HomeMy WebLinkAboutSUS437ect 7114
RELATIONSHIPS REPORT
VOLUME NO. 1
DECEMBER 1984
for:
HARZA-EBASCO SUSITNA JOINT VENTURE
rt was
ec
&
E soc
s
ants
E.,
&
ton tants
E .. es
t s
s
E6
s
E .. es
T &
s
rt
by 0
ed within this
Alaska
i.
reservo
of
c
of
st
Study Team conducted field studies to
, relative abundance, and habitat
selected resident fish populations in the
s of
Sus
of Alaska, Arctic Environmental Information and Data
) conducted the instream temperature modeling st-udies, a
in this evaluation.. Mr .. Paul Meyer and Mr., Joe Labelle
ed for ass ling the supporting technical information and
of Instream Ice ses
t of this reporto
s
assistance p
rev
,, S eve t
hydro
processesc
of
cl
rt
ology, s
f
0
0
I
v
VII
is
River Fish
of Adult
and Timing of
Resident Species
and Utilization of Hab
Evaluation Species
CHARACTERISTICS AND PHYSICAL PROCESSES
MIDDLE RIVER HABITATS
Characteristics
Processes
Water Quality and Limnology
and Ice Processes
INFLUENCE OF STREAMFLOW AND INSTREAM HYDRAULICS ON
MIDDLE SUSITNA RIVER HABITATS
Hab Types and Categories
to Instream Hydraulics
I
II-13
IV-28
1
1
V-11
3
1
l
I-.
I
1 ..
2
IV-5 ..
le IV-6 ..
s
I
distribution and
events for Sus
f f
in
1950-1982 (R&M uLJJu.;~u
1
of times breached for duration
indicated based on analys of Gold
record 1950-1984.
Sediment transport processes components
and their relative importance in
maintenance of habitat.
the
With-project influence on sediment transfer
processes and sediment loading.
water quality
Susitna
sources
vi
II
IV-19
IV-25
0
10
1
12
3
3
15 ..
5
16. Occurrences
are 7
1"
at se
s 19
i
1
1
i
F
I
structure of re
of
s
habitat types of the Sus r
II distribution of salmon spatvning
ferent habitat types of the iliiddle
Susitna River (ADF&G 1984c). •
II 3. Relative abundance and distribution of
juvenile salmon within different habitat
types of the middle Susitna River (ADF&G
1984c).
I
12
I 1
II 16
II
III-
re IV-lD Stream network within the Susitna River Basin. IV-2
re
IV-2. Estimated percent contribution to flow at
Gold Creek0 IV-4
IV-3. Comparison between natural and anticipated
1
t
annual flood frequency curves
Susitna River (Source:
1983).
and l f
7
12
3
6
re
0
1
V-7
re V·-9
V-10.
11
2
s
over
l ll
l
2
V-
V-2
V-
F
1 "
6.,
7
18c
19
1"
cover
at duration
itat cat
j
water
j
j
\tlater e
WUA forecasts
velocity crite
velocity criteria ..
Comparison between WUA forecasts
and cover criteria
s
j
Simulated effect of reducing fine
deposition at two study sites ..
sediment
V-22o Comparison between WUA forecasts using ADF&G
and revised rearing hab at model.
V-23a Percent of total wetted surface area provid
WUA for rearing chinook at Side Channel 21
and Upper Side Channel 11.
1
Figure VI-lo Phenology and habitat utilization of midd
itna River salmon mainstem, tributary,
slough s ..
VI-2 .. ect itat
F 3. th
3
9
0
53
13
VI 1
t
structure
as an
abiotic
analyses,
ctrum of to inform a
educational backgrounds
proposed project about: potentially
the proposed project may on f
Susitna River control the availability
By meeting this objective, report 11
Authority and resource agencies to reach an
tream flow regime (and associated mitigation p
minimize impacts and possibl~ enhance existing midd
fish resources.
) 1
Susitna River
antic
are
tat
anc.e of severa
of
ect s
statements are
rature
1
e
s
i
s of
f
e
scenar s on
most
s
tna 1 of on a
pert
on
tream nut
project ef
by Harza-Ebasco,
Susitna
the potential for
s of
s, and changes in
A draft report based on literature
ata available through June 1984 was prepared in
( 1) rese:rvoir and instream temperature modeling; ( 2)
t criteria Susit""la River f s
stage; and (3) evaluation of luences of
t on existing fish hab
descri.b tream
reservo ing scenar an eva
stream t ratures on
s of antic wi
on ice processes was {: in
of
ect stTeam
A
of t .sE:~
A ft
ec t s am
r 4
s
of
{
ec consists of
for construct
a si
mouth o
5
would impound a
s capac of )
capacity of 3.7 maf&
be installed the
and dissolved concentrations,
1 to .fish resources., An underground powerhouse wou cant
s rators with an installed capacity of 1020 ),
an estimated average annual energy output of 3460 g t hours
)., Maximum possible outflow from powerhouse at o
21,000 cfs.. The cone valves are to 24,000 c at
pool (APA 1983).,
The ohase of the proposed construct of
645 foot concrttc for
by 2002. construct ~ site
32 tream of Watana dam
reservoir wi 7ll800 a
0 \.-lOU 6 mws n
an A 1
(
turb summer
;: Yentna
""' at RM 28. 1..
s
town of
a
et 1) "
1 3)
are
) summer
st lows and
l
e.
area of
mountains to
Gulkana
streams
ice covered
5
c
west,
97) .. junct
rs
Glacier
west course 3
f sou
c
t
t
Susitna
s on
rs
near
litna
g
0
t
f
tream of
a b
le
Devil
a b
supports popu tions of
or sport f
chinook, sockeye, coho, chum,
Dolly Varden, and burbot,.
s returning sockeye, chum 5I coho and p
Sport fishing is concentrated in clear water t
commerc l
arie
to Susitna River for chinook, coho, pink salmon, rainbow trout
ling~
truction and operation of the proposed p ect will notably re ce
st lows during the summer months and increase them during
er months, leading to a more uniform annual flow eye
ratures and turbidities will similarly af
and turb stream
tem channel areas wi
ef areas ..
greatest
site-s ve ci it in areas
mains tern.
f c s s st " s
on
Stream
most
sser
summer
on
ral to
e
i
e ect on
as
f
re to
1 0 (
resources
Susitna
s tem d t ture
t the Susitna River fluctuate
of factors fecting
outside the river bas This
romous species such as Pac..~ fie salmon,
1 cycles in freshwater estuarine mar
survival and commercial catches significantly
lmon returning to spawn in the Susitna River and its t
is
a
e
0
Wi in the freshwater environment other factors such as late summer
fall high flows, cold-dry winters, predation, and sport f
lso fish populat In add ion, long·-term re onse of
lt fish populations to perturbat either or outs
ronmen t immed e 1 y A t
to seve years fore an effect
t al, is ref rease or crease
tent of t
To avoid many of the uncertainties associated with f tuat
p ls f
roe
(S r 1
itat is often
sen 1979~
rna g
flow
19 7 ) .
is ions
leas
na
is in f
1 of itna r
t f
f ats ..
eco fluvial s
i s mouth (Burton
characteristics such as
and vegetative cover (land use) are
s of basin runoff and erosional
mani t as a river system. The macrohabitat roach s
itudinal transition channel morphology, water
bio ica.l community which results from the interaction of se
watershed charact tics .. Based on natural variabili
tem as well as the anticipated project impacts, the 320
of Susitna River may be divided into four or d
This focused specifically on
, or 1 Canyon, of itna
s t
of the
e 1 th
ts
er
r_ and its assoc glaciers
tr streams t e of t proposed
So
to
as and
Ano in riverine
constant
t
to manner
to
sur
ve i ' cover, lity'
s ructure of our me
f
eco
p
re
one
river
or tr
rivers.
studies is
s
1978).
var
ion Wi
0
1
to
tween
0
is
of
as
as the
lee
use cone
f
ect cover
strate or ect cover to
ituations of
s
itat cond
of locat of re s
s
of no s at
itions wi or
are mains tern,
por ion
area the river
as major side -.JU t::A.-y mouths, a si~
persists over a wide dis
even area In
s c a
in respons o
4) • an examp is
side channels that exis
d ls to clear wat s
ace .area
project
1 amount of circumst
in
es water into c
s it ions an se
ls
st.=tement clear water may provide ter i ions
id water is supported by a number of s
s of sockeye juveniles rearing in glacial and c
Peninsula (Koenings & Kyle 1982); naturally stunt
s juveniles in the Kasilof River (Koenings,
rates among non-salmonid warm water spec
comm.) •
g grown in c vs.
turbid fish ponds elsewhere in the country (Buck 1956). Additional
evidence is provided by the Susitna River as well, re 0+ ch
J les rearing in cleanrater t ave roximat 5
percent more growth during the summer 0+ chinook in
s channels (Dana Schmidt, ADF&G~ 1
The hierarchical structure of our proc
hab at s sites habitat categories, to
~3crohabitat level is diagrammed in F
s rut"'ture of our analysis is similar to the s
sen tat to river t re
I
* comm~).
from
itat types
re II-2
ro-
site to rep:::e-
0 tream
i s (Bove~~ 1
1982)
b ic fference bet-ween methode
s it at
uses wet
ions
structure our more
of f
1
spec.
se 0 app the habita model s 0
h ita 0 various in si
ts il
of
struc f
sties of
river ac
variat
i
it at avai i
our
envircnment are
it at:
nstem dis
lu
l
0
af
c sification of surface area whi s
r. e H fund amen 1
of our forecas the
t~ within a e at various ls
e area of each habitat in t 1
been estimat at tern
to 23,000 cfs using d measurements on 1 in
phot Trihey 1984).,
ic areas wi Susi.tna r to v ior1s
in mainstem and ir habitat e
sur e area any midd Susitna River discharge between
9, 23,000 cfs. Additional pho raphy been obtained or s
p that will limits of the ace area model a
of mainstem d cfs to over cfs.
At m.ic area is used an
to ir va1.iatiJns in s
f on ili f it at A s f as
total su ace aref, of s s te expressed as
referred) habitat for the l
evaluated (Bovee and Mi uch
sene
l 0
(:O oci , s s rate campo ion j
s of the wuA index in ou s
d s inc between clear tu t prov
basis to ate es 0
the itna
of
forecast HABAREA mo 1 Seasona
water s mains em c be
recasts re ive s 0
i ·e s
A s 0 t
structural s of our
d F I
mainstem d inf s t
f
and hydraul c racte
mainstem dis drivine le o
to uti at.
middle indicate rent:
h story s rent i ·ements and it
d erent mic itat pre rences. sp• c s and li stage
a the second t Season of so an
t ar t it is by speci t .e cies life
s
h
ci data have been obtained and 0
l ana es
e stream
tna to em d
ion can to e sponse of f i t
s in stream t
1 descr
sponse of s or specif c areas 0
ion and amount a
water mod 1 ~3
response of f it at
c and f boundary i
provide forecasts of
ace area luenced st terations and
uantitative
ective
emperature
ices of habitat avai ili can
1
Hot..;rever
applications to s
to estimate the feet of altered streamf
water on mac itat f pro tion
time will support limit
s s 1 itats.
r
I
l
I I RES AND
rview of Sus tna Rive
:i.n sitna 0
t
t
e of commerc
f
rou
common names of 1
II I·-
t salmon commerc cat inates in a
rm ave cat
$1.7~9 to
comme 1984). recent
f sa in
f wi lion t in 1 2 and
over 6e7 lion sh in 1983 (Table III-2).
