HomeMy WebLinkAboutAPA161FERC LICENSE APPUCATION
EXHIBIT E
NOVEMBER 15,1982
CHAPTER 10
DRAFT
SUSITNA HYDROELECTRIC PROJECT
Prepared by:
•
l-__ALASKA P()WER AUTHOR ITY __---'
,~
SUSITNA HYDROELECTRIC PROJECT
FERC LICENSE APPLICATION
EXHIBIT E
CHAPTER 10
DRAFT
NOVEMBER 15,1982
L:
I""'-
od')Prepared by:
i.
M
M
ARLIS
Alaska Resources
.Library &Information Services
Anchorage ..Alaska
--T,_r:__ALASKA POWER AUTHOR ITY __--.-I
SUS ITNA HYDROELECTR IC PROJECT
EXHIBIT E
VOLUME 5 CHAPTER 10
ALTERNATIVE LOCATIONS,DESIGNS,AND ENERGY SOURCES
TABLE OF CONTENTS
Pag~
10 -AL TERNA TI VES TO THE SUS ITNA PROJECT •••••••••••.••.••••••••E:-10-1
10.1 -Al ternative Hydroelectric Sites E 10-1
(a)Non-Susitna Hydroelectric Alternatives ••••••••£-10-1
(b)Environmental Assessment of Selected
Alternat ive Sites E-10-7
(c)Upper-Susitna Basin Hydroelectric Alternatives E-10-13
10.2 -Altern at ive Fac i1 ity Designs E-1O-28
(a)Watana Facil ity Design Alternatives ••••••••.••E-10-29
(b)Devil Canyon Facil ity Design Alternatives .....E-10-30
(c)Access Al ternat ives •••••••••••••••••••••.•..••E-1O-31
(d)Transmission Alternatives E-1O-37
(e)Borrow Site Alternatives •••.•••.•••••.••.••.•.E-1O-62
10.3 -Alternative Electrical Energy Sources .••••••••••..•E-1O-81
(a)Coal-Fired Generation Alternatives E-10-81
(b)Tidal Power Altern at ives...•....••. ...•• . •• E-10-89
(c)Thermal Al ternat ives Other Than Coal •••.•.••••E-10-106
(d)Nuclear Power Altern at ive E-1O-116
(e)Bi omass •••...••.•...•..•....•••.......•.•...••E-I0-120
(f)Geothennal ...•••..••.•.•••...•.•..••••••••.•.•E-10-123
(g)Wind ...................•.............'E-IO-128
(h)Sol ar E-IO·-135
10.4 -Env ironmental Consequences of License Den i a1 •••....E.;.10-138
LIST OF REFERENCES
LIST OF TABLES
LIST OF FIGURES
ARLIS
Alaska Resources
Library &Informatton Servtces
AoC~~f~";,;;.AidSka
LIST OF TABLES
,~
Tabl e
E.10.1
E.10.2
E.1O.3
E.10.4
E.I0.5
E.1O.6
E.10.7
E.10.8
£010.9
E.10.1O
E.lO.11
E.1O.12
E.lO .13
E.1O.14
E.10.15
E.1O.16
E.10.17
E.10.18
E.10.19
E.10.20
E.10.21
E.10.22
E.10.23
£.10.24
E.10.25
E.10.26
£.10.27
E.10.28
LlO.29
£.10.30
E.1O.31
£.10.32
£.10 .33
Title
Summary of Resu1 ts of Screening Process
Sites Eliminated in Second Iteration
Evaluation Criteria
Sensitivity Scaling
Sensitivity Scaling of Evaluation Criteria
Site Evaluations
Site Evaluation Matrix
Criteria Weight Adjustments
Site Capacity Groups
Ranki ng Results
Shortlisted Sites
Altern at i ve Hydro Development Pl ans
Operating and Economic Parameters for Selected Hydroelectric Plants
Potential Hydroelectric Development
Results of Screening Model
Environmental Eval uation of Devi 1 Canyon Dam and Tunnel Scheme
Social Evaluation of Susitna Basin Development Schemes/Plans
Overall Evaluation of Tun'ne1 Scheme and Devil Canyon Dam Scheme
Environmental Eval uat i on of Watana/Devil Canyon and Hi gh Dev il
Canyon/Vee Development Plans
Overall Eva1 uat ion of the High Devi'l Canyon/Vee and Watana/Devi 1
Canyon Dam Plans
Environmental Constraints -Southern Study Area
Environmental Constraints -Central Study Area
Environmental Constraints -Northern Study Area
Summary of Screening Results
Alaskan Gas Fields
Alaskan Oil Fields
Sulfur Dioxide Emissions for Various Technologies
Particulate Matter Emissions for Various Technologies
Nitrogen Oxides Emissions For Various Technologies
National Ambient Air Quality Standards and Prevention of Significant
Deterioration Increments for Selected Air Pollutants
Water Qual ity Data for Sel ected Al askan Rivers
Fuel Availability for Wood and Municipal Wastes
Approximate Required Temperature of Geothermal Fluids For Various
Appl icat ions
LIST OF FIGURES
LI0.1
LI0.2
L10.3
LlO.4
E.1O.5
LI0.6
£.10.7
LI0.8
Title
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
Watana Borrow Si te Map
Devil Canyon Index Map
Potential Ti9al Power Sites
10 -At TERNATIVE LOCATIONS,DESIGNS,AND.ENERGY SOURCES
This chapter presents the results of assessments of the environmental
impacts of alternatives to the proposed Susitna Hydroelectric Project.
Included in this assessment is a consideration of alternative hydro-
electric generating sites outside the upper Susitna basin and alterna-
tive sites within the basin.The alternatives considered in
formulating the proposed project are discussed.Finally,an
environmental assessment of alternative methods of generation,
coal-fired hydroelectric,gas oil and tidal and other alternatives,is
presented in terms of differential environmental impact.
10.1 ..Alternative Hydroelectric Sites
(a)Non-Susitna Hydroelectric Alternatives
The ana lysi s of alternat i ve sites for non-Susitna hydropower
development followed the plan formulation and selection
methodology discussed in Exhibit B.
Step 1 in the plan formulation and selection process was to define
the overall objective of the exercise.For Step 2 of the process,
all feasible sites were identified for inclusion in the subsequent
screening process.The screening process (Step 3)eliminated.
those sites that did not meet the screening criteria and yielded
candidates which could be refined to include in the formulation of
Rai lbelt generation plans (Step 4).
Detai 1s of each of the above pl anni ng steps are gi ven below and
presented in Figure E.I0.1.The objective of the process was to
determine the opt imum Ra ilbelt generat ion pl an which incorporates
the proposed non-Susitna hydroelectric alternatives.
(i)Screening of Candidate Sites
As discussed in Exhibit B,numerous studies of
hydroelectric potential in Alaska have been undertaken.A
significant amount of the identified potential is located
in the Railbelt region.Review of the above studies and in
particular the various pUblished inventories of potential
r--sites identified a total 'of 91 patenti al sites (Table
E.10.1).All of these sites are technically feasible and,
under Step 2 of the planning process,were identified for
inclusion in the subsequent screening exercise.
The screening process appl ied to these sites for this
analysis required the application of four iterations with
progressively more stringent criteri a.
E-10-1
-First Iteration
The first screen or iteration determined which sites were
not economically viable and rejected these sites.The
standard for economic viability in this iteration was
defined as energy production cost less than 50 mills per
kWh,based on economic parameters.This value for energy
production cost was considered to be a reasonable upper
limit consistent with Susitna Basin alternatives for this
phase of the selection process.
As a result of this screen,26 sites were el iminated from
the planning process (Table E.1O.1).The remaining 65
sites were subjected to a second iteration of screening
which included additional criteria onenvi ronment a1
acceptabil ity.
-Second Iteration
The inclusion of environmental criteria into the planning
process required a significant data survey to obtain·
information on the location of existing and published
sources of environmental data.A detailed review of this
data and the sources used are presented in Reference 1.
The basic data collected identified two levels of detail
of environmental screening.The purpose of the first
level of screening was to el iminate thos·e sites which
were 1east acceptable from an envi ronmental standpoi nt.
Rejection of sites occurred if:
o They would cause significant impacts within the
boundaries of an existing National Park,Wild and
Scenic River,National Wilderness Area,or a proclaimed
National Monument area;
o Or they were located on a river in which:
.Anadromous fish are known to exist;
The annual passage of fish at the site exceeds
50,000;and
.Upstream from the site,a confluence with a tributary
occurs in which a major spawning or fishing area is
located.
E-10-2
-
-
I~
r-.
.-
The definitiohofthe abOve ex-elusiOn criteria was made
only after a review of the possible impacts of hydropower
development on the natural environment and the effects of
land issues on particular site development.
Of the 65 sites remaining after the preliminary economic
screening,19 sites were eliminated on the basis of the
requirements set for the second screen.These sites
appear in Table E.10.1,and the reason for their
rejection in Table E.IO.2.The location of the remaining
46 sites appears in Figure E.I0.2.
-Third Iteration
The reduction in the number of sites to 46 allowed a
reasonab 1e reassessment of the capital and energy
production costs for each of the remaining sites to be
made.Adjustments were made to take into account
transmission 1ine costs necessary to 1ink each site to
the proposed Anchorage-Fairbanks intertie.This
iteration resulted in the rejection of 18 sites based on
jUdgmental elimination of the more obvious uneconomic or
less environmentally acceptable sites (Table E.I0.l).
The remaining 28 sites were subjected to a fourth
iteration which entailed a more detailed numerical
environmental assessment.
-Fourth Iteration
To facilitate analysis,the remalnlng 28 sites were
categorized into sizes as follows:
o Less than 25 MW:5 sites;
o 25 MW to 100 MW:15 sites;and
o Greater than 100 MW:8 sites.
The fourth and final screen was performed using a
detailed numerical environmental assessment which
considered eight criteria chosen to represent the
sensitivity of the natural and human environments at each
of the sites.
The eight evaluation criteria are listed in Table E.IO.3.
For each of the evaluation criteria,a system of
sensitivity scaling was used to rate the relative
sensitivity of each site.A letter (A,B,C or 0)was
assigned to each site for each of the eight criteria to
represent this sensitivity.The scale rating system is
defined in Table E.IO.4.
E-IO-3
Each evaluation criterion has a definitive significance
to the Alaskan environment and degree of sensitivity to
impact (Reference 1,Appendix C2).A summary of the
evaluation and comparison of each site on the basis of
these criteria is presented in the following paragraphs.
(ii)Basis of Evaluation
The criteri a were initially weighted in accordance with
their rel at ive significance in compari sons.The first four
criteria--big game t agricultural potential,birds,and
anadromous fi sheri es were chosen to represent the most
significant features of the natural environment.These
resources require protection and careful management because
of their position in the Alaskan environment t their roles
in the existing patterns of life of the state residents,
and their importance in the future growth and economic
independence of the state.They were viewed as more
important than the following four criteri a because of their
quantifiable and significant position in the lives of the
Al askan people.
The remaining four criteria--wilderness;cultural,
recreation and scientific features;restricted land use;
and access--were chosen to represent the inst itutional
factors to be considered in determining any future land
use.These are special features which have been identified
or protected by governmental 1aws or programs and may have
varying degrees of protected status;or the criteri a
represent ex;st ing 1and status which maybe subject to
change by the potent ia 1 deve 1opments.
Data rel at ing to each of these criteri a were campi 1ed
separately and recorded for each site,forming a data-base
matrix.Then,based on these data,a system of sensitivity
scaling was developed to represent the relative sensitivity
of each environmental resource (by criterion)at each site.
A detailed explanation of the scale rating may be found in
Tab 1e E.10 .5.
The scale ratings for the criteria at each site were
recorded in the evaluation matrix.Site evaluations of the
28 sites under consideration are given in Table E.I0.6.
Prel iminary data regarding techn leal factors were al so
recorded for each potential development.Parameters
included installed capacity,development type (dam or
divers i on),dam hei ght t and new 1and fl aoded by
impoundment.The complete evaluation matrix may be found
in Table E.I0.7.
E-1O-4
-
-.
-.
-
,~
(iii)
In this manner,the envit6n~ental data were reduced to a
form from which a relat.ive comparison of sites could be
made.The compari son was carri ed out by means of a rank ing
process.
Rank Weighting and ScorinQ
For the purpose of evaluating the environmental criteria,
the following relative weights were assigned to the
criteri a.A higher val ue indicates greater importance or
sensitivity than a lower value.
Big Game
Agricultural Potential
Birds
Anadromous Fisheries
Wilderness Values
Cultural Val ues
Land Use
Access
8
7
8
10
4
4
5
4
The criteri a wei ghts for the fi rst four criteri a were then
adjusted down,depending on related technical factors of
the development scheme.
All the sites were ranked in terms of their dam heights
which were assumed to be the factor having the greatest
impact on anadromous fi sheri es.
Sites were also ranked in terms of their new reservoir
area,or the amount of new land flooded,which was
cons idered to be the one factor with greatest impact on
agriculture,bird habitat,and big game habitat.The same
adjustments were made for the big game,agricultural
potentials,and bird habitat weights based an this flooded
area impact (see Table E.IO.8).
The scale indicators were also given a weighted value as
fallows:
o B =5
o C =3
o 0 =1
To compute the ranking score,the seal e wei ghts were
multiplied by the adjusted criteria weights for each
criteria and the resulting products were added.
E-IO-5
Two scores were then computed.The total score is the sum
af all eight criteria.The partial score is the sum af the
first faur criteria only,which gives an indication of the
relative importance af the existing natural resources in
comparison to the total score.
(iv)Evaluation Results
The evaluation of sites took place in the following manner:
sites were first divided into three groups in terms of
thei r capac ity.
Based on the economics,the best sites were chosen and
environmentally evaluated as described above.Table E.10.9
lists the number of sites evaluated in each of the capacity
groups in ascending order according to their total scores
for each of the groups.The partial score was also
compared.The sites were then grouped as better,
acceptable,questionable,or unacceptable,based on the
scores.
The partial and total scores for each of the sites ,grouped
according to capacity,appear in Table E.10.10.
5i xteen sites were chosen for further cons i derat ion.Three
constraints were used to identify these 16 sites.First~
the most economical sites which had passed the
enviroi1mental screening were chosen.Second,sites with a
very good environmental impact rating which had passed the
economic screening were chosen.And finally,a
representative number of sites in each capacity group were
to be chosen (Table £.10.11).
From the list of 16 sites,10 were selected for detailed
development and cost estimates required as input to the
generation pl anning.The ten sites chosen are underl ined
in Table £.10.1.
Further discussion of the basis of selection of these 10
sites is presented in Reference 1,Appendix C2.
(v)Plan Formulation and Evaluation
Steps 4 and 5 in the planning process was the formulation
of the preferred sites identified in Step 3 into Railbelt
generation scenarios.To adequately formulate these
scenarios,the engineering,energy,and environmental
aspects of the ten short-listed sites were further refined
(Step 4).
E-I0-6
-
-
,~
(b)
This resulted in forMulation of the ten sites into five
development plans incorporating various combinations of
these sites as input to the Step 5 evaluations.The five
development plans are given in Table E.1O.12.
The essential objective of Step 5 was established as the
derivation of the optimum plan for the future Railbelt
generation,incorporating non-Susitna hydro generation as
well as required thermal generation.The methodology used
in the eval uat ion of altern at i ve generati on scenari os for
the Railbelt is discussed in detail in Reference 2,Section
8.The criterion on which the preferred plan was finally
selected in these activities was least present-worth cost
based on economic parameters established in Reference 2,
Section 8.
The selected potenti al non-Susitna hydro developments
(Table E.10.13)were ranked in terms of their economic cost
of energy.These developments were then introduced into
the all-thermal generating scenario in groups of two or
three.The most economic schemes were introduced first
followed by the less economic schemes.
On the basis of these evaluations,the most viable
alternative to the Susitna project was found to be the
development of the Chakachamna,Keetna,and Snow sites for
hydroelectric power,supplemented with a thermal generating
facility.The potential environmental impacts of
hydroelectric development at these sites are discussed
below;discussion of the environmental effects of thermal
development is in Section 10.3(a).
Environmental Assessment of Selected Alternative Sites
The analysis of alternative development scenarios outside the
upper Susitna Basin showed Chakachamna,Snow and Keetna
hydroelectric sites offer the most suitable schemes for
development.Because maximum total power production from these
three sites would be only 650 MW,additional thermal and tidal
development would also be required.The potential environmental
impacts of hydroelectric development at these three sites are
discussed below;coal-fired thermal and tidal power are discussed
in Sections 10.3(a)and 10.3(b).
The Chakachanmna area has been studied previously for
hydroelectric development and is currently under study by the
Power Authority (3).As such,fairly detailed information is·
available.Keetna and Snow,however,have not been intensively
studied and information is limited primarily to non-specific
inventory data and resource maps.
E-10-7
(i)Description of Chakachamna Site
Chakachamna Lake is located in the Alaska range
approximately 80 miles west of Anchorage.The lake is
drained by the Chakachatna River which runs southeasterly
out of the lake and eventually into Cook Inlet.The most
likely dev€lopment of Chakachamna Lake would be with a lake
tap of Chakachamna Lake with a diversion tunnel
(approximately 23 feet in diameter)to the MacArthur River
Basin.This development would provide some allocation of
water for fish purposes.The power pl ant woul d have an
installed capacity of 330 MW and could provide
approximately 1~446GWH of firm energy.Transmission lines
would run from the siteto a location near the Chugach
Electric Association (CEA)Beluga power plant and would
then parallel existing lines to a submarine crossing of
Knik Arm and then to a terminal on the eastern shore
(3)•
-Topography and Geology
Chakachamna Lake is located in a deep valley of the
Alaska range surrounded by glaciers and high mountains.
From an elevation of approximately 1200,land elevation
drops fairly rapidly to sea level within 40 miles.In
lower elevations,drainage is poor with numerous wetlands
present.
Lake Chakachamna was formed by the Barrier Glacier and
associated morainal deposits descending from the south
side of Mount Spurr.The area is underlain by
semi-consolidated volcanic debris of late Tertiary or
Quaternary age and,closer to Cook Inlet,by alluvial and
tidal sand,silt,and gravel of Holocene age (4).Past
movement by gl aciers has resulted in scattered boulders
and glacially scattered till.Chakachamna Lake,the
south side of the Chakachatna River Valley,and the
MacArthur River Canyon are bordered by granitic bedrock.
The north side of the Chakachatna River Valley is
bordered by va lcanic bedrock.
-Surf~ce Hydrology
Chakachamna lake is approximately 13 miles in length and
is 1.5 to 3.0 miles wide.Inflow to the lake is
primarily glacial in origin and consists of the
Nagishl amina and Chi 11 igan Rivers entering from the north
(6)..
E-10-8
~,
~,
~-
rp%"'l.
The Chakachatna Ri ver or;gi nates at the out 1et of
Chakachamna Lake and flows easterly approximately 15
miles through a canyon and then through lowland areas to
Cook Inlet.Mean annual discharge at its origin is 3645
cfs with a range from 441 cfs in Apri 1 to 12,000 cfs in
July;average annual stream flow at the reservoir site is
estimated at 2.5 million acre feet (3).The total length
is 36 miles and the total drainage area is 1,620 square
mil es.
The MacArthur River originates from the MacArthur glacier
and is also fed by the Blockade glacier.The river is
later joined by waters from Noaukta Slough,which carry
water from the Chakachatna River.The MacArthur Ri ver
continues to the confluence with the Chakachatna and then
empties into Trading Bay.
-Terrestrial Ecology
Vegetation in the project area varies with elevation and
moisture conditions.The major community types present
inc 1ude spruce forest;bogs,and wi 11 ow th ic kets .
Dominant species present include paper birch~black
cottonwood,alder,bog blueberry,and willow (3).
Big game species utilizing the area include moose,
caribou~black bear,and grizzly bear.Other species
present include wolverine~mink~and various small
mammals (3).
Birds present in the area are typical for the area of
Alaska~with peak numbers and species occurring during
the spring and fall migration periods.Goldeneyes were
observed nesting ;n the area in 1960 with other waterfowl
spec i es present duri ng mi grat i on.inc 1ud;ng redheads.
greenwingetl teal and mallards;bald eagles and trumpeter
swans are known to nest in the area primari 1y near Cook
In 1 et (3).
-Aquatic Ecology
The water of the tri butari es to Chakachamna Lake~the
lake itself and the Chakachatna and MacArthur Rivers
provide a variety of water temperatures,water quality
and substrate,resulting in various types of aquatic
habitats.
E-IO-9
Chakachamna Lake contains popul ations of lake trout,
Dolly Varden,whitefish and sculpins (6).More
importantly,sockeye salmon migrate up the Chakachatna
River and spawn within Chakachamna Lake.Although the
lake is not heavily utilized by sport fishermen,these
spawning salmon contribute to the commercial fisheries of
Cook Inlet.
The Chakachatna River is utilized by a wider variety of
fish species.The upper reaches are characterized by
boulders and swift currents and do not appear to be a
spawning area.The main stem of the Chakachatna River is
ut i 1i zed primari ly as an avenue for fi sh to travel to
Chakachamna Lake and its tributori es.Spawning of
anadromous fish has primarily taken place in the
tributaries to the Chakachatna River and Chakachamna Lake
along with some cl ear water s10 ughs adj acent to th e
Chakachatna River.
The MacArthur River supports a fishery similar to that of
the Chakachatna (7).Dolly Varden are present with
chinook,coho,pink,sockeye,and chum salmon present as
spawners in the side channels.Pygmy whitefish occur
further downstream (3).
-Cultural Resources
The Alaska Heritage Resource Survey File maintained by
the State Historic Preservation Office 1 ists no sites.
present in the Chakachamna project area.The area has
not been thorougly studied and further investigations
would be necessary should the project proceed.
-Socioeconomics'
The Chakachamna project is located in a sparsely
populated area of the Kenai Peninsula Borough.The only
corrrnunity in the vicinity of the project area is the
native village of.Tyonek,papulation 239.Commercial
fishing and subsistence activities are the major sources
of income with some employment provided by timber
harvesting,gas and oil exploration activities and
go v ernmen temp 10 ymen t.
Housing consists primarily of prefabricated structures.
One schoo 1 serves grades K through 12,with a current
enrollment of 146.Poli~e protection is provided by the
E-IO-IO
-
-
~I
~,
-
-
,~
(i i )
Alaskan State Troopers,headed by a resident constable.
Fire protection is provided by the U.S.Bureau of Land
Management.Medical services are available in a medical
center located in the village.Water is supplied from a
nearby lake and wastewater disposed via septic systems.
Transportation is limited to gravel surface roads and
small airstrips.
The Kenai Borough and City of Anchorage would likely
contribute to the work force for the project.The work
force in the Borough is 12,300,with 9.8 percent
unemployed;Anchorage has a work force of 91,671,with
6.9 percent unemployment (3).
Description of Snow Site
The Snow site is located on the Snow River in the Kenai
Peninsula (Figure E.10.2).Power development would include
.a dam with diversion through a tunnel approximately 7,500
to 10,000 feet in length.A transmission line would extend
from the site northward for nine miles to Kenai Lake and
then northwesterly for 16 miles to tie in with existing
lines.
The Snow Ri ver at the proposed dams ite flows ina deep
narrow gorge cut into bedrock on the floor of a glacial
valley.GrayWacke and slate are exposed and this
overburden is evident (8).The river flows west and north
into the south end of the Kenai Lake.The average annual
streamflow at the damsite is estimated at 510,000 to
535,000 cfs.The damsite would be fed by 105 square miles
of the river's 166 square mile drainage area (S).
Vegetation in the area is primari ly a hemlock-spruce
forest.Black bear,wolf and dall sheep are known to occur
in the area,and a moose concentration area is present.
Waterfowl util ize the area both for nesting and molting.
No anadromous fish are known to occur in the Snow Ri ver,
but sockeye and coho salmon are present in the drainage.
Rainbow trout and whitefish also occur in Kenai Lake.
Reports consulted listed no known cultural resource sites
in the Snow area.
E-lO-ll
(iii)Description of Keetna Site
The Keetna site is located on the Talkeetna River,
approximately 70 miles north of Anchorage (Figure E.10.2).
Power development would include a dam with a diversion
tunnel.
The Talkeetna River,with headwaters in the Talkeetna
mountains,flows southwesterly to its confl uence with the
Susitna River.The damsite has.a drainage area of 1,260
square miles;stream flow records indicate discharge at the
site to be 1,690,000 acre feet (8).
Vegetation on the lower elevations of the valley are
pr imaril y upland spruce-h ardwood forest.Th e upper
elevations have little vegetation.Black bear and brown
bear are present and the area is a known moose
concentrat ion area.,iJ.,caribou winter range is nearby.
Four species of anadramous fish are present in the area
(chinook,sockeye,coho,and chum salmon).The chinook
salmon is known to spawn in tri butari es upstream of the
proposed site.
Reports consulted 1i sted no known cultural resources at the
site.
(iv)Environmental Impacts of Selected Alternatives
Most env ironmental impacts at the Chakachamna,Snow and
Keetna sites would be those that typically occur with
hydroelectric development.Vegetation and wi ldl ife habitat
would be lost,resulting in a reduction in carrying
capacity and wildl ife popul atians at the site.Based on
the availability of habitat in surrounding areas,this
would likely not be a major impact.Reductions in fish
populations would reduce the food source for bears,eagles,
and other fish-eating wildlife;this could affect local
populations.Creation of a reservoir at the Snow and
Keetnasites would provide a different habitat type and
benefit such speci es groups as waterfowl and fur bearers.
Any archaeo 1ogica 1 or hi stari c sites in the reservo ir areas
would be flooded.On-ground surveys,salvage operations
and protection of areas outside the reservoir but within
the construction area,would mitigate most of these
potent i alimpacts.
The Keetna reservoir would inundate two scenic areas;
Sentinel Rock and Granite Gorge.
E-IO-12
-
Socioeconomic impacts would be simil ar at each site.It is
expected there would be an increase in population in the
towns near the site and associated increase in demand for
housing,schools and other services.Because all three
sites are located within 100 miles of Anchorage,it is
expected much of the labor force would be drawn from this
area where an adequate work force is pres ent .Con st ruct i on
camps would likely be erected to house workers,thereby
reducing demand on surrounding towns.Socioeconomic
impacts for the Chakachamna site would be simi 1ar to those
described for thermal development but of lesser magnitude.
The greatest potenti al impact of these developments is to
the fisheries resources,part icul arlyat the Chakachamna
site.Creation of the reservoir at the Keetna and Snow
sites would flood river areas,thereby reducing this type
of habitat.At the Keetna site,spawning areas may be
affected and upstream migration of the anadromous salmon
also curtailed,unless fish ladders are constructed and
adequate downstream flows maintained.At this time,the
detailed studies necessary to determine adequate flows for
power generation and fishery maintenance have not been
conducted.
Dam and power development at the Chakachamna site has the
potential to negatively impact anadromous fish.This
impact would result from decreased flowing or dewatering
from the upper portions of the Chakachatna River,
alterations in water qual ity,loss of spawning habitat,or
decrease in the food base.All of these impacts,if 1arge
enough,could impact the commercial fisheries of Cook
Inl et;the magnitude of these impacts would depend upon the
design and operating scheme to produce power.
The diversion into the MacArthur River via tunnels would
increased flows and coul d result in changes in water
qual ity and temperature,perhaps affect ing the abil ity of
anadromous fish to migrate upstream to the spawning areas.
(c).Upper Susitna Basin Hydroelectric Alternatives
A second feature of the alternatives analysis involved the
consideration of alternative sites within the Upper Susitna Basin.
This process involved consideration of technical,economical,
environmental,and social aspects.
E-10-13
This section describes the environmental consideration involved in
the selection of Devil Canyon/Watana sites as the preferred sites
within the Upper Susitna Basin and also presents a brief
comparison of the environmental impacts associated with
alternatives that proved economically feasible.This section
concentrates on the environmental aspects of the selection
process.Details of the technical and economic aspects of this
evaluation are discussed in Reference 2,Section 8,and also in
Reference 1,Section 8.
The objectives of the selection process were to determine the
optimum Susitna Basin Development Plan and to conduct a
prel iminary environmental assessment of the alternatives in order
to compare those judged economically feasible.The selection
process followed the Generic Plan Formulation and Selection
Methodology described in Exhibit B.Damsites were identified
following the objectives described above.These sites were then
screened and assessed through a sequential unarrowing down u
process to arrive at a recommended plan (Figure E.10.4).
(i)Damsite Selection
In the previous Susitna Basin studies discussed in
Reference 2,Section 4,12 damsites were identified in the
upper portion of the basin,i.e.,upstream from Gold Creek
(see Figure E.10.5).These sites are listed below:
-Gold Creek
-Olson (alternative name:Susitna II)
-Devi 1 Canyon
-High Devil Canyon (alternative name:Susitna I)
-Devil Creek
-Watana
-Susitna III
Vee
-Maci aren
-Denal i
-Butte Creek
-Tyone
Longitudinal profi les of the Susitna River and probable
typical reservoir levels associated with the selected
sites were prepared to depict which sites were mutually
exclusive,i.e.,those which cannot be developed jointly
since the downstream site would inundate the upstream
site.All relevant data concerning dam type,capital
cost,power,and energy output were assembled (Reference
2,Section 8).Results appear in Table E.I0.14.
£-10-14
-
~I
-
-,
I~
,~
I,
(ii)SiteScreening
The objective of this screening exercise was to eliminate
sites which would obviously not feature in the initial
stages of a Susitna Basin development pl an and which,
therefore,do not require any further study at this stage.
Three basic screening criteria are used;these include
environmental,alternative sites,and energy
contribution.
-Environmental Screening Criteria
The potential impact on the environment of a reservoir
located at each of the sites was assessed and
catagorized as being relatively unacceptable,
significant,or moderate.
o Unacceptable Sites
Sites in this category are classified as unacceptable
because either their impact on the environment would
be extremely severe or there are obviously better
alternatives available.Under the current
circumstances,it is expected that it would be
difficult to obtain the necessary agency approval,
permits,and licenses to develop these sites.
The Gold Creek and Olson sites both fall into this
category.As salmon are known to migrate up Portage
Creek,a development at either of these sites would
obstruct this migration and inundate spawning grounds.
Available information indicates that salmon do not
migrate through Devil Canyon to the river reaches
beyond because of the steep fall and high flow
velocities.
Development of the mid-reaches of the Tyone River
would result in the inundation of sensitive big game
and waterfowl areas,provide access to a large expanse
of wilderness area,and contribute only a small amount
of storage and energy to any Sus itna development.
Since more acceptable alternatives are obviously
available,the Tyone site is also considered
unacceptab 1e.
o Sites With Significant Impact
Between Devil Canyon and the Oshetna River,the
Susitna River is confined to a relatively steep river
valley.Upstream from the Oshetna River the
E-IO-15
surro undi ng topography fl attens,and any development
in this area has the potential of flooding large areas
even for relatively low dams.Since the Denali
Highway is relatively close by,this area is not as
isolated as the Upper Tyone River Basin.It is still
very sensitive in terms of potential impact on big
game and waterfowl.The sites at Butte Creek,Denal i,
Mac 1aren,and,to a 1esser extent,Vee fi t into th is
category.
o Sites With Moderate Impact
Sites between Dev i1 Canyon and the Oshetna Ri ver have
a lower potential environmental impact.These sites
include the Devil Canyon,High Devil Canyon,Devil
Creek,Watana and Susitna sites,and,to a lesser
extent,the Vee site.
-Alternative Sites
Sites whi ch are close to each other and can be regarded
as alternative dam locations can be treated as one site
for project definition study purposes.The two sites
which fall into this category are Devil Creek,which can
be regarded as an alternative to the High Devil Canyon
site,and Butte Creek,which is an alternative to the
Denali site.
-Energy Contribution
The total Susitna Basin potential has been assessed at
6,700 aWh.As discussed in the load forecasts in
Exhibit B,additional future energy requirements for the
period 1982 to 2010 are forecast to range from 2,400 to
13,500 GWh.It was therefore decided to limit the
minimum size of any power development in the Susitna
Basin to an average annual energy production in the
range of 500 to 1,000 GWh.The upstream sites such as
Maclaren,Denali,Butte Creek,and Tyone do not meet
this minimum energy generation criterion.
-Scr.eeni"9 Process
The screening process involved eliminating all sites
fall ing in the unacceptable environmental impact and
alternative site categories,Those failing to meet the
energy contribution criteri a were al so e 1 im;nated unl ess
they had some potential for upstream regulation.The
resu lts of th is proces s are as fa 11 ows :
E-10-16
-
-
(ii i)
o The unacceptable site environmental category
eliminated the Gold Creek,Olson,and Tyone sites.
o The alternative sites category el iminated the Devi 1
Creek and Butte Creek sites.
o No additional sites were eliminated for failing to
meet the energy contribution criteria.The remaining
sites upstream from Vee,i.e.,Maclaren and Denal i,
were retained to insure that further study be directed
toward determining the need and viability of providing
flow regulation in the headwaters of the Susitna.
Formulation of SusitnaBasinDevelopment Plans
In order to obtain a more uniform and reliable data base
for studying the seven sites remaining,it was necessary
to develop engineering 1ayouts for these sites and
re-eval uate the costs.In addition,it was al so necessary
to study staged developments at several of the larger
dams.These 1 ayouts were then used to assess the sites
and plans from an environmental perspective.
The results of the site-screen ing exerci se descri bed above
indicate that the Susitna Basin Development Plan should
incorporate a combination of several major dams and
powerhouses located at one or more of the following
s itas:
-Devil Canyon,
-High Devil Canyon,
-Watana,
-Susitna III,
-Vee.
In addition,the following two sites should be considered
as candidates for supplementary upstream flow regulation:
-MacLaren,
-Denali.
To establish very quickly the likely optimum combination
of dams,a computer screening model was used to directly
identify the types of pl ans that are most economic.
Results of these runs indicate that the Devil
Canyon/Watana or the High Devil Canyon/Vee combinations
are the most economic.In addition to these two basic
development pl ans,a tunnel scheme,which provides
potent i a1 environmental advantages by rep1 aci ng the Devi 1
Canyon dam with a long power tunnel,and a development
plan involving the two most economic damsites,High Devil
Canyon and Watana,were also introduced.These studies
are described in more detail in Table LIO.15.
E-10-17
These studies resulted in three basic plans involving dam
combinations and one dam/tunnel combination.There were
Plan 1 which involved the Watana-Devil Canyon sites;Plan
2,the High Devil Canyon-Vee sites;Pl an 3,the
Watana-tunnel concept;and Pl an 4,Watana ..Hi gh Devil
Canyon sites.
-Plan 1
Three subplans were developed:
o Subplan 1.1:Stage 1 involves constructing Watana Dam
to its full height and installing 800 IYlW.Stage 2
involves constructing Devil Canyon Dam and installing
600~..
o Subplan 1.2:For this sUbplan,construction of the
Watana dam is staged from a crest elevation of 2,060
feet to 2,225 feet.The powerhouse is also staged
from 400 MW to 800 MW.As for SUbplan 1.1,the final
stage involves Devil Canyon with an installed capacity
of 600 MW.
o Subplan 1.3:This subplan is similar to SUbplan 1.2
except that only the powerhouse and not the dam at
Watana is staged.
-Plan 2
Th ree s ubp lan s were a 1so deve loped under Plan 2:
o Subplan 2.1:This subplan involves constructing the
High Devil Canyon Dam first with an installed capacity
of 800 MW.The second stage involves constructing the
Vee Dam with an installed capacity of 400MW.
o SUbplan2.2:For this subplan,the construction of
High Devil Canyon Dam is staged from a crest elevation
of 1,630 to 1,775 feet.The installed capacity is
also staged from 400 to 800 MW.As for Subplan 2.1,
Vee follows with 400 MW of installed capacity.
a Subplan 2.3:This subplan is similar to Subplan 2.2
except that only the powerhouse and not the dam at
High OevilCanyon is staged.
E-l0-18
-
~l
FA
,
""'"
-Plan 3
This plan involves a long power tunnel to replace the
Devil Canyon dam in the Watana/Devil Canyon development
plan.The tunnel alternative could develop similar head
as the Devil Canyon dam development and would avoid some
environmental impacts by avoiding inundating Devil
Canyon.Because of low winter flows in the river.a
tunnel alternative was considered only as a second stage
to the Watana development.
A plan involving a tunnel to develop the Devi 1 Canyon
dam head and a 245-foot-high re-regulation dam and
reservoir was selected with the capacity to regulate
diurnal fluctuations caused by the peaking operation at
Watana.The plan involves two subplans.
o Subplan 3.1:This subplan involves initial
construction of Watana and installation of 800 MW of
capacity.The next stage involves the construction of
the downstream re-regulation dam to a crest elevation
of 1,500 feet and a IS-mile-long tunnel.A total of
300 MW would be installed at the end of the tunnel and
a further 30~IW at there-regulation dam.An
additional 50 MW of capacity would be installed at the
Watana powerhouse to facilitate peaking operations.
o Subp191'l 3.2:This subpl an is essentially the same as
Subp 1 an 3.f except that coo s tructi on of the i 0 itia1
800 MW powerhouse at Watana is staged.
-Pl an 4
This single pl an was developed to evaluate the
development of the two most economic damsites,Watana
and High Devil Canyon.jointly.Stage 1 involves
constructingWatana to its full height with an installed
capacity of 400 MW.Stage 2 involves increasing the
capacity at Watana to 800 MW.Stage 3 invol ves
construct i ng Hi gh Devi 1 Canyon to a crest el evat i on of
1470 so that the reservoir extends to just downstream
from Watana.In order to develop the full head between
Watana and Portage Creek,an additional smaller dam
would be added downstream from High Devil Canyon.This
dam waul d be located just upstream from Portage Creek so
as not to interfere with the anadromous fisheries.It
would have a crest elevation of 1030 and an installed
capacity of 150 MW.For purposes of these studies,th"is
site is referred to as the Portage Creek site.
E-10-19
(iv)Plan Evaluation Process
The overall objective of this step in the evaluation
process was to select the preferred basin development
plan.A preliminary evaluation of plans was initially
undertaken to determine broad comparisons of the available
alternatives.This was followed byappropri ate
adjustments to the plans and a more detailed evaluation
and compari son.
Table E.10.14 lists pertinent details such as capital
costs and energy yields associated with the selected
plans.The cost information was obtained from the
engineering layout studies.The energy yield information
was developed using a multi-reservoir computer model.
A more detailed description of the model appears in
Reference 2,Section 8.
In the process of evaluating the schemes,it became
apparent that there would be environmental problems
associated with allowing daily peaking operations from the
most downstream reservoir in each of the plans described
above.In order to avoid these potential problems while
still maintaining operational flexibility to peak on a
daily basis,re-regulation facilities were incorporated in
the four basic plans.These facilities incorporate both
structural measures,such as re-regul ation dams,and
modified operational procedures under a series of form
modifi ed pl ans,E1 through E4.
-El Pl ans
For Subplans 1.1 to 1.3,a low,temporary re-regulation
dam is constructed downstream from Watana during the
stage in which the generating capacity is increased to
800 MW.This dam would re-regulate the outflows from
Watana and allow daily peaking operations.It has been
assumed that it woul d be poss ib 1e to incorporate thi s
dam with the diversion works at the Devil Canyon site,
and an allowance of $100 million has been made to cover
any additional costs associated with this approach.
In the final stage,only 400 MW of capacity is added to
the dam at Devil Canyon instead of the original 600 MW.
Reservoir operating rules are changed so that Devil
Canyon dam acts as the re-regulation dam for Watana.
E-10-20
-
.~
-E2 Plans
For Subplans 2.1 to 2.3,a permanent re-regulation dam
is located downstream from the High Devil Canyon site,
while at the same time,the generating capacity is
increased to 800 MW.An allowance of $140 million has
been made to cover the costs of such a dam.
An additional Subplan £2.4 was established.This plan
is similar to E2.3 except that the re.,.regulation dam is
ut il i zed for power product ion.The dams it e is loeated
at the Portage Creek site with a crest level set to
uti 1 i ze the full head.A 150 MW powerhouse is
installed.As this dami s to serve as a re-regul at ing
facil ity,it is constructed at the same time as the
capacity of High Devil CanyOn is increased to 800 MW,
i.e.,during Stage 2.
-E3 Pl an
TheWatana tunnel development pl an already incorporates
an adequate degree of re-regulation,and the E3.1 Plan
is,therefore,identical to the 3.1 Plan.
-E4 Plans
The E4.1 Pl an in corpor ates a re...regu 1at ion dam
downstream from Watana during Stage 2.As for the £1
Pl ans,it has been assumed that it would be possible to
incorporate this dam as part of the diversion
arrangements at the High Devil Canyon site,and an
allowance of 5100 million has been made to cover the
costs.The energy and cost information for these pl ans
is presented in Exhibit 8 .
These evaluations odsically reinforce the results of the
screening model;for a total energy production
capabil ity of up to approx imately 4,000GWh,Pl an E2
(High Devi 1 Canyon)provides the most economic energy
whil e for capabil it i es in the range of 6,000 GWh,Pl an
E1 (Watana-Devil Canyon)is the most economic.
(v)Comearisoo.of Plans
The evaluat ion and compari son of the various basin
development plans described above,was undertaken in a
seri es of steps.
In the first step,for determining the optimum staging
concept associated with each basic plan (i.e.,the optimum
sUbplan)economic criteria only are used and the
E-10-21
-_._-------~~-----
least-cost staging concept is adopted.For assessing
which pl an is the most appropri ate,a more detai led
evaluation process incorporating economic,environmental,
social,and energy contribution aspects is taken into
account.
Economic aval uat ion of the Susitna Basin development pl ans
was conductad vi a a computer simul at i on planning mOdel
(OGP5)of tha entire generating systam.This model and
the results ara describad in Reference 2,Sect ion 8.
As outlined in tha generic methodology (Exhibit B),the
final evaluation of the development plans is to be
undertaken by a perceived comparison process on the basis
of appropriate criteria.The following criteria are used
to evaluate the shortlisted basin development plans.They
generally contain the requirements of the generic process
with the exception that an additional criterion,.energy
contribution,is added.The objective of including this
criterion is to insure that full consideration is given to
the total basin energy potential that is developed by the
various pl ans.
-Economic Criteria
The parameter used is the total present-worth cost of
the total Railbelt generating system for the period 1980
to 2040 1 isted and discussed in Exhibit B.
-Environmental Criteria
A qualitative assessment of the environmental impact on
the ecological,cultural,and aesthetic resources is
undertaken for each plan.Emphasis is placed on
identifying major concerns so that these could be
combined with the other evaluation attributes in an
overall assessment of the plan.
-Social Criteria
This attribute includes determination of the potential
non-renewable resource displacement,the impact on the
state and local economy,and the risks and consequences
of major structural failures caused by seismic events.
Impacts on the economy refer to the effects of an
investment plan on economic variables.
E-10 ..22
-
~i
-
-
.....
