Lake Louise area.Most of the
lakes and ponds immediately adjacent to the proposed impoundment area are
classified according to Cowardin et al.(1979)as:Lacustrine-Limnetic-
Unconsolidated Bottom or Aquatic Bed;-or Lacustrine-Littoral-Aquatic Bed
or Unconsolidated Bottom.
The dominant IItrue ll aquatic vascular species of the water bodies were:
horsetail,bur reed,water sedge,yellow pond lily,mare's tail,and
bladderwort..Dominant IIbank ll or edge species included:horsetail,
bluejoint,cotton grass,water sedge,marsh fivefinger,and buckbean.
The Susitna River and its fast-flowing tributaries are essentially devoid
of aquat ic vegetat i on.
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3.2 -Description of Wildlife Resources
(a)Big Game
A variety of methods were employed to study·the big game species
associated with the Susitna project.Dall sheep was the only species
which was studied without the use of radio-telemetry;sheep numbers were
determined through the use of aerial surveys.Radio collars were placed
on moose (upstream and downstream),caribou,wolf,wolverine,brown bear,
and black bear.The resulting telemetry data were utilized to determine
movement patterns,home range size,den locations,calving grounds,
habitat utilization,and territory size and location.
Aerial census procedures were also employed in the case of moose
(upstream and downstream)and caribou.Several different estimating
techniques were applied to the census and survey data to determine the
distribution and abundance of moose as well as the size of the Nelchina
caribou herd.
A variety of physiological and morphometric data were collected on
animals during the radio-collaring procedure.This included the analysis
of blood and hair samples,teeth (for aging),and the measurement of
important morphometric features.
Both bear and wolf dens were visited on the ground and their character-
istics recorded.Two wolf dens were intensively monitored to determine
daily activity patterns and the reaction of denning wolves to various
types of human disturbance.Wolf scats were also collected from den and
rendezvous sites and analyzed for food habits information.The Jay Creek
mineral lick,used by Dall sheep,was visited to determine the extent of
usage and to collect soil samples for mineral analysis.
A detailed survey of browse availability and utilization was conducted
along the lower Susitna River from Devil Canyon to the Delta Islands.
This entailed determining the relative amount of five key browse species
that were available along numerous sampling transects in addition to the
percentage of each species that had been utilized by moose.
The common and scientific names of the big game species are presented on
Table 3.8.
(i)Moose -Downstream
Because the ADF&G Phase I report on downstream moose studi es was
not yet available,the following description of downstream moose
is based on a compilation of information taken from previous ADF&G
Susitna reports.As a result,the conclusions should be viewed as
preliminary,and in some cases obvious voids exist in the data.
The information that was available,however,is sufficient to
develop at least a preliminary understanding of the moose resource
associated with the lower Susitna River.
3-19
Prior to 1930,few moose were found in the Susitna Valley (Spencer
and Chatelain 1953),At that time,moose likely utilized riparian
habitats and what few browse species were available in the mature
spruce-hardwood forest.It wasn't until man-caused fires and
clearing of land during and after rai lroad construction created
prime moose habitat that the moose population rapidly increased.
In the early 1950 1 s the Susitna Valley was termed "probably the
most productive moose habitat in the [Alaska]Territory"(Chatelain
1951).Rausch (1958)stated that the period of peak moose
abundance along the railroad between Houston and Talkeetna was
February and that movement from the foothi lls to the rai lroad
tracks was basically seasonal and influenced,but not necessarily
caused,by deep snow.The moose population presently remains at
relatively high levels.
For the Susitna studies,a total of 39 moose over a two-year period
were radio-collared in an attempt to determine the movement
patterns of and timing of riverine use by moose that frequent the
lower Susitna River.Of these 39 moose,10 were collared in 1980
and 29 in 1981.Some moose slipped their collars,and one was
killed by a hunter,which left a total of 35 moose with functional
collars during the spring of 1981.These 35 moose had been
captured in the following general locations:Devil Canyon to Gold
Creek -4,Gold Creek to Talkeetna -6,Talkeetna to Sunshine
Bridge -6,Montana Creek to Sheep Creek Slough -9,and Kashwitna
River to Delta Islands -10.Of these 35 moose,eight were males
ranging in age from 2 to 11 years,and 27 were females ranging in
age from 3 to 21 years.
-Distribution and Movement Patterns
Due to differences in the number of radio-collared moose that
were monitored in 1980 (6)versus 1981 (35)and the absence of a
summarizing report from ADF&G,the following discussion of moose
movements and distribution is broken down into the two study
periods for which data are presently available:1980 and the
first 7 months of 1981.
o 1980 Study Period
During 1980,a total of 131 radio relocations were made;of
these 89 (68%)were vi sua 1 observat ions of the moose.All
three types of migratory patterns [as presented by LeResche
(1974)]were found in the study area:Type A,resident;Type
B,migratory between two ranges;and Type C,migratory among
three ranges.The bulls were either Type A or Type C.Each of
the three collared cows exhibited a different type of migratory
behavior.
Home range size and migration distances of moose in the area
studied were likely intermediate to those found for moose in
other parts of Alaska or North America.This characteristic
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is a function of physiography,since the availability of all
life requisites between an area just west of the Susitna River
eastward to the Talkeetna Mountain benches makes longer moose
movements unnecessary.
From observations of the moose that winter on the river below
Talkeetna,it was learned that some calve,summer,rut,and
possibly winter in the flats west of the Susitna;some calve,
summer,rut,and poss ib1y winter in the forest between the
river and the mountains;others spend spring,summer,fall,and
possibly winter in the western benches and drainages of the
Talkeetna Mountains.
Several rutting areas were documented.These were found deep
into the creek and river drainages of the Talkeetna Mountains
and on the benchl and near timberl ine at the mouths of these
canyons.Rutting bulls in the lowlands aggregated less and
were frequently alone or in small groups of 2 to 5 moose.
No specific calving areas were recorded,but cows appeared to
calve frequently on river islands.On boat trips up and down
river in late May and in June,it was obvious that a fair
a1though unknown number of cows had done so.Four cows wi th
newborn calves were observed along the river,and the tracks of
several others were seen on mud banks of islands.
The movement of moose on the river floodplain in late summer
and early fall was less certain.In fall it appeared (from
overflights but no quantitative data collection)that moose did
not remain on the river floodplain.ADF&G biologists,however,
observed them crossing the river,and hunter success along the
ri ver in September also indi cated that moose were near the
river in fall.
In general the home and seasonal range sizes were quite varied.
Because there were some Type A moose in the stud~group,h~me
ranges were as small as approximately 65 km (25 mi ).
Seasona 1 ranges were often small er.2 Type C2 moose had home
ranges at least as large as 233 km (90 mi).The timing
and distances of migration were equally as varied.(For
example,one cow moved from her summering to rutting area in
early August,while another did so in late September).The
longest distance traveled between summering and rutting areas
was 64 km (40 mi).
o 1981 Study Period (January through July)
Not long after the moose were captured and radio-collared,they
began to emigrate from the river basin.By the end of Apri 1
1981,only four of the 35 radio-collared moose were still
within the confines of the river banks.
3-21
On 28 April.1981.of the 25 moose radio-collared within the
river basin south of Talkeetna.20 had moved to the west of the
Susitna River.two were still in the river basin and only three
were to the east of the river.
Of the 19 moose captured and radi o-co 11 ared on the Sus itna
between Talkeetna and the Delta Islands.several in the Delta
Island area itself remained within the confines of the river.
Three of these spent a considerable amount of time on riverine
islands;one of these three.which had been within the confines
of the river since it was collared.moved off the river to the
west only during the last week of July.Most others between
Talkeetna and the Delta Islands left the river and did not
return to it during calving.Only one of the 19 was east of
the Susitna River at the end of July.and it was only dur-ing
the last week of July that this moose moved to that location.
Moose captured on the Susitna River north of Talkeetna also
left the river shortly after being radio-collared.but unlike
those captured below Ta"lkeetna.these appeared to return to the
river between late May and early June.a time when calving
normally occurs.Two cow moose who are residents in an area
north of Talkeetna made relatively long forays [24-40 km (15-25
mi)]into apparently new range.Within a week or so.they were
back in their usual range.
Several of the moose that have been monitored for more than one
year have visited locations where they were found the last
year.Though some di stances traversed were great [25-40 km
(15-25 mi)].relocations within the same hectare or so were not
uncommon.
These data suggest that.for the 1980-1981 winter of relatively
little snowfall.most of the moose using the riparian habitat
came from the generally flat land to the west and that.because
great quantities of snow did not accumulate in the Talkeetna
Mountains.moose from the mountain area did not migrate to the
river basin.It is also possible that migrant moose from the
Talkeetna Mountains did winter in the river basin but simply
spent spring and summer to the west of the Sus itna before
returning to the mountainous habitat in the fall.
For moose south of Talkeetna.movements of 16-24 km (10-15 mi)
to the west of the river basin were not uncommon.These
patterns of movement may be re 1ated to the depth of snow an d
the patterns of its disappearance in early spring.Areas to
the west of the Sus itna appeared to become snowfree before
those to the east.This was particularly evident on the small
knobs that rise to the elevations slightly above the general
terrain and muskeg in the area.These higher sites are slight-
ly drier and support birch in amounts equal to that of spruce.
It is assumed that the disappearance of snow accelerated plant
phenology on the west side of the river;it may have.in turn.
attracted moose from the riparian habitats to the east.
3-22
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For moose north of Talkeetna,movements to areas more than 5 km
(3 mi)from the ri ver have not occurred.Even in a year of
relatively little snowfall,areas to the north of Talkeetna
along the Susitna had an accumulation of 0.6 m ( 2 ft)or more.
Because such snow depths presumab 1y di scourage lengthy move-
ments by moose and also because forage sp.ecies in that area are
more confined to the riparian habitats,resident moose were
relatively sedentary compared to those south of Talkeetna.
-Habitat Use
A preliminary consideration of the data revealed that during
1980,climax mixed birch/spruce (of high or medium density)was
the habitat in which moose were observed in 46%of the
observations.The remaining observati onswere made in a variety
of habi tats inc 1udi ng b1 ad spruce.,muskeg bogs,a lderlwi 1 low.,
willow,alder,cottonwood/spruce and bluejoint fields.
It was surprising to find moose making so much use of mature
conifer/hardwood vegetation,but an obvious bi as;n technique may
account for the data.Most fl ights,and therefore most
observations,were made from mid-morning to mid-afternoon.This
was a time when most moose were bedded down.They may haveealen
ina different habitat type earl i er in the day or after the
observation,but for ruminating they sought more protective
cover.
On the other hand,on two separate radio-locating flights (18
June and 22 July)an unusual number of moose were observed in
open muskeg/meadow habitats.It cou 1d be that particu 1ar type{s)
of aquatic/semi -aquatic vegetation became available at those
times and attracted moose into the relatively open habitats.
Circumstantial evidence provides another possible explanation for
moose using the open habitats.Several moose were observed
runni ng and shaki ng their necks and heads.One moose,up to its
shoulders in water,was observed behaving in a similar manner.
These behaviors appeared to be the res lilt of insect harassment.,
and it is possible that moose were seeking relief in the open
habitats where wind currents move more rapidly because of the
lack of interfering vegetation.
In late May,several small groupings of moose were observed in
areas on riverine is 1 ands where beavers had cut down mature
cottonwood trees.It appeared that the moose had gathered to
feed on the leaves and buds in the crown portions of the downed
trees.Similar situations of temporary food availability
probably arise when spring flood waters erode river and island
banks and undermi ne the root systems of mature trees so they
become top heavy,fall,and become available to moose.
3-23
-Food Habits
Only one study has been conducted in the vicinity of the study
area to determine what moose eat.Rumen samples from rai lroad
killed moose were collected by Rausch in 1957 and analyzed by
Shepherd (1958).From 122 samples,17 different food items were
identified.Willow,birch and aspen comprised 97%of the
identifiable material.These moose probably had been feeding in
mixed birch/spruce habitats in several successional stages near
the railroad tracks where they were killed.Along the river,few
birch and no aspen were found and,therefore,moose using the
river would have a different diet than that indicated by the
above study.
-Browse Availability and Utilization
In 1980,in the overall study area,dense-cl imax cottonwood/
spruce (13.1%)and sparse-low cottonwood/willow/alder (12.3%)
were the most frequent ly encountered habitats.In the Sheep
Creek Study Site,dense-medi um and dense-tall cottonwood/
willow/alder (18.4%and 15.9%,respectively)were the most
abundant habitat types.
A mean of 1.4 browse pl ants/m 2 was recorded for all habitat
types in the overall study area,and many habitats had browse
densities close to that value.Browse species were most utilized
in equisetum/willow (49.2%)and medium-tall cottonwood/willow/
alder (36.4%)habitats and least utilized in medium-dense climax
cottonwood/spruce (6.9%)and sparse-climax birch/spruce (4.0%).
Willow and cottonwood occurred IllOSt frequently in habitats that
were in early successional stages of cottonwood/willow/alder.
The percentages of utilization of these two species were:willow
-36.5%;cottonwood -16.2%.The utilization of each was
greatest,however,in habitats in which it less frequently
occurred.Birch was seldom found on floodplain habitats,but,
where it did occur near the river,it was well utilized (26.9%).
Highbush cranberry and rose were found most in tall or fl imax
habitats.~ean densities for highbush cranberry (1.1/m2 )and
rose (0.9/m )wer~higher than those for willow (O.7/m )and
cottonwood (0.6/m).The mean utilization of highbush
cranberry (15.9%)was similar to that of cottonwood (16.2%)but
both highbush cranberry and rose had lower percentages of
utilizaion than did willow (36.5%).
On the Sheep Creek Study Site,as in the overall study area,
about 20%of available browse plants were utilized.Dense-medi~m
cottonwood/willow/alder contained the greatest density (2.6/m )
of browse plants,but medium-tall cottonwood/willow/alder had the
highest percentage of utilization (35.2%)of its available
browse.
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Approximately one-third of the available willow on the Sheep
Creek Study Si~e was utilized by moose.Willow was most dense
(2.4 plants/m)in dense-medium cottonwood/alder/willow but
utilized most (70.3%)in medium-climax cotton~ood/willow!alder.
Cottonwood was less dense than willow (1.2/m vs 1.6/m 2 )and
utilized much less (only 8.5%).No birch was found on the Sheep
Creek Study Site.As in the overall study area,highbush
cranberry and rose were most abundant in cl imax tipe habitats.
There were mean densities of 1.5 and 1.0 plants/m for the two
species,respectively.Highbush cranberry was utilized twice as
much as rose (16.3%vs 8.3%).
General observations indicated that alder was seldom browsed by
moose,but in some localities a small alder clump could be
heavily browsed.Some islands with good moose browse apparently
are not used by moose over winter:moose sign indicated heavy
use of some islands in the past but no use at the time of
observation.
(ii)Moose -Upstream
The history of the Game Management Unit (GMU)13 moose population
has been described by Rausch (1969),Bishop and Rausch (197"4),
McIlroy (1974),and Ballard and Taylor (1980).Briefly,the GMU 13
moose population increased during the 1950's and peaked about 1960.
After the severe winter of 1961-62,the population began declining
and continued to decline with the severe winters occurring in
1965-66, 1971-72,and 1978-79.Fall calf-cow ratios,in addition
to nearly all other population ratios,declined sharply and reached
a record low for the basin in 1975.Although the decline was
attributed to a variety of factors,predation by wolves was
suspected of preventing the moose population from recovering during
mild winters.
From 11 through 23 April 1980,40 adult moose (37 females and three
males)were captured and radio-collared in the Susitna moose study
area (F i gure 3.10).Three of these moose represented an ima 1s that
had been radio-collared during previous studies.During March and
May 1981,in an effort to provide additional movement information
on portions of the Susitna study area not adequately sampled in
1980,an additional 34 moose (18 adults and 16 calves)were
captured and radio-collared.
-Population Biology
o Age Structure
The average age of the 37 cow moose captured in spring 1980 was
9.4 years (s.d.=3.8),while the three bulls averaged 4.3 years
(s.d.=0.6L The 12 adult cows captured in 1981 averaged 7.6
years (s.d.=2.9).Mean ages of cow moose tagged in the upper
Susitna River basin in 1976 and 1977 (Ballard and Taylor 1980)
were compared with those captured in 1980 and were found to be
significantly younger (P<0.05).
3-25
o Pregnancy Rates
Of the 37 cow moose captured and examined in April 1980,23
(62%)were determined to be pregnant,while in 1981,11 of 14
(79%)were pregnant.Observations of the radi o-co 11 ared cows
following capture in 1980,however,revealed that four cows
which had been diagnosed as not pregnant subsequently had
calves.Therefore,the actual pregnancy rate for 1980 was at
least 73%and may have been higher.The 1980 and 1981
pregnancy rates may,in actuality,have been comparable to the
88%observed in 1977,which was similar to rates determined
elsewhere in Alaska (Ballard and Taylor 1980).
o Calf Production and Survival
Calf moose comprised 13%of the moose observed during the
distribution survey in March 1980.This low calf percentage
reflects poor calf survival during 1979-80,probably a result
of predation (both bear and wolf)and perhaps some winter
starvation.Farther upstream,above the Denali Highway,where
both bear and wo lf dens it i es had been experimentally lowered
(Ballard et ale 1980),calf moose comprised 33%of the moose
counted inlate May 1980,reflecting increased calf survival
because of the lower predator densities.During 1980,of 32
cow moose radio-collared during the Susitna studies,19 were
subsequently observed with 30 calves for an obs~rved calving
rate of 0.94 calves/cow.Fifty-eight percent of the cows
producing calves had twins.These rates of calf production
were quite comparable with those observed in 1977 and 1978
(Ballard and Tobey 1981).
Mortality of newborn moose calves in 1980 was high.By
1 August 1980,23 (77%)of the calves known to be associated
with radio-collared cows were missing.Rates of 1980 calf loss
were compared with those observed in 1977 and 1978.Although
causes of moose calf mortality were not determined in 1980,the
pattern of loss was quite similar to that observed in 1977 and
1978 when predation by brown bears was responsible for 79%of
the calf deaths (Ballard et ale 1981a).Calf mortality
appeared to continue at a highllevel in 1981 as well.
During the 1981 calving season,radio-collared moose were not
monitored intensively enough to document parturition dates and
rates of calf loss.Of the 46 sexually mature cow moose which
could have produced calves,however,only 20 (43.5%)were
observed with calves.Four (20%)produced twins.The calving
rate for known producers was 1.2 calves/cow.Of the 24 known
calves,14 (58.3%)were missing by 28 July.This pattern of
calf loss is quite similar to that in 1977,1978,and 1980,
when predation by bears accounted for most of the losses.
Overall calf survival,however,may have improved in 1981.
3-26
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o Condition Assessment and Carrying Capacity
Criteria developed by Franzmann and LeResche (1978)were
utilized to assess the physical status of Susitna study area
moose.Analyses performed on moose tagged in 1975 and 1977 had
suggested that Susitna moose were in good physical condition
relative to other Alaskan moose populations (Ballard and Taylor
1980).Adult moose examined in spring 1979,however,had the
lowest blood parameters of any moose examined in GMU 13 and
were judged to be nutritionally stressed because of the
severity of the winter of 1978-79 (op.cit.).
Blood values were determined for 34 individual moose sampled in
April 1980 and 13 adults sampled in 1981.The blood data
collected in 1980 and 1981 suggested that over the previous few
years,the physical condition of moose had deteriorated to some
degree.One reason for their condition may have been poor
quality habitat.It is generally accepted that good moose
habitat is closely linked with the frequency of wildfire.
Since there have not been any sizeable wildlfires in GMU 13 for
at least 30 to 35 years (Ballard and Taylor 1980),a gradual
deterioration in habitat quality may be occurring.Even though
the quality or condition of moose habitat may be gradually
deteriorating,however,available evidence suggests that the
population is not yet at carrying capacity.
Although no formal browsing studies have been conducted in
GMU 13,casual observations along the Susitna River and
elsewhere -in the unit suggest that the browsing intensity may
be similar to that in Mount McKinley National Park (Denali
National Park and Preserve)as reported by Wolf and Cowling
(1981).Even at a heavy level of browsing intensity,however,
the McKinley moose herd does not appear to be limited by range
conditions but,instead,by predation (QP.o cit.).Wolf and
Cowling (1981)speculated that the McKinley herd could increase
an additional 10-15%before reaching carrying capacity.It is
possible that moose in GMU 13 are also below range carrying
capacity,as evidenced by moose population increases following
reductions in predator densities.
Studi es of moose ca lf morta 1ity -in the upper Sus itna Ri ver
basin north of the Denal i Highway suggested that predation by
bears was responsible for 79%of the early calf losses (Ballard
et al.1981a).A bear reduction program reduced early neonatal
TOsses from an estimated 55%to an estimated 9%(Ballard et al.
1981b).--
On the other hand,if the available moose range were at
carrying capacity,a significant number of calves would have
been expected to have died from starvation during the first
winter following the bear reduction program.Such was not the
case;the first and second year winter mortality was only 6%
and 4%,respectively (QQ.cit.).It can be inferred from that
3-27
increase in the moose population that the population is not
limited,at least on a short-term basis,by range conditions.
Further,it is possible that a 15%increase in the moose
population to reach carrying capacity is actually minimal for
that area because the bear reduction program alone may have
allowed the population to increase by as much as 19%.In
summary,it appears that although blood data suggested that
range quality in the Susitna study area has deteriorated to a~
undetermined degree,other evidence suggests that the range
could support a larger number of moose.
o Population Estimates
Three previously establ ished moose census areas are located
within the Susitna study area.These are count areas 6,7,and
14.Surveys of these count areas were used to generate an
est imate of the number of moose present in the Sus itna study
area during fall 1980.
Count areas 7 and 14 (Fig.3.11)were intensively censused from
5 through 8 November 1980.A total of 743 moose ~ere censused
within 26 sample areas 2 which amounted to 948 km or 39%of
the total of 2,448 km for count areas 7 ~nd 14.Based on
the 26 sample areas,35%of the 2,448 km census area was
classified as low moose density;38%,as medium moose density
and 27%,as high moose density.Also,based upon census data,
each stratification wa 2 estimated to contain the following
number of moose/km:low--0.434,medi um--O.713 and
high--1.439.Thus,the estimated fall population for count
areas 7 and 14 was 1,986.:!:.371 (90%CI).
Next,in an effort to generate a sightability correction
factor,portions of 10 sample areas within count areas 7 and 14
were randomly chosen and were resurveyed at a greater sampling
intensity.With the additional surveying effort,it was esti-
mated that during the census,approximately 98%of the moose
were being observed yielding a correction factor of 1.03.
Therefore,the adjusted population estimate for count areas 7
and 14 was 2,046 .:!:.382 (90 %CI).
On 29 November,in an attempt to provide a gross fall
population estimate for the entire study area,those portions
of the Sus itna study area whi ch had not been censused were
stratified.A total of 179 moose was observed during 3.6 hour~
of surveying time'2 The area stratified amounted to 2,150 km
of 2 which 1,456 km were classified as low moose ~ensity;663
km,as medium moose density;and only 31 km,as high
moose density.The area covered by each stratum was then
multiplied by the individual density estimates derived for
count areas 7 and 14 to derive a crude population estimate of
1,151 moose.This figure,added to the population estimate for
count areas 7 and 14,resulted in an estimated population in
early November 1980 for the study area west of the Susitna and
Oshetna rivers of approximately 3,197 moose.
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Using methods similar to those described in the preceding
paragraph,relative moose densities in count area 6 (Figure
3.11)were also stratified.This procedure was undertaken
because count area 6 has a migratory population of moose which
overwinter in th 2 vicinity of the mou 2h of the Oshetna River.
Of the 1,217 km stratified 528 km (43%)were classified
as low moose density,53~km~(44%)were classified as medium
moose density and 153 km (13%)were classified as high moose
density.Extrapolating the average moose densities per stratum
derived for count areas 7 and 14 to the area of each stratum in
count area 6,it was grossly estimated that the fall moose
population for count area 6 was 830 animals.
o Movement Pattern
Between October 1976 and mid-August 1981,over 2,700 locations
were obtained on approximately 207 moose of both sex and all
age classes in the Susitna and Nelchina River basins of south-
central Alaska (Ballard and Taylor 1980;Ballard et al.1981a,
1981b).Radio-collared moose exhibited all of the-types of
movements described by LeResche (1974)for moose in North
America.For purposes of this report,however,they could
basically be divided into two groups,sedentary and migratory.
A sedentary moose is defined as one which confi~es its
movements to a relatively small area and where portions of the
summer and winter range overlap.A migratory moose,on the
other hand,is defined as one with a relatively large home
range with non-overlapping summer and winter home ranges.The
1atter type of moose often moves from 16 to 93 km between
seasonal home ranges.
In earlier moose movement studies (Ballard and Taylor 1980,
Ballard et al.1981a),it was suggested that most of the
migratory-moose were located from Jay Creek and eastward.
Additional information collected in 1981 suggested that a large
number of migratory moose also occur in the Watana Creek area.
Movement patterns of most moose examined from 1976 through 1981
From October 1976 through December 1981,33 radio-collared
moose crossed the Susitna River a minimum of 73 occasions.Of
the 75 moose captured in 1980 and 1981,15 crossed the river in
the area of the proposed impoundments a minimum of 40 times.
Of the 40 river crossings,all occurred during May through
November.Distribution of the crossings was as follows:
May -20%,June -7.5%,July -12.5%,August -12.5%,September
-25%,October -12.5%,and November -10%.
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appeared to approximate the
ies of the mainstem rivers
movements in the upper
north-south pattern.
drainage patterns of the tributar-
in the area.Consequently,most
Susitna River basin involve a
3-29
On 24 March 1981,the Susitna River was censused for moose
crossings from the mouth of Portage Creek to the mouth of the
Tyone River.A total of 73 sets of moose tracks was observed
crossing the river on this date.Based upon locations of
radio-collared moose and upon track sightings,crossings of the
Susitna River appear to occur throughout the proposed
impoundment area but appear to be relatively concentrated in
the fo 11 owi ng areas:from the mouth of Fog Creek to the area
opposite Stephan Lake,from the mouth of Deadman Creek upstream
for approximately eight ki lometers,from Watana Creek to Jay
Creek,and from Goose Creek upstream to Clearwater Creek.
o Home Range
Home ranges of rad~o-co11ared moose were relatitely large,
av 2rag ing 224.2 km and ranging from 3.8 km to 2,011
km.LeResche (1974)reported that,regardless of how far a
moose moved between seasons,seasonal home ranges of moose were
consistently small.A preliminary analysis of seasonal home
range data where migration points were excluded suggested that
moose in GrvlU 13 have significantly larger home (anges than
those reported in the literature (Ballard and Taylor 1980).It
is suspected that a more thorough analysis of these data will
demonstrate that seasonal home ranges are substantially larger
than reported earl i er (QQ.cit.).Ba11ard~.~.(980)and
Ballard and Taylor (1980)compared the summer home ranges of
cow moose accompanied by calves with those reported elsewhere
in North America and found that ranges of GMU 13 moose were
substantially larger.They also determined that predator
densities influenced the movements and,subsequently,the home-
range sizes of the cow-calf pairs.The large seasonal and the
total home-range sizes reported in the present study probably
reflect an adaptation by moose to exploit habitats which are
only available on a seasonal basis.
-Distribution
o Fall
The general distribution of moose in November 1980 was
reflected in stratification surveys conducted as part of a
census.Both count areas 7 and 14 were stratified from
fixed-wing aircraft from 2 through 4 November 1980.The Devi 1
Canyon area was stratified on 29 November and count area 6 on
9 November 1980.
Based upon relative differences in moose tracks,numbers of
moose observed,and homogeneity of habitat types,moose
densities were stratified as high,medium,and low.Distri-
bution patterns exhibited by radio-collared moose (Figure
3.11)were similar to those derived from the survey;generally
moose dens it i es were greater in up 1and regi ons located away
from the proposed impoundment areas west of Jay Creek but were
greater closer to the Watana impoundment east of Jay and Kosina
creeks because of the proximity of upland areas.
3-30
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o Winter
A moose winter distribution survey was conducted from 4 through
25 March 1980 in portions of the Susitna River basin containing
subpopulations of moose which could be influenced by the
proposed project.In 26.1 hours of survey effort,1,086 moose
were counted.Undoubtedly,not all moose in the area were
observed during this cursory survey.General distribution of
observed moose is depicted in Figure 3.12.
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1 Approximately 60 moose (6%)were observed
would be inundated at normal pool level.
obse'rved in the Devi 1 Canyon impoundment
were in the Watana impoundment,with 38 of
concentrated at Watana Creek.
at elevations which
Only two moose were
area;the remainder
these 58 moose (66%)
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Although relatively few moose were observed along the Susitna
River bottomlands,large concentrations of tracks indicated
that moose had utilized these areas earlier in the winter.It
is likely that heavy cover in these low areas decreased the
likelihood of observing moose which were present.Among these
bottoml and areas,1arge track concentrati ons were observed at
the mouths of Watana Lake,Watana Creek,Jay Creek,and the
Oshetna River.Tracks and subjective observations suggested
that most moose had moved from the lowland areas which were
covered by relatively deep snow to higher windswept elevations,
where snow cover was nearly absent.
On 26 and 28 March 1981,the Devi 1 Canyon and Watana impound-
ment areas were intens ive ly censused in an attempt to assess
the number of moose that might be displaced during winter 2by
the reservoirs.In the Devi 1 Canyon impoundment (144 km ),
28 moose (0.19 moose/km 2 )were observed.It was estimated
that 94%of the moose had been counted,yielding a correction
factor of 1.06.Thus,the adjusted population estim~te for the
Devil Canyon impoundment was 30 moose (0.21 moose/km ).
In the Watana impoundment (188 km 2 ),42 moose (0.22
moose/km 2 )were counted.The estimate of 42 moose within the
Watana impoundment area was not adjusted.The low numbers of
moose occupying the two impoundments was not surprising since
radio-locations suggested that during this relatively mild
winter,most moose were located away from the impoundment.
o Calving Areas
To determine if calving concentration areas occurred in or
adjacent to the proposed impoundment areas,all observations of
radio-collared moose between 15 May and 15 June 1977 through
1981 were plotted.Although moose parturition apparently
occurs in scattered areas throughout GMU 13,several areas of
concentrati on were evi dent.They incl uded the regi on around
Coal Creek and its tributaries,along and near the Susitna
3-31
River from the mouth of Tyone River downstream to a point
several miles downstream from Clarence Lake Creek,from Jay
Creek to Watana Creek,at the mouths of Deadman and Tsusena
creeks,from Fog Creek to Stephan Lake,and across the Susitna
at Fog Creek to Devil Creek.
-Habitat Utilization
o Elevation
Average monthly elevations at which radio-collared moose were
located from October 1976 through mid-August 1981 are
summarized in Table 3.9.Generally,moose occupied relatively
low elevations during late spring and early summer (x=785 m for
April and 805 m for May).As summer progressed,moose
generally moved to higher elevations,with the highest average
elevation occurring in December (x=901 m).Statistical
comparisons suggest that many of the average monthly va lues
were quite similar but there were significant differences
between winter and summer elevations.
In earlier studies of moose movements in GMU 13,both
VanBallenberghe (1978)and Ballard and Taylor (1980)described
the altitudinal movements of moose:"During summer these moose
occupied areas at about 2500-3000 ft [762-914 mJ elevation,and
during winter habitat types at the 1800-2200 ft [548-761 mJ
elevation were utilized."The analyses provided in Table
3.9 do not fit this pattern.Summer elevational use appears to
be quite similar,but winter elevational use during this study
was different.Mean monthly elevations from December through
March ranged from 818 m to 900 m,which were considerably
higher than the 549 m-671 m elevations reported in earl ier
studies.Moreover,although portions of the data used for this
analysis were derived from the earlier movements studies
reported by Ballard and Taylor (1980),over half of the
locations were obtained during 1980 and 1981.From October
1976 through mid-August 1981,with the exception of 1978-79,
winters were relatively mild in terms of total snow depth.
Since during the winter of 1978-79,only a few radio-locations
were obtained,the combined data primarily represents the
altitudinal movements of moose during relatively mild winters.
The altitudina 1 movements depicted in this study suggest that
moose occupied relatively high elevations during winter.These
resu lts confl i ct somewhat with the commonly accepted theory
that moose use lowland elevations during winter.It is
generally assumed that deep snow drives moose from the
highlands,forcing them to concentrate on low elevation winter
range.This type of movement pattern was not prevalent during
this study.It is possible that during this study,snow depths
at higher elevations were reduced because of high winds and
temperature inversions.This circumstance would have resulted
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in a greater availability of browse at the higher elevations
than at lower elevations,where snow depths were likely to be
greater.Consequently,moose were not forced to concentrate on
low elevation winter range,which would only be used when
up 1and snow depths become excess i ve.Therefore,moose wi nter
movement and concentration patterns exhibited during this study
may only reflect those of mild winters.
o Vegetation Types
Vegetation types dominated by spruce comprised the most
frequently used habitats,with sparse and medium density-medium
height black spruce accounting for 35%of the total observa-
tions.This finding was not particularly surprising since the
classification system was based on overstory vegetation and the
IIspruce-moose"association is well recognized.In the upper
Susitna drainage basin,spruce and shrub types combined
comprise 59%of the total area but during the study received
over 90%year-round use by moose.
Use of upland shrub-willow habitat types corresponded with
observed elevational movements of moose.Use of this habitat
type was at its lowest during the month of Apri 1,when moose
were at relatively low elevations just prior to calving.Use
gradually increased through summer,reaching a plateau of 43%
in October and remaining at a relatively high use percentage
through February.As mentioned earlier,it was suspected that
the use of relatively high elevations from late fall through
winter may have been the result of mild winters.
During calving in May,sparse and medium dense-medium height
spruce habitats were utilized by moose.We suspect these lower
elevational types are selected by cow moose because of their
value as escape cover and because new foliage emerges earlier
than that of other vegetat i on types.Based on aeri a1 obser-
vations,several habitat types,such as birch,alder,and
several spruce types did not appear to be selected by moose.
(iii)Caribou
The Nelchina caribou herd,one of 22 herds in Alaska (Davis 1978),
is important to sport and subs i stence hunters because of its size
and proximity to population centers in southcentral Alaska.
Currently,the Nelchina herd contains about 6%of the total
statewide caribou population (325,000).As a measure of the
interest in caribou,between 1954 and 1981,over 100,000 Nelchina
caribou were killed by hunters (Skoog 1968;unpublished data Alaska
Department of Fish and Game).Another indication of hunter
interest is that in 1981,6,662 people applied for 1,600 permits to
hunt for Nelchina caribou .
3-33
-Distribution and Movement Patterns
Th 2 herd occupies an area of approximately 51,800 km 2 (20,000
mi )bounded by four mountain ranges:the Alaska Range to the
north,the Wrangell Mountains on the east,the Chugach Mountains
to the south,and the Talkeetna Mountains to the west (Hemming
1971).The Nelchina range contains a variety of habitats,from
spruce-covered lowlands to steep,barren mountains.Human
development is largely limited to the peripheries of the
Nelchina range and consists pr-imarily of the Alaska Railroad,
Parks Highway,Denali Highway,Richardson Highway,trans-Alaskan
Pipeline,and Glenn Highway.
Use of the Nelchina range during this study by radio-collared
caribou from the main herd is portrayed by Figure 3.13.Two
major areas that were used extensively at times in the past
received minimal use during the study period.These areas were
the northwestern portion of the range,including drainages of
the Chulitna,Nenana,and upper Susitna rivers and the far
eastern portion of the range,including the Mentasta and
Wrangell Mountains.
During the past 30 years,Nelchina caribou have used numerous
winter ranges from the Nenana-Yanert Fork drainages to the
Talkeetna River and east to the Mentasta and Wrangell Mountains
(Skoog 1968,Hemming 1971).During the winter of 1980-81,the
Nelchina herd wintered on the Lake Louise Flat and the middle
portion of the Gakona and Chistochina River drainages.
Considerable use of the western foothills of th~Alphabet Hills
was also noted.
The primary migratory route from winter range on the Lake Louise
Flat to the calving grounds in the eastern Talkeetna Mountains
was westward across the flat from Crosswind Lake and Lake
Louise into the Talkeetna Mountains on a front from Lone Butte
to Kosina Creek.
It appeared that many an ima 1s used the frozen Sus itna River
between the Oshetna River and Kosina Creek as a travel route in
the spring of 1981.In the spring of 1980,one radio-collared
animal moved south and crossed the Susitna River near the mouth
of Deadman Creek.Many animals historically used this route to
the calving grounds after wintering in upper Susitna-Nenana
drainages (Skoog 1968).
Since 1949,the first year for which records are available~
Nelchina ~aribou have utilized an area of about 2,590 km
(1,000 mi )in the northern Talkeetna Mountains for calving
(Skoog 1968,Hemming 1971,Bos 1974).While the precise areas
utilized have varied,calving has taken place between Fog Lakes
and the Little Nelchina River at about 900 m and 1400 m eleva-
tion.
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Observations during the calving period (15 May -10 June of 1980
and 1981)indicated the calving activities occurred in drainages
of Kosina Creek,Goose Creek,Black River and Oshetna River
(Figure 3.14).Observations of females outside this area during
the calving period were of nonbreeders which reached the calving
grounds later in the calving period.During the calving period,
radio-collared Nelchina bulls were found in a wide variety of
locations mostly in transit to summer ranges.
Historically,the female-calf segment of the Nelchina herd has
primarily summered in two areas:the eastern Ta "'keetna
Mountains and across the Susitna River in the Brushkana,Butte,
Deadman,Watana,Jay,and Coal creeks complex (Skoog 1968,
Hemming 1971).In most years between 1950 and 1973,varying
proportions of the female-calf segment (ranging from 0-100%)
crossed the Susitna River from the calving grounds to the summer
range on the north side of the river.The female-calf segment
of the Nelchina herd spent the summer period (11 June through 31
July)of both 1980 and 1981 -in the northern and eastern slopes
of the Talkeetna Mountains.Summering radio-collared males were
found in many locations in the high country of the Nelchina
basin.
In both 1980 and 1981,autumn (1 Augus t through 31 September)
was a time of cons i derab 1e movement and di spersa 1 by both cows
and bu 11 s.It appeared that,compared to the obvi ous
segregation in June and July,considerable mingling of the sexes
occurred.In mid-to late August 1980 a portion of the main
summering concentrations moved out of the Talkeetna Mountains
onto the western portion of the Lake Louise Flat,and in some
cases,into the Alphabet Hills.Through September,the distri-
bution remained relatively stable,with the main herd divided
between the northeastern Talkeetna Mountains,the Lake Louise
Flat,and the Alphabet Hills.
Historically,Nelchina caribou have rutted in a number of
locations;however,Lake Louise Flat and the eastern Talkeetna
Mountains have been the most widely used.The Deadman Lake
area was also used extensively during the rut in many of the
years when major segments of the herd summered in the area.
During both 1980 and 1981,considerable movement from west to
east occurred during the rut.In both years,a portion of the
herd was in the eastern foothills of the Talkeetna Mountains in
early October,but by mid-October,most animals were in the
northern Lake Louise Flat.In 1980,a small group remained in
the Slide Mountain area.In 1981,on the other hand,a third to
a half of the herd had crossed the Richardson Highway and
trans-Alaskan pipeline by 10 October.
-Subherds
Radio-collars were placed on animals in three suspected sub-
herds,one in the area of the Talkeetna River,the second in the
Chuni lna Hills region,and the third from the upper Susitna-
3-35
Nenana drainages.Because of the changeable nature of caribou
movements and the brevity of the study period,the results are
tentative.
Small groups of caribou,including cows and calves,have been
seen in most of the side drainages of the upper Talkeetna River.
This appears to be a legitimate,resident subherd,probably
composed of <400 animals.Some spatial overlap with the main
Nelchina herd does occur,however.
Three caribou in this upper Talkeetna River subherd (two adult
females and one adult male)were collared on 18 Apri 1 1980.
These animals were relocated 50 times and were always found in
drainages of the upper Talkeetna River or in the upper reaches
of the nearby Chickaloon River (Figure 3.15).One female raised
a calf in 1980,and both raised calves in 1981.The male spent
the summer of 1980 in the mountains west of the Talkeetna
River.
During late April 1980,one adult bull and one adult cow were
collared in the Chunilna Hills.The cow died within a month
of capture.The bull remained in the Chunilna Hills through
November,when it shed its collar.Two additional females were
collared in the spring of 1981,both of which subsequently gave
birth to calves in the area.Relocations of Chunilna Hills
caribou are shown in Figure 3.15.No overlap with radio-
collared animals from the main herd or other subherds was noted,
although one female did move across the Talkeetna River.The
Chunilna Hills group appears to be a resident subherd numbering
<350 animals.
During early IVlay 1980,four adult females and one adult male
were radio-collared from the upper Susitna-Nenana subherd
(Figure 3.15).One Df the females migrated to the main Nelchina
calving area,summered in the Talkeetna Mountains,migrated back
through the upper Susitna-Nenana area in the fall,and rejoined
the main Nelchina herd on the Lake Louise flat during the rut
and early winter.The other three females remained in the upper
Susitna-Nenana area throughout the study period,two producing
calves in 1980 and two having young in 1981.The bull summered
in the Clearwater Mountains,then joined the main Nelchina herd
during the rut in the Lake Louise Flat.It seems likely that a
resident subherd of <1,000 caribou exists in this area;however,
the situation is confounded by movements of animals from the
main Nelchina herd through the area and by use of the area by
summering bulls from the main Nelchina herd.
-Habitat Use
Habitat use by caribou was examined in the main Nelchina herd
and the three identified subherds by recording vegetation type
and elevation on each relocation of radio-collared caribou.The
vegetation classifications were simplifications of Viereck and
Dyrness's (1980)level I categories.Categories used included
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spruce forest (virtually no use of deciduous or mixed forest
types was seen),tundra and herbaceous,shrubland,and bare
substrate.For seasonal analyses,the following categories were
used:calving,20 May to 10 June;summer,11 June to 31 July;
autumn,1 August to 30 September;rut,1 to 20 October;winter,
21 October to 31 March;spring migration,1 April to 19 May.
With the exception of their use of shrublands and bare sub-
strate,habitat used by bulls and cows was significantly diff-
erent (P<O.Ol).In the main Nelchina herd,bulls were found
more often in spruce forest and cows in tundra and herbaceous
vegetative types.Male and female radio-collared caribou from
the main herd,likewise,showed significant (P<O.OOl)differ-
ences in seasonal habitat use.The main differences were heavy
use of spruce forests during the rut,winter,and spring and
.increased use of the tundra-herbaceous type during calving and
summer.Both sexes occurred with nearly equal frequency in
shrublands;however,seasonal use patterns were different.
Female use of shrublands occurred nearly equally in spring,
calving,and summer,while male use peaked in summer and
autumn.
Radio-collared caribou from the upper Susitna-Nenana,Talkeetna
River,and Chunilna Hills subherds were primarily found in
tundra-herbaceous vegetati ve type.Shrub 1ands were a lso used
frequently by animals from the upper Susitna-Nenana and Chunilna
Hills area.
Male and female radio-collared caribou from the main Nelchina
herd were located at similar elevations during autumn,the rut,
and winter.During spring migration,calving,and summer,
however,females were found at significantly higher elevations
than males.During spring and calving,males lagged far behind
the females,remaining longer on winter range and then often
spending the summer period in the lower shrublands.
Mean elevations for relocations of radio-collared animals during
all seasons was greater (P<0.05)for the Talkeetna River (1,440
m)and upper Susitna-Nenana (1,171 m)subherds than for the main
Nelchina herd (1,050 m).Chuni lna Hi lls caribou were found at
slightly lower but not significantly different elevations (996
m)from the main Nelchina herd.
-Population Size and Composition
Census activities during 1980 were conducted from 2 to 5 July.
A total of 17 ,061 caribou were counted in the primary post-
calving aggregation.An additional 244 (including cows and
calves)were found in peripheral areas.Therefore,the post-
calving aggregation totaled 17,305 caribou with an estimated
composition of 2,808 males>1 year;9,285 females>1 year;and
5,212 calves.--
3-37
Fall composition data were collected on 14 October 1980,when
the main Nelchina herd was distributed on the Lake Louise Flat.
The estimated 1980 fall population was 18,713 caribou.The
ratio of males>1 year to 100 females>1 year was 61.9,the
highest ever recorded for the Nelchina herd.An increase in the
proportion of males would be expected for a herd which is
increasing and previously had a relatively low proportion of
males.Bergerud (1980)pointed out that a herd with good
recruitment and a young age structure will have large numbers of
young bulls.
The 1981 census was conducted from 23 to 25 June.The estimate
of the post-calving aggregation was 19,264 caribou with 10,416
females ~1 year,3,035 males ~1 year;and 5,813 calves.
Fall composition sampling was conducted on 19 October 1981 be-
tween Ewan Lake and the Chistochina River.The ratios of males
> 1 year (60.4)and calves (42.9)per 100 cows>1 year were
nearly identical to those estimated in October 1980 ..Because of
poor weather,the composition count was conducted about one ,week
later than normal.It appeared that some bulls had separated
from the cow-calf segment,and males may thus have been slightly
underrepresented in the sampling.The estimated 1981 fall
population was 20,730 caribou.The presence of all radio-
collared females from the main Nelchina herd in th&census area
in 1981 and all but one in 1980 lent confidence in the accuracy
of the population estimates.
In recent years the herd had experienced a growth phase,
1950-60;a peak,1962-1967;a decline,1967-1973;and then
another growth phase,1974-1981 (Table 3.10),The technique
currently used to estimate herd size (aerial photo-direct count
extrapolation caribou census technique)has not always produced
precise estimates;however,a trend of herd growth since about
1974 is apparent when the complete series of estimates is
examined.
Alaska Department of Fish and Game management objectives for the
Nelchina herd include:(1)restricting the harvest until a
population level of 20,000 animals older than calves is reached,
(2)maintaining a minimum sex ratio of 25 males/100 females,(3)
providing for the greatest opportunity to participate in hunting
caribou,and (4)providing for an optimum harvest of caribou.
To allow for continued herd growth,harvest of the herd is
currently restricted by a permit system.
-Mortality
Three radio-collared caribou died of natural causes.Estimates
of annual natural mortality rates were 0.067 ~for females
> 1 year,and 0.138 ~for males > 1 year based on the
number of observed mortalities of radiQ:.collared caribou and the
number of animal years monitored (Trent and Rongstad 1974).
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These estimates were probably somewhat low as only one
winter-spring period,when most mortality of caribou older than
calves normally occurs (Skoog 1968),was included,while two
summer periods,when natural mortality is minimal,were cons-
idered.
Calf survival from birth to 11 months of age (May 1980 to April
1981)was estimated from a theoretical birth rate of 0.66 calves
per cow > 1 year (Skoog 1968,Bergerud 1978)and an observed
ratio inApril of 0.30 calves per cow>1 year.This ratio was
corrected to account for those females (0.95)who survived
between May 1980 and April 1981 (Fuller and Keith 1981).
Estimated calf survival was,therefore,0.43.
Reported hunter harvest for the Nelchina caribou herd has
averaged about 670 animals annually over the past 10 years
(Table 3.11).Females have composed about 25%of the reported
harvest.Hunter numbers have been controlled by permit since
1977 .
(i v)Wolf
From 20 February 1980 through May 1981,36 gray wolves from six
individual packs were captured and radio-collared for this study.
Seven wolves were recaptured on one or more occasions for
re-collaring.Twenty-one (57%)of the captured wolves were males
(six pups and 15 adults)and 15 (43%)were females (seven pups and
eight adults).Six of the 23 were recaptured from earlier studies.
From January 1980 through October 1981,individual radio locations
were obtained for the 36 radio-collared wolves,yielding an average
of approximately 33 locations per animal.A total of 2,255 wolf
sightings were made while locating the radio-collared packs,which
represented 437 pack days.(A pack day is defi ned as any day on
which a pack was located one or more times.)Radio contact with at
least four and perhaps as many as six wolf packs occupying habitats
along the Susitna River near the proposed impoundments was not
established during this study.
-Territories and Population Numbers
For the purposes of this report,Etkin's (964)definition of
territoriality was used,that is,"any behavior on the part of an
animal which tends to confine •••its movements to a particular
location."Most definitions of territoriality assume that the
territory is defended against intruders.Although wolves in the
Nelchina basin apparently do,at times,defend their territories
against other wolves,intrusions into a neighboring territory
often occur when the home pack is not using that portion of the
area.
Table 3.12 summarizes territory sizes for the six wolf packs
which have been intensively -investigated for the Susitna hydro-
electric studies.Territory sizes for the six packs averaged
1,414 km 2 ,which was almost identical with sizes determined
3-39
for other wolf packs in Game Management Unit (GMU)13 (Ballard et
a 1.1981 c)•
Figure 3.16 depicts the spatial arrangement of known and
suspected wolf territory boundaries in the project area during
1980 and 1981.Based upon track counts,publ ic sightings,and
radio locations of radio-collared packs and previous studies,at
least six and perhaps seven wolf packs occupy portions of the
Susitna River which would be directly affected by the Devil
Canyon or Watana impoundments.
Wolf territories were essentially non-overlapping during the
course of any particular year (Ballard et al.1981c).What
overl ap appeared to occur was either seasona l-in nature or was
the result of the manner in which territories were plotted.
Numbers of wolves estimated to occur -in at least 13 wolf packs
known to occur in the study area are presented in Table 3.13.
Spring 1980 and 1981 estimates represent the post-hunting
population while those in fall represent gains due to
reproduction and dispersal prior to hunting and trapping losses.
-Den and Rendezvous Sites
General locations of both den and rendezvous sites located from
1975 through 1981 in GMU 13 are depicted in Figure 3.17.Use of
these sites by wolves in GMU 13 was fairly traditional.Of the
23 sites examined,at least six have been used a minimum of three
seasons.Several have been used during two seasons since 1975.
The average elevation of the 23 sites was 775 m (s.d.=108 m)
rangi ng from 610 m to 1,097 m.Most den sites were old red fox
den sites which had been dug out by wolves.Most sites consisted
of three to four large holes and were characterized by several
small holes,which are commonly referred to as pup holes and
which are rarely,if ever,used.Most sites were located on
slightly elevated areas,with sandy soil providing good drainage.
Although we found that holes were oriented in all directions,
most were found on south to northeast exposures.Thirteen of the
sites examined contained what were termed "whelping chambers"
which were usually located back from the main entrance.
Table 3.14 summarizes the distances of discovered den and
rendezvous sites from both the Devi 1 Canyon and Watana
impoundments.Four den sites and one rendezvous site occurred
within 8 km of the reservoirs.It should be noted that the
figures contained on Table 3.14 must be considered absolute
minimums because they pertain primarily to the area lying east of
Deadman and Kosina Creeks.
-Elevation and Seasonal Usage of Habitat Types by the Watana Pack
Because the Watana pack was intensively monitored,sufficient
data were gathered with which to characterize the elevational and
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habitat usage of a pack.Radio location data for the Watana pack
were plotted on 1:63,000-scale vegetation maps.Data points
which did not specifically fall within one habitat were tallied
as in an ecotone between the two types.
According to this analysis eight of 24 habitat types were not
used,either singly or in combination as an ecotone by the Watana
wolf pack during the study period (April 1980 through October
1981).The unused types included snow and ice,wet sedge grass,
closed balsam poplar,open balsam poplar,willow shrub,grass-
land,disturbed,and lakes.The non-use of lakes is misleading
and is a result of the sampling period's having occurred during
warm months.Wolf packs frequently make kills on or at the edge
of lakes and streams during winter.
Of the 18 habitat or ecotone types used by the Watana wolf pack,
ten were monotypes.Assuming the radio-location data and the
boundaries of the habitat types were accurate,wolves were loca-
ted in the monotypes on 58%of the occasions they were located.
Of the 10 monotypes,low shrub,woodland black spruce,closed
tall shrub,open black spruce,and birch shrub accounted for 86%
of the use.Thirty-six (43%)of 86 locations occurred in ecotone
areas.Seventeen (81%)of the 21 classified ecotone areas were
used only once.Twenty (56%)of 36 uses,however,involved one
of the shrub habitat types.Overall,shrub habitat types
accounted for 50%of all use.
The average monthly elevation occupied by the Watana pack members
ranged from 673 m in April to 1,021 m in November.Sample sizes
were too low to compare seasonal changes in elevational use.
-Food Hab its
During 1980 and 1981,six radio-collared wolf packs were observed
on 83 kills.Moose comprised 57%of the kills,while caribou
comprised 33%.Other prey,such as snowshoe hare,beaver,
muskrat,and other small mammals made up the remaining percentage
of kills.Moose calves accounted for 51%of the moose kills,
while for caribou,calves comprised 7%of the kills.
Table 3.15 summarizes wolf summer food habits as determined from
analyses of scats collected at den and rendezvous sites during
1980 and 1981.Moose of a 11 ages were the most important summer
food items during both years of study.However,it is suspected
that the importance of calf moose is probably over-emphasized by
these data.
Studies of wolf food habits in GMU 13 since 1975 have suggested
that moose are the single most important food item (Ballard et
ale 1981cL This trend appears to have continued in 1980 and
1981 as well,except that caribou appear to have increased in
importance as a prey item.
3-41
Based on data collected during this study and data collected in
GMU 13 from 1970 to 1972 and from 1975 through 1979,it was
concluded that wolves were preying upon relatively healthy calf
and short yearling moose.During severe winters,wolves also
preyed upon relatively healthy adult moose,and this predation
was in proportion to the occurrence of that age class of moose in
the total population.During average or mild winters however,
wolves preyed more heavily on older adult moose.
The annual percentage of observed caribou kills has varied from
4%to 30%.Excluding 1978,when the main body of the Nelchina
caribou herd wintered in the Wrangell Mountains and thus were
largely unavailable to GMU 13 wolves during winter,the
importance of caribou in the diet of wolves appears to have
increased.(Wolf diet averaged 18%caribou for 1975 through 1977
in comparison to 26%caribou for 1979 through 1981).Some of the
annual difference in percentage of occurrence of caribou could be
attributed to the difference in the locations of wolf packs
studied during these time periods.Caribou'distribution,
however,is probably,at least in part,a function of their
density.The Nelchina herd reached a record low of approximately
7,500 in 1972.Since that time the population has increased so
that by 1981 the herd numbered over 20,000.It is suspected that
the increase in the caribou population generally has made caribou
more available to wolves throughout GMU 13 .•If true,this
pattern would suggest that as the herd grows even larger,caribou
will also become more important as wolf prey.Assuming wolf
populations in GMU 13 increase slightly or remain stable,a
larger caribou population may have some positive benefits for
moose,in that a larger percentage of the kills may be comprised
of caribou,relieving the moose population from some predation
morta 1ity.
-Predation Rates
Winter predation rates were estimated for three packs,through
the use of intensive radio monitoring and by back tracking.A
detailed discussion of these rates follows.
From 23 January through 27 March 1980,members of the Susitna
pack were observed on nine kills.These data were divided into
two periods because of changes in pack numbers.The first period
extended from 23 January through 12 February 1980,during which
time the pack numbered seven (three adults,two yearlings,and
two pups).During this interva 1,they preyed upon four caribou
and one adult moose for a kill rate of 1/4.2 days.Caribou
comprised 80%of the kills in 1980,while in 1979,all of the
observed prey were moose.Di fferences appeared to be re 1ated to
the availability of prey.In 1979 few,if any,caribou had been
available to this pack,while in 1980 relatively large numbers of
caribou were present.
3-42
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During the second sampling period,from 12 March through 27 March
1980,this pack numbered four wolves,providing an opportunity to
compare ki 11 rates for the pack when its numbers were lower.
Kills were comprised of one adult moose,one calf moose,and two
adult caribou.The kill rate was 1/4.0 days,which was fairly
close to the rate of kill observed when the pack included seven
members.
During early 1980,the Tyone Creek pack of two adults and six
pups was monitored during a 54-day period (23 January through 16
March 1980).The pack was observed on 11 kills:three adult
moose,seven calf moose,and one adult caribou.The prey species
used by this pack were similar to those observed in 1979.In
1979,however,when the pack was comprised of two adults,calf
moose comprised only 29%of the kills,while in 1980,when the
pack numbered eight wolves,calves comprised 64%of the kills.
This difference could indicate a change in prey selectivity based
on pack composition.This pack was observed on a fresh ki 11 at
the rate of 1/4.9 days.
From 9 January through 26 January 1981,an attempt was made to
determine the predation rate of the Tolsona Pack on caribou by
attempting to locate the pack every other day.During this
peri od,the pack numbered 14 to 15 wo 1ves and appeared to be
feeding quite heavily on car"ibou.A total of four kills were
observed--two adult caribou,one adult moose and one calf moose.
Based upon these data,this pack of 15 wolves preyed upon a moose
or caribou at the rate of 1/4.5 days.Comparison of this rate
with other predation data (this study and Ballard et al.1981c)
reveals that the rate was well below the rate believed-necessary
for the pack to maintain its size and productivity.Therefore,
it is be 1ieved that several ki lls were not detected during the
study period.
Data concerning predation rates during summer were collected on
the Watana Pack.At the initiation of the study,three members
split off from the pack,leaving the main pack with eight
members.From 10 May through 23 June 1981,the eight remaining
members of the main Watana Pack wer~observed on only six kills.
The kills were comprised of two adult caribou (one was unclassi-
fied and assumed to be an adult),two calf moose,one adult
moose,and one unknown species.In addition to the kills,pack
members were known to have twice visited an adult caribou which
had been killed by a black bear,revisited one old moose once,
and visited the unknown species kill on three separate occasions.
The observed kill rate of 1/7.5 days is well below the winter
rate of 1/4 to 5 days.
Peterson (1980)believed that summer wolf predation rates were
lower than those of winter.Studies of two wolf packs elsewhere
in GMU 13,however,suggested that predation rates in summer were
equal to or greater than those occurring in winter.It is be-
lieved that the low summer rate for the Watana Pack was the re-
sult of poor visibility and of a lack of radio-contact with the
alpha male.
3-43
From 10 May through 28 May 1981,the three wolves,mentioned
above,that had separated from the main Watana Pack functioned as
a distinct pack themselves.These three adults were observed on
a total of four kills over a 19-day period,with a kill rate of
1/4.8 days.The kills consisted of two adult moose,one yearling
moose,and one ca lf moose.Thi s part i cu 1ar set of data then,
does not support the hypothesis of smaller packs having lower
predation rates.
Although there appear to be some inconsistencies in the data as
well as variation among seasonal and pack predation rates,there
is sufficient evidence to estimate a kill rate for wolves in this
area.Therefore,for purposes of this report a year-round
predation rate for a pack of wolves was assumed to be 1 kill/5.0
days.
An effort was made to integrate these data collected in wolf
predation rates with data regarding populations of prey species
in the same area.Based upon an intens i ve census of the study
area in fall 1980,it was estimated that a portion of the wolf
study area contained 1,985 moose (see Figure 3.11).The area
censused roughly corresponds to an area which would be occupied
by five wolf packs.
Using the census and the stratified moose data along with the
estimate of five wolf packs,an attempt was made to assess the
importance of wolf predation to the study area moose population.
It was assumed that each pack made an ungul ate ki 11 once every
fi ve days and that from 60-70%of the ki 11 s were compri sed of
moose,32%of which were calves.Based upon these assumptions,
it was estimated that wolves were annually preying upon 11%to
13%of the study area's fall moose population.Percent mortality
of calves present in fall ranged from 16%to 18%,while mortality
on adu lts of both sexes ranged from 10%to 11%.It shou 1d be
pointed out that these calculations are based on a prey base
present in November,and thus,the mortality figures are slightly
inflated.Based upon calf and yearling mortality studies
conducted in and adjacent to the Sus itna study area,it was
estimated that between 9%and 24%of the fall calves were
succumbing to wolf predation.The new estimate obviously falls
within the latter range.
Determining the level of wolf predation on caribou for the study
area required a slightly different approach because of the
seasonal nature of caribou distribution.The impact of wolf pre-
dation on caribou was estimated by assuming that 25 wolf packs
occur within the range of the main Nelchina herd and its subherds
in 1981.A mortality rate was estimated for 1972,when the
Nelchina herd numbered a record low of approximately 7,500
animals and approximately 45 wolf packs occurred in the range of
this herd.Further,a year-round predation rate of 1 k"ill/5.0
days was assumed.The assumption was also that caribou comprised
20%to 30%of the annual wo lf di et.No separati on was made be-
tween ca lf and adu It caribou because ex i st ing wo lf data do not
3-44
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suggest selection of the calf age class.Based upon these
assumptions,it was estimated that in 1972,wolf predation
accounted for an annual morta 1ity rate of from 9%to 13%.In
1981,with the herd at approximately 22,000 animals and with 25
wolf packs present in its range,it was estimated that current
caribou annual mortality from wolf predation ranged from 2%to
3%.
-Hunting -Trapping Mortality
Wolf harvests in the study area and "in GMU 13 from 1971 through
1981 ranged from a high of 128 wolves in 1977-78 to a low of 45
wolves in 1980-81.The low harvest in 1980-81 was attributed to
poor weather and relatively low wolf densities.
From 1971-72 through 1975-76,ground trapping was the most common
method of harvesting wolves in GMU 13,accounting for 59%of the
tota 1 harvest.From 1976-77 through 1978-79 grou nd shooti ng
(primarily hunting using access via aircraft)was the most common
method of harvest.In 1980-81 trapping again was the most preva-
1ent method both because poor snow conditions di d not allow
wolves to be tracked from airplane and because the density of
wolf populations was reduced.
(v)Wolver-ine
Historically,very few studies have been conducted dealing with
wolverine ecology or the impact of human development on this
species.There is indirect evidence,however,that in Canada,
wolverine populations have decl ined as human influence increased
(Van Zyll de Jong 1975).No historical information exists
regarding wolverine populations in the upper Susitna basin.
-Distribution and Movement Patterns
Relocation data for five radio-collared wolverine,sightings of
unmarked wolverine or wolverine tracks,and ADF&G harvest data
yielded a total of 144 point locations scattered throughout the
proposed impoundment vicinity.Distribution seems to be complete
throughout the study area;however,the data indicate that con-
centrations are generally centered in hilly topography above
treeline.There are inherent biases within the data,though
since most of the track sightings and the commercial harvest
occurred during the spring (March-May),when wolverine generally
inhabit higher elevations (Hornocker and Hash 1981).
Radio-tracking data suggest that changes in wolverine distribu-
tion occur throughout the year.Van Zyll de Jong (1975),in
Canada,suggested that food avai 1abi 1ity influences changes in
wolverine distribution.Three different movements by wolverine
in this study seemed to be induced by food supply .
3-45
-Home Range
Radio-collared wolverine were located on 104 occasions during
these studi es.Home ranges were determined for five wo lverin 2;
however,only the home range of wolverine No.040 (627 km )
represents an annua~home range.The range of a lactating female
(No.042)was 86 km .
Oi rect compari son of home range sizes of Sus itna wo 1veri ne with
findings for other radio-telemetry studies is difficult due to
this study's sample size and the differences in sampling periods.
Compari ng home range sizes for males from study areas in north-
western Alaska (Magoun 1979),the Susitna River basin,and north-
western Montana (Hornocker and Hash 1981),it appears that male
wolverine in Alaska have a larger home range.Home range re-
quirements for lactating females,however,were similar for the
Susitna basin,northwestern Alaska and northwestern Montana.The
generally larger home ranges of wolverine in Alaska are probably
related to both fewer choices and lower density of prey.
-Population Estimates
An accurate estimation of wolverine density within the impound-
ment area is ~ifficult to obtain with the available data.Within
the 2,727 km core portion of the study area (F,igure 3.18),
including the two proposed impoundments,where intensive radio-
telemetry studies were conducted,a minimum of nine adult
wolverine occurred,pr~viding a minimum density estimate of one
adult wolverine/303 km .By using several different kinds of
est imates,the study area can be projected to support 11 to 21
ad~lt wolverine,giving an estimated density range of from 1/248
km to 1/130 km 2 .Using this range of adults,the estimated
number of kits added annually to the study area I s population
ranges from eight to 26.These figures yield a total population
estimate,of between 19 and 47 wolverine.
-Habitat Utilization
As a result of the small number of animals radio-collared,infor-
mation concerning habitat use by this species was rather limited.
Wolverine No.040 was the only animal which provided sufficient
data to indicate seasonal changes.
Wolverine No.040 utilized six of the 11 different habitat types
within its home range.By frequency of observation,low shrub
(37.5%),sedges and grass tundra (22.5%),open spruce (20%),and
mixed open spruce (10%)habitats were preferred.It should be
noted that 040 utilized low shrub habitat in a lower proportion
to the amount of that habitat available (37.5%vs.55.5%),while
it ut i 1i zed sedge grass and open spruce habitats in greater
proportion than that habitat's availability (22.5%vs.18.5%and
20%vs.9%,respectively).Seasonal habitat preferences were
also apparent.Seventy-five percent (six of eight observations)
3-46
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of open spruce usage occurred between mid-December and 1 Apri 1,
and 67%(six of nine)usage of sedge grass tundra habitats
occurred between May and 1 September.
Wolverines 043 and 044 displayed preference for ecotone habitats,
since 34.6%(9 of 26)and 61.5%(8 of 13)of their relocations
were present in these transition zones.Preference for or avoi-
dance of homogenous habitat types was impossible to separate
because of these animals'preference for ecotonal areas.
All of the radio-collared wolverine displayed an increased use of
lower elevation areas during winter and early spring (December
through March).The mean seasonal elevation values are 760 m
(summer)and 948 m (fall).Hornocker and Hash (1981)also
reported an elevational decline during winter for wolverines in
northwestern Montana.
-Food Habits
It is well known that wolverines are not only well adapted for
carrion feeding but also that carrion is important in the
wolverine diet (Hornocker and Hash 1981,Rausch and Pearson 1972,
Pulliainen 1968,Haglund 1966,Krott 1959).Some authors
indicate,however,that wolverine additionally use smaller prey,
such as marmot,snowshoe hare,Arctic ground squirrels,microtine
rodents,and birds and that this use is extensive,especially in
the spring and summer (Hornocker and Hash 1981,Magoun 1979,and
Krott 1959).
Data collected during the course of the Susitna studies agrees
with this information on food habits.Winter food habits data of
Susitna wolverines indicate the increased importance of lower
elevations and forested areas.The upper reaches of the proposed
Watana impoundment area support a high density of moose during
the winter.From mid-December to 1 April,75%of wolverine No.
040·s locations were within that area.During March 1981,at
least two wolverine were using that area and were observed using
three different moose carcasses.Ground tracking during December
1980 indicated that wolverine were alsD preying on small mammals.
The numerous locations of wolverines 043 and 044 within ecotones
is probably related to an abundant food source.It is well
known that ecotones are usually high in plant diversity and,
likewise,support a diverse microtine population.
As previously mentioned,there is a pronounced trend of
wolverines using higher elevations in spring,summer,and fall.
During these times,there are large numbers of ground squirrels,
pikas,and marmots throughout the high country (APA 1981).Also
present in the tundra habitats are 13 species of ground-nesting
birds (Cooper,pers.comm.).An excellent example of this shift
from lower elevation forests during winter to alpine tundra areas
during spring was demonstrated by wolverine No.040.Similarly,
wolverine 044 moved a straight line distance of 70 km from an
3-47
open spruce habitat (427 m elevation)to a tundra habitat (991 m
elevation)coinciding with small mammal emergence,caribou use,
and bird nesting season.This wolverine remained above treeline
until 26 September 1980.
-Harvest
Trappers and hunters harvested 27 wo lverine from the study area
during Phase I studies,20 during 1979-80 and seven during
1980-81.The low take dur i ng 1980-81 was probab 1y a resu lt of
poor snow and weather conditions.During the 1979-80 trapping
season,an estimated 23%to 31%of the population was harvested.
It is poss ib1e that the 1eve 1 of that harvest may have been
excessive,thereby lowering the wolverine population.
(vi)Brown Bear
Brown bears are widely distributed and abundant in Alaska.Brown
bears seem well adapted to open areas of tundra or grasslands,
although they do inhabit a variety of different habitats in Alaska.
In contrast to Alaskan popu 1ati ons,brown bear di stri but i on and
abundance in the contiguous United States has greatly declined over
the years.One reason is that bears using relatively open habitat
are cons i derab 1y more vu 1nerab 1e to hunters,with the resu lt that
more animals are killed.In addition,because brown bears
frequently represent a danger to man,they are eliminated or
confined.Brown bear abundance is usually incompatible with
increasing human presence except in a few parks where bears are
given a legal priority over human developmental activities.As a
result,except in Alaska and parts of Canada,this species is
currently classified as endangered.
In the last 20 years,brown bear populations in Alaska have in-
creased,and the current populations appear to be abundant,young,
and productive.Fall harvests in the period 1973-1980 averaged 64
bears/year (30-84 bears/year)in Alaska's Game Management Unit
(GMU)13,which includes the upper Susitna basin.This level of
harvest is suspected to be less than the maximum sustainable yield
of this population.Even with the recent addition of spring
seasons,most of the harvest still occurs during the fall,when
bears are taken incidental to moose or caribou hunts.
Recorded brown bear harvests in the Sus itna hydroelectric project
study area,1973-1980,have averaged IS/year (9-24/year).Hunting
in the study area largely depends upon access by air,including
some hunting by guided hunters,although many bears are taken from
the Denali Highway.Indeed,the largest proportion of study area
brown bears are taken from subregions that include the Denali
Highway.
-Population Biology
The number of brown bear captures in connection with the Susitna
hydroelectric studies in 1980 and 1981 totaled 53.This total
3-48
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includes 11 recaptures of bears in order to replace radio-
collars.Six bears,primarily males with large necks,shed their
radio-collars,and four bears were known to have been shot by
hunters.Four bears died during capture or recapture efforts.
Five or more radio-locations were obtained for five male and 14
female brown bears.Primarily because of large males'shedding
radio-collars,the numbers of radio-locations for males (l09)
have been fewer than for females (422),Part of this disparity
also resulted because seven females were intensively monitored in
spring 1981 (114 locations),while only one male (14 locations)
was so closely followed.
The age structure of bears captured for the Susitna studies is
essentially equivalent to that of intensive 1979 studies in the
upper Susitna,to ten years of GMU 13 harvest data,and to the
subsample of radio-collared individuals (Table 3.16).As
mentioned,however,the subsample of radio-collared "individuals
is biased in favor of females.Thus,these data indicate that
the sample of study animals is reasonably representative in terms
of age structure but biased in terms of sex ratios.
Brown bears in the study area appear to be healthy and highly
product i ve.Based on ni ne 1itters with newborn cubs observed
with marked adults since 1978,the mean litter size was 2.3
(range=1-3).An unmarked bear with four cubs was also observed.
The mean litter size of newborn cubs is equivalent to highly
productive bear populations on Kodiak island (Hensel et al.1969)
and on the Alaska Peninsula,(Glenn et al.1976)and 15 higher
than has been found in a relatively unproductive population in
the Brooks Range (Reynolds 1976).
Of ten cubs in five litters produced in 1981,three (in three
litters)were lost during the summer of 1981.Two cubs in a
litter of three were lost in 1979 studies,as were two yearlings
or cubs in a litter of three in the same year.No other losses
from yearling or two-year-old litters were observed,suggesting
that offspring mortality is concentrated on cub classes.Causes
of cub losses have not been determined,although predation by
male brown bears is considered most probable.
Brown bear females in the study area typically accompany their
offspring through their yearling year and wean them as
two-year-olds in Mayor June of the following year.Many of the
females breed again soon after their offspring are weaned;in all
three cases in which the subsequent year1s data are available,
this breeding was successful,with newborn cubs as evidence.For
these three bears,the reproductive interval was three years,
doubtless additional data will reveal a mean reproductive
interval for adult females of between three and four years.
3-49
Typically,female brown bears in the study area first breed at
three or four years of age and produce their fi rst 1itter when
they are four or five years old.The data suggest that about 44%
of the four-year-old females produce litters,33%of the remain-
ing barren five-year-olds,and 50%of the remaining barren six-
year-olds.Obviously,some of the five-and six-year-old barren
females could have previously produced,but lost,litters.All
seven or eight-year-old females that have been caught were either
with litters or showed evidence of having had a litter
previously.Based on these data,it appears that for every 100
females (>4 years),about 44 will produce their first litter at
age four,-20 at age fi ve,19 at age six,and 18 at age seven
[these estimates are slightly more conservative,(that is,less
product i ve),than indi cated by ava i 1ab 1e data].Based on these
calculations,the mean age at which these 100 females produce
their first litter is 5.2 years.
Bear population estimates are exceptionally difficult to obtain
and an accurate estimate was not achieved during the Phase I bear
studies.Two reasons for the difficulty are the apparent
abundance of brown bears in the Susitna study area and the lar~e
home-range sizes 20f Nelchina brown bears [average=570 km,
range=192-1,380 km (Ballard et~.in press)].
An imprecise estimate of brown bear density was obtained,
however,from intensive trapping and mark-recapture techniques
conducted in the Susitna River headwaters in 1979 (Miller and
Ba~lard 1980).Based on this density estimate ff one bear/41-62
km,the Susitna study area of 8,473 km would have a
population of 100-206 brown bears.It is our subjective
evaluation that brown bear density in the Susitna study area is
more likely to be higher rather than lower than that estimated in
our earlier study.This estimate is compared with other North
American estimates in Table 3.17.
The 1980-81 den sites for 13 radio-collared brown bears were
located and measured;an additional three dens were located for
unmarked individuals.Brown bear den sites ranged in elevation
from 710 m to 1,570 m (2,330 to 5,150 ft);the average elevation
of 29 dens was 1,274 m (s.d.=231 m).Brown bears in the study
area typically denned on moderately sloping southerly exposures.
Their dens were dug in gravelly soil,and no evidence of reuse of
the previously used den was observed.
-Home Range and Movement Patterns
Home-range sizes for brown bears radio-collared during this study
are presented and compared with results of 1978 studies on nearby
ranges (Ballard et al.in press)in Table 3.18.Significant
differences among1978,1980,and 1981 data sets were obtained
only for females,which had smaller home ranges "in 1980 than in
either 1978 (P<0.05)or 1981 (P<0.10).
3-50
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In comparison with studies -in other portions of Alaska,Canada,
and Montana,brown bears in the study area have relatively large
home ranges (Table 3.19).Only in northwestern Alaska,\'~here a
relatively unproductive population resides,have larger home
ranges been reported.Canadian,Montanan,and other Alaskan
populations,except the northwest group also have a greater den-
sity than that of the study population (Table 3.17).Although a
clear relationship has not been established,home-range size and
bear dens ity appear to be inverse ly related,and both seem a
function of the distribution and abundance of food resources.
The relatively large home ranges and low densities of study-area
brown bears may reflect,therefore,relatively low primary
productivity of food items important to brown bears in the study
area.In addition to or instead of low primary productivity,
these data may also reflect a patchy and wide-spaced distribution
of important food items.Supporting this relationship are
observations indicat"ing that in areas of Alaska where salmon
represent a primary source of food,such as on Kodi ak Is 1and or
on the Alaskan Peninsula,home ranges tend to be smaller and
densities higher (Table 3.19).Confounding this apparent
relationship,however,is the ostensibly high productivity of
study-area brown bear populations.If food were limiting this
population,a relatively lower reproductive potential,such as
has been found in northwestern Alaska,would be expected.
Prairie Creek,which flows from Stephan Lake to the Talkeetna
River is well known as an area where brown bears concentrate in
July and August to feed on salmon.Local residents have reported
seeing 20 bears at one time on Prairie Creek.Here,on 10 August
1980,past the king salmon peak,13 brown bears were observed at
one time,and it is estimated that 30 to 40 individual brown
bears fished in this area in the summer of 1980.
During the study,in both 1980 and 1981,radio-collared brown
bears moved to Prairie Creek to fish for salmon.Unfortunately,
poor weather conditions in 1981 made flights to relocate animals
impossible and prevented complete documentation of how many bears
made this movement.A minimum of four bears (of 11 with active
radio-collars)moved to Prairie Creek in 1980 and two (of 18)in
1981.The longest distance moved by a bear to Prairie Creek was
58 km (G293 in 1981).Four of these six bears were documented to
have crossed the proposed impoundment areas.All of the radi 0-
collared bears seen at Prairie Creek had portions of their home
ranges north of the Susitna River and,therefore,had to cross
the river en route to or from Prairie Creek.The maximum number
of times an individual brown bear was known to have crossed the
Susitna River was ten.
The importance of the Prairie Creek salmon run to study-area
brown bears will be difficult to evaluate.Without access to
salmon,moderately dense brown bear populations currently exist
in the Nelchina Basin.It is possible,however,that the avail-
ability of this interior run of salmon might provide nutritional
3-51
benefits that result in local bear populations that are either
more dense or less nutritionally stressed than adjacent
populations without access to a salmon run.In the latter case,
less nutritional stress may produce larger individuals in the
species.
Seasonal movements of brown bears to areas where moose or caribou
congregate,such as calving grounds,are difficult to document.
For one thing,moose calving areas are poorly defined.In
addition,movements of bears in the spring to prey on calves
cannot readi ly be distinguished from their movements to these
same areas which may be motivated by the presence of relatively
more abundant early spring forage.For four bears,however,
apparent directional movements to or from caribou calving grounds
were observed.
ADF&G biologists conducting caribou surveys (S.Eide,R.Tobey,
and K.Pitcher,pers.comm.)regularly report seeing many brown
bears associated with the Nelchina herd.For example,in early
July 1980,during caribou surveys on the upper Oshetna River,
these biologists made in~idental observations of 22 brown bears
in approximately 673 km of survey area.Th~s number repre-
sents a minimum bear density of one bear/31 km.Since only a
fraction (perhaps a third)of the bears present were likely to
have been seen by biologists concentrating on caribou,the actual
local bear density in this area was doubtless much higher.In
1981,these biologists,conducting the same survey in about the
same area,saw no bears,even though some radio-collared
individuals were known to be present.
The available data strongly support the theory that early spring
is the period when many brown bears are most intensively
utilizing the proposed impoundment area (conservatively defined
for this analysis as within 1.6 km of the high-water mark of the
proposed impoundments).Of 12 bears radio-collared in spring
1980,six were located in the proposed impoundment area at least
once (Table 3.20).The mean elevation of these observations was
605 m for the Watana area and 601 m for the Devi 1 Canyon area
(Table 3.20).The mean elevation of observation was below pro-
posed high water lines for Watana but not for Devil Canyon.
Even without prevalent over wintering berries,the same pattern
was evident in spring 1981.Excluding females with newborn cubs,
which tend to remain at high elevations throughout the year,
eight (62%)of the radio-collared bears were located in proposed
impoundment areas in spring 1981 (47%if those females with
newborn cubs are included)(Table 3.20).Of these eight bears,
seven ut i 1 i zed the Watana impoundment area and one the Devi 1
Canyon area.The mean elevation of the spring observations
within the Watana area was 640 m,or below the high water line of
the proposed Watana impoundment (Table 3.20).
These data represent minimal values for early spring use of
proposed impoundment areas by brown bears in the study area.
3-52
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Other bears,particularly those relocated relatively infrequently
in the spring,could also have utilized these areas without
having been found there during weekly monitoring flights.
-Habitat Relationships
The habitat in which a bear was found when located from the air
was recorded.To facilitate interpretation,these data were
lumped into five gross habitat categories.These data,by month
of observation,are given in Table 3.21,which also includes 85
habitat observations for uncaptured bears observed during
radio-tracking flights.
Brown bear use of spruce habitats,which are concentrated in and
around the proposed impoundments,were highest in May and June.
Later in the summer,bears tended to move to shrublands at higher
elevations.In winter (October-April),when bears were in dens,
71%of the observations were in the "other"category of habitat
(Table 3.21).These were mostly snow or rock.
These observations were lumped to contrast habitat use in the
"spring"(1 May to 30 June)with that during the rest of the
year.This specific observation permitted subsequent examination
of the general hypothesis that brown bears use the spruce
habitats near the impoundments relatively more at this time than
during the rest of the year.The relatively higher use of spruce
habitats in the spring was significant (Chi square=10.3,1 d.f.,
P <0.005).This pattern would have been even more significant
if females with newborn cubs had been excluded from the analysis.
As mentioned bef,ore,females with newborn cubs tend to remain at
high elevations away from the impoundments throughout the year
following birth of their litter;of 68 habitat points for such
bears,only two were in spruce (49%were in shrublands,35%in
other,10%in tundra,and 4%in riparian).
-Predation Rates
In a 1978-1979 study conducted in the headwaters of the Susitna
River and in nearby study areas (Ballard et ale 1981a),brown
bears were shown to be significant predators-ofrnoose calves.In
related studies of 23 radio-collared brown bears intensively
monitored twice a day in spring 1978,14 (61%)were observed on
at least 1 calf moose ki 11 (maximum=nine calf moose ki lls)
(Spraker ~~.1981).
The results of this 1978 study were compared with the results of
intensive (daily)spring monitoring of eight brown bears in the
Susitna study area.During this period totaling 102 visual
observation days,one monitored,subadult,female brown bear
killed three moose calves,and another subadult female killed two
adult moose.In addition,three animals of unknown species were
observed to have been killed by brown bears,and in three other
cases,brown bears were strongly suspected to have been involved
3-53
in kills.Even incorporating these suspected kills,the observed
predation rate 0/10.2 days)was lower than in the 1978 study.
Of the total number of brown bear observations,radio-collared
bears were seen on four calf moose,four adult moose,one adult
caribou,and three unknown species,and were observed in five
additional cases where a ki 11 was suspected but not observed.
Because of relatively infrequent monitoring and the limited
visibility of kills in the relatively thicker vegetation in the
Sus itna study area,these data doubt 1ess underrepresent actual
predation rates.
(vii)Black Bear
Black bears,which have a very wide range in North America and are
still abundant throughout most of their original range,are
similarly widely distributed and abundant in Alaska.Black bear
distribution in Alaska coincides closely with the distribution of
forests,with the most abundant populations occurring in open
forests rather than heavy timber;extensive open areas are usually
avoided,however.
The abundance of black bears combined with relatively light hunting
pressure in the upper Susitna basin permits a year-long open
hunting season and an annual bag limit of three bears.An annual
average of 66 black bears have been taken in Game Ma~agement Unit
(GMU)13 from 1973 to 1980 (58-85 bears/year).Most of the
harvest,74%,occurs in the fall season when bears are taken
incidental to moose or caribou hunts.An average of only 23%of
the GMU 13 black bear harvest has been taken by non-residents.
Recorded black bear harvests in the Susitna study area,1973 to
1980,have averaged eight per year (1-15).In the study area,as
in GMU 13 as a whole,black bear harvests have been increasing
in recent years,with the largest recorded annual take occurring in
1980.In the study area,the largest harvests have occurred in the
region farthest downstream on the Susitna River between the
Talkeetna and Indian Rivers,the only portion of the study area
currently accessible by river boat or highway vehicle.
-Population Biology
The number of black bear captures in connection with the Susitna
Hydroelectric Project studies in 1980 and 1981 totaled 53.This
total included five recaptures of bears to replace radio-collars
and one recapture of a bear that had previously shed its collar.
Two bears shed their radio-collars;hunters ki lled six bears;
four bears died of unknown causes;one died during capture eff-
orts;and the collar was not replaced on another bear recaptured
because its neck was infected.