most tant spec s to the upper t cornmerc fishe
is In 19 t of 2 1 million f
in Inlet '{JJas at $13 * 5 mi ion F ADF&G
comm.. 1 4) The estimated contribution of Susi na Rive
pe ( ' r" ~0 commerc is 10
1 s l contr between 0
sa 0 er In f ch
represents a worth of between Sl 4 mil ion and $4.1 milllon
mo e i
s f i
1 , s if s
Bas
h
trout
Arctic
Esox lucius pike
Catost
Catostomus catostomus · se sue r
L,ota ta t
Gasteroste
spine stickleback
i.:ne s
Cott
s
ADF&G
catch
5 19
2
l
1
1
2,
2, 3'
153,61.9
,690 2 ~ ' 0
177,729 32 22
470,450 2 278,197
100,952 33,422
275, 813, 5
100S)636 ,624
80 933 628,580
104,420 326,1
200,125 483,730
7,372 3 ~359
1 ' 208,710 1' 6 744
14,792 2 ~ 192,975 544,1
17,303 2,622, 7 219,234 1 '68 7 ' 2
13,738 924,415 265 166 72,982
12,497 1 584,392 3 623 1,871,058
11 548 1 ~ 3' 4 5>073 127,857
3 237,376 777,132 ,972
( l) 5' ,070 5 ' 1 73,555
2,103, 3,000 6
339 even-1 576
J,?BS 20~416
( l) F&G Prel Data Commercial Fish D:i.vision
l
l 07
316,44L+
531 825
29 037
1,119 1 4
269~85
775 167
327
6 l
667 573
396~8
951,796
469, 7
1,233,733
571,9
650 357
387 078
842 j 9
1 428 621
659 190
rage
5 118'
l 926 658
4' 138 8
2,919 621
6,25 737
6~742,273
3 861 8
3 0 8 l 0
the coho
F ADF
of Sus River churn to
es imated 0 85 pe
ion of Su
l
of
In
p sa cont
1 4 In t commerc
June to avo
est
about 10
the last
streams
1
years (1981 1984)
f
rs
about 8 er G
19 ) .
t of
and
harvests, which account for over percent of the commerc
sa
value
he fishery, have
species (Table III-2)a
in 1 2
The Susi tna
mu i ec s rt
Cook Inlet communities.
long-term average catches for those
r and were reco
1 3.
many its t ies pro s a
eas access rom Anchorage
Since 1978, the Susitna s
tributaries have accounted for an annual average of
r and
7 l 00
of t f ls L 9 7 9 l l 81 1982 98
) i e 3 7 19
I
.0
s s
(RM 4 . 5
t occurs t
ss
s t
trout
ss
areas in
sistence
istence
res s.
and in
sou t of
sistence
s
Susitna
Arctic
3
River
to
of
an
of
sitna River
on Sus
k sistence harvest has
s
s
annual
from 2,8 0
is pe iod
harves
s
t l l t 0 'I
f occurs
of
service out of
trout
Susitna Ri.ver.
Susitna Basin are
resource for
imari
1
if
Ind
prov
fish
s
itna
even
in
roximate 30 miles (50
mouth~ is
inook
J
1983 F&G
rt
sto
inook
984b)
rima i
The
250 so e
H
·------·---------
cit:: a
l
2
83
8
Br L
83
8
3
81
2
r
IP 1 ~t
Harvest J!.
1 '443 !J
3~237
5
3!)
429
11;124,000
4
77711
521,
ADF&C
AD
tna at on +
Estimated "~
Percent Susitna L.
Mean
10
85
85
85
85
50
10
10
10
Range
(10-30)
(10-30)
( 10-30)
ries
ro, February
1
670,6
62~900
716~550
1,214!1650
9 ,.4
247r
388!l
2
p
297!1000
481~
2
t on
1
575,
926
---· . ------··-·---·---··--·-
4
T fish harvest for Southcen ra A1
Re ive Abundance of Adult Salmon
sa roduc tribu aries to the Susitna River
Yentna River ra (Rl1 28) tna River
tna River Numerous o
p of
est or
1) :
0 sub-bas
o Yentna sub-basin;
o the itna sub-basin;
o Talkeetna-Devil Canyon sub-bas
Lower Susitna River Sub-basin
Sus River sub-basin includLs tna
of oining tributary drainages within the e
Inlet to Sunshine Station with the exception of
(RM 28). Escapement estimates for the Susi
in are inferred by subtracting the ADF&G escapements Yentna
Station [Tributary Mile (TRM) 04] and Sunshine Station (RM 80)
the total Susitna River escapements estimated by ADF&G (1 ).
Because total escapement estimates are based in part on profess
judgment, the description of escapements to the lower Susitna. River
sub-basin provided in Table III-5 should be viewed as approximations.
During even numbered years, when pink salmon runs are
approximately 500,000 salmon spawn in the lower Sus
This represents about 24 percent of the est 2ol llion
in the Susitna River basin during even numbered yearso
The lower Susitna River sub-basin also provides important habitat for
coho salmon~ About 46 percent of the annual coho escapement spawn in
in.. sockeye and t~s s to
count 5 of tot
H
H
Tab rage
Sockele l Chum 2
% of % of
in Number Total Number Total
Susitna 5
to 80) 11,900 5 17,000 5 39,900
Yen
( 28) i 1 9,200 48 19,500 5 20ll000
to 98o6) 116,000 46 295,600 83 24li700
tna-8 1 Canyon
(::J1 98o6 to 152) 2,800 1 24' 100 7 2,200
Total Susitna
2
3
5
6
7
8
100 356,200 100 86,800
1981 3 ave of ADF&G second-run sockeye
1 1-83 ave of ADF&G escapement estimates (ADF&G
Even year 1 only; odd year 1981 and 1983 ave
1982-83 average of ADF&G escapement estimates
Lower Susitna sub-basin equals total Sus
Yentna sub-basin escapement equals Yentna
Talkeet litna in e
Susitna
escapement p us:
in escapement
return downstreum. Mil
Ta
23
28
3
l
r
Even 427,
Odd
F.ven 447,
Odd 48
Even 3 ,400
Odd 40,600
54!1800
Odd 4ll400
l 267,900
Odd 138~200
)
tna Station
~-··n~--~···---·~·
32 Even 4
33 113'
35
Even 4
29 62, 5
4 Even 9
3 9, 4
2
l
2
c
s
t ibut
ana Creek and
in
ill 000 salmon ent
about 29
escapement for the
p
sockeye escapement into the
on
, accounting for 48 percent of the
0
of
:rt
sockeye escapement of 250,000 fish.. About 23
coho escapement enter this sub-basin. The annual e
chum salmon into the Yentna sub-basin is about 5 percent of the total
escapement to the Susitna Basino
Talkeetna-Chulitna Sub-basin
Talkeetna-Chulitna sub-basin includes both the
River drainages, and that portion of the Susitna and
its tributaries upstream from Sunshine Station (RM 80) to the
confluencee · Escapement estimates for this sub-bas are
derived by subtracting the estimated es s for
Talkeetna-Devil Canyon sub-basin from ADF&G escape:nents at ine
Station~
III-10
enter
f
rates est
2" 1
000
have
to
(1
I 1
est
cons s
) are:
are
f
to account
30
on t
es
st
annual t
the contribution
account 0
to s to i
II
0
Salmon
are
of j salmon J.n
other
ream redistribution of
juveniles results in movement
re, the llowing di.scussion .; based
sional judgment ..
from smo
on
salmon rear in the middle Susitna River for one to mont
pink salmon spend little cime in this re~ch (ADF&G 1 ) ~
Because of this short freshwater res:trlence tif':P 9 it is expected that
after emergence the relative abundance of juvl ~.e chum and pink would
lect sub-basin adult spawner relat oundanceG This assumes
that fecundities and egg-to-emergent fry survival rates are not
s ly different between sub-basinsc Thus, is
most juvenile would rear the
whereas juvenile relat abundance would
Susitna, Yentna and the
This is based on abundance of
presented in Tab III-So As chum and pink smolts begin to
Susitna
to re 0
j
of
re
leave this
smo
sub-bas
1
f chinook, coho and sockeye
tive to
move
f midd Susitna River throughout the summer
s occurring in June, July and August (ADF&G 1984c).
sockeye juveniles that remain in the middle
ve
ative
are
ut e rearing habitats until September and October when they move to
habitats. Age 1+ chinook, coho and sockeye and ~ge
outmigrate from the middle Susitna River primarily in ~une
1984c) ..
specie~ such as rainbow trout and Arctic grayling primarily
use aquatic s within middle Susitna
of their life cycle.. However, movements between sub-basins may
for .. some species such as Dolly
te , and whitefish (ADF&G 1984c)~
or
mainstem.
, water
itna
season of
0
)
am.o1..1nts
structure
, stream
year
TT 1
f
) "
s
f
River as well as
at
-I. t Susitnc r.
is as ions
t amount of s
courses
as
g su:cmer
most no t
trout
summer st
winter f are
Channels are relatively s le, we
cobbles and boulderso Interst t
particles are generally filled a
of small gravels and glacial sands.. Isolated sits
s and gravels exist, however they are usually unstab
Groundwater upwellings and clearwater tributary inflow appear to be
inconsequential determinants of the overall char~cteristics of
u.~.a.~~...~. ... ,.;)tem habitat except du!"ing winter when they domir:,,:tte mainstem
water quality conditions.
Channel Habitats
s
no
t
classi
s
habitat found in those portions of
low during the summer, become
periods of low convenience
ion and analysis, side channels are defined as
10 of tot f s a glven ion in
I
of
1 habi s
courses
line o mid-channe margins o
0 s
amount of
s
t
concentrat
1 )
of s
are s
velocities
itats .. However,
ition often provide subopt
and juvenile fish.
1 1
j_
presence or absence of clearwater inflow,
at
as
or tributaries, is not considered a critical
s iment
s and
it
er
designation of side channel habitat~ However, a strong positive
correlation exists between the location of such clearwater and
location of chum salmon spawning sites that exist within s
channel habitats (ADF&G 1984d) .. In addition, tributary
groundwater inflow prevents some side channel
COI!lp ely dewatered when mainstem flnws
Octobere These clearwater areas are t of rtant
primary production prior to the formation of a winter ice coverc
s
tion of clearwater ll s habitats
are most p
at s s
II 1
ls 0
events or ice
h mainhtem
j t of s
connects
A we
it
) ~
to
) s
the ) 0
to a trea.m
1982) ..
percent of all middle Sus sa
habitats and essent
occurs side slough habitat (ADF&G 1981, 1 )
spring, large numbers of juvenile chum and sockeye can
in side sloughs. During summer, moderate numbers of juveni
and chinook make use of side-slough habitats, with
ities increasing during the fall-winter transition (ADF&G 1
Small numbers of resident species are also present throughout
year.
Considerable variation in water chemistry has been documented
s
s sloughs and pr::fn. cipally a function of local runoff terns
basin characteristics when the side sloughs are not
overtopped, water
characteristics of
sloughs display the
mainstem (ADF&G 1982b). s
mainstem or sloughs
side
tter habitat for aquatic organisns
1 areas largely because side sloughs convey turb i.vater
ly 0 ................... ls anti contain warmer water year
l
s s
f mainstem d
tem is often sufficient to overt
f some s
increases
coarse
Whe.n is occurs
as water in the s
events
cobbles o
areas. Perhaps
of water, s
itats do not appear to be as
would be in 1
a
or
ats.
s are not overtopped, surface water
independently of mainstem temperatures 1
or
water temperatures in side sloughs are strongly
groundwater. In many instances during winter,
of the upwelling water is sufficient to maintain relat
ine
or
as
free conditions in the side sloughs throughout winter (Trihey 1 2
ADF&G 1983a)~
Q.eland Slough Habitats
Upland slough habitats are clearwater systems which exist in
si.de channels or overflo~"" channels.. They differ from s
habitats in several ways.. The most apparent reason for many of
differences is because the elevation of upstream berm,
separates these from adjacent mainstem or side
suff to overtopping in all but most extreme flood or
jam eventso Upland sloughs typically possess well
are often ll near zero f ve
s
III-
is o
slough,
· habitats
resent up s
of
to
rate at
to storm events re
The rapid increase in
f
0
........................ tem
to response o
or
em water
reflect the integration of its
characteristics and are independent of mainstem flow,
regimese Middle Susitna River tributary streams convey
of
water throughout the year which originates from snowmelt, rainfall
runoff or groundwater base flow.