Energy Contribution
The parameter used is the total amount of energy
produced from the specific development plan.An
assessment of the energy development foregone is also
undertaken.This energy loss is inherent to the plan
and cannot eas il y be recovered by subsequent staged
developments.
Economic and technical compari sons are di scussed in
Exhibit B;environmental,soci al,and summary
comparisons appear in Tables E.10.16 through E.10.18.
(vi)Results of Evaluation Process
The various attributes outlined above have been determined
for each plan.Some of the attributes are quantitative
whi 1e others are qual it at ive.Over a 11 eval uat ion is based
on a comparison of similar types of attributes for each
plan.In cases where the attri butes associated with one
plan all indicate equality or superiority with respect to
another plan,the decision as to the best plan is clear
cut.In other cases where some attributes indicate
superiority and others inferiority,these differences are
highlighted and trade-off decisions are made to determine
the preferred development pl an.In cases where these
trade-offs have had to be made,they are relatively
convincing and the decision-making process can,therefore,
be regarded as fairly robust.In addition,these
trade-offs are clearly identified so the reader can
independently address the judgment decisions made.
The overall evaluation process is conducted in a series of
steps.At each step,only a pair of plans is evaluated.
Thesuperi or pl an is then passed on to the next step for
evaluation against an alternative plan.
(vii)Devil Canyon Dam Versus Tunnel
The first step in the process involves the evaluation of
theWatana-Devil Canyon dam plan (E1.3)and the Watana
tunnel plan (E3.1).As Watana is common to both plans,
the eva1uat ion is based on a comp ar i son of th e Dev il
Canyon dam and tunne 1 schemes.
In order to assist in'the evaluation in terms of economic
criteria,additional information was obtained by analyzing
the results of the OGP5 computer runs.This information,
presented in Exhibit B,n lustrates the breakdown of the
total system present-worth cost in terms of capital
investment,fuel,and operation and maintenance costs.
E-10-23
-Economic Comparison
From an economic point of view,the Devil Canyon dam
scheme is superior.On a present worth basis,the
tunnel scheme is $680 million or about 12 percent more
expensive than the dam scheme.For a low-demand growth
rate,this cost difference would be reduced slightly to
$610 mi 11 ion.Even if the tunnel scheme costs are
halved,the total cost difference would still amount to
$380 million.Consideration of the sensitivity of the
basic ~conomic evaluation to potential changes in
capital cost estimate,the period of economic analysis,
the discount rate,fuel costs,fuel cost escalation,and
economic plant lives do not change the basic economic
superiority of the dam scheme over the tunnel scheme.
-Environmental Comparison
The environmental comparison of the two schemes is
summarized in Table E.I0.16.Overall,the tunnel scheme
is judged to be superior because:
o It offers the potential for enhancing anadromous fish
populations downstream from the re-regulation dam
because of the more uniform flow distribution that
will be achieved in this reach;
o It inundates 13 mil es 1ess of res i dent fi sheri es
habitat in river and major tributari es;
o It has a lower impact on wildlife habitat because of
the smaller inundation of habitat by the re-regulation
dam;
o It has a lower potential for inundating archaeological
sites because of the smaller reservoir involved;
o It would preserve much of the characteri st i cs of the
Devil Canyon gorge,which is considered to be an
aesthetic·and recreational resource.
-Soc i a1 Comparison
Table £.10.17 summarizes the evaluation in terms of the
social criteria of the two schemes.In terms of impact
on state and local economics and risks resulting from
seismic exposure,the two schemes are rated equally.
However,the dam scheme has,because of its higher
energy yield,more potential for displacing nonrenewable
E-10-24 -.:
I~
I~
energy resources,and,therefore,scores a s light
overall plus in terms of the social evaluation
criteri a.
-Energy Comparison
The results show that the dam scheme has a greater
potential for energy production and develops a larger
portion of the basin's potential.The dam scheme is,
therefore,jUdged to be superior from the energy
contribution standpoint.
-Overall Comparison
The overall evaluation of the two schemes is summarized
in Tabl e LI0.18.The est imated cost saving of $680
minion in favor of the dam scheme is considered to
outweigh the reduction in the overall environmental
impact of the tunnel scheme.The dam scheme is,
therefore,judged to be superior overall.
(viii)Watana-Oevil Canyon Versus High Devil Canyon-Vee
The second step in the development selection process
involves an evaluation of the Watana-Devil Canyon (E1.3)
and the High Devil Canyon-Vee (E2.3)development plans.
-Economic Comparison
In terms of the economic criteri a,the Watana-Oevi 1
Canyon plan is less costly by $520 million.As for the
dam-tunnel evaluation discussed above,the sensitivity
of this decision to potential changes in the various
parameters considered (i.e.,load forecast,discount
rates,etc.)does not change the basic superiority of
the Watana-Oevil Canyon PI an.
-Environmental Comparison
The evaluation in terms of the environmental criteria is
summarized in Table E.1O.19.In assessing these plans,
a reach-by-reach comparison is made for the section of
the Sus itna Ri ver between Portage Creek and the Tyone
River.The Watana-Oevil Canyon scheme would create more
potential environmental impacts in the Watana Creek
area.However,it is judged that the potential
environmental impacts which would occur in the upper
E-10 ..25
reaches of the ri ver with a Hi gh Devi 1 Canyon-Vee
development are more severe in comparison overall.
From a fisheries perspective,both schemes would have a
similar effect on the downstream anadromous fisheries,
although the High Devil Canyon-Vee scheme would produce
a slightly greater impact on the resident fisheries in
the Upper Susitna Basin.
The High Devil Canyon-Vee scheme would inundate
approximately 14 percent (15 miles)more critical,
winter,riverbottom moose habitat than the Watana-Oevi1
Canyon scheme.The High Devil Canyon-Vee scheme wou1 d
inundate a large area upstream from the Vee site
utilized by three subpopulation of moose that range in
the northeast section of the basin.The Watana-Devil
Canyon scheme would avoid the potenti a1 impacts on moose
in the upper section of the river;however,a larger
percentage of the Watana Creek basin woul d inundated.
The condition of the subpopu1ation of moose utilizin~
this Watana Creek Basin and the quality of the habitat
appears to be decreasing.Habitat manipulation measures
could be implemented in this area to improve the moose
habitat.
Neverthe 1ess,it is consoi dered th at the upstream moose
habitat losses associated with the High Devil Canyon-Vee
scheme would probably be greater than the Watana Creek
losses associ ated with the Watana-Devi 1 Canyon scheme.
A major factor to be considered in comparing the two
development plans is the potential effects on caribou in
the region.It is judged that the increased length of
river flooded,especially upstream from the Vee damsite,
woul d result in the Hi gh Devil Canyon-Vee p1 an creating
a greater potential diversion of the Ne1china herd's
range.In add it ion,a 1arger area of cari bou range
would be directly inundated by the Vee reservoir.
The area flooded by the Vee reservoir is also considered
important to some key furbearers,particularly red fox.
In a compari son of th is area with the Wat ana Creek area
that would be inundated with the Watana-Devi 1 Canyon
scheme,the area upstream from Vee is judged to be more
important for furbearers.
As previously mentioned,the area between Devil Canyon
and the Oshetna River on the Susitna River is confined
to a relatively steep river valley.Along these valley
slopes are habitats important to birds and black bears.
E-10-26
-
~.
Since the Watana reservoir would flood the river section
between the Watana damsite and the Oshetna River to a
higher elevation than would the High Devil Canyon
reservoir (2200 as compared to 1750),the High Devil
Canyon-Vee pl an woul d retain the integrity of more of
this river valley slope habitat.
From the archaeological studies done to date,there
tends to be an increase in site intens ity as one
progresses towards the northeast section of the Upper
Susitna Basin.The High Devil Canyon-Vee plan would
result in more extens i ve i nundat i on and increased access
to the northeasterly section of the basin.This plan is
judged to have a greater potential for directly or
indirectly affecting archaeological sites.
Because of the wilderness nature of the Upper Susitna
Basin,the creation of increased access associated with
project development could have a significant influence
on future uses and management of the area.The High
Devil Canyon-Vee plan would involve the construction of
a dam at the Vee site and the creation of a reservoir in
the more northeasterly section of the basin.This plan
would thus create inherent access to more wilderness
than would the Watana-Devil Canyon scheme.As it is
easier to extend access than to limit it,inherent
access requirements are detrimental,and the Watana·
Devil Canyon scheme is judged to be more acceptable in
this regard.
Except for the increased loss of river valley,bird,and
black bear habitat,the Watana-Devil Canyon development
pl an is judged to be more environmentally acceptabl e
than the High Devil Canyon.Vee pl an .
•Energy Comparison
The evaluation of the two plans in terms of energy
contribution criteria shows the Watana-Devil Canyon
scheme to be superior because of its higher energy
potential and the fact that it develops a higher
proportion of the basin's potential.
Table E.10.17 summarizes the evaluation in terms of the
soci a 1 criteri a.As in the case of the dam versus
tunnel comparison,the Watana·Devil Canyon plan is
E·1O-27
judged to have a slight advantage over the ,High Devil
Canyon-Vee pl an because of its greater potenti al for
displacing nonrenewable resources.
-Overall Comparison
The overall evaluation is summarized in Table E.10.20
and indicates that the Watana-Devi 1 Canyon pl ans are
generally superior to all the other evaluation
criteria.
(ix)Preferred Susitna Basin Development Plan
Compari sons of the Watana-Oevil Canyon pl an with the
Watana tunnel plan and the High Devil Canyon-Vee plans are
judged to favor the Watana-Devil Canyon plan in each
case.
The Watana-Devil Canyon plan is therefore selected as the
preferred Susitna Basin development plan,as a basis for
continuation of more detailed design optimization and
environmental studies.
10.2 -Alternative Facilty Designs
(a)Watana Facility Design Alternatives
Environmental factors considered in Watana facil ity design are
summarized below.
(i)Oi Vers ion/Emergency Release Fac il it i es
Tables 8.61 and B.62 of Exhibit B show the mlnlmum flow
releases from the Watana and Devil Canyon dams required to
maintain an adequate flow at Gold Creek.These release
levels have been established to avoid adverse affects on
the Salmon fishery downstream.
At an early stage of the study,it was established that
some form of low level release facility was required to
permit lowering of the reservoir in the event of an extreme
emergency,and to meet instream flow requirements during
filling of the reservoir.The most economical alternative
available would involve converting one of the diversion
tunnels to permanent use as a low level outlet facility.
Since it would be necessary to maintain the diversion
scheme in service during construction of th elow level
outlet works,two or more diversion tunnels would be
required.The use of two diversion tunnels also provides
an additional measure of security to the diversion scheme
in case of the loss of service of one tunnel.
E-10-28
-
"""
-
,~
(i i )Mai n Spill way
During development of the general arrangements for both the
Watana and Devil Canyon dams,a restriction was imposed on
the amount of excess di ssol ved nitrogen permitted in the
spi llway discharges.Supersaturat ion occurs when aerated
flows are subjected to pressures greater than 30 to 40 feet
of head which forces excess nitrogen into solution.This
occurs when water is subjected to the high pressures that
occur in deep plunge pools or at large hydraulic jumps.
The excess nitrogen would not be dissipated within the
downstream Devil Canyon reservoir and a buildup of nitrogen
concentrat ion coul d occur throughout the body of water.It
would eventually be dishcarged downstream from Devi 1 Canyon
with harmful effects on the fish population.On the basis
of an evaluation of the related impacts,and discussions
with interested federal and state agencies,spillway
facilities will be designed to limit discharges of water
from either Watana or Devi 1 Canyon that may become
supersaturated with nitrogen to a recurrence period of not
less than 1:50 years.
Three basic alternative spillway types were examined:
-Chute spillway with flip bucket;
-Chute spillway with stilling basin;and
-Cascade spillway
Consideration was also given to combinations of these
alternatives with or without supplemental facilities such
as valved tunnels and an emergency spillway fuse plug for
handling the PMF discharge.
The stilling basin spillway is very costly and the
operating head of 800 feet is beyond precedent experience.
Erosion downstream should not be a problem but cavitation
of the chute could occur.This scheme was therefore
eliminated from further consideration.
The cascade spillway was also not favored for technical and
economi c reasons.However,th is arrangement does have an
advantage in that it provides a means of preventing
nitrogen supersaturation in the downstream discharges from
the project which could be harmful to the fish population.
A cascade configuration would reduce the dissolved nitrogen
content,and hence,this alternative was retained for
further evaluation.The capacity of the cascade was
reduced and an emergency rock channel spi llway was incl uded
to take the extreme floods.
E-10-29
(iii)Power Intake and Water Passages
Apart from the potential nitrogen supersaturation problem
discussed above,the major environmental constraints on the
design of the power facil ities are:
-Control of downstream river temperatures;and
-Control of downstream flows.
The intake design has been modified to enable power plant
flows to be drawn from the reservoir at four different
levels throughout the anticipated range of reservoir
drawdown for energy production in order to control the
downstream ri ver temperatures withi n acceptabl e 1imits.
Minimum flows at Gold Creek during the critical summer
months have been studied to mitigate the project impacts on
sa lmon spawni ng downstream of Devil Canyon.These mi nimum
flows represent a constraint on the reservoir operation,
and influence the computation of average and firm energy
produced by the Susitna development.
(iv)Outlet Facilities
As a provision for drawing down the reservoir in case of
emergency,a mid-level release will be provided.The
intake to these f.acil ities will be located at depth
adjacent to the power facilities intake structures.Flows
wi 11 then be passed downstream through a concrete-l ioed
tunne 1,di scharging beneath the downstream end of the mai n
spi 11 way flip bucket.Inortiel"to overcome potential
nitrogen supersaturation problems,a system of fixed cone
valves will be installed at the downstream end of the
outlet facilities.The valves will be sized to discharge
in conjunction with the powerhouse operating at 7000 cfs
capacity,flows up to the equivalent routed 50-year flood.
(b)Devil Canyon Facility Design Alternatives
(i)Installed Capacity
The decision to operate Devil Canyon primari 1y as a based
loaded plant was governed by the following main
considerations:
-Daily peaking is more effectively performed at Watana
than at Devi 1 Canyon;and
-Excessive fluctuations in discharge from the Devil Canyon
dam may have an undesirable impact on mitigation measures
incorporated in the final design to protect the
downstream fisheries.
E-l0-30
-
~.
( i i )
Given this mode of operation,the required installed
capacity at Devil Canyon has been determined as the maximum
capacity needed to utilize the available energy from the
hydrological flows of record,as modified by the reservoir
operation rule curves.
Spillway Capacity
The avoidance of nitrogen supersaturation in the downstream
flow also will apply to Devil Canyon.Thus,the discharge
of water possibly supersaturated with nitrogen from Devil
Canyon will be limited to a recurrence period of not less
than 1:50 years by the use of solid cone valves similar to
Watana.
(iii)Power Intake and Water Passages
In addition to potential nitrogen-saturation problems
caused by spillway operation,the major impacts of the
Devil Canyon power intake faeil ities development will be:
-Changes in the temperature regime of the river;and
,-Fluctuations in downstream river flows and levels.
Temperature model ing has indicated that a multiple level
intake design at Devil Canyon would assist downstream water
temperature control.Consequently,the intake design at
Devil Canyon will incorporte a multi-level draw-off about
80 feet below maximum reservoir operating level (El 1455).
The Devil c.anyon station wi 11 normally be operated as a
base loaded pl ant throughout the year,to satisfy the
requirement of no significant daily variation in power
flow.
(c)Access Alternatives
,~
(1)Plan Selection
Detailed access studies resulted in the development of
eighteen possible access plans within three corridors.
An initial evaluation was made to determine the plan in
each corridor that was most responsive to project
objectives as well as inputs from the conmunity and
agencies.The project objectives of cost and schedule
control along with the need to have maximum fl exibi lty of
access were given prime consideration.A flexible support
system util izing both road and rail was considered a
necessity to reduce risks and control costs.Access pl ans
E-10-31
that could not provide access within one year of receipt of
the F£RC license or imposed a restraint on construction
activities were therefore eliminated.Plans that did not
provide access between sites for the operation and
maintenance phase of the project were also eliminated.In
addition~a number of plans were eliminated because more
recently developed plans were superior to similar plans
within the same corridor by virtue of the fact that they
reduced community and agency concerns.The initial
evaluation reduced the acceptable options to the following
three alternative access corridors:
Corridor 1 -Parks Highway to Watana via north side of
Susitna River
Corridor 2 -Parks Highway to Watana via south side of
Susitna River
Corridor 3 -Denali Highway to Watana
The eighteen alternatives were developed by laying out
routes on topographical maps in accordance with accepted
road and rail design criteria.Subsequent field
investigations resulted in minor modifications to reduce
environmental impacts and improve alignment.
(ii)Plan Evaluation
Plan "evaluation and screening are discussed in detail in
Exhibit B~Section 2.6 (e).As the result of the
evaluation process~three plans were chosen as best
representing the three corridors:Plan 13 "North"~Plan 16
"South"~and Plan 18 "Denali -North".
The potential environmental impacts of the three plans are
presented below.
-Wildlife and Habitat
The three selected alternative access routes are made up
of five distinct wildlife and habitat segments:
1.Hurricane to Devil Canyon:This segment is composed
almost entirely of productive mixed fore$t~
ripari an~and wet 1ands habitats important to moose~
furbearers~and birds.It includes three areas
where slopes of over 30 percent will require
side-hill cuts~all above wetland zones vulnerable
to erosion related impacts.
£-10-32
-
-
""'"
I~
-
,~
2.Gold Creek to Devil Canyon:This segment is
composed of mixed forest and wetland habitats,but
includes less wetland habitat and fewer wetland
habitat types than the Hurricane to Devil Canyon
segment.Although this segment contains habitat
suitable for moose,black bears,furbearers and
birds it has the least potential for adverse impacts
to wildl ife of the five segments considered.
3.Devil Canyon to Watana (North Side):The following
comments apply to both the Denali-North and North
routes.This segment traverses a varied mixture of
forest,shrub,and tundra habitat types,generally
of medium to low productivity as wildlife habitat.
It crosses the Devil sand Tsusena Creek drai nages
and passes by Swimming Bear Lake which contains
habitat suitabl e for furbearers.
4.Devil Canyon to Watana {South Side}:Thi s segment
is highly varied with respect to habitat types,
contai ni ng complex mi xtures of forest,shrub,
tundra,wet 1ands,and ripari an vegetation.The
western portion is mostly tundra and shrub,with
forest and wetlands occurring along the eastern
portion in the vicinity of Prairie Creek,Stephan
Lake,and Tsusenaand Deadman Creeks.Prai ri e Creek
Lake,and Tsuse'na and Deadman Creeks.Prairie Creek
supports a high concentration of brown bears and the
lower Tsusena and Deadman Creek areas support
lightly hunted concentrations of moose and black
bears.The Stephan Lake area supports high
densities of moose and bears.Access development in
this segment would probably result in habitat loss
or alteration,increased hunting and human-bear
conflicts.
5.Denali Highway to Watana:This segment is primarily
composed of shrub and tundra vegetat i on types~with
1 ittle productive forest habitat present.Although
habitat diversity is relatively low along this
segment,the southern portion along Deadman Creek
contai ns an important brown bear concentrat i on and
browse for moose.This segment crosses a peripheral
portion ~f the range of the Nelchina caribou herd
and there is evidence that as herd size increases,
caribou are likely to migrate across the route and
calve in the vicinity.Although it is not possible
to predict with any certainty how the physical
presence of the road itself or traffic will affect
caribou movements,population size or productivity
it is ,ikely that a variety of site-specific
mitigation measures will be necessary to protect the
herd.
E-10-33
The three access plans are made up of the following
combinations of route segments:
North
South
Denali-North
Segment s 1 and 3
Segments 1,2,and 4
Segments 2,3,and 5
The North route has the least potential for creating
adverse impacts to wildlife and habitat for it traverses
or approaches the fewest areas of productive habitat and
zones of species concentration or movement.The
wildlife impacts of the South Plan can be expected to be
greater than those of the North Pl an due to the
proximity of the route to Prairie Creek,Stephan Lake
and the Fog Lakes,which currently support high
densities of moose and black and brown bears.In
particular Prairie Creek supports what may be the
highest concentration of brown bears in the Susitna
Basin.Although the Denali-North Plan has the potential
for disturbances of caribou,brown bear and black bear
concentrations and movement zones,it is considered that
the potential for adverse impacts with the South Plan is
greater.
Fisheries
All three alternative routes would have direct and
indirect impacts on the fi sheri es.Oi rect impacts
include the affects on water quality and aquatic habitat
whereas increased angling pressure is an indirect
impact.A qual itat ive compari son of the fi shery impacts
related to the alternative plans was undertaken.The
parameters used to assess impacts along each route
included:the number of streams crossed,the number and
length of lateral transits (i.e.,where the roadway
parallels the streams and runoff from the roadway can
run directly into the stream),the number of watersheds
affected,and the presence of resident and anadromous
fish.
The three access pl an altern at ives incorporate
combinations of seven distinct fishery segments.
1.Hurricane to Devil Canyon:Seven stream cross i ngs
will be required along this route,including Indian
River which is an important salmon spawning river.
Both the Chul itna River watershed and the Susitna
River watershed are affected by this route.The
increased access to Indian River will be an
important indirect impact to the segment.
[-10-34
i~
I'"""'
,
,;-»
Approximately 1.8 miles of cuts into banks greater
than 30 degrees occur along this ~oute requiring
erosion control measures to preserve the water
quality and aquatic habitat.
2.Gold Creek to Devil Canyon:This segment crosses
six streams and is expected to have minimal direct
and indirect impacts.Anadromous fi sh spawning is
likely in some streams but impacts are expected to
be minimal.Approximately 2.5 miles of cuts into
banks greater than 30 degrees occur in this section.
In the Denali-North Plan,this segment would be
railroad whereas in the South Pl an it would be
road.
3.Devil Canyon to Watana (North Side,North Plan):
This segment crosses twenty streams and laterally
transits four rivers for a total distance of
approximately twelve miles.Seven miles of this
lateral transit parallels Portage Creek which is an
important salmon spawning area.
4.Devil Canyon to Watana (North Side,Denali-North
Plan):The difference between this segment and
segment 3 described above is that it avoids Portage
Creek by traversing through a pass four miles to the
east.The number of streams crossed is consequently
reduced to twel ve,and the number of 1ateral
transits is reduced to two with a total distance of
four miles.
5.Devil Canyon to Watana (South Side):The portion
between the Sus itna Ri ver cross i n9 and Devil Canyon
requires nine stearn crossings,but it is unlikely
that these contain significant fish populations.
The portion of this segment from Watana to the
Susitna River is not expected to have any major
direct impacts,however,increased angling pressure
in the vicinity of Stephan Lake may result due to
the proximity of the access road.The segment
crosses both the Susitna and the Talkeetna
watershed"Seven mi 1es of cut into banks of greater
than 30 degrees occur in this segment.
6.Denal i Highway to Watana:The segment from the
Denal i Highway to the Watana damsite has twenty-two
stream crossings and passes from the Nenana into the
Susitna watershed.Much of the route crosses or is
in proximity to seasonal grayl ing habitat and runs
parallel to Deadman Creek for nearly ten miles.If
£-10 ...35
recruitment and growth rates are low along this
segment it is unlikely that resident populations
could sustain heavy fishing pressure.Hence,this
segment has a high potential for impacting the local
grayling population.
7.Denali Highway:The Denali Highway from Cantwell to
the Watana access turnoff will require upgrading.
The upgrading will involve only minor realignment
and neg1 igib 1e alter at ion to present stream
crossings.The segment crosses eleven streams and
laterally transits two rivers for a total distance
of five miles.There is no anadromous fish spawning
in this segment and little direct or indirect impact
is expected.
The three alternative access routes are compri sed of
the following segments:
-
The Denali ..North Plan is likely to have a
significant direct and indirect impact on gray1 ing
fisheries given the number of stream crossings,
1atera1 transits,and watershed affected.
Anadromous fisheries impact will be minimal and wi 11
only be significant along the railroad spur between
Go 1d Creek and Dev i1 Canyon.
The South Plan is likely to create significant
direct and indirect impacts at Indian River,which
is an important salmon spawning river.Anadromous
fisheries impacts will also occur in the Gold Creek
to Devil Canyon segment as for the Dena1i ..North
Plan.In addition indirect impacts may occur in the
Stephan Lake area.
North
South
Dena 1i ..North
Segments 1 and 3
Segments 1,2,and 5
Segments 2,4,6 and 7
--
-
The North Plan,like the South Plan may impact
salmon spawning activity in Indian River.
Significant impacts are likely along Portage Creek
due to water qual ity impacts through increased
eros i on and due to indirect impacts such as
increased angling pressure.
With any of the selected plans,direct and indirect
effects can be minimized through proper engineering
des ign and prudent management.Criteria for the
development of borrow areas and the design of
bridges and culverts for the proposed access plan
together with mitigation recommendations are
discussed in Exhibit E.
E-10-36
-
-,
-
(d)Transmission Alternatives
( i )
(i i )
Corridor Selection MethodoloQY
Development of the proposed Susitna project wi 11 require a
transmission system to deliver electric power to the
Rai lbelt area.The bui lding of the Anchorage-Fai rbanks
Intertie System will result in a corridor and route for the
Susitna transmission lines between Willow and Healy.Three
areas have been studied for corridor selection:the
northern area connecting Healy with Fairbanks;the central
area connecting the Watana and Devil Canyon damsites with
the Interti e;and the southern area connect i ng Wi 11 ow with
Anchorage.
Using the selection criteria discussed in Exhibit B,
Section 2.7 (b),corridors 3 to 5 miles wide were selected
in each of the three study areas.These corridors were
then eval uated to determine whi ch ones met the more
specific screening criteria (Exhibit B,Section 2.7 (c)).
This screening process resulted in one corridor in each
area being desi~nated as the recommended corridor for the
transmission line.
Envi ronmental Sel ect ion Criteri a
The environmental criteria used in selection of the
candidate corridors are listed below.
Primary
Secondary
Criteri a
Development
Existing Transmission
Right-of-Way
Land Status
Topography
Vegetat ion
E-10-37
Selection
Avoid existing or
proposed developed
areas.
Parall el where
possible.
Avoid private
lands,wildlife
refuges ,parks.
Select gentle
relief where
possible.
Avoid heavily
timbered areas.
Since the corridors that were studied range in width from
three to five miles,the base criteria had to be applied to
broad areas.Some of the criteria used in the
environmental selection process were also pertinent to the
technical and economical analysis.For example,it is
economically advantageous to avoid high right-of-way costs
in developed areas;and gentle topog raphy enh ances
technical reliability through ease of access.
(iii)Identification of Corridors
The Susitna transmission line corridors that were selected
for further screening are located in three geographical
areas:
-The southern Study area between Wi llow and Anchorage;
-The central study area between Watana,Devil Canyon,and
the Intertie;and
-The northern study area between Healy and Fairbanks.
Twenty-two corridors were selected and are described in
Exhibit B,Section 2.7 (b)and shown in Exhibit B figures
B.47,B.48,and B.49.
(iv)Environmental Screening Criteria
Because of the potenti al,adverse environmental impacts
from transmission line construction and operation,
environmental criteria were carefully scrutinized in the
screening process.Past experience has shown the primary
environmental considerations to be:
-Aesthetic and Visual (including impacts to recreation)
-Land Use (includin9 ownership and presence of existing
rights-of-way)
Also of significance in the evaluation process are:
-Length
-Topogr aphy
-Soil s
-Cultural Resources
-Vegetat ion
-Fishery Resources
-Wildlife Resources
E-10-38
I~
,~
,/f!!J:I:ltiA.
Primary Aspects:
o Aesthetic and Visual
The presence of large transmission line structures in
undeveloped areas ~as the potential for adverse
aesthet ic impacts.Furthermore,the presence of these
lines can conflict with recreational use,particularly
those nonconsumptive recreational activities such as
hiking and bird watching where great emphasis is
placed on scenic values.The number of road crossings
encountered by transmission line corridors is also a
factor that needs to be inventoried because of the
potential for visual impacts.The number of roads
crossed,the manner in which they are crossed,the
nature of existing vegetation at the crossing site
(i.e.,potential visual screening),and the number and
type of motorists using the highway all influence the
desirabil ity of one corridor versus another.
Therefore,when screening the previously selected
corri dors,cons i derat i on was foe used on the presence
of recreational areas,hiking tl"ails,heavily utilized
lakes,vistas,and highways where views of
transmission line facilities would be undesirable.
o Land Use
The three primary components of land use
considerations are:1)land status/ownership,2)
existing rights-of-way,and 3)existing and proposed
development.
Land/Status/Ownersh iP
The ownership of land to be crossed by a
transmission line is important because certain types
of ownership present more restrictions than others.
For example,some recreation areas such as state and
federal parks,game refuges and military lands,
among others,present possible constraints to
corridor routing.Private landowners generally do
not want transmission lines on their lands.This
information,when known in advance,permits corridor
routing to avaid such restrictive areas and to occur
in areas where land use conflicts can be minimized .
.Existins Rights-of-Way
Paralleling existing rights-af-way tends to result
in less environmental impact than that which is
E-10-39
associated with a new right-of-way because the
creation of a new right-of-way may provide a means
of access to areas normally accessible only on foot.
This can be a critical factor if it opens sensitive,
ecological areas to all terrain vehicles ..
Impact on soils,vegetation,stream crossings,and
others of the inventory categories can also be
lessened through the paralleling of existing access
roads and cleared rights-of-way.Some impact is
still felt,however,even though a right-of-way may
exist in the area.For example,cultural resources
may not have been identified in the original routing
effort.Wetlands present under existing
transmission lines may likewise be negatively
influenced if ground access to the vicinity of the
tower locations is required.
There are common occasions where paralleling an
existing facility is not desirable.This is
particularly true in the case of highways that offer
the potential for visual impacts and in situations
where paralleling a poorly sited transmission
facility would only compound an existing problem.
Existing and Proposed Developments
This inventory identifies such things as
agricultural use;planned urban developments,such
as the proposed capital site;existing residential
and cabin developments;the'location of airports and
of 1akes used for float planes;and s imil ar types of
information.Such information is essential for
locating transmission line corridors appropriately,
as it presents conflicts with these land use
act ivit i es.
Secondary Aspects:
o Length
The length of a transmission line is an environmental
factor and,as such,was considered in the screening
process.A longer line will require more construction
activity than a shorter line,will disturb more land
area,and will have a greater inherent probability of
encountering environmental constraints.
£-10-40
~,
-
-
.~,
-
,~
o Topography
The natural features of the terrain are significant
from the standpoint that they offer both positive and
negative aspects to transmission 1 ine routing.Steep
slopes,for example,present both difficult
construct ion and soil stabil i zation probl ems with
potent ially long-term,negative environmental
consequences.Also,ridge crossings have the
potential for visual impacts.At the same time,
slopes and elevation changes present opportunities for
rout i ng transmi ss ion 1i nes so as to screen them from
both travel routes and exi sting communities.When
planning corridors then,the identification of changes
in relief is an important factor.
o Soils
Soil s are important from several standpoints.First
of all,scarification of the land often occurs during
the construction of transmission lines.As a result,
vegetation regeneration is affected>as are the
rel ated features of soi 1 stabi 1i ty and erosion
potential.In addition,the development and
installation of access roads,where necessary,are
very dependent upon soil types.Tower designs and
locations are dictated by the types of soils
encountered in any particu.lar corridor segment.
Consequently,the review of existing soils information
is very significant.
o Cultural Resources
The avoidance of known or potential sites of cultural
resources is an important component of the routing of
transmission lines.In planning for Susitna Project
transmission lines,however,information on the
presence of cultural resources is,for the most part,
unavailable.An appropriate program for identifying
and mitigating impacts of the finally selected route
is necessary.
o Vegetation
The consideration of the presence and location of
various plant communities is essential in transmission
line siting.The inventory of plant communities,such
as those of a tall-growing nature or wetlands,is
significant from the standpoint of construction,
clearing,and access road development requirements.
E-10-41
In addition,identification of locations of endangered
and threatened plant species is also critical.While
several Alaskan plant species are currently under
review by the U.S.Fishand Wildlife Service,none are
presently listed under the Endangered Species Act of
1973.No corridor traverses any location known to
support these identified plant species.
o Fishery Resources
The presence or absence of resident or anadromous fish
in a stream is a significant factor in evaluating
suitable transmission line corridors.The corridor's
effects on a stream1s resources must be viewed from
the standpoint of possible disturbance to fish
species,potential loss of habitat,and possible
destruction of spawning beds.In addition,certain
species of fish are more sensitive than others to
disturbance.
Closely related to this consideration is the number of
stream crossings.The nature of the soils and
vegetation in the vicinity of the streams and the
manner in which the streams are to be crossed are also
important environmental considerations when routing
transmission lines.Potential stream degradation,
impact on fi sh habitat through di sturbance,and
long-term negative consequences resulting from
siltation of spawning beds are all concerns that need
evaluation in corridor routing.Therefore,the number
of stream crossings and the presence of fish species
and habitat value were considered when data were
avai 1ab 1e.
o Wildlife Resources
The three major groups of wildlife which must be
considered in transmission corridor screening are big
game,birds,and furbearers.Of all the wil dl ife
species to be considered in the course of routing
studies for transmission lines,big game species
(together with endangered species)are most
significant.Many of the big game species,including
griZZly bear,caribou,and sheep,are particularly
sensitive to human intrusion into relatively
undisturbed areas.Calving grounds,denning areas,
and other important Qt unique habitat areas as
identified by the Alaska Department of Fish and Game
were incorporated into the screening process.
E-10-42
-
-~
-
-
-
Many species of birds such as raptors and swans are
sensitive to human disturbance.Identifying the
presence and location of nesting raptors and swans
permits avoidance of traditional nesting areas.
Moreover,if this category is investigated,the
presence of endangered species (viz,peregrine
falcons)can be determined.
Important habitat for furbearers exists along many
potential transmission line corridors in the rai1be1t
area,and its loss or disruption would have a direct
effect on these animal popu1 at ions.Invest i gat ing
habitat preferences,noting existing habitat,and
identifying populations through available information
are important steps in addressing the selection of
environmentally acceptable al ternati ves.
(v)Environmental Screening Methodolosy
In order to compare the altern at i ve corridors from an
environmental standpoint,the environmental criteri a
discussed above were combined into environmental constraint
tables (Tables £10.21,£10.22,and £10.23).These tables
combine information for each corridor segment under study.
This permitted the assignment of an environmental rating,
which identifies the relative rating of each corridor
within each of the three study areas.The assignment of
environment a1 rat i ngs is a subj ect i ve techni que intended as
an aid to corridor screening.Those corridors that are
recommended are identified with an lIA,"while those
corri dors that are acceptab 1e but not preferred are
identified with a "C."Finally,those corridors that are
considered unacceptable are identified with an uF.1I
(vi)Screening Results
Table E.l0.24 summarizes the comparisons of the 22
corridors studied in the southern,central,and northern
study areas.Environmental,economical,and technical
ratings are presented as well as a summary rating for each
corridor.Because of the critical importance of
enviromental considerations,any corridor which received an
F rating for environmental impacts was assigned a summary
rating of F.Thus,a corridor which may be excellent from
a technical and economic viewpoint was considered not
acceptable if the environmental rating was unacceptable.
E-10-43
Descriptions of the rationale for each corridor's rating
are presented below.
-Southern Study Area
Three alternative corridors were evaluated in the
southern study area.As previously identified~two
corridors connect Willow with Point MacKenzie.The
third corridor connects Willow with Anchorage.
o Corridor One (ABCI)-Willow to Anchorage vai Palmer
Technical and Economical
This 73-mile corridor is the longest of the three
being considered for the southern area.As a
consequence,there will be more clearing of
right-of-way required,more miles of line,and more
towers.Several highway and railway crossings will
also be encountered,including crossing of the Glenn
Highway.The corridor is located in a
well-developed,inhabited area which will require
easements on private properties.There also could
be a problem of radio and television interference.
Env ironment a1
Several constraints were identified in evaluating
this corridor,chief among which were constraints
under the land use category.
A new right-of-way would be required from Willow to
a point in the vicinity of Palmer.This would
necessitate the development of a pioneer access road
and,since this area is wooded,attendant vegetation
clearing and opening of a previously inaccessible
area.The corridor al so bisects 1ands in the
vicinity of Willow that have been proposed for use
as the new capital site.
Between Ek1utna and Anchorage,this route parallels
an existing transmission line that now crosses
extensively developed areas.Paralleling existing
corridors usually is the most appropriate means of
traversing developed areas.Because homes and
associated buildings abut the right-of-way,however,
additional routes through this developed area
present problems,among which aesthetics is most
important.In addition,this corridor alternative
crosses 5 rivers and 28 creeks potentially
E-10-44
-
-
-
-
affecting not only the rivers and streams but also
fish species inhabiting these water courses.From
the standpoint of aesthetics,a transmission line in
the vicinity of Gooding Lake would negatively affect
an existing bird-watching area.However,because
this area is not heavily utilized and routing
variations are available within the corridor,it is
considered environmentally acceptable.
Ratings:
Technical
C
Economical
C
Envi ronmenta 1
C
Summary
C
o Corridor Two (ADFC)
Red Shirt Lake
Willow to Point MacKenzie via
~,
.Technical and Economical
Corridor ADFC crosses the fewest number of rivers
and roads in the southern study area.It has the
advantage of paralleling an existing tractor trail
for a good portion of its length,thereby reducing
the need for new access roads.Easy access will
allow maintenance and repairs to be carried out in
minimal time.This corridor also occurs at low
elevations and is approximately one ...half the length
of Corridor One.
Environmental
This corridor crosses extensive wetlands from Willow
to Point MacKenzie.At higher elevations or in the
better drained sites~extensive forest cover is
encountered.Good agricultural soils have been
identified in the vicinity of this corridor;the
state pl ans an agricul tural 1ands sal e for areas to
be traversed by this corridor.The corridor also
crosses the Sus itna Fl atsGame Refuge.The presence
of an existing tractor trail near considerable
portions of this corridor diminishes the
significance of some of these constraints.
Furthermore~its short length and the fact that it
has only one river and eight creek crossings
increases its environmental acceptability.
Ratings:
Techni cal
A
Economi ca 1
A
E-10-45
Environmental
A
Summary
A
-
AEFC)-Willow to Point MacKenzie via
Technical and Economical
o ,..-~~~~--'-----'------------------
This corridor has the same physical features as
Corridor Two.80th corridors have extensive
wetlands.AEFC cuts across a developed recreational
area and hence will require special routing
procedures to circumvent some of the private
property it will traverse.This corridor is very
accessible.Technically~because of its short
length and low elevation,it is a desirable
corridor,but economically it would be costly to
obtain easements and to route the line through the
several privately owned properties .
.Environmental
As with the previous corridor,this route crosses
extensive wetlands requiring,in the better drained
areas,extensive clearing of associated forest.
Just south of Willow,this route passes through the
Nancy lakes recreation area.Substantial
deve lopment of both resident ia1 and recreat i ana 1
facilities has occurred in the past and is
continuing.These facilities would be affected by
the presence of the transmission line~not only from
a land use standpoint~but also from an aestnetics
standpoint.Because of this unavoidable land use
confli~t associated with this corridor,particularly
in the Nancy lake area,it is not considered to be
environmentally acceptable.
~,
-
Ratings:
Technical
A
Economi ca 1
C
Environmental
F
Summary
F
-Central Study Area
Fifteen corridors utilizing different combinations of
corridor segments were identified in the central study
area.These corridors connect the damsites with the
Intertie at four separate locations.These locations
are in the vicinity of Indian River near its confluence
with the Susitna River and near the communities of
Chulitna,Summit,and Cantwell.
E-10-46
Because of the range in length of the corridors~those
with long lengths were assigned low economic ratings.
These corridors~numbers Four (ABCJHI)~Five (ABECJHI),
Seven (CEBAHI),Eight (CBAG),Nine (CEBAG),Ten (CJAG),
and Twelve (JACJHI),have lengths of 76 to 97 miles.In
addition to these,Corridors Four and Six (CBAHI)were
assigned an F technical rating because they cross
mountainous areas over 4,000 feet in elevation.
Corridors Four and Six were rated unacceptable
technically and therefore were eliminated because
reliability cannot be compromised.The remaining six
corridors,although unacceptable economically (F
rating)~were evaluated on an environmental basis.This
was done to determine whether one of these long
corridors was much more acceptable environmentally than
a shorter one.
Therefore,environmental information is presented for
the eight abovementioned corridors.This is followed
by a discussion of the economic,technical~and
environmental features of the remaining seven corridors
in the central study area.
Corri dors Technicall y and/or Economi cally Unacceptab1 e
o Corridor Four (ABCJHI)-Watana to Intertie via Devil
CreekPasslEastForkChuHtna River
This corridor connects Devil Canyon with Watana and
exits the Devil Canyon project to the north following
the drai nages of Devi 1,Portage,and Tsusena Creeks.
To route thi s corri dor to the Intert ie as required,
the 1 ine crosses some mountain passes over 4,000 feet
in elevation with steep slopes and shallow bedrock
areas (Corridor Segment CJHI).
The transmission line would interrupt the existing
viewshed of the recreation facility at High Lake.
Existing patterns of land use in the vicinity of High
Lake may a150 be significantly disrupted by the
transmission line.Once on the north side of the
river,this corridor crosses 42 creeks between
Dev il Canyon and the connection with the Intert i e.
Potential for stream degradation exists because of the
1 ack of existing access.Sensitive wild1 ife species,
such as caribou,wolves,and brown bear,as well as a
golden eagle nest site,could be potentially harmed by
"this corridor.
E-10 ...47
Ratings:
Technical
F
Economi cal
F
Environmental
F
Summary
F
Q Corridor Five (ABECJHI)-Watana to Intertie via
Stephan Lake and thetast Fork Chul itna River
,~
FF
Env ironment aI
F
Economica 1
This corridor crosses areas of high elevations and
shallow soils underlain by bedrock.Land use
constraints are encountered in the vicinity of both
High Lake and Stephan Lake,two significant recreation
and lodge areas.Re1 at i vel y important waterfowl and
mi grat i n9 swan habitat wou1 d be affected,as wou1 d
habitat for some of the majorbi g game species.In
addition,this corridor makes 42 creek crossings.
Extensive vegetation clearing would be required,
opening areas to access.Because of the visual
impacts and increased access,this corridor received
an F rating.
Ratings:
Technical
Summary
F
a Corridor Six (CBAHI)-Devil Canyon to the Intertie
vi a Tsusena Creek/Chul itna Ri ver
Reversing the sequence by which the damsites are
connected,Corridor Six extends from Devil Canyon to
Watana (Corri dor Segment CSA)and from Watana north
along Tsusena Creek to the point of connection with
the Intertie near·Summit Lake (Corridor Segment AHI).
