HomeMy WebLinkAboutSUS10002PRE-AUTHORIZATION ASSESSMENT
OF THE
SUSITNA RIVER HYDROELECTRIC PROJECTS:
PRELIMINARY INVESTIGATIONS OF
WATER QUALITY AND
AQUATIC SPECIES COMPOSITION
SPORT FISH SECTION
BY
JAMES C.RIIS
FISHERIES BIOLOGIST
ALASKA DEPARTMENT OF FISH AND GA~E
SPORT FISH DIVISION
ANCHORAGE
TABLE OF CONTENTS
Page No.
LIST OF TABLES i i
L1ST OF FIGURES i v
INTRODUCTION 1
STUDY AREA 2
MATERIALS AND IVIETHODS 2
RESULTS AND DISCUSSION 3
FISHERIES 3
BENTHOS 8
LIMNOLOGY 11
CONCLUSION 44
ACKNOWLEDGMENTS 44
POTENTIAL IMPACTS 45
RECOMMENDATIONS 47
LITERATURE CITED 49
APPENDIX 50
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Number
1
2
3
4
5
6
7
LIST OF TABLES
Title
Results of Winter Fry Sampling in t1ainstem Susitna,
Devi1 t s Canyon Project,1975.
Fish Collected in Sloughs Between Talkeetna and
Portage Creek,Devil 's Canyon Project,1975.
Age Analysis of Grayling Sampled from Portage Creek,
Devil's Canyon Project,1975.
Length Variation of Grayling Sampled from Portage
Creek,Devi1 's Canyon Project,1975.
West Side Susitna River Chinook Salmon Escapement
Surveys,1975.
East Side Susitna River Chinook Salmon Escapement
Surveys,1975.
Aquatic Invertebrates Collected in Clearwater
.Tributaries of the Susitna River,Devil's Canyon
Project,1975.
Page~
5
7
9
9
10 -
10
12
8
9
10
11
12
13
14
Aquatic Invertebrates Collected in Susitna River,
Devi1 's Canyon Project,1975.
Maximum and Minimum Daily Water Temperatures from the
Susitna River at Parks Highway Bridge,Devi1 's
Canyon Project,1975.
Maximum and Minimum Daily Water Temperatures from
Willow Creek,Devil's Canyon Project,1975.
Maximum and Minimum Daily Water Temperatures from Birch
Creek,Devil's Canyon Project,1975.
Highest,Lowest,and Mean Values of Limno1ogical Data
Collected from the Susitna River and Seven Tributaries
of the Susitna River Between and Including Willow and
Montana Creeks,Devil 's Canyon Project,1975.
A compilation of U.S.Geological Survey Limnological
Data of Specific Concern,Collected from Susitna River
Tributaries,l"1ontana,Sheep,and Casvlell Creeks,Devil's
Canyon Project,1975.
Water Quality Analysis of Samples by U.S.Geological
Survey Central Laboratory in Salt Lake City,Utah,
Collected March 25,1975 from the Susitna River at
Sunshine,Devil 's Canyon Project,1975.
i i
13
17
18
19
21
23
24
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List of Tables (Cont).
Number Title Page No.
15 Compiled Data of Interest Collected by U.S.Geological 24
Survey from the Susitna River at Sunshine,Devil '5
Canyon Project,1975.
16 Limnol ogi ca 1 Data Collected on Four Tributaries of the 41
Susitna River between Talkeetna and Devil Canyon,Devil's
Canyon Project,1975.
17 Limnological Data Collected from the Susitna River 41
Immediately Upstream from Gold Creek,Devil '5 Canyon
Project,1975.
18 Li mn 0 1og i cal Data Collected from the Susitna River 41
Immediately Upstream from Portage Creek,Devil I 5
Canyon Project,1975.
19 Limnological Data Collected from Fifteen Sloughs 42
Along the Susitna River Between Talkeetna and
Portage Creek,Devil '5 Canyon Project,1975.
20 Limnological Data Collected April 24,1975 from the 43
Impoundment Area of the Susitna River near Jay,Watana,
and Deadman Creeks,Devil's Canyon Project,1975.
iii
LIST OF FIGURES
Number Title
1
2
3
4
5
6
7
8
9
10
11
Daily Water Temperatures of the Susitna River Approxi-
mately Three Hundred Yards Downstream from the Parks
Highway Bridge,Devil's Canyon Project,1975.
Maximum Daily Water Temperatures of Birch Creek
Approximately Five Hundred Yards Upstream of the
Alaska Railroad,Devills Canyon Project,1975.
Maximum Daily Water Temperatures of Willow Creek
Approximately Two Hundred Yards Upstream of the
Confluence with Deception Creek,Devil IS Canyon
Proj ect,1975.
Limnological Data Collected from the Susitna River
at the Parks Highway Bridge,March 26 to August 18,
Devil IS Canyon Project,1975.
Limnological Data Collected from Montana Creek at
the Highway Bridge,March 26 to August 18,Devills
Canyon Project,1975.
Limnological Data Collected from Sheep Creek at the
Highway Bridge,March 4 to August 18,Devil1s
Canyon Project,1975.
Limnological Data Collected from Goose Creek at the
Highway Bridge,March 4 to August 18,Devil's
Canyon Project,1975.
Limnological Data Collected from Caswell Creek at
the Highway Bridge,March 26 to August 18,Devil's
Canyon Project,1975.
Limnological Data Collected from Kashwitna River at
the Highway Bridge,April 24 to August 18,Devil's
Canyon Project,1975.
Limnological Data Collected from Little Willow Creek
at the Highway Bridge,April 24 to August 18,Devil1s
Canyon Project,1975.
Limnological Data Collected from Willow Creek at
the Highway Bridge,March 26 to August 18.Devills
Canyon Project,1975.
iv
Page No.
14
15
16
25 &26
27 &28
29 &30
31 &32
33 &34
35 &36
37 &38
39 &40
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Pre-authorization Assessment of the Susitna River Hydroelectric Projects:
Preliminary Investigations of lVater Quality and Fish Species Composition.
ABSTRACT
Biological investigations of the Susitna River and selected tributaries
were conducted from February 10,1975 to September 30,1975 to obtain base-
line data regarding indigenous fish populations,available aquatic habitat,
and water quality which will aid in the definition of biological areas of
concern requiring additional study prior to authorization of hydroelectric
development by the U.S.Anny Corps of Engineers.
INTRODUCT ION
Anadromous fish stocks of Cook Inlet and the Susitna River drainage,the
largest fresh water system in Cook Inlet,have historically been of great
value to the economy of Southcentral Alaska.
Canmercial fishing has been tile principle use of the anadromous fish
resource,but in recent years,both anadromous and resident fresh water fish
species indigenous to Upper Cook Inlet and the Susitna River system have
become increasingly important to the recreational user.
TIle direct cunulative value to recreational and commercial fishermen,
and indirect values to the many and varied supportive services and communities
dcriving benefit,makes the fishery resources of the Susi tna River an
extremely valuable resource.
The salmon stocks utilizing the Susitna River drainage,particularly
the chinook (Oncorhynchus tshawyts ch a),and coho salmon,(0.kisutch),are
currently at depressed levels.Chinook salmon stocks have~een the target of
extensive commercial and recreational fishing closures since the early
1960's.Management of these stocks is currently at a most important,if
not critical,stage.The proposed hydroelectric development of the Susitna
River basin will have a number of identifiable,and currently undefined,
effects upon the existing quality of water and aquatic }labitat necessary for
perpetuation of the anadromous and resident fish species.
The U.S.Army Corps of Engineers has stated downstream Susitna River
flows will be significantly altered by regulation,existing seasonal patterns
of silt and sediment transport will be different,stream temperatures and
water quality parameters may be affected,and 50,500 acres,including 82
river miles,of natural stream will be impounded by the Devil-Watana dam
impoundments.
The United States Fish and Ivildlife Service,pursuant to provisions in
the Fish and Wildlife Coordination Act and the "Cooperative Agreement between
the Service and the State of Alaska,Department of Fish and Game"provided
funding to the Sport Fish Division (Alaska Department of Fish and Game)in the
amount of $8,000 during the period July 1,1974 to June 30,1975,and
$16,000 during the period July 1,1975 and June 30,1976 for biological
surveys and studies of the Susitna River basin.
1
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With the available funds study objectives were to:1)determine resident
and anadromous sport fish species present and their distribution in the main-
stem Susitna River,its tributaries,and peripheral slough areas;2)measure
chemical,physical,and biological parameters associated with the mainstem
and important tributaries;3)determine the most acceptable sampling
techniques for the highly variable conditions existing in the Susitna River;
and 4)define future studies required to fully identify the impacts and
effects of hydroelectric development upon the Susitna River fishery resource.
Study results are discussed in the following text,conclusions presented
where possible,and recoTIIDlendations made for further definitive biological
investigations.
STIJDY AREA
The hydroelectric project under study will have major effects upon the
Susitna River which drains an area of approximately 20,000 square miles.That
portion of the river above the proposed Devil Canyon dam site drains approxi-
mately 6,000 square miles.The Susitna River basin is bounded on the east
by the Copper River plateau and the Talkeetna Mountains,on the west and
north by the mountains of the Alaska Range,and on the south by the Talkeetna
Mountains and Cook Inlet.
The Maclaren,the Oshetna,and the Tyone rivers are the largest tribu-
taries of the Susitna River above Devil Canyon.The Tyone River is the only
one of the three which is non-glacial.There are munerous smaller tribu-
taries which fluctuate greatly in seasonal rate of flow,but remain silt
free or clear throughout the year.
The Susitna River tributaries below Devil Canyon,for the most part,
originate in the surrmmding mountains.The Chulitna,Talkeetna,and Yentna
are the major tributaries,all of which are glacial.Clear water tributaries
below Devil Canyon collectively exert considerable influence and are the
major fish producing waters in this system.The major non-glacial tribu-
taries include:Portage Creek,Indian River,Montana Creek,Goose Creek,
Sheep Creek,Little Willow and Willow Creeks,Deshka River,and Alexander
Creek.
The work described in this report was conducted on the Susitna River
primarily from Portage Creek (located approximately three miles below
Devil Canyon)downstream to the mouth of the Yentna River.
One field trip into the upstream impoundment area during late winter
was accomplished to attempt the capture of mains tern residing fish.Time
and budgetary restraints precluded additional field studies in the upstream
impoundment area during the 1975 summer field season.