Tributaries to the middle Susitna River provide the only
spawning of chinook salmon, and nearly all the coho and pink
spawning occurs in this river segment (ADF&G l
Approximately half the chum salmon escapement to middle
River also ary habitat. salmon j
outmigrate sho
to two months,
in t
ter emergence and juvenile chum in one
but a percentage of emergent chinook and coho
streams for several months fo emergence
such as Arct and
lso st
to
extent t
s feeding station
1982a). 1 mou associat
within
significant spawning habitat for pink and chum
l
s tion of Evaluation
of ion species llowed the 1
uses are
to s
concern
were
s 1984) ..
slough side channel
to be affected by project
ion a synop of base
t of evaluation species ..
adult salmon conducted 1 1 3
of Fish and .Game (ADF&G 1984a)
and s sloughs are the primary spa"ming areas
f ies of Pacific salmon that occur in the middle reach of
itna River (Figure III-2) .. Comparatively small numbers of f
in mainstem, side channel, upland slough and tributary
s.
and sockeye are the most abundant of the four species that spawn
in non-tributary habitats in the Talkeetna-to-Devil Canyon reach of
Susitna River (ADF&G 1984a) .. The estimated number of chum salmon
spawning in non-tributary habitats within the middle Susitna River
averaged 4,200 fish per year for the 1981-83 period of record (ADF&G
1984a). Approximately 1~600 sockeye per year spawned exclusively in
slough habitat during
channels and side s ..... vu.;!!::.~L;J
same period.. A few pink salmon uti.lize s
for spawning during even-numbered years
(ADF&G l984a)
non-tributary hab
Similarly, only a few coho salmon spawn in
s of the Susitna River (ADF&G 1984a).
SL
f chum
middle Susi
s ll 9
annual s
s
eleven s l
for more 95 s
1 3' 11
56 chum salmon in the mainstt:!m
tream of of the Indian River (ADF&G 1
occurrence of sockeye salmon in itna
than slough habitats.
sockeye salmon spawning areas commonly overlap at of
ions where sockeye spawning has been observed (ADF&G 1
overlap is likely a result of similar timing and
requirements (ADF&G 1984a and d).. Because chum salmon appear to
more constrained by passage restrictions and low water depth during
spawning than sockeye salmon, the initial evaluation and analysis of
f relationships on existing salmon spawning in the middle Susitna
River on chum salmon with the assumption that sockeye salmon 11
respond similarly.
Depending upon the season of the year, rearing habitat for j
salmon is in varying degrees by all j c habitat
found middle Susitna River. Among non-t
hab ats, juve:_nile salmon densities are highest in side and up
sloughs side channel areas (Figure III-3). Extensive samp
j not tern s, ly o
1 f wate
H
H
H
I
20
GO
00
40
30
20
tO
2.9
TR18UTAR!£S UPLAND
.8
SIDE
:;
SWE
SLOUGHS
0···~ ---~r------+-""""""---+--·--1
lRt8UTAP.SfS UPlAND SliDE SIDf.
SLOUGHS CHANNElS SlOUGHS
60
50
40
30
20
!0
0
TR UPLAND
f
j
i ies
are most
se
s is
in t
s
contrast., j
are most numerous
l
mainstem d
1984)c reason, two spectes,
on ion available from f
not been selected for evaluat
ect-induced changes to
s are not expected to significantly affect important
ions including rainbow trout, Arctic grayling
populations are low and appear to be limited by
those associated with mainstem discharge.
j
s s
res
0
Wi the exception of burbot, important resident species on the middle
River are mainly associated with tributary habitats a
trout and Arctic grayling are important sport species
basin .. spawning and rearing for these two species occur almost
in tributary and tributary mouth habitats.,
individuals of both species use mainstem habitats for overwintering
The availability of and rearing hab s appears to
popu ion of rainbow trout (ADF&G l984c).
habitat types other t
h
associated
lakes. the project little ef on
III-·
s
are
is p ic
as soc wi
turbid
project condit
to occupy mains tem hab
greater than 30 NTUs
still cause ext
to occupy depths greater than 3 ft t
IV) Burbot populations are likely
1984c).. The production of other resident
i
tern
ect
to maintaining burbot populations in the middle itna
S significant changes to these populations are not
burbot population levels are not likely to change
icantly ..
habitat relationships analysis continues, additional fish may
included in the evaluation species list .. Overwintering rainbow
trout and rearing juvenile grayling may be appropriate candidates ..
species 'ViThose populations may influenced by project
ions will also be considered for evaluation species status
I stages such as chum, chinook and pink salmon spawning
evaluated in
currently spa~m primarily in habitats other than the mainstem
and side channels of the middle Susitna Rivere The physical
are
ics of
to
II
channel
ec
itats in
tems uti
s water
ff
t
(13,020
INFLUENCING
AND
RIVER
), Mount ) ,
Other average 7 ll 000 to 9,
Tributaries in the eastern
and in
ions averaging 6,000 to 7,000 and decreas
northwest, the mountains
land dissected by deep g
Cook Inlet is the Susitna lowlands ll a b
in ion from sea level to 500 feet,
to 250 feet (Figure IV-1).
Between
in
re
drainage basin lies i.n a zone of discontinuous permafrost.
mountainous areas, discotltinuous permafrost is generally present e In
lowlands and upland areas below 3, 000 feet, there are iso
masses of permafrost in areas with fine-grained deposits. The basin
logy consists largely of extensive unconsolidated deposits derived
from glacierse Glacial moraines and gravels fill U-shaped valleys in
land areas. Gravelly till outwash in the lowlands on
upland slopes are overlain by shallow to moderately deep silty so
Windblown silt covers upland areas& Steep upper slopes
lly and loamy deposits with many bedrock exposurese On
flank of Alaska Rang~e and south-facing slopes of the
Mountains, soils are well-drained, and gravelly to loamy.
Poorly gravelly and stony loams wi permafrost are present
on slopes of f bottomss
eros on s severe on s s.
H < I
N
f !0 lncrfjmenh
Scol1: 1":
at
in eep
\~>Jell-drained
or come
Sea across
slopes of
much heavier
tna
re
in
Susitna River is ty~ical of unregulated northern glacial rs
relatively high turbid streamflow during summer
clearwater flo-yr during winter .. Sources of water influent to
itna River can be classified as: glacial melt, tributary inf
non-point surface ~unoff, and groundwater inflow. :'he relative
importance of each of these contributions to the mainstem discharge at
Gold varies seasonally (Figure IV-2)0 Snowmelt runoff and
rainfall cause a rapid rise in streamflows during May
Juneo Over half of the annual floods occur this
2 Estimat cant ion flow Go
Figure m-2
glaciated portions of the upper Susitna Basin play a s
role in shaping the annual hydrograph for the Susitna River at Go
Creek (USGS stream gage station 15292000).. Located on the southern
slopes of the Alaska Range, these glaciated regions receive
greatest amount of precipitation that falls in the basine
covering about 290 square miles, act as rese
maintaining moderately high streamflows throughout summer.
those ions of upper not covered by
of steep bedrock exposures or shallow
runoff and
occur, ically in late summer and fallo
events have 87
tot occurs
1) ants ( 1 1)
of the reamf at ld
on MacLaren River near
f
IV-1 of statist
at et .. 19
2,452 1, 3 7
2,028 1, 7
1,900 1,123 713
21)650 1,377 745
211%890 13,277 3,
50,580 27, 15,
34,400 24,383 16,1
38,538 21,996 8,879
21,240 13;175 5 3
8,212 5,757 3
4,192 2,568 1
3,264 1,793
16 445 9 1 4 785
As temperatures drop during fall, glacial melt subsides
streamflows decrease. By November, streamflows ~ave decreased to
approximately one tenth of midsummer values .. An ice cover, which
generally persists until mid-Hay, forms on the middle Susitna River
during November and December.. During winter, flow in the
River is maintained by the Tyone River which drains Lake
Sus Lake and Tyone Lake, and by groundwater to
smaller tributaries t~ the Susttna River
groundwater inflow is thought to remain fairly constant throughout
s increases winter as lows
g ia1 me non-point runoff ceaseo
f the Susitna River
ciation sno'W'Ule f
e summer
er f
July
August
September
55
9
24
3
occur
are often
exists among monthly ratios for
flottrs to their respective
eptember (R&M Consultants 1981)6 Flow is
1
the summer, with occasional sudden increases as
1
to the highly variable, and sometimes erratic, precip ion
Susitna River streamflo'#TS show the most variation in
and late in October, periods com_monly associated with
breakup and the onset of freeze up. From November through April, low
temperatures cause surface water in the basin to freeze,
stable but gradually declining groundwater inflow and baseflow
headwater lakes maintain mainstem streamflow.
The natural flow regime of the middle Susitna River
be signif altered by project operatio . (Figure IV-3).
ect be less than
May August as water stored in
wintero Variability the middle Susi tna
by
reservo
100
90
80
70
60
50
U)
LL 40 0
0
0
0
w
1.02 Ul 1.25 2
RECURRENCE INTERVAL
NOTE: BASED ON WEEKLY RESERVOIR
SIMULATIONS.
5 10 20 50 100
low
of 9700
st
s.::ven to
by
to ,000
c.omm .. ).
As a of
amount er
term d.Ve
1981), the
of
stream
f
to
2 .. 5
~ 1
are
) for normal
to fps
1984,
its of
f
or
2).
1 ) "
are
of
are
can also
access to
at potential spawning
i tat may be reduced ..
cause dewatering of
or, during the winter, freez
areas or
1 seasonal streamflows may also adversely j
rearing by restricting fish access to stream.bank cover or
rearing habitats •
.£.ide S!ough Habit~.. Side sloughs are overflow channels along
floodplain margin that convey clear water originating from small
and/or upwelling groundwater.. A non-vegetated alluvial
connects the head of the slough to the mainstem or a s
channels A well-vegetated gravel bar or island parallels the s
from the mainstem (or channel) ..
intermediate and low-flow periods$ mainstem water surface elevations
are insufficient to overtop the alluvial berm at the upstream
) of slough. ~ mains~em st is often Juff at
the downstream (mouth) of the
ext a. feet upstream
slough to cause a b
slougho
to
of
of the s
amounts
to ut
of
increases
f
cover for j
was p
on
subsequent sections ·
~ is important to
variability in detennining
ion of overtopping events (Table IV-3)0
Upwellin_g
Water which rises from the streambed has been recognized as s
influencing the spawning behavior of chum and sockeye salmon
(Kogl 1965, Wilson et al. 1981, Koski 1975, ADF&G l984d). water
connnonly referred to as "upwelling" by
of s characterist flow direction into
biologists
stream 1 ..