Access roads are present 1y absent along most of thi s
corridor,and a pioneer route would need to be
established.This corridor also traverses elevations
above 4,000 feet and encounters shallow soils
underlain by bedrock.Wetlands,extensive farest
cover,and 32 creek crossings also constrain the
development of this corridor.A bald eagle nest in
the vicinity of Tsusena Butte,as well as the presence
of sensitive big game species such as caribou and
sheep,present additional constraints to the routing
of the corridor.This corridor was rated F,primarily
because of increased access and potenti a1 negative
impact on sensitive wildlife species.
-
-.
E-10-48
Ratings:
Techn i cal
F
Economical
C
Environmental
F
Summary
F
o Corridor Seven (CEBAHI)-Devil Canyon to Intertie via
Stephan Lake and Chulitna River
The primary environmental constraints associ ated with
this corridor are the result of visual and increased
are the result of vi sual and increased access impacts.
The corridor crosses near residential and recreational
facilities at Stephan Lake and is in the viewshed of
the Alaska range.Access road construction would be
necessary through wetlands and areas of heavy timber.
In addition~the corridor crosses 45 creeks,including
some with val uabl e spawni ng areas.It a1 so crosses
habitat for wolves and bears,including Prairie Creek
which is heavily used by brown bears during salmon
runs.This offers the potential for increased bear-
human contacts.
Again,because of potential for visual impacts and
increased access,this corridor received an F rating.
Ratings:
Technical
C
Economi cal
F
Env ironmenta 1
F
Summary
F
o Corridor fight (CBAG)-Devil Canyon to Intertie via
Deadman}Brushkana Creeks and Denal 1 Highway
Constraints in the categories of land use,aesthetics,
and fish and wildl ife resources are present in this
corridor.Among the longest of corridors under
consideration~this route passes near recreation
areas,isolated cabins,lakes used by float planes,
and land-based airstrips.In traversing lands from
the Watana Dams ite to the poi nt of connect len with the
Intertie,the route also intrudes upon some scenic
areas.Along much of its length,the corridor crosses
woodlands and,since a pioneer access road probably
would be required,vegetation clearing would likely be
extens ive.Once north of the Watana Dams ite,the
transmission line corridor makes 35 creek crossings
and traverses the habitat not only for a variety of
sensitive big game species but also for waterfowl and
raptors.In addition,the line passes near the
location of an active bald eagle nest on Deadman
Creek.
For these reasons,a rating of F was assigned.
Ratings:
Technical
C
Economi cal
F
Environmental
F
Summary
F
o Corridor Nine (CEBAG)-Devil Canyon to Intertie vi a
Stephan Lake and Denali Highway
Corridor Nine is the longest under construction in the
central study area and,hence,would require
disturbance of the largest land areas.It also
crosses areas of shallow bedrock,important waterfowl
migratory habitat at Stephan Lake,and 48 creeks,
including valuable spawning areas.
The corri dor passes near Stephan Lake,ut i1i zed
heavily for recreation,and any line constructed in
this area would be visible when looking towards the
looking towards the Alaska range.Although one of the
proposed access roads to the dams ites does occur in
thts area offering the potential for parallel
rights-of-way,the extreme length of this corridor and
the potential for unavoidable adverse land use and
aesthetic impacts result in its being judged
unacceptable.Thus,an F rating was assigned.
-
Ratings:
Techn i cal
C
Economical
F
Environmental
F
Summary
F
o Corridor Ten (CJAG)-Devil Canyon to Intertie via
North Shore,Susitna River,and Denali Highway
This is the second longest of the corridors under
investigation by this study.Routing above 3,000 feet
and its concomitant bedrock and steep slopes are
important restrictions of this corridor.It would
also encounter the land use constraints identified in
Corridor Nine,as well as several other drawbacks,
most notable of which are in the areas of aesthetics
and fish and wildl ife resources.Forty-seven creek
crossings would be required by this corridor.
This corridor could also parallel one of the proposed
access roads.However,as with Corridor Nine,its
long length,land use,and visual impacts do not make
it an acceptable corridor.
E-10-50
'"'""
All of the above and particularly the aesthetic
constraints result in an F rating.
Rat il1gs:
Technical
C
Economical
F
Environmental
F
Summary
F
,-
o Corridor Twelve (JA-CJHI)-Devil Canyon -Watana to
!ntertie vi a Devil/Chulitna RlVer
Thi s corri dor has a number of environmental
constraints which together make it environmentally
unacceptable.land use conflicts would likely occur,
since much of the land crossed is private1y owned.
In addition,aesthetic impacts would occur in the High
Lakes area,because the corridor is in the viewshed of
the Alaska Range.Finally,the corridor crosses 40
creeks,including valuable salmon-spawning grounds,
and crosses near a golden eagle nest.
This corridor,primarily because of impacts to access,
private lands,and aesthetics,received an F rating.
Ratings:
Techni cal
C
Economical
F
Environmental
F
Summary
F
I~
,~
Corridors Technically and Economic all yAcceptabl e
o Corridor One (ABeD)...Watana to the Intertie via South
Shore of the Susitna Rive~
.Technical and Economical
Corri dor One is one of the shortest corridors
considered,approximately 40 miles long,making it
economically favorable.No technical restrict ions
were observed along the entire length of this
corridor .
.Environmental
Because of its short length,environmental ,
disturbance caused by transmission line construction
would be reduced.The more noteworthy constraints
are those identified under the categories of land
use and vegetation.Corridor One would require the
development of a new right-of-way between Watana and
Devil Canyon with some opportunity existing to
utilize the COE-developed road for access between
£-10-51
the Intertie and Devil Canyon.The potential does
exist in this corridor to use one of the proposed
access roads currently under consideration.
Wetlands and discontinuous forest cover occur in the
corridor,especially in the eastern third of the
route.Access road development,if required in this
area,and the associated vegetation clearing present
additional constraints to this corridor.
Ratings:
Technical
A
Economi cal
A
Environmental
A
Summary
A -
o Corridor Two (ABECD)-Watana to Intertie via
Stephen Cake
.Technical and Economical
This corridor is approximately five miles longer
than Corridor One and would require an additional
five mile5 of access road for construction purposes.
The corridor will rise to a maximum elevation of
3,600 feet,and also crosses wetlands and extensive
forest cover.This higher elevation,increased
clearing,and longer length result in a lower
technical and economic rating than Corridor One.
Environmental
This corridor is identical to Corridor One with the
exception of Corridor Segment BEC.Because of this
deviation,several additional problems arise in this
corridor as compared with Corridor One.First,an
access road about nine miles longer than that
required for the construction of Corridor One would
be needed.A new road may al so have to be developed
along most of this route,which would also cross
wetland and forested areas.Residential and
recreational facilities at Stephan Lake and the much
higher visibility of the transmission facilities to
the users of this recreation area would be a major
constraint posed by this corridor.
The corridor would also intrude upon habitat for
wolves,!}ear,and caribou,as well as for raptors
and waterfowl.Of note,brown bears utilizing the
fish resources of Prairie Creek would likely
encounter this alternative corridor more
E-1O-52
-
~,
frequently than they would Corridor One,thus
potentially bringing bears and people into close
contact.
,~
These potential impacts to aesthetics and creation
of new access road result in this corridor being
environmentally unacceptable.
Ratings:
Technical
C
Economical
C
En vi ronmenta 1
F
Summary
F
o Corridor Three (AJCF)-Watana to Intertie via North
Shore of the Susitna River
.TeChnical and Economical
This corridor is similar in length to Corridor Two
and shares the same technical and economical
considerations.Tilere are no existing roads for
nearly the entire length,and it does encounter some
steep slopes.These will reduce the reliability of
the line and add to the cost of construction .
.Environmental
Summary
C
Env ironment a1
C
Economi cal
C
The corridor in this area would likely require a
pioneer access road.This route would also be
impeded by the existence of recreation facilities in
the vicinity of High Lake and,more significantly,
Otter Lake.The corridor is within sight of
recreation facilities at these lakes and may also
interfere with the use of High Lake by planes during
certain weather conditions.·The route a1 so crosses
Indian River and Portage Creek;both streams support
significant salmon resources.Potential damage to
spawning areas could occur as a result of
construction along this corridor.An active golden
eagle nest exists in the Devil Creek vicinity.This
species is sensitive to development activities and
caul d be adversely affected by Corri dor Three.
Ratings:
Technic al
C
--
E-10-53
o Corridor Eleven (CJAHI)-Devil Canyon to the Intertie
via Tsusena CreeklChul1tha Rlver
·Technical and Economical
This corridor has a disadvantage over the others
discussed because of its la-mile length.New access
roads and vegetative clearing would be required for
a cons i derab 1e port ion of the corr i dor,thereby
increasing costs of construction.
~,
·Envi ronment a1
Corridor Segments CJA (part of Corridor Three)and
AHI(part of Corridor Six)comprise this alternative
and,as such,have been previously discussed.The
long length of this corridor,its crossing of 36
creeks,and development of a new right-of-way and
1and use confl icts contribute to an unacceptable
environmental rating.
Ratings:
Techn ica1
C
Economical
C
Envi ronmenta 1
F
Summary
F
o Corridor Thirteen (ABCF)-Watana to Devil Canyon via
South Shore,Devi 1 Canyon to Intert ie vi a North Shore,
Sus itna River
·Technical and Economical
This corridor,41 miles in length,is one of the
shorter ones being considered.Although it crosses
deep ravines,and forest clearing will be required
over a considerable portion of its length,it is
rated high technically because of its short length
and low elevation.
~,
Env ironment a1
-
Summary
A
Environmental
A
Economical
C
Since this corridor combines segments from Corridor
One (ABC)and Corridor Three (CF),the same
constraints for those two routes apply which have
been previously described.This corridor presents a
few environmental problems.Conflicts with
recreation near Otter Lake can be resolved through
careful selection of one final right-of-way.
Ratings:
Technical
A
-
E-10-54
o Corridor Fourteen (AJCD)-Watana to Devil Canyon via
North Shore,Devil Canyon to Intertie via South Shore,
Susitna RlVer
·Technical and Economical
This corridor is also one of the shortest among the
fifteen studied in the central area.Some access
roads will be required for this corridor and some
clearing necessary.Advantage will be taken of the
proposed project access road where possible to
locate the transmission line close by.
Corridor Fourteen is rated as recommended both
economically and technically,because of gentle
re 1i ef,short 1ength,and small amount s of
clearing.
·Environmental
Summary
A
Environment a1
C
Economical
A
This corri dor reverses the routing between dams ites
and the Intertie proposed by Corridor Thirteen.
Constrai nts are,therefore,the same as those
present ed for Corr i dors Three and One,and are not
great.However,the unavoidable conflict with land
use at High Lake results in a Crating.
Ratings:
Technical
A
a Corridor Fifteen (ABECF)-Watana to Devil Canyon via
Stephan Lake,Devil CanyOn to Intertie via North
$hore,5usitna River
·Technical and Economical
This corridor is approximately 45 miles long and
would require construction of new access roads and
forest clearing for almost its entire length.These
negative economical points contribute to the low
rating of this corridor.
·Environmental
This corridor combines segments from Corridor Two
(ABEe)and Corridor Three (CF).The constraints for
these corridors have been presented under their
respective discussions.Extensive new access and
detrimental visual impacts near Stephan Lake were
E-10 ....55
the primary constraints along the corridor segment
from Corridor Two which resulted in an unacceptable
environmental rating.
Ratings:
Technical
C
Economical
C
Environmental
F
Summary
F
Northern Study Area
Constraints appeared in the routing of all four
corridors evaluated in the northern study area.The
shortest route was 85 miles and the longest was 115
miles.Topography and soils restrictions are
constraints to each of the corridors evaluated.In
addition,the two eastern corridors of the study area
cross mountain slopes.Each of the corridors would be
highly visible in the floodplain of the Tanana River.
Major highways skirt these floodplains at some distance
to the north,however;and only scattered,isolated
residential areas would be encountered by the corridors.
Little information has been collected concerning the
cultural resources in the vicinity of any of the four
corridors of this study area.The Dry Creek
archaeologic site near Healy has been identified;
however,the presence of numerous sites in the foothills
of the Al aska Range and in the vicinity of the Tanana
River are suspected.Additional constraints peculiar to
the four separate corridors are presented below.
o Corridor One (ABC)-Healy to Fairbanks via Parks
Highway
.Technical and Economical
This corridor crosses the fewest water courses in
the northern study area.Although it is
approximately four miles longer than Corridor Two,
it is technically favored because of the existence
of potential access roads for almost the entire
1ength.
.Env ironment a1
Because it parall el s an exi sti ng transportation
corridor for much of its length,this corridor would
permit 1 ine routing that would avoid most visually
sensitive areas.The three proposed road crossings
for this corridor (as opposed to the 19 road
crossings of the Healy-Fairbanks transmission 1 ine)
E-10-56
~,
"""
-
could occur at points where roadside development
exists,in areas of visual absorbtion capability or
in areas recommended to be opened to long-distance
views (D.N.R.1981).
Four rivers and 40 creeks are crossed by this
corridor,with potent i al for impacts.It crosses
the fewest number of water courses of any route
under consideration in the northern study area.In
add it ion,the inactive nest site of a pai r of
peregrine falcons occurs within this proposed
corridor.
As with visual impacts,land use,wildlife,and
fishery resource impacts can be lessened through
careful route location and utilization of existing
access.Impacts on forest clearing can also be
1essened through the shari ng of exist ing
transmission line corridors.
Rat lngs:
Technical
A
Economical
A
Envi ronment a 1
A
Summary
A
o Corridor Two (ABDC)-Healy to Fairbanks vi a Wood
River·Crossins
Technical and Economical
This is the shortest corridor (86 miles)studied in
this area.Although comparable to Corridor One,it
crosses additional wetlands,increasing the
technical difficulty of transmission line
construction.Development of roads will also pose a
major constraint.
[nv i ronmenta 1
Corridor Two is the shortest under consideration in
the northern study area.As it is a vari at ion of
Corridor One,many of the same constraints apply
here.The lack of existing rights-of·way is a
constraint throughout much of this route.Prior to
crossing the Tanana River,this corridor deviates
farther to the northeast than does Corridor One,
thereby crossing additional wet soils;thus,
access-road development poses a major constraint.
Forest clearing would be necessary in the broad
floodplain of the Tanana River.While it is the
shortest route,this corridor still crosses 5 rivers
E-10-57
-----_._-_._--------,--~-----
and 44 creeks as well as prime habitat and important
habitat for peregrines and golden eag1es~These
constraints,and visual and public land conflicts,
result in a Crating.
Ratings:
Technical
C
Economical
A
En vironment a1
C
Summary
C
o Corridor Three (AEDC)-Healy to Fairbanks via Healy
Creek and Japa~Hl1ls
.Technical and Economical
This 115-mi1e corridor is the longest in the
northern study area.Its considerable length would
contribute substantially to increased costs of
construction.The crossing of areas over 4,500 feet
in elevation results in the corridor's being
technically unacceptable for reasons discussed
above.
Environmental
This corridor crosses a high mountain pass and,in
some locations,encounters bedrock overlaid with
shallow,wet soils.Access is a problem because,
except for the road into the Usibelli coal fields,
no rights-of-way exist along the route.Crossing
the broad floodpl ain of the Tanana and Wood Rivers
would require extensive forest clearing and result
in aesthetic impacts.In addition,this corridor
involves 3 river and 72 creek crossings.Prime
habitat for caribou,peregrine falcons,sheep,and
waterfowl as well as important habitat for golden
eagles and brown bear would be affected.
The increased length and increased visual impacts
result in this corridor's being environmentally
unacceptable.
Ratings:
Technical
F
Economical
C
E-l0-58
En vironment a1
F
SummaryF.
o Corridor Four (AEF)-Healy to Fairbanks via Wood
River and Fo~t Wainwright
.Technical and Economical
The technical and economical constraints associ ated
with this corridor are the same as those in Corridor
Three.The long distance of this corridor (105
miles)and the crossing of areas over 4,500 feet in
elevation reduce its attractiveness from a technical
and economical viewpoint.
Env i ronmenta 1
Corridor Four is very simil ar to Corridor Three in
that it parallels Healy Creek drainage north.
Therefore,impacts to this mountainous region would
be identical to those described for this corridor
segment in Corridor Three.In the vicinity of Japan
Hills,however,the corridor parallels an existing
sl ed road for part of its 1ength as it traverses the
wet,heavily forested floodplain of the Tanana and
Wood Rivers. Clearing requirements might,
therefore,be reduced,as would be the need for
access roads in this area.Important habitat or
prime habitat for peregrine falcons,bald eagles,
sheep,caribou,and brown bear exists within this
corridor.This corridor is unacceptable from a land
use standpoint because it is within the Bl air Lake
Air Force active bombing range,precluding further
consideration of this corridor.
Rat ings:
Techn i cal
F
(vii)Proposed Corridor
Economical
C
En vironment a1
F
Summary
F
fi'i"im
I~
The Recommended corridor for the Susitna Project consists
of the following segments:
-Southern study area,Corridor ADFC;
-Central study area,Corridor ABCD;and
-Northern study area,Corridor ABC.
This corridor is shown in Exhibit B,Figures 8.51 through
8.57.
E-lO-59
(viii)Route Selection Methodology
After identifying the preferred transmission line
corridors,the next step in the route selection process
involved the analysis of the data as gathered and presented
on the base maps.The map is used to select possible
routes within each of the three selected corridors.By
placing all major constraints (e.g.,area of high visual
exposure,private 1ands,endangered speci es,etc.)on one
map,a route of least impact was selected.Existing
facilities,such as transmission lines and tractor trails
within the study area,were also considered during the
selection of a minimum impact route.Whenever possible,
the routes were selected near existing or proposed access
roads,sharing whenever possible existing rights-of-way.
The data base used in this analysis was obtained from the
following sources:
-An up-to-date land status study;
-Existing aerial photos;
-New aerial photos conducted for selected sections of the
previously recommended transmission line corridors;
-Environmental studies including aesthetic
considerations;
-Climatological studies;
-Geotechnical exploration;
-Additional field studies;and
-Public opinions.
(ix)Environmental Route Selection Criteria
The purpose of this section is to identify three selected
routes:one from Healy to Fairbanks,the second from the
Watana and Devil Canyon damsites to the Intertie,and the
third from Willow to Anchorage.Route location objectives
were to obtain an optimum combination of reliability and
cost with the fewest environmental problems.
The previously chosen corridors were subject to a process
of refining and evaluation based on the same technical,
economic,and environmental criteria used in corridor
selection.In addition,special emphasis was concentrated
on the following points:
-Satisfy the regul atory and permit requirements;
-Selection of routing that provides for minimum visibility
from highways and homes;and
-Avoidance of developed agricultural lands and dwellings.
E-10-60
~,
~,
-
The corridors selected were analyzed to arrive at the route
width which is the most compatible with the environment and
also meet the engineering and economic objectives.The
environmental analysis was conducted by the process
described below:
Literature Review
Data from various literature sources,agency
communications,and site visits were reviewed to
inventory existing environmental vari ables.From such
an inventory,it was possible to identify environmental
constraints in the recorrrnended corridor locations.Data
sources were cataloged and filed for later retrieval.
Avoidance Routing by Constraint Analysis
To establish the most appropriate location for a
transmission line route,it was necessary to identify
those environmental constraints that could be
impediments to the development of such a route.Many
specific constraints were identified during the
preliminary screening;others were determined during the
1981 field investigations.
By utilizing information on topography,existing and
purposed land use,aesthetics,ecological features,and
cultural resourCes as they exist within the corridors,
and by careful placement of the route with these
considerations in mind,impact on these various
constraints was minimized.
Base Maps and Overlays
Constraint analysis information was placed on base maps.
Constraints were identified and presented on overlays to
the base maps.This mapping process involved using both
existing information and that acquired through Susitna
Project studies.This information was first categorized
as to its potential for constraining the development of
a transmission line route within the preferred corridor
and then placed on maps of the corridors.Environmental
constrai nts were ident ifi ed and recorded di rect ly onto
the base maps.Overlays to the base maps were prepared
indicating the type and extent of the encountered
constraints.
E-10-61
Three overlays were prepared for each map:one for
visual constraints~one for man-made,and one for
biological constraints.These maps are presented in
Reference 22.
(ix)Results and Conclusions
A study of existing information along with data from aerial
overf1 ights was used to locate the recommended route in
each of the southern,central,and northern study areas.
Additional environmental information and land status
studies made it possible to align the routes to avoid any
restraints.
The proposed transmission line route is presented in
Exhibit G.The marked route represents the center1 ine of a
400-foot right-of-way which is sufficient for three
single-circuit,parallel lines.Between Devil Canyon and
the Intertie~the right-of-way is 700 feet to accommodate
five single-circuit lines.
(e)Borrow Site Alternatives
(i)Watana Borrow Sites
A total of seven borrow sites and three quarry sites have
been identified for dam construction material (A~B,C,D,
E,F,H,I~J,and L)(Figure ElO.6).Of these~Borrow
Sites 0 and H are considered as potential sources for
semipervious to pervious material;Sites C,E,and F for
granular material;Sites I and J for pervious gravel;and
Quarry Sites A,B,and L for rock fill.
Several of these sites (B~C~and F)~previously identified
by the Corp of Engineers,were not considered as primary
sites for this study because:1)a source of suitable
material exists closer to the damsite;2)of adverse
environmental impacts;3)of insufficient quantity;or 4)
poor quality of the material.Therefore,no work was
performed in these areas during 1980-81.These sites,
however,have not been totally eliminated from
consideration as alternative sources and are therefore
included in this discussion.
Since adequate quality and quantity of quarry rock are
readily available adjacent to the damsites,the quarry
investigation was principally limited to general field
reconnaissance to delineate boundaries of the quarry sites
and to determine approximate reserve capacity.This
allowed for a more detailed investigation in the borrow
sites.
E-10-62
-
....
-
"""
...."
The b9rrow investigations consisted of seismic refraction
surveys,test pits,auger holes,instrumentation,and
laboratory testing.The results of this study are
discussed below.
Each site is presented in the following sequence:
(1)Proposed use of the material and why the site was
selected;
(2)Location and geology,including topography,
geomorphology,vegetation,climatic data,groundwater,
permafrost,and stratigraphy;
(3)Reserves,lithology,and zonation;and
(4)Engineering properties which include index properties
and 1aboratory test results.
Laboratory test results on samples from the borrow areas
are shown in Reference 21.
Quarry SHe A
o Proposed Use
Quarry Site A is a large exposed diorite and andesite
porphyry rock knob at the south abutment of the Watana
damsite.The predominant rock type is diorite.The
proposed use for the quarry is for blasted rockfill
and riprap.
Quarry Site A was selected based on its apparent good
rock qual ity and close proximity to the damsite.
o Location and Geology
The boundari es of Quarry Site A incll.Jde the bedrock
IIknob ll from approximate Elevation 2300 to about 2600.
The knob covers an area approximately one square mile.
Glacial scouring has gouged out east-west swales in
the rock.These swales likely corresponded with
fractured,sheared,and altered zones within the rock
body.Overburden ranges from 0 to several feet over
the site.Vegetation is limited to scrubby spruce,
vines,and tundra,with limited alder growth in the
lower areas.Surface water is evident only in
isolated deeper swales.The groundwater table is
expected to be deep in this area with an estimated
average depth to the water table from 50 to 100 feet.
It is likely that the groundwater level will be near
the quarry floor during operation,but inflows are
expected to be small,diminishing with time.
E-10-63
Although no borings have been drilled in this site,it
is likely that permafrost will be encountered as
shallow as 5 feet in depth.The permafrost,however,
is near the thaw point and,because of the high
exposure to sunlight in this area,is expected to
dissipate rapidly.The permafrost zones are expected
to be more common in the more fractured and sheared
zones.
The western portion of the site has been mapped as
sheared andesite porphyry with the remainder of the
site being gray diorite.Mapping on the northern half
of the site showed the rock to grade between black
andes ite porphyry and a coarse-grai ned gray andesite
with sections grading into diorite.Despite these
lithologic variations,the rock body is relatively
homogeneous.Based on ai rphoto i nterpretat i on,severe
shearing and alteration appear to be present on the
northeast corner of the delineated site area.
o Reserves
The rock exposure in Quarry Site A provided adequate
confidence in assessing the quality and quantity of
available rockfill necessary for feasibility.
Allowing for spoilage of poor quality rock caused by
alteration and fracturing,and assuming a minimum
bottom elevation of 2300,the estimated volume of
sheared or 'r,eathered rock i's 23 mi 11 ion cubic yards
(mcy)and 71 mcy of good quality rock.
Additional rock fill,if required,can be obtained by
deepening the quarry to near the proposed dam crest
elevation of 2210 without adversely affecting the dam
foundation or integrity of the reservoir.
o Engineering Properties
Weathering and freeze-thaw tests were conducted to
determine the rock's resistance to severe
environmental conditions.Results indicate that the
rock is very resistant to abrasion and mechanical
breakdown,seldom losing strength or durability in
presence of water and demonstrating high resistance to
breakdown by freeze-thaw.
E-10-64
-
....
,~
,~
~.
The rock is expected to make excellent riprap,rock
shell,or road foundation material.
Quarry Site B
o Proposed Use
Quarry Site B was identified in previous
investigations as a potential rock quarry for dam
construction.The area was identified based on
outcrops exposed between Elevations 1700 and 2000
along the Susitna River and Deadman Creek.During the
1980-81 field reconnaissance,mapping and additional
sei smic refract ion surveys were performed in thi s
area.
o Locat i on and Geo logy
Quarry Site B is located about two miles upstream from
the damsite between Elevations 1700 and 2000.This
area init i ally appeared economically attractive
because of the short-haul distance and low-haul
gradient to the damsite.However,geologic mapping
and seismic refraction surveys performed in this area
indicate that the rock is interfingered with poor
quality sedimentary volcanic and metamorphic rocks
with thick overburden in several areas.
Vegetation cover is heavy,consisting of dense alder
marshes and al der with aspen and bl ack spruce in the
higher,drier areas.The entire south-facing side of
the site is wet and marshy with numerous permafrost
features.The quarry side faci ng Deadman Creek is
dry,with thick till overburden,which appears frozen.
Permafrost in the area is expected to be continuous
and deep.Surface runoff from Borrow Site 0 flows
southward passing through Quarry Site B.
o Reserves
Because of 1)the deep overburden;2)generally poor
rock quality;and 3)the extreme vegetation and
topographic relief,Quarry Site B was not considered
as a primary quarry site.Therefore,no reserve
quantities were determined for feasibility.
E-10-65
o Engineering Properties
No material property testing was performed for this
area.
Borrow Site C
o Propo sed Use
Borrow Site C was identified in previous studies as a
possible source of gravels and sands for filter
material.The 1980-81 investigation identified
adequate volumes of granular material much closer to
the damsite in Borrow Site E.Therefore,no
additional work was performed in this area during this
study.
o Location and Geology
Borrow Site C,as delineated by the COE,extends from
a point approximately 4-1/2 miles upstream from
Tsusena Butte to the northwest toe of the butte.The
site is a broad glacial valley filled with till and
alluvium.Vegetation ranges from alpine tundra on the
valley walls to heavy brush and mixed trees at the
lower elevations,thinning to mixed grass and tundra
near the river and on terraces.The groundwater tabl e
is assumed to be a subdued replica of the topography,
being shallow on the valley walls with gradients
towards the valley floor.Groundwater migration is
expected to be rapid through the highly permeable
alluvial material.Permafrost may be intermittent.
The stratigraphy appears to consist of over 200 feet
of basal till overlain by outwash,and reworked
outwash alluvium.The upper 100 to 200 feet of
material is believed to be saturated gravels and
sands.
o Reserves
Because the site is not currently being considered as
a borrow source,no detailed quantity estimate has
been made.However,assuming an approximate area of
1,500 acres and an excavation depth of 15 feet above
water tabl e,a gravel quantity on the order of 25 mcy
can be approximated.Additional quantities may be
obtained at depth;however,further studies will be
required to determine the volumes.
E-10-66
-
-.
-
o Engineering Properties
The test pit and reconnai ssance mapping show the
material in the floodplain and terraces to be a 4-inch
minus,well-washed gravel with approximately 60
percent gravel,40 percent sand,and negligible fines.
The gradations are representative of a clean,
well-washed material with a percentage of cobbles and
fines at depth.
Borrow Site 0
o Proposed Use
Borrow Site 0 was identified in 1975 as a potential
primary source for impervious and semi pervious
material by the COE.
Based on the field studies performed by the COE in
1978,it was tentatively concluded that:
-Borrow Site D had potentially large quantities of
clay an d s 11 t ;
-The deposit was of adequate volume to provide the
estimated quantity of material needed for
construction;and
-The site had favorable topography and hydrology for
borrow development.
As a result of these previous studies,Borrow Site D
became a primary site for detailed investigation
during the 198081 study.
o Location and Geology
Borrow Site 0 lies on a broad plateau immediately
northwest of theWatana dams ite.The southern edge of
the site lies approximately 1/2 mile northeast of the
dam limits and extends eastward towards Deadman Creek
for a distance of approximately 3 miles.The
topography slopes upward from the damsite elevation of
2150 northward to approximate Elevation 2450.
The ground surface has localized benches and swales up
to 50 feet in height.The ground surface drops off
steeply at the slopes of Deadman Creek and the Susitna
River.
Vegetation is predominantly tundra and sedge grass
averaging about one foot thick with isolated strands
of spruce trees on the higher and dryer portions of
the site.
Climatic conditions are similar to those at the
damsite with the exception that the borrow site is
more exposed to winds and sunlight.The relatively
open roll i ng topography is conduct i ve to drift i ng and
blowing snow~frequently resulting in drifts up to six
feet deep.
The northwest portion of the site has numerous lakes
and shallow ponds with the remaining portions of the
site having localized standing water perched on either
permafrost or impervious soi 1s.Surface runoff is
towards Deadman Creek to the northeast and Tsusena
Creek to the west.Generally,much of the area is
poorly drained,with many of the low-lying areas wet
and boggy.
Instrumentation installed throughout the borrow site
shows intermittent "warm"permafrost.Temperatures in
the permafrost zones are all within the _1°C range.
Thermistor plots show annual frost penetration of
approximately 15 to 20 feet.Annual amplitude
(fluctuation)in ground temperature reaches depths of
20 to 40 feet.The greatest depth of temperature
amplitude isin the unfrozen holes~while the
permafrost holes reach 20 to 25 feet.This may be
caused by either the effect of greater water content
at the freezing interface lessening th,e seasonal
energy vari ations,or the thicker vegetation cover in
the permafrost area causing better insulation.
o Reserves
The boundaries of the horrow site are somewhat
arbitrary,being limited on the south side by the
apparent limit of undisturbed material;to the east by
Deadman Creek;to the northwest by low topography;and
to the north by shallowing bedrock.If further
studies indicate the need for additional materials~it
may be feasible to extend the borrow site to the
northwest and west.Factors to be considered in
borrow site expansion are:
Siting of other facilities in this area;
-Impacts on the relict channel;
-Haul distance;and
-Environmental impacts.
The reserve estimates for Borrow Site D have assumed
an average material thickness throughout the site
limits.Based on the currently established boundaries
(encompassing about 1~075 acres)and an excavation
depth of 120 feet~a total of 200 mcy of material is
available..
E-10-68
~'
-
-
-
~,
-
-
-
o Engineering Properties
Grain size distribution within the borrow site ranges
from coarse gravels to clay.Almost all samples were
well graded~ranging from gravel to fine silt and/or
clay.Moisture contents range from a low of 6 percent
to a high of 42.5 percent with an average of
approximately 14 percent.
Borrow Site E
o Proposed Use
Borrow Site E was identified by the COE as a principal
source of concrete aggregate and fi Her materi a1 for
the Watana dam.The apparent volume of material and
its close proximity to the site made it the primary
site for detailed investigations during the 1980-81
program.
Location and Geology
Borrow Site E is located three mi les downstream from the
dams ite on the north bank at the confl uence of Tsusena
Creek and the Susitna River.The site is a large flat
alluvial fan deposit which extends for 12,000 feet
east-west and approximately 2,000 feet northward from
the Susitna River up Tsusena Creek.Elevation across
the site varies from a low of 1410 near river level to
1700 where the alluvial and terrace materials lap
against the valley walls to the north.
The area is vegetated by dense spruce and some alders,
tundra,and isolated brush.Vegetation cover averages
about one foot thick underlain by up to four feet of
fine silts and volcanic ash.
Groundwater
feet deep.
from winter
material.
was found to be generally greater than 10
Groundwater levels fluctuate up to five feet
to summer,indicating a free draining
The hydrologic regime shows summer peak flows in the
area reaching approximate Elevation 1435-1440 at the
north of Tsusena Creek.This elevation corresponds with
the limit of scoured and unvegetated river bank.The
estimated 50year flood level is approximately 1,473
feet.
E-10-69
The underlying bedrock overlain by a sequence of
bou1dery till,river and floodplain gravels and sands.
As in the case of Borrow Site D,the grain size
distribution in Site E varies from boulders to fine
silt and clay.Within this wide range of soil types,
five distinct soil gradations (A through E)can be
delineated.However,the complex depositional history
and the limited exploration performed in this area
does not allow for ready correlation of these soil
types over the site.Generally,however,the finer
s 11 ts and sands are found in the upper fi ve feet of
the depos it .Several abandoned ri ver channels of
either the Tsusena Creek or the Susitna River cross
cut the site.The infilling and cross cutting of
these streams and rivers through the site has resu lted
in a complex heterogeneous mixing of the materials.
Exploration indicates that,although the five
principal soil types are persistent within the site,
they vary in depth from near ·surface to approximately
40 to 70 feet.
No permafrost has been encountered in the borrow site,
probably because the site has a south-facing exposure
and has a continuous thawing effect caused by the
flowing river.Seasonal frost,up to 3to 6 feet
deep,was observed in test pits that encountered
groundwater (mi d-March 1981)and up to at 1east 13
feet in pits on the northwest side of the site that
did not intercept the groundwater table.In areas of
shallow groundwater,the frost was almost eXClusively
confined to the upper shallow sand and silt layers,
while dry gravels showed deeper frost penetration.
Annual frost penetration may be assumed to be about 3
to 6 feet in silty or clayey soils and at least 11
feet in loose dry gravels.
o Reserves
Quantities were calculated on the basis of known and
inferred deposits above and below the current river
regime.Assuming an overall surface area of
approximately 750 to 800 acres,the estimated quantity
of material above river elevation is 34 mcy.An
additional volume of 52 mcy is available below river
elevation assuming a total maximum depth of excavation
of 125 feet in the southwest corner of the borrow
E-10-70
-
site,decreasing to a minimum of 20 feet in the
northeast corner.
Approximately 80 percent of the identified material in
the borrow site is within the floodplain area,10
percent in the hillside terraces,and 10 percent in
the Tsusena Creek segment.
Average stripping is estimated at one foot of
vegetat ion and three to four feet of fine grained
material.
o Engineering Properties
The soi 1 units A through E range from coarse sandy
gravel through gravelly sand,silty sand,cobbles and
boulders,silty sand and silt.Several of these
material units correlate well with the material in
Sites I and J.Moisture contents for the silts range
from 25 to 30 percent;sand from 4 to 15 percent;and
gravels from 1 to 5 percent.The percentage of
material over 6 inches is roughly estimated at 10
percent with the over-12-inch estimated at 5 percent.
Selective mining may be possible to extract particular
types of material.Further detailed investigations in
this area will be required to accurately define the
location and continuity of stratigraphic units.
Borrow Site F
o Proposed Use
Borrow Site F was identified by the COE as a potential
source of filter material for the main dam.
Prel iminary work performed by the CDE showed the site
to have limited quantities of material spread over a
large area.For this reason,Borrow Site E became the
preferred site,with Borrow Site F being considered as
an alternative source for construction material for
access roads,runways,and camp construction.
o Location anu Geology
Borrow Site F occupies the middl e stretch of Tsusena
Creek from just above the high waterfall to north of
Cl ark Creek where it abuts Borrow Site C.The
northeast portion of the valley is confined by the
flank of Tsusena Butte and its talus slopes.The
E-10-71
vegetation in the area is mixed spruce and tundra~
with isolated areas of undergrowth and alders.
Groundwater is expected to be near surface.Limited
permafrost is likely to be encountered in north-and
west-facing exposures but is expected to thaw readily
when exposed during summer months.Deposits above
stream level are expected to be fairly well drained
with lower areas saturated.
Limited test pits indicate the material in Borrow Site
F is the same as that in Borrow Site C.The depth of
clean sands and gravels is estimated to be
approximately 20 to 30 feet~ranging from a shallow 5
feet to a maximum of 40 feet.The area consists of a
.series of gravel bars and terraces extending ~p to
1,500 feet away from the stream.
o Reserves
No detailed topography was obtained for the site;
however,assuming a conservative depth of 20 feet of
material,a total volume of approximately 15 to 25 mcy
is likely available.
Additional investigation in this area will be required
to confirm these volumes.
a Engineering Properties
Test pits excavated by the COE show gravelly sand
overlain by a very thin silt and sandy silt cover.No
detailed testing was performed on this material.
Borrow Site H
o Proposed Use
Borrow Site H has been defined as an alternative site
to Borrow Site 0 for impervious and semipervious
material.
a Location and Geology
The topography of Borrow Site His generally roll lng,
sloping towards the Susitna River.Elevations range
from 1400 to 2400 across the site and av~rage about
2100.Most of the sHe is covered by swamps and
marshes,indicating poor drainage.The vegetation
consists of thick tundra,muskeg,alder~and
underbrush growth.
E-10-72
-
Groundwater and surface water are perched on top of
impervious material with numerous seeps and ponded
surface water.The extensive coverage of spruce trees
may be indicative of a degrading permafrost area.A
large ice deposit exists in a slump exposure on the
west end of the site.The deposit and associated
solifluction flow with a multiple regressive headwall
are approximately 100 to 150 feet across.
Of the eight auger holes drilled in the site~six
encountered permafrost at depths ranging from 0 to 14
feet in depth.All the holes but one showed the water
tab 1e at or near the surface.
The site stratigraphy consists of an average of 1.5
feet of organics,underlain by 1.5 to 4~5 feet of
brown sand or si lt materi al with traces of organics.
Below this upper material,most of the holes show
mixed silt,sandy silt,and sandy clay to depths of 6
to 13 feet,which in turn is underlain by zones of
gravels,gravelly sand,and mixed silts with sand and
gravel.A color change from brown to gray occurs at
depths of 6 to 28 feet.Insufficient data exist to
allow for detailed stratigraphic correlation across
the site.
o Reserves
The quantity estimate has assumed a relatively
homogeneous mix of material over a surface area of 800
acres,with 5.5 feet of stripping required to remove
organics and clean silts and sands.Assuming an
estimated usable thickness of 32 feet (based on
drilling data)approximately 35 mcy of material is
available from this site.
a Engineering Properties
A detailed assessment of the grain size distribution
shows three distinct gradation groupings (A through
C).Gradation A denotes a gravelly sand~
characteri zed by 1ess than 40 percent fi nes and a
significant fraction exceeding 3/4 inch;B is a silty
sand without the generally coarser fraction;and C is
a silt unit which is generally less than 1 inch in
maximum particle size and contains in excess of 40
percent fines.
E-10-73
In conclusion,Borrow Site H material is considered
suitable for use as impervious and semi pervious fill.
However,problems such as wet swampy conditions,
permafrost,and the lengthy haul distance to the site
may affect the potenti al use of this site as a borrow
source.
Borrow Sites I and J
o Proposed.Use
Reconnaissance mapping was performed within a lO-mile
radius of the damsite to locate potential sources of
freedraining gravels for use in the dam shell.The
large volume needs of this material requires that the
source be relatively close to the damsite and in an
area that would minimize environmental impacts during
borrowing operations.As a result,the Susitna River
valley alluvium was delineated as a potential borrow
source.
o Location and Geology
A seismic refraction survey performed across the river
channel indicated large quantities of sands and gravel
within the river and floodplain deposits both upstream
and downstream from the damsite.
BOrrow Site I extends from the western limits of
Borrow Site E downstream fOr a di stance of
approximately 9 miles,encompassing a wide zone of
terrace and floodplain deposits.
Borrow Site J extends upstream from the damsite for a
distance of approximately 7.6 miles.The site area
extends from river bank to river bank and includes
several terraces and stream deltas.
Borrow Sites I and J are fully withi n the confi nes of
the Devil Canyon and Watana reservoirs,respectively.
Both sites are in an active fluvial environment.
Borrow Site J is flanked by bedrock,talus and
till-covered valley walls;while Borrow Site I
includes extensive terraces extending several hundred
feet up the valley walls above river level.
E-1O-74
-
~i
-
~,
-.
~-
o Reserves
For purposes of volume calculation,it was assumed
that all materials with seismic velocity of 6,500 feet
per second represented suitable gravel deposits.
Materials with velocities higher than 6,500 were
assumed to be either too bou1dery or dense.Not
included in the estimate were:
-The river material between the two sites;
-Material between the west boundary of Site J and the
downstream area of the damsite;and
-The section from the damsite to Borrow Site E.
This last area was considered to require excessive
dredging and could likely affect the hydraulics of the
tailwater.
An active slope failure was identified near Borrow
Site H.If further studies show that the excavation
of river material beneath this slide may result in
slope failure,than.this section of alluvium will be
left in place.In summary,a total of 125 mcy of
material were estimated in Borrow Site I extending a
distance of 8.5 miles downstream and 75 mcy in Borrow
Site J over a distance of 7 miles upstream.
o Engineering Properties
Three basic gradations are present within the two sites.
These are fine grained silty sand,sand and gravel.The
fine silty sand fraction was encountered in 25 percent
of the test pits and ranged in thickness from 6 inches
to 6 feet.The second gradation is a sand which varies
from a well-sorted clean sand to a gravelly poorly
sorted sand.This type of material was encountered in
only 15 percent of the 22 pits,and where present,
underlies the silt layer with an average thickness of
about 4 feet.The bu1 k of the sampl es are of a
moderately sorted gravel mixed with from 20 to 40
percent of sand and silt with less than 5 percent silt
and clay size fraction.
Quarry Site l
a Proposed Use
Quarry Site L has been identified as a source for
cofferdam shell material.
E-10-75
--_._--_._,,-------~-------
o Location and Geology
Quarry Site Lis located 400 feet upstream from the
proposed upstream cofferdam on the south bank.The
site is a rock knob immediately adjacent to the river
which is separated from the main valley walls by a
topographically low swale that has been mapped as a
rel ict channel.
The rock in the quarry area is diorite along the
western portion of the knob with andesitic sills or
dikes found farther upstream.The rock exposure
facing the river is sound with very few shears or
fractures.The vegetation is heavy brush with tall
deciduous trees on the knob and alders with brush in
the swal e to the south.Litt 1e surface water is
present on the knob;however,the low lying swale is
marshy.Permafrost may be expected to be present
throughout the rock mass.