Five or more radio-locations were obtained for 14 male and 11
female black bears.The age structure of the sample of radio-
collared individuals was comparable to that of captured bears
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in the study area in general but was somewhat older than the
subsample of black bears taken by sport hunters in GMU 13 (Table
3.22),This discrepancy probably resulted from the tendency of
hunters to take younger~less experienced bears as opposed to the
effort of the study·s techniques to capture a random selection of
study-area animals.It is also possible that black bear hunters
along the road system,where much of the harvest occurs~are
sampling a more heavily harvested and,therefore,younger
population than exists near the proposed impoundments.Males
represented a smaller proportion in the study than they did in
hunter kills in GMU 13,probably because by ranging greater
distances~the males become more vulnerable to hunters.These
data suggest that black bears marked for Susitna studies are
reasonably representative of the existing black bear population.
Black bear populations in the study area appeared to be
productive and healthy.This finding was somewhat surprising
because the study area is situated on the northern limit of black
bear distribution south of the Alaska Range.Apparently,the
habitat is adequate even though limited in extent.
Eight litters with a total of 16 cubs were observed with
radio-collared females in 1980 and 1981.Five of these litters
were not observed until between June and August~so they may have
experienced some losses between early spring and the date of
their first observation.This possibility aside,the observed
litter size was 2.0 (1-3)cubs/litter.The observed litter size
for seven litters of yearling black bears was 1.9.In compari-
son,on the Kenai Peninsula~seven radio-collared females had a
mean litter size of 1.9 upon emergence from natal dens (compiled
from Schwartz and Franzmann 1980,1981).
In the Sus itna study area between May and August 1981,one cub in
a litter of two was lost~one was lost from a litter of three,
and both were lost from another litter of two.Counting only the
four litters initially observed by June~four of nine cubs (44%)
were lost~all in 1981.On the Kenai Peninsula on the other
hand ~no cub losses have been obser:ved (Schwartz and Franzmann
1980 and 1981).
Three black bears with apparent yearling offspring were captured
in 1980 (offspring were not captured).One of these weaned its
offspring in 1980 and produced new cubs in 1981,a reproductive
interval of two years.The third bear relocated its den in April
1980;perhaps its original den had collapsed~killing its litter.
No den re 1ocat ions were observed for other bears.A two-year
reproducti ve interval is,therefore,probab 1y the min imum;
additional data will undoubtedly indicate a mean interval of
between two and three years.The mean reproductive interval for
an unproductive Montana population was over three years,and the
percentage of adu lt females accompan i ed by cubs was low (15.6%)
(Jonkel and Cowan 1971).
3-55
Three bears produced litters at five years of age and one bear at
six years of age.Assuming no previous litters and correct
aging,these bears became reproductively mature and successfully
bred at four and five years,respectively.On the Kenai
Peninsula,seven females (aged four years)had cub litters
(Schwartz and Franzmann 1980,1981),suggesting that reproduct-
ive maturity may be reached a year earlier on the Kenai.For an
unproductive population in Montana,no females were observed in
estrus prior to 4.5 years of age and no bears successfully
produced litters at less than between six and seven years (Jonkel
and Cowan 1971).
Available data are inadequate to calculate productivity of the
Susitna-area black bear population,but available data on
productivity parameters suggest it does not have quite the
reproductive potential of the Kenai population.The basis for
this assertion is primarily the older age for reproductive
maturity.The Susitna population may also have a lower recruit-
ment rate (based primarily on higher rates of cub losses).
The recruitment rate is the rate at which the adult population is
increased after cub and yearl ing losses and other reductions in
subadult population are taken into account.Relative to the
unproductive Montana population,however,the Susitna population
appears highly productive,equivalent to productive populations
in the mi dwest.It shou 1d be noted,however,that these com-
parisons are highly speculative at this point.
No reliable black bear density estimates are available from the
study area or adjacent areas.Compared to other Alaskan
habitats,however,portions of the study area appeared to be very
densely populated by black bears.The only available data that
permit even a crude density estimate come from sightings of
marked and unmarked black bears during the August 1980 tagging
operation.In 1 1/2 days of spotting effort 08,19 August
1981),35 bears,four of which were marked,were seen in approxi-
mately 259 km 2 of search area.A radio-tracking effort on
August 14 verified the presence of seven radio-collared black
bears in the search area.A straightforward Lincoln Index on
these observations yield1 an approximation of 61 bears in this
area or one bear/4.1 km.An "adjusted ll index (Ricker 1975)
yields an estimate of 58 bears (s.d.=19).A highly speculative
estimate of the number of black bears in the study area is
possible from this ~ensity estimation.Assuming that roughly
one-third 0,400 km )of the study area is acceptable black
bear habitat,this density figure would yield a population
estimate of 341 black bears in the study area.These estimates
should be viewed cautiously,however,as there are many possible
sources of bias in the technique of estimating densities and it
covers only a small portion of the study area at a season when
bears might have concentrated in search of a locally abundant
food source.
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Regardless,the density estimate of one bear/4.1 km 2 falls
roughly at the mid-point of reported black bears densities in
North America and is only slightly lower than the most
intensively studied nearby population (Kenai Peninsula,Schwartz
and Franzmann 1981)(Table 3.23).In fact,the above density
approximation is probably too low rather than too high,at least
in the habitats where black bear density is highest.
Den sites for 1980 were located and measured for 14 radio-
collared black bears;two additional approximate den locations
were recorded but the actual dens were not found.The distri-
bution of known black bear den sites indicated that study-area
black bears tend to den in steep terrain along the main Susitna
River or its feeder streams.As one proceeds upstream through
the study area,the band of acceptable denning habitat apparently
becomes progressively narrower and more confined to
the immediate vicinity of the Susitna River,in much the same
pattern as that for overall black bear distribution.
Black bear den sites ranged in elevation from 396 m to 1,323 m;
only one bear,however,denned at an elevation above 914 m.
Typically,black bears in the study area denned at elevations
between 457 m and 762 m elevation.Of 16 den sites found in the
vi ci nity of the proposed Devi 1 Canyon impoundment,the average
elevation was 664 m (range =454-1,323 m;S.D.=86 m).Two black
bear dens were observed downstream of the Devi 1 Canyon site in
1981.
Of the 14 dens used in 1980/81 that have been located on the
ground,eight were in natural cavities or caves,and six were
excavated.Based on evidence found at the den site,all of the
natural cavity dens examined and one of the dug dens examined
had apparently been utilized previously.A determination of
previ ous use cou 1d not be made for four dens.Four of the dens
examined in 1981 were apparently reused by radio-collared black
bears in the winter of 1981/82,three dens by the same individual
that had utilized the den the preceding year.
These data on reuse of den sites may indicate either a scarcity
of acceptable denning sites in the study area or simply habitua-
tion.Of 18 den sites examined on the Kenai Peninsula,eight
had been previously used and ten were newly constructed.Only
one bear reused the same den in successive years (Schwartz and
Franzmann 1981)..In relation to this Kenai study,reuse of den
sites appears higher in the Susitna area.All of the dens in the
Kenai study were excavated (Schwartz pers.comm.)compared to
only 43%in the Susitna area.
-Home Range and Movement Pattern
Mean home ranges and ages for bears older than 2.0 years are
given in Table 3.24.The data for these two years are not
completely comparable,as different individuals were observed
dur ing di fferent seasons.In any case,it appears that these
3-57
home ranges tend to be 1arger than has been r 2corded for black
bears 20n the Kenai Peninsula,that is,16.7 km for females and
98 km for males (Schwartz and Franzmann 1981).In the Kenai
study,however,a more conservative method was used to calculate
home-range sizes.In the Susitna study,the home range sizes
reported include,for many bears,1arge areas where no observa-
tions were made.This situation is especially true for the 1981
data when many bears moved long distances in late summer to
foraging sites;these home ranges could be viewed as two seasonal
home ranges connected by a narrow transportation corridor rather
than as one home range.
Larger home ranges in 1981,compared to those of 1980,were
observed for all groupings of individuals but were significant
only for males (P<O.Ol)and for both sexes combined (P<0.05).
Some of this increase was doubtless caused by the greater number
of observations per bear in 1981,but it is evident that home
ranges in 1981 were both much more variable and larger than in
1980.The greater movements in 1981 probably reflect the
apparent relatively poor 1981 berry crop,which necessitated
greater movements to fi nd acceptab 1e foragi ng areas.In 1981
black bears were observed north of the Denali Highway near
Susitna Lodge (R.Halford,pers.comm.),a relatively rare
occurrence which also supports the theory that 1981 was a year of
atypically extensive black bear movements.
In late summer of 1980 (late July-August),many black bears made
seasonal movements to the tablelands between the spruce forests
along the Susitna River and the mountains north of the river.It
is suspected that these movements were motivated by ripening
berries,which may be more abundant in these relatively open
areas than in the spruce forests where bl ack bears are more
commonly found during the rest of the year.In 1981,the move-
ments were similar,but many more bears moved much greater
di stances.The suppos i ti on is that the apparent scarc i ty of
berries in 1981 in the tablelands prompted these more extensive
movements,which are in turn,reflected in comparisons of annual
home range sizes.These movements are likely motivated by
searches for better forage or for fish as a substitute for the
berries that were in short supply.For example,three males
moved downstream of the main study area in fall 1981,apparently
to fish for salmon downstream of Devil Canyon.
Based on available data and supposition,the pattern of black
bear movements can be summarized as follows.In years of normal
or acceptable berry crops,many bears in late summer move to
somewhat higher country adjacent to the spruce habitats along the
river,returning to their lower spring and early summer home
ranges to den.Mos t of these 1ate summer movements are upstream
(east)and a bit north.In years of subnormal berry crops,most
individuals range more extensively,and many of these move long
distances upstream or downstream in search of acceptable foraging
areas or areas where salmon are available.Some of the
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individuals making these extensive movements do not return to
their former home ranges,but most do.Females with newborn cubs
are exceptions to this rule,making less extensive movements,
regardless of the berry crop,than other bears or than they
themselves do in years when they do not have cubs.In late
summer and fall,especially in poor berry years,the more
extensive movements of black bears may bring them in closer
contact with areas frequented by brown bears at thi s time,and
this proximity may result in increased mortality of black bears.
-Habitat Relationships
Each black bear location was classified into one of 23 habitat
classification categories for 724 observations made from the air.
These data were then consolidated into five gross habitat
categories;the results are presented on Table 3.25.
Black bear use of spruce habitats,concentrated in the vicinity
of the proposed impoundments,was common throughout the year but
was least prevalent in late summer.In August,black bears were
more commonly found in shrubland habitats adjacent to the spruce
forests (Table 3.25).As mentioned,it is suspected that this
late seasonal movement was motivated by the relative abundance of
ripening berries on these tablelands.
The hypothesis that spruce habitats were used less frequently in
late summer (16 July-31 August)was tested by contrasting the
percentage of occurrence of radio-collared individuals in spruce
habitats dlJring this season <36%of 251 observations)with that
of the rest of the year (44%of 547 observat ions).The di ffer-
ence was significant (Chi square=4.7,1 d.f.,P<0.05).There was
a significant difference between males and females in late
summer use of spruce habitats (Chi square =4.4,1 d.f.,P<0.05).
In the late summer,43%of 126 observations of females were in
spruce habitats compared to 30%of 125 observations of males.
-Predation Rates
Black bear predation on moose calves is prevalent on the Kenai
Peninsula (Franzmann et al.1980).Of 23 radio-collared black
bears followed in thelKenai study,five (22%)were known to have
preyed on moose calves (Schwartz and Franzmann,in press).No
predation occurred in areas where moose browse rehabilita-
tion had occurred;all predation occurred in IJncrushed areas of
regrowth vegetation resulting from a 1947 forest fire (op cit.).
If this same model hOlds true in the Susitna study area,-Which is
comprised of vegetation in a relatively undisturbed state,high
levels of predation on moose calves by black bears would be
expected.
3-59
Daily monitoring of three black bears in the Susitna study area
during the period 21 May-22 June 1981 resulted in 73 point
locations.During this period,one black bear,(a five-year-old
male),was observed on one calf moose kill and one adult caribou
ki 11.This bear was also observed on a ki 11 of an adult radio-
collared moose on 22 July.No other predation was observed
during the period of intensive monitoring.Subsequent regular
monitoring of black bears resulted in no additional known kills
of ungulates.
It is believed that calf moose are more important spring prey
than indicated by these data.Many kills were likely missed
because of relatively infrequent monitoring,the difficulty of
spotting kills in heavy vegetation,and the low numbers of
intensively monitored black bears.
(viii)Dall Sheep
The study area surveyed for Dall sheep includes all drainages
flowing into the Susitna River from Gold Creek to Kosina Creek on
the south and from Gold Creek to the Denali Highway on the north.
Survey efforts were confi ned to areas of known or suspected Da 11
sheep habitat.The resu lts of the sheep surveys are organi zed
below according to well-defined sheep subpopulations.
-Portage -Tsusena Creek Area
During July 1980,a total of 72 sheep (seven legal rams,12
lambs,and 54 unidentified)was counted in the Portage Creek and
Tsusena Creek drainages.The only previous ADF&G survey in this
area was a 1977 count of 91 sheep (eight legal rams,18 lambs,65
others).The 1977 survey included the Jack River drainage,which
was not surveyed in 1980.The sheep sighted were located fairly
high up in the drainages and relatively far from the proposed
impoundments.
-Watana Mountain -Grebe Mountain Area
During July 1980,only eight sheep (one ram,seven unidentified)
were observed in the Watana Mountain-Grebe Mountain area.Ob-
servations in 1977 suggested that at least 34 sheep were present
on Mt.Watana.Numerous observations exist of sheep in the
Terrace Creek area,but no sheep were observed there during the
1980 survey.Either the sheep had migrated from the area,or
they were missed during the 1980 survey.
A winter distribution survey was conducted in the same area that
had been surveyed in July 1980.During winter,a total of 28 to
30 sheep were observed.If data collected during these two sur-
veys were representative of the sheep population,they would
indicate that sheep were migrating into the area during winter.
All sheep observations,however,were located on the southern
extreme of the count area,well away from the·proposed Watana
impoundment.
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-Watana Hills Area
The Watana Hills area was designated as a population trend count
area for Dall sheep by ADF&G in 1967 and since that time has been
surveyed eight times.The 1981 count of 209 sheep was the second
highest number of sheep recorded for this area.The percentage
of lambs was similar to past years and suggests that productivity
and survival are remaining constant.Although the 1981 count was
relatively high,it is believed to be accurate since the popula-
tion is suspected to have remained stable or perhaps to have
increased slightly.
-Jay Creek Mineral Lick
Observations recorded during the spring of 1980 strongly
suggested the presence of a mineral lick on the cliffs along the
lower reaches of Jay Creek near its confluence with the Susitna
River.The lick is within the Watana Hills area.The possible
existence of a mineral lick very close to the proposed Watana
impoundment generated detailed studies in 1981.
The mineral lick at Jay Creek was examined on 9 May 1981.
Portions of the lick were found to extend below the proposed
average maximum pool elevation of the Watana impoundment.Sheep
usage of the area ranged from the Jay Creek stream bottom to the
top of the bluff and for an undetermined distance away from the
bluff.On the day of examination,five Dall sheep were observed
actively scraping and eating soil from this area.This further
suggests that minerals are the main attraction.
A total of 34 separate observations of sheep using the mineral
lick were made over a 50-day period,starting on 6 May and ending
on 24 June 1981.The 1argest si ngl e group observed at the Jay
Creek site consisted of 15 sheep.This number represents
approximately 7%of the observed Watana Hills summer population
and approximately 17%of the observed Watana Hills winter
population.
Sheep were also observed frequenting other locations adjacent to
the Jay Creek mineral site.On 23 and 25 May 1981,two groups of
six and 12 rams,respectively,were observed scraping and eating
soil on the ridge located on the east side of Jay Creek,directly
opposite the main lick area.On seven occasions during June,
sheep of different age classes were observed at an area
approximately 3 km upstream from the main mineral area.This
area also appears to be mineralized.
The use of the Jay Creek 1i ck seems to be confined to May and
June.An aerial summer distribution survey was conducted on 28
Ju ly 1981,and no sheep were observed at the Jay Creek area.
Ten ewes and yearlings were observed,however,actively utilizing
a known mineral lick in the drainage of the east fork of Watana
Creek,approximately 11 km north of the Jay Creek site.
3-61
-Sport Harvest
The 1980 harvest within the Susitna sheep study area was 13
sheep.Eight of these were considered to be trophy quality rams
with horn lengths greater than 89 cm (35 in).Most of the
harvest occurred in the Watana Hills area.
(b)Furbearers
During 1980 and 1981,a variety of methods were employed to assess
furbearer populations in the vicinity of the proposed impoundments and
also downstream (Figure 3.19),The species studied included red fox,
pine marten,beaver,muskrat,mink,river otter,coyote,lynx,short-
tailed weasel,and least weasel.Both the common and scientific names of
these furbearer species mentioned in the text are presented in Table
3.8.
Seventeen red foxes and 17 pi ne marten were equi pped wi th radi 0 co 11 ars
and relocated at frequent intervals.Radio-equipped animals were
re located both from the ground and with the use of a he 1i copter.In
addition,fox dens were located through a combination of ground and
helicopter searches.The diets of both foxes and marten were studied by
following trails in snow and noting feeding activity,collecting food
remains at dens,and conducting gross analyses of scats and stomach
contents.
Another method of assessing furbearer populations was the a3signment of
transects.Fourteen aerial snow transects were established between
Portage Creek and the Tyone River (Figure 3.20).Each transect was
oriented perpendicular to the Susitna River and extended for 4.8 km on
either side of the river.The transects were then surveyed from a
helicopter,and all furbearer tracks were recorded.
The extent of beaver and muskrat populations was investigated in the
upper basin during 1980 by means of an aerial survey of both beaver dams
and lodges and muskrat pushups.Downstream beavers were surveyed from a
point 3 km above the confluence with the Indian River to a point 4 km
below the confluence with the Kashwitna River.During 1980 this area was
surveyed from a river boat and in 1981 from fixed-wing aircraft.
(i)Red Fox
Red foxes and their sign have been observed throughout the upper
Susitna basin.In the vicinity of the proposed Devil Canyon and
Watana impoundments,the population of red foxes generally
increases from Devi 1 Canyon upstream to the mouth of the Tyone
River (Table 3.26).Some red foxes utilize tributaries and deltas
of tributaries during autumn,then shift to alpine zones in winter,
as both snow depth and the vo 1ume of water fl owi ng over the ice
increase along the river.Other foxes remain above timberl ine
throughout most of the year.Fox numbers upstream from Vee Canyon
and in alpine areas adjacent to the proposed impoundment zones
appear to be comparable to those in Denali National Park and
Preserve and other portions of interior and southern Alaska
(Buskirk,pers.obs.).
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The dens ity of red foxes in the Sus itna study area appears to be
low compared to densities of red foxes in midwestern states.Pils
and Martin (1978),Sargent et al.(1975),Scott and Klimstra (1955)
and Shick (1952)working m W'lsconsin,North Dakota,Iowa,and
Michigan,respectivel{,estimated the density of fox families to be
one family per 10 k~.In summer 1981,six active fox dens were
found on aI,751 km portion of the Sus itna study area.On the
basis of the sighting of two fox pups at an additional den site,it
is likely that at least seven dens were occupie~by fox families
during 1981.This is one fox family per 250 km.In all proba-
bility,not all dens in the study area were found.If only half ~f
the active dens were found,the figure is one family per 125 kill •
Correspondingly if only one-third of the activz dens were found,
the estimate wou~d be one family per 83 km compared to one
family per 10 km estimated in midwestern states.Considering
the effort spent searching for fox dens 2during the study period,
the estimate of one fox family per 83 km is probably reasonable,
if not slightly high.
Trappers have act i ve 1y pursued red foxes throughout the regi on.
Harvests of red fox pelts have generally been highest upstream from
Vee Canyon.Emphasis has been placed on trapping red foxes along
the Susitna and Maclaren rivers downstream from the Denali Highway
to a few kilometers below the mouth of the Tyone River.A local
trapper and fur buyer reported (pers.comm.)that during the 1ate
1950's and early 1960's,another trapper of his acquaintance took
300-350 fox per year in this area.
The fur buyer also recalls that on an April 1959 trip down the
Sus itna to the Tyone Ri ver,he saw 15 to 20 foxes.It is note-
worthy that these foxes were present after a heavy trapper-take of
foxes occurred during the 1958-59 trapping season.While the
historical estimates of red fox numbers downstream from Vee Canyon
to Devil Canyon are limited,fox numbers have been low in this area
since the mid-1970's;it is felt that their numbers remain
consistently low.In substantiation of this belief,during the
1979-80 trappi ng season,two trappers worki ng along Tsusena Creek
took only two foxes;another trapper captured one fox in the Fog
Lakes area;a third caught no foxes whi le trapping around Stephan
Lake.
Principal foods of red foxes during spring and summer include
Arctic ground squirrels,red-backed voles,and singing voles.
Ptarmigan are taken throughout the year,but they are of major
importance to foxes during the winter.Trails in snow show that
foxes commonly forage in areas above timberline frequented by large
flocks of ptarmigan.Murie (1944)states that ground squirrels in
McKinley Park (now Denali National Park and Preserve)were abundant
and much used by foxes.He has little to say relating to the use
of ptarmigan,however,because at the time of his studies,
populations of these birds were low in the park.
Foxes take muskrats where available,and they may be relatively
important to foxes around large lakes such as Stephan,Clarence,
3-63
and Deadman.Dispersing young muskrats and muskrats at pushups are
particularly vulnerable to predation by foxes.A trapper reported
observing foxes hunting muskrats during winter at pushups on
Stephan Lake.Aerial and ground observation at Clarence Lake
during this study indicates that foxes frequently visit muskrat
pushups.
In parts of the study area,carrion may also be important to red
foxes.Caribou carcasses appear to be the main source of carrion
in the Clarence Lake area,where sport hunting is relatively heavy
during fall.Two foxes near Watana Camp also fed on remains of a
caribou and on a moose carcass through most of winter 1980-1981.
In addition,two foxes were observed in October 1981 feeding on a
sheep killed by wolves on the east fork of Watana Creek.
In general,snowshoe hares may be another important component in
the red fox diet (Dickson 1938).Snowshoe hares are scarce in the
Susitna study area,however,[see Section 3.2(d)]and,therefore,
relatively unimportant in the diets of foxes here.No hare remains
were noted either at two active fox dens found in 1980 or at six
active dens observed during summer 1981.In addition,no evidence
of foxes preying on hares was found during trail sampling of foxes
in either 1980 or 1981.This scarcity of hares may,in part,be
responsible for both the relatively low number of foxes found in
the area as well as for the seasonal shifts to higher elevations
where ptarmigan are available.
During the study,19 fox dens were located,six of which were
active during summer 1981.Of the 19 dens,18 were north of the
Sus itna River,and one was south.Several dens were concentrated
in the upper Watana Creek and upper Deadman Creek drainages.While
there are probably more dens south of the Susitna River than were
located,extensive searches were conducted,and no others were
found.Thus,a 1though south of the ri ver,the Stephan Lake -
Prairie Creek area appears to be well suited for red fox dens,
aspect,physiography,and vegetation are generally more favorable
for denning and hunting on the north side of the river.The
study's findings corroborated this analysis.The extent of den use
varied among these sites.Some sites were comprised of extensive
burrow complexes and are probably used every year.Others appeared
to be used less frequently,and in some cases,they seemed to serve
only as winter resting sites.
Dens of red foxes typically occur between 1,000 and 1,200 m eleva-
tion in areas of rolling hills adjacent to mountains.A lake
covering four hectares or more or a creek is usually located
nearby.Vegetation surrounding den sites typically includes alpine
tundra (Dryas-l ichen),shrub tundra (medium and low shrub with
tussocks,sphagnum dwarf bi rch,low wi llow,and ericaceous
shrub-sedge)and mat and cushion tundra (Dryas-sedge,willow,and
ericaceous shrubs).
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Red fox dens are found on prominences up to 5 m higher than the
surrounding area.The soil type is usually silt and relatively
rock free.Murie (1944)reported:"Red fox dens in McKinley Park
[Denali National Park]were in the open and in the woods,on sunny
kno 11 s far up the slopes,and on the flats.Most of them were dug
in sandy loam.."
Murie's findings are similar to those of this study except that
ground and air searches did not reveal fox dens in the woods.
Allison (971),working in Denali National Park,recorded dens in
habitats similar to the denning habitats observed during this
study.Except for alder,Allison mentioned no plants over four
feet (1.2 m)high near dens.On the other hand,some fox dens have
been seen in the woods in Denali National Park (Buskirk,pers.
obs.).
Red fox dens usually had a complex of burrow entrances,most
oriented to the south but some facing west.The number of
entrances present per den ranged from three to 27,with one
alternative den generally located within 200 m of the main den.
A11 active dens located were in or near areas of medium to high
ground squirrel density.As noted above,ground squirrels are an
important food item during the denning season.
Red foxes begin denning activities in the Susitna basin during late
April or early May.One female in the study,over a two-day
period,moved almost 16 km from her winter range to a den site.In
another instance,an adult female reared pups in 1981 at a den
where she had been a pup in 1980.
Ranges remained constant throughout the summer.An adult male
occupied a minimum summer range of 36.8 km 2 in 1981.Another
male occupied a range of approximately 20 km 2.From late
August into October,juveniles utilized progressively larger areas
around natal dens.
Dispersal occurred in early to mid-October.Allison (1971)
reported that in Denali National Park,fox families vacated dens by
mid-August.Storm (972)found that foxes in Iowa and Illinois
used den sites unti 1 late July and remained together as a family
unit into October.Sheldon (1950)observed that some fox families
in his central New York study area stayed together unti 1 September
and that the latest date for an occupied den was 10 July 1947.The
latest date reported for foxes at dens in Alaska is 11 August
(Magoun,pers.comm.).Findings in the Susitna area suggest that a
period of roughly one month may pass between abandonment of the den
site and dispersal of the young.This period contrasts with the
three months between abandonment of the den site and di spersa 1 in
Storm's study area in Iowa and Illinois.
Recorded di spersa 1 di stances ranged from 16 km to 64 km.Of ten
juvenile red foxes collared in 1981,nine have completely left the
3-65
area.Extensive aerial searches with radio receivers failed to
produce signals from any juvenile foxes within 80 km of their natal
dens.
Large creeks as we 11 as the Sus itna Ri ver appear to present no
barrier to foxes intent on crossing them.For example,one adult
male regularly crossed Deadman Creek,and two juvenile red foxes
crossed the even larger Susitna River in October,when slush ice
was flowing down the main channel.
(ii)Pine Marten
Pine marten are locally abundant in the vicinity of the proposed
Devi 1 Canyon and Watana impoundments.Informati on from former and
present trappers indicates that marten have historically been
important to trappers and are presently the most economically
important species to trappers in the vicinity of the impoundment
zones.
Data from aerial transects flown in November 1980 (Table 3.26)
indicate that marten are present along that portion of the Susitna
River that was surveyed (Portage Creek to Tyone River),with the
highest concentration of marten tracks between Devil Creek and Vee
Canyon.In terms of elevation,marten were most numerous below
1,000 m,probably because forested vegetation communities
(coniferous,deciduous,and mixed)are likewise r~stricted to
elevations below 1,000 m.
Diets of marten were studied by identifying food remains in scats
and in the gastrointestinal tracts of animals caught locally by
trappers.Over 450 gastrointestinal tracts and scats were
collected.Data from an earlier study in Alaska (Lensink 1954)
indicated that mice were the principal food of marten south of Lake
l'vlinchumina.Similarly,gross examination of scats at the time of
collection suggests that mice are the principal food of Susitna
marten;however,major seasonal shifts in the diet of Susitna
marten are suspected.The results of scat examination and snow
tracking also indicate that the fruits of bog blueberry,mountain
cranberry,crowberry,and prickly rose are eaten in autumn and
winter.
Based on data collected during 1980,the home ranges of three male
marten covered a minimum of 4.74 km 2 ,5.44 km 2 and
4.87 km 2 ,respectively.These estimates assume the following:
1.Creeks and the Susitna River form home range boundaries
during summer.
2.Marten home ranges do not extend above treeline during
summer.Movements of marten beyond the home ranges
depicted by some resting locations may be significant
and could indicate considerably larger home range
sizes.
3-66
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Many estimates of North American marten home ranges reported in the
literature (for example,Hawley and Newby 1957 and Lensink 1954)
are based upon capture-mark-recapture methods.Archi ba 1d (1980)
has shown that,for the same animals,home range sizes determined
by telemetry are greater than home range sizes determined from
trappi ng gri d methods.Archi ba 1d found that te 1emetry-based home
ranges for five marten over one year in age (two males,three
females)averaged 4.1 km 2 •Also using radiotelemetry,Mech and
Rogers (1977)found four marten (three males,one female)in
Minnesota to have an average home range size of 12.8 km 2 .
Data from radiotelemetry work show that fidel ity to home ranges
varies considerably.For instance,while home ranges of adult male
marten appear to be mutually exclusive,overlap with home ranges of
other sex/age class marten does occur.In addition,marten do not
readily cross bodies of water which require them to swim.Thus,
the Susitna River and larger tributary creeks form home range
boundaries for many marten.Home range data on four male marten
captured during 1980 are presented on Table 3.27 and Figure
3.21.
A female marten of unknown age and a juveni 1e male both possessed
home ranges with two centers of activity separated by several
kilometers.The highest elevation of any marten radiolocation was
810 m,but in one instance,marten scats were found at an elevation
of 970 m.As noted above,however,it appears that marten seldom
travel higher than 1,000 m.
In general,marten rest above ground during summer months and below
ground in winter.Winter resting sites of marten consist almost
exclusively of active red squirrel middens.Consistent with this
behavior,of 34 marten resting sites found during the study,26
were active red squirrel middens,two were inactive red squirrel
middens,three were red squirrel grass nests in white spruce trees,
and three were burrows or holes of unknown origin in soil.All of
these resting sites were in forest or woodland vegetation types.
(iii)Beaver and Muskrat
Beavers and muskrats occur throughout the Susitna drainage from the
delta of the SI.Jsitna River on Cook Inlet upstream along the river
and its tributaries to elevations above 1,000 m.Both species
occur in lakes and marshes from sea level to above 1,000 m.
Populations of beavers or muskrats or both are present along
slow-flowing sections of most larger creeks,particularly where
lakes drain into streams.Examples include the Stephan
Lake/Prairie Creek drainage and the Deadman Creek/Deadman Lake
drainage.
During early winter,muskrats construct small lodges,or pushups,
in the forming ice cover on ponds.These pushups are used as
feeding sites,resting areas,and defecation sites.They remain
intact until breakup and can be used as an indication of muskrat
3-67
presence and general abundance.During the spring 1980,aerial
surveys for pushups upstream from Gold Creek showed muskrats
occurred in only 27 of the 103 lakes and ponds sampled.
Trapping for beavers and muskrats has historically been common
along the Susitna below Devil Canyon,along major tributaries,
including Indian River and Portage Creek;and around larger lakes,
such as Stephan Lake.
Sign of both species is also common in suitable aquatic habitats
above timberline.Trappers'reports suggest that they seldom
pursue beavers or muskrats inhabiting alpine streams and lakes
because the reward does not justify the effort involved.While
these animals do represent an important fur resource,both species,
at higher elevations,are also particularly vulnerable to
envi ronmenta 1 a lterat ions and/or to overharvest because of their
dependence upon small,isolated riparian habitats.
The farther downstream from Devil Canyon one moves,the greater is
the beaver and muskrat use of riparian habitats along the Susitna
River.Surveys of their sign,conducted from river boats during
summer 1980 (Table 3.28)and from fixed-wing aircraft during summer
1981,indicate that between Devil Canyon and Talkeetna,beavers are
1 imited to occas i ona 1 forag i ng sites and lodges along protected
banks of the river,sloughs,and lower reaches of feeder streams.
No sign of muskrats was noted along this section of the Susitna.
Between Ta"lkeetna and l"'lontana Creek,sign of beavers is common
along sloughs,in deltas of tributaries,and along stable banks of
braided river channels.Sign of muskrats in this stretch is
limited to sloughs and marsh areas near the mouths of feeder
streams.From Montana Creek to Delta Islands,sign of beavers is
present almost continuously.The numerous islands and sloughs
provide ideal habitats for foraging,caching food,and building
lodges.
Results of this survey agree with the findings of Boyce (1974)and
Haka 1a (1952),who reported that beavers inA1aska favor 1akes or
slow-flowing streams bordered by subcl imax stages of shrub and
mixed coniferous and deciduous forests.This description fits the
area between Montana Creek and the Delta Isl ands,and the earl ier
findings were corroborated by this study.Similarly,this study
and an earlier study (Retzer 1955)confirmed that large rivers with
narrow valleys and high velocity flows,such as the area between
Devil Canyon and Talkeetna,are generally sparsely populated by
beavers.
(iv)Mink
In the upper basin,mink tracks were observed along all major
tributary creeks below 1200 m in elevation and near some streams
and lakes.A total of 34 mink tracks were counted along aerial
transects in November 1980 (Table 3.26).Of these,27 were in
riparian or lake shore habitats.In addition,mink tracks were
noted along the lower Susitna River during the downstream beaver
survey.
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(v)River Otter
Tracks of river otters were often sighted along the river,on
tributary creeks to 1200 m elevation,and around Stephan and other
large lakes.In November 1980,an unusually high incidence of
otter tracks was noted on shelf-ice along the Susitna River in the
proposed impoundment lones.A survey was carried out in which 37
points on the river between Portage Creek and the Oshetna River
were examined for the presence of otter tracks (Fi gure 3.20).
Forty-three otter tracks were present at 17 of these points (Table
3.29),Although the significance of these tracks is not clear,
they may represent upriver or downriver movements of otters prior
to freeze-up.Another possibility is that otters were concentrated
along the river to feed on grayling leaving tributaries at freeze-
up to overwinter in the Susitna River.
Other trails observed were of otters traveling cross-country,away
from bodi es of water.Such tracks may represent di spersa 1 of
subadult animals and have been noted by members of the furbearer
study team in other areas of southcentral Alaska.Loca 1 trappers
seldom take river otters because they are relatively difficult to
trap and their pelt values have usually not been high enough to
justify the effort.
(vi)Coyotes
Coyotes occur in the study area,but their distribution is genera-
lly restricted to areas downstream from Devil Canyon.No coyotes
or their tracks were observed by the furbearer team.On 12
September 1980,a coyote was heard howling a short distance south-
west of the Stephan Lake Lodge.An employee of the Alaska Railroad
at Gold Creek reported trapping one coyote and seeing tracks of
others during the winter of 1979-80.During the past several
years,coyotes have been commonly noted in the Indian River-Canyon
area,their howling heard often.Upstream from Devil Canyon,
however,coyotes are less common.None of the trappers contacted
during the course of this study reported seeing or trapping coyotes
upstream from Devil Creek.The distribution and abundance of
coyotes in the region is probably limited by wolves rather than by
habitat and/or food availability.Within their home range,wolves
are usually aggressive toward coyotes.
(vii)Lynx
Lynx occur in the study area,but their distribution is very
limited.On 19 November 1980,probable lynx tracks were observed
on the Susitna River bar across from the mouth of Goose Creek.On
22 October 1981,this area was visited by members of the furbearer
study team,and a dense concentration of lynx tracks and scats was
discovered.On 30 October 1981,two team members also found lynx
tracks at the mouth of Jay Creek,and on 3 November 1981,lynx
tracks were noted along Goose Creek 1.6 km from the mouth.Two
trappers from Glenallen reported taking lynx in the vicinity of the
3-69
mouth of the Oshetna River during winter 1976-77.Their impression
was that lynx had not been numerous before or since that time.In
the vi cin ity of the proposed impoundments,trappers reported no
sightings of lynx or their tracks.Reports from trappers in the
Gold Creek area suggest that in recent years,lynx have been
uncommon downstream from Devil Canyon.
Although,with the exception of the upper reaches of the proposed
Watana impoundment,lynx appear to be uncommon in the study area at
present,populations may have been significantly higher in the
past.The historical frequency of natural fire appears to increase
between Portage Creek and the Tyone River.It may be that in these
burned areas in the past,snowshoe hares,upon which lynx feed,
have periodically been numerous and that at those times,lynx
numbers were correspondingly higher.
(viii)Short-tailed Weasel
Short-tailed weasels are locally abundant in the study area.Their
tracks have been observed in a variety of habitat types from the
banks of the Susitna River to elevations over 1500 'm.Seven
hundred and forty-six tracks of short-tailed weasels were observed
during transect surveys in November 1980 (Table 3.26);328 (44 %)
were counted on a si ngl e transect near the Tyone Ri ver.Four
hundred and eighty-nine (66%)of the tracks were observed in
woodland white or black spruce vegetation types,and a~additional
190 (25%)were counted in medium (Betula)shrub types.Trappers on
upper Tsusena Creek,in the Fog Lakes area,and elsewhere in the
study area take short-tailed wease 1s both i ntenti ona lly and
incidentally to the trapping of other species.
(ix)Least Weasel
Observations suggest that least weasels occur sparsely throughout
the study area.Several sets of tracks believed to be those of
least weasels were observed on lower Watana Creek in March 1980.
The carcass of a least weasel taken by a trapper at Fog Lakes was
obta ined in February 1981,and alive 1east weasel was observed
near the southeast edge of proposed Borrow Area A on 25 October
1981.Whi le not abundant throughout the study area in general,
least weasels may be locally common;however,their small size and
secretive behavior make confirmation of their presence difficult.
(x)Furbearer/Habitat Relationships
Over 800 fox-habitat sample points obtained through trailing in
winter,aerial surveys (Table 3.30),and radio-tracking show that
foxes prefer two basic habitat groups:a combination of black
spruce woodland and medium shrub tundra and a combination of alpine
tundra,low shrub tundra,and mat and cushion tundra.The
vegetation types in each group were found to be in close
association in the study area.
3-70
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Habitat preferences of foxes were sampled throughout the year.The
black spruce woodland and medium shrub tundra group accounted for
46.5%of all sampled locations,and the alpine tundra,low shrub
and mat and cushion tundra group covered 48%of all locations.
Pine marten favor conifer-dominated forest and woodland habitat
types for foraging and resting.Of 1,353 marten tracks located in
identified habitat types in November 1980,605 (45%)were in
woodland black spruce,525 (39%)in woodland white spruce,54 (4%)
in mixed forest,and 29 (2%)in mixed woodland (Table 3.30).Of 34
marten resting sites located by radiotelemetry,13 (38%)were in
mixed forest,eight (24%)in white spruce forest,eight (24%)in
mixed woodland,and five (15%)in other woodland types.Although
marten do make occasional forays'into shrub tundra and marsh types,
the proximity of trees is clearly important.In late summer and
autumn,bogs and Carex marshes are important foraging sites.
Vegetation types avoided by marten include higher alpine types and
large,pure stands of deciduous trees.
In the vicinity of the proposed impoundments,beaver dams,lodges,
food caches,and foraging sites were noted to elevations above
1,000 m on many slow-flowing sections of creeks and near the
outlets of lakes.In alpine areas,willow appears to be the major
food,but some dwarf birch and alder are utilized.Along forested
banks of creeks in the impoundment zones and along the Sus itna
River below Devil Canyon,beavers prefer aspen and cottonwood where
available,although willow and some birch are utilized.Sign of
beavers is increasingly abundant along sloughs and slower-moving
channels of the Susitna River downstream from Gold Creek to Delta
Islands.
Muskrats occur in lakes,ponds,small streams,sloughs,and marshes
throughout the study area.Shallow areas with aquatic vegetation,
particularly sedges,are preferred foraging sites.
Data from aerial transects and direct observation of sign confirm
that habitats most important to mfnk in the study area,as
elsewhere,are creek and river banks,lake shores,and marshes.
For most of the winter,mink utilize areas under ice.
Results of aerial transects and direct examination of otter sign
show that otter forage almost excl us ive ly in riverine and
lacustrine habitats.Otters make use of under-ice habitats during
winter,although the extent and nature of this utilization is
unknown.
Short-tailed weasels exhibit much broader habitat preferences than
other small mustelids.Of 746 weasel tracks classified during
November 1980 aerial transects (Table 3.30),401 were found in
black spruce woodland,190 in medium (primarily Betula)shrub
tundra,88 -in white spruce woodland,and 29 in mat and cushion
tundra.Direct observation of sign supports the inference that
short-tailed weasels can meet their food and cover needs in a
variety of structurally and phytologically diverse habitat types.
3-71
Lynx appear to be concentrated in the limited riparian communities
and the recently burned areas where hares are present.
(c)Birds
Field studies were conducted during the following periods:6 July to 4
October 1980,8 to 10 February 1981,and 17 April to 23 October 1981.
Activities included helicopter surveys of raptor cliff-nesting habitat
and,during waterfowl migration,of selected waterbodies;385 party-hours
of breeding bird censusing;53 party-hours of ground censusing of water-
birds;44 party-hours of ground observations of raptor/raven nest sites;
and more than 630 party-hours of general bi rd surveys.The common and
scientific names of birds mentioned in the text are presented on Table
3.31.
.(i)Species Composition and Relative Abundance
To date,135 species of birds have been recorded in the upper
Susitna River basin study area.The relative abundance of these
species (see Table 3.32 to 3.35)is largely a function of habitat
availability,with common redpoll,savannah sparrow,white-crowned
sparrow,1ap 1and 1ongspur,and tree sparrow the most abundant
species.Redpolls are habitat generalists,while the other
abundant spec i es are bi rds of the shrub 1ands (dwarf,low,and
medium shrubs),vegetation types that cover 67%of the region (APA
1981 ).
On the basis of current information,13 species are ranked as
rare in the region:three raptors (osprey,American kestrel,
boreal owl);three species of prairie ducks (gadwall,blue-winged
teal,ring-necked duck);three sandpipers (upland sandpiper,
surfbird,sanderling);three small land birds (black-backed
three-toed woodpecker,western wood pewee,ye 11 ow warb 1er);and
ruffed grouse.Most of these birds are at the periphery of their
geographic ranges,although lack of appropriate habitat may limit
a few.All,however,are represented by 1arger,hea lthy
populations in other portions of Alaska.
An eastern kingbird,spotted on 11 July 1980,is considered
accidental in the region.In Alaska this species is a regular
visitant only in the southeast;it is casual elsewhere in the
state (Kessel and Gibson 1978).
(ii)Breeding Bird Densities
Breeding bird censuses,using the territory mapping method
(International Bird Census Committee 1970),were conducted between
20 May and 3 July 1981.Twelve square,ten hectare (25-acre)
census plots were selected in relatively uniform patches of
vegetation that represented each of the major woody avian habitats
(after Kessel 1979)present in the region.Eight early-morning
censuses were taken on each plot to determine the avian population
levels supported by the different habitats and the density of
territories of each bird species in each habitat.
3-72
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Avian population levels varied greatly among the different
habitats (Table 3.36),as,of course,did the level of use of each
habitat by different species (Table 3.37).The presence or
absence of a given species in a habitat is largely a function
of species'habitat preferences (see below),but habitat occupancy
levels are affected by a number of factors,including in interior
Alaska,habitat structural complexity and primary productivity
(Spindler and Kessel 1980).
Generally,in the upper Susitna River basin,the forest and
woodland habitats supported higher densities and/or biomasses of
birds than did the shrub communities.Highest densities in
forests were found at the downstream (Sherman)balsam poplar
forest plot,which supported 60.9 bird territoriesllO ha,and
lowest densities were found in the white spruce forest plot at the
mouth of Kosina Creek (15.7 territoriesllO ha).Of the shrub
habitats,low-medium willow shrub had the highest densities (45.4
territories/l0 ha),and the dwarf shrub-alpine tundra the lowest
«11 territoriesllO ha).Tall alder shrub was also low (12.5
territoriesllO haL Alpine tundra areas of upland cliffs and
block-fields and of mat and cushion tundra had the lowest bird
usage but supported some bird species not generally found in other
habitats.Species in the alpine tundra included white-tailed
ptarmigan,horned lark,wheatear,water p-ipit,gray-crowned
rosy finch,and snow bunting.
Prel iminary comparisons between occupancy levels in habitats of
the upper Susitna River basin and those in similar habitats in the
upper Tanana River valley (Spindler and Kessel 1980)show many
parallels.In both regions,white birch forest and the mixed
deciduous-coniferous forest supported intermediate levels of bird
populations and coniferous forest the lowest levels.The
scattered woodland and dwarf forest habitats,with their openness
and added shrub components,however,also supported intermedi ate
occupancy levels,even with major coniferous components.The
lower-height shrub thickets had low numbers of species,apparently
because of relatively simple habitat structure,and there were
differences in occupancy levels between plots with a dry substrate
and ones with high substrate moisture.Habitat diversity and a
wet substrate probably allowed higher occupancy levels on the
Susitna low-medium willow shrub plot compared to other shrub
plots.
The most conspicuous difference between the upper Susitna and
Tanana valleys was in the tall shrub thickets.Tall shrubs in
interior Alaska supported the highest avian occupancy levels of
any habitat (Spindler and Kessel 1980),but unlike the Susitna
study area,these thickets were dominated by wi llow,th-inleaf
alder,and balsam poplar,which have average to above average
levels of primary productivity.The tall shrub thickets of the
Susitna study area were composed almost entirely of American
green or Sitka alder,which have relatively low levels of primary
productivity (Spindler and Kessel 1980)and which,in interior
Alaska and on the Seward Peninsula,also support relatively few
birds (Kessel pers.obs.).
3-73
(iii)Waterbird Use of Wetlands
-Summer Populations
In respect to both numbers of spec i es and numbers of
individuals,the wetlands of the region supported relatively few
waterbirds during the summer.The relative abundance of loons,
grebes,and waterfowl determined from all observations is shown
in Table 3.32.The number and density of adults and broods of
waterbirds observed during the intensive ground surveys of 28
ponds and lakes during July are shown in Table 3.38.
The density of adult birds derived from the intensive ground
survey of 20.5 km 2 of wetlands was 23.8 adults/km 2 •By
comparison,a similar census of 13 of the more productive
waterbodies of the upper Tanana River valley,east-central
Alaska,in 1977 and 1979 showed 183.3 and 110.9 adults/km 2
of wetlands,respectively (Spindler et ale in press).Regional
comparisons of densities obtained by~e-waterbody census method
can only be made if the distribution of waterbody slze classes
is similar between regions (ibid).,which was the case for'the
sets of sampled waterbodies used here.The number of broods
directly corresponded to the low bird density,with 2.9
broods/km 2 of wetlands in the upper Susitna River Basin in
1981,compared to an average of 6.2 broods/km 2 ip the upper
Tanana River valley (ibid.).In 1979,productivity in the
eastern portion of the upper Tanana River valley study area was
30-40%lower than historical levels at some of the most pro-
ductive Alaskan wetlands,like Minto lakes and the Yukon Flats
(J.G.King,U.S.Fish and Wildlife Service,pers.comm.).
Thus,during the summer,the waterbodi es of the upper Sus i tna
River basin appear to support a relatively impoverished
waterfowl population.
The species composition of waterfowl in the region showed some
differences from that of central Alaska as a whole,in part
reflecting the subalpine nature of much of the study area.
Oldsquaw and black scoter were the most productive of the
waterfowl in 1981 (Table 3.38).Both species are pr'imarily
tundra nesters,and the Alaska Range is the only inland nesting
location known for the black scoter in Alaska (Gabrielson and
lincoln 1959).On the other hand,the pintail,which is one of
the most numerous ducks in central Alaska,occurred 'in rela-
tively small numbers in the study area,in spite of the fact
that because of severe drought in the Canadi an prairie
provinces,both 1980 and 1981 were high population years for
pintails in Alaska (King and Conant 1980,Conant and King
1981).
Trumpeter swans bred commonly at the eastern end of the study
area,from the vicinity of the Oshetna River at least to the
Maclaren River.On a random flight over the ponds of this area
on 4 August 1981,19 observations of trumpeter swans were made.
Forty adult birds were counted,including nine pairs with
3-74
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broods,totaling 28 cygnets.This area is the western edge of
the Gulkana Basin trumpeter swan population,which has more than
doubled during the past five years (J.G.King,U.S.Fish and
Wildlife Service,pers.comm.).
-Populations During Migration
Studies covered one spring and two fall migratory periods.
Aerial surveys were begun earlier and conducted more frequently
in fall 1980 than in 1981 because during the first year,it was
necessary to learn the use patterns in the region.The fall
1981 surveys were begun 1ater in September than those of 1980
and continued unti 1 most of the waterbodies were frozen.An
attempt was made to time the first 1981 survey to catch the peak
of waterfowl migration,but that effort apparently failed
because of a somewhat earlier movement of wigeon,pintail,and
scaup that year.During both fall periods,however,the
patterns of migration and of waterbody use were similar.
Summaries of the numbers and species composition of loons,
grebes,and waterfowl enumerated in the upper basin during
aerial surveys in fall 1980 and 1981 and spring 1981 are given
in Tables 3.39 to 3.41.Relative abundance rankings for
species in fall and spring appear in Table 3.32.Based on these
data,the upper Susitna River basin,which is on a high plateau
between the Alaska Range and the Talkeetna Mountains,does not
appear to be a major migration route for waterbirds (contra U.S.
Army Corps of Engineers 1977).
Scaup,including both lesser and greater scaup,were the most
numerous species group during both spring and fall.Relatively
large numbers of mallards and American wigeon also moved through
during both seasons (although the fall 1981 surveys missed the
peak wigeon migration).Pintails were common during spring
migrat i on but uncommon in fa 11.Few geese or cranes were seen
at either season.
The upper Susitna River basin was-less important to migratory
waterfowl in spring than in fall.The difference was probably
due largely to the ice breakup,which occurred after the main
spring migratory movement of many species,especially the
dabbling ducks and the common goldeneye.
During their migration,early migrants used both the Susitna
River itself and the thawed edges of lakes.Use of the region's
waterbod i es increased toward the end of May,concurrent wi th
more open water and with the influx of the later-arriving loons,
grebes,scaup,oldsquaw,scoters,and mergansers.
On 7 May 1981,an aerial survey was done along the Susitna River
from Devi 1 Canyon to Cook Inlet to ascertain the magnitude of
waterfowl use during spring migration.The results are
presented in Table 3.42.In general,comparatively few
waterfowl were noted using the river.Waterfowl abundance
3-75
appeared to increase as one progressed downstream from Devi 1
Canyon,probably because of changes "in river morphology that
correspond to various reaches of the Susitna River.That
portion of the river between Cook Inlet and the Delta Islands is
highly braided and is characterized by slow-flowing sloughs and,
thus,provi des a greater area of water su i tab 1e for waterfowl
use.The upper reaches of the ri ver,near Devi 1 Canyon,are
more channelized,faster flowing,and,therefore,less suitable
for resting migrants.
(iv)Breeding by Cliff-nesting Raptors,Ravens,and Eagles
Information on use of the region by breeding raptors and ravens
was derived from 1)helicopter surveys on 6 July 1980 and on 16
and 17 May 1981,of all cliff habitat along the Susitna River and
its tributaries,from Portage Creek (1980)and Indian River (1981)
to the mouth of the Tyone River,and on 3 and 5 Ju 1y 1981,of
habitats along the proposed access routes;2)ground visits
between 20 May and 13 July 1981 to all 1980 and 1981 active nest
sites;3)special ground and aerial searches of vegetated cliff
habitat to discover potential peregrine habitat;4)supplemental
observat ions made whenever flyi ng over or worki ng near raptor
habitat,and 5)miscellaneous observations made throughout the
study period.
During the ground visits,photographs as well as verbal
descriptions were obtained for each active nest site,and all the
cliff habitat along the river system was classified according to
its apparent quality for nest sites."A"cliff habitat had cliffs
1arge enough to support a nest,had ledges and nooks for nest
placement,and had little loose material;"B"cliffs had these
same attributes but were smaller and perhaps not large enough to
support a nest;and "e"cliffs had loose substrates (dirt and rock
banks or loose talus)and probably would not have been used by
raptors.
-Summer Populations
In all,43 raptor/raven nest sites were located during 1980 and
1981,20 of which were inactive in both years.Presumably,
these inactive sites function either as alternative sites or are
used in years of higher population levels.Of the 23 nests that
were active in at least one year,at least five were used both
years,each by the same species (Table 3.43).Active sites
during the two years of study included those of ten golden
eagle,six bald eagle,four common raven,one and perhaps two
gyrfalcon,and one goshawk.
In 1974,White (1974)found ten active nests within this same
geographic area:two gyrfalcons,one bald eagle,and seven
common ravens.He reported 14 "inactive nests,ascribing eight
to ravens and three each to golden and bald eagles.The reason
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for the substantially different species composition between the
two sets of surveys,that is,more ravens and fewer eagles in
1974,is unknown.
The density of active golden eagle nests in both 1980 and 1981
(one pair per 14.8 km )was similar to that along the Dalton
Highway through the Brooks Range in 1979 (one active nest per
15.7 km )(D.G.Roseneau,pers.comm.)--the Brooks Range having
one of the highest populations of golden eagles in Alaska.
Murie (1944),in Mt.McKinley (now Denali National Park)
National Park,found active nests as close as 1.6 and 2.4 km to
each other in 1941 and 1939,respectively.Pairs of golden
eagles regularly bui ld and maintain a number of simultaneous
nests,which they use as alternative sites in various years
(Brown and Amadon 1968),some several kilometers apart (D.G.
Roseneau,pers.comm.).It has been suggested (White et al.
1977)that local populations increase during years of higllhare
populations,but hares were relatively scarce on the upper
Susitna in 1980 and 1981.Murie (1944)also found that ground
squirrels were a major prey of golden eagles in Mt.McKinley
National Park in 1939-1941,and this species was abundant in the
Susitna area during our study.
Bald eagle densities in the upper Susitna River drainage appear
slightly lower than those of interior Alaska,where Roseneau et
al.(1981)reported 44 nests,25 active in 1980,in the vicinity
of the Alaska Highway and Tanana River between Fairbanks and the
U.S.-Canada border,a distance of approximately 480 km.
On 26 June 1981,an aerial survey was taken along the Susitna
River from Cook Inlet to Portage Creek in order to ascertain the
use of the lower river by nesting bald eagles.A similar survey
was done in early April 1980 by the U.S.Fish and Wildlife
Service (USF&WS).An attempt was made during the 1981 flight to
locate all nests previously reported by the USF&WS.During the
1981 survey,nine active eagle nests were found (Table 3.44),
five of which had previously been noted by the USF&WS.In
addition,13 bald eagles (ten adults and three immatures)were
sighted.Based on the discovery of nine nests and on the
sighting of five adult birds in the vicinity of nests which,
a lthough reported by the USF&WS,were not located duri ng thi s
survey,it is likely that a minimum of 14 to 15 active nests are
present between Cook Inlet and Portage Creek.Since weather
conditions impaired the effectiveness of the 1981 survey and
thus limited the total number of nests located,it is reasonable
to speculate that the actual number of active nests could be
closer to 20.
Compared to eagle abundance,gyrfalcons are uncommon in central
Alaska,but they nest throughout the Alaska Range.Cade (1960)
estimated the total Alaska population at about 200-300 pairs,
whereas Roseneau et a 1.(1981)thought there were more,but
fewer than 500 pair~Numbers in a given area may vary
considerably from year to year (Cade 1960,Roseneau 1972)but
probably not over large geographic regions (Roseneau 1972).For
example,gyrfalcons in northern and western Alaska have low site
3-77
fidelity from one year to the next (Cade 1960,Roseneau 1972).
In the Alaska Range,however,most sites are used every year
(Bente 1981).
There were no confirmed sightings of peregrine falcons in the
region during our study,in spite of the many hours spent in
ornithological field work and in raptor habitat.White (1974),
however,saw two individual peregrines during his June 1974
survey but found no sign of nesting.One bird was a II s ingle
adult male .•.roosting on a cliff about 4 miles upriver from
the Devil Canyon Dam axis,1I and the other was a II su b-adult ..•
about 15 miles upriver from the Devil Canyon Dam axis.1I White
(ibid.)stated that the Yentna-Chulitna-Susitna-Matanuska
dra inage bas in II seem ingl y represents an hi atus in the breedi ng
range of breeding peregrines ...,11 and Roseneau et al.(1981)
stated that lithe Sus itna and Copper rivers both provi de . . .
[very few]. . •potential nesting ~reas for peregrines.1I
Only one osprey was observed during the two seasons of study,on
23 May 1981 (John Ireland,pers.comm.)at one of the lakes near
Stephan Lake.
Breeding Chronologies
No special effort was made to obtain data o~the breeding
biology of raptors and ravens in the Susitna study area.
Because the breeding season is a period when most birds are
relatively sensitive to disturbance,attempts were not made
during this study to establish breeding chronologies for nesting
species.Table 3.45,however,shows the breeding chronologies
of eagles,gyrfalcons,and common ravens in interior Alaska.
(v)Avifauna/Habitat Relationships
A general overview of bird habitat preferences can be obtained
from the density of territories of various species in the habitats
represented by the bird census plots (Table 3.37),the assumption
being that species occur in greatest densities in their
preferred habitats.Similarly,some information on habitat
preferences can be obtained from our general surveys,in which we
recorded the number of individuals of each species seen per
kilometer in various habitats (data not shown).
The following,based on data from the bird censuses and the
general bird surveys,is a list of the most abundant species found
during the summer in each of the major avian habitats of the upper
Susitna River basin:
-Lacustrine waters and shorelines:Arctic tern,mew gull,
lesser and greater scaup,common loon
-Fluviatile waters,shorelines,and alluvia:spotted
sandpiper,mew gull,violet-green swallow,harlequin
duck
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-Upland cliffs and block-fields:gray-crowned rosy finch,
common redpoll,horned lark,American golden plover,water
pipit
-Dwarf shrub mat:water pipit,American golden plover,
horned lark,lapland longspur,rock ptarmigan
-Low shrub:savannah sparrow,tree sparrow,lapland
longspur,white-crowned sparrow
-Medium shrub:tree sparrow,white-crowned sparrow,savannah
sparrow,Arctic warbler,Wilson's warbler
-Tall shrub:hermit thrush,Wilson's warbler,fox
sparrow,white-crowned sparrow,tree sparrow
-Scattered woodland and dwarf forest:white-crowned
sparrow,American robin,Bohemian waxwing,tree sparrow,
ruby-crowned kinglet
-Mixed deciduous-coniferous forest:hermit thrush,dark-eyed
junco,yellow-rumped warbler,Swainson's thrush,varied
thrush
-Deciduous forest:yellow-rumped warbler,common redpoll,
Swainson's thrush,blackpoll warbler
-Coniferous forest:ruby-crowned kinglet,varied thrush,
dark-eyed junco,yellow-rumped warbler,Swainson's
thrush
Non-game (Small)Mammals
(i)Species Composition and Relative Abundance
Sixteen species of small mammals were recorded in the upper Susitna
River basin during the two years of study (Table 3.46).
Trapline surveys conducted during one spring and two fall periods
involved a total of 16,776 trap-nights of effort and resulted in
the capture of 1,753 microtine rodents (six species)and 1,747
shrews (four species).The two most abundant animals,constituting
67%of total captures,were northern red-backed voles,represented
by 1,382 specimens,and masked shrews,represented by 1,286
spec imens.Other shrews captured were Arctic shrews (297
specimens),dusky shrews (153),and pygmy shrews (11).Microtus
specimens included 203 tundra voles,68 meadow voles,and 75
singing voles.Brown lemmings (20)and northern bog lemmings (4)
were also taken.
Capture results from 12 sites sampled during all three trapping
periods indicated a pronounced temporal difference in small mammal
abundance (Fig.3.22).Trapping in fall 1980 resulted in 941
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captures,compared to 125 the following May and 1,231 in fall 1981.
Comparison of fall numbers shows that tundra voles were twice as
abundant in 1981 as in 1980,red-backed voles 1.7 times more
abundant,and masked shrews 1.3 times more abundant.Fall capture
numbers of meadow voles,Arctic shrews,and pygmy shrews were about
equal,while dusky shrews were sharply lower.Brown lemmings (six
specimens)and bog lemmings (three)were taken in 1981 only.The
low number of captures in May 1981 probably resulted from cessation
of breeding in late fall and from overwinter mortality.Regardless
of the temporal differences in population levels,the relative
abundance ranki ng among spec i es remai ned the same,that is,the
common species remained common and the rare continued to be rare.
Six additional small mammal species occurred in the study area but
were not caught on trapline surveys.For example,Arctic ground
squirrels were abundant and widespread in the high country,while
two other alpine species,collared pikas and hoary marmots,were
only locally common.At lower elevations,red squirrels were
fairly common.Porcupines were uncommon.Snowshoe hares,nowhere
numerous,were generally restricted to areas east of Watana Creek.
Localized II poc kets"of hares were reported in the vicinities of Jay
Creek,Goose Creek,and the Oshetna River.The scarcity of hares
in the study area was probably due more to a scarcity of suitable
habitat than to a low stage of a population cycle.Noticeably
absent from the Susitna basin were recent burns and riparian shrub
thickets,habitats most preferred by hares in other areas of
central Alaska.
(ii)Small Mammal/Habitat Relationships
Standardized trapline transects were established on sites repre-
senting the small-mammal habitats of the region.Using a cluster
analysis technique (Dixon and Brown 1979),42 trapping sites were
classified on the basis of their floristic similarity into three
main vegetation types:1)herbaceous dwarf and low shrub sites;2)
coniferous forest sites;and 3)mixed deciduous-coniferous forest,
deciduous forest,and tall shrub sites.Figure 3.23 shows small
mammal abundance patterns across this spectrum of habitat types.
Shrews and red-backed voles occupied a broad range of habitat
types.Masked shrews,the numerically dominant shrew species,were
caught on all 42 sites,while Arctic shrews were taken on 29,dusky
shrews on 23,and the locally rare pygmy shrew on only four (not
shown on figure),Generally,shrews were most abundant in balsam
poplar forest,grassland,and alder shrub communities.
Red-backed voles,the dominant microtine of the region,were
found on all but five sites,indicating this species·ecological
fleXibility.Across this broad range of occupied sites,red-backed
voles were most numerous in forest and shrubland communities,
,particularly open and woodland spruce,and balsam poplar forest.
Herbaceous meadows,especially wet sites,were generally avoided.
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Microtus species had a more restricted habitat distribution.
Tundra voles and meadow voles occurred primarily in herbaceous
me adows and bogs domi nated by sedge and grass vegetation.Such
sites included wet sedge-grass,riverine herb/low shrub meadows,
and sedge tussock seepages in black spruce woodland.Tundra voles
occurred on 22 sites,compared to ten for meadow voles,suggesting
the former species had greater habitat tolerance.Colonies of
singing voles were found only above treeline in tundra and shrub
habitats.They were most abundant in open willow-birch shrub
communities on relatively dry sites.
Brown lemmings were trapped irregularly at or above treeline in
herbaceous and shrub communities.Bog lemmings (not shown on
figure)were caught at lower elevations in wet sedge-grass/low
shrub sites (two captures),grassland (one),and near a seepage in
white spruce forest (one).
Arctic ground squirrels dominated well-drained herbaceous and shrub
tundra habitats above treeline,while collared pikas and hoary
marmots were more restricted to rock habitats at the higher eleva-
tions.Red squirrels were confined almost exclusively to conifer-
ous and mixed coniferous-deciduous forests and to woodlands within
the river basin.Porcupines were encountered in a variety of
forest and woodland communities.Snowshoe hares were in forest,
woodland,and tall shrub habitats .
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3.3 Description of Fish Resources
The baseline information described in this section is based primarily on reports
prepared by the Alaska Department of Fish and Game (ADF&G)on Susitna River
investigations conducted during the winter of 1980-81 and through 1981.These
reports incluqed studies on the adult anadromous species and on juvenile anadromous
and resident species as well as on aquatic habitat and instream flow.Previously
completed ADF&G reports and other pertinent literature have been used,where
possible,to supplement this information.
The contribution to Cook Inlet of the Susitna River above Talkeetna can be
estimated using the ADF&G 1981 salmon studies,the Cook Inlet commercial fishery
harvest information,previous ADF&G salmon studies on the Susitna River,and
standard harvest to escapement ratios for the five Pacific salmon species.
In the adult anadromous studies,the locations of the sonar counting and fishwheel
field stations are shown in Figure 3.24.The locations of the primary tributaries
and sloughs in the Sus itna River downstream of Devi 1 Canyon are shown in Fi gures
3.25 through 3.30.
For the lower Susitna juvenile anadromous and resident fishes investigations,the
study area was divided into two reporting reaches:Cook Inlet to Talkeetna,which
was the first 157 km of the Susitna,and the Talkeetna to Devi 1 Canyon segment,
which was approximately 86 km in length.Thirty-nine habitat locations and 44
sampling sites were located.These are listed in Table 3.47.
Based on a preliminary reconnaissance of the upper Susitna River basin,eight major
tributaries were selected for more detailed fisheries studies.These tributaries
were:Fog and Tsusena creeks in the vicinity of the proposed Devil Canyon
impoundment and in the proposed Watana impoundment,Deadman,Watana,Kosina,Jay,
and Goose creeks and the Oshetna River.For the purpose of this study,the first
1.6 km of these streams from their confluence with the Susitna River were
designated as habitat locations.Sampling at the confluences "included areas 90 m
upstream and downstream of the respective confluence to assess mainstem
utilization.Sampling evidence was placed on the tributaries,however,and not on
the Susitna mainstem because it ~."as thought that the tributaries contained the
major fish resource in this region during the summer._
The aquatic habitat and instream flow studies during the summer field season
involved data collection and analyses on water quality and hydrologic conditions in
addition to the mapping of designated habitat sites between Cook Inlet and the
Oshetna River.These areas included mainstem regions,sloughs,tributary
confluences,and some upstream tributary localities.In all references to river
kilometers in the text,it should be noted that distances are measured beginning
with the river mouth as river kilometer O.
Several sites in the study area were examined in greater detail than were other
areas in order to evaluate the relationships between mainstem hydraulic and water
conditions and fisheries habitat in slough areas between Talkeetna and Devil
Canyon.The study was divided into two segments:1)water quality and discharge
data collection and (2)surveying and discharge measurements.
In order that impact analyses and mitigation assessments be made,a substantial
amount of information and data generated by other project participants was
3-83
utilized.Engineering and hydrological information provided by Acres American as
well as hydrological and water quality information supplied by R&M Consultants and
the United States Geological Survey (USGS)were used in conjunction with the
available baseline fisheries data.
Since the above studies did not deal with the fish resources of the proposed
northern transmission corridor from Healy to Fairbanks,a description of those
resources is presented here.The Tanana River probably possesses the most valuable
fish resource,with chinook,chum,and coho salmon found in the system.Throughout
this northern region,several resident fish are known to occur.These include
Arctic grayling,Dolly Varden,sheefish,burbot,northern pike,and several species
of whitefish (ADF&G 1978).Fish resources in the southern segment of the
transmission line corridor are essentially the same as those discussed in the
following fish ecology report.
(a)Anadromous Species
(i)Salmon
In the following discussion of Pacific salmon species,the common
names of chinook,sockeye,pink,chum,and coho salmon have been
used.There are many other common names used throughout the
geographic ranges of these species,and their indiscriminate use
can result in a good deal of confusion.
For chinook salmon,the other most frequently used common name is
ki ng salmon.Sockeye salmon are also referred to as red sa lmon.
It should be mentioned that the land-locked form of the sockeye is
called kokanee.For the pink salmon,other frequently used common
names are humpback salmon or simply,humpback.Chum salmon are
also referred to as dog salmon,and coho salmon can be called
silver salmon.The scientific names for the salmon species
mentioned above and for all other fish species discussed in the
fish ecology report are listed in Table 3.48.
Throughout the di scuss i on of salmon,reference is made to Devi 1
Canyon's being a natural barrier to salmon migration,a phenomenon
which had previously been assumed but with little investigative
support.Fisheries and hydrologic studies conducted during the
past year have confirmed that salmon do not migrate through Devi 1
Canyon,despite the fact that fish were reported to exhibit milling
or holding behavior in the lower portion of Devil Canyon.
In the following discussions on salmon migration periods,reference
is made to the peak migration periods.This was usually determined
by plots of fishwheel catches per hour throughout the sampling
season.The time period in which the catches of individuals was
the greatest was determined to be the peak migration period.In
discussing migration time rates,these rates are valid only if
there is no fundamental variation in migrational timing between
Susitna River stocks of the various salmon species.
It is known,at least in some cases,that salmon migration rates
are influenced by variations in river discharge patterns.This
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phenomenon was seen in the fishwheel and sonar counting studies
made on chinook salmon.Comparisons of catch rates and provisional
USGS discharge data indicated a resumption of upstream migration
following periods of high water.
-Adu It
o Chinook Salmon
In the lower Susitna River~the adult chinook salmon migration
begins in late May and ends in early to mid-July.
Historically~by 1 July~90%or more of the escapement have
migrated past the Sus itna Stati on regi on ~41 km upstream of
Cook Inlet (ADF&G 1972).
Fie 1d s tudi es conducted dur i ng the 1981 se ason su bs tant i ated
that the migration run had already begun before fishwheel
sampling was operational on 19 June.As a result~the precise
onset of migration in the lower Susitna River could not be
determined.At Yentna Station~mean hourly fishwheel catches
indicated that the migration was over by 9 July.
Similarly~sonar counts made during the initial days of
operation at Sunshine Station suggested that a significant
segment of the escapement had already migrated past this
location prior to the 23 June sonar counter installation.This
occurrence was also the case at the Ta 1keetna site ~where a
sizable portion of escapement had already passed before 22
June~when the sonar counters were initially
operational.Migrating chinooks were already found to be
present at Curry~upstream of Talkeetna~on 16 June.
Fishwheel catches and sonar counter data indicated that the
peak of upstream migration at Sunshine Station occurred on 23
June and that migration ceased about 10 July.No peak
migration period could be determined at Talkeetna~but
migration had stopped by 7 July.The peak of the migration at
Curry occurred on 23 June~while the run was essentially over
in this region by July 4.Sonar counter data for chinook
salmon is shown in Table 3.49.
The majority of Susitna Station fish sampled for age analyses
were found to be three-and four-year-old individuals.Five-
and six-year-old fish were present but in smaller numbers.At
the Yentna Station~four-year-old fish~followed by
six-year-olds~were the two dominant age classes in the
migration run •
Age samples collected at Sunshine~Talkeetna~and Curry
Stations can be considered characteristic of the chinook
escapement.There was a higher percentage of younger fish~
mainly three-year-olds~sampled at Sunshine Station than at
either the Ta 1keetna or Curry Stations.Four-year-o 1d
individuals were dominant in the samples~except at Talkeetna~,
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where six-and four-year-olds were equally abundant.
Seven-year-old fish were relatively scarce at Sunshine and
Talkeetna.None was identified from the Curry Station sample.
Radio telemetry studies indicated that the confluence of the
Ta"lkeetna,Chulitna,and Susitna rivers may be a milling area
for migrating adult chinook salmon.All of the fish tagged at
the Talkeetna site (which is 165 km upstream of the confluence)
moved downstream and remained either at the confluence or
downstream of this area for several days or weeks before moving
upstream.This downstream movement was not seen in fish radio
tagged at the Curry site.
Some fish were found to enter one or more tributaries on their
migration run to their natal stream.Also,two radio tagged
individuals were found milling in lower Devil Canyon,
approximately 240 km upstream of Cook Inlet,and later entered
tributaries downstream of Devil Canyon.
Chinooks spawn in the tributaries of the Susitna River system
and do not utilize the mainstem Susitna for spawning purposes.
Some of the more notable spawning tributaries include:
Alexander Creek,Deshka River (Kroto Creek),Willow Creek,
Clear Creek (Chunilna Creek),Chulitna River,Peters Creek,
Lake Creek,and Talachulitna River.In the Susitna system
upstream of Talkeetna,Indian River and Portage Creek are
important spawning tributaries.Essentially,July and early
August constitute the spawning period for chinooks in the
Susitna River system.
The escapement counts for the east side Susitna River tributary
streams between 1976 and 1981 were rated as only "fair"to
"poor."Surveys conducted in 1981 on Indian River and Portage
Creek,however,rated the escapements for these two streams as
above average.
Given the lack of total Cook Inlet escapement data,the Susitna
River contribution of chinook salmon is not known.The basis
for estimating chinook salmon escapement is primarily index
counts of clear water tributary streams.The Susitna drainage
estimate for chinook production is in the range of 105,000 to
115,000 sa lmon.Between one and 2%of the Sus itna escapement
use the Susitna River above Talkeetna,the area of most
profound impact.
o Sockeye Salmon
Apportioned sonar counts and a summary of fishwheel catches
discussed below for sockeye salmon are shown in Tables 3.50 and
3.51,respectively.Tag/recapture estimates are shown in Table
3.52.
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At Susitna Station,the sockeye salmon migration pr-incipally
extended from 29 June to 24 August,with the midpoint of the
run occurring on 17 July.A total of 340,232 individuals were
counted by Si de Scan Sonar (SSS)counters,whi 1e 75%of the
escapement passed during a 13-day period from 11 July to 23
July.Fishwheel operations indicated that the peak migration
occurred between 10 and 19 July.
A total of 139,401 sockeye were counted at the Yentna Station.
The migration commenced on 1 July,and the midpoint of the run
was determined to occur on 16 July.The migration run had
ended by 3 August.The majority of the total fish count was
made between 12 and 23 July.Fishwheel catches indicated that
the migration peak was between 13 and 15 July.
Sonar counts at Sunshine Station totaled 89,906.The migration
began on approximately 16 July,reached a midpoint on 23 July,
and ended on 20 August.Seventy-fi ve percent of the sockeye
migrated past this location between 19 and 28 July.Based on
fishwheel,catch records,the peak of the migration occurred
between 18 and 23 July.
At Talkeetna Station,3,464 sockeye were counted.The
migration commenced on 23 July and was completed by 8 August.
The midpoint occurred on 31 July.A significant majority of
the total count was made between 23 July and 6 August.It
appeared from fishwheel catch data that the migration peak
occurred between 27 July and 1 August.
.....The Curry Station fishwheel counts
Results indicated that the migration
reached a midpoint on 5 August,and
September.
totaled 470 sockeyes.
commenced on 18 July,
was not over unt i 1 29
....
From the sonar data,the migrational timing of sockeye salmon
indicates that those fish passing Susitna Station enroute to
the Yentna River made the 10 km trip in one day or less.
Individuals migrating past Susitna Station toward Sunshine
Station covered this distance-in an average of 8 days (11
km/day)and reached Talkeetna Station in an average time of 13
days (7.4 km/day).
Tag/recapture data indicated that the minimum travel time
between Sunshine and Talkeetna Station and Curry Station was
approximately five days or a travel speed of approximately 5.6
km/day.
Based on tagging operations,population estimates were
calculated;these estimates may not accurately reflect the
actual number of fish utilizing the various portions of the
Susitna system.Sockeye population estimates derived from
tagging operations indicated that approximately 130,489 sockeye
were present at Sunshine;4,809 at Talkeetna;and 2,804 at
Curry Station.
3-87
Sockeye salmon age composition analyses indicated that a
significant majority of the sockeye samples at each station
were age 52 that is,five years old with two years in fresh
water.The second most abundant age class was 42 ,followed
by age 6 2 •Five-year-old fish comprised approximately 86%of
the return at Susitna Station and Yentna Station,73%at
Sunshine and Talkeetna Station,and 70%at Curry Station.
In the Ta"lkeetna to Devi 1 Canyon reach,adult sockeyes were
observed in Sloughs 3B,3A,6A,8A,9,9A,9B,11, 17,19,20,
and 21 and "in lower McKenzie Creek (Figures 3.25-3.30).Peak
spawning occurred during the last week of August and the first
three weeks of September.Of the locations listed,sockeyes
were most numerous in Slough 8A,9B,and 11,where peak
spawning ground counts were 177,81,and 893 sockeye salmon,
respectively.
The 20-year average Cook Inlet harvest for sockeye salmon was
1,168,198.Sockeye salmon escapement and stock separation
information for Cook Inlet show that approximately 23%of the
1979 Cook Inlet run and approximately 19%of the 1980 run were
classsified as originating from the Susitna River.
Approx imate 1y 5%of the Cook In 1et sockeye run escapes at
Susitna Station and approximately .05%in the reach above
Talkeetna.
o Pink Salmon
Apportioned sonar counts and a summary of fishwheel catches
discussed below for pink salmon are shown in Tables 3.50·and
3.51,respectively.Tag/recapture estimates are shown in Table
3.52.The adult migration for pink salmon in the Susitna River
system was found to beg"in essenti ally around 10 July and to
terminate during the third week in August.In the vicinity of
Talkeetna and Curry stations,the peak migration period lasted
from the last week of July until the middle of August.
Sonar counts at Susitna Station totaled 113~349 pinks.The
migration period started approximately on 10 July,with the
midpoint occurring on 25 July.The migration run at Susitna
Station terminated on 21 August.Seventy-five percent of the
escapement passed this region between 15 July and 29 July.
Fishwheel catches indicated that the migration peak had
occurred between 21 July and 3 August.
At the Yentna Station,36,053 pink salmon were enumerated by
the sonar counters.The migration began here on approxi-
mately 14 July;the migration's midpoint was 27 July;and its
cessation date was 20 August.Between 21 July and 2 August,a
significant percentage of the total pink salmon run counted at
the Yentna Station had passed this station.Fishwheel catches
indicated that the migration peak lasted from 21 July to 6
August.
The number of individuals counted at the Sunshine Station sonar
site totaled 72,945.The migration run did not begin at
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Sunshine Station until approximately 23 July,essentially two
weeks later than at Susitna Station.The midpoint date for
the run was 1 August,with completion on 20 August.
Seventy-five percent of the migration was counted between 28
July and 9 August.Fishwheel catches showed the migration peak
to have occurred between 29 July and 9 August.
Talkeetna Station counts totaled 2,529 pink salmon.The
migration period was found to be similar to that at Sunshine
Station:the migration run at Ta"'keetna essentially began on
27 July,reached a midpoint on 6 August and had ceased on 20
August.Seventy-fi ve percent of the escapement passed
Talkeetna Station between 29 July and 9 August.Peak fishwheel
catches occurred between 1 and 10 August.
At Curry Station,the pink migration began on 31 July,reached
a midpoint by 8 August,and terminated approximately 19 August.
Between 4 and 19 August,75%of the escapement passed Curry
Station.
Population estimates derived from tag and recapture data
indicated that approximately 53,101 pink salmon were present at
Sunshine Station;2,335 at Talkeetna Station;and 1,146 present
at Curry Station.It shou 1d be emphas i zed that these resu lts
are from the odd-year pink run,and population estimates would
be substantially higher during the even-year run.
The migrational rates based on plots of sonar and fishwheel
catch data indicated that pink salmon took an average of three
days to reach Yentna Station from Susitna Station,a distance
of approximately 10 km.This represents an average travel
speed of roughly 3 km per day.Between Susitna Station and
Sunshine Station,the average travel time was 9 days with a
travel rate of 10km/day.Travel time between Susitna Station
and Talkeetna Station was approximately 12 days with a travel
rate of around 10 km/day.Tag and recapture data on pink
salmon indicated that travel time between Sunshine and
Ta"[keetna Station ranged from .2 to 30 days.Pink salmon
averaged three days of travel time or 10 km/day between
Talkeetna and Curry Stations with a range of travel time
between one and 13 days.
Sp<;l.wning pink salmon were found in Sloughs 3A,8,and A and
also in Whiskers Creek,Chase Creek,Lane Creek,Fourth of July
Creek,Fifth of July Creek,Sku 11 Creek,Sherman Creek,Indi an
River,and Jack Long Creek (Figures 3.25-3.30).The highest
peak spawning count with-in an index area was in Lane Creek,
where 291 fish were recorded.Peak spawning occurred in a
ten-day period from 19 August to 28 August.The stream survey
counts are index counts and do not reflect total number of
spawning fish present in the stream surveyed.
The average even -year pi nk sa lmon Cook In 1et harvest for 20
years is approximately 1,671,194.It is also estimated that
85-90%of the Cook Inlet harvest originates in the Susitna.In
1981,odd-year pink salmon data were collected by ADF&G.The
20-year average for odd-year pink salmon harvest from Cook
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Inlet is 148,073 fish,but with a range of 23,963 to 554,184.
The harvest to escapement ratio of 3.8 to 1 for pink salmon
indicates that 19%of the Cook Inlet run escapes back to the
Susitna River drainage for spawning and rearing.This 19%of
the Cook Inlet run is equal to 100%of the odd-year Susitna
pink salmon that pass Susitna Station.Roughly 3%of these
fish use the area above Talkeetna for spawning.Thus,97%of
the Susitna pink salmon run use other reaches of the river for
spawning.
o Chum Salmon
Apport i oned sonar counts and a summary of fi s hwhee 1 catches
discussed below for chum salmon are shown in Tables 3.50 and
3.51,respectively.Tag/recapture estimates are shown in Table
3.52.
The chum salmon migration began during the second week of July
and ended during the beginning of September.In the Susitna
River upstream of Talkeetna,the period from late July until
the end of August was the peak migration period.Unl ike the
pink salmon,a peak migration period of seven to ten days c8uld
not be established for chum;rather,the chum migration seemed
to be distributed over a longer period of time.
A total of 46,461 chums were counted at Susitna Station by the
SSS counters.The migration arrived at Susitna Station on 10
July,reached a midpoint on 27 July,and ended on 25 August.
Seventy-fi ve percent of the escapement was counted between 15
July and 6 August.Fishwheel catches indicated that the
migration peak occurred between 3 August and 7 August.
The Yentna Stati on enumerated 19,765 indi vi dua 1s.The
migration run essentially began at Yentna Station on 13 July,
reached its midpoint on 29 July,and ceased on 24 August.A
significant majority of the fish were counted between 18 July
and 15 August.Fishwheels operated at Yentna Station
indicated that the migration run reached its peak between 20
and 23 July.
Counts at the Sunshine Station totaled 59,630 chums.The
migration run at this location commenced on 22 July,reached a
midpoint on 6 August,and ended on approximately 6 September.
Seventy-five percent of the fish were counted between 27 July
and 24 August.The peak of chum migration at Sunshine Station,
as indicated by fishwheel catches,occurred between 17 and 19
August.
A total of 10,036 chum salmon were counted at Talkeetna
Station.The beginning of the migration was approximately 28
July.The midpoint was reached on 8 August,and the migration
ended on 29 August.The majority of the escapement was counted
between 30 July and 29 August.No narrowly defined peak period
was ascertained from the fishwheel catches.
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Fishwheel catches at Curry Station indicated that the chum
migration began approximately 29 July.The runls midpoint was
16 August,and the migration terminated on 2 September.
Chum salmon averaged four days of travel time between Susitna
Station and Yentna Station for a travel speed of 2.5 km/day.
Average travel time between Susitna Station and Sunshine
Station was 10 days,which is a travel rate of 9 km/day.The
migration period between Susitna Station and Talkeetna Station
averaged 14 days or approximately 9 km/day.
Chum salmon tagged at Sunshine Station took between two and
nine days to reach Talkeetna Station.Between Talkeetna
Station and Curry Station the number of travel days ranged from
one to 24 days with an average travel time of approximately 4.5
days and a travel rate of aproximately 6 km/day.
Tag and recapture data determined that approx imate 1y 262,851
were present at Sunshine;20,385 at Ta"lkeetna Station;and
13,068 at Curry Station.Although these are estimates,the
relative abundance at the various river regions can be seen.
At each site,age 4 chum salmon from the 1977 brood year
dominated the catch,comprising,on the average,86%of the
sample.Second in abundance were age 5 fish,followed by age 3
individuals.The most noticeable difference in age class
structure occurred among the chums sampled at Curry Station.
At this site,the percentage of age 5 fish was higher than at
other locations,while the percentage of age 3 fish was lower.