MATERIALS AND METHODS
Travel to and from sampling sites during the winter was accomplished
via a fixed wing aircraft on skis.A 20-foot riverboat,powered by an 8S
horsepower outboard,was used to travel on the Susitna River during the ice-
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free months.Chinook salmon escapement cOlUlts were made with the use of
fixed wing aircraft (supercub),Bell-47 helicopter,and grmmd surveys.
Adul t and rearing salmonids were collected with gill nets,minnow traps,
set lines,seines,dip nets,rod and reel,and electroshocker.
Benthic invertebrates were collected with artificial substrates which
consisted of wire vegetable baskets lined with nylon screen cloth and filled
with rocks taken from the stream bed.The baskets were left in the water for
a period of approximately 30 days.A hand screen was also used to collect
benthos samples.
"In situ"analysis of alkalinity as caCo ,total hardness and pH on
samples from the Susitna River and the seven ~ast side tributaries below the
Parks Highway Bridge was perfonned at biweekly intervals,using a Hach chemical
kit,Model Al-36B.Samples were collected approximately one to three meters
from the bank,at or near the surface.Temperatures at sample collection
points were recorded from just below the surface.
Conductivity and turbidity samples for the Susitna River and the seven
east side tributaries were collected at the same time as the above samples,
placed in one-liter polyethylene bottles,and analyzed at the U.S.Geological
Survey,Division of Water Resources Laboratory,using the Hach 2l00A
turbidmeter and a Beckman RB3 conductivity meter.All conductivity measure-
ments were standardized at 25OC.
All thennographic data collected from the Susitna River and two tribu-
taries were gathered using a Ryan thennograph model D-30,which was reset
every 30 days.Temperatures were recorded in Fahrenheit on thennograph tape.
The Susitna River water quality parameters from upstream of the Parks
Highway bridge were gathered using a Hach chemical kit model DR-EL/2.Two
sample sites were used;one approximately SO meters above Portage Creek and
the other about 150 meters above Gold Creek.All samples were collected
approximately five to ten meters from the bank,at or near the surface.Re-
stricted access and limited time prohibited more extensive data collection
during the field season.
The Susitna River sloughs and tributaries between Devil Canyon and
Talkeetna were also analyzed with Hach chemical kits,model DR-EL/2 and
Al-36B.All measurements were made approximately two to five meters from the
bank and SO meters from the mouths of the sloughs,at or near the surface.
Temperatures were recorded in Fahrenheit to the nearest whole degree and
later converted to the nearest 0.50 centigrade.
RESULTS AND DISCUSSION
FISHERIES
Interviews with staff members provide evidence of resident and rearing
anadromous salmonid fishes migrating downstream from the tributaries into the
mains tern Susitna River during the fall,and back ups team into the tributaries
during the spring.A hypothesis was fonmlated that this migration occurs in
3
part because of severe icing conditions and reduced flaws in the tributaries
during the ''linter months,which rlaY result in 1)territorial displacement of
certain species and sizes of fish,and 2)winter habitat preferences,i.e.,
Arctic grayl ing (Thymallus arcticus)appear to prefer larger bodies of water
during the winter,substantial space and,in r.eneral,a higher qllality
environment may be provided for afluatic species.Concern about this undefined
Dligration is the basis for designing a biological and limnological study
the included the tributaries as well as the rlainstem Susi tna River.
The Commercial Fish Division initiated studies in 1974 on the sloughs
and mainstem Susitna River from the Chulitna River upstream to Devil Canyon
(Barrett,1974).This work was continued and expanded into the Talkeetna
and Omli tna Rivers (Friese,1975).It was not the intent of the Sport Fish
Division to duplicate work conducted by Barrett and Friese,but to supple-
ment it ''lith lirmological data and to further study resident species and
habitat areas not included in their prior and on-going studies.
The numbers of fish and/or species collected during the fishery studies
are not statistically significant in that the smnple sizes or numbers
collected are inadequate to define specific population sizes.The samples
obtained are important,however,as they document the presence of a mnnber
of fish species,seasonally,in both the Susitna River mainstem and tribu-
tarv waters.
The seasonal fisheries investigations have provided considerable insight
into 1)the extreme difficulty in assessing either summer or winter mainstem
Susi tna River fish stocks due to high flows carrying debris and extreme ice
and snow conditions respectively,and 2)future study requirements necessary
to determine the significance and extent of the intra-system migrational
phenomenon exhibited by resident and anadromous fish species.
Winter:
\'linter investigations to document the presence of rearing salmonid fry
in the mainstem Susi tna River began February 10,1975 and continued through
April,1975.The mainstem Susi tna River was sanpled with minnow traps,
r,ill nets,and electroshocker at 11 locations between Susitna station and
the Parks Higln'lay Bridge,a distance of approximately 50 miles,and two
locations above Devil Canyon.Studies conducted during March and April,
1975 documented rearing coho,dlinook,chum,(0.keta),grayling,sculpin
(Cot t~cognatus),burbot (Lota Iota),whi tefiS'h ~egonus_3:')and sucker
(Catostomus catostomus)over-winterin~in the mainstem Susitna River down-
stream from the ParkS Highway Bridge (Table 1).The sampling sites and dis-
tribution findings are also plotted on aerial photographs in the Appendix
of this report.
Minnohl traps were installed in ~1ontana Creek,near the three forks,
and Willow Creek,under the highway bridge,during the first week of April,
1975 when water with enough depth under the ice could be found to effectively
fish a trap.Prior to this date,difficulty was experienced in finding
sufficient water levels under the ice to set minnow traps in the tributaries.
Five Dolly Varden (Salvelinus malma)ranging from 85 mm to 142 rom were
trapped in Willow Creek and four Chinook fry ranging from 48 rrrrn to 74 mm were
captured in Montana Creek.
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Table 1.Results of Winter Fry Sampling in ~!ainstem Sllsitna River,Devills
Canyon Project,1975.
Date
Feb.10
Mar.18
Mar.19
Mar.25
Apr.10
Apr.23
Apr.28
Apr.30
Location
Directly off mouth
of Sheep Creek
2.3 miles south of
Montana Creek
2 miles south of
Kashwi tna River
Directly off mouth
of Deshka River
Directly off mouth
Montana Creek
Directly off mouth
Caswell Creek
2.2 miles north of
Willow Creek
100 yards down-
stream Jay Creck
100 yards dO\\'D-
stream Deadman Cr.
50 yards upstream
Montana Cr.mouth
Susitna Station
3 miles south of
Parks Hwy.Bridge
Sampling
Method
6 ~Iinnow Traps
6 Minnow Traps
6 MinnO\'J Traps
12 Minnow Traps
8 Set Lines
4 Minnow Traps
6 Minnow Traps
25 Minnow Traps
12 Hinnow Traps
1 Gi 11 Net
6 Minnow Traps
1 Gill Net
Electroshocker
Electroshocker
Electroshocker
Hours
Sampled
24
72
72
48
48
48
48
192
48
48
24
24
Number and
Species Captured
o
2 SS
1 S
1 SS
a
o
o
3 KS
o
o
o
o
7 CS
1 GR
1 WF
1 BB
1 S
1 SC
*SS -coho salmon,KS-chinook salmon,CS-ch~m salmon,S-sucker,GR-grayling,
WF-whitefish,BB-burbot,SC-sculpin
5
Minnow traps and gill nets were installed in tIle mainstem Susitna River
above Devil Canyon from April 21 to April 24,1975.A gill net and 12
minnow traps were stationed 100 yards downstream from Jay Creek for 24 hours
with negative results.Six traps and one gill net ,{ere placed 100 yards
downstream from Deadman Creek for 12 hours,also without capturing fish.
The most successful winter sampling technique for the Susitna River
appeared to be the backpack electroshocker.Hrn~ever,this technique is
limited to late winter after certain areas become ice free and before high
silt laden flows begin.Minnow traps were not as effective during the
winter as during the summer because fish are lethargic in cold water and may
not enter the trap as readily.Thus,samples collected may not be indicative
of fish numbers present at any given site.There is a need for testing of
more effective trapping or fish collecting devices during the winter season.
Summer:
Summer investigations of fish species inhabiting the rnainstem Susitna
River began June 17,1975.Following a reconnaissance and general familiari-
zation trip to identify potential sampling sites,a base camp was established
on the Deshka River near the confluence with the Susitna River.Beginning
the week of June 23,1975,a crew of two biologists spent four days each week
through July,1975 sampling for rearing fish in the mainstem Susitna River
from the Parks Highway Bridge dm..'llstream.The results of this five week
sampling period indicate the following:1)Anadromous salmon fry,rainbow
trout,and grayling are scarce in the silt laden water of the mainstem
Susitna River during this time of year and,2)whitefish,sculpin,and suckers
were commonly captured in the turbid Susitna River.Two coho fry,50 and
69 mm in length,were captured at a sandbar near the mouth of Sheep Creek and
two chinook fry,59 and 60 rom in length,were collected downstream of
Willow Creek.With the exception of these four fry,no other salmon fry,
rainbow trout,or grayling were captured in the Susitna River when the silt
load was high.The reasons for the scarcity of salmonids in the mainstem
Susitna could be attributed to a preference for clearwater by these species
and the outmigration of chinook and coho salmon smol ts,pink and chum salmon
fry before sampling efforts were initiated.The only sampling techniques
which proved feasible for collecting fry during the high flow period of the
Susitna River were hand seines and dip nets.Gill nets were ineffective
because of drifting debris in the river during the high summer flows.The
backpack electroshocker is also unsatisfactory when turbidity is high be-
cause affected fish cannot be seen or captured.
On August 6,1975 the base camp was moved from the Deshka River to
Gold Creek.Sloughs in the Gold Creek area and upstream to Devil Canyon
were sampled for fish in conjunction with the limnological study.Results of
the fish collections are shown in Tm)le 2.Seining was conducted at four
sites in the mainstem Susitna between Gold Creek at Portage Creek with
negative results.
Winter and summer observations of rearing fry in the Susitna River lend
support to the hypothesis that salmonids migrate downstream from tributaries
during the fall to overwinter in the Susitna and return to the tributaries
during the spring.
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Table 2.Fish Collected in Sloughs Between Talkeetna and Port.age Creek)
Devil's.Canyon Project,1975.
