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February 13,1984
1.8.2/4.3.1.1
VENTURE
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CONFIDENTIAL;PRIVILEGED WORK
PRODUCT PREPARED IN ANTICpATIO,N
OF LITIGATION;RESTRICTED A,)'.\,
DISTRIBUTION t ,-tJ
Mr.Jon S.Ferguson
Project Manager
Alaska Power Authority
334 West 5th Avenue
Anchorage,Alaska 99501
Subject:Susitna Hydroelectric Project
Lower River Plan of Study
Dear Mr.Ferguson:
Enclosed for your review and comment is the second draft of the report
entitled,"Lower Susitna River Fisheries Resources Plan of Study."We
are requesting comments by Friday,February 17,1984.I realize that
with the first Agency Workshop scheduled this Wednesday time is at a
premium.However,FY85 planning should proceed as rapidly as possible.-
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If you have any questions regarding these plans or schedule,please
contact Dr.Jim Thrall or Dr.Larry Gilbertson.~~~
//~v-,';;;;Very 71$lt..;t ~u ,s,.
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Pro j ~'C.tj)-i-{ec t or
cc Enc:as noted
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R.Fleming,Power Authority
E.Marchegiani,Power Authority
T.Arminski,Power Authority
T.Trent.ADF&G
N.Hernandez,HE
J.Thrall,HE
L.Gilbertson,HE
40471 IS
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CONFIDENTiAL;PRIVILEGED WORK
PRODUCT PREPARED IN ANTIC/PATlON
OF LITIGATION;RESTRICTED
DISTRIBUTION
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LOWER SUS ITNA RIVER
FISHERIES RESOURCES
PLAN OF STUDY
SECOND DRAFT
HARZA-EBASCO
Susitna Joint Venture
ARLIS
Alaska Resources
Library &Informat1on ServIces
Anchorage,Alaska
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_..------.............._-._------"--_.-~--_.TABLE OF CONTENTS
Page
1.0 INTRODUCTION .. ...··· · · · · · · ········1-1
2.0 GENERAL APPROACH .. .···· ·· · ·· · · ····· ·
2-1
3.0 PHYSICAL CHANGES AND FISHERY IMPACT ISSUES ·· · · · ··3-1
3.1 SUMMARY OF IMPACT ISSUES ·· ·
·3-1
3.2 PH YSICAL CHANGES · ···3-1
3.2.1 Discharge ·· ···· · ·
· · ·
3-1
3.2.2 Water Temperature ··· ·
······· ··3-5
.-3.2.3 Suspended Sediment (Turbidity)3-7
3.2.4 Bedload Sediment ········3-10
3.2.5 Ice Processes · ·····3-12
4.0 LOWER RIVER MORPHOLOGICAL ASSESSMENT ··········4-1.-
5.0 FISHERIES IMPACT ISSUES ······ ··········5-1
5.1 ACCESS TO SPAWNING GROUNDS ··· ·· ··· ·
···5-1
5.1.1 Background ··· ·· ··· ·····5--1
5.1.2 Information and Study Needs ·5-4
(:0 5.1.3 Study Location ··· · ·
··5-5
I""'-5.1 .4 Study Methodology 5-5l"J ··· ··· · ··r>-,......
.q-
.q-
(:>5.2 CHANGESIIIJ AVAILABILITY OF SPAWNIt.lG HABITAT 5-8(:>· ·
··-0
1.0
1.0r......5.2.1 Background 5-8('I')··· · · ···('I')5.2.2 Information and Study Needs 5-10····
5.2.3 Study Locat ion ·· ····· ·· · ·
·5-11
.....5.2.1:1 Study Methodology ·· ·
· · · · ·· ·
·5-11
i
TABLE OF CQNTfNTS
5.3 CHANGE IN INCUBA nON SUCCESS • • ••• •a • • • •5-12
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5.3.1
5.3.2
5.3.3
5.3.4
Background • • • • • • • • •
Information and Study Needs •••
Study Location •••• • • .
Study Methodology ••••••
...5-12
5-14
5-14
5-15
5.4 OKANGES IN AVAILABILITY OF SUITABLE REARI~G
AND OVERWINTERING HABITAT • . • • • • ••••e • •5-17
. . .
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5.4.1
5.4.2
5.4.3
5.4.4
Background ••• • • . • •
Information and Study Needs • • ••••
Study Location •••••••
Study Methodology • .
5-17
5-21
5-22
5-22
.....5.5 ALTERED JUVENILE OUTMIGRATION PATTERN 5-25
-5.5.1
5.5.2
5.5.3
5.5.4
Background • . • ••• • • •
Information and Study Needs •
Study Location •
Study Methodology •
5-25
5-26
5-27
5-27
6.0 REFERENCES CITED •••••••
i i
6-1
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5.3 CHANGE IN INCUBATION SUCCESS 0 ••••••••,00"5-12
5.3.1
5.3.2
5.3.3
5.3.4
Background •••••
Information and Study Needs •
Study Location •••••
Study Methodology • •••••
. .
5-12
5-14
5-14
5-15
5.4 CHANGES IN AVAILABILITY OF SUITABLE REARING
AND OVERWINTERING HABITAT •••••••••o • •"5-17
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5.4.1
5.4.2
5.4.3
5.4.4
Background ••• • • • • ••••• •
Information and Study Needs ••••••••
Study Location •••• • • • •
Study Methodology • •
5-17
5-21
5-22
5-22
5.5 ALTERED JUVENILE OUTMIGRATION PATTERN 5-25
. .
5.5.1
5.5.2
5.5.3
5.5.4
Background •Q 0 D ~0 •0 Q •Q •~D • •
Information and Study Needs •.••••
Study Location •••
Study Methodology • •
5-25
5-26
5-27
5-27
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6.0 REFERENCES CITED • • • • • . . •
i;
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6-1
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1.0 INTRODUCTION
The Alaska Power Authority (APA)is proposing to construct two
hydroelectric dams on the Susitna River,Alaska.Licensing of the
proposed projects with the Federal Energy Regulatory Commission (FERC)'
requires'that APA provide an'analysis of the environmental impacts of ,.
_the project.It is expected that the distribution,abundance,and
production of fish stocks both upstream and downstream of the dams will
change as a result of the project.Thus far,the aquatic studies and
hence the a~sessment of environmental impacts has been largely limited,,
to the Susitna River from Talkeetna to the Oshetna River (the upstream
bounqary of the reservoir impoundment).This emphasis on the middle
(Talkeetna to Devil Canyon)and upper (Devil Canyon to the Oshetna
River)reaches of the Susitna occurred because project related impacts
above Talkeetna are expected to be most severe.In the lower river,it
is exoected that streamflow from tributaries'would-reduc'e the magnitude
of physical changes (e.g.~changes in Jdischarge)caused by the
project.Therefore the assessment of potential environmental impacts
downstream from Talkeetna has been limited.
Resource mana-gement agencies expressed,concern that there was little
quantitative support to justify the cop~Jusion that project related
impacts to fishery resources downstream'of Talkeetna would not be
significant.In response to this concern,the Harza-Ebasco Joint
Venture (HIE)has developed 'a comprehensive program for the evaluation
of impacts to fishery r~rces in the lower river.The leveT"lft
effort reqlilrea"-t~--~~o;-~1'i7~h'th-i-~-t-~'~k-~-ii~ldepe;dupo~the ex l,St i ng ~
data base and the magnitude of potential impacts.Since project ~-~
operation cannot be used to control flow in the lower river~flow-
related impacts will not be mitigated through ~low regul~iion ~t tbe
project dam.Therefore,studies planned for the lower river will not'
need the high level of resolution as previous studies conducted for the
middle river.~ather,studies outlined are design~d to assess .
potential impacts for th~purpose of identifying andlplanning an
alternative mitigation program.
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___Ih~_plaJ'1 __Qt_$t~gY__~UJ_b~~~eQ ~y _~h_~APA a~_!.~ool to coordinate and ~_
implemen~studies on the lower river,which will be conducted by
participants of the aquatic studies team.The plan responds to agency
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issues and complies with state and federal statutes and regulations.
As a "blueprint"the study plan is compared with the study results to
determine whether the stated objectives have been accomplished.
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2.0 GENERAL APPROACH----~-_.,-------------~------
The general approach of the lower river study plan is to use an
incremental process through which fishery impact issues can be
evaluated.In Section 3.0,specific impact issues are identified
through a review of the predicted physical changes expected in the
lower river as a result of the project.In Section 4.0,the lower
river is stratified into segments with cOl1lTlon morphological and flow
characteristics.An analysis of impact issues within each segment will
provide a perspective or prioritization for assessing the significance
of each impact.In Section 5.0,existing data and work in progress
(e.g.,fish distribution and abundance,computer simulation models)are
surveyed,and i nformat ion gaps are i dent ified.If the impac~/i s
expected to be significant and more information is needed,then an
outline of the study design and analysis required to accomplish the
impact assessment is provided.The need for new field studies or model
development will be conditional,i.e.,dependent upon the results of
other studies or data analysis of higher priority.Therefore the
assessments of impact issues are coordinated for the purpose of
eliminating unnecessary time and effort.
The primary emphasis of the lower river studies is focused on the
abundance and distribution of the five Pacific salmon species which
occur in the Susitna River.Previous studies in the middle river were
concerned with salmon because of their high recreational and commercial
;I'importance.It is assumed that provisions to maintain salmon
~populations will also allow for the maintenance of the populations of
~~:;:~fish species,particularly spprtfish such as rainbpw trput and
~c grayling.
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--JoO-PJHSICAL CHANGES AND FISHERY IM.2A.tL.lS-SUES-_
3.1 SUMMARY OF IMPACT ISSUES
Based on expected changes in stream discharge,water temperature,ice
processes,and sediment processes~the following were identified as
potentially significant fishery impact issues:
1)
2)
3)
Restriction of access by resident and anadromousfish to
spawning grounds in tri~lrtariesan(r~id~chan~~l-s;
Change in availability of suitable spawning habitat;
Change in incubation success;
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4)Change in availability of suitable rearing and overwintering
habitat for juvenile and resident fish;
5)Altered juvenile outmigration patterns.