Another result of this study is that chums were found to spawn
in the Susitna mainstem.Of the 12 mainstem sampling sites,
evi dence of chum spawn i ng was found at ten.Severa 1 of these
sites were located in the river mainstem of the Curry Station.
C~um salmon were present in Sloughs 1,2,6A,8,8B,Moose,
A,A,8A,9,9B,9A,11, 13,15,17,19,20,21,and 21A
(Figure 3.25-3.30).They were also found within the survey
reaches of Whiskers Creek,Chase -Creek,Lane Creek,Lower
McKenzie Creek,Skull Creek,Sherman Creek,Fourth of July
Creek,and Indian River.The peak spawning activity in the
sloughs occurred during the last two weeks of August and the
first two weeks of September.The highest counts were recorded
in Sloughs 8,8A,9,11,and 21,where 302,620,260,411,and
274 chums,respectively,were found spawning.Based on the
limited stream survey data,the peak spawning period was
approximately one week earlier than that observed in slough
spawning areas.The highest peak count in an index area was
regi stered in Lane Creek,where 76 chums were cou nted on 23
August.
Eleven chum salmon were radio tagged between 30 July and 12
August.Their movements were monitored from 30 July through
3-91
August 1981.Ten of the 11 fish were tagged between 6 and 12
August.Seven fish were tagged at Curry Station,and four were
tagged at Talkeetna Station;five were females,and six were
males.
The primary destinations of radio tagged chums were Susitna
River sloughs,clear water tributaries,and the confluence
zones of tributary streams.Four fish entered Susitna River
sloughs 21,11,Moose,and an unnamed slough near rkm 156,
respectively (Figures 3.25,3.29 and 3.30).Three fish entered
the Indian River.One fish entered Sherman Creek before
returning to the mainstem Susitna River,where it held within
4.8 km of the Fourth of July Creek confluence zone.Another
fish stayed in the mainstem Susitna River at river ki lometer
191.One individual swam down the Susitna River and entered
the Chulitna River,while another fish was last detected at
river kilometer 203.2 in the Susitna River.Radio tagged chums
entered spawning areas between 8 August and 23 August.
Maximum sustained yield total run for Cook Inlet chum salmon
harvest are estimated at approximately 1,000,000,based upon a
historic sustained harvest of 700,000 fish and a harvest to
escapement rati 0 for chum sa lmon of 2.2 to 1.The Sus itna
River proportion of the harvest,based upon historic data and
assuming that 90%of the Cook Inlet chum salmon harvest
originates from the Susitna,totals apprixmately 630,000 fish.
Thus,it is estimated that on the average,280,000 +chum
salmon return to the Susitna River to spawn each year.-This
figure means that approximately 28%of the Cook Inlet run of
1,000,000 chum salmon escapes to the Susitna.For a worst case
estimate,using 1974 data,the estimated Susitna escapement
would be approximately 150,000.Based upon available data and
ADF&G 's 1980 study program,the best estimate of chum salmon
escapement in the reach of the Susitna River above Talkeetna is
in the 20,000 to 30,000 range.This number is approximately
20%of the total Susitna run,which is considered a fairly
liberal percentage.
o Coho Salmon
Apportioned sonar counts and a summary of fishwheel catches
discussed below for coho salmon are shown in Tables 3.50 and
3.51,respectively.Tag/recapture estimates are shown in Table
3.52.
For the Susitna River system as a whole,the adult coho
migration period runs from approximately the third week of July
until early October.The coho are the last species of Pacific
salmon to migrate up the Susitna.Late July through August is
the major migrational period for the coho in the Susitna River
segment above Ta"lkeetna.Field investigations conducted in
fall 1981 indicated,however,that coho salmon were still
spawning in early October (Barrett,pers.comm.1981).
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A total of 33,470 coho sa lmon were enumerated across the SSS
counters at Susitna Station.The migration began,reached a
midpoint,and ended on 20 July,28 July,and 25 August,
respectively.Approximately 75%of the fish passed in the time
period between 23 July and 16 August.Fishwheel catches
indicated a migration peak occurring between 25 July and 30
Ju ly.
At the Yentna Station,17,017 coho were enumerated by the sonar
counters.The migration essentially began on 22 July,reaching
a mi dpoi nton 31 July and end-j ng on 20 Augus t.The major
portion of the run passed this location between 23 July and 16
August.The peak of migration,shown from fishwheel catches,
occurred between 23 July and 6 August.
SSS counters at Sunshsine counted 22,793 coho salmon.The
beginning of the migrational period was 29 July,reaching a
midpoint on 18 August and ending on 5 September.Seventy-five
percent of the migration run was counted between 4 August and
24 August.Fishwheel catches indicated a peak migration period
between 18 August and 25 August.
At Talkeetna,3,522 coho were enumerated by sonar counters.
July 30 was the beginning of the migration run,24 August the
midpoint,and 11 September the termination.The majority of
coho were counted between 11 August and 1 September.Fishwheel
catches indicated a migrational peak period occurring between
19 August and 30 August.
Curry Station fishwheel catches indicated that the coho
migration began in this location on 5 August,was at its
midpoint on 22 August,and ended on 4 September.
Population estimates derived from tagging and recapture
operations indicated that approximately 19,841 salmon were
present at Sunshine Station;3,306 at Ta lkeetna Station;and
1,041 at Curry Station.The majority of individuals sampled
for age analyses were age 43,from the 1977 brood year,
fo 11 owed by age 32,from the 1978 brood year.Less than 10%
of the coho escapement consisted of other age classes.
The average migrational travel time for coho salmon between
Sus itna Station and Yentna Stat i on was two days,whi ch was a
travel rate of approximately 5 km/day.An average of fourteen
days were required to reach Sunshine from Susitna Station.
Total travel time from Susitna Station beyond Sunshine Station
to Talkeetna Station was approximately 24 days and represented
a migration rate of 6.2 km/day to Sunshine Station from Susitna
Station and 5 km/day between Susitna Station and Talkeetna
Station.
Tag recapture of marked coho indicated that between Talkeetna
and Curry Stations,the migration took between two and 15 days
with an average travel time of 4.5 days.This was a migra-
tional rate of approximately 6 km/day.
3-93
Coho salmon were reported to spawn in the Susitna River
ma i nstem at three of the 12 study sites.At one site,coho
were found spawning in the same area as chum salmon.Two of
the three mainstem sites were located in the vicinity of Curry
Station.
Coho were also seen in Slough 9;however,the vast majority of
spawning fish were located in various tributaries.These
included Whiskers Creek,Chase Creek,Lane Creek,Gash Creek,
Lower McKenzie Creek,Fourth of July Creek,Indian River,and
Portage Creek (Figures 3.25-3.30).The highest densities of
coho,based on peak index counts,were in Whiskers Creek,Chase
Creek,Gash Creek,and Indian River,where 70,80,141,and 85
coho salmon,respectively,were recorded spawning in a s"ingle
survey.The survey data indicate that the spawning peak
probably occurred in the second and third week of September.
Ten coho salmon were radi 0 tagged from 31 August through 4
September,four at Curry Station and six at Talkeetna Station.
Coho displayed one or all three types of directional movement:
downstream,upstream,or mu 1t i -di recti ona 1.Coho movement di d
not appear to be influenced by flow conditions within the
Sus itna River.
In any case,about 8%to 10%of these fish reach the area above
Ta 1keetna.Us i ng the harvest versus escapement ratios of 2.2
to 1,the 1981 sonar counts at Talkeetna indicate that from
7,000 to 8,000 Cook Inlet coho salmon harvested for 1981 can be
attributed to this reach of the river.A significant sport
fishery exists for coho in the river above Talkeetna,but this
harvest is probab 1y a small fract i on of the total harvest and
has not been included in these figures.
-Juvenile
It should be noted that a significant portion of the discussion
on juvenile salmon is presented as the percent occurrence at
respective sampling locations.The actual number of individuals
collected at some of the sampling sites was quite small and
translates into low catch per unit effort values.These percent
occurrences are indicative of the overa~l general distribution of
the species under discussion and are not intended to present
definitive findings as to the relative abundance of juvenile
salmon in the specific habitats of the Susitna River system.
This is particularly true in regard to winter sampling data which
was minimal.
o Chinook
During the winter,the majority of juvenile chinook salmon were
captured at slough and mainstem Susitna River sites.In
summer,most of the chinook juveniles were collected at
tributary mouth sites.Two age classes,(0+and 1+)were
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identified.Age 1+,however,were not captured after July in
the Talkeetna to Devi 1 Canyon stretch and not after August in
the Cook Inlet to Talkeetna reach.
Sites associated with tributary mouths appear to provide
important milling areas for juvenile chinook salmon in the Cook
Inlet to Talkeetna reach.The change to clear water conditions
which occurs during the winter makes the Susitna River and its
sloughs primary overwintering sites as icing and lowered flow
conditions develop in the tributary streams.A more detailed
narrative is included below.
The vast majority of juveni le chinook sa lmon in the Susitna
River basin spend one winter in fresh water before migrating to
the sea.A comparison of the freshwater ages of chinook
sampled at Susitna and Yentna stations indicated that nearly
all of these fish had migrated to sea after spending one winter
in fresh water.Similarly,at Ta"lkeetna and Curry stations,
nearly 95%had migrated to the ocean after spending one winter
in fresh water.The remaining population had smolted before
their first winter at Sunshine.Only 5%of the Sunshine
Station fish sample had smolted prior to their first winter,
while 95%did so after spending one winter in the system.
Juvenile chinook salmon were captured beginning with the first
winter sampling conducted in November 1980.Surveys continued
through IVlay and pointed up the presence of rearing chinooks
from Alexander Creek upstream to Portage Creek.
Eleven of 18 (61%)habitat location sites sampled in the Cook
Inlet to Ta"lkeetna reach from November through May contained
juvenile chinook salmon.Some were collected at four of six
(67%)mainstem and slough habitat locations and at seven of 12
(58%)tributary mouth habitat location sites in this reach.
Consistent catches were observed at Sunshine Creek and Rustic
Wilderness (Figure 3.32).The highest catch rate for juveni le
chinooks in this reach occurred during March at Rustic
Wilderness,where 2.7 fish per trap were captured.
Juveni le chinooks were captured at eight of the 12 habitat
locations sampled between Talkeetna and Devil Canyon from
January through April 1981.More specifically,they were
collected at seven of eight (88%)mainstem and slough habitat
locations and at one of four (25%)tributary mouth habitat
locations in this reach.Although rearing chinooks were
consistently noted at Slough 8A,Slough 10,and Slough 20,the
highest individual catch of juveniles during winter sampling
was observed in March in an open lead at Slough 6A (Figures
3.26, 3.28,and 3.29).Twenty fish were captured in a single
trap set at this location.
Sampling took place on Indian River and on Portage Creek from
February through Apri 1 1981.Indi an River was surveyed from
its mouth to approximately 13 km upstream,while Portage Creek
was surveyed from its mouth to approximately 10 km upstream.
3-95
During March,small numbers of juvenile chinooks,all from the
1979 brood class,were observed in Indian River,while April
surveys showed the presence of both 1979 and 1980 brood
classes.The highest catch rate of 0.3 fish per trap was
recorded during March at a spot 4.3 km upstream in the Indian
River.Juvenile fish,also all from the 1979 brood class,were
likewise observed in March at Portage Creek.The highest catch
rate of 0.8 fish per trap was recorded in an area of Portage
Creek 15.2 km upstream from its mouth.
During sampling conducted in the period from 1 June to 30
September 1981 of the summer field season,juvenile chinook
salmon were captured at habitat location sites from Alexander
Creek upstream to Portage Creek.Moreover,selected fish
habitat sites located on Indian River and Portage Creek
produced catches of juveni le chinooks when sampled in June,
August,and October.During the 1981 studies,chinook
juveniles were not observed,however,above Susitna River
kilometer 238.
Juveni le chinooks were captured at 43 of 44 (97.8%)of the
habitat location sites surveyed between Cook Inlet and Devi 1
Canyon during the summer months.In fact,Kroto Slough mouth
was the only habitat location site where juveni les were not
observed.Beg inn ingin Ap r i 1,with the fir st cap t ures 0 f
juvenile chinooks from the 1980 brood year,two age classes,
age 0+and age 1+,were present.
Chinook juveni les were observed at over 50%of the habitat
location sites surveyed in the Cook Inlet to Talkeetna reach
from June through September 1981.The highest incidence of
juveniles was recorded during early July and late September,
when over 75%of the sites surveyed produced fish.Ten (37.0%)
of the habitat sites in this reach showed a 100%incidence of
juvenile chinooks for the surveys,while 19 (70.4%)of the
sites had at least at 50%incidence of occurrence.
In this reach,catches during the June through September
surveys were generally higher at tributary location sites than
those observed at mainstem river or slough sites.Catches at
tributary mouth habitat location sites illustrated a high
"incidence of occurrence throughout the summer,ranging from
60.0%of the sites sampled in early June to 93.3%in early
Ju ly.
On the other hand,throughout most of the summer in this reach,
a lower percentage of incidence was recorded at mainstem and
slough sites than at tributary mouth sites.The percentage of
incidence of juvenile chinooks in mainstem slough habitat site
catches ranged from 27.3%in early August to 87.5%in late
September.
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Two age classes of juvenile chinook salmon,0+and 1+,were
collected at habitat location sites in the lower Susitna River
from June to September 1981;these age cl asses represented
brood years 1979 and 1980.The catch per unit effort of
chinook salmon age 0+for the Talkeetna to Dev"j 1 Canyon reach
ranged from 0.0 fish per trap at Mainstem-Curry throughout the
season to a catch rate of 12.0 fish per trap recorded at Fourth
of July Creek.As the season progressed,however,an increase
in catch per unit effort of age 0+fish was apparent at most
habitat locations in this reach.This increase was most
obvious in the late September survey at Whiskers Creek Slough,
Slough 6A,Slough 10,and Slough 20 (Figures 3.25,3.26,and
3.29).As none of these sites are known spawning areas for
chinook salmon,this seasonal change indicates a redistribution
of chinooks age 0+from areas of high post-emergent density to
more favorable conditions as fish size increased and the season
progressed.
The percentage of incidence of age 0+chinook salmon in habitat
location catches in the Talkeetna to Devil Canyon reach
increased from 15%of the locations sampled in late June to 92%
of the locations in early September.
The chinook salmon age 1+catch rates recorded during the
summer in the Talkeetna to Devil Canyon reach were low compared
to those catch rates observed in this reach during the winter
surveys.Winter catch rates reached a high of 10.0 fish per
trap compared to a high of 0.4 fi sh per trap for summer
surveys.This reduction in catch rate indicated that a
majority of age 1+chinook salmon had moved out of the
Talkeetna to Devil Canyon reach prior to the initiation of
sampling in early June.
Age 0+chinook catches were recorded at 80-100%of the
tributary mouth habitat locations surveyed from early July
through 1ate September.As the season progressed,mainstem
slough habitat location catches indicated a net increase in
percentage of incidence from a low of 20.0%in late June to a
high of 87.5%in early September.Age 0+chinooks appeared to
extend their distribution from tributary streams and stream
mouth sites into mainstem and slough sites as the summer
advanced.Indian River mouth was the only habitat location in
this reach producing chinooks age 0+for 100%of the surveys.
Chinook salmon age 1+were observed at 45%of the sites
surveyed during the first two weeks of June.This figure
decreased through late July,however,and these chinooks
completely disappeared from this reach prior to the early
August survey.It is presumed these age 1+chinooks were
smolts undertaking a seaward migration,with the peak movement
occurring prior to the early June sampling.No chinook salmon
age 1+were captured between Talkeetna and Devi 1 Canyon after
the last two weeks of July.
3-97
At Indi an River selected fish habitat sites,juveni le chinook
salmon were captured during all three sampling periods.All
sites sampled in August and October recorded the presence of
juvenile chinooks,with the highest catches occurring in August
at site 2,11.5 km up the Indian River,where 7.0 fish per trap
were observed.Indian River selected fish habitat site 3A,
19.2 km up the Indian River,produced the highest catch in
October -1.9 fish per trap.
No juvenile chinooks were captured in Portage Creek during the
June survey.The highest catch for Portage Creek was observed
at site 1 (7.2 km up Portage Creek)in August where 10.4
chinook salmon age 0+per trap were recorded.In October,the
fish per trap at this site had decreased to 4.4.
Two age classes of juvenile chinook salmon were present in
habitat site catches made during early June between Cook Inlet
and Talkeetna.Analysis of length frequency composition for
3,646 juvenile chinook salmon measured by two-week period$from
June through September indicates that age 1+chinooks were no
longer present in this reach after August 31.On the other
hand,age 0+chi nook salmon remained throughout the summer.
The range of lengths for age 0+and age 1+can be approximated
from the length frequency data;however,it is .impossible to
determine the extent of overl ap or to establ ish accurately a
point of division between these two ages of chinook salmon in
the Cook Inlet to Talkeetna reach of the Susitna River.
o Sockeye
Winter sampling in March and April produced 25 sockeye fry at
Slough 11,one individual each at Slough 9,and an individual
downstream of Talkeetna.Sockeye fry were collected at
Alexander Creek,Birch Creek,and Cache Creek in September.
The outmigration period for sockeye is thought to occur during
May and June.
o Pink
In both Slough 11 and Indian River,sac fry of pink salmon
appeared on 23 March.Pink salmon fry were collected at
Mainstem Slough,Slough 8A,Fourth of July Creek,and Slough 10
during June and July.The outmigration period for pink salmon
occurs primarily during the month of May.
o Chum
Approximately 1,700 juvenile chum salmon were captured during
the sampl ing effort conducted in the summer field season of
1981.Beach seining at Slough 11 (Gold Creek area)on 19 June
accounted for 1,650 chum fry,while 13 chum fry were captured
by beach seine in Slough 19.Chum fry were also captured in
Alexander Creek during July.The outmigration period for chum
salmon is believed to occur during May and June.
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a Coho
Juveni le coho salmon were co llected throughout the study area
with the majority of individuals captured at tributary mouth
sites during both winter and summer.Between Talkeetna and
Devil Canyon,the occurrence of individuals was greater at
slough sites in the winter and at tributary mouth sites in
summer.Three age classes (0+,1+,2+)were identified.Age
2+individuals were not captured after May in the Talkeetna to
Devil Canyon reach and not after mid-June in the Cook Inlet to
Talkeetna reach.A detailed narrative of these findings is
given below.
Age c1 ass determi nati ons were made by correlating camp 1emen-
tary length/frequency and scale analysis data.Discussion of
distribution and relative abundance is provided by age class
for juvenile coho salmon in the Talkeetna to Devil Canyon reach
only.Because of the extensive overlap in lengths for age
classes of juvenile coho captured downstream of Talkeetna,
distribution and relative abundance of all age classes will be
discussed collectively for this reach.
Juveni 1e coho were captured at a total of 11 of the 18 (51ro)
habitat location sites sampled in the Cook Inlet to Talkeetna
reach from November to May.During this time,juveni 1e coho
were collected at two of six <33%)mainstem habitat location
sites and at nine of 12 (75%)tributary mouth habitat location
sites.Juvenile coho salmon occurred in greater than 40%of
the habitat location site catches each month from November to
May,except during December and April,when no catch was
recorded.
The highest individual catch per unit effort for the Cook Inlet
to Talkeetna reach was 1.2 fish per trap day,observed at the
mouth of Sunshine Creek.Relatively high catch rates were also
recorded in January and again in March at a side channel
habitat location site located near Rustic Wilderness and in
November,at the mouth of Montaoa Creek.
From December 1980 to April 1981,juveni le coho were captured
at six of the 12 (50%)habitat location sites sampled between
Talkeetna and Devi 1 Canyon.During this t"ime,juveni 1es were
collected at five of eight (62%)mainstem habitat location
sites and at one of four (25%)tributary mouth habitat location
sites.Of these latter four sites,only Whiskers Creek,
sampled during March contained any juvenile coho.In addition,
no juveni 1es were encountered at the mouths of Lane Creek,
Indian River,or Portage Creek in 1980-81 winter sampling.
Juvenile coho salmon were present,however,at 50%or more of
the mainstem and slough habitat location sites sampled in the
Talkeetna to Devi 1 Canyon reach each month from February 1981
to April 1981.No juvenile coho salmon were collected during
January at any habitat location sites upstream from Talkeetna.
3-99
Five selected fish habitat sites on Indian River,with the
farthest upstream being 12.8 km,and six selected fish habi-
tat sites on Portage Creek between 4.8 km and 18.9 km upstream
were sampled in February,March,and April 1981.Although a
single juvenile coho was collected at Indian River (1.8 km
upstream)during April,no juveniles were encountered in
Portage Creek in any of these months.
The highest individual catch per unit effort was 8.0
fish per trap,observed at Slough 6A in March 198!.
Relatively high catch rates were also recorded at Whiskers
Creek mouth in March and,also in March,at Slough 8A.
From June to September 1981,juvenile coho salmon were
collected at 86.7%of the habitat location sites in the lower
Susitna River.These sites extended from the mouth of
Alexander Creek to the mouth of Portage Creek.Catches of
juveni le coho were also recorded at selected fish habitat
sites at Indi an River and Portage Creek during August and
October.
In the Cook Inlet to Talkeetna reach,from June to September,
juvenile coho salmon were collected at 25 of the 27 (92.6%)
habitat location sites.The incidence of juveniles in catches
at habitat location sites ranged from 42.9%in late June to
83.3%in early September.Juvenile coho catches were recorded
at all (100%)of the tributary mouth habitat location sites in
the Cook Inlet to Talkeetna River reach one or more times
during the summer of 1981.The incidence of juvenile coho
salmon in catches at tributary mouth habitat location sites
ranged from 66.7%in late June to 100%in late August and
early September.
Catches of juvenile coho were recorded at 82%of the mainstem
and slough habitat location sites in the Cook Inlet to
Talkeetna River reach from June to September.The incidence
of juvenile coho salmon at mainstem and slough habitat
location sites ranged from 11.1%in late June to 62.5%in late
September.
Below Talkeetna,the highest catch per unit effort,41.0
juvenile fish per trap,was recorded at the mouth of Caswell
Creek in late August.Relatively high catch rates were also
observed from late July to early September at the mouths of
Birch Creek,Sheep Creek Slough,Sunshine Creek,and Montana
Creek.In the Talkeetna to Devi 1 Canyon reach from June to
September,juvenile coho were collected at 13 of the 17
(76.5%)habitat locations.
Two age classes of juvenile coho salmon,1+and 2+,from brood
years 1978 and 1979 were captured at habitat location sites in
the lower Susitna River from November 1980 to May 1981.Age
0+coho salmon,offspring of brood year 1980,were collected
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at 12 of the 17 (70.6%)Talkeetna to Devi 1 Canyon habitat
locations,while age 1+were observed at seven of the 17
(41.2%)sites.No juveniles from brood year 1978 (age 2+)
were observed in Talkeetna to Devi 1 Canyon habitat locat'ion
catches during the summer 1981.Age 0+coho distribution
progressively increased from early June through the summer and
was most extensive in early September,when the fish were
collected at 53.9%of the habitat locations upstream from
Ta-Ikeetna to Devi 1 Canyon.The incidence of age 1+coho
salmon it'!catches at habitat locations ranged from 11.8%in
late July and late September to 30.8%in early September.
Throughout the summer,occurrence of age 0+fi sh was more
consistent at tributary mouth locations than at mainstem or
slough locations.During this same period,age 1+coho
appeared in a lower percentage of both tr-ibutary mouth and
mainstem-slough habitat locations.
Age 0+coho were also observed in Indian River and Portage
Creek at selected fish habitat sites.Distribution was more
extensive,however,in Indian River,where age 0+coho were
co 11 ected from Indi an Ri ver at 4.3,11.4,and 19.2 km up-
stream.Age 0+fi sh were observed in Portage Creek (7.2 km
upstream)only once during the season in October.
The highest age 0+coho catch per unit effort,7.0 fish per
trap,was recorded at Whiskers Creek in late August.Com-
paratively high age 0+catch rates were also recorded at
Whiskers Creek mouth during each two-week interval throughout
the summer.Relatively high catch rates for age 0+coho
salmon were likewise recorded at Slough 6A and Fourth of July
Creek during August and September and at Indian River,19.2 km
upstream,in August.
The highest age 1+coho catch per unit effort,0.6 juveniles
per trap,was recorded at both Whiskers Creek during early
July~nd at Slough 6A during late August.Consistent catches
were recorded throughout the summer at both these sites.
(ii)Other Anadromous Species
Bering Cisco
Prior to this study,Bering cisco were not known to inhabit the
Susitna River.Bering cisco were first captured at river
kilometer (rkm)126 by the lower east bank fishwheel at Sunshine
Station on August 25.The fishwheel catch rate on cisco
gradually increased unti 1 it peaked between 17 and 21 September.
At IViainstem Slough and the mouth of Kroto Slough,Bering cisco
were taken by gill net on 10 September and again at Mainstem
Slough on 14 and 28 September.
Electrofi s hing conducted 25 September through 15 October
demonstrated that Bering cisco were dispersed in the Susitna
River from rkm 112 to rkm 161 (measured from the mouth of the
3-101
Susitna).Relatively large numbers were located near Sunshine
Station,Montana Creek,and the mainstem west bank at rkm 119.
One hundred ninety Susitna River Bering cisco were aged.The
majority of fish were age 4 (88%),with the remaining age 3 (9%)
and age 5 (3%).
Sexually mature Bering cisco were captured from habitat
locations over a 112 km reach of the Susitna River.Although
spawning sites may generally occur throughout this reach,
electrofishing surveys were only able to identify three areas of
spawning concentrations.These sites were opposite Sunshine
Station,opposite the mouth of Montana Creek,and at rkm 119 to
rkm 120 of the mainstem along the west bank.
Susitna River Bering cisco appear to be the anadromous form.The
fish captured and identified were evidently undertaking their
spawning migration,as no substantiated occurrence of the species
was noted prior to 25 August 1981.The fish evidently began
their spawning migration up the Susitna River from Cook Inlet in
August and arrived at the Sunshine Station fishwheel sjte over a
five-week period from August 25 to September 30.Fish captufed
by the fishwheel during this time were all bright silver and
appeared to be sexually mature;although,with normal handl ing,
they did not produce a discharge of eggs or milt.
From 4 through 7 October,relatively large numbers.of Bering
cisco,dispersed along gradually sloping gravel bars in the
Montana Creek-Sunshine Station area,were located by electro-
fishing.Random necropsy showed all fish to contain mature sex
products,but none had yet spawned.
Electrofishing was again conducted in the l'vlontana-Sunshine area
from 13 through 15 October.All fish handled on these dates
freely expelled either eggs or milt or were already spent.From
these observations,spawning appeared to peak during the second
week of October.
-Eulachon
Eulachon are known to utilize the Susitna River system at least
as far upstream as the Deshka River-Susitna River confluence.
The eu 1achon is an anadromous member of·the sme 1t fami ly but
spends most of its 1ife in the marine envi ronment.Adults are
believed to live at moderate ocean depths in the vicinity of the
echo-scattering layer and in proximity to shore.In the northern
portion of its range,spawning does not occur until May.
Upstream migration from the ocean begins when river water
temperatures reach approximately 4.4°C and ceases as temperatures
exceed 7.8°C.The migration runs usually take place in larger
rivers (such as the Susitna mainstem),but spawning grounds may
be located in tributary systems.The timing of the Susitna River
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migration run and the location of spawning grounds have not been
determined.A compilation of life history and ecology
information by Terrestrial Environmental Specialists,Inc.(APA
1981)contains additional details from available literature on
the eulachon.
(b)Resident Species
(i)Impoundment Zones and Vicinity
The following section describes the fisheries resource of the upper
Susitna River basin in the proposed impoundment regions.Of
greatest significance was the presence of sizeable grayling
populations throughout the tributaries.In general,though,
information on the Susitna mainstem in this region remains
limited.
The numbers of individuals of several species,including burbot,
round whitefish,longnose suckers,and cottids,are rather small.
It is not known whether this is because of the limited populations
of these species,to sampling site locations,or to sampling effic-
ency.As a result,conclusions drawn from the information present-
ed are preliminary.
-Arctic Grayling
During the 1981 studies of the Upper Susitna River,3,279 adult
Arctic grayling over 135 mm fork length were captured.Table
3.53 lists grayling catches by tributary and month.Arctic
grayling were collected at 100%of the habitat location sites in
the upper Susitna River during the 1981 season.
The population estimate for Arctic grayling in the upper Susitna
River study area calculated at the 95%confidence level (4dO,
is 10,279 with a range of 9,194 to 11,654.This population level
would give an average of approximately 501 adult grayling per
clearwater tributary mi le or 121 per _river mile incl uding the
main Susitna,to be inundated.Tagged grayling demonstrated
interchange between tributaries using the main Susitna as a
migratory corridor.
Kosina Creek has the highest estimate for an individual tributary
at 2,787 (range 2,228-3,720)followed by the Oshetna River at
2,017 (range 1,525-2,976).Fog Creek had the lowest estimate at
176 (range 115-369).No estimate is listed for Watana Creek,
although Watana is included in the study area total estimate,
because the low number of tagged fish recovered would have
resulted in an estimate with an unacceptably wide range of
values.
Three hundred eighty-one upper Susitna River Arctic grayling from
hook and line and gill net catches were aged by using scale
analysis.These fish ranged from age 1 to age 8;age 5 and age 6
3-103
were dominant,comprising 33.9%and 31.5%of the sample,
respectively.
Arctic grayling examined during May and early July exhibited spent
gonads and frayed dorsal and caudal fins,indicating that they had
already spawned.Fish in this condition were collected at the
mouths of the tributaries.
In the course of the upper Susitna River study,a total of 2,652
Arctic grayling were tagged and released during 1981.As a result,
there is some indication of Arctic grayling -intrasystem migration
in the upper Susitna River drainage.Preliminary analysis
indicates not only a wide range of movement within the individual
tributaries but also inter-tributary migration.
-Lake Trout
Lake trout were found only in Sally Lake and Deadman Lake (Figure
3.35,two selected fish habitat sites in the upper Susitna River
basin,both of which support a limited sport fishery.Of these two
sites,only Sally Lake will be inundated by the proposed Watana
impoundment.All 1ake trout were captured by gi 11 net and rod and
reel and all within 39 m of the shoreline in less than 1.8 m of
water.Gear was fished at various depths of up to 12 m -in Sally
Lake.A total of 35 lake trout were captured,32 in Sally Lake and
three in Deadman Lake.All Deadman Lake fish were captured by hook
and line,while gill nets produced the greatest results in Sally
Lake.Catch per rod and reel hour was highest in Deadman Lake,
where it was 0.75/hour.
Scales were taken from 19 lake trout collected in Sally Lake.Only
seven scales were readable,and all of these were age 5.During
mid-August,both pre-spawning and post-spawning lake trout were
captured in Sally Lake.
-Burbot
Burbot were collected at all eight upper Susitna River habitat
locations between May and September 1981.The percentage of
incidence of burbot in sampling catches ranged from 50%of the
locations sampled in May to 100%of the locations sampled in July.
Catch rates for all streams combi ned var i ed from 0.53 burbot per
trotline day in May to 0.95 in September.The second highest catch
rate,0.73 burbot per trotline day,was recorded in July.Although
sampling was also conducted upstream in the tributary study areas,
all burbot catches were made in the Susitna mainstem,immediately
up-or downstream of the tributary confluences with the Susitna.
Jay Creek,with a May to September average catch rate of 1.14
burbot per trotline day and total catch of 32 burbot,was the most
consistently productive habitat location,followed closely by
Watana and Goose creeks.
3-104
Oto 1iths were
determination.
bur bot caught,
res pect i ve 1y.
-Round Whitefish
removed from 54 burbot and analyzed for age
Age cl asses 4,5,and 6 made up the majority of
comprising 25%, 20%,and 35%of the sample
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Round whitefish were captured at all habitat locations sampled in
the upper Susitna River system,except Fog,Deadman,and Goose
creeks.Jay and Kosina creeks were the most productive.The
percentage of incidence of round whitefish at habitat locations
ranged from 33%in July to 7%in September.The capture of 47
juvenile round whitefish (18-52 mm)at Jay Creek was achieved by
using seines and electroshockers.
Twenty-two upper Susitna River round whitefish from gill net
catches were aged by scale analysis.Ages ranged from 6 to 8,
with age 7 encountered most frequently.
-Longnose Sucker
Longnose suckers were found in all habitat locations except Fog
and Tsusena creeks.All adu 1t suckers were captured in gi 11 nets
set immediately upstream or downstream of the confluence of the
tributary streams.A total of 144 suckers were captured from May
to September.The mouth of Watana Creek produced cons i stent
catches of suckers for a tota 1 of 75.In Ju ly suckers were
caught in all habitat locations fished.(Kosina and Fog creeks
were not fished.)This species was caught in 25%of the habitat
locations fished in May and in September.
Scales of 90 upper Susitna River longnose suckers were removed and
analyzed.Age classes 7,8,and 9 made up the majority of long-
nose suckers and comprised 25%,36%,and 20%of the sample,
respectively.Juvenile longnose suckers (24-105 mm)were captured
in sloughs and backwater areas of the Susitna River at Jay.
Kosina,and Watana creeks.
-Sculpins
Thirty-eight sculpins were taken during 352 minnow trap days from
upper Susitna River reach habitat locations.Habitat locations
associated with clear water and other tributaries were most
productive.The catch rate from May to September 1982 was
O.ll/trap day.The largest numbers of sculpins were recorded for
Fog Creek.Tsusena Creek.and the Oshetna River,with total
catches of 8,9,and 10.respectively.Tsusena Creek had the
highest catch rate at 0.23/trap day,while no sculpins were
captured at Jay Creek during this study.Sally Lake,a selected
fish habitat site,was minnow trapped only during May and resulted
in the collection of four sculpins .
3-105
-Miscellaneous Species
During the course of the 1981 field studies,a single specimen
each of humpback whitefish and Dolly Varden was captured.The
humpback whitefish was a male,347 mm fork length taken at the
mouth of Kosina Creek on September 24.The single Dolly Varden
was taken at the mouth of Fog Creek on 25 Augus t.Th is fi sh was
also a male,235 mm fork length.Possible occurrences of the
Alaska whitefi shand 1ake whitefi sh have been reported in the
Susitna River drainage (McPhail and Lindsey 1970,Williams 1968).
As discussed below,these two species are not readily distingui-
shed from the humpback whitefish.The presently known range of
the humpback whitefish in Alaska is restricted to rivers which
empty into the Bering,Chukchi,and Beaufort seas (Morrow 1980).
Dolly Varden are known to be present in this portion of Alaska
(Morrow 1980).
(ii)Downstream (below Devil Canyon)
-Arctic Grayling
Arctic grayling were first captured at rkm 150,1.6 km southwest
of the head of Birch Creek Slough on 19 February 1981.Throughout
the winter months,gill netting under the ice infrequently
produced grayl ing.Gi 11 net catches of adul t grayl ing increased
sharply from 1 to 15 May at the mouths of the Deshka.River and
Cache Creek Slough.After 15 May,catches declined at all habitat
locations on the Susitna River between Cook Inlet and Devil
Canyon.Incidence of Arctic grayling,however,principally
juveni le and immature,ranged from 10%to 20%of the 44 habitat
location sites sampled during each two-week period throughout the
summer months.In September,catches of adult grayling at
tributary mouths increased.At that time,relatively large
numbers of these fish were located on the Susitna River at
Kashwitna River,Montana Creek,Birch Creek Slough,Lane Creek,
Indian River,and Portage Creek.
Age determinations were made on 174 Arctic grayling caught on the
Susitna River between Alexander Creek and Portage Creek.These
fi sh ranged in age from age 0+to age 10.The most preva 1ent age
classes captured were age 5 (17.9%)and age 6 (23.4%).
Arctic grayling began their spawning migration in the Susitna
River in late April and a substantial increase in grayling catches
by gill net was noted at the mouths of the Deshka River and Cache
Creek between 1 May and 15 May.Necropsies showed most of the
fish were sexually mature,but since manipulation of the fishes'
abdom"j na 1 caviti es produced no mi It or eggs,the fi sh were not
fUlly ripe.
No evidence of Arctic grayling spawning was found at any sampling
locations between Cook Inlet and Devi 1 Canyon during the 1981
season.It can only be speculated that the adult Arctic grayling
from the Susitna River migrate into non-glacial tributaries to
spawn some time in late April or May.
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-Rainbow Trout
Rainbow trout were collected at seven tributary and four mainstem
habitat location sites along the Susitna River from Alexander
Creek to Slough 10 (rkm 214)from November 1980 to May 1981.This
species did not appear consistently in catches from any of the
locations sampled,but low densities of rainbow trout appeared
throughout the winter months.
Rainbow trout were captured at a total of 89%of the habitat
locations in the Cook Inlet to Devil Canyon reach.The percentage
of incidence of catches in the Cook Inlet to Talkeetna and the
Talkeetna to Devil Canyon reaches was 81%and 94%,respectively.
In the Cook Inlet to Talkeetna reach,the percentage of incidence
of catches at habitat location sites ranged from a low of 7%
during the first two weeks of A~gust,to a high of 50%during the
first two weeks of September.
The incidence of rainbow trout in habitat locations sampled
remained in the 20%to 30%range from the first of June through
30 July and again from 15 August to 30 August.The low percentage
of incidence occurring from 1 August to 14 August was probably due
to coinciding high water levels and the resulting ineffectiveness
of the sampling gear.
Habitat locations associated with tributary streams produced
higher catches per unit effort than did the mainstem locations.
Cons i stent catches of rainbow trout were recorded at Anderson
Creek,Alexander Creek,and Deshka River habitat location sites.
Catch per gill net at Anderson Creek rose to 9.0 in late
September,while during the last two weeks of August,highs of 1.0
and 0.8 fish per trotline were reached at Alexander Creek and the
Deshka River,respectively.
In the Talkeetna to Devil Canyon reach,the percentage of
incidence of rainbow trout catches at h9.bitat locations ranged
from 77%during late June and again in early September,to a low
of 18%in early August.The June peak is probably due to the
presence and movements of spawning fish~while the high in
September reflects movement downstream to winter habitat.
The low percentage of incidence in early August,as in the Cook
Inlet to Talkeetna reach,was probably caused by high flood stage
waters and associated factors.Rainbow trout were captured at all
habitat locations,with the exception of the mainstem site below
Portage Creek.The most consistent catches occurred at tributary
mouth and slough habitat locations.Catches per gi 11 net ranged
from 0.0 to 6.0 per day at tributary and slough locations,with
the high of 6.0 rainbows per day recorded at Whiskers Creek Slough
during late June.Hook and line catches produced highs of 2.0
3-107
and 7.0 ra"inbows per hour at Portage Creek and Whiskers Slough,
respectively.High catches per unit effort at Whiskers Creek and
Whiskers Slough in June are attributed to the presence of
spawning rainbows.
One hundred eighty-four Susitna River rainbow trout collected
from Cook Inlet to Devil Canyon by fishwheel,trotline,electro-
fishing,and hook and line were aged using scale analysis.Age
classes 3,4,and 5 made up the majority of the fish at 30.8%,
32.0%,and 19.9%of the total sample,respectively.The age
class composition was similar for each report"ing reach of the
lower Susitna River.Rainbow trout in the age sample ranged from
age 1 to age 7.
-Burbot
From November 1980 through May 1981,burbot were captured by
various sampling gear placed in the Susitna River at a total of
42 habitat locations and selected fish habitat sites beginning at
the mouth of Alexander Creek and extending to a mainstem site at
rkm 118.
Habitat locations and selected fish habitat sites downstream of
Talkeetna,particularly the mouth of the Deshka River,the mouth
of Alexander Creek,and four mainstem sites located at rkm 16,
69,97,and 134,yielded the highest catch rates.
Burbot were occasionally encountered in habitat locations or
selected sites located upstream of Talkeetna during the winter
and those catches were made exclusively at mainstem sites.The
mainstem site opposite Curry recorded the highest catch rate of
all sites above Talkeetna.
The distribution of burbot in the Cook Inlet to Talkeetna reach,
as indicated by the percentage of habitat location sites
recording catches of burbot by any gear type,appeared to
increase as the summer progressed.Burbot catch rates generally
remained low and varied through June and July at most habitat
locations.One location,a large,stable eddy located just
upstream of the Parks Highway bridge,recorded the most
consistent catches of burbot throughout the year.During August
and September,catch rates generally increased,and the percent-
age of habitat locations recording catches of burbot rose to a
maximum of 88%for the first two weeks of September.In
addition,burbot were also abundant at the mouths of the Deshka
River,Alexander Creek,and the Birch Creek Slough.
The incidence of burbot catches in the Talkeetna to Devil Canyon
reach decreased steadi ly from early June to mid-July when only
mainstem sites at rkm 193,198,and 235 were producing catches.
After July 16,the percentage of habitat location sites recording
catches sharply increased,while sloughs,creek mouths,and
mainstem sites all recorded catches of burbot.
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The catch per unit effort from June to September vari ed from 0.0
to 3.0 burbot per trotline day.Throughout the reach upstream of
Talkeetna,the mainstem site 3.2 km below Portage Creek and a
mainstem site at rkm 183 were the most productive,while Slough
11 and the mouth of Whiskers Creek recorded the lowest catches.
At no time during this period of sampling did a stream mouth site
s how any cons i stent catch per un it effort except for Lane Creek
in late August and September.Lane Creek is a clear,cold
tributary that,until the last two weeks of August 1981,flowed
straight into the Susitna River.At that time,the creek changed
course and began fl owi ng into a slough channel of the Sus itna
River.After thi s change,the catch per unit effort increased
and stayed fairly consistent until the end of September.
Sma 11 but cons i stent catches of juvenil e burbot were recorded
during late August and September at both the mouth of the Deshka
River and the mouth of Alexander Creek.Juvenile burbot were
occasionally found at only six other locations from Cook Inlet to
Devil Canyon during this study.
Electrofishing surveys conducted during August,September,and
October 1981 succeeded in locating burbot in mainstem and slough
channels of the Susitna River from rkm 70 to rkm 160.Catch
rates varied from 0.0 to 12.8 burbot per hour,but as these
surveys were not designed to reflect relative abundance of
burbot,the results could only be used to further document the
distribution.
Age classes 4,5,and 8 made up the majority of burbot,and
comprised 14%,11%,and 12.5%of the sample,respectively.Of
Of the burbot used for age determi nat ion,age 4 averaged 407 mm
(range 303-520 mm),age 5 averaged 439 mm (range 365-620 mm),and
age 8 averaged 559 mm (range 465-647 mm).
Burbot are known to spawn from mid-December to early April.
Female burbot collected in the Susitna River beginning in early
Septmber were observed with well-developed eggs.Throughout June
and through September,both sexually mature and immature burbot
were observed.
-Round Whitefish
Round whitefish were captured at only four habitat locations
during winter studies from November 1980 to May 1981;all of
these sites were located downstream of Ta"lkeetna.Small numbers
of round whitefi sh were taken in gi 11 nets set at the mouth of
Sunsh i ne Creek in March and agai n in gi 11 nets set dur i ng May at
the mouths of the Deshka and Kashwitna Rivers as well as in Cache
Creek Slough.As indicated by the direction from which they hit
the nets,the fish were all captured while moving upstream.
3-109
The presence of round whitefish near the mouths of tributary
streams in March and May,after no catches were made in these
same locations during November through February,indicated a
general pattern of movement into these areas and on into these
tributaries.
Round whitefish were collected at 30%of the habitat location
sites sampled from Cook Inlet to Talkeetna during the first two
weeks of June.The mouth of Sunshine Creek recorded the highest
catch rate of all gear types,5.5 fish per gill net night.After
June 15,the incidence of round whitefish in habitat location
catches downstream of Talkeetna dropped to between 0.0%and 11.1%
of location sites sampled until the last two weeks of September,
when catch incidence rose to 45%of all sites sampled.During
these weeks,round whi tefi sh were co 11 ected at three mai nstem
sites and six tributary mouth sites downstream of Talkeetna.
Round whitefish were more consistent "in sampling gear catches
above Talkeetna from June through September.The inci dence of
round whitefish catches ranged from 17.6%to 44.4%during June
and July,then dropped to 0.0%in the first two weeks of August.
The incidence of round whitefish in catches remained below 10.0%
of sites sampled until the last two weeks of September when 35.3%
of sites sampled recorded catches of round whitefish.The
highest and most consistent catch rates were recorded at sloughs
6A and 10 and at the mouths of both Indi an River af'ld Portage
Creek.
Forty-five Susitna River round whitefish,from fishwheel,gi 11
net,and electrofishing catches made from Cook Inlet to Devi 1
Canyon,were aged using scale analysis.Round whitefish analyzed
for age composition ranged from age 0+to age 8,with age 4 being
encountered most often.
-Humpback Whitefish
(In the discussions pertaining to the resident fish species of
the Susitna River Study area,ADF&G has listed three species of
whitefish as humpback whitefish.The three species are the
humpback whitefish,Alaska whitefish,and lake whitefish.The
difficulty in readily distinguishing among these three species
necessitated this action.)
The first capture and observation of a humpback whitefish
occurred on 12 February,4.2 km below the mouth of Montana Creek.
This fish,caught in an under-ice gi 11 net,was the only one of
its kind captured that winter.During June,relatively large
numbers of humpback whitefish were also collected at the mouth of
Anderson Creek,Sunshine Creek,Slough 6A,and Portage Creek.
From mid-July until September,humpback whitefish were collected
at habitat locations on the Susitna River between Cook Inlet and
Devil Canyon.Adults were more frequently collected in the
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1 to 15 September time period and were more common in the
habitats sampled below Talkeetna than in the river reach above
Talkeetna.
The ages of 67 Susitna River humpback whitefish were confirmed
via scale analysis.The fish ranged in age from age 2 to age 7.
Age 4 fish,which made up 31.3%of the aged catch,was the
predominant age class encountered.Age 3,age 5,and age 6 fish
each composed 19.4%of those fish aged .
Between 1 and 30 June,large gi 11 net catches were made on the
Susitna at Anderson Creek,Sunshine Creek,Slough 6A,and Portage
Creek.Necropsies indicated that the fish in these catches were
sexually mature but not ready to spawn.Between 26 August and 14
September,170 humpback whitefish were caught at the Sunshine
fishwheel.Inspections of fish caught from mid-September to
early October showed well-developed gonads,but again,the fish
were not yet ripe.No hijmpback whitefish were caught or observed
after 7 October.
During the 1981 season,between Cook Inlet and Devi 1 Canyon,no
evidence of spawning among humpback whitefish was collected at
any sampl-ing location.Consequently,one could only speculate
that humpback whitefish spawn in the Susitna River some time
after 7 October.
-Longnose Sucker
Longnose suckers were first captured and observed at the mouths
of the Deshka River and Cache Creek Slough on 9 May.By early
June,longnose suckers were dispersed on the Susitna River
between Kroto Slough and Portage Creek.The percentage of
habitat locations at which longnose suckers were captured by
gill net was relatively high during the early part of the summer
and then decreased during mid-summer.The percentage increased
again during September in the lower river,but not above
Talkeetna.The highest fall gill .net catches were reported at
the Deshka River and Sheep Creek Slough.An increased presence
of longnose suckers was also found in September in the mainstem
Susitna below Talkeetna.
Juvenile longnose suckers were continually present,primarily in
the Susitna River below Curry.As the season progressed,
however,they shifted farther downriver.
One hundred ninety-seven longnose suckers taken from the Susitna
River by fishwheel,gill net,and electrofishing gear were aged
by scale analysis.The majority of these fish were age 6 and 7,
comprising 33%and 22%percent of the catch,respectively.The
oldest fish caught,representing 3%of the catch,were age 9.
3-111
-Dolly Varden
November through May sampling within the Susitna River from Cook
Inlet to Devil Canyon produced a catch of two Dolly Varden.One
was taken by gill net from Little Willow Creek;the other,by
trotline at rkm 134.
From June to September 1981,Dolly Varden were collected at a
total of 52%of the habitat locations in the Cook Inlet to
Ta 1keetna reac h.The occurrence of Dolly Varden in habitat
location catches by two-week periods varied from a low of 8%in
the last two weeks of August to a high of 29%in the last two
weeks of September.Tri butary stream mouth habitat locat ions
produced the most consistent catches of Dolly Varden,with the
highest catches occurring in late June at the mouth of the
Kashwitna River.
In the Talkeetna to Devil Canyon reach,Dolly Varden were
collected at a total of 59%of the habitat locations.From June
to September,the occurrence of Dolly Varden in habitat location
catches varied from a high of 21%in June to a zero catch in
July.Catches of Dolly Varden occurred in this reach again,
however,in August and September.A total of 17 Dolly Varden
were captured in habitat locations at the mouths of Indian River
and Portage Creek;a selected fish habitat site at the mouth of
Billion Slough produced seven of the 17 fish captured.Other
sites in this reach produced only one Dolly Varden.
The higher incidence of Dolly Varden catches during July may be
directly related to the migration and spawning at this time of
pink,chum,and sockeye salmon,upon whose eggs Dolly Varden
feed.The higher catch incidence in September can be attributed
to two factors:Dolly Varden had moved into their own spawning
areas within the clearwater tributaries,and they,had begun
outmigration into their wintering habitat.
During helicopter surveys of upper Indian River and upper Portage
Creek,a stunted population of Dolly Varden was observed.In the
lower Susitna River study,these fish were found only within
upper Portage Creek and upper Indian River.Minnow traps
produced good catches of these fish:Indian River,50 fish;
Portage Creek,127 fish.
-Threespine Stickleback
Threespine stickleback were collected at 37 (84%)of the 44
habitat locations in the Cook Inlet to Devil Canyon reach of the
Susitna River from Alexander Creek to the mainstem Susitna Island
site.Catch per unit effort rates in the Cook Inlet to Talkeetna
reach were higher,overall,than those in the Talkeetna to Devil
Canyon reach.
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The number of habitat locations that produced threespine
stickleback was highest in June (84%)and declined steadily to
16%in September.The higher percentage in early summer
indicated that fish observed then had been involved in spring
spawning movement,activity that had disappeared by September.
Except Goose Creek 1,all habitat locations in the Cook Inlet to
Talkeetna reach produced stickleback.Twelve of the 17 habitat
locations in the Talkeetna to Devil Canyon reach produced catches
of this species.
-Cottids
Between November 1980 and October 1981,cottids were captured at
40 (91%)of the 44 habitat locations in the Cook Inlet to Devi 1
Canyon reach of the Susitna River.The percentage of habitat
locations producing catches in the Cook Inlet to Talkeetna
portion of the reach ranged from a high of 70%in late August to
a low of 42%"in late July.For the Ta"lkeetna to Devil Canyon
reach,there was a high of 76%in early July and a low of 35%in
late September.
-Lamprey
Arctic lamprey were captured at 14 habitat location sites between
rkm 16 and rkm 162,which were surveyed from November 1980
through September 1981.During the winter surveys,the only
habitat location site to produce Arctic lamprey was Rustic
Wilderness,where only one lamprey was captured.All other lam-
prey were collected during the summer surveys.
The highest catch was recorded in early July at Whiskers Creek.
These lampreys had an estimated length of 70 mm and were captured
in a single trap which had become buried in the si It.The
highest catch frequency was recorded during the 1 to 15 September
sampling period when 27.8%of all sites surveyed produced
lamprey.All productive habitat location site surveys during
this period occurred at tributary sites downstream of rkm 81.
The lowest incidence of capture for this species,3.7%,was
observed in the 16-31 July sampling period.
-Northern Pike
During the 1950's,northern pike were illegally transplanted by
private individuals into the Susitna River drainage.As a
result,northerns have been reported in the Yentna River drainage
in Bulchitna,Hewitt,and Whiskey Lakes (Kubik,pers.comm.).
A northern pi ke,measuri ng 715 mm fork 1ength and aged at ni ne
years,was captured on 11 September 1981 in a gill net set over-
night,150 m upstream of the mouth of Kroto Slough.This fish is
the first northern pike recorded in the mainstem Susitna River
and is believed to have migrated out of Bulchitna Lake.This
migration became possible where a hydraulic barrier washed out,
thereby allowing northern pike into the Yentna River.
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(c)Aquatic Habitat
(i)Impoundment Zones and Vicinity
In the proposed Devi 1 Canyon impoundment zone,habi tat eva 1uat ion
sites were established at Fog Creek,at the Susitna mainstem near
Tsusena Creek,and at Tsusena Creek.Both the mainstem of the
Susitna as well as Fog and Tsusena creeks contained highly
oxygenated water with pH values near seven or slightly higher.
Conductivity values for all sites were moderate in range;turbidity
levels were low in the two tributaries,with a moderate increase in
the mainstem.Temperatures in both the tributaries and the
mainstem were simil ar,with maximum recorded temperatures usua lly
above 100C.
Within the proposed Watana impoundment,habitat evaluation sites
were located at:Susitna mainstelll near Deadman Creek,Deadman
Creek,Sus itna mai nstem near Watana Creek,Watana Creek,Sus itna
mainstem near Kosina Creek,Kosina Creek,Susitna mainstem near Jay
Creek,Jay Creek,Sus i tna ma i nstem near Goose Creek,Goose Creek,
Susitna mainstem near Oshetna River,and Oshetna River.The same
trends in measured parameters discussed for the Devil Canyon
impoundment are also present in these locations:well-oxygenated
water,usually slightly basic pH,moderate conductivity levels,low
turbidity levels in the tributaries compared to tnose in the
mainstem,and similar water temperature ranges.
Watana Creek is located at river kilometer 305 on the north side of
the Susitna River and is approximately 13 km upstream from the
proposed Watana dam.Watana Creek is a shallow meandering stream.
It has a gradual gradient,resulting in a moderate flow with few
pools interspersed between the predominant riffle areas.The
substrate consists mostly of gravel and rubble.The water is often
turbid during the summer because of heavy rains and unstable soils
present upstream.
Kosina Creek,located at river kilometer 324 on the south side of
the Susitna River,lies approximately 32 km upstream from the
proposed Watana dam.Kosina Creek is a deep and turbulent stream,
predominantly whitewater interspersed with deep pools and shallower
riffle areas.Substrates consist mostly of sand,large cobble,and
boulders.The stream channel is stable and is situated in a narrow
valley with a moderate gradient.It is often braided,with total
widths frequently around 30 111.
Jay Creek is located at river ki lometer 328 on the north side of
the Susitna River and lies approximately 35 km upstream of the
proposed Watana dam.Jay Creek is a relatively narrow,shallow
stream,predominantly riffle with a moderate flow.Substrate
consists of gravel,cobble,and rubble,often embedded in sand.
Although the water is generally clear,unstable soils in upstream
areas often result in landsl ides which can change the water to a
turbid condition within minutes.
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Located at river ki lometer 360 on the south side of the Susitna
River approximately 69 km upstream from the proposed Watana dam,
Goose Creek is a narrow,shallow stream.The habitat is predomin-
antly riffle with a moderate flow and few pools.Substrate
consists of rubble,cobble,and boulders,often embedded in sand.
The stream channels and banks are stable;the water usually remains
clear even during period of moderate rain.
The Oshetna River,located at river kilometer 363 on the south side
of the Susitna River,lies approximately 72 km upstream from the
proposed Watana dam.The Oshetna River is a large,meandering
stream approximately 30-40 m wide with an average depth of one
meter.Streamflow is slow to moderate,with alternating pool and
riffle areas.Substrate consists mostly of rubble and cobble,with
some large boulders.The stream channel is stable throughout the
study area and contains many large gravel bars.This stream is
partially under glacial influence,and the water is often turbid
even during periods of dry weather.
(ii)Downstream (below Devil Canyon)
Sampling was conducted in various reaches of the Susitna River from
Cook Inlet to Devil Canyon.These included the Yentna reach,
Sunshine reach,Talkeetna reach,and Gold Creek reach (Figures
3.31,3.32,3.33,and 3.34.In addition,five selected habitat
evaluation sites in the vicinity of Gold Creek were studied in
greater deta il (F i gure 3.34).
Water qual ity measurements in the Yentna reach were made at the
following locations:Alexander Creek,Anderson Creek,Kroto
Slough,Mainstem Slough,Deshka River,Lower Delta Islands,and
Little Willow Creek.The tributaries,sloughs,and mainstem
sampling localities all exhibited high dissolved oxygen readings.
The pH values were generally in the high-six to middle-seven range,
except for the Deshka River and Little Willow Creek readings,which
were at the lower limits of this range.The most notable
di fference between tri butary and other areas was the much lower
turbidity levels recorded in the former.Anderson Creek,the only
exception to this pattern,registered high levels.
Areas sampled in the Sunshine reach of the Susitna included:
Rustic Wilderness,Kashwitna River,Caswell Creek,Slough West
Bank,Sheep Creek Slough,Goose Creek,Mainstem West Bank,Montana
Creek,and Rabideux Creek.All waters were well oxygenated,and pH
values,typically around 7.0 or less in the tributary areas
sampled,were slightly higher at slough and mainstem sites.
Conductivity was generally low in the tributaries and moderately
high in the mainstem and slough sites.Rabideux Creek showed the
highest conductivity readings for any of the tributaries sampled in
this region.Turbidity readings were extremely low in most of the
tributaries,especially in Caswell and Montana creeks.
3-115
Sampling sites in the Talkeetna reach included:Mainstem 1,
Sunshine Creek,Birch Creek Slough,Birch Creek,Cache Creek
Slough,Cache Creek below Talkeetna and Whiskers Creek Slough,
Whiskers Creek,Slough 6A,Lane Creek,and Mainstem 2 above
Talkeetna.In general,high dissolved oxygen levels were present
in all of the study areas sampled.The exception was Cache Creek,
where a low dissolved oxygen reading during the latter part of the
salmon run was attributed to low flows during this particular
sampling period.The lower ranges of pH readings in this region,
for example at Whiskers Creek and Whiskers Creek Slough,may have
been due to more acidic flow than was present in the more
downstream areas sampled.Conductivity readings were generally
moderate,and,when the influence of the mainstem Susitna was
negligible,turbidity levels were generally lower in the
tributaries and in the sloughs than in the mainstem.
In the Gold Creek reach, the general habitat evaluation sites
included:Mainstem Susitna at Curry,Susitna Side Channel,
Mainstem Susitna Gravel Bar,Slough 8A,4th of July Creek,Slough
10,Slough 11,Mainstem Susitna -Inside Bend,Indian River,
Mainstem Susitna Island,and Portage Creek.In general,the trends
seen in the previously discussed stretch of river were also seen in
this stretch.
The ranges for the recorded parameters are shown in Table 3.54.In
this table,unless listed differently,the ranges given for the
tributary sites include all of the sampling sites from that
particular tributary.The only really significant trend seen in
the upstream tributary sampling was that turbidity levels were
generally higher at the tributary mouths.This characteristic was
undoubtedly caused by mainstem Susitna influence.
The five selected habitat evaluation sites studied were sloughs
located along the Susitna River from approximately 8 km downstream
of Sherman to approximately 6.4 km upstream of Indian River.The
sloughs studied were:Sloughs 8A,9,16B,19,and 21.
Slough SA is approximately 2.9 km in length.The initial .4 km
from the mouth upstream is influenced by the mainstem Susitna River
and,except during periods of extremely low river flow,a backwater
area is created in the slough.Above this area,during the study,
the flow was free,obstructed only by beaver dams located within
the middle section of the slough.Slough 8A can be characterized
as having sloping,1.8-meter cutbanks and six IIheads ll which,except
during periods of low mainstem discharge,contributed flow from the
mainstem.During those periods,flow was generated through
groundwater percolation and water release from beaver dams.
Sockeye and chum salmon were observed spawning in the lower
stretches of the slough,which was the longest of the five sloughs
sampled and exhibited the greatest diversity.Because they were so
long,sloughs 8 and 9 had transects only at their IIheads"and
mouths.
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Slough 9 is an open water channel approximately 1.9 km long,with
sloping,1.8-meter cutbanks and substrate composed of gravel,
rubble,and cobble.The main source of water for the slough
consisted of flow from the mainstem Susitna River except during
periods of low discharge.Two small tributaries,which were
located on the northeast and southeast banks,maintained flow in
the slough during low discharge periods.They provided the entire
low-flow discharge.The northeast tributary was a known site for
coho spawning.
Slough l6B is a free-flowing channel approximately .6 km in length
and consisting of steep cutbanks ranging from .3 m to 1.5 m in
height along both sides of the entire length of the slough.The
substrate observed during the study was fairly homogeneous
throughout and consisted primarily of gravel and rubble.The main
source of flow was from the mainstem Susitna River,which entered
the head of the slough.During periods of low mainstem discharge,
as the head of the slough was dewatered,the slough itself became
isolated from mainstem influence,and groundwater percolation alone
contributed most of the water.Although spawning was not observed
during the present surveys,a few chum salmon carcasses were found
in dewatered areas within the slough.
Slough 19,which is largely spring-fed,is backed up at its mouth
by the Susitna River,forming a pool approximately half the
slough's length.At the time of the study,the slough itself was
approximately .3 km in length,with sloping,1.5-meter cutbanks in
the upper portion and generally sloping banks throughout the lower
portion.The substrate was composed of 100%silt and scant aquatic
vegetation from the slough's mouth approximately 60-90 m upstream.
Above this distance,the substrate was primarily gravel,with a
layer of silt ending with cobble and rubble near the head of the
slough.Sockeye were observed spawning in this slough.Redds were
located by noting areas where the fish had fanned the silt to gain
access to the underlying gravel.
Slough 21 is a forked,open channel stream approximately .8 km long
with sloping,1.5-meter cutbanks.Except during periods of low
discharge,the main source of water is the mainstem Susitna River.
At low discharge of the mainstem,however,the slough is fed by a
small,clearwater tributary entering the northeast channel of the
slough.During the study period,this tributary along with ground
water percolation,maintained water in the main channel and
northeast channel,while the northwest channel was dewatered.From
the mouth to approximately 225 m upstream,the substrate was
composed primari 1y of S"r lt sparsely interspersed with grave 1 and
cobble.Above this portion of the main.channel and in the
northeast channel,the substrate was composed of silt,gravel,and
rubble.It was in these channels that all spawning activity was
observed.
3-117
The northeast channel substrate consisted primarily of rubble and
cobble interspersed with gravel.During the sampling period,no
fish were observed spawning in this site.This channel was also
the first to dewater.The northeast channel,as a result of the
contribution of a small tributary,was never found dewatered,nor
was the main channel of the slough.The sites along Slough 21 were
selected because varied types of habitat,water quality,and fish
activities,such as spawning and rearing,were represented.
In general,average water temperature in the sloughs during the
June,July,and early September sampl ing periods was 9.0°C or
higher,decreasing significantly in late September,when average
water temperature ranged between 1.8°C and 5.6°C.Although data
were limited,a comparison between surface and intergravel
temperatures indicated that intergravel temperatures remained
constant at 3.0°C,and surface water temperatures varied diurnally
between 4.5°C and 8.5°C.The intergravel temperatures were
consistently 2°C below the lowest recorded surface temperatures.
Dissolved oxygen readings were usually near 100%saturation u~til a
slight decrease occurred in September.Generally,the slough sam-
ples showed moderately high conductivity readings;moderate
alkalinity levels;pH readings in the middle-six to middle-seven
range;and,for the most part,fairly typical cation,anion,heavy
and trace metals,and nutrient levels.The most .notable metal
concentrations were those reported for iron.Turbidity levels in
the sloughs were high when sloughs were apparently influenced by
mainstem water.
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3.4 -Threatened or Endangered Species
(a)P1 ants
At present,no plant species are officially listed for Alaska by federal
or state authorities as endangered or threatened;however,37 species are
currently under review by the U.S.Fish and Wildlife Service (USDI 1980b)
for possible protection under the Endangered Species Act of 1973.A
recent publication by Murray (1980)discusses the habitat,distribution,
and key traits of most of these species.None of these species are known
to occur,however,in the upper Susitna River basin.
A list of species (Table 3.55)extracted from Murray (1980)was believed
to contain the most likely plants of this category that could potentially
occur in the Susitna River drainage and in the landscape to be modified
by the construction of the proposed dams and associated facilities.
Since the upper reaches of the drainage were expected to be the least
affected,however,the major portion of the present survey was devoted to
the study of potent i a1 habitats in and around the impoundments.The
genera 1 habit at requi rements and occurrence of these pl ant spec i es were
known from previous taxonomic and ecological study in Alaska and from
information given by Hulten (1968).For instance,several of the
endangered species and the only threatened species,(Smelowskia
pyriformis),favor well-drained rocky or scree slopes.
Field searches were made in potential habitats in August 1980 and early
July 1981.On each field trip,aerial and ground reconnaissance was made
by three to four botanists and agronomi sts with the purpose,thereby,of
increasing the probability of finding the pertinent plant species.
Following an assessment of potential habitat,specific field surveys were
conducted in the following areas:1)the upper drainage basin,
specifically alpine areas near the Susitna and West Fork Gl aciers;2)the
lowlands of the upper drainage basin,Macl aren and Tyone Rivers,ridges,
terraces,and periglacial features;3)the lower drainage,outcrops,and
promontories along the Susitna River near Watana Creek,Kosina Creek,and
gravel bars in the river bed;4)alternative access routes;and 5)Borrow
Pit A (Figure 9.7).
Calcareous outcrop areas found in 1980 were surveyed again in 1981,but
earlier in the season.A prominent light-colored outcrop on the
northwest flank of Mt.Watana supported a mat and cushion vegetation type
in which many calciphilic species were present.The exposed bench was
both well-drained and calcareous,requirements for several of the species
being sought.
The Kosina Creek calcareous outcrop area was re-surveyed in 1981 to make
observations at an earlier phenological time and to obtain flowering
specimens of the Taraxacum species collected there in 1980.Several
flowering p1 ants of Taraxacum were collected in 1981,and the preliminary
determination indicated that the species was T.alaskanum,a common
species in some areas.The aspect of the Kosi na Creek outcrops is
north-facing,and the dark soil around the calcareous rocks is rather
fine-grained.The Kosina Creek outcrops are almost accordant both with
3-119
the calcareous outcrops on the northwest side of Mt.Watana and with the
calcareous lag gravel domes west of Watana Creek.The Taraxacum
collections were made in proximity to the calcareous rocks of the
outcrop,and none were found in the surrounding vegetation types;one may
thus assume that the species has calciphilic tendencies.Saxifraga
oppositifolia and Rhododendron lapponicum,two recognized calciphiles,
were notably abundant in the Kosina Creek outcrop area.
The northern alternative access route to the proposed dam sites (from the
Denali Highway,not the recommended route)was surveyed in July
1981 by the plant ecology team.Two sites were studied on the ground;
the rest of the route was observed from low-level helicopter flights.
A sandy,blowout area on the northwest side of Deadman Mountain on this
northern access route was chosen for ground study.The well-drained
habitat was believed to be a favorable site for several of the endangered
and threatened species.Vegetation was a shrubby heath-birch-willow
type.A second site on the south side of Deadman Mountain was also
studied in connection with the survey of the alternative access route to
Watana from the Denali Highway.A series of dry ridges,probably glacial
moraines or terraces,was present,and the vegetation on two of these
ridges was surveyed.The vegetation was typically a mat and cushion
type.A later survey was made of this northern alternative access route
and a ground study site was chosen on the east side of Deadman Mountain
near the 1200 m elevation.The area was characterized by dry,rocky,
windblown ridges vegetated by mat and cushion species,and in the lower
and moister sites,by low shrub willow-birch-heath vegetation.
In none of the three survey areas on the alternat ive access route from
the Denali Highway were any of the spec i es in quest i on found.The other
access routes were similarly surveyed,but the plants in question were
apparently absent there as well.
The vegetation in the vicinity of Borrow Pit A was surveyed in July 1981.
The low ridge area was characterized by rocky outcrops intermixed with
low areas containing knee-high,shrubby vegetation.In shallow
depressions or ravines,the vegetation included both more herbs and
grasses and tall er shrubs such as alder.No threatened or endangered
species were found.
(b)Wildlife
The only endangered wildlife species,listed by either the U.S.Fish and
Wildlife Service or the State of Alaska,that could possibly occur in the
upper basin study area is the peregrine falcon.No evidence of this
species'nesting or even migrating through the study area was discovered
during the course of this study.Suitable cliff-nesting habitat was
surveyed in both 1980 and 1981 with no peregrine nests found.In addi-
tion,despite the following ornithological effort expended during the
course of this study no peregrines were seen:385 party-hours of breed-
ing bird censusing;53 party-hours of ground censusing of waterbirds;44
party-hours of ground observations of raptor/raven nest sites;and more
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than 630 party-hours of general bird surveys.Furthermore,qual ified
observers performing the other field studies were requested to report any
incidental observations of noteworthy species;no confirmed sightings of
peregrines were reported.
The only confirmed historical records of peregrines in the upper basin
study area are presented by White (1974),who saw two individual pere-
grines during his June 1974 survey,but found no sign of nesting.One
bird was a "single adult male ...roosting on a cliff about 4 miles
upriver from the Devil Canyon-dam axis,"and the other was a "su b-adult
..about 15 miles upriver from the Devil Canyon dam axis."White (ibid)
stated that the Yentna-Chulitna-Susitna-Matanuska drainage basin
"seem ingly represents an hiatus in the breeding range of breeding
peregrines ...",and Roseneau et al.(1981)stated that lithe Susitna
and Copper rivers both provide ..-.TVery few]...potential nesting
areas for peregrines."
Peregrine falcons are a concern along the transmission line north-ern
study area.A nest site is located east of the proposed transmission
route crossing of the Tanana River.The nest was not active during 1981
but was used prior to this time.Whether or not it will be used again is
unknown.
(c)Fish
The U.S.Department of Interior,Fish and Wildlife Service,does not list
any fish species in Alaska as being threatened or endangered (Richard
Wilmot,pers.comm.1981).The State of Alaska Endangered Species Act
includes no fish species on its list of endangered species.
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3.5 -Anticipated Impacts on Botanical Resources
r Potential impacts on vegetation were identified by review of pertinent literature
and by discussion with various specialists knowledgeable regarding the problems
associated with hydroelectric development.Anticipated impact areas in the upper
basin and transmission corridors were identified by overlaying expected activities
on vegetation/habitat maps.Calculations of area size were made based on vertical
project i on.Because of slope,the actual area to be impacted wi 11 be somewhat
higher than that presented.The general location of proposed facilities is
presented in Figure 9.7.Impact analysis for the downstream floodplain consisted
of relating the general changes in flow during reservoir filling and operation to
plant succession trends.
(a)Watana Dam and Impoundment
(i)Construction
The obvi ous impact of construct i ng the dam and of fi 11 i ng the
Watana reservoir will be the elimination of portions of different
vegetation/habitat types.The hectares of each vegetation/habitat
type to be affected are presented in comparison with the total
hectares of those types in the entire upper Susitna River basin and
in an area within 16 km of the upper river (Table 3.56).
At a maximum pool elevation of 666 m (2185 ft)the Watana
impoundment will inundate approximately 14,691 ha.Of those,
12,587 ha are vegetated and represent 0.9%of all the vegetated
area of the upper bas in.Much of the impoundment area coul d be
classified as wetland (Table 3.7).Primary losses will occur in
the woodl and and open spruce stands and in the open mi xed forests.
Birch forests wi 11 be substanti ally affected by the impo~ndment.
relatively more so than any other vegetation/habitat type (Table
3.56).The other types which would experience a relatively major
impact are conifer-deciduous forests and balsam poplar forests.
Additional impact on vegetation may occur beyond the impoundment
areas,if roads or other activities associated with clearing the
woody vegetation from the impoungment zone are not restricted to
the impoundment area.As discussed under mitigation (Section 3.9),
restriction of disturbance to the impoundment area will limit the
extent of this impact.
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Construction activities at the dam site,borrow sites,airstrip,
construction camp and village sites will result in a loss of
additional hectares of vegetation (Table 3.56).Proposed camp and
village sites,airstrip site,and borrow areas will be located
primarily in woodl and bl ack spruce and low shrub stands.Borrow
areas D and Hal so cover 1arge mi xed forest st ands.Borrow areas
may eventually be revegetated and are discussed in more detai 1 in
Section 3.5 (c)--Borrow Areas.
All of the aforementioned construction activities will be almost
entirely contained within an area designated as a construction
zone.This zone (Figure 9.7)represents the maximum area of
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potential construction disturbance.It is unlikely that this
entire zone will be directly affected;however,if all the
vegetation is removed from this zone,13,725 ha will be lost in
addition to that in the reservoir area lost by inundation (Table
3.56).This loss represents 0.8%of the entire upper basin.
Reclamation of areas that will only be temporarily affected will
reduce this loss and is discussed under Section 3.9 (b).
The significance of these losses,aside from the vegetation loss
itself,will be the associated loss of habitat for wildlife.The
principal losses for big game will be a reduced food supply for
black bears and moose.Browse supp 1i es in the impoundment area are
margi na 1 and do not represent a 1ate wi nter reserve for moose.
Birch and mixed forest stands,however,provide bears with
substantial supplies,which are particularly important in early
spring.A more detailed discussion of the impacts on big game is
presented in Section 3.6 (a)(i).
(ii)Operation and Maintenance
The pool elevation of the Watana reservoir will vary an average of
27 m (90 ft),with a low of 639 m (2095 ft)in May,and a gradual
increase to a full pool elevation of 666 m (2185 ft)during
September.The drawdown zone (from full pool to low pool)
will be essentially unvegetated.During dry years,however,the
full pool target elevation may not be attained and exposed areas
that are not flooded may become naturally revegetated for a short
period until they are flooded again.The greatest potential for
this type of revegetation exists in areas of gentle slope,suCh as
the Watana Creek area.
The Watana reservoir is located in a region of discontinuous
permafrost.Consequently,there is potenti al for large earthflows
and slumps,especially on north-facing slopes,as the relatively
warm reservoir thaws adjacent permafrost.This type of disturbance
will most likely occur on black spruce sites and may lead in
places,to their replacement,by alder stands and,possibly,by
open paper birch stands.Bank erosion from above the full pool
elevation may also result from wave action and altered subsurface
drainage.
An impact noted by Baxter and Glaude (1980)for northern reservoirs
is the potential for peat masses to float to the surface of the
reservoir.This type of impact should not be extensive at the
Watana reservoir,since only a small amount of the peat-forming wet
sedge-grass vegetation will be inundated.Some potential for such
an occurrence does,however,exist in the Watana Creek area.
There are two other minor impacts that may occur during the
operation of the Watana facility:the potential modification of
local climate and the icing of vegetation around the dam outflow.
In general,large bodies of water influence the local climate by
acting as cold sinks in winter,thereby delaying the initiation of
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spring,and as heat sinks in summer,thus extending localized warm
weather.It has been estimated that such influence will be
restricted to within about 1.6 km of the reservoir shoreline.
Local c1 imatic changes may,in turn,result in mi nor changes in
vegetation phenology.The severity and extent of this potential
change in vegetation is difficult to predict.They may,however,
include a localized delay in snowmelt and in greening of vegetation
in spring and,possibly,a delay in leaf-fall in autumn.Any
impact on vegetation in the spring may be moderated somewhat,
however,since the pool e1evat ion wi 11 be at its lowest point and
thus,the distance from the water edge to the vegetation edge will
be at its greatest.
At the dam outflow,ice fog will probably occur during winter
months when the temperature is in the approximate range of -12°C to
-23°C (+10°F to -100F).This ice fog will freeze on contact with
vegetation and may accumul ate to create loads sufficient to break
twigs.Although this impact will be very localized,birch trees,
because of their many small branches,will be the most susceptible
to damage...
(b)Dev il Canyon Dam and Impoundment
(i)Construction
Construct i on and fi 11 i ng of the Devil Canyon dam and impoundment
will eliminate an estimated 3,214 ha of vegetation/habitat types
(Table 3.57).Primary vegetation losses will be of open and closed
mixed forests and open spruce forest.Construction activities at
the dam,camp,and village sites will further eliminate or modify
at least another 223 ha of vegetation,primarily closed mixed
forest.An est imated 1,706 ha of wet 1ands are with in these di rect
impact areas (Table 3.7).
If the entire construction zone (Figure 9.7)is affected,5,688 ha
will be lost in addition to the reservoir area (Table 3.57).It
should be noted that the area of the construction zone represents a
maximum potential loss;a certain portion of this area will proba-
bly not be disturbed and reclamation activities may restore areas
temporarily affected.The maximum potential loss,including the
construction zone and reservoir area,represents 8,884 ha and 0.5%
of the entire upper basin.
Vegetation losses at Devil Canyon wi 11 not be significant in terms
of moose or caribou,since most of the affected area is situated on
steep slopes which are generally inaccess'ib1e to these ungulates.
These areas do,however,provide a relatively large forage supply
for black bears.Big game impacts are detailed in Section 3.6 (b)
( i ) .
(ii)Operation and Maintenance
The pool elevation of the Devil Canyon reservoir will fluctuate an
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average of 17 m (55 ft)during the year.The drawdown zone created
by this fluctuation will essentially be devoid of vegetation.As
discussed for the Watana reservoi r,vegetat i on may invade some
portions of this zone when the full pool target elevation is not
attained.On the other hand,since much of the Devil Canyon
reservoir is very steep-sided,this invasion may only occur at the
very upper reaches of the reservoir in the Tsusena Creek vicinity.
As discussed for the Watana reservoir,erosion of material from
above the pool elevation may occur after filling.The extent of
this impact will vary,depending on many factors,but the amount of
slumping will probably be less than that at Watana.
Localized climatic changes may also occur around the Devil Canyon
reservoir.Because of the long,narrow configuration of the
reservoir,however,which leaves relatively smaller surface area
exposed to create cl imat ic change,the potenti al for such change
will be less than that expected for the Watana reservoir.Any such
changes are,therefore,expected to have a negligibl.e effect on
surrounding vegetation.
Finally,the operation of the Devil Canyon reservoir will result in
changes in downstream flows,downstream water temperatures,and ice
conditions.The impacts of these changes on vegetation are
discussed in Section 3.5 (d)-Downstream Floodplain .•
(c)Borrow Areas
The complete development of all borrow areas at both Devil Canyon and
Watana will destroy an estimated 1,751 ha of vegetation/habitat types
(Tables 3.56 and 3.57).Those portions of the borrow areas within the
impoundment and those associated with access road construction are not
included in this estimate.This estimate does include,however,those
borrow areas within the construction zones previously discussed.Wood-
land and open spruce,low mixed shrub,and birch shrub will be the
principal types affected.Borrow Area K,which is a quarry associated
with the Devil Canyon dam,is covered primarily by mixed forests.
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The total impact from borrow areas will probably be less than the 1,751
ha estimated,since certain areas (possibly A and H)may not be used and
others may be only partially developed.Also,'reclamation of all these
areas is possible [(see Section 3.9 (b)].Areas that are developed
should not,therefore,be permanently destroyed as a terrestrial habitat ,,',
but may remain changed in terms of the type of habitat for a long period
of time.
The development of borrow areas may also influence vegetation in adjacent
areas by lowering the water table.This type of impact will probably
only occur to any noticeable extent around Borrow Area D,where adjacent
land to the north and west may be influenced.This impact will be
localized,however,and will probably result in only minor species
composition changes in the areas affected.
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(d)Downstream Floodplain
(i)Construction
Decreased flows during the period of filling will enable vegetation
to move into the upper portions of what is now submerged river
bottom.Between the Devil Canyon dam site and 0.5 km above the
confluence of the Susitna and Chulitna rivers,the development of
vegetation,however,will be relatively negligible,since most of
the area to be exposed consists of rocky substrate,rather than
smaller particles suitable for the rooting of vegetation.Thus,
vegetation will probably be limited to fireweed,horsetails,dryas,
sweetvetch,and possibly some other pioneering species.Another
hindrance to vegetation development is that plants will be re-
stri cted to interst ices of the rock-armored ri ver bottom.l"1ore-
over,the filling period will not be long enough for sufficient
wind-blown soil to accumulate to allow for further vegetation
development.
Because of decreased flows,areas that are presently horsetail
communities will quickly develop into balsam poplar sapling and
willow communities.The rate of this change depends on the syn-
chronization of seed crops with adequate precipitation and suitable
temperatures.The areas supporting horsetail are relatively
limited,however,most occurring within 11 km upstream of the
confluence of the Susitna and Chulitna rivers.During the period
of reservoir filling the impact on vegetation below the Susitna-
Chulitna confluence is expected to be negligible.
(ii)Operation and Maintenance
At Gold Creek,river flows during the growing season (May to
September)wi 11 be reduced from an average of about 20,000 cfs to
an average of about 10,000 cfs.Seasonal floods will essentially
be eliminated.As a result,some of the presently unvegetated bank
areas in the reach from Devi 1 Canyon to the Sus itna-Chul i tna
confluence will begin to develop horsetail,dryas,willow,and
balsam poplar communities.Barring disturbances by ice jams,
willow and balsam poplar saplings will develop within five years of
the last disturbing influence on sites presently having sandy or
silty substrates.
Establishment of significant cover on rocky sites may require
several decades while adequate wind-blown sands and silts accumu-
late;even then,vegetation will be dwarfed and slow-growing for
several more decades.In the downstream Susitna above Talkeetna,
the area above the level of the river during 40,000 cfs flows is
already vegetated.Below that level,most of this area has a rocky
substrate,not conducive to lush growth.Consequently,the overall
increase in vegetation cover for this reach of the river will be
mi nimal .
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Since the Devil Canyon to Talkeetna reach of the river is expected
to remain largely ice-free.a principal environmental force
maintaining early successional vegetation will be absent during
operation.This gap will allow present early successional
vegetation to advance to later forest types.During some winters,
however.accumulations of ice fog on vegetation adjacent to the
wider sections of the river may break down trees and tall shrubs.
creating brush fields of young balsam poplar.willow.and alder.
This effect is not expected to proceed beyond bank-side vegeta-
tion.
Below Talkeetna.the effects of either reduced or increased flows
will be moderated by the contributions of the Chulitna and
Talkeetna rivers.While the degree of moderation is uncertain,
certai n trends in impacts can be expected.For example.the
primary impact of decreased summer flow below Talkeetna will be to
allow early successional vegetation to move down onto sites that
are presently eroded by high summer flows.Thus,until a new
equilibrium with the river is reached.new early successional
stands will migrate toward the new level of peak flows.while older
early successional stands (then less affected by high flows)will
advance to alder and immature balsam poplar types.
The time required for transition from early successional stands of
willow and balsam poplar to mid-successional stages is roughly
equal to that required for establishment of new early successional
stands (that is,six to eight years).The total area covered by
the new stands is expected to be nearly equal to that lost to mid-
successional vegetation.
The above sequence of events may be negated by floods from the
Chulitna or Talkeetna rivers or,in rare instances.by flood water
passing the Susitna project.Such events may maintain the distri-
bution of vegetation types on the floodplain below Talkeetna
similar to the way it is at present.
(e)Access Route
(i)Construction
Const ruct i on of the Park s Hi ghway-to-Devil Canyon/Watana access
road (including railroad yard and all potential borrow areas)will
disturb approximately 900 hectares of vegetation,providing that
machinery stays within 30 m (100 feet)of the center line (Table
3.58).Primary losses will be to open and closed conifer-
deciduous forests and low shrub types.
The total direct impact of the permanent access road may be
somewhat less extensive than the aforementioned estimate.since the
roadbed will only be about 14 m (45 feet)wide and all the
identified borrow areas may not be used.Between Gold Creek and
Devil Canyon,however,the pioneer road will probably cover
separate ground from the route of the permanent access road and,
therefore.will result in additional temporary impact.Eventual
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revegetation will restore these areas.