Downwelling intergravel flow are two other types of
f which occur in stream channels are to
materials (Figure
in both
two
As the term f from stream into
st to a near
1
0
1
3
5
0
3
3
1
0
2
2
4
2
7
25 3
27~000 3
33,000 1
,000 0
!0000 1
,000 0
imes b
is of Go
3
0
2
2
4
6
3
5
3
0
0
2
2
3
3
2
5
4
2
-1
6
0
2
0
1
3
3
3
3
2
3
>10
------·
0 33 459
3 27 412
4
12 13
13 10 263
11 8 218
6 3 118
6 1
3 1 55
2 1
August 12 through September 8
1 2 0 1 8
3 6 5 7 25 628
4 6 9 13 15 431
6 8 4 7 6 224
7 3 3 6 3 141
3 2 3 3 3 99
0 1 2 3 1 46
0 1 3 2 1 42
2 1 1 3 0 31
1 1 2 2 0 26
11
-
N
In r
p
is
to
f in stream
source to
water
is term water
s satu
soil zones. two zones
The plan shape s
of so
present ..
subsurface geologic structure
elevation of the water table at
of water supply .. a
for groundwater consists of precipitation acent
water bodies.. Precipitation infiltrates into the soil, f
the unsaturated zone as "interflow", and reaches the saturated
zone$ Because of this increased water·supply, the groundwater tab
t
In
in elevation. Sometimes excess water appears along streambanks,
outcrops, or steep hillsides as bank seepage ..
of drought caused by lack precipitation or cold
ing precipitation (snow) and shallow subsurface
elevation of the water table declines because of a
of availab water supply®
like of middle Susitna River,
are its of gkQ .... ..!.Y..J..
s 1 ) il terns
IV-3
of
which
occur
s
mountains
control
occur under the berms at the heads of side sloughs
as long as the required geologic couditions are present and a source
such as the mainstem, exists for the quantities of water
In addition to the influence of subsurface alluvial deposits on
location rate of upwelling water, water supply is
the river valley most persistent water is river
Through the
groundwatero At some down valley location,
this water as upwellinge In the middle Susitna
upwelling app~ars to along east banka
water
to water
rises and falls
14
water to
er
, much of
across
f
in
and
f
serve as a source
have a
tab
extents
appears to reach a minimum e
rates of
to early November period; upwelling f will
a minim~tm rate and areal extent. The temporal
will be reduced as the mainstem stage lowers and
of precipitation ceases du~ to freezing temperatures. The
upwelling flows will be supplied by the regional
er
componenta At sites where upwelling is continuously provided by
regional groundwater component, viable habitat will be maintained;
high mortality is suspected at sites where upwelling reduced to
ion in temporal upwelling0 As ice formation increases
mainstem stage, the temporal groundwater component will again
regional groundwater component and increase upwelling rates and
extents.
Under th-project conditions, upwelling flows may not be reduced to
extent of upwelling flows it
fall riod0 The mainstem s ed to be
at a e ect rat r
IV-15
itions in the late fallu
continue to
November
to so unt
is one o
of
sockeye itna
1
s f
to be the life stage most
in middle Susitna River. Chum
, and embryos of other species spawned in the area of
, benefit from the upwelling flows. During incubation~
for successful development of embryos, principally
its thermal characteristics. It also ensures the
and alevins and inhibits the clogging of streambed
fine particulates.
Upwelling flows appear to reach a minimum immediately
when mainstem discharges range from 3,000 to
During this period upwelling are cons to
the regional groundwater of
mainstem discharges and minimum upwelling f
limit success of s were
mainstem and flows. Many embryos are
ene ll the v le incubation habitat is
e transit of
r
f
r to
5,000
0
in
0
of
ice
r
and
s runoff
ant water f
are than
in s
to an
precipitation ceases
side
juvenile
is usually higher than tem waters
apparently attract
mortality (ADF&G 1984c)~
1 i
f
source o
£
the
s section,
ical processes
tors of
rt Proces
is u
mass
s of
and
McNeil ( 1
cal
s the success of
have shown
survival of to fry in
1964, McNeil 1965, Cooper 1965,
of aquatic. habitat for
trate composition.
is
a macrohabitat le·vel, the channels of the middle
stable given the range of streamflows and
which they are subjected. Review of aerial photography
approximate 35 year period (from 1949-51 to 1977-80)
River are
tions
over
plan form of the m:iddle Susitna River has changed 1 tle (AEIDC
1984a) ~ Although many non-vegetated gravel bars have appeared and
some peripheral areas have changed, a preponderance of and
habitats appear unchanged over this period ..
Channel Stability of Habitat Types
Six habitat types have been identified in middle itna r:
mainstem, s channtel, side slough, tributary, tribut
up slough. Each habitat type can be characteriz by the re
specific sediment processes have on the
(Tab IV-4).
18
\.0
IV-4p
Type
Sediment transport processes
mcintenance of habitat~
Suspended Bed
and Large
Channels Secondary Primary
Channe and
Sloughs Primary Secondary
Minor Primary
Slough Secondary Minor
s
Ice
Primary Secondary
Primary Primary Minor
Primary Minor
Secondary Minor
-~-------
are
rocesses~
are
summer st
or more ..
mean
to t
more
:ikely occur,
to reform channel to
in the mainstem and
s
size to res erosion or transport by
,000 cfs. The cobbles and boulders const an armor
has developed as a result of previous flood events t
r
ion
of
substrate sizes downstream. The cobbles and boulders remain
as a well graded protective layer for the more he
materials. High discharges would have the capaci to
e the armor layer and transport underlying streambed materials
downstrea..1, but a new armor layer would likely develop as the f
and cobbles and boulders eroded from upstream locat are
redeposited. The entire bed elevation of the middle Sus River
during these events since the sands gravels eroded
materials underlying the armor coat would likely not redeposit~
Evidence of such long-term channel degradation has do
analysis of (AEIDC 1984a)e
of subst"t ate in itna Rivfr to erosion
cement fine and
si s f
vo
hab
2) scour jams during b
4) scour t
comparison to
streamflows, ice SCOUl of first two
secondary importance .. The two are 0
scour by block ice is primarily a b
As large ice floes are moved downstream,
ial exists for direct interaction between block ice
st or channel bottomse Suspended sediment samples
in late May cr early June following breakup typically contain
percentages of sand, which may indicate stream channel or bank scour
(Knott and Lipscomb 1983)$ Bank erosion by ice-block abrasion may
severe (Knott and Lipscomb 1983)e
f
lo
jams during breakup cause local staging
increase flow velocities and sccur potential ..
cons
High veloci
d a channel bottom or bank can result severe
scour .. The sudden release of an ice jam can also cause
s ficant scour potential in the form of a flood wave conveying
blocks of ice ..
es to t
s are fi.l
sus
ice s
, se
ttom is sensi
to
momentum
mass ..
or contact b
to
by encas
vegetation& The denudation of
serves to increase
of the shoreline to scour
the ive contribution of
thought to be minor, the process can
by d
of fish habitats along the channel margin.
t s
at ion
Of the sediment transport ses
described in the previous section, two have dominant ro
formation and maintenance of side sloughs and side channels.. These
are: 1) high flow events, and 2) ice jams during breakup ..
scour by block ice, anchor ice processes, and shore ice processes are
less active in these habitats&
S sloughs and side channels are generally
size that they were formed by
f of high flows through side sloughs
varies s s
process may be important in maintaining and flushing sed s
tatso sites of ice jamse
jam can stream water 1 to
jam
s
sources,
at
s
Of the
rai
s
channel or in
high flow events
mouths.. Most
gradient systems with a
of sediment during flood events.
to t
torm causing a flood is widespread, the Susitna
have a high discharge concurrent with, or soon after.,
ses
discharge in the tributary.. Most sediments carried by
will be transported downstream by the Susitna River.
However, du·ring localized storms, a tributary may flood while the
mains tern
vic
River remains relatively lowo In such cases, the delta at the
may build up with large deposits of gravels
delta extend
Subsequent high discharges
away ..
out
the itna
Susitna r
wi
Upland slough habitr.;.ts are largely isolated from
processes. The exception is in the
where mainstem may intrude as a
di
er areas cont te
(
rocesses
ion of a reservo:tr
to occur
f events a
over
are
delta format a
~1hich may characteristic of t
Sus River.
flood peaks and frequency associated with project ion
reduce sediment transport into upland slough mouths
intrusion.. Ice processes do not significantly
transport in upland sl~tghs.
Watana and Devil Canyon reservoirs will trap nearly all sediments
size and larger.. Project discharges will also
concentrations of fine silts, but the concentration will more
year.. concentrations may not cause
cement
sufficient to
armor layer, but the flood may not
streambed materials and remove f
ly f interstitial coarse
gravels ..
assessment of ect
ect is
s
s
Tr
Tr
1 p
2
itat Type
tem and Large
Channels
ls
Sloughs
Mou
s
ect rmal
ect on iment
High
Suspended Bed Events
Reduced Reduced Reduced
Magnitude
and Freq-
uency
~educed Reduced Reduced
Magnitude
and Freq-
uency
Reduced Reduced Reduced
Magnitude
and Freq-
uency
Reduced Reduced
regime is reservoir f t
t is lPlarm-water re
roce
Ice
1 1 1 s ma
2
Milder~ Less l l
2 2 Reduced ce
Minimal l l None l None
2
Hi Less 1 l ,
2 2
ture mat
e e
scour
most
11
)
ice
This
of
s
tem, s
s severe
occurs
ect discharges will to
j
1
channel banks and bottoms.. In some s
low overtopping discharges, mechanical scour b
increased. Project flows will be higher winter
of some side sloughs may resultG
ect influence on anchor ice sediment transport processes
to be minimal" The principal influence will be to lay
ice formation by one to two months. There may b~ some
sediment transport in those side sloughs and side channels
be breached by project discharge levels during of
cover ..
Sediment transport by shore ice processes
natural levelso The increased
ect cover would
probably
t
tant amount
a
shoreline frozen into the with-proj ec-:t ice cover.
However, during summer wou
scour
I
scour b
s 1
as
IV-27
<tJater, as
matter it
at as so
River ffers not in terms of its mo
tern of its water
of a hab type to f
in low or water
River, turbidity is an
'iiJater quality
aquatic habitat types
that may
two distinct
1
sitna
but
s
water season: clear water or turbid water. Thus, it is use 1 1)
examine the water quality characteristics of both clear
\rJater aquatic habitats; 2) identify how the water quali
turbid
of these
ic habitat s on a basis; 3) determine
changes in turn ...:.e quali of
water accounts test amoun~ of wett
area in the River n.e to S t and
su ace runoff
are grea est, dis so sol conductivi
ini pH. and the concentrations of the
anions and most cations tend to be at their st leve of the year
stream tu
1 rus
0
of a 0
year IV-6
ions remain re ive constant he
variation summer as
of 0
ter
dis t entire of
System (
low to tern
amount contact
of the watershed than runoff
thus contains more dissolved substancesQ
ic water quality characteristics of
through a given chanrtel may differ
tions provided above, depending on local
of local runo or the compos
or
and d1.st
or
tf
)
itself
g
so
he
l.on of
soils, and vegetation .. Nonetheles3, a generalized seasonal
water quality regime unique to each itat seems to prevail, and
knowledge of it provides useful insight into the direct
irect role water quali p as a of f it at
to Devil Canyon of the itna River.
A son of winter water quality
Susitna River at (Tab ) a seasonal contrast
in itions of the mainstem and its associated
s st a f er is cove
it ions
Sol
Phosphorous
(
)
)
rate-nit as N (N0 3-N)
Recoverable Cadmium [Cd(t)]
Recoverable Copper [Cu(t)]
le Iron [Fe(t)]
Recoverable [ (t)]
[ (t)]
[ ( t))
( t)]
tants 1981
(sut~ttme
62
5~6
19
'3 .. 0
4.2
2 .. 2
11 .. 5 mg
102% -1
1 1 11
2 .. 5
em ' 25°C)
ts
as
as
15 pcu 1 120 ~g -1
0.15 mg !l
2eQ tJg !l
70 J.lg 1
14,000
0.30
30
70 -1 1
1
)
2
22
2 2
<5
<100
<10
0
2
10
h c
C) g 1
s.
ransition b
1970)0 amount of ace area
em
rom
c to 20, c
tuate cons -1 ( 9 -1 , 6 7 0 mg 1 ) ,
1
transition 1.s
1 A ma erial may
f path along the into
channels and sloughs@ h
ood organis~s and some of
production. At prevailing springt
( 100 NTU), the mainstem margin and side channels
inue to support a low to moderate level of primary p
velocity is not The euphotic zone at t
es
N 1984)$
In summer, tem flows are at their highest The total
by h area available for production is
that light
OoS ft (Van 1984)s Many of ec are
in st e:J.r ins tar at this time (To
co comm.,) ..
ir natal t taries move to
seem to be concentrated in
s s
Juveni
i
areas of
1
out of
itats,
mainstem and side
ic itats
0
b
s
by
so
of s s
tumn trans
stream f
ls
ita.ts
1984
' a
mostly by a not
probab
b in terms of b
f s
e
ace area
of t
s p
zone at ies of 20 NTU
es 5 f (Van Nieuwenhuyse 1984)* f of
stops at fr-eezeup. Some of this product s
or in place.
sloughs present a unique seasonal pattern of streamflow water
ity that is important to many fish species inhabiting the midd
sitna River. Side slough habitat cons ts of clear water mainta
upwelling or local ace runoff in overflow
st of s s char act
of upstream of the s
ly trans rms s s
to s channel itat.