3.2 PHYSICAL CHANGES
Identification and assessment of impacts on fisheries resources in the
lower river requires that project related changes in the physical
conditions of the lower river be established.This requires an
assessment of current conditions and a prediction of conditions during
initial reservoir filling and project operations.The most significant
project related changes are expected to involve discharge,temperature,
turbidity,ice orocesses,and sediment processes;each of these are
discussed separately below.
3.2.1 Discharge
The operation of the Susitna Hydroelectric Project is based on a power
production scenario that provides beneficial economics while
maintaining enough discharge to provide for downstream aquatic
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-I'"es~urces (Acres "American 1983).Operating schedule C presented in the
license application was defined as the most environmentally and
economically feasible.Reservoirs will be drawn down during the peak
energy demand months of wi nter and fi lled during the summer,thus
resulting in downstream flows that will be greater than natural
conditions in the winter and less than natural conditions in the summer.
Mainstem discharge patterns during reservoir operations were predicted
initially by Acres American,Inc.for the FERC license application.
Results of these simulations are given in the FERC license application
in Chapters 1 and 2 of Exhibit E (Acres American 1983).
Recently,AEIDC (1983a)compared natural and with-project flow
conditions in order to statistically find the point in the river where
operational flows become indistinguishable from natural flow
conditions.This was accomplished by reconstructing Susitna River mean
monthly discharges for the water years 1950 through 1981 at all gage
stations and significant tributary confluences between the Watana dam
and RM 25 using historical streamflow data and a water balance computer
program (H20BAL).With-project streamflows are determined by using
reservoir operations models developed by ACRES which estimate release
discharge after accounting for power production.The reservoir
operations model applies operation specifications to predict average
discharge for each month in the 32 year water supply data base.
Results of these simulations (for a 2 dam scenario)demonstrated that
flow increase of greater than 100 percent will occur during the mid
winter months (December,January,February,and March)as far
downstream as the most downstream station used in the simulation (i.e.,
RM 26).At Sunshine,average flow agumentations are estimated to range
between 219 percent and 301 percent for this period (Table 3-1).
Lesser flow augmentation will also occur during October,November,and
Aoril;whereas flow decreases will occur between May and September and
will be most severe in June and July (Table 3-1).At Susitna (RM 26),
\
average flow reductions are predicted to range from 4 percent to 15
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TABLE 1
PREDICTED AVERAGE MONTHLY DOWNSTREAM FLOWS AND PERCENT CHANGE
AT SUN9HNE (RM 87)AND SUSITNA STATION (RM 26)FOR lliE
TWO DAM SCENARIO (FROM AEIDC 1983a)
3-3
percent,whereas "at Sunshine (RMS.7LredlJctions are estimated to be 9
percent to 28 percent.Data for eleven lower stations are provided for
one and two dam scenarios by AEIDC (1983a).
While differences in flow from natural conditions clearly decrease
moving downstream due to the influence of tributaries,efforts to
statistically define river reaches where post project flows differ
significantly from natural conditions were unsuccessful (AEIDC 1983).
Consequently,it is not possible to 1imit the area where flow related
impacts occur;it will be necessary to include the entire lower river
when assessing discharge related impacts.
Decreases in streamflow during summery may restrict access to spawning
areas and change the suitability of habitat utilized for spawning and
rearing.The increased flows during winter and spring may change the
area available for overwinter rearing and in{luence travel time of
outmigrating smolts.
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Monthly flow changes in the lower river have been adequately addressed,
but flow changes on a shorter time period (i.e.,weekly and daily)have
yet to be adequately addressed.This may be especially important for
changes in flood flows which have a significant effect on upstream
migrations of adults (ADF&G 1983a),spawning habitat,ice proce~ses
(e.g.,breakup),and bed scour.Flood events will be most severe in
the late summer when the reservoir is full and least significant in the
spring because the storage capacity of the reservoir will be greatest.
For example,the license application predicts that the 1 in 10 year
flood at Sunshine station will be reduced from 144,000 cfs to 89,000
cfs.Flood durations will be extended beyond the natural conditions
because of the need to discharge until the storage volume criterion is
reestablished.A weekly reservoir simulation model was developed to
predict weekly downstream discharges in the FERC license application.
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·-3.2.1 ·Water Temoerature
The temperature regime of the Susitna River downstream of the project
dams is expected to change during both filling and operations.Any
changes,even small ones of D.SoC to 1.DoC,may have a significant
effect on aquatic resources in the lower river.Many behavioral and
physiological attributes of fish are dependent on water temperature,
including habitat selection,migration timing of juveniles and adults,
instream movements,food consumption,development rates of incubating
salmonid embryos,and growth of juvenile and adult fish.Thus,
predicting downstream temperature regimes and relating these /
predictions to temperature preferences of and tolerances of aquatic
resources is an important comoonent of evaluating impacts in the lower
river.Two of the major concerns about downstream temperature changes
are that temperature differentials at tributary confluences will delay
mi grations of juvenil e and adult sa lmoni ds and season a1 temperature
regimes may change in various habitat types,thus affecting growth,
development rate,and survival of fish in the lower Susitna River.
In the FERC license application,predictions of downstream temperatures
were made using a downstream temperature model,HEATSIM.Input data to
this model includes simulated reservoir temperatures (using a model
OYRESM),reservoir operations,water balance data,and historical
temperature data.Results of these simulations are discussed in
Chaoter 2 of the FERC license application.Recently,AEIDC has
simulated downstream temperatures using another river temperature
model,SNTEMP.A description of this model,including input data,
validation,and calibration is provided in AEIDC (1983b).This model
has some advantages over the HEATSIM model (e.g.,tributary input)and
will thus allow for a more realistic simulation.
Initial predictions of downstream temperatures using the SNTEMP model
are described in AEIDC (1983b)in addition to efforts to statistically
define where predicted downstream temperatures differ significantly
from natural conditions.These analyses have only compared natural and
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with-project condHfons duri ng surmterfi 11 i ng (second SUfl111er only)and
summer operations using hydrologic and meteorologic data from periods
of normals maximum,and minimum downstream temperatures.However,
reservoir release temperature information is very sparse for
operational conditions as the OYRESM model has only been run for 1981
meteorological conditions and predictions are only possible to Sunshine
station.
Utilizing simulations of both AEIOC and the FERC license application,
the following points about lower river post project temperatures can be
made:
1)During the second year of filling,the temperature regime,
during June to August,in the reach downstream of Talkeetna is
predicted to be 1°to 2°lower than the natural regime,
regardless of hydrologic and meteorologic conditions in
whatever year the filling occurs.
2)During operations,there will be observable temperature
changes downstream of Tal keetrrcr~-Theextent and magnitude of
these changes cannot be predicted at present.Expected
changes include:
a)Lower summer temperatures because of the reduced mainstem
flow and subsequent proportional increase in contribution
by the Chulitna and Talkeetna rivers.
b}During early fall,downstream temperatures would be above
aoc for some length of the river downstream of Talkeetna
and for an undetermined period of time (depending on
meteorologic and hydrologic conditions).
c)In late fall and wi~ter,the river is anticipated to be
normal (i.e.,aOC)by the time it reaches Talkeetna,
thus,conditions would be similar to natural.
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__d)Between Talkeetna and Suns_nine stati_on,June through _
August water temperatures will be reduced and those in
September increased as compared to natural conditions
(two dam scenario)(Table 3-2).
Project related changes in downstream temperatures have yet to be
adequately addressed.Work in progress (by AEIOC)will address most of
the information needs.For operation scenarios,OYRESM predictions for
reservoir release temperatures will be expanded by AEIOC to include all
months of the ice free season for a range of meteorologic conditions.
3.2.3 Suspended Sediment (Turbidity)
Sediment particles that are transported in a stream while being held in
suspension by the turbulent components of the water are classified as
suspended sediments.Within the Susitna,glacial outwash contributes
most fine sediment.Analyses of suspended sediment and turbidity in
the Susitna River has been conducted by R&M (1982c,see page E-2-200)
and the USGS (unpub1.),while periodic measurements of turbidity at
specific habitat locations in the lower river have been obtained by
ADF&G as part of their Aquatic Habitat and Instream Flow Study program
(e.g.,Figures E.5.7 to E.5.34,ADF&G [AH]1981,Chapter 2 of the FERC
License Application [po E-2-28 to E-2-30],and Table 4-0-45 AOF&G [AH]
1983).These measurements indicate that under natural conditions,
summer turbidities are highest (up to 1,056 NTU,1,620 mg/1 as measured
at Sunshine by the USGS);and winter turbidities are low (e.g.,0-2
mg/l in March as measured at Sunshine).
Most suspended sediment in the lower river is from the three major
tributaries,especially the Chulitna River.Downstream of the
confluence,the Yentna River is the major additional source of sediment
because it is glacier fed.Although the glacier fed rivers are the
major sediment source,some bank erosion and resuspension of deposited
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TABLE 3-2
MONlHlY TEMPERATURES (OC)AT THE THREE RIVERS CONFLUENCE (RM 98)
AND SUNSH INE (RM 84)IN JUNE-SEPTEMBER FOR SEVERAL
PROJECT SCENARIOS (FROM AEIDC 1983b)
Year 2 of One Dam Two Dam
Natural~.!Fill i ng!/Operat ion.!!.!Operation.!!.!