(ii)Operation and Maintenance
During operation of the road,impacts may extend beyond the road
base itself.Where the road restricts drainage,woody vegetation
types will shift toward sedge-grass tundra and wet seqge-grass
conditions.Areas which are presently wet but which will become
drier will experience a gradual invasion of shrubs and trees,
depending on specific soil/site conditions.
Accumulations of dust on roadside vegetation may cause snow melt to
occur two to three week searl i er for a di stance of 30-100 m either
side of the road (CRREL 1980).This factor,associated with
accumulations of some elements,(particularly calcium),in road
dust and changes in photosynthes is,may substant i ally reduce the
density of four-angled Cassiope,stiff clubmoss,sphagnum
moss,Cl ad ina,and other mosses and 1i chens;on the other hand,
cottongrass may increase (CRREL 1980).Such shifts in vegetation
composition would not be obvious to any but the trained observer
and should not cause any soil erosion problems.
The most significant source of impact associated with the access
road may be damage caused by unrestricted off-road vehicle traffic
(Sparrow et al.1978).The llloSt extensive impact of such use would
be on willOwand shrub bi rch.Sedges woul d be most resistant to
damage.The most significant damage,however,would occur on
upland tundra communities,where soils are shallow and rocky.The
potential restriction of off-road vehicle traffic is discussed
under mitigation (See Section 3.9 (b)).
Considerable potential for fire also exists,especially during the
spring.The remoteness of the region increases the time required
to reach a site and to bring a fire under control.Thus,while
such an event may be localized,it may a.lso extend over vast areas.
In any event,fires will cause changes in the vegetation similar to
those whi ch have occurred hi stor ica lly from nat ura lly occurri ng
wildfires (that is,vegetation would be set back to early
successional stages).Neither the wet areas nor the sparsely
vegetated upland tundra communities will support a significant
fire.The birch and low mixed shrub,the black and white spruce,
and the mixed conifer-deciduous forest habitat types,however,may
ignite into substantial fires.Fire could revert these latter
types to seral brush communities,highly productive of moose
browse.
(f)Transmission Line
(i)Construction
Construction of the transmission line will result in long-term
vegetation impacts where tower structures and permanent access
roads are placed.In addition,movement of machinery over the
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ground will temporarily set back brush growth.The major impact of
construction will be to reduce the overstory cover of trees.Where
spruce trees are cut.spruce bark beetle problems may arise.
The estimated amounts of different vegetation types that will be
within the right-of-way are presented in Table 3.59.Additional
areas may be affected if access roads are placed outside of this
right-of-way.
The transmission line between the dams and the intertie will
primarily traverse closed conifer-deciduous forests and the birch
shrub type.Utilization of the access road to the dams will help
1 imit the impact in this area.From Healy to Fairbanks the trans-
mission line traverses open spruce forests.open conifer-deciduous
forests.and low mixed shrubs.Extensive clearing will be required
along this route from the Tanana River to Fairbanks.Within the
route segment between Willow to Cook Inlet.the primary vegetation
types include open spruce.closed conifer-deciduous forests.and
wet sedge-grass types.Clearing will also be required in the
forested areas here.
At several places.the transmission lines will cross wetlands.
They are especially common in the Tanana Flats region of the
northern corridor (from the Nenana crossing to the Tanana River)
and along the southern portion of the Willow-to-Cook Inlet
corridor.Small wetland areas may be spanned witpout impact.
providing precautions are taken during construction.Larger
expanses of wetlands.though.will be adversely affected.but
impacts could be minimized if construction time is restricted to
winter.Potential impacts include direct disturbance of wetland
vegetation (and resultant loss of wildlife habitat)as well as
changes in drainage patterns and possible erosion problems.
(ii)Operation and Maintenance
Maintenance of the transmission right-of-way may require the topp-
ing or removal of the taller tree species.such as white spruce.
birch.aspen.balsam poplar.and tamarack.If these trees are
removed.shrubby undergrowth is expected to acce 1erate growth and
to thicken.and the number of individuals of some shade-tolerant
species are expected to decrease temporarily until shrubs thicken.
Periodic clearing of trees along the trarismission right-of-way is
expected to benefit wildlife from the standpoint of increased
forage producti on once the animals become accustomed to the sound
of the lines [See Section 3.6 (f)].
Impact on vegetation may also occur in the vicinity of the
transmission line as a result of increased ATV use.Such use may
be especially common where the transmission lines cross roads or
other existing access points.
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3.6 -Anticipated Impacts on Wildlife Resources
(a)Watana Dam and Impoundment
(i)Big Game
For the purposes of this discussion,the proposed Watana facility
includes the dam,spillway,camp,village,airstrip,and
impoundment as well as the construction zone around the dam site.
Borrow areas associated with the construction of this facility are
addressed separately [see Section 3.6(c)(i)].
-Moose
The construction and operation of the Watana dam and impoundment
will negatively impact moose in several ways.The most obvious
and probably the most important impact of the proposed facility
on moose will be the direct loss of habitat.It is anticipated
that 26,813 ha of habitat will be either permanently lost or
temporarily disturbed.Of this total,14,691 ha will be inun-
dated and permanently lost,and the remaining 12,122 ha w-ill be
lost as a result of other facility components.A portion of this
12,122 wi 11 be permanent ly lost,but at a min imum,50%may be
available for reclamation.Regardless of how much can be
restored,the figure of 26,813 ha does represent the immedi ate
loss of moose habitat which will occur.
The severity of the impact of this habitat loss will vary within
the moose population.Those moose that have home ranges that
fall primarily within the impact zone will be displaced and be
forced into adjacent areas where they will suffer high mortality.
This is most likely to affect relatively sedentary moose which
typically u'tilize a small area as both summer and winter range.
(Within the upper basin,most radio-collared moose which
di splayed such a sedentary pattern were found west of Watana
Creek.)Impacts on moose that ut -j 1i ze the impoundment zone on a
limited or seasonal basis will be Qifferent and more difficult to
predict although it is likely that these moose too will be
reduced in number.
The -impoundment zone appears to serve two major functions for
moose which shift home ranges from summer to winter:(1)as
winter habitat and (2)as an area which provides green forage
early in the spring.Moose that use the impoundment zone as
winter habitat typically spend the summer months at high
elevations and then move down to lower elevations,frequently to
river bottoms,during winter when deep snow at higher elevations
impedes movement and reduces the ava il abil ity of food.During
the course of these studies,however,radio-collared moose did
not display this type of movement pattern,probably due to mild
winter conditions.It is therefore likely that the movement data
on moose do not reflect typical movement patterns of moose during
more severe winters.Therefore,the lowlands along the river
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which will be flooded should still be considered of importance to
the moose population as winter habitat.
The level at which this winter habitat could support moose during
a severe winter,though,is questionable.In the absence of
detailed browse surveys within the impact zone,it is impossible
to determine how many moose could be supported there under harsh
winter conditions.Cursory and sUbjective conclusions developed
during the course of the Sus itna studi es suggested that the
quantity of browse along the river is low and appears to be
virtually completely utilized by December.Based on this pre-
liminary conclusion,on the blood data (which suggested that the
condition of Susitna moose had deteriorated over the past few
years),and on the apparent lack of any significant fires in the
past 30 to 35 years,it appears that the impoundment zone may not
presently be of any significant value as a winter food reserve
for moose.If a natural fire were to occur in the forested areas
along the river sometime in the future,the value of the proposed
impoundment zone as a wintering area for moose would be greatly
improved.The construction of the Watana faci 1ity,of course,
would preclude that possibility.
The other manner in which the impoundment zone serves the needs
of both sedentary and migratory moose is by providing green
forage early in the spring.Such forage is most prevalent on
south-facing slopes,which are the first areas to become snow
free and allow for the early emergence of herbaceous plants.The
availability of these plants is very important to moose,in
particular to pregnant and lactating cows which have a very high
nutritional demand.A very large proportion of the south-facing
slopes in the area wi 11 be flooded by the Watana impoundment.
What this will mean for the moose population will depend to a
large degree on the severity of winter conditions.Following a
mild winter,moose may not be nutritionally stressed enough to be
impacted by this reduction in early spring forage.Following a
more severe winter,however,the early availabi lity of green
forage may help to reduce starvation mortality.
The relatively sedentary moose which·are displaced from the im-
poundment zone will aggravate the situation described above,
since they wi 11 compete for food with moose already inhabit i ng
adjacent areas.This will likely hasten the process of range
deterioration that appears to be currently underway.The
severity of this situation and the damage which will be done to
vegetation will depend on the ability of the surrounding area to
support additional moose and on the predation rate of wolves on
these moose.If sufficient wolf predation takes place before the
habitat is over-utilized,the long term quality of the habitat
may not be too severely affected.In this case,the key element
will be the degree to which wolves are adversely affected by the
project.Being more sensitive to disturbance than moose,it is
possible that,at least at first,the wolf population will be
reduced to a greater degree than the moose population thus al-
lowing for greater moose survival and consequently greater poten-
tential for habitat damage because of an overabundance of moose.
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In addition to direct habitat loss,the moose in the area may be
adversely affected by microclimatic changes caused by the
impoundment.It is predicted that the Watana -impoundment wi 11
alter the microclimate in the immediate downwind areas.Temp-
eratures may be reduced sufficiently in some areas to retard the
emergence of spring vegetation which,as previously explained,
moose utilize for forage in early spring.Although this
possibi lity of microcl imatic effects impacting moose through an
influence on vegetation does exist,it is not likely to be of
major significance due to the distances that will exist in early
spring between the permanent shorel ine and open water.Because
of the projected drawdown schedule,the impoundment should be at
its lowest level at or following the breakup of ice.In areas
where the impoundment is very wide,such as the Watana Creek
drainage,the potential for microclimatic changes are greatest
because moving air will pass over a greater distance of water.
It is also in such areas,however,that the greatest distances
will exist,due to topographic features,between open water at
this time of the year and the shoreline:in many areas these
distances will exceed the 1.6 km zone of influence predicted for
microcl imatic changes.In those sections where the impoundment
is narrow,such as east of Jay Creek,the potential for
microclimatic changes is less because of the reduced surface area
of water.In these areas,however,the di stance between water
and shorel-ine will be minimal in early spring,again due to
topography.In other words,where the potential for
microclimatic changes is greatest,the vegetation is far from the
water,and where the vegetation is near the water,the possibi-
lity for microclimatic changes is less.
The potential for microclimatic changes having an impact on moose
is far greater during the winter months when the impoundment is
ice-covered.The relatively smooth surface of the ice will
reduce the frictional drag of winds,which are from the east and
northeast during winter and this will cause the blowing and
drifting of snow for several kilometers inland on the downwind
(west and southwest)side of the reservoir.It is therefore
1 ikely that,in many areas downwind of the impoundment,snow
accumulations will be far greater than those that presently occur
in the area.This will greatly restrict the use of such areas by
moose in the winter.First of all,deep drifts will improve the
ability of wolves to kill moose in these areas.There will also
be less browse available.Finally,moose weakened by passing
through such drifts will be more vulnerable to wolf predation.
In summary,moose will be impacted through the loss of 26,813 ha
of habitat and a reduction in usable winter habitat downwind of
the impoundment due to snow depths.Th i sloss wi 11 cause the
direct displacement of those moose whose home ranges are located
primarily within the project area.It will also reduce signifi-
cantly the availability of early spring forage,which is of some
importance,and,following severe winter conditions,probably
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critical to many moose in the area.The project will also
eliminate a possible wintering area which is presently of
questionable value.Although other factors may also affect moose
(such as increased difficulty in negotiating ice conditions
during breakup and disturbance from human activity around
construction and clearing operations),they are all relatively
minor in comparison to the direct and indirect loss of habitat.
How many moose will be adversely affected and the degree to which
the carrying capacity of the area will be reduced are currently
unknown.Based on the census data collected and the distribution
of moose use,it is possible that 400 moose may be severely
impacted as a resu lt of di rect di sp 1acement or loss of major
portions of their home ranges.An additional 800 moose could be
impacted to a lesser degree through an overall reduction in the
carrying capacity of the region and overcrowding from displaced
moose.This is a very rough estimate and the actual numbers
could vary as much as 50%(200 to 600 severely impacted and 400
to 1200 moderately impacted).Possible mitigation measures to
reduce these impacts are discussed in Section 3.9.
-Caribou
The amount of caribou habitat lost as a result of the inundation
of terrain by the Watana impoundment wi 11 be insignificant.
Less than one percent of caribou habitat in the upper Susitna
River basin will be inundated by both the Devil Canyon,and Watana
impoundments combined.Furthermore,the habitat to be lost is of
low quality.
The proposed reservoir,however,does intercept an historically
important migration route of the Nelchina caribou herd across the
Susitna River between Deadman and Jay creeks.Ice conditions on
the shoreline of the impoundment may act as an obstacle to future
crossings of the impoundment,and the ice conditions on the
impoundment itself may constitute an additional obstacle to
migrating caribou.
The annual drawdown of the reservoir in winter will result in the
impoundment being at its lowest level at the time of the spring
migration,in late April and early May.At this low point,the
impoundment wi 11 average approximately 27 m (90 ft)lower than
when it is full in September.The gradual winter drawdown will
result in the formation of ice shelves grounded on the shQre.
These shelves will fracture into linear strips as the supporting
water recedes and strands the ice on the shore.The width of the
strips and the difference in height between adjacent shelves will
depend upon the thickness of the ice.The thinnest shelves will
be lodged highest on the banks in early winter.Where the slopes
of the shoreline are gradual,such as along the Watana Creek
drainage,the shelves will be wide and flat and more easily
traversed.Where the banks are steeper,the shelves will be
fractured into smaller blocks and pile up as ice moves up from
below and slides down from above;these areas may be more
difficult for caribou to cross.
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These spring conditions in the impoundment will be significantly
different from those occurring at present in spring along the
Susitna River in the vicinity of the traditional caribou
crossing.The ice shelf area wi 11 be wider than the present
shelves formed on the river bank.The breakup also will be
delayed for several weeks.The risks involved in crossing the
impoundment wi 11 be different from those associ ated with the
swiftly flowing river carrying river ice floes downstream.
During this period,crossing the reservoir would be hazardous to
caribou.
In addition,during the winter months,the prevailing winds are
from the east and northeast.They wi 11 pus h snow across the
smooth ice of the impoundment to pi le up and form a deep snow
bank along the downwind shore.During the spring breakup,this
snow bank wi 11 be alternately soft during the warmer days and
crusted during the chi 11 nights.It may constitute another
obstacle to caribou attempting to climb the south bank.
This migration route was used in the past by a considerable
portion of the Nelchina herd when it frequented the northwest
portion of its distribution,but has been used by only small
numbers of caribou since 1971,with the possible exception of
1976.It is not possible to predict when the herd might return
to its former migration patterns,but it is reasonable to expect
that it will at some period in the future,especially if the herd
population increases dramatically.When the route was utilized,
it was used by three di st i nct mi grat i ng groups:(1)pregnant
cows and yearlings migrating southward during late April and May
across the river to the traditional calving grounds in the Kosina
Creek and Oshetna River valleys;(2)cows and calves during the
post-calving migration to northern summer ranges in late June and
July;and (3)mixed bands of caribou during August and September.
The conditions that caribou will face in the impoundment during
the later migrations will be much different from those described
for the spring migration.During the summer and early autumn,
the impoundment wi 11 be reaching its full level and wi 11
const itute a 1Otlg,narrow 1ake averagi ng approx imatel y 1-2 km
wide.It is not expected that the caribou will experience any
special difficulties in crossing the reservoir during those
periods;caribou are excellent swimmers,and they regularly cross
lakes when migrating.
Migrating caribou could respond in a variety of ways to the
changed envi ronment which the impoundment wi 11 create.The
severity of the obstacle caused by the shore ice shelves will
vary depending on the stage of breakup and the point at which the
caribou reach the impoundment;they may approach at a steep bank
or a gradually sloping shoreline.
The possible reactions produce a variety of potential results in
the future distribution of the Nelchina herd.In one scenario,
the migrating caribou will travel along the shore until they find
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a safe crossing point,as they do at present.In another,the
caribou will attempt to cross a hazardous section of the
reservoir and suffer increased injury or mortality.In a third,
the caribou will continue eastward along the north shore of the
impoundment towards the big bend of the Susitna River and cross
the river above the confluence of the river with Goose Creek or
the Oshetna River,where the impoundment largely will be drained
at this time of year and contain a flowing river.This last
action would lead to a delay of a day or two in reaching the
calving grounds with unpredictable consequences for the pregnant
cows.In a final scenario,the obstacles associated with the
impoundment might constitute such a formidable barrier that the
caribou will be forced to turn back and to bear their calves on
the alpine plateau,between the Susitna and Nenana Rivers.This
area is already recognized as a secondary calving ground.
The last scenario described above might cause a temporary
separation of the cow and bull groups.The worst possible case
is that it would cause the isolation of a sizable portion of the
herd in the northwest portion of the range which has been used in
the past as both summer and winter habitat.At present,this
area supports a small subherd that is estimated to total less
than 1,000 animals.
Although it is difficult to predict how caribou will react,
based on the present knowledge of caribou behavior the possible
reactions of the Nelchina herd to the impoundment have been
placed in the following order,starting with the most likely
reaction and proceeding to the least likely reaction.
1.The caribou will manage to cross the impoundment
safely in the Watana and Kosina creek area.
2.The caribou will travel eastward and cross the
Susitna River in the vicinity of the Oshetna and
Tyone rivers on ice-covered flats.
3.The caribou will make hazardous crossings with
increased mortality.
4.The caribou will refuse to cross the impoundment
and return northward.
The number of activities associated with the construction phase
of the Watana dam const itute potenti a 1 short-term impacts on
caribou.The clearing of woody material from the impoundment
area prior to flooding may disturb migrating caribou for a period
of up to five years before filling is complete.Caribou
migrating southward in spring or northward in summer may be
disturbed by the unnatural cleared area in the impoundment zone.
Air traffic in and out of the Watana construction camp,
particularly low-level helicopter traffic,also constitutes a
potential impact upon the caribou.If low-level flights occur
over the nearby traditional calving grounds,a deleterious impact
upon the whole Nelchina herd could result.Similarly,any ground
travel by workers to the calving grounds could constitute a
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serious disturbance to the caribou at a particularly sensitive
period during their annual cycle.The dam site is a considerable
distance from the calving grounds,but work crews clearing the
impoundment zone will be much closer.Mitigation measures
proposed to deal with this problem are presented in Section 3.9 •
-Wolf
The most severe impact of the proposed Watana impoundment on
wolves will be a reduction in the abundance of prey,in
particular moose and caribou.As previously discussed,the
likelihood of a major impact on caribou is not great,and
therefore the prime avenue of impact on the local wolf population
will be a reduction in the number of moose.There will
definitely be fewer moose present in the area;and due to
overcrowding by displaced moose,there will likely be some
reduction in the total carrying capacity of the area.Since
moose are the prime and most dependable food source for wolves,
there wi 11 also be a parallel reduction in the resident wolf
population.
This predicted reduction in wolves represents the long-term
-impact.For a short time following the filling of the im-
poundment,there may be an increase in wolf numbers.This
possibility is based on the assumption that wolf numbers will not
be reduced as a result of some other aspect of the project such
as disturbance from human activity.As discussed in the des-
cription of impacts on moose,displacement which results in
increased population density and competition for food may reduce
the vigor of individual moose and improve the ability of wolves
to secure food for a few years.Increased ease of obtaining food
may result in wolves requiring smaller territories,and thus
provide opportunities for the establishment of more packs.
Greater food availabi lity may also result in improved reproduc-
t i ve success on the part of res i dent packs.In addit i on,as
mentioned in the moose section,deep snow drifts downwind of the
impoundment during winter may further increase the vulnerability
of moose to wo lf predat i on.The change in moose vul nerabi 1ity
will,however,be of short duration;following the overall
reduction in the number of moose and the carrying capacity of the
adjacent areas,the mechanisms that served to increase the wolf
population will be reversed and the net result will be fewer
wolves.
If the impact on moose is restricted to the area "immediately
within and adjacent to the impoundment,at least six or seven
resident wolf packs will be affected as described above.The
impact of wolves farther removed from the impoundment will depend
on how far the impoundment will have an influence on moose.
An associated factor in the long-term impact on wolves concerns
the future of the Nelchina caribou herd.Since the impoundment
is not expected to have a severe impact on that herd,caribou
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wi 11 sti 11 be available to wolves as an alternative to moose.
Because of the ir mi grator y nature,car i bou are 1es s important
than moose to the long-term maintenance of wolf numbers.Yet,if
the Nelchina herd continues to increase,it is possible that,to
some degree,caribou wi 11 compensate for the predicted loss of
moose.The increase in the size of the caribou herd is not
necessarily related to the project but is dependent to some
extent on the current management objectives of ADF&G.The number
of wolves and,more importantly,the locations of wolf packs that
may benefit from an increase in the size of the caribou herd will
vary and are impossible to predict.
Another direct manner in which the Watana impoundment may impact
wolves is through the loss of den sites.Since not all of the
wo 1f packs that are res i dent near the impoundment were radi 0-
collared during the course of these studies,it is not known how
many den sites may be lost.At least one and perhaps two den
sites are very close to the impoundment and may be abandoned
because of flooding or project-related disturbance.Based upon
the characteristics of den sites examined during these studies
and the apparent abundance of such sites in the area,it is not
believed that the availability of den sites is a limiting factor
for local wolf populations.The loss of some den sites as a
result of flooding is therefore considered insignificant in
comparison to the reduction in prey.Although it is pure specu-
lation at this point,it should be noted,however,that since
most wolf dens are enlarged red fox dens,the long-t~rm status of
the fox population may be important to the availability of
suitable wolf dens.The fox population is not presently very
high,and there are many old fox dens still available;should the
Susitna project result in a major reduction in the number of
foxes,however,the long-term availabi lity of denning sites for
wolves may ultimately be lower.
Increased air traffic and disturbance resulting from the clearing
of the Watana impoundment are also sources of potential impacts
on wolves.Although observations suggest that denning wolves can
adjust to air traffic,they appear to be very intolerant of
ground disturbances.Therefore,since at least two known den
sites are close to the edge of the Watana impoundment,the
clearing activities required to remove woody vegetation,if they
are conducted during the denning period (May through July),could
result in den abandonment and pup loss.This would most likely
be a short-term impact and,assuming that the den sites were used
following the disturbance,the overall impact might not be of
major consequence.
-Wolverine
The construction and operation of the Watana facility will impact
wolverines in basically three ways.The first is the loss of
habitat that wi 11 resu lt from the impoundment and associ ated
facilities.As mentioned,this loss will total 26,813 ha.This
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loss of habitat and associ ated foraging areas wi 11 reduce the
ability of the area to support wolverines to some unknown
degree.
The second impact is related to the expected reduction in the
number of moose and the associated reduction in wolves.Although
wolverines do directly prey on a variety of animals,they are
well known as scavengers which feed on large animals such as
moose and caribou that have been killed by wolves.The reduction
in moose and wolf numbers will mean that fewer wolf-killed moose
will be available for use by wolverines.As discussed in the
wolf section,for a few years following inundation,there may be
a short-term increase in wolf-killed moose.Therefore,this
impact on wolverines may take several years to materialize and
will actually occur after the moose and wolf populations become
lower.
The third and probably the most critical impact on wolverines
will be disturbance by human activity.This species requires
expanses of remote,uninhabited area.The development of a
highly concentrated center of human activity around the Watana
dam site plus the human activity associated with the clearing of
the impoundment will most likely render a large portion of the
1and adjacent to the Watana impoundment unacceptab 1e to wo lver-
ines.The disturbance associated with the clearing activities
wi 11 be of a short term nature and the area adjacent to the
impoundment may be suitable for wolverines following inundation;
the permanent facilities around the dam site,however,will
preclude the presence of wolverines in that portion of the upper
Susitna basin.
In summary,the Watana impoundment and associated facilities will
result in a reduction in the wolverine population.The mechan-
isms of impact include habitat loss,reduction in wolf-killed
ungulates,and human activity.The core portion of the wolverine
study area,which includes the Watana impoundment,was estimated
to contain 11 to 21 adult wolverines during the current studies.
It is likely,because of the sensi-tivity of this species to
disturbance,that the majority of these wolverines will be
displaced during the construction and filling phases of the
project.The extent to which wolverines will use the area
following the activities associated with construction and filling
is unknown,but it is likely that the upper portions of the
impoundment area will pfove suitable for some wolverine use.
-Brown Bear
As is the case for other big game species,brown bears will be
impacted by the Watana facility through a loss of habitat.
Because brown bears exhi bi t very 1arge home ranges whi ch are
characterized by major seasonal shifts in usage,the 26,813 ha of
habitat that will be lost is used to various degrees by brown
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bears.The use of the impoundment area represents only a portion
of the total area covered by this species over the course of a
year.Based on radio-telemetry data and knowledge of brown bear
habits.it has been determi ned that it is un 1 ike 1y that the
Watana facility will cause the loss of any individual brown
bear's home range.As can be seen from Table 3.60.the highest
percentage of overlap of a radio-collared brown bear's home range
and the Watana impoundment was 25.1%(for bear number 281).
Bears number 280 and 340 had home ranges that overl apped the
impoundment area by 11.3%and 10.1%.respectively.The remaining
bears had home ranges that each overlapped the impoundment area
by less than 10%.
Although brown bears appeared to use the impoundment zone
throughout the non-denning season.the greatest use probably
occurred in early spring follow"ing their emergence from winter
dens.There is a pronounced tendency for brown bears to move
from the high elevations where dens are located to the lower
elevations along the river at this time of the year.The reason
for this movement is felt to be the attractiveness of areas along
the south-facing slopes near the Susitna River which are the
first to become snow free and thus make available overwintering
berries and early herbaceous growth.It is also possible that
bears are attracted to these areas because of the increased
likelihood of finding winter-killed moose there.
The importance of these early snow-free areas to brown bears is
not known.Regardless.for the purpose of impact prediction.it
is assumed that the south-facing slopes that wi 11 be flooded
(which represent a large proportion of the south-facing slopes in
the area)are of some importance to brown bears.and that their
loss will reduce.to some unknown degree.the ability of the
upper basin to support a brown bear population comparable in
numbers to the current one.
The Watana impoundment may also function as a barrer to seasonal
movements of brown bears.Several radio-collared bears moved
long distances to utilize the salmon in Prairie Creek.Brown
bears also concentrated in the calving area of the Nelchina
caribou herd where they were suspected of preying on calves.The
bears mayor may not find the impoundment an insurmountable
barri er.That bears are ab 1e to cross the Sus itna River under
high flow conditions suggests that a relatively placid reservoir.
especially at constricted points.should not be a barrier.If
port ions of the impoundment were to prove a barri er to brown
bears.the tendency for bears to travel long distances should
enable them to locate acceptable crossing points or even circum-
navigate the impoundment.
As in the case of the nutritional importance of early snow-free
slopes.it is not known how important the salmon and caribou
calves are to bears.Obviously.many bears in the upper Susitna
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and Nelchina basins exist without salmon as a food source.Yet,
it is cruc ia1 to note that the greater the number of these
seasonal foraging areas that are lost,the greater wi 11 be the
reduction in carrying capacity for brown bears.The relatively
large home ranges of brown bears in the project area could be the
result of widely dispersed food sources.Thus,the loss of any
food source,either directly through flooding or indirectly
through blocked access,could be significant to the bear
population.This is especially true if more than one type of
food is eliminated.It is likely that the brown bear population
will be lowered due to the direct loss of habitat.The loss of
additional food sources (such as Prairie Creek salmon)could
greatly increase that loss.
Another impact on brown bear will be disturbance caused by human
activity.Brown bears are fairly intolerant of human presence
and will either withdraw from the zone of disturbance,in effect
causing a further loss of usable habitat,or possibly come into
direct conflict with humans.Any direct confrontation between
bears and humans,such as would be caused by improperly disposed
food refuse,would likely result in the need to destroy or remove
the bear.
The one aspect of brown bear biology that will not be influenced
by the Watana impoundment is denning.Brown bears den at high
elevations which wi 11 be far removed from both the impoundment
and disturbing human activity at Watana.Air traffic,however,
could be a source of disturbance.No known brown bear dens will
be inundated by the Watana impoundment,and it is unlikely that
any undiscovered dens will be flooded.
In summary,the Watana impoundment and associated facilities will
negatively affect brown bears.The mechanisms of impact will
include:(1)direct habitat loss (especially that of probably
significant early spring habitat),(2)possible blockage of the
movement of bears to seasonally important foraging areas,and (3)
potential indirect habitat loss resulting from disturbance by and
conflicts with humans.In the absence of accurate population
estimates,it is impossible to predict how many bears will be
impacted.Because of the far-ranging movement patterns displayed
by Susitna brown bears,the loss of any seasonal foraging areas
will be a major impact on this population,however 1 and could
cause a significant reduction in the number of bears that inhabit
the area.
-Black Bear
Of all the big game species which inhabit the area,the black
bear wi 11 be the most severely impacted by the Watana
impoundment.Because of the association between black bears and
forested habitats,the loss of 26,813 ha,most of which is
suitable black bear habitat,will result in a drastic reduction
in the number of black bears upstream from the Watana dam.The
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vast majority of the suitable bl ack bear habitat east of the
Watana dam site is within the area of the proposed impoundment.
Black bears are more sedentary than brown bears and spend a
greater proportion of their time in these habitat types.As
indicated on Tables 3.60 and 3.61,a far greater percentage of
black bear than brown bear home ranges will be lost.In three
cases,more than 40%of an individual radio-collared black bear's
home range will be lost.The types of areas that will be lost
are very important for black bears during spring,summer,and
winter.Early fall is the only time when black bears tend to
leave the forested areas in order to feed on ripening berries in
shrub habitats located at slightly higher elevations.The
construction zone around the Watanadam site will also eliminate
a large area of such shrub communities.
Unlike brown bears,which den at higher elevations,black bears
den on the slopes along the Susitna River and nearby tributaries
and will thus be severely impacted by flooding.Proceeding
upstream through the study area,the band of acceptab 1e denni ng
habitat becomes progressively narrower and more confined to,the
immediate vicinity of the Susitna River.Therefore,the impact
of den loss wi 11 also become more pronounced farther upstream
from the Watana dam.Typically,black bears in the study area
denned at elevations between 457 m 0,500 ft)and 762 m (2,500
ft).Of the 13 den sites found in the vicinity of the Watana
impoundment,9 would be flooded by a pool elevation of 666 m
(2,185 ft).
Black bears in the Susitna basin also differ from brown bears in
regard to their reuse of den sites.None of the radio-collared
brown bears that were tracked for two years reused the same den.
Of the located black bear dens,all of the natural cavity dens
examined and one of the dug dens examined had been previously
utilized.This suggests that the availability of suitable den
sites is limited and therefore increases the significance of the
predicted den loss.
Along the Susitna River,upstream from the Watana dam site,the
best black bear habitat is found on the steep slopes (especially
the south-fac i ng slopes)and the habitat becomes 1ess su itab 1e
farther from the edge of these slopes where the density of trees
becomes lower.Therefore,not only will the impoundment
eliminate a large amount of black bear habitat,it will eliminate
virtually all of the prime habitat,leaving only marginal habitat
unflooded.Thus,the simple quantification of hectares of
habitat lost does not accurately reflect the magnitude of that
loss.The habitat which will remain is of marginal value to
black bears not only for foraging and denning but also as
protective cover from brown bears.
In summary,although the Watana impoundment will impact black
bears in a variety of ways,they are all insignificant and moot
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in comparison to the direct loss of critical,prime habitat:
there will be a major reduction in the number of black bears
inhabiting the project area.East of Jay Creek,because of the
constricted nature of the forested habitat in that area,it is
likely that virtually all resident black bears will be lost.The
degree of loss wi 11 be gradually 1ess as on proceeds west from
Jay Creek to the Watana dam site.In the absence of accurate
density estimates,in addition to the many unknowns concerning
the response of both black bears and brown bears which influence
the abundance of bl ack bears,it is difficult to accurately
pred i ct the magnitude of the loss that wi 11 occur between Jay
Creek and the Watana dam.Based on the data available,however,
it woul d be reasonab 1e to assume that between 70%and 90%of the
bears resident in this area will be eliminated.The percentage
of loss will probably be lower as one approaches the Watana dam
from the east.
Dall Sheep
Of the three sheep herds identified in the upper Susitna basin
during these studies (Portage-Tsusena Creek,Watana-Grebe
Mountain,and Watana Hills),only the Watana Hills herd will be
impacted by the Watana impoundment.This herd occupies the
mountainous region north of the Susitna River and east of Watana
Creek.The 1980 count of the Watana Hills herd indicated that
209 sheep were present.The Watana impoundment wi 11 inundate
a portion of the Jay Creek mineral lick and none of the rest of
the area used by the herd.
As described in Section 3.2{a)(viii),this mineral lick is
located on cliffs along Jay Creek very close to its confluence
with the Sus itna River.Pre 1imi nary observat ions indi cate that
sheep use much of the cliff area,from the river bottom up to and
beyond the upper rim.Sheep use appears to be concentrated
during the months of May and June.Observations of numerous
sheep using the lick at the same time and experience with mineral
licks in other parts of Alaska indicate that it is likely that a
large proportion of the Watana Hills herd visits the lick during
spring.
It is difficult to determine to what extent this herd will be
negatively impacted,if at all,by the loss of a portion of the
lick.There are several other known licks within the range of
this herd,but there is insufficient data available to ascertain
the relative importance of each lick to the herd.Also,it is
not known if sheep wi 11 cont i nue to use the Jay Creek 1 i ck
following flooding.Although a portion of the lick will be
flooded,as a result of the proposed drawdown schedule,the
greatest proportion of the lick will be exposed during May and
June when sheep use it.It is not known whether or not sheep
wi 11 conti nue to use any part of the 1 i ck once the project is
operating.It is even more difficult to predict if sheep will
use that portion of the lick that will be exposed during May and
June and under water duri ng the rest of the year.
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Because of the high degree of use that the sheep make of it and
their willingness to expose themselves to possible wolf predation
in order to reach the lick,it should be assumed that the Jay
Creek mineral lick is of major significance to the Watana Hills
herd.The impact on the herd if flooding renders the lick
unacceptable is a matter for speculation.If inadequate
alternative mineral sources are available at other licks within
the range of these sheep,the possible loss of the Jay Creek lick
may result in a reduced ability of the area to support sheep.
In summary,the Jay Creek mi nera 1 1 i ck wi 11 be affected by the
Watana impoundment.The degree to which sheep wi 11 use the
remaining portions of the lick following inundation and the
significance of the lick to the Watana Hills sheep herd are
unknown.The total loss or abandonment of the lick,however,
could have a possible negative impact on the Watana Hills sheep
herd and lower the carrying capacity of that area for sheep.
(ii)Furbearers
The flooding of the Watana reservoir wi 11 el iminate 15,320 ha of
furbearer habitat,the majority of whi ch is terrestri a 1 habitat.
Because of the annual fluctuations of water levels,the draw-down
zone and the aquatic habitat created wi 11 be of 1 imited va 1ue to
otters,mink,muskrats,and beavers.
As a result of their great dependence upon forested habitats along
the Susitna River and its tributaries,the species most severely
affected by the inundation of terrestrial habitat will be pine
marten.During summer and autumn,foxes utilize riparian zones
along the Susitna River and its tributaries.Flooding of these
areas may,therefore,reduce the carrying capacity of the region
for foxes.None of the fox dens found during these studies will be
flooded.Due to the nature of fox den sites it is likely that only
a few,if any,undiscovered dens will be flooded.
At the present time,lynx appear to be restricted to habitats along
the lower reaches of some tributaries and adjacent to the Susitna
River between Vee Canyon and the Tyone River.Flooding of these
sites may,therefore,totally eliminate lynx from the immediate
vicinity of the Watana impoundment.Because lynx are dependent on
snowshoe hares for food and since hares appear to be restricted
currently to areas within the upper reaches of the Watana
impoundment,the future of lynx in the area wi 11 depend on the
status of hares in areas adjacent to the impoundment.Some form of
habitat alteration,either through natural or artificial means,
will have to occur if hares,and thus lynx,are to become abundant
in the project area.
Development and maintenance of the construction camps and village
associated with the Watana impoundment will displace a limited
number of furbearers.The presence of the camps will probably
result in the abandonment of a fox den located west of Deadman
Creek.Although this den was not used for rearing pups during the
study,indications were noted of past natal use and winter resting
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us e.Foxes may exper i ence addi tiona 1 nega t i ve consequences if
domestic dogs,with the potential for introducing rabies into the
fox population,are housed at the village or camp.
Foxes wi 11 a1so be negat i ve 1y affected if project personne 1,by
s tori ng garbage or di spos i ng it ina manner that 1eaves food
available,deliberately or unwittingly provide food for them.Such
a practice may leave the animals dependent upon this food source
and may also result in artificially high fox populations.
Humans may also experience negative effects of their proximity to
tradit iona 1 wil dl ife habitats.Property cou 1d be damaged and
workers exposed to bites and to wildl ife-transmitted diseases if
foxes,marten,or weasels are attracted to the camps by workers who
feed them directly or who establish feeding stations.
In summary,the Watana impoundment and its associ ated faci 1ities
wi 11 result in a loss of furbearer habitat.Pine marten will be
most severely impacted by these facilities with foxes being
impacted to a lesser degree.The result will be the direct loss,
through mortality,of those animals that will be displaced,and a
subsequent reduction "in the carrying capacity of the area for
furbearers.
(iii)Birds and Non-game Mammals
-Dam and Impoundment
The genera 1 types of impact on raptors that can resu lt from
development activities have been well described by Roseneau et
al.(1981),and Tables 3.62 and 3.63,which summarize di"S"="
tUrbance factors,are taken from their report.Inundation is an
additional potential impact from hydroelectric projects.The
Watana impoundment will flood 15.1 km of the better quality
raptor cliffs (type "A"),leaving only 0.9 km of Type "A"cliff
not inundated (Table 3.64).Four active and four inactive golden
eagle nest sites,two active and one inactive bald eagle sites,
and two inactive raven sites will be destroyed by inundation
(Table 3.65).Loss of this nesting habitat will force these
birds to other sites,either along the remaining cl iffs of the
Susitna River and its tributaries,in the nearby cliff/tor habi-
tat (cliffs and high,craggy hills)of the uplands,or in the
case of bald eagles,to other nest trees.Unflooded cliff habi-
tat in the surrounding area (for example,along Fog and Tsusena
creeks)may increase in importance to these birds.If fish
became available in the impoundment,large trees surrounding the
impoundment might be used for nesting by bald eagles.
The impoundment will inundate 70 km 2 of forest habitat,which
generally includes the most productive avian habitats of the
study area (Table 3.36).A number of bird species are restricted
to forest habitats for breeding (see Table 3.37).Most of these
species are short-lived (except goshawks and great horned owls),
and healthy populations occur in adjacent regions.Red squirrels
and porcupines are also forest species and also occur commonly in
adjacent regions.
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Flooding of the fluviatile shorelines and alluvia,both in the
main Susitna River and up the mouths of tributary creeks,will
destroy breeding habitat of a few bird species (harlequin duck,
common merganser,semipalmated plover,spotted sandpiper,
wandering tattler,Arctic tern,dipper),some of which are
considered uncommon,but none rare,in the region.Impact on
wintering habitat of the dipper (open water along fast-running
t ri butari es and in the Sus itna River channe 1)may be the most
serious impact in this category because local alternative sites
of open water might not be available.Flooding will also deprive
early migrant waterfowl of one of the first sources of open water
in the region--the rapidly flowing waters of the Susitna River.
It is expected,however,that the project wi 11 result in open
water year round below Devil Canyon,at least as far as Talkeetna
[see Sect i on 3.6 (d )(vi)] .
The large impoundment that will be formed may provide habitat for
waterbi rds,but the degree of ut i1i zat i on wi 11 depend upon the
rate and kind of development of food resources in the new lake.
Because of the late spring thaw,the lake will be available only
for the late-migrating diving ducks,loons,and gre~es;in fall,
however,it may remain open long enough to be used by late-
migrating swans.As with the other large lakes of the region,a
low level of use by breeding waterfowl can be anticipated
(provided food resources are available).The anticipated draw-
down zone wi 11 impede use of the reservoi r edge by nest i ng loons
and grebes,which usually nest at the edge of sedge~shorelines or
on small low-lying islands.Migrant shorebirds,who primarily
move through central Alaska during the last three weeks of May,
wi 11 probably use exposed areas of the drawdown zone for rest ing
and feeding.This zone will be of little use to small mammals.
-Camp/Village Sites
The impacts of camp/vi 11 age sites will be of two mai n types:1)
habitat destruction and alteration and 2)disturbance to animals
themselves,by various types of human activities during and after
construction.The latter impact applies more to birds than to
small mammals.The amount and types of habitat that will be
directly damaged appear inconsequential to the bird and small
mamma 1 popul at ions of the area,primari ly because these upl and
habitats are widespread in the region.Ground squirrels can be
expected to increase and become tame,especially if fed by
workers,and would probably become pests about the camp and
village sites.Some birds,too,such as ravens,magpies,and mew
gull s,wi 11 be attracted to any open refuse dumps.The present
plan,however,is to cover the 1andfi 11 with soi 1 dai ly to
prevent this and other problems associated with birds and mammals
using dumps as food sources.If this plan is carried out,the
problem wil.l diminish.
Perhaps more important,there coul d be si gni fi cant effects on
sensitive bird species and habitats in nearby areas,primarily on
raptors and waterbirds that use wetlands.Increased air traffic
over the Fog Lakes wetlands as a result of activities about the
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dam site or over the Stephan Lake area as a result of trips
between Watana and Devi 1 Canyon camps/vi 11 ages/dam sites cou 1d
adversely affect the waterfowl populations.Although some
species may,to a certain degree,acclimate to such disturbance,
the net result will be a reduction in the suitability of these
areas for raptors and waterfowl.
A few waterbirds use the small,scattered ponds between Deadman
and Tsusena creeks,but because their numbers are small,
potent i all osses through human i nfl uence wi 11 be mi nor compared
to their overall population levels in the region.
The Watana camp site is in the general vicinity of raptor/raven
cliff habitat along lower Deadman Creek.An active raven nest
and territorial merlins were observed here in 1981.The habitat
in this location will be flooded by the impoundment,however,so
the major impact here wi 11 be the habitat IS prox imity to the
reservoir and not to the camp.Depending on its exact location,
the village site could be within 1.5 km of a bald eagle nest that
was active in both 1980 and 1981,or within 2 km of two raven
nest sites,one active and one inactive,along Tsusena Creek.
(b)Devil Canyon Dam and Impoundment
(i)Big Game
A total of 8,736 ha of habitat will be lost as a result of the
construction of the Devil Canyon facility.This total includes the
impoundment,dam,spillway,and camp and also the constructipn zone
around the dam site.Impacts of borrow areas associated with the
construction of the Devil Canyon dam are addressed in Section 3.6
(c).Of this total,3,196 ha will be permanently lost through
flooding,and the remaining 5,540 ha lost as a result of other
facility components.Some of the 5,540 ha will be reclaimed
following use,and will probably,to some degree,serve as habitat
for big game in the future.
-Moose
The Devi 1 Canyon impoundment and _assoc i ated project faci 1it i es
will impact moose in the same manner as described for the
proposed Watana impoundment [see Section 3.6(aHi)].Because
fewer moose were found in the vicinity of the Devil Canyon
impoundment,the impacts of the facility should be less than
those predicted for Watana.
The primary reason for the difference in moose abundance
(depicted on Figure 3.12)is that moose in the Devil Canyon area
are more sedentary than those in the Watana area,especially the
easternmost portion of the Watana impoundment.Moose were
tallied during March 1980 -in areas that abutted the Watana and
Devil Canyon impoundments.Of the total 636 moose counted,only
106 were in the vi cinity of the Devi 1 Canyon impoundment,and
only two were actually in the impoundment zone.During an
intensive survey of the impoundment zones during March 1981,30
3-147
moose were estimated to be present in the proposed Devi 1 Canyon
impoundment zone.The difference between the two years is
probably a result of the level of intensity employed in the
survey effort.Thirty is probably a more typical number of moose
than two.Yet,it is likely,because of the mild winter
conditions that prevailed during these surveys,that this
reported extent of use of the impoundment zone does not represent
the situation as it would exist during more harsh winter
conditions,when more moose would be expected near the river.
Another difference between the two impoundments is the difference
in their expected impacts on microclimatic conditions.The same
type of changes described for Watana wi 11 probably occur around
the Devil Canyon impoundment,but,because of the smaller size
and narrower configuration of the Devi 1 Canyon impoundment,the
degree to which microclimatic conditions will change and affect
vegetation will probably be less than at Watana.Although there
will be less of an exposed drawdown zone in Devil Canyon and thus
the open water will be close to shoreline vegetation,the
distances that air will move over open water will be less than in
many portions of the Watana impoundment,and so the net impact
will be less.The same principle holds true for blowing and
drifting snow during winter.Blowing snow will be deposited over
1and areas on the downwind side of the impoundment,but because
of the size and orientation of the impoundment,the impact of
such snow drifts will probably be more localized and less severe
than at Watana.
In summary,moose will be impacted through habitat loss,and the
number of moose present in the Devi 1 Canyon impoundment zone and
adjacent areas will be reduced.The mechanisms described for
impacting moose in the Watana impoundment area also will function
to impact moose in the vicinity of the Devil Canyon impoundment.
The total loss of moose will be less than at Watana as fewer
moose are present,1ess habit at wi 11 be lost,and there wi 11 be
reduced impacts from changes in mi crocl imat ic condit i on s.Based
on the moose census and distribution data,approximately 100
moose may be severely impacted as a result of direct displacement
or the loss of major portions of their home ranges.An addi-
tional 200 moose could be moderately impacted as the result of an
overall reduct ion in the carryi ng capac ity of the regi on.Thi s
is a very rough estimate,and the actual number of moose impacted
coul d differ by as much as 50%(50 to 150 severely impacted and
100 to 300 moderately impacted).
-Caribou
The construction of the Devil Canyon dam and impoundment will
have an insignificant impact on the Nelchina caribou herd.The
terrain to be flooded contains low quality caribou habitat.The
scarcity of caribou trails crossing the valley in this area
indicates little caribou traffic.The Chunilna Hills subherd,
which occupies the plateau south of the Susitna River,consists
of fewer than 350 animals.This subherd is relatively
sedentary.
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-Wolf
The same mechanisms that will function to impact wolves in the
vicinity of the Watana impoundment [see Section 3.6(a)(i)]will
also serve to impact wolves residing near the Devil Canyon
impoundment.In general,the predicted reduction in the number
of moose inhabiting the area will result in the presence of fewer
wolves.Three or four resident wolf packs are suspected to
inhabit the area adjacent to or just west of the Devil Canyon dam
and impoundment (see Fi gure 3.16)and coul d be impacted by a
reduction in the number of moose available in that general area.
As discussed for the Watana impoundment,impacts on moose wi 11
represent a short-term benefit,but a long-term detriment,to the
wolves in the area.
Desp ite the simil arity of impacts on wo 1ves in the two impound-
ment zones,there is one major difference which could increase
the relative magnitude of the predicted impacts on wolf packs in
the Devil Canyon area.Wolves in the vicinity of the Watana im-
poundment frequently have access to caribou as alternative prey.
Because of the migration patterns of the Nelchina herd,there is
and has historically been comparatively little use of the area
west of Devil Creek by Nelchina caribou.Therefore,the wolf
packs that wi 11 be affected by the Devi 1 Canyon faci 1ity are
probably totally dependent on moose for their winter food supply,
and a reduction in the number of moose available to these packs
may represent a more severe impact than that suffered by wolves
residing east of the Watana dam site.
-Wolverine
Because of the lack of accurate census data on wolverines,it is
impossible to predict exactly how many wolverines will be nega-
tively impacted by the Devil Canyon impoundment.As described in
the discussion of the Watana impoundment [Section 3.6(a)(i)],
wolverines will be impacted by habitat loss,a reduction in the
availability of wolf-killed moose,and disturbance by human
activity.Since wolverines are typically a low density species
even under ideal habitat conditions,the number of wolverines
that will be impacted by the Devil Canyon facility will be low.
Following the clearing of the Watana impoundment,it is expected
that there will be relatively little human activity in the upper
reaches of the impoundment;this situation might allow for
wolverines to use the area again sometime in the future.The
disturbance of wolverines around the proposed Devil Canyon
impoundment wi 11 be more permanent.The presence of an access
road and transmission lines between the two dam sites as well as
a center of human activity at each dam site may preclude the
existence of any resident wolverines on the north side of the
Devi 1 Canyon impoundment.If there is no additional development,
the 1and area south of the Devil Canyon impoundment coul d be
utilized by wolverines following the clearing and filling
operations.
3-149
-Brown Bear
Bec au se there is 1es s open co unt ry adj acent to th e Dev i 1 Canyon
impoundment than to the Watana impoundment,there are fewer brown
bears in the vicinity.As can be seen on Table 3.60,only five
of the radio-collared brown bears had home ranges that overlapped
the Devil Canyon impoundment lone,and in all cases the
percentage of overlap was relatively small.Therefore,although
the Devil Canyon impoundment will be detrimental to brown bears
in the same fash i on as will the Watana impoundment [see Sect i on
3.6(a)(i)]there will be fewer brown bears impacted by the Devil
Canyon facility.
The severity of the predicted impacts will be less because of
differences in the proportion of spring foraging habitat lost.
In the Watana impoundment,a large proportion of the south-facing
slopes will be lost.Because of differences in pool level and
associated topography,a far greater proportion of spring
foraging areas will be left in the Devil Canyon irnpoundment area
than at Watana.
The Devil Canyon impoundment also will be a potential barrier·to
the movement of brown bears to Prai ri e Creek to feed on salmon.
Although the Devil Canyon impoundment will be narrower than that
at Watana and,therefore,brown bears might find crossing the
impoundment less of an obstacle,it will be more difficult for
brown bears in th is area to move around it because of other
project components that wi 11 be present at each end.It is
possible,however,that the placid reservoir will be more easily
crossed than the flowing waters of the river.
-Bl ack Bear
The proposed Devil Canyon impoundment will have less severe
impacts on local black bear populations than will the Watana
impoundment [see Section 3.6(a)(i)J,but impacts will be marked
regardless.Table 3.61 presents the percentage of overlap
between the Devi 1 Canyon impoundment and the home ranges of
radio-collared black bears.
The average elevation of black bear dens in the vicinity of the
Devil Canyon impoundment was 664 m (2,178 o ft)with a range of 454
m (1,490 ft)to 1,323 m (4,340 ft).Of 16 black bear dens found
in the vicinity of the Devil Canyon impoundment,only one would
be flooded by a maximum pool elevation of 444 m (1,455 ft).
There will also be a large area of suitable foraging habitat left
adjacent to the impoundment.There wi 11 be a reduct i on in the
number of black bears in the area,but,unlike the impact at the
Watana impoundment (where the vast majority of the suitable black
bear habitat in that portion of the upper basin will be lost),
the relative magnitude of the impact of the loss of habitat at
Devi 1 Canyon wi 11 be reduced by the proximi ty of 1arge areas of
suitabl e habitat.
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-Dall Sheep
None of the three sheep herds identified in the upper Susitna
basin during these studies (Portage-Tsusena Creek,Watana-Grebe
Mountain,and I~atana Hills)will be affected by the proposed
Devil Canyon impoundment.The herd closest to the impoundment is
the Portage-Tsusena Creek herd;a total of 72 sheep were counted
in this herd during July 1980.This herd occupies the
mountainous area northwest of the Devi 1 Canyon impoundment and
should not be affected in any manner by the impoundment.
(ii)Furbearers
The proposed Devil Canyon impoundment will eliminate approximately
2,834 ha of furbearer habitat,the majority of which would be
terrestrial habitat.The greatest impact of this flooding would be
on pine marten and,to a lesser degree,red foxes.None of the fox
dens found during this study would be flooded by the Devil Canyon
impoundment.Due to the nature of fox den sites,it is likely that
only a few,if any,undiscovered dens would be flooded.The
elimination of some riverine aquatic habitat would also result in a
reduction of the number of mink and river otters that the area can
support.Since beavers and muskrats utilize the area within the
Devil Canyon impoundment zone very little at this time,there will
be relatively less impact on these species.
Because of the drawdown schedule,the aquatic habitat created by
this reservoir will be of limited value to otters,mink,beavers,
and muskrats.For example,Murray (1961)indicated that the annual
rise and fall from the normal water level should be no more than
0.6 m for beavers to utilize an area.The unvegetated drawdown
zone will also reduce the suitability of the newly created aquatic
habitat for species such as mink and otters.
The construction camp and village associated with the Devil Canyon
impoundment will displace a limited number of furbearers.At Devil
Canyon,problems are expected to be similar to but not as serious
as those in the Watana impoundment zone because furbearer numbers
are generally lower near Devil Canyon.
(iii)Birds and Non-game Mammals
-Impoundment
The Devil Canyon impoundment will involve many of the same
consequences to birds and non-game mamma 1s as the Watana im-
poundment will create.Inundation,which will flood 27.4 km of
type "A"raptor cl iffs and leave 24.9 km not inundated (Table
3.64),will destroy one active and two inactive golden eagle nest
sites and two raven sites,one active and·one inactive (Table
3.65)•
For some reason,in spite of the presence of cl iffs with good
structural characteristics,Devil Canyon itself is little used
for raptor nesting.Possibly,the deep,narrow canyon with its
3-151
often strong and buffeting winds makes this area undesirable for
raptors.With the filling of the deeper,narrow portions of the
canyon upstream of the Devil Canyon dam,the environmental
conditions along the remaining type "All cliffs may conceivably be
altered enough to attract nesting raptors and ravens.That is,
the remaining canyon will be wider and shallower and perhaps have
less violent winds and,thus,be more hospitable to nesting
birds.
Finally,cliffs along Portage and Devil creeks and others
draining into the south side of the proposed Devi 1 Canyon im-
poundment may become more important to birds displaced by
inundation.Moreover,if the reservoir supports fish,then bald
eagles may nest in large trees around the impoundment.
In addition to c1 iff habitat,the Devi 1 Canyon impoundment wi 11
destroy 25 km 2 of forest habitat,which a number of bird
species as well as red squirrels and porcupines rely on for
breeding sites (see Tables 3.36 and 3.37).
Flooding associated with Devil Canyon will destroy the breeding
habitats of the same few unusual bird species as those affected
by the Watana inundation.Likewise,early migrant waterfowl may
lose sections of the Susitna River that represent some of the
region's first sources of open water.This loss of early open
water may be compensated for by the ava i 1abi 1i ty of open water
throughout the winter and spring below the proposed Devil Canyon
dam at least as far downstream as Ta"lkeetna.
Like Watana,the Devil Canyon reservoir may offer habitat in the
spring to some late-migrating diving ducks,loons,and grebes
and,in fall,to late-migrating swans.In addition,if food is
available,it may also be used to a limited extent by breeding
waterfowl.On the other hand,the changed shorel ine at the
Devil Canyon site probably will not create the level of impact
that Watana will exert.The steep slope of the shoreline will
limit waterbird nesting habitat around the impoundment.
Moreover,the steeper and smaller drawdown area will be less
attractive to migrant shorebirds than the Watana drawdown zone
wi 11 be.
-Dam Site
Cheechako Creek,the tributary canyon 1.0 km southeast of Devil
Canyon dam site and south-southeast of Borrow Area G,contains
raptor cliff habitat.A gyrfalcon nested here in 1974 (White
1974),and in 1981 a goshawk nested in birch woods on the east
bank.The dam project itself may avoid damage to this tributary
above the impoundment level.Depending upon the proximity and
degree of human activity associated with a proposed recreation
facility,raptors that may be driven away by construction
activities may return to nest on the c1 iffs after construction
activities subside.
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-Camp/Village Sites
The impact of the Devil Canyon camp/village sites will generally
be the same as those at the Watana sites,that is,hab i tat de-
struction and alteration compounded by disruption from human
activities during and after construction.Habitat loss will
consist of 75 ha of closed conifer-deciduous forest.
An active golden eagle nest site along the north side of the
Susitna River,below the dam site,is 1.5 km from the camp site
and 1.6 km from the vi llage site.In 1974,a gyrfalcon nested
(White 1974)in the canyon (Cheechako Creek)2.2 km east of the
village site.This nest site was active in 1980 (species
unknown)and was inactive in 1981.
No wetlands significant to waterfowl occur in this area,but air
traffic between Devi 1 Canyon and Watana camp/vi 11age/dam sites
could adversely impact the relatively important Stephan Lake
wetlands.Although some duck species may acclimate to the air
traffic,it is unlikely that swans will successfully make the
adjus tment.
(c)Borrow Areas
(i)Big Game
The major impact that the borrow areas for dam construction wi 11
have on big game species is the loss of habitat:a total of 1,751
ha will be disturbed (excluding those borrow areas that will
eventually be inundated)and thus lost as habitat.The specific
plant community types and corresponding quantities affected can be
found on Tables 3.56 and 3.57.The cover types that comprise most
of the area to be disturbed are woodland spruce (black and white),
mixed low shrub,birch shrub,and closed mixed forest.To some
extent,the habitat loss wi 11 be temporary.With rec1 amation
efforts,many of the borrow areas will be restored to a level that
will permit some use by big game.
This loss of habitat will affect big game species to various
degrees.Moose and black bears will incur the greatest impact.
All of the land area encompassed by the proposed borrow sites is
used by moose;the greatest use probably occurs in borrow areas D,
E,F,and H (see Figures 3.11 and 3.12).Since most of the moose
in the vicinity of the Watana dam site are relatively sedentary,
the borrow areas there will probably result in the loss of such a
large portion of the annual home range of these moose that they
will be displaced.Displaced moose will incur high mortality and
for a short time period could compete for food with moose in
adjacent areas.The net impact will be fewer moose in the area of
the borrow sites and,as a result of overcrowding,a possible
long-term reduction in the carrying capacity of adjacent areas.
3-153
Black bears in the borrow areas will be impacted in several ways,
all of which are similar to those described in Sections 3.6(a)(i)
and 3.6(b)(i).With the exception of 70 ha of mat and cushion
tundra in Borrow Area A,the area to be lost is all suitable black
bear habitat.All of the forested portion is good habitat during
winter (when bears den),spring,and summer.The shrub types
(mixed low and birch)serve as early fall foraging areas for black
bears when berries are available.The greatest loss of forest
types will be in Borrow Areas A,E,H,I,and K.Fall habitat
areas (shrub)that will be lost are found primarily in borrow areas
D and F and,to a lesser extent,in Borrow Area A.
Most of the borrow sites will be located at elevations within the
acceptable range of denning elevations for black bears in the area
(457 m -762 m).Due to relatively flat topography,Borrow Areas A
and D are probably not good denning areas,and thus their loss will
represent only a loss of foraging sites.Borrow Area F is probably
too far north of the forested zone along the river to be used for
denn i ng by b1ad bears.The greatest potent ia1 for the loss of
denning sites as a result of borrow activities is in Borrow Areas
E,H,I,and K.Borrow Area E,located along the lower reaches of
Tsusena Creek,is probably good denning habitat;because of its
proximity to the Watana construction area,however,it is likely
that this area and any denning potential it offers,will be
disturbed in many ways other than through borrow activities.
Borrow Area I will be almost entirely within the Devil Canyon
impoundment with the exception of 34 ha.This 34 ha.,however is
composed of closed mixed forest and open black spruce situated
along the slopes adjacent to the Devil Canyon impoundment zone and
is therefore probably good denning habitat.Borrow Areas Hand K
are also situated in suitable bear denni ng areas;both of these
borrow areas are south of the Susitna River,however,and,since
the data collected on black bears suggests that there is less black
bear activity south of the river than north of the river,the loss
of denning sites from Borrow Areas Hand K many not be too
extensive.
Brown bears,wolverines,and wolves will also be impacted by the
borrow areas,but probably to a lesser degree than moose and black
bears.The primary impact on these species will be a reduction in
numbers of prey.This impact will primarily affect wolves,and to
a lesser degree,brown bears and wolverines.Brown bears will also
lose some spring foraging habitat.A more detailed discussion of
these two types of impact was presented in Section 3.6(a)(i).In
addition to habitat loss.wolves,wolverines,and brown bears will
be impacted through di sturbance by the human acti vity associ ated
with the borrow activities.Blasting and the movement of large
vehicles in these areas wi 11 most 1ikely cause these species to
totally avoid the areas while they are being used.
Caribou will also be impacted by the borrow areas but not to the
degree described for other big game species.There is relatively
little caribou use of the areas identified for borrow sites.Most
of the use that does occur is attributable to summer use by bulls.
It is unlikely that the cow/calf segment of the Nelchina herd will
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come close to the borrow areas during annual movements.As a
result,the borrow areas will represent primarily a loss of summer
bull habitat.Since bull caribou appear to be less sensitive than
other portions of the herd to human activity and disturbance,they
may continue to use adjacent areas.Considering the intensity and
magn i tude of di sturbance that wi 11 be assoc i ated wi th the borrow
areas,however,they will probably avoid the immediate vicinity of
each borrow area (possibly by more than 2 kilometers).Borrow
Areas A,D,and F are the areas most likely to result in this
limited loss of caribou habitat.
Due to the location of the borrow areas,there should be no impact
on Dall sheep.The closest known sheep usage is on Mt.Watana,
which is approximately 10 to 16 km east of proposed Borrow Area A.
The herd that used Mt.Watana (Watana-Grebe Mountain herd)was not
noted in the vicinity of Mt.Watana during the 1980 survey.They
were located in the southern extreme of the survey area,well away
from the proposed Watana impoundment area.
Although the borrow areas may affect big game in other ways (such
as through the creation of dust which could reduce the productivity
of vegetation in adjacent downwind areas),the prime impacts will
be habitat loss and disturbance by human activity.The habitat
loss is likely to affect moose and black bears more than other big
game species.Disturbance,on the other hand,will probably be
more significant for wolves,brown bears,and wolverines.
(ii)Furbearers
Excavation of borrow sites would have negative effects upon fur-
bearers using the area.Borrow Areas A,D,E,H,and K (Figure 9.7)
would primarily impact pine marten,red fox,and short-ta-iled
weasels.Because of the relatively large area of land involved,
developing Borrow Areas E and F,along Tsusena Creek,would nega-
tively affect red foxes,pine marten,mink,otters,and short-
tailed weasels throughout a sizable portion of the drainage of that
creek.
If 1eft un vegetated fo llowing excavation,the borrow areas wou 1d
have little long-term value to furbearers.The extent of vegeta-
tion restoration measures would determine-the future suitability of
restored habitats for various furbearer species.The creation of
herbaceous and shrub vegetation may be attractive to small mammals
and birds and could provide valuable foraging habitat for foxes,
short-tailed weasels,least weasels,and coyotes,especially if
vegetative heterogeneity is established.Because of the dependence
of pine marten on conifer forests and,specifically,on red
squirrel middens,it is highly unlikely that marten would use
revegetated borrow areas in less than 100 years.
(iii)Birds and Non-game Mammals
Mining of borrow areas will cause two main types of impact:1)
habitat destruction and a lterat i on and 2)di rect di sturbances re-
sulting from human activities.The amount and types of habitat
to be affected by possible borrow areas appear insignificant to the
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total bird and small mammal populations of the area,primarily
because these habitats are widespread in the region.Some borrow
areas will eventually be flooded,anyway,and the others will be
recontoured and revegetated.
The specific effects of borrow mining wi 11 vary somewhat at each
site,depending on the types of habitats destroyed and the types
remaining after construction and reclamation activities.While
birds and small mammals dependent on the destroyed or altered habi-
tats will disappear,those species favoring the newly created habi-
tats will increase their populations.Replacement shrub and forest
habitats will be slow in forming because of the harsh environment.
Overall,the impact of borrow areas wi 11 be greater on forest
habitats than on shrub habitats,partly because forest areas are
considerably less abundant in the region.In addition,a high
proportion of these already less extensive forest habitats will be
inundated by the proposed reservoirs.Thus,the additional loss of
forest habitats to borrow areas will have more impact on the
avifauna than will the destruction of relatively prevalent shrub
habitats.
The activity and noise surrounding the mlnlng operations might
disturb breeding raptors and ravens at nearby cliffs.Table 3.66
is a list of the nest sites within about 1.6 km of the proposed
borrow areas and thus those potentially subject to di sturbance.
Any nest sites not in use by 1 June in any year may be considered
inactive in that year (Roseaneau et al.1981)and not subject to
the impact of construction noises and the movement of equipment ..
(d)Downstream Impacts
(i)Moose
Moose that use the Susitna River area downstream of Devi 1 Canyon
may be impacted by the project.The manner in which moose could be
impacted relates to changes in the quantity of browse available for
winter forage.As discussed in Section 3.2(a)(i),moose congregate
along the Susitna River during severe winters and subsist on browse
that is associated with the early successional vegetation in the
riparian zone.As a result,the riparian zone of the Susitna River
downstream of Devi 1 Canyon is a critical factor in maintaining a
healthy moose population over a very large area.
The browse species upon which moose rely are typically found
growing abundantly on newly disturbed islands or sand bars:such
islands are constantly being created and removed by the action of
the river.The mechanism of creating new sites suitable for the
invasion of browse species which serve the winter food needs of
moose is compl icated and incl udes a variety of factors such as
flooding,ice scouring,and silt deposition.Since the creation of
such sites is dependent to a large extent upon the flow regime of
the river including the timing and duration of floods,the volume
of ice moving in the river,and the silt load of the water,the
flow regulation and changes in other aspects of the river that will
3-156
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resu It from the Sus itna project may poss ib1y alter these
mechanisms.[Details of the plant succession process that is
operative in this area are presented in Section 3.1(b),and
information concerning the availability and utilization of browse
along the lower river appears in Section 3.2(a)(i)J.
The possible degree of alteration of the present flow regime varies
substantially between that portion of the river upstream of
Talkeetna and that portion downstream from Talkeetna.Since
tributaries between Devi 1 Canyon and Talkeetna contribute
relatively little flow,the project will result in major changes in
the hydrologic characteristics of this part of the river.The
situation downstream from Talkeetna is considerably different.At
Talkeetna,water is added to the Susitna from both the Chulitna and
Talkeetna rivers.In addition,downstream from Talkeetna numerous
tributaries and eventually the Yentna River continue to add water
to the Susitna.In other words,at and below Talkeetna the changes
in the hydrologic characteristics of the river as a result of the
project wi 11 be considerably less.Since there is such a marked
difference between these two reaches of the river,the discussion
of impacts on moose is most appropriately presented in two
sections.
-Devil Canyon to Talkeetna
In this reach of the river,it is anticipated that the project
will have very little negative impact on moose.The moose that
use this area appear to be relatively sedentary,and,therefore,
any impact wi 11 be confi ned to those moose that are res i dent in
the area immediately adjacent to the river.In the absence of
census data,it is impossible to present the number of moose that
are associated with this area.
A detailed description of the vegetation changes that may occur
along this part of the Susitna River is presented in Section 3.5
(d).Between Devil Canyon and Talkeetna,the Susitna River is
well channelized with comparatively few islands and sand bars.
Therefore,the quantity of available browse is probably less than
what can be found along the more braided reaches of the river
south of Talkeetna.
Since it is predicted that seasonal floods will be totally
eliminated in this area some of the currently unvegetated areas
along the river will begin to develop some early successional
vegetation.Due to the very rocky substrate in the river bottom,
however,it is unlikely that any significant increase in
vegetative development will take place.
In general,there will be a trend for the development of more
mature vegetation on some of the islands.This process will
occur because the project will result in less ice formation along
this part of the river.Flowing ice is a very powerful force in
the disturbance of streamside vegetation.
3-157
This trend towards more mature vegetation could be offset,
however,by an increase in the frequency and duration of ice fog
along the river.In the absence of ice cover during the winter,
the difference in temperature between the water and the air will
generate ice fog which will in turn accumulate on streamside
vegetat i on.Although the ice fog is not expected to be very
damag-ing,it will probably result in broken branches on tall
shrubs and trees.An increase in young balsam poplar,willow,
and alder would result.Two of these species,balsam poplar and
willow,are important browse species,and,therefore,moose would
probably benefit from this aspect of the project.
In summary,there should be little negative impact on moose
residing along that portion of the Susitna River between
Talkeetna and Devil Canyon.Although changes in the flow regime
of the river wi 11 be greatest in this area,there should be
little reduction in the amount of available moose browse along
the river.An increase in the duration and frequency of ice fog
may serve to increase the quantity of browse available along the
river,thus either negating any minor loss or possibly even
resulting in more available browse than currently exists.
-Talkeetna to Cook Inlet
That portion of the Susitna downstream from Talkeetna differs
from the upstream portion (Talkeetna to Devi 1 Can..yon)in many
respects,three of which are important for moose.First,as one
proceeds downstream from Talkeetna,the river becomes
progressively wider and more braided with a corresponding
increase in the number of islands.These islands are less stable
than those above Talkeetna;a considerable amount of land is
washed away each year,and new bars and is 1ands are created.
Second,the extent of moose use is greater south of Ta-Ikeetna.
The winter forage along the lower Susitna is utilized by moose
from a large geographic range extending to the Talkeetna
Mountains to the east and across the extensive flat marshy area
lying to the west of the river.The third major difference is
the fact that the changes brought about by the Sus itna project
will be considerably less south of than north of Talkeetna.This
is because,as previously mentioned,water from several other
major sources is added to the Susitna at and below Talkeetna and
wi 11 reduce the project1s effects there.Thus,any changes in
available moose browse are not expected to be major.
If the Sus itna project does cause some s 1owi ng of the rate at
which islands are developed and removed,the moose population
that uses the area wi 11 be subject to two successive changes.
First,there wi 11 be a short-term increase in the amount of
browse as a result of the increased stability of the substrate
which will allow early succession vegetation to move down onto
the sites that are presently eroded by high summer flows.This
increase in early successional vegetation and associated moose
browse is likely to prevail for 10 to 20 years.High rates of
use would retard the rate of succession and prolong the
situation.Ultimately,however plant succession will proceed to
3-158
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the point where plants no longer serve as suitable browse,and
the abi 1ity of the area to support moose under severe winter
conditions will be reduced.A general although unknown decrease
in the moose population would therefore follow.The timing of
such a reduction will probably be determined by the occurrence of
harsh winter conditions.
A more indirect impact on the moose population in this area is
related to the status of the beaver population.Beavers are a
factor in determining the composition of vegetation in the areas
they inhabit.Should the beaver population along the lower river
be negatively impacted by the project there could be a corres-
ponding negative impact on moose.It is possible,however,that
increased winter flows may in fact allow for greater beaver
abundance downstream of Talkeetna.Should this occur,the
increase in beavers in the long run might assist in negating any
negative impacts on the moose population.The impacts on beaver
are discussed in Section 3.6(d)(iii).
In summary,the changes in hydrologic parameters brought about by
the project downstream from Talkeetna may be sufficiently diluted
to have 1 ittle if any impact on moose.Should a change result,
however,it is expected to be minor in magnitude and to result
first in a short-term increase in the amount of browse available
to moose and then in a long-term decrease in browse.Any impact
on the beaver population could also have an impact on moose:a
positive impact on beavers would have corresponding positive
impact on moose;a negative impact on beavers would have negative
consequences for moose.
(i i)Bears
Both black and brown bears have been reported to utilize the
Susitna River downstream from Devil Canyon for fishing.The
majority of the bears noted feeding on salmon in this reach of the
river were black bears,and the feeding activity was concentrated
during August and early September coinciding with salmon spawning.
Since changes in the flow regime of the river are expected to
drastically reduce salmon spawning in the side channels and sloughs
of the river between Talkeetna and Devi 1 Canyon,the opportunity
for bears to feed on salmon in these areas will be correspondingly
reduced,unless mitigative actions for the fish habitat are
undertaken [see Section 3.9(d)J.The loss of this salmon resource
will likely affect bears in two different areas.
The primary impact will be on bears that reside in relatively close
proximity to the river.The food supply represented by salmon
spawning in tributaries is not expected to be directly affected by
project flows,so competition among bears for this resource will
likely increase.The overall result will likely be a general
reduction in the number of bears inhabiting the area,especially in
the number of black bears,which are more likely to be permanent
residents in the locally available forested habitats.
3-159
Bear populations in more distant regions will also be impacted.It
appears that in addition to the resident bears which feed on
salmon,some bears travel long distances to take advantage of this
resource.During 1981,when a total failure of the berry crop in
the upper bas in was noted,two rad io-co 11 ared black bears moved
from the vicinity of the Devil Canyon impoundment downstream to
Gold Creek.Based on the numerous bears noted along the river
dur i ng 1981,it is thought that bears probab 1y trave 1ed to the
river from many areas to take advantage of this alternative food
source.Therefore,the loss of this food source would impact bear
populations,both black and brown,over a very large area.
Salmon probably represent the most dependable source of pre-denning
food.Therefore,during years when other pre-denning food items
are not avail ab 1e,the 1ack of an abundant sa lmon resource cou 1d
result in many bears entering dens later than normal and probably
in less than optimal condition.Under such conditions,populations
could decline as a result of starvation during the winter and
higher cub losses due to lactation failure.
The overall impact of the loss of salmon habitat downstream from
Devil Canyon will be a long-term reduction in the number of bears
that inhabit the region,especially north,east,and west of that
portion of the Susitna River between Talkeetna and Devil Canyon.
(iii)Aquatic Furbearers
Projected changes in the flow of the Susitna River downstream from
the Devi 1 Canyon dam could result in marked changes in aquatic
furbearer habitat.The nature and the degree of change wi 11 vary
for various portions of the river below Devil Canyon.The greatest
change in flow regime will occur between Devil Canyon and
Talkeetna.At present,this area is relatively poor habitat for
beavers (Table 3.28),and,therefore,any negative impact on
beavers will be relatively minor.Since the likelihood of a
reduction in fish populations is greatest in this area,however,
there could be a corresponding negative impact on river otters and
mink.Changes in water turbidity are also likely in this portion
of the river but should not affect either aquatic (beaver and
muskrat)or semiaquatic (river otter and mink)fur'bearers since
they are not known to select habitats on the basis of water
turbidity.
The situation between Talkeetna and Cook Inlet is different in two
respects from that in the stretch between Ta 1keetna and Devi 1
Canyon.Fi rst,as one progresses farther downstream from
Ta-Ikeetna,the suitability of the river for use by beavers in-
creases (Table 3.28).On the other hand,the changes in flow
regimes caused by the project become continually diluted and,thus,
less likely to result in an impact on beavers.It is difficult to
determine the extent or even the direction of any impact associated
with these changes.If a change in subclimax,riparian vegetation
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results,it could mean a reduced food supply for beavers;however,
since beavers are themselves a force in creating such subcl imax
vegetation,this situation may not negatively affect current beaver
populations.
Reduced summer flows could also cause a decrease in the areas
usable for beavers at that time of the year,either directly or by
allowing for a long-term reduction in the number of available
sloughs.The latter are highly useful areas for beavers.
I ncreased wi nter flow,however,may provi de greater opportunit i es
for overwintering beavers.Since it is unknown whether summer or
winter habitat components are prime factors in controlling the
density of beavers in this area,it is difficult to predict exactly
what changes wi 11 resu 1t.At the present time,however,some
general speculations can be advanced.First,those portions of the
river that contain the greatest numbers of beavers are also those
areas that will be least affected by changes in flow regimes,that
is,those areas farther downstream from the Devi 1 Canyon dam.
Second,any changes in riparian vegetation may be negated by the
activity of beavers themselves.And third,increased winter flows
may result in improved overwintering opportunities.In summary,
that portion of the river that has the fewest beavers will be most
affected,while that portion that has high numbers of beavers will
experience the least impact.
{iv)Marine Mammals
Severa 1 hundred be 1uga whales concentrate in the upper Cook In 1et
area to feed on anadromous fish.Whales have even been reported to
enter the lower reaches of the Susitna River during times when
salmon and other anadromous fish are present.Little is known
concerning these whales and the extent to which they are dependent
on anyone of the .many food sources available in the Cook Inlet
region.
The potential for the Susitna Hydroelectric Project having an
impact on beluga whales that inhabit Cook Inlet is dependent upon
the net effect of the project on Cook Inlet salmon,and is tempered
by the availability of alternative food sources.Based on the
current predictions of the effect of the project on Cook Inlet
salmon populations,and with the possible alternative food sources,
it appears unlikely that the Susitna project will have any
significant effect on the total food source available to these
whales.
(v)Bald Eagles
The survey of nesting bald eagles conducted in 1981 resulted in an
estimate of 15 to 20 active nests between Cook Inlet and Portage
Creek.This estimate could be converted to an estimate of one nest
per 15.8 km of river (based on 15 nests)or one nest per 11.9 km of
river (based on 20 nests).The nesting eagle population along the
Sus itna River cou 1d be affected by the proposed project in two
ways.First,the availability of suitable nesting trees could be
3-161
altered.Along the lower river,eagles appear to prefer to erect
nests in decadent balsam poplar trees.It is unlikely,because of
the abundance of such nesting sites,that changes in river flow
could appreciably reduce the number of such nesting sites.In
fact,if reduced flows result in any changes in the plant
succession trends,such changes would likely favor conditions that
permit the development of older,more mature,and thus more
suitable balsam poplars.
The second avenue of potential impact is related to changes in the
food supply for eagles,in particular,salmon.The potential for a
reduction in available salmon appears to be greatest between
Talkeetna and Devil Canyon,and thus,any corresponding impact on
eagles would most likely occur in this vicinity.Considering the
density of nesting eagles along the river,however,and the like-
lihood of salmon1s continuing to be generally abundant,especially
south of Talkeetna,there should be little,if any,negative impact
on the number of eagles nesting here.If any such impact on bald
eag 1es occurs it wou 1d be in the area between Ta"1 keetna and Devi 1
Canyon,which had relatively few nests active during 1981.In
fact,any stranding of fish as a result of lower water levels could
temporarily increase the food supply for eagles in such locations.
(vi)Waterfowl
Based on the data collected during a survey of river use by
migrating spring waterfowl (Table 3.42),it does not appear that
the Susitna River is heavily used by these birds.The proposed
action may possibly affect this limited use by reducing the area of
calm water,such as sloughs,available to migrants.Although such
a reduction is possible between Ta"lkeetna and Devil Canyon,this
area was found to be the least used portion of the river (Table
3.42).The project is expected to result in open water year round
below Devil Canyon,at least as far as Talkeetna.In the spring,
early migrants may use this new source of open water.
In contrast to the mainstem Susitna River,waterfowl do make
considerable use of the estuary portion of Cook Inlet near the
mouth of the Susitna.The suitability of the tidal flats used by
waterfowl in this area could be endangered by a reduction in water
levels.Because of the extensive tidal influence,however,it is
unlikely that a small change in the Susitna will sufficiently alter
the coastal marshes of Cook Inlet as to make them unattractive to
migrating and nesting waterfowl.
(e)Access Route
(i)Big Game
The proposed access road will impact big game in two ways:through
loss of habitat and by enabling greater access by people into the
area.The first source of impact,habitat loss,will be relatively
minor in comparison to the increase in access that will take place.
A total of 614 ha wi 11 be lost to the access road right-of-way
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[assuming a right-of-way 61 m (200 ft)wide]with an additional 267
ha lost for access road borrow areas and 22 ha lost for a railroad
yard.All access road components combi ned total 903 ha.Closed
mixed forest (313 hal and birch shrub (140 hal are the most common
communi ty types that wi 11 be impacted.The other commun i ty types
involved with the access road are each represented by less than 75
ha.This loss of habitat will affect big game species in the same
fashion as previously discussed [see Sections 3.6(a)(i),3.6(b)
(i ),an d 3.6 (c )(i )] .
The improved access that wi 11 be ava"il ab 1e as a resu lt of the
construction of a road from Gold Creek to Watana will have a
definite impact on the big game resource.At the present time,
there is very little human activity in the upper Susitna basin.
With the except i on of a few cabi ns and the seasona 1 presence of
hunters,the big game animals in the upper basin are basically free
of disturbance by humans.The construction and operation of the
Susitna project will change this situation dramatically.Some
species will tolerate additional human presence,while others will
either totally avoid areas of human activity or temporarily come in
conflict with humans.Improved access will also increase and
change the distribution of hunting pressure in the upper basin,
exposing to hunting some subpopulations which have been previously
unaffected by that activity.Although regulated hunting is not
considered to be generically detrimental to game species,there
will be resulting change in the abundance,distribution,and sex
and age composition of certain species and subpopulations.
The greatest changes will most likely occur along that portion of
the access road between Devi 1 Canyon and Watana.Presently,this
area is one of the more remote portions of the upper Susitna basin.
Between Devil Canyon and Gold Creek,some level of ground access
already exists and the addition of a major construction road in
that area wi 11 not resu 1tin as major a change as wi 11 the Devi 1
Canyon to Watana segment.A1though the access road wi 11
unquestionably have a negative impact on the big game resource,the
magnitude and distribution of that impact wi 11 depend to a large
extent on the manner,if any,in which access and hunting are
regulated by appropriate state agencies-following construction.
If unregulated access is permitted,the zone of impact essentially
will be defined by the ability of people to travel distances off
the road with ATVs.If,on the other han d,ATV us e is prohi b ited
or regulated,the zone of impact will be greatly reduced and
probably limited to within a few kilometers of the road.The types
of impacts that could result are many and vary among the species
concerned.If hunting is permitted from the road,all big game
species will gradually adjust to this situation and either avoid
the road or become far more secretive in its vicinity.If hunting
is not permitted from the road,it is likely that moose,bull
caribou,and black bears will not react negatively to the presence
of either the road or human activities along it.Wolves,
wolverines,and brown bears are big game species that will most
likely avoid the road,especially during the construction period
when numerous large vehicles will be present.
3-163
Impact of the road on the Nelchina caribou herd will probably be
minimal;any effects will be greatest during the construction
phase.That portion of the road west of Devil Canyon dam traverses
an area of low-quality caribou habitat that is seldom visited by
caribou.The construction of this section will have negligible
impacts on cari bou.The proposed route between Devi 1 Canyon and
Watana,on the other hand,traverses an area of shrub land and
tundra that consists of fairly good summer range.At present this
area is marginally occupied by caribou;these are predominantly
scattered groups of bulls.No major pathways of migration are
located west of Deadman Creek.The road will not provide easy
access to presently critical and remote caribou habitat such as the
calv-ing area.Car'fbou mortality result-ing from collisions with
vehicles wi 11 probably be minimal.It is expected that caribou
generally will avoid the vicinity of the road,although bulls are
known to be more tolerant of traffic than cows and calves (Cameron
and Whitton 1978).It is possible that the road may influence the
success of predator attacks on caribou,but since caribou use of
the area traversed by the road is low,the si gni fi cance of thi s
possibility is not great.
Brown bears could be impacted as a reault of a change in the
hunt i ng pressure,a di srupt i on of current movement patterns,or
both.If hunting is permitted from the road,there will be an
-increase in the harvest of brown bears "in this region.Available
data suggest that this increased hunting effort is unl ikely to
significantly impact brown bear populations,although a combination
of improved access and the liberalization of seasons and bag limits
could result in local overharvests of brown bear subpopulations.
Most likely any such overharvest would result in a reduction in
bear density and a lowering of age structure rather than in an
elimination of subpopulations.