In winter s s
up'i,;ell e:roundwater (
it at for
rt:s ent juveni
contain
198
ryes
romous
numerous open
) ' T11US t
and overvinter
fi
maintained
provide int ragrave 1.
opportunities for
i
and p
this ransition
emerge f
or
in
0
s
are connec
are
tern water ..
tic
side s
tics
subject to turbid
tream juncture with the mainstem or a s
s
suspended sediment load carried in by
rms
s
a.t
s a
mains tern
) .
set backwater and thus presents a substrate
farther upstream in the sloughs.,
rent from
F observations by EWT&A suggest that some of the sediment carried
sloughs seems to become part of an organic of
(probably involving
in turn is usually covered by a
covers most
to 3 inches in diameter, can be
tem and s channel
wi
poss (S Univ.
e icate as much as
tot rus can
p
of
6
s)
tomse
mate 2
throughout the system in
It is ssib
some role this
Montana pers comm. 1984)
percent or more of this
bio i avai
This
in
ions
e S ll 1
t
on
to
is t from s s i
runoff
tics of up itats
are influenced by ff
tem ..
all aquatic habitat types, the sea~onal water
tern displayed by the tributaries is close linked to ir
regimes. This pattern of considerab
tributaries--most notably Po Creek, Ind
st since it
River, and
July most of f ion s
em
at
s
in
1 1 , 1 9 8 2 , l 9 8 4a) • streams spawning,
amounts habitat
most productive of
The
i
in water f from it.
macronutrients
p
soi o
does not exist, or s in
ic habitats in
, may
midd
ion of t
soi
of
water 1
of a stream
solids contained
e concentrations of
prevail streams
sp
t
f is
much of
f
f
environment
trans
of
1
ion
er
ice snow cover on
cover on
s
ive
to 8°C by mid-May air temperatures have
freshet has filled the tributary channel runoff from
ting snow. Ice redistributes much of the cobble substrate and
out organic inorganic debris as well as much of
(Hynes 1970)" This eros
concentration
chemical
while, as in the mainstem,
causes an in
low of sur runoff
di tes winter concentrat of dissolved solidse It is 1
t serves as a reset
system 9 in ef cleans it in ion for the eco ical
events to
5
b
0
a tant
p as
a
serves as
or
are
continues
s
Susitna River and
of
s
0
0°C an cove
d lodge
t
f
tic
t
of
St
this repo c f
1 re
l 2
in. suspens
consist p
d create a tu
ion ir mass than imates
concentrat om
reserve (s) ye:ar wi h
(Van Ni
t
200
magnitude will
between 60 and 600 NTU
zone depths of
1984) ..
in suspended levels in middle
1982)~
et al 1 2)
0 4
of
Susitna River likely result in existing sediments and find sands
n streambed materials to be transported downstream (Harz co
l ) & Additionally, if short term peak flow events disturbed
s materials and cleared rstitial spaces of f
connection sub ace
f probab improve .. ions 11 in turn
success rate r
by salmon and colonization rates of on
benthic rates during summer.
p tion in the reach of Susitna River presently
to be concentrated in the sp and 1 periods of
7
.::rature
teria
of
in stream
rates of
1 increase 1.n
use as em
of f io to survi.vP vli hin
of stream t to
is a narrower of "pre
sm rates of are most f j_
are upper t
1
ferred temperature range for adult salmon
River ranges from 6 to l2°C (AEIDC 1984b).. Juveni
i
slightly warmer temperatures rearing, generally rang from 7 to
14 °C (Tab IV-7).. These s are ·consistent wi
pre t range of 7 to l3°C by McNeil and Bai
(1975) for
incubation
s successfully
t up to
increases are cons
vu to co
between 4 and 1 C sa
t
rates
roximately 14°C~
ion
tr.~mental ~
t res until
between 2
direct.. re to stream
stream
t r temperature
Salmon embryos are also
ac.cumula ed
7
1
AEIDC 1984b
s ream
from literature sources
2 .. 16 0
4.,Q-14a0
0-14 .. 0
2 .. 16 .. 0
Smolt Migration 4 .. 18 .. 0
Adult Migration 5 .. 0-18 .. 0
Spawning 1 7 .. 0-18 .. 0
Incubation 0-13 .. 0
Smolt Migration 4 .. 0-13 .. 0
Adult Migration 2.0-~t:> .. O
Spawning 1 5 .. 0-14 .. 0
Incubation 0-16 .. 0
Rearing 2 .. 0-16 .. 0
Sm.olt Migration 4 .. 0-16 .. 0
Adult Migration 2.,0-18 .. 0
Spawning 1 2.0-17 .. 0
Incubation 0-14 .. 0
Smolt Migration 2 .. 0-16 .. 0
de,~lopment rate increases as
units or days to emergence
See Figure 1
i
rature
15 0
12 0
12 0
60 l .0
4.5 0
7
8
4®
5
7 .. 0-14.0
6~0-11 .. 0
6e 13 .. 0
4 .. 10.0
6. 12 .. 0
f sens
can tole
p
1
CTU' s can as an
of chum
forecast emergence time us
and other pertinent literature
AEIDC (1984b) .. The tween mean
and development rate for
is the form of a nomograph (Figure ) ~
nomograph can be used to forecast the date of 50
given the spawning dat~ and the mean daily intragravel water
for the incubation period.. A straight line proj from
spawning date ou the left axis through the mean incubation
on the middle axis identifies the date of emergence on the
axis ..
1 A centigrade temperature unit is the index used to measure
inf of on embryonic development is def as
one 24 hour 1 °C above freezing (0°C)" stream
4 and 5°C provide 140 cent
one month ..
l
Sus
-Slough
-s 11
-Slough 21
3
3
5 -Anchorage
5 -Anchorage
5 Laboratory -Anchorage
5 Laboratory -Anchorage
1 Calculated from the tim~ of SO percent hatching to the time of 50
emergence
2 had occurred as of April 20
3 (1981)
4 Waldron, Eklutna Hatchery, _ommunication
5 from and (1983)
(
not
in
variation of
rivers
c
or
occurs
is highly
solar az which inf
ion unit area and
of the river by the processes
the construction or operation
i
of
ect. However 9 the amount and temperature of water to a
river also affects its temperature. Construction and operation of
Susitna Project will substantially alter thes~ t
relationships by the redistributi.::>n of the available water
supply and its associated heat energy through the year.
Sources of water influent to the Susitna River are classified as:
glacial melt, tributary inflow, non-point surface runoff,
groundwater inflow. The importance of
to
to
flow and temperature at Gold Creek varies seasonally.
and non-point surface runoff
to rainstorms j) and glacial
ly a summer phenomenao Groundwater _
fairly constant throughout
snow me
water
e
runoff cease
near 0°C
waters are
a p
normally from zero
~n 11 or l2°C from late June to
rea~ ·apidly during May but gradually
at
em
Octo\ Water temperatures in side channe
temperatures except in side channel areas do not
wu.~tl•~tem water during periods of low flowm Except when
wu .• u.~tem flow, surface water temperatures in
of mainstem water temperatures even
occasionally be the same temperature (Table IV-9)m
side sloughs
though both
Water
are
Sloughs receive nearly all of their clear water flow from local runoff
groundwater inflow. Due to their relatively large surface areas
comparison to their depth and flow rate, sloughs are quicker to
warm
water
coolQ Hence daily fluctuations in side slough surface water
s
are more exaggerated than for mainstem or s
(ADF&G 1984f).. When sloughs receive substant 1
snowmelt or rainfall runoff, their water
t the temperature of
f p by
runoff G
1
1
1
1
I
/'
I
/
/
+
/
/'
s
2
0
T'-..... --
'
'
cation
s
s 9
] l
s 21
tem
LRX 29
LRX 53
e:
Source:
Comparison
mainstem
RM
125,.4
126 .. 4
128 .. 7
135 .. 7
141 .. 8
126 .. 1
140.2
sur
1982
Feb Mar Apr
2 .. 5 3 .. 1
1 .. 6 1 .. 9 3., l
o .. o 2 .. 9
0 .. 0 0 .. 0 2 .. 5
are simulated
occurs0 Thus April
8 .. 9
10 .. 9
10 .. 8
an
-·--
6 .. 5 2@4 1 .. 7 0 0 0 4 1&3
5 .. 8 4,4 2 5 3 8 • 3
5 .. 9 2 .. 3 3 4~
3 .. 3 3 e l 2.,9 2.,9 2 .. 9 2 .. 9 3e0 G 5 6 0
2.,2 1 .. 1 0 .. 8
6 .. 5 0 .. 6
6.,4 0 6
cover ier in
are
summer
s
ratures
are
water,
areas extreme co
of 0 C water s
1
occurs
as
are by
ect stream
water
warmer
water re
3 or c
water ..
events
water
but not
content
most
are
of
ect
stream
it
ream
IV-1 .,
Susitna River
Reservoir
stream
conditions
19826
load demand in later years of
use of the Devil Canyon cone values
~~1armer mean summer temperatures (AEIDC
ect design and operation has a notable
0
mains
I
8 .. 5
7 9
us
summers
s
on
and flow rate of water discharged from the dam(s)~
anticipated operating range of the project, the temperature of
r outflow has a greater influence on downstream water
temperatures than flow rate. Table IV-11 displays s
downstream temperatures for two situations: the water week 34,
the downstream release temperatures are equal but release rate dif
and water week 45 where release rates are equal but their temperatures
differ. The weekly simulation period is the same within each
thereby eliminating do\~stream temperature differences
influences., T11e 1 .. 8 °C temperature difference. shown in
second case results in a much greater downstream
that resulting
in flow) shown in
most not of
810 cfs f
case ..
ect construct
rature
s
(13
from
on
f 1
s
53
23
13
3
tream
reservo
50
140
130
120
110
99
2002
Demand
4 .. 5
4 .. 9
5 .. 4
6 .. 0
6 .. 5
7 .. 1
t
d
5270 0 c
c
2020
4 .. 5 8 .. 2
5 .. 0 8 .. 5 1
5 .. 5 8 .. 6 1 ~
6 .. 1 9o0 1 4
6 .. 7 9 .. 4 10 ..
7 .. 3 9 .. 8 llmO
0
Susitna River
p
f rate~
occurrence warmer stream
on
to seven
as stream as it does
in meteorology is most s
15 to -25 °C air temperature increase
There
periods
from the -dams and result p
a rapid upstream progression o.f
(Gemperline 1984). Table IV-12
tream
of the influence. winter air temperature has on s ed
water temperatures.