Month °C °C °C °C
June
Confluence 7.2-9.9 6.1-8.1 8.0 7.6
~Sunshine 7.2-10.3 6.5-9.3 8.2 7.9
-.July
Confluence 8.7-10.6 7.6-9.1 8.1 7.9
Sunshine 8.9-11.2 8.2-10.3 8.1 7.9
~
August
Confluence 7.5-9.7 6.5-8.2 8.2 7.5
Sunshine 7.5-10.2 6.7-9.1 8.1 7.6
.....
September
Confluence 4.7-6.6 4.6-6.1 6.7 6.6-Sunshine 3.9-6.6 3.8-6.2 6.6 6.6
~,
!/15 year simulation (1968-1982).
~/Using 1981 hydrologic and meteorologic data and results of DYRESM
mode 1 for 1981.
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sediment occu~s.Because of the dilution of water by tributaries,
turbidities and suspended sediment concentrations decrease between
Sunshine and Susitna Station (Figures E-2-78,81).
During filling and operation of the project,the reservoirs will act as
sediment traps which will decrease the overall amount of suspended
sediment moving downstream.A significant enough decrease in turbidity
will enhance light penetration (thus increasing production)but
(
eliminate the use of turbid water as cover by sa1monid juveniles
rearing in the river.A modeling study (on Watana Reservoir)was
conducted by Peratrovich,Nottingham,and Drage (1982)to predict
downstream turbidities in the middle river.The study predicted that
turbidities in the middle river would range from 20-50 NTU in the
summer and 10-20 NTU in the winter,and that the reservoir would retain
about 80 percent of the natural sediment load (Figure E.2.80).The
relative change in suspended sediment/turbidity levels below the
confluence of the Chulitna,Talkeetna,and Susitna rivers was estimated
using a mass balance relationship.The license application (Chapter 2)
predicted that at a flow of 12,000 cfs,the suspende~sediment below
the confluence would be decreased by 3 percent in summer,whereas at a
filling flow of 6,000 cfs,the suspended sediment concentration could
increase by apProximately 8 percent.Any decreases in the suspended
sediment concentrations and turbidity in summer will not likely be of
significance to the aquatic resources in the lower river.This is
because that in order for turbidity decreases to be significant to
benthic production or to decrease cover available for rearing fish,
turbidity must be in the lower end of the 20-50 NTU range (AEIDC
1983b).Because of the high suspended sediment load of the Chulitna
River (twice the Susitna above the confluence),decreases below 50 NTU
will not occur.
During winter.suspended sediment concentrations have not yet been
predicted quantitatively.Because the suspended sediment concentration
of water released from the reservoir will be increased over natural
conditions,concentrations in the lower river will also be evaluated.
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Although the inflow of tributaries below the confluence will dilute the
suspended sediments,concentrations will still be higher than under
natural conditions.Also there is a concern that increased winter
flows will re-susoend deposited sediments resulting in a further
increase in concentration of suspended sediment.Juvenile and resident
salmonids utilize riverine habitats during the winter.Therefore,
unnaturally high suspended sediment levels at this time may affect fish
behavior and adversely affect fish populations.
3.2.4 Bedload Sediment
In addition to the sediment that is suspended in the river,there is
also considerable bedload sediment discharge.Bedload is coarse
sediment (usually gravel,but in some cases sand)that is transported
on or near the streambed.The heavily glaciated basin of the Chulitna
River results in considerable bed material.Measurements of natural
bedload sediment discharge for the Susitna River basin are available
from the USGS (inpubl.)and R&M (1982c),(page E-2-200,Chapter 2,
License Application),although data are only available for the summer
months (June-September)in 1981 and 1982.At Sunshine in 1982,bedload
discharge in the summer ranged from approximately 1,000 ton/day to
13,600 ton/day (USGS unpubl).In general,the total natural bedload
measured in the Susitna,Chulitna,and Talkeetna rivers is two to five
times larger than at Sunshine,indicating that the excess material is
deposited somewhere above Sunshine (e.g.,either between Talkeetna and
Sunshine or the Chulitna confluence and Chulitna measuring station RM
18).A large portion of the load is derived from the Chulitna which
contributes approximately 15 times the bedload volume of the Susitna
River near the confluence (page E-2-26,Chapter 2,License Application).
Project related changes in the flow regime (i.e.,decreased flow in the
summer and increased flow in the winter compared to natural conditions)
will affect the amount of bedload material movement.Sediment will be
deposited if the supply exceeds the transport capacity of the stream (a
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function of sediment ioad and discharge)and picked up if the reverse
situation'develops.Thus,deposition of sediment (i.e.,oversupply of
sediment)will cause the channel to rise and widen (aggradation),
whereas an undersupply results in the removal of sediment which leads
to a channel shape that is narrower and deeper (degradation).Changes
in channel morphology will affect bed elevation which affects river
stage at a given discharge.Since the surface area of backwater areas
are influenced by stage,available fish habitat and tributary access in
the vicinity of the three river confluence could be changed.At this
time only a qualitative evaluation of bedload sediment is possible.
During summer,decreases in flow and the trapping effect of the
reservoirs will result in less bedload material movement in the Susitna
upstream of Talkeetna;thus,below the confluence of the Talkeetna,
Chulitna,and Susitna,the total amount of bed material being moved
will be less than at present.It is possible that the decrease in flow
will cause the Chulitna and Talkeetna to deposit some of their bed
material at the three rivers confluence and could result in increased
aggradation of the channel in this area.Below the three rivers
confluence,less bed material will move because of the decreased
magnitude of peak flood discharges.The combination of decreased flow,
lower suspended sediment discharge,and lower bedload discharge may
result in less streambed scour downstream which may cause some areas to
become more favorable areas for fish spawning.
In the winter,flows will be increased.This may result in an increase
in the amount of bedload discharge over natural winter levels.
However,as the glaciers do not discharge sediment during this period,
material moved by the rivers will be existing bed material (such as
from the three rivers confluence area).Channel degradation during
winter in the three rivers confluence area may counteract the increased
degradation that may occur during the summer •
4810A
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,fllIllIlIlIA
3.~.5 Ice Processes
Ice processes dominate the Susitna River and its hydraulic features for
a major part (7-8 months)of the year.The presence of river ice and
the dynamics of its formation and breakup significantly influence
stage,temperature.some sediment related processes (for example,bed
scour and bank erosion),and channel morphology (as a result of ice jam
staging and flooding).Many of these features affected by the ice are
variables that affect the usability of habitat by fish (e.g.,depth and
velocity).
Natural ice processes in the Susitna River have been qualitatively
evaluated (i.e.,observation)by R&M (1981,1982a,1982b,1982c,1983,
Steve Bredthauer Personal COlTlT1unication)and Schoch (1983)(see
AEIDC).These studies and studies in progress have led to a partial
understanding of natural ice processes (i.e.,formation,ice cover,
breakup),a description of which is provided in Chapter 2 of the
License Application (p.E-2-22 to E-2-25).
Ice processes are primarily an interaction of temperature and discharge
in addition to other factors (e.g.,channel shape).Thus,project
related changes in temperature and flow will cause changes in the
natural ice process,which in turn will impact processes (e.g.,scour)
that affect fish habitat.An attempt to quantitatively model post
project ice processes was attempted by ACRES (1983,page E-2-124 to
E-2-127)using an ice simulation model (ICESIM).The downstream
temperature model used was HEATSIM.This model could not be
successfully calibrated using available field data,thus current
predictions of project related ice processes are only qualitative.In
the lower river,ice cover starts when an ice bridge forms in a
constricted bend of the river near RM 10.Heavy slush ice from the
upper Susitna,Chulitna,and Talkeetna basins where subfreezing
temperature first occur begins to backup behind the ice bridge and
causes an ice cover to progress upstream.With the project,fraz;l
4810A
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.-
.....
-
ice from the upper Sus;tna-i>as;n will be blocked by the dams and ice
fonnatiorr below the dams will be greatly delayed due to release of
water that is wanner than natural conditions.Frazil ice will be
generated on the lower river,but at a later date and possibly in much
lower quantities.Consequently,the ice bridge at RM 10 and subsequent
ice cover will fonn at a later date,or possibly not at all in warm
years if insufficient ice is generated.The volume of ice passing
Sus;tna Station from Yentna and Susitna needs to be quantified and
correlated to time of ice bridge formation at RM 10.During ice
fonnation,increases in river stage (e.g.,3-4 ft in area above
Kashwitna River to Talkeetna,Steve Bredthauer,Personal Communication)
cause side channels to be overtopped and large expanses of the
floodplain are covered with water and ice.However,these high river
levels are temporary,as water levels drop after the ice front
orogresses upstream and open leads developed.Higher winter flows with
the project may increase staging and affect the availability of winter
rearing habitat.Temporary stage increase may allow greater access to
suitable wintering habitat.On the other hand,staging may cause fish
to move into areas that may be dewatered,resulting in stranding and
fi sh losses •
It must be recognized that ice processes may be so dynamic that
quantitative predictions of post project conditions may be impossible
through a modeling effort.
4810A
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I"'"
·4•.o_LQWERR I VER MORPHOLOGICAL ASSESSMENT
The lower river morphological assessment,currently in progress,is
critical for the assessment of streamflow related impacts on fish
habitat.Data based on aerial photographic reconnaissance,ground
truthing and cross-sectional surveys are being analyzed to quantify
fishery habitat changes that will result from the proposed alterations
in streamflow.(R&M unpublished).
Since habitat quantity and quality in the lower river varies as a
result of channel morphology and added tributary stream flow;potential
impacts from flow alteration will vary depending upon location.
Identifying the location and magnitude of potential impacts on fish is
difficult because the lower river has a complex morphology and is 98
miles long.Therefore,in order to to facilitate an impact assessment,
the river has been stratified into five segments that are
distinguishable in flow and channel morphology.
Segment I:RM 98.5 to RM 78 -This segment is immediately downstream
of the Chulitna confluence,extending to the side channel just above
the confluence with Montana Creek.The river is braided,with the main
channel meandering through a wide gravel floodplain.Relatively few
side channel complexes through vegetated islands exist.