Quarry Site L 1ies opposite liThe Fins ll feature which
is exposed on the north abutment;however,extensive
mappi ng in thi s area shows no apparent sheari ng or
fracture that could be correlative with the extension
of this feature.
o Reserves
Because of limited bedrock control,the site has been
delineated into two zones for estimating reserves.
Zone I delimits the total potential reserves based on
assumed overburden and rock volumes,while Zone II
identifies that volume of rock that,with a high
degree of confidence,is known to be present.Based
on field mapping and airphoto interpretation,the
total useable volume of material has been estimated to
be 1.3 mcy for Zone I and 1.2 mcy for Zone II,over an
area of 20 acres.
o Engineering Properties
No testing was performed on rock samples for Quarry
Site L.However,based on field mapping,it appears
that the rock properties and quantities will be
similar to those at the damsite.
E-10-76
....
.....
-
-
-
-
-.
,~
,~
-
(ii)Devil Canyon Borrow Sites
One borrow site and one quarry site were identified for the
Devil Canyon study (Figure E.lO.?).Borrow Site G was
investigated as a source for concrete aggregate and Quarry
Site K for rockfill.Despite detailed reconnaissance
mapping around the site,no local source for impervious or
semipervious material could be found.As a result,Borrow
Site 0 from the Watana inventory has been delineated as the
principal source for this material.Further investigations
may identify a more locally available source.The
following sections provide a detailed discussion of the
borrow and quarry sites for the Devil Canyon development.
Borrow Site G
o Proposed Use
Borrow Site G was previously identified by the USSR
and investigated to a 1imitedextent by the CaE
as a primary source for concrete aggregate.Bec ause
of its close proximity to the damsite and apparent
large volume of material,it became a principal area
for investigation.
o location and Geology
.Borrow Site G is located approximately 1,000 feet
upstream from the proposed damsite.The area
delineated as Borrow Site G is a large flat fan or
terrace that extends outward from the south bank of
the river for a distance of approximately 2,000 feet.
The site extends for a distance of approximately
1,200 feet ea~t-west.Cheechako Creek exits from a
gorge and discharges into the Susitna River at the
eastern edge of the borrow site.The fan is generally
flat-lying at Elevation 1000,approximately 80 feet
above river level.Higher terrace levels that form
part of the borrow site are found along the southern
edge of the site above Elevation 1100.
Vegetation is scattered brush with mixed deciduous
trees found on the floodplain and fan portions.On
the southern hillside portion of the borrow site,
heavy vegetation is evident with dense trees and
underbrush.The ground cover averages up to 0.5 foot
E-10-77
in thickness and is generally underlain by 1 to a
maximum of 6.5 feet of silts and silty sands.This
silt layer averages 1.5 feet thick on the flat-lying
deposits,and up to 2 feet thick on the hillsides
above Elevation 950.
No groundwater was encountered in any of the
explorations.The high permeability of the material
provides for rapid drainage of the water to the river.
Annual frost penetration can be expected to be from E
to 15 feet.No permafrost has been encountered in the
area.
The borrow material has been classified into four
basic types,based on the interpretation of field
mapping and explorations.The four types of material
are:Susitna River alluvial gravels and sand,ancient
terraces,Cheechako Creek all uvi urn,and talus.
The large fan deposits are a combination of rounded
alluvi al fan and river terrace gravel s composed of
various volcanic and metamorphic rocks and some
sedimentary rock pebbles.This material is
well-washed alluvial material.
o Reserves
The quantities of fine sands and gravels above river
level have been estimated to be approximately 1.1 and
1.9 mcy,respectively.Additional quantities could be
obtained by excavating below river level.The
quantity of material from the ancient terrain is
tentatively estimated to be approximately 2 mcy.
This~however,has been based on an inferred depth to
bedrock.If bedrock is shallower than estimated,this
quantity would be less.
Cheechako Creek alluviaum is estimated at 1.1 mcy,
while the quantity of talus is 55,000 mcy.Talus
quantities are too small to warrant consideration as a
borrow material.
An estimate of the total quantity of borrow material
is about 3 mcy with an additional 3 mcy potentially
available from inferred resources.The increase in
river level caused by diversion during construction
may affect the quantity of available material from
this site.Therefore,further work will be required
in subsequent studies to accurately determine
available quantities and methods and schedules for
exc av at i on.
E-10-78
-
.~
-
o Engineering Properties
The deposit is a gravel and sand source composed of
rounded granitic and volcanic gravels,with a few
boulders up to 3 feet in diameter.Deteriorated
materi al s compri se about 8 to 10 percent of the
s ampl es.
Testing performed by the USSR indicates that about 2
to 4 percent of the material was considered adverse
materi alfor concrete aggregate.
Two distinct grain sizes are found in the site:1)
from the auger holes,a fairly uniform,well sorted
coarse sand with low fine content and 2)from the test
trenches,a fairly well-graded gravelly sand averaging
10 percent passing No.22 sieve.The principal
reason that the auger drilling did not encounter the
coarser material is likely reflective of the sampling
technique where the auger sampl ing could not recover
the coarser fractions.
A finer silty layer overlies much of the borrow site.
Samples from the higher elevations are more sandy than
those from the fan area.
Based on observed conditions,the grain sizes from the
trenches are considered more representative of the
material in Borrow Site G at depth,while the finer
fraction represents the near surface material.
-Quarry Site K
o Proposed Use
Quarry Site K was identified during this study as a
source for rockfill for the construction of the
proposed saddle dam on the south abutment.
o Location and Geology
The proposed quarry site is approximately 5,300 feet
south of the saddle damsite,at approximate Elevation
1900.The site consists of an east-west face of
exposed rock cliffs extending to 200 feet in height.
Vegetation is limited to tundra and scattered scrub
trees.
E-10-79
Drainatjein the area is excellent with runoff around
the proposed quarry site being diverted to the north
and east toward Cheechako Creek.The groundwater
table is expected to be low and confined to open
fractures and shears.
The bedrock is a white-gray topink,;"gray,medium
grained,biotite granodiorite similar to that at the
Watana damsite.The rock has undergone slight
met amorph ism and cont a ins inc 1us ions of the arg ill it e
country rock.with local gneissic texture.The rock is
generally massive and blocky,as evidenced by large,
blocky,talus slopes at the base of the cliffs.
The rock is probably part of a larger bathol ith of
probable Tertiary age which has intruded the
sedimentary rocks at the damsite.
o Reserves
The 1imits that have been defined for the quarry site
have been based on rock exposure.Additional material
covered by shallow overburden is likely to be
available,if required.However,since the need for
rock fill is expected to be small,no attempt was made
to extend the quarry site to its maximum 1 imits.The
primary quarry site is east ofCheechako Creek.This
area was sel ected primarily because of its close
proximity to the damsite and high cliff faces which is
conducive to rapid quarrying.The low area west of
the site was not included because of possible poor
quality sheared rock.A secondary (backup)quarry
source was del ineated west of the primary site.
Because of the extensive exposure of excellent quality
rock in this area,additional exploration was not
considered necessary for this study.
The approx imate volume of rock determi ned to be
available in the primary site is about 2.5 mcy per 50
feet of excavated depth,or approximately 7.5 mcy
within about a 30-acre area.The·alternative backup
site to the west of Quarry K has been estimated to
contain an additional 35 rncy for 150 feet of depth,
covering some 145 acres.
o Engineering Properties
The granodiorite was selected over the more locally
available argillite and graywacke because of the
uncertainty about the durabil ity of the argill ite and
graywacke under severe c1 imat ic condit ions.
£-10-80
.-
-
-
-
-
-
The properties of the granodi oriteare expected to be
similar to those found at the Watana damsite.
Freeze-thaw and wet-drying (absorption)tests
performed on rock types simi 1 ar to those found on
Quarry K by the COE exhibited freeze-thaw losses of <1
percent at 200 cycles and absorption losses of 0.3
percent.Both tests showed the rock to be extremel y
sound and competent.
10.3 -Alternative Electrical Energx Sources
A detailed study of the Alaska Railbe1t Generating Alternatives was
undertaken by Battelle Pacific Northwest Lab.Most of the information
in this section is taken from reports documenting that study (20).
(a)Coal-Fired Generation Alternative
Previous studies have indicated that alternative generating
resources available to supply power to the Railbelt region include
use of the Beluga coal fields.The economic and technical
feasibility of developing this resource and of the selection
process utilized to conclude the economic feasibility of Beluga
coal,is discussed in Exhibit B.
Information presented in this section was extracted from previous
reports prepared in conjunction with studies of developing the
Beluga coal fields (4,5,9,19).Because specifics of plant
design and location are not available,the existing environment is
described for the general area and impacts are discussed in
generic terms only.
"For purposes of this evaluation,an electrical generating plant
with total capacity of 400 MW was assumed.Coal would be
strip-mined from the Beluga fields,transpm'ted to the plants,and
burned to produce electricity.Treatment of waste streams,
including air,water,and sol id waste,would occur at the site.
Approximately 1.5 million tons of coal per year would be burned.
A construction camp would be built near the site,and a permanent
vi 11 age mai ntai ned for mining personnel and pl ant operators.
(i )Existipg Environmental Condition
The Beluga coal fields are located approximately 50 to 60
miles southwest of Anchorage on the western side of Cook
Inlet.The coalfields are bordered by Cook Inlet on the
east and south,the Chakachatna River on the west,and the
Beluga River,Beluga Lake,and Capps Glacier on the north
(13).
E-10-81
-Air Quality
Air quality in the Cook Inlet and Beluga coal field area
can be described as good.The Cook Inlet Air Quality
Control Region is designated as a Class II Attainment area
for all criteria pollutants.The Tuxedni National
Wildl ife Refuge approximately 80 miles southwest of the
project area is Cl ass I Atta.i nment area for all criteri a
po llutants.
-Topography,Geo 109Y,and So i 1s
The topography of the western shore of Cook Inl et is
.dominated by high glaciated mountains dropping rapidly to
a glacial moraine/outwash plateau which slopes gently to
the sea.The outwash/moraine deposits begin at an
elevation of approximately 2500 and drop to tidewater in
30 to 50 miles (4).
The major geologic feature of the area is the Nikolai
moraine which lies in contact with sedimentary Tertiary
rocks (9).Most coals occur in the Tyonek Formation of
the Tertiary Kenai Group (10).The area is geologically
young with higher upland elevations consisting of slightly
to moderately modifi ed gl aci al morai nes and associ ated
drifts.
The lowland areas are mantled with glacial deposits and
overlaid by silt loam.
Soils are variable in the area.Generally,soils in the
southern portion of the area are sandy but poorly drained,
and soils in the west are well drained and dark,formed in
fine volcanic ash and loam.Soi ls in the east and
northern.areas range from poorly drained fibrous peat to
well-drained loamy soils of acidic nature.
-Surface Hydro 1ogy
The three major river systems in the Beluga coal field
area are the Chakachatna,Bel uga,and Chuitna4 The
Chakachatna is the 1 argest,with headwaters in Chakachamna
Lake and a 1,620-square-mile drainage area,and a length
of 36 miles.The Chuitna River begins near Capps Glacier,
flows 27 miles,and drains approximately 150 s~uare miles.
The Beluga River is 35 miles in length and drains 930
squaremi 1es (9).
E-10-82
-
_.!J,
--
-
r~
-Terrestrial Ecosystem
o Flora
Four major vegetative communities in the region are the
upland spruce-hardwood forest,high brush,wet tundra,
and alpine tundra.
The upland spruce-hardwood forest is centered in the
southern and central portions of the Bel uga area and
covers 40 percent of the area (9).This forest is
composed of paper birch,quaking aspen,black
cottonwood,and balsam poplar (4).
The high brush community in the west central portion of
the Beluga district covers 15 percent of the land area.
This type occupies a wide variety of soil types and may
occur as pure thickets in low-lying areas.Principal
species include sitka sider,raspberry dogwood,and
spirea (4,9).
The wet tundra pl ant community occupies 7 percent of the
area in the extreme southwest portion and along the
eastern boundary.The vegetative mat is dominated by
sedges and cottongrass,with scattered woody and
herbaceous plants.Principal species include willow,
birch,labrador tea,grasses,and lichens.
The alpine tundra area occupies less than 3 percent of
the land area and occurs only at the higher elevations.
This community comprises primarily low mat plants,both
woody and herbaceous.Principal species include
birches,willows,blueberry,rhododendron,and sedges.
o Fauna
The area of the Beluga coal fields supports wildlife
popul ation typical for this area of Al aska.Big game in
the areas include moose,black bear,and brown bear.
Both spec i es of bear den in the area and ut il i ze the
Selvon fishery as a food source (4).A major fall and
winter concentration of moose occurs in the high brush
community in the west central portion of the coal fields
near the Chuitna River.They are also found throughout
the area during other times of the year (9).
A high diversity of bird life is present in the area,
particularly during the fall and spring migration
periods.Active nesting sites of bald eagles and
trumpeter swans occur on the Chuitna River and peregrine
E-10-83
falcons occur in the area (4).The
heavily utilized by waterfowl (9).
whales,and other species of marine
Inlet near the study area.
-Aquatic Ecosystem
coastal areas are
Harbor seals,Beluga
mamalsoccupy Cook
-
The cold,running waters of river and streams in the area
support both resident and anadramous fisheries.The
Chuitna River supports five species of salmon (pink,king,
chum,coho,and sockeye)plus rainbow trout,Dolly Varden
and round white fish (9).Nikolai Creek,Jo's Creek,Pitt
Creek,and Sted at an a Creek are also known to support
anadramous fish populations.
-Mari ne Ecosystem
The Cook Inlet region just south of the Beluga coal fields
is a diverse area,with both aquatic and terrestrial
habitats.Intertidal and shallow subtidal habitats
contain broad expanses of gravel and sand and extensive
areas of mud flats.These areas show varying levels of
productivity,with the mud flat areas generally at low
levels (4).Dominant fauna present include pelecypods and
polychaete worms.The area of gravel and sand support
moderate densities of amphipods and isopods.
The Cook In 1et area is also import ant to -commerc i a1 and
sport fisheries.Four species of salmon and halibut
utilize this area and are harvested on a commercial basis,
as are herring,shrimp,and crabs.Commercial salmon
harvested in 1980 was estimated at 20.4 million pounds
with a value of $18 million.The average annual herring
catch is 6.4 million pounds,worth approximately $1.3
million.The smaller halibut fisheries yield
approximately 0.6 million pounds,worth $400,000,while
the shellfish harvest of crab and shrimp yields 16 million
pounds annually,worth $8.5 million (4).
Subsistence fishing is also conducted by local natives,
particularly by those from the Tyonek area.Species
harvested include clams,bottomfish,salmon,and smelt.
The diverse wetland and aquatic habitats support large
numbers of birds,particularly during the migration
periods.The coastal wetl ands and mud fl ats are heavily
utilized by waterfowl,cranes,and shorebirds,while the
offshore waters and sea cliffs are inhabited by sea birds
such as gulls,puffins,and murres.
E-10-84
~,
-
(~
-
J~'
Marine marrmals present in the Cook Inlet area include
seals,whales,and dolphins.Only the harbor seal and
Bel uga whale are known to occur in the upper Cook Inlet.
-Cultural Resources
Historic sites occur within the modern town of Tyonek.
Other sites nearby include Californsky's fish camp,old
village sites,and cemeteries.Few archaeological sites
are believed to be in the area,primarily because the
violent actions of the tide would have destroyed most of
the sites left by coastal-dwelling natives.
-Socioeconomic Conditions
The only substant i al settlement on the west coast of Cook
Inlet is Tyonek,inhabited by approximately 270 Tanaina
Indians.The village is typical of many small villages in
Alaska,with high unemployment.Recently,government
programs have somewhat alleviated this problem.
Employment on the west side of Cook inlet is supplied by
three commerci al devel oprnents:the Chugach generat i ng
station,Kodiak lumber mill,and crude oil processing and
transportation facilities.Commercial fishing and
subsistence activities are the major sources of income.
Hous i ng cons i sts primaril y of prefabricated structures.
One school,with total enrollment of 140,serves
kindergarten through the 12th grade.Pol ice protection is
provided by the Alaska State Troopers utilizing a resident
constable.Fire protection is provided by the U.S.Bureau
of Land Management.Medical services are available in a
medical center located in the village.Water is supplied
from a nearby lake and wastewater disposed of via septic
systems (4,9).
Transportation facilities in the areas are limited to
gravel lagging roads and small airstrips.
(ii)Environmental Impacts
-Air Qual itt
Coal mining and power generation will result in emissions
to the atmosphere of particul ate matter,nitrogen oxide,
sulfur oxide,carbon monoxi de,and hydrocarbons,as well
as lesser amounts of other pollutants.Their impacts
cannot be quantified without detailed air monitoring and
modeling;however,some generalizations can be made.
E-10-85
Mining emissions would comprise primarily particulate
matter from vehicul ar traffic,surface disturbance,and
wind across coal piles and disturbed areas.Heavy
equipment operations would also result in nitrogen oxide,
carbon monoxide,hydrocarbon,·and sulfur oxide emissions.
Beluga coal is characterized as sub-bituminous (6,500-
7,500 Btullb)with low sulfer (0.2 percent),high moisture
(25 to 28 percent)and high ash ~ontent (14 to 25 percent)
(4).This sulfur and heat content is comparable to that
of Powder River Basin coal in Wyoming,but the moisture
content is approximately twice the Powder River value.
Utilizing these figures and calculations from previous
reports yields approximate daily emission rates for a 700
MW facility (11).
-
-
Exact amounts of these pollutants and of nitrogen oxides
cannot be calculated without specific design criteria and
detail s on poll ution-control devices.
A Prevention of Significant Deterioration (PSD)review
would be necessary prior to construction.This process
would require that any emissions be within the allowable
increments established in the Clear Air Act regulations.
However,because the area is currently relatively free of
air pollution,the emissions from coal mining and
generating station operation would likely resu1t in a
noticeable degradation of existing air quality.In
addition,short term maximum concentrations could,under
certain meteorological conditions,exceed the National
Ambient Air Quality standards near the power plant (10).
This would would be particularly true during periods of
inversion.
S02
Fly ash
40 to 60 tons per day (no scrubber)
3 to 5 tons per day (with preci pitators)
-
-
-Topogr aphy,Gea logy,land So i1 5
Coal mining and construction of the generating facil ities
have the potenti al to impact topography and soi 1s in the
area.Mining operations would unavoidably change the
topoqraphy of the area,although reclamation and
compl iance with regulations of the Surface Mining Control
and Reclamation Act would minimize these impacts.Soil
eros i on from mini ng and pl ant construct ion activit i es
could also occur if proper precautions are not
implemented.
-Hydrology
E-10-86
Little is known about ground water resources in the area
(4).Strip mining has the potenti a1 to degrade the water
qual ity and interferes with ground water flows..
Regu1 at ions of the Surf ace Mi ni ng Control and Rec 1 am at ion
Act and the state of Alaska would require these impacts be
minimized.
Surface water could be affected from runoff from the mined
area,coal storage piles,site grading,road building,and
other construction activities.Plant operation would also
result in polluted and heated water from electrical
generation.Potential sources of contamination are acid
mi ne drainage,treatment chemical s,dust,spoil-pil e
runoff,fuel spillage,ash,and industrial waste.This
could impact surface water qual ity through changes in
turbidity,rates of photosynthesis,dissolved oxygen,
temperature,pH,and heavy metals.
It can be expected all point sources of discharge will
meet Federal New Source Performance standards and other
regulations of the Federal Water Pollution Control Act.
However,because of the high water quality of the river
and streams in the area,any impacts will be noticeable.
In addition,because of the seasonal fluctuation of flows
in the area,the impacts of sedimentation and other water
quality effects may be increased (10).
-Terrestrial Ecosystems
Surface mining will unavoidably result in the removal of
vegetation and wildlife habitat.If not properly restored
and revegetated,erosion would result and the habitat
permanently reduced in value.The areas of the generating
facility,roads,and ancillary facilities would be
permanently removed as wildlife habitat.
In addition to the direct impacts to wildlife,secondary
effectsWQu1 d al so occur.These include increased
hunt ing pressure on moose and bear bec ause of a 1 arger
human population and greater activity.New roads will add
access to the area,resulting in habitat disruption and
disturbance to the animals.This reduction in habitat and
other secondary effects will result in a substantial loss
in carrying capacity for most wildlife species and a
subsequent decline in their population levels.
-Aquatic and Marine Ecosystems
The impacts to aquatic and marine ecosystems would depend
primarily upon the effectiveness of siltation control
E-10-87
devices and degree of water treatment.Some aquatic
habitat would be lost because of mining activities.In
addition,increase sedimentation,interuption or reduction
in flows,and degradation of water qual ity could all
result in negative impacts to aquatic habitats,thereby
reducing fish population in the area.The potential also
exists for thanges in water quality to interfere with .
anadromous fish runs and reproduction,thereby affecting
marine resources in Cook Inlet.Impacts to other marine
resources,unless water qual ity is severely impaired,are
not expected to occur.
-Cultural Resources
Potenti al impacts to cultural resources incl ude
disturbance of sites,destruction of artifacts,and
increased access to the areas resulting in disturbances to
sites previously inaccessible.A cultural resource survey
would be required on all areas to be mi ned or bui lt upon.
If significant sites are discovered,mitigation will
likely occur,utilizing either avoidance or salvage
operat ions.
Thus,with the exception of the disturbance of areas
outside the project site but not currently accessible,
impacts to cultural resources shoul d be mitigatab 1e.
-Soc i oeconomi c Cond it ions
There are many impacts which affect socioeconomic factors
in an area.These include construction camp location (if
any),commuter modes,f ami 1y re 1oc at ion,worker need for
serv ices ,amount of local labor avail able,and
construction schedules.Thus,only generalized impacts
can be predicted.
Depending upon the size of the generation facility,direct
and indirect jobs will range .from 400 to 1,300 (4,9).
Most of these workers would likely come from the available
work force in Anchorage,with some from the Kenai
Peninsula and the local village of Tyonek.
If a construction camp or new vill age were created near
the plant site,local population would increase by several
thousand.This would require construction of new roads,
sewage and water systems,and other infrastructures
necessary to support these workers and their famil ies.
Some of these services would be supplied by the Kenai
Peninsula Borough,but most would likely be supplied
E-10-88.
------------------------~~-~-----
-
-,
-
-
either by the state of Alaska or the company building and
operating the generating facility.Thus,financial
impacts to the borough should be small (4).However,
because the Beluga coal fields are only 75 miles from
Anchorage,it is not likely a large,permanent village
would be required,since most workers would prefer to live
in the construction camp and leave their famil ies in the
Anchorage area.
The generating facility could add substantially to tax
revenues in the Kenai-Soldotna area.This revenue would
1 ike 1y expand government services in the area and thereby
create add it i onal employment opportuniti es.
Finally,there would likely be impacts to the village of
Tyonek.The large generation facility would result in
increased contact with non-native people and their way of
life.There could also be conflicts with subsistence
hunting and fishing activities and a potential,through
sport hunting,to reduce the resource basesut il i zed by
the natives.These increased contacts with non-natives
could result in the continued erosion of native customs
and cultural values.
Employment opportunit i es woul d be avail ab 1e for Tyonek
village residents.In addition,native business could
likely increase to supply goods or services to the
construct i on workers and construct i on site.Thus,the
project would result in positive economic benefits to the
vi 11 age.
In summary,socioeconomic impacts to the area of plant
development would not be great,primarily because of the
proximity of the site to the greater Anchorage area.
This area would supply most of the labor force and absorb
most of the impacts from development of goods and services
to supply the site.Popul ation levels at the site would
increase,with the magnitude dependent on the nature of
the construttioncamp;however,it is 1 ikely there would
not be more relocation of families to the site.Positive
economic benefits would occur to the native village of
Tyonek,but potential negative impacts to the cultural
values also exist.
(b)Tidal Power Alternatives
The Cook Inlet area has long been recognized as having some of the
highest tidal ranges in the world,with mean tide ranges of mare
than 30 feet at Sunrise on Turnagain Arm,26 feet at Anchorage,
and decreas i ng towards the lower reaches of Cook Inl et to 15 feet
£-10-89
or so near Seldovia.Information concerning feasibility of tidal
powergenerat i on and environmental impacts were gathered mai nly
from current studies being conducted for the Office of the
Governor,State of Alaska.Initial studies of Cook Inlet tidal
power development (12)have concluded that generation from tide
fluctuation is technically feasible,and numerous conceptual
schemes ranging in estimated capacity of 50 MW to 25,900 MW have
been developed..
(i)Preferred Tidal Schemes
Studies conducted for the Governor·;;office (16)have
i nd ic ated three sites are best su i ted for tid a1 power
development.This analysis,based on capacity,energy
generation and costs,considered sixteen sites and chose
the following (Figure E.10.6):
-Rainbow -This site crossed Turnagain Arm from a point
near the mouth of Rainbow Creek to a point approximately
two mi les east of Resurrect i on Creek.
-Point MacKenzie/Point Woronzof -This site crosses Knik
Arm near Anchorage.
Eagle Bay/Goose Bay -Thi s site crosses Kni k Arm at the
narrowing of the channel along Eagle and Goose bays.
Tidal power generation basically involves impounding water
at high tide level and converting the head difference
between the corresponding basin and the ebbing tide.
Present technology allows for extraction of this energy by
low-head hydraulic turbines to generate electricity.A
tid a1 power gener at i on proj ect ,therefore,we u1d i nvo 1ve
construction of dams,sl uice ways,powerhouses,and
transmission lines (12)..
(ii)Environmental Considerations
Environmental assessments of the preferred Cook Inlet
tidal development involve consideration of physical and
biological characteristics anticipated impacts,and short-
and long·term effects.
-Physical Characteristics
Several major characteri sties of Cook Inlet are rel evant
to an understanding of the processes and the potential
for change in the estuarine environment.These are the
tidal regime,hydrology,sediment load,and climate.
E-10-90
..
-
-
-
The mean tider'ange il1 Knik and Turnagain Arms is 25 to
30 feet.This extreme tidal variation,combined with
shallow water depths,results in a high velocity
current,turbulence,and high levels of suspended
sediments.Thus,suspended sediment load is also
affected by the hi gh concentration of silts and
sediments present in glacial runoff that enters Cook
In let.
Runoff from glaciers also affects the salinity
concentration in Cook Inlet.In the summer months,when
freshwater flows are high,salt concentrations drop and
suspended load increases.In the wi nter,as streamflows
diminish,salinity concentration increases.
-Biological Characteristics
Cook Inlet is an estuary where freshwater and saltwater
env i ronments meet.These are as are us ua 11 y high 1y
productive partly because of high nutrient levels.
In Knik and Turnagain Arms,high turbidity and limited
light penetration result in low biological productivity.
Resident and shell-fishery populations are present only
in low numbers;however,anadromous fish do use the
tlJrbid water for passage between the lower inlet and the
natural streams.Five species of salmon are found in
the tributaries to the Knik and Turnagain Arms~
Comparatively,the Knik Arm tributaries appear to·
sustain a more significant anadromous fishery than
Turnagain Arm.The important salmon rivers in Turnagain
Arm are Chickaloon River,Bird Creek,Indian Creek,
Portage Creek,Resurrection Creek,and Six Mile Creek.
Of these,the 1 argest salmon runs have been identified
in the Chickaloon River.In Knik Arm,the most
important salmon tributary is the Little Susitna River.
Other important streams are Fish Creek,Wasilla Creek,
Cottonwood Creek,Knik River and Matanuska River.
Intertidal areas,mud flats,and lowlands are extensive
in the Cook Inlet area partially because of the wide
tidal fluctuations.Mud flats are broad expanses with
1ittle vegetation.Above these areas are marshl and
habitats,supporting grasses,emergents,submergents,
and shrub vegetation.In terms of biological
productivity,these coastal marshes are the most
important areas within Cook Inlet.They provide
important nest i ngand staging habitat for hundreds of
thousands of shorebirds and waterfowl during the spring
and fall migrations.This results in extensive
E-10-9l
recreational hunting opportunities for Alaska's most
heavi ly popul ated area.During the years from 1971 to
1976,approximately 30 percent of the state duck harvest
occurred in Cook Inlet.
Five coastal marshes in Cook Inlet are protected as
st ate game refuges;four of these are in prox imi ty to
proposed tidal power development sites.They are Potter
Point,located just south of Anchorage at the mouth of
Turnagain Arm;Palmer Hayflats,in the upper reaches of
Knik Arm;Goose Bay,on Knik Arm ten miles north of
Anchorage;and Susitna Fl ats,to the west of Point
MacKenzie at the mouth of the Susitna and Little Susitna
rivers.Other important marshl ands not protected as
refuges are Eagle River Flats,across Knik Arm from
Goose Bay,and Chickaloon Flats,across Turnagain Arm
from Potter Point.
Although Cook Inlet is not an important habitat area for
marine mammals,a few species do occasionally migrate to
the area.Bel uga whal es are known to occur in the water
offshore from Anchorage.
The endangered Arctic peregrine falcon is known to nest
in the upper Cook Inl et region and to util i ze coastal
areas during the miqration periods.Bald eagles,not
cl ass ifi ed as endangered in Al aska,also are present in
the reg ion.No endangered waterfowl spec ies have been
verified in Cook Inlet,although habitat for the
Aleutian Canadian goose may occur in the southern
reaches of the Inlet.
-Ant i cipated Impacts
The construction and operation ofa tidal power plant in
either Knik or Turnagain Arm will affect the physical
processes of Cook Inlet and cause changes that may
directly or indirectly influence the natural
environment.These impacts can be divided into
short-term and long-term effects.
-Short-Term Effects
Short-term effects are those associ ated with
construction activities and include:
o Site development and construct i on;
o Site access and traffic;
o Operation of equipment;
o Dredging and dredged material disposal;and
o Development of construction material sources.
E-l0-92
.....
-.
-
-
-
These short-term activities will affect,for the most
part,only the environment in the vicinity of the site
and will extend for the construction period.Some
permanent changes will occur in the environment,such as
placement of permanent facilities,but the effects will
be site-specific.It should be noted that many of the
negative impacts normally associated with construction
can be eliminated by proper wastewater facilities,
erosion control methods,and other mitigating measures.
o Dredge and Fi 11
The activities associated with dredging and filling
may cause the most significant construction effect,
because of the quantities of materials being moved and
the necessary use of remote sites for dredged material
disposal and acquisition of construction materials.
The Eagle Bay and Rainbow sites will both require
dredgi ng of 30 mill ion cubi c yards of sed iments from
the inlet bottom.Most of this will not be suitable
as construction material and will need to be
transported from the site for disposal.Acceptable
sites for marine dumping can be found downstream where
the Inlet broadens,but care must be taken to avoid
commercial fisheries located in the Fire Island
vicinity.The dredged material itself is not polluted
or chemically contaminated.The physical constituents
of the dredged material are likely to be similar to
the bottom sediments found further downstream.
Disposal of dredged materi al may temporarily disturb
bottom organisms,but habitats would soon be
re-established.Careful planning in the timing and
choice of disposal sites can insure minimal impacts.
Because little of the dredged material at either the
Eagle Bay or Rainbow sites would be suitable as
construction materi a 1,upwards of seven mi 11 ion cubic
yards of fi 11 materi al must be procured from offs ite
sources.This would cause disturbance of upland
habitats resulting from the activities of excavation
and transport.Unavoidable impact of these activities
may be reduced by avoiding development in sensitive
environments.
The Point MacKenzie site is most attractive from the
standpoint of dredge/fi 11 operations.Less than one
quarter of the dredging required for either Rainbow or
Eagle Bay will be necessary for Point MacKenzie.
Additionally,a substantial portion of the material
removed will be rock,gravel,and sand that may be
appropriate for dam construction.This further
diminishes the volumes required for acquisition and
disposal.
o Site Access and Traffic
[stabl ishing access to the site by land and by sea and
providi ng for the high vol urne of traffic that wi 11
occur during the construction period will affect the
environment.Roads and marine docking facil ities will
be constructed.Marine traffic for construction
purposes,delivery of equipment,and dredging
operations will occur in areas where little or no
shipping or boating of any type has occurred.Access
roads will be established in previously undeveloped
areas.
To minimize these impacts,land routes can be chosen
to avoid sensitive areas such as waterfowl habitat,
and the high volumes of traffic can be limited to
construction periods.Marine traffic is not likely to
affect the few resident species nor block the mobile
anadromous species as they migrate up and downstream.
The marshl ands,waterfowl habitats,and upl and game
reserves would be most affected by development,noise,
and traffic activities.
o Site Development and Construction
The preparation of the site for construction,as ~'Jell
as the activities associated with construction,will
have its greatest impa(:ts on the site itself.
Alterations of topography and existing habitats will
occur.The presence of large,noise-producing
equipment and human activity will be disruptive to
habitats.
Site development can be conducted in a manner that
will minimize impacts.Minimization of land use,
implementation of plans for erosion control and
landscaping,and development of permanently useful
facilities such as dry docks will aid in reducing
impacts.
Noise factors are potentially most significant at the
Eagle Bay site,which is located only a few miles
upstream from Goose Bay State Game Refuge.The noise
levels have the potential to disrupt waterfowl,but
habituation can be expected.
£-19-94
-
The marine construction activities will affect the
aqu at ic env ironment.Dredg ing,fi 11 placement,dry
dock construct ion,caisson construct i an,and
installation will occur in the water.There are few
resident species to be disturbed,but migration of
anadromous fish may be affected.It is likely that
measures to insure fish passage will be required
during all stages of construction,reducing these
impacts.
-Lang-Term Effects
Certain aspects of plant operation may alter the
physical regime of the estuary.These will be discussed
in terms of their environmental implications:
•the altered tidal regime and estuarine hydrology;and
·the alteration of hydraulic characteristics:
currents/velocities,erasion/sedimentation.
Additionally,the fallowing lang-term impacts will be
considered:
·impacts added by the causeway alternative.
a Effects of an Altered Tidal.Regime
The process of capturing the tide in a basin behind
the barrier and regulating the flaws through it has
two important consequences.First,the mean tide
level in the newly farmed basin will be raised by
several feet.Second,the mean tide range will be
substantially decreased.Mean high tide levels will
probably be slightly lower and mean law tide levels
will be higher than what presently exist.
The result of these changes can be conceptualized as
fallows.The extent of the mud flats will likely be
somewhat diminished.The lowest reaches of the mud
flats will remain totally submerged,since the tide
will never reach its previous law levels.At the
upper 1imits of the mud flats,marshl and vegetation
may encroach seaward.As the frequency of inundat ions
decreases at the edges of the marshl and,marsh grasses
will grow an the farmer edges of the mud flats.This
will result in shifts in locating mud flats and
poss ib 1e changes in acreages.
Other changes may alter the distribution of plant
types an the lands affected by the tides.A net
increase in the mean water level may alter the water
tab 1e and hence runoff and at her hyd ro lag ic
E-10-95
characteristics of adjacent marshlands.Also
significant is the effect of altered salinities that
may occur as tidal waters are stored in the basin.
There is some potent i al th at i ntrus i on of saltwater
may have harmful effects on the ground water tab le.
It should be noted that the Cook Inl et marshl ands are
high stress environments,characterized by large
seasonal vari at i on of sal ines.Therefore,changes in
seasonal variation of salinities will probably not be
detrimental to marshland vegetation.
Other hydrologic characteristics could be affected,
such as backwater and flooding.The raised water
table could affect lowland drainage and vegetation.
It appears that,although the potential for alteration
is great,it is also possible that only slight changes
in populations will occur that will not greatly alter
the nature of the environment as a habitat for
waterfowl,shorebirds,and furbearing species.
The tidal regime may al so be altered downstream from
the barrier.However,the impoundment of a portion of
high tide water behind the barrier will not greatly
alter existing water levels or tidal fluctuation
downstream.Possible effects caused by resonance of
tidal waves will have to be studied in detail,but it
appears likely that the effects of the barrier will
have much greater potential for impact upstream from
the dam.
o Hydraulic Characteristics of the Basin
Regulation of flow in the basin will affect hydraulics
local to the dam itself,as well as having more
widespread impacts.EXisting current patterns and
velocities throughout the basin would be altered.The
most noticeable change will occur near the dam where
the concentration of flow velocities through turbines
and sluiceways would alter local flow patterns.These
local high velocities will be dissipated with
increasing distance from the dam.The decreased tidal
range may result in an overall decrease in turbulence
and mixing,although the tide range will still be
substantial in rel ation to the depth of water so that
the regime of total mixing may not be altered.
The effect of siltation on the environment and on the
operation of the tidal power pl ant has not been full y
assessed.Investigations of sedimentation in the Bay
of Fundy,La Rance and other construction reported
E-l0-96
-
-
~\
that siltation caused by construction within the tidal
flow is a function of:the degree of flow reduction
caused by construction;the availability of
appropriate sized sediment in the water;and the
combined supply of material to the site.
Knowledge of the origin of sediments and the existing
transport mechanism is necessary to analysis of the
1atter.
Sedimentation and erosion processes may be affected in
the silt-laden estuary.The mud flats and bottom
conditions of the Arms are highly mobile.Changes can
result from a net increase or a net decrease in
velocities and from redistribution of wave energy on
the shoreline.These will have the greatest potential
for harmful impacts to the natural environment on the
shorelines of marshlands~where erosion of the
outlying mud flats could result in eventual erosion of
the marshland and loss of habitat.It is possible,
however,that a net decrease in energy in the basin
(lower tide range~decreased mixing~decreased tide
range)will result in higher sedimentation rates.If
this is the case,it may cause decreased storage in
the basin~and correspondingly~a buildup of mud flats
and an extension of marshlands.
The effects of sedimentation may also be significant
downstream from a barrier in Cook Inlet.Observation
of recently constructed causeways at Windsor,Nova
Scotia,and on the Petitcodiac estuary in New
Brunswick reveals the development of large,
mid-channel mud flats seawards of the barrier caused
by local flow reductions.This could result in a
reduction of sediments which are normally deposited
further downstream in the estuary.Effects on
navigation may be significant in the Knik Arm where
shoaling is already a problem in the approaches to
Anchorage harbor.
Another factor related to sediment load in the Inlet
waters is that of penetration of light as required for
biological productivity.At present~high turbidities
limit light penetration.This may be the limiting
factor for growth of the aquatic food chains.It is
possible that along with a decrease in sediment load,
an increase in food production could result in a
habitat more amenable to aquatic species.
o Causeway Development
E-10-97
The addition of a causeway to the tidal power project
would not create any additional impacts to the
upstream and shoreline environment.The most
significant impacts would result from development of a
permanent road through previously undeveloped areas
and from the residential and commercial growth that
would occur because of the new access.Other impacts
to the Inlet include increased traffic noise across
the causeway and increased human access to the
wetlands for recreational purposes.
(i i i)Effects on Biological Resources
Construction and operation of a tidal power facility has
the potential to affect anadromous fish in Cook Inlet.
Because of the commerci al and recreational importance of
this resource,specific mitigation techniques would have
to be developed to minimize these impacts.
Anadromous fi sh return to their natural streams to spawn.
The mechanism by which they locate these streams is not
fully understood,but it is bel ieved the fish respond to
changes in water chemistry.Thus,although it is unl ikely
retiming of tides will affect the hydrology and physical
or chemical composition of water upstream from the reach
of tidal fluctuations,the changes in sediment load and
sal inity of water below the power facil ities could
potentially affect the migration.
The 1 argest salmon runs in Turnagain Arm occur in the
Chickaloon River.Since the river is located
approximately 10 miles downstream from the Rainbow site,
migration should not be directly affected.In the Knik
Arm area,the most important salmon tributary is the
Little Susitna River,which is 10 miles downstream
from the Point MacKenzie site;impacts there also should
not be great.However,in both cases,it should be noted
that as fish appproach their natal streams,they may
wander as far as 10 miles past the mouth before turning
back to the ultimate goal.In this manner,the Point
MacKenzie and Rainbow sites could conceivably affect
migration to the Littl~Susitna and Chickaloon River,
respect ively,although the dams ites appear to be the
limits of the interaction zone.
-Wetlands and Waterfowl Habitat
There are three primary mechanisms by which the tidal
plant would directly cause impacts to marshlands:
E-lO-98
-
,.,..
,~
I
.-I
1~
-
a Oi strubance along the shores of the impounded bas in;
a Interaction with the construction site,noise,
activity,and equipment;and
a Imposition of an altered flow regime downstream from
the dam.
Of these three primary impacts,the potentially most
significant would be the effects of the altered tidal
regime on the stabil ityand productivity of the
marshland ecosystems within the impoundment basin.
Altered sedimentation patterns could result in eroded
shorel ines.A rai sed water table could result in a more
saline ground water table.Altered surface hydrology
may affect filtering and transport of nutrients and
organics within the marsh.A loss of marsh area and a
loss of vegetation types required for support of bird
populations can be envisioned,thus diminishing
productivity and resulting in degradation of the
waterfowl habitat.
Alternatively,sedimentation may result in an
enlargement of marsh1ands.Effects of changes in
hydrology,inundations,and nutrient supplies could
produce an environment more attractive to waterfowl and
other species.Somewhere between the best case and the
worst case lie any number of variations where,for
example,vegetation or land areas may be altered but
have 1 itt 1e impact on bird popul at ions.The conc 1 us i on,
at this point,is that the interactions between
hydrology,hydraulics,and the wetland ecosystem must be
better understood in order to predict effects with more
rel i abil ity.This should be the main focus of future
environmental studies.
Operation of the tidal project may affect the hydraulics
of the inlet downstream from the dam.These effects
should be studied in greater detail for their impacts on
coastal marshlands.Later phases of engineering studies
should include modeling the effects of the dam on
downstream hydraul ics and water 1evel s to determi ne
ecological impacts.
-Mar i ne Mammals
Construction of tidal-generating facilities could affect
the movement of marine mammals in the area.Care must
be taken in des ign of intake structures and dam
approaches to prevent harm to these animals in the event
of their interaction with the structure.Other mammals
may also be involved,and their movements !may extend to
E-10-99
the other damsites.This question should be more
thoroughly investigated in later studies,including
potential effects on marine mammal food sources.
(iv)Other Effects
-Water Quality
Present water quality is characterized by extremely high
turbidity,relatively high dissolved oxygen content,
variable salinity and nutrient concentrations,and low
levels of primary biological productivity.Several
activities associated with the tidal project may affect
water quality.These include the excavation and
construction of the dam,increased ship traffic,and
operation of marine equipment,as well as the regulation
of flows to and from the basin.
Dredging,excavation,and placement of materials for dam
construction in the submarine and intertidal
envi ronments may temporarily increase suspended sediment
concentrations near the dam.Given the existing
turbulence and turbidity of the water,this should not
be a problem.Additionally,the introduction of new
materials (sand,rock,gravel)from other sources may
result in leaching of some chemical constituents not
normally found in the waters.The possibility of
serious chemical problems ;s very small.
The presence of construction equipment,tugs,barges and
human activity indicates an increased possibil ity for
such accidents as oil spills,fires,dumping of debris,
and di spas a1 of untreated sewage into the water.
Adherence to health and safety plans and control of
construction areas can minimize most undesirable
effects.