The second most important variable, and one over which project des
operation has some degree of control, is the temperature of
reserve outflow. The amount of water being released from
reservoir also influences winter stream temperature but it is not as
a variable as outf temperature or
downstream temperatures for two cases: (1)
dam temperatures are the same but flow volumes change (in
case a 59 and (2) d8m release f are
ively constant actually a 11 increase)
As in the previous example for summer releases,
rf:: in the
,10
5
0
JUNE JULY
IV-12
constant
Note: Both simulations are for Devil Canyon dam, 2002 Demand@
5
23
13
3
Downstream
reservoi
1
140
1
120
110
99
(
12,
2002
lo3
0.7
0
0
0
0
d
s 71
1 c
1 .. 3 2 7
0 .. 9 2 .. 2
0 .. 4 1.,5 0
0 0.,8 0
0 0&2 0
0 -0 0
s 1983) ..
, in.stream
a
Talkeetna-to-Devil-Canyon
on a recognition of
to understand the
in text, brief definitions have
f i
(1 for the most common types of ice found in
itna River ..
0
0
0
0
Frazil -Individual crystals of ice generally
form when water becomes supercoolede
to
Frazil Slush -Fraz ice crystals have strong cohesive
prop~rties and tend to agglomerate into loosely
clusters that resemble slush.. The slush eventually
sufficient mass and buoyancy to counteract the f
turbulence and float on water surface ..
Slush -Similar to frazil but formed by sely
packed snow particles stream ..
-Black ice as individual s
in near zero areas
an cover ..
iescent er
1 velocity
(<1 ft/sec)
1
l
0
s
feet
cover
to such an extent a
of
to this cons at same rate as
water velocitye An accumulat of
occurs at the constriction which
continu.ous solid ice eover or bridge ..
usually prevents slush rafts from continuing tream
therefore an upstream accumulation or progression of ice
initiated ..
o Hummocked Ice -This is the most common form of ice cover on
the Susitna mainstem and side channel areas. Essentially
is formed by continuous accumulation of slush rafts
progressively build up behind ice bridges causing
cover to migrate upstream during
Most ice covers are
concentration of fraz
supercooled (0°C),
season
as
as a re
river water
to
f
s
14).,
on the
rate
of
rate
near the conf
1 ) "
over by
s
1 9
a.
at
moves
of 5
cover ..
ry of freeze up observations for several locations thi Tal
reach f Susitna Ri Source: R&M Consultants 1980-81, 1
River Mile 1980-1981 1981 982
Nov G 29 Nov 18 5
Dec 12 Dec. 31
Confl 98 .. 6 Mid-Nov. Nov. 5 Dec
n 10303 Nov. 8
19 104.3 DecG
n 106 .. 2 Nov. 9
108.0 Dec .. 2
u 112.,9 Dec., 3
113 .. 7 Nov. 15
McKenzi Creek 1160 7 Nov~
n 118.,8 Dec .. 5
120 .. 7 Nov. 20 Dec
124 .. 5 Nov. 20
!! 126 .. 5 Dece 8
u 127 .. 0 Mid-Decu Nov. 22
S1 128 .. 3 Nov. 29
n 130g9 Dec. 1 Jan
51 11 135.3 Dec. 6
Gold Creek 136 .. 6 Dec. 12 Early Jan. Jane 14 Jan.
Creek 148 .. 9 Dec. 23
Source: R&M Consultants
ive warm
area to a narrow, Some s
movement, en to
f ten causes
erosion of the of
usually occurs rapidly after
cover.. These leads usually s
, opening
freeze over
ice cover, and most leads are closed by
ice progression from the Susitna/Chulitna
terminates in the vicinity of Gold Creek , about to
upstream from the confluence, by December or early Januarye
Gold Creek to Devil Canyo_!!.. Freezeup occurs gradually in the
a
Gold Creek (RM 136) to Devil Canyon (RM 150), with a complete ice
cover in place much later than in
not until March (R&M Consultants
reach below Gold Creek, usually
1983) .. The ice not
generally progress beyond the vicinity of Gold Creek because
lack of frazil ice input upper river freezes over. Also,
is late in forming here because of the relatively high velocities
caused by the steeper and s
reach.
bo build out from shore
season, water
across
areas
area
occurs
are
to
bonded by
at its
1 The only water at
over
1
A occurs as
a
ice cover
numerous
areas of er
the
areal')
cover
tants
of
near
elevationsll' water exis s
f
cover tances
to
occurs onto
to
water
water
in sags
quickly
rises and erod~s
collapses into the
coverll
accumulating in small jams ..
wider and longer,. This
the from Talkeetna-to-Devil Canyon;
river below Talkeetna open leads occur
overflow of mainstem water onto the ice cover is f
of rising water levels ..
disintegration of the ice cover into individual fragments or f
, of
the drift of these floes downstream and out of the river is called
breakup drive.. The natural spring breakur. drive is ly
associated with rapid flow increases, due to ion
lift and fracture the ice surf ace.. When
becomes high enough to break and move t,
breakup drive beginso s intensity is dependent upon meteorolog
condit during the pre-breakup periods
Major jams generally occur in shallow reaches a narrow
channel one bank, or at s0
or jams are acent to
a catas
in
1 76, as
ice overflow
a or s
cause
of 0
f truct cover occurs in to
jams in succes
mass and momentum to next jam downstream.. This continues until
is t clean of ice except for st
been pushed well up ·onto water
several weeks before
modeling runs show that operation of the Susitna River Hydro-
tric Project would have significant effects on the ice processes
of the Susitna River, especially in the Talkeetna to Devil Canyon
reach, due to changes ~n flows and water temperatures in the
below the dams.. Generally, winter flows would be several times
greater than they are under natural winter conditions, and winter
water temperatures would be OG4 C to 6o4 C where are normally 0°C
immediately below dams (AEIDC 1984b)= The ICECAL
Susitna Joint Venture was used to s
river ice condi under various scenarios of p ect operat
wi Watana operating alone a~d conjunction with D~vil Canyon
r demand ::.,ituations, with ic
source
on this
warmer water
warmer water
to 4 to 6
1
e
a
2
not coo to
to
5 ice p
itna Joint
e
5
8
., 18
.. 5
-1996 Demand
Nov .. 28 140
Dec .. 25 137
Dec .. 28 l
Dec .. 12 127
Dec .. 17 March 27 127
1 Demand
Nov .. 28 Mayl 142
Dec .. 19 16 1
-2002 Demand
3E 2 Dec .. 2 May 137
77 Jan .. 10 April 20 1
1-82 Dec .. 30 March 12 1
1982-83 Dec .. 22 March 20 123
Dams -2020 Demand
1971-72
1982-83
Legend:
Notes:
Dec., 3 April 15 133
Dec .. 1 '~ March 12 127
B -Observed natural break ups
E -Melt-out date is extrapolated from results when
occurring beyond April 30
N -cover for natural conditions extends upstream of
Gold (River Mile 137) by means of lateral
bridging ..
I .... Computed
(River
front progression
137) is approximation
1.,
2 ..
closure by lat
natural conditions.
r
assume
)
b
occur,
b
assumes one
in
during eup to be signif
that reach 11 cover forms
2 to 7 feet ·higher than
both dams opera~ional, stages
than normalo Downstream from the ice
channels would be overtopped more frequently IV-16)e
discharges would be higher than normal but no
occur upstream from the ice front's maximum position
ls in that reach would be 1 to 3 feet lower than natural
staging levels with Watana operatinb alone, and 1 to 5 feet lower
both dams operating.. Therefore, no sloughs should be overtopped
However~ lack of freezeu.p staging in this reach of
prevent or reduce groundwater upwelling in the sloughs& Na
staging causes approximately the same hydraulic to t
between the mainstem and adjacent sloughs as occurs
With project place and no freezeup staging
hydraulic head would re~duced ..
Since the ice would not as !I or as
summer
t
idlySI
p ect as more areas of
water
16
ions
Wata:na
,......,,__"""'""' __
101 .. 5 6/6 6/6
112 .. 0 6 5
112.,3 6/6 5/6
8 114Gl 6/6 6/6
115 .. 5 6/6 6/6
115,9 6/6 6/6
120-.0 6/6 3/6
123 .. 5 6/6 4
126 .. 1 5/6 4/6
127 .. 1 4/6 2/6
9 129 .. 3 4/6 2/6
9 u 130 .. 6 3/6 0
131.8 3/6 2/6
133 .. 7 3/6 1/6
u/s 134 .. 3 4/6 1/6
d 135.3 3/6 0
136 .. 5 4/6 2/6
tes:
1
2
ncase C" instream flow requirements and "inflow-matching" reservoir
release temperatures are assumed for with-project simulations.
For example, 4/6 means that 4 of the 6 with-project simulations
resulted in a higher maximum river stage than the natural
conditions for corresponding winters.
Source: Harza-Ebasco Susitna Joint Venture, l984a
7
1
of i
ion
no continuous
no breakup or
to shor~ would probably s
p of border ice might
ream., Ice the river reach above the
, but would not drift into this area
it would be trapped in the reservoirs.
s
ect
as it
spring breakup drive is usually brought on by rapid f
increases that lift and fracture the ice covere The proposed ect
reservoirs would regulate such seasonal flows, yielding a more s
flow regime and. resulting in a slow meltout of the ice cover
warmer-than-normal water temperatures ect
cause the upstream of cover to
earlier in the season than normal.. spring me
Watana operating alone predicted to be 4 to 6
normal, 7 to 8 both
By May, flow in the river would be s4~··~·~
project ins to store incoming flows from
processes
itna area e
s
in the tna River wou
ams
norm; _ of
f from the ect ..
s
breakup commonly cause rapid and
water elevations. The water continues to
jam releases or the rising water can spill out
..... """ .......... tem into adjacent side channels or sloughs.. · This
of riverbank to be eroded.. Ice scars have been
until
cause
on
trees in some localized areas as high as 10 feet above the stream
The sediment transport associated with these events can raise
or lower the elevation of berms at th~ upstream end of sloughs~ Ice
floes left stranded in channels and sloughs during breakup can depos
a layer of silt as they melte
processes the mainstem river are important
character of the slough habitat, Besides reworking trates and
flushing debris and beaver dams from the sloughs could o
be potential barriers to upstream migrants !l ice processes are
cousidered important for maintaining the groundwater lling in the
sloughs winter months* This is critical in maint~4U~Ua
ion as
ect st as
l
encase many
f
can remove
j can
water,
of cover,
can
ice jams ..
on
by
ON RIVER
River ..
are not
value
relative
fish ut
Six major
within the Talkeetna-to-Devil
mainstem, side channel, side s
tributary mouth ..
surface area of each habitat type in the
reach has been estimated for mainstem discharges
f
s
f::om
9 to 23,000 cfs at Gold Creek (USGS gage 15292000) using
measurements on 1 inch = 1,000 feet aerial photographs (Klinger and
1984).
Surface areas of clearwater habitat types, such as upland sloughs,
and tributary mouths, collectively represent
one of the wetted surface area within the middle itna
and Trihey 1984). The surface areas of hab t
exhibit le to mainste·m d V-l)o
t areas may more to runoff
to ions in mainstem dis
t rate
of of s 1, s surf ace areas
N
wo
RM 1
1
At 9 s
approximate
s.,
er at the
of
at
This is
and numerous part
occurs in the single
109~ and upstream Qf RM 14So
amounts of
of
of
occurs
tween
.... ""'._& ...... s consist
mainstem habitat regardless d.~·-u~~·
some specific areas within the middle Susitna River
as or side channels and tributary mouths, a designated habitat
ts over a wide range ui mainstem discharge even though
area and habitat quality may change significantly. In
instances, the classification of specific areas may change from one
habitat type to another in response to mainstem discharge (Klinger and
1984). Such an example is transformation of some turbid
water channels at 23,000 cfs to clear water side sloughs at
f An important characteristic of s
to their as fish habitat, to f
, and lime of they exist as one habitat or the
(ADF&G 1984d) e
ly re to habitat transformation is concept of
(i e ..
itna
location changes
is an
from
in
as
it
ion
at Gold
1983)
0
icu
movement
a
a
area of all ar~e.as
area .. areas are
on
areas
de channels~ side sloughs, or
a side or lough was
areas ..
amount of surface area is expected to be trans-
one to another as a of proj
(Klinger and Trihey 1984) .. This was
the basic framework for the extrapo ion methode
focuses on the dynamic change in system
the system as flows a summer em
,000 cfs to a discharge
because 23,000 a typical
cont.A..u,u.v'u.o::\1 overlapping was
are used to trans rmat of
~.ua . ..Ltl~;::)tem d_._., ... _,,"""
s a f
i r
1. Descri-tion of Hab
0 -
I -
III -............................. !
a
not possess suf
lead throughout
at
at
IV -areas which persist as
at a mainstem discharge less
V -Mainstem or side channel shoals which
distinct side channels at a mainstem discharge
than 23,000 cfs ..