Segment II:RM 78 to RM 51 -This segment extends from the side
channel above Montana Creek to the point at the head of the Delta
Islands where the river splits into two major channels.The segment is
characterized by side channel complexes along the entire reach.
Segment III:RM 51 to RM 42.5 (Delta Islands)
This segment encompasses the reach in which two major channels exist,
one on the east and one on the west side.A major island side channel
complex exists between the two main channels.The segment ends where
the two main channels rejoin.
48l5A
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-
,....
.-
---Segment-IV:RM 42.5 to RM 28;-S---'This segment extends from the lower
end of th~Delta Islands to the confluence with the Yentna River.The
reach is characterized by a braided pattern,with several significant
side channel complexes.The Deshka River enters this reach.
Segment V:RM 28.5 to RM 0 -This segment extends from the Yentna
River confluence to Cook Inlet.The reach is primarily a split channel
configuration down to RM 19,the head of Alexander Slough.The Susitna
River has two channels from this point to Cook Inlet,with the main
channel on the east side.
Within the segments,four major habitat classifications have been
identified,based on morphological characteristics.These are defined
below:
Mainstem Channel:That portion of the river floodplain between the
vegetated boundaries.This includes the wide gravel floodplain,plus
isolated vegetated islands.Two subclassifications exist:
1)Mainstem river
2)Alluvial island complex:areas of broad gravel islands with
numerous subchannels which dewater as flow decreases.
Side Channel Complex:Groups of side channels flowing through
vegetated islands.These are normally on one stde of the river or the
other,but may inc!yde areas (such as the Delta IslandsTinfhe middle
of the river.T~o subclassifications exist:
1)Lateral side channel:the outside channel of the complex,closest
to the edge of the floodplain.This channel collects any
groundwater seepage or tributary inflow from the river banks.
2)Medial side channel:Overflow channels which dewater as mainstem
flow decreases.
4815A
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,
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SlOUgJl~:~imple ~_tlarmels which are gen~al:ll'_~_vertopped only at high
flows.
Tributary Mouths:The area between the downstream extent of a
tributary plume and the upstream effect of backwater.
The variation in each of the habitat classifications with changes in
flow are being determined from aerial photographic flights conducted at
four streamflows ranging from 13,600 cfs to 56,500 cfs (flow measured
at Sunshine).An analysis of water surface area change with changes in
flow for the major habitat classifications will be used to determine
the magnitude and location for project related impacts on aquatic
habitat.By combining the results of this analysis with information on
fish utilization by habitat classification,an assessment of flow
related impacts on fish can be accomplished.Where fisheries
information is not available,the stratification results will provide
rationale based on habitat sensitivity to discharge,for selecting
representative study sites for conducting further field investigations.
48l5A
4-3
-
1""'
.,...
F'
"I
-------~5.0-FTSHERIESIMPACr-fSS-UES
Based UDon discussions with aquatic studies team members,results of
studies on the middle river,and the physical changes expected in the
lower river.The following were identified in Section 3.0 as
potentially significant fisheries impact issues:
1)Access to spawning grounds
2)Changes in availability of spawning habitat
3)Changes in incubation success
4)Changes in availability of suitable rearing and overwintering
habitat for juvenile and resident fish.
5)Altered juvenile outmigration patterns.
5.1 ACCESS TO SPAWNING GROUNDS
5.1.1 Background
\
Within the lower Susitna River,very little spawning by Pacific salmon
seems to occur in the mainstem or side channel sites.ADF&G examined
potential mainstem and side channel spawning sites in tfle--rowe-;::--;iver
using e1ectroshockers and drift gill nets.In 1981 ~-s-rx---T'ocations were
found in the mainstem where chum salmon were spawning (ADF&G 1981a
[AA]).In 1982,811 sites~ere surveyed between RM 7.0 and RM 98.5 and
no spawning salmon were found (ADF&G 1983a Appendix 2-F [AAJ).Turbid
water in the lower river prevents visual observation of spawning;thus,
it is possible that more spawning may occur than was detectable with
electrofishing gear.
48l6A
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.....
------Mos-f.-spawning appararit1y occurs in tributaries or sloughs (ADF&G 1980a,
198Gb,1981b,1982,p.£-3-553)in the lower river.Between Talkeetna
and Cook Inlet there are eight major and numerous smaller tributaries
that are utilized by adult salmon to varying degrees.Surveys for
spawning chinook have been conducted regularly in the lower river in
•July and August,1976 to 1982 (Table 5-1).No systematic surveys of
spawning by pink,chum,coho,and sockeye have been conducted in lower
river tributaries.While escapement surveys have been conduc-ted in
tributaries (e.g.,Birch Creek)between Sunshine and Talkeetna,these
surveys have been very limited in scooe (e.g.,ADF&G 1981AA -Appendix
Table £J).
In addition to recewlng the bulk of the salmon spawning in the lower
river,tributaries in the lower river also provide the major spawning
habitat for grayling and rainbow trout.Studies by AOF&G (1981,
1983AA)suggest resident fish migrate into tributaries to spawn and
feed after overwintering in mainstem,sloughs,or side channel
habitats.Dolly Varden apparently enter tributaries to spawn in the
fall whereas most of the other species spawn in the spring.
Other than tributaries,tributary mouth habitat and adjacent sloughs
probably receive most of the rest of the escapement of anadromous and
resident fish.Sloughs without tributaries probably provide spawning
habitat,but there has been no systematic evaluation of the magnitude
of slough spawning in the lower river •
Several project related ohysical changes (primarily discharge)will
occur that may make some sloughs and tributaries less accessible to
adult anadromous and resident fish.Main channel stage is a function
of discharge in the Susitna and thus influences the depths at the
mouths of some sloughs.At sufficiently low discharge,water depths
are insufficient to provide access for fish seeking to soawn in sloughs
or tributaries that enter through sloughs.Thus far,access conditions
as a function of discharge have only been evaluated at some middle
river sloughs;no lower river evaluations have yet been conducted.
1I816A
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.....
TABLE 5-1
~"----"-.~---------CHINOmr-SAlJIDN ESCA-PEMENTCOmnS IN -jH E---------
LOWER SUSITNA RIVER BASIN STREAMS FROM 1976 TO 1981!/
Year
Strleam 1976 1977 1978 1979 1980 1981 1982
Ale:)(ander Creek 5,412 9,246 5,854 6,215 !!/.Q./2,546....
Deslhka Ri ver 21,693 39,642 24,639 27,385 .Q./b/16,000 fj
Wi llow Creek 1,660 1,065 1,661 1,086 2./1,357 592 ~/
~
324 E../2./316 ~/Little Willow Creek 833 598 436 459
Kashwitna River
(North Fork)203 336 362 457 .Q./557 156 ~/
She1ep Creek 455 630 1,209 778 Q/1,013 527 ~/
Goose Creek 160 133 283 f../.Q./262 140 ~/
Montana Creek 1,445 1,443 881 1,094 £/2./814 887 ~/
Prairie Creek 6,513 5,790 5,154
2./.Q./1,900 3,844-Clear Creek 1,237 769 997 864 £/.Q./2./982
Chulitna River
(East Fork)112 168 59 2./b/b/119 ~/
Chulitna River (MF)1,870 1,782 900 .!?/~j ~/644 ~/
~Chulitna River 124 229 62 .!?/£/.!?/100 ~/
Hono 1u1u Creek 24 36 13 37 .!?/l?J 27 ~/
Byers Creek 53 69 2./28 .Q./.!?/7 ~/
Troublesome Creek 92 95 2./.Q./12./Q/36 ~/
Bunco Creek 112 136 2./58 2./.Q./198
Peters Creek 2,280 4,102 1,335 2./£/2./Q/
Lake Creek 3,735 7,391 8,931 4,196 2./.!?/3,577-.Q./Ta1achulitna River 1,319 1,856 1,375 1,648 2,129 3,101
Canyon Creek 44 135 f../s../S./84 s./
""""Quartz Creek f./8 f./f./s./8 S./
Red Creek f./1,511 385 f./S./749 s./
-~
~/1976-1980 counts (ADF&G/Kubik,S.W.),1981 and 1982 from ADF&G Sus itna Hydro
(1981,1983)•
.!?/No total count due to high turbid water.
c/Not counted.
~/Poor counting conditions.
e/Counts conducted after peak spawning.
~I/Estimated peak spawning count (ADF&G/Delaney,K).
4816A
5-3
tributaries to
abundance,and species
~\
5-4 \
\
Survey of riverine habitat types and
utilization by salmon (i.e.,timing,
composition).
4816A
1)
2r.oject _related~cMn9-es-_jnJ:ljs_charge m~.Y also affect access to
tributaries.Changes in mainstem stage may cause some tributaries to
become oerched,forming shallow delta like areas impassable by salmon.
If tributary mouths became sufficiently perched (i.e ••above the level
of the mainstem),access of anadromous and resident fish into them may
be impeded.Specific studies of access into lower river tributaries
have not been conducted.However,R&M (1982b -hydraulic studies)
studied perching at the mouths of tributaries within the middle river
and concluded that flows in most tributaries would be sufficient to
downcut through the delta to establish a channel at a new gradient.
Using this information and other data collected by ADF&G and R&M,
Trihey (1983)conducted an incremental analysis of access into two
tributaries in the middle river:Portage Creek and Indian River.He
concluded that access into these tributaries would not be ,a problem at
Gold Creek flows as low as 8.000 cfs because downcutting by the
tributaries will establish new entrance conditions that allow access to
spawning areas.
-
-
-
~~II,;!\I
i1 \I ~'",..Yli/l~
~;/A
-
-
.