Slough .Species Number Fish
Date ""Number "'Collected .'Collected .'Site'(mm)
Aug.13 11 Chinook 1 53
Grayling 1 56
Sucker 1 49
13 Grayling 1 46
Whitefish 1 37
Aug.14 IS Chinook 4 43-53
.16 Whitefish 1 50
19 Whitefish 5 39-45
Aug.IS 20 Chinook .10 52-66
Grayling 2 43~62
21 Grayling 2 56~58
Whitefish 5 39-48
.-Aug.19 17 Coho 2 39,48
Grayling 4 33-65
Burbot 1 59
Sucker 1 52
18 Chinook 4 51-55
Coho 4 39-54
Grayling 1 53
Whitefish 3 48-53
Bur bot 1 49
.Sucker 2 .47 ~54
..'".":
7
Arctic grayling are the most common resident recreationally important
species indigenous to the Susitna River Basin.Grayling occur in the
majority of fresh water tributaries of the Susitna River,both upstream and
downstream of the Devil's Canyon Dam site,and were documented specifically
in those irrnnediate downstream tributaries of Portage and Fourth of July
creeks,and Indian River.
An age-length frequency of 33 grayling collected from Portage Creek is
presented in Tables 3 and 4 as general indication of grayling size and age
composition.
Arctic grayling e~libit intra-system migrations and a need exists for
comprehensive studies of these seasonal movements and their significance to
determine the overall effects of the potential loss of any of their aquatic
habi tat.
All five species of salmon utilize the Susitna River and all are
equally important.The Sport Fish Division recognizes dIe chinook and coho
salmon as having the greatest potential for satisfying future recreational
needs.The COJluuercial Fish Division studies pink,chum,and sockeye
(Q.nerka)salmon and reported on these species in their section.
A number of key tributaries of the Susitna River were selected for
chinook salmon escapement during 1975 (Tables 5 and 6).It should be noted
these escapement counts do not constitute total numbers,but indicate
relative abundance and depict the importance of the Susi tna River as an
avenue of access.IJpstream impoundment may affect the migration of fish into
key spawning streams.Prior to impoundment the magnitude of anadromous
sabnon escapements should be enumerated totally.
Benthos
Species diversity has become widely used as an indicator of water
quality.Diversity indices may be applied to any hiotic community but have
had widest application with the benthos.Such indices relate the number of
kinds of organisms to the total number of organisms and to the number of
individuals of each kind.Undisturbed natural communities are assumed to
have a high diversity;that is,a relatively large number of species,with
no species having disproportionately large mnnbers of individuals,(Lind,
1974).Diversity is considered to be a sensitive hioa~say fOT assessin?
environmental stress (Cantlon,1969;Wilhm,1970).The diversity of a
conununi ty is a meaningful parameter \'lhich can be measured (Warren,1971).
Warren emphasized the importance of diversity in defining the environmental
impacts of changes to a system.To properly assess impacts,a diversi ty
index should be computed,using identical methodology,before,during,and
after construction.
In order to use a species as an indicator organism,its envirormlental
requirements must be reasonably well defined within rather narrow limits
(HcCoy,1974).It has been demonstrated that presence of srecies in the
orders Ephemeroptera and Plecoptera in streams indicate unpolluted waters.
Members of hoth these orders were observed on rocks in the impoundment area
of the Susi tna River during the late \lfinter field trip,April 21 throw~h
April 24,1975 and downstream of Devil Canyon throU,l:;hout the sumner.
8
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Tabls 3.Age Analy41.or Crayllpg Saopl&d fr~Poreaas Creek.D~vl1'.
C"~YQn ProJect.Aus'ue 12.IH5.
30-
!.
u.
2n
JtJ•...
~U..
0..•1
~
10
.,
.s
I
Table 4.L«nSth Varla~1I of Cn,.l1l:l1 5-,.1_f..-Portq.er-s.Onn".em"",Projeee,
AU;ilUt U.1975.
IU
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9
Table 5.West Side Susitna River Chinook Salmon Escapement,Devil's Canyon
Proj ect,1975 ..
Helicopter
Stream Counts
Deshka River System
Alexander Creek -System
Lake Creek System*
Talachulitna River *
Peters Creek*
Canyon Creek*
Total
4,737
1,878
281
120
14
2
7,032
Table 6.East Side Susitna River Chinook Salmon Escapement,Devil's Canyon
Project,1975.
Stream
Willo\\'Creek
Little Willow Creek
Kashwitna River
Sheep Creek
Goose Creek
f'.10ntana Creek
Chunilna Creek*
East Fork Chulitna River*
Middle Fork Chulitna River*
Prairie Creek*
Indian River
Portage Creek
Helicopter
Aerial Counts
103
33
101
Fixed Wing
Aerial Counts
42
13
7
55
31
32
Ground Counts
177
229
369
Total
Total All Counts
237 180 775
1,192
*Not a direct tributary to Susitna River;however,salmon must use the
Susitna as a pathway to arrive at these rivers.
10
Benthic invertebrates were sampled during the sununer season with eight
artificial substrates (Tables 6 and 7).Substrates were placed in the main-
stem Susitna River one Inile upstream from the Deshka River,100 yarQ~upstream
of Willow Creek,and :i.rronediately above Gold Creek.Waterfall Creek and
Fourth of July Creek,which are clear water tributaries of the Susi tna,were
also sampled.All locations with the exception of Fourth of July Creek were
sampled with two artificial substrates for a period of 30 days.Fourth of
JUly Creek was sampled by hand holding a screen (36"x 36")and stirring the
substrate innnediately upstream.Aquatic insects collected in both the
Susi tna and tributaries are typical of clean cold water streams in Alaska.
Due to the restricted time fr<D1\e available for this study and report pre-
paration,aquatic invertebrates are keyed only to family.
Limnology
TIle limnological study was initiated March 26,1975 establishing
sample sites on the Susitna River and all major east side tributaries from
the Parks Highway Bridge dOl'lnstream.Water samples were collected on a bi-weekly
basis at the bridge crossings of eadl tributary.Parameters measured were water
temperature,pt!,turbidity,conductivity,total alkalinity,total hardness,and
dissolved oxygen.
Temperatures were also monitored with Ryan Themographs C',10del d-30 0 F.)
in the Susitna River,Rirch Creek,and l~illow Creek.It is interesting to
note the similarity in temperature trends between the Susitna River and note
the similarity in temperature trends between the St~itna River and tributaries
(Figures 1,2,and 3).For example,both the Susi tna River and Wi 11rn'1 Creek
measured 32 o P.on April 1,1975.A slow ,.,ranning trend was observed in both
rivers until May 14,1975 when temperatures of both rivers were measured at
approximately 34 0 F.A steady upward trend occurs after May 15 until the
maximum temperature was reached in mid-July.The maximum water temperature
in the Susitna River was 55.50 F.July 12,1975.Willow Creek exhibited a
maximtim of 56 0 F.during the period July 7 through July 10,1975.Maximum
and minimum daily water temperatures monitored by the thennographs are
presented in Tables 9 and 10.The temperature remained relatively stable in
both rivers between July 15 and August 30,1975,fluctuating between 48 0 F.
and 53 0 F.TIle water temperature began to decrease by September 5,1975 and
was 45 0 F.in both the Susitna River and Willow Creek on September 23,1975
when the thennographs were removed.
East side tributaries of the Susi tna River downstream from the Parks
Highway Bridge do not have lake systems present,but are the result of
surface and subsurface runoff from the surrounding mountaiI)S-and foothills.
Montana Creek,Sheep Creek,rJOose Creek,Caswell Creek,Kasoo.tna River,and
Little Willow Creek temperatures were taken biweekly and trends were con-
sistent with measurements of the Susitna River and Willow Creek (Figures 4-11).
Birch Creek was selected as a thermograph site to collect tempr~ature
data on a creek draining a lake.Birch Creek is the outlet of Fish Lake and
empties into the Susitna River upstream of the Parks Highway Bridge.It also
differed from the tributaries downstream of the Parks Highway Bridge by having
less gradient and vohnne.Temperatures were considerably wanner in Birch
Creek,as suspected,reaching a high of 69 0 F.on July 10,1975 (Table 11).
Lentic environments have the capacity to retain heat,resulting in different
thennal patterns than lotic environments.Lakes also act as a buffer by
stabilizing fluctuating flows.The thennal pattenlS and stabilized flows in
the outlets of lakes benefit productivity.
11
Table7.AquaticInvertebratesCollectedinClearwaterTributariesoftheSusitnaRiver,DevilCanyonProject,1975.I-'""LocationFourthofJulyCreekWaterfallCreekOrder--TrichopteraDipteriaPlecopteraEphemeropteraTurbellariaDipteraP1ecopteraEphemeropteraOligochaetaGastropodaFamilySericostomatidaeRhyacophilidaeRhyacophilidaePerlodidaePer10didaeHeptageniidaeBaetidaeType1Type2Type3Type4Type5Type6Per10didaeBaetidaeType1Type2No.14115763164110231711315Co1lectiortMethodHandScreenArtificialSub-stratebasket(2)CollectionDates:Aug13Aug7 -Sep7
~.II I 1IItI I 1 1•••)iTable8.AquaticInvertebratesCollectedinSusitnaRiver,DevilCanyonProject,1975......wLocationMainstemSusitnaUpstreamfromGoldCreekMainstemSusitnaUpstreamfromWillowCreekrilainstemSusitnaUpstreamfromDcshkaRiverOrder.--TrichopteraDipteraPlccoptcraEphemeropteraOlgochaetaTricopteraDipteraEphemeropteraPlecopteraTricopteraPlccoptcraEphcmeropteraFamilyRhyacophilidaeType1Type2PcrloclidacPerlodidaeBaetidaeSericostomatidaeHeptageniidaeBaetodaePerlodidaeScricostomatidaePerloclidaeI-IcptageniidacNo.134I51I325781113CollectionMethod·ArtificialSub-stratebasket(2)ArtificialSub-stratebasket(2)ArtificialSub-stratebasket(2)CollectionDatesAug7 -Sep7Jul1 -Sop1Jul1 -Aug1
Figure1.Daily\VaterTemperatures(MonitoredwithaRyanThermograph)oftheSusitnaRiverApproximatelyThreeHundredYardsDownstreamfromtheParksHighwayBridge,DevilsCanyonProject,June20toSeptember23,1975.15.6oJ60.....~10.00SOQ).j.J'"0'M(1jQ)Hr-Ollr-'MCi.j.JH>=:r-Q)(llu~4.4040o.0OJ32ok-II\I•Apr1Hay1Jun1Jul1Aug1Sep1Note:TemreraturestakenpriortoJune20thwerewithathermometeronabi-monthlybasis.