The access road,in part i cu 1ar that port i on between Devi 1 Canyon
and Watana,could also function as a deterrent to brown bears
moving to Prairie Creek in late summer to feed on salmon.This
type of impact and its ramifications have been discussed in
Sections 3.6(a)(i)and 3.6(b)(i).The possibility of this
happeni ng is greatest during the construction period when large
volumes of heavy vehicles will be using the road.The possibility
would also be high following construction if the Devil Canyon
impoundment acts as a further deterrent,but especially if hunting
is permitted from the road.If bears are allowed to encounter the
road without being harassed,there is a greater chance that they
will find crossing the road acceptable.The major problem is thus
during the construction period.Since it is likely that the
movement to Prairie Creek is a learned behavior passed on from
adult females to cubs and yearlings,the disruption of this
behavior for 5 to 10 years could lead to the extinction of this
behavior.This would result in a lower capacity for the area,in
total,to support the brown bear numbers that presently exist,
although it is possible that at some time in the future,following
construction,bears would again locate the Prairie Creek salmon
resource and reestablish this behavior pattern.
3-164
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Due to their wi lderness characteristics and intolerance of human
presence,the access road will probably result in wolverines
abandoning the area,especially during the construction period.
Following construction,they may again inhabit areas nearby,but
they will probably never regain complete use of the area traversed
by the road.
There will be little,if any,impact of the road on Dall sheep.
The only possibility of any influence would be on the Portage-
Tsusena Creek herd if hunting from the road were permitted and
sheep hunters us-ing ATVs would be able to gain access to the
southern portion of the area presently utilized by these sheep.
But again,regulated hunting is not considered a negative source of
impact any may simply allow for the utilization of a resource that
has up to this point been unavailable.
(ii)Furbearers
If care is taken to avoid wetland areas,the physical disturbance
and habitat loss from road construct i on wi 11 be re 1at i ve 1y minor
because of the small amount of land involved.The segment of the
proposed access route between Parks Highway and Gold Creek poses
the greatest potential for impact on aquatic furbearers.The
long-term negative effects of borrow site development for fill for
roads will depend upon the extent of restoration measures.Borrow
sites or extended sections of roadways in or adjacent to wetland
areas or stands of white spruce or near fox dens could be harmful.
The most serious impact from road construction will arise from
improved human access.The effects of pub 1ic use of roads wi 11
consist primarily of increased harvest and human disturbance of
furbearers in the study area.Roads will provide convenient access
to areas which are now and have historically been remote.The
severity of this impact will depend upon regulatory measures
imposed.
Red foxes and,to a lesser degree,marten will be most affected by
road use.The greatest impact to foxes as a result of increased
human activity will occur along the northern portion of the access
road between Devi 1 Canyon and Watana.Foxes presently use this
area for denning.The impact on marten wi 11 not be great along
this stretch of the road,but marten populations between Gold Creek
and Devil Canyon will probably be reduced by additional trapping
pressure that could be associated with the access road.
Vehicle-wildlife collisions will be another source of impact to
furbearers.The severity of this impact is difficult to predict
because of the paucity of relevant published information.
Indications are,however,that losses of furbearers as a result of
collisions with vehicles will be relatively low.
(iii)Birds and Non-game Mammals
Construction,maintenance,and use of the access route would have
three main types of impacts:1)destruction of habitat for the
3-165
roadbed itself and alteration of habitat adjacent to the road and
in borrow areas,2)disturbances,such as noise and moving
equipment,along the road,and 3)increased access to the region,
and,therefore increased use by humans.The effect of this last
impact on birds and small mammals is undetermined at this time,but
would be greatest on the larger birds,including waterfowl and
raptors.
Birds and small mammals dependent on the habitats destroyed or
altered by construction would disappear from the immediate area of
the road and borrow areas.On the other hand,after construction,
populations of species that favor the newly created habitats will
increase.Retarded plant successional development,such as that
found adjacent to roads and railroads,will provide habitat for
several species of shrubland sparrows and for small mammals
generally restricted to open plant communities dominated by
herbaceous species--Arctic ground squirrel,tundra vole,and meadow
vole.Although borrow areas will be revegetated,recovery of shrub
and forest habi tats at borrow areas wi 11 be slow because of the
harsh environment at the elevations of much of the ac~ess route.
Recovery rates of forested areas may be faster along Indian River
because these areas are at lower elevations and are somewhat more
protected than other forested sites.Known raptor and raven nest
sites within 1.6 km (1 mi le)of the access route or access route
borrow areas are as follows:
Bald eagle nest in balsam poplar near the junction of the
Indian and Susitna rivers is only 500 m from the access road
and 100 m from Borrow Area 1.
Gyrfalcon nest (1974)and goshawk nest (1981)in a canyon
just east of Devil Canyon dam site are about 1.6 km from
the road.
Two raven nest sites are within 0.5 km of the access road
along Tsusena Creek.
Wetlands likely to be adversely affected by the access route are
primarily those along Indian River and in the Chulitna Pass area.
The degree to which these wet 1ands will be "impacted wi 11 depend
upon the exact alignment of the road.These wet 1ands have been
viewed only cursorily from the air,so specific effects or levels
thereof cannot be predicted.One lake,a productive alpine lake
east of upper Devi 1 Creek,appears close enough to be seriously
influenced by the segment of the access route between the two dam
sites.The route,however,could be "fine-tuned"to avoid serious
impact to this waterbody.
(f)Transmission Line
(i)Big Game
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-Central Study Area (Dams to Intertie)
In the central study area,the construction and operation of the
transmission facility will impact big game species through
disturbance and habitat alteration.Little habitat will actually
be lost due to the transmission line;"in most cases a change "in
habitat will occur rather than an actual loss.The right-of-way
will encompass approximately 927 ha (see Table 3.59).The five
most common vegetation types within this 927 ha area are closed
mixed forest (347 ha),birch shrub (109 ha),open mixed forest
(95 ha),mixed low shrub (82 ha),and woodland white spruce (82
ha).Because of the relatively low height of the dominant plant
species,there should be little disturbance of the two shrub
types.The three forested communities plus other less abundant
forested communities,however,will require the removal of tall
vegetation.This wi 11 result in a change from forested types to
vegetation types dominated by low shrubs or young trees.
Moose and black bears are the two big game species most likely to
be impacted by this type of habitat alteration.The impact on
black bears will probably be insignificant and may actually be
benefi cia 1 since it wi 11 resu lt in an increased di vers ity of
vegetation types within the affected area.In spite of disturb-
ance during construction and maintenance operations,moose will
probably be benefited by the clearing of forested areas.This
will allow for the development of early successional community
types which will provide an increase in the quantity of browse.
Thus,it can be predicted that the carrying capacity of the area
traversed by much of the transmission corridor will be increased
for moose.
The disturbance of big game species as a result of the trans-
mission line will be greatest during the construction period.
The proximity of the transmission 1 ine to the access road wi 11
greatly reduce the significance of any disturbing activities,
however,since disturbance from the access road will be far
greater.As discussed in previous sections,the magnitude of
this type of impact wi 11 vary among the big game species:moose
and black bears are the most tolerant of disturbance;wolves,
wolverines,and brown bears are the least tolerant.Caribou may
also suffer some from construction activities,but,since there
is presently very little caribou use of the area,it is
anticipated that only a few summering bulls will be bothered by
construction activities.
The same relationship of the transmission line with the access
road applies to the possibly blocking of movement patterns.
Althouqh the transmission line construction activities do have
the po"tential to interfere with the movement of some species
(brown bears in particular),the access road is more likely to
result in this impact prior to the construction of the
transmission line.During operation,however,noise from the
conductors (especially in bad weather)may repel animals even at
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times when there is little traffic on the road.The issue of
poss ib1e improvement inhuman access that cou 1d resu lt from a
transmission line is moot,since the access road represents a far
greater potential for this type of impact.
The likelihood of some level of synergistic effect occurring as a
result of the proximity of the transmission line to the access
road should not be ignored.This effect may be especially
significant during the operation phase.Although the major
di sturbance from the construction phase of the access road wi 11
no longer be operative,it is possible that animals will find it
more difficult to cross two corridors that wi 11 be in close
proximity than it would be to cross two more widely separated,
especially at times when both traffic is frequent and the
conductors are particularly noisy.
In summary,the transmission line in the central study area will
have little negative impact on big game species over most of its
length.In forested areas,there will probably be an improvement
in moose habitat.Disturbance and access impacts associated with
the transmission 1ine in most areas wi 11 be overshadowed by
similar and more severe impacts emanating from the adjacent
access road.During operation,however,more sensitive big game
species,such as brown bears,could be disturbed to a greater
extent due to the close proximity of the transmission line to the
access road.
-Northern Study area (Healy to Fairbanks)
The primary type of impact that can be expected to occur in the
northern study area is habitat alteration.The transmission line
right-of-way in this area will utilize approximately 1,923 ha
(see Table 3.59),The four most common vegetation types in the
proposed right-of-way are open spruce (685 ha),mixed low shrub
(294 ha),open mixed forest (251 ha),and open deciduous forest
(150 haL A variety of other community types are represented by
lesser amounts,in all cases less than 100 ha each.The greatest
change wi 11 be in the forested areas,which represent three of
the four most common types.
The clearing of forested communities is expected to be of benefit
to moose,since it will result in the creation of early
successional vegetation stages which typically provide much more
browse than the mature types that presently exist.In all cases,
community types that will be so affected are very widespread and
abundant in the area,so the change of these community types will
not represent a significant negative impact on any big game
species.In addition to moose,it is likely that black bears
wi 11 also benefit from the increased plant community diversity
that will occur.Predatory species,such as wolf,where they
occur,will benefit indirectly from the increase in moose.
As described for the central study area,most of the disturbance
wi 11 occur during the construction period and wi 11 be min ima 1
following construction.Improved access wi 11 result from the
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establishment of a transmission corridor.The magnitude of the
impacts of the increase in both disturbance and access will vary
along portions of the proposed line and will be least detrimental
in areas where the line will be in close proximity to already
existing road or transmission corridors and greatest in areas
where the line deviates from existing corridors.The two species
most likely to be associated with the line (moose and black
bears)are,however,relatively insensitive to disturbance
resulting from human activity and should not be severely
impacted.
-Southern Study Area (Willow to Cook Inlet)
A total of 866 ha will be affected by that portion of the
proposed transmission line between Wi llow and Cook Inlet (see
Table 3.59).The four most common vegetation types traversed by
this segment of the line are closed mixed forest (307 ha),closed
birch forest (115 ha),open mixed forest (112 ha),and wet sedge
grass (101 ha).Other community types,the majority of which are
forest types,are also present in lesser amounts.Based on these
figures,it is obvious that the greatest impact on big game will
result from habitat alteration.As explained previously,this
will entail a change from forested communities to shrub-dominated
communi ties.The two bi g game speci es that wi 11 be primari ly
associated with this segment of the transmission line are moose
and black bear.These species,and moose in particular,should
benefit from the habitat alteration that will result.
The disturbance and improved access that wi 11 result from this
line will represent a potential for negative impacts on these
species.Significant disturbance will be,however,of a
temporary nature and confined primarily to the construction
phase,although maintenance of the facilities and right-of-way
wjll also cause occasional disturbance.In the case of both
di sturbance and improved access,the net impact wi 11 be
relatively minor;the area between Willow and Cook Inlet is
already heavily subject to human activity,and it is likely that
these two species have already adjusted to existing in close
proximity to humans.
(ii)Furbearers
The construction and operation of the transmission line will likely
affect furbearer species in two ways.First,the creation of a
cleared corridor will probably result in some level of additional
access for trappers.Increased trapping attributable solely to the
transmission line is most likely to occur along portions of the
northern and southern study area,where access into certain areas
will be improved by the right-of-way.A.lthough some additional
trapping pressure wi 11 result,it is unl ikely that there wi 11 be
long-term detrimental impact on furbearers.Within the centra 1
study area,on the other hand,the proximity of the access road
will represent a far greater avenue of human access than the
transmission line.
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The second manner in which the transmission line will affect
furbearers is in those portions where forested vegetation wi 11 be
cleared.The clearing of vegetation and the operation and mainten-
ance procedures will result in the creation of early successional
plant communities,which will most likely be of value as habitat
for a variety of small mammals,nesting birds,and snowshoe hares.
These prey species will then be utilized by predators such as
foxes,marten,short-tailed weasels,and coyotes.In those areas
where vegetation clearing will not be required,especially between
Devil Canyon and Watana dams,there should be negligible impact on
furbearers.
(iii)Birds and Non-game Mammals
In the central and southern study areas,the major impact on avian
and small mammal species resulting from the construction and oper-
at i on of the transmi ss i on 1i ne wi 11 be the a lterat i on of habitat.
In areas where vegetation clearing will not be required,the im-
pacts on these species will be negligible.Where clearing is nec-
essitated,there will be some impact,but it will be in the form of
a change in species composition and not necessarily a reduction in
the number of birds and small mammals using the corridor.This
change will entai 1 a reduction in those species that irihabit
forested communities and an increase in those species that require
plant communities in an earlier stage of succession,such as shrub
or grassland type communities.
In the northern study area,the same changes can be expected where
clearing is required.In addition,there are several other issues
of concern regarding birds along the proposed route.Of prime
interest is the proximity of a peregrine falcon nesting site
located along the Tanana River east of the proposed transmission
route.The nest was inactive during 1981 but was used prior to
this time.Whether or not it will be used again is unknown.If
the nest is active during the construction of the line,the birds
may abandon it as a result of the disturbance.If the nest remains
inactive during the line construction,however,it will most likely
be acceptable for later use during the operational phase of the
line.If necessary,the transmission line in this area could be
constructed during a time period that would reduce the liklihood of
disturbing nesting peregrines.Furthermore,a Section 7
consultation,as required by the Endangered Species Act,will be
conducted with the U.S.Fish and Wildlife Service to help insure
that the peregrine nest is not impacted.
Another concern along the northern study area is the proximity of
several trumpeter swan nesting areas.North of the Tanana River,
the center line of the transmission route passes within 0.4 km of a
swan nesting area.South of the Tanana,the center 1ine is ap-
proximately 1.6 km from two other nesting areas.All other
identified swan nesting sites are farther than 1.6 km from the
center line.As in the case of the peregrine falcon,construction
activities,especially blasting,might result in the temporary
abandonment of that nest located 0.4 km from the 1ine.No long-
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term impacts on swans are anticipated,however.The only other
manner in which swans might be affected by the 1ine is through
collisions with wires,an event most likely to occur under poor
visibility conditions.
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3.7 -Anticipated Impacts on Fish Resources
(a)Watana Dam and Impoundment
The impacts associ ated with the development of the impoundments of the
Susitna Hydroelectric Project are divided into construction impacts,
including those connected with filling time,and operation impacts.
Table 3.67 identifies potential impact issues associated with the various
project stages of hydroelectric facilities.
(i)Construction
Construction impacts can be subdivided into impacts resulting from
construction of the cofferdams and those arising from construction
of the main dam.The impacts associated with cofferdam
construction are relatively brief,however,and the major dam1s
construction will begin soon after the cofferdams are complete.
The effects of the major dam will essentially be a continuation of
those created by the cofferdam,so both types will be treated as
one for this section of the report.
An obvious impact that has occurred on other hydroelectric projects
and will al so occur on th is project concerns changes in water
quality.These changes can be expected when a lentic environment
replaces a lotic system.Physical changes,such as temperature and
turbidity,as well as chemical changes associated with such factors
as leaching of nutrients and minerals from the reservoir area soils
will impact the aquatic organisms that currently inhabit the
reservoi r area.Inundat i on of the mai nstem and tri butari es wi 11
eliminate present habitat in those areas.
The construction of the Watana dam and the subsequent development
of the impoundment wi 11 affect the mainstem resident fish species
by eliminating approximately 85 km of mainstem riverine habitat.
The mainstem has populations of burbot and round whitefish,which
are often associated with the mouths of cl ear water tributaries.
In addition,sculpins,longnose sucker,Dolly Varden and Arctic
grayling have been found in this section of the drainage.The
grayl i ng,however,has been primarily associ ated with the cl ear
water tributaries.
Inundation of the mainstem,although it wi 11 cause a loss of
riverine habitat,is not expected to affect adversely the fish
popul ati ons that are present.It is expected that the reservoir
will provide the habitat necessary for the existing populations of
burbot,longnose sucker,and whitefish to sustain themselves and
possibly even to increase.In addition,studies show that 85-95%
of the incoming sediment will be trapped and will settle out in the
Watana reservoir.Thus clear or almost clear water may be present
in the upper Watana reservoir waters during the winter.As a re-
sult,additional or improved overwintering sites may be available.
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Moreover,overwi ntering areas that are associated with the cl ear
water flows of the area's tributaries will probably also increase.
While the drawdown during the winter months reduces this area,the
remainder is still many times the pre-project stream area.The
flooded tributary areas will be much deeper and should continue to
have clear water entering them from the tributaries.These areas
caul d provi de add it i ana 1 overwi ntering areas for such tri butary
fish as grayling.It is not known,however,whether overwintering
habitat availability is a population-limiting factor in this
region.These areas may poss'ibly become productive habitat for
other life stages of the fish populations.
Many tributaries enter the mainstem Susitna in the area that wi 11
be affected by both construction of the dam and inundation by
impounded waters.The impacts associated with construction of both
the cofferdam and the Watana dam wi 11 be concentrated in the
tributaries closest to the actual dam site,namely,Tsusena and
Deadman creek s.These both contain grayl-j ng.Deadman Creek w-i 11
also be affected by inundation,but Tsusena Creek is downstream of
the Watana dam and,thus,will not be flooded by the Watana im-
poundment.It will,however,be affected by other project
facilities [Section 3.7 (c)].It is expected that Tsusena and
Deadman creeks will be further affected during construction,
primari ly by additional sport fishing pressure exerted by
construction personnel.
During dam construction,Tsusena Creek will be additionally af-
fected by the planned removal of gravel.This process will affect
the stream habitat of Tsusena Creek (see Section 3.7 (c),Borrow
Areas).In addition,a water supply dam to be constructed on
Tsusena Creek will eliminate migratory movement of resident species
through this area.The impoundment behind the water supply dam
may,however,provide additional over-wintering habitat.
Deadman Creek lies approximately 1.6 km upstream from the proposed
Watana dam.A large waterfall,which is presently a barrier to
fi sh mi grat ion,is located about 1.6 km upstream from the creek IS
mouth.Approximately 3.7 stream kilometers would be inundated by
the proposed impoundment,which would also inundate the waterfall
and allow fish migration between Deadman Lake,about 10 km up-
stream,and the Susitna River.
In addition to Tsusena and Deadman creeks,which are in the imme-
diate vicinity of the proposed Watana dam,other Susitna tributar-
ies will be affected by the creation of the Watana impoundment.
These include Watana,Kosina,Jay,and Goose creeks,and the
Oshetna River,all of which are upstream of the dam site.At
Watana Creek,about 14 stream kilometers will be inundated by the
proposed impoundment;at Kosina,approximately 6.4 stream
kilometers;at Jay Creek,about 5.0;at Goose,approximately 2.4;
and at the Oshetna River,about 3.2 stream kilometers.
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A primary concern in regard to fisheries is the impact of the
Watana impoundment upon the Arcti c grayl ing popul at ions in the
region.ADF&G (1981)has estimated that 10,000 +grayling inhabit
the areas of the streams and mainstem that will-be inundated,and
most of the impact will be felt in those streams in the vicinity of
the Watana impoundment.Grayling in all the streams mentioned
are not presently subject to heavy sport fishing pressure.Thus,
although a moderate amount of increased sport fishing pressure may
occur on the streams distant from the dam site,it is not expected
to be a significant consequence.
Grayling populations in the tributaries are probably near their
maximum,with some natural limiting factor controlling any
increases.The limiting factors could be the number of spawning
sites or overwintering areas,the amount of available food,or a
combination of several factors.If overwintering areas are the
limiting factor,then grayling could be moving downstream during
the winter to find suitable sites.If they move through Devil
Canyon,they would not be able to ascend the canyon in the spring.
It is evident,however,that a large portion of the suitable
stream habitat currently used by the grayl ing in the cl earwater
tributary areas within the Watana impoundment zone will be lost to
the inundating waters.There is also a possible loss of some
spawning areas associated with the mainstem that are fed by clear
water.Overwintering habitat presently available in the Susitna
mainstem will be lost,but replaced by impoundment lake waters.
Clearwater rearing habitat that support this population in the
tributaries will be lost by inundation.Sally Lake (Figure 3.35),
an 18-hectare clearwater lake with a population of both grayling
and lake trout,would be eliminated.
(ii)Operation and Maintenance
Operation of the Watana power development will necessitate an
annual fluctuation in the reservoir surface water elevation.At
full capacity,the reservoir maximum surface elevation will be 666
m (2185 ft.m.s.l .).During an average year,the reservoir will be
drawn down 27 m (90 feet).During a succession of dry years,
however,the reservoir may be drawn down 43 m (140 feet)from the
maximum surface elevation.Drawdowns of this magnitude will
eliminate shallow shoreline environments which are necessary for
the reproduction,shelter,and food requirements of many fish
species.
The annual fluctuation,a characteristic of all hydroelectric power
developments except run-of-river,will create a broad,barren
shoreline that,at the end of the winter season,will be exposed.
Duri ng the summer,water bei ng stored in the Watana impoundment
will cover this shoreline.During filling and in the early years
of operation,mud slides will occur as the soils in the reservoir
become saturated and the water levels fluctuate.
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During winter months,as the reservoir waters are drawn down to
provide power,ice shelving is also expected.Ice formation in the
impoundment will be different from the formation of ice that
currently takes place in the same reach of the Susitna River.A
fairly uniform thickness of approximately 80 cm can be expected
throughout the reservoir.The timing of ice formation,however,is
expected to be consistent with present patterns.The reservoir ice
is expected to begin forming along the shore about the middle of
October,the same time as it presently begins.
Ice jamming may occur in Watana Creek and in the Susitna River near
the Oshetna River and Goose Creek.Another ice-related impact has
to do with ice jamm"j ng.Wi ndi I1g channe 1s with steep banks and the
possible supply of large quantities of ice from upstream are
indicators for jamming.Ice will only affect the fish popula-
tions,though,if it limits access either to tributaries in the
spring for spawning or access to the reservoir for overwintering.
Such restriction is not expected to happen,however.Any ice
formations that block the stream will be quickly eroded by the high
flows from the tributaries in the spring.
The Watana reservoir with a storage volume of 9,625,000 acre-feet
has a ratio of capacity to inflow of approximately 1.82.Prelim-
inary estimates indicate that from 85-95%of incoming sediment will
be trapped in the reservoir,with particles smaller than two
microns possibly passing through.The sediment-laden streamflow
from the Susitna mainstem will initially spread through the
reservoir as either surface flow,interflow,or underflow,
depending on the relative densities of the reservoir waters and the
Susitna waters.Increased winter turbidity levels are expected to
be the impact associated with the reservoir sedimentation process.
The fish that currently inhabit the mainstem are presently
subjected to glacial stream conditions much more severe than they
will be during the operation of the project.Reservoir turbidity
should not be a negative impact on longnose suckers,round white-
fish,or burbot --the species most likely to inhabit the
reservoir.
Temperature cond it ions in the Watana reservoi r wi 11 be different
from those that now occur in the mainstem and tributaries,although
the reservoir will not actually stratify.A gradual temperature
decrease with depth will occur in summer until water temperature is
4°C.In winter the temperature will increase with depth from O°C
to 4°C,with the top 5+meters predicted to be colder than 4°C.
Thi s temperature structure is not expected to cause an adverse
impact on reservoir fish.
(b)Devil Canyon Dam and Impoundment
(i)Construction
Construction impacts for the Devi 1 Canyon development are expected
to be similar to the Watana impacts.Construction of the cofferdam
is expected to increase temporarily the downstream load of
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suspended solids.The two micron and smaller fraction of the
sediments may remain in suspension and pass through the Watana
reservoir to Devil Canyon.If this happens,construction of the
cofferdam during low water periods of the year,when water is
normally clear,will result in slightly more turbid conditions
downstream.Turbidity from construction during high water flows
would be far less noticeable.In addition,during the period when
the Watana deve lopment comes on 1ine and the Devi 1 Canyon project
begi ns,increased fl ows for power generat i on wi 11 be di scharged
downstream.The increased flow of water wi 11 have the effect of
diluting any additional sediments caused by cofferdam construction.
No other di rect impact of actual construction of the Devi 1 Canyon
dam is expected.
An indirect impact of construction that can be expected,however,
is increased fishing pressure on the sport fish in the tributaries
near the construction site.With the possible exception of
sa lmon fi sh i ng on Portage Creek,these tri butary areas are not
currently subject to high fishing pressure.In fact,the grayling
populations in the impoundment tributaries are probably at their
maximum density levels.Increased fishing pressure will alter
these population levels as well as fish populations in Portage
Creek and Indian River.
Impoundment of the Susitna waters will provide the major impact in
the Devil Canyon development.Inundation of the mainstem and
tributaries will alter the present habitat of resident fish in this
reach.These streams will be flooded to the 443.5 m (1455 ft)msl
e1evat ion.
The tri butari es in the Devi 1 Canyon impoundment area,however,are
characterized as having steep slopes with occasional barriers,such
as waterfalls.Cheechako,Devi 1 and Tsusena creeks,three creeks
entering the Devil Canyon impoundment,all contain waterfalls.
These falls w"ill not be inundated by the creation of the
impoundment and will still function as effective barriers to fish
passage.
Because of the glacial input,the mainstem is very turbid during
the summer months and is not,therefore,considered to be prime
fishery habitat.Resident species have,however,been collected in
the mainstem.Longnose suckers,round whitefish,and burbot are
the major contri butors to the mai nstem fi shery.Impoundment of
waters is not expected to adversely affect these fish populations.
On the other hand,grayling populations,which inhabit portions of
the tributaries.will be affected by the habitat change.Loss of
spawning areas near the stream mouths could be a negative impact.
In addition,the impoundment will surely increase overwintering
area.In conjunction with the loss of the riverine environment
will be the creat i on of a 1ake envi ronment.The change from a
lotic to lentic environment will probably be accompanied by a shift
in species composition.For example.burbot.longnose suckers,and
possibly whitefish would be present as opposed to grayling.
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Finally.in addition to the other tributarie$mentioned above.Fog
Creek.located at river kilometer 278 on the south side of the
Susitna River.and approximately 37 km upstream from the proposed
Devil Canyon dam.would be inundated by the proposed impoundment to
a point approximately 1 km upstream of its mouth.
(ii)Operation and Maintenance
The Devi 1 Canyon deve lopment wi 11 be operated in conjunction with
the Watana dam.located just upstream of the Devil Canyon impound-
ment.Annual drawdown at Devi 1 Canyon will be about 17 m (55 ft).
As in the Watana impoundment.drawdowns of such magnitude will
eliminate shallow shoreline environments in the reservoir.which
are necessary for the reproduction.shelter.and food requirements
of many fish species.
The Devil Canyon impoundment will have a capacity to inflow ratio
of .16.making it much more reactive to upstream influences than
the Watana project will be.The outflow from the Watana project.
however.will provi de water with chemi cal characteri st i cs di ffer-
ent from those currently prevailing in the Susitna River ..In
addition.leaching of minerals and nutrients from the reservoir
soils will further change the chemistry of the water.Until the
banks stabilize.mud slides from the steep slopes into the
reservoir will increase the rate of input of minerals from the
soils.The extent of this impact on both the Devi~Canyon and
Watana development cannot be fully assessed.however.on the basis
of current information;at present.little is known about the zone
of mi nera 1i zat i on or about the soi 1 nutri ents.A decrease in the
suspended sediment load entering the Devil Canyon reservoir.which
results from the Watana operation.should permit an increase in
1 ight penetration and a corresponding increase in primary
productivity.
(c)Borrow Areas
Impacts associated with the construction phase of the project in regard
to borrow and quarry areas would result from direct excavation of
stream bed material and sedimentation problems caused by runoff or
meltoff entering nearby aquatic habitats.Heavy metals which could
degrade the existing water quality of these aquatic habitats.could also
be an impact associated with runoff and meltoff from excavated areas.It
shoul d be noted that borrow or quarry areas not located near any streams
or lakes would not have any impact on fish resources.
The most significant and long-term impacts could result from Areas E and
F (Figure 9.7).Area E is situated near the mouth of Tsusena Creek.an
area which would be inundated;area F would be along sections of the
creek that would not be inundated by the impoundment.Persistent
siltation problems could occur and affect the remaining resident fish
populations.especially grayling.A similar situation could exist at
Area H in regard to Fog Creek and Area D with respect to Deadman Creek.
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Those areas which would eventually be inundated by the impoundments could
cause a temporary impact which could be either fairly significant or
rather minimal,depending upon the size and/or location of the borrow
area in question.
For example,Area L would be inundated by the Watana impoundment,and any
impact di rect 1y associ ated with thi s area wou 1d be temporary and
insignificant in comparison to inundation of the region.The same also
can be said of Area J,although the Susitna stream bed excavation would
certainly hasten the destruction of resident fish habitat in the Susitna
mainstem.
Most of Area I,located in the mainstem Susitna River,will be inundated
by the Devi 1 Canyon impoundment.Its impact upon the fish habitat in
this section of the Susitna would,therefore,normally be termed insig-
nificant.The extent of this area,however,and the fact that siltation
could occur well downstream and possibly affect resident and perhaps
anadromous speci es I reproducti ve habitat in the Sus itna River make the
potential impact from Area I of some significance.As this situation
points out,areas that will only be partially inundated by the Devil
Canyon reservoir could be a persistent source of siltation as water
levels in the impoundment rise and fall.On the other hand,while this
increase in siltation could reduce primary productivity in the reservoir,
it would probably not create any significant impact on the fishery.
Excavation at Area G could have a similar impact if siltation is
permitted downstream of the Devil Canyon dam site.Even though this area
is closer to portions of the river utilized by salmon,the much smaller
size of Area G in comparison to Area I could limit its impact.Area G
would not be of any impact following inundation.
(d)Downstream Impacts
(i)Construction
-River Mouth to Talkeetna
Construction-related impacts on downstream resident fisheries are
related to changes in discharge,water quality,water tempera-
ture,ice formation,and geomorphological changes in the river.
These changes are caused by the re-routing of the Susitna flow
through diversion structures during the construction of the dams,
disturbances of the river or its tributaries during construction,
and reduction in flows during the filling of the reservoirs.
During the immediate construction period,water will be diverted
around the dam construction site by means of a bypass tunnel.
This structure should pass the run-of-river discharge unti 1 the
dams are to be fi 11ed.Discharge changes from the pre-project
conditions during this initial diversion period will probably be
minor and not significantly affect downstream fisheries.
3-179
During the filling period,a net loss of downstream water to the
fisheries will occur over several years.The monthly mean and
annual frequency duration curves for the Sunshine Station project
decreases in the monthly discharges for June,July,and August.
Increases in discharge occur in October through May.There is no
significant change in discharge during the month of September.
An analysis of the natural variability of flows has been prepared
for data collected at gaging stations located at Gold Creek and
Susitna Station on the Susitna River and from the Chulitna and
Talkeetna rivers.A comparison of the pre-and post-project
discharges at the Sunshine Station indicate the post-project
monthly average discharge would be approximately 69%of the
pre-project discharge during June,77%during July,85%during
August,and 94%during September.The flow variability data were
not available for the Sunshine site,but patterns were very
similar for the four sites evaluated,with Talkeetna the most
variable and Susitna Station the least.Gold Creek and the
Chul i tna Station data were simi 1ar and intermedi ate between the
other two sites.
For purposes of comparison of natural variability with the
post-project changes,the Gold Creek data were used as
representative of the lower river conditions.The data analysis
indicated that post-project average monthly flows resemble the
annual average low flows that occur over one day during June and
July and are slightly below the three-day occurrence.The
post-project August flows are simil ar to those that normally
occur over a 14-day period,while the September flows are not
significantly different from the natural flow.October
post-project flows are higher than those which occur normally but
are within the natural variabil ity that occurs over a 14-day
period at Sunshine Station.Winter flows during this filling
period should not deviate from the natural conditions.
Post-project water qual ity changes have been presented only for
sediment with regard to the trap efficiency of the reservoirs.
Trap efficiency was estimated to be between 85%and 97%,with
particle sizes of less than two microns remaining in suspension.
A general statement that the turbidity of the river water below
Devil Canyon will decrease during the summer and increase in the
winter appears to be appropriate.The winter increase in tur-
bidity may even be noticeable below Ta"lkeetna.Turbidity values
in the winter are currently less than 5 NTU's.
Examination of other water quality parameters measured throughout
the year does not indicate any abnormally high concentrations
that may be limiting to aquatic life.Increases in nutrient
concentrations should result from the flooding of vegetation
with in the impoundments.Phosphorous concentrat i on s are often
associated with increases in productivity.Increases in nutrients
in glacial systems that are light-limiting,however,do not
3-180
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necessarily cause increases in production.Downstream nutrient
increases are ali ke ly consequence of the const ruct i on of the
project,although predictions of these concentrations have not
been made.
Be 1ow the confl uence of the Sus itna and Chul itna ri vers,summer
changes in water quality should not be perceptible because of the
influence of the Chulitna on the mainstem river and the natural
variability of water quality within the system.
Temperature changes have only been projected for the portion of
the Susitna above Talkeetna.During dam construction,no effect
on river temperature should occur.During the filling period,
warmer winter temperatures are projected.The temperature
changes in the river below Talkeetna have not been analyzed,but
they woul d appear to be mi nor.Duri ng the fi 11 i ng of the
reservoirs,the small winter flows are projected to have only
mi nor i nfl uence at the three-river confl uence area near
Talkeetna.The filling flow will be similar to normal winter
flows,allowing the river to cool between Devil Canyon and
Talkeetna at a rate more rapid than that which will occur during
operat ion.
The few effects on temperature during the summer period should
not be discernible below Talkeetna because of the reduced flow
contribution of the upper Susitna on the main channel during this
period.
Ice conditions will change somewhat in post-project conditions
during operation.During filling and construction,however,the
normal winter flows should not create any significant changes in
ice formation below the Chulitna river confluence.
During the filling period,flood peaks from the Susitna will be
eliminated while the flood waters contributed by the other
tributaries will continue.This change should provide more
channel stability than that which now occurs,but the differences
will probably not have perceptible changes on any of the fish
habitat in the lower river.
o Anadromous Species
The Susitna hydroelectric project's effect on the runs of
anadromous fi sh in the lower Sus itna River from the mouth to
the confluence of the Talkeetna River - a distance of about 157
km has not been fully established at this time.This portion
of the river flows through a broad floodplain with some
shifting (or instability)of the channels,and in places,the
channel is divided into numerous channels.Only about 20%of
the total flow in the lower Susitna originates from the river
and its tributaries above the confluence of the Talkeetna
River.Thus,any effect of the hydroelectric dams would,in
general,be masked by the discharge of water from the
tributaries flowing into the lower Susitna.
3-181
At the same time,however,the lower Susitna River provides the
sole migratory route for the very large runs of salmon that
enter the various tributaries below the Talkeetna to spawn and
for the young returning to the sea.The effect on migration of
salmon of any change in the flow regime of the Susitna,though
small and whether beneficial or detrimental,would be magnified
in importance accordingly.
The extent to which various species of salmon spawn in the main
channels of the lower Susitna River and its adjacent sloughs is
not known at this time,nor is the extent to which the main
channel may serve as a nursery area for the juvenile coho,
chinook,and possibly sockeye salmon.
In addition to these general effects upon the salmon population
that are attributable to the Susitna project,other impacts
will occur and will vary with the project activity in question.
That is,the impact associated with dam construction,for
example,will differ from the effects of filling the reservoir,
and these wi 11 vary from the impact of opE;rat i ng and
maintaining the facility.
During the construction and filling period,minimal flows
ranging from 900 cfs in the winter to 6,000 cfs in the summer
will be discharged from the dam.As the reservoirs gradually
fill,there will be no provision for adjustment of water
temperature to satisfy the needs of early development of salmon
eggs.It should be noted that during filling,the temperature
of the water is expected to reach the near ambient level by the
time it reaches Gold Creek in both summer and winter and should
have little effect on the spawning or migrating salmon in the
lower Susitna River.
Also,during the filling of the reservoir,a gradual decrease
in turbidity in the summer and an increase in level of chemical
constituents of the water as a result of leaching from the
soils can be expected.Turbidity will be slightly less in the
summer months of glacial melt but will be overshadowed by the
turbidity load of the Chulitna River.
Any addition of nutrients will tend to increase the biological
productivity of the stream;exceptions would be concentrations
of toxic chemicals (for example,copper and iron),but whether
such concentrations will exist is not presently known.
It is not expected that the reduced flows that wi 11 occur in
late spring and summer will be sufficient to cause any physical
block to salmon migration.On the contrary,those flows should
improve the migratory conditions for salmon ascending the lower
Susitna River by reducing the water velocities and thus
requiring the salmon to expend less energy during their
migration upstream.Conditions for access to the small sloughs
and tributaries used by salmon for spawning could be affected
3-182
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with an expected lower i ng of the water 1eve 1 by from .3-.6 min
the vicinity of Susitna Station.The reduced flows would have
minimal effect on the mainstem spawning if it occurs.
o Resident Species
The resident fish probably spawn primarily in clearwater
tributaries of the Susitna,with possible spawning in the
mainstem by burbot,longnose sucker,and whitefish.During the
winter months,many of the tributary residents outmigrate from
the tributaries and overwinter in the mainstem.This movement
has been inferred from capture data gathered during the fall
and spri ng near tri butary mouths.Informat ion on the di stri-
bution of juvenile residents by season is minimal.Based on
existing data,no major impacts are Projected for the resident
species below the Susitna and Chulitna confluences during
construction and filling.
-Talkeetna to Devil Canyon
There are two periods to be considered when describing potential
impact issues in the Susitna River downstream of Devi 1 Canyon
during the construction phase.The first period is the
construction time.The river area affected during this period
will be minor and will be contained within the cofferdams.At
most,there may be some minor modification of turbidity levels
from time to time during the constructi on of the cofferdams and
diversion tunnel and during the road-building activities.This
modification is not expected to be significant,however.During
the cofferdam stage of construction,the cofferdams must not be
overtopped.The river flows will be passed as the river runs
through the discharqe ports.Discharge will not change
appreciably during the dams'construction period;except at the
start of diversion,there will be no modification of flow.
One concern during the construction period is the accidental
spill of chemicals and petroleum products in the impoundment
area.Such accidents would primarily affect local fisheries in
the impoundment area and,depending of course on the magnitude of
the spill,should have minor consequences on downstream areas.
The second period of the construction phase that is expected to
affect fish populations in the Susitna River downstream of Devil
Canyon is the filling time,when water in the reservoirs will be
brought to a usable level.This filling is expected to begin
before the main dams are completed.There will be a subtraction
of flow and minimal,if any,change in river bed morphology.The
filling period will also mark the beginning of any changes that
may occur in the deltas of incoming streams .
The main interference to flow will occur during the short period
of time needed to bring the pool levels behind the cofferdam to
an operating head in order for the diversion works to function.
3-183
Since Watana dam will be fully developed before Devil Canyon dam
is started,there will be two short interruptions of flow as the
two reservoirs are filled.
As the dams get higher,the water levels of the lakes forming
behind them will also rise.The incoming flows will be modified
to the extent that storage will permit,and a safety freeboard
level will be provided to prevent overtopping of the works during
an unusual flood.Particularly during summer,there will
probably be some modification of flow,which will equal the
volume of stored water behind the uncompleted structure.
As the reservoirs approach their lower operating levels,
conditions closely approaching operating conditions will exist.
This situation will provide some benefits from lowered flood
flows but will not contribute additional flows for the summer
period unless these are allowed for in the filling schedule.
Thus,substantial changes in the summer flows will occur,which
will,in turn,considerably reduce the flow in the side channels
and sloughs in this reach to only local run-off and spring-fed
flow.With normal flood peaks that occur during summer
eliminated during the filling period,a more stable channel will
be created and the bedload movement that occurs during this time
will be reduced.
With the summer flows well below the natural variability of the
river under pre-project conditions,it is expected that the
sloughs from below Devil Canyon to Talkeetna will be affected in
that adequate water will not be made available to them.The
sloughs in question will be those that fish have been found to
use either for spawning or for spawning and rearing.Approxi-
mately 40 such slough areas have been identified in this stretch
of the Susitna River.
At some time during the filling period,density water layers will
form in the impoundment.Firm control of temperature will
probably not be possible until the reservoirs have reached their
lower operating levels.Temperature modification caused by the
Watana reservoir will probably equilibrate by the time the water
reaches Portage Creek.
Present monthly average temperature changes have been recorded,
and post-project temperature changes expected to occur during the
filling of the reservo'ir have been projected for this reach at
the Gold Creek site and near the mouth of the river at the
Chulitna confluence.Depending upon the summer flow level
provided,there wi 11 be modifications of natural temperatures in
the spilled water after the stratification resulting from the
formation of density water layers occurs.In general,
temperatures will decrease slightly in the summer and increase
more markedly in the spring and fall.Thi.s temperature pattern
3-184
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delay formation of winter ice cover over the Susitna
Talkeetna and,with substantial increases in
during Apri 1 and May,to accelerate breakup in the
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spring.
Apart from temperatures,there may be some other modifi cat ions of
water quality.These alterations would primarily be at the
beginning of the storage of silt in the reservoir areas or at the
beginning of discharge of less silt-ladened water below the
projects.In addition,if the diversion tunnels are installed in
the winter,the sediment level may be significant unless proper
mitigative actions are taken to prevent any sediment additions to
the river.If,on the other hand,the by-pass tunnels are
installed in the summer,the "increase in sediment levels will be
only minor.
Nutrient levels (phosphorous and nitrogen compounds)will
probably also increase in the impoundments during the fi 11 ing
peri od as vegetat i on with in the impoundment becomes inundated.
The consequences of these increases on downstream water qual ity
h ave not been determi ned,however.Bes i des the phosphorous and
nitrogen compounds,no other chemi ca 1 parameters have exh-j bited
abnormal levels that might be detrimental to aquatic life under
pre-project conditions.It should be noted that there are
presently no data to suggest any adverse effects on water quality
related to these other chemical parameters during reservoir
construction and filling.Furthermore,there are only limited
d at a on mi nera1i zat i on 1eve 1s with the reservoi r areas,and as a
result,no forecast can be made as to the effect on downstream
fishery of alterations in mineralization levels.
During the winter months,very little change in usable habitat is
likely,either during construction or filling of the reservoirs.
Unlike summer flows,winter flows should be very similar to those
occurring before construction begins.The only major difference
between winter and summer impacts is that,as noted above,if
diversion tunnels are installed in winter,they could result in
significant additions of sediment to the river.
o Anadromous Species
Estimates of the number of each salmon species to be affected
in this reach of the river are discussed in section (iii)
below.One change in the habitat that ·will result from the
Susitna project is that the low summer flows wi 11 dewater the
side sloughs along the river.
The low summer flows will be due,in part,to the planned
diversion tunnels.Although the water drop may be rather
sudden,the river should quickly recover as the narrow segment
is filled upstream from the cofferdam.Thus,the effect on
salmon populations is expected to be minor.
3-185
o Resident Species
During the summer,resident fish in this reach of the mainstem
are primarily burbot and longnose suckers.During the fi 11 ing
period,most other residents are associated with the mouths of
clear water tributaries.During the early spring and late fall
sampling periods,adults were more often associated with the
mainstem than they were during the summer.This difference
probably refl ects mi gratory movements between the cl ear water
tributaries.
During the late summer months,whitefish,grayling,and rainbow
trout fry have been found to use the slough habitats,pointing
up the rel at ive importance of these areas to the rearing of
juveniles.Very little information on winter distribution is
available.
Geomorphological changes,in general,should not adversely
affect the resident fish in that,with a decreased vari abi 1ity
in discharge,a more stable channel should result.f'iIore
specifically,however,as described above,dewatering of the
side slough habitats will occur during the summer months,with
water from springs being the only contribution to these areas.
Even though the effects of reduced Susitna flows on the
rech arge of these spri ngs is not known,the port i on of the
resident fisheries using these areas should be reduced.On the
other hand,most of the resi dent fi sh are dependent on cl ear
water tributaries,and these are not likely to be affected by
the project.The significance to the overall population size
of the rearing fish using these areas is not known.
The decrease in scouring floods during the summer should make
the mainstem more hospitable to resident fish than under
pre-project conditions.Sufficient information is lacking,
however,as to whether the post-project condi t ions wi 11 be a
sufficient enough improvement in habitat to enhance the
current,almost non-existent use of this type of habitat.The
decreased flows during the spring and fall should not signifi-
cantly affect the inter-system migration that occurs at this
time.One reason is that no fish passage problems are
anticipated;moreover,no other changes in water quality are
expected which may cause any adverse impacts.
The temperature changes described above are well within the
range of tolerance of the resident species,so no direct effect
is anticipated.If temperature changes trigger migratory
movements of overwintering fish,however,premature migration
may occur.The delay in ice formation and the earlier spring
breakup that is likely to occur during reservoir filling also
as a result of temperature modifi cat ions wi 11 probably have a
minor impact on the resident fisheries.The full effect of
either of these change on the resident species is not known,
however.
3-186
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Geomorphological changes,in general,should not adversely
affect the resident fish,in that with a decreased variabili-
ty in discharge,a more stable channel should result.
(ii)Operation and Maintenance
-Estuary
The proposed Susitna hydroelectric project will alter the monthly
and seasonal discharge patterns of the Susitna River.Based on a
simulated 30-year average,flow increases over existing
conditions will occur during the October through April period,
with monthly average flows increasing from approximately 50%to
120%in the Sus itna Stat i on regi on.The greatest increases wi 11
occur during the December through March period.Summer discharge
levels will be decreased slightly,with the maximum monthly
average decrease in discharge being approximately 15%at Susitna
Station.This maximum decrease will occur during June.
The effect on the upper Cook Inlet estuary of altered discharge
patterns will be of much smaller magnitude than those which may
possibly occur in the Susitna River between Talkeetna and Devil
Canyon.The difference in importance is mainly because the upper
Sus itna River contri butes rough lyon ly 20%of the total Sus itna
River discharge entering Cook Inlet.
The Sus itna does contri bute a si gnifi cant port i on of the total
volume of fresh water entering Cook Inlet annually.It has been
estimated that the Susitna and the other rivers entering the Knik
Arm contribute nearly 80%of this volume.The Susitna River
alone is responsible for approximately 60%of the annual
freshwater contribution to the inlet.During the operation,
first,of Watana and,then,of Watana and Devil Canyon as well as
during the filling of the Watana impoundment,however,changes in
the annual freshwater contribution entering Cook Inlet from the
Susitna will be negligible.
Increased winter discharges will increase the volume of fresh
water entering the estuary during the winter and may lower sal-
inity levels in the vicinity of the river mouth.Strong tidal
action in this region is likely to result in water's being mixed
fairly rapidly through the water column.Such mixing will
further reduce the possibility of the formation of a well-defined
surface layer characterized by significantly lower salinities.
Air temperatures are low enough during November and December,
however,to cause the rapid onset of freezing,despite minor
variations near the Susitna River mouth in either the salinity or
water temperature.The ice breakup pattern in the spring could
be altered slightly by the decrease in the volume of the annual
freshet.
In general,substantial decreases in turbidity levels in an
estuary coul d i nfl uence product ivi ty and result in an increase in
3-187
predation upon larval and juvenile fishes.particularly pink
salmon.Studies have shown that predation on juvenile pink
salmon in estuarine environments can be exceedingly high.Since
much of this predation is based upon visibility,lower turbidity
levels can increase predation considerably.Decreased turbidity
levels in the estuarine plume.however.could increase primary
productivity levels.This decreased turbidity could result in a
corresponding drop in the extinction coefficient which indicates
a greater amount of light penetration into the water column.
Increased winter flows could shift the region of maximum
productivity in the upper estuary farther from the river mouth
region.Effects upon estuarine ecological conditions will
probably be minor.
As mentioned previously,however,the maximum decreases during
the May through August period in the lower Susitna near Cook
Inlet will be,on the average,approximately 15%and will occur
during June.Decreases of around 10%are anticipated during May,
July,and August.These changes are not thought to be of
significance,especially when compared to the mean monthly
fl uctuat i on s on a year-to-year bas is.These have been est il11ated
to be over 50%in July and over 100%during June and August.It
would appear that predicted post-project changes in summer
discharge levels will not affect smolt outmigration or adult
spawning migration patterns in the vicinity of the upper Cook
Inlet estuary.
As discussed in Section 3.6 (d),the impacts to the various
marine mammals and birds utilizing the upper Cook Inlet estuary
should be minimal.Among these are the belugas,or white whales,
which frequent the area between Anchorage and the mouth of the
Beluga River.Some changes in the sedimentation processes within
the estuary,may occur,however,especially in the delta
regions.
-River Mouth to Talkeetna
The operation period for the dams is assumed to begin at the time
when power generation starts.At that time,there will be a
gradual shift from the previous 900 cfs winter flow discharge
during the filling period to an average 9,000 cfs flow during
full operation.The projected summer flow will range from 5,000
to 17,000 cfs,with some periods of spill resulting from heavy
summer rain and glacial melt.
The operation and maintenance of the proposed Susitna Hydro
Project will alter the physical and chemical parameters at the
lower river in the same way that these characteristics will
change during the filling period in the summer.During the
winter,however,additional water will be discharqed from the
reservoir pool,increasing downstream flows and providing
conditions that do not normally occur under the natural flow
regime.
3-188
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During the operation and maintenance of this project,discharge
in the lower river will decrease somewhat during the summer
months and increase substanti ally during the winter.For the
Sunshine Station,the monthly mean and annual frequency duration
curves project decreases in the average month ly di scharge for
June,July,and August.Increases in discharge will occur in
October through May.No significant change in di scharge is
projected for September.
Data analysis indicates that post-project operation average
monthly flows will resemble the historic average low flows that
occur over one day during said month and are slightly below the
average low flow three-day occurrence of June and July.The
post-project August flows will be similar to those that normally
occur over a 14-day period,while the September flows will not
differ significantly from the natural flow.October post-project
flows will be higher than those which occur normally but will be
within the natural variability that occurs over a 14-day period.
Post-project flows at Sunshine Station during November,December,
January,February,March,and April will be well above the normal
variability.The largest departure from the normal conditions
will occur in December when normal winter flows of 4,200 cfs at
Sunshine will be increased three-fold to 12,000 cfs.This change
wi 11 increase the stage at the Sunshine station about one meter.
The channel at this station is much narrower than at other
portions of the lower river,so this stage change should project
a maximum that could be expected to occur.During this winter
period the total wetted surface area of the Susitna River below
Talkeetna will increase above the normally wetted area of
pre-project conditions.
As in the construction phase,an increase in turbidity levels
during the winter should be noticeable below Talkeetna in that
the Susitna under post-project water conditions will be the
dominant flow contributor during these months.On the other
hand,during the summer months,the turbidity below Talkeetna
should not change appreciably because of the minor contribution
of the Susitna in this reach to the suspended sediment load.
Examination of other water qual ity parameters measured through-
out the year does not indicate any abnormal concentrations that
may be limiting to aquatic life.Increases in nutrient
concentrations should result from the flooding of vegetation
within the impoundments.Phosphorous concentrations are often
associated with increases in productivity.Increases in
nutrients in glacial systems,however,which are already light
limiting,do not necessarily cause increases in production.
Downstream nutrient increases are a likely consequence of the
construction of the project,although predictions of these
concentrations have not been made.
3-189
Below the confluence of the Susitna and ChlJl itna rivers,summer
changes in water quality should not be perceptible,both because
of the influence of the Chulitna on the mainstem river and
because of the natural variability of water quality within the
system.
Temperature changes have been projected for the portion of the
Susitna above Talkeetna only.By the time the water in the lower
Susitna reaches the confluence of the Talkeetna,there is likely
to be no difference in the water temperatures of the two rivers.
During operation of the reservoirs,the larger winter flows,
which will also be warmer than present winter flows,are
projected to have only minor influences at the three-river
confluence area near Talkeetna.
In the confluence area near Talkeetna,ice conditions will be
substantially altered during the operation of the project.Under
normal year temperature conditions,the increased winter water
temperatures are not expected to allow an ice cover to form above
the confluence.Consequently,a delay in ice formation will
probably occur in the river as far down as the Parks Highway
bridge.If ice is formed in November.the discharge is projected
to increase by approximately one-third during the month of
December.Ice jams and aufeis formation should occur at
increased rates in this reach,creating high backwaters in the
vicinity of Talkeetna.This ice should not have adverse effects
on resident fisheries habitat but may cause flooding under normal
condit ions.
During the operation of the dam,flood peaks from the Susitna
will be reduced,but the flood contributed by the other
tributaries will continue.The flood events that currently occur
every two years at Sunshine bridge will occur every 10 years
during operation.The five-year peak flood that will occur under
post-project conditions is predicted to be the same as the
present 25-year flood.These changes are likely to provide more
channel stability than that which now occurs.
o Anadromous Species
The decreased summer flows that are projected may inhibit or
prevent salmon from entering some of the spawning sloughs.
Bering cisco enter the river in mid-September and spawn in the
mainstem in the area between Montana Creek and Talkeetna during
the first week of October.They apparently outmigrate to the
ocean immediately after spawning.The times of emergence of
the young and outmigration of the juveniles to the estuary have
not been established.Based on the available data,however,
no impacts are currently foreseen for any of the project
phases.
Little is presently known about the use of the Susitna River
by the eulachon.It would be expected that this species would
3-190
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spawn in some tributaries or in the Susitna mainstem.Eulachon
upstream migration runs are temperature triggered.Since tem-
perature in the river mouth region will not be altered,migra-
tional runs will not be affected.On the basis of available
information,it thus appears that there will probably be no
impacts during any of the project phases.
o Resident Species
The species investigated by ADF&G during the summer of 1981
(with reconnaissance investigations during the winter of
1980-81)included rainbow trout,Arctic grayling,burbot,round
whitefish,humpback whitefish,longnose sucker,Dolly Varden,
threespine stickleback,cottids,Arctic lamprey,and northern
pike.
These resident species probably spawn primarily in clear water
tributaries to the Susitna with possible spawning in the
mainstem by burbot,longnose suckers,and whitefish.During
the winter months,many of the tributary residents outmigrate
from the tributaries and overwinter in the mainstem.This
movement has been inferred from capture data during the fall
and spring near tributary mouths.Information on the seasonal
distribution of juvenile residents is minimal.
Although very small changes in temperature regime are projected
below Talkeetna,those that do take place will occur primarily
during the winter months.These changes will all be well
within the tolerance ranges of the resident species.
In post-project conditions,geomorphological changes in the
system should be very minor in terms of their effects upon
resident fisheries habitat.Because of reduced flows during
the summer,there is a potential for aggradation near the
confluence of the Susitna and Chulitna rivers but these changes
should not affect fisheries habitat of the resident species.
Ice processes wi 11 change in the confluence area but are not
anticipated to create problems for resident fishery habitat.
-Talkeetna to Devil Canyon
o Anadromous Species
The third period of concern when assessing the impact of the
Susitna project on local fisheries is the start of the
operation,when varying flows either will be discharged through
the power units or will be spilled.The following impact
discussion is based on the current proposed operation of the
facilities for maximum power production.The desired flows
will be supplied,in part,through Cone valves.With the jets
dispersing the outflow,there should be no penetration to carry
air below a .6 m depth in the plunge pool.The only exception
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would be a major flood occurring at 50-year or longer
intervals.There is now supersaturation of dissolved gas
(oxygen and nitrogen)at high flows in the Devi 1 Canyon area,
but these levels are below critical levels [Figure 3.36 (APA
1981)J.
It is evident that this stream becomes more turbulent and
entrains more air at higher flows.It is possible that with
the reduction of flow in the canyons even a small increase of
saturated gas in the plunge pool will not increase present
natural levels below Devil Canyon.
As mentioned above,the period of filling is the time when
possible changes will begin in the deltas of the incoming
streams because at that time there wi 11 be a loss of support
level.This change will continue until stability is reached.
The period of existing minimum flow in the river will be
altered to become the period of the maximum discharge through
the power units.This flow,however,is below that which would
be needed to wet the sloughs,between Devil .Canyon and
Talkeetna which are presently used by salmon for spawning or
rearing.Thus,approximately 40 sloughs,and,in particular,
important chum salmon spawning habitat will be lost by the
proposed project flows.
Various studies have been undertaken to il1dicate the
temperatures that may be expected be 1ow Watana dam and be 1ow
both Watana and Devil Canyon dams,when both are in operation.
It is expected that as a result of river modifications caused
by the project,the entire winter flow pattern will be changed
at least to Talkeetna.With this change in winter flow and
temperature pattern,ice producti on wou 1d be altered.Wh i le
this alteration poses no problem above Talkeetna,it represents
a potential problem to both fish and fish habitat below
Talkeetna.
The clear water sources,or the aquifers,that suppl y the
sloughs in the winter are presently unknown.In some cases,
this water is apparently supplied from bank storage,and it is
speculated that,in some cases the flow has an origin in the
main river channel,with the water being cl arified by passing
through the gravels of an island.In the absence of this
information,it cannot be predicted whether or not these
areas will remain as salmon producers.
Recent studies have indicated that there will be significant
storage of river-borne particles in the Watana reservoir.
Below the two dams there wi 11 be cl arification of flow during
summer.This clarity,in turn,can alter the food production
and the usefulness of the river for improved salmon production.
Increased predation on young salmon,however,is also a
possibility.
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Linder the maximum power production scheduled,there still will
be periodic spills from Watana reservoir,which must be passed
through Devil Canyon into the natural river bed.The level of
these flows will be important with respect to their effect upon
the morphology of the river downstream to Talkeetna,
particularly their effect upon the morphology of the side
sloughs or side channels where fish may now be produced.
o Resident Species
During the operation of the Susitna hydro project,physical
habitat in the reach of river between Talkeetna and Devi 1
Canyon will be changed the most.For example,during the
operat i on phase of the program,substanti al changes in the
summer flows will occur.These flows will considerably alter
the flow in the side channels and sloughs in this reach,
reducing it to local run-off and spring flow.
Duri ng operat i on,sediment will probably decrease in the lower
river during the summer months and increase during the winter.
Like the increases expected during filling,nutrient levels
(phosphorous and nitrogen compounds)are al so 1i kely to
increase during the operational period as vegetation within the
impoundment becomes inundated.The consequences of these
increases on downstream water quality,however,have not been
determined.The limited data base does not indicate that,
under pre-project conditions,any other chemicals are present
at enough levels to be detrimental to aquatic life.Similarly,
current available data suggest no adverse effects of reservoir
operation on water quality in relation to these other chemical
parameters.
The normal flood peaks that occur during the summer will
be substantially reduced during the operation of the project,
creating a more stable channel and reducing the bedload
movement that occurs.The fall spills,whenever,they occur,
however,may disrupt the newly stabilized stream bed.
The resi dent fi sh found thro~ghout the year in thi s reach of
the ri ver are primarily burbot and longnose suckers.Other
residents are chiefly associated with the mouths of clear water
tributaries.During the early spring and late fall sampling
periods,adults were found associated more often with the
mainstem than they were during the summer.This probably
reflects migratory movements between the clear water
tributaries and the mainstem.Very little information on
winter distribution is available.Friese (1975)found
whitefish,grayling,and rainbow trout fry using the slough
habitats during the late summer months,a reflection of the
relative importance of these areas to rearing juveniles.
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During the winter months. a significant increase in the wetted
area of the main channel should occur.Dewatering of the side
slough habitats will occur during the summer months,wnen water
from springs will be the only contribution to these areas.The
effects of reduced Susitna flows on the recharge of these
springs is not known.While the portion of the resident
fisheries using these areas will probably be reduced.most of
the resident fish are dependent on clear water tributaries.and
these areas will not be affected by the project.The
significance of the rearing fish using these areas to the
overall population is not known.
The decrease in scouring floods during the summer should
make the mainstem more hospitable to resident fish during
the summer than it is under pre-project conditions.However.
insufficient information is available as to whether the
post -project condit ions wi 11 result in suffic i ent improvement
in habitat to enhance the current.almost non-existent use of
this type of habitat.The decreased flows during the spring.
when inter-system migration of resident fish occurs.should not
significantly affect this activity.No fish passage problems
are anticipated.nor are there any changes in water quality
anticipated which suggest adverse impacts.
Temperature effects on the river above Talkeetna will be most
noticeable during the winter months.These temperatures will
be well within the tolerance range of the resident species.so
no direct effect will be expected.
(iii)Overview of Impacts on Salmon -Talkeetna to Devil Canyon
The following discussion is an estimate of the magnitude of the
Susitna Hydroelectric Project's impact upon the five salmon species
utilizing the Talkeetna to Devil Canyon reach of the Susitna River.
As stated earlier.between 1%and 2%of the Susitna escapement use
this reach of the river.
It is believed that the primary spawning sites for chinook salmon
in this reach of the river are located in the tributaries.
particul arly Indi an River and Portage Creek.Although the use of
this stretch as a migrational route will not likely be hampered by
project flow.potential loss of rearing habitat here may be an
adverse impact on the chinook.
As a result of the impacts in the Talkeetna to Devi 1 Canyon reach
of the Susitna.approximately 14.000 of the annual sockeye salmon
harvest in the Cook Inlet could be lost.All of the sockeye salmon
in the Susitna River reach above Talkeetna were found only in the
slough habitats.Yet to be defined for this reach of the river.
however.is the location of rearing habitat for the sockeye.There
are no lakes in this area to which they have access.If it is
assumed that.at this time.the sockeye have contributed on an
equal bas is with sockeye from other port ions of the Sus itna with
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known rearing habitats,then the impact wi 11 be a loss of all or
most of the slough spawning habitat in the Talkeetna to Devil
Canyon reach.This loss will alter the Susitna escapement by
approximately 1%and the Cook Inlet run by about .05%
It is expected that practically the entire adverse impact on pink
salmon wi 11 occur in the reach of river above Talkeetna.Based on
1981 escapement data,if all spawning habitat were lost above
Talkeetna,it would impact approximately 2%of the Cook Inlet
harvest or approximately 9,000 to 10,000 odd-year run pink salmon.
Since the odd-year pink salmon were found spawning primarily in the
tributaries in this reach of the river and not in the side channels
of the rna i nstem,what impact upon them that occurs is not expected
to be extensive.Even-year pink salmon must,by virtue of their
numbers,be less selective about the choice of spawning sites.It
is,therefore,anticipated that even-year pink salmon will be found
in all available habitat;however,1982 information is needed to
address this impact in detail.
Seventy percent of the Cook Inlet harvest run of coho salmon are
estimated to originate from the Susitna River drainage.The Cook
Inlet annual harvest for 20 years of record is 231,000 coho salmon.
Preliminary sources have indicated that the 1981 Cook Inlet coho
salmon harvest was a record catch of nearly 500,000 fi sh.An
excessive harvest may have occurred and could be responsible for
the low escapement of coho into the Susitna in 1981.Twenty-two
percent of the Cook Inlet run returns to the Susitna River for
reproduct i on.In 1981 th is was estimated to be approximately
33,000 to 34,000 fish by the ADF&G.Coho escapement was thought to
be rather weak during 1981 and the coho population is thought to be
somewhat depressed.As a result,the 1981 figure is probably below
the long-term average.
Most of the coho salmon that go above Talkeetna use tributaries for
spawning,although some mainstem spawning has been observed.Thus,
impact of power flows on the coho salmon in this reach is not
expected to be severe.
It is anticipated that the flows associated with power production
will all but eliminate access to essentially all of the ~loughs in
the Talkeetna to Devi 1 Canyon reach of the Susitna River.The
sloughs are used extensively by chum salmon for spawning.This
1 ack of access will adversely affect the chum salmon causing a
severe reduction in their population in this section of the Susitna
River.On the other hand,at least 80%of the chum salmon in the
Susitna River use other areas for spawning.
The percentage of all five Pacific salmon species that use the
Susitna River above Talkeetna is low.In some cases,the impact
associated with the power project will be minimal,as with the
chinook.In other cases,such as with the chum salmon,
consequences will be more severe.With regard to the useful
habitats of the Pacific salmon,the remainder of the Susitna
drainage,including the major tributaries and the Yentna,Chulitna,
and Talkeetna rivers,will not be affected.
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(e)Access Route
(i)Construction
Impacts on fish resources from access road construction could
effect both anadromous and resident fish species.With proper
mit i gat i on procedures,however,these effects are not expected to
be severe.Stream bank and stream bed disturbances during
construction could disturb spawning,rearing,or shelter habitat in
the immediate construction zone or could result in the siltation of
these habitats downstream.Fai lure to remove fall en trees and
other debris resulting from construction activities could prevent
fish passage in both an upstream or downstream direction.Such
obstructions would most likely be a problem in the smaller
streams.
Oil residue and bacterial as well as nutrient contamination
resulting from the presence of construction vehicles,facilities,
and the construction work force and families could degrade the
water quality of any nearby aquatic habitats.This contamination
waul d be of greatest impact in sma 11 er tri butari es or 1akes where
the potential dilution of any contaminants would be limited.
The proposed access plan includes a road from the Parks Highway at
Hurricane to Gold Creek,a road to Devil Canyon on the south side
of the Susitna,and a north-side connection between the two dams.
If this plan is implemented,the anadromous fish populations of
Indian River,in particular,and the Susitna River generally could
be affected during the construction phase.The construction of a
bridge across the Indian River and the access road along the Indian
River could both create siltation problems for spawning salmon
species,in particular,king,chum,and coho salmon.Resident
species could also be affected.
The construction of two bridges across the Susitna (near Gold Creek
and at Devil Canyon)could also cause siltation problems downstream
of both construction sites.This siltation could be detrimental to
salmon utilizing the mainstem Susitna for spawning;both chum and
coho salmon spawning sites have been identified in this general
region of the mainstem.
The access road segment between Gold Creek and the Devil Canyon dam
site would cross several small tributaries located south of the
Susitna River.Most or all of these streams contain grayling
popUlations,which may be affected during road construction.
More significant grayling populations could be affected along the
Devi 1 Canyon to Watana port i on of the access road.Devi 1 and
Tsusena creeks,which would be crossed,have fairly sizable
grayling populations.Since the areas of these creeks that will be
crossed by the access road wi 11 not be inundated by the Devi 1
Canyon impoundment,these crossings must be considered possible
addit iona1 impacts.
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Increases in angling pressure from the presence of a larger number
of construction workers and their families could affect the salmon
and resident fish populations throughout the regions where
satellite and large construction camps and villages are located.
Specifically,the presence of a construction camp at Hurricane
could increase fishing pressure upon the Indian River salmon
stocks.The Gold Creek camp could increase the pressure on both
the Indian and the Susitna rivers.Salmon stocks in Portage Creek
could be influenced by the camp location at Devil Canyon.The fish
to be affected by the Watana camp popul at i on are most 1i ke ly to be
grayling in the Watana and possibly Tsusena creeks.
The same type of construction-related impacts noted above are
possible during pioneer road construction.The same area between
the Devi 1 Canyon and the Watana dam sites that could be affected by
access road building may also experience changes from pioneer road
building.The segment between Gold Creek and Devil Canyon w"ill
affect areas additional to those to be affected by the permanent
road.On the other hand,because of the small er workforce,the
contamination and pollution impacts would be fewer and the angling
pressure far less during pioneer road construction.
Sedimentation problems may also be an impact associated with
borrow pits used for access road construction.These problems
would be minimal,however,compared to those created by the borrow
and quarry areas used for dam construction.
(ii)Operation and Maintenance
The most s ignifi cant potent i al impacts assoc i ated with the
operat i on and maintenance of the access road will ari se from two
different sources.First,a lack of maintenance of the stream
crossings could result in a degeneration of those areas,which
could,in turn,affect the fish populations.The second major
impact on fisheries could be triggered by the failure of the stream
crossings themselves or the failure of any road design or
construction methods that may have been implemented,in fact,to
limit or to eliminate siltation or blockages to fish passage.
General road maintenance and repair could have the same types of
effects as those associated with construction,but the levels
of these impacts would be lower than those of their construction
period counterparts.With proper design and adequate maintenance
of stream crossings these significant potential impacts can
virtually be eliminated.
(iii)Public Access
The presence of the access road and any allowance of permanent
access on the pioneer road could have a significant impact upon the
fi sh resource within the vi cinity of these routes.Increased
publ ic access could result in a corresponding increase in angl ing
pressure.In contrast to a more temporary increase in angl ing
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pressure associated with the presence of the construction
population,public access would create a long-term or permanent
impact.An example of such a long-term consequence is the possible
creation of a permanent village near the Watana dam site.The
regions of greatest access would be the entire stretch of the
Indian River.with its salmon fishery,and the grayling and lake
trout populations in the upper basin.
Resident fish species may be particularly vulnerable to excessive
fishing pressure because of their late maturity and slow
growth rate.In the case of the grayling,the ease with which they
may be caught by hook and line makes this species particularly
vulnerable to angling pressure.
(f)Transmission Line
(i)Construction
Transmission line construction could affect fish habitat through
direct streambed disturbance or by causing siltation problew~
downstream.This siltation would occur during the movement Jf
construction equipment or materials through streams that need tv be
crossed.If stream cross i ngs are constructed,the same impacts
could occur,and problems with fish passage could arise if these
structures should fail.In general,however,impacts associated
with tranmission line construction should be minimal.
Impacts associated with construction camps used during transmission
line construction would be similar to those associated with con-
struction camps for access road building.The same camp sites will
be used for both construction projects.Thus,the same possibility
of contamination and angling pressure impacts discussed in relation
to access road construction will exist for transmission line
construction.
(ii)Operation and Maintenance
In terms of fisheries,impacts associated with the operation and
maintenance of transmission lines should also be minimal.
Streambed disturbances during routine maintenance and operation
should be insignificant.Any stream crossings erected during the
transmission line construction phase,if not properly maintained,
could result in fish passage blockage.In the northern corridor,
stream crossings over the Tanana and Nenana Rivers could be
significant.Indian River and Susitna River crossings.in the
central area,are also important crossing sites.In the southern
corridor,critical stream crossings will be made over Willow Creek
and the Little Susitna River.
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3.8 -Anticipated Impacts on Threatened or Endangered Species
(a)Plants
None of the plant species under review for possible protection under the
Endangered Species Act of 1973 are known to occur in the vicinity of any
proposed project facil ities,nor were any of these species found during
searches of potential habitat [Section 3.4(a)J.Although some potential
habitat does exist in the upper basin,it is distant from any proposed
facilities.As a result,it is not anticipated that any of these species
will be adversely affected by any project activity.
(b)Wild1 ife
No endangered wi 1dlife species are presently known to occur in the
project area in the upper basin [see Section 3.4(b)J.As previously
noted,the peregrine falcon is the only species that could occur in the
project area and no peregrines were documented during the present study.
This does not,however,mean that peregrines will not,sometime in the
future,attempt to use the cliff habitat along the Susitna River or
adjacent tributaries for nesting purposes.Some of the cliff habitat
will have been inundated,but some will remain [Section 3.6(a)and (b)].
One may specul ate that if peregrines attempt to breed in the project area
following construction of the hydroelectric facilities they would stand a
good chance of being successful.Due to construction activity,the
possibility of successful breeding during the construction phase might be
considerably less,depending upon the proximity of the selected nest site
to the construction sites.
There is a possibility that future use of the peregrine nest site located
near the Tanana River may be affected by the transmission line.The nest
was not active during 1981 but could conceivably be used at some time in
the future.If the nest is active during the construction of the line,
the birds may abandon it as a result of the disturbance.If the nest
remains inactive during the line construction,however,it may be
acceptable for later use during the operational phase of the line.
(c)Fish
Since there are no threatened or endangered fish species listed for the
State of Alaska,there can be no impact in regard to this topic.
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~3.9 -Mitigation of Impacts on Fish,Wildlife,and Botanical Resources
(a)Mitigation Policy and Approach
The mitigation policy and approach was developed by TES in cooperation
with Acres American and the Alaska Power Authority.The text was
re 1eased by the Power Authori ty for agency revi ew and comment.The
following text is a revision of the original,incorporating agency
comments.
1 -INTRODUCTION
The fish and wildlife mitigation aspects of the Susitna project have been
addressed through a Fisheries Mitigation Core Group,a Wildlife Mitigation Core
Group,and a Fish and Wildlife Mitigation Review Group.The two core groups
consist of staff members of Terrestrial Environmental Specialists,Inc.,
consultants with expertise in special areas (caribou,furbearers,anadromous
fish,etc.),and a representative of the Alaska Department of Fish and Game.
The purpose of the two core groups is to develop the technical specifics of the
mitigation policy and plans.
The purpose of the Review Group is to review and comment on the results of the
core groups.Agencies represented on the Mitigation Review Group are:
Alaska Department of Natural Resources
Alaska Department of Fish and Game
U.S.Fish and Wildlife Service
U.S.Environmental Protection Agency
U.S.Bureau of Land Management
National Marine Fisheries Service
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A mandate of the APA charter is to develop suppl ies of electrical energy to
meet the present and future needs of the state of Alaska.APA also recognizes
the value of our natural resources and accepts the responsibility of ensuring
that the development of any new projects is as compatible as possible with the
fish and wildlife resources of the state and that the overall effects of any
such projects will be beneficial to the state as a whole.In this regard APA
has prepared a Fisheries and Wildlife Mitigation Policy for the Susitna
Hydroelectric Project as contained herein.
2 -LEGAL MANDATES
There are numerous state and federal laws and regulations that specifically
require mitigation planning.The mitigation policy and plans contained within
this document are designed to comply with the collective and specific intent of
these legal mandates.Following are the major laws or regulations that require
the consideration and eventual implementation of mitigation efforts.
Protection of Fish and Game (AS 16.05.870)
The Alaska state laws pertaining to the disturbance of streams important to
anadromous fish address the need to mitigate impacts on fish and game that may
result from such action.The pertinent portion of item (c)from Section
16.05.870 reads as follows:
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II If the Commi ss i oner determi nes to do so ~he s ha 11,in the letter of
acknowledgement,require the person or governmental agency to submit to him
full plans and specifications of the proposed construction or work,
complete pl ans and specifications for the proper protection of fish and
game in connection with the construction or work~or in connection with the
use,and the approximate date the construction,work,or use will begin,
and shall require the person or governmental agency to obtain written
approval from him as to the sufficiency of the plans or specifications
before the proposed construction or use is begun."
National Environmental Policy Act
The National Environmental Policy Act (NEPA)(42 USC 4321-4347)was designed to
encourage the consideration of environmental concerns in the planning of
federally controlled projects.Regulations pertaining to the implementation of
NEPA have been issued by the Council on Environmental Quality (40 CFR
1500-1508;43 FR 55990;corrected by 44 FR 873 Title 40,Chapter V,Part 1500).
Items (e)and (f)under Section 1500.2 (Policy)of these regulations describe
the responsibilities of federal agencies in regard to mitigation.
Federal agencies shall to the fullest extent possible:
"(e)Use the NEPA process to identify and assess the reasonable
alternatives to proposed actions that will avoid or minimize adverse
effects of these actions upon the quality of the human environment.
(f)Use all practicable means,consistent with the requirements of the Act
and other essential considerations of national policy,to restore and
enhance the quality of the human environment and avoid or minimize any
possible adverse effects of their actions upon the quality of the human
environment."
Federal Energy Regulatory Commission
Federal Energy Regulatory Commission (FERC)regulations also refer directly to
the need for mitigation actions on the part of the developers of hydroelectric
projects (18 CFR Part 4).The following reference is quoted from Section 4.41
of the Notice of Final Rule as it appeared in the November 13~1981,issue of
the Federal Register (46 FR 55926-55954)and was adopted.Exhibit E of a FERC
license application should include,among other information,
"•.•a description of any measures or facilities recommended by state or
Federal agencies for the mitigation of impacts on fish,wi ldl ife,and
botanical resources,or for the protection or enhancement of these
resources..II
The regulations go on to require details concerning mitigation including a
description of measures and facilities,schedule,costs,and funding sources.
Fish and Wildlife Coordination Act (915 USC 661-667)
Item (a)of Section 662 of the Fish and Wildlife Coordination Act describes the
role of the federal agencies in reviewing federally licensed water projects.
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II ••such department or agency first shall consult with the United States
Fish and Wildlife Service,Department of the Interior,and with the head of
the agency exercising administration over the wildlife resources of the
particular State wherein the impoundment,diversion,or other control
facility is to be constructed,with view to conservation of wildlife
resources by prevent i ng loss of and damage to such resources as we 11 as
provi di ng for the deve lopment and improvement thereof in connect i on with
such water-resource development.1I
FERC will comply with the consultation provisions of the Fish and Wildlife
Coordination Act.
3 -GENERAL POLICIES TO BE CARRIED OUT BY THE APPLICANT
3.1 -Basic Intent of the Applicant
In fUlfilling its mandate,an objective of the Alaska Power Authority (APA)is to
mitigate the negative impacts of the Susitna Project on the fish and wildl ife
resources.This goal will be achieved through comprehensive planning during the
early stages of project development and through a program of ongoing consultation
with the appropriate resource agencies.Since the APA realizes that highly coordi-
nated planning will be necessary to achieve this goal,a decision-making methodol-
ogy has been developed to provide a framework for addressing each impact and the
mitigation options available.This methodology outline also identifies the process
for resolving conflicts that may develop between APA and the resource agencies.
The FERC will resolve any disputes which the agencies and APA cannot resolve.
The mitigation plan will be submitted by the APA to the FERC as a component of the
license application.Prior to this,any draft mitigation plans will be submitted
to resource agencies for formal review and comment.The final mitigation plan to
be implemented will be stipulated by the FERC.The ultimate responsibility for
insuring implementation of the plan will be that of the APA and will be carried out
by the APA or any other organization charged with managing the project as
stipulated by the FERC.
3.2 -Consultation with Natural Resources Agencies and the Public
In order to achieve the above-mentioned goals,it will be necessary to provide
opportunities for the review and evaluation of concerns and recommendations from
the public as well as federal and state agencies.During the early stages of
planning,representatives of state and federal agencies will be encouraged to
consult with the applicant and the applicant1s representatives,as members of the
Fish and Wildlife Mitigation Review Group.Additional review and evaluation of the
mitigation plan will be provided through formal agency comments in response to
state and/or federally administered licensing and permitting programs.
APA will consider all concerns expressed by members of the general public and
regulatory agencies regarding the mitigation plan.Input from the public will be
given appropriate consideration in the decision-making process as it pertains to
the direction of the mitigation effort and the selection of mitigation options.
3.3 -Implementation of the Mitigation Plan
The ultimate responsiblity for insuring implementation of the mitigation plan rests
with APA.Prior to implementing the plan,an agreement will be reached as to the
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most efficient manner in which to execute the plan.The agreement will determine
which organization w"ill serve to carry out various portions of the plan and will
include stipulations to insure adherence to the accepted plan.
Realizing that a mitigation monitoring team will be necessary to insure the proper
and successful execution of the mitigation plan,part of the plan will detail the
structure and responsibilities of such a monitoring body.The successful
organization and operation of a monitoring team will require both funding and
commitments.These matters will be resolved through negotiation leading to mutual
agreement among the various involved parties after the mitigation plan is complete
and the necessary level of resources can be more accurately defined.
3.4 -Modification of the Mitigation Plan
As part of the mitigation plan,a monitoring plan will be established,the purpose
of which will be to monitor fish and wildlife populations during the construction
and operation of the project to determine the effectiveness of the plan as well as
to identify problems that were not anticipated during the initial preparation of
the plan.
The mitigation plan will be sufficiently flexible so that if data secured during
the monitoring of fish and wildlife populations indicate that the mitigation effort
should be modified,the mitigation plan can be adjusted accordingly.This may
involve an increased effort in some areas where the original plan has proven
ineffective,as well as a reduction of effort where impacts failed to materialize
as predicted.Any modifications to the mitigation plan proposed by the monitoring
team will not be implemented without consultation with appropriate state and
federal agencies and approval of APA and FERC.The need for continuing this
monitoring will be reviewed periodically.The monitoring program will be
terminated when the need for further mitigation is considered unnecessary,subject
to FERC approval.
4 -APPROACH TO DEVELOPING THE FISH AND WILDLIFE MITIGATION PLANS
The development of the Susitna Fish and Wildlife Mitigation Plans will follow a
logical step-by-step process.Figure 1 [Figure 3.37J illustrates this process and
identifies the major components of the process.Also identified in Figure 1
[Figure 3.37J are the organizations responsible for each step.The following
discussion is based on Figure 1 [Figure 3.37]and uses the numbers in the lower
right corner of each block of that figure for reference purposes.
The first step in the approach (Step 1)entails the identification of impacts that
wi 11 occur as a result of the project.Each impacted reSource and the nature and
extent of the impact will be defined.The fish and wildlife resources will vary
in definition and may include a population,subpopulation,habitat type,or
geographic area.The nature and degree of impact on each respective resource will
be predicted to the greatest extent possible.This step will be the responsibility
of the Core Group of the Mitigation Task Force.
Following the identification of impact issues,the Core Group will agree upon a
logical order of priority for addressing the impact issues.This will include
ranking resources in order of their importance.The ranking will take into
consideration a variety of factors such as ecological value,consumptive value,and
nonconsumptive value.Other factors may be considered in the ranking if deemed
necessary.The impact issues will also be considered in regard to the confidence
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associated with the impact prediction.In other words,those resources that will
most certainly be impacted will be given priority over impact issues where there is
less confidence in the impact's actually occurring.The result of this dual
~prioritization will be the application of mitigation planning efforts in a logical
and effective manner.The results of the prioritization process will be reviewed
by the Fish and Wildlife Mitigation Review Group.
Step 2 is the option analysis procedure to be performed by the Core Group.The
intent of this procedure is to consider each impact issue,starting with high
priority issues,and reviewing all practicable mitigation options.
Mitigation for each impact issue will be considered according to the types and
sequence identified by the CEQ (Figure 2 [Figure 3.38J)'If a proposed form of
mitigation is technically infeasible,only partially effective,or in conflict with
other project objectives,additional options will be evaluated.All options
considered will be evaluated and documented.The result of this process will be an
identification and evaluation of feasible mitigation options for each impact issue
and a description of residual impacts.
Additional items that may be addressed by the Core Group include an identification
of organizations qualified to execute the mitigation plan and recommendations con-
cerning the staffing,funding and responsibilities of the mitigation monitoring
team.
Step 3 concerns the development of an acceptable mitigation plan.The feasible
mitigation options identified through Step 2 will be forwarded to the mitigation
review group for informal agency review and comment.Any recommendations received
from the review group will be considered by APA and the Core Group,prior to the
preparation of draft fisheries and wildlife mitigation plans.These draft plans
will be sent to the Fish and Wildlife Mitigation Review Group for comment and then,
following revision,to the FERC as a component of the license application.The
final fish and wildlife mitigation plans to be implemented will be stipulated by
the FERC following discussions with APA and appropriate natural resource agencies.
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Step 4 will be the implementation of the plan as agreed to during Step 3.This
will commence,as appropriate,following the reaching of an agreement by all
parties.
During the implementation of the plan,which will include both the construction and
operation phases of the project until further mitigation is deemed unnecessary,the
mitigation monitoring team will review the work and evaluate the effectiveness of
the plan (Step 5).To accomplish this goal,the monitor"ing team will have the
res pons i bi 1ity of assuri ng that the agreed upon plan is properl y executed by the
designated organizations.The team will be provided with the results of ongoing
monitoring efforts.This will enable the team to determine in which cases the
mitigation plan is effective,where it has proven to be less than effective,and
also in which cases the predicted impact did not materialize and the proposed
mitigation efforts are unnecessary.The monitoring team wi 11 submit regularly
scheduled reports concerning the mitigation effort,and where appropriate,propose
modifications to the plan.If stipulated in the FERC license,such reports would
be distributed to FERC and State and Federal regulatory agencies.