Ll 5..•,.,...1..~.~r:~formati on and Study Needs£tf.t:·~f the large number of spawners that utilize the lower rive:~~:J !Vtj(tri butar;es,it is crit;ca 1 that acces s be adequate 1y as ses sed in the/~.'.~d/l.',i,l/lower river.Results of access studies conducted in the middle river
tX 11",'.t cannot be extrapolated to the lower river because of differences in
~l~channel morphology and differences in the response of stage to flow.
'\[~11 Due to the lack of information on salmon utilization of all riverine
I 'habitat types (see Section 4.0 for description of habitat types)and
insufficient data on access,the following studies are needed:
-------------------------=:.::::.-~...!.:.-_-------------_..
"""
.-
.,
2)---Eva 1uate __S-a 1mon_access vs mains terrLf l~-,!-f 0 r:_s~l~te_d trj _gut ari ~~L_~~~__
side channels,and sloughs in the "'ower ri ver.
5.1.3 Study Location
Since the lower river has eight major and numerous smaller tributaries
plus riverine associated habitats extending over 98 miles,it is
necessary to utilize a site selection procedure for evaluating salmon
access.Therefore,study site selection will be based on:1)degree
~f habitat utilization,and 2)extent of habitat dewatering expected
with project flows.Sites considered most important based on this
criteria will be studied.Sites of lesser importance but utilized for
access will be evaluated from a study of a subsample of representative
sites.Sites selected for the subsample will represent the various
types of habitat (see Section 4.0)utilized by salmon during
immigration •
5.1.4 Study Methodology
Habitat Utilization
The utilization of tributary habitat by migrating salmon will be
determined by aerial surveys conducted weekly from mid July to the time
of ice formation in autumn.All salmon will be counted in t~e area
enalrnr-f~-~~ower end of a clear tributary plume to one third of
a mile upstream of t~;ibutary ~
Utilization of the mainstem and side channels will be determined from
weekly aerial surveys conducted from the end of August to early -L/
October;a period when water clarity is sufficient t;-;;ll-o-w-vrslnfl--"-~,
determination of sp~~~Surveys during this time period will likely
f;iss··pink saTmOn~d chi nook salmon spawners because of earl i er run
(timing,but include chum salmon,sockeye salmon,and coho salmon _
/spawners.The habitat utilized by the latter species should be
'--------------------------------------------------------------------------------------
4816A
5-5
I
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i ~
irFdicatlveortnenabTtaT used by the former.Thus,the surveys wi 11
provide ah identification of run timing,an estimate of species
composition,and an estimate of relative extent of habitat utilization.
Aq:ess Evaluation
A preliminary,assessment of the extent of habitat dewatering in
critical access areas can be determined from the results bf the lower
river morphological assessment s~udy.The response of water surface
area to changes in flow in habitat utilized for access will be used as
the first approach to idenfifying.probl~m areas and to eliminate
nonproblem sites.,
Sites that cannot be eliminated by a simple ~nalYSiS of cross-secti07 .
depth versus river stage will require a more rigorous analysis of .
threshhold access conditions as outlined in Figure 5-1.An'index of .
passage conditions for each study site will be developed based on
morphological characteristics of any critical access reach which occurs
in the site and an estimate of the percentage of the surface area
within the critical reach which is navigable by.salmon.These indices
will be developed from thalweg profiles,cross-sections in the critical
access reaches,and mainstem rating curves.These will be used to
develop an aver~ge of water surface elevation for the critical passage
reach against mainstem flow.For a series of mainstem flows,the
oroportion of cross-sectional areas which meet the 0.3 foot depth
criterion (Trihey 1982)will be determined.The cross-sectional area
proportions wilT be integrated with thalweg profiles and water surface
profiles to determine the proportion of the critical passage reach
which meets the less than 100 foot.length criterion.In addition,the
0.3 foot mini~um depth for less than 100 feet criterion will be
verified through documentation of the numbers of fish gaining access
under various flow conditions.
4816A
5-6
....
....
-
-
....
.....
·,
FIGURE 5-1-----------
EVALUATION OF CONDITIONS FOR ADULT SALMON
ACCESS TO SPAWNING HABITATS
Timing of Expected Project L.R.Morph.Extent of Salmon
Salmon Access '"Discharge Assessment Utilization
I
~
Critical Habitat Needing
Further Evaluation
~
I r 1
Mainstem Rating X-Section at Thalweg Substrate
Curve Critical Passages Profi les Composition
L D50
I T ~I I 1(
1
Channel
Degradation
Potential
IWSELinPassageReachPassageCriterion./I
vs Mainstem Flow Function of "'
Depth and Length
\/\It
Passage Efficiency Index
vs Mainstem Flow
Hydrologic Modeling-Reservoir Operations
\IWaterSa1ance,"
'.oJ Time Series and1FrequencyAnalysis
_i_
Impact Evaluation f---------
48l6A
5-7
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I
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-
.,
A oassage efficiency index for a continuum of mainstem flows will be
~----,_.--_._-_..---,_.._-----_.__.-_.---------'....
develope~for each study location and for each species.Each species/
location index will consist of critical discharge values which define
no access and uninhibited access conditions and a curve depicting
access efficiency between these critical discharge levels.These
indices will then be accumulated by habitat type and by species to
define mainstem discharge necessary to provide adequate access
conditions.In turn,the habitat indices will be accumulated into one
index for all habitats in the lower Susitna River.
5.2 CHANGES IN AVAILABILITY OF SPA~ING HABITAT
5.2.1 Background
Relatively few fish seem to spawn in habitats that may be directly
affected by project physical changes.The magnitude of spawning in
side channels and the mainstem were evaluated in 1981 and 1982 by ADF&G
(1981,1983-AA).Other than 6 sites where spawning chum salmon were
found in 1981,salmon were not found spawning in side channel or
mainstemsites.The timing and abundance of adult spawning salmon in
sloughs between Sunshine and Talkeetna were periodically surveyed by
ADF&G in 1981 and 1982 (e.g.,Birch Creek).However,no other sloughs
in the lower river have been surveyed.Bering cisco have been found
spawning in three mainstem sites located between RM 75 and 80 (ADF&G
1981,Summary Report).A preliminary evaluation of Bering cisco
spawning habitat characteristics can be found in ADF&G (198l,summary;
1983c,AH -Appendix F).
Some data on habitat available for salmon spawning can be found in
ADF&G Aquatic Habitat and Instream Flow Reports,including depths,
velocity,substrate,and temperature (see Table 5-2 for the location of
this data).However,this data is of limited use in comprehensively
evaluating available habitat in the lower river because it is
incomplete (i.e.,missing data or some parameters were not collected)
4816A
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~"d.
J,,,
-
.TABU 5-2__
INFORMATION AVAILABLE IN ADF&G REPORTS ON
HABITAT CHARACTERISTICS IN THE LOWER RIVER
Location and Variable Citation
Chum Channel
Velocity AH,Table 4-6-1 1983
Depth AH,Table 4-B-l 1983
Discharge AH,Table 4-A-l 1983
Rabideux Slough-
Ve loci ty AH,Table 4-8-2 1983
Depth AH,Table 4-B-2 1983-Discharge AH,Table 4-A-1 1983
-.
(1981)Thermograph Sites
~(see oage E--14q ADF&G 1981a AH,Appendix EC 1981
AH for listing of sites)
Thermograph Sites (1983)AH,Appendix C 1983
.....
.....
4816A
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....
-
....
-andtne data was not collected in a representative manner •.Moreever.
because changes may occur in the river that alter the characteristics
of habitat in an area.it is doubtful that this data could be compared
with information on utilized habitat collected several years hence •
The quantity and quality of habitat available for salmon spawners in
side channels and the mainstem is directly dependent on mainstem
factors (e.g ••discharge.temperature.ice and sediment processes).
Side slough habitat is dependent on groundwater upwelling which may be
influenced by discharge in the Susitna River.Additionally.the
quality of slough habitat (i.e ••siltation and aquatic vegetation)is
affected by the frequency and magnitude of overtopping.(The only
evaluation of overtopping in a lower river slough was conducted in
Rabideux slough -see Appendix E.2.A of the license applicatiorr.)
Consequently.project operations may have an impact on the location and
availability of spawning habitat in the mainstem.side channels.and
sloughs.However.impacts may be both positive and negative.For
example,reducing flows in the summer may dewater some spawning areas
located on the river margins.whereas more stable flows and decreased
bedload movement under project conditions may provide additional
suitable conditions for spawning in new areas.Ultimately.the nature
of many habitats could be altered as a result of operations of the
project.Some side channels may become side sloughs (by reducing the
frequency of overtopping)and become more usable by salmon.
5.2.2 Information and Study Needs
Because of the lack of information on utilization of riverine habitats
by spawning salmon.it is necessary to assess the relative abundance
and distribution of spawners in riverine habitats in order to determine
if spawning habitat evaluation studies are needed.If spawner surveys
demonstrate a significant number (defined by ADF&G)of spawners utilize
riverine habitat.then potential changes in availability of spawning
habitat with project flows must be evaluated.The following specific
studies are needed:
4816A
5-10
r·
I • _ _J L~r_y~y of ri ~gri nl!.hab i tat types t_o_dete-"nirle~t11 i zat i on ~__~t __
spawn~ng salmon (i.e.,timing,abundance,and species composition).
2)Evaluation of the effects of project flows on the availability of
habitat suitable for spawning salmon.
5.2.3 Study Location
.-
I
Study site selection will be based on:1)degree of habitat
utilization,and 2)extent of habitat dewatering expected with project
flows.Sites considered most important based on this criteria will be
studi ed.Sites of 1esser importance but ut 11 i zed by spawners will be
evaluated from a study of a subsample of representative sites.Sites
selected from the subsample will represent the various types of habitat
(see Section 4.0)utilized by salmon during spawning.
5.2.4 Study Methodology
Habitat Utilization
Use methods described for Section 5.1.4.In addition,an analysis of
results from the lower river morphological assessment study will be
used to target spawner surveys on habitats that are not dewatered under
natural flows during the period of spawning and incubation.This
selection procedure will concentrate effort of the survey on only those
sites where spawning and incubation could be successful.