lFigure2.MaximumDailyWaterTemperatures(MonitoredwithaRyanThermograph)ofBirchCreekApproxi~?tP1yFiveHundredYardsUpstreamoftheAlaskaRailroad,DevilCanyonProject,April10toAugust30,1975.21.2°170°15.6°~60°....C)10.0°1.j..JU1"C",""roC)~..r::bj)l=:''""Q)50°.j..J~l=:.c:Q)rou~4.4°J40°·o0°I-'}Ol•......'/•1i"(Apr1May1Jun1Ju11Aug1Sep1
Figure3.MaximumDailyWaterTemperatureU1onitoredwithaRyanThermograph)ofWillowCreekApproximatelyTwoHundredYardsUpstreamoftheConfluencewithDeceptionCreek,DevilCanyonProject,April10toSeptember23,1975.15.0°...j60°.....0'\<!>10.0°50°"D01-'('(j'"'"'"'(j)b/)..c......I=:.j.J(j)I=:H(j)..cu{"jw...4.4°40°0.0°J32°1/l.£.---------,,-------ij----------rl--------.,-------........--------Apr1May1Jun1Ju11,IAug1Sep1
-
Table .9.Haximum and ~Iinimum Daily Water Temperatures CF-"Ryan"Thermo-
graph,~Iodel 0-30)from the Susitna River at Parks Highway Bridge,
Devil Canyon Project,1975.
........ ... . . .
Temperature Temperature Temperature
Date Max..Min.Date Hax.Hin.Date Hax.Hin •
Jun 20 49.0 Ju1 22 51.5 51.0 Aug 23 53.0
21 49.0 23 51.5 24 53.0 52.0
22 4'9.0 48.0 24 51.5 25 52.0
23 47.8 47.8 25 51.0 26 52.0
24 48.8 47.8 26 52.0 51.0 27 52.0
25 49.0 27 52.0 28 52.0 50.0
26 49.0 28 52.0 51.5 29 50.0 48.0
27 49.0 29 51.5 30 48.0
28 50.0 49.0 30 51.5 51.0 31 48.0
29 50.0 31 51.0 Sep 1 48.0
30 50.0 49.0 Aug 1 52.0 51.0 2 53.0 48.0
Ju1 1 49.0 2 52.0 3 53.0 49.0
2 49.0 3 52.0 4 52.0 48.0
3 49.0 4 52.0 5 52.0 49.0
4 49.0 5 52.0 51.0 6 50.0 48.0
5 49.0 6 51.0 7 48.0
6 50.0 .49.0 7 51.0 8 48.0
7 51.0 50.0 8 51.0 9 47.5
8 52.0 51.0 9 51.0 10 47.0
9 54.0 52.0 10 51.0 11 47.0
10 55.0 54.0 11 51.0 12 47.0
11 55.0 12 52.0 13 46.0
12 55.5 54.0 13 52.0 14 46.0 45.0
13 54.0 53.0 14 52.0 15 45.0
14 53.0 51.5 15 52.0 16 45.0
15 51.7 16 52.0 17 45.0
16 51.7 50.5 17 52.0 51.0 18 45.0
17 52.0 51.0 18 50.5 19 45.0
18 52.0 19 50.5 20 45.0
19 52.0 51.0 20 50.5 21 45.0
20.51.0 21 50.5 22 45.0
21 51.0 22 53.0 23 45.0
17
TABLE 10.Haximum and Hinimum Daily Water Ter.lperatures (OF_Ryan Thermograph,
Model 0-30)from Willow Creek,Devil Canyon Project,1975.
,Temperature Tewperature Temperature
Date Halt.~lin.Date Hax.Hin.Date ~lax.Hin.
Apr 10 34.0 Jon 5 43.0 37.0 Jul 31 50.0
11 34.0 6 43.0 39.0 Aug 1 51.0 50.0
12 34.0 7 44.0 38.0 2 52.0 51.0
13 34.0 8 44.0 39.0 3 52.0 51.0
14 34.0 9 44.0 38.0 4 53.0 51.0
15 34.0 10 43.0 38.0 5 53.0
16 34.0 11 43.0 39.0 6 51.0
17 34.0 12 44.0 38.0 7 51.0 50.0
18 34.0 13 44.0 38.0 8 50.0
19 34.0 14 45.0 40.0 9 50.0
20 34.0 15 44.0 40.0 10 49.0 48.0
21 34,.0 16 44.0 11 49.0
22 34.0 17 44.0 12 49.0
23 34.0 18 44.0 13 49.0
24 34.0 19 44.0 14 51.0 49.0
25 34.0 20 45.0 44.0 IS 51.0
26 35.0 21 44.0 43.0 16 51.0 49.0
27 35.0 22 43.0 17 50.0
28 35.0 23 45.0 43.0 18 50.0
29 35.0 24 45.0 19 50.0
30 35.0 25 46.0 45.0 20 50.0
May 1 35.0 26 50.0 46.0 21 50.0
2 35.0 27 52.0 46.0 22 50.0
3 35.0 28 47.0 23 50.0
4 35.0 29 46.0 24 50.0
5 35.0 30 46.0 25'50.0
6 35.0 Jul 1 48.0 46.0 26 50.0
7 36.0 35.0 2 48.0 27 52.0 50.0
8 38.0 35.0 3 47.0 46.0 28 48.0
9 36.0 4 51.0 46.0 29 48.0 :;.
10 36.0 35.0 5 54.0 49.0 30 48.0
11 35.0 6 54.0 50.0 31 47.0
12 34.0 7 56.0 52.0 Sep 1 48.0 47.0
13 34.0 8 56.0 52.0 2 48.0
14 34.0 9 --56.0 53.0 3 48.0
IS 36.0 35.0 10 56.0 54.0 4 48.0
16 36.0 35.0 11 55.0 52.0 5 47.0 44.0
17 36.0 12 51.0 49.0 6 44.0
18 36.0 13 51.0 49.0 7 44.0 42.0
19 39.0 36.0 14 51.0 8 44.0 42.0
20 40.0 35.0 IS 50.0 48.0 9 44.0 42.0
21 38.0 35.0 16 52.0 48.0 10 44.0 42.0
22 38.0 36.0 17 52.0 11 43.0
23 42.0 37.0 18 52.0 51.0 12 45.0 40.0
24 42.0 39.0 19 51.0 49.0 13 44.0 40.0
25 38.0 36.0 20 50.0 49.0 14 43.0 41.0
26 42.0 36.0 21 49.0 IS 45.0 43.0
27 40.0 36.0 22 49.0 16 44.0
28 43.0 37.0 23 50.0 49.0 -17 44.0
29 42.0 36.0 24 50.0 18 44.0
30 42.0 36.0 25 50.0 19 43.0
31 46.0 35.0 26 50.0 20 45.0 43.0
Jun 1 43.0 38.0 27 52.0 50.0 21 44.0 43.0
2 42.0 40.0 28 52.0 22 45.0 43.0
3 42.0 38.0 29 51.0 23 45.0 44.0
4 42.0 38.0 30 50.0
18
_.
Table II.Maximum and Minimum Daily Water Temperatures (OF_"Ryan"Thermo-
graph,Model D-30)·from Birch Creek,Devil Canyon Project,1975.
Temperature Temperature Temperature
Date lvlax.~lin.Date'.~lax.~'ti.n .Date Hax.t-1in ..
Apr 11 38.0 May 29 47.0 46.0 Jul 15 59.0
12 38.0 36.0 30 47.0 46.0 16 59.0
13 37.0 35.0 31 48.0 46.0 17 59.0
14 35.0 Jun 1 50.0 48.0 18 59.0
15 35.7 35.0 2 51.0 19 59.0
16 35.5 3 51.0 20 59.0
17 35.5 4 51.0 21 59.0 57.0
18 35.7 35.0 5 51.0 50.0 22 60.0 59.0
19 36.0 .34.0 6 51.0 50.0 23 60.0
20 36.0 34.0 7 51.0 24 60.0 59.0
21 36.0 34.5 8 51.0 25 59.0
22 37.0 35.0 9 51.0 50.0 26 60.0 59.0
23 38.0 35.0 10 52.0 51.0 27 60.0
24 38.0 36.0 11 54.0 52.0 28 60.0 58.0
25 37.0 36.0 12 54.0 29 58.0
26 37.0 36.0 13 54.0 52.0 30 58.0
27 37.0 36.0 14 54.0 31 58.0
28 38.0 .36.0 15 54.0 Aug 1 60.0 58.0
29 38.0 36.0 16 54.0 2 59.0 57.0
30 38.0 37.0 17 54.0 3 56.0
May 1 38.1 36.3 18 54.0 4 60.0 56.0
2 39.0 36.0 19 54.0 5 59.0 58.0
3 40.0 38.0 20 55.0 6 59.0
4 38.0 21 56.0 55.0 7 59.0
5 38.0 22 55.0 54.0 8 59.0
6 39.0 37.0 23 54.0 53.0 9 out'of order
7 38.0 36.2 24 55.0 53.0 10 out of order
8 38.3 37.0 25 55.0 11 out of order
9 38.8 38.0 26 59.0 55.0 12 out of order
10 38.0 27 59.0 57.0 13 out of order
11 38.0 28 60.0 58.0 14 out of order
12 38.0 29 60.0 58.0 15 out of order
13 38.0 30 58.0 57.0 16 out ,of order
14 38.0 Ju1 1 58.0 57.0 17 out of order
15 38.0 2 58.0 56.0 18 out of order
16 38.0 3 59.0 56.0 19 out of order
17 39.0 4 60.0 59.0 20 out of order
18 39.0 5 59.0 21 ou~of order
19 39.0 6 62.0 59.0 22 58.0
20 39.5 7 62.0 23 58.0 57.0
21 40.0 8 64.0 62.0 24 57.0 56.0-22 40.0 9 66.0 63.0 25 56.0
23 41.0 40.0 10 69.0 66.0 26 56.0
24 41.0 11 68.0 27 56.0 53.0
25 41.0 12 68.0 64.0 28 53.0 52.0
26 41.0 13 64.0 61.0 29 53.0 52.0
27 43.0 41.0 14 61.0 59.0 30 52.0
28 45.0 43.0
19
/
The highest,lowest and mean values of limnological data collected from
the Susitna Riyer and east side tributaries downstream of the Parks Highway
Bridge are presented in Table 12.