VI -Mainstem or side channel shoals which become
appreciably dewatered but persist as shoals at a
mainstem discharge less than 23,000 cfs~
Category VII -Mainstem or side channel shoals which transform to
slough habitat at a mainstem discharge less
23,000 cfs, and possess sufficient ling to
maintain an open lead throughout
VIII -side channel shoals
habitat at a mainstem
do not possess
an open lead throughout
IX -.Any water course which is wet at 23,000 cfs t
becomes at a mainstem dischargeo
an
to
X -at at
v
I
a
s
exists can substitute for
trans at 167 0
assessment ect ef ts on
areas in
at
) e
in
an increase in
in dewatered areas
of habitat for fish. The
decrease in side channel and the in s
types to fish are less obvious. Although it is poss
characterize some of the attributes of the specific
s es
belong in these categories, a more refined ana of
microhabitat variables (e .. g .. , depth, velocity, substrate, etc@)
necessary to fully assess the capability of a riverine habitat to
support fish ..
0
18000 l 12500 10600 7 1
32 32 32 32
10 15 24 25 27 33
5 6 10 10 13 12
52 47 36 23
4 4 7 9 11 10
6 21 21 17 -11 7 7
2 2 3 5 5 4 4
8 2 2 3 4 6 5
9 6 6 8 9 13 18
1 33 32 27 27 25 23
167 167 167 167 167 167 16 7'
i
c;., • ...,.....,:
~ C..l"'((-s
11.0
j <10
• ; .t;@ ) -I ao
UG t®
@ @
(C~)
d
ic areas c ssi
c
V·=lO
1
certain
of
(PR) are
or
stream
of f
as
I
areas
f
movement to ano
movement
strenuous e
-mov~ment to
re of
wi
a or
ficu
even
of success
(ADF&G 1 ) .
of stream
movement f
stream
of
some of teris ics
res ions inc
as
V-
since the
e
3 rest areas
more
j
of
movement
tO SUrlllOUDt 1973ll Sec
restrictions
salmon is gr~ater ies
son 1972)c Adult coho, sockeye, and p
passage restrictions the condit
unsuccessful for chum or chinook; thus, of
for chum or chinook salmon is conservatively taken as
of coho, sockeye, and pink salmon.. Resident
trout ically have shallower minimum depth criteria for passage
and thus would not be restricted by depth as often as salmon
be, but the maximum velocity criteria for trout is lower
f:'r salmon (Thompson 1972) ..
Parameters affecting passage of juvenile res and
species intJ, out of, and within their rearing habitats
shallow flow depth and high velocities.. most restrictive
cond ions j passage would be entrapment, where poo
containing juveniles become isolated surface flows re to
zeroe High ities (<2 .. 0 fps) in. channels with interst ial
s icles or les and bou s to
p areas d
V-3
ion s a
t
j
habitats r
for succes
s
success 1
are to
water season.,
tent
succes
is
ion in the mains
sources
succes s a s
s itats.. S sloughs are ed by so
s
success
Thus, successful
into and within the s
to need for successful
smoltsa Juvenile salmon also use s
s slough habitats have similar passage characterist s
habitats except breaching is less frequente Thus,
restrictions described for unbrea.ched side channel sites would app
o side slough habitats more frequently during the spawning season~
sage into and within side slough sites is provided by breach
on
or local flow conditions.. Even in side slough s es ~
breaching is relatively frequent during the spawning season
natural flow regimes" Backwater provides for passage through
t and sometimes second passage reaches upstream of the s
mouth during much of spawning season~ Slough flow, when increas
by rainstorm f the local area provide for pas of
adults through some reaches
15
s de
s
or out of
to
process 1 1 3)
tween habitat availabi
conditions is assessed by
fo passage is available$ As
at passage reaches in a slough or side channel a
cumulative effect of backwater, breaching, and f
a
Analysis of escapement timing to sloughs and flow history during
1981-198: spawning season provides the information necessary to
delineate the period in which combinations of backwater, breaching,
and local flow are mos~ important for passageo
Selection of the period from August 12
September 8 for chum salmon passage into and within sloughs and s
channels of middle itna River is based on chum t
mainstem at Station (RM 120) and the es of first
counts in six sloughs that contain the majority of s
spawning chum salmon in middle Susitna Rivere These s (
9, 9A, 11, 20 21) are locat tween RM 125 1420
1
2
one to two
1
a
Poor
unt s
pas
8 covers
may
water
s
s
one
counts
near
are
uti
t
981, 198
Station
mou
er
ion rema
of
0
success
sage
ca
scharge at Go
tween
r eva
passage occurs
tion (b
for passage.. For
at a passage
)
s
es
be or exceeded 80 percent of
only, 20 percent of the time due to
t 6
often
ropof·
f
f
0
rcent of the time if an average groundwater flow were
Since backwater, breaching, ter
of a
tained from a f
upwelling are functions of mainstem discharge,
certain depth being equalled or exceeded is
analysis for the period of rest ..
ion of local flow (
conditions will be comp ed as 198t4.
f occur ly ly at
The
sloughs side
number of site was b
s b
Analys of
1 ) to
ld
s s
of was
( V-3). is
a t: one
t
0
of b at se s
(%) (
28 10
6
19,000 9
s 11 42~ 5
1 16,000 97
.. .., ' .... 1 12~000 97
s 21 25,000 4.3 5
9
10
0
sloughs ..
cfs is
2
occurrence f
b
ss
s
9
, on the
with
through passage
to produce
)
a mainstem
backwater
pas
of the 35 ye.:1rs ..
I. This discharge 97
At Passage Reach II a mainstem
discharge of 15,600 is needed, which so occurred 97 rcent of
time (Figure V-6)e However, ave~~ge number of days year t t
was provided PR I PR 12
8 were 25 .. 6 .. 5 ..
ant ipat ect flows, tern flow 0
b tes or cause
season.6
rtance of f in some of se t
ions wi described in f ft of his
5 1
25
N
1
1
resenting
:f
to fish ..
cover
to
wei
itat suitability criteria for
An of
Usable Area (WUA) calculated model
cause several of the variables
st low variations, weighted usable area may cons
s low dependent habitat availability index.
in
lJ.
) ..
t
middle
-tnfluence s
However~ a
for success 1
Susitna River
if as an
2
evaluated us
substrate
chum and
habitats
ant
so
(ADF&G
itat
t
1
0 f
t
a
are not
to ar-eas
on
to upwelling in
oped by ADF&G for
slough and side channel habitats ass
to streambed material sizes from one to
f
A). This range includes much larger part
are commonly cited the literature as being
chum and sockeye salmon. Literature values ical
s
es
r
coarse sands to fi.ve-inch material; th 1 I 4 to three inches
the most size
between
to the
(Hale 1981) ..
litt. .. ature is
1 on
select of redd sites .. Apparently, such a small amount of good
sitna River itats
ever st .
l.
s are assoc is
trate sizes ( s)
may st
s s
\
\
\
9
RIJ
SUBSTRATE CODE
\
\
\
\ \
~
\
\
\
'\
V(l.QClT"!'
0.0 1.0
1.0 1.0 z.o o.s
Q---o SOCKEYE
0~-----¥------F-----~-----T~~~
1.0 2..0 3.0 4.0 5.0
.9 LOl
.a
~ .1
0
~
0
LO
VELOCITY ( FT/SEC)
2..0
SOCKEYE
SUITABILITY CRITERIA
$UITA!Ut.I1'Y
~ IHOgx
o.oo 0.0
0.20 o.o
o •. :so 0.2
0.,1!:1 O.SI
o.n 1.0
1!.00 1.0
0=--Q SOCKEYE
3.0 4.0
DEPTH (FT)
5.0
~
o.oo
0.20
0.!'10
0.1!!0
®.CO
6.0
substrate
ilities
areas or
., 1981) ..
chum
o velocities less 1 .. 3
B)~ As the mean column velocity at the
leO fps, suitability declines more rapidly t
Microhabitat areas
4.5 fps are considered unusable
The ADF&G criteria s
2 3 fps
1978, Wilson et 1981,
may
spawning
Sus were
t a narrow
suitabi ty criteria developed
mean column velocities exc
both species.
ilit to
1980, 1981) e
used to
and salmon
in s itats
range it
oth1~r invest
i
t
it at
were
b col itats of
0
st
s
1
are cons
th s
et .. 1981) ..
re
locations~ Bot~
within four
vicinity (ADF&G 1984a,d) .. Although
response curves spawning
at of these four study sites, they are,
(Figure V-8) .. minor differences that
r c
curves) b
, qui
between
itat response curves for these two species are attributable t
dif rences between depth and velocity suitabi criteriae
between · 0. 2
A
ly
0 .. 8
to
ut
of
ana is
sui tab
sockeye
is assigned to
a sl ly li
in excess of 1 fps
iso ed observations, 1 soc~eye salmon
occurred in sloughs
sa t
similar to
are bo more numerous
itats ..
sa
ass
in
rements
1 ) In
ita
f
.11.0 80
f"LOW (Cf'S)
~ SOCI<EYE
~~ ,_------------------------------------------------------,
2
0 ~-----~----~------~--
0 ICO
St:JE: CHAt\; EL 2 1 , ........... ,
n
i1
WUA to
itatsc
curves area we
'~'M'a ter at
water
f~rence eness of
area as a measure
feature in these graphs for II
of WUA values. The highest occurs
ively high discharge after rhe slough is
f The habitat response curves for these two
rapidly as the channel is overtopped and
e slightly increasing or decreasing with site
itat Category III sites, the WUA is not closely
site for the discharges analyzed.. WUA values remain
constant as flow increases. The shape of the WUA fun~tion relative to
change in gross area indicates the stability of hab
magnitude of the WUA function is controlled by fixed
attributes, and substrate while s
velocity distribution or variable
maximum amount of at
not area
area of s
s sites were 16
of
si s
(
11
) ~
to 1 .. 0
0 to 0 .. 5
21
to an
to mean co
0 to 1., 3
con-
s 11
over
0~~----~-------F~--·~~--~----~~m------~------~------~------~
0 100 150 200~
f
300 350
(C )
10
1 , UP
:/!(\
2£
:i:ll
710 -b: Ul
H~
ld.
i;B
1@
~ \
f,l '
"'
:1
0
@ tO
SIDE CHANNEL 21 SIDE CHANN
C"'IJiill ~~Oilo $PA>l!07~>;!ilil«:$
2116
24
;u
E E
:!!Cil
, fa ...
161
u.o..! , .$ ...
I
120"'! 1Z-,
100 .J 10,
I
(!10 ~ tll"''
'1\0 ~ 1!11..;
e.Q ~ <Ill-
20 a
0 0
e 1() Cl
(til'S)
A re ns di
. (
}.