The presence of the dam and the resultant flow patterns
may act as a physical barrier which limits exchange of
salt~nutrients,sediments,etc.,between the freshwater
inflows and the saltwater influence from the ocean.
Although the total flow of water may be reduced by the
dam,1 arge vol umes of water wi 11 still be exchanged.A
well-mixed basin would result,although local flow
patterns and water quality may be affected.
It appears th at,though there are many potent ia1s for
impact to water quality,the associated risks are low.
-Climatology
E-10-100
-
-
-
-
Short-term and long-term changes in the cl imate of the
regi on may occ ur as a res ult of tid a 1 power deve 10 pment .
Changes in ice formation,for example,could alter air
temperatures in the basin vicinity.
-Rare and Endangered Species
It is not anticipated that tidal power development would
affect the endangered peregrine falcon ..
(v)Socioeconomic Assessment
The socioeconomic issues of a tidal development would be
similar to those of other capital intensive developments,
part icul arly to those of a 1arge hydropower proJect.The
construction period,characterized by very high levels of
activity and expenditure,would be followed by a long
operational period during which these levels would become
quite low.Annual costs of operation consist mainly of
capital charges.The costs of maintenance andrepl acement
woul d be quite small compared to these capital charges,
and the other costs of operating the facil ity would be
negligible •.
A tidal project presents,however,certain aspects and
options that are very different from more conventional
power modes and which may yield distinctly different
social and economic results.The folloWing examples will
illustrate the characteristics in the tidal power
development that may make it unique from the socioeconomic
viewpoint:
Storage and generation will take place in the sea.
Consequently,very few,if any,relocations of people
and very little reallocation of land and water
resources will be required.
-One of the more likely construction options will be the
floating in of hugh prefabricated caissons and sinking
them on 1ocat i on as components of the structure.If
this method is adopted,a significant amount of the work
may be done off the site.
-Depending upon final design and the site selected for
development,a tidal project in the Cook Inlet will
require from 30 to 60 turbine-generating units.Such a
large number may be sufficient to justify establishment
of a local industry for their manufacture and overhaul.
E-l0-101
-Tidal power will be generated in surges lasting from 4
to 6 hours followed by interruptions of approximately
8-1/2 to 6-1/2 hours duration (adding up to lunar cycle
of 12 hours and 25 minutes).Energy-intensive
i ndustri es that coul d work on the rhythm of power
availability might find the general region of tidal
power plants to be an attractive location.
(v i )Impact on Adj acent Land Uses
The major impacts from tidal development in the Cook Inlet
would occur in the Greater Anchorage Area Borough located
in the south-central portion of Alaska at the head of
Cook Inlet on a roughly tri angul arareaof 1and between
the two estuarine drainages,Knik and Turnagain Arms.
The areas within the boundaries of the municipality of
Anchorage suitable for urban development are to the west
of Chugach State Park,south and east including
Alyeska-Girdwood ,and north and east to Eagle
River-Birchwood.Potential changes in 1and use would be
to convert these areas into industrial use as businesses
are attracted by availability of power.
(vii)Materials Origin Supply Study
The raw materials,intermediate goods,and equipment
required for a tidal project can be grouped into three
main categories:
-Raw Materials
These materials incl ude aggregate,rock,cement,and
lumber.It is expected that aggregate and rock can be
supplied locally.The final aggregate (sand)will be
transported from the Palmer area.The coarse aggregate
for concrete wi 11 be crushed in the roc k quarry areas
near the selected sites as follows:
o Rainbow:North and south side of Turnagain
Arm--5-mile haul
o Point MacKenzie:North side of Turnagain area near
Rainbowsite--30-mile haul
~
!
-
o Eagle Bay:Mount Magnificant--15-mile haul
An estimate of direct laborrequ;red for the production
of these items indicates that about 300 to 400 jobs may
be involved during the construction period.
E-l0-l02
(viii)
-Steel Products
These i nc1 ude rei nforcement and fabricated gates.It is
likely that these supplies would be from sources outside
A1 aska.
-Generating Equipment
This includes hydroelectric and electrical equipment~
such as the turbines ~generators ~transformers,and
switchgear.This equipment would be suppl ied from North
America or Europe depending on market conditions.
labor Supply and Limitations
A preliminary estimate indicates that the direct~onsite~
labor requirements for the three sites considered would be
approximately as follows:
Eagle Point
Site Rainbow Bay MacKenzi e
Average man-years per year:
Over 7.5 years 1~875
10.5 years 2~OOO
11.5 years 2~500
Peak demand man-years per
year:2~OOO 2~200 2~750
The peak labor requirements for any site development are
not much higher than the average requirement~and it is
likely that careful scheduling of the work will make it
possible to arrange for a relatively steady level of
employment throughout the construction period.
For each of the sites~the total demand amounts to less
than 3 percent of the total labor force and about 50
percent of the construction labor force in the impact
region (Anchorage-Mat-Su Borough)as of March 1981.It
1ike1y~therefore~that a large part of the labor that
would be foequifoed during the 1990s could be foecruited in
the surrounding region.
In 1980~the unemployment rate was about 8 percent in
Anchorage-Mat-Su region immediately around and north of
the project sites~12 percent in the Gulf Coast region and
10 percent in the state of A1 aska.It is possible the
rate of employment would be lower during the 1990s than at
present~but it seems unlikely it will have become very
E-10 ..103
low.Most probably,sufficient labor will be ava lable in
the reg i on around the project sites and construct on of
one of the projects would likely offer a welcome
contribution to reduction of unemployment in the area
during the years of construction.
Supplementary labor requirements,in addition to the
direct onsite requirements,are of two types.The first
consists of 1abor employed in the production of suppl ies,
such as cement,concrete,lumber,aggregate,steel
products,turbines,generators,and other electrical
products.Parts of these activities will not be located
in the impact region,or even in the state of Al aska.A
preliminary estimate indicated that possibly up to 300 or
400 additional jobs in the production of raw materials
could be created in the Anchorage region during the
construction period if in-state manufacturing facil ities
are developed.
Another type of supplementary labor requirement consists
of additional jobs to supply the demand for services by
the labor employed onsite and in supply activities.
(ix)Community Impact
Direct,onsite employment would reach,in the peak years,
about 2,000 to 2,750.The impact region would be the
municipality of Anchorage.A socioeconomic study by the
Bureau of Land Management indicates that population growth
in Anchorage was responsive to the growth in economic
activities:Kenai oil,Prudhoe Lease,and Trans-Alaska
pipel ine construction.The popul ation of the municipal ity
of Anchorage was estimated in that study at 195,654 as of
July 1,1979.It is likely that Anchorage could supply
labor and services of sufficient variety to accolTmodate a
project of this size.
The temporary construction activities may provide
opportunities to strengthen the local infrastructure and
provide lasting benefits.Transport facilities,for
ex amp 1e,would have to be improved to faci 1 it ate
construction.For site access,new roads or upgrading of
existing roads would h,ave to be done except at Eagle
Point.Adjustments near the mi 1 itary airport would be
necessary at Point MacKenzie.A viaduct off the highway
over existing railroad tracks (north side)would be built
at Rainbow as well asa road to the storage and work area
along the shore (north side).Whenever possibl e,
expansion of the transport facilities as required for
construction should take into account opportunities to
E-10-104
-
-
.....
create lasting Beneficial effects,but at the same time
should not necessarily interfere with existing
communities.It will be desirable,if and when a decision
is made to build one of the projects,to initiate joint
planning with municipal authorities early as possible to
minimize the unavoidable strains on the communities and to
maximize the benefits that can be obtained from the
r-temporary increase in activity in the area.
(x)Impacts of a Causeway
Construction of a tidal power project at any site
considered in this study could be planned to provide a
causeway.At Rainbow,a crossing of Turnagain Arm could
be bui 1t as an integrated part of the
tidal power project,and,therefore,its costs would be
reduced.Turnagain Arm Crossing between the Anchorage
area and the Kenai Peninsula has been considered in
various studies over the past 30 years.It has been
recognized that a major improvement such as a crossing of
Turnagai n Arm would have a great impact on the area wh i ch
it serves or through which it passes.
Tourism plays a major role in the regional economics of
the Anchorage-Kenai area.The openi ng up of territory
heretofore unserved by a highway becomes of major
import ance.
Alaska with its scenary has likewise unlimited potential
for recreation.Good transportation makes realization -of
these potentials possible as well as being one of the
basic ingredients of commerce and industry.The
improvement of the basic network of transportation within
the Anchorage-Kenai area will produce favorable results
with all of these activities.
A crossing of Turnagain Arm would bring the city of Kenai,
the center ofa rapidly growing petroleum industry,to the
existing hiqhway system.The 1968 study by the Alaska
Department of Highways indicated that the distance between
the city of Kenai and Anchorage through the crossing would
be 94 miles bj way of a lowlevel highway,whereas the
distance over existing roads is 154 miles over mountain
roads with long grades and passes subject to heavy
snowfall.
The construction of a tidal power project at either site,
Point MacKenzie or Eagle Bay,could also be planned
jointly with a Knik Arm crossing.A causeway crossing
joining the two sides of Knik Arm near Anchorage would
E-10-105
provide civil benefits as well as defense benefits.The
1972 study by the state of Al aska Department of Highways
indicated that the crossing will allow future economic
development of the west side of Knik Arm~which would
certainly add to the potent i a1 of the metropol itan area of
Anchorage (13).It waul d shorten the Anchorage-Fairbanks
highway and al so would provide the necessary access for a
new international airport on the west side of the arm.
Such a facility presents an interesting stimulus for the
future economic development of the west side of Knik Arm.
In addition,the causeway crossing would provide means for
deve 1opment access of 1 ands north of Kn i k Arm.The
geographic posit i on of Anchorage~bei ng presentl y
surrounded by water,mountains~and mil itary facil ities,
makes the development of the 1 ands north and west of Kni k
Arm very desirable.A crossing of Knik Arm would give
access to the Beluga area and the Alaska Peninsula with
its mineral and recreation potentials.
(e)Thermal Alternatives Other than Coal
(i)Natural Gas
Natural gas.resources available or potentially available to
the Railbelt region include the North Slope (Prudhoe Bay)
reserves and the Cook Inlet reserves.Informat i on on
these reserves is summarized in Table E.10.21.
The Prudhoe Bay Fi e1 d contains the 1 argest aceumu1 ati on of
o i1 and 9 as ever discovered on the North Jl.mer ic an
continent.The in-place gas volumes in the field are
estimated to be in excess of 40 trillion cubic feet (Tef).
With losses eonsidered~recoverable gas reserves are
estimated at 29 Tcf.Gas can be made available for sale
from the Prudhoe Bay Field at a rate of at least 2.0
billion cubic feet per day (Bcfd)and possibly slightly
more than 2.5 Bcfd.At this rate,gas deliveries can be
sustained for 25 to 35 years~depending on the sales rate
and ultimate gas recovery efficiency.
During the mid-seventies~three natural gas transport
systems were proposed to market natural gas from the North
Slope Fields to the Lower 48.Two over1 and pipe1 ine routes
(Alcan and Arctic)and apipeline!LNG tanker (E1 Paso)
route were considered.The Alcan and Arctic pipeline
routes traversed Alaska and Canada for some 4000 to 5000
miles,terminating in the central U.S.for distribution to
pOints east and/or west.The El Paso proposal involved an
overland pipeline route thatwQuld generally follow the
Alyeska oil pipeline utility corridor for approximately 800
E-10-106
miles.A liquefaction plant would process approximately 37
million cubic meters of gas per day.The transfer station
was proposed at Point Gravinia south of the Valdez
termination point.Eleven 165,000 cubic meter cryogenic
tankers would transport the LNG to Point Conception in
California for regasification.
The studies noted above concluded with the decision to
construct a 4800 mil e,2.4 Bcfd,Al aska-Canada Natural Gas
pipelinep.roject,costing between $22 and $40 billion.rne
pipeline project would passapprox imately 60 miles
northeast of Fairbanks.Although the project was in the
active planning and design phase for several years,it is
now inactive due to financial difficulty.
The Cook Inlet reserves (Table E.10.25)are relatively
small in comparison to the North Slope reserves.Gas
reserves are estimated at 4.2 Tcf as compared to 29 Tcf in
Prudhoe Bay.Of the 4.2 Tcf,approximately 3.5 Tcf is
available for use,the remaining reserves are considered
shut-in at this time.The gas production capability in the
Kenai Peninsula and Cook Inlet region far exceeds demand,
as no major transportation system exists to export markets.
As a result of this situation,the two Anchorage electric
utilities have a supply of natural gas at a very economic
price.Export facilities for Cook Inlet natural gas
include one operating and one proposed LNG scheme.The
facility in operation,the Nikiski terminal,owned and
operated by Phi 11 ips-Marathon is located on the eastern
shore of Cook Inlet.Two Liberian cryogenic tankers
transport LNG some 4000 miles to Japan.Volume produced is
185 MMCFD with raw natural gas requirements of 70 percent
from a platform in Cook Inlet and 30 percent from existing
on-shore fields.
There is also some potential for a gasline spur to be
constructed from the Cook Inlet region some 310 miles north
to intersect with the proposed Alaska-Canada Natural Gas
pipeline project in order to.market the Cook Inlet gas.
This concept has not been extensively studied but could
prove to be a viable alternative •
.(ii)Oil
Both the North Slope and the Cook Inlet Fields have
significant quantities of oil resources as seen in Table
E.10.26.North Slope reserves are estimated at 8375
million barrels.Oil reserves in the Cook Inlet region are
estimated at 198 million barrels.As of 1979,the bulk of
E-10-107
Alaska crude oil production (92.1 percent)came from
Prudhoe Bay,with the remainder from Cook Inlet.Net
production in 1979 was 1.4 million barrels per day.
Oil resources from the Prudhoe Bay field are transported
via the 800 mile trans-Alaska pipeline at a rate of 1.2
million barrels per day.In excess of 600 ships per year
deliver oil from the port of Valdez to the west,Gulf and
east coasts of the U.S.Approximately 2 percent (or 10
million barrels)of the Prudhoe Bay crude oil was used in
Alaska refineries and along the pipeline route to power
pump stations.The North Pole Refinery,located 14 miles
southeast of Fairbanks,is suppl i ed from the trans-A1 aska
pipeline via a spur.Refining capacity is around 25,000
barrels per day with home heating oils,diesel and jet
fuels the primary products.
Much of the installed generating capacity owned by
Fairbanks utilities is fue1d by oil.FMUS has 38.2 MW and
GVEA has 186 MW of oi l-fired capacity.Due to the hi gh
cost of oil,these utilities use available coal-fired
capacity as much as possible with oil used as standby and
for peaking purposes.
Crude oil from offshore and onshore Kenai oil fields is
refined at Kenai primarily for use in-state.Thermal
generating stations in Anchorage rely on oil as standby
fuel only.
(iii)Diesel
Most diesel plants in operation today are standby units or
peaking generation equipment.Nearly all the continuous
duty units have been placed on standby service for several
years due to the high oil prices and the consequent high
cost of operation.The lack of system interconnection and
the remote nature of localized village load centers has
required the installation of many small diesel units.The
installed capacity of these diesel units is 64.9 MW and
these units are solely used for load following.The high
cost of diesel fuel makes new diesel plants expensive
investments for all but emergency usew
(iv)Environmental Considerations
-Air Pollution
Several kinds of air pollutants are normally emitted by
fuel-burning power plants.These include particulate
E-10-108
~-
matter,sulfur dioX'ide,ni'trogen oxides,carbon monoxide,
unburned hydrocarbons,water vapor,noise and odors.
o Particulate Matter
Particulate matter consists of finely divided solid
material in the air.Natural types of particulate
matter are abundant and incl ude wind-borne soil,sea
salt particles,volcanic ash,pollen,and forest fire
ash.Man-made particulate matter includes smoke,metal
fumes,sail-generated dust,cement dust,and grain
dust.On the basis of data collected by the U.S.
Environmental Protection Agency (EPA),total suspended
particulate matter (TSP)has been determined to cause
adverse human health effects and property damage.
Fuel combustion power plants produce particulate matter
in the form of unburned carbon and non-combustible
mineral s.Part i cul atesare removed from fl ue gas by
use of electrostatic precipitators or fabric filters
(baghouses).They are routinely required,however,and
collection efficiencies can be very high (in excess of
99 percent).
o Sulfur Dioxide
Sulfur dioxide (S02)is a gaseous air pollutant which
is emitted during combustion of fuels that contain
sulfur.Residual oil contains sulfur in amounts of a
few tenths of a percent to a few percent,while
pipeline natural gas contains relatively little sulfur.
Sulfur dioxide,like particulate matter,has been
identified as being harmful to human health,and it
appears to be particularly serious when combined with
high concentrations of particulate matter.It is
damaging to many plant species,including several food
crops such as beans.
o Nitrogen Oxides
Nitrogen ox ides (N02 and NO,pr imar i1 y)are gas eo us
air pollutants which form as a result of high-
temperature combustion or oxidation of fuel-bound
nitrogen.Nitrogen oxides damage plants and play an
important role in photochemical smog.
Pollution control technology for nitrogen oxides has
developed more slowly than for most other air
pollutants.Lack of chemical reactivity with
conventional scrubbing compounds is the main
difficulty.Thus current control strategies focus on
control of NO x production.Principal strategies
.include control of combustion temperatures (lower
combustion temperatures retard formation of NO x )and
control of combustion air supplies to minimize
introduction of excess air (containing 78 percent
nitrogen).
o Carbon Monoxide
Carbon monoxide (CO)emissions result from incomplete
combustion of carbon-containing compounds.Generally,
hi gh COemi ss ions result from suboptimal combustion
conditions and can be reduced by using appropriate
firing techniques.However,CO emissions can never be
eliminated completely,using even the most modern
combustion techniques and clean fuels.CO emissions
are regul ated under the Cl ean Air Act because of their
toxic effect on humans and animals.
o Water Vapor
Pl urnes of condensed water vapor wi 11 emanate from a wet
cooling tower as its exhaust is cooled below its
saturation point.The plume will persist downwind of
the tower until the water vapor is diluted to a level
below saturation.In cold or cool,moist c1 imates the
plumes are particularly long because the ambient air
can hold little added moisture.Formation of these
plumes is particularly hazardous during "fogging"
conditions when a high wind speed causes the plume to
travel along the ground.During freezing conditions,
such plumes may lead to ice formation on nearby roads
and structures.Plume generation,fogging,and icing
can be controlled or virtually eliminated through the
use of wet/dry or dry cooling towers.
o Noi se and Odor
Noise levels beyond the plant property line can be
controlled by equipment design or installation of
barriers.Generally noise and odors are not as great a
concern as the air pollutants contained in exhaust
gasses.
-Comparison of Projected Emissions
The critical comparison of fuel combustion technologies
fat their imapcts on air quality is determined by the
E-l0-1l0
-
-
anticipated rate of emissions of each of the pollutants.
Emission levels for the various technologies are
presented for sulfur dioxide in Table E.I0.27,for
particulates in Table £.10.28,and for nitrogen oxides in
Table E.I0.29.Data are taken from EPA publications or
the enforced New Source Performance Standards.
The development of these tables are based on various
assumptions.A 33 percent efficiency of conversion is
assumed for steam electric pl ants,and a 25 percent
efficiency for combustion turbines.For the power plant
sizes provided in the tables,emissions are directly
proportional to the heat rate input for a given
technology.The following heat input,factors were
assumed:for oil 20,000 Btu/lb;and for natural gas
1,000 Btu/standard cubic foot.
-Regulatory Framework
In 1970,the federal Clean Air Act established the
national strategy in air pollution control.The Act
establ ished New Source Performance Standards (NSPS)for
new stationary sources,including fuel combustion
facilities.Levels of acceptable ambient air quality
(Nat i ona 1 Ambi ent Ai r Qual ity Standards)were al so
establ ished,and the regul ations were promulgated to
maintain these standards or reduce pollution levels where
the standards were exceeded.
New source performance standards (NSPS)have been
promul gated for coal-fi red steam el ectri c power pl ants,
and for combustion turbines.In addition,any combustion
facility designed to burn coal or coal mixtures,or is
capable of burning any amount of coal,or if such use is
planned,is subject to the coal-fired power plant
standards.Standards of all owab 1e emi S5 ions for each
fuel combustion technology for each major pollutant for a
range of stzes for power plants are presented in Tables
E.I0.27 through E.I0.29.The standards are being
enforced for both newly constructed and significantly
retrofitted faciT ities and represent the expected level
of controlled emissions from these power plants.
In Al aska,the Department of Environmental Conservat ion
enforces regulations regarding ambient air quality
standards and source performance standards.A permit to
operate will be required for all fuel-burning electric
generating equipment greater than 250 kW generating
capacity.
E-10-111
Major changes were made to the Cl ean Ai r Act in 1977 when
the Prevention of Significant Deterioration (PSD)program
was added by Congress.The PSO program has estab 1 i shed
limits of acceptable deterioration in existing ambient
air quality (S03 andTSP)throughout the United States.
Pristine areas of'national significance (Class I areas),
were set aside with very small increments in allowable
deterioration.The remainder of the country was allowed
a greater 1eve 1 of deter i or at ion.at her regu 1ator y
factors apply to areas where the pollution levels are
above the national standards.State and local agencies
may take over the admi ni strati on of these programs
through the development of a state implementation plan
acceptable to the EPA.See Table £.10.30 for National
Ambient Air Quality Standards and allowable PSD
i ncrernent s.
The PSO program is currently administered by the U.S.
EPA.A PSO review will be triggered if emissions of any
pollutant are above 100 tons per year for coal-fired
power plants or above 250 tons per year for the other
power plants.The review entails a demonstration of
compl i ance with ambi ent air qual ity standards,the
employment of best available control technology,a
demonstration that allowable PSO increments of pollutant
concentrations (currently promulgated for sulfur dioxide
and suspended particulates)will not be violated,and a
discussion of the impact of pollutant emissions on soils,
vegetation,and vi sibil ity.It also generally includes a
full year I s an-site monitoring of air qual ity and
meteorological conditions prior to the issuance of a
permit to construct.In the near future,PSO control
over other major pollutants,including NOx 'CO,
ox idants,and hydrocarbons wi 11 be promul gated.
Obtaining a PSD permit represents one of the 1argest
single obstacles to the construction of a major
fuel-burning facility.
Al aska has two permanent Cl ass I areas in or near the
Railbelt region,Denali National Park and the pre-1980
areas of the Tuxedni Wildl ife Refuge.The new National
Parks and Wildl ife Preserves have not been i ncuded in the
oriqinal designation,but the state may designate
additional Class I areas in the future.New major
facilities located near Class I areas cannot cause a
violation of the PSD increment near a Class I area;this
requirement presents a significant constraint to the
development of nearby faci 1 ities.
E-10-112
-.
-
A potenti ally important aspect of the PSD program to
development of electric power generation in the Railbe1t
region is that Denali National Park (Mt.McKinley
National Park prior to passage of the 1980 A1 aska Lands
Act)is Class I,and it lies close to Alaska's only
operating coal mine and the existing coal-fired electric
generating unit (25 MWe)at Healy.Although the PSD
program does not affect ex i st i ng units,an expanded
coal-burning facility at Healy would have to comply with
Class I PSD increments for S02 and TSP.Decisions to
permit increased air pollution near Class I areas can
only be made after careful eva1 uat ion of all the
consequences of such a decision.Furthermore,Congress
required that Class I areas must be protected from
impariment of vi sibil ity resulting from man-made air
pollution.The impact of visibility requirements on
Class I areas are not yet fully known.
-Water Poll ut i on
Potential sources of water pollution include cooling
system b lowdown,demi neral i zer regenerat i on wastewater,
fuel oil releases,and miscellaneous cleaning wastes.
o Cooling Water 810wdown
In general,the operat ion of all steam cyc1 es requi re
substanti a1 .amounts of cool ing water and therefore
produce cool ing water b1owdown.The quantity and
qual ity of this wastewater depend upon the type of
cooling system used and the specific characteristics of
the source.In general,total dissolved solids (TDS),
chlorine,and waste heat are the primary pollutants of
concern.
o Deminera1izer Regeneration Wastewaters
All steam cycle facilities produce deminera1izer
regeneration wastewaters which have high TDS levels and
generally low pH values.
a Fuel Oil Re1 eases
Potential oil pollution impacts are associated with
oil-fired power plants and other facilities which may
use oil as an auxiliary fuel.These include fuel
storage areas and the accidental release of oil through
E-10-113
spillage or tank rupture.Potentially significant
impacts which may result from oil releases are
generally mitigated through the mandatory implementa-
tion ofa Spill Prevention Control and Countermeasures
(SPCC)Plan,as required under 40 CFR 110 and 40 CFR
112.This plan is intended to ensure the complete
containment of all releases and the proper recovery or
disposal of any waste nil.The plan must also be
formulated in light of the Alaska Oil and Hazardous
Substances Pollution Regulations.
a Miscellaneous Wastewaters
All steam cycle plants have many other miscellaneous
wastewaters that are derived from floor drainage,
system component cleaning,and domestic water use.,The
quantity and qual ity of these wastewaters wi 11 vary
considerably,but oil and grease,suspended solids,and
metals are the effluents of most concern.
All of these enumerated wastewaters are strictly
managed within a specific steam cycle facility.The
management vehi cl e is generally termed a Il wa ter and
wastewater management plan"and in some technologies is
developed in conjunction with a "solid waste management
plan ll
•The purpose of these studies is to balance
enVironmental,engineering,and cost considerations,
and develop a pl ant desi gn and operat iona1 procedures
operat ion that ensures p1 ant rel i abil ity and
environmental compatibility,and minimizes costs.
For plants developed in the Railbelt region,relevant
regulations would include the Clean Water Act and its
associated National Pollutant Discharge Elimination
System (NPOES)permit requirements and federal effluent
limitation guidelines;Alaska State water quality
standards,which regulate all parameters of concern in
all Alaska waters depending upon the specific water
resource1s designated use;the Resource Conservation
and Recovery Act and Alaska solid waste disposal
requirements;and the Toxic Substances Control Act.
Compliance with all regulations does not eliminate
water resource impacts.Al aska water quality standards
permit a wastewater discharge mixing zone;water
quality ~oncentrations will therefore be altered in
this area:.Downstream water quality will also be
altered,as receiving stream standards are rarely
identical to the existing site-specific water quality
regime of the receiving water body.If secondary
E-1O-114
-
'"''''
'"'"
,~
impacts associated with wastewater discharges such as
those to aquatic ecosystems are deemed significant,
further waste management and treatment technologies may
be employed.Water quality impacts can only be avoided
if the plant is designed to operate in a "zero
discharge"mode.This is technically possible for all
steam cycle facilities,but can be extremely costly.
Values for selected rivers in the Railbelt region are
given in Table E.10.31.Based on these values,there
does not appear to be any extraordinary or unusual
water quality characteristic which would preclude
construction or operation of a properly designed steam
cycle facility.Most of the river systems can be
considered moderately mineralized based upon the total
dissolved solids values and the concentrations of the
major ionic components.Values for calcium,magnesium,
and silica are not low and will limit the natural reuse
(without treatment)of a number of wastewater streams,
most significantly cooling tower blowdown.
"Standardized Jl power plant water management
technologies will be required to mitigate any adverse
water quality impacts.Also,based on the sufficiently
high bicarbonate levels and alkaline pH values,appears
these natural waters to have sufficient assimilative
capacity to mitigate effects from potential acid rain
events.
-Hydrologic Impacts
Impacts to the hydrological regime of ground and surface
water resources can result from the physical placement of
the power plant and its associated facilities,and from
the specific location and operation of a generating
plant's intake and discharge structures.The siting of
the power plant may necessitate the elimination or
diversion of surface water bodies and will modify the
area's runoff pattern.Stream diversion and flow
concentration may result in increased stream channel
erosion and downstream flooding.Proper site selection
and design can minimi ze these impacts.If,after sit ing,
localized impacts remain a concern,various mitigative
techniques,such as runoff flow equalization,runoff
energy dissipation,and stream slope stabilization may be
employed.
Other hydrological impacts can result from the siting and
operation of the power plant's makeup water system and
wastewater discharge system.The physical placement of
these structures can change the local flow regime and
E-l0-115
possibly obstruct navigation in a surface water body.
Potential impacts associated with these structures are
generally mitigated,however,through facility siting and
structure orientation.Discharge of power plant
wastewaters may create local ized disturbances in the flow
regime and velocity characteristics of the receiving
water body.This potential problem is minimized through
proper diffuser design,location,and orientation.
Consumpt i ve water losses associ ated with the power pl ant
may also affect hydrological regimes by reducing the
downstream flow of the water resource.However,as
discussed previously,surface water supplies in the
Railbelt region are plentiful.Hydrologic impacts due to
reduced streamflow should therefore not be significant.
(d)Nuclear Steam Electric
Nuclear steam electric generation is a mature,commercially
available technology.At present,some 73 units with a total
installed capacity of 54,000 MWeare operable in the United
States.An additional 104 units representing approximately
116,000 MWe of capacity have either been ordered or are in some
phase of the licensing or construction process.Canada,France,
Germany,Japan,Sweden,and the United Kingdom also have a large
nuclear steam electric capacity based either on U.S.developed
technology or on technologies developed within those respective
countri es.
In spite of this impressive backlog of experience,nuclear power
is experiencing social and political problems that might seriously
affect its viability.These problems manifest themselves in
licensing and permit delays,and are thus of significance to the
Al askan electrical supply situation given their cost and schedule
impacts.
Diminished load growth rates,concerns over nuclear weapons
proliferation,adverse public opinion fueled by the Three-Mile
Island accident,expanding regulatory activity,and lack of overt
support at the highest political levels have all resulted in no
new domestic orders for nuclear units since 1977.The industry is
currently maintaining its viability through completion of backlog
work on domestic units and by pursuing new foreign orders.
The State of Alaska1s policy on nuclear power is expressed in the
legislation establishing the Alaska Power Authority.The Power
Authority may not develop nuclear power plants.
(i)Siting and Fuel Requirements
E-10-116
-
-
,""'"Nuclear plant siting has more constraints than other
technologies because of stringent regulatory requirements
resulting from the potential consequences of accidents
involving the release of radioactive materials.These
requirements alone,however~would not be expected to bar
the development of nuclear power in Alaska.
Under the siting criteria of the Nuclear Regulatory
Commission (10 CFR 100),nuclear facilities must be
isolated to the degree that proper exclusion areas and low
population zones may be maintained around the facility.
Nominal distances ranging from 2,000 to 5,000 feet to the
nearest boundary (encompass i ng areas of 250 to 2,000 acres)
are typically sufficient to meet the first criterion for
almost any sized nuclear facility.Additionally,a
physical separation of 3 to 5 miles from areas of moderate
popul at i on dens ity a11 ows comp 1 i ance with the second
criterion.These requirements are of little real
consequence in the present case considering the low
population densities existing in the Railbelt region.
Seismic characteristics of a potential site are a major
factor in plant siting since the nuclear plant must be
designed to accommodate forces that result from earthquake
activity.Total exclusion of nuclear plants on this basis
is not indicated since nuclear plants have been designed
and constructed on a worldwide basis in each of the seismic
zones found in the Railbelt region.
In addition to meeting the specific nuclear safety
requirements of the U.S.Nuclear Regulatory Commission,
a nuclear plant site must meet the more typical
criteria required of any large steam-electric generation
technology.A 1,000-MW nuclear project represents a major
long-term construction effort,involving the transportation
of bulky and heavy equipment and large quantities of
construction materials.Means of transportation capable of
handling these items limit the potential Railbelt sites to
the corridor along the Alaska Railroad and port areas of
Cook In 1et and Pr i nce Wi 11 i am Sound.As noted prev i 0 us 1y,
it is necessary to site a nuclear plant in an area of low
population density.This requirement for remote siting
must be balanced against the cost of transmission
facilities required to deliver power to high-density
population areas and load centers.
The heat rejected by a I,OOO-MW plant is substantial;a
potential site must thus have a sufficient supply of
cooling water to remove the heat in a manner complying with
environmental criteria for thermal discharges.Once-
,E-l0-1l7
through cooling of a 1000-MWe facility requires a water
flow of approximately 3,000 cfs and would almost certainly
require coastal siting.Closed cycle systems require less
water than once-through systems (probably less than 100
cfs),thus expanding the range of siting options to some of
the rivers of the region.
Reactor fuel,a highly refined form of enriched uranium
fabricated into complex fuel elements,is not produced in
Al aska and would have to be obtained from fuel fabrication
fac Hit i es located in the western portion of the United
States.The proximity of the nuclear plant to the fuel
source is relatively unimportant compared to fossil-fired
and geothermal plants.Uranium is a high-energy density
fuel,and refueling is accomplished on a batch rather than
a continual basiS.Refuel ing is required about once a year
and is usually scheduled during summer months in cold
cl imates to prevent weather induced del ays and to occur
during periods of low electrical demand.
Current estimates indicate known uranium supplies are
sufficient to fuel only those reactors now in service or
under construction for their estimated lifetime.However,
the latest nuclear designs are capable of being fueled by
plutonium as well as uranium,and assuming that breeder
reactors,producing surplus fuel~grade plutonium,become
commercial,then long-term fuel supply should not be a
limiting factor.Although Alaska has identified uranium
deposits,the economic forces for developing the resource
are tied to the world market conditions rather than to the
use of uranium as fuel for nuclear plants located in
Al aska.
(ii)Environmental Considerations
Water resource impacts associ ated with the construction and
operation of a nuclear power plant are generally mitigated
through appropri ate pl ant sit ing and a water and wastewater
management program.It shoul d be noted,however,that due
to the large capacities required for nuclear power stations
(1000 MW),the magnitUde of water withdrawal impacts
associated with a given site may be greater than for other
baseload technologies.Magnitude,however,does not
necessarily imply significance.A favorable attribute of
nuclear pwoer is the lack of wastewater and solid waste
associated with fuel handling,combustion,and flue gas
treatment experienced in other combustion steam cycle
technologies.
E-10-118
....
-.
,~Nuclear power plants cause no deterioration in the air
quality of the locale,other than the routine or accidental
release of radionuc1ides.To assess the potential dosages
of these radioactive materials,a complex meteorological
monitoring program is required.The wind speeds and
dispersive power of the atmosphere playa crucial role in
diluting the effluent.Generally,sites in sheltered
valleys and near population or agricultural centers are not
optimal from a meteorological point of view.large amounts
of heat are also emitted by nuclear power plants.Some
modification of microc1imatic conditions onsite will be
noted,but these modifications will be imperceptible
offsite.The U.S.Nuclear Regulatory Commission will
ensure that the ambient meteorological conditions are
properly measured and considered in the siting of a
nuclear power plant.These constraints will not preclude
the construction of such a facility at many locations in
the Rai1be1t region.
In addition to the effects on aquatic and marine eco-
systems resulting from cooling water withdrawal and thermal
discharges common to other steam cycle plants,nuclear
facilities have the potential for routine low level and
possibly accidental higher level discharge of radionuclides
into the aquatic environment.The minimum size for a
nuc1 ear faci 1ity (1,000 MW)indicates that these plants
would be the largest water users of any steam cycle plants,
using approximately 310,000 gpm for once-through cooling
systems and 6,200 gpm for recirculating cooling water
systems.Their rate of use (gpm/MW)is also higher than
many other technologies because of somewhat lower plant
efficiencies.Potential impingement and entrainment
impacts would therefore be somewhat higher than for other
base10ad technologies of comparable size.Detrimental
effects of discharge may also be high because of the large
quantity of water used.But the discharge water may have
fewer hazardous compounds than may be found in other steam
cycle wastewaters.
The predominant biotic impact on terrestrial biota is
habitat loss.Nuclear power plants require land areas
(100-150 acres)second in size to those of coa1-and
biomass-fired plants.Furthermore,lands surrounding the
plant island are at least temporarily modified by ancillary
construction activities (i.e.,laydown areas,roads,etc.).
Partial recovery of these lands could possibly be
accomplished through revegetation.Other imapcts difficult
to mitigate could be accidental releases of radionuclides.
The effects of such accidents on soils,vegetation,and
E-10 ..119
animals could be substantial.However~proper plant design
and construction should prevent these emissions.One
positive feature of nuclear power is the absence of air
.poll ution emissions and resulting effects on biota.
(iii)Potential Application in the Railbelt Region
Fuel availability and siting constraints would probably not
significantly impair construction of commercial nuclear
power plants in Alaska.Potential sites,however,would
have to be near existing or potential port facilities or
along the Alaska Railroad because of the need to deliver
large amounts of construction material and very large and
heavy components to the site.Interior siting would have
more favorable seismic conditions.
More constrai ni ng than site avail abil ity is the rated
capacity of available nuclear units in comparison with
forecasted electrical demand in the Railbelt region.The
Railbelt System,with a forecasted interconnected load of
1,550 MW in 2010,will probably be too small to accommodate
even the smaller nuclear power units,primarily from the
point of view of system reliability.If nuclear power were
available to the Railbelt System,significant reserve
capacity would still have to be available to provide
generating capacity during scheduled and unscheduled
outages.
In addition,the l.arge capacity of most current nuclear
units 1imits the adaptabi 1 ity to growth to very 1arge
increments,which are not characteristic of projected
Rail be It demands.Nuc 1ear capac ity is not added eas il y ~as
a strict licensing,construction,and operation process
must be followed.
(e)Biomass
Biomass fuels potentially available in the Railbelt region for
power generation include sawmill residue and municipal waste.
Biomass fuel s have been used in industri al power pl ants for many
years.Biomass plants are distinct from fossil-fired units in
that maximum pl.ant capacities are relatively small;in addition,
they have specialized fuel handling requirements.The generally
accepted capacity range for biomass-fired power plants are
approximately 5 to 60 MW (l4).The moisture content of the fuel,
as well as the scale of operation,introduces thermal
inefficiencies into the power plant system.
(i)Siting and Fuel Requirements
E-10-120
-
-
-
-
Biomass fuels are generally inexpensive but are
characterized by high moisture content,low bulk densities,
and modest heating values.Typical net heating values of
biomass fuel s are compared to coal below:
Since the supply of anyone biomass fuel may be
insufficient to support a power plant,provisions may have
to be made for dual fuel firing (e.g.,wood and municipal
waste).For example,the estimated supply of both wood and
municipal waste biomass fuel in Greater Anchorage will
support a 19-MW power pl ant operating 24 hr/day at a heat
rate of 15,000 BtD/kWh.
Fuel
r~uni ci pa 1 Waste
Peat
Wood
Coal
Btu/1b
4,000
5,000
4,500
9,000
The rate of fuel consumption is a function of efficiency
and plant scale.Fuel consumption as a function of plant
capacity is presented below.
Hourly Fuel Truck
Plant Size Requirements Loads
(Megawatts)(Tons)Per Hour
5 11
15 25 1
25 40 2
35 55 3
50 80 4
Sit ing requirements for biomass-fired power pl ants are
dictated by the condition of the fuel,location of the
fuel source,and cooling water requirements.Because
biomass fuels are high in moisture content and low in bulk
density,economical transport distances do not exceed 50
miles (15).Biomass power plants are thus typically sited
at,or close to,the fuel source and may function as part
ofa cogeneration system.Sites must be accessible to all-
weather highways since biomass fuels are usually
transported by trUCk.(Approximately four trucks per hour
would be required,for example,for a 50-1'l1W plant.)
While proximity to the fuel source may be the most limiting
factor,sites also must be accessible to water for process
and cool ing purposes.Land area requirements are a
function of scale,extent of fuel storage,and other design
E-10-121
parameters.Typically,a 5-MW stand-alone power plant will
require 10 acres;a 50-fv1\04 stand-alone plant will require 50
acres.
Plants that use peat will require additional land for air
drying the fuel.A 1 to 3-month fuel supply should be
provided to assure fuel availability during prolonged
periods of inclement weather.
(ii)Environmental Considerations
Water resource impacts associ ated with the construction and
operation of a biomass-fired power plant are not expected
to be significant or difficult to mitigate in 1ight of the
small plant capacities that are considered likely.
The burning of biomass could lead to significant impacts
on ambient air quality.Impacts arise largely from
particulate matter and nitrogen oxides emitted by the
system.The emissions of particulates can be
well-controlled by using techniques such as electrostatic
precipitators or baghouses.The tradeoff between emission
contro 1s and project costs must be assessed at each
facility,but wood burning facilities larger than about 5
MWe will require the app1 ication of these air pollution
control systems.
Potentially significant impacts to aquatic systems from
biomass plants are similar to other steam cycle plants and
result from the water withdrawal and eff1 uent di scharge.
Although these plants are second only to geothermal
facilities in rate of water use (730 gpm/MW),their total
use for a typical plant would only exceed that of oil and
natural gas-fired plants because of the small size of
prospective plants.Approximately 18,250 gpm and 362 gpm
would be required for once-through and recirculating
cooling water systems,respectively.Proper siting and
design of intake and discharge structures could reduce
these impacts.
The major impact on the terrestrial biota is the loss or
modification of habitat.Land requirements for biomass-
fired plants,approximately 50 acres for a 50-MW plant,are
similar to coal-fired plants,and are generally
intermediate between those for nuclear and the other steam
cycle power plants.
Potential primary locations of biomass-fired power plants
in the Railbe1t region are near Fairbanks,Soldatna,
£-10-122
~,
-
-
-
-
(iii)
Anchorage,and Nenarl'a.Landssurtounding these five areas
contain seasonal ranges of moose.Waterfowl also inhabit
these areas with high use occurring along the Matunuska and
Susitna River deltas near Anchorage,and areas around
Nenana.The Soldatna region also contains populations of
black bear and calving~migration corridors,and seasonal
ranges of caribou.Populations of mountain goats,caribou,
and Dall sheep occupy habitats in the Sus itna and Matunuska
River drainages near Anchorage.Impacts on these animal
populations will depend on the characteristics of the
specific site and the densities of the wildlife populations
in the site area.Due to the relatively small plant
capacities involved,however,impacts should be minimized
through the plant siting process.
Potential Applications in the Railbelt Region
Potential sources of biomass fuels in the Railbelt region
include peat,mill residue from small sawmills,and
municipal waste from the cities of Fairbanks and
Anchorage.
Fuel availability for wood residue and municipal waste in
the Railbelt region is shown in Table E.I0.32.
Only broad ranges of wood residue availability have been
developed since little information is available on lumber
production as a function of markets,lumber recovery,and
internal fuel markets.Volumes of municipal waste have
been identified from studies of refuse recycling in the
Anchorage area (16).Fuel supplies for a wood or municipal
waste-fired biomass pl ant may be sufficient in greater
Anchorage,but marginal in Fairbanks or the Kenai
Peninsula.Peat deposits are substantial but many other
fuels are available which compete economically with peat.
Biomass power plants in the Rail belt region may potentially
contribute 0.5 percent to 5 percent of future power needs.
As SUCh,the biomass-fired units would be central station
installations capable of serving individual community load
centers or interconnection to a Railbelt power grid.