A more detailed analysis can be made by referring to Figures 4 through
11,which represent the six limnological characterisitcs measured in the
Susitna River and seven east side tributaries.
Hydrogen ion concentration in the tributaries exhibited a tendency to
rise during the swmner (Figures 4 through 11).A similar rise is also evident
in the hydrogen ion data collected from the Susitna River at the Parks High-
way Bridge.
Total alkalinity,represented in Figures 4 through 11,exhibited an
overall rise throughout the swmner months;except in the Kashwitna River,
which demonstrates a less distinct increase.The highs and lows varied
depending upon the tributary (Table 12),although the maximwn limits in all
cases were no greater than 86 mg/l Cac03'It appears the lower Susitna
River has a greater total alkalinity than its tributaries.
Hardness,(Figures 4 through 11)shows a decrease from the end of March
to the middle of May.For example,it dropped from 85 mg/1 Cac03 to 17
mg/l CaC0 3 at Caswell Creek.This drop,in all seven lower Susitna River
tributaries,appears to have occurred just as the waters began to warm sig-
nificantly.As swmner progressed,it appears the hardness of these waters
remained relatively low and stable.The relative stability reflected in
Susitna River tributarial waters during the months of July and August is
evident in information presented in Figure 4.These comparisons demonstrate
a constant 51 mg/l Cac03 through July and August,whereas the relative
stability of tributarial waters ranges between 17 and 34 mg/l Cac03.It
would appear the tributarial waters have a consistently lesser degree of
hardness than the Susitna River waters with the same relatively low swmner-
time constancy.Tributaries exhibited high late winter hardness levels.
Conductivity measurements for the seven east side lower Susitna tribu-
taries (Figures 4 through 11)all reflect a similar decrease from late
winter to early swmner with 28 rnmlos/crn reflecting the average low and
107 umhos/crn reflecting the average high.Once the minimum specific con-
ductance is reached from the middle of May to the middle of June,a general
rise in conductance is observed during the swmner months.Samples collected
on June 27,reflect an abnormally high increase in specific conductance,
which may be attributed to extreme heavy rains prior to or during sample
collection.The Susitna River displays a substantially higher specific
conductance than that of the seven east side tributaries and a general
increase from early June through August.
There appears to be no consistent trend in turbidity in all seven east
side Susitna River tributaries under investigation.Both the Kashwitna River
and Ca9Well Creek demonstrated an increase in turbidity from mid-April to
mid-August.This increase was significantly greater in the Kashwitna River
because of its glacial origin.However,there was a high degree of fluctua-
tion in turbidity in both streams.A similar fluctuation was demonstrated in
the remaining five tributaries,i.e.,Montana,Goose,Sheep,Little Willow and
Willow creeks (Figures 4 through 11).This high variability in turbidity can,
in all likelillood,be attributed to precipitation.
20
-
,-..I-....,....-1-I .TAIlI.E12.Hithest,LowestandIleanValuesofLimnologicalDataCollectedFromThoSusitnaRiverandSevenTributariesoftheSusitnaRiver.Time"interTotnlrerio<lTCr.lporllturoContluctIvltyTurbidityAHnlinltyIInrtlne$$Collected(e)(~mhos/cm)(Jnl)pH(1ll&/I-CaC03)(noS/I.CoiC03)Tribuury1975IlighLow~le3nHighLowHcanlIighLowIleanHighLow~feanHighLowMean!!is.h1.0\0').!eanSusitnaRiveratParksHigh~3YBridge3/26-8/1813.00.08.22107412618535lOS8.S7.S7.9103344812051105~IontanaCreek3/26-8/1814.50.08.2lOS2748270.34.97.56.77.2681731511725GooseCreek4/4-8/1812.00.07.3772743640.39.47.7 6.7 7.1681734341724SheepCreek4/4-8/1814.00.07.7803046311.04.37.66.67.1681737Sl1731NI-'CaswellCreek5/14•8/1816.50.010.61753062281.05.17.66.67.2681742861736hshwltnaRiver4/24-8/1813.06.58.97737531102.0387.66.97.351173g681737LittleWillowCreek4/24-8/1814.00.06.8732041151.22.87.S6.67.0861738Sl1727WillowCreek3/26•0/1814.00.06.7J602673200.53.67.76.67.2Sl1739601737Hote:Thisdatawascollecteobiweeklyfromeachofthetributariesduringthetimeframeindicated.Thisisgeneralinformationonly,amoredetailedanalysiscanbemadebyreferringtoFigures4through11.
Turbidity in the Susitna River was relatively low at 5S Jackson turbidity
tmits during May and Jtme (figure 4).On JUly 7 a substantial rise to 170
J.T.U.was measured and a peak of 185 J.T.U.was reached on August 18,1975.
The maxirrn.mJ.reading for east side tributaries below the Parks Highway Bridge
was 110 J.T.U.in the Kashwitna River on August 18,1975.
Data collected by the U.S.Geological Survey on three Susitna River
east side tributaries provides a limited means with which to compare data
collected in this study between March and September,1975,(Table 13).
With respect to Montana Creek,the available figures would tend to
support temperature,pH,hardness and specific conductance as detennined in
the field during the summer of 1975.Sheep Creek figures cannot be compared
due to the time frame in which the one set of data was collected.With re-
spect to Caswell Creek,temperature and specific conductance are the only
parameters which fall closely within the range of U.S.Geological Survey
data.Hardness and pH are significantly different from more recently collected
data.
The base camp was relocated from the Deshka River upstream to Gold
Creek on August 6,1975 to collect limnological data on the Susitna River
and tributaries closer to the proposed dam site.
Data collected at four tributaries,i.e.,Fourth of July,Gold,and
Portage creeks,and Indian River,are shown in Table 16.Because only a
single sample was collected,no trends are observable.One tributary,Gold
Creek,does differ from the remaining tributaries,however,in that it re-
flected a significantly higher pH,total alkalinity,and hardness.No fish
popUlations were fotmd in Gold Creek other than a few grayling,at the mouth.
A probable reason for the absence of fish is a placer gold mining operation
approximately 6.5 miles up the Gold Creek Canyon.Findings for Fourth of
July Creek,Indian River,and Portage Creek are within the range of para-
meters investigated on the lower portion of the Susitna River tributaries.
Chemical and physi.cal parameters collected at two locations along the
Susitna River at Portage Creek and Gold Creek are presented in Tables 17
and 18.All data were collected on four different days and will be valuable
for future comparative analysis.Hardness and total alkalinity may be con-
sistent within specified limits at both Gold Creek and Portage Creek.
Conductivity,in many previous cases,tended to increase over the spring
and summer months;although later winter-early spring findings have demon-
stated an tmusually high specific conductance.This same apparent trend
appears true for the Susitna River at Stmshine,although data is limited.
The freshwater sloughs adjacent to the Susitna River,as identified by
Barrett (1974)and Friese (1975)between Talkeetna and Portage Creek are
important salmonid habitat.These sloughs are used for both spawning and
rearing and could be greatly affected by changes in the flow regime.
Table 19 is a compilation of field investigations reflecting the l:iJIm.o-
logical data collected on sloughs 8 through 21,along the Susitna River from
August 7 through 14.In all cases,except slough 12,there were fish fry
22
J1TABLE13.ACompilotionofU.S.GeologicalSurveyLimnologicalDataofSpecificConcern,CollectedFromSusitnaRiverTributario$,SuspendedDissolvedDissolvedWaterSpecificSedimentOrtho-I\itnteGNameofTempcnturoConductanceDischargeSuspendedDisch"rCoNitroteHardnessPhosphateNitr.iteTributoryDoto(C)(urMos/cm)CcCs)SediJ1lent(Tons/Doy)r.!!(mfl/l-N03)(mg/I-CoC03)(mg/l-P)(mg/l.:;02G/;03)--~lontonaCreek7/1/717.0242,28020S1,2608/9/719.S243,5001831.7S09/17/718.543376220.7.21.00IS8/11/72 16.547182--7.4-17.00.OSIVw9/26/724.S37606- -6.3-13.11.03SheepCreek3/4/72-63---7.50.3625CaslIeliCreek9/8/72.13.S5423- -6.8.-20.05.009/26/724.05131--7.2-19.02.00
1ab1e 14.Water Quality Analysis'of Samples by the U.S.Geological Survey
'Central Laboratory in Salt Lake City ~Utah.Collected Harch 25 ~
1975 from the Susitna River at Sunshine.
Alk ...Tot (as CaC03)mg/l 71 ~02+N03 as N Diss mg/l 0.21
Bicarbonate mg/l 86 Phos Ortho Dis as P mg/l 0.04
Calcium Diss mg/l 29 Phosphate Dis Ortho mg/l 0.12
Chloride Diss .myl 21 .Potassium Diss og/1 2.1
Color 0 Residur Dis Cae 1 Sum mg/l 137
Conductivi t.Y.242 Residue Dis Ton/Aft 0.19
Fl uoricle IH?s mg/l 0.2 Residue Dis l8De mg/1 141
Hardness Noncarb mg/1 20 Sar .0.5
Hardness Total .mg/1 91 Silica~Dissolved mg/l 9.2
Iron Dissolved ug/l 10 Sodium Diss myl 11
Magnesium Diss ..mg/l 4.5 .Sodium Percent ..20
~~nganese Dissolved ug/i 0 Sulfate Diss mg/l 17 -_.
Nitrogen NHf as N tot mg/l :Nitrogen TotOrg N mg/l 0.180.05
Nitrogen Tot as N mg/l 0.42 Nitrogen Tot KJD as N mg/l 0.23
.Nitrogen Tot as ~03 mg/l 1.9 N02+N03 as N Tot mg/l 0.19
Phosphorus Tot as .P ,mg/l 0.01
.'Cations Anions
mg/l ineq/l ""!DgJ1 meqil.~....
:Calcium Diss "29 '1;448 Bicarbonate 86 .1.410
Magnesium Diss 4.5 0.371 Chloride Oiss 21 0.593
PotassiuJil Diss .2.1-0".054 Fluoride Diss 0.2 0.011
Sodiutl Diss 11 0.479 Sulfate Diss .17'0.345
~02+N03 as N D
-0.21 0.015
Total 2.34~·Total .2.381
.IlIlIiJt1.