Evaluation of Spawning Habitat Availability
The first approach to evaluation of flow affects on spawning habitat
will be based on changes in surface area.The response of water
surface area in spawning habitats to changes in river flow will be
determined with results from the lower river morphological assessment
4816A
5-11
r
....
--
-
---~-sttJdy.---Ghangesln areaG-f-ide-ntiffed--spawning-sJteswi 11 beplotted -_
with rive,..discharge to evalute the effects of expected project flows
on availability of spawning habitats.
Spawning sites with a significant level of utilization may require
modeling (IFG-4)of depth,velocity,and substrate conditions to enable
prediction of changes in habitat availability with changes in flow •
Data requirements and methods required for this approach are described
in Harza-Ebasco (1983,Section 4.2.4.1).
5.3 CHANGE IN INCUBATION SUCCESS
5.3.1 Background
Eggs deposited in the lower river will be influenced by project changes
in physical conditions.This includes eggs deposited in the mainstem,(tJ ~'
side channels,tributary mouths,and sloughs.At present,no surveys l~.~v U
have been conducted to estimate the potential egg deposition,potential ~
fry emergence,or time of emergence for these lower river habitats.
There are several physical impacts that the project may have that could
affect incubation conditions.First,altered depth and velocities could
affect incubation.Also,if the rate and amount of groundwater
upwelling in sloughs is related to mainstem flow,then the intergravel
flows incubating embryos may be altered.However,because eggs would
be deposited at flows lower than normal and increases in flow (and
hence upwe 11 ing)are expected to occur in wi nter,th is impact is not
expected to be significant and may be a positive impact.
Second,staging due to ice formation may be higher than during natural
conditions as a result of increased winter streamflows.As a
consequence,berms at the upstream end of some sloughs and side
channels (where spawning has occurred)and downstream of the ice front
could overtop and inundate incubating embryos with cold mainstem (DOC)
water.As a result of overtopping,the developmental rate of these
-!
4816A
5-12 ./
r
I ----
-
,~
r~
----eggs--cou1d bede1ayea or eggs k-i11ed due to thermal shock.--5tue};-es--·
during wi'nter in Slough SA of the middle river demonstrated that
overtopping with cold mainstem water as a result of ice jams depressed
the temperature of intragrave1 water and delayed development of chum
and sockeye embryos (ADF&G 1983e).The net effect of reducing
incubation temperatures could be a delay in emergence and/or a smaller
size at emergence,both of which could decrease fry survival.
Third,in the fall the higher temperature of the release water will
extend downstream into the lower river and increase the developmental
rate of embryo·s which could result in premature emergence.Fry
emerging too early are desychronized with environmental conditions and
may experience conditions (i.e.,reduced food supply)that decrease
their growth and survival.
Fourth,higher winter susoended sediment loads and bedload sediment
could silt over some salmon redds.As a result,egg-to-fry survival
may be reduced.
Fifth,if ice breakup is more severe than under natural conditions
(e.g.,because of an increase in the amount of ice),some scouring of
redds in side channels or side sloughs may occur.Consequently,
mortality of embryos or a1evins may be increased.
Current assessment efforts are inadequate to assess impacts during
incubation.Predictions of project temperature,suspended sediments,
and ice processes are needed during the period of incubation;
predictions of flow may be sufficient to assess impact during
incubation.Relationships between surface water and intragrave1
temperature have been studied (AOF&G 1983e),but relationships between
upwelling temperatures have yet to be established.The effects of
delayed emergence due to cold water on embryos survival needs to be
determined,but the effects of temperature on embryo development rates
4816A
5-13
are known (Waangard al1-dBurJ~.e.Lt981t._Th~ha_s J:)~e!Ll1..-2 inJ9_rJ!lctt.ion _
collected on when,where,and how many eggs are deposited in
potentially affected lower river habitats.
5.3.2 I nf ~.y-N-ee4s-----«__~_---~-----__-_-------------
...---
....-/T<tle utilization of riverine habitats by salmon for incubation must be
assessed in order to determine if studies of incubation habitat are
necessary.If riverine habitats provide a significant portion of the·
egg incubation sites for the lower Susitna River,then t~e following
studies are needed:
-
-
1)
----'--------------,--
Evaluatio.n of the relationship between mainstenLflow and~?
i:ijlr~avel flow-:ate and temperature of incubation sites in
riverine habitats utilized by incubating salmon embryos.
....
-
.....
2)Determination of the effects of coldwater downwelling from channel
overtopoing on the survival to emergence and condition of
incubating salmon embryos.
3)Determination of the effects of changes in upwelling rate and
temperature as a result of change in mainstem flow on the survival
to emergence and condition of incubating salmon embryos.
5.3.3 Study Location
StUdy site selection will be based on:1)degree of ha~itat
utilization t and 2)extent of habitat dewatering expected with project
flows.Sites considered most important based on this criteria will be
studied.Sites of lesser importance but utilized for incubation will
be evaluated from a study of a subsamo1e of representative sites.
Sites selected for the subsamp1e will represent the various types of
habitat (see Section 4.0)utilized for incubation by salmon.
4816A
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~---------------------------'--
....
-
.-
-
-
.....
....
~I
5.3.4 Study Methodelo~y---
Habitat Utilization
Use methods described in Sections 5.1.4 and 5.2.4.
Relationship Between Mainstem Flow and Intragrave1 Flow Rate and
Temperature
Methods for this task will be described by Harza/Ebasco hydrology group.
Evaluation of Cold Water Downwelling on Embryo Survival
Side channel or slough habitats that are utilized by spawning salmon
and are overtopped as a result of ice staging will be selected for
study.Known lots of fertilized salmon eggs will be placed in Vibert
boxes and buried in the gravel at typical spawning sites.Intragravel
and surface water temperatures will be continuously monitored during
the incubation period.Boxes will be removed at periodic intervals
including immediately following a cold water overtopping event.
Developmental rate and survival of embryos will be evaluated and
relationships between temperature and overtopping events determined.
I
Intragravel percu1ation rate and dissolved oxygen will also be measured
periodically to assess these effects on embryo survival.Results of
these analyses~combined with the extent of habitat utilization t will
be used to assess overall impacts on incubation (Figure 5-2).
Evaluation of Upwelling and Temperature Changes on Embryo Survival
Results from the study on determining the relationship between mainstem
flow and intragravel flow rate and temperature (Section 5.3.4)would be
combined with results from the embryo development study (Section 5.3.4)
and data from Waangard and Burger (1983)t to develop a predictive
48l6A
.....
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r
.....
________._ELGURL.5~2 __
EVALUATION OF INCUBATION SUCCESS
Mainstem Flow vSI/Life Stage
Slough or Side ....Utilization
Channel Flow Period
v
Ice Formation/~Slough or Side Channel ~Intragravel
Breakup vs Surface Temperature Perculation Rate
Staging Model and Temperature
I
J ,1
Perculation Rate Accumulated TU vs j
vs Embryo Development Embryo Development I
and Survival Rate and Survival
I
I
,II
I Species
I
Salmon Habitat Embryo Development
Utilization IFecundity,Rate and Survival
Numbers I
Potential Egg
Deposition
Impact Evaluation
4816A
5-16
r-,
i
l A
....,
....
.....
model .__In_tragr-a~aLflowa_ndtemoerature_cgr'!di tJons__expected with
project f~ows could be perdicted for selected representative habitat
sites.Imoacts on embryo survival would be estimated from
relationships between embryo survival and predicted physical conditions.
5.4 CHANGES IN AVAILABILITY OF SUITABLE REARING AND OVERWINTERING
HABITAT
5.4.1 Background
Juvenile anadromous and resident fish rear in Susitna riverine habitats
throughout the year.Information on the distribution and abundance and
size of these fish in lower river habitats has been collected by ADF&G
in 1981 and 1982 (ADF&G 1981c,AOF&G 1983b -RJ).A variety of
sampling gears were utilized (e.g.,e1ectroshocking,seines,trot
lines.gil1nets,minnow traps)to capture fish and samples were
obtained in both summer and winter.In the lower river twice monthly
samples were taken in both years from the vicinity of five designated
fish habitat (DFH)sites:Radideux,Whitefish,Birch,Sunshine,and
Goose Creeks (see Aopendix A,AOF&G 1982 (RJ)and Appendix B ADF&G
19R1c (RJ)for catch data,summary tables are also available in each
reoort -for example ADF&G 1981 -Table E.3.2.8 and E.3.2.9).A
number of other sites (i .e.,selected fish habitat (SFH sites)were
also intermittenly sampled (see same appendices).Some information on
water quality (e.g.,temperature,turbidity),discharqe,and
watersurface elevations are available at some sites but in particular
for the five creeks listed above (Table 5-3).
Results of fish surveys suggest the following major conclusions:
1)Coho and chinook were the most abundant soecies,especially in
1981.Early in outmigration.coho and chinook were more abundant
below then above the Chulitna.Lower river coho tended to be
larger.Towards the end of August,chinook and coho catches
4816A
5-17
.-.
9 .
TABLE 5-3
.CATCH AND HABITAT DATA FOR RESIDENT AND JUVENILE
ANADROMOUS FISH IN ADF&G REPORTS
DFH Sites Years Data
Catch Data
Water Qua 1ity
RJ,1981c,ADF&G Table E.3.2.8,E.3.2.9,E.3.2.15,
E.3.1.4,E.3.1.5,E.3.1.9,E.3.2.1
E.3.2.2, E.3.2.3,Appendix EB.
RJ,1983b,ADF&G 3-3-11,B-3-13,3-13-16,3-3-18,
3-3-21,3-3-23,3-3-32,3-3-28
Apoendix Table 3-A.
AH,1983c,ADF&G Appendix 4-0,(pp.40-44 to 4-0-68),
Appendix I (4-1-2 to 4-1-9),Apoen.