20
0 0.5 1.0 2.0 2 5
L
F
it at
rovide a re ive s
s
us
21 at s
or exceeded 90 of same as
or 10 percent of t
II sites are also relatively
11 has a flat habitat duration curve from 100 to
or exceeded.. Higher habita~ values assoctated b
ions occur more frequently than in category I~
Salmon
Microhabitat Preferences. Extensive field studies have been
ADF&G to determine the seasonal movement and habitat
of juvenile chinook, chum, coho and sockeye salmon
Susitna River (ADF&G 1984b) .. Juvenile coho salmon rear
i e
1
21
F"low Ouuat ion Curve
TiME fQUAlff D OR EXCEEDED
UPPER SIDE U
Ff ow Duratioo Curvo
IEQU OR EXCf
SLOUGH 9
Fso• CtJr\los
TiME EQUAlfD OR fXCffOfO
EQUAl£
(
summer
water t
areas assoc
1
chinook
us
compares
juvenile salmon as a means
from unfavorable water
s
as submerged macrophytes, large substrate
undercut banks provide both types of shelter
t
t
(Burger et ala 1981, Bustard and Narver 1975, Bjornn 1971
and Koski 1977)c One significant result of the ADF&G
0
s is the use of turbidity by juvenile chinook as covero
le chinook were commonly found in low-velocity turbid water
(100-200 NTU) without object cover but were rarely observed
locity, clearwater (under 10 NTU) without object cover.,
luence of idity on the ion of juvenile chinook
habitats was so pronounced ility
velocity and ect cover were developed ADF&G r c
id water (Figures 15 and l6)e
curves assign
0" fps
water ..
water,
s to ve it
between 0 o 35
e 3) ana
to
0
0.57
1.0
0.50 I
0.65 1.0 0.60
0.8 0.68 0.38
\ I. I 0 0.25
L40 0.25 0.15
\ 0.18 0.01
2.00 0.12 0.02 \ 0.06 0.01
\ 0.0 0.0
0.6 \ Clear water thml 10 NTU \ Turbid water 800 to
\
\
\
0.4 \
0.2
0.0 -L.----............ ----"""'f"""'-----~~~-~_:,.:==~~WP-~~--__,
0 0.5 1.0
1
2 3
No Cover
4
Oebns and
Dead foil
5
R
more
t
(
tors to
1
were
habitat
at
) <>
ty curves
mean co
to apparent j
ADF&G reported the mean co
by 50 foot cell (mid-cell
that juvenile fish may have occupied
developed by Burger and Bechtel are
velocities measured in the immediate vicinity of
servations or (point velocities)~
stream
as
fish in clear water are more 1ikely to
lower velocities
ice of
(one half
cover are
to 0 .. 65
0 to 0 .. 5
was
a
0.8
0.6
..
0.4
0.2
. -
0 0.5 LO
0
I
1
s
water
0 to 0 .. 5
using point
as data
from the ADF&G
water ( ~ 4 fps) j
measurements ra
water currents, they are more to
water column away from·object cover
(1 to 200 NTU) than if it is ( 10
than 0.4 fps, the distribution of
id water will likely become more strongly
velocity, and when velocities exceed 1 .. 0 fps, object cover
as important to juvenile chinook in turbid water as it
clear water. However, since these young fish do not appear to ent
well in turbid water, they cannot make use of object cover
available and are therefore redistributed in microhabitats
currents ..
mainstem
small , juvenile chinook
cover are most
or near
v
water
65
p
s
juveni
1
areas (
areas ssessing
velocity ranges utilized j
water is
cover availability.
to
Gi.ven.
most
high
that presently ~xist in
ial between streambed icles are
glacial sands in most areas veloc
would exist at moderate to high mainstem
discharges when water at the site clears
tween 0 35
to find interstitial spaces betv.Meen streambed
with fine sediments and a good food supply is in riff areas
were subjected to relatively high velocities when the site was
braached. Generally these types of riffle areas occur at j of
site ..
on the following ications have been to
itat suitability criteria for juveni.le chinook.. The cover
by ADF&G for water
However
water have ined such
s
ut
unct
water cover
cover
water
ADF&G 1984c
water were
factor
mean cat
cover categories (Table )o
of turbidity
idity on
chinook salmon.
Number of Fish
.8
2.,5
4.,0
5.7
7 .. 2
3.5
4.2
4.8
5 .. 5
6 .. 0
lication of these turbidity factors to ADF&G
suit ility of cover
0&83
water cover
r
id water condit if 50 object cover sent
more ect cover
18) .. The suitability of
in
of j
cover .. water
2 3
Cover
4
Debris and
Deadfall
r 1 rua
5 7 8 9
Gravel
(
j
more
t j
water at
importance of cover to j
cover conditions
tes ~nder natural condi most no
light, occurred at the very
) where lo~"l7-veloci ty water is more likely
strates in the mid-channel zoneo WUA indices
chinook using cover criteria for low and high
are presented in Figure V-20. Identical habitat
s
s
curves are forecast for low turbidity conditions because the ADF&G
water cover criteria is used in both modelse
of modified id water cover results
a 25 percent reduci:ion in WUA indices from
ect: ion, the larger (
are by
tream of
cove f
20000
6000
40000
21
--
20000
0000
ADf&G WUA
so 75 100 021
SITE fLO~ ( Cf S)
/
ADf8G WUA
~~-------------·
SITE FLOW (CfS) SITE flOW (
on
1)"
j
Criteria ADF&G
Criteria
Velocity Criteria
for juvenile chinook salmon at Side Channel 21
11 using the ADF&G and revised rearing hab
to total surface area. in Figure V-22 as functions of tem
discharge.. The upstJ:eam berms at these sites can be at
mainstem discharges of 9,200 cfs and 13,000 cfs, respectively ..
low turbidity conditions exist at the Side Channel 21
the mainstem discharge less than 9 ~~ 200 cf s,
whenever the mainstem discharge exceeds 9,200
re ionship discharge
Upper Side 1 11 t
13,000 cfs ..
of hab
by
at r~sponse curve sfor j
ion tween cover avai
, cover seems to
amount of
same
1 ..
Turbidi
numb1r 9
10,000
41,000
40poG
11,000
c
W IOQOOO
1: c !1,000
IOPOO
UJ~tOOO
ro~ooo
+-=-----~------~------~------~----~~-=---=mFmc=-~~==w
0
100000
0._--~------------~--------~--------~----------------~F-~---------------r~
1 14000
21
100000
areas
i
in the
between weighted usable area
flow dependent percentage
a lesser percent~ge
avai.labl~ as rearing habitat6 Th:A..:J
suitable velocities for reari~g fish
rate increases w~tted surface area; a common
occurrence gradient channels.. most
rearing habitat occurs at tern
area
f
rc
OF
)
of
water
b t
cs
s
an
stream
structure,
on
areas
are
j
attracts
areas until ) .. Chum f out-
j
areas unt
1
ats
to warrant
of
1"
15 45
25
51
t
t
j
1
by trans
and incubation
Susitna River. The
microhabitat variable
f
areas by chum salmon and it significant
survival rates(ADF&G 1984c, 1984b). Table VI-2,
e the influences of existing physical habitat
and incubation in each habitat type.
of mainstem habitats by spawning chum salmon is limited by
1
season
~
Velocities between 5 and 9 fps (Harza-Ebasco 1984e)
many areas and substrates are
with silts (R&M
but to a
access to
degree.. S
e and are
areas
mos
1
s
nstem
-3
-1
0
0
0
-4
+1
t on -1
-1
0
0
-3
=2
-9
~1 ..,:z
0
0
0
0
.. 2
-2
Index value -1
PART D
0
composition -2
sediment -3
+1
-2
0
0
!ndex value -9
-~~··""~!
Evaluation scale
+3 extremel
+2
+1
0
-1
-2
·"'3
cal cond
Side
Channel
-2
+2 .. ,
-1
0
0
... 3
-2
-1
. ----~~~i~
•1
-1
0
0
0
0
-2
-3
-9
+1
... 2
·2
+1
-2
0
0
"'6
Si
51
+6
+3
+1
0
0
0
+2
··1
+7
~
+3
'Fl
0
0
0
0
+2 _,
+8
+2
+2 ... ,
+1
+2
0
-1
+7
during the season eval
0
0
0 0
+4
+3 +2
~1 +1
0
0
0 0
+2 -2
0 2
+4
+2 ~r
~i +2
0
0 0
0
0 0
+2
0
+5 +3
+2 +1
+1 +2
0 0
+2 +2
+2 +3
0 0
0 0
+10 -ID6
-
are
conditions
high
1984 (ADF&G 1984b).
covers over eeeper pools
conditions in sloughs are relatively
adequate depth, water
can occupy interstitial spaces the
times sloughs
overtopping
ion IV).. The
are overtopped by mainstem flows during
events are caused by ice cover formation
influx of cold mainstem water into side s
reduces
rates
water and
(see
s
as water
streambed
to near zero,.
ice may form on
overtopping events do not common
~t most slough s ..
of co is most
near 0°C water
in mainstem
t
(
..
'
j
f
out summer ..
areas
c
s
cover
and s 1 s are
areas o
2 ft are most
areas, st
can cause large changes area.,
as discharge
contrast to side channel habitats, c
as side sloughs and upland sloughs provide a
physical environment for juvenile fish
Although their water temperatures in most of the
cooler (l0°C) than would exist
(12-l4°C) they are quite suitab Unless slough is ove
f
st
conveying a large amount of mainstem water, velocit
channel are generally within the tolerance
stream
most stressful
to occur
concentrat
summer adverse
s to
f (2 11 s
r j
water
s
most of
em
~----,_.---...-~
+1 5
+7 2 -7
-9 3 6
-6 +10
-29 -24 +28 +20 +13
1
stream
( ant
on stream 1
ice conditions ..
control as soc
will
conditions for spawning~
River.. Some i.n
in construction and operation of the projectQ
or influence through ion, facility or
With-project summer streamflows are expected to be approximate one
half naturally occurring average monthly values
are to increase five fold (APA 1983) ..
s variability in the annual flow cycle
flood resulting in more
r ~~ a
i
1
f
p
f
to
to
attenuate t
store solar energy
and winter months.
in the fall probably
co 1984c) ..
te 'l:varmer s t
instream water quality and temperature are
negotiations in that with-projects conditions may either
1
er or
mitigat opportunities being considered .. Although it
_necessary to evaluate the influence of project design and on
ect water quality and conditions, must
over which control
s and of p
p ect "<vill of control over
stream water o[
of control exist over
it
1 v ) G
-1 /.
1
t
f
i
stream
UJLIIdo.l..ll,<l ..... tem are most sens
ly
by variations
1982b)"
nature and degree of change
project design and operation is bounded by
and physical laws of science as well as
unavoidable effects of project construction may
Susitna River fish habitats. Most notably is the
all suspended sediment currently being t
19
Susitna River .. Reduction in mid-summer suspended sed
concentrations is expected to in .more
ions for fish that
with the
likely be a
st
on a more s
or control
of ect
mos
of
s
ions
on stream extent
control over
season
would
mainstem
temperatures in slough
mainstem and side channel
formation of an ice covet·, it is
coo
t
ion would stabilize along shorelines and ly
bars. This change would likely improve summer
due to greater availability of terrestrial insects
shoreline cover ..
s
and
t
of winter ice cover would also ly ef
associated with the naturally occurring
an cover would st
those channe water warmer
can of control over st
Susitna River (Harza-Ebasco 1984i)~
low in
cou
to s i
f
0
h
overwinte
were f
events ..
2 3 Jl 4;
VII REFERENCES
of Fish and
II Report ..
s I and II, and
1
rt:
Fish and Game.. 1
-II Baeic Data Report ..
flow studies~ 1982, Appendix
of Fish and Game.. 1984a ..
, Report No.. 1: Ar·Jlt Anadromous
-October 1983. Prepared for Alaska Power Authority,
AK.. 380 pp ..
Department of Fish and Game. 1984bc
fishery, 1983.. Prepared by James
Tyonek subsistence
Browning 31 Divis
Commercial Fisheriese Soldotna, Alaska~
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Final