Table'15.Compiled Data of Interest Collected by U.~.Geological Survey
from.the Susitna River at Sunshine...
-."'Specific Suspended
Conductance Sediment
Date Pl!.(umhos/ern)(mg/l).
.~~
7/2/71 7.5 138 .1 ..040
7/2/71 7.5 131 1~140
8/11/71 9.0 170 3.)510
24
Figure 4.Limnological Data Collected from the Susitna River
at the Parks Highway Bridge,March 26 to August 18,
Devil's Canyon Project.1975.
0 16.0 9.0
0
I
w 12.0c::8.0::J
I-<c::w 8.0 ~1.0a.
::::E
11.1
t-
o:4.0 6.0
11.1
I-
~0.0 5.0
25
"Figure 4.(Cant.)
220
LimnologicaJ Data Collected from the Susitna River at
the Parks Highway Bridge.March 26 to August 18.
Deyil's Canyon Project.1975.
180
.....
U
::I
"0
Cou
210
200
190
180
1]0
160
150
140
130
120
110
100
90
80
70
170 -
160
150
140
120
110
loa
90
80
70
60
50
40
30
I .
?/26
26
Fig.5.Limnological Data Collected froIT!Montana Creek at the High\'Iay
Bridge,March 26 to August 18,Devil's Canyon Project,1975.
9.0
8.0
4./30'5/2.7 6 7 7.21 6//8
5/14 ell I 7/7 8/4
DATE-J975
3/26
6.
~7.0
,3/26 4/30 em"6/271'2'11/16
" ' .',6/11 7/7 8/4
DATE-1975
uo
I
~16'.0
:::>
~12.0
a:w
~8.
w
1-'4.0
a:w
~O.
;:
tt')
0u f()
<t 0 ,u u
CJ)<«u
...J en
.......«
(!)...J~.......
I 5 C!)->-~l-I
,·Z CI)
20
...J
en /'-'"
l.LJ
<t:Z:x=10 0 10...J a:«3/28 4/30 5/27 6/27 7/21 8/1S «3/28 6 27
M4 6/11 7/7 8/4 ::r:6/11 7/7
...J DATE-1975 DATE-1975
~
0.r-
-27
Fig.s.(Cont).Linmological Data Collected from ~lontana Creek at the
Highh'ay Bridge,March 26 to August 18,Dcvil's Canyon Project,]975.
10
.....',
roo
::5
u 90
.......en ::>0 80::I:...._c
::E J
J::(70 >-
J ....>-C....60>m
0::::....50 ::>u f-
::>c .
z 40
0u
30
...
DATE-1975 -
4/30 5/zr s/zr 7/2.'e/18
~1r4 .6/11 7/7 8/4
DATE--1975
28
-'"
Fig.6.Limnological Data Collected from Sheep Creek at ~he Bridge,
f'.larch 4 Through August 18 ,.Devil J s Canyon Project,1975.
c.>o
I
~16.0
::J
~12.0
0::
l1J
~8.0
w
.I-4.
0:
W~0.0
3:
4/4 e/zr 8/zr '1/2'8/184/3~6/11 7n 8/4
DATE-/975
9.0
8.0
:::I:7.
Co
6.0
4/4 S/f4 8/1'7/7 6/4
4/30 r¥27 6/27 7/21 e/18
DATE-1975
tc')
0 \.0
<t rt')-0 0en90c.>50<t <tc.>
...J 70 en 40.......<t(!)yIV!~...J
I 50 -.~30.>-:::E .\l-I-30 enz 20-en ..._~.-...J W-<t Z
~10 I I £:)10 I...J 4/4 1l/14 6/11 7/7 e/4 0::4/4 5/14 6/11 7/7·8/4-<t .4/30 1l/27 6/Z7 7/21 e/18 <t 4/30 11/27 6/27 7/21 e/18
...J .DATE-1975 :::I:DATE-J975.~
0r--
-29
Fig.6.(~ont).Linmological Data Collected from Sheep Creek at the
Bridge,March 4 Through August 18,Devil's Canyon Project,1975.
....
-
-
-
4/4 II 14 7/7 8/4
.4/30 5/27 6/27 7/21 .8/IS
DATE-1975
~:::>-,u 80 I-10
"J
en I
0 70 r:c I-~Q~6 -
I mr0::5
I-:::>
>50 l-
I-
(.)40 ~::::>
0z
0 30
(.)4/4 !5/H 6/11 7/7 8/4
4/30 !5/27 6/2.7 7/21 8/18
DATE-1975
..'
30
Fig.7.Limno1ogica1 Dat;a Collected from'Goose Creek at the Bridge,
March 4 Through August 18,Devil's Canyon Project,1975.'
(,)
0.16.0-
w
0:::
::::>12.0
tia:w 8.
0..
~
,W 4.0
t-
a:w O.O..J--~-r--;---r---r--r--r--r-..,...--.---t;4/4 8/27 6/27 7/21 8/18
__8/11 7/7 8/4
;:DATE-1975
&>
(,)
4:(
(,)
~90
....J
~70
,:E .•>-50.t-
z
-I 30«
~
....J 10-4---r-.--rI--'Ir--jr--rj"""'Tj--..--.,---,....-«4/4 8/14 8/11 7/7 8/4
4/30 8/27 8/27 7/2'8/18
~DATE-1975
.0.-
31
9.0
8.0
:::I:7.0
a.
6.0
DATE-1975
4/4 a/14 6/11 7/7.8/4
4/30 8/27 6/27 7/2'8/18
DATE-1975
-,
Fig.7.(Cont).Lirnnological Data Collected from Goose Creek at the
Bridge,~larch 4 Through August 18,Devil's Canyon Project,1975.
DATE-1975 -
.,.
50
::::>10....
J
I>-....
o
~5
:::>....
-4/4 e/l4 6/11 7/7 6/4
4/30 ~6/27 7/21 e/18
~80
u
~70o:z:
::!:60
T-
~5
>
....4u
:::>
~30
o
u 20--r--.-~.,..--..,.-....--....--....--....--....--
~.5
4/30 OJ/27 6/27 7/21 8/le
ti/14 6/11 7/7 8/9
DATE-/975·
32
Fig.8.Limnological Data Collected from Cas\vell Creek at the Bridge,
t-Iarch 26 Through August 18,Devil's Canyon Project,1975.
()
0 16.0,w
0:
:J 12.0
ti
0:::8.0wa..
..;.0..::i!:w 4.
I-
0::O.w
ti~
fJ/zr IS/V 7:21 8/18
6/11 7/1 8/4
DATE-1975
:I:
0.
9.0
8/18
DATE-1975
I i
5/14 6/11 7/7 8/4
5/21 6/27 7/21 B/19
DATE-1975
10 3/28
90
tt)80
ou«70u
en
<t 60
..-1......
(!)50
:i:,
~40
wzo 30
0::
<t
:c 20
5/14 6/11 7/7 8/4
lS/Z1 6/27 7/21 8/18
DATE-1975
"!I/2S -
t()ou«u
en
<t
-l
(?>
::;E 40,
..>-
I-
Z
-l
<J:2
~
-l
<J:
-I
.~
o
I-
33
Fig.8.(Cont).Limnological Data ColI ected from Cas\~ell Creek at theBridge,March 26 Tnrough August 18,Devil's Canyon Project,1975.
180-
170
160
150
140
10
:::E 130u ::>"-I-en
0 120 -:>
I:t:>-~I-5~110I Cl
>-[D
r-roo 0:::>>r-
I-
900
:::::>.
Clz 800u
70
6
50
.40
3 I •I ,
3/26 .15/14 6/11 7/7 8/4
5/27 6/27 7/21 8/la
DATE-/975
5/14 6Ilt 7/7 8/4
5/27 6/27 7/21 e/18
DATE-1975
.-
-
-
-
-
...
34
-
Fig.9.Lirnnological Data Collected from the Kashldtna River at the Bridge,
ApriJ 24.1nrough August 18,Devil's Canyon Project,1975.
(.)o
I
W
0::16.0:::>
~a:12.
wn.~8.0
w
'I-4.0
o
9.
8.0
=[7.0
6.0
5/27 6/21 7/21 8/19
6/11 7/7 8/4
5.()-I"-;r--Y-.,--r-...,--r--,,..-r--~......--
4/24 !ill 4 8/11 7/7 8/4
4/ao fS/27 8/ZT 7/21 e/ls
DATE-1975 DATE-I975
Iii i .1 I \
4/24 ~/14 6/11 7/7 8/4
4/30 em 6/27 7/21 8/18
DATE-1975
rt)
0u«
(J
rn
<C
rt)70.-J
.......0
(!)7 u 60::«uI.>-rn 50I-50 <C
--Z -J.--.......-J :3 (!)40
<C ~~I-J 10 •rn 3«4/24 5/14 6/11 7/7 8/"rn
4fro e/21 e/27 7/21 8/18 W-J Z 20~DATE-J975 Cl
0::0 <Ci-:r 10
35
Fig.9.(Cant)._LinmologicaL Data Collected from the Kashl'l'itna River at
the Bridge;April 24 Through August 18,Devil's Canyon Project,197S.
100
~80 50()......en 700:c ::::>~
~60 r-
I J
>-I
r-50 >-t->0r-4 CD0
::::>n:
0 ::::>
z 30 t-
O 4/2.4.~/14 ,6/11 7/7 8/4 10()4/30 ~/2.7 6/27 7/2/8/18
DATE-1975
5
I
4/30 !!I/27 6/27 1/2/e/18
e/l4 6(11 717 8/4
bATE-'1915
36
..'
_.
Fig.10.Limnological Data Collected from Little WillOl';Creek at the
Bridge,April 24 Through August 18,Devi1's Canyon Project,1975.
(,)
0
I
Wa:::16.0 9.0
:::>
~8.0a:::12.
wa.:I:::!:0.7.0
w
I-4."S.O
0::
W 5.0I-0.0 J I I I I I ,I<4/24 M4 6/11 7/1 8/4 4/24 1l/14 tI/1I 7/7 8/4:=4/3!J t5/27 6/27 7/21 8/18 4/30 Ilm 6/27 7/21 8/18
-OATE-1975 DATE-1975
rt)-0
U
oct
U 1'1)"
C/)0
<::u«
"-.oJ 90 u
......(/)50
(!)<C::::10 -140I
>-.....