In the event that plan modifications are recommended (Step 6),they will be
reviewed by a Core Group and appropriate options considered (Step 2).The results
of the option analysis will then be passed on to the APA and the resource agencies
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for negotiation of modifications to the plan (Step 3),Following the reaching of
an agreement on the modifications,they will be implemented (Step 4)and monitored
(Step 5).
Following satisfactory implementation of any plan modifications,the mitigation
planning process and monitoring will terminate (Steps 7 and 8).
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(b)Mitigation of Impacts on Botanical Resources
The discussion of mitigation of impacts on botanical resources centers
around avoidance,minimization,compensation,and rectification.
Avoidance and minimization are,in many instances,related.These types
of mitigation involve refraining from unnecessary ground disturbance and
regulating particularly disruptive activities,especially those
involving heavy machinery and ATV use during summer and fall.
Some of these first mitigation considerations have been incorporated
into the timing of construction,the layout and the location of certain
proposed facilities.For example,placing of the transmission corridor
close to the access road will minimize impact on vegetation by
encourag i ng use of the road for access to tower structures.Winter
construction would also limit ground disturbance.
Locating some temporary facilities or undertaking some construction
activities within the future impoundment zone will also help minimize
the impact on vegetation.If,for instance,access roads or other
ground disturbing activities related to the selective clearing of the
drawdown area are restricted to the impoundment zone,which will
eventually be flooded,then associated impacts will be limited.
The location,too,within the reservoirs of several of the potential
borrow areas is another examp 1e of how the tota 1 impact on vegetati on
will be minimized.
As mentioned above,regulation of ATV use is an important aspect of
avoidance/minimization mitigation methods.During the construction
period,if ATV use from the access road is restricted,then a potential
impact on vegetation will be minimized.If this restriction is extended
into the operation stage (especially from Devil Canyon to Watana),then
impact will be further limited.
Another mitigation technique of this type concerns permafrost.In areas
along the access road where drainage patterns may be changed,installing
culverts or other drainage viaducts will control impacts associated with
those changes.A sufficiently thick insulating layer of gravel,placed
directly on the vegetation mat,will limit the potential for melting of
permafrost.This standard construction technique will avoid those
impacts on vegetation associated with permafrost disturbance.
Slash from spruce trees that are cut from the access road or
transmission right-of-way will increase the potential for spruce bark
beetle infestation.The burning of the spruce slash would limit or
remove this potential.
In areas that wi 11 be di rect ly affected,such as the impoundment zones,
dams and spillways,airstrip and other permanent facilities,the
el imination of vegetation/habitat area cannot be avoided.Compensation
for losses of w"ildlife habitat could be provided,however,"in adjacent
open and woodland spruce stands and/or downstream balsam poplar stands.
Downstream balsam poplar stands,in particular,provide the greatest
opportunity for increased browse production and are located in prime
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moose range,where "increased browse production can be more fully
utilized by a consistently productive herd.Compensation techniques
could include clearing (commercial or otherwise)and/or burning to
enhance sprouting of poplar,birch,and willow species.Commercial
clearing of downstream stands will be economically attractive,and will
benefit moose,and will probably also increase the value of timber in
the area,as decadent and diseased stands of balsam poplar and birch are
cut and replaced by younger,healthier growth.Compensation,as a
mitigation technique,for the benefit of wildlife is discussed in
greater detail in the wildlife section [3.9 (c)].
Although permanent facilities will eliminate certain areas as
vegetation/habitat types,impact from temporary facilities or activities
can be somewhat rectified by reclamation.Standard construction
practices of either recontouring or creating gentle slopes wi 11 help
avoid erosion problems and will aid reclamation efforts.Borrow areas,
access road cuts,areas of construction activity,and temporary facility
sites will be revegetated upon completion of construction.This
revegetation process will be greatly simplified and accelerated by
stockpiling both topsoil and the organic layer during construction.
The stockpiling and redistribution of this material is the most
important part of reclamation.Redistribution of these materials and
subsequent fertilization will,in many instances,restore the vegetation
cover.The first step in the process is to mix organic mat~rial into
the upper 10 cm of mineral soils.Adequate fertilization can be
accomplished by using fertilizer mixtures high in phosphorous [such as
(N,P,K)10-20-10,8-32-16,etc.]and applying the fertilizer at a rate
sufficient to supply 85 to 110 kg of nitrogen per hectare (75 to 100
lbs.of nitrogen per acre).During the second and third growing
seasons,follow-up treatments at one-half to one-third the original
rate will probably be warranted.
With topsoil in place,fertilization alone will often provide the
necessary impetus for natural revegetation.Where erosion potential or
aesthetic considerations are great,however,more intensive revegetation
practices involving mulching and seeding,preferably with native
species,will be employed.Experience in other regions of Alaska
indicates that a relatively light seeding rate,which would establish a
sparse stand of grass,is the best way to encourage rapid re-invasion of
native plants.Ten to 20 well-established grass plants per square meter
(one or two per sq uare foot)wou 1d be adequate on sites not threatened
by erosion.
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(c)Mitigation of Impacts on Wildlife Resources
Following is a discussion of various means that could be employed
to mitigate the impacts on wildlife resources that will be incurred
as a result of the Susitna project.Mitigation options are
identified for each impact issue.The options are then discussed
and the most viable courses of action are identified.
Since the impacts are not of equal significance,they have been
grouped into three categories.The results of this grouping are
presented on Table 3.68.The impact issue numbers on Table 3.68
correspond to the numbers associated with the discussion below.
The three categories are high priority,moderate priority,and low
priority.Criteria applied in the determination of these
categories included the importance of the resource (both biological
and consumptive),the likelihood of the impact occurring,and the
severity of the impact on the resource.The purpose of this
approach was to insure that the emphasis of the mitigation effort
is applied in the most appropriate manner.
-(W-l)Watana and Devil Canyon Impoundments -Mink and River
Otter
Creation of both impoundments will result in the loss of riverine
and terrestrial habitat and an associated decrease in the
available food base [See Sections 3.6 (a)(ii)and 3.6(b)(ii)].
a Mitigation Options
Due to the nature of this impact,compensation is the only form
of mit i gat ion t hat is fe as ib1e•Sin ce it wo u1d be i mp 0 s sib 1e
to create suitable terrestrial habitat,in-kind'compensation
would require taking appropriate steps to insure that the
aquatic habitat created by the impoundments would supply an
adequate food base for these two furbearer speci es.If that
approach is not possible,some form of out-of-kind compensation
would be required.
o Discussion
There would be a negative impact on mink and river otter as a
result of the elimination of a considerable amount of both
terrestri a1 and riverine habitat.Conversely,the creation of
two 1arge impoundments wi 11 resu lt ina net increase in the
amount of aquatic habitat available.The important question is
how suitable the impoundments will be "in providing available
feeding opportunities for mink and river otter.The impound-
ments may,without any action on the part of the appl icant,
provi de an adequate food base to compensate for the predi cted
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loss.Until further details are available,it is difficult to
quantify this potential.There are thus three scenarios
associated with this situation:1)the impoundments will be
su itab 1e for a healthy fi sheri es resource and that resource
will develop naturally,2)the reservoirs will be suitable for
the establishment of a fisheries resource but the introduction
of fish will be required to stimulate the growth of that
resource,and 3)the impoundments wi 11 not be capab 1e,from a
limnological standpoint,of supporting an adequate fisheries
resource.
o Conclusion
The predicted impacts on mink and river otter could be
mitigated to some degree by a program of establishing a viable
fisheries resource in the two impoundments.The first step in
such a program would entail determining the suitability of the
impoundments to support fish.If the impoundments were
determined to be suitable for fish,and if natural processes
were determined to be insufficient to develop such a fish
resource,a stocking program could be implemented to stimulate
the creation of a suitable fish population,which would also
provide recreational fishing opportunities.If the development
of a fisheries resource,either naturally or as a result of
artificial means,were not to prove feasible,the impact could
be compensated for through some other species.
-(W-2)Watana and Devil Canyon Impoundments -Pine Marten
Creation of both impoundments wi 11 result in the loss of pine
marten habitat by flooding [see Sections 3.6(a)(ii)and 3.6(b)
(ii)J.
o Mitigation Options
It will be impossible to avoid this impact entirely,and unless
a project with a lower pool elevation were to be built,no
minimization opportunities exist.Therefore,the only feasible
form of mitigation is through compensation in an out-of-kind
manner.
o Discussion
Due to the nature of pine marten habitat,it will be impossible
to manage or create compensatory habi tat in the project area.
In addition,this species will be severely affected in the
project area because the bulk of suitable marten habitat lies
within the project impoundment zones.
o Conclusion
Since the marten is an important resource to trappers,any
out-of-kind compensatory action would most appropriately in-
volve other furbearer species if at all possible.If the loss
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of marten habitat and the resultant impact on marten were
to be compensated for by improving the habitat for some other
furbearer species,either within the project area or outside of
the project area,the result would be no net loss to the total
furbearer resource.If full compensation were not
accomplished,the net loss to the resource would be
attributable to the Susitna hydroelectric project.
-(W-3)Watana and Devil Canyon Impoundments -Cliff-nesting
Raptors
Due to inundation,a total of 42.5 km of good nesting cliffs will
be lost.This reduction in the number of available nesting sites
will result in an increase in the importance of the remaining
good nesting cliffs in the vicinity of the proposed impoundments
[see Sections 3.6(aHiii)and 3.6(b)(iii)].
o Mitigation Options
Although it would be impossible to avoid this impact,it could
be minimized by taking action to allow raptors to utilize the
remaining sites.If the raptors do not find the remaining nest
sites acceptable,or if attempts to protect these sites fail,
it is unlikely that the impact could be compensated for in any
in-kind manner,thus necessitating an out-of-kind act of
compensation.The following options exist and would serve to
minimize the impact by protecting remaining sites.
1.Planning by people such as recreation specialists could
attempt to avoid schemes that would bring people in
proximity to cliff-nesting sites,at least during the
sensitive time period (gyrfalcon:15 February-15 August and
golden eagle:1 April-31 August)or until June 1 when a
nesting site could be determined to be inactive.
2.Activities associated with the clearing of woody material
from the impoundments could be scheduled so as to avoid
those areas where suitable nesting habitat is expected to
remain following flooding.
3.During the construction and operation phases of the project,
helicopter traffic could be restricted,unless absolutely
necessary,from those areas that are suitable nesting sites.
This restriction would need to apply only during the
sensitive time period.See Impact Issue W-23 for details on
air traffic restrictions.
o Discussion
It would be preferable that raptors currently nesting along the
river not be unduly harassed during the construction phase.
This protection would increase the likelihood of these birds
utilizing alternative sites as presently used sites are inun-
dated.It would be possible to identify potential alternative
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sites prior to the start of construction.If these sites could
be protected,the impact associated with the loss of presently
used sites might be minimized.
o Conclusion
If the options identified above were to be implemented,the
impact on cliff-nesting raptors could be reduced.Of the three
options,numbers 1 and 3 would have the greatest likelihood of
achieving the desired reduction in impact.Option number 2
might or might not prove of importance depending on the
proximity of areas to be cleared to nesting sites.It is
ant i ci pated,that due to topographi c factors,the amount of
clearing necessary near nesting sites would probably be
minimal.If the remaining nest sites were to prove to be un-
acceptable to raptors,the possibility of erecting artificial
nest platforms could also be investigated.
-(W-4)Watana and Devil Canyon Impoundment -Bald Eagle
The two impoundments will result -in the loss of bald eagle
feeding habitat and the flooding of two of the six active .nests
and the one known inactive nest in the area,[see Sections 3.6
(a )(iii)an d 3.6 (b )(iii)].
o Mitigation Options
A variety of steps could be taken to mlnlmlze,and if
necessary,compensate for the loss of nesting sites and feeding
habi tat.
1.During the clearing of the impoundments,clumps of tall
spruce trees (where they are available)could be left uncut
along the impoundment at 1 to 2 km interva ls.The cl umps
selected should be located in the cleared zone as far from
the normal high pool level as possible to avoid their being
washed away during unusually high water periods.If other
conditions permit the existence of a large eagle population,
but suitable trees are not available,artificial perching
sites could also be provided.
2.Following inundation,eagle nesting could be monitored to
determine if eagles are successfully locating and using
alternative sites.If it were determined that the eagle
population had suffered due to a failure to use the
remaining nesting opportunities,artificial nesting plat-
forms could be erected in suitable locations.
3.If limnological conditions were suitable,and the impound-
ments did not naturally develop a suitable fisheries
resource,efforts could be undertaken to stock fish species
to generate a good food base for bald eagles.Species with
recreational fishing potential could be selected.
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o Discussion
Although some eagle nests and suitable nesting sites will be
lost as a result of the project,the creation of two large
impoundments may,if suitable conditions exist,result in a
greater abundance of bald eagles using this area in the future
than are currently found here.If the proper steps were taken,
this potenti al increase in eagle abundance and some form of
management could function as a form of out-of-kind compensation
to offset losses suffered by other species.
o Conclusion
The three mitigation options identified above would all be
feasible and if implemented could serve not only to minimize
the magnitude of the predicted impact,but also possibly to
increase the present bald eagle population as a form of
compensation for impacts on other species.Of the three
options,numbers 2 and 3 would be the most important in terms
of achieving the desired goal.
-(W-5)Watana and Devil Canyon Impoundments -Forest-dwelling and
Riverine Bird and Small Mammal Species
The two impoundments wi 11 inundate a 1arge percentage of the
forested habitats in the vicinity of the project with a resulting
negative impact on those bird and small mammal species that
utilize these habitat types [see Sections 3.6(a)(iii)and 3.6(b)
(iii n.
o Mitigation Options
It will be impossible to avoid this impact entirely,and unless
a project with a lower pool level is selected,no minimization
opportunities exist.In-kind compensation is also not feasible
since it would be impossible through habitat management
techni ques to create comparab 1e habitat in the project area.
Thus,the only form of mitigation that is feasible is out-of-
kind compensation through a different species or group of
species.
o Discussion
In the vi cini ty of the project the type of habitat assoc i ated
with this group is found primarily within the impoundment
zones.Thus,avian and small mammal species that utilize the
vegetation cover types that will be inundated will be severely
impacted within the project area.
o Conclusion
Since direct in-kind compensation is not practical,the only
practical way to offset the losses incurred in this situation
would be to increase compensatory efforts in regard to other
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species where practical mitigation options do exist.One
possibility along these lines would be to compensate for this
loss of terrestrial habitat by taking advantage of the newly
created aquatic habitat (see Impact Issue W-17).
-(W-6)Watana and Devi 1 Canyon Impoundments -Upper Basin Moose
Population
The inundation resulting from the two impoundments wi 11 reduce
the capacity of the area to support moose.Details of this
impact are presented in Sections 3.6 (a)(i)and 3.6(b)(i).
o Mitigation Options
The only appropriate form of mitigation in regard to this
impact issue would be compensation:it would be feasible
through habitat management to compensate for the loss that will
be incurred.Habitat management efforts could be carried out
in any of the following areas:1)the upper basin adjacent to
the new impoundments,2)selected portions of the lower basin,
3)a combination of upstream and downstream areas,or 4)some
area totally removed from the influence of the project.
The only practical approach to improving moose habitat in the
upstream area may be through prescribed burning.In the
downstream area,it would be possible to improve moose habitat
directly either on selected river islands and/or associated
riparian areas,or in more upland situations east of the river.
On the islands with more mature stands of timber,logging
operations could provide the needed habitat alterations:in
those areas that do not contain mature balsam poplar trees,
prescribed burning could provide the needed alterations.In
upland areas,either burning,crushing,logging,or a
combination of all three are possible management options.
o Discussion
The first determination is whether the mitigation efforts
should be implemented in the immediate vicinity of the impact
(upstream)or if more distant areas are acceptable
(downstream).The factors in this decision would be the con-
sequences for the moose population itself,for related species,
and for sportsmen.Along the lower river,there are proven
techniques available that would,with a high degree of
certainty,be effective in achieving the desired mitigation.
On the other hand,in the upper basin the only practical option
appears to be prescribed burning,and this technique may not be
able to produce the desired results under the environmental
conditi ons present.An upstream management effort might so
alter the habitat as to enable the existence of a moose popu-
lation at an artifically high level,and unless long-term
management efforts were continued,there would ultimately be a
reduction in carrying capacity.(Of course,management efforts
in the downstream area might also result in a high moose popu-
lation that would require long-term management.)By not
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managing the upstream area,the moose population would be
allowed to reach a new,lower level that natural conditions
could support.
The status of moose in the upper bas in is important to a
variety of other species,including:(1)wolves and bears,
which prey on moose;(2)caribou,which would probably incur
higher wolf predation if the moose population decreased;and
(3)numerous scavengers,such as the wolverine and red fox that
frequently utilize wolf-killed moose for food.Therefore,
allowing the project to reduce the carrying capacity of the
upper bas in for moose wou 1d have indi rect impacts on other
species.
The impact on sportsmen,although not a biological
consideration,should also be factored into the choice.
Failing to support upstream moose would not be taken favorably
by hunters who use that area,but 1ikewi se the "improvement of
moose habitat in the downstream area would be viewed positively
by sportsmen there.In addition,improved access to the upper
basin will probably result in greater hunting pressure and an
associated demand for game.
An associ ated aspect is the impact that habi tat management
would have on other species:some species in addition to moose
would also benefit from this type of habitat alteration,while
other species would be negatively influenced.
As noted in the list of mitigation options,both the upstream
and downstream areas might not be acceptable,and management
efforts cou 1d be considered for other appropri ate porti ons of
the state.Areas of possible consideration could be portions
of the upper Susitna basin far removed from the project areas,
the Tanana Flats near Fairbanks,the Kenai Peninsula,etc.
o ConcllJsion
The impact on moose and other species that utilize moose could
be mitigated by improving habitat in both the upper basin
adjacent to the proposed impoundments and in the lower bas in
(see Impact Issue W-13).If habitat management in the upper
bas in were to be conducted,research efforts wou 1d fi rst have
to be undertaken to gain an understanding of how burning would
affect vegetation and,if the results were to prove favorable,
a program of prescribed burning could be undertaken.Since the
effectiveness of burning is currently questionable,a program
of moose habitat improvement along the lower river could also
be developed.The ultimate decision as to the distribution of
effort between these two areas wou 1d have to await the deter-
mination of the usefulness of burning in the upper basin.
-(W-7)Watana and Devil Canyon Impoundment -Black Bear
The two impoundments will severely impact local black bear popu-
lations [see Sections 3.6(a)(i)and 3.6(b)(i)]by eliminating a
large portion of both foraging habitat and denning sites.
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o Mitigation Options
The only options in regard to this impact issue are
compensation by improving black bear habitat in some other
area or compensation in an out-of-kind fashion through some
other species.
o Discussion
The presence of a large and healthy brown bear population in
adjacent areas and the restriction of forested habitats to the
river area restricts the areas inhabited by black bears.
Therefore,the black bear population in the project area will
be severely impacted,since the impoundments will result in the
elimination of most of this habitat in the area.Although the
biological consequences to the total Alaskan black bear
population will be minimal,black bears are of local value as a
game animal.Since there is no possibility of managing the
adjacent areas for black bears,the choices are to compensate
through mitigation efforts directed at other species,to
attempt to improve black bear habitat in areas outside of the
upper basin,or to do both.Although the black bear is an
abundant species in Alaska,as evidenced by the liberal game
regulations,demands for this species as a game animal will
probably -increase in the future.Thus,this "resource will
probably be more important in the future than it is now.
o Conclusion
A thorough 1iterature revi ew of the habitat req ui rements of
black bears could be conducted to identify any practical
management techniques.These techniques could be implemented
in conjunction with moose management along the lower river to
improve the same areas for black bears.Encouraging greater
black bear abundance,however,could reduce moose calf survival
and thus be counterproductive to the goals of the moose
management program.On the other hand,the loss of black bears
could be compensated for by improving the status or abundance
of other species,as,for instance,the above mentioned moose.
-(W-8)Watana and Devil Canyon Impoundments -Brown Bear
The impoundments created by the Watana and Devil Canyon dams will
flood an area that is currently used as spring foraging habitat
by brown bears [see Section 3.6(a)(i)and 3.6(b)(i)J.
o Mitigation Options
Out-of-kind compensation is the only appropriate form of
mitigation of this impact.
o Discussion
The distribution of the brown bear is not as restricted to the
impoundment area in the upper basin,as is the distribution of
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the black bear.and thus the inundation of that area will
result in the elimination of only a portion of the total area
used by this species.As in the case of the black bear (see
Impact Issue W-7l.it would be impossible to create in another
area habitat similar to that lost to inundation.At the
present time.it is impossible to predict how much the loss of
this area.which appears to be most important during spring.
will mean to the brown bear population.This loss.however.
will be only one of several project-related impacts on brown
bears (see Impact Issues W-14.W-16. W-17. W-18.W-20.and
W-23l;it may not be in itself of a critical nature.but in
conjunction with other impacts may severely influence the
future of this species in the project area.
o Conclusion
Little could be done to compensate directly for this impact.
Some level of mitigation could be achieved by:1)increasing
compensation efforts directed towards other species.and 2l
implementing mitigation options for other impacts on this
species to reduce the combined impact on brown bears.
-(W-9l Watana and Devil Canyon Impoundments -Wolf
The Watana and Devi 1 Canyon impoundments wi 11 have a negati ve
impact on several wolf packs.The two impoundments will flood
moose habitat.and the predi cted resu lt is a reduct i on in the
number of moose that wi 11 be ab le to inhabit the project area
[see Sections 3.6(a)(il and 3.6(b)(ilJ.This reduction in the
number of moose will affect wolves since moose serve as an
important.if not the most important.food source for wolves.
o Mitigation Options
The only feasible form of mitigation would be to take steps to
maintain the present abundance of moose in the upper basin.If
this were to prove impossible.the impact on wolves would have
to be compensated for in some out-of-kind manner .
o Discussion
The extent to which the reduction in moose will impact this
species is difficult to predict.although it will certainly
have some negative impact.Although wolves feed on moose.they
also kill numerous caribou;the distribution of caribou.
however.varies both from year to year and also among seasons.
Thus.caribou do not represent as consistently available a
source of food as do moose.Whether or not the upper bas -j n
could successfully be managed for moose is questionable and
the extent to which the moose population could be maintained
through management is unknown (see discussion on Impact Issue
W-6l.Yet.the location of moose management efforts and their
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success would be one factor that would influence greatly the
future status of wolves in the upper basin.
o Conclusion
If the options for managing upper basin moose (as identified in
Impact Issue W-6)were to be implemented successfully.the
impact on wolves could be minimized.The project w-ill impact
wolves in other ways.and although each impact may not appear
severe by itself.collectively they represent a major impact on
this species;therefore.the total impact of the project on
wolves wi 11 depend on the overall mitigation of impacts on
wolves.
-(W-IO)Watana Impoundment -Dall Sheep
The impoundment created by the Watana dam seasonally will flood a
major portion of the Jay Creek mineral lick and thus may
negatively impact the sheep population that currently uses it
[see Section 3.6(a)(i)].
o Mitigation Options
Compensation for this loss would be the only poss'ible form of
mitigation.An artifical lick within the range of the sheep
that currently use the Jay Creek lick could replace the
inundated mineral lick.
o Discussion
It appears that at least a portion of the Jay Creek lick will
be inundated during a part of the year.It is possible.
however.that the 1i ck wi 11 not be under water dur i ng May and
June.when most use of the 1ick occurs.Whether or not the
lick will still be usable or acceptable to sheep under project
conditions is a matter for speculation.It is also not known
how dependent the sheep population is on this lick.
Considering the frequency of use and the will"ingness of sheep
to expose themselves to predation in order to reach the lick.
however.it must be of some significance to them.
o Conclusion
The following steps could be taken to mitigate this impact:
1.Efforts currently underway to determine the chemical
composition of the lick and the number of sheep using the
lick could continue.
2.Following inundation.monitoring efforts could be under-
taken to actually document the reaction of sheep to the
change and the extent to which they continue to use the
1i ck.
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3.If the lick is abandoned following flooding,or if the use
of it is reduced substantially,an artifical lick could be
established using mineral blocks specifically designed to
match or improve upon the chemical composition of the
current lick.The artificial lick would need to be placed
within the natural range of these sheep and preferably in a
location where sheep would be less vulnerable to
predation.
-(W-ll)Watana Impoundment -Caribou
It is possible that ice conditions and/or floating debris will
act as a barrier to migrating caribou [see Section 3.6(a)(i)].
o Mitigation Options
The potential problems associated with floating debris acting
as a barrier would be minimized by totally clearing all woody
material from the reservoir site.If problems were to
materialize with floating debris,a removal program,could
eliminate the barrier.Another option,which would also
mitigate the potential impact of hazardous ice conditions,
would be to erect temporary fences to direct migrating caribou
to safer crossing points.If attempts to direct the Nelchina
herd to safe crossing points were to fail,and the herd were to
be blocked totally from reaching the present calving area,the
only other mitigation option would be to insure that the area
it selects for calving would be protected during the calving
period.
o Discussion
The severity of thi s impact wi 11 depend on four factors:1)
whether or not conditions actually develop which create
barriers,2)whether or not the caribou are able to locate safe
crossing points,3)whether or not the herd has to cross the
impoundment,and 4)if they are forced to calve in a new area,
whether or not that area will prove suitab 1e for successfu 1
calving.In the past,the Nelchina herd frequently has
wintered north of the Susitna River and so has crossed the
river as it moves to the calving area on the south side.
During the past few years,however,it has wintered east of the
calving area (particularly on the Lake Louise Flats)and so has
moved in a westerly direction to reach the calving area.
Likewise,the herd has not recently moved across the river from
south to north after calving,although such a post-calving
movement frequently has occurred in the past.It is impossible
to predict whether or not the current movement patterns wi 11
pers i st after the impoundment is created.Cons i deri ng the
tendency of caribou herds to suddenly shift migratory patterns,
however,it is likely that sometime following inundation they
will again attempt to cross in a southerly direction en route
to the calving area and/or in a northerly direction following
the calving period.
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If,as a result of the project rafts of debris,shelf ice,or
both exist,and if and when such a crossing takes place,the
movement of the herd could be blocked or altered.The
conditions present during a crossing attempt will probably vary
greatly from area to area and from year to year,and presently
it is predicted that caribou will attempt to locate safe
crossing points if faced with hazardous conditions.They may
also attempt to circumvent the situation by moving around the
entire impoundment on the eastern end.If they fail to select
safe crossing points,it might be possible to erect temporary
fences to alter the direction of their movement and guide them
to safer points.If all this were to fail and the herd were to
be blocked tota 11 y by the Watana impoundment and forced to
calve elsewhere,some means could be found to insure the total
protection of the herd from human disturbance as it attempts to
adjust to a new calving situation.
o Conclusion
If the potential for severe impacts on caribou·materializes,
they could be avoided or minimized through a program of
monitoring,fencing,protection,and debris removal.To
eliminate some of the unknowns associated with mitigating these
potential impacts,the movements of the herd could be monitored
from late winter through the post-calving period.Any such
monitoring effort would need to continue until~it were to be
demonstrated that the herd had either successfu lly negoti ated
the impoundment in crossing,or had established a new calving
area that would reduce the need for future crossings.In other
words,such a monitoring effort would have to continue for at
least several years following the first attempt of the herd to
cross the impoundment.It is impossible,of course,to predict
at this point how long it might be until the Nelchina herd
actually attempts a crossing under operating conditions.
During the first several springs following the initiation of
the proj ect,a reconnaissance survey cou 1d be conducted to
ascertain the condition of drawdown ice conditions and the
existence of any floating debris sufficiently extensive to
serve as a barrier.
This information would be needed if an attempt to alter the
direction of migratory movements by fencing were to be made.
Depending on this review of crossing conditions,a plan for
establishing temporary fences could be prepared;if it appears
that traditional crossing points will be difficult for caribou
to negotiate,fencing material could be placed so that,if
monitoring efforts indicated the likelihood of an attempted
crossing,fences could be erected quickly.
The fencing would create a visual barrier,not necessarily a
physical one.Thus,relatively inexpensive material such as
snow fencing or even burlap sheeting could be used.In order
to avoid undue interference with other species,such a fencing
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effort would be employed only when the herd is migrating
towards the river and appears to be heading for hazardous
crossing points.
If a new calving area is established,it may be feasible to
protect the herd from human disturbance during the calving
period.Such protection could include a total closure to all
human activity during the calving and post-calving periods as
well as air traffic restrictions specifying a minimum flight
altitude of at least 300 m (1,000 ft)above ground during the
calving period and over the post-calving aggregation.
-(W-12)Operation of Devil Canyon Dam -Downstream Beavers
Changes in the flow regime caused by the Devi 1 Canyon dam wi 11
affect beavers living downstream from the dam [see Section 3.6
(d)(iii)J.Reduced summer flows may result in the availability
of fewer sloughs for use by these aquatic furbearers.The daily
fluctuations in flow may also cause unstable ice conditions and
make it very difficult for beavers to maintain winter food
caches.
o Mitigation Options
The predi cted impact on aquat ic furbearers in thi s area cou 1d
be minimized by reducing the degree of daily flow fluctuations
during the winter months and by operating the dam so that flow
regimens are as close to natural conditions as possible.
o Discussion
The exact extent of this impact is difficult to predict at this
time and wi 11 differ between the areas north and south of
Talkeetna.Although there may be less summer habitat
available,it is possible that higher winter flows may actually
increase the amount of suitable overwintering habitat for
beavers.If unstable ice conditions exist due to daily
fluctuations,however,there could be a net decrease in beaver
abundance because they will not be able to maintain food caches
which are normally frozen in place by ice.It is anticipated
that such ice problems would be most prevalent north of
Talkeetna which has comparatively fewer beavers than the area
south of Talkeetna.
In addit i on to servi ng as an important fur resource,beavers
inhabit ing the flood p1ain 0 f the lowe r Sus it na Ri ve r a 1s 0 aid
in the creation of moose browse by cutt-ing trees and opening
areas for the generation of early successional shrub species.
Thus,any negative impact on beavers in this area could
indirectly reduce the winter carrying capacity for moose.At
this time,it is impossible to state what proportion of the
moose browse is the result of beaver activity in comparison to
other factors that influence the generation of browse.
3-221
o Conclusion
If the Devil Canyon dam were to be operated so as to reduce the
magnitude of daily fluctuations,then the possibility of
negatively impacting downstream beavers would be reduced.
Since the activities of beavers can influence the status of
other species,such as moose,studies documenting the degree of
this influence could also be undertaken.Such studies would be
necessary if the total impact on downstream moose,and thus the
level of compensatory efforts required,were to be determined
(see Impact Issues W-6 and W-13).
-(W-13)Operation of Devil Canyon Dam -Downstream Moose
Downstream from Devil Canyon to Cook Inlet there may be an
alteration of plant succession trends due to flow regulation.
As a result,there may be a reduction over time in the amount of
winter browse available to moose that rely on this area during
winter,especially when deep snows prevail [see Section 3.6(d)
(i)J.
o Mitigation Options
There are several management techniques that could be employed
to improve moose habitat in this area in order to compensate
for possible reductions in the quantity of browse.These
include:1)commercial logging of mature balsam poplar trees
on selected islands;2)prescribed burning of islands that are
not dominated by mature balsam poplar trees;3)logging,
burning,or crushing of vegetation in upland areas east of the
river.
o Discussion
Based on the information currently available,it is difficult
to accurately predict the extent of this impact.Trends in the
quant ity of browse wi 11 be predi ctab 1e,as the nature of the
river and the number of factors that influence the creation and
movements of islands are understood.Still,it will probably
be impossible to ever determine the actual quantity of browse
that may be lost as a result of the project.If the regulation
of the river does cause a reduction -in the creation of new
islands (and thus areas suitable for the invasion of browse
species such as willow),it is expected that two changes will
occur in sequence.First,many areas that would have been
washed away under present flow conditions wi 11 remain secure
enough for the development of moose browse;as a result,there
will be a short-term (10 -20 years)increase in the amount of
browse available to moose.But,second,as plant succession
proceeds and the vegetat i on matures there wi 11 be a gradua 1
long-term reduction in the capacity of the riparian area to
support moose during deep snow conditions;there will thus be a
reduction in the abundance of moose.
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o Conclusions
The possible loss of moose browse could be mitigated if a
habitat management program were developed to improve the
habitat in the area south of Devil Canyon to support wintering
moose.As previously discussed (Impact Issue W-6),this area
could also compensate for moose habitat losses in the upper
basin.
Moose currently use the riparian area during severe winters.
They move to the river both from the east and the west.Those
who move into this area from the east move down from the
foothills of the Talkeetna Mountains,and many are killed
crossing the Parks Highway and the Alaska Railroad.If manage-
ment efforts were to be directed at areas east of these two
transportation corridors,these moose might no longer move into
the riparian area to browse.On the other hand,management
efforts directly on the river could be undertaken to provide
browse for those moose that would continue to enter the
riparian area from the west.
The first step would be to identify appropriate areas for
management activities;considerations would include ownership
and vegetation types,and a correlation of this information
with census and movement data being collected by ADF&G.Where
appropriate,blocks of mature trees could be removed by
commercial logging operations.Prescribed burning could also
be used;but due to the extent of human habitation in this
area,there could be severe constraints on burning.The use of
vegetation crushers also would be a possible management
technique in areas where burning and logging might not be
feasible.
-(W-14)Clearoing of Woody Material From the Impoundments -All
Upstream Big Game Species
Big game species will avoid the area being cleared during the
period of clearing [see Sections 3.6(a)(i)and 3.6(b)(i)J.
o Mitigation Options
In order to minimize the magnitude of this impact on animals
existing adjacent to the proposed impoundment zones,the
clearing of woody material in the drawdown zone could be
conducted during the later portion of the filling period.This
would also leave more habitat intact for a longer time.
Therefore,the temporal magnitude of the habitat loss that will
result from the impoundment will be reduced.In certain cases,
the timing of clearing activities could be scheduled so as to
minimize disturbance of important wildlife areas.
3-223
o Discussion
There is little justification for a large mitigative effort in
this area since this impact will be relatively short and
basically will impact animals that will be far more severely
impacted by inundation and the associ ated permanent loss of
habitat.In addition,there will be differences in the
severity of the disturbance depending on the associ ated big
game species.
o Conclusion
If the impoundment zone were to be cleared during the filling
peri od,then the temporal magni tude of thi s impact cou 1d be
minimized.The only other mitigation opportunities associated
with this impact concern the Jay Creek mineral lick (see Impact
Issue W-10).Since sheep may be able to use this lick follow-
ing inundation,disturbance resulting from any necessary
clearing activities in this vicinity could be avoided if no
clearing were to be conducted within 2 km (1 mile)of the lick
during the months of May and June.This would
enable the uninterrupted use of the lick by sheep and possibly
allow for continued use following filling.
-(W-15)Clearing of Woody Material from the Watana Impoundment -
Caribou
The activities associated with the clearing of woody material
from the Watana impoundment will disturb caribou migration to the
ca 1vi ng area south of the ri ver and/or post-ca 1vi ng movement to
the area north of the river [see Section 3.6(a)(i)J.
o Mitigation Options
Two options exist to avoid or mlmmlZe the magnitude of this
impact:1)clearing activities could be scheduled to avoid
areas used as crossings during the migratory period,and 2)
travel lanes could be left uncut to provide sheltered routes
across the impoundment zone during the construction period.
o Discussion
Caribou movement patterns are unpredictable.During the
cl eari ng peri od a major movement of the Ne 1chi na herd through
the impoundment zone en route to or from the ca lvi ng area may
or may not occur.(Such movements have occurred in the past.)
In order to avoid undue disturbance of this critical activity,
certain steps could be taken to minimize disturbance of
migrating caribou.Late winter and early spring monitoring of
the herd cou 1d be conducted to predi ct if any act i on were
necessary.Clearing schedules could be kept flexible enough to
accommodate a shift in the location of clearing efforts if
necessary.
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It can be argued that 1itt 1e attention shou 1d be devoted to
this short-term impact since a reservoir wi 11 ultimately cover
the area in question.Even though the disturbance of migration
caused by clearing activities admittedly is a short-term
impact,it is also one of many forms of impact to which the
Ne1china herd will be subjected as a result of the project (see
Impact Issues W-ll,W,14,W-17,W-18,W-20,W-22,and W-23).
Each impact may not by itself represent a severe impact on the
herd,but collectively there could be a major disruption of the
activities of this herd with associated negative consequences.
Therefore,it is·important that each cari bou -re 1ated impact
issue be mitigated to the fullest extent possible in order to
minimize the collective effects of all forms of impact.
The major issue in this case is the disruption of the movement
of the herd to and from its calving area.If the herd is
permitted to cross the river during the clearing and filling
phases of the project,its chances of making successful
crossings during operation will be increased.
o Conclusion
This impact could be avoided or minimized if travel lanes were
to be left uncut until absolutely necessary.Such travel lanes
would have to be located between Deadman and Jay creeks and
would have to be at least 0.8 km wide.Three or four such
lanes would appear to be adequate and would have to be
continuous from one side of the impoundment zone to the other.
During the clearing period,the Nelchina herd could be
monitored by ADF&G (especially in late winter and early spring)
so that the possibil ity of the herd attempting to cross the
river from north to south could be determined.If such
monitoring efforts indicate that a crossing is about to occur,
clearing operations could be halted in the crossing area for
the four to six week period during.which crossing normally
takes place.(This will likely occur from early April to
mid-May.)Any monitoring effort could continue during the
early post-ca lvi ng period,and,if it appears that the
post-ca 1vi ng aggregation of cows and ca 1ves wi 11 cross the
river moving north,clearing activities could be temporarily
halted in the area of crossing.
-(W-16)Construction Camps/Vi llages and All Access Roads -Red
Fox,Black Bear,Brown Bear,Ground Squirrel,Gulls,and Raven
These species could be negatively impacted as a result of illegal
feeding by personnel associated with the construction and opera-
tion of the Susitna project.Improper disposal of garbage would
also result in an impact on these species.
3-225
o Mitigation Options
The following options exist to avoid and/or mlnlmlZe impacts
associated with the feeding of wild animals by humans and the
acquired dependency of wild animals on available refuse.
Current plans to cover the landfills with soil on a daily basis
would help minimize this potential problem.
1.All camp facilities (especially landfills)could be
securely fenced with the bottom edge of the fences buried
0.5 m (18 in)below ground.
2.Secure garbage containers could be available in all work
areas,and all refuse could be collected and incinerated
or disposed of in a properly operated landfill.
3.Work crews could be hired and charged with picking up all
discarded refuse from work areas and along all access
roads.
4.State laws prohibiting the feeding of wild animals could be
strictly enforced by security personnel and repeated
violators dismissed from their positions of employment and
permanently prohibited from future work on any aspect of
the project.
5.A mandatory education program for all project personnel
could be prepared and implemented.
o Discussion
Through proper planning and a concerted effort,this is one
impact that could be minimized,if not totally avoided.The
key element in the successful execution of these options would
be the personnel responsible for the actions of all workers
associated with the construction effort.It therefore would be
critical that all supervisory personnel be impressed with the
need to prevent illegal feeding of wildlife and be committed
to maintaining a preventative program to that end.All
constructi on contracts and uni on agreements entered into for
this project could clearly identify the agreed-upon rules and
regulations that pertain to this issue and the consequences to
workers who fail to comply.
o Conclusion
If the mitigation options identified above were to be implemen-
ted and if the Watana landfi 11 were to be covered dai ly as
planned,the probability of avoiding or minimizing this impact
would be very high.
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-(W-17)Main Access Road~Borrow Areas~Access Roads to Borrow
Areas~and Construction Camps -All Furbearer Species~Many Avian
and Small Mammal Species~and All Big Game Species Except Dall
Sheep
These project components will result in a loss of habitat for the
i ndi cated wildl ife resources.Detail s of these impacts are
presented in Sections 3.6(a)~3.6{b)~3.6{c)and 3.6(e).
o Mitigation Options
The magnitude of this impact could be reduced by arranging camp
facilities compactly and keeping them as close to work are"as as
feasible.Permanent facilities (main access road and town
site)will represent a permanent loss of habitat~and compensa-
tory actions through habitat management could be impl emented.
Areas containing temporary facilities (borrow areas~roads to
borrow areas ~and temporary camp facil it i es)coul d be restored
to a condition that would provide usable wildlife habitat.
o Discussion
There are basically three levels of consideration involved with
this issue.First~through careful planning the magnitude of
the habitat loss associated with these project components could
be minimized to some degree.Second~temporary use areas~such
as borrow areas and portions of camp facilities~could be
restored to allow for some future use by wildlife.And
third~unavoidabl e losses that wi 11 result from the permanent
portion of the project could be mitigated through compensatory
action.
o Conclusion
If the following steps are taken~the anticipated habitat
losses associated with the project components mentioned above
could be mitigated.
1.As presently proposed~camp facilities will be arranged
compactly and located close to work areas in order to avoid
undue habitat disturbance.
2.Present ly there are pl ans to restore temporary use areas
(borrow areas~roads to borrow areas~and temporary
portions of the camp).All topsoil removed from these
areas will be stockpiled and saved.In addition~any top-
soil removed from areas that will be permanently disturbed
could be saved and added to the stockpiles.Following the
use of each area~the topsoil will be reappl ied and the
area regraded~if necessary~to avoid erosion.Restored
areas will then be seeded lightly with grasses and
fertilized to stimulate the initial growth of native
vegetation.During the first year of such an effort~
3-227
the recommended fertilizer is a mix high in phosphorous (such
as N,P,K 10-20-10 or 8-32-16)applied at a rate sufficient to
supply 85-110 kg of nitrogen per hectare (75-100 lbs per acre).
During the second growing season,these areas should be
fertilized at a rate one-half that of the initial treatment.
During the third growing season,they should be fertilized at a
rate one-third that of the initial treatment.
3.To compensate for permanent losses to big game species,habitat
management efforts could be directed toward moose.
In the case of avian species,efforts could be expended to
improve habitat for certa"in waterfowl in the newly created
aquatic habitat of the impoundments in order to compensate for
the loss of terrestrial habitat and associated terrestrial
species.Once the limnological suitability of the impoundments
to support a good fisheries resource can be determined,an
adequate fisheries food base in the impoundments could be
insured by stocking appropriate fish species.This aspect of
such a compensation program would also benefit aquatic fur-
bearers,and such stocking would additionally have recreational
potential.Following the establ ishment of a food base,nest
boxes could be erected in adjacent forest areas to provide
nesting opportunities for cavity-nesting waterfowl such as
goldeneye and bufflehead.
-(W-18)Borrow Areas and Access Roads to Borrow Areas -All
Upstream Big Game Species Except Dall Sheep
The activities associated with borrow excavation and
transportation wi 11 cause an avoidance reaction by and resultant
habitat loss to big game species during the construction period
[see Section 3.6(c)(i)].
o Mitigation Options
The only option to mlnlmlze the magnitude of this impact would
be to schedule activity and equipment movement so as to allow
animals to utilize the area adjacent to the borrow areas for a
portion of each 24-hour period.
o Discussion
Limiting human activity in these areas to certain portions of
the day may prove effective only for some species.It is
likely that moose would benefit from such an arrangement,while
species with a greater aversion to man,such as wolf and
wolverine,would not respond positively to such an approach.
o Conclusion
Duration of this impact will be only the construction period,
and it is likely that any scheduling program would be only
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partially effective.Thus,restoration of these areas so as to
secure the long-term availability of the habitat could be more
effective than a scheduling program.
-(W-19)All Access Roads -Moose and Caribou
Moose and caribou may be killed as a result of collisions with
vehicles using both the main access road and the access roads to
borrow areas [see Section 3.6 (e)].
o Mitigation Options
Although it is unlikely that this impact could be totally
avoided,steps could be taken to minimize the magnitude of this
impact.Construction workers,and especially truck drivers,
could be educated concerning the value of wildlife in the area
and the need to minimize negative impacts through careful and
thoughtful driving.Warning signs could be erected in areas of
high collision potential.Speed limits that would reduce the
frequency of collisions could be posted and enforced.During
winter months when moose and caribou may frequent roads to take
advantage of superior traveling conditions,numerous pull-off
areas could be plowed clear to give animals opportunities to
escape vehicles.
o Discussion
The severity of this impact will depend on several factors,the
volume and speed of project-associated traffic,the attitude of
the drivers,and the depth and duration of winter snow.
Collisions will be a continuing hazard,to both wildlife and
motorists,during operation of the project,especially if
public access is allowed.
o Conclusion
In conjunction with the educational program to reduce the
illegal feeding of animals (see Impact Issue W-16),an attempt
could be made to impress upon workers (especially those workers
who will be driving trucks and other large equipment)the value
of wildlife and the need to avoid killing animals through
collisions with vehicles.Speed limits could also be establi-
shed on the access road and strictly enforced.The appropriate
rate of speed would depend on the design of the road,the types
of vehicles using the road,etc.To mitigate this potential
impact,the speed limit could be kept as low as possible while
still allowing for the timely movement of equipment and
personnel.Due to the increased frequency of collisions after
dark,it would also be advantageous to have two speed limits:
one for daylight hours and a lower limit for night.The
placement of warning signs at known crossing points could alert
motorists to the increased likelihood of encountering moose or
caribou on the road.
3-229
When extremely deep snow conditions prevail,pull-off areas
could be provided along the road to provide opportunities
particularly for moose to get out of the way of vehicles.The
number of suc h pu ll-off areas and the spac i ng between them
would probably vary depending on the associated vegetation
cover type and the distribution of the impacted species.
Therefore,prior to road construction,areas could be
identified where pull-off points will be needed.
-(W-20)Access Roads and Construction Camps All Upstream
Furbearer and Big Game Species,Except Dall Sheep
These project components will result in increased human activity
and resulting disturbance and harassment of wildlife,and in
increased hunting and trapping pressure on the wildlife resource
[see Sections 3.6(a)(i),3.6(b)(i)and 3.6(e)(i)].
o Mitigation Options
During both the construction and post-construction period there
are three options associated with human access and activity in
the project areas.First,no effort could be undertaken to
restrict or control human access or activity;second,efforts
could be undertaken to restrict totally additional activity;
and third,is a compromise option in which human access would
be permitted during certain times of the year and/or in certain
areas.
o Discussion
The improved access associated with the Susitna project and the
impact of that improved access on both furbearer and bi g game
species may represent the most severe single avenue of impact
on wi ldl ife as a result of this project.It may exceed those
impacts associated with habitat loss due to inundation and
other aspects of the project that disturb habitats.It is
therefore very important that the negative aspects of this
source of impact be minimized to the greatest extent possible.
Because of the differences in the available control options and
also differences in the magnitude of the impact potential,this
issue will be considered separately for the construction period
and the post-construction period.
Construction Period
During this period there will be a great number of people in
the area throughout the year,and the potential for disturbing
wildlife is very high.It is assumed,however,that no public
use of the access road will be allowed during the construction
period.Thus,during this period the opportunity for controll-
ing human activity is greatest since the majority of personnel
in the area wi 11 be under the di rect contro 1 of the camp
managers and will be in the area primarily for work purposes.
3-230
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Therefore,although the potential for negative impact is great
dur"ing the construction period,the opportunity to minimize
that impact also would be available and could be used.
Post-construction Period
It is assumed that following construction the access road to
Devil Canyon wi 11 be open to the genera 1 pub 1ic for whatever
use they wish to make of it.It is also assumed that imposing
some restrictions on public use beyond Devil Canyon is a
potential mitigation option.The magnitude and nature of human
activity durinq this period is expected to differ from that of
the construction period,and thus different considerations
apply to mitigation planning for the post-construction period.
o Conclusion
The specific steps that could be taken to mitigate these
impacts differ in the construction and the post-construction
periods and are thus discussed separately.
Construction Period
The best policy that could be adopted for the construction
peri od wou 1d be that project personne 1 wou 1d have no greater
access to the upper basin than that available to the general
public except,of course,access to the actual construction
sites.All project personnel could be required to travel
directly from the start of the access road to the camp or work
area without stopping except in emergencies.Personnel could
be restricted from leaving the access road for any reason
including to hunt or trap.From mid-April to mid-September,
all traffic could be restricted to a time period extending from
two hours after sunrise to two hours before sunset in order to
provide opportunities for big game species,especially brown
bears,to cross the highway without being disturbed by traffic.
The need for continuing such a restriction could be determined
by means of a monitori ng program dur ing the fi rst year of
access road use under this restriction.
Post-construction Period
Following the construction period,when the road (at least to
Devil Canyon)is open to the general public,ADF&G could
monitor the status of big game populations in the area and take
whatever regulatory steps would be practical to prevent a game
harvest in excess of that which would allow for a sustained
yield.The value of continuing some restrictions in access
beyond Devil Canyon could be evaluated during the initial years
of the post-construction period.In order to minimize undue
disturbance of big game,in particular,caribou during the
calving and post-calving period,ATV activity from the access
road could be prohibited entirely or at least from 1 May to 15
August of each year.
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There would be considerable merit to prohibiting ATV use
entirely.Such a prohibition would help reduce long-term
destruction of vegetation.Restriction of ATV use would be
particularly important between Devi 1 Canyon and Watana,where
the road traverses open terrain.
-(W-21)Construction Camps and Village -Red Fox and Wolf
The housing of domestic dogs at the camps and villages represents
the potential for the introduction of rabies into native canid
species.Improper control of dogs could also result in the
creation of a population of feral dogs [see Sections 3.6(aHii)
and 3.6(bHii)J.
o Mitigation Options
There are two options available to avoid or mlnlmlze the
possibility of this impact taking place:1)total prohibition
of all dogs in the camp facilities,or 2)regulations
concerning the housing and control of domestic dogs.
o Discussion
It is believed that at the present time rabies and feral dogs
are not a problem in the upper Susitna basin.The housing of
domestic dogs at the camp facilities represents th&potential
for both of these situations to change.The introduction of
rabies would have a potentially severe impact on native
carnivores,especially foxes and wolves,which are highly
susceptible to the disease.The establishment of a feral dog
population would also be a negative impact,although the
potential severity of that impact is less than the scenario of
a rabies epidemic.
o Conclusion
This impact could be avoided or minimized while sti 11
permitting the housing of domestic dogs by camp residents if
certain precautions were exercised.Such precautions would
include registering all dogs housed in the camp with the camp
manager.To prevent the introduction of rabies,certification
of immunization could accompany any such registration rule.
The potential problem of dogs becoming feral could be avoided
by requiring dogs to be under control at all times.If any
dog were found outside of the camp area,and not under direct
control of the owner,the dog could be destroyed by camp
security personnel if reasonable attempts to capture it were to
prove futile.
(W-22)Construction Camps and Access Roads -All Upper Basin
Wildlife Species
If unauthorized fires occur,the result could be the destruction
or alteration of habitat for many wildlife species.The impacts
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on the wildlife resource that could result from unplanned fires
are great.
o Mitigation Options
In order to avoid this impact,preventative measures could be
taken to minimize the potential for the occurrence of uncon-
trolled fires.Adequate fire fighting equipment could be made
available to extinguish any fires that occur at those times and
places where the impact would be undesirable (see following
discussion).
o Discussion
It has been recognized that fire can be a positive ecological
force,rejuvenating vegetation,improving certain wildlife
habitats,and releasing soil nutrients.According to field
evidences of old burns and restricted tree ages,fire has long
been a natural part of the ecosystem in this area.Burns in
other northern areas seem to be related to weather patterns and
climatic changes.The same may be said for the upper Susitna
basin.Hence,the effects of fires of human origin would not
be incongruent with the overall scheme of nature.If human
safety and property were not threatened,there might be
instances when fires could be left to burn their natural
course.
On the other hand,since the consequences of fire can be
extensive,proper precautions would have to be taken.In
addition,in attempting to maintain control over the
vegetation/habitat types in specific areas,uncontrolled fire
is generally undesirable.
o Conclusion
Part of an educat i on/ori entat i on program for workers (Impact
Issues W-16 and W-19),could deal with fire prevention,fire
fighting plans and the potential harm to wildlife that fire
represents.A program of fire prevention and fire fighting
plans could be prepared by the camp manager and strictly
enforced.Adequate fire fighting equipment and knowledgeable
operators could also be available in the event that a fire
occurs.To identify the potential for fires occurring,and
thus the level of preventative measures needed during periods
of high fire potential,camp personnel could periodically
contact the BLM for an evaluation of fire potential.This
would be especially important during periods of hot,dry
weather.If these precautions were to be taken,the potential
for a fire that would negatively impact wildlife would be
greatly reduced.Fires that would ultimately benefit wildlife
and do not threaten human safety or property cou 1d be allowed
to burn.A plan could be prepared which would outline various
levels of fire suppression to be employed in various portions
of the project area.
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-(W-23)Air Traffic -All Big Game Species,Raptors,and Trumpeter
Swans
These species will be negatively impacted as a result of
disturbance caused by air traffic,especially low-flying,large
helicopters.
o Mitigation Options
Although there is no way to totally avoid disturbing wildlife
as a result of air traffic,there are several options for
minimizing this impact.In general,restrictions in both the
altitude and location of flying activity could be employed to
keep the disturbance to a minimum.Seasonal restrictions also
could prove helpful in some cases.Since wildlife species vary
in their sensitivity to aircraft disturbance,restrictions
could be developed to avoid the most sensitive species (such as
brown bears,nesting raptors and trumpeter swans).
o Discussion
It is anticipated that over time some species will acclimate to
air traffic,and the negative aspects of disturbance will be
reduced.Other species (trumpeter swans,brown bears,and
nesting raptors,for example)may be negatively impacted before
any such adjustment level is achieved,if one ever is.
Therefore,it is very important that air traffic restrictions
be designed to minimize impact on such sensitive species.
o Conclusion
If the impact of air traffic disturbance on wildlife is to be
minimized,the following restrictions would be required:
1.All air traffic wo~ld fly directly to and from the camps or
work sites with no unnecessary diversions.
2.Flight distances and weather permitting,all air traffic
would maintain an altitude of at least 150 m (500 ft)above
ground throughout the upper basin during all seasons.
3.A minimum altitude of 300 m (1000 ft)above ground should
be maintained in the following areas:
-caribou calving area (May and June)and over any
post-calving aggregations (June and July)
wolf dens (April through July)
bald eagle nests (15 March -31 August)including a
horizontal restriction zone of a 0.4-km (0.25 mi)radius
gyrfalcon nests (15 February -15 August)including a
horizontal restriction zone of a 0.4-km (0.25 mi)radius
golden eagle nests (1 April -31 August)including a
horizontal restriction zone of 0.8-km (0.50 mi)radius
the Jay Creek sheep lick (May and June)
nesting trumpeter swans near the Oshetna River and other
adjacent areas in the upper reaches of the Watana
impoundment (May through July).
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Some of these areas would have to be identified on a yearly
basis in order to keep the location of such critical areas
up to date and available for review by personnel responsi-
ble for controlling air traffic.
4.Minimize the number of private planes using the Watana
airstrip,perhaps by limiting the availability of tie-down
spaces •
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(d)Mitigation of Impacts on Fish Resources
Under pre-project conditions,fish in the Susitna River are subject
to highly variable stream conditions.These conditions are
controlled by the extremes in weather and climate of the region.
During the summer months,high flows are caused by melting glacial
ice,and even higher peak flows occur when a storm coincides with
the already high summer flows.In the winter,neither of these
events take pl ace,and the flow is reduced to less than 5%of its
summer volume.These circumstances,in conjunction with with the
streambed and sediment conditions that accompany them,make the
Susitna mainstem a less than ideal fishery habitat.In fact,most
salmon spawning activity is confined to tributaries and slough
environments.
The primary impact areas of the hydroelectric development are the
reservoir areas and the Susitna River from Talkeetna to Devil
Canyon.The dams themselves will not curtail the migration of any
anadromous species because Devil Canyon is,even now,a natural
barrier to such migration.The project will,however,alter in many
ways the conditions to which fish are subject.Post-project
conditions,for example,will alter the timing and volume of
downstream flows.Summer peaks will be reduced,and winter flows
will increase.Both of these changes could be beneficial to the
fish using the Susitna River,but adverse effects are also
possible.
The degree to which the project wi 11 change conditions and the
impacts accompanying those changes wi 11 also vary by project stage
and location.The stages considered are construction,including
filling,and operation and maintenance.The project locations are
the Devi 1 Canyon and Watana impoundments,the Susitna River reach
downstream to Talkeetna,the reach between Talkeetna and Cook Inlet,
and the access road and transmission line routes.
For both the project stages and the locations,various mitigation
options are available.These approaches have been preliminarily
examined with close attention to the following order:avoiding the
impact,minimizing the impact,rectifying the impact,reducing or
eliminating the impact over time,and compensating for the impact.
Reducing or eliminating impacts includes basic monitoring both of
the resource as impacts develop and of the planned mitigation
measures.
Mitigation options for dealing with the project's impacts can be
categorized in several ways.Operational procedure is one such
category.Operational procedures can be designed that will avoid
or minimize impacts on the fish or allow for the rectification,
reduction over time,or compensation of impacts.Some of these
procedures may be project limiting,however,because they may offset
project economics or power output.
3-237
Regulation of downstream flow to meet fishery needs would be the
primary operational procedure for mitigative purposes.An
additional flow that could be provided through operational
procedures would provide a sufficient amount of water at the proper
time to permit or to stimulate outmigration.The power operational
flow could probably be adjusted to meet this need.Although daily
peaking at the Devil Canyon facility is,in general,viewed as
potentially detr"imental,under certain circumstances daily peaking
for a short time during this period of outmigration could be
benefi ci alto the fi shery.Operat i ona 1 procedures that are
primarily for power production,with some possible minor
modifications,will stabilize the river channel,change the
formation of tributary deltas,and reduce summer floods.
Construction or design procedures can also avoid adverse impacts or,
at least,minimize them.These include the use of special valves
for spilling excess water to avoid or minimize dissolved gas super-
saturation and the use of multilevel intakes to regulate water
temperatures.Both of these techniques will be described below.
Modification of the existing stream by excavating or by adding
gravel to build spawning areas is another type of mitigation
opportunity.The placement of the dams on the Sus itna Ri ver wi 11
act to control the extreme conditions that occur naturally and,as
will be discussed,may make the conditions in the ma"instem more
favorable for fish.
Such modifications of the stream,side channels,or sloughs could
replace or even increase the amount of usable habitat.The
construction of artificial spawning channels or hatcheries can also
be used as a mitigative measure to compensate for loss of fish
production,but maintaining existing habitat or creating new
habitats by way of the modifications just mentioned are more
promising options.
A final category of possible mitigation is the management of
existing fishery resources to increase their productivity,including
the possible stocking of unproductive but viable areas.
-Impoundments
The impacts associated with construction will be of relatively
short duration and masked by the inundation of the area.
Intensive management of the recreational fishing in the
tributaries above the impoundment water level during the
construction stage,however,could protect the grayling
populations not directly affected by the construction activities.
In addition,insuring that effluent discharges are compatible
with the stream's water quality,or discharging waste effluents
from the sewage treatment facility somewhere other than into
Deadman Creek above the Watana impoundment's upper water level,
would protect the grayling fishery that will remain after
inundation.
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For the resident fish,the inundation of the mainstem will
probably result in the formation of new habitats that are as
hospitable to the fish as former habitats.Furthermore,since no
anadromous fish occur above Devi 1 Canyon,no impacts on
anadromous fish are associated with the actual impoundments.
Avoiding or minimizing impacts associated with operation and
maintenance of the Watana impoundment is restricted by
engineering and economic aspects of the project.For example,
fluctuation of the water level and storage of water is necessary
to provide needed power during the cold months,which are also
the periods of low flow.On the other hand,however,the annual
fluctuations of approximately 27 m (90 ft)in Watana will inhibit
the formation of a littoral zone,which is a general requirement
for cover and food for rearing fish in lakes;for some species,
it is also a necessity for spawning habitat.
Aoverse impacts may be rectified by managing the stream areas not
inundated or by developing a resident sport fishery in the
reservoirs,the latter of which could provide a replacement for
lost stream fishery habitat.Development of a resident reservoir
fishery may be limited by post-project water quality of the
reservoirs.
The ability to establish a fishery in the reservoir will depend
on the water quality characteristics that develop.Although
fisheries in other glacially fed lakes in this region have not
been very productive,indications are that conditions could be
present that would allow at least a limited fishery to be
established in the impoundments.A clear,productive upper layer
of water in the reservoir wi 11 aid in the development of such a
fishery.Initial investigations on the settling rate of incoming
sediment,combined with the length and depth of the Watana
reservoir,indicate that the necessary clear layer could develop.
The fraction of incoming sediment measuring two microns or less,
however,may cause the reservoir to remain cloudy in summer and,
thus,limit the prospects for establishing a good reservoir
fishery.
Gas balance of nitrogen and oxygen in the Devil Canyon reservoir
is another impact that can be solved.Installing cone-type
valves for spilling instead of using conventional spillways will
solve the problem of entrain"ing nitrogen and oxygen and thus
eliminate a problem for fish in the Devil Canyon reservoir and
downstream.A further control is to prevent the valve discharges
from plunging more than .6 m,on the average,below the surface.
This precaution would keep the levels at or above those naturally
occurring.These measures are part of the proposed design.
As previously mentioned,the placement of the Devil Canyon
facility at the upper limit of the salmon migration is a positive
factor in the design of the project.No part of the present
range or habitat of the five species of Pacific salmon is
3-239
excluded by the project.Although it is not within the scope of
this study to evaluate the enhancement potential of the upper
Susitna River basin above Devil Canyon,whether or not the
project precludes this possible enhancement can be evaluated on a
preliminary basis.For example,to permit salmon access farther
into the upper basin,the natural barrier of Devil Canyon
(without the project)or the barrier represented by the dams
(with the project)would need to be circumvented in some manner.
More significant,however,is the consideration that any
enhancement plans for the basin above Devil Canyon requiring the
use of the Susitna for outmigration would be made more difficult
by the downstream passage prob 1ems presented by the dams.A
suggestion has been offered in the past for enhancing the salmon
resources of the upper basin by connecting Lake Louise to the
Copper River drainage.Such enhancement,while never entertained
by the present study,would not be precluded by the Susitna
project.Of course,if any suitable habitat for salmon presently
exists in the areas of the planned impoundment zones,it would be
eliminated by inundation.Obviously,any proposed action to
permit salmon access to the reaches of the upper basin wher~they
do not occur naturally would have other environmental
implications that would need to be evaluated.
-Downstream
Mitigation activities associated with downstream impacts during
the construction stage would be minimal.Avoiding or minimizing
impacts could be accomplished principally by close inspection of
the work to see that all prudent measures are undertaken to
reduce turbidity or to prevent any toxic materials from entering
the river.
Impacts associ ated with downstream temperature regimes cou ld be
avoided during some periods of the year and minimized during
other periods by the use of multilevel intakes which would
provide a mixed flow with water temperatures equal or near to
naturally occurring conditions.The appropriate multilevel
intakes,if included in the design,will allow for temperature
regu 1ati on of di scharged waters.Downstream water temperatures
can then be regulated to follow the naturally occurring
temperature regime as closely as possible and thus to reduce or
minimize the impact on fish resources.Table 3.70 gives the
predicted temperature values with intake structures that wi 11
draw from the surface and the depths of the reservoirs.Stream
reaches that will have the correct temperature conditions for egg
development and emergence at the proper time could be considered
for management of salmon fisheries and for modifications to
provide additional habitat.
If the primary water supply for developing salmon eggs during the
winter comes from aquifers that are charged by high water levels
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in the Susitna River,then presently projected flows during the
summer will not be sufficient to recharge these aquifers.In
addition,during the post-project period,the projected summer
flows wi 11 not allow salmon access to many slough and side
channel areas.Avoidance of this impact may require increasing
the river flows either during the summer or sometime before the
winter season begins for whatever length of time is necessary to
recharge the aquifers.It is believed that a downstream flow of
approximately 19,000 cfs for about 50 to 60 days,keyed specif-
ically to spawning salmon needs,would avoid most or all of the
impacts on the salmon fishery in the Talkeetna to Devi 1 Canyon
reach by allowing slough and side channel access.Some flow less
than 17,000 cfs for the same period of time could minimize the
impacts,but what that flow rate is is unknown.
For success in reconstructing habitat areas,modifying existing
habitats,and altering the streambed in any way,a stipulated
flow would have to be maintained that would provide the necessary
water of the required quality.The alteration of the sloughs or
mainstem to provide for spawning type habitat would be similar to
creating an artificial spawning channel but with the benefit of
maintaining the wild stock of fish.Flows adequate for
outmigration would need to be maintained for any management or
other mitigation option to work.Flow regulation fitted to the
needs of outmigrating salmon could probably be accommodated
with "in the constraints of project operations.The need for and
success of this flow manipulation for outmigration would be
dependent,however,upon having previously maintained or
established conditions necessary for spawning,incubation,and
rearing of some of the salmon species.
Reari ng habitat for speci es that currently us e the slough and
side channel areas may still be available in the mainstem during
the post-project period.It is not known whether the conditions
that may be present would meet the habitat needs for rearing.
Artificial spawning channels and hatcheries could also be
considered.The use of artificial spawning channels and
hatcheries can be used to replace the fish that would be lost
during the post-project period.The placement of these type of
facilities,however,depends on finding a source of water that is
suitable.In addition,for the fish produced from artificial
spawning channels and/or·hatcheries to be useful to the
commercial fishery the location is critical.Such facilities
must be placed in a location that will allow maximum harvest of
hatchery or spawning channel fish without affecting the
management of the natural runs.
The use of the mainstem Susitna as a transportation route should
not be affected by the project flows.Likewise,tributary access
should not be blocked,as it is anticipated that high flows from
the tributaries wi 11 lower the mouths to the post-project stream
levels.Once the flows can be regulated from the partially
filled reservoirs,certain levels could be provided to coincide
with the timing of the salmon runs.At these times,stipulated
3-241
flow levels would be implemented that are suited to the needs of
the salmon with consideration either to improvements of the
stream channel or side sloughs or to other mitigative measures
which may be undertaken.
Stable summer flows and increased winter flows,accompanied by a
reducti on in turbi dity during the summer,shou 1d increase the
habitat available for resident fish.In addition,another
positive impact of increased winter flows will be the possible
addition of overwintering areas for both salmon and resident
fish.On the basis of available information or post-project
mainstem habitat conditions for the rearing of fish,however,it
is difficult to assess accurately the actual suitability of this
habitat for overwintering.
A more stable channel and reduced or eliminated floods would make
it possible to insure that any river area used by fish for
spawning would not be destroyed by a major flood.In addition,
except during an unusual flood period,any gravel deposited for
spawning purposes would not be carried away.
Controlling floods and eliminating flood peaks could be made
possible by operational procedures that reduce or eliminate
spills.Many operational modes have been examined in an effort
to accomplish this objective.Presently,spills from the
hydroe 1ectr ic deve 1opment are not expected to occur more
frequently than four or five times in 30 years,with only one of
the spills being of significant volume.Additionally,
consistent,stable summer flows may be necessary to mitigate
post~project impacts in the Devil Canyon to Talkeetna reach.
Prior to completion of the Devil Canyon dam,the downstream reach
of the Sus itna may be affected by da ily peaki ng at the Watana
reservoir.During this period,currently projected to be nine to
ten years long,the daily fluctuations in flow are expected to be
about 4,000 cfs,with flows ranging from approximately 8,000 cfs
to 12,000 cfs.The Devil Canyon cofferdam will be in place
during this time,however,and its presence is expected to
attenuate,to some extent,the daily flow variation downstream.
Should additional regulations of these flows be necessary for
fishery mitigation,a re-regulation device could be installed on
the cofferdam.Once the Devil Canyon dam is in place,the
peaking at Watana wi 11 not affect the downstream reach because
Devil Canyon will have the effect of re-regulating the flows.
Some daily peaking is currently planned for the Devil Canyon
facility,but it will be of relatively small magnitude.
Significant power peaking flows,however,would cause downstream
impacts of a much greater magnitude.
A construction activity that could potentially provide a positive
impact is associated with the construction of the tailrace tunnel
at Devil Canyon.It has been suggested that the rock excavated
during construction of the tailrace tunnel be crushed to the size
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of spawning gravel and returned to the Susitna River.If this
action were taken,the gravel would be a positive addition to the
Susitna's substrate,since in the reach from Devil Canyon to
Talkeetna,the river is presently thought to contain very limited
suitable spawning gravel.The reduction in flow and the limiting
of flood peaks,both described above,will make it possible for
spawning-size gravel to possibly provide a substrate for
improving fishery habitat in the mainstem.
Another aspect of flow that has been examined is the mechanism
for spilling from the two dams.The present plan provides for
all floods up to the one-in-50-year flood to be passed through
cone-type valves.As described above under Impoundments,this
procedure for spilling will reduce the plunging of spilled waters
to an average of about 0.6 m or 1ess.Thi s contro 1 of p1ungi ng
flows will provide benefits downstream similar to those afforded
the reservoir,that is,it should keep the supersatura-tion of
gases,particularly nitrogen and oxygen,at or below the level
that occurs naturally below Devil Canyon.
Be low the confl uence of the Chu 1itna,Sus itna,and Talkeetna
rivers,the contribution of waters from the Chulitna and
Talkeetna rivers is expected to reduce greatly or to el iminate
the potential for impacts resulting from flow alteration in the
upper river.In addition,the load contribution from the
Chulitna River will probably mask any reduction in suspended
material caused by settling behind the dams.As one progresses
downstream,the differences between pre-and post-project
conditions wi 11 be less and less apparent unti 1,eventually,any
change will be well within the range of natural fluctuations.No
adverse water quality changes are expected in the lower Sus itna
River.Possibly the change in flows below Talkeetna could lower
the stage in certain areas and thus 1imit access to some of the
sloughs and side channels used for spawning.Should this happen,
then a possible mitigation measure that would avoid impacts or
minimize them would consist of some alteration at the mouths of
the sloughs or tributaries.
Reducing or eliminating impacts through stream stocking and lake
fertilization may also be used.Several lakes in the Susitna
River drainage that may have management potential have already
been identified by the Fisheries Rehabilitation Enhancement
&Development (FRED)Division of ADF&G.These,plus other
possible locations,could be considered for future management
activities.
The number of fish that will be adversely affected by the project
represents a relatively small portion of the total fish
population using the Susitna River system.Mitigation of these
adverse impacts could most likely be accomplished by a program
combining various approaches;such techniques may even improve
the fisheries.Although improvement of fish stocks is not a re-
quirement,considering the present size of the stocks versus its
potential size with active management,improvement of the fish
resource is a definite possibility.
3-243
-Access Road -Borrow Areas -Transmission Lines
A majority of potential impacts associated with the construction,
operat i on,and maintenance of access roads,borrow areas,and
transmission lines can either be reduced significantly or
eliminated completely.A major portion of the impacts associated
with public access and stream sedimentation will be avoided if
the mitigation measures already descr'ibed by Acres are
implemented (Acres American Access Route Selection Report 1981).
For example,it is assumed that the access road will be
controlled as a private road during construction of both dams and
that,subsequent to construction,management policies will be
established for future use of the road.Furthermore,many
potential impacts can be avoided if restrictions on off-road
vehicle use are imposed and if some restrictions are placed on
public access beyond Devil Canyon.Additionally,it has been
assumed that,whenever feasible,borrow sites for the access road
(as well as those for dam construction)will have a buffer strip
of undisturbed land between them and any nearby aquatic habitat.
Such a buffer strip,however,is not currently planned for'Borrow
Area F,along Tsusena Creek,a lthou~h the streambed itse If will
not be excavated.Finally,it has been assumed that borrow sites
will be revegetated [Section 3.9 (b)(ii)].
o Road Design and Construction
Road design and construction can incorporate measures to
minimize mass-movement erosion of sediment into streams
represented by soil creep,slump earth flows,debris
avalanches,and debris torrents.Control of these phenomena
can be accomplished by avoiding placing roads on the midslope
of steep,unstable slopes;by reducing excavation to a minimum;
in conjunction with a balanced earthwork design,by designing
cut and fill slopes at proper slope angles;by providing
vegetative or artificial stabilization of cut and fill slopes;
and by constructing retaining walls to contain unstable
slopes.Except at stream cross i ngs,roads can be situated so
as to provi de a buffer stri p of undi s turbed 1and between the
road and any streams.In addition,if bridges and arch
culverts are used for stream crossings where anadromous or
migratory resident fishes are present,the potential for impact
on these species will be minimized.It is assumed that
culverts will be of appropriate size and design and will be
installed properly to permit fish passage.Any low water
crossings may cause impacts if downstream fish resources are
present.Where any suc h cross -j ngs are used,impacts can be
reduced if the crossings are properly maintained and utilized
only by light vehicular traffic and not by large construction
vehicles.
It is assumed that permafrost areas wi 11 be avoided whenever
possible.Any permafrost regions that cannot be avoided could
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perhaps be crossed on slopes where bedrock is near the mant 1e
surface.If high ice waste pi les are compact and covered with
some form of insulation,rapid melting and subsequent siltation
in streams can be prevented.
Erosion resulting from drainage from road surfaces can be
minimized.Designs such as open-top culverts,rolled grades,
cross drains,or shallow ditches are usually suitable drainage
devices.
Some potential impacts can be avoided if construction work
within or adjacent to streams and water channels is not
attempted during periods of high streamflow,intensive
rainfall,when migratory fish are spawning,or during crucial
rearing times.This mitigation approach applies to
transmission line construction as well as to access road
construction.
Stream di sturbance and resu ltant impact on fi sh can occur if
logs are skidded or yarded across any stream;such impacts are
avoidable.Similar potential impacts can be avoided if log
landings are not located on the banks of any stream containing
a viable fishery.Logging operations could leave a buffer
stri p of undi sturbed nround and brus h a long the stream bank.
In addition,if hea';2quipment is not operated on the stream
banks or in the stream channels,it will help minimize
siltation.Finally,logging debris can be chipped for use in
stabilizing cut banks.
Oil residue from construction equipment and the possible
bacterial and nutrient contamination of aquatic habitats
resulting from the presence of construction personnel can be
minimized by following the standard precautions of the
construction industry.It is assumed that oi 1 from machinery
will be disposed of properly and not buried at the site.
Portable chemical toilets will eliminate possible bacterial
and/or nutrient contamination.
o Public Access/Angling Pressure
To control publ ic access further and to protect the fisheries
resource from unwarranted angling pressure,additional
mitigation measures can be implemented.These would include
recommendations made to the proper Alaska management and
regulatory agencies to control fishing pressure in the region.
Such recommendations will apply especially to the salmon
fishery in Indian River and to the grayling and lake trout
fishery of the upper basin.Some potential impacts will be
avoided if the pioneer road is made inaccessible to public use
following its original use.
3-245
TABLE 3.1:
Common Name
alpine sweetvetch
American green alder
American red raspberry
COMMON AND SCIENTIFIC NAMES OF PLANT SPECIES
APPEARING IN THE TEXT
Scientific Name
Hedysarum alpinum
Alnus crispa or A.c.subsp.
crispa
Rubus idaeus
-
balsam poplar (cottonwood)
bearberry
Beauverd spiraea
bigelow sedge
birch
black spruce
bladderwort
bluejoint
bog blueberry
bunchberry
bur reed
cotton grass
crowberry
currant
diamond willow
dryas
dwarf arctic birch
feltleaf willow
feather moss
highbush cranberry
horsetail
Populus balsamifera
Arctostaphylos spp.
Spiraea beau verdi ana
Carex bigelowii
Betula spp.
Picea mariana
Calamagrostis canadensis
Cornus canadensis
Sparganium angustifolium
Eriophorum spp.
Empetrum nigrum
Salix planifolia
Dryas spp.
Betula nana
Salix alaxensis
Hylocomnium sp.
Viburnum edule
Common Name
Labr ador te a
larch (tamarack)
lupine
mare's tail
meadow horsetail
mountain cranberry
nagoonberry
northern Labrador tea
oak fern
paper birch
prickly rose
resin birch
sedge
Sitka alder
sphagnum moss
tall blueberry willow
thinleaf alder
trembling aspen
twinflower
water sedge
white spruce
willow
woodland horsetail
wormwood
yellow pond lily
TABLE 3.1 (continued)
Botanical Name
Ledum groenlandicum
Larix laricina
HlQQuris vulgaris
Equisetum arvense or E.pratense
Vaccinium vitis-idaea
Rubus arcticus
Ledum decumbens
gymnocarpium dryopteris
Betula ~yrifera
Rosa acicularis--------
Betula glandulosa
Carex spp.
Alnus sinuata or A.~ispa
subsp.,?inuata
Sphagnum spp.
Salix novae-angli~~
Alnus tenuifolia
Populus tremuloides
Linnaea borealis
Carex aquatilis
Picea glauca
Salix spp.
fggisetum silvaticum
Artemisia telisii
Nuphar polysepalum
TABLE 3.2:HECTARES AND PERCENTAGE or TOTAL AREA COVERED BY
VEGETATION/HABITAT TYPES IN THE UPPER SUSITNA RIVER BASIN
(ABOVE GOLD CREEK)(a)
;-
I
I
....
f""l'
I
,....
I
,.....
I
,...
i
......
( b )Percent of
VEGETATION/HABITAT TYPE Hectares To ta 1 Area
Total Vegetation 1,387,607 85.08
Forest 348,232 21.35
Conifer 307,586 18.86
Woodland spruce 188,391 11.55
Open spruce 118,873 7.29
Closed spruce 323 0.02
Deciduous 1,290 0.08
Open birch 968 0.06
Closed birch 323 0.02
Mixed 39,355 2.41
Open 23,387 1.43
Closed 15,968 0.98
Tundra 394,685 24.20
Wet sed ge grass 4,839 0.30
(Mesic)sedge grass 184,358 11.30
Herbaceous alpine 807 0.05
Mat and cushion 65,001 3.99
Mat and cushion/sedge grass 139,680 8.56
Shrub land 644,690 39.53
Tall shrub 129,035 7.91
Lo w shrub 515,655 31.62
Birch 33 ,549 2.06
Wi 110w 10,645 0.65
Mixed 471,461 28.91
Unvegetated 243,392 14.92
Water 39,840 2.44
Lakes 25,162 1.54
Rivers 14,678 0.90
Rock 113,712 6.97
Snow and ice 89,841 5.51
Total Area 1,630,999 100.00
a.Based on maps produced at a scale of 1:250,000.
b.Differences in resolution as a result of differences in scale may result
in some discrepancies for common areas between these figures and those
presented in Table 3.3.
TABLE 3.3:HECTARES AND PERCENTAGE OF TOTAL AREA COVERED BY
VEGETATION/HABITAT TYPES FOR THE AREA 16 KM ON EITHER
SIDE OF THE SUSITNA RIVER FROM GOLD CREEK TO THE MACLAREN
RIVER(a)
VEGETATION/HABITAT TYPE
Forest
Conifer
Woodland spruce-black
Woodland spruce-white
Open spruce-black
Open spruce-white
Deciduous
Open birch
Closed birch
Closed balsam poplar
Mixed
Open conifer deciduous
Closed conifer deciduous
Tundra
Wet sedge grass
Sedge grass
Sedge shrub
Mat and cushion
Shrub land
Open tall shrub
Closed tall shrub
Birch shrub
Willow shrub
Mixed low shrub
Herbaceous
Grassland
Disturbed
Unvegetated
Rock
Snow and ice
Water
Rive r
Lake
Total Area
( b )
Hectares
142,306
115,04B
62,993
13,291
28,304
10,460
4,393
1,498
2,324
571
22,865
9,639
13,226
114,728
3,517
27 ,505
20,073
63,633
177,264
15,524
15,767
42,880
8,230
94,863
18
1,079
24
26,979
16,603
249
4,236
5,891
462,398
Percent of
To ta 1 Are a
30.75
24.87
13.62
2.87
6.12
2.26
.94
O.32
0.50
0.12
4.94
2.08
2.86
24.81
0.76
5.95
4.34
13.76
38.34
3.36
3.41
9.27
1.78
20.52
0.01
0.23
0.01
5.83
3.59
0.05
0.92
1.27
99.98
a.Based on maps produced at a scale of 1:63,360.
b.Differences in resolution as a result of differences in map scale may
result in some discrepancies for common areas between these figures and
those presented in Table 3.2.
TABLE 3.4:HECTARES AND PERCENT OF TOTAL AREA COVERED BY VEGETATION/HABITAT
TYPES WITHIN THE HEALY TO FAIRBANKS TRANSMISSION CORRIDOR
r
"""'
-i
i
F'!
1
(a)
VEGETATION/HABITAT TYPE
Forest
Woodland spruce
Op en sp ruce
Closed spruce
Woodland deciduous
Open deciduous
Closed deciduous
Woodland conifer-deciduous
Open conifer-deciduous
Closed conifer-deciduous
Open spruce/open deciduous
Open spruce/wet sedge-grass/
open deciduous
Open spruce/low shrub/wet sedge-
grass/open deciduous
Open spruce/low shrub
Tundra
Wet sedge-grass
Sedge grass
Sedge shrub
Sedge-grass/mat and cushion
Shrubland
low mixed shrub
willow shrub
low shrub/wet sedge-grass
Agricultural land
Disturbed
Unvegetated
Lakes
River
Gravel
TOTAL AREA
Percent of
Hectares Tot a 1 Are a
86.830 77.9
1.812 1.6
31,739 28.5
1.347 1.2
993 .9
12,553 11.3
10,384 9.3
961 0.9
12.502 11.2
4,125 3.7
948 0.9
1.993 1.8
7,008 6.3
465 0.4
4,407 3.9
2,268 2.0
277 O.2
566 .5
1,296 1.2
17.199 15.4
15,405 13.8
58 .05
1,736 1.6
175 • 2
431 .4
2,467 2.2
196 .2
2,143 1.9
128 .1
Ill,509 100.0
-
-i
!,
a.The Tanana Flats portion of the transmission corridor is
extremely complex mosaics of various vegetation types.
various complexes were recognized.
an area of
As a result.
TABLE 3.5:HECTARES AND PERCENT OF TOTAL AREA COVERED BY VEGETATION/HABITAT
TYPES WITHIN THE WILLOW TO COOK INLET TRANSMISSION CoRRI~D~O~R _
VEGETATION/HABITAT TYPE
Forest
Woodland spruce
Open spruce
Closed spruce
Open birch
Closed birch
Open balsam poplar
Closed balsam poplar
Open conifer-deciduous
Closed conifer-deciduous
Wet sedge-grass
Shrubland
Closed tall shrub
Low mixed shrub
Lakes
Disturbed
TOTAL AREA
Hectares
25,851
2,457
3,402
3,226
16
3,638
100
172
1,697
11,143
9,123
2,213
92
2,121
1,011
381
38,579
Percent of
Total Area
67.0
6.3
8.8
8.4
.04
9.4
• 3
.5
4.4
28.9
23.7
5.7
.2
5.5
2.6
1.0
100.0
-
TABLE 3.6:VASCULAR PLANT SPECIES RECORDED IN THE UPPER SUSITNA RIVER
BASIN WHICH ARE OUTSIDE OF THEIR RANGE AS REPORTED BY
HULTEN (196B)
r
~I
-
(a)
(a)
(a)
Eguisetum fluviatile
Lycopodium selago spp.selago
Lycopodium complanatum
Picea mariana
Carex filifolia
Danthonia intermedia
Luzula wahlenbergii
Veratrum ..'{iride
Platanthera convallariaefolia
Platanthera ~ilatata
Plata nth era hyperborea
Listera cordata----
Echinopanax horridum
Senecio sheldonensis
~ica ~
Ranunculus occidentalis
Potentilla biflora
Rubus id~
Rubus pedatus
Galium triflorum
Pedicularis kanei kanei-------
Pedicularis ~iflorus
Potamogeton robbinsii
r-
I
i"""
I
r
L
-j
a.Viereck and Little (1972)include the upper Susitna River basin in the
range of this species.