Since the biomass-fired systems are relatively small t they
are particularly adaptable to the modest incremental
capacity needs forecast for the Railbelt region .
.(f)Geothermal
Geothermal energy is defined as the heat generated within the
earth's interior.If this heat is close to the surface,it may be
E-l0-123
tapped as an energy source.Geothermal energy may be util ized for
electricity generation,which usually requires temperatures of at
least 280°F, or for direct applications at temperatures less than
280°F.Direct heating applicatiuons include space heating for
homes and businesses,applications in agriculture and aquaculture,
industrial process heating,and r~creational or therapeutic use in
pools.Approximate required temperatures of geothermal fluids for
various appl ications is presented in Table E.I0.33.
Three types of geothermal resources hold potential for
development:hydrothermal,geopressured brine~and hot dry
rock.Only hydrothermal systems are in commercial
operation today.Although hot dry rock resources represent
over half the U.S.geothermal potential,satisfactory
technologies have not yet been developed for extracting
heat from th is resource.Hydrothermal geothermal resources
are classified as vapor-dominated or liquid-dominated
systems.A typical vapor dominated system produces
saturated to slightly superheated steam at pressures of 435
to 500 psi and temperatures of approximately 450°F.
Liquid-dominated systems may be subdivided into two types,
those producing high enthalpy fluids greater than 200
calories/gram (360 Btu/lb),and those producing low
enthalpy fluids less than 200 calories/gram.The high
enthalpy fluids may be used to generate electrical power;
the lower enthalpy fluids may be useful for direct heating
appl ications.
Wells drilled into high enthalpy,liquid-dominated systems
produce a mixture of steam and water.The steam may be
separated for turbine operation to produce electricity.
(i)Siting Requirements
Geothermal pl ants ate always located at the site of the
geothermal resource.The four most important siting
criteri a used to eval uate geothermal resources for
appli~ation to electric power production are:
o Fluid temperatures in excess of approximately 140°C
(280°F);
o Heat sources at depths less than 10,000 ft with a
temperature gradient at 25°F per 1,000 ft;
o Good rock permeab-Il ity to allow heat exchange fl uid to
flow readily;and
E-10-124
~.
o Water recharge capability to maintain production.
Individual geothermal wells should have a capacity to
supply 2 MW of electricity.The power station's long-term
viability is dependent on the prediction of reservoir
energy capacity and management of reservoir development.
The site must have access available for construction~
operation,and maintenance personnel,and a source of water
available for condenser cooling (and injection in the hot
rock technology).
The land area required for the electrical generating and
auxiliary equipment portion of a geothermal plant will be
similar to that required for an oil-fired unit;however,
the total land area will be vastly larger because of the
diffuse location of the wells.A 10 MW plant,excluding
wells,can be situated on approximately 5 acres of land.
After exploratory wells are sunk to determine the most.
productive locations (both for production and injection
wells),the plant would be located based on minimum cost of
pipelines and other siting factors.A network of piping
would then be established to complete the installation.
(ii)Environmental Impacts
A problem unique to geothermal steam cycles involves the
water qual ity characteristics of the geothermal fluid and
the subsequent disposal method.This fluid is generally
saline and,because of this characteristic,most geothermal
plants in the United States mitigate this potential problem
through reinjection into the geothermal zone.If the
geothermal zone is highly pressurized,however~not all of
the brine may be reinjected,and alternative treatment and
disposal methods must be considered.For geothermal fields
located in the Chigmit Mountains~brine disposal in Cook
Inlet should not prove to be too difficult.The interior
fields,however,could reuqire extensive wastewater
treatment facilities to properly mitigate water quality
impacts to freshwater resources and comply with all
relevant Alaska regulations.Depending upon a specific
fie1d 's water quality characteristics,the costs associated
with these treatment facilities could also preclude
development.
Geothermal plants have the highest per megawatt water use
of any steam cycle plant (845 gpm/MW).A maximum size
plant for the Railbelt region (50 MW)would use less water
than only nuclear-fired or coal-fired plants,with a total
E-10-125
water use rate of 42,200 gpm or 750 gpm for once-through
and recirculating cooling water systems,respectively.
Emissions of gases and particulates into the atmosp~ere
from the development of geothermal resources will consist
primarily of carbon dioxide and hydrogen sulfide (H2S).
Other emissions may consist of ammonia,methane~boron,
mercury~arsenic compounds~fine rock particles,and
radioactive elements.There is considerable variability in
the nature and amount of these emissions~and this
uncertainty can be removed only by testing wells in the
proposed project area.Emissions are also a function of
operational techniques.If the reinjection of geothermal
fluids is used~emissions into the atmosphere may be
reduced to nearly zero.Even when reinjection is not used~
H2S emissions can be controlled by oxidizing this
compound to sulfur dioxide (S02)and subsequently using
conventional scrubber technology on the product gases.
Emissions may also be controlled in the water stream by an
"iron catalyst"system or a Stretford sulfur recovery unit.
Efficiencies of these systems have ranged as high as 90
percent H2S removal.At the Geysers generating area in
Ca 1i forn i a,H2S concentrat ions average 220 ppm by wei ght.
The power pl ants emit about 3 1b/hr of H2S per megawatt
of generating capacity.Regulation of emissions of other
toxic compounds can be controlled by various techniques as
stipulated by the regulations governing the specific
hazardous air po 11 utants.Control of hazardous pollutants
wi 11 probably not prec 1ude the development of geothermal
resources in the Railbelt region.
In addition to major potential impacts associated with
water withdrawal and effluent discharge that are similar
for all steam cycle plants,geothermal plants have some
uni que problems that may have hazardous effects on the
aquatic environment.Geothermal water is often high in
slats and trace metal concentrations,and is often caustic.
The caustic nature of the solution often corrodes pipes,
which can add to the toxic nature of the brine.Current
regulations require reinjection of spent geothermal fluid;
however,entry of these brine solutions into the aquatic
environment either by discharge,accidental spills,or
groundwater seepage~could cause acute and chronic water
qual ity effects.
One of the major geothermal potential areas in the Railbelt
is located in the Wrangell Mountains near Glennallen.This
area drains into the Copper River,which is a major
salmonid stream.The result of accidental discharge of
geothermal fluids into this system may have significant
E-10-126
-
-
(iii)
impacts on these fish,and other aquatic organisms,
depending on the size and location of the release.
Other large geothermal areas are in the Chigmit ~ountains
on the west side of Cook Inlet.Much of this area is close
to the marine environment.In general,geothermal waters
would have less detrimental effects on marine organisms
(because of their natural tolerance to high salt
concentrations)than on fresh water organisms.
The primary impact resulting from geothermal plants on the
terrestrial ~iota is habitat loss.Land requirements for
geothermal plant facilities,on a per-kilowatt basis,are
comparab1 e to those for oil and natural gas p1 ants.
Biomass,coal,and nuclear plants require larger tracts of
1and than geothermal,either from the standpoi nt of
capacity or kilowatt production.However,geothermal lands
are more likely to be located in remote areas than other
steam cycl e power p1 ants.Di sturbances to these areas
could be extensive depending on the land requirements of
the geothermal well field.
Primary geothermal development locations are within the
Wrangell and Chigmit Mountains.The latter area is remote
and is inhabited by populations of moose and black bear.
The Wrangell Mountain area is generally more accessible and
includes populations of moose,Dal1 sheep,caribou,and
possibly mountain goats.Impacts could be greatest in
remote areas since an extensive road network would have to
be built to service the well field.Roads would cause the
direct destruction of habitat and also impose additional
disturbances to wildlife and vegetation from increased
accessibility to people.
Potential Application in the Rai1be1t Region
Only hot dry rock (hot igneous)and low-temperature,
liquid-dominated hydrothermal convection systems have been
identified in or near the Railbelt region.Some
low-temperature geothermal resources in the Fairbanks area
are used for heating swimming pools and for space heating.
In southwest A1 aska some use is made of geothermal
resources for heating greenhouses as well as space heating.
Hot dry rock geothermal resources with temperatures that
may behi gh enough to generate electricity have been
discovered in the Wrangell and Chigmit Mountains.The
Wrangell system,located approximately 200 miles from
Anchorage,has subsurface temperatures exceeding 1200°F.
The Chigmit System,to the west of Cook Inlet,is isolated
.from the load centers by 200 miles of rugged terrain.
E-10-127
Little is known about the geothermal properties of either
system.
A geothermal resource in granite rock has been identified
in the WillDW area.A deep exploration well was discovered
to have a bottom hole temperature of 170°F.Exploration
data to date indicate that while this resource may prove
useful for low temperature applications,its relatively low
temperature makes it an unlikely source for electric
generation.
The geothermal areas (with the exception of Mt.Spurn)of
both Wrangell and ChigmH Mountains are located in lands
designated as National Parks.The federal Geothermal Steam
Act prohibits leasing and developing National Park lands.
If,however,townships within these areas are sel ected by a
Native corporation under the Alaskan Native Claims
Settlement Act,and if the surface and subsurface estates
are conveyed to private ownership,then the federal
government jurisdiction would not apply,and development
could be possible.The Alaska National Interest Lands
Conservation Act of 1980 allows the granting of rights-of-
way for pipelines,transmission lines and other facilities
across National Interest Lands for access to resources
surrounded by National Interest Lands.
(g)Wind
Until the mid 1930s,wind energy supplied a significant amount of
energy to rural areas of the United States.With the advent of
rural electrification,wind energy ceased to be competitive with
other power alternatives.However,rising fuel costs and the
increased cost of power from competing technologies has renewed
interest in the development of wind resources.This energy source
may come to playa significant role in electric power generation
in rura 1 areas,small communit ies,and poss i bl Y for 1arge
interconnected energy systems..
(i)Large Wind Systems
Large wind turbines are being developed in response to this
renewed interest and are in a demonstration phase.In
1979,a MOO-I,2-MW,200 ft di ameter turbine was completed
at Boone,North Carol ina.Three MOD-2 wind turbines,rated
at 2.5-MW capacity,are under construction near Goldendale,
Washington by the Bonneville Power Administration,U.S.
Department of Energy,and NASA.These and other wind
turbi nes in the I-MW range of rated output are avail ab 1 e
for production,but benefits of assembly line production
E-10-128
-
,~
have not been realized.Commercially available,mass
produced wind machines are at present quite small and only
avail abl e in unit sizes of about 5 kW,with the maximum at
45 kW.This section will focus on large wind turbines of
0.1 MW rated capacity or more such as mi ght by employed as
centralized power generating facilities by a utility.
-Siting Requirements
The siting of the wind turbines is crucial in wind energy
conversion systems.The most significant siting
consideration is average wind speed and variability.
These depend nnlarge-scale weather patterns but are also
affected by local topography,which can enhance or reduce
the average wind speeds ..Since wind energy potential is
directly proportional to the cube of the wind speed,
siting wind machines to take advantage of even small
incremental increases in wind speed is important (17).
Extremely high winds and turbulence may damage the wind
turbines,and any sites eXhibiting these characteristics
must be avoided.
Other important siting considerations include the
proximity of the site to load centers,site access,
founding conditions,and meteorological conditions.
Undesirable meteorological conditions in addition to
turbulence include glazing conditions,blowing sand or
dust,heavy accumulations of snow,and extreme cold.
-Environmental Considerations
Wind turbines extract energy from the atmosphere and
therefore have the potential of causing slight
modifi cat ions to the surroundi ng climate.Wi nd speeds
will be slightly reduced at surface levels and to a
distance equivalent to five rotor diameters,which for a
single 2.5-MW facility would be approximately 1500 ft.
Small modifications in precipitation patterns may be
expected,but total rainfall over a wide area will not be
affected.Nearby temperatures,evaporation,snowfall,
and snow drift patterns will be affected only slightly.
The microclimatic impacts will be qualitatively
5 imi 1ar to those noted around 1arge isolated trees or
tall structures.
The rotation of the turbine blades may interfere with
television,radio,and microwave transmission.
Interference has been noted within 0.6 miles (1 km)of
relatively small wind turbines.The nature of the
interference depends on signal frequencies,blade
E-10-129
--~----------_._,_._-=--------~_._._.----
rotation rate,number of blades,and wind turbine design.
A judicious siting strategy could help to avoid these
impacts.
Stream siltation effects from site and road construction
are the only potential aquatic and marine impacts
associated with this technology.Silt in streams may
adversely affect feeding and spawning of fish,
particularly salmonids which are common in the Railbelt
region.These potential problems can be avoided by proper
construction techniques and should not be significant
unless extremely large wind farms are developed.
Wind-powered energy requires varying amounts of land area
for development.The amounts of area required depend on
number,spacing,and types of wind-powered units used.
This can range from approximately 2 acres for one 2.5-MW
generating unit to over 100 square miles for a 1000 MW
wind farm.These developments,due to requirements for
persistent high-velocity winds,would probably be
estab 1 i shed in remote areas.
Because of the land requirements involved,the
potentially remote siting locations and the possible need
for clear;ng of vegetat ion,the greate$t impact resulting
from wind energy projects on terrestrial biota would be
loss or disturbance of habitat.Wind generating
structures could also affect migratory birds by causing
collisions.Other potential impacts include low
frequency noise emanating from the generators and
modification of local atmospheric conditions from air
turbulence created by the rotating blades.The impacts
of these latter disturbances on wildlife,however,are
presently unclear.
Environmentally sensitive areas in the Railbelt region
presently proposed for wind energy development are
exposed coastal areas along the Gulf of Al aska,and
possibly hilltops and ridgelines in the interior.
Alteration of coastal bluffs could negatively affect
seasonal ranges of mountain goats of the Kenai Mountain
Range,and nesting colonies of sea birds in the Chugach
Islands,Resurrection Bay,Harris Bay,Nuka Pass,and
other areas along the Gulf Coast.Shoreline development
could affect harbor seals and migratory birds.Harbor
seals utilize much of the coastline for hauling-out.The
Copper River Delta is a key waterfowl area.Scattered
use of shoreline habitat by black bear,brown bear,and
Sitka blacktailed deer occurs in Prince William Sound.
The presence of wi nd energy structures in any of these
areas could potentially cause collisions with migrating
E-10-130
"""
-
-
~-
.....
( i i )
waterfowl,bald eagles,peregrine falcons (endangered
species),and other birds,if situated in migratory
corridors.Inland development of wind energy could
negatively affect Dall sheep,mountain goat,moose,and
caribou if situated on critical range lands.
These terrestrial imapcts can generally be mitigated by
siting plants in areas of low wildlife use.This would
include avoiding critical ranges of big game,traditional
haul-out areas of seals and nesting colonies of birds,
and known migratory bird corridors or key feeding areas.
The feasibility of mitigation will,of course,depend on
the size of the wind energy development.
-Potential Application to Railbelt Energy Demand
A wind-turbine system consisting of five machines has
been installed at Gambell on St.Lawrence Island in
Alaska to provide wind electric power for community
.facilities.Another wind turbine has been installed at
Nelson Lagoon on the Alaskan Peninsula.
Studies to identify wind energy resources in the Railbelt
would require a significant data base.Such a data base
is currently lacking.Currently available literature is
not adequate to comprehensively identify potential wind
energy conversion system sites in the Railbelt region.
Studi es necessary to assess wi nd energy potent i al
include:preparing and examining detailed contour
patterns of the terrain,modeling selected sites,
monitoring meteorological conditions at prime sites for
at least one year (preferably three years),analyses
using modeled and measured data,developing site-specific
wind duration curves,and selecting final sites.
The University of Alaska has conducted a preliminary
assessment of wind power potential in Alaska.The.
results of these studies indicated a potential for
favorable sites for wind energy development at exposed
coastal locations and possibly along ridgelines or hills
in the interior (19).
Small Wind Systems
Small wind energy conversion systems (SWECS)are wind
machines with rated output of 100 kW or less.Typically
these machines would be sited in a dispersed manner,at
individual residences or in small communities,as compared
to the large wind energy conversion systems which would be
E-l0-13l
sited,generally in clusters,as centralized power
production facilities.
Small wind energy conversion systems are available in
horizontal and in vertical axis configuration.The
horizontal areas machines exhibit superior efficiency but
require a substantial tower to support the generating
equi pment as we 11 as the blades.In add it ion,the
blade/generator assembly must revolve in conformance with
changing wind direction,requiring provision of head
bearings and slip rings and machine orientation devices.
Although of lower efficiency than horizontal axis machines,
the vertical axis generator is located in a fixed position
near the ground,minimi zing tower stn.tcture and
eliminating the need for head bearings or slip rings.
Because of these advantages,vertical axis machines may
exhibit superior cost characteristics in the small wind
machine sizes.
A number of small wind machines are now in commercial
production in sizes ranging from 0.1 to 37 kW.
Historically,battery-charging systems have been the
primary application for Small Wind Energy Conversion
Systems in Al aska;however,this is beginning to change.
The subject of this study has been concerned with SWECS
which interface directly with the utility grid.Off-grid
installations were not considered.
-Siting Requirements
A wind speed of 7 to 10 mph is required to start most
SWECS producing power.An annual average of 10 mph is
usually considered a lower economic cut-off for most
applications;however,this is very dependent on the
site,energy costs,and particular wind generator
design.
Turbulent energy is the worst for SWECS.It can be
caused by trees,buildings,and topography.Because wind
acts like a fluid in that it slows down when it
encounters an object or rough terrain,the higher up from
the ground,the stronger the wind.Thus each site must
be evaluated for terrain and what affect that may have on
winds speeds at different heights.
E-10-132
.....,
-
-
-
-
-
-
,~
A small wind machine which is to be intertied to the
utility grid must be reasonably close to existing or
planned power lines.This requirement may eliminate many
ridge tops because of the high transmission line losses.
-Environmental Impacts
Studies have shown some enhancement of local wildlife due
to downwind shelters,as well as a possible adverse
impact on low flying night migratory birds in bad
weather.However,the kill rate is not significant.
Aesthetic intrusiveness is difficult to assess and highly
subjective.Many people surveyed have found small wind
machines to be visually pleasing.Small generators noise
is not significant with proper blade design.
Small wi nd machi nes mounted on towers requ i red no more
than 100 sq ft at the base plus any exclusion area which
the owner wishes to fence off for safety reasons (usually
no more than about five blade diameters).
Radio frequency interference can be mitigated with proper
blade design (nonmetallic)and siting.
Potential safety risks involve the possibility of tower
or blade failure aircraft collision.Actions taken to
decrease those ~isks incl~de:
o maintenance of an exclusion area around the turbine;
o automatic monitoring of turbine operation;
o regular preventative maintenance;
o visitor control measures;and
o adherence to FAA requirements for tall structures.
-Potential Application to the Railbelt Resion
Until recently there were only a handful of SWECS
manufacturers.Today there are over 50 with a half dozen
mass producing generators at a respectable rate (20-200/
month).
A dealership and repair network is already in existence
in the Railbelt region and would grow as the number of
E-10-133
installed WECS increases.Engineering and design
expertise is also present in the region.Five system
design organizations,four suppliers and one installer
were operating in the Railbelt in 1981.
The major obstacle to the availability of wind generators
seems to be the lack of venture capital in an unstable
economic climate,which makes needed plant expansion
difficult for manufacturers.Once the market penetration
and mass production has brought the unit cost down and
manufacturers have internalized major R&D efforts,then
widespread use of SWECS may become a reality.
Wind data have historically been collected from airports
at a height usually no greater than 30 ft.Wind
generators are typically not located near airports (which
are usually sited in locations protected from winds)and
are placed at least twice as high as conventional
meteorological stations.A few examples will illustrate
the problem:
o The annual average recorded for Anchorage is 5 mph
taken at the international airport.Closer to the
mountains at the site of an installed wind generator
the average is 6 mph.At Flat Top Mountain,a
homeowner who pl ans to install a SWECS has recorded
months of 15 mph averages.
o In Homer the recorded annual average is 9 mph at the
airport,while on the II sp it ll the average is reported to
be closer to 13 mph.Further up the hill at the site
for an 18 kW SWECS,the winds have not been measured
but are expected to be better than at the airport.
o In Fairbanks the average is recorded as 4 mph,yet as
one climibs out of the valley the average wind speed
almost triples near Murphy Dome.
This suggests that existing data are not very helpful in
determining the potential of SWECS in the Railbelt.The
number of mountain passes with channel ing effects,
glaciers with their constant source of winds,and coastal
regions with the windy maritime influences yield
thousands af potential SWECS sites in the Railbelt.
Because of the lack of data taken for siting small wind
machines,there is no quantitative means for assessing
the possible contribution SWECS would have in the
Railbelt region.Howevel"'";since most of the population
lives in two known areas of low winds (Anchorage and
E-10-134
-
......
--
(h)
Fairbanks),it is reasonable to assume that without
large-scale utilization of "wind farms,"only a small
percentage of the total Railbelt load could be met by
wind power (less than 10 percent)in the next five years.
If a decision were made to develop clusters of SWECS,
then this contribution could become significant in the
midterm (five to ten years).
Sol ar
Two basic methods for generating electric power from solar
radiation are under development,solar thermal conversion and
photovoltaic systems.Solar thermal systems convert solar
radiation to heat in a working fluid.This working fluid can
include water,steam,air,various solutions,and molten metals.
Energy is realized as work when the fluid is used to drive a
turbine.Photovoltaic systems is a more direct approach.Solar
energy is converted to electric energy by the activation of
electrons in photosensitive substances.
At present,commercially available photovoltaic cells are made of
silicon wafers and assembled largely by hand.Nearly two dozen
technologies and automatic assembly techniques are under
development.Photovoltaic technology is undergoing a burst of
innovation comparable to the integrated circuit-semiconductor
technology.New and more efficient cell designs have been
proposed capable of converting 30 to 40 percent of the sunlight
falling on them to electricity.
Both solar technologies suffer from the same constraints.
Available solar energy is diurnally and seasonally variable and is
subject to uncertainties of cloud cover and precipitation.Solar
energy resources must be employed as a "fuel saving"option or
they must be installed with adequate storage capacity.In
addition,if the diurnal and annual cycles are out of phase with
solar energy potential cycles,the inducements for development of
this resource are further reduced.The energy demand and solar
availability cycles are out of phase in the Railbelt region,where
demand generally peaks in winter and at night.
( i )Siting Requirements
Solar electric generating systems are optimally located in
areas with clear skies.The geographic latitude of the
proposed site al so pl ays an important rol e in determining
the intensity of solar insolation.Low sun angles,
characteristic of high latitudes,provide less solar
radiation per unit area of the earth's surface,requiring
greater collector area to achieve a given rated capacity.
E-l0-l35
Increasing the "tilt"of collectors relative to the surface
of the earth increases the solar power density per unit
area of collector but results in shading of a.djacent
collection devices at low sun angles.These factors place
severe constraints on the development of solar energy in
the Railbelt region.
In addition to the 1atitudinaland cloudiness constraints,
potential sites must not be shaded by topographic or
vegetative features.This type of shading does not present
a severe restriction for development in the Railbelt
region.The potential for snow andice accumulation also
"inhibits development of solar energy resources.
(ii)Environmental Considerations
Photovo Haic systems do not requi re cooling water or other
continuous process feedwater for their efficient operation.
Small quantities of water are required for domestic uses,
equipment cleaning,and other miscellaneous uses,but if
standard engineering practice is followed,water resource
effects should be insignificant.If hot water cogeneration
systems are employed in conjunction with photovoltaic
systems,continuous feectwater will be required to offset
system losses.In light of the small plant capacities that
would be considered for the Railbelt and the absence of
cooling water requirements,water resource effects should
be mi nimal .
The development of solar thermal conversion systems would
produce water resource effects similar to other of steam
cycle facilities.Boiler feedwater and condenser cooling
water will be requi red and wi 11 necessitate proper
management techniques.Water requirements are extremely
site-specific as efficiencies ranging from 10 to 70 percent
are possible depending upon climatic factors.However,in
light of the small capacities considered,impacts should
not be significant.
Solar thermal conversion systems may also be operated
utilizing a working fluid other than water.Fluids such as
1i quid sodi urn,sod i urn hydroxi de,hydrocarbon oil s,and
sodium and potassium nitrates and nitrites have the
potenti al to adversely affect water qual ity through
accidental spills and normal system flushing.Specialized
transportation and handling techniques will be required to
minimize spill risk and properly mitigate potential
impacts.
E-10-136
~,
-
-
-
-
1""".
(iii)
Water resource impacts would also occur if pumped storage
facilities were utilized as the energy storage technology
for eitherphotovoltaic or solar thermal conversion
systems.
Solar thermal andphotovoltaic electric power conversion
systems have no impact on ambient air quality because they
do not emit gaseous pollutants.Water vapor plumes may
emanate from cooling systems associated with solar thermal
processes,however.These plumes will be substantially
reduced because solar thermal systems operate best in full
sunlight when the air tends to be well below saturation.
The water droplets are quickly evaporated into a dry
atmosphere.The p1 urnes can a1 so be mit igated by us i ng dry
or wet/dry cooling tower systems.
Some modification of the microclimate will occur near a
solar energy facility.The heat is merely redistributed
within the facility and will not affect climatic conditions
offsite.The climatic response of these facilities will be
similar to that of any comparably large construction
project.
Due to minimal water requirements,the operation of
photovoltaic systems will have insignificant impacts on
fresh or marine aquatic biota but sol ar thermal conversion
plants may have impacts similar to those of other steam
cycle plants.These impacts,however,should be small and
easy to mitigate in light of the small plant capacities
considered.
The major terrestri al impact assoc i ated with photovo ltai c
or solar thermal conversion systems is habitat loss.If
these systems are located in remote areas,the potential
for wildlife disturbance through increased human access may
also be significant.Spills of non-water working fluids if
used,could adversely affect local ecosystems.In general,
however,impacts to the terrestrial biota of the Railbelt
region should be minimal,since power plant capacities for
both photovoltaic and thermal conversion systems will be
small.
Potent ia1 App 1it at ion to the Rai 1be It Reg i on
Data collected at Fairbanks and at Matanuska,near
Anchorage,ref1 ect the influence of both cloudiness and the
annual cycle in sun angle at these locations.At Fairbanks
the total daily solar radiation on a horizontal surface is
E-10-137
13 Btu/ft2 in December and 1969 Btu/ft 2 in June.At
Matanuska these values range from 48 Btu/ft 2 in December
to 1730 Btu/ft2 in June.In compari son,in the ari d
southwestern United States,January values of 1200
Btu/ft 2 are common with many areas having July val ues
over 2500 Btu/ft2 .Even in less favored areas such as
Minnesota,these same values vary from 550 Btu/ft 2 to
2000 Btu/ft2 during the year.These data indicate that
while there is an abundant supply of solar energy on a
horizontal surface in midsummer in Al aska,the mid-winter
values are an order of magnitude less than those of even
poor sites in the remainder of the country.The obvious
lack of sunshine in the winter restrains the development of
solar energy in the Railbelt region.Even on south-facing
vertical walls,the daily total solar radiation in
Matanuska is only 300 Btu/ft2 in December,which
indicates that the mere reorientation of collecting
surfaces will not alleviate the siting constraint.
None of the existing or developing solar photovoltaic
technologies represents an economically viable form of
large-scale electric power generation in the Railbelt.
Current systems provide only a few watts of output and are
not currently planned for large-scale application.
10.4 ...Environmental Consequences of License Denial
Should the FERC license for the Susitna Hydroelectric project be
denied,the State of Alaska \",uuld have to pursue other electrical power
generating schemes.These other schemes would necessarily include
heavy reliance on thermal sources if the projected energy demand is to
be met.
As discussed previously,thermal generation is associated with
increased air pollution problems,increased fuel storage problems,
increased surf ace and groundwater contami nat i on problems,increased
waste disposal problems,and increased fuel transportation problems.
The Alaskan environment would be exposed to these risks.
The majority of Alaska 1 s population would be denied a source of power
generation that offers long term stability in power costs with relative
insulation from the influence of inflation and fossil fuel prices
dictated largely by internation politi~al economic events.Further,
the non ...renewable fossil fuel resources used would be lost for future
use or for use in locations where hydroelectric potential is
unavai 1ab 1e.
E-l0 ...l38
-
-
Potential benefits would be centered in the upper Susitna basin where
access road and transmission line corridors would remain in their
natural state.Public access would remain limited and established
wildlife patterns would remain undisturbed.In addition,the flow
modification and thermal problem that might result from the dams would
not affect anadromous fish.
E-10-139
References
1.Acres .american Incorporated,1981,Susitna Hydroelectric Project,
Develoement Select ion Report.Prepared for the Al aska Power
Authonty.
2.Acres Anerican Incorporated,1982,Susitna Hydroelectric Project,
Feasibility Report,Vol.1.Prepared for the Al aska Power
Authority.
3.Bechtel Civil and Minerals,Inc.,1981,Chakachamna Hydroelectric
Project,Interim Report.
4.Cook Inlet Region,Inc.and Placer Amex,Inc.,1981,Coal to
Methanol Feasibility Study,Beluga Methanol Project,Volume IV,
Environmental..
5.Cook Inlet Region,Inc.and Placer Amex,Inc.,1981,Coal to
Methanol Project,Final Report,Volume IV.
6.U.S.Fish and Wil dl He Service,1962,Unpubl i shed letter to Bureau
of Reclamation.
7.Alaska Power Admininistration,1980,Hydroelectric Alternatives
for the Alaska Rai 1belt.
8.U.S.Department of Energy,1980,Hydroelectric Alternatives for
the Alaska Railbelt,prepared for Alaska Power Administration,
Juneau.
9.Commerce and Economic Development,Di vi sicn of Energy and Power
Deve 1opment,1980,Alaska Regi on a1 Energy Resources Planning
Project Phase 2,Coal,Hydroelectric,and Energy Alternatives,
Volumel -BelugaCoal District Analysis.
10.Battelle Northwest,1978,Natural Coal Util ization Assessment.
The Impact of Increased Coal Consumption in the Pacific Northwest,
OSDOE,BNwL=RAp-Zl,UC-11.
11.U.S.Fish and Wildl ife Service,1978,Impact of Coal Fired Power
Plants on Fi sh,Wi ldl ife,and their Habitats,Biol,Service
Program.
12.Acres .american Incorporated,1981,Prel iminary Assessment of Cook
Inlet Tidal Power,Phase 1 Report,State of Alaska,Office of the
GO vernor....fr
13.State of Al aska,1972,Knik Arm Highway Crossing,Department of
Highways,Anchorage.
E-10-140
-
-
References (Continued)
14.Bethel,J.S.et al.1979,Energy From Wood.A report to the U.S.
Congress,Office of Technology Assessment.Seattle,Washington,
College of Forest Resources,University of Washington.
lS.Tillman,a.A.,1978,Wood as an Energy Resource.New York,
Academi c Press.
16.Nebesky,W.,Institute of Social and Economic Research,1980,An
Economic Evaluation of the Potential for Recycling Waste Materials
in AnchOrage,Alaska.
17.Hill,P.G.,1977,Power Generation..Cambridge,MIT Press.
18.Wentink,T.,Jr.,1979,Alaskan Wind Power Study.Conference and
Workshop on Wind Energy Characteristics and Wind Energy Siting,p.
243 ff.
19.Battelle Pacific Northwest Laboratories/EBASCO,1981,Baluga Coal.
Report,prepared for the Office of the Governor,State of Alaska.
20.Battell e Pac ifi c Northwest Laboratori es,1982,Rail bel t Electri c
Power Alternatives Study:Evaluation of Railbelt Electric Energy
Plans,prepared for the Office of the GOv'ernor,State of Al aska.
21.Acres Ameri can Inc.,1982,Sus itna Hydroe lectr ic Project,1980-81
Geotechn i cal Report,Append ix F,prepared by the Al aska Power
Authority.
22.Acres American Inc.,Terrestrial Environmental Specialist,Inc.,
1982,Transmission Line Selected Route,prepared for the Alaska
Power Authority.
E-10-141
TABLE E.10.1:SUMMARY OF RESULTS Of SCREENING PROCESS
Elimination EfTm I nat Ion Elimination ----·---------rrlm I nat ion
Iteration Iteration Iteration Iteration
t I I I
Site t 2 3 4 Site t 2 3 4 Site I 2 3 4 Site I 2 3 4
A Illson Creek fox It Lowe It Talachuiltna River It
Bel uga LOwer It Gakona It Lower Ch uI i tna It Talkeetnna R.-Sheep It
Beluga Upper it Gerstle It Lucy It Tal keetna - 2
Big Delta It Gran I te Gorge It t~cC I Ure Bay it Tanana HI ver it
Brad I ey Lake it Grant Lake It t~cKI n ley RI ver it Tazllna it
Bremmer R.-Sa I mon it Greenstone *McLaren River It Tebay Lake It
Bremmer R.-5.f.it Gulkana River It t411110n Dollar it Teklanlka *Browne Hanaglta *Moose Horn It Tiekel River It
Sruskasna Healy *Nellie Juan River It Tokichltna It
Cache flickS Nellie Juan R.-Upper It Totatlan I ka It
Canyon Creek It "JiiCl<R i ver It Ohio It Tustumena It
Caribou Creek It Johnson It Power Creel{It Vachon Island It
Carlo It Junction Island It Power Creek -t It Whiskers It
rtl Cathedral Bluffs It Kanhs hoa RI var *Ramport It Wood Canyon It
I Chakachalllna Kasilof River It Sanford It Yanert - 2
It
--'
0 Chulitna E.F.It I<eetna Sheep Creek *Yentna It
I Chulitna Hurrican It Renal Lake It Sheep Creek -t It
--'
·Po ChulltnaW.f.It Kenai Lower *511ver Lake It
N Cleave It Killey River It Skwentna It
Coal It King Mtn It Snow
Coffee It Klutina *-soTanon Gulch It
Crescent Lake It Kotslna It Stelters Ranch It
Crescent Lake - 2
it Lake Creek Lower It Strand II ne Lake
Deadman Creek It Lake Creek Upper It Summit lake It
Eagle River It Lane It Talachulltna It
-
Notes:
( I )Final site selection underl ined.
it Site eliminated from further COilS iderllt Ion.
I I .1 t J J ~.J I J I J ;J I t I
TABLE E.10.2:SITES ELIMINATED IN SECOND ITERATION
Site Criterion
Carlo Denal i National Park.National Park Wilderness
Yanert - 2
,~
-
Heal y
Lake Creek Upper
t"cKinley River
Teklanika
Cleave
\'4000 Canyon
Tebay Lake
Hanagita
Gakona
Sanford
Cresent Lake
Kas i lof River
Mi II ion Dollar
Rampart
Vachon 1s I and
Junction Island
Power Creek
Gu I kana
Denal i National Park
Wrangell-St.£1 ias National Park &Preserve,
National Park Wilderness.Major Fishery
Wrangell-St.Elias National Park &Preserve,
r~ional Park Wilderness
Wrangell-St.El las National Park &Preserve
Lake Clark National Park
Major Fishery
\'4i I d &Scen ie Ri ver
£-10-143
TABLE E.l0.3:EVALUATION CRITERIA
Eva Iuat ion Cr iter ia Genera I Concerns
(t)Big Game
(2)Agricultural Potential
(3)Waterfowl,Raptors &
Endangered Spec i es
(4)Anadromous Fisheries
(5)Wilderness Consideration
(6)CUltural,Recreation
&Sc i ent if ic Features
(7)Restricted Land Use
(8)Access
-P~otection of wildt ife resources
-Protection of existing and potential
agricultural resources
-Protection of wildlife resources
-Protect ion of fisheries
-Protection of wilderness and unique
features
-Protect ion of exi st i ng and i dent I fi ad
potential features
-Consideration of legal restriction to
land use
-Identification of areas where the
greatest change wou I d occur
E-10-144
-
-
...
TABLE E.10.4:SENSITIVITY SCALING
Scale Ratins Definition
A.E>CLUS ION
B.H IGi SENS IT I VITY
MODERATE SENS IT I VITY
D.L~1 SENSITIVITY
The significance of one factor is great
enough to axc I ude a site from further
consideration.There is little or no
possibility for mitigation of extreme adverse
impacts,or development of the site is
I egall y proh i bi ted.
1)The rrost sens it i ve components of the
env ironmental cr i teri a wou'l d be dIsturbed
by development,or
2)T here ex j sts a high potenT i aI for future
confl ict which should be investigaTed in
a more deTai led assessment.
Areas of concern were I ass important tha n
those in "B"above.
1)Areas of concerns are comrron for most or
many of the sites.
2)Concerns are less important than those of
"C"above.
3)The available i.nformation alone is not
enough to indicate a greater
sign i f icance.
£-10-145
r"""'W .......-..-.....-.....
TABLE E.IO.5:SENSIT I VITY SCALING OF EVALUAT ION CRITERIA
·Evaluatlon Criteria SCALE
A B C 0
EXCllJs ion High Moderate Low
Big Game:-seasonal concentrat Ion -big game present
-are key range areas -bear denn i ng area
-cal v I nJL areas _
-habitat or distribu-
tion area for bear
AgricUltural Potential - -upland or lowland
50115 sultab Ie for
__J_C1rrnJflfL
-marginal farming soils -no Identified agri-
cultural potential
fT1
I.....
o
I....
-l::>en
Waterfowl.Raptors and
Endangered Species
Anadromous Fisheries
-nest I ng areas for:-high-dens i ty water fow I
•Peregr I ne Fal can area
•Canada Goose -waterfowl migration
•Trumputee Swan and hunting area
-year-round habitat -waterfowl migrat ion
for neritic seabirds route
and rap10rs -waterfowl nest Ing or
-key migration area molt area
-major anadromous fish -three or more species -less than three
corridor for three or present or spawning species present or
more species -Identified as a major spawning
-more than 50.000 anadromous fish area -Iden'tltled as an Impor-
sa I mon pass I n9_sJ.:t:El _tClrlt f I sll area
-medium or low density
waterfow I areas
-waterfow I present
-not Ident!fi ed as
a spawn I ng or
rearing area.
Wilderness Consideration
Cu I tural.Recreat lanai and
Scientific Features
All of tho fo Ilowl ng
-good-to-hlgh quality:
•seen Ie area
•natural features
•primitive values
-selected for wilderness
cons Iderat ion
-existing or proposed
his tor Ie I andmarl~
-reserve proposed for
the Ecological Reserve
System
Two of the following
-good-to-h I gh qua II ty:
•scenic area
•natural features
•primitive value
-site in or close to an
area Se I ected for
wilderness consideration
-Site affects one or
more of the fol lOWing:
•boat I ng potenti al
•recreat lonal potenti al
•historic feature
•his tor Ic tr a II
•archaeological site
•ecological reserve
nomlnat Ion
•cultural feature
One or less of the
following
-good-to-h igh qua Ilty:
•scen Ie area
•natural features
•pr imltl ve val us
-site near one of the
factors in B or C
•,I !I I J J I I J I 1 J m I
1 i I i J J
v~
i -1 )j J 1 i )
TABLE E.IO.5 (Continued)
tVai uat Ion Cr I ter I a SCALE
ABC
__________Exc I us lon ~liJnh Moderate
D
Low
IT1
I
-.I
o
I
--'
+:>
'.J
Restr Icted Land Use
Access
-Significant impact to:
•Existing national
park
Federal lands with-
drawn by National
Monument ProcI amat ions
-Impact to:
•Nat lonal 1'111 dl i fe
range
State park
•State game refuge,
range.or wilderness
preservation area
-no existing roads,
railroads or alrpol"ts
-terral n rough and
access difficult
-increase access to
wi Iderness area
-Increase:
•Nat lonal forest
•Proposed 1'111 d and
scen ic river
•National resource
area
•Forest land Withdrawn
for mineral ~ntry
-existing trai I s
-proposed roads or
-existing airports
-close to existing
roads
-In one of the
following:
•State land
Native land
•None of A.B.C
-existing roads or
ra Ilroads
-existing power lines
TA~LE E.10.6:SITE EVALUATIONS
-Black and Grizzly bear -~ne Identified
present
-~ne (dentl f i ed-'tbatfng:areas
-NJne
-Good-to-hlgh'quaJlty
scenery
-G>od-to-h Igh""'l uaJ Ity
scenery
I
-High-to-good'qu"llty
SCen Ie &rea
-Area -,under w"j"f'de'r'nes's
conS iderat10n
-Good-to-hlgh-<luallty
scenery
-Primitive and natural
featureS'
-~ne
-NJne
-~ne (dentl fled
-TwO 's~'pecfes''present
-Low,dens tty of water-
fowl
-NestIng and molting
area
-Peregrine Falcon
nesting areas
-Low,Aens I ty of water-
fowl
...;'WaTer-tow'l nest 1ng and
mol tlng area
-Opland sph"'",hard-
Wood forest
-febre thlln 50 percent
marg inal!y sui tab Ie
for farm log
-~ne Identl fled
-25 to 30 percent of
SO iI marg Inal 1y sui t-
abla tor fannIng
-hi ah qua I ltv forests
-Black and Grizzly bear
present
-fJoose present
-Ci5Irlbou winter range
-BI ack bear habitat
-Moose pr ase nt
-BI ack and Grlzzl y bear
present
-Moose present
-Black and Grizzly bear
present
...MooSe ,present
-CaribOu-winter ranae
AI'I son Crook
Bradley Lake
Browne
Bruskasna
Cha kachamna
-More,tha,n 50 percent of -Low dens I ty of 'water-
I and,marglnal tor farm Ing foWl
-Uplandsprwe-hardwoad -Nesting and molting
forest area
Coffee
Cathedral BI uffs
Hicks
-81 ack and Gr Izzi y bear
present
-Moose present
-BI ~k and Gr I zzl y bear
pr.esent
-MoOse .p'rasent
-Dall sheep present
-Moose concentrat Ion area
-Bt ack and Grl zzl y bear
present
-Car lbou present
-Moose winter I ng area
-More than 50 percent of
upparlaoo suitable for
agrIculTure
-Good.'forests
--NJna ,'Ii:Js'n't l'f Yed
-Key waterfowlhabi tat
o;;':r~~~W~~::5Tln51 a'ri(J
,.;.Four speci es ~esent,,,
two spawn ing In area
...;Ckle species present
;""'Far'-dol"n~Jtream from
site ani y
-Noneldentlflad
-Q,od scenery
~~heldent1fled -~nel dehtLfloo
""""c.'Noae'Identl f (ed
-~ne Ident'lf(ed
';;';N:lpr'eserit
restr,lctlons
Johnson -Black and Griuly~ar
present
-Moose,car lbou 'and
bIson present
-25 to 50 percent of
upland """suitable
for farm Ing
-Up I and spr '"'e-hard ""ad
forest
-low dens Ity of waterfow I
-Nesting and noltlng area
-Sa lmon s pawn I ng area,
one specIes present
-~ne Identl fl ad -Boat I ng potent I aj -~ne I dentl fl Oll
!<.eetna -Blac:k;,~nd Grizzly bear
present
-Car lbou wInter area
-Moose fa II/wi nTar
concentration area
-r-6he Identl fled -~ne Identi f I ad -Four species present J
one specIes spawn log
near site
-G>od-to-h igh-<lual ity
Jr Imltlve lands
-High boating potent I al -~ne identl fl.ed
Kenai Lake -Black and Grizzly bear
present
-Oall sheep habitat
-Moose fail/wi nter
concentration area
-~ne Identl fied
-Coastal,hem I ock-
sitka spruce foreST
-Waterfowl nestIng and
moltIng area
-Four species present,
two spawn Ing
-Hlgh-<luallty scenery
-Natural features
-Boating ipotentlal -ChUgach N3t lanai
Forest
.,1\gr IcuffUral ~ferfoWI,'.R=3pters,Ailadranous WI I derness CultlJ",-ah :ijfk:r.eaT:V"J!ia1r.,0 .•'Res'tr'ic~ea -,
Big Game._.____Potent@1 Endangered Species Fisheries Consideration and Sclentlf.!c,Features<,.'"Land Use
TABLE I;.10.6 (Continued)
$',te ____Evatuati~~'CriTeria
KI utlna -Bla.=k,'and Grizzly bear
present
-Car 1bou present
-r-blse fall concentra-
tion area
-25 to 50 percent of
SO JI 5 marg Inal for
farmJng
-Clll'Itate,marg-Inal for
farming upland spruce-
hardwood forest
-low~ens I ty waterfowl
area
-Nesting and lIK>ltlng
area
-Two spec:ies present.