(!)
I-~30z50
.J C/)
(/)
<C 30 W20~z
-.oJ 0
<C 10 a:::10I<C-I 4/24 8/14 e/ll 7/7 8/4 :z:4/24 5/14 6/11 7/7 8/4
<C 4/30 6/27 6/27 7/21 8/18 4/30 5/2.7 6/27 7/21 e/18
I-DATE-1975 DATE-19750r-
..
37
Fig.10.(Cant).Limnological Data Collected from Little Willow Creck at
the Bridge,April 24 Through August 18.Devills Canyon PToject,197S.'
~~()........
~70
:E ::;)
::(60 l-
I "":)
>-I
f-50 >-
>f-
f-0
()40 ED
::;)c:
0 :::>z 30 f-a
()
20-L-'lr-"-.Jf---.-r---r--r-....................--
4/24 ~/14 S/Il 7/7 80M
4/30 Mo7 S/2T 7/21 a/18
DATE.-1975
10
5
I
.4/30 5/2T 6/27 T/2(e/ls
&'14 8/11 7/7 8/4
DATE-1975
38 -
Fig.11.Limnological Data Collected from WillO\~Creek at the Bridge.
r.larch ·26 Through August 18,Devil's Canyon Project,1975.
3/28
8.0
5.O~..,---.-r-.---r--.I--C-,r-r--r-.,.
4/30 e/Z7 e/27 7 21 a/18
e/14 6/11 7/7 8/4
DATE-1975
6.0
9.0
~7.0
e/27 6/27 7/2\8/18
6/11 7/7 8/4
.DATE-1975
{)o
Iw 16.0
0:
:::>!;:t 12.0
c:::wa.8.0
::
~wl-4.0
0:w O.O,...L.--t-::r===h-.-.-r--r--r--......,r-
~a/28
3:
-
4/30 &1'27 6)27 7/21 8/18
5/14 13/11 7/7 8/4
DATE-1975·
ro
0
0
<t ....0
en«ro
...J90 o 60-0......~(!)0::=70 50
I .en>-«
-1-5 ..J 40z......
:J (!)
<t30 ~30~
..J en
<t enw 20
..J !/l1S 4/30 e/27 em 7/21 B/l8 Z
<t e/I..6/11 7/7 8/4 CrDATE-1975 0::100«a/21S~.:I:
-..
39.
Fig.11.(Cant).Limnological Data Collected from ~';i110\"Creek at the
BridgeJ.March 26 Through August IS,Devil's Canyon Project,1975.
-
10
-5
5
::>
I-
J
I
>-".'
.....
0
CD
0:
::J
t-,
/
I I ( I I t
e/27 5/Z7 7/2 r a/18
6/11.7/7 a/~
.DATE-1975
160
150
140
130
120
~u 110.....en
0
:I:100~
J
I 90>-l-
S;
~80
(.)
:J
'0 70z
0u 6
50
40
30
20 !I I I I
"$/2Ji 4/30
e/14
-1 .......--:-,---:-,---r---,.---,.--.---T'""""",,"",-.--
4/30 e/27 6/27 7/21 aIrs
5/+-5/11 7/,..a/40 .
DATE,..1975
-
".
40
Table 16.Limnological Data Collected from Four Tributaries of the 5usitna River.
Tributary
Fourth of Gold Indian
Type of Data JUly Creek Creek River
,.."l\<o;r Date (1975)8/9 8/13 8/19
Time 4:13 p.m.6:00 p.c.11 :50 a.m.
Depth range (feet)1-3 .5-3 1-4
Water temperature (C)14.0 12.0 9.0
pH 7.5 8.1 7.5
Total alkalinity (mg/l as CaC03)34 120 34
Hardness (mg/l as CaC03)17 160 34
Dissolved oxygen (mg/l as 02)9 11 11
Portage
Creek
8/10
5:00 p.m.
.5-4
9.0
7.5
51
34
11
.Table 17.Limnological Data Collected from the Susitna River I:;unediately Above Gold Creek,August 1975.-
Type of Data
Water temperature (C)
pH .
Total alkalinity (mg/l as CaC0 3)
Hardness (mg/l as Ca003)
Dissolved oxygen (mg/l as 02)
Orthophosphate (mg/l as P)
Nitrate (mg/l as N)
.Nitrate (mg/l as N)
Turbidity (FTU)
Specific conductance (unhos/cm)
8/13
6:00 p.m.
14.0
8.0
86.0
.94.0-
11.0
70.0
165.0
8/18
3:00 IZ.m.
12.0
8.0
86.0
110.0
10.0
0.04
>0.01
>0.10
Table 18.Limnological Data Collected from the Susitna River I~ediately Above Portage Creek,
August 1975.
....8/12 8/18
~Type of Data 1:10 p.m.3:00 p.in.
Water temperature (C)13.0 11.0
pH 8.0 8.0
Total alkaliniLy (mg/l as CaC0 3)68.0 .94.0
Hardness (mg/l as CaCO_)68.0 103.0
Dissolved oxygen (mg/!~as O2)13.0 11.0
Orthophosphate (mg/l as P)0.05 0.05-Nitrite (mg/l as N)0.01 0.02
Nitrate (mg/l as N)0.5 0.3
Turbidity (FTIi)85.0 190.0
-'.
-
--.
41
TABLE19.LimnologicalDataCollectedFromFifteenSloughsAlongTheSusitnaRiverBetweenTalkeetnaAndPortageCrecK...TotalDissolvedSloughDateDepthTemp.BottomAlkalinityHardnessOxygenNumber1975Time(feet)(C)Type·pit(mg/1-CaC03)(rng/1-CaC03)(mgl1-b2)------.......8a8/92:50pm-'13.5S,Sa,G,C7.58668898/91:16pm0.858.0S,Sa,G,C.7.05168. 7lOa8/7--9.5H,S,G7.06868lOb8/7--10.0H,S,G,C7.586100118/7-2.308.5Sa,G,C7.510312010128/7,.-5.5~I,S,G,C7.51371208~l'V138/134:25pm0.666.5Sa,G7.5lq31009148/7,1,469.0S,Sn,G,C7.06851-158/812:0Spm1.6313.5S,Sa,r.7.051349168/81:26pm0.507.0S,G,C6.551347.'.178/149:00am0.834.5S,G,C7.051518188/149:40am0.758.0.H,S,Sa7.568689198/1011:25am2.949.5S;Sa,G,C7.586688208/10If:13pm-9.5S,Sa,G,C8.068518218/101:33pm-10.0S,Sa,G,C,B7.5103868*H-Muck,S-Silt,Sa-Sand,G -Gravel,C -Cobble,D -Boulderl
c,"f---II-~TABLE20.LimnologicalDataCollectedfromtheImpoundmentAreaoftheSusitnaRiverNearJay,Watana,andDeadmanCreeks,Devil'sCanyonProject,April24,1975.JayCreekWatanaCreekDeadmanCreekTypeofData(100Yds.Downstream)(3Mi.Upstream)(100Yds.Downstream)DepthSurfaceSurfaceSurfaceWaterTemperature(C)0.00.00.0pH8.07.57.5TotalAlkalinity(mg/lasCaC03)102.6102.651.3Hardness(mg/lasCaC03)119.7136.868.4DissolvedOxygen13.013.a13.0lIloTurbidity(JTU)w0.50.50.4Conductivity(Alllhos/cm)280255220
present,including grayling,burbot,rainbow trout,whitefish,coho,and
chinook salmon.
Except for slough 12,total alkalinity measurements ranged from 51 mg/l
to 103 mg/l caC03.Harclness values ranged from 34 mg/l to 120 mg/l caC0 3 •
Dissolved oxygen measurements ranged from 7 to 10 p.p.m.
Table 20 shows the results reveal no alarming readings and are charac-
teristic of undisturbed Alaska rivers.
The section of the Susitna River between Devil Canyon and Talkeetna
will be most adversely affected by flow regulation of a hydroelectric dam.
This section of river has not had a systematic limnological study conducted
on a year-round basis.An expanded linmological study is necessary to
fully understand the present characterisitcs of the Susitna River.
CONCLUSION
The Alaska Department of Fish and Game has not conducted studies of
limnological characteristics or indigenous fish stocks of the mainstem
Susitna River prior to 1974.Therefore,comparative data are either minimal
or non-existent.
This fisheries study documented anadromous and resident fish fry utilizing
the Susitna River for rearing during the winter when the water is silt free.
It appears the majority of salmonids migrate to freshwater tributaries and
other periphery areas of the Susitna River when the silt loads increase dur-
ing the sunnner.This undefined migration warrants additional study which
should attempt to define species composition of the Susitna River on a
seasonal basis.The section of river which will be most affected is
directly downstream of the proposed Devil Canyon Dam site.A limited amount
of sampling of resident fish stocks in this area revealed popUlations of
grayling in all tributaries except Gold Creek.The timing in which these
grayling and other resident fish utilize the Susitna River is not known,and
should be documented.
The limnological aspect of this study contains important baseline data
that should be continued and expanded in order to document changes in water
chemistry following iriIpoundment.It has become apparent during this study
that one of the more critical areas which require additional research is
definition of flows.Minimum seasonal flows should be established through
regulation to i~sure access in and out of sloughs for fish.
ACKNOWLEDGEMENTS
The author wishes to acknOWledge the assistance of Jeffrey D.Hock,
temporary Fishery Biologist,the U.S.Geological Survey,Water Resources
Division,for their advice and use of their laboratory,and the IJ.S.Fish
and Wildlife Service for funding.
44
.....
-
...'
-
-
....
POTFNIIAL IMPACTS
Following is a list of impacts the Fisheries Divisions of the Alaska
Department of Fish &Game has compiled.This is not necessarily a complete
list,as other impacts may become apparent during the course of the study .
Environmental impacts will occur both up and downstream from the dams.Two
phases of development of the hydroelectric facilities will occur:(1)the
construction period projected to extend over a l2-year period,and (2)the
operation of the facility.Environmental impacts of this project will be
(1)those occurring during the construction period,and (2)those occurring
during the post-construction period which constitutes the entire life of
the project.