( a )
TABLE 3.7:HECTARES OF DIFFERENT WETLAND TYPES BY PROJECT COMPONENT
Watana FacilityI
LI Impoundment,Camp,Village
Wetland Type I Dam and Spillways and·Airstrip I
I I
A D E
Borrow Areas __
F H
Palustrine
forested
Palustrine
scrub-shrub
Palustrine
emergent
Lacustrine
emergent
Lacustrine
Riverine
TOTAL
Wetland Type
Palustrine
forested
Palustr ine
scrub-shrub
Palustrine
emergent
Lacustrine
emergent
Lacustrine
Riverine
7,408
1 ,126
139
4
54
.Ll!!..?
10,913
Impoundment,
Dam and Spillways
800
43
12
1
810
252 16 133 80 345 15
142 62 212 199 38
8 8
8
------
150 322 236 133 279 383 15
Devil Canyon FacilitY...-_______
Camp and Village Borrow Area K
11
29
TOTAL 1,666 -0-40
a.Wetland types according to Cowardin,et al.(1979),
~~~1)1 ~]>-~-;j ~~
'~'j 1
r
I
TABLE 3.8:COMMON AND SCIENTIFIC NAMES OF FURBEARER AND BIG GAME SPECIES
MENTIONED IN THE TEXT
r
r
"
r
Beaver
Castor canadensis
Muskrat
Ondatra zibethicus
Coyote
Canis latrans
Gray wo If
Canis lupus
Red fox
Vulpes fulva
Black bear
Ursus americanus
Brown bear
Ursus arctos
Pine marten
Martes americana
Least weasel
Mustela nivalis
Short-tailed weasel
Mustela erminea----
Min k
Mustela vison
Wolverine
Gulo ~
River otter
Lutra canadensis
Lynx
Felis ~
Moose
Alce~~ces
Barren ground caribou
Rangifer tarandus
Dall sheep
Ovis dalli
TABLE 3.9:SUMMARY OF ELEVATIoNAL USE (IN METERS)BY APPROXIMATELY 200 RADIO-COLLARED MOOSE
(BOTH SEXES AND ALL AGE CLASSES)FROM OCTOBER 1976 THROUGH MID-AUGUST 1981 I N THE
UPPER SUSITNA AND NELCHINA RIVER BASINS OF SoUTHCENTRAL ALASKA
Month -Jan.Feb.Mar.Apr.May June July Aug.Se pt.Oct.Nov.Dec.To ta 1
Me an
elevation 853 834 788 785 805 820 840 850 837 913 900 900 838
Standard
deviation 140.8 142.6 134.8 140.8 136.9 130.0 161.9 155.3 137.7 14B.9 146.4 145.0
Range of
elevation
Min.549 427 518 457 427 396 ---549 549 427 442 457
Max.1,189 1,189 1,402 1,250 1,158 1,341 1,280 1,463 1,219 1,280 1,341 1,402
Sample
size 66 98 285 204 341 424 218 174 130 193 168 116 2,417
11 ~~J \1 1 ~;~l ~1 n ~'J ;J ~:l j
TABLE 3.10:NELCHINA CARIBOU HERD POPULATION ESTIMATES,IN FALL
UNLESS OTHERWISE NOTED
r
-!
Year
1955
1962
1967
1972
1973
1976
1977
1978
1980
1981
Total
Estimate
40,000(a)
71 OOO(b),
61 000(e),
7,842
7,693
8,081
13 ,936
18,981
18,713
2o,730(d)
Female
Estimate
4,800
4,646
4,979
7,509
9,866
9,164
10,172
Male
Estimate
1,622
1,268
1,663
2,868
4,429
5,673
6,195
Calf
Estimate
1,420
1,779
1,439
3,559
4,686
3,876
4,364
a.
.....b •
I
I
c.
d.,....
I
I
I"""'
r
r
r
r
IPIl'III
I
Watson and Scott (1956),February census.
Siniff and Skoog (1964),February census,perhaps should be adjusted
downward by as many as 5,000 caribou due to presence of Mentasta herd.
Felt by some to be an unreasonably high estimate.
Preliminary estimate,awaiting final female harvest data.
TABLE 3.11:REPORTED HUNTER HARVEST OF THE NELCHINA CARIBOU
HERD,1972-1981
Year Total Har vest Females Males----------No.un No.un
,rr:'~
1972 555 153 (28 )338 (72)
v7:7"",
1973 629 203 (33 )411 (67)
1974 1,036 343 (34 )656 (66)
1975 669 201 (31 )441 (69)
1976 776 201 (26 )560 (74)
1977 360 77 (22 )275 (78)
P"""
1978 539 III (21 )416 ( 79 )
1979 630 90 (14)509 (81)
fi'!''''-1
1980 621 117 (21 )453 ( 79 )
(a)
1981 856 144 (I8 )675 (82)
a.Preliminary data
r TABLE 3.12:SUMMARY OF TERRITORY SIZES FOR WOLF PACKS STUDIED AS PART OF THE
SUSITNA HYDROELECTRIC PROJECT STUDIES DURING 19BO and 19B1 IN
SOUTHCENTRAL ALASKA
ro-
I
-
......
Pack
Fish Lake
Susitna
Susitna-Sinona
To 1sona
Tyone Creek
Watana
x
S.D.
Territory Size (km 2 )
943
1,453
1,20B
2,541
943
1,3B 3
1,412
541
TABLE 3.13 :ESTIMATE OF NUMBERS OF WOLVES BY INDIVIDUAL PACK INHABITING THE
SUSITNA HYDROELECTRIC STUDY AREA IN SPRING AND FALL 1980 AND 1981
Spring 1980 Fall 1980 Spring Fall
Pack Area (Post-Hunt)(Prehunt)1981 1981
----
But te Lake 3-47 3-4+3 5
Fish Lake 7 2 9 12+
Jay Creek 6 7-87 7 10
F"'
Keg Cre ek 7 7 2-3 2-3
Maclaren Rive r 2 4-5 7 2-3
Portage Cre ek 7 7 7 6
Stephan Lake 2+11 7 7
Susitna 4 10 5 4
Susitna-Sinona 4 4-5 2 7
Talsona 9 16 13 15
Tyone Creek 4 2 0 7
Upper Talkeetna Rive r ?7 7 2
Watana 5 14 8 14
Total 40 77 42-43 72-74
1 -]_._-)1 1 ----1 --]-)---j )J "]J 1 1 1
TABLE 3.14:SUMMARY OF WOLF DEN AND RENDEZVOUS SITES DISCOVERED FROM 1975 THROUGH
1981 OCCURRING WITHIN AN 80 KILOMETER RADIUS OF THE PROPOSED SUSITNA
_____________~H~Y=DROELECTRIC PROJECT IN SOUTHCENTRAL ALASKA
Kilometers from upper
water-level
Site
Pack Type Year of
Name Site Documented Use
8
24
32
40
Watana
Watana
Deadman
Jay Creek
Stephan Lake
Tyone Creek
Susitna
Susitna
Brushkana
Mendeltna
Susitna
Keg Creek
Clearwater
Rendezvous
Den
Den
Den
Den
De n
Rendezvous
Rendezvous
Den
Rendezvous
Den
Den
Den
80&81
80 t 81
75
78
76
79
80
80
75
76
79 &80
75 t 76 t &78
76
48 Tolsona
Tolsona
Den 80 &Mendeltna Rendezvous 77
Rendezvous 80 &Mendeltna Den 77
48
56
64
80+
Mendeltna
Mendeltna
Mendeltna
Mendeltna
Mendeltna
Hogan Hill
Hogan Hill
Sinona
Sinona
Rendezvous
Den
Rendezvous
Rendez vou s
Den
Den
Den
Den
Den
77
77
77
77
76 t 77
78
75
78
77
TABLE 3.15:COMPARISONS OF FOOD REMAINS IN WOLF SCATS COLLECTED AT DEN
AND RENDEZVOUS SITES IN 1980 AND 1981 FROM GMU-13 OF SoUTHCENTRAL
________~A~LA SKA
Food Items 1980 1981 r~=
727 Scats 290 Scats
!I Items IV Occurrences #Items IV Occurrences'0 ,0
pr~
Adu It Moose 105 12.00 24 6.15
Ca If Moose 369 42.17 87 22.31
Moo se ,Age Unknown 22 2.51 21 5.38 fF''"
Adu It Caribou 30 3.43 31 7.95
Calf Caribou 13 1.49 19 4.87
Caribou,Age Unknown 8 0.91 5 1.28
Moose or Caribou 31 3.54 9 2.31
Beaver 48 5.49 37 9.49
Muskrat 26 2.97 24 6.15
Snowshoe Hare 55 6.29 21 5.38
Microtine 40 4.57 37 9.49
Unidentified Small Mamma 1 15 1.71 20 5.13
Bird 16 1.83 8 2.05
Fish 1 0.11 2 0.51
Vegetation 22 2.51 5 1.2B
\'/0 If 4 0.46 1 0.26
Unknown 70 8.DO 39 10.00
Total 875 100.00 390 100.00
~.
~1 .-1 ~-1 "]-1 --1 ))~l ]--·~-l ~--l "--1 --1 -]--_.._-]
(a)
TABLE 3.16:AVERAGE SPRING AGES OF SUSITNA AREA BROWN BEAR SUBPOPULATIONS
Males Females
Avg.
Average Average Both
Spring Age Spring Age Sexes %
Subpopulations (Years)(Range)n (Years)(Range)n (Years)Males
GMU 13 fall
harvests,
1970-1980 8.0 (3.5-23.5)208 7.7 (3.5-28.5)191 7.9 52
1979 Upper Susitna
studies (Miller &
Ballard 1980)7.4 (3.5-21.5)17 7.4 (3.5-16.5)15 7.4 53
1980-81 Susitna
Hydro studies(b)7.7 (3.5-14.5)14 7.9 (3.5-13.5)15 7.8 48
Su-Hydro studies
radio-collared bears
'101/>5 locations(b)6.0 (3.5-10.5)4 8.6 (3.5-13.5)13 8.0 24
a.Includes only bears of known sex and age that are 3.0 or older,spring age calculated as age +.5 years.
b.Average of age at first capture
TABLE 3.17:REPORTED BROWN BEAR DENSITIES IN NORTH AMERIC.~A __
3v 2 2
=mi /be ar km /bear
0.6 1.6
6.0 15.5
8.2 21.2
11.0 28.5
9-11 23-27
16-24 41-62
(c)( c )
88 (16-300)288 (42-780)
100 260
Location
Kodiak Island,AK
Alaska Peninsula,AK
Glacier Nat.Park,Mont ana
Glacier Nat.Park,B.C.
SW Yukon Territory
Upper Susitna R.,AK
Western Brooks Range (NPR-A),AK
Eastern Brooks Range,AK
Source
( a )
Troyer and Hensel 1964
( b )
Unpublished data (Glenn pers.comm.)
( a )
Martinka 1974
( a )
Mundy and Flook 1973
( a )
Pearson 1975
Miller and Ballard 1980
Reynolds 1980
Re yno Ids 1976
a.Taken from Pearson 1975.
b.Data refer to a 1,800 mi 2 intensively studied area of the central Alaska Peninsula.
c.Mean is for the whole of the Nat.Pet.Reserve,AK,the range represents values for
different habitat types in this reserve where the highest density occurred in an
intensively studied experimental area.
';]ill tI ~~~!tI ~J J.,I
-1 J --I 1 -1 '-1 '1 '],---1 1 ]--I ~]
(a)(b)
TABLE 3.18:COMPARISONS OF MEAN HOME RANGE SIZE OF BROWN BEARS RADIO-COLLARED IN 1978,'1980 AND 1981 STUDIES
IN GMU-13
19781978
MALES (c)
1980 1981 1978
FEMALES (c)
1980 1981
________BOTH SEXES (c)
1980 1981
Mean home range
size (km 2 )769 845 1061 488 160 343 572 409 487
S.D 396 439 1390 222 48 302 356 422 660
Range =282-1381 495-1409 100-2655 193-734 82-233 50-1136 193-1381 82-1409 50-2655
n 10 4 3 12 7 12 22 11 15
Mean age of
sa mp Ie 6.9 5.5 7.0 8.8 8.9 8.4 7.9 7.6 8.1
Range 3-11 3-10 4-11 4-13 3-13 3-14 3-13 3-13 3-14
Mean No.
relocations/
bear =16.2 10.8 12.7 24.9 II.7 20.8 21.0 II.4 19.1
Range =8-29 8-14 8-21 12-33 6-15 13-35 8-33 6-15 8-35
%Males 45 36 20
%of fema les 8 0 33
w/newborn cubs
a.Includes all bears 3 years of age or older
b.Source:Ballard et al.(in press)
c.Includes data through 1 September 1981 only,actual 1981 home range sizes will be larger when all
1981 points are included in analysis
TABLE 3.19:COMPARISON OF REPORTED HOME RANGE SIZES OF BROWN/GRIZZLY BEARS IN NORTH
AMERICA(a)
Sample Me an
Are a Sex size home range (km 2 )Source
Kodiak Island,Ak.M 7 24 Berns et al.1977
F 23 12
Yellowstone National M 6 161 Craighead 1976
Park F 14 73
Southwestern Yukon M 5 287 Pearson 1975
F 8 B6
Northern Yuko n M 9 414 Pearson 1975
F 12 73
Western Montana M 3 513 Rockwell et a1.
F 1 104 1978
Nelchina Basin M 14 790 Susitna studies
F 19 316 (1978 &1980 results
only)
Northwestern Alaska M 8 1350 Reynolds 1980
F 18 344
a.Adapted from Reyno Ids 1980
(a)
TABLE 3.20:EARLY SPRING USE OF DEVIL CANYON AND WATANA IMPOUNDMENT AREAS BY
RADIO-COLLARED BROWN BEARS
r
( a )
Bear visited impoundment area?
(No.observations in/total observations)
Spring 1980 Spring 1981
BEAR
ID (age)
MALES
Mean elevation of
observations in im-
poundment area (S.D.)
1980 1981
sub totals (6/17)r
G34 2 ( 2 )
G293 (3)
G214 (4)
G280 (5)
G308a (6)
G294 (10)
no (0/4)
yes (2/4)(to
no (0/3)
no (0/2)
yes (4/4)(to
no (0/4)
no (oil)
Wat ana)
yes (1o/16)(to Wat ana)
Devil )no 1.Q/3)
(10/24)
2038(-)
2030(331)
1721(344)
,.....
i
I
r-,
r
i
r
FEMALES
G335 ( 2 )no (0/20 )
G281 (3)yes (3/5)(to Wat ana)yes (9/26)(to Wat ana)2025(-)2119(254)
G340 (3)yes (9/26)(to Watana)2083(301)
G308b ( 5 )yes (l/5)(to Devil)yes (6/7)(to Devil)1350(-)1863(309)
G344 (5)(b)no (0/6 )(w/2 cubs
G331 (6)yes (l/8)(to Watana)1850(-)
G341 ( 6 )yes (l2/17)(to Watana)2160(474)
G313 (6 )no (0/5)no (0/10)
G277 (10 )no (0/4)
G312 (10)(b)yes (1/4 to Watana no (0/1 0)w/2 cubs 1750(-)
G334 (10 )yes (1/22)(to Watana)2525(-)
G283 (12)(b)yes (3/5)(to Devil no (0/9)w/2 cubs 2500(-)
G299 (13)no (0/2)yes (4/1o)(to Watana)2063(103)
G337 (13)(b)no 0/7 w/3 cub s
subtotals (8/30)(42/178)
total (13/37)(52/202)
a.Defined as within 1 mile of impoundment prior to 19 June.
b.Females with newborn cubs tend to remain at high elevations throughout the summer.
TABLE 3.21 :NIJMBE R OF AERIAL BROWN BE AR OBSERVATIONS BY MONTH IN EACH OF FIVE
HABITAT CATEGORIES
Habitat May June July August September Oct.-April Ro w i1!';;:~'
Total un
SPRUCE 44 50 17 16 9 5 141 l~·~:"
Row IV 31.2 35.5 12.1 11.3 6.4 3. 5 (25.0)'"
Column IV 31.0 29.6 19.3 17.6 25.0 13.2'"
1!"'7"'(
RIPARIAN 16 26 22 20 4 1 89
Row IV 18.0 29.2 24.7 22.5 4.5 1.1 (15.8)'"
Column IV 11.3 15.4 25.0 22.0 11.1 2 . 6'"
SHRUB LAND 39 75 46 52 21 5 23B
Row IV 16.4 31.5 19.3 21.B B.8 2.1 (42.2)'"
Column IV 27.5 44..4 52.3 57.1 58.3 13.2'"
~
TUNDRA 12 14 1 1 0 0 2B
Row IV 42.9 50.0 3.6 3.6 0 0 (5.0 ),0
Column %B.5 8.3 1.1 1.1 0 0
OTHER 31 4 2 2 2 27 68
Row IV 45.6 5.9 2.9 2.9 2.9 39.7 (12.1)'"Column IV 21.8 2.4 2.3 2.2 5.6 71.1,0
Column Total 142 169 88 91 36 38 564
0;)(25.2)(30.0)(15.6) (16.1)( 6 .4)(6.7)(100.0)
~,
~'
].~..~]....]C'~~1 1 ]1 .-1 ----1 "--J 1
( a )
TABLE 3.22:AVERAGE SPRING AGES Of BLACK BEAR SUBPOPULATIONS IN THE SUSITNA AREA AND KENAI PENINSULA
Males females
Avg.
Average Average Both
Spring Age Spring Age Sexes ...
'"
Subpopulations (Years)(Range)n (Years)(Ra.!Ule)n (Years)Males
GMU 13 harvests*
1973-1980 5.6 (2.5-18.5)115 5.9 (2.5-11.5)60 5.7 66
1980-1981 Su-
Hydro studies**6.6 (2.5-10.5)19 8.1 (4.5-12.5)13 7.2 59
Su-Hydro studies
radio-collared bears
wi ~5 relocations**6.9 (2.5-10.5)14 8.0 (4.5-11.5)11 7.4 56
Kenai Peninsula
studies 1978-1980***6.2 (-)45 5.0 (-)42 5.6 52
a.Includes only bears of known sex and that are 2.0 years or older,spring age calculated as +.5 years.
*Includes all bear (~2 years)aged and sexed,in recent years not all teeth have been sectioned and read
**
***
Represents age at first capture
Based on total bears known to be alive in each of the years of the study (same bear counted more than once).
This procedure should yield a relatively older mean age than the procedure used in calculating mean age in
Susitna studies.Data from the Kenai Peninsula from C.Schwartz,ADf&G,pers.comm.
TABLE 3.23:DENSITIES OF BLACK BEARS AS ESTIMATED IN STUDIES CONDUCTED IN
DIFFERENT LOCALITIES
Source
(a)
McIlroy (1972)
Location
Alaska (coastal population)
.2ml
Per Bear
O.1
km 2
Per Bear
0.3
Lindzey and Meslow (1977)
Poelker and Hartwell (1973)
Washington (an island population)0.3
Washington (mainland population)0.7-1.0
0.8
1.8-2.6
Piekielek and Burton (1975)
Beecham (1980)
Jonkel and Cowan (1971)
LeCount (1980)
Pelton and Burghardt (1976)
Kemp (1972)
Modafferi (1978)
Schwartz and Franzmann (1981)
Erickson and Petrides (1964)
Spencer (1955)
Clarke (1977)
California
Idaho (Council area)
Idaho (Lowell area)
Montana (Bear Creek)
Arizona
Tennessee
Alberta
Prince William Sound,Alaska
Kenai Peninsula,Alaska
Michigan
Maine
New York (Adirondacks)
New York (Catskills)
New York (Allegany State Park)
0.8-1.0
0.8
0.9
0.8-1.7
0.8
0.5-1.0
1 .0
1.2
1 .5
3.4
5.6
2.6
3.7
10.0
2.1-2.6
2 • 1
2.3
2.1-4.4
2 • 1
1.3-2.6
2.6
3.1
3.9
8.8
14.5
6.7
9.6
25.9
a.Probably estimated during season concentration.
Source:Modified from Modafferi 1978
--1 --1 J 1 --l 1 --1 1 J -]--l
(a)
TABLE 3.24:COMPARISONS OF MEAN HOME RANGE SIZE OF BLACK BEARS RADIO-TRACKED IN 1980 and 1981 STUDIES IN GMU 13
MALES FEMALES BOTH SEXES
1980 1981 1980 &1981 1980 1981 1980 &1981 1980 1981 1980 &1981
Mean home range
size (km 2 )46 250 153 16 219 117 31 235 136
S.D 42 180 167 16 368 274 35 278 223
Range 4-136 37 -611 4-611 3-45 12-1036 3-1036 3-136 12-1036 3-1036
n 10 11 21 10 10 20 20 21 41
Mean age of
sample 6.3 7.4 6.9 7.8 8.1 8.0 7.1 7.7 7.4
Range 2-10 3-11 2-11 5-11 4-12 5-12 2-11 3-12 2-12
Mean No.
relocations/
be ar =9.2 19.4 14.5 10.4 16.5 13.5 9.8 18.0 14.0
Range 5-17 7-40 5-40 6-20 6-34 6-34 5-20 6-40 5-40
%Males 50 52 51
%of Females
w/newborn cubs 30 40 35
a.Includes all bears 2 years of age or older
,T',
TABLE 3.25 :NUMBER OF AERIAL BLACK BE AR OBSERVATIONS BY MONTH IN EACH OF
FIVE HABITAT CATEGORIES
Habitat May June July August September Od.-Apri1 Row
Total (%)lttVT 1
SPRUCE 82 95 54 68 44 15 358
Row lY 22.9 26.5 15.1 19.0 12.3 4.2 (39.4)'";ll;~,f'--,
Column lY 50.3 46.3 35.8 31.8 30.8 46.9'"
RIPARIAN 23 33 23 18 23 1 121
Row lY 19.0 27.3 19.0 14.9 19.0 .8 (13.3)'"
Column lY 14.1 16.1 15.2 8.4 16.1 3.1'"
lllmF~
SHRUBLAND 50 70 69 119 71 9 388
Row 0'12.9 18.0 17.8 30.7 18.3 2.3 (42.7)'"
Column lY 30.7 34.1 45.7 55.6 49.7 28.1'"
TUNDRA 3 3 3 6 2 0 17
Row 0'17.6 17.6 17.6 35.3 11.8 0 (1.9 )'"
Column %1.8 1.5 2.0 2.8 1.4 0
p,-r,O'i
OTHER 5 4 2 3 3 7 24
Row lY 20.8 16.7 8.3 12.5 12.5 29.2 (2.6 )'"
Column lY 3.1 2.0 1.3 1.4 2.1 21.9'"
Column Total 163 205 151 214 143 32 9 08 p'JP~",
(%)(18.0)(22.6)(16.6) (23.6)(15.7)(3.5)(loo.o)
TABLE 3.26:TABULATION OF NOVEMBER,1980 AERIAL SNOW TRANSECT DATA,
INDICATING THE NUMBER OF FURBEARER TRACKS,BY SPECIES
NOTED ON TRANSE,CT (a)
Species
,....
I Transect Pine Red Short-tailed River Transect
Number Marten Fox Weasel Mink Otter Totals--------
01 41 1 3 5 2 52
02 80 0 7 1 6 94
,,-,
03 91 9 5 3 0 108
04 198 0 20 0 3 221
05 84 0 11 1 0 96
06 163 0 6 0 1 170
07 202 23 39 0 2 266
!"""
08 86 11 0 2 5 104
09 85 11 1 2 0 99-,
(
i 10 125 9520 2 3 245
,....11 39 30 58 2 1 130
12 40 38 96 5 1 180
~
13 7 60 77 5 3 152
14 112 10 328 6 3 459
Species
TOTALS 1353 213 746 34 30 2376
a.See Figure 3.20 for location of transects
TABLE 3.27:BACKGROUND INFORMATION FOR RADIO-COLLARED MARTEN,TSUSENA CREEK AREA,1980
Collar Age Weight Capture
Number Sex Class (g)Date Remarks
519 male adu 1t 1440 22 Au g 80 Testes scrotal
23 Aug 80 Released from trap
25 Sep 80 Released from trap
520 male adult 1370 27 Au g 80 Testes scrotal
518 male adult 1380 9 Sep 80 Testes receding
1120 25 Nov 80 Transmitter de ad,
last heard 12 No v,
transmitter re-
placed
516 male ?1260 2 Nov 80 Th is animal caught by
a trapper on 28 Nov.
.~-.::1 ~':~~~1i
( a )
TABLE 3.28:OCCURRENCE OF BEAVER SIGNS ALONG THREE SECTIONS OF THE LOWER
SUSITNA RIVER
____________________~B.eaver Sign
River Kilometers Number Cuttings Number Houses
Section Surveyed Cuttings per Km Houses per Km
Section I 62 12 .19 2 .03
(b)
Section II 30 7 .23 (.46)2 .06 (.12 )
Section I I I 26 16 .62 (1.86)4 .15 (.45 )
Entire Survey 118 35 .30 8 .07
a.Section I:Devil Canyon to Confluence with Talkeetna and Chulitna Rivers,
Section II:Confluence with Talkeetna and Chulitna Rivers to Confluence with
Montana Creek,Section 111:Confluence with Montana Creek to Delta Islands
b.Numbers in parenthesis are adjustments to realistically reflect signs
present in Sections II and III.Signs were multiplied by a correction
factor of 2 in Section II and a factor of 3 in Section III.The in-
creasing width and braiding of the river permitted the team to see
approximately half the signs in Section II and only a fourth to a third
in Section III.
TABLE 3.29:RESULTS OF OTTER AND MINK SURVEYS,SUSITNA RIVER,10 THROUGH 12
NOVEMBER 1980.NUMBERS OF TRACKS OF EACH SPECIES OBSERVED AT NORTH
AND SOUTH SIDE S OF 37 RIVER CHECK POINTS(a)
Checkpoint North South--------
Numbers Otters Mink Otters Mink ~';";
01 3 0 0 0
02 0 2 0 0
03 0 0 0 0
04 0 0 3 1
05 0 0 2 0
06 0 0 0 0
07 0 1 0 1
08 0 0 0 2
09 0 0 1 0
10 0 0 0 2
11 4 1 0 1
12 3 1 0 0 P:"
13 0 0 0 1
14 2 0 3 1
15 0 0 4 0
16 3 1 0 2
17 0 3 0 4
18 0 0 0 2
N'
19 0 0 1 2
20 2 0 1 0
21 1 1 0 0
22 0 0 0 0
23 2 1 0 2
24 0 0 0 0
25 0 0 0 0 I""'·"·'
26 0 0 0 0
27 0 0 4 0
28 0 0 4 0
29 0 0 0 2
30 0 0 0 0
31 0 0 0 0
32 0 0 0 3 t""'""
33 0 2 0 3
34 0 1 0 2
35 0 1 2 3
36 0 0 2 2
37 0 1 0 2
a.See Figure 3.20 for location of checkpoints
F'Fr\
TABLE 3.30:TABULATIONS OF NOVEMBER,1980 AERIAL SNOW TRANSECT DATA,
INDICATING THE DISTRIBUTION OF FURBEARER TRACKS,BY SPECIES
NOTED IN VARIOUS VEGETATION TYPES
Species
Short-Vegetation
Vegetation(a)Pine Re d Tailed River Type
Type Marten Fox Weasel Mink Otter Totals
White Spruce For est 35 1 4 0 0 40
Birch Forest 3 0 2 0 0 5
Poplar Forest 0 0 1 0 0 1
Black Spruce Forest 0 2 0 0 0 2
Mixe d Forest 54 0 1 0 0 55
,.....Mat &:Cushion Tundra 3 5 29 0 0 37,
l Sedge-grass Tundra 7 3 0 0 0 10
White Spruce Woodland 525 5 88 1 0 619
Black Spruce Woodland 605 61 401 3 1 1071rMixedWoodland2905 0 0 34
Low Shrub 12 9 8 0 0 29
Medium Sh rub 35 108 190 0 0 333
r-AIder Shrub 25 2 11 0 0 38,
River Ice (Including
She 1 f Ice)2 1 2 20 20 45
Lake Ice 0 4 0 0 0 4
Creek Ice 6 0 2 4 2 14
Mar sh 3 4 0 3 0 10
River Bar 9 8 1 3 7 28
Rock 0 0 1 0 0 1
r Species Totals 1353 213 746 34 30 2376
I
{
r-I a.0-10%Forest Canopy Cover Sh rubI=I 11-60%Forest Canopy Cover Woodland=
60+%Forest Canopy Cover =Forest
25+%Secondary Tree Species =Mixed
____--=-T.:..:A.::.BLE 3.31:
Common loon
Gavia immer------
Arct ic loon
Gavia ~ctic.!!
Red-throated loon
Gavia stellata
COMMON AND SCIENTIFIC NAMES OF BIRDS MENTIONED IN TEXT
Blue-winged teal
Anas discors-------
American wigeon
Anas americana
Northern shoveler
Anas clypeata
Red-necked grebe
Podiceps grise gena
Horned grebe
Podic~auritus
Whistling swan
Olor columbianus
Trumpeter swan
Olor buccinator
Br ant
Branta bernicla
Canada goose
Bran!..!!canadensis
White-fronted goose
Anser albifrons
Snow goose
Chen caerulescens
Mallard
Anas platyrhynchos
Gadwall
Anas strepera
Pintail
Anas acuta
American green-winged teal
Anas crecca carolinensis
Re dhe ad
Aythya americana
Ring-necked duck
Aythya £ollaris
Canvasback
Aythya valisineria
Greater scaup
Aythya marila
Lesser scaup
Aythya affinis
Common goldeneye
Bucephala clangula
Barrow's goldeneye
Bucephala isl.!!~ic.!!
Bufflehead
Bucephala albeola
Oldsquaw
Clangula ~mali~
Harlequin duck
Histrionicus histrionicus
White-winged seater
Melanitta deglandi
Surf seater
Melanitta perspicillata
fl:"·--'
.....
-
r
I
Black scoter
Melanitta nigra
Common merganser
Mergus merganser
Red-breasted merganser
Me~serrator
Goshawk
Accipiter gentilis
Sharp-shinned hawk
Accipiter striatus
Red-tailed hawk
Buteo jamaicensis
Golden eagle
Aguila chrysaetos
TABLE 3.31 -Page 2 of 5
Ruffed grouse
Bonas.!!umbellu~
Willow ptarmigan
Lagopus l..!!.9~
Rock ptarmigan
Lagopus mutus
White-tailed ptarmigan
1.!!.9.Q..P..!!..§.leucurus
Sandhill crane
Grus canadensis
American golden plover
Plu~ialis dominica
Surfbird
~!:!.!.iza vir.9..!!!..!!
I"""
I
-r
(::
Bald eagle
Haliaeetus leucocephalus
Marsh hawk
Circus cyaneus
Osprey
Pandion haliaetus
Gyrfalcon
Falco rusticolus
Peregrine falcon
Falco peregrinus
Merlin
Falco columbarius
American kestrel
Falco sparverius
Spruce grouse
Canachites canadensis
Semipalmated plover
Charadrius semipalmatus
Common snipe
Capella Q.!!llinago
Whimbrel
Numenius phaeopus
Upland sandpiper
Bartramia longicauda
Spotted sandpiper
Actitis macularia
Solitary sandpiper
Trin.9..!!solitaria
Greater yellowlegs
l£inga malanoleuca
Lesser yellowlegs
1£i n.9..!!fl a v.iP.~
Wandering tattler
Heteroscelus incanus----
Pectoral sandpiper
Calidris melanotos
Baird's sandpiper
Calidris bairdii
Least sandpiper
Calidris minutilla
Semipalmated sandpiper
Calidris pusilla
Sanderling
Calidris alba-----
Northern phalarope
.hQbipes .lQbat~
TABLE 3.31 -Page 3 of 5
Short-eared owl
Asio flammeus
Boreal owl
~goli~funereus
Belted kingfisher
Megaceryle alcY.Q.!!
Common flicker
Colaptes auratus
Hairy woodpecker
Picoides villosus-----
Downy woodpecker
Picoides ~bescens
Black-backed three-toed woodpecker
Picoides arcticus------
Long-billed dowitcher
Limnodromus ~col02i!.£eus
Long-tailed jaeger
Stercorarius longicaudus
Herring gull
l.§rus argentatus
Mew gull
l.§.E.~can us
Bonaparte's gull
Larus phila.!!~hia
Arctic tern
Sterna paradisea
Great horned owl
~ubo virginianus
Hawk owl
Surnia ulu1...§.
Northern three-toed woodpecker
Picoid~tridactylus
Eastern kingbird
lIT2.!!nus ~2.!!nus
Say's phoebe
~ornis ~
Alder flycatcher
Empidonax alnorum
Olive-sided flycatcher
Nuttallornis borealis
Western wood pewee
Contopus sordidulus
Horned lark
Eremophila ~estris
Violet-green swallow
Tachycineta thalassin.§.
-
I"""r
Bank swallow
Riparia riparia
Tree swallow
Iridoprocne bicolor
TABLE 3.31 -Page 4 of 5
Wheatear
Oenanthe oenanthe
Townsend's solitaire
~estes townsendi
......
......
r
Cliff swallow
Petrochelidon QY£rhonota
Gray jay
Perisoreus canadensis
Black-billed magpie
Pica pica
Common raven
Corvus corax
Black-capped chickadee
Par~atricapillus
Boreal chickadee
Parus hudsonicus
Brown creeper
Certhia familiaris
Dip per
Cinclus mexicanus-----
American robin
Turdus migratorius
Varied thrush
Ixoreus naevius----
Hermit thrush
Catharus guttata
Swainson's thrush
Catharus ustulatus
Gray-cheeked thrush
Catharus minimus
Arctic warbler
Phylloscopus borealis
Golden-crowned kinglet
Regulus satrapa
Ruby-crowned kinglet
Regulus calendula
Water pipit
Anthus spinoletta
Bohemian waxwing
Bombycilla garrulus
Northern shrike
Lanius excubitor
Orange-crowned warbler
Vermivora celat~
Yellow warbler
Dendroica petechia
Yellow-rumped warbler
Dendroica coronata
Blackpoll warbler
Dendroica striata
Northern waterthrush
Seiur~noveboracensis
Wilson's warbler
Wilsonia pusilla
Rusty blackbird
Euphagus carolinus
Pine grosbeak
Pinicola enucleator
Gray-crowned rosy finch
Leucosticte tephrocotis
Common redpoll
Carduelis flammea
Pine siskin
Carduelis pinus
White-winged crossbill
l.Qxia leucoptera
TABLE 3.31 -Page 5 of 5
White-crowned sparrow
Zonotrichia leucophr~
Golden-crowned sparrow
Zonotrichia atricapilla
Fox sparrow
Passerella iliaca
Lincoln's sparrow
Melospiza lincolnii
Lapland longspur
Calcarius lapponicus
Savannah sparrow
Passerculus sandwichensis
Dark-eyed junco
Junco ~malis
Tree sparrow
Spizella ~borea
Smith's longspur
Calcar ius pictus
Snow bunting
Plectrophenax nivalis
~~~]~~~1 ---1 1 --].---1 ~--]-.,--_....]-1 1 --------)--1 ]
TABLE 3.32:RELATIVE ABUNDANCE OF LOONS,GREBES,AND WATERFOWL,UPPER SUSITNA RIVER BASIN,ALASKA,
BASED PRIMARILY ON TOTAL NUMBER OBSERVED ON 1980 and 1981 AERIAL SURVEYS AND 1981
GROUND SURVEYS
Spring Migration Fall Migration Summer
(Aerial &Ground,
1981)
No.Species
(Aerial:7 Sept-3 Oct 80
15 Sept-23 Oct 81)
No.Species
(Ground,1981)
No.Species
262 Am,"'.o "g,oo J
215 Green-winged teal
210 Scoter spp.FAIRLY
140 Goldeneye spp.COMMON
102 Oldsquaw
Merganser spp.
Snow goose (=1 flock)
Canada goose
Northern shoveler
Swan spp.
Redhead
Bufflehead
Common loon
Arctic loon
White-fronted goose
Red-necked grebe
Canvasback
Red-throated loon
Horned grebe
3 Blue-winged teal]
3 Gadwall
2 Ring-necked duck
2658 Scaup spp.--COMMON
905 Mallard l874Americanwigeon
718 Goldeneye spp.FAIRLY
551 Scoter spp.COMMON
514 Bufflehead
UNCOMMON
FAIRLY
COMMON
16 Northern shoveler
11 Red-breasted merganser
8 Red-throated loon
8 Barrow's goldeneye
7 Red-necked grebe
7 Common goldeneye
5 Horned grebe
5 Common merganser
4 Arctic loon
94 Scaup
(incl.41 Lesser,
27 Greater)
81 White-winged seater
(inc!.flock of 65)
60 Pintail
59 Trumpeter swan(a)
55 Oldsquaw
47 Mallard
33 Sur f seater
32 American wigeon
28 Green-winged teal
26 Black seater
25 Common loon
24 Harlequin duck
RARE
UNCOMMON
Ring-necked duck (1980)J
Blue-winged teal (1980)
Merganser spp.
Swan spp.
Pintail
Green-winged teal
Oldsquaw
Canada goose
Horned grebe (1980)
Red-necked grebe
Northern shoveler
Common loon
14
1
299
277
233
142
111
71
35
33
28
17UNCOMMON
RARE
COMMON
Scaup spp.J-
Mallard
Pintail
52
51
46
43
43
31
23
11
8
6
5
4
3
3
802
394
366
a.40 from aerial survey
TABLE 3.33:RELATIVE ABUNDANCE OF LARGE LANDBIRDS AND CRANES,UPPER
SUSITNA RIVER BASIN,ALASKA,BASED PRIMARILY ON TOTAL NUMBER
OBSERVED 17 APRIL-23 OCTOBER 19B1,EXCLUDING OBSERVATIONS
FRO M AI R-"-Cc...oR.;..;A_F-'.T _
No.Species F'~'"
182 Rock Ptarmigan I pi"''''',
I
139 Common Rave n I COMMON
I
137 Willow Ptarmigan J %'?""',
71 Golden eagle I
I
52 Spruce grouse I FAIRLY COM Mo N
I
40 Marsh hawk J
I
27 Bald eagle I
I
21 White-tailed ptarmigan I
I peT"
16 Goshawk I
I
15 Sandhill Crane I
I ,...:.
07 Gyrfalcon I UNCOMMON
I
07 Gre at horned owl I !"",',O-,",
I
07 Short-eared owl I
I
06 Red-tailed hawk I
I
03 Merlin I
I P;::S:'I
02 Sharp-shinned hawk I
I
02 Hawk owl J
01 Osprey I
I ~-,~
01 American kestrel (1980)I
I RARE
01 Ruffed grouse I
I
01 Boreal a wI J
p;c-
....
i
TABLE 3.34:RELATIVE ABUNDANCE OF SHOREBIRDS AND GULLS,UPPER
SUSITNA RIVER BASIN,ALASKA,BASED PRIMARILY ON TOTAL
NUMBER OBSERVED 17 APRIL-23 OCTOBER 1981,BUT
SUPPLEMENTED BY DATA FROM LATE SUMMER AND FALL
1981 FOR RARE SPECIES
-
-,
-i
No.
163
146
114
103
78
69
58
55
51
44
34
22
20
19
17
12
09
09
06
03
06
01
01
Species
Mew gull I
I
American golden plover I
I
Common snipe I
I
Spotted sandpiper J
Northern phalarope I
I
Arctic tern I
I
Lesser yellowlegs I
I
Long-tailed jaeger I
I
Least sandpiper J
Bonaparte's gull I
I
Baird's sandpiper I
I
Semipalmated plover I
I
Herring gull I
I
Greater yellowlegs I
I
Whimbrel I
I
Semipalmated sandpiper I
I
Wandering tattler I
I
Pectoral sandpiper I
I
Solitary sandpiper I
I
Long-billed dowitcher J
Upland sandpiper (1980)I
I
Surfbird (1980)I
I
Sanderling (1980)J
COMMON
FAIRLY COMMON
UNCOMMON
RARE
TABLE 3.35:RELATIVE ABUNDANCE OF SMALL LANDBIRDS,UPPER SUSITNA RIVER BASIN,ALASKA,BASED PRIMARILY ON
TOTAL NUMBER OBSERVED 17 APRIL-23 OCTOBER 1981,SUPPLEMENTED BY DATA FROM LATE SUMMER AND FALL
1980 FOR THE LESS NUMEROUS SPECIES
No.Species No.Species No.Species
Horned lark
Dark-eyed junco
Ruby-crowned kinglet
Yellow-rumped warbler
Water pipit
Varied thrush
Gray jay
Wilson's warbler
Bohemian waxwing
American robin
Hermit thrush
1 Black-backed three-I
toed woodpecker (1980)I RARE
4 Western wood pewee (1980 I
2 Yellow warbler (+3 in I
1980)J
1 Eastern kingbird
(1980)--ACCIDENTAL
UNCOMMON
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
Brown creeper I
Hairy woodpecker I
Orange-crowned warbler I
Pine grosbeak I
Say's phoebe I
Northern shrike (+27 in 1980)I
Townsend's solitaire (+4 in 1980)1
Smith's longspur (+5 in 1980)I
Downy woodpecker (+8 in 1980)I
Golden-crowned kinglet (+11 in I
1980)J
53 Bank swallow
46 Cliff swallow
45 Gray-crowned rosy finch
42 Black-capped chickadee
41 Golden-crowned sparrow
35 Lincoln's sparrow
33 Rusty blackbird
29 Dipper
26 Pine siskin
23 Northern three-toed woodpecker
23Wheatear
22 Black-billed magpie
16 Belted kingfisher
16 Olive-sided flycatcher
14 Alder flycatcher
13 Common flicker
11
10
10
09
05
03
02
02
01
01
ABUNDANT
COMMON
I
I
I
II FAIRLY
II COMMON
I
I
I
J
Common redpoll I
Savannah sparrow I
Whi te-crowned sparrow I
Lapland longspur I
Tree sparrow J
I
I
I
I
I
I
I
I
I
I
J
White-winged crossbill
Fox sparrow
Swainson's thrush
Blackpoll warbler
Boreal chickadee
Snow bunting
Arctic warbler
Tree swallow
Violet-green swallow
Northern waterthrush
Gray-cheeked thrush
420
398
343
316
288
258
257
249
225
211
195
179
163
146
145
129
98
71
64
62
55
54
1161
669
631
588
583
~J ~i
TABLE 3.36:AVIAN HABITAT OCCUPANCY LEVELS,UPPER SUSITNA RIVER
BASIN,BREEDING SEASON,1981
Density
No •species (No.Biomass Species
(No.breeding territories/(Grams/diversity
Avian Census Plot species)10 ha)10 ha)( H' )
Cottonwood Forest 21(16 )60.9 3653 2.55
Mixed Deciduous-~22(13)Coniferous Forest I I 34.6 1836 2.07
Mixed Deciduous-
r""Coniferous Forest I 18(14)41.8 1709 2.47
i,
Paper Birch Forest 18(10)38.1 1814 2.05
White Spruce
Scattered Woodland 23(16)43.8 177 5 2.29
"""Black Sp ruceI
{Dwar f Forest 23(13)24.B 1166 2.43
Low-Medium
Willow Shrub 14(6)45.4 1413 1.56
r-White Sp ruce Forest IB(8)15.7 1059 1.8 3
Medium Birch Shrub 10 (5)32.5 952 1.48
!""'"Ta 11 Alder Sh rub 15(10)12.5 888 2.05
Dwarf-Low Birch
Shrub 11 (6)10.6 355 1.29
Alpine Tundra 8 (7)3.9 211 1.73
-
-
-
pr:llIl,
I
!
TABLE 3.37:NUMBER or TERRITORIES or EACH BIRD SPECIES ON EACH 10-HECT ARE CENSUS PLOT,
UPPER SUSITNA RIVER BASI.!!L ALASKA,19B1
White White Wh I te Black
Dwarf-Low Medium Low-Medium Tall Spruce-Sp ruce Sp r uce Spruce
BIrch Birch WIlla w AI de r Cotton-Paper Paper Paper Whi t e Scattered Dwarf
Alp Ine Shrub Shrub Shrub Sh rub Wood Birch Birch Birch Sp ruca Woodland forest
Species Tundra ThIcket Thicket Thicket Thicket forest forest fareet I forest II forest
Pintail J61
Goshawk
Mar sh hawk
Spruce grouse v v v 1.0 1.0 v
Ruf fe d grouse +(a)
Willow ptarmigan 0.5
Rock ptarmigan 0.7
White-tailed ptarmigan +
American golden plover
Greater ye IIo wIegs +
Common snipe v v 0.5 1.0
Baird's sandpiper O.B
Long-tailed jaeger
Short-eared owl
Common flicker
Hairy woodpecker 1.0 1.0
Downy woodpecker 0.5
N.three-toed woodpecker v 0.3 1.0
Alder flycatcher
Oliva-aidad flycatcher 1.0
Horned lark 0.3
Tree swallow
Gray jay 1.0 v 0.5 0.5 1.0 +
BIack-bIIIad magpIe
Common raven
Black-capped chickadee I.B
Boreal chickadee v 1.7 1.0 v v 1.0
Brown creeper 2.0 1.0
American robin 0.5 v v 0.5 0.5
Varied thrush 1.5 10.0 3.5 2.5 3.3 2.9
Hermit thrush 2.2 v 6.I 3.B
Swainson'a t h rush 6.9 5.5 5.4 B.O 3.0
Gray-cheeked thrush 3.B v v 3.9 2.5
Arctic warbler 4.B 3.6 2.B
Ruby-crowned kInglet v v 3.3 1.0 4.2 O.B 4.0
Water pipit 0.5
Bohemian waxwing
Orange-crowned warbler
Yellow-rumpad warbler +7.0 9.B 7.5 9.5 1.0 O.B 2.5
BIackpoIl warbler v 4.4 3.9 I.B 0.5 2.0 1.5
Northern watBrthrush 6.1 +2.5
Wilaon's warbler B.B 9.2 1.2 4.0 3.B 4.0 9.4
Ruaty blackbIrd
Common redpoll v v 1.5 v 2.5 2.0 2.0 3.0 v 0.5 1.0
Pine siskin
White-winged croasbill
Savannah sparrow 1.0 5.B 3.0 12.3 v 2.5 O.B
Dark-eyed junco 2.B I.B 2.5 3.9 4.5 2.5 2.0 2.0
Tre e sparrow 2.5 II.B 15.0 1.5 7.9 2.6
Whiie-crowned sparrow 0.3 4.1 3.B +3.5 6.5 2.5
rox sparrow v 1.6 4.6 1.0 1.9 v 3.5 2.9
Lincoln's sparrow
Lapland longspur 1.0 0.8
Snow bunting 0.2
a.Small portion of a breeding territory on census plot,counted aa 0.1 in density and diveraity calculationa
b.Visitor to plot
"i ~
r
TABLE 3.38:NUMBER OF ADULT WATERBIRDS (OR INDEPENDENT YOUNG)AND BROODS
FOUND ON 28 WATERBODIES (TOTAL =20.5 KM 2 OF WETLANDS),
_______...;::u;..;..P-'-P-=E..:..:R--e:;.S;..;..u S IT NA RI VER BAS l!:h ALAS ~.::.U.:.L...:..Y-=-I.::..9.:;.B-=-I _
Species (a)No.Adu Its No.Broods
-
.....,
r
"'"'i
i
r
I
[
White-winged seater 81 (incl.flock 65)0
Arctic tern 48 0
oldsquaw 47 11
Mew gull 43 7
Les se r scaup 36 4
Scaup sp.9 1
Surf seater 33 2
Black seater 26 11
Seater sp.6 1
Greater scaup 25 0
Northern phalarope 23 0
Common loon 22 3
Trumpeter swan 16 1
Mallard 10 1
Red-throated 100 n.8 0
American wigeon 8 6
Red-necked grebe 7 1
Pintail 7 2
Northern shoveler 7 1
Goldeneye sp.6 I(Common goldeneye)
Horned grebe 5 5
Bonaparte's gull 5 0
Bald eag Ie 3 0
Arctic loon 2 0
Green-winged te al 2 1
Red-breasted merganser 1 1
Merganser sp.1 _0_
TOTAL 487 60
No./km 2 23.8 2.9
a.Arranged in decreasing order of adult numbers.
TABLE 3.39 :SUMMARY OF TOTAL NUMBERS AND SPECIES COMPOSITION OF WATERBIRDS SEEN ON SURVEYED WATERBODIES
DURING AERIAL SURVEYS OF THE UPPER SUSITNA RIVER BASI~FALL 1980
DA TE OF SURVEY
Species 7 Sept 11 Sep t 16 Sep t 20 Sep t 26 Sep t 3 Oct TO TA l
Loon spp.4 1 5
Common loon 3 2 3 8
Red-necked grebe 2 3 4 5 3 17
Horned grebe 1 4 17 9 2 2 35
Swan spp.34 29 9 12 20 104
Canada goose 1 20 21
American wigeon 155 325 97 8B 56 721
Green-winged teal 30 B3 9 1 2 125
Mallard 10 64 14 116 110 124 438
Pintail 60 60 53 21 3 4 201
81ue-winged teal 1 1
Northern shoveler 8 20 28
Ring-necked duck 2 12 14
Scaup spp.165 347 499 370 293 180 1854
01dsquaw 7 4 13 13 16 4 57
Black seater 8 38 25 24 10 105
Seater spp.(a)6 56 72 134
Surf scoter 5 4 2 11
White-winged seater 10 1 6 1 18
Bufflehead 33 40 95 127 101 396
Goldeneye spp.15 36 68 124 95 133 471
Merganser spp.8 30 36 ~19 161---
TOTAL BIRDS 270 803 1241 953 927 731 492 5
Total wetland area
surveyed (km 2 )13.11 22.08 25.76 27.53 29.00 24.25
Density (birds!km 2
of wetlands)20.6 36.4 48.2 34.6 32.0 30.1
a.Surf or White-winged seater
'1 11 1 J ..~]"j
1 ~'-1 ,------')1 1 ."--1 ,·-----1 ----1 ~---J 1 ~----1 r-'l
TABLE 3.40:SUMMARY OF TOTAL NUMBERS AND SPECIES COMPOSITION OF WATERBIRDS SEEN ON SURVEYED WATERBODIES
DURING AERIAL SURVEYS OF THE UPPER SUSITNA RIVER BASI~~F~A~L~L~1~98~1 ___
DATE OF SURVEY
Species ,15-16_S~pL _2.§.~t 26 Sept-9 Oct 12-19 oct 20-23 oct TOTAL
Common loon
Arctic loon
Red-throated loon
Loon spp.
Red-necked grebe
Horned grebe
2
12
3
3
3
1
1 9
16
Whistling swan
Trumpeter swan 6
Swan spp.
Canada goose
Mallard 41
Pintail 32
Green-winged teal 13
Northern shoveler
American wigeon 133
Canvasback
Redhead
Scaup,greater and lesser 479
Goldeneye,common &Barrow's 18
Buff lehead 17
01dsquaw 15
White-winged seater
Surf seater
Black seater 1
Seater spp.69
Common merganser
Red-breasted merganser
Merganser spp.77
18
41
153
3
166
125
20
31
6
38
24
10
25
131
14
51
68
29
7
69
2
1
1
14
22
50
142
5
90
36
52
1
13
29
1
92
2
~
13
42
30
101
50
467
32
16
152
786
247
118
54
82
29
10
162
3
133
TOTAL BIRDS
Total wetland ~rea
sur veyed (km )
Km 2 of 100%frozen
waterbodies surveyed(a)
Density (birds km 2 of
wet lands
915
25.68
o
35.6
607
25.68
1.41
23.6
436
21.31
3.91
20.5
568
11.57
3.76(b)
49.1
13
6.62
2.00
1.96
2539
a.Other waterbodies had at least some open water.
b.An additional 9.22 km 2 of 100%frozen waterbodies were not surveyed in mid-October because they were known
to be frozen.By late October only Stephan Lake and one adjacent lake still had some open water.
TABLE 3.41:SUMMARY OF TOTAL NUMBERS AND SPECIES COMPOSITION OF WATERBIRDS SEEN ON SURVEYED WATERBODIES
______________~D~U~R~I~N=G AERIAL SURVEYS OF THE UPPER SUSITNA RIVER BASI~N~!~S~P~R~I~N,~G~!~1~9~8~1~_
DATE OF SURVEY
~ies 3 May 10 May 26 May TOTAL
Common 100 n 4 4
Arctic 100 n 5 5
Red-throated 2 2
Loon spp.3 4 7
Red-necked grebe 4 4
Horned grebe 1 1 2
Whistling swan
Trumpeter swan 2 6 8
Swan spp.11 10 21
Canada goose
Mallard 97 78 121 296
Pintail 71 70 116 257
Green-winged teal 67 47 38 152
Northern shoveler 12 28 40
American wigeon 5 94 99 198
Canvasback 1 1
Redhead 28 28
Scaup!greater and lesser 103 513 616
Goldeneye,common and Barrow's 51 38 89
Bufflehead 2 10 12
Oldsquaw 2 84 86
White-winged scoter 16 16
Sur f scoter 4 35 39
Black scoter 1 42 43
Scoter spp.12 74 86
Common me r ganser 7 7
Red-breasted merganser 2 2
Merganser spp.--------25 -~
TOTAL BIRDS 242 492 1312 2046
Total wetland area surveyed (km 2 )25.68 25.68 25.68
Km 2 of 10 O~~fr ozen waterbodies
surveyed (a)14.31 1.97 0
Density (birds/km 2 of wetlands)9.4 19.2 51.1
a.Other waterbodies had at least some open water.
)l ~l ]1 \i ,7l 1 ~H ~-1 :1 ~~]J I 2J :J 1 -,
TABLE 3.42:
.....
~
!
WATERFOWL NOTED ALONG THE SUSITNA RIVER BETWEEN DEVIL CANYON
________"'"'A--'N..;..D_C 00 KIN LE..:..T.L.t -..:...7~M A",-,-Y---=-19::...8;:...1=--_
Devil Canyon to Talkeetna
r
I
I
Mallard
Pintail
American
American
18
13
green-winged
wigeon - 2
teal -34
Talkeetna to Montana Creek
Canvasback
Goldeneye spp.
Merganser spp.
2
-11
7
r'"
i
Mallard 23
American green-winged teal
Scaup spp.2
5
Goldeneye spp.
Bufflehead - 2
Merganser spp.
6
6
(a)
Montana Creek to Kashwitna Lake
Mallard 23 Goldeneye spp.2
Pintail 3 Bufflehead -14,.....American green-winged teal 3 Scoter spp.2
American wigeon 14 Merganser spp.61
~i
r Mallard 7
American wigeon 4
( a )
Kashwitna Lake to Yentna River
Yentna River to Cook Inlet
Goldeneye spp.
Merganser spp.
3
8
I
I""'"
I
i
a.
r
I
....
I
rI,
I""'"
[
Loon spp.8 Mallard 2
Grebe spp.4 American wigeon 9
Swan spp.60 Canvasback 4
Canada goose 1 Scaup spp.100
Brant 2 Goldeneye spp.10
Wh i te-fronted goose 80 Merganser spp.172
Geese 8pp.9
Approximately halfway between Kashwitna River and Willow Creek.
TABLE 3.43:LOCATION OF ACTIVE RAPToR AND RAVEN
Substrate ( a )
elevation Active
Nest Species m (feet)1980 1981
A Bald eagle 490 (1600)X 0
B Bald eagle 690 (2260)X X
NEST SITES,UPPER SUSITNA RIVER BASIN~ALASKA,1980 AND 1981
Nest Location
8.0 km up Susitna River from the mouth of Watana Creek.On
wooded island in live,15 m white spruce.
4.5 km up oshetna River from its confluence with the Susitna
River.Nest 4 m from edge of west river bank in a 22 m
white spruce.
C Golden eagle 750 (2450)X 0 3.5 km upriver from Vee Ca nyo n and O.7 km up a narrow canyon
on the north side oft he Susitna River.Ne st 26 m up a 33 m
cliff,100 m back from and 6.7 m above unnamed creek.
D Golden eagle 700 (2300)X 0 4.0 km up the Susitna River from the mouth of Jay Creek an d
in canyon on north side a f the Susitna.Nest 5 m up 13 m
cliff,10 m back from and 18 m abo ve unnamed creek.
E Golden eagle 640 (2100)X X 2.5 km up Ja y Creek from its junction with Susitna River.
Nest 5 m up 30 m cliff,150 m from west bank and 115 m abo ve
Jay Creek.
F
G
H
Golden eagle
Golden eagle
Unknown
550 (1800)
490 (1600)
490 (1600)
X
X
X
o
o
o
1.0 km down Susitna River from the mouth of Kosina Creek.
Nest 32 km up 38 m cliff on north riverbank.
4.0 km down Susitna River from the mouth of Watana Creek.
Nest 13 m up 23 m cliff,40 m back from and 34 m above the
north bank of the river.
6.8 km down Susitna River from mouth of Devil Creek and 4.0
km up a gorge on south side of the Susitna.Nest 100 m up
105 m cliff of creek canyon.Occupied by a gyrfalcon in
1974 (White 1974).
a.X =active
o =inactive
=site not located in 1980
1
J --~-l --J -J -J J --1 -~J -...1 --:)---]____)1 ._~~]1
TABLE 3.43 -Page 2 of 3
1980 1981NestSpecies
Substrate
elevation
m (feet)
Active
(a)
Nest Location
I
J
K
Golden eagle
Raven
Bald eagle
365 (1200)
520 (1700)
760 (2500)
x
x
x
x
?
x
0.5 km up Devil Creek from its mouth.Nest 30 m up 45 m
vegetated cliff,100 m back from and 120 m above Devil
Creek,on west bank.
1.0 km up Devil Creek from its mouth.Nest near top of cliff
of west bank.Could not relocate nest in 1981.
9.0 km up Deadman Creek from its mouth.Nest on top of 15 m
broken-topped cottonwood,25 m from north side of Deadman
Creek.
L Bald eagle 275 (900)X X 1.0 km up Susitna River from confluence with Indian River.
Nest on top of 23 m broken-topped cottonwood,4 m from north
river bank.
M Golden eagle 305 (1000)-X 2.0 km up Susitna Rive r from the mouth of Po rt age Cr ee k.
Nest on moderate-sized cliff on north bank,but not relocat-
ed on ground check.
N Bald eagle 580 (1900)-X On south shore of sma 11 lake,1.0 km east of NE end 0 f
Stephan Lake.Nest on top of 13 m broken-topped cottonwood.
0 Raven 470 (1550)-X 2.0 km up Fog Creek fr om mouth.Nest 9 m up 23 m cli ff on
west bank,17 m back from an d 23 m above c re e k.
P Raven 550 (1800)-X 5.0 km up Tsusena Creek from mouth.Ne s ton cliff on east
bank of creek.
Q Raven 625 (2050)-X 1.0 km up Deadman Cr eek from mouth.Nest 13 m up 32 m cliff
on east bank of creek.
R Golden eagle 975 (3200)-X 8.0 km down Susitna River from the mouth of Kosina Creek.
Nest 7 m up 12 m cli ff on tor abo ve sout h bank of river.
Nest Species
Substrate
elevation
m (feet)
TABLE 3.43 -Page 3 of 3
( a )
__~cti~
1980 1981 Nest Location
5
T
Bald eagle
Golden eagle
540 (1775)
685 (2250)
o
o
x
x
2.0 km up Susitna River from the mouth of Kosina Creek.
Nest 25 m up 33 m cliff on north bank of river.
4.0 km up Susitna River from the mouth of Jay Creek,in can-
yon on north side'of river.Nest 1 m up 5 m vegetated cliff,
14 m back from and 33 m above unnamed creek.
u Gyr fa Icon 71 5 (2350)x At Vee Canyon.
Susitna River.
Nest 100 m up 113 m cliff at south bank of
V
00
Golden eagle
Goshawk
750 (2450)
550 (1800)
o x
x
3.5 km up Susitna River from Vee Canyon and 0.7 km up narrow
canyon on north side of Susitna River.Nest 8 m up 12 m
cliff,81 m back from and 67 m above unnamed creek.
2.0 km southwest of Devil Canyon dam site.
'1 'j 1 ~11 '1 1 \1 ~"]JI)J
r
I
TABLE 3.44:BALD EAGLE OBSERVATIONS NOTED DURING THE 26 JUNE 19B1 FLIGHT ALONG THE
____________~S~USITNA RIVER FROM COOK INLET TO POR_T~A~G=E-=C~R=E=E~K __
r
r
r
Observation Range Township
Active nest 7W 16N
Active nest 7W 16N
1 adult bird 6W IBN
1 immature bird 6W IB N
Active nest 6W 19N
1 adu It bird 5W 20N
1 adult bird 5W 22N
Active nest 5W 22N
Active nest 5W 22N
1 adu It bird 5W 24N
Active nest 5W 25N
1 adu It bird 5W 25N
Active nest 5W 26N
Active nest 3W 30N
1 immature bird 2W 31N
1 immature bird 2W 3lN
Active nest 2W 31 N
Comments
1 adult bird on nest
1 adult bird on nest
1 adult bird on nest
2 adult birds on nest
TABLE 3.45:BREEDING CHRONOLOGIES OF EAGLE~GYRFALCON~D COMMON RAVEN IN INTERIOR ALASKA
DATES OF PHASES OF BREEDING CYCLE
( a )
Species Status Arrival/courtship Egg-Laying Incubation Nestlings Fledging/dispersal
Golden eagle(b)M 5 Mar-3D Apr 1 Apr-IO May 15 Apr-20 June 1 June-l Sept 1 Au g-2 5 Sep t
Bald eagle(b)M/R 10 Mar-l May 20 Mar-IO May 30 Apr-3D June 20 May-15 Sept 1 Aug-3D Sept
Gyrfalcon(b)R 1 Mar-ID Apr 1 Apr-2D May 5 Apr-25 June 15 May-15 Aug 10 July-3D Sept
Raven(c)R 1 Mar-15 Apr 1 Apr-5 May 5 Apr-25 May 25 Apr-25 June 25 May-15 July
a.M =migrant,R =resident
b.Data summarized from Roseneau et al.(19Bl)
c.Based on calculations from Kessel (unpubl.data)and Brown (1974)
1 J j ~\\~11 l ~:1 J '1;j J 'J '])
-
,.....
I
r
I
l.
,...
I
i
r
TABLE 3.46:SPECIES OF SMALL MAMMALS FOUND IN THE UPPER SUSITNA RIVER BASIN,
ALAS KA,198 O-,-,-A.;.;.N~D-=.1.::..9~8.::.1 _
Order INSECTIVORA
Family Soricidae
Sorex cinereus,masked shrew
Sorex monticolus,dusky shrew
Sorex arcticus,arctic shrew
Sorex ~l,pygmy shrew
Order LAGOMORPHA
Family Ochotonidae
Ochotona collaris,collared pika
Family Leporidae
~~americanus,snowshoe hare
Order RODENTIA
Family Sciuridae
Marmota cali~~,hoary marmot
Spermophilus QarrYll,arctic ground squirrel
Tamiasciurus hudsonicus,red squirrel
Family Cricetidae
Clethrionomys rutilus,northern red-backed vole
Microtus pennsylvanicus,meadow vole
Microtus oeconomus,tundra vole
Microtus miuru~,singing vole
Lemmus sibiricus,brown lemming
~aptomys borealis,northern bog lemming
Family Erethizontidae
Erethizon dorsatu~,porcupine
TABLE 3.47:HABITAT LOCATIONS BETWEEN COOK INLET AND DEVIL CANYON SAMPLED
DURING THE JUVENILE ANADROMOUS AND RESIDENT F~I~S~H~S~T~U.~D~Y __
Estuary to Talkeetna
Alexander Creek
Anderson Creek
Kroto Slough Mouth
Mainstem Susitna Slough
Mid Kroto Slough
Deshka River
Delta Islands
Little Willow Creek
Rustic Wilderness
Kashwitna River
Caswell Creek
Slough West Bank
Sheep Creek Slough
Goose Creek
Mainstem Susitna West Bank
Montana Creek
Mainstem 1
Sunshine Creek
Birch Creek Slough
Birch Creek
Cache Creek Slough
Cache Creek
Talkeetna to Devil Can~
Whiskers Creek Slough
Whiskers Creek
Slough 6A
Lane Creek
Mainstem 2
Mainstem Susitna -Curry
Susitna Side Channel
Mainstem Susitna -Gravel Bar
Slough 8A
Fourth of July Creek
Slough 10
Slough 11
Mainstem Susitna Gold Creek
Indian River
Slough 20
Mainstem Susitna -Island
Portage Creek
Site
( a )
A,B,C
A,B,C
(b )
1,2
f"I'.'--'~
a.Letter designation indicates multiple sampling sites in that particular
region.
b.Number designation indicates two different sample locations near mouth
of Goose Creek.
,....
!
TABLE 3.48:COMMON AND SCIENTIFIC NAMES OF FISH SPECIES APPEARING IN THE TEXT
r
-
r
f
COMMON NAME
Arctic Lamprey
8ering Cisco
Lake Whitefish (Humpback whitefish)
Humpback Whitefish
Alaska Whitefish (Humpback whitefish)
Pink Salmon
Chum Salmon
Coho Salmon
Sockeye Salmon
Chinook Salmon
Round Whitefish
Rainbow Trout
Dolly Varden
Lake Trout
Sheefish
Arctic Grayling
Eulachon
Northern Pike
Longnose Sucker
Burbot
Threespine Stickleback
Sculpin
SCIENTIFIC NAME
Lampeta japonica
Coregonus laurettae
Coregonus clupeaformis
Coregonus pidschian
Coregonus nelsoni
Oncorhynchus gorbuscha
Oncorhynchus keta
Oncorhynchus kisutch
Oncorhynchus nerk~
Oncorhynchus tsawytscha
Prosopium cylindraceum
Salmo gairdneri
Salve linus malma--------
Salve linus namaycush
Stenodus leucichthys
Thymallus arcticus
Thaleichthys pacificus
Esox lucius
Catostomus catostomus
Lata Iota
Gasterosteus aculeatus
Cottus sp.
TABLE 3.49:APPORTIONED SONAR COUNTS OF CHINOOK SALMON BY SAMPLING STATION,
ANADROMOUS ADULT INVESTIGATIONS,1981
SAMP LI NG
LOCATION
Susitna Station
Yentna Station
Sunshine Station
Talkeetna Station
SONAR
OPERATING PERIOD
27 June-2 September
29 June-2 September
23 June-15 August
22 June -15 Au gu s t
CHINOOK SALMON
COUNTED
1,752
427
2,415
1,154
-'~)---1 -1 --1 ~]--oJ --1 --J ---]]-)-----1 _-______]
1 -]-1
TABLE 3.50 :APPORTIONED SONAR COUNTS AND PETERSEN POPULATION (TAG/RECAPTURE)ESTIMATES BY SPECIES AND
SAMPLING LOCATION,ADULT ANADROMOUS INVESTIGATIONS,1981
ESCAPEMENT ESTIMATES
SAMPLING SOCKEYE PINK CHUM COHO
LOCA TION Sonar Petersen Sonar Petersen Sonar Petersen Sonar Petersen
Susitna
Station 340,232 -113,349 -46,461 -33.470
Yentna
Station 139,401 -36,053 -19,765 -17,017
Sunshine
Station 89,906 130,489 72,945 49,501 59,630 262,851 22,793 19,841
Talkeetna
Station 3,464 4,809 2,529 2,335 10,036 20,835 3,522 3,306
Curry
Station -2,804 -1,041 -13,068 -1,146
~;",
TAS LE 3.51 :SUMMARY OF FISH WHEE L CATCHES BY SPECIES AND SAMPLING LOCATION,
ADULT ANADROMOUS INVESTIGATIONS,1981
F";.~-'
CATCH
SAMPLING
LOCATION SOCKEYE PIN K CHUM COHO f'T"."">
Susitna
Station 4,OB7 691 250 329
Yentna
Station 7,000 2,729 1,415 1,122
Sunshine
Stat io n 9,528 7,099 9,168 2,92B
Talkeetna
Station 398 379 1,2B 5 533
Curry
Station 470 229 1,276 IB 2 ~:
TABLE 3.52:PETERSEN POPULATION ESTIMATES AND CORRESPONDING 95%CONFIDENCE
INTERVALS OF SOCKEYE,PINK,CHUM,AND COHO SALMON MIGRATING TO
SUNSHINE,TALKEETNA AND CURRY STATIONS,ADULT ANADROMOUS
______.--::.I'-'-N~V.:::.E~S.TI GAT I °N~S..L'--=:.1~9~B..:.l --;-_
SP EC IE~S _
r
"""I
LOCATION OF
POPULATION
ESTIMATE
Sunshine
Station
Talkeetna
Station
Curry
Station
(a)
PARAMETER
m
c
r
N
95%C.l.
m
c
r
N
95%C.l.
m
c
r
N
95%C.l.
SOCKEYE
B,179
4,B31
296
133,489
120,219-
150,051
322
4,167
279
4,809
4,320-
5,424
356
3,040
386
2,804
2,565-
3,092
PINK
5,900
6,175
736
49,501
46,357-
53,101
258
724
80
2,335
1,935-
2,943
181
69
12
1,041
687-
2,143
CHUM
7,600
9,265
270
262,851
235,207-
297,859
1,142
5,944
333
20,835
18,413-
22,829
1,079
4,033
333
13,068
11,849-
14,566
COHO
2,240
2,845
347
19,841
18,061-
22,011
454
852
117
3,306
2,830-
3,975
131
105
12
1,146
748-
2,452
a.m =Number of fish marked (adjusted for tag loss)
c =Total fish examined for marks during sampling census
r =Total number of marked fish observed during sampling census
N =Population estimate
C.I.=Confidence interval around N
TAB LE 3.53 :ARC TIC GRAYLING TOTAL CATCH BY MONTH IN THE UPPER SUSITNA
RIVER DRAINAGE,1981.
TRIBUTARY MA Y JUNE JU LY AUGUST SEPTEMBER TO TAL
(a)
Fog Cree k 30 17 38 5 5 95
(a)
Tsusena Creek 23 75 133 53 9 293
~;.,
Deadman Creek 53 86 110 23 3 275
Watana Creek 4 52 18 184 55 313
Kosina Creek 139 263 238 73 177 890
Jay Creek 84 181 74 21 68 428
Goose Cree k 128 163 82 41 13 427
oshetna River 24 93 157 73 167 514
Sa lly Lake 13 4 26 43
Deadman Lake 1 1
TOTAL 498 934 850 499 498 3,279 1""'7;
a.Tr ibut ar ies in the proposed Devi 1 Canyon impoundment.
~I
1 )"---j '1 -----]--1 -J -1 -1 ]-)-1
TABLE 3.54:RANGES OR VALUES RECORDED FOR PARAMETERS MEASURED AT STUDY SITES IN THE SUSITNA RIVER AND ITS
TRIBUTARIES DURING THE SUMMER FIELD SEASO~N~I~1~9~8~1 ___
RIVER REACH
RivBr Mouth to TalkBBtna
TEMPER ATURE
(C 0 )
00
(mg/1)Ph
SPECIFIC
CONDUCTIVITY
(micromhos/cm)
TURBIDITY
(N TU )
AIBxandBr CrBBk 11.6-17.8 8.8-10.2 6.4-7.2 78-99 .99-36
AndBrson CrBBk 6.0-14.3 8.4-11.3 6.5-7.9 70-123 4-190
Kroto Slou~h mouth 5.9-16.8 8.3-9.9 6.8-7.4 89-199 18-150
Mid-Kroto Slough 8.9-15.2 9.8-10.9 7.3-7.4 94-132 21-200
MainstBm Slough 3.6-14.3 9.7-12.0 7.0-7.4 81-137 24-225
OBshka RivBr 3.9-19.4 8.2-12.0 5.95-7.4 28-80 1.60-90
LowBr OBlta Islands 10.9-13.2 9.7-10.6 7.6 103-118 110-150
Li t t IB Willow CrBBk 2.0-15.5 9.9-12.4 5.45-6.90 34-39 1.5-18
Rustic WildBrnBss 8.5-14.2 8.9-12.1 6.9-7.5 67-72 61-150
Kashwitna RiVBr 6.4-7.1 9.8-12.9 6.4-7.1 24-36 4.5-42
CaswBll CrBBk 9.0-16.0 7.6-11.3 6.1-7.0 17-461 1.0-1.9
Slough WBSt Bank 6.4-10.8 8.0-12.1 6.8-7.6 68-216 21-210
ShBBp CrBBk Slough 7.8-18.0 9.3-11.0 6.2-7.2 29-47 2.2-4.0
GOOSB CrBBk 6.3-10.7 9.2-12.1 6.0-7.1 18-37 .4-4.5
GOOSB CrBBk Slough 7.7-11.0 10.6-12.1 6.8-7.7 56~82 9.1-12.0
MainstBm WBSt Bank 3.2-10.0 10.5-12.6 6.7-8.0 76-142 6.3-255
Montana CrBBk 10.9-12.6 10.0-11.9 6.0-6.7 21-37 .3-1.7
RabidBux CrBBk 15.8-18.9 7.4 6.9-7.0 88-108 22.5-68
MainstBm 1 7.7-12.8 10.3-11.3 6.4-7.5 78-145 25-170
SunshinB CrBBk 8.9-15.5 9.8-10.9 5.6-7.3 40-65 1.6-23
Birch CrBBk Slough 8.4-16.0 9.4-10.3 6.2-7.4 67-132 2.4-95
Birch CrBBk 8.8-15.4 9.4-11.1 5.7-7.2 43-100 .5-7.5
CachB CrBBk Slough 4.9-14.1 11.2-12.3 6.2-7.7 57-135 80-270
CachB CrBBk 5.5-11.9 5.0-12.2 5.7-7.3 31-304 .6-22
Tab Ie 3.54 (Page 2 of 3 )
TEMPERATURE DO CONDUCTIVITY TURBIDITY
RIVER REACH (CO)(mg/l)Ph (micromhos/cm)(NTU)
Talkeetna to Devil Can~
Whiskers Creek Slough 7.6-18.0 10.5-11.6 5.3-6.6 18-43 .5-23
Whiskers Creek 4.8-16.5 10.7-12.8 5.1-6.6 15-31 .6-3.7
Slough 6A 4.8-16.5 1l.8 5.6-7.1 42-113 1.0-22
Lane Creek 5.2-9.8 10.9 6.4-7.2 45-65 .6-5.4
Mainstem 2 5.3-15.2 11.6 6.6-7.4 99-158 13-135
Mainstem at Curry 6.9-15.0 9.1-10.9 7.2-7.5 98-152 23-11 0
Susitna Side Channel 8.1-16.3 9.5-10.3 6.7-7.6 77-129 22-93
Mainstem Susitna Gravel Bar .6-14.5 9.6-11.0 7.3-7.8 104-167 7.5-230
Slough 8A 4.5-16.4 8.8-10.5 6.8-7.6 118-16o .7-205
4th of July Creek 2.0-15.0 9.5-10.1 6.3-6.7 15-27 .4-3.0
Slough 10 2.7-12.8 9.0-10.7 7.0-7.8 101-171 1.5-130
Slough 11 4.0-9.7 9.3-10.7 6.8-7.1 144-210 1.5-98
Mainstem Susitna-Inside Bend 1.8-11.8 10.5-11.8 7.0-7.6 92-168 9-150
Indian River (mouth).5-12.2 8.6-10.6 5.75-7.4 31-52 2-15
Indian River 2.7-8.4 6.8-12.3 5.7-6.8 38-52 .5-3.4
Slough 20 1.5-14.8 10.3-11.0 6.9-7.4 39-104 3.8-11.5
Mainstem Susitna-Island 2.7-11.7 10.3-11.9 7.2-7.5 66-150 13-140
Portage Creek (mouth)2.9-8.9 10.0-11.0 6.6-7.1 55-98 2.3-25
Portage Creek 1.5-9.4 10.2-12.3 6.05-7.2 48-158 .25-3.8
Devil CanYon~oundment Zone
and Vicinfu
Fog Creek 6.1-10.4 10.4-11.6 7.3-7.5 73-90 .34-1.50
Mainstem by Tsusena Creek 8.6-10.0 9.8-12.2 7.3-7.5 106-107 48-125
Tsusena Creek (mouth and
upstream)7.5-9.8 9.9-13.2 6.8-7.3 55-71 .6-1.8
Watana Impoundment Zone a~iciniiY
Mainstem by Deadman Creek 8.4-12.6 9.9-11.6 7.3-7.7 100-138 51-130
Deadman Creek 7.6-12.4 9.4-16.6 7.0-7.5 44-79 .68-2.3
Mainstem by Watana Creek 8.0-11.7 9.6-11.7 7.1-7.7 109-132 58
4 ~,1!1l!~.~1 q ~I l l11,1 ~~
1 ~l 1 -~l J 1 1 1
Table 3.54 (Page J of 3)
TEMPERATURE DD CONDUCTIVITY TURBIDITY
~IVER REACH (CO)(mg/1)Ph (micromhos/cm)(NTU)
Watana Impoundment Zone
and Vicinity (cont'd)
Mainstem by Deadman Creek 8.4-12.6 9.9-11.6 7.3-7.7 100-138 51-130
Deadman Creek 7.6-12.4 9.4-16.6 7.0-7.5 44-79 .68-2.3
Mainstem by Watana Creek 8.0-11.7 9.6-11.7 7.1-7.7 109-132 58
Watana Creek 1.5-11.4 9.5-14.3 7.1-7.7 101-248 1.3-9.8
Mainstem by Kosina Creek 3.3-12.4 9.0-12.1 7.1-7.6 106-146 10-145
Kosina 2.7-12.3 9.1-13.7 7.1-7.6 53-68 .5-4.4
Msinstem by Jay Creek 6.7-11.4 9.1-12.3 7.1-7.7 100-135 19-155
Jay Creek 3.6-9.7 9.9-13.2 7.4-7.9 124-175 .5-8.6
Mainstem by Goose Creek 5.0-13.7 8.5-12.0 7.3-7.7 100-152 23-155
Goose Creek 4.2-14.6 8.6-13.8 7.0-7.5 47-66 .32-2.2
Mainstem by Oshetna Creek 6.3-12.2 9.3-12.3 7.4-7.6 101-152 24-175
Oshetna River 5.2-12.6 8.9-12.1 7.2-7.6 65-135 1.2-19
TABLE 3.55:LIST OF ENDANGERED AND THREATENED PLANT SPECIES(a)SOUGHT IN
THE UPPER SUSITNA BASIN SURVEYS
Species and Habitat Unofficial Status (b)
Endangered species
Smelowskia pyriformis Drury &Rollins Threatened species
Nort hAmer ican endemic
calcareous scree,talus,In upper Kuskokwim R.dralnage
Aster yukonensis Cronq.Endangered specles
North American endemic
river banks,dry streambeds,rlver delta sands and gravels
Kluane Lake,Koyukuk River
Montia bostockli (A.E.Porslld)S.L.Welsh Endangered species
------North American endemic
wet,alpine meadows,St.Elias Mtns.,Wrangell Mtns.
Papaver alboroseum Hult.Endangered specles
Amphi-Ber mgian
well-dralned alpine tundra,Wrangell Mtns.,St.Ellas Mtns.
Cook Inlet lowlands,Alaska Range
Podistera yukonensis Math &Const.Endangered species
North American endemic
S.-faclng rocky slopes,grasslands at low elevations,
Eagle area,Yukon border
Smelowskia borealis (Greene)Drury &Rollins Endangered species
var.v illosa
North American endemic
alpine calcareous scree,Mt.McKinley Park,Alaska Range
Taraxacum carneocoloratum Nels.
North Amerlcan endemic
alpine rocky slopes,Alaska Range,Yukon Ogilvle Mtns.
Other Endangered Species Possibilities
Cryptantha shackletteana
Eriogonum flavum var.aguillnum
Eryslmum asperum var.angustatum
Upper Yukon River
Eagle,Alaska
Upper Yukon River
a.Species information and status from Murray (1980).
b.All species are under review by the U.S.Fish &Wildlife Service for
inclusion in the Endangered Specles Act of 1973.
"~~]1 J 7~]]]J '~"~]"J ~~]·-1 .~-1 ]
TABLE 3.56:HECTARES Of OIffERENT VEGETATION TYPES TO BE IMPACTEO BY THE WATANA fACILITY COMPAREO WITH TOTAL
HECTARES Of THAT TYPE IN THE ENTIRE UPPER BASIN AND IN THE AREA WITHIN 16 KM Of THE SUSITNA RIVER
I I I 1Lf a c iIi t y Com p 0 n e n t a I I ~of I
I I 1 I I I I I I Up pe r I ~0 f
I I I I 1 1 Borrow Areas I I I Basin I Area
Vegetation/Habitat lOam and I Impound-I I I I I 1 I I I I Conatruction I (b)I Total I for
Type I Spillways I ment I Camp I Village I Airetripl A I 0 I Elf 1 H I I I Zone(a)I Total I for 1 Type
I I I I I 1 I 1 I I I I I _Ilh.!l.L.lY.lleJ
16 kill
(c)
Th at
9.5
.36
54.2
3.5
17.5
.5
5.0
18.6
11.5
15.4
10.2
40.B
21.4
.5
10.2
0.1
0.7
3.8
1.5
1.8
7.8
3.7
2.6
250.0
(b)
.7
1.0
.4
8
35
27
62
29
34
631719
227
287
443
66
651
45
2104
59
22
13
1
46
6
17
1
I I I I I --,---I 1 I I 1 1 I I
I 34 1
1 0784 I I I IBII 5311801 8 1 I 4511 34 I 7825 118609 1 5 •3 113.1
I I , I I I 1 I I I I 1 1 1
I 8 I 3870 I 1 I 179 I 16 I I I 224 I I 2564 I 6434}I
I I 1 I I I I 1 I 1 I I I 4.2I I 397 I I I I I 71 1 69 I I I 1133 I 1530 I
I I 2864 I I I I I 121 I 15 I 1499 I 4363 J I 4.6
I I 769 /I 2 I I 62 I 11 I 1 303 /1072 1
I 1 I 325 I I I I I 1 I 286 I 611 I 63.1
I 13 I 460 I I I 5 I I I I 38 I 498 ldJ 1154.2 1dJ
poplarl I 3 I I I I I I I I 3 I (e)
I I I I I I I I I I II5I1337I1I32I I 106 I I 453 I 1790 I 7.7
I I I I I I I I I I I II7I759I / I I /47 I 1 I 19 I 1549 I 230B 1 14.5
I I 84 I I I 70 I 8 1 I I 1 502 I 586 I .2
I I 84 1 1 I I 8 I I I I 91 I 175 I 3.6
I I 1 I I I 1 I I I I II I 1 I I I 29 I 29 ,
I 1 70 I I I 1 382 I 382 II1718112241199381I494266611
I I 1 I I I I 227,.I
I I 1 121 1 287J 1I13I48811952915I3358I 10.0
I I I 4 17 252 I 318 I 3.0
I 4 I 751241 21 1775 124261 0 .5
I I 1 I 45 I
I 1 I I I
I I I 1 II I 1 2 I 456 I 2560 I 1.0
I 1 2 I I I 59 I 0.05
I I 1 I I 1I12I2007I I I 1 I I 2B7 I 2294 I 15.6
I I 38 I I 8 I 1 1 1 1 I 1 169 1 207 1 0.8 I
I I I I I I I I 1 I I I I 1I93I14691I63I70I17I33312871180I280I489134I13725I2841611.7 I 6.2
I L I 1_I I I .1 I I_-.L ,I 1 I I
TOTAL
forest
Woodland'spruce-
black
Woodland spruce-
white
Open epruce-black
Open epruce-white
Open birch
Cloeed birch
Closed balsam
Open conifer-
deciduous
Closed conifer-
deci duous
Tundra
Wet sedge-graae
Sedge-grass
Sedge shrub
Mat and cushion
Shrubland
Open tall shrub
Closed tall shrub
Birch shrub
Willow shrub
Mixed low shrub
Herbaceous
Grassland
Oisturbed
Unvegetated
Rock
Snow and ice
River
Lake
a.
b.
c.
d.
e.