AH
Water Velocity AH.1983c.ADF&G Aooendix I (4-I-2 to 4-1-9),Aopendix
B (Rabideux -4-B-3).
Discharge,WSEL AH 9 1983c,ADF&G Appendix A (4-A-46 to
4-A-48)(4-A-173 to 4-A-178)
4816A
5-18
..
t
~'.__-...incr-eased-.-in--the-mainstem.In
tributary mouths and sloughs.
for non-turbid waters and both
water conditions.
the 5 UlJIIleLt-5QllLe fi ~Il re9x_~d i n___~
Coho exhibited a strong preference
chinook and coho preferred warmer
2)Chum and pinks were only rarely caught in the lower river and
primarily.in sloughs,probably as result of collection gear.
3)Rainbow trout were present in small numbers in the lower river and
tended to be associated wih the clear water areas associated with
tributaries.They overwintered in the mainstem near'the mouth of
tributaries.Extensive lower river migrantions were not apparent
from radio tag data.
4)Burbot,whitefish,and longnose sucker used some mainst~m and side
channel areas for rearing.Catches tended to be very small.
Burbot avoided clearwater areas and were mostly associated with the
mainstem.
Project related physical changes in the lower river may have several
impacts on resident and juvenile anadromous fish rearing in the lower
river.A list of potential impacts in order of priority are:
1)Area of hydraulic habitat and cover availability may be increased
in the winter and decreased in the summer.
2)Increased stage height and increased probability of side channel
and slough overtopping during ice staging may reduce availability
of overwintering habitat.
3)Increased suspended sediment and turbidity in winter may reduce the
suitability and availability of overwinter habitat in the mainstem,
side channels,and sloughs.
4)Warmer fall-winter temperatures and cooler summer temperatures may
have an impact on growth rates.
4816A
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-
-
....
_____:r~_~a!~!_~~~~aJ~~_~_~~f 2!0wth~a~_e ~~fe~_t __!_e 1a~~v~_to_predicted
temperature are available,but sufficient knowledge on the subject is
available in the literature;effects of turbidity on fish behavior at
low temperature is unknown,but a review of literature concerning
winter habitats and data on turbidity could be used to evaluate the
problem;and the effects of slough overtopping on winter habitat has
not been studied.AOF&G has analyzed the relationship between mainstem
discharge and the availability of hydraulic habitat for juvenile
rearing at the five lower river OFH sites between June and September
(AOF&G 1983d Appendix F Synopsis).This was accomplished by
classifying OFH sites into zones (based upon water source,water
velocity,and backwater influence).A habitat index (HI)that could be
plotted against discharge was developed by relating catch variations
between zones to changes in water surface area of the zones.These
results are oresented graphically and in tables for chinook at Goose,
Rabideux and Birch creeks (Appendix Table F-13;Figure F-3,F-4,F-5),
coho at Sunshine and Birch creeks (Appendix table F-14;Figure F-7,
F-A),sockeye at Birch Creek (Appendix Tale F-15;Figure F-10)and chum
at Birch Creek (Aopendix Table F-16;Figure F-13).Variations in
mainstem discharge clearly affected the habitat utilized by each of the
species and there were considerable differences between species
(Appendix Figure F-17).Aopendix G of the ADF&Gd 1983 Synopsis report
also orovides an analysis of major habitat use by soecies in the summer
that incorporates lower river sites (uo1and slough -Whitefish;side
slouqhs -Rabideux and Birch Creek;side channel -Goose and Sunshine
Creeks).All of the lower river habitat sites that have been studied
are located above RM 73.Therefore information will be needed from
habitat sites located further downstream.
The HI aoproach for assessing flow related impacts is site specific and
would be of limited use in the lower river.The HI can be used to
distinguish habitat values at various flows within a site,but is not a
good comparation between sites.The HI is very data dependent and does
4Rl6A
5-20
e .
r
QotJ)rovide an extrapolatable model;therefore~if fish data and water-----.__.----,----_...--~----_..--------.-
surface area measurements are not available for certain flows,rearing
values must be subjectively assigned.An alternative procedure for
evaluting flow related impacts on habitat will need to be developed for
the lower river.
The utilization of lower river habitat for rearing during summer and
winter has been documented by AOF&G studies (AOF&G 1981c~ADF&G 1983b -
R.J.).But~the relative importance of riverine habitat compared to
tributary habitat has not been quantified.Studies that provide the
abundance of salmonids jn the different habitat types would provide a
perspective as to the importance of riverine versus tributary habitat
to the fish nopulation.
5.4.2 Information and Study Needs
1)Determination of the species composition,abundance~and timing of
riverine habitat utilization by juvenile and resident salmonids
during summer and winter.
2)Determination of the relationshin between mainstem discharge and
availability of suitable rearing habitat for summer and winter
~oeriods.
I
-
3)Determine the effects of side channel or slough overtopping as a
result of ice staging on habitat utilization and survival of
rearing salmonids.
4)Evaluate the Dotential effects of susoended sediment and turbidity
on the behavior and survival of juvenile salmonids at low (less
than 2°C)temperatures.
5)Evaluate the effects of small temperature change (~2°C)expected
with project conditions on the growth of juvenile salmonids.
4816A
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-
-
"""
---_·····~-~.4.3 Study Location
Habitat utilization study sites will be stratified to include sampling
of the four major riverine habitat types (see Section 4.0)with effort
oroportioned by river segment according to level of flow related
impact.The level of impact among river segments will be determined
from results of the lower river morohological assessment study.
Selection of study sites for determination of the relationship between
mainstem discharge and rearing habitat will be based on a stratified
sample design.Sites will be stratified on the basis of major habitat
tYPe and relative extent of utilization by rearing fish (or proximity
to natal spawning area).The level of effort (i.e.,number of study
sites)will be proportioned within river segments by extent of fish
utilization,and between river segments according to the level of flow
related impact.
Habitats representative of the four habitat types that are utilized by
rearing fish during winter,and have channel overtopping conditions
based on observations during ice formation (R&M 1983.unpublished data)
will be selected for studies of overtopping.
5.d.4 Study Methodology
Habitat Utilization
During summer,surveys will be conducted in selected study sites at
bimonthly intervals.Samples will be collected with a variety of
sampling gear (see ADF&G 1981c and 1983b -RJ)and catch data expressed
as catch per unit effort (CPUE).During winter.utilization will be
based on the distribution and CPUE data derived from samples collected
on last sample date that is prior to ice formation.Because water
temperatures will be close to aoc at this time,it is assumed that
juvenile fish will have completed any movements among habitats prior to
the ice cover period.
48l6A
5-22
.-
-I
i
I
I""'"
I
i
-
.-
······------·-Re..lat-ionship Between Mainstem Discharge and Rearing_H~.bitat in Summer
Determination of the relationship between juvenile salmon rearing
habitat and mainstem flow involves two types of analysis.The first
involves utilization of the IFG-4 hydraulic models and the PHABSIM
habitat simulation model.This procedure will be used for habitats
that are known to have a stable channel morphology.The second
analysis makes use of an incremental analysis based on a regression of
mainstem flow vs surface area of specific habitat units that are
defined by:persence or absence of cover,certain depth-velocity-
substrate combinations,presence or absence of turbid water,and
certain temperature ranges.This procedure will be used for habitats
that are not assumed to remain stable with time.The rationale for
employing this procedure is based on the assumption that the size of
habitat units will change with mainstem discharge,but the relative
distribution of representative habitat units will remain constant for a
given discharge regardless of periodic changes in channel morphology.
Both procedures will require habitat preference curves that relate the
presence of juvenile salmon to depth,velocity,substrate composition,
cover,turbidity,and temperature.Habitat preference data will be
developed for each species from observations of individuals for coho
and chinook,and observation of fish groups for sockeye and chum.
The IFG-4/PHABSIM model will be calibrated with hydraulic data
collected at several different flows and will include measurements of
depth,velocity,substrate composition,and cover.The habitat unit
model will be calibrated with unit area data collected at six different
flows that encompass the flow range expected with the project.
Evaluation of impacts from flow changes on rearing will be based on the
timing of habitat utilization (Section 5.4.3),combined with analysis
of predicted habitat conditions under natural historic flows and flows
expected with the project.
4816.40
5-23
.-,
-
1telat ionshi p Between Ma i nstem--{}tsc-h-arge-andR~a-rlng Habita-t-i-n-··W-l-Ater
The determination of flow vS habitat relationships during winter cannot
be developed until information on the feasibility of measuring physical
and biological parameters under the ice is available.The first task
will be to develop a set of efficient procedures for measuring physical
parameters (i .e.,depth,velocity,turbidity,temperature)underneath
an ice cover.The second task will be to determine the variability in
parameter values during winter and develop a relationship between
mainstem flow and each parameter.The third task will be to develop a
procedure for measuring the overwinter survival of fish rearing in
specific habitat types.Perhaps a measure of the change in population
size between the times of ice formation and ice breakup could be
employed.The final task would be to develop a relationship between
mainstem flow and overwinter survival for representative habitat types
or habitat units.
Re1ationshi~Between Channel Overtopping and Survival of Rearing
Salmonids
The procedures developed for winter habitat studies (Section 5.4.3)
would be utilized for assessing the impacts of channel overtopping.
Effects of Suspended Sediment on Survival and Behavior of Juvenile
Salmon
A review of the literature concerning juvenile sa1monid behavior at low
temperatures,and effects of suspended sediment on behavior and
survival,will provide the information necessary for estimating the
magnitude of impact expected with project conditions.If the predicted
impacts are considered significant,then an impact assessment procedure
will be developed.
4816A
5-24
-
-
'Effects of Temperature on Growth of Juvenile Salmon
The relationship between temperature and fish growth is well documented
in the scientific literature.Based on this information,fish growth
vs water temoerature curves will be develooed for natural water
temperature and project temperature regimes for each species during the
summer rearing period.The growth vs temperature curves will be used
to assess the time period and magnitude of project impacts.