Construction Period Impacts
Construction of the dams will necessitate the diversion of the Susitna
River from its natural course.The major effect during this period is ex-
pected to be an increase in silt load due to construction activities.This
decrease in water qualify may cause the following impacts:
1.Disorientation of adult salmon returning to their horne streams may result
in a decrease of fish production in the upper areas of the river.
2.Change in substrate composition in sloughs resulting in decreased
spawning and rearing area.Chtnn and sockeye salmon are known to
utilize these areas for spawning.
3.Lack of clearwater conditions during fall and winter months limiting
fry from utilizing the mainstem Susitna River for rearing.
4.Degradation of water quality resulting in possible alterations in the
aquatic food chain.Some orders of insects,important food i terns for
salmon fry,may be unable to adapt to the changed water quality.
5.Reduced flows associated with filling of the reservoir may reduce
downstream spawning habitat and could alter fish distribution below
dam.During the low flow construction period a substantial risk of
water pollution from concrete pouring,oil spillage,etc.will be
present.
6.Reduction in run of salmon could follow reduction of flow (Penn,1975).
Reducing flows could result in reduced access for salmon utilizing
the upper stream areas.
Post-Construction Impacts
1.Turbidity -The Susitna River currently carries a heavy load of glacial
silt in spring and surrnner.The river's water is clear during fall and
winter months.Impoundment will result in increased turbidity and
silt loads year-round.Also,turbidity may be increased if there is
pennafrost in the area (Afton,1975).This condition may cons tribute to:
a.Inability of fry to utilize the rnainstem for rearing.
45
d.
f.
b.Decreased summer turbidity allows greater light penetration which
would encourage more primary production.Rate of zooplankton
development may not necessarily be increased due to possible
lower temperature in April-May period.Rearing salmon depend on
zooplankton stock at this time.
c.Influence of bedrock on impotmdment water quality may affect
fisheries (Duthie and Ostrofsky,1975).
d.Increased mortality due to decreased summer turbidity resulting
in higher predation success.
e.Decreased spring and summer turbidity would likely limit downstream
migration to the darker hours,thereby extending the downstream
migration periods further than at present since some migration
occurs in the turbid waters during daylight.There is evidence
suggesting that increased time to migrate increases yotmg
salmon mortality (Geen,1975).
2.Temperature -Normal temperature regimes will be altered by impotmdment.
Various effects may be seen.These include,but are not limited to:
a.Any change in downstream fall temperatures could affect spawning
success of salmon.There is evidence that relatively high tem-
peratures are associated with poor returning Ytms (Geen,1975).
b.Changes in the incubation period of salmon eggs and incubation
condi tions .
c.Premature fry emergence and seaward migration due to increased
rate of development could result in increased mortality because
the migration may occur prior to the warming of estuaries and the
development of estuarine zooplankton populations.
Alteration of the normal thermal regime would change the overall
productivity of the river,which could add extreme stress to fry
populations.
e.Summer temperature decrease could affect upstream migrational time
for adult salmon.
Changes in the aquatic food chain,due to the inability of some
organisms to adapt to even slight thermal alterations.
3.Chemical and Physical Parameters.
a.Supersaturation of nitrogen and oxygen depletion resulting
from stratification and spillage are possible,impacting down-
stream fishes for an tmknown distance.
b.Increases in dissolved nitrogen gas can also be due to air vented
into turbines to reduce negative pressures during weekend periods
of sustained low generating levels (Ruggles and Watt,1975).
46
...
-
c.Dams slow water transport which gives more time for the
biochemical oxygen demand to consume available oxygen,thus re-
ducing dissolved oxygen content.Dissolved oxygen levels will
probably be altered due to changes in river conditions.Low
levels could preclude the suvival of fish in downstream
slough areas.
d.Conductivity,alkalinity,and pH can increase after impouncbnent
construction (Geen,1975).
4.Organic Debris
a.Debris has a time frame of 100-200 years,reduced with time,
resulting from forest drowning.
5.Flows
a.Altered lake levels may result in flooding,slumping,erosion,and
general shoreline degradation.Littoral zone changes affect
fisheries.
b.Changed ice regimes can also affect river and lake shorelines.
A change in water quality can be expected due to erosion and
sediment processes from altered water levels,flows and ice
regimes,(Dickson,1975).
c.Changes in substrate composition of spawning areas due to lack of
natural scouring;this would also affect winter survival of eggs.
d.Decreases in water levels during June and July will affect adult
access to spawning areas.
e.Reduced discharge during summer could alter upstream migration of
salmon.
f.Reduction of flow could affect survival of young salmonids moving
to saline water during April-May.Seaward migration is directly
related to river velocity and therefore could extend this period,
(Geen,1975).
g.Reduction of nonnal spring and summer flows could result in a
decrease of fry rearing habitat and could leave out-migrating
smolts stranded.
RECCMvtENDATIONS
Before the full effects of this project on fish and wildlife are identi-
fied,considerable studies are necessary which will be both long term and
costly.Following is a brief resume of biological studies and investigational
goals required prior to final definition of impacts resulting from impouncbnent
of the Susitna River at Devil Canyon and Watana.
I
47
U.S.G.S.,and other appropriate agencies.The following is a partial
list of necessary information:
1.Current unregulated flows and projected regulated flows.
2.Temperature regimes.
3.Turbidity and sediment data.
4.Anticipated physical changes to the natural locations,on a
seasonal basis....
II A cO&irehensive fishery study to address adult and juvenile sallnonid
abun ance,distribution,migrational patterns,and age composition by
species for areas both upstream and downstream of the proposed Devil
Canyon Dam.
The Cook Inlet fishery is of mixed stock and presents many problems for
its proper management.Total escapement data by species is not avail-
able for the Susitna River drainage.Until total escapement into the
drainage is determined the value of the sallnon stocks in the upper
Susitna River cannot be evaluated.Spawning ground surveys demonstrate
the importance of this area to chum and pink sallnon.
-
Data collected since JUly 1974 provides baseline information only.
Generalizations may be made,but sufficient information is not avail-
able to detennine full impacts of dam construction and operation upon
the fishery.Intense investigational projects should be initiated in
the study area to provide pre-construction data to adequately evaluate
possible impacts.
III A study of affected habitat areas will be conducted in conjunction with
the fisheries program.Productivity and limiting factors can be de-
fined by a thorough lirrmological study.Physical,chemical,and
biological conditions of the Susitna River and other affected areas
should be examined.Specific concerns are:
1.Changes in quality and quantity of spawning habitat both upstream
and downstream of the proposed dam sites as a result of (a)flow
and releases,(b)innundation of upstream areas and (c)effects
of periodic pool fill and drawdown.
2.Effects upon the habitat and fisheries resource directly as a
result of construction activities.
3.Effects of increased human use resulting from improved air and
road access upon both the Susitna River drainage and adjacent
fisheries.
4.Environmental assessment of transmission line system to determine
effects of stream crossings upon resident and anadromous fish
populations and habitat during both construction and subsequent
operational IT~intenance.
For further information on biological study proposals refer to the
package presented to U.S.Fish and Wildlife Service and U.S.Anny Corps
of Engineers on November 18,1975.
48
-
-
-
Atton,F.M.1975.
Saskatchewan.
32:101-105.
LITERATURE CITED
Impact Analysis:Hindsight and Foresight in
Journal of the Fisheries Research Board of Canada.
Barrett,B.M.1974.An Assessment Study of the Anadromous Fish Populations
in the Upper Susitna River Watershed Between Devil Canyon and the Chulitna
River.Alaska Department of Fish and Game.1-56.
Cantlon,J.E.1969.The Stability of Natural Populations and Their
Sensitivity to Technology in Diversity and Stability of Ecological
Systems.Brookhaven Symposia in Biology.22:197-206.
Dickson.I.W.1975.Hydroelectric Development of the Nelson River System
in Northern Manitoba.Journal of the Fisheries Research Board of
Canada.32:106-116.
Duthie.H.C.,and M.L.Ostrofsky.1975.Environmental Impact of the
Churchill Falls (Labrador)Hydroelectric Project:A Preliminary
Assessment.Journal of the Fisheries Research Board of Canada.
32:11 7-125.
Friese,N.V.1975.
lations of the
Proposed Devi 1
Fish and Game.
Pre-authorization Assessment
Upper Susitna River Watershed
Canyon Hydroelectric Project.
1-121.
of Anadromous Fish Popu-
in the Vicinity of the
Alaska Department of
Geen.G.H.1975.Ecological Consequences of the Proposed t·10ran Dam on
The Fraser River.Journal of the Fisheries Research Board of Canada.
32:126-135.
Lind,O.T.1974.Common Methods in Limnology.St.louis,C.V.Mosby Co .•
154p.
McCoy,G.A.1974.Preconstruction Assessment of Biological Quality of
The Chena and Little Chena River in the Vicinity of the Chena Lakes
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Penn.A.F.1975.Development of James Bay:The Role of Environmental
Impact Assessment in Determining the Legal Right to an Interlocutory
Injunction.Journal of the Fisheries Research Board of Canada.
32:136-160.
Ruggles,C.P.,and W.O.Watt.1975.Ecological Changes Due to Hydroelectric
Development on the Saint John River.Journal of the Fisheries Research
Board of Canada.32:161-170.
Warren,C.E.1971.Biology and Water Pollution Control.Philadelphia,
W.O.Saunders Co.434p.
49
Welch,P.S.1952.Limnology.New York,McGraw-Hill Book Co.538 p.
Wilhm,J.L.1970.Range of Diversity Index in Benthic Macroinvertebrate
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No.5,pt.2,p R22l-R224.
APPENDIX
The aerial photographs in this appendix show the sample sites (fish,
linmological,and benthos)used in this study.The exact site was located
under the letter which denotes the type of sample ...A,R,B,or L.
There is approximately a six-mile stretch of river near the Shennan
area not covered by aerial photographs.With the exception of this stretch,
the river is completely covered by photographs from Devil Canyon downstream
to the mouth.The scale from Gold Creek downstream is 1:63.360 and the
scale upstream from Gold Creek is 1:30.000.These photographs were taken
in July,1975.
LEGEND
A -Adult fish
R -Rearing fish
B -Benthos sample site
L -Limnological study points
W-Winter collection
S -Summer collection
KS-King salmon
SS-Silver salmon
50
RS -Red Salmon
CS -Chum salmon
PS -Pink salmon
RT -Rainbow trout
GR -Grayling
DV -Dolly Varden
BU -Burbot
WF -Whitefish
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