This area encompasses all Facility componente except the impoundment,with the exception of minor portions of Borrow Areas f snd I.
Impoundment plus construction zone.
An area 16 km on either side of the Susitna River From Gold Creek to the mouth of the Maclaren River (See figures 3.2 through 3.4).
Hectares of closed birch are apparently greater in the impact areas than For the entire basin,because the baein was mapped at a much smaller scale,
and many of the closed birch etends did not appear st that ecale.
Areas of'this type were too small to be mapped at the scale of which the upper Susitna River basin wae mapped.
.3
4.8
2.9
3.9
3.7
.1
0.5
.B
1.0
.7
.6
.2
1.9
23.8
0.2
5.B
.07
.005
22.4
0.6
3.8
3.8
7.7
12.2
25.2
ice
TO TAL
Unvegetated
Rock
Snow and
Rive r
Lake
TABLE 3.57:HECTARES Of DIffERENT VEGETATION TYPES TO BE IMPACTED BY THE DEVIL CANYON fACILITY
COMPARED WITH TOTAL HECTARES Of THAT TYPE IN THE ENTIRE UPPER BASIN AND IN THE AREA
WITHIN 16 KM Of THE SUSITNA RIVER
I I
facility Component I %of I
, I I I I Up pe r I
I I I I I Basin I %of 16 km
Vegetation/Habitat Dam and ,Impound-I I I Borrow Construction (b)'Total I Area (c)
Type Spillways I ment I Camp I Village I Area K Zone(a)Total I for I for That
,I ~I That Type I Type
I I I I I
forest 16 I 22B9 I 36 I 39 119 4504 6793 I 1.9 I
Woodland spruce-I I ,, ,
black I I 133'I 46 ,179}I I
Woodland apruce-I I I I I .36 ,
white I I 20 I I 4BO I 500 I I
Open apruce-black I 4 I 300 I I 11 785 I 10B51>I 1.6 I
Open spruce-white I I 329 I I 474 I B03 J I I
Open birch I I 57 I I 126 I IB3 I 18.9 I
Closed birch I 3 I 430 I I 156 ,586 ldl '181 Id )I
Open balsam poplar I I 6 I I I 6 I (e)I
Cloaed balsam poplarl ,B I I 14 I 22 I (e)I
Open conifer-I I I I I I I
deciduous I 7 I 279 I I I 279 11.2 I
Cloaed conifer-I I I I I , I
deciduous I 2 I 727 I 36 39 108 I 2423 I 3150 I 19.7 I
Tundra I '11 I I 211 I 222 I 0.06 I
Wet sedge-grass I I 11 I 192 I 203 I 4.2 I
Sedge grass I 'I 18 IB I .01 I
Sedge shrub I I I 1 1 I 0 I
Mat and cushion',,I I
Shrubland I I 70 I I 18 B02 872 I 0.2 I
Open tall shrub I I 2 I ,125 127"}>I .2 I
Closed tall shrub I I 1 I I 165 166J I I
Birch ahrub I I 49 I I '18 266 315 I .9 I
Willow shrub I I 14 I I I 34 4B 1.5 I
Mixed low-ahrub I I 4 I I I 212 216 I .05 I
Herbaceous I I I I I I I
Grassland I I I I I I I
Disturbed I I I I I I 'I
I I , I I'I II2I826'I I 11 I 171 997 I .4 I
I '15 I I I I 2 17 I .02 I
I I I I I I I II1I810I I I I 13 7 947'6.5 I
I 1 I 1 I I I 11 I 32 33 I 0.13 I
I I I I 'I I II18I3196I36I39I14BI5688B8B4I0.5 I
I I I I I I I ~
8.This area encompasses all facility components except the impoundment.
b.Impoundment plua construction zone.
c.An area 16 km on either side of the Susitna River from Gold Creek to the mouth of the Maclaren River (see figures 3.2
through 3.4).
d.Hectares of closed birch are apparently greater in the impact areas then for the entire basin,because the basin was
mapped at a much smaller scale,and many of the closed birch standa did not appear at that scale.
e.8alsam poplar standa were too small to be mepped at the scale of which the upper Susitna River basin was mapped.
~
,,1 'J ;'I r,?~:'1l
J ;}~j
I~TABLE 3.58 :HECTARES OF DIFFERENT VEGETATION TYPES TO BE IMPACTED BY THE ACCESS
ROAD WITH TOTAL HECTARES OF THAT TYPE IN THE UPPER BASIN AND THE AREA
WITHIN 16 KM OF THE SUSITNA RIVER
I I I
I I I
I F ac i li t y Component I IV of I IV of'"'"L I Upper I 16 km
"""'I Rai 1-1 Basin I Area (a)
VEGETATION/HABITAT TYPE I Right-of-Way Borrow road I of Tha tl of That
I (61 m wide)Areas Yard I Total Type I Type
"""'Forest
Woodland spruce 2.0 16.7 18.7 .001 0.02
Open spruce 38.3 3 5.5 73.8 .06 0.2,-Open birch 10.8 10.8 1.0 0.7
C 10 sed birch 4.4 1.8 6.2 2.0 0.3
Closed balsam poplar 14.7 11.0 25.7 4.0
Open conifer-deciduous 68.7 4.0 72.7 0.7
Closed conifer-deciduous 163.8 141.0 7.8 312.6 2.0
Tundra,....
Wet sedge-grass 8.8 1.3 10.1 0.2 0.3
Sedge shrub 17.7 17.7 0.09
Mat and cu s h ion 26.5 26.5 0.04 0.04
Shrub land
Tall shrub 63.0 11.0 74.0 0.06 0.03
I""'"Low bir ch shrub 108.0 32.0 140.0 0.4 0.33
Low mixed shrub 69.0 3.5 72.5 0.01 0.08
Herbaceous-Grassland 14.6 14.6 1.0
Disturbed 2.0 7.5 9.5 39.0
Unvegetated
Lakes 13.7 13.7 0.05 0.23....River 2.5 2.5 0.02 0.06
Rock 1.5 1.5 0.001 0.01
.-
I
TOTAL AREA 613.9 266.8 22.4 903.1
(b)
0.06
(b)
0.20
",..
a.An area 16 km on either side of the Susitna River from Gold Creek to
the mouth of the Maclaren River.
b.This figure is not a summation of this column,but a percentage
determined by dividing the total area to be impacted by the total
available area.
Total
Rights-
Of.Wsy
TABLE 3.59:HECTARES Of DIffERENT VEGETATION TYPES TO BE IMPACTED BY THE TRANSMISSION
fACILITY COMPARED WITH TOTAL HECTARES Of THAT TYPE IN THE TRANSMISSION
CORRIDORS
I I I (a)
L~~to fairbanka I Dama to Intertie I Willow to Cook Inle."-t--!I _
I (b)I I (b)1 I (b >I .
I Right-of-I %of I Right-of-I %of I Right-of-I %of
VEGETATION/HABITAT TYPE I Way I Corridor I Way I Corridorl Way I Corridor
foreat
Woodland spruce-black
Woodland spruce -white
Open spruce-black
Open spruce-White
Cloaed spruce
Open deciduous
Cloaed deciduous
Open birch
Closed birch
Woodland conifer-deciduous
Open conifer-deciduous
Closed conifer-deciduous
Open spruce/open deciduous
Open spruce/wet sedge-grass/
open deciduous
Open apruce/low shrub/wet sedge-
grass/open deciduous
1533.7
}44.4
}6B5.2
74.6
149.7
76.3
2B.B
251.0
60.2
30.8
43.0
70.1
1.8
}2.5
}2.2
5.5
1.2
0.7
3.0
2.0
1.5
3.2
2.2
1.0
587.1
2.5
82.0
4.9
24.5
20.4
10.B
95.4
346.6
1.7
0.1
1.7
0.2
0.6
2.5
0.6
1.9
3.0
713.5
]-20.7
}9B.0
61.7
114.8
Ill.8
306.5
2.8
}O.B
}2.9
1.9
3.2
6.6
2.8
2834.3
}149.6
}812.6
136.3
149.7
76.3
20.4
125.6
28.8
458.2
713.3
30.8
43.0
70.1
~~qj l ~-.J,
"'
r-
TABLE 3.60:AREA OF OVE RLAP OF BROWN BEAR HOME RAN GES AND THE WATANA AND
DEVIL CANYON IMPOUNDMENTS
2
2 Area of intersection (km )with impoundment
Bear ID (age)Home Range (km )Watana Devil Canyon %
MALES
342a(2)1774 0 16.3 0.9r'"293 (3)4135 155.4 0.8 3.8
214 (4)975 50.0 0 5.1
280 (5)743 84.1 0 11 .3
294(10)611 0 13.7 2.2
FEMALES
335 ( 2 )179 0 0 0
281 (3)(w!cubs in
,81)330 82.7 0 25.1
340 (3)613 62.1 0 10.1
/""'"30 8b (5)191 0 14.4 7.5
344 (5)246 0 0 0
331 (6)1136 50.4 0 4.4
341 (6)536 43.6 0 8.1
313 ( 9 )218 0 0 0
277(10)147 0 0 0-312(10)(w!cubs in
,81 )280 1 .2 0 0.004
334(10)(w!cubs in
I""'"'81 )11 1 0 0 0
283(12)323 0 12.9 4.0
299(13)585 54.5 0 9.3
r-337(13)(w!cubs in
'81 )270 0 0 0
-
.-i
r
TABLE 3.61 :AREA OF oVE RLAP OF BLACK BEAR HOME RANGES AND THE WATANA AND
DEV IL CANYON IMPOUNDMENTS
2
2 Area of intersection (km )with impoundment
Bear 10 (age)Home Range (km )Watana Devil Canyon IV
'"
MALES
330 (1)10 0 0 0
323 ( 2)383 1 . 0 21 .7 5.9
319 (3)146 0 14.1 9.7
291 (4)20 0 1 .6 8.0
322 (4)10 2.5 0 25.0 F"
324 (5)400 0.4 9.8 2.6
342B(5)611 139.9 0 22.9
343B(5)289 0 11.8 4 . 1
302 ( 8 )326 98.9 0 30.3
303 (8)142 0 3.1 2.2
305 ( 9 )48 0 0 0
346 (9)62 13.9 0 22.4
348 (9)388 34.5 2.0 9.4
287(10)292 6.3 2.5 3.0
304(10)51 0 0 0
FEMALES
329 (1)15 6.8 0 45.3
349 (4)36 11 .4 0 31 .7
318 ( 5 )1051 112.4 4.3 11 •1
327 ( 5 )32 14.1 0 44.1
328 ( 6 )30 0 0.9 3.0
301 (n 26 7.0 0 26.9
317 (7)19 0 0 0
290 ( 8 )163 0 10.6 6.5
289 (9)47 21 .4 0 45.5
288(10)7 0 0 0
321(10)774 91 .8 5.4 12.6
~:r,'.-.'
325(11)146 9.7 3.3 8.9
~
I
Disturbance
TABLE 3.62:GENERAL TYPES or IMPACTS TO RAPTORS
-
-
Construction and Operation Activities
sudden loud noises (e.g.,blasting,gas venting,etc.)can lead to
panic flights and damage to nest contents
noise,human presence,etc.can lead to disruption of daily
activities
Aircraft Passage
sudden appearance 'and noise can lea~to panic flights and damage to
nest contents
Human Presence Near Nests
inadvertent -chance occurrence of people (and dogs)near nests;
people may be unaware of nest,raptors,or raptor alarm behavior
deliberate -curious passersby,naturalists,photographers,
researchers can have impacts if safeguards are not taken
Direct Impacts
Intentionally Destructive Acts (as a result of increased public access)
shoot~ng
legal or illegal removal of eggs,young,or adults
rolling of rocks off cliff tops
cutting of nest trees
Man-made Structures and Obstructions
raptors may be struck on roads where they may perch or feed
raptors may strike wires,fences,etc.
raptors may be electrocuted on power poles
raptors sometimes attack aircraft,or may accidentally strike aircraft
Environmental Contaminants
deliberate application and accidental release of insecticides,
herbicides,petro-chemicals,and toxic industrial materials can affect
raptors and prey by affecting hormones,enzymes,shell thickness,bird
behavior,egg fertility and viability,and survival rates of nestlings,r fledglings,immatures and adults
Source:Roseneau et al.1981
r-
I,
TABLE 3.62 (continued)
Changes in Prey Availability
decrease in prey abundance or loss of nearby hunting areas may affect
territory size,efficiency of hunting,nest occupancy,nesting success,
condition of adults and young
changes may result from aircraft overflights,construction and
maintenance activities,public access,etc.
Habitat Loss
Abandonment of area due to destruction of nest,perch or important
hunting habitat
I"'""
i
!
Timing
Wint er
TABLE 3.63:DISTURBANCE OF RAPTORS --INFLUENCE OF TIMING
Possible Effects of Disturbance
Raptor may abandon nest,roosting cliff,or hunting area
(e.g.,Gyrfalcon)
,....
Arrival and
courtship
Egg-laying
Incubation
Nestling
phase
F ledgli ng
Migrant raptor may be forced to use alternative nest site (if
available),may remain but refuse to breed or may abandon
nest site
Partial clutch may be abandoned and remainder (or full
clutch)laid at alternative nest;breeding effort may cease
or site may be abandoned
Eggs may be chilled,overheated,or preyed upon if parents
are kept off nest too long;sudden flushing from nest may
destroy eggs;male may cease incubating;clutch or site may
be abandoned
Chilling,overheating,or predation of young may occur if
adults are kept off nest;sudden flushing of parent may injure
or kill nestlings;malnutrition and death may result from
missed feedings;premature flying of nestlings from nest may
cause injury or death;adults may abandon nest or site
Missed feedings may result in malnutrition or death;
fledglings may become lost if disturbed in high winds;
increased chance of injury due to extra moving about;parents
may abandon brood or site
r
!
!
Night panic flight may occur and birds may become lost or suffer
injury or death
General Undue expense of energy;increased risk of injury to alarmed
or defending birds;missed hunting opportunities
Source:Roseneau et al.1981
TABLE 3.64:LINEAR DISTANCES OF CLIFFS IN VICINITY OF PROPOSED
IMPOUNDMENTS,AND DISTANCES THAT WOULD BE INUNDATED
Devil Canyon Reservoir
Watana Reservoir
Type of
cliff(a)
A
B
C
A
B
C
Length inundated
(km)
27.4
8.3
2.4
15 • 1
5.1
1 .6
Length above
waterline
(km)
24.9
7.9
1.6
0.9
o
0.3
a."A"cliff habitat had cliffs large enough to support a nest,had ledges and
nooks for nest placement,and had little loose material;"B"cliffs had
these same attributes but were smaller and perhaps not large enough to
support a nest;and "e"cliffs had loose substrates (dirt and rock banks or
loose talus)and probably would not have been used by raptors.
'1 '-c-]~~l r---~J ---]""""']e-l '1 "',"']']---l -"J
TABLE 3.65:NUMBER OF KNOWN RAPTOR OR RAVEN NEST SITES IN UPPER SUSITNA RIVER BA SIN,ALASKA,THAT WOULD BE
INUNDATED BY DEVIL CANYON AND WATANA RESERVOIRS
Active ne sts that Inactive nests th at
would be flooded would be flooded
Total no.Total no.Tot al flooded
Species act i ve nests inactive nests Devil Canyon Watana Devil Canyon Wat ana nests
Golden Eagle 10 9 1 4 2 3 10
Bald Eagle 6 1 0 2 0 1 3
Gyrfalcon 1 0 0 0 0 0 0
Gosh awk 1 0 0 0 0 0 0
Common Raven 4 7 1 0 1 2 4
Unknown 1 3 0 0 0 0 0
TOTALS 23 20 2 6 3 6 17
TABLE 3.66:RAPToR/RAVEN NEST SITES WITHIN 1.6 km OF POTENTIAL BORROW
AREAS
Borrow Area Species
E golden eagle
E raven
H raven
H unknown
H r Bven
H gyrfalcon
K goshawk
K gyrfalcon
Distance from
Borrow Area
0.2 km
0.5 km
0.3 km
0.4 km
O.B km
0.0 km
1 .6 km
1 .6 km
Comments
two nest sites
three nest sites
1974 nest (White 1974)
1974 nest (White 1974)
p-
TABLE 3.67:
1 -c-~--~1 ~-l -~~-l C]-1 --cl "1 1 -1
A GENERAL ASSESSMENT OF POTENTIAL FISH ECOLOGY IMPACT ISSUES BY PROJECT
___________________________STAGE FOR THE ENTIRE SUSITNA RIVER STUDY AREA UNDER POST-PROJECT FLOWS
(a)
Project Stages
CC,CD,RD,0
CD,0
CD
o
o
CD,0
o
CD
Potential Impact Issues
Changes in the water quality
Alteration Df the temperature structure
of the stream.
Possibility of excessive dissolved gas
(nitrogen and oxygen)concentrations
caused by plunging flows
Development of new ice-free areas.
Change in ice conditions below Talkeetna
affecting downstream movement of fish.
Summer and winter flow changes and the
impact on fish reproduction,growth,and
predation as well as critical flows for
transportation (including access to
tributaries and sloughs)
Effect on present type of fish
collection devices in Cook Inlet
Extension of upstream anadromous fishery
General Assessment
Decreases in turbidity levels expected above
Talkeetna in summer and minor increases
above Talkeetna in winter.
Impact not yet determined.Greatest concern
is for salmon egg development,especially
during filling and in the Talkeetna to Devil
Canyon reach.
No major impacts expected with appropriate
dam design and construction procedures,as
proposed.
Level of impact not known.
Level of impact on downstream fish movement
not known.
Level of information on impact on fish re-
production and growth not well-known.Access
to main tributaries should not be impacted
but acceSs to sloughs above Talkeetna by
adult salmon eliminated.
No impact expected.
Salmon passage through Devil Canyon possible
during filling.After Devil Canyon dam is
constructed,limit of migration will revert
to present location.
a.Project stages:
CC -Construction of the cofferdam and river diversion
CD -Construction of the dam and reservoir filling time
RD -Development of limnological conditions and fishery management
in the reservoir after filling
o -Operational stage including start-up
TABLE 3.67 (continued)
( a )
Project Stages
o
CD,0
o
CD,RD,0
RD,0
CD,0
CD,RD,0
CD,0
Potential Impact Issues
Bank scour caused by piping effect of
increased flows under the ice
Bed scour as affected by changing flows
and ice
Potential for increased production by
the addition of new spawning areas and
new rearing areas
Formation (and management)of new
lakes (impoundments)
Changes in personal use fishery
Potential stranding of juveniles and
exposure of redds due to die 1 variation
Changes in the habitats of downstream
resident fish populations
Effects on rearing,fish passage and
egg incubation in the Susitna River
from its mouth upstream to Talkeetna
General Assessment
No major impacts predicted above Talkeetna
Impact below Talkeetna not known.
Decreases in scouring due to flood control.
Open water year-round above Talkeetna may
increase enhancement opportunities if proper
flow control utilized.
Potential for mainstem spawning enhancment
as a mitigative measure.
Some tributary and mainstem Susitna habitat
eliminated.Impoundment may increase amount
of overwintering habitat for grayling and
development of a resident fishery possible.
Major increases in impoundment areas and
Indian River possible.
Under present project scheme,no significant
impact predicted.Potential problem would
occur,however,if there were to be signifi-
cant power peaking at the Devil Canyon
facility.
If power peaking is minimal,overall impact
on resident fish downstream is expected to
be minimal.
Detailed predictions as to the level of im-
pacts on fisheries in this reach have not
been established with the information
presently available.
lj .~,~'1 11 ~].
J
______~T~A~B.LE 3.68:PRIORITY ORGANIZATION OF WILDLIFE MITIGATION IMPACT ISSUES
High Priority Wildlife
Imp act I 5..=sc..:u:...:e"-s=--'-P..=rc..:0'-'......i e:::...::cc..:t'---'C"-o:;:..:::m..t:pc..:0:...:n.;.:e::...:..:n..=t '---'Rc:...::.e..=5c..:0:...:u:..;r:...:.c.:::e _
r
-
r
W-6
W-B
W-9
W-20
Moderate Priority
Impact Issues
W-2
W-3
W-4
W-7
W-ll
W-12
W-13
W-15
W-17
W-22
W-23
Watana and Devil Canyon Impoundments
Watana and Devil Canyon Impoundments
Watana and Devil Canyon Impoundments
Access Roads and
Construction Camps
Project Component
Watana and Devil Canyon Impoundments
Watana and Devil Canyon Impoundments
Watana and Devil Canyon Impoundments
Watana and Devil Canyon Impoundments
Watana Impoundment
Operation of Devil Canyon Dam
Operation of Devil Canyon Dam
Clearing of Woody Material from
the Watana Impoundment
Main Access Road,Borrow Areas,Access
Roads to Borrow Areas,and all Con-
struction Camps/Villages
Construction Camps and Access Roads
Air Traffic
Upper Basin
Moose
Brown Bear
Wolf
All Upstream Fur-
bearer and Big
Game Species
Wildli fe
Resource
Pine Marten
Cliff-nesting
Raptors
Bald Eagle
Black Bear
Caribou
Downstream Beavers
Downstream Moose
Caribou
All Fur bearer Spe-
cies,Many Avian
and Small Mammal
Species,and all
Big Game Species
except Dall Sheep
All Upper Basin
Wildlife Species
All Big Game
Species,Raptors
and Trumpeter
Swans
Low Priority
Impact Issues
W-l
W-5
W-IO
W-14
W-16
W-18
W-19
W-21
TABLE 3.68 (Continued)
Project Component
Watana and Devil Canyon Impoundments
Watana and Devil Canyon Impoundments
Watana Impoundment
Clearing of Woody Material from
Impoundments
Construction Camps/Villages and
all Access Roads
Borrow Areas and Access Roads
to Borrow Areas
All Access Roads
Construction Camps and Villages
Wildlife
Resource
Mink and River
Ot te r
Forest-dwelling
and Riverine Bird
and Small Mammal
Species
Dall Sheep
All Upstream Big
Game Species
Red fox,Wolf,
Black and Bro wn
Bear,Ground
Squirrel,Gulls
and Ravens
All Upstream Big
Game Species except
Dall Sheep
Moose and Caribou
Red Fox and Wolf
piC'l
~l ~~~~""j "-1 "~.)'-'~']e'j '-1 ....~].'~~l ~'~'~l ']1 1 ~
TABLE 3.69:PREDICTED DOWNSTREAM WATER TEMPERATURES (OC)FOR AN AVERAGE
YEAR WITH PROJECT FLoWS(a)
Cross(b)
Section Jan Feb Mar Apr May Jun Jul Aug Sep Oct No v Dec
LRX 68 (Portage
Creek)3.9 3.9 :L9 3.9 5.7 7.1 9.8 9.6 7.6 4.3 3.9 3.9
LRX 61 3.8 3.8 3.9 3.9 5.8 7.1 9.8 9.7 7.6 4.3 3.9 3.8
LRX 54 3.3 3.5 3.7 4.0 6.1 7.5 10.1 10.1 7.7 4.2 3.5 3.5
LRX 47 3.0 3.2 3.6 4.1 6.2 7.8 10.2 10.3 7.8 4.2 3.4 3.3
LRX 41 (Go Id
Cre ek)2.9 3.2 3.6 4.1 6.3 7.9 10.3 10.4 7.8 4.2 3.3 3.2
LRX 34 2.6 2.9 3.4 4.2 6.5 8.2 10.5 10.7 7.9 4.1 3.0 2.9
LRX 27 2.1 2.5 3.3 4.3 6.8 8.6 10.7 11.0 8.0 4.1 2.7 2.5
LRX 21 1.7 2.3 3.2 4.4 7.0 8.9 10.9 11.3 8.1 4.0 2.5 2.2
LRX 15 1.1 1.8 3.0 4.5 7.3 9.4 11.2 11.8 8.2 3.9 2.1 1.7
LRX 9 0.5 1.4 2.8 4.7 7.7 9.9 11.5 12.2 8.3 3.8 1.7 1.3
LRX 3 (Talkeetna)0.1 1.1 2.6 4.8 7.9 10.3 11.7 12.6 8.4 3.8 1.4 0.9
Discharge
Below DC
(efs)10514 8883 8072 7903 9344 10288 9070 8665 6972 7403 9425 11864
a.Assumes operation for maximum power production,a floating intake at Watana,and a single level
intake at 21.3 m (70 ft)at Devil Canyon.
b.LRX refers to R&M river cross sections.
;/UNIVERSITY OF ALASKA
VEGETATION MAP OF THE UPPER SU~
~."-~....,.,.,,,....,...."....
'li .HOIfQO'.'
,;
~d"<>~
Miles
0 10 20
i !!
0 10 20 30
Kilometers
0
;ITNA RIVER BASIN
0""",'"~"'''0",·"",,,,""""'0",00","',",,,,
B "AT CU~KICNiSEOH~flJl.S-S TU~DAA
W ALPIN~KERBACEOUS-TUHORA
~OPENTA~LSHRU8
0"""",",,D·""·",,,,
E3 C,•••",
W \Io'OOOlJl.~OSPAUCE
~
[W]
CZJ
~.""""",m.mEJQP(~"'~EDFORE5T
~CLOSEDIoII~EDFaRE5,
~•
FIGURE 3.1
.,,;.~-
VEGETATION I HABITAT MAP OF AN AREA WITHIN 16 KM OF THE
UNIVERSITY OF ALASKA
Miles
Kilorn.eters
3•4 5
2-2 3
0016TURBEil
~WH~~O~~;UDCE
~BIA~~09:~RES1"
~8IR~:E:OREST
I VEGEnTION KEY l
~~O~K
~5110-'~"~ICE
r::::::::!9EOBE ~RASS
~TUNDRA
~BI~CHSI1RUB
o GRASSLAND
~LAKES
~8LA~:ES~IIUCE
~BL:KDDSLpA:~CE
~SH:~:G~UNDIUo
~Sm:EE~RAS8
o ¥WILLOW SHRUB
~LDWSHFlUB
o BA2sLA°t,lSEpOOPLAFI
o I3Al~::f<lpOPLAR
~MI;.:~~O~~~EST
o 1
o•
('I).
('I)
wa:
~
Cl
u.
UPPER SUS1TI\JA RIVER,WESTERN PORTION
FIGURE 3.2
VEGETATION I HABITAT MAP OF AN AREA WITHIN 16 KM OF THE
UNIVERSITY OF ALASKA
Miles
Ki IOFQ,flters
3•4 5
2-2 3
~ROCI(
QSMO'Jl'GI<dICr.
~5ED:EE~RASS
~8L..~:ES~RUCE
~BL:C~D5LpARN~CE
I ~EGETATION KEY
0HERB/ICEDUS
~5EDeoEGfI"SS~JTUNORA
r::::l NAT o~d CUSHION~TUNDIIA
0 LAICE$
0015TURBEO
0W,LLO..,SHIWB
~8IRCHSHRUB
0GFUSSLANil
GLOW SHRUB
o 1
o•
wz-...J
::I:
()....
e:(
::i
UPPER SUSITNA RIVER,CENTRAL PORTION
FIGURE 3.3 [iii]
M.
M
Wa::::»
"u.
",'f?-...v,;r
~~~~
....."-~
'6r P
~
~
~
~
Yf",
J III
,~
.~
/<''''j,,#)~
UNIVERSITY OF ALASKA
VEGETATION I HABITAT MAP OF AN AREA WITHIN 16 KM OF THE
-~S$
&v
~~ET""TIOH KE~I
~ROCK
0SHOWGncliCE
~SH:~~G~UNORA
~SEO:EE:R""SS
~Wfjl~~O~~RN:CE
~8IR~~OS:~REST
0SAL~::NpCPL"'R
~MI~~~O;~~[ST
GSIRCHSHRUB
0WILLOWSHRU~
o LOW SHRUB
~GRA:SSLANO
~LAKES
00ISTURI![O
o
'''"~0 2 3---a 1 2 3 4 5
Miles
Kilometers-
¥.f5
"J -,
UPPER SUS/TNA RIVER,EASTERN PORTION
FIGURE 3.4 [B]
./.
"'0
oP;;y;;;;JV-r
FIGURE 3.6 MATCHLINE
PREPARED BY TES/UNIVERSITY OF ALASKA
'-'1'-
VEGETATION I HABITAT MAP OF HEALY TO FAIRBANKS TRt
Kilometers
Miles
5
~CROP
GillTATION ,noCLOSEDSPRUCE
~OPEN SPRUCE
~WOODLA"O
SPRUCE
~CLOSED
l)[CIDlJOUS
~OPEN
DECIDUOUS
~CLOSED
WIXED
~DPEN
MI)lED
~WOODLAND
MIXED
0 LOW SHRUB
~WET SEDGE
~RASS
o OEVELDP[D
3 4
o ROCk
o LAKE
2o
\
..
"..",""
,-
_11 ~
IISSION CORRIDOR,NORTHERN PORTION
FIGURE 3.5 •
--------------------------------~---------------------------------------------------
I
I
.-~...
,.
PREPARED BY TES I UNIVERSITY OF ALASKA
FIGURE 3.5 MATCHLINE
(
FIGURE 3.7 MATCHLINE
VEGETATION /HABITAT MAP OF HEALY TO FAIRBANKS TRfl
f
~"AT~n~Ng~:IfIO"
o CROP
~LAKE
o ROCK
I 'VEGETATION 'EY
~CLOSED SPRUCE
B OPEN SPRUCE
~WOODLAND
SPRUCE
~CLOSED
DECIDUOUS
G OPEN
DECIDUOUS
@J CLOSEO
MIXED
G OPEN
MIXED
~WOOD-l.A-ND
NJXED
~LOW SHRUB
EJ WET SEDGE
GRA.SS
o DEYEl.OPED
.,,"',
.,-.....
•
) •11
.4.
I
()
,iQ
+;--'-.---":;;-_-".----
i .i __
I··I
0."
,'001<-4>
tJ "'~0 2 3 Miles~\,-'<,;0 2 3 4 5 Kilometers
~,:;.CII'.,
~-~----,------~--:,,)-.".,
----'.---.".-
•j "
~_:,---'-..-
'4,),~
IISSION CORRIDOR,CENTRAL PORTION
FIGURE 3.•[Ii
w
Z
...J
::I:o....
et
~
•.."!'
:C:I
-'.'!.
.t;
PREPARED BY TES/UNIVERSITY OF ALASKA
VEGETATION I HABITAT MAP OF HEALY TO FAIRBANKS TRP
I VEGETATION IliE'
~Llft,kE
~CLOSED SPRUCE
o OPEN SPROCE
CL09ED
MIXED
OPEN
YIXI!:D
OPEN
OEClDOO09
WOODLAND
SPRUCE
WET SEDGE
GRASS
WOODLAND
MIXED
CLOSED
D£ClDODOS
SEDGE GRASS
TONDRA
~
G
o
~
~
~
~
~MAT ;~~N~~:HJ,QN.
o CROP
o ROCK
o DEVELOPED
-.o.
Kilofll¥.ters
Miles3
5
2
3 42o
.y'
SSION CORRIDOR,SOUTHERN PORTION
FIGURE 3.7
1,,.'
(
/
/
.',
'1-,":I
'I '.I'r'j
If""
;"1'•.\
,"
t ~,
,','
,~I '~,'
I,'
,"~I
" I
I I,'I ,1,
"i','"
"'
",..'~I I ~
;,~,
I;,
",
,,,j ~,
,,!'
--';",;'.
-
VEGETATION /HABITAT MAP OF WILLOW TO POINT MAC KENZIE TRA
NIVERSITY OF ALASKA
W
Z
...I
::I:
)lJO
l-
e:(
~
="-'"'1,~,/,*,0)
(M
,,:Wa:
~
C'
D1i.'--,:..l~~~~:":::-~~~~....::l.1~~"""":::<~2iCL.:::...L.""""=t--LL
.~
LIT:GETATION KEY
~CLOSED SPRUCE
r-:::::l WET~SEDGE GRASS
OPEN
SPRUCE
WOODLAND
SPRUCE
~CLOSED~BIRCH FOREST
~OPEN
~BIRCH FOREST
~CLOSED~BALSAM POPLAR
~OPEN~BALSAM POPLAR
~CLOSED~MIXED FOREST
~OPEN~MIXED FOREST
~CLOSED~TALL SHRUB
B LOW SHRUB
~DISTURBED
GJ.LAKES
o 2 3 Miles
o 2 3 4 5 Kilorri'elers
NSMISSION CORRIDOR,NORTHERN PORTION
FIGURE 3.8
/
';'
".j ,
!,J
PREPARED BY TES I UNIVERSITY OF ALASKA
VEGETATION /HABITAT MAP OF WILLOW TO POINT MAC KENZIE
l ..
;;~""~""
...--~--_.~- -~--._:~~......-.,->...::/
c.,~,~~"c-~i
I VEGETATION KEY IoCLOSEDSPRUCE
~WET~I SEDGE GRASS
OPEN
SPRUCE
WOODLAND
SPRUCE
1::;:1 CLOSED~J BIRCH FOREST
r-:::l OPEN
~BIRCH FOREST
~CLOSED~BALSAM POPLAR
r-;::;1 OPEN~BALSAM POPLAR
~CLOSED~MI)(ED FOREST
~OPE"!~MIXED FOAEST
~CLOSED~TALL SHRUB
@]LOW SHRUB
~DISTURBED
~LAKES
1,
..P
1
,-,1;.
o
o
.~'o
o 2 3
2
4
3
5
Miles
Kif'bmeters
I.NSMISSION CORRIDOR,SOUTHERN
I
PORTION
FIGURE 3.9
-~)c----l 1 ~J ~.._-~---1 "-1 1 )1 1 --'J -1 ---1 -1 --.-1 ---~-l 1
o 10 20 30 40 Miles
__•I
o 20 30 60 Kilometers
PREPARED BY TES I ADF&G
BOUNDARIES OF THE SUSITNA MOOSE STUDY AREA -UPSTREAM
FIGURE 3.,0.
~]C-j ~-~C~-'j ~l --)]--J 1 -1 .---"__-_C)'-~~J -J -.....)---1 J
LEGEND
FIGURE 3.11 [iii]
Louise
/'---~
/1
BOUNDARIES OF ESTABLISHED MOOSE COUNT AREAS
o 10 20 30mi.---~o 10 20 30 40km.
/--
(~
J
DEVIL CANYON
//DAMSITE
o
LOW DENSITY
o DENSITY
MEDIUM DENSITY
HIGH DENSITY
PREPARED BY TES/ADF&G
••••••••COUNT AREA
BOUNDARY
RELATIVE DENSITIES OF MOOSE AS
DETERMINED FROM STRATIFICATION
AND CENSUS FLIGHTS MADE DURING
NOVEMBER 1980.
..
--1 --1 -1 -J .---1 --1 ~--1 --1 -1 -1 ---J ---1 --J --j ---1 --__e)--]
'\
"l"
\
o 10 20 30mi.___•J-
o 10 20 30 40km.
I
';l
~~.fV'J
/
--...J,/.,.
BASIN BOUNDARY ~,;J
/
DEVIL CANYON,",,,xSITE~
River\.,.'X_/"\....",.
o
PREPARED BY TES/ADF&G
RELATIVE DISTRIBUTION OF MOOSE OBSERVED DURING A WINTER
DISTRIBUTION SURVEY CONDUCTED FROM 4 THROUGH 25 MARCH 1980
FIGURE 3.12 [iii]
c',C~~J )c~'l c1 _c
1 "c'l '-1 cc)c1 1 ],ccl 1 ']cc e).c...C)c•
cre<e k
'(\\\'00.
c'"~
\~o••S!',-0
r
~~~
~
Stephan
Lake
RiUf:'....
"~
"o,,0
",0
.C-i'u
o 10 20 Miles
-Io102030 Kilometers
LEGEND
~AREAS OF HIGH USE
o
PREPARED BY TES/ADF&G
DISTRIBUTION OF MAIN NELCHINA RADIO-COLLARED CARIBOU,
14 APRIL 1980 THROUGH 29 SEPTEMBER 1981
FIGURE 3.13 [j]
~---l -1 1 -------1 ccccc,C]1 1
*
o
~
•FEMALES
*MALES
LEGEND
*
*
**
Qj
"i:;:
*
o 10 20 Miles
-Io102030 Kilometers
•
•
;;,
~
~o,,0
".0
.~o
*
-';,
b
•
Rille....
Stephan
Lake
,~o
~C0
r-..'
N'O Cre'e!r
C"\.\'0
y
.~
.~
~
PREPARED BY TES/ADF&G
DISTRIBUTION OF NELCHINA RADIO-COLLARED CARIBOU
DURING THE CALVING PERIOD,15 MAY THROUGH 10 JUNE,1980 AND 1981
FIGURE 3.14 [iii
1 "'1 "'c'l C "1 "'J -"1 c '~J "'1 J ,.~]]
,
I -1
o
FIGURE 3.15 [iii
*UPPER TALKEETNA RIVER SUBHERD
•CHUNILNA HILLS SUBHERD
o UPPER SUSITNA -NENANA SUBHERD
~
LEGEND
OJ."I::C
o 10 20 Miles
-Io102030 Kilometers
~
Cri?
"cf
"'"
o
o
LOCATION OF RADIO-COLLARED CARIBOU IN SUBHERDS,
9 MAY 1980 THROUGH 22 SEPTEMBER 1981
*
ca
'"","iJ~·
"~
'S
o
* \**It}**i
~*~
.
~
Rib /iii;",
"c
~.c.."---,0
Stephan
Lake
•
••
•
\,,0••~,,"
•
)·'1"0 ..,,~
C creek•
y
-~
~~
~
PREPARED BY TES/ADF&G
~-~J---~)-1 '--1-~1 ,c-"l 'J ]']'J "1 "'-1 --]"-'1 ")-"1 "'),"1 'J
LEGEND
W Watana Pack
TC Tyone Creek Pack
S Susitna Pack
T Toisona Pack
FL Fish Lake Pack
SS Susitna -Sinona Pack
1::'::';,1-SUSPECTED PACK TERRITORIES
PACK TERRITORIES CONFIRMED BY
RADIO COLLARED MEMBERS
o o 10 20 30 40 Miles
__•I
o 20 30 60 Kilometers
PREPARED BY TESfADF&G
SUSPECTED LOCATIONS AND TERRITORIAL BOUNDARIES
OF WOLF PACKS DURING 1980 and 1981
FIGURE 3.16 [Ii
1 c~el --1 J -~-]1 _.--1 -].---1 -1 1
GENERAL LOCATION AND YEAR OF USE OF _15
OBSERVED WOLF DEN AND RENDEZVOUS SITES
DISCOVERED IN THE SUSITNA HYDROELECTRIC PROJECT AREA
FROM 1975 THROUGH 1981
PREPARED BY TES/ADF&G FIGURE 3.17 [iii]
\
River ".-J
/'-,/
.-/L _8
""I
I.9tiL
""'\.1~\-..?
11 ~_
-13-12
/"-----
I
-14
v--"".:......../\•....-rYi"--,
\
BASIN ~
BOUNDARY~
'\
\
~o 10 20 30mi.---~o 10 20 30 40km.
LEGEND
1.SUSPECTED STEPHAN LAKE DEN -1976.
2.BRUSHKANA DEN -1975
3.DEADMAN DEN -1975.
4.W ATANA RENDEZVOUS SITE -1980.
5.WATANA DEN -1980.
6.JAY CREEK DEN -1978.
7.CLEARWATER DEN -1976.
8.KEG CREEK DEN -1975,1976, 1977.
9.SUSITNA RENDEZVOUS SITE -1980.
10.SUSITNA RENDEZVOUS SITE -1980.
11.SUSITNA DEN -1979,1980.
12.TOLSONA DEN -1980,1981.
MENDELTNA RENDEZVOUS
SITE -1977.
13.TOLSONA RENDEZVOUS
SITE·1980.
MENDELTNA DEN -1977.
14.MENDEL TNA RENDEZVOUS
SITE -1976.
15.MENDELTNA RENDEZVOUS
SITE -1977.
16.TYONE CREEK DEN -1979.
o
],.~]]1 '1 -~1 "1 1 ']"'1 ..··1 1 .""-1 .)1
LEGEND
~STUDY AREA
KY\~\:;I CORE AREA
o
PREPARED BY TES/ADF&G
o 10 20 30mi.---~o 10 20 30 40km.
."l
BASIN BOUNDARY
FIGURE 3.18 [j]
o
o
~--l 1
Miles
10
~~~~
20
-...I
-,)
/;,;(:"""".!~'I:,
-c-]~-l 1 1
:....-
',*">:1 00'-.
.-...,..
J
PREPARED BY TES
FURBEARER STUDY AREA -UPSTREAM
FIGURE 3.19 •
....a
,
J
~
.J
I....a
'I
..J
...
ii
..J
-
.....
~
0_
:5
~
%
<"<;>-::>
Q
A -1
A-6o~
.._.11:A-7
.....
0)
c-,
'"o
'"'"::iI
0:
-4
o~
»I'il III
:::JlJ,.l .~(")Ul
::::ro;ALASKA
r'g ---CANADA--
/'
o
»m
::D
»r
-i
O~
OI Z-imen
-i°mmAO::D""U-iOen
»Z-nZ-ioOen::D
S:-n-n-OcZ::D JJA-
.0
llJ
I
_en m
00(;)>
~nQ
S:Z::D
~~~r
-enm
O::D
-n en-....»
0-»
Z
I ~-u~0
z:;s:0 iD3(/)CD
CDu;
"1J
"'Tl
G)
C
:Dm
w
No
~~
:Dm
"1J»
:Dmo
OJ-<
--Im
Cfl
Cz<:m
:D
Cfl
:;)
o
"'Tl
»r»
Cfl
A»
3 km
2 Miles
2
•
ELEVATIONS IN FEET
a
o
...No.516
o No.518
•No.519
f).No.520
(T)Trap Location
•
LEGEND
«'\«:<::D
';{',~...J\««U
r-
I,
-
.....
I
-i
-I
TRACKING LOCATIONS FOR FOUR
RADIO-COLLARED MALE MARTEN,1980
PREPARED BY TES I UNIVERSITY OF ALASKA FIGURE 3.21 •
600-600
0
r-
,,,
500
,,....500 ,
),
0 ,,,,,,,
400-I 400 I-l/Jw MS I ,a:
~0 ,R-bV ,
I-a.\,0 ,.....<C \<.>,\,
u.\I \,
0 300-\I 300 \a:\\
,
w 1 ,ca \\:!:\
,
\
,
~,Iz\\r--\
,
\
,
200 \
,
200 \
,
\
,
\,
\
,
\,
~1 \,
AS \,\,
\,\,
100-O.\,
100 \,
OS··.\,0..\ 1
!""".\1...0...0PS...
,.-..---.--0 T'"T'"0 T'"T'"co co co co co co
'"'"'"'"'"'"T'"T'"T'"T'"T'"T'"
Cl ~Cl Cl ~Cl
~::I «::I ::I «::I«::i!:««::i!:«
SHREWS VOLES
11'-1
I
MS Masked Shrew R-bV Northern Red-backed Vole
AS Arctic Shrew TV Tundra Vole
OS Dusky Shrew MV Meadow Vole
I"'"PS Pygmy ShrewI
,...
TEMPORAL VARIATION IN NUMBERS OF SMALL
MAMMAL CAPTURES AT 12 SITES IN THE UPPER
SUSITNA RIVER BASIN,ALASKA
PREPARED BY TES /UNIVERSITY OF ALASKA FIGURE ,,,[lUlU
1 1 --]]-1 --1 1 )--1 ---J 1 --1 1
70 MASKED SHREW I·70 MEADOW VOLE
50 I:60 I
50 :I.50 I
I • •I40I..I 40 I• • i ••- •30 •I I 30 I
20 ··1 I·20 I
• I ••••••••~..•I
10 •••I.I 10.I•••••• ••·.1 •••••I •••
o 0
70.ARCTIC SHREW:70 TUNDRA VOLE I
60 I I 60 I I
I 1 I I
50 I I 50 I I
40 I I 40 I I
I I •I.I30I30II
20·:I·20 I·I
10 ••I...I • • •10..:I
••••••I ••••••Ie.••••••••••I ••••~..••o 0
70 DUSKY SHREW 70 SINGING VOLE
60 I 60 II•I50I50
I
40 I 40 III30I30
I
20 I 20 III10
•••••I•••••
10
••••••••..-.•-••1
0 0
70
60
00
40
30
20
10
NORTHERN RED-BACKED VOLE 70 BROWN LEMMING
I •I 60
I •I
I I 50
I •I ••40
I •••I •30•I I·••I •I·•••••§?20•••I •••~•I.•••••10••••••0
HERBACEOUS-I CONIFEROUS I MIXED &HERBACEOUS·CONIFEROUS MIXED &
DWARF &LOW SHRUB I FOREST I DECIDUOUS FOREST-DWARF &LOW SHRUB FOREST DECIDUOUS FORES1-
I I TALL SHRUB TALL SHRUB
HDc;CGRAS5 I'SEOGE·(iR/l,5~LOW I 'OPEN ---?WOODLAND BOG 'lURCH teALSAr.!-}TALL TAU
SHRliE!'llINlJfOlI WilLOW 5HRUB ~:SPRUCE SPRUCE -t ISPRUC~POPLAR AlDEA""GAASS
,I I
SEDGE·GRr,s:,;ISEDGE·GRASS/LOW I I OPEN WOODLAND I BIRCH IlAL5AM TALL TAU-
SHRUB/TUNDRA WILLOW SHAUB ~:SPRUCE ....SPRUCE ...SOG I 5PRUC-f'"f>O~I_AH"IH.DER;GRA.SIC
~I
ABUNDANCE PATTERNS OF EIGHT SMALL MAMMAL SPECIES
RELATIVE TO VEGETATION TYPES AT 42 SITES IN THE
UPPER SUSITNA RIVER BASIN,ALASKA 29 JULY -30 AUGUST 1981
PREPARED BY TES!UNIVERSITY OF ALASKA FIGURE 3.23 [Ai
CJ -J -I ,_c··--lc ...-]_.~l ~c-l ,o..'}0 --l --].0.01 -1--]---1 ----1 1
PREPARED BY TES/ADF&G
DEVIL CANYON
~....
FIELD STATIONS,ADULT ANADROMOUS
INVESTIGATIONS,ADF &G SUSITNA HYDROELECTRIC STUDIES,198'1
FIGURE 3.24 [Ii]
Slough 1
TALKEETNA STATION
A MATCHLINE
~o
Whiskers Creek -
o River Mile
r
-i
r
r
I"""
i
SLOUGH LOCATIONS AND PRIMARY TRIBUTARIES
OF THE SUSITNA RIVER FROM ABOVE THE
CHULITNA RIVER CONFLUENCE TO SLOUGH 4 (RKm 168)IAPD ('I
PREPARED BY TES I ADF&G FIGURE 3.25 un 0
l"-
i
-
f
l,\
r-
i
-
-
r"
I
j
o
o River Mile
Slough 6A--
-Slough 8
--Lane Creek
;)--_..Gash Creek
Oxbow 1
Slough 6 --
Slough 5
--Chase Creek
A MATCHLINE_..L.-.J,..;;...;.."";;
SLOUGH LOCATIONS AND PRIMARY TRIBUTARIES
OF THE SUSITNA RIVER BETWEEN
CHASE CREEK AND SLOUGH 8
PREPARED BY TESIADF&G FIGURE 3.26 [i]
r
....
r
-!
r
l.
r
I
r
r
"
r
o
o River Mile
Oxbow 2~-
RM 115 (RKm 1c:.c85,-,-}..r:::..L.~~
f----Slough 88
Slough 8C
-Slough 80
--Deadhorse Creek
-Little Portage Creek
--Me Kenzie Creek
---Lower Me Kenzie Creek
....
/"""
I
t
SLOUGH LOCATIONS AND PRIMARY TRIBUTARIES
OF THE SUSITNA RIVER BETWEEN LOWER
MCKENZIE CREEK AND SLOUGH 8B
PREPARED 8Y TES/AOF&G FIGURE 327 [i]
-
I"'"
I
r
!"""
l
l
I"""
I
rI,
r
l
I"""
[
,.....
I
i
""'"I
i
I
o RiverMile
o MATCHLINE
Fourth of July Creek --
--Sherman Creek
Vf------Slough 9
-Slough 8A
--Slough A
-Skull Creek
--Slough A'
Fifth of July Creek /
-Moose Slough
__L....-...L--.:C=--MATCH LI NE
--
,.....
I
SLOUGH LOCATIONS AND PRIMARY TRIBUTARIES
OF THE SUSITNA RIVER BETWEEN
MOOSE SLOUGH AND FOURTH OF JULY CREEK I A~I[l1
PREPARED BY TES I ADF&G FIGURE 3.28 10lO
r
-
r
..-
!
o RiverMile
E MATCHLINE
-Slough 20
-Slough 19
Slough 16
Slough 15-
-Gold Creek
GOLD CREEK STATION
Slough 10 -
r
I.
SLOUGH LOCATIONS AND PRIMARY TRIBUTARIES
OF THE SUSITNA RIVER BETWEEN
SLOUGH 9A (RKm 214)AND SLOUGH 20 (RKm 225)ru;;l
PREPARED BY TES /ADF&G FIGURE 3.29l11l1J
-i
-
I"'"
I
l
"...,
i
Portage Creek-
o
o River Mile
--Jack Long Creek
Slough 21
E MATCHLINE
SLOUGH LOCATIONS AND PRIMARY TRIBUTARIES
OF TH E SUSITNA RIVER BETWEEN
SLOUGH 21 (RKm 227)AN D DEVI L CANYON
PREPARED BY TES/ADF&G FIGURE 3.30 [iii]
-
r
I"""
I
rI
i
r
l
r
\
r
COOK INLET
o 5 10 Miles
~o 5 10 15 Kilometers
YENTNA STUDY REACH
PREPARED BY TES/ADF&G
YENTNA
STUDY
REACH
I
I '....r--'I - -I
,~,1 ANCHORAGE
r--,r----'--L..._J
FIGURE 3.31 [iii]
FIGURE 3.32 [iii
River
o 5 10 Miles
~o 5 10 15 Kilometers
SUNSHINE STUDY REACH
PREPARED BY TES I ADF&G
r
\
-i
r
,....
f
i
l
r
o 5 10 Miles
~o 5 10 15 Kilometers
River
~
<:I}
<:I}
~
U
><~
<:I}
""Cl
::0
-0
CC_____.,.-.uiii
Parks
Highway
Bridge
TALKEETNA
STUDY
REACH
-
r
-.r
r
r
!
r
\.
r
l
r
TALKEETNA STUDY REACH
PREPARED BY TES/ADF&G FIGURE 3.3,1iiJ
....
PREPARED BY TES I ADF&G
o 5 10 Miles
~o 5 10 15 Kilometers
FIGURE 3.34 [iii]GOLD CREEK STUDY REACH
~
<::>'l....
U
X
~
<::>'l
-'\j..:0
Cl
c:x:""-5~',,;--
r
I
r
r
....,
r
\,
"
r:-
!
I
l"-
I
I
-,
....
~l '~~I ...~').~~~1 ')j
o 5 10 Miles
~
o 5 10 15 Kilometers
......((.....
.Denali
Highway Bridge
IMPOUNDMENT
STUDY
REACH
Rive,.
DEVIL CANYON
DAM'SITE fl 8~
~
~o
o
/
•
4••I
I
..r----...-I
PREPARED BY TES/ADF&G
IMPOUNDMENT STUDY REACH
FIGURE 3.35 •
~"'~l "--1 -'j _.']1 -'1 'C)'cJ ~-'l "~,,c'l ·'-1 "-'),cc'-"")""'1 "']_..]j
~~~~~~~~~~~~~f~}Xf~~~};~11~i:¥
Total gas saturation
IInlllll Nitrogen saturation
......Oxygen saturation
i_."W1.ti.lI':'i Areas of suspected gas
entrainment
",V;;;,
";,
;;;
;;
;;;;\\W,"""""'/'/""'",'/'""""'/'/'/',,,'/'//',""/"""""""'/"'/1
;\\
;;;\\\"~~""""""""""""""""""""""""""""""I";;\\\
;;;;\\\\\
";\\\.......;~\.....
..................................................
•••••••••••••..........
(/)m
~
"0
(],)
>
0 110(/)
(/)
0-0
c:
0.....105<U....
:::J.....
<U
U)
(],)
C>
<U.....100c
(],)
()....
(],)
(L
95
.6 1 2 3 4 5 6 7 8 9 10 11 12 13
Miles above mouth of Portage Creek
PREPARED BY TES
DISSOLVED GAS SATURATION IN VICINITY OF DEVIL CANYON,
12 JUNE 1981
FIGURE 3.36 •
r
I
r-
i
[
r-"
I
I
("-I
I
I
!
r
r'"
I
i
(
IDENTIFICATION OF
IMPACTS &PRIORITIES
1
NEGOTIATION OF ACCEPTABLE PLAN
~1I.-_---1
6
8
r
PREPARED BY TES/ACRES
FISH AND WILDLIFE MITIGATION PLAN
DEVELOPMENT AND IMPLEMENTATION
FIGURE 3.37 [i]
r-
f
f·
r-r
I
,....
1
I
\
PARTIAL AVOIDANCE ~.__......TOTAL AVOIDANCE
NO AVOIDANCE
SOME MINIMIZATION
NO MINIMIZATION
~.
,....
j'
I'""I
PARTIAL RECTIFICATION <lllIII••••
TOTAL RECTIFICATION
NO RECTIFICATION
SOME REDUCTION
NO REDUCTION
,....
PARTIAL COMPENSATION
NO COMPENSATION
TOTAL COMPENSATION
-
PREPARED BY TES
OPTION ANALYSIS
FIGURE 3.38 •
r
,
t
,....,
r
r-
I
i
r--I
4 -REPORT ON HISTORIC AND ARCHEOLOGICAL RESOURCES
4.1 -Agency Consultation
(a)Consultation Methods
Archeological and historical resources must be identified for federally
funded or 1 icensed projects such as the Susitna Hydroelectric Project
(FERC 1981).Before any archeological testing can be conducted,
appropriate federal and state permits must be obtained.Moreover,no
other project-related ground-dist'urbing activities (e.g.geotechnical)
can be performed until the sites are cleared for cultural resources by an
archeologist with the appropriate federal and state archeological
permits.
The University of Al aska Museum obtained a Federal Antiquities Permit.
Formal appl ication,including vitae of support and supervisory
individuals,was made to the National Park Service and the necessary
permits received for 1980-81.In addition to the Federal Antiquities
Permit,a State Antiquities Permit was obtained for land within the study
area,designated "State Selected",that is,lands chosen by the State of
Alaska as part of the Alaska Native Claims Settlement Act of 1971.
Through both oral and written communications,the State Historic
Preservation Officer and State Archeologist have been advised of cultural
resource investigations associated with the Susitna project.Copies of
the Procedures Manual (APA 1980),Pl an of Study (Acres 1980),and the
1980 Annual Report for the Cultural Resources Investigation (APA 1981a)
were submitted for their review and comment and to document compliance
with appropriate state and federal legislation.
(b)Summary of Comments
Comments concerning the Federal Antiquities Permit appl ications were in
the form of stipulations to the permits by the National Park Service,the
Bureau of Land Management,and the U.S.Fish and Wildlife Service.These
comments specified the conditions of the permit.
The research design (Plan of Study,Procedures Manual)and the 1980
Cultural Resources Invest igat ion Annual Report were rev iewed by Mr.
Robert Shaw~State Historic Preservation Officer (SHPO),and by Mr.
Douglas Reger,State Archeologist.They concluded that the Annual Report
documents the survey act iv iti es conducted dur ing 1980 and adequately
accompl ished the tasks outl ined in the proposed work pl an.The SHPO
considers the work to date,however,to be prel iminary;reconnaissance
and testing should continue for areas not yet examined.In addition,
specific areas of disturbance and ancillary facilities must still receive
archeological clearance.Access roads and material sites must still be
examined in detail for cultural resources,and a mitigation plan must be
formulated.Both authorities feel that FERC should,and probably will,
include mitigation provisions when a permit is issued.Finally,the SHPO
and the State Archeologist must review the final report when it becomes
avail able.
4-1
4.2 -Survey Methods
(a)Objectives
The cultural resource program [see 4.2 (b)(ii)]had two objectives.The
first was to identify and document archeological and historical sites in
the Susitna study area.An archeological site is any area or structure
dating prior to 1897 and important to native Alaskan cultures.An
historical site dates from 1897,with the first native contact with
western culture,to 1949.The sites examined to meet this first
objective were in the impoundment zones,along portions of transmission
1 ine corridors,along the routes of proposed access roads,in borrow
areas,and in any other areas with the potential for experiencing ground
disturbance.
The second object ive of the cultural resource program was to test and
evaluate resources found in any of these areas,to address site
si gnifi cance,assess impact,and propose mit igat i on measures.
(b)Methods
(i)Study Areas
The cultural resources investigation involved three geographic
sections:the central,southern,and northern study areas.The
central study area,in which most of the efforts were concentrated,
included an area from approximately 3 km below Devtl Canyon on the
west to the Tyone River on the east and extended approximately 2 km
outside of the proposed Devil Canyon and Watana impoundments on the
Sus itna River.Areas affected by the other subtasks I ongoi ng
studies were also included in this study area (APA 1981a).
This central study area for cultural resources also includes the
transmission line alternatives from the dam sites to Gold Creek and
parts of some of the access road corridor alternatives.The
transmission line study areas also included northern and southern
sections.Descriptions of the alternative corridors can be found
in the Transmission Line Subtask 8.01 Close Out Report (Acres
1981).In brief,the northern section,approximately 8 km wide,is
a corridor from Healy to Ester;the southern section is an
approximately 8-km-wide corridor from Willow to Knik Arm;and the
central study area is from Watana dam west to the intertie.
The access road study area cons i sted of a number of alternat ive
corridors.One commenced on the Parks Highway near Hurricane;
another enters the study area from the Denali Highway;and the last
alternative provides access from Gold Creek.The Access Route
Selection Report,Subtask 2.10 (R&M 1981),and the Environmental
Analys is of Access Road Alternat ives (APA 1981b)provi de detail ed
descri pt ions of the access route a lternat i ves.
(ii)The Five-Step Program
In order to comply with regulations pertaining to cultural
resources and to provide the data necessary for preparation of the
4-2
-
r
I~
r
.....
I
I
-
Feas'ibility Report and the Federal Energy Regulatory Commission
license application,a five-step program was implemented.
Prefield Tasks --Step 1:Federal and state permits were applied
for and received.Federal Antiquities Permits (#80AK-23,
#81AK-209)and State of Alaska Permits (#80-1,#81-11)were
obtained for the project [see Section 4.1 (a),Consultation
Methods].A literature review of available documents pertaining to
the history,prehistory,ethnology,geology,flora,and fauna of
the study area was conducted (APA 1981a,Appendi x A and B).Us i ng
this information,a research design and strategy was formulated.
The research design integrated current data into a tentative
cultural chronology,which expl icated hypotheses that could aid in
the evaluation of sites located during survey and testing (APA
1980,1981a).The research strategy was structured to predict,
within the limits of contemporary archeological method and theory,
archeological site locations in relation to physical and
topographic features (APA 1981a).
Archeological sites occur in direct relation to associated
physical,topographic,and ecological features.Based on the
analysis of site locational data from regions adjacent to the study
area,the features characteristically associated with archeological
site occurrence are:areas of high topographic relief;natural
constrictions that would tend to concentrate game animals;
well-drained,relatively level areas;and lake,stream,and river
margins.Such areas were included in the survey locales selected
for examination.
Based on the delineated cultural chronology,documented topography,
ecological settings for sites within each culture period,and
geological evaluation of the study area,119 survey locales were
identified within the central study area as having relatively high
potential for archeological site occurrence.Aerial photography
interpretation was also conducted to delineate regional geology and
survey locales and to assess archeological potential.
Reconnaissance Testing Step 2:Reconnaissance-level
archeological testing consists of searches for cultural resources
on and below ground surface.Surface testing usually involves the
visual examination of areas where the soil is exposed,deflated,or
eroded.Sub-surface testing generally includes digging a hole
approximately 30 cm by 30 cm (a shovel test)and examining the
excavated soil for artifacts.
Archeological and historical sites within the central study area
were located and documented by using this technique.Detailed
site-specific information was recorded,including the geomorphic
feature on which the site was located,topographic setting,
elevation,slope,exposure,view,and stratigraphy as well as
details concerning the surrounding terrain.Survey forms were used
to record data on each site located as well as on each survey
locale investigated (APA 1980,1981a).
4-3
As specified in 36 CFR 66,a reconnaissance-level survey should be
used only as a prel iminary to intensive survey,since a
reconnaissance level survey and testing program is not intended to
cover 100%of the area.With this in mind and based upon the
st andard cultural resource research strategy,a 1imited but
representative portion of the study area,considered as having high
probability for archeological sites,was tested for cultural
resources.In addition,locales associated with proposed borrow
sources,access routes,transmission corridors,and areas affected
by geotechnical and other preconstruction studies were also
examined at various levels of intensity for cultural resources.
Reconnaissance-level testing,in and immediately surrounding the
proposed Devi 1 Canyon and Watana impoundment zone,in proposed
borrow areas,and in other areas affected by geotechnical and other
preconstruction studies,consisted of surface.and subsurface tests
as descri bed above (APA 1980).For the proposed access corri dors,
testing and surveys consisted of the identification of potential
cultural resource sites through the analysis of aerial photographs
and topographic maps and through limited,on-the-ground examination
of natural exposures.
For the proposed southern and northern transmission corridors,a
cur sory,four-hour fly-over was conducted to i dent i fy areas with
potential for cultural resource sites;on-the-ground examination of
natural exposures was limited to a few sites here.Data from the
reconnaissance-level testing in and around the impoundment zone and
from the access road routing analysis was used to evaluate the
cultural resources probability of transmission corridors in the
central study region.Also used in this analysis was information
from the State Archeologist1s Office files regarding the locations
of known archeological sites in the central,southern,and northern
transmission corridors (Acres 1981).
Systematic Testing Step 3:After a site is located by
reconnaissance-level testing,a few selected square meters of the
site are intensively excavated.All artifacts and features are
recorded,using standard archeological field methods.Systematic
testing was used to collect data to address site significance and
impact prior to developing individual mitigation measures and a
general mitigation plan (see Sections 4.4 and 4.5).Systematic
testing required transit surveys of sites,topographic mapping,and
excavation of selected units using standard archeological methods.
Since the number of sites that could be tested was limited,those
sites were given precedence that had the greatest potential for
producing data that would assist in developing an overall cultural
chronology for the upper Susitna River valley.This method enabled
extrapolation to other sites not subject to this level of testing.
Analysis and Report Preparation --Step 4:This process entailed
compiling the individual reports for each phase of the cultural
resources investigation as well as synthesizing and evaluating all
data gathered.Part of the evaluation included dating carbon
samples gathered from sites,using radiocarbon analysis.Step 4
also involved preparing and submitting reports on the progress and
results of the cultural resource studies.
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As part of the process of analysis and prior to recommending
mitigation measures,it is first necessary to determine if the site
or group of sites is significant.Determination of significance is
based on the application of National Register of Historic Places
criteria (36 CFR 60.6).which define significant sites as follows:
"The quality of significance in
American history.architecture.
archeology.and culture is present
in districts.sites.buildings,
structures.and objects of State and
local importance that possess
integrity of location.design,
setting.materials,workmanship.
fee 1i ng and assoc i at i on and:
(a)That are associated with events
that have made a significant
contribution to the broad patterns of
our history;or
(b)That are associated with the 1ives
of persons significant in our past;or
(c)That embody the distinctive
characteristics of a type,period,or
method of construction,or that
represent the work of a master,or
that possess high artistic values.or
that represent a significant and
distinguishable entity whose
components may lack individual
distinction;or
(d)That have yielded,or may be
likely to yield,information important
in prehistory or history."
A site or group of sites is eligible for inclusion in the National
Register of Historic Places if it is determined to be significant.
FERC regulations require a description of impacts on sites or
properties either listed in.or recommended as eligible for.the
National Register of Historic Places.The management plan for the
mitigation (including avoidance)of impacts on historical and
archeological sites and resources is to be based upon
recommendations from the SHPO and the National Park Service.The
appl icant may include an expl anation of vari ations from those
recommendations (FERC 1981).
To locate and document sites for this project,a program of
reconnaissance-level testing was implemented.In order to gather
sufficient data on which to base an evaluation of significance.
systematic testing was employed.In most cases (a notable
exception being historic cabins).systematic testing is necessary
to assess significance.To date,relatively few of the known
archeological sites have been systematically tested;therefore.a
determination of significance for most sites is not possible.
4-5
Significance implies a frame of reference;a problem orientation;a
geographic,temporal,or other context against which significance
is evaluated.Sites can be significant on several levels.Through
application of National Register criteria,a site may be evaluated
either as a single entity or in terms of its relationship to a
group of sites;that is,it may have relative significance.If all
of the sites within a drainage system such as the upper Susitna
were known and the region itself well studied (which it is not),
relative significance of sites or groups of sites could be
estab 1i shed with some degree of confi dence.When a site or group
of sites is located,however,in an area like the Susitna basin,
which is relatively unknown archeologically,it is difficult to
establish relative significance.
Significance ifself is also a relative term,used in an historic
context dependent on the current state of knowledge,on the method
and theory employed,and on research questions asked.New
techniques and methods have enabled archeologists to collect new
and different types of data,which,in turn,allow new questions to
be formulated and addressed.Currently,National Register criteria
for significance pertaining to archeological sites generally
emphasize research potential,site integrity,and/or public
appreciation;however,these criteria are subject to ongoing
mod if ic at i on.
Althouqh all the sites located as a result of this study are
related geographically and many,no doubt,temporally,
determination of the exact relationships awaits further study.
Most of the sites were found assoc i ated with one or more of three
tephras,which will provide limiting dates for most of the sites in
a restricted geographic context.Those dated sites will,in turn,
provide a unique and scientifically important opportunity to
construct the first cultural chronology for the upper Susitna River
basin.It may be appropriate to state that all sites are
significant and collectively hold the potential for defining the
prehistory for this region of Alaska,a task which has not yet been
accomplished.All the sites may,therefore,be eligible for
inclusion in the National Register.
Curation --Step 5:As required by federal law,all cultural
material was catalogued and accessioned to the University of Alaska
Museum along with all supporting documentation.The University of
Alaska Museum was designated on the Federal Antiquities Permit as
the repository for cultural material and documentation resulting
from this study.All artifactual material and supporting
documentation is,therefore,housed at the University of Alaska
Museum,Fairbanks,Alaska.
4.3 -Historical and Archeological Sites in the Project Area
(a)Central Study Area
Duri ng the summers of 1980 and 1981,in an effort to exami ne as much of
the study area as possible,111 of the 119 possible survey areas were
surveyed and tested,employing both surface and subsurface testing
4-6
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techniques.Examined were areas associated with the Watana and Devil
Canyon dams and impoundments,proposed borrow sources and assoc i ated
facilities,geotechnical areas,access routes and transmission line,and
areas containing archeological sites as reported by project personnel.A
tota 1 of 116 sites were actually located and documented duri ng the two
field seasons (Figures 4.1 through 4.3).Because of the large area
covered and the number of sites located,however,it was only possible to
systematically test 18 of those 116 sites.
Analysis of the field data presented is preliminary.As confirmed by the
SHPO,the number of sites found in the upper Susitna basin was
unexpectedly large (Shaw 1981 pers.comm.).Preliminary analysis of
faunal material from both reconnaissance and systematic testing indicates
that the majority identified represent caribou.Three volcanic ash
layers (tephras)were found in the study area.Radiocarbon testing has
produced preliminary limiting dates for these three layers.Although not
all the dates from similar stratigraphic units correspond,the radio-
carbon dates suggest that the upper 1ayer is between 1800 and 2300
radiocarbon years B.P.;the middle layer,2800 to 3200 radiocarbon years
B.P.;and the lower layer,older than 4700 radiocarbon years B.P.The
ability to correlate most archeological sites and individual components
within sites with the volcanic ash layers is highly significant,because
it is virtually unprecedented that so many sites could be accurately
dated without the uniform presence of carbon.Thus,all sites
collectively can provide information concerning the history and
prehistory of the upper Susitna valley (see Section 4.4).Preliminary
analysis of the data indicates that collectively,at least,all of the
archeological sites may be eligible for listing in the National Register
of Historic Places.Impacts on these sites are identified in Section 4.4
and a preliminary mitigation plan is presented in Section 4.5.
As described above,prior to any field work and as part of the overall
research design,a tentative cultural chronology for the upper Susitna
basin was developed.This cultural chronology which was based upon a
1 iterature search,appears in the Cultural Resources Procedures Manual
(APA 1980)and 1980 Annual Report (APA 1981a).The chronology suggested
that sites spanning the past ca.10,000 years would be found in the study
area.Preliminary analysis of cultural resources located during the two
field seasons of this project indicates that sites representing all
culture periods outlined in the tentative chronology occur in the study
area.A literature review of the archeology of central Alaska is also
presented in these reports.
Historical sites consist mostly of trappers'cabins.One collapsed
cabin might have been a line cabin used by Oscar Vogel in the 1930'sand
1940's.Another site,consisting of a cabin,kennels,and an outhouse,
was the trapping headquarters of Elmer Simco.The cabin was built in the
early 1930 1 s.At the mouth of Portage Creek is an inscription carved in
the rock and dated 1897,with the names of William Dickey and three other
individuals.Dickey was one of the first white men in the region.These
sites may meet some of the National Register criteria.The Simco cabin,
for example,may be considered to lIembody the distinctive characteristics
of a type,period,or method of construction.1I The Dickey inscription,
if genuine,may perhaps be considered to be lIassociated with the lives of
4-7
persons significant in our pastil.None of the historical sites in the
area,however,have yet been determined to be eligible for the National
Register.
(b)Southern and Northern Study Areas
Results from the southern and northern portions of the transmission line
route are presented in Figures 4.4,4.5,and 4.6.The cultural resource
sites indicated on these figures were determined from the files of the
St ate Archeo 1ogi st.One site,located on the edge of a northeast-
southwest trending terrace overlooking the Nenana River near Alaska
Railroad Mile Number 383,was discovered during a helicopter review of
the proposed transmission line routes.Areas of high potential for the
discovery of cultural resources are also illustrated in these figures.
4.4 -Impacts on Historic and Archeological Sites
To define the levels of impact that the Susitna Hydroelectric Project will
have on specific sites or groups of sites,the definition of the Advisory
Council on Historic Preservation was used.That [36 CRF 800.3 (a)J
definition states:
IIDirect effects are caused by the
undertaking and occur at the same time
and place.Indirect effects include
those caused by the undertaking that are
later in time or farther removed in
distance,but are still reasonably
forseeable.Such effects may include
changes in the pattern of land use,
population or growth rate that may
affect on properties of historical,
architectural,archeological,or
cultural significance.1I
In terms of the Susitna Project,sites directly affected are those which will
experience ground disturbing activities associated with preconstruction,
construction,operation,overall land modification,and ancillary development
of the project.These include dam construction sites,spillways,access
roads,borrow areas,camps,villages,transmission line rights-of-way,
staging areas and railroad yard,airstrip,and reservoirs behind the Devil
Canyon and Watana dams (Figure 9.7).A further consideration is the types of
activities that will take place in these areas.
Indi rect impact wi 11 occur on sites affected by altered tri butary hydrology
(erosion and soil saturation)brought about by the filling and lowering of
the reservoirs,by greater access to remote areas,by increased population in
the area during and after construction,by some project maintenance and
related activities,and by ancillary development expected to occur as a
result of the project.While some indirect results of the project on
surrounding sites are virtually assured,others are more difficult to
predi ct.An impact to sites or groups of sites can be predi cted to occur,
for example,as a result of expected recreational development or activity.
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The archeological profession has a third level of impacts called potential.
Potential impact is connected with possible future development resulting from
the project but which can not at present be predicted.Potential impact
could become direct or indirect depending on how these activities affect the
areas containing cultural resources.
(a)Central Study Area
Cultural resouce sites found in the central study area are located on
Figures 4.1 through 4.3.Those sites to be either directly or indirectly
affected by the project are distinguishable on these figures.
(i)Watana Dam and Impoundment
Two historic sites and 24 archeological sites will be directly
affected.One historic site and 23 archeological sites may be
indirectly affected.
(ii)Devil Canyon Dam and Impoundment
One historical and seven archeological sites will be directly
impacted.Three sites (one archeological,two historical)
including the Dickey inscription may be indirectly affected.
(iii)Borrow Areas,Associated Facilities,and Areas Disturbed by
Geotechnical Testing
One historic site and 10 archeological sites will be directly
affected by act i vit i es assoc i ated with these areas.Three
archeological sites may receive indirect impact.In any case,many
of these sites will have been directly or indirectly affected by
the Watana dam and reservoir.
(iv)Access Route
Although no historic sites are known to occur in the access road
corridor,eight archeological sites will be directly impacted
unless mitigative actions are taken.Six archeological sites may
be indirectly affected.Sites spared direct impact by minor
realignment of the route would still be subject to indirect
impact.
(v)Transmission Lines
Currently proposed transmission line routes contain seven known
archeological sites that could be directly impacted.An additional
seven sites may be indirectly impacted.Direct impacts (but not
necessarily indirect impacts)can be avoided by the actual routing
of the right-of-way.
(vi)Other Areas
The category "other areas II includes archeological sites identified
outside of the study area in addition to those sites within the
study area that will not be directly or indirectly affected by the
4-9
project.There are 42 such sites.They are placed in the
potenti al impact category since future impacts cannot at present be
predicted.As required by the FERC license application guidelines,
these sites are identified so that early in the pl anning stages of
the Susitna Hydroelectric Project all current data on cultural
resources are available to project planners.For example,if
Borrow Area F (along Tsusena Creek)were to be further enlarged to
the north,a number of cultural resource sites would likely be
directly or indirectly impacted.Other sites near Big Bones Ridge
(east of the Oshetna River),have a much more remote possibility of
being directly or indirectly impacted.
(b)Southern and Northern Transmission Corridors
Figures 4.4 through 4.6 illustrate known archeological sites along the
proposed transmission corridors in the southern and northern study areas.
The information regarding these sites was obtained from the files of the
State Archeologist.Known sites were a consideration in the transmission
line routing.These figures also illustrate areas with a high potential
for containing cultural resources,which were also a consideration in the
routing.
As discussed previously [see Section 4.2 (b)],no reconnaissance-level
testing for cultural resources was conducted.Therefore,undiscovered
sites may occur in the route.Although a potenti al does exist for
impacts on such sites,it may be possible to avoid at lea~t the direct
impacts during alignment of the actual right-of-way.
4.5 -Mitigation of Impacts on Historic and Archeological Sites
(a)Mitigation Policy and Approach
It is mandated by federal law (FERC 1981,United States 1974)that the
effect of any federal project or federally 1 icensed project on cultural
resources must be assessed and mitigation measures developed to lessen or
avoid the impact on these resources.Mitigation is a basic management
tool,providing options for either preserving,avoiding,or excavating
cultural resources.Although the concept of mitigation continues to be
refined,it clearly consists of three options:avoidance,preservation,
and investigation.
(i)Avoidance
Avoidance consists of any measures that avoid adverse effects of a
project on cultural resources.Avoidance in and of itself may not
be totally effective if not coupled with a preservation program.
The program should ensure that an historic or archeological site is
protected from the immediate adverse effect of the project (direct
impacts)and is not inadvertently damaged in the future as a result
of the project (indirect "impacts).For the Susitna Hydroelectric
Project,potential damage may result from,but is not limited to,
operation of the facilities,increased access to remote areas,
recreational activities,induced private development,and the
induced transfer of 1ands from federal and state governments to
corporate or private parties (and vice versa).Therefore,
4-10
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avoid ance must be cons i dered in terms of both
goals,the latter aimed at protecting cultural
immediate construction phase of the dam
f ac il it i es .
(ii)Preservation
short and long-range
resources beyond the
and its ancillary
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Preservation is any protective measure that results in the
reduction or avoidance of impacts on cultural resources through
physical maintenance or that prevents their further deterioration
or destruction.Preservation,as with avoidance,implies both
short-term and long-term measures.Preservat ion may consi st of
such techniques as stabilization,reconstruction,construction of a
barrier around the site,patrolling and monitoring the site,public
education,or the establishment of an archeological preserve.Of
all the preservation options available for the Susitna project,
public education may have the greatest potential for long-term
preservation not only of a particular site or group of sites but
also of all cultural resources in general.
(iii)Investigation
Investigation (systematic excavation)aims at collecting and
conserving archeological data in a scientific manner that addresses
significant questions about the past (USDI 1980b).A program of
this type means that data recovery procedures are developed for
each site or group of sites,analyses of materials collected are
undertaken,and the results are disseminated to professional and
public audiences.In addition to investigation as a method of
avoiding adverse effects,a site could be investigated,either
parti ally or in whol e if it appears to fit the research needs of
the overall cultural resource management program;it contains
information critical to the larger mitigation program;or it cannot
be protected from indirect impacts that may result from an increase
of off-the-road traffic,recreational use,the number of people in
the area,or site visibility.
(b)Mitigation Plan
Any mitigation plan must be based on an evaluation of project
consequences to the total resource,including both known and undiscovered
sites.Therefore,because only a portion of the area to be affected by
the Susitna Hydroelectric Project has been surveyed and investigated,any
mitigation plan must include a program to examine the entire area and to
mitigate adverse effects on all significant sites.
FERC regulations (FERC 1981)require that final recommendations be
submitted to the Alaska State Historic Preservation Officer for review
and comment.Following this step,a mitigation plan will be submitted as
part of the Susitna project's application.Prior to actually
implementing any mitigation plan,however,project managers must permit
the Advisory Council on Historic Preservation to comnent on the plan'S
efficacy.Compliance with recommendations to mitigate the effect of the
Susitna Hydroelectric Project on cultural resources is the responsibility
of the Alaska Power Authority.
4-11
(i)Details of Plan (Preliminary)
Mitigation of the impact on all sites that will be adversely
affected by the dams,impoundments,and ancillary facilities of the
Susitna Hydroelectric Project,either directly or indirectly,can
be accomplished by investigation as described above.Avoidance and
preservation may be a viable option for minimizing some indirect
impacts.Mitigation of potential impacts on sites in the Other
Areas category [Section 4.4 (a)(iii)],as well as impacts of the
access road and the transmission routes,can likely be achieved by
avoidance with an accompanying protection plan as described above.
-Impoundment Zones and Ancillary Facilities
Mitigation of the direct impact on eight sites and the indirect
impact on two sites in the Devil Canyon dam and impoundment area
can be accomplished by investigation;the Dickey inscription can
be avoided and preserved.Likewise,mitigation of the direct
impact on 26 sites and indirect impact on 24 sites in the Watana
dam and impoundment zone can also be achieved by investigation.
Finally,mitigation of the direct effects to 11 borrow area sites
and indirect impact on three other such sites can be accomplished
by investigation.Avoidance and preservation may also be a
viable alternative for mitigating indirect impacts to some
sites.
-Access Route
Mit i gat i on of the di rect impact of the project on ei ght sites and
indirect effects on six sites along the access route can be
accomplished by investigation.If realignment of the route can
be accomplished in certain areas,mitigation of direct impacts by
avoidance is possible;preservation or investigation could then
mitigate indirect impacts.r"'"
-Transmission Route
In the central study area,investigation,avoidance,and/or
preservation would mitigate the direct impact on seven sites and
indirect impact on seven sites;avoidance may mitigate the direct
impacts,but not necessari ly the indirect impacts,so preserva-
tion (or even investigation)would likely still be needed.
Currently,available data do not enumerate the sites that may be
directly or indirectly affected by the transmission line in the
southern and northern study area.It is assumed that once a
transmission route is surveyed,a reconnaissance-level survey
will be conducted.Since the transmission line right-of-way can,
in most cases,be aligned to skirt any cultural resources
located,mitigation of known sites can be accomplished primarily
by avoidance and preservation.The effects on those sites that
cannot be avoided by aligning tower locations and/or access roads
can be mitigated by investigation.
4-12
.....
-Other Areas
The 42 cultural resource sites included in "Other Areas"are in
the category of potential impacts.One reason for including them
in any mitigation plan is that if either the proposed project or
future land use changes in any way,then a site previously deemed
unaffected may,in fact,experience some consequences.In that
event,impacts would then be direct or indirect.Thus,the
existence of these areas should be recognized,and mitigation
should involve avoidance or preservation.If these measures do
not appear likely to be effective,investigation is possible.
(ii)State and Federal Agency Recommendations and Applicant's Variation
from these Recommendations
Final mitigation recommendations and the mitigation plan itself
Ii""'"
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wi 11 be submi tted to the State Hi stori c
the National Park Service for review and
and recommendations will be included
application.
4-13
Preservation Officer and
comment.Their comments
in the FERC license
KNOWN CULTURAL RESOURCES SITES,C
PREPARED BY TES I UNIVERSITY OF ALASKA
UJz
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5~;;C===?1p Miles
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10 15 Kilometers
LEGEND
•SITES DIRECTLY OR INDIRECTLY IMPACTED
o SITES OUTSIDE OF IMPACT AREA
AL STUDY AREA -MAP I
FIGURE 4.1 [Ii
KNOWN CUlrURAL RESOURCES SITES,CENTR
JNIVERSITY OF ALASKA
5 15 Kilometers10
5,0---=,10 Miles
I
o.,lIII---
o
AL STUDY AREA -MAP II.
FIGURE 4.,.
FIGURE 4.2 MATC
KNOWN CUlrURAL RESOURCES SITES,CENTR
NIVERSITY OF ALASKA
~+-_-----------i.~~-------+----T--I-:f.
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AL STUDY AREA -MAP III.
"5 10 Miles~N ~1----·5··1==:::10=======;11~5I"Kilometers
FIGURE '.3 Iii]
O 'o 5:'10i _)1'
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LEGEND
o KNOWN SITES
l1li AREAS OF HIGH POTENTIAL FOR CULTURAL RESOURCES
~j ,&Jtt 3,~6~~5W.1!-~I Ziiik u •iltiC'.G ,'-.-5 s~r::::,:,,:::\;~i,::','
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PREPARED BY TES
!
KNOWN SITES AND AREAS OF HIGH POTENTIAL FOR
CULTURAL RESOURCES,SOUTHERN STUDY AREA
FIGURE 4.4 •
-----------
FIGURE 4.6 MATCHLINE
\\o o 5 10 Miles
-;..II
o 5 10 15 Kilometers
700 .....
PREPARED BY TES
f KNOWN SITES AND AREAS OF HIGH POTENTIAL FOR
CULTURAL RESOURCES,NORTHERN STUDY AREA-MAP I
FIGURE 4.5.
<,
O 0 5 /10
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LEGEND
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o KNOWN SITES
..AREAS OF HIGH POTENTIAL FOR CULTURAL RESOURCES
PREPARED BY TES
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KNOWN SITES AND AREAS OF HIGH POTENTIAL FOR
CULTURAL RESOURCES,NORTHERN STUDY AREA -MAP II
FIGURE 4.••
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