5.5 ALTERED JUVENILE OUTMIGRATION PATTERN
5.5.1 Background
The outmigration of juvenile salmonids in the Susitna River has been
studied in 1981 and 1982 by the ADF&G (ADF&G 1981c,ADF&G 1983b -
R.J.).Limited data are available on the timing of migration,soecies
comoosition,age structure,and size of outmigrating fish.In the
lower river,samoles were collected with minnow traps,beach seines,
and electrofishing gear throughout the spring open water period.Based
on these samoles plus information from one smolt trao located above the
confluence of the Chulitna River,the general migration timing is
known.Chinook salmon outmigrants peak during May and June with all
age 1+fish leaving the stream by early August.The coho salmon
outmigration also peaks during May and June,but continues through the
summer to the onset of ice cover.Chum salmon fry rear for one to two
months before the peak of their outmigration which occurs during June.
The sockeye outmigration is similar to that of chinook with a peak in
early July and ending by August.The pink salmon outmigration was not
sampled adequately to determine the migration peaks,but limited
captures of pink fry indicate most fish outmigrate before June.
The relationship between juvenile outmigration and environmental
variables (i.e.,discharge,water temperature,and day length)was
examined for fish emigration from the river above the Chulitna
4816A
5-25
-
...r-
,.....
I
-
confluence in 1982 (ADF&G 1983d -Appendix H).In general most
relationships were significant.but correlation coefficients were
moderate to low.Factors that could account for the low correlations
include:incomplete catch data for entire outmigration period;
attempting correlations with seasonal data rather than for shorter.
daily or weekly events;and,lack of site specific data for most
Physical variables.
Several ohysical factors are considered to have a causal relationship
with juvenile salmon outmigration.Discharge will effect the travel
time of downstream migrants and river stage can influence access of
juveniles migrating from sloughs to the mainstem.Spring freshets can
disolace juveniles resulting in Dulses in timing and numbers of
outmigrants.In some cases,rearing juveniles may be displaced
downstream to the estuary or lower mainstem before reaching a preferred
size for migration and smoltification.Survival of the outmigrant
population could be highly dependent upon the mainstem flow regime.
Conceivably,the projected reduction in streamflow during spring as a
result of project operations would minimize fish disolacements due to
flushing flows.On the other hand,reduced flows may increase
outmigration travel times,thus increasing vulnerability of migrants to
predation.Turbidity is an important factor in providing cover for
outmigrating juvenile salmon.This may be esoecially important in the
$usitna River because periods of darkness (juvenile salmon migrate
mostly at night in non-turbid rivers)are short during the scring
migration.Some reductions in turbidity are expected during spring as
a result of the reduction in river discharge (see section on suspended
sediment).However the magnitude of reduction in turbidity will be
small relative to the naturally high levels.Thus no changes in fish
survival relative to this factor are expected.
5.5.2 Information and Study Needs
1)Determine the relationship between mainstem discharge and timing of
habitat utilization,and types of riverine habitat utilized during
the outmigration period.
48l6A
5-26
_.
-t
i I
--
2)Determine the relationship between short term (i.e.,daily)and
longer term (seasonal)mainstem flow fluctuations,and migration
timing and travel time of juvenile salmon outmigrants.
5.5.3 Study Location
Studies on the timing of habitat utilization and types of habitat
utilized during the outmigration period will be conducted at the same
sites selected for the juvenile salmon habitat utilization study
(Section 5.4.3).Studies of outmigration timing and travel time for
the lower river between Cook Inlet and Talkeetna will be evaluated from
outmigrant monitoring stations located at Talkeetna (RM 98)and near
Flathorn Lake (RM 20).
5.5.4 Study Methodology
Outmigrant Habitat Utilization
Determination of the timing of habjtat utilization and types of habitat
utilized by outmigrant salmon will be evaluated from periodic sample
collections following ice breakup as described in Section 5.4.4 for
studies of rearing habitat.
Relationship Between Mainstem Flow and Outmigration Timing and Migrant
Travel Time
The sizes,number,and timing of outmigrating juvenile salmon will be
correlated with daily and seasonal flow fluctuations.This information
will be used to evaluate the importance of mainstem flow on
outmigration and to assess the potential impacts of project flows on
changes in outmigration timing.Outmigration data from the Talkeetna
Station will be compared with data from Flathorn to estimate the travel
time and growth of juvenile salmon that migrate through the lower
river.This information will be correlated with mainstem flow and the
results will be used to assess the potential impacts of project flows.
4816A
5-27
-
-
·6.0 REFERE~CES CITED ..
Acres American,Inc.1983.Application for license for major project,
Susitna Hydroelectric Project,before the Federal Energy Regulatory
Commission.Vol.SA.Exhibit E,Chaps.1 and 2.Alaska Power
Authority.Susitna Hydroelectric Project.1 vol.
Alaska Dept.of Fish &Game.1983a.Susitna hydro aquatic studies,
phase 2 basic data report.Vol.2.Adult anadromous fisheries
studies,1982.First Draft Report.Anchorage,AK.Alaska Power
Authority.Susitna Hydro Aquatic Studies.Report for Acres
American,Inc.2 vols.
Alaska Oeot.of Fish &Game.1983b.Susitna hydro aquatic studies,
phase 2 basic data report.Vol.3.Resident and juvenile
anadromous fish studies on the Susitna River below Devil Canyon,
1982.Final Reoort.Anchorage,AK.Alaska Power Authority.
Susitna Hydro Aquatic Studies.Reoort for Acres American,Inc.2
vols.
Alaska Dept.of Fish &Game.1983c.Susitna hydro aquatic studies,
phase 2 baseline data report.Vol.4.Aquatic habitat and
instream flow studies,1982.Final Reoort.Anchorage,AK.Alaska
Power Authority.Susitna Hydro Studies.Report for Acres
American,Inc.3 vols.
Alaska Dept.of Fish &Game.1983d.Susitna hydro aquatic studies.
phase 2.Synopsis of the 1982 aquatic studies and analysis of fish
and habitat relationships.Final Report (Summary).Anchorage,
AK.Alaska Power Authority.Susitna Hydro Aquatic Studies.152
PD.
Alaska Dept.of Fish &Game.1983e.Susitna hydro aquatic studies,
phase 2 data report.Winter aquatic studies (October 1982-May
1983).Final Report.Anchorage,AK.Alaska Power Authority.
Susitna Hydro Aquatic Studies.Report for Harza-Ebasco Susitna
Joint Venture.140 pp.
Alaska Dept.of Fish &Game.1982.Adult anadromous fisheries
project,stock separation feasibility report.Final Draft Report.
Anchorage.AK.Alaska Power Authority.Susitna Hydro Aquatic
Studies.Report for Acres American,Inc.1 vol.
Alaska Deot.of Fish &Game.1981a.Aquatic habitat and instream flow
project.Final Draft Report.Anchorage,AK.Alaska Power
Authority.Susitna Hydro Aquatic Studies.Report for Acres
American~Inc.2 vols.in 3.
4833A
6-1
-I
P"""'-••"'-~
'.*.
-
.-
-
-i
'J~
--Alaska Oept of Fish &Game.198tb.Adult anadromous fisheries
project.Final Draft Report.Anchorage.AK.Alaska Power
Authority.Susitna Hydro Aquatic Studies.Report for Acres
American,Inc.1 vol.
Alaska O~!pt.of Fish &Game.1981c.Juvenile anadromous fish study On
the 'lower Sus Hna Ri ver.Fina 1 Draft Report.Anchorage.AK.
Alaska Power Authority.Susitna Hydro Aquatic Studies.Report for
Acres American,Inc.1 vol.
Alaska.IJniv.,Arctic Environmental Information and Data Center.1983a.
Examination of discharge and temperature changes due to the
proposed Susitna Hydroelectric Project.Draft Report.Anchorage.
AK.Alaska Power Authority.Report for Harza-Ebasco Susitna Joint
Venture.
Alaska,Univ.,Arctic Environmental Information and Data Center.1983b.
Susitna Hydroelectric Project Aquatic Impact Assessment:Effects
of project-related changes in temperature.turbidity,and stream
discharge on upper Susitna salmon resources during June through
September.Alaska Power Authorty Report for Harza-Ebasco Susitna
Joint Venture.
Harza-Ebasco Susitna Joint Venture.1983.Detailed plan of study
Susitna Hydroelectric Project,Aquatic Program.Fiscal Year 1984.
Draft Report to Alaska Power Authority.
R &M Consultants.Inc.1983.Field data index.Anchorage.AK.
Alaska Power Authority.Susitna Hydroelectric Project.Report for
Acres American,Inc.1 vol.
R &MConsultants,Inc.1982a.Ice observation 1981-82.Anchorage.
AK.Alaska Power Authority.Susitna Hydroelectric Project.
Report for Acres American.Inc.1 vol.
R &MConsultants,Inc.1982b.Hydraulic and ice studies.Anchorage.
AK.Alaska Power Authority.Susitna Hydroelectric Project •
Report for Acres American,Inc.1 vol.
R &MConsultants,Inc.1982c.Reservoir sedimentation.Anchorage,
AK.Alaska Power Authority.Susitna Hydroelectric Project.
Report for Acres American,Inc.1 vol.
R &M Consultants\}Inc.1981.Ice observations 1980-81.Anchorage,
AK.Alaska Power Authority.Susitna Hydroelectric Project.
Report for Acres American,Inc.1 vol.
Schoch,G.C.1983.Environmental Susitna River ice study 1982-83.
Preliminary Draft Report.R &M Consultants,Inc.Anchorage,AK.
Alaska Power Authority.Susitna Hydroelectric Project.Report for
Harza-Ebasco Susitna Joint Venture.184 pp.
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