.one species spawn In
vicinIty of site
-,H!i'gh-q:ua'I"ity;Scenery
-.NaTural',fonnat Ions.
-Pr Imitive lands
-SeleCted .for wf\der-'
ness consideration
Boating:ix>t~ntlal ..-None Identlfed
-Black andG-lzzly bear -None Identified -Ye.r-round h.bltat for -One species present,-Good-to-hlgh-'luallty -13o<I+I09'af.e-o pote-ntial
present -Coastal western hemlock-neritic seabirds and nnre'downstream scenery
-Hlgh----.gens'I!Lof seals sltlgl__.spruce forest raptors'-Primitive ~value'
Strandllne Laka -Moose,black bear -25 to 50 percent margl--Nesting and-molting
hab,ltat.."":,,,...".,'oal .faniltng sed I s area
~.(3r I zz ty.,bear "present;,,,-...A'I,p·l nec_tundra"h
--None Identl fl ed
-Nolle Idantl fl ed
"'None Identlfjej
-loc.ted.In Chugach
ret lonal .Forest
-None Identl fled
-Ch ugac~!'lot Ion al
For'as
""'~:''-Lb~~:t'~'n~'~~'t-~'"
bohler of Ch ugach
J-et''onal For'est,
.-None I dent I fl ed
-B.o'at I n9 ::oPP6:(1-~'1'lt i'es
ldentl fl ed
i
!
-Nona Idon·t1-fI ed
I·
-Proposel.'ocor''1flcal
reseryol"lte
-Ooaf.lng!"'tantl.1
i,--,',:,','",;:,..--.
~:Bo~tlng \·6t.ea'
.'."".-HI.stor-it,al·.·tfa,i,'J'-s:~
-None IdentifIed
-Area,seh~ct,Ed','f6r,'.>', -
wi I derness,-consld'eratton '
-Good-to-hlgh-'lu.llfY'
'.sceoer.y.",_:';',.
-Area,sel,ected,'.for:"',>".',:<:-,'::,:;,
Wf I derness,eonS 1derat.lo'n
-None Identified
-Good-to-hlgh,-quallty
scenery
-Pr imitive lands
-.None Identl fl ed
-Good~to-h Igh,-qual ity
scenery
-Prlmitl've,lands
-FIve species present
and spawn in sIte
viein Ity ,
,;,.Qle specJ9Spre5ent,
others dOWnstr'eam of
site
-Fo'urs.~~I~~'",Present,
three spawn'log In
'vicinity
~ftb'~~
,
;;;'fThree .specles.present.
"·tspawn I ng.In area
I
-t-bne presant-
-Four spec I es'present,
one species spawns at
site
-low-denslty waterfowl
area
-Nesting .nd lIK>ltlng
area
-'Medlum-denslty waterfowl
area,,:,'
-Nesting and molting
area
-Nolle Identified
-Mora than 50 percent
of the soils In upper-
lands suitable for
farm I ng
-Bottomland spru:::e-
pop I ar forest
-~ri.e 'Identified __~Per;'egrf~,e,.Falcon
-Coastal.weste,rn hemlock-nestlng'ar,ea
sitKa spruce forest
-tIore',than·5'O parc,entof
tl1e upl and soHs sui t-
able for farm Lng
-50,parcen,t"o:f,upperlands -,Low-dens-lty 'waterfow,1
sult·abl.e }or."f.e;trmtn.g ..".,-~rea_.__.__"_
-.Lowland spr.u::,e ...-Nesting and rolttng
hardwood forest area
-None Identified
- B lack bear present
-t-blse present
-Car ibou present
-Black and G-tzzly bear
present
-Car'lbou,present
-Black and G-Izzly bear
prese'nt
-Moo'sep'resent
-Black and G-lzzi y bear
p,r~sen't
-Moose wi nter c6ncentra';'
-tton"area
-Black.nd G-Izzly bear
presnt
-Moose fall/Winter con-
cen trat 10n area
-CarIbou Winter ranQe
LDwe
Lane
LDwer Ch u I Itn.
Silver Lake
Skwentna
Snow -"31 ack6earprese~t ~None>ldentl fred -Nest 109 ond IllOltlng
-0.1 I sheep h.b Itats area
-t-bose wi n'fer 'eo'ncen'tr'a-":'
t·lon are:a
Tal lceetna 2
Cache
Tazllna
-Black .nd G-lzzly bear
present
-fJoosa wfnter concen-
tr'at'lo il··ar,ea
-Carlbo-u·winter -range
-BI ack and G-lzzi Y beat
present
-·tIoOse·'!'f!lter.r'i;!·ng,e
-Car lbou ,:'w inter range
-None i dent;fled
--Nona Identified
-towl and spruce-hi:lrdwood
forest
-None Identified
-Med'i urn-dens i ty water-
fowl area
-Nestlrg .nd molting
area
-Four s pee 1as of sa !Iron
present_spawning areas
identi fi ad
-Two species present,
at site 'and upstrean
-Good-to-h Igh,-qual ity
scenery
-Primitive lands
-None Identl lied
-Boatlrg potential
-BoaflrgLpotenti"
~None 'dentl fled
"'None Identified
Toklchltn.-Black bear present -More than 50 percent of -Medium-density water--Four species 'pre'sent,-Border prlmit,ive area -Boat I ng!'poteht I al
-Moose present solis are usable for fowl area three species spawn In
'-CariboU presJ!!'lt farming (in upper lands)-Nesting arid molt~n.Q __area site vlcl!!lty___-----f
-None Identified
TABLE Eo 10.6 (Continued)
STTe Evaluation Criteria
Agricultural Wa-fifr~.-Fap~~Anadranous ----~-Wil-d~CuTtural,'RecreatIonal,RestricTed
BIQ Game PotenTial Endanqered Species Fisheries ConsideraTion and Scientific features Land Use
Tustumera
Upper Bel uga
Up?er Nellie
Juan
-BI ack bear hab Itat
-Dall shee?habItat
-Moose present
-GrIzzly bear present
-Moose pr ese n't
-61 ac:k bear habiTat
-None Identified
-More than 50 percenT of
upperlands are suitable
tor farrn Ing
-lowland spru:e-hardwood
foreST
-ttl..Identl tied
-Coastal wastern hem I ock-
sitka spurce foreST
-None identifIed
-Med I um dens I ty water-
fowl ;:rea
-Nesting and molting
area
-ttlne Identltled
-None identified
-Four spec I as rresen't,
two species spawn In
area
-ttlne Identl tl ed
-Sel ected for wi I dernass
conS I dar-aT Ion
-Good-1"o-hlgh-qual Ity
scenery
-Na tur 81 feaTures
-Primitive lands
-None Identltled
-SelectEd for wilderness
consideraTIon
-High primitive,scenic,
and naTura I feaTures
-None identified
-Boat tng iarea
-Boat I ng :,potentl al
-LocaTed In !<anal
tet Ion 81 Moose Ra "g6
-Site within a
des Ignated Not lonal
Wli derness area
-None identi 11 ad
-Chugach Not lonal
Forest
Whl skers -Black and Grizzly bear -'0 percent ot upperlands
presenT suitable for fanning
-Moose present -Bot.tanland spruce-
-Caribou present po.plar forest
-low-denslty waterfowl
area
-Nostlng and molting
area
-Five species present,
two spawn In area
-ttlne identltled -Boatlng:potentlal -ttlne Identlfled
Yentna -Black and Grlnly ~~
present
-Moose,sprlng/sumner/
winter concentraTion
-2'to '0 percent of
soIls In lowlands are
suitable tor tarmlng
-Bottom 1and spruce-popl ar
forest
-Medium-densiTy water-
fOWl area
-Nost I ng and molt I ng
area
-Five species spawn In
area
-ttlne Identl fl ad -Boating ;potential -ttlne Idanti fl ed
TABLE E.l0.7:SITE EVALUATION fIlITRIX
Waterfowl,Instal led Land
Big Agricultural Raptors.Anadromous Wlldernass Cult,Recrea,Restr icted Capocity Dam flooded
Game Potential Ends.Species Fisheries Cons i derat i on &ScientifIc Land Use Access (MW)Scheme Height (ttl (Acres)
Crescent La ke C 0 0 B C C A B --Reservoir <150 <5000
w/Diverslon
Chakachamnfl C 0 C C B C B C >100 Reservoir <150 <5000
w/Dl vers ion
lower Bel uga C D C B 0 C n D <25 Reservoir <150 <5000
and ~m
Cof fee C B C B 0 C 0 D 25-100 Dam Clnd <150 <5000
Reservoir
I.\>per Bel uga C B C B 0 C 0 D 25-100 Dam a I1d 150-350 5000 to
Reservoir 1OD,000
Strand line Lake C C C D C D 0 0 <25 Reservoh'<150 <5000
wiLli 'lars ion
Bradley Lake C C B 0 C C 0 D 25-100 Hestlrvoir <15D <5DOO
W/DI 'liars Ion
Kasi lot River C B C A 0 C B D --Reservoir 15D-350 >100,DDD
w/DI verslan
Tustumana C 0 D D B D B B <25 Reservolr <150 <5000
w/Oj versIon
Kenai Lower C B C B C C B 0 25-100 M Dam and <150 <5000
R9SAf'Volr
KenCll Lake B D C B C D C 0 >\00 Dam and >}50 5000 to
Reservoir 100,000
Crescent Laka-2 C D C C C C C 0 <25 Reservoir <150 <5000
wlDlverslon
Grant Lake B D C B C C C 0 <25 Reservoir <150 <5000
w/Dlversion
Snow B 0 C 0 0 C C 0 25-100 Reservoir 150-350 5000 to
w/Dlverslon 100,000
MeCI ure Bay D D B C B D C C <25 ReservoIr <150 <5000
W/Di version
Upper Nell i e Juan R C 0 0 0 B C C <25 Reservoir <150 <5000
W/Diverslon
Allison Creek D D B C D D D D <25 Reserve Ir <150 <5000
w/Dj vers ion
Solomon GUlch 0 0 B C 0 0 0 D <25 Reservoir <150 <5000
w/Dlvers Ion
Lowe C D B C C C D 0 25-100 Dam and 150-350 5000 to
Reservoir 100,000
Silver Lake D 0 B C C C C c.<25 Reservo Jr <150 <5000
w/DI vers Ion
Power Creek D D B A C C c C <25 ReSl;;lrvolr <150 <5000
W/Divers ion
Mill ion Dollar D D B A B C C C --Dam and <150 5000 to
Reservoir 1DO,000
TABLE E.1o..7 (ConTinued)
Waterfowl,Installed Land
Big Agricultural Raptors,Anadromous Wi I derness Cu ItJ Recrea,Restricted CapaciTy Dam FI",dod
Game POTential·Endg.Speci es Fisheries Consideration &Sclentific Lond Use Access (MW)Sd1eme Height (ftl (Acres)
KeeTna B 0 0 B 0 C 0 C 25-100 Dam and >350 5000 to
Reservo Ir ,100,000
Gran iTe Gorge B 0 0 B C C 0 C 25-100 Reservo Ir 150-350 <5000
w/Di vers ion
Tal keetna-2 B 0 0 B C C 0 C 25-100 Dam and >350 5000 to
ReservoIr 100,000
Greenstone B 0 0 B C C 0 C 25-100 Reservoir 150-350 <5000
w/Di vers 10n
Cache B 0 D B C C 0 C 25-100 Dam and 150-350 <5000
Reservoir
Hicks B 0 C 0 0 0 0 0 25-100 Dam and 150-350 <5000
Reservolr
Rampart C B B A 0 C C -->100 Dam and >350 i >100..000
Reservoir
Vachon IsI and B B C A 0 C 0 G >100 Dam and <150 >100,000
Reservoir
Junction Island B B C A 0 C 0 G >100 Demand \50-350 >100,000
Reservoir
Kantishna River C B C B 0 C 0 C 25-100 Dam and <150 >100,000
Reservoir
McKinley River B 0 C 0 "C A ----Dam and 150-350 <5000
Reservoir
Teklanika River B 0 0 0 B 0 A 8 Dam and >350 5000 to
ReservoIr I DO,000
Browne B C 0 0 0 c !0 0 >100 Dam and 150-350 5000 to
Reservoir 100.000
Healy B C 0 0 B 8 A 0 --Dam and 150-350 5000 TO
Reservoir 100.000
Carlo B 0 0 0 B C A 0 --Dam and 150-350 <5000
Reservo ir
Yaner1"-2 B 0 0 0 B C A 0 --Dam and 150-350 5000 to
Reservoir '100.ODD
Brus}l;asna B 0 C 0 0 8 0 0 25-100 Dam and 150-350 '5000 to
Reservoir '100.000
Tanana B B C B 0 C 0 0 25-100 Dam and <150 5000 TO
Reservoir 100.000
Gerstle B B C C 0 C 0 C 25-100 Dam and <150 <5000
Resorvoir
Johnson C 8 C C 0 C 0 0 >100 Dam and <150 '5000 TO
Reservoir 100.000
Cathetfr.1 BI ufts B C C C 0 0 0 0 >100 Dam and 150-350 5000 TO
Reservoir 100.000
i-land
;FJooded
I (Acres)
TABLE E.10.7 (Continued)
Waterfowl,-----------------.-----rnstalled
Big Agrfc;ultura~Raptors,Anadromous Wilderness Cult,Recrea,Restricted CapaciTy Dam
Game Potential Enda.Species Fisherles ConsIderation &-ScientifIc Land US~Access_~_{MW)~I:l_~e Height (ft)
Dam and 150-350
Reservoir
Reservoir <150
w/Di vers ion
J:"',,_"~.
Cleave
:J'loo~CanYo.n
Teb.y Lake
Hanag ita
Klutlna
Tazllna
Gakona
Sanford
c
c
c
c
B
B
o
o
c
o
c
c
c
B
B
c
c
c
c
c
B
B
B
B
D
o
o
c
B
D
c
c
c
c
A
A
A
c
A
A
o
B
a
D
D
25-100
>100
Dam and
Reservoir
Dam and
ReservoIr
Reservoir
w/Di vers ion
Darn and
ReserVOir
Dam and
Reservoir
150-35D
>350
<150
150-350
5DOO to
100,000
>100,000
i
i
j <5000
I<500D
[
I
I
I
j 50DO TO
1,100,000
i 5000 to
j 100,000
Gu I kana
Yentna
B
B
c
B c
B D
c
25-100
>100
Reservoir 150-350
w/Di vers Ion
Dam and <150
ReservoIr
5DOO TO
100,000
>100,000
Reservoir <150
w/Dlversion
Talachultna
SkwenTna
Lake Creek Upper
Lake Creek Lower
Lower Chul ii"na
Toklchltna
Coal
Olio
Chulitna
Wh Iskers
Lane
Sheep Creek
c
c
c
c
B
B
B
c
c
B
B
o
a
D
B
c
c
c
c
c
c
c
c
c
c
B
c
B
B
c
c
c
B
D
o
c
c·
c
c
c
c
o
c
c
c
c
c
c
c
c
c
c
c
c
D
A
o
o
c
c
c
c
D
D
D
o
c
c
c
25-100
25-100
25-100
>100
25-100
25-100
25-100
25-100
>'00
25-100
Dam and
Reservo ir
Dam and
Reservoir
Dam and
Reservoir
Dam and
Reservoir
Dam and
Reservoir
Dam and
Reservoir
Dam and
Reservoir
Dam and
Reservoir
Dam and
Reservoir
Dam and
Reservoir
Dam and
Reservoir
<150
>350
150-35D
150-350
150-350
150-350
150-350
150-350
<150
150-350
>350
i 5000 TO
:100,000
I
'500D to
100,000
<5000
<50DO
<5DOO
5000 to
100,DOO
<50DO
<5000
<500D
<5000
<5000
<5000
TABLE E.l0.a:CRITERIA WE1GHT ADJUSTMENTS
fIoj USTe<welQOTS
,uarn tie I QnT KE servo /'Irec
10 itial
Weiqht ++++++++++++
Big Game 8 6 7 8
Agr Icul tural
Potential 7 5 6 7
Birds 8 6 7 8
FisherIes 10 8 9 10
TABLE E.l0.9:SITE CAPACITY GROUPS
Site Group
<25 MW
25-lOa MW
>100 MW
NO.•ot ::lITeS
Evaluated
5
15
8
E-10-154
No.OT :>r1"es
Accepted
3
4 - 6
4
TABLE E.l0.10:RANKING RESULTS
Site Grouo Partial Score Total Score
Sites:<25 MW
Strandl ine Lake 59 85
.Nell ie Juan Upper 37 96
Tustumena 37 106
AI I i son Creek 65 82 """1
Si lver Lake 65 111
Sites:25 -100 MW
H ieks 62
~,
79
Bruskasna 71 104
Brad i ey Lake 71 104
Snow 71 106
Cache 86 127 ,.~.
lowe 89 122
Keetna 89 131
Tal keetna - 2
98 134
Coffee 101 126 ~jWhiskers101134
Klutina 101 142
lower Chulitiua.106 139
8el uga Upper 117 142
Talachultna River 126 159 -Skwentna 136 169
Sites >100 MW
Chakaehamna 65 134
Browne 69 94
Tazl ina 89 124
Johnson 96 121
Cathedral Bluffs 101 126
Lane 106 139
Kenai Lake 112 147
Tokiehitna 117 150
-
E-10-155
TABLE E.l0.ll:SHORTLISTED SliES
llV j ronmental i-..,..._..................I--.;r;a;,r:.;:oi6:.:c~i..;..J,Tv"",",.,...._4-_.....,..,......,.."..,..-__
.:.R::::6..:,T;:.;in~-+,....;::;_..::.:::.....:.:;.:.,...-+_=.:5 -_..:,110;:.;:.0,.;.:.:.;MW_-I-__..:,11.:::.:::.OO..:"l"::;.lW:..-_
Good
Acceptable
Poor
Strand!ine lake*
A1I j son Creek*
Tustumena
Si Iver Lake
Hicks*
Snow*
Cache*
Bruskasna*
Keetna*
Tal keetna-2*
Lower Chu I itna
Browne*
JohnsQn
Chakachamna*
Lane
Tokichitna
*10 sel acted 51 tes
E-10-156
TABLE E.l0.12:ALTERNATIVE HYDRO DEVELOPMENT PLANS
Installed On-Li ne
Plan Description Capacity Date
A.l Chakachamna 500 1993
Keetna 100 1997
1'1.2 Chakachamna 500 1993
Keetna 100 1997
Snolll 50 2002
A.3 Chakachamna 500 1993
Keetna 100 1996
Snolll 50 1998
Strandl ine 20 1998
.AII i son Creek 8 1998
1'1.4 Chakachamna 500 1993
Keetna 100 1996
Snow 50 2002
Strand I ine 20 2002
Allison Creek 8 2002
A.5 Chakachamna 500 1993
Keetna 100 1996
Snow 50 2002
Tal keetna -2 SO 2002
Cache 50 2002
Strand line 20 2002
AII i son Creek 8 2002
£-10-157
-
TABLE E.l0.13:OPERAT ING AND ECONOMIC PARAI~ETERS FOR SELECTED HYDROELECTRIC PLANTS
t-1ax.Average Economic
Gross I nstal led Annua I Plant Cap i t~1 Cost of
Head Capacity Energy Factor Cos 6 Energy
No~Site River Ft.(MW)(Gwh)(%>($10 )($/1000 Kwh)
1 Snow Snow 690 50 220 50 255 45
2 Bruskasna Nenana 235 30 140 53 238 113
3 Keetna Tal keetna 330 100 395 45 477 47
4 Cache Tal keetna 310 50 220 51 564 100
5 Browne Nenana 195 100 410 47 625 59
<5 TaI keetna-2 Talkeetna 350 50 215 50 500 90
7 Hicks Matanuska 275 60 245 46 529 84
8 Chakachamna Chakachatna 945 500 1925 44 1480 30
9 All ison AI I i son Creek 1270 8 33 47 54 125
10 Strandl i.ne
Lake Bel uga 810 20 85 49 126 115
NOTES;
TTT"l'f,cluding engineering and owner's administrative costs but excluding AFOC.
E-10-158
TABLE £.10.14:SUSHNA DEV£LOPr-ENi PLA~
Cumulative
Stage/Incremental Data Sy~t~JD_D~J~
Annual
Maximum Energy
Capital Cost·Earliest Reservoir Seasonal Product Ion Plant
$Millions CKi-llllG Full Supply (k-i~w-Firm Avg.Factor
Plan Dah 1 G\'4-I.%Stage ConstructIon (1980 va lues)Level -ft.down-ft GWi
1.I I Watana 2225 ft 80lMW 1860 1993 2200 150 2670 3250 46
2 DevIl Canyon 1410 H
ITl 600MW 1000 1996 1450 100 5500 6230 51
I TOTAL 5 YST EM 1400 MW 2660
--'
0
I
--'
tTl 1.2 1 Watana 2060 ft 400 MW 1510 1992 2000 100 1110 2110 60\0
2 Watana raJ sa to
2225 ft 360 1995 2200 150 2670 2990 85
3 Watana add 400 MW
2
capac lty 130 1995 2200 150 2670 3250 46
4 Dev \I Canyon 1470 ft
600 MW 1000 1996 1450 100 5500 6230 51
TOTAL SYSTEM 1400 MW 3060
1.3 1 Watana 2225 f"t 400 M~I 1140 1993 2200 150 2670 2990 85
2 Watana add 400 MW
capac Ity 150 1993 2200 150 2670 3250 46
3 Devil Canyon 1470 ft
600 MW 1000 1996 1450 100 5500 6230 51
TOTAL SYSTB~1400 MW 2890
J ,I J j •~il-~J t t I J t J
~i ~-1 j -,}l ]}»1 1 E 1
TABLE E.to.t 4 (Conti nued)
Cumulative
Stage/increme~tal Data System Data
Annual
Maximum Energy
Capital Cost Earliest Reservoir Seasonal Product Ion Plant
$Millions On-line fu II Suppl y Lraw-Firm Avg.factor
Plan Stage Construction (1980 va lues)Date 1 GItt GItt %Level -ft.down-ft.
2.1 1 High Dev II Canyon
1775 tt 800 MW 1500 1994
3
1750 150 2460 3400 49
2 Vw 23.50 ft 400 MW 1060 1997 2330 150 3870 4910 47
TOTAL SYSTB-1 1200 MW 2560
2.2 1 High Devil Canyon
fT1 3
I 1630 tt 400 MW 1\40 1993 1610 100 1770 2020 58
-'2 High Dev II Canyon0
I add 400 MW Capac I.ty--'
O"l raise dam 1u 1775 ft 500 1996 1750 150 2460 3400 49
0 3 Vee 2350 ft 400 MW 1060 1997 2330 150 3870 4910 47
TOTAL SYSTB-1 1200 MW 2700
2.3 1 High Dev II Canyon
3
1775 ft 400 MW 1390 1994 1750 150 2400 2760 79
2 l-llgh Dav II Canyon
add 400 MW capac Ity 140 199tl 1750 150 2460 3400 49
3 Vee 2350 tt 400 MW 1060 1997 2330 150 3870 4910 47
TOTAL SYSTEM 1200 MW 2590
3.1 1 Watana 2225 ft 800 MW 1860 1993 2200 150 2670 3250 46
2 Watana add 50 MW
tunnel 330MW 1500 1995 1475 4 4890 5430 53
TOTAL SYSTEM 1180 MW 3360
TA6LE E.10.14 Cont luued)
CU/llulatlve
~~._._~__.~...S_t~g~I ncrementa I Data ._.§..YE.!emJ:l!'JCl ..__
Plan
3.2
Annual
Maximum Energy
Capital Cost Earliest RQservo Ir Seasonal Product Ion Plant
$Millions On-Hne Full Supply Draw';'Firm Avg.Factor
-_1
Stage CClnstructlon (1980 values)DateL.evel -ft•..ct()wn-ft.C3_Wj_GIti ...%
1 \'Iatana 2225 ft 400 MW 1740 1993 2200 150 2670 2990 85
2 Watana add 400 MW
capacity 150 1994 2200 150 2670 3250 46
3 Tunnel 330 MW add
50 MW to Watana 1500 1995 1475 4 4690 5430 53
3390 .
rrt 4.I 1 WatanaI
-"3a2225ft400MW17401995 2200 150 2670 2990 85I
-"2 Watana add 400 MWmcapacity 150 1996 2200 150 2670 3250 46--'
3 HIgh Dev i I Canyon
1470 ft 400 MW 860 1998 1450 100 4520 5280 50
4 Portage Creek.
1030ft 1501'41'1 650 2000 1020 50 5110 6000 51
TOTAL SYST8I1 1350 MW 3400
NOTES:
(1)Allowing for a 3 year overlap construction period between major darns.
(2)Plan 1.2 Stage 315 less expensive than Plan 1.3 Stage 2 due to lower mobilization costs.
(3)Assumes FERC I icense can be fll ad by June 1984,Ie.2 years later than for the Watana/Dev II Canyon Plan I.
J J J J D J J ~I J -]c!J •.,a )
1 I )i j j -)j 1 '1
TABLE E.I0.15:RESULTS OF SCREENING MODEL
Total Demand Optimal Solution First SUboptimal Solution Second SUboptimal Solution
Max.Inst.Total Max.Inst.Total Max.Inst.lotal
Cap.Energy Site Water Cap.Cost Site Water Cap.Cost Site Water Cap.Cost
Run MW GWh Names Level MW $fill II ion Names Level MW $mi II ion Names Level MW $ml II ion
400 1750 High 1580 400 885 Devil 1450 400 970 Watana 1950 400 980
Devi I Canyon
Canyon
2 800 3500 High 1750 BOO 1500 Watana 1900 450 1130 Watana 2200 BOO 1860
Devi I
Canyon
Devil
Canyon 1250 350 710
rr1 TOTAL 800 1840
I
--'
0
I 3 1200 5250 Watana 2110 700 1690 High 1750 800 1500 High 1750 820 1500
--'
CJ)Dev II Devi I
N Canyon Canyon
Devi I 1350 500 000 Vee 2350 400 1060 Susi trw 2300 380 1260
Canyon III
TOTAL 1200 2490 TOTAL 1200 2560 TOTAL 1200 2760
4 1400 6150 Watana 2150 740 1770
N 0 SOLUTION N 0 SOLUTION
Devil 1450 660 1000
Canyon
TABLE E.l0.16:ENV I RONMENTAL EVALUAT ION OF DEV IL CANYON DAM AND TUNNEL SCHEME
Env IronmentElI
Attr i bute
EcologIcal:
Concerns
Appraisal Scheme jud.ged to_hC!"e
(Differences in impact Identification the least Potential imp2lcf"
of two schemes)of difference Ap.Qralsal Judgment Iwnna!:DC
--Downstream Fisher I as
and Wildlife
Resident Fisheries:
Wi I dll fe:
CUltural:
Effects resulting
from changes In
water quantity and
quality.
Loss of resident
fisheries habitat.
Loss of wildlife
habitat.
Inundation of
archaeol og ical
sites.
No sIgnificant difference
between schemes regard i ng
effects downstream from
Dev i I Canyon.
Difference in reach
between Dev i I Canyon
dam and tunnel re-
regulation dam.
Minimal differences
between schemes.
Minimal differences
between schemes.
Potential differences
between schemes.
With the tunnel scheme cofl-
walled.flows between regula-
tion dam and downstream power-
house of ters potent I aI for
anadromou5 f i sheri as enhance-
nent in this 11 mile reach of
the river.
Devil Canyon dam would Inundate
27 miles of the SusitnEl River
and approx I matel y 2 mil es of
Dev I I Creek.The tunnel scheme
would Inundate 16 miles of the
SusitncL River.
The most sensitive wildlife ha-
bitat In this reach Is upstream
from the tunnel re-regulation
dam where there is no sIgnifi-
cant difference between the
schemes.The Dev i I Canyon dam
scheme in addition lnundates the
river valley between the two
damsites resulting in a ITK)derate
Increase tn impacts to wildlife.
Due to the I arger area I nun-
dated,the probab III ty of i n-
undating archeloolog fCell sites
lsi ncreased.
Not a factor in leva I uatlon of
scheme.
Iff i sher i as enhancement oppor-
tun i ty can be rea 11 zed the tun-
nel scheme offers a positive
mit igat Ion measure not ava II <til e
with the Devil Canyon dam
scherre.This opportlJllty Is
cons idered noderate and favors
the tunnel scheme.However,
there are no current plans for
such enhancenent and feasibil-
ity is uncertain.Fbtential
val lie is therefore not sign 1-
ficant relative to additional
cost of tunnel.
Loss of habitat with dam scheme Is
less than 5%,of total for Susi tna
main stem.This reach of river is
therefore not considered to be
highly significant for resident
fisherIes and thus the difference
between the schemes is minor and
favors the tunne I scheme.
Moderate wi Idllfe populations of
noose,black bBar,weasel,fox,
wolverine,other small mammal s
and songbIrds and Some riparian
cliff habitat for ravens and
raptors,In 11 miles of river,
would be lost with the dam scheme.
Thus,the difference in loss of
wildlife habitat is conSidered
moderate and favors the toonel
schBme.
Significant archeological
sites,if ldentl fi ed,can rroba-
bly be excavated.Additional
costs caul d range from severa I
hundreds to hundreds of thousands
of dollars,but are st III consider-
ably less than the additional cost
of the tunnel scherre.This concern
is not considered a factor in scheme
evaluation.
x
x
x
Land Use;Inundation oJ.pevil Significant difference
Canyon.between schemes.
The Dev i I Canyon is cons I dered
a uniQLIe resource,80 percent
of which would be inundated by
the Dev i I Canyon dam scheme.
This would result in a loss of
both an aesthetIc value plus
the potent I al for wh ite water
recreat ion.
The aesthet ic and to some extent
the recreational losses aSSJcl-
ated with the deve I opment of the
Devil ,Canyon delm is the TTlClin
aspect favorTng the tunnel scheme.
However,current recreat ionell uses
of Dev II Canyon are low due to
lImited access.Ra:;reClt ion develop-
ment of the areCl is similelr for
both schemes.
x
OVERALL EVALUATION:The tunnel scheme has overall a lower impact on the environment.
1 )))»J 1 1 )1 1 I 1
TABLE £.10.17:SOCIAL EVALUATION Of SUSITNA BASiN DEVELOPMENT SCHEMES/PLANS
SOci a I -Tun nOT--lJev i I Can yon
Aspect Par~met~Sc:he~Q~m Jlcheme
fllg-h Dev i I CanyonF Watana/Dev i I
Veo Plan ~'lnYl:ln_PLan __HemE\rks
All projects would have similar Impacts on the state and
local economy.
Potential
non-renewab Ie
resource
dl sp I acement
Impact on
state economy
Impact on
local economy
Million tons
Beluga coal
over 50 years
]
80 110 170 210 Dev i I Canyon dam scheme
potential higher than
tunnel scheme.Watana/
Dev i I Canyon plan higher
than High Devlt Canyon/
Vee plan.
IT!
I
-'o
I
-'
O"l
..j:::o
Seismic
exposure
HI sk of major
structural
tal lure
Potential
impact of
fall ure on
human I I fe.
All projects designed to slmilarlevals of safety.
Any dam failures would affect the same downstream
population.
Essentially no difference
between plans/schemes.
Overall
Evaluation
I.Dev II Canyon dam su per lor to tunnel.
2.Watana/Dev i I Canyon super lor"to Hi gh Dev i I Canyon/Vee pI an.
TABLE E.10.18:OVERALL EVALUAT ION OF TUNNEL SCHEME AND DEV IL CANYON DAM SCHE~1E
ATTR 1BUT I::
Economic
Energy
Contr ibut ion
Env ironmental
Social
Overal I
Eval uatIon
SOfSERl5RpC'\N
Devit Canyon Dam
Dev i I Canyon Dam
Tunnel
Devil Canyon Dam (MargInal l
Devil Canyon dam scheme is superior
T radeoffs made:
Economic advantage of dam scheme
is jUdged to outwe igh the reduced
environmental impact associated
with the tunnel scheme.
E-l0-165
.....
TABLE E.10.19'ENV IRONMENTAL EVALUAT ION OF WATANA/OEV I L CANYON ANO HIGH DEV IL CANYON/VEE DEVELOPMENT PLANS
Environmental Attribute Plan Comparison AppraIsal JudQment
Plan jUdged to ihave the
I east potent I a 1---impact'-
HOC/V-W/OC
ECj~°tJ:~~~~i es
2)Wildlife
a}M:>ose
b}Caribou
No significanT di fference in effects on downstream
anadromous fisheries.
HOC/V would inundate approximately 95 miles of the
Susitna River and 26 miles of tributary streams,in-
cl uding the lyone River.
W/OC wou Id inundate approx imatel y 84 mi I €IS of the
Susitna River and 24 miles of tributary streams,
inc I ud f ng Watana Creek.
HDC/V would inundaTe 123 miles of criTical winter
river-boTTom habiTat.
W/CC would inundaTe 108 miles of thIs rIver-botTon
habitaT.
HOC/V would InundaTe a large area UpsTream from Vee
UTi!i2ed by three sUb-populations of I1IXJse That range
in the northeaST section of The basin.
W/OC would inundaTe the WaTana Cr~ek area uti!ized by
moose.The condiTion of This sUb-popUlaTion of IOOOse
and The qual ity of the habiTaT they are using appears
TO -be decreasing.
The Increased length of river flooded,especially up-
STream from the Vee damsiTe,would result in The
HOC/V plan creating a greaTer potential division of
The Nelchina herd's range.In addition,an increase
in range would be direcTly Inundated by the Vee res-
ervoir.
Because of the avoidance of the Tyona River"
lesser Inundation of resident fisheries
habitat,and no significant di'fference in the
effects on anadrOlOOus fisheries)'the W/OC plan
is JUdged to have less impact.\
Because of the lower potenti al for direct
Impact on 1'OO0se populations within the
Sus ;Tn13,The W/OC p I an is Judged super iar.
Because of The potentIal for a greaTer Impact
on the Nelch Ina carfbou herd,the HDC/V scheme
is considered inferior.
x
c)Furbearers
d)Birds and Bears
CulTural:
The area flooded by the Vee reservoir is considered Because of The lessTer potential for impact on
importanT TO some key furbearers,part icu I arl y red fox.furbearers The W/OC is jUdged to be su per ior.
This area is jUdged TO be roore importanT than The
WaTana Creek area ThaT wou I d be inundaTed by The W/OC
pi an.
ForeST hablti:tt,ImportanT for birds and black bears,The HCC/V plan Is jUdged superIor.
exisTs along the val ley slopes.The loss of this habi-
Tat would be greater wiTh The W/OC plan.
There Is a high potential for discovery of arcJlaeolog-The W/OC plan is jUdged to have a lower po-
kal sites in The eaTerfy regIon of The Upper SusiTna Tent i i:tl effect on archaeolC9ical sites.
Basin.The HOC/V plan has a greater poTenTi al of
affecting these sites.For OTher reaches of The river
the difference between plans is considered minimal.
x
x
x
TABLE E.10.19 (ConTi nued J
Envl ronmenta I Attr i buts PI an Compar i son _Appra I sa I Judgment
Plan jUdged to:have The
least potential Impact
HOC/V------.voc
Aesthetic/
~With eiTher scheme,the aesthetic qual ity of both
Devil CCinyon and Vee Canyon would be impaired.The
HOC/V Plan would also inundate Tsusena Falls.
Because of construcTion at Yee Dam site and the size
of ·the Vee Reservoir,the HDC/V plan would inherently
create access to rrore wi I dar-ness area than WQuld the
W/OC plan.
Both plans impact the valley aesthetics.The
difference is considered minimal.
As it is easIer to extend access than to
I fmiT it,Inherent oc:cess requirenenTs were
considered detrimental and The W/OC plan is
jUdged superior.The ecological sensitivity
of the area opened by the HOC/Y plan r-ein-
for-ces this jUdgrrent.
x
OVEI1ALL EVALUATION:The W/CC plan is jUdged To be superior TO the HCC/V plan.
(The lower impact on birds and bears associated with HOC/V plan Is considered to be outweighed by all
the other impacts which favour The W/CC~lan.)
Notes:
W =Watana Dam
CC =Dev i I Canyon Dam
HOC =High Dev i I Canyon Dam
V =Vee Dam
TABLE E.lo.20:OVERALL EVALUiHION OF THE HIG-i DEVIL CANYONjVEE
AND WATANA/OEV IL CANYON DAM PLANS
AI tRIBUTE SUPERIOR I'LAN
Economic WaTana/Devil Canyon
Energy
ContrIbution Watana/Devil Canyon
Env ironmental Watana/Dev i j Canyon
Social Watana/Devil Canyon (Marginal)
OveraJ I •
Evaluation Plan with Watana/Oevil Canyon is
super lor
Tradeotfs made:t~ne
E-10-168
,I'
Table £.10.21
(lillirolllllelltd tonstrdnt.·-Southern studyArn (Willow to Anchoralllil/roint HlicKenlle)
,..,.,
I
--'o
I
-"0'1
to
Conldor--.-
(AW)
Z
(AOfC)
J
(AfFC)
.Leng'"
,]
38
19
1opoYfaphy/So I Is
!iiio sol1'i'Wllb
seVIII'1I lI_UAtlons
to 0"road trav.l.
IlIIlII VOOd 'yrl.
cultural so h
thst of routI
potenUll1y wet,
tilth severe
lIal tattoos to
off rold trlvll.
10lllf!good Iyrl-
,culturll so Is
SAme IS Corridor 2
lind Use
liIiiliIfrigmrTil
M;r.shlenUI1 usn
nnr 'al.r.propos.d
upltd sUe.MUch U.S.
Mfltt,ry Wdl.,Prlv,te.
Intlll'I'SIl S.lletlod
lind '
Tntt Is 0II1y uhttng
lOll,residential Ind
recreltlona'Irea'i
Susltna Flat.laMe
tletuye;Agrlcultunl
lind sale
No known ex'stlng ROWI
residential Ind recre-
Itlon.l use IrelS,
Including Hlncy Likes.
lakes used by flOAt
planes;Igrlculturll
land .11.,
AesthettcI
fillbroil,'lrallf
trill plnlleHog
IMcept I,on ct.:
Gooding l.bird-
wdchln,areAl
Ii crolltllllS 0'
Slenn '''y,1
crossing 0'
Parks lIwy
Susttnl nits
Sue Refuge.
Idltarod Tra n •
I croulng of
Parh I.,y
lake arel louth
of IlIllow,
Idltlrod Tran;
I crossing of
Parks Ilwy
Cultural Resources I
ArcliiOlolllc sHes-
data void
Artheologlc Iites-
dAta void
·"r,heologlc sltes-
dAta 1I0id
Vegetltlon
tftl,nif$dong
Deception Ck.
Ind It ftoltlnush
a'ver crossing.
extenstve clearing
In upllnd,'ores ted
arllll need.d
Extenstve wetl.ndsi
during needed In
forested lrelS "
Extensive ~tllnds.
elea,rlng needed tn
forested areas
Fish Resources
Sriver alld 28
creek crosslllgs,
Vllullble spawntng
sites,especlilly
sallllllll:
~11t Inl
H,lanlukl Ina
dati void
1 river Ind 8
creek crossings;
vlluable spawolng
sttes ••specl,IIY
11111100:
l.SusUnl II.
dlta void
1 rilier Ind 8
creek cross hl9S i
Vlluable spawning
sites,especl.lly
ullllOn:
1.Susltnl R.
data void
Wlldille Resources
Panes tllrli~
flear Wlterfowl In4
shorebird nesting
Ind 'eedlng Ireas,
Ind irel'used by
brown bear
Passes through or
nell'wlter'owl and
shorebird nesUng.
feeding,Ind _Igra-
lIol\arelS,and areas
used by 'urbearers
Ind brown beir
Same IS Corridor Z
EnvlrOlllllillltll1
Ratlng lJ
._----~-
C
It
F
I.Col5t,l Irel probAbly hIS IliIny sUes,1Vlllibie IIterilture 1I0t
Yilt revlewad.
b.A·rocOWBende4
I:•Acceptable but not recOlI_ended
F •IInl.cceptAb Ie
_J o ]I I J J I j oJ J )}J o ,t J J oJ I
-,
B }~11
J 1 l -,J 1 I l 1 ..
Table £.10.22
invi-"ORUtent.i Constraint$--£.:ntril Study Area fDa.Stte.to Int-erlfe)
length
~!._(KHesl TOI!O!lf.ef/Solls .land Use Aesthetics CultUfal ResoUfces ~l!g@t~tlol!f lib Resourfes Wildlife Resources
[nv Irolllnental
R.tI1l9a__
I
[ADCD)40 C...oues sevenl
deep ralllnesi
.bout 1000'
chage In
elevation;
SOllie wet 50115
tittle existing
ROW except Corps
rll-.;IIOsl1,
Vlll.ge Selection
JAd Private Lands
fog Lates;
Stepha..like;
proposed aecest
road
Archeologlt sites
near lIatana dam sIte,
Stephan Lake and fog
lakes;data voId frOiR
Gold Creel to Devil
Canyon;hlstorte sites
near the communities of
Gold Creelt and Canyon
Wet hods In
eastern third of
corridor;
extellslve forest-
clear 1119 'Ieeded
1 rIver alld 11 creek
crosslnysi valuable
spilwnlng areas,
ekpec lat ly 9rayllnll:
"ata void
UnIdentified raptor nest
located 011 trlb.to
Susltna;passes tllrough,
habItat for:upt 01"5 ,
furbea ...e ...s,wolves,
1ol0 Iver hui,hrolol1 bur,
tarlbou
A
2
.AB£CO)
P1
!...JaAJCf)
I
--'.....,
a
•ABC JIll )
45
41
n
CrosUs sevenl
deep ravines;
abollt 2000'
change In elev.i
sOllie steep
slopes;SOIOO
Iolet soils·
£roues severll
deep nv Ines;
abollt 2000'
changll In
eleVAtion;
SOllie steep
slopes;SIlilH!
IolCt solis
£...osses seven I
deep rav Ines;
>2000'th.nge
In e1ev.tlon;
rOllt Ing above
4000';Sleep
slopes,Sllllle
wet 50115;
sha lIow bed-
rock In IIts,
L ttUe exlsUng
ROW except Crops
rd.and at 0;rec.
and resld,Ire.s;
floltpl.ne Areas;
llOSUy VIIl.ge
Selection .lId
Private LAnd$
No ulsl.lng .ROW
except al ';ree.
areas;float
plane ArUS;
IIUStly VIlI.ge
5e led Ion and
Private landi
resld.l rec.
developmellt In
a...ca of Otterl.
alld old sled rd.
No ex 1st IlIg ROW.
ree.areas and
Isolated cabIns,
lakes used b)'
f10ill planes,
wch Village
5e lect/oll l alld
fOil lakes,
Slepllall lake;
proposed actess'
road;h1g/1
country (PrairIe
..(huHtllA Ck.
drajnlges)alld
vlewsbed of
Ahskl Range
vtewshlld of
Aluh Raoge ..
IlIgh lake;pro·
posed access rd.
fog hles.
Stephan lake;
proposed 'teen
nl;vlewshed of
At ash Ilange
SaRli!.s Corr I dor 1
Archeologlc sjles by
Walaoa daM site,..near
Portage Clt./SUSltlll R.
confluence;possible
situ .Ioog Susltna II.;
IIlsto..-lc sites Ilear
co"~nltills of Gold
(k.and Canyoo
Archeo 1091c s Itesnear
Watana d..slte,
Stephan 1.and fog
lakes.poss Ib te sites
aloog pass between
draInages;data void
between /I and I
lIet Iantts In
eastern half of
corridor;
extensive forest.
c1ear/ng needed
forest-clearing
needed In western
half
SIIIa II well /lnd
areilS In JA
arel;edens tve
forest-clearing
needed;data voId
I ...tver and 11 creek
crossings,valuable
spawnIng areas,
espeCially g...ayllng:
data votd
14 creek trossln9;
valuah Ie spawn 11111
areas.especially
grayllog alld S411llllll:
rndlan RIver
Portage C...eelt.
data void
1 river and 42 creel
crossings;valuable
spawn Inll ....e.s,
espec hlly IIra)'llng
Puses U,;-ough habltlt for:
raptors,Iolate ...fowl,~Iyr.t·
Ing swaos,furbearers,
carIbou,wolves,Iololverlne.
brownbu,-
Goldcn eagle neU along
Devfl Cit.near High L••
active raven nest on Devil
Cit ••passes throu~1 hAb It at
for:r~lo...s,furbeare ...s,
wolves,b...own bear
Golden eagle nest along
Devil Cit.near High l..
ca'·tbou IOOvemenL a...eiI;
passes throu!lt hah Itat
fa ...:r"lltOl's,Iolaterfowl,
furhearers,wolves,
wolverillc,browlI bea...
f
(:
(;
·yft.·-"
a ,A.r el:onnlellded
(;•acceptah Ie but 1I0t ...ecOlllllended
f .•unacceplab Ie
,.
Table E.I0.22 (Cont1d)
Envlron/nenta)Constraints -Central Study Area (Dam Sites to Inlertle)
_~~__Aes~
Ito knoll/lleds t Ing fcJg Lak liS and
ROW;reC ••reas Stephln Lake;
.nd Isolated proposed access
cabins;float rd.;fsuseni
plAne area;8utte;vlewshed
Suslt8a arei Ind of Alask.Range
near I Ire Vlnlge .
Se led 101)Land
-.£!!.Hur41L..R~~f!.Jl!~!:!~.
SaRIe as Corr Idor 4
.__~c:~'!.t~~...1 ~.!Il.J!e~~~~!LC!!~~"
C
f
(Important ba1d eagle
holbltat by Denali IIwy.
and Deadman L.;unchecked
bahl eay Ie nest lIear
husen.Butte;I'asses
through h olb It at for:
r aptors,furbearers,
wolves,wolver"le,
brown bear
Bald eagle nest s.e.of
fsusena Butle;area of
cilrlbou ADvement.passes
through habitat for:
raptors.walerfowl,fur-
bearers,wolves.wolverine,
brown bear
SalllC as torr hlor 6,with
Imjlortant WAterfowl tnd
mlg,..t Ing swan hab \tat
at Stephan Lake
EIIV t1lIlIlIle'lt ..I
J!!~~'-I(e!!~!!r~1._____Rdll!f!l
Sallie ai (orr Idor 4
with Important water fowl
alld ..Igr at 1,,'.1 swan hab It at
"Stephan lake
45 t ..eek cross Ing;
yaluable spawning
areas,especially
guyllng:
data \'old
4l creek crossings;
VAluable spawning
areas.especIally
yr 4y11.ng and SIIhllOl':
datA void
1 river and 41 creek
Cl'os.slngs;valuable
spawning areas,
expec lally '.Iraylln!l:
dilta vo I"
32 creek crossings;
valuable spawning
.reas,espeelilily
grayling:
dah void
htens hie wet-
lauds In Stephan
L.,fog takes,
husena Butte
.r~eas;edens hie
forest-clearing
needed
Wet l.nds In .IA
andStephiln Lake
areas;extensive
forest-cleAring
needed
btenslve wet-
hudsfrolll 8 to
near husen.
Butte;edens've
forest -c I earl ng
needed
Well;lnds Iletween
8 Iud-mountains.
extensive foresl-
clearing ueeded
Same IS Corridor 6
An:heo log Ie s lLes Ileal'
Walana dan.5 ite,fog
Lakes.Stephan lake
and a long /IeadlDan ek.
Archeologle sites near
V.tanl d~site.fog
likes and Stephan L;
data vuld belween II
and I
fOil Lakes and
Stephan Lake.
proposed acess
rd.;high
country (Pralrle-
Chunltna Ch);
husen..Bulle.
vlewshed of
Alaska Range.
fog I.aku;
StephilnLake;
IlIgll L.te;
proposed access
rd;v lell/shedat
Alash llallge
fog lakes;
Stephan lake;
access rd;
scen Ie area of
Deadman Ck.;,
vlewsbed of
Alash Range
Same as Corridor
~
No e~lstlng ROW;
rec.areas IIld
Isohted cabIns;
noat phnll
areas;.Ir stdll
and airport;
lI,ch Village
Selection and
fede...1 land
Same 45 Corridor
6
length
Cordd!:!!-.___(I,tH~l ~!~'Jl!'l/Solh
5 82 C..055e5 seven I
(ADfCJIII.deep rilvlnes;
c111llgeS ·'n
e lent 'on >2000'i
.-out I"y Above
4000';steep
5 lop.1!5;SOIl'e wet
so lis.stlallow
bednlck In ..15
Ii 60 Crosses sever.I
«(BAiJI t deep ..vInes.
cbanges I"
e 1eulla"of
abo!!!1600',
routing above
4000';shep
slopes;some wet
so 1\s;sba 11011/
bedrock in lilts.
n1
I.......
Croues sevenl0773
•(CEPAIIO deep r41V Ines.
--'change In.............elev~tlon of about
1600'.rout Iny
.bove 3000';
steep Slope'j
Slllllll wet sol 5;
.sh.llow bedrock
In mis.
e 90 bosses sl'verai
(COAG.deep rav Ines;
(haoge III
elevation of .wout
1600';rout Ing
Above 3000 I ;
stel'P slopes;
sOllie wet soIls;
,I",\low bedrock
In lit 5 •
»•J J I
"-
j t J .1 it I I J »
}j -1
,I'
I ]1 }j i ~D 1 --1
Tab1e £.10.22 (Cont'd)
[n",trll!l!!!t!!1!4t C!l!!~tr.l!lh -eentr.1 Study A.'el eDam Situ tu InlllrUe)
Llln!.!tb
J~r Idar__(HIIIlS!_lupa1J[lphllSolh Veye!atlon fish Resources
hv Ir unllwn141
_~~~U!!9.-_
9
:UAG)
10
:JAG)
7"'u
C;:JAlII )
I
-'
'"N
12
JA·i;.111l )
95
91
69
70
Croues severl'
det:p n~Ines,
ch4nges In
elev,tlon of about
1600'irlJut Ing
abo~e 3000'i I teep
5 lopes i SIlIIlll wet
50115.shillow
bedrock In.is.
SIllIII!AS torr ldor
8
'roues ieven1
deep ra~Ines'i
cltallges In
elevaUon of
1000';rout Ing
above 3000',
ste~l S'opesi S~e
wet solh;
shlllOlol bedrock
In mls.
Sime as Corr Idllr
11
land Use
SIlIIe u Can Idar
B
No ulstlngROlli
rec.arus and
Isolated cabIns;
flolt plane
areas.Ilrllrlp
.nd airport.
DUtly Vllhg8
SelecllOll a"d
federal Land
No IlKIstlng ROlli
rec.a.-eiaS and
Iso lated cab Ins;
fllIat plane
arels i lIIllilly
VIllage Selection
iand Prlv.te land
Mo eKlstlngROUi
rec.areas and
Iso lllled clb Ins i
float plane
area,musll1
VI'I4ge Selection
and Pr Ivate land
Aestlletln
fog Ulles:
stell"a"take,
'lfoposed .ccess
rdihl1jh countrl
('ralrle ,"d
(hunHna th.);
Peldolan etl.,
v Iewslled of
Alaska Range
IIlgll 1 likes Met;
propose<!,ccen
rd.;~a4ian Ck.
draln.ge.;"Iew-
shed It Alaska
Ranll8
High t.akes areai
proposed access
rd,;vlcwslled
Ilf Alaskl Ranllll
IIlgII lakes arel;
prol/osed access
rd.;Tsusena
Buttei vlewslted
of Alaska Range
CultUrAl Resources
Same as (orr ldar 0
Arclleologlc sttes
ne ....llitana d.slie
and along Oea~Gan Ck..
AI'cheo lug 11:5 Ites
near Watana d~slle
Archeolog'c sUe
lIE ar Wiltana dillll 5 lle i
poss.ble sItes along
PISS belween drainAges
Wetlands In
stephan 1./fog
Lakes Ire.,,;
eKhnslve fures~·
cleartng needed
Slaan weUands
In JA Irea;
eXlenslve forest-
clearIng needed
Small wet lind
areas tn JA
.ru;SOllle
forest-clelrlng
needed
5laall wetl and
areas In JA
area;fairly
edenshe
forest dear Ilig
needed
1 river all,l 48 creek
truSS lngs i vat uab Ie
spllwn In,areas,
expecla Iy grafllng:
data voId
1 river and 41 creek
crosslngsi valuable
spawning .reas,
expect"l)'grayling:
d..ta voId
36 creek cross lngs ;
val uab Ie spawn Ing
areas,especIally
graylIng and sal~n:
data wId
40 creek cr.usslngsi
valuable spawning
areas,.espec I al I)'
grayling and sa IlIOn:
d4la voId
WildlIfe Resuu~ces
Sallie IS Carr Illor 8,
wllh Imporlant waterfowl
and 1Il1yr allng swall hlb Ihl
al Stephan Like
Golden eagle nest along Pev II
Ck.nellr HlgII lakei unchecked
bald eagle nest nelr lsusena
Bulle,.rea of tilrtbou AKwe-
.Jenti panes through hablUt
tor:rtptors,waterfowl,
fll~bearers.browA bear
Golden eagle llesl along
Pevll Ck.near IlIyh l~kei
bald eagle nest s.e.of
Tsuse"a 8utte;passes
through hNlllal for:
raplurs,furbearers,
bro.."bellr
Golden ellgle nest along
Dcvll Ck.near IlIgh lake,
passes tllrougb habllat
fur:r aplors.furlJearers.
wo hes,hrowo bear
r
c
r
,.
Table f.10.22 (Cont'd)
(nvlronment"ConSlralnts -Central Study Areo (DilRJ Sites to Intertle)
L4nd Use Aesthetics
lin Ident Ir ted uptor nest A
on tributary til Sus Itna,
passes thrllughhabUat for:
raptllrs,furbe.rers,wolves.
wolver'lne.browR bear,
caribou .
Corridor
Jl
(ADCr)
length
J~!.lest
4.1
T0l!0gral!hy/So Us
(rosses sevenl
deep ravInes;.
IIbout 1000'
(!laRge In
elevat lOR;some
wet solh
No known exist Ing
ROW e~cept .t f;
rec.are.s;float
pbne OIre6S;
resld.and rec.
use near Oller
l.and old sled
rd.;Isohted
ublns.mostly
Village Selection
land;SOllie P....v6Le
lind
Fog Lakes.
Stephan l.;
proposed aecess
rd.
Cultord Resources
Are:heo log Ie sites near
WatOlni di\lll.site,.
Port.ge Ck./Susltna A.
e:onfluence.Stephan l..
Ind fog L'ahs,Ilislorle
st tes;Ilear eOll11111n I ties
of Canyon and ljo Id Ck.
,.
Vl!g~tilt Ill.n
Wet.!ands In
eastern third
of corridor;
extenJi Ive
forest-clear'ng
needed
fish Aesour.ces
15 creek crossings;
valuable spawning
areas ,especially
grayl tny aRd ulmon:
Indian River
Porhge Creek
data voM
IIlhU Ire Resources
fnv Iromnental
~_A~~_!!!!l~_
fTl
I........
a
I-.-.....I
W
14
(A.leu)
41 Cros ses deep
rllvlne It Dullu..;.bout 2000'
choflgc In
elevation;routing
•bove 3000';some
steep slopes;
sOllie wet 50115
little exlstlng
ROW.e~ccllt 0 lei
Cor'ps rd.and
.t 0;rec.arellS;
Iso hted cab ins;
fillleh Village
Seletllon bnd;.
some Private
lalld
Vlewshed of
Alask.hll!le
and IlIgh Lllke;
proposed access
road
Are:heo log Ie:5 Ites hy
"dana d~n site.
possible s~tes along
Susltna A.;historic
sites Ilear conDIlIR It les
of Canyon and Gold Ck •
Forest-e:learlng
fleeded hl westero
haH
1 river alld Hi e:reek
cross tnys;valuable
spawnlll\l areas.
especially grayling:
data void
Go Idell eagle nes t In Pev II
Ck./III!lh .dke arlla;active
fIIvell nest lilt Dev tiCk.;
passes throu!ll tlabltat fllr:
raptors,furbearers.wolves.
browlI bear.car Ibou
"
,15
(1I0fef)
45 Crosses several
deep ray Ine5;
.hout 2000'chllnge
In elevat Ion;
sOllie wet 50 lis
No known existing
ROW except at f;
ree.are,s;float
plane OIreas.
resld.and rec.
use Ilear Otter
l.and old sled
rd.;ISlllatel.l
e:ab Ins;1II0stly
Vi Hage Select 1011
land wit'"50lne
Pr Ivate land
fog lakes;Same as [orrldor 13
Stephan Lake;
proposed access
rllild;h1l1h
country.(Prairie
and Chonllnl [ks.
dnlnages);
vlewshed of
Alaska Range
Wetlands In
eastern half
of corr Idoq
extens Ive forest-
clearing needed
15 creek cross logs;
valuable spawnlllg
.rellS,especially
grayl ing allel salmon:
Indian Alver
Portage Creek
data void
Impor tant waterfowl and
mlgrattng swan habitat
at Stephan L.;passes
lhrou!#l habitat for:
rail tOr's ,waterfowl.
hu"bearers.wolves.
wo I vcr tne.brown bear.
Cal"Iboll
f
J )I J I t t ,I J I .1 J ;1 j
L )}.1 1 1 )1 l
Tabl e LI0.23
1
Envtml'dllCntc!Constraints -HerU!!m!St!!dy Area-(l!cilly to faIrbanks)
Corridor--.---(AUC)
length
(Hl1es)
~9o--
Topography/Salls
!ome wet sol~
wI til severe
limitations to
off-rOAd traffIc
Land tlse
Atr~
resIdentIal al-eas
and isoht~d cablnsi
some U.S.MilItary
Wltkdrawl and Native
land
Aesthetics
J cross tng5ilr
hrh lilly;
Nenana A.-
scenic area
Cultural Resources
Archeo1ogtc stIeS
probable stnce
there Is a lnown
sIte nearbYi datI'
voId
Vegetalton
Exlens tve we'~t-1a-n-d~s-,
forest dearh.g needed
lila Inly north of the
Tanana RIver
fIsh Resources
TrIYcr and 40 creeli
crossin9Si valuable
spawnIng s!tes:
hnMa RIve.'
data voId
a [uvlronme
WIldlife Resources Ralln
J'asseSfiirou~--i-
near prlure habitat
for:peregrines,
walel'fowl.("rbearers,
moose;
passes through or
m~I'r IUII,orta"t
habllat for:pere-
grlnes,golden eagles
I.Source:VanBaHenberghe personal cOlll1lUnlcallon.J>rlme habltilt ~
IIIlnlllllJln alllOullt of Ialld necessl'ry to provide I'sustaIned yIeld
for a species;bned IIPOII knowledge of that species'needs from
experience of ADFIG personnel,Important habitat.land whIch
AIlf&G considers not as critical to a spedes as Is PrlDle habltd
but Is valuable.'
b.A ~reeOrnDCndcl'
(:~aceelllable but 1101 prelened
f •u,uccept,wle
2
(AIlOC )
fTl
I
-Jo
I
-'......
.p.)
(Af.lIC)
4
(ml
-06
115
105
Severe IIl11ltltlons
to off-road tnfflc
In wel 50115 of
the nals
Chlnge In elevltlon
of about 2500';
sleep slopes;
shilliow bedrock In
mts.;severe Ilmlt-
atloJls to off-'I'old
tranlc In the
nats
San~IS CorrIdor )
No exIsting ROW n.
of Browne;
scattered resIdent III
Ind Iso Ia ted
cablnsi alrstrlpi
fort Wainwright
HI I I tary Reser-
1I1It Ion
No existing ROW
beyond nealy/Cody
Ck.confluence;
Isolated cablnsi
Ilrstrlpsi fort
WainwrIght MilItary
Re~ervat1011
AlrstrlpSi Isolated
cablnsi fort Wain-
wright III lllary
Resel-valton
J crossings of
Parks lilly,
III gil v Is 1M IIty
In open flats
I crossIng of
Parks IlwYI
Illgh visIbilIty
ln open nats
Itlgh vlslblltty
In open nits
Dry Creek
archcologlc slle
near Ilea ly i
Ilos51bte sites
along river
crossIngs;data
lIold
try Creek
archeolo~lc sIte
,nul'lIealy;
rosslble sites
neu Japan lit 11 s
and In lhe lilts.,
datil voId
Archeologlc sites
near Pry Creek and
fort \la Inwdyht,
possible slles near
lanana RIver;data
,void
Probably extensive
wetlands between
Wood and Tanana
AlveI'S;edens Ive
tares t clear-Illy
needed R.of
hnanl'River
frobabl,extensIve
wetlands between
Wood and lanana
RIvers,extensIve
forest clearing
needed n.of
Tanana River;
dati l.cking for
southerll Ilart
Probably extellslve
wetlands between
Woud lind hnana
AlveI'S
5 rIver and 44 creek
crossings;valuahle
spawnIng s Itcs:
Wooll River
data voId
)rIver and 12 creek
crossings;vl'luab'e
'sl'aWlllng sI les:
Wood IIlver
data voId
J river and 60 creek
crossings;valuable
spawning sItes:
Wood Aher
data voId
Paues through or
near rwlmehabl ht
for:peregrines,
waterfowl,f"rbear~rs;
passes through or
near Important habitat
for:golden eagles,
other raplors
Passes throug"01',,:<-
near Ildme ha"l hte-"
(or:peregr hllis,.
waterfowl,furbel'rers,
urlboll.sheeI';
.,asses thruugh or nul'
hillort<lllthabltat for:
golden eagles,browlI
bear
f'ilsses lIn'ollgh or
nea I'prlDl!!Ilab Ita t
fOl-:llereyl'lnes,bald
eagl es,wa IeI'fuwl •
furbearers,caribou,
sheerl;
passes through or
nea,-1"II,orld"t habitat
for:golden el'gles,
brown bear
f.
r.
E-l0-175
-
-
TABLE E.10.25:ALASKAN GAS FIELDS
r
I
Locat!on/FI~ld
North Slope:
Prudhoe Bay
East UmiaT
Kav ik
Kamik
South Barrow2
Cook I ntet:
Total:
1
Remaining Reserves
Gas
(bi Ilion cubic feet)
29,000
Unknown
lh known
lhknown
25
29,025+
Product
Dest Inat ion
or Field
Status
PI pel ine construction to
Lower 48 underway
Shut-In
Shut-in
Shut-In
Barrow res i dent i al and
comnerci al users
Albert Kaloa
Beaver Creek
Bel uga
Birch Hill
Falls Creek
Ivan River
Kenai
Lew!s River
McArthur Ri ver
Iobq.uawki e
Nicolai Creek
North Cook Inlet
North Fork
North Middle Ground ShJal
Stal"'l ing
Swanson River
West Forel and
West Fork
Total:
Notes:
~
SOiree:Reference ( )
Lh known
250
767
20
80
5
1313
lhknown
78
None
17
1074
20
125
23
300
120
1
4189+
Shut-In
Local
Bel uga River Power PI ant (CEA)·
Shut-in
Shut-in
Shut-i n
LNG PI ant,AnchorEge and
Kenai users
Sh ut-j n
Local
Fi eld Abandoned
Granite pt.Field
LNG Pl ant
Shut-in
Sh ut-i n
Kenai users
Sh ut-ln
Shut-in
Shut-I n
,-
(l)Recoverable reserves estimated to show m~nitude of fr~l doni y.
(2)Prod uc i 09.
E-l0-176
TABLE E.10.26:ALASKAN 0IL FIELDS -
LocaTioo/Field
North Slope:
Prudooe aa/
Simpson
t.ynu
Umiat
Total:
1
.Rema in log Reserves
Gas
(million barrels)
8,375
Lhknown
Lhknown
Unknown
8,375+
Produ:t
!JeST inat Ion
or Fiel d
STatus
P1 pel Ine 10 Val dez
Shut-in
Shut-in
ShuT-In
-
-Cook Inlet:
Beaver Creek.
~an i te Po lot
McArthur Rive.-
Middle Ground St-oal
Redoubt Shoal
Swan son River
Trad ing Ba'(
Tota!:
Notes:
Soiree:Reference ( )
o
21
118
36
None
22
4
198+.
Refinery
cri ft River Terminal
cr I ft River Term Inal
NI kiski Tennlnal
Fi el d Abandoned
NI kiski Terminal
Nikiski Terminal
-
-
(1)Recoverab Ie reserves est imated to st-ow magn itude of ti al doni y.
(2)Produc I ng.
E-1O-177
-
lABLE £.10.27:SULFUR DIOXIDE EMISSIONS FOR VARIOUS TECHNOLOGIES
Technology
Steam EI ectr ic
Oi I (a)
Gas
Combustion lurbine
all
Gas (b)
Emi ss [on Rate
(lb/106 Btu)
a.20
0.0006
a.30
Annual Emissions at 75%
Load Factor (1ons/Yr)
Faci I itt Size (MWe)
131 329 1314 2628 3942
o 1 4 8 12
269 673
(a)New S:>urce Performance Standard.
(b)Negligible.
E-10-178
TABLEE.l0.28;PARTICUI,.ATE I4\TTER EMISSIONS FOR VARIOUS TECHNOLOGIES -
Technology
STeam EI ectr Ic
01 I (a)
Gas(b)
Combustion Turbine
Oil
Gas (c)
Gni S5 ion RaTe
([b/106 BTU)
~03
~01
~05
Annual Emiss ions at 75%
Load Factor (Tons!Yr)
Faci I ity Size tMWe)
20 49 197 394 591
716 66 131 197
46 125
(a)New S;)lrce Performance Standard.
(b)Typical.
(c)Neg I i9 Ib Ie.
£-10-179
TA8L~E.l0.29:NITROGEN OXIDES EMISSIONS FOR VARIOUS TECHNOLOGIES
Technology
Steam EI ectr ic
01 I (a)
GasCa)
Combustion Turbine
01 I
Gas Lb )
Gnl ss ion Rate
(I b/l06 Btu)
a.59
Annual Gnisslons at 75%
Load Factor (Tons/'fr)
Fac j I irY Size (MWe)
197 493 1971 3942 591 3
131 329 1314 2628 3942
530 1272
r
Ca)New SJurce Performance Standard.
Cb)Comparable to oil.
E-l0-180
TABLE Eo Hl30 W,T10W,L AMBIENT AIR QU'\LITY STANffiRDS AND ffiEVENTION (f
SIGNIFICANT DETERIORATION INCREMENTS FOR SELECTED AIR POLLUTANTS
National Ambient Prevent Ion of 51 gn I f Icant
A Ir Quality Deterioration Increments
Standard Class I ClasS II
Pollutant 3-11 (a)24-h(a)Annua I 3-h 24-h Annua I 30-h 24-h Annual
Total Suspended
Part Ic ul a!e Matter tbne 150(b)60(b)3(c)l'bne 37 19 lIbne 10 5
(g/m )260 75
Sui fur Olox Ide
(g/m3 )BOO'b)365(d)ao(d)512 91 20 25 5 2
Nitrogen Dioxide
(g/m3 )None t-bne 100(d)N/A N/A 1'4/A N/A N/A N/A
lTl
Carbon Mo~oxlde(e)I
-'a (mg/m )None N/A N/A N/A N/A N/A N/A
I
-'
CO
-'
N/A -Not appl leab Ie (no standards have been Issued).
(a)Not to be exceeded more than once par year.
(b)Sec~ndary or wei fare-protecting standard.
(c)Annual geometric mean,advisory Indicator of canpllance.
(d)Primary or health-protecting standard.
(e)Carbon monoxide pr ImarY3ambient air quality standar~s are as fol lows.The val ue not to be exceeded more
than 1 hr/yr Is 40 mg/m (~ay be changed to 29 mg/m ;the val ue not to be exceeded IOOre than one 8-h
per lod per year lsI 0 mg/m •
...
:J c,}I J I )!I ct I J )J !
1 J })1 1 --,--J ;1 ])1 1 )
TABLE E.IO.31 W\TER QUALITY DATA fOR SELECTED ALASKAN RIVERS (a)
Silica Iron Ma ngana sa Cal c I urn Magnes I urn Sod J urn Potas sl urn
Rl var /locat I on Stat Ion No.Flow (cfs)(!!!S/I )
(mg/I)(mg/I)(mg/I)(mg/I)(mg/I)(mg/I)
Copper River near Chitina 15212000 6,100 14 ----36 ~3 12 I.6
159.000 8.5 --U 02 23 3.5 4.3 ao
Matanuska River at Palmer 15284000 11,600 4.5 U 02 --28 1.8 3,8 Q9
566 cd (}01 --44 4.8 8.9 (}9
Susltna River at Gold Creek 15292000 34,000 5.7 ----12 1.4 3,1 I.3
1.960 11 U19 --34 4.5 11 2.4
Sus I tna RI ver at Sus I tna Stat Ion 15294350 6,700 10 Q 09 U13 26 4.2 7.1 I.5
148.000 3,6 a.07 0.85 17 1.3 1.8 1.5
Chena River at Fairbanks 15514000 10,200 &4 1.7 (l 75 12 1.3 1.I 1.1
182 23 3.2 UB2 36 7.6 4.9 2.8
rrI
I Tanana River at Nenana 15515000 4,740 19 54 10 4.6 49--'----
0 34.300 7.4 ----24 5.0 1.7 1.9I
--'co Nenana RI ver near Heal y 15516000 491 8.2 ----36 10 5.6 46N8,750 4.0 (l55 --16 3.6 '1.7 L4
Gu I kana RI ver at Sourdough 15200280 286
6,130
Tal keotna River near Tal kaetna 15292700 1,930 7.3 ----19 1.2 8.3 1.0
19.600 5.I ----8.1 1.0 a6 Q 5
Yukon RI ver at Ruby 15564800 345,000 &2 (l 19 Q 02 27 &1 42 1.9
26.9(1)12 Q 39 Q 02 46 10 3.9 40
Chakachutna River near Tyonek 15294500 6.640 5.3 0.03 Q 01 ~I '1.1 1.4 1.5
15.100 5.3 (l94 Q 05 14 1.8 1.5 1.7
Skwentna River near Skwentna 15294300 6.760 11 ----17 5.0 4.4 Q9
1.330 13 ----26 4.3 7.7 1.7
Lowe RI ver near Va I dez 15226500 --5.0 ----26 0.8 1.2 47
390 1.0 U 04 (l02 22 1.0 1.4 2.5
Fortymlle River near Steel Creek --1.100 11 (l08 --20 7.5 4.6 I.2
(a)Adapted from U.S.Go So Water Illta Report AK-77-1 and U So Go 50 ~en PI I e Report 76-513.
TABLE E.10.31 wo.TER QUALITY DATA fOR SELECTED ALASKAN RIVERS (a)(Contd)
SII lea Iron Manganese Calcium Magnesium Sodium Potassium
£'t I ver/l.ocat I 00 Station No.Flow (efs)(mg/I)(mg/I) (mg/I)(mg/I)(mg/I)(mg/f)--!mall )
Copper RI ver near Gh I tina 15212000 116 26 18 0.9 ----174 12
78 15 ~2 0 ----98 7.6
t4atanuska River at Palmer 15284000 61 29 45 nz ----~10
·100 41 13 a.25 ----169 a 1
Susltna River at Gold Greek 15292000 36 nO 4,,0 a.14 ----52 n8
98 12 29 0.11 ----152 ao
SU51tna River at Susltoa Station 15294350 82 15 13 n 24 no --116 6.9
59 13 42 a.05 1.1 11.3 64 a I
Chena River at Fairbanks 15514000 30 10 a.7 a.27 ----54 10
rn 140 13 4 1 a.52 -- --
165 46
I.......Tanana River at Nenana 15515000 173 33 44 a.30 ----212 7.50
I 72 34 45 0.10 ----In 1.2
-'
();)
Nenana River near Healy 15518000 102 51 ~O nil 169 10w----
57 14 1.1 a.09 ----74 10
Gul kana River at Sourdough 15200280 110 ----a.15 a.03 I a.1 --7.5
40 ----a.04 n15 11.0 --1.1
Talkeetna River near Talkeetna 15292700 52 10 12 --0.00 10\.1 91 7.7
28 46 46 n 20 n 08 11.7 37 48
Yukon River at Ruby 15564800 94 1.4 n2 n04 ----113 16
165 25 1.3 n 23 ----183
GhakachutnaRlver near Tyonek 15294500 26 12 40 n 00 ----46 7.1
26 11 I.4 n 0:S ----51 15
Skwentna RI ver near Skwentna 15294300 52 20 nO a.05 ----91 7.4
77 24 12 n18 ----130 1 I
Lowe River near Valdez 15226500 57 ~2 n8 n 32 ----100 7.6
46 22 1.2 a.34 ----17 13
fortym 11 e RI vel'near Steel Creek --65 37 ll5 a.47 ----116 14
)..J •"J ~.J ••!t .cl I .J ,,»)•I
i""'",
TABLE E.l0.32:FUEL AVAILABILITY FOR WOOD AND MUNICIPAL WASTES
Railbelt Da ily Tons Wood Fuel Mun ici pal Refuse
Region (Tons/Day)(Tons;Oay)
Greater Anchorage 200 -600 400
Kenai Pen insul a 60 -180
Fairbanks 10 -30 150
Nenana 40 -140
E-10-184
TABLE F.10.33:APFROXII4ATE REQUiRED m;\PERATlRE cr:e::OTHE~AL FLUII))
FOR VARIOUS APPLICATIONS
"C
200
190
100
Saturated 170
Steam
160
150
140
130
120
110
100
90
80
Hot 70
Water
60
50
40
30
20
Evaporation of hlghl y concentrated solllt Ions
Refrigeration by armonla absorption
Digestion in paper pul p (Kraft)
Heavy water via hydrogen sulfide process
Dryl ng of di atom~10 us earth
Dryl ng of fl sh meal
Dry i ng of timber
Alumina via Bayer's process
[)-ying farm products at high rates
Canning of food
Evaporaton In sugar refining
Extrcx:tion of salts by evaporation and crystallization
Fresh water by distil fat Ion
Most mUlti-effect evaporation;concentration of sal ine
sol ution
Dry!ng and CIT Ing of aggregate 51 abs
Dry i ng of organ Ie mater i al s.seaweeds,grass,
vag etab I es,eil:.
Wash I ng and dry i ng of.woo I
Oryi ng of stock fi sh
Intense de-Ie I ng operat Ions
Space-heating (bull dings and greenhouse)
Refr igeratlon (lower temperature limit)
An Imal husbandry
Greenhouses by combined space and h:Jtbed heating
Mushroom grow j n9
Sal neology
So II warm I ng
Swimming pools,biodegradation,fermentations
Warm water for year..,.ound min ing In cold cl imatas
De-icing
Hait::hing of fish;fi sh farming
E-10-185
Convent lanai power
product Ion ,...
-
'~fI B i l ..-1 1 --]1 1
COMPUTER MODE LS
TO DETERMINE
LEAST COST DAM
COMBINATIONS
DATA ON DiffERENT
THERMAL GENERATING
SOURCES J
-----'--IJ COMPUTER MODELS I
TO EVALUATE
-POWER AND
ENERGY YIELDS
-SYSTEMWIDE
ECONOMICS
ENGINEERING
LAYOUT AND I •
COST STUDIES
SCREEN
PREVIOUS
STUDIES AND
FIELD
RECON NAISSANCE
CRITERIA
ECONOMIC.
ENVIRONMENTAL
SOCIAL
ENERGY
CONTRIBUTION
WATANA/DEVIL
CANYON
PLUS THERMAL
LEGEND
~STEP NUMBER IN
STANDARD PROCESS .
(APPENDIX A)
ADDITIONAL SITES
PORTAGE CREEK
OIS HIGH DEVIL CANYON
DiS WATANA
OBJECTIVE
ECONOMIC
WATANA I DEVIL
CANYON .
.,HIGH DEVIL.
CANYON I VEE
HIGH DEVIL
CANYON I WATANA
..
CRITERIA DEVIL CANYON
ECONOMICS HIGH DEVIL
ENVIRONMENTAL CANYON
A WATANAS~!t:NATIVE SUSITNA nr
ENERGY VEE
CONTRIBUTION MACLAREN
DENALI
GOLD CREEK
DEVIL CANYON
HIGH DEVILCAN'fON
DEVIL CREEK
WATANA
SUSITNA m
VEE
MACLAREN
DENALI
BUTTE CREEK
TYONE
SUSITNA BASIN PLAN FORMULATION AND SELECTION PROCESS
.FIGURE E.lOI
~-
154"152·ISO"14S"1440 14Z"
@ I \
I
0
i
scA~e;.""~<:S (APPFHlXIMATeI
&8 .0
a·25 loIW 2S'100MW->leo 1;Wi/
,.STFl'ANDLINE L.13.WHISK'RS 26.SNOW 39.LANE
2.LOWER 8EI.UGA 14.CO"'L 21.KENAI LOWER 49.TOKICHITN",
3 •lOWER LAK-E CR.15.CHULITNA ZB.GERSTLE 41.'i'ENTNA
4.At.L ISON cR.16.OHIO 29.TANANA R.42.CATHEORAL SlUFFS
-5.CRE:SCE;NT LAilE 2 11.LOWER CHULITIiA 30.8R1JSKASNA 4J.JOHNSON
6.GRANT LAKE 18.CACHE 31.KANrlSH"A R.44.BROWNE
7.MCCLURE BAY ,g.GREENSTONE 32.UPPER BELUGA 45.JUNCTION IS,
8.UPPER NfLWE JUAN 20.TALK£HNA 2 33.COFFEE 46 •"",;,ON IS
9.POWER CREEK 21.GRANITE GOFIGE 34.GULKANA R.47'.fAZ ILNA
10.SIL\lE!'l l.AKE 22.KEnNA 35.(LI..lTiNA 48.KENAI LAKE
11.SO!-OMOM GUl.CH 23.SHEEP CREEl<36.,RADLEY L"'KE 49.CHAKACHA","'"
\2.ruSiUMENA 24.SI<:WENTNA ~7.HICK'S sm;;
25.fAL"CHUUTItA 38.LOWE
SELECTED ALTERNATIVE HYDROELECTRIC SITES FIGURE E.lQ2
3
1954
948
A L~:·~'JES!UL '.18A:!!.6"-=""=1 ·_24_5Jt!.!~.!!.rt'Ji.!!'.:rti.!i.!r.~M:!.!:---.-;-1_0_0;'2'.I.,""·.
i
2i.I.I=I.I[I.I.·.,-):.['.:......:-:-54 ...
I gaO 1990 2000 2010
~
2 2ooo,
>-
!:::u
~,
«u
10 LEGEND
a
:t:
~6
ooo
>-
(!)
~4
Z
W
2
D·HYDROELECTRIC
If~lJt~COAL 'FI~eD THERMAL
[2]'GAS FlREO THERMAL
•OIL FIRED THERMAL(NOT SHOWN ON ENERGY DIAGRAM)
NOTE:RESULTS OBTAINED FROM
OGPS RUN L FL 7
KEETNA
CHAKACHAMNA
EXISTING AND COMMITTED
0 .......-....1-----------------------------........"-:""--.1/980 1990 2000 2010
TIME
GENERATION SCENARIO INCORPORATING THERMAL
AND ALTERNATIVE HYDROPOWER DEVELOPMENTS
...MEDIUM LOAD FORECAST'".FIGURE E.lO.3
j ]j i 1 ------]1 -I 1 -1
DATA ON DIFFERENT
THERMAL GENERATING
-.SOURCES
n ~
StTE
SEL.ECTION
-PREVIOUS
STUDIES
CRITERIA
ECONOMICS
ENVIRONMENTAL
4 ITERATIONS
ENGENEERtNG
LAYOUTS AND
COST STUDIES
OBJECTIVE
ECONOMICS
COMPUTER MODELS TO
EVALUATE
-POWER AND
ENERGY YIELDS
•SYSTEM WIDE
.ECONOMICS
CRITERtA
ECONOMICS
SNOW (S)
BRUSKASNA (8)
KEETNA (K)-
CACHE (CA)
BROWNE (8R)
TALKEETNA -2 (T-Z)
HICKS (H)
CHAKACHAMNA (C H)
ALLISON CREEt((AC)
STRANDLINE LAKE (5L)
•CHI K
-CH,K.S
•CH.K,S,SL,AC
-CH.K,S,SL,AC
-CH,K,S,SL.AC.CA,T-2
CH ,K,S a THERMAL
LEGEND
•...1.:\STEP NUMBER
IN STANDARD
PROCESS
(APPENDIX A)
FORMULATION OF PLANS INCORPORATING NON"SUSITNA HYDRO GENERATION
FIGURE EJO.4
l I )1 1 1 )J ]])I
_/",.-----
".-..,J---'"..,J .FIGURE E.IO.5
30 MILES
tAl.KEETNA RIVER
.::;...--.-
=::.=.=__=,_==-=--115
OAMS1TES PROPOSED BY OTHERS
(APPROX,)
o
SCALE L..-:::=--_
f...._./""-.-.....:""I ""'\\If.~~®l.EGEND ()J
.N ,..,..UPPER SUS/TNA
.TYONE ...OAMSITE C)X-"'.I4TERSHED 80UNDARY
(fASf fC§K /'""'"'\
/«57 ...\
(FORK
~?J~",I ~'"_
1"\"""f.~
"\,i .-""-,/"\1
\
BORROW I QUARRY L.IMITS
SCALE:0 ..I MILIES
~<>I -_.\.'
\')",~-J -1 .;.'.....,-.",;~(.,f!(;
~"--":,,t-;;=#.'
,,/'I'
J>(
LEGEND
C::~=:;]
NOTE'
I.MAP IHOE':SHOWN ON FIGURE:6.1
.--v;!!'>'/
LOCATION MAP
~/f--""",!!.,,
ot....\'~1\\,..#/~...~1:;\
~
'./?.~.eTC]
-y.c~~.s..-'..~~~'.,~.4~~~fA~/?.--:::..~~riE -~FI.-i ...J •\'l'~!~i \[!i r
,....:1;;/~.
;Y rfiORR~TE E '.\.
LYBORROW S·./'.,)('-Z ~.......
SITE D I
/'\~\.\~.~..~,~~:~,~
~"."""~."';""""•.j.,,;,,'.,"i~'.
/1/
II/BORROWIt"",~II\Jl
\
@
WATAHA
BORROW SITE MAP
FI GURE E.IO.6 I
,'./OOQ'~1.a
,'.500'FlGUt£7U
FIGURE E.lO.7
1000 ZOOO Fl£T==
SCALE AFTE.R IlEDUCTIOH
DONlO"Sltt &
OPLORATIOH '-·500'AGURl!!l1
DAMSlTE'TOfI r::I e£DROCIC 1'.500'f'lIUft!.12
GE;OLOGIC IILlP 1'·500'flGl.lM 1.S
T.&ILRAeE MEA 1·.1000'fIGIUIIlI!:1.14
QU"'R~Y 5IT£/(
*
INDEX
BLOCK AREA COVERED *SCALE FGURE
NO.REFalEN':E
NOTES
I.TOPOGRAPHY AHD DE.TAILI SMQW"OM INDlJV1DUAL
fIIiiURE'!.
CD
®
®
@
'CA\,.I
LEGENDG !IORROW I QUARRY SITE LIMITS
,,
~()--~--COlDCflIDC.F~_~'t ,-~I'is I -I ....~""":
lIIA"""1"'.-'...E"~1 S~~I""lIr-,\~~fif 18'~!J \'.~r--I"1\-.JL J.~~"3 ')JOO"'L"","~)---!JAK.....-.-ok'(f./I ..............-!V
At:J'f \--);~/
\~&'-'1rP-"'7-~/ii~.;!F'-'v -Yo.•.'L'•Q~~I '-.;j SCALE
foIAP
§I
g'
wi
~
~.
j,
§
DEVIL CANVON
INDEX MAP
~~
,.'-211l!OO
~
N !..211J)OQ
•s.ztZ~
flJ.U~_
.....0.000
•
.,..,..000
N UXl,COO
..3231.000 ~
......-
..-
--1 J 1 !J J 1 ]1 J 1 1
I
62°N __
L
_
®
ILIAMNA LAKE
j::
Q
N
10
POTENTtAL TIDAL POWER SITES
~
Q
co
V
SITE LIST
I.POINT MACKENZIE
2.EAGLE BAY
3.RAINBOW
o 37 74 MILES
KAU E !
(APPROX.)
FIGURE E.10.8