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SUSITNA HYDROELECTRIC PROJECT
APPENDIX 8.8
RESERVOIR SEDIMEtJTATJON
JANUARY 1982
I
Prepared fer:
~~~· __ ALASK.L\ PO'NER
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ALJl-t-IORrfY ----·~-J -·-----
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
'
APPENDIX 8.8
RESERVOIR SEDIMENTATION
JANUARY 1982
Prepared for:
ACRES AMERICAN INCORPORATED
1000 Liberty Bank Building
Main at ·court
Buffalo, New York 14202
Telephone (716) 853-7525
Prepared by: ..
R&M CONSULTANTS, INC.
5024 Cordova Street
Anchorage, Alaska 99502
Telephone: (907) 279-0483
ALASKA POWER AUTHORITY
SUSITNA HYDROELECTRIC PROJECT
TASK 3 ... HYDROLOGY
SUBTASK 3.07-CLOSEOUT REPORT-RESERVOIR SEDIMENTATJON
TABLE oc: CONTENTS
LIST OF TABLES
LIST OF FIGURES
1 -PURPOSE AND SCOPE OF STUDY
2 -SUMMARY OF RESERVOIR SEDIMENTATION
3 -TRAP EFFICIENCY
3.1 -Factors Influencing Trap Efficiency
3.2 -Trap Efficiency Estimates
3.3 -Trap Efficiency during Reservoir Filling
4 -RESERVOIR SEDIMENTATION
4.1 -Sediment Load
4. 2 -Unit Weight of Deposited Sediment
4~3 -Volume of Sediment Deposits
5 -SEDIMENTATION PROCESSES AND
SEDIMENT DISTRIBUTION
5,. 1 -Delta Deposits
5. 2 ~ Glacial Lake-Floor Distribution
5. 3 -Glacial Lake Temperatures
6 -RESERVOIR AND DOWNSTREAM TURBIDITY
6.1 -Pre-Project Turbidity
6. 2 -Factors Affecting Turbidity
6. 3 -Post-Project Turbidity
7 -PROJECTED RESERVOIR SEDIMENTATION
REFERENCES
APPENDIX A -SETTLING COLUMN STUDIES
APPENDIX B -ANNOTATED BIBLlOGRAPHY
-i ..
PAGE
n
Hi
1-1
2-1
3 ... 1
3=1
3-2
3-3
4-1
4-1
4-2
4-2
5-1
5-1
5-2
5-3
6-1
6-2
6-3
7-1
LIST OF TABLES
Number Title
3.1 Estimated Trap Efficiencies during
Reservoir Filling
-H -
Page
3 .. 4
LIST OF FIGURES
Number
3.1
3.2
4.2
5.1
5 ') . '·
5.3
5.4
5.5
5.6
6.1
6.2
A.1
A.2
0
Title
Trap Efficiency Curves
Turbidity at Inflow and Outflow Streams
for Kamloops Lake, British Columbia
Suspended-Sediment Rating Curves,
Susitna River
Suspended-Sediment Size Analysis,
Susitna Riv.er
Delta Formation at Lake Mead and Lake
Lillooet
Temperature and Turbidity I so lines,
Kamloops Lake
Schematic of Sedimentation Processes,
KamJoops Lake
Water Temperature Profiles, Bradley Lake,
Alaska, and Kluane Lake, Yukon Territory
Temperature Profiles, Malaspina Lake, Alaska,
and dur'ing Strong Underflow, Lillouet Lake,
B.C.
Temperature Profiles, Garibaldi Lake 1 B.C.
· Turbidity vs. Suspendea Sediment
Concentration, Susitna River
Average Annual Turbidity Pattern,
Susitna River
Turbidity vs. Time, Settling Column Study
Suspended Sediment Concentration vs Time,
Settling Column Sample (28,000 cfs)
Suspended Sediment Concentration vs Time
Settling Column Sample (17 ,200 cfs)
-iii -
Page
g ... s
3-5
4-3
4-4
5-5
5-6
5-7
5-8
5-9
6-4
6-6
6-6
A-2
A-3
1 -PURPOSE AND SCOPE OF STUDY
The purpose of this report is to present the resufts of analyses of
sedimentation within the proposed Watana and DevU Canyon
Reservoirs~ Analyses of the sedimentation were complicated due to
the large percentage of very fine suspended sediment contributed
by glaciers in the Susitna River headwaters, possibly making
results from the usual analytical t€!chniques to be in error.
The approach to analyzing the rf~servoir trap efficiency was to
first analyze the trap efficiency of the reservoirs based on the
capacity-inflow ratio. A I iteratur~e search was then conducted to
determine the trap efficiency of natural glacial lakes and to gather
information on their sedimentation processes. Settling column
studies of suspended sediment s;jmples from the Susitna River were
then conducted to gather empirical data. The information from
these three information sources was then assimilated to project the
reservoir sedimentation processes.
The annual sediment load entering the reservoirs was estimated
using the flow duration sediment rating curve method for the
nearest gaging stations and v:.n estimated sediment yield for the
area draining directly into the reservoirs. The unit weight and
volume of the deposited sediments were estimated using standard
techniques.
Modelling of sediment deposition within the reservoirs was
considered but was not deemed appropriate or necessary at this
time.. The settling properties of the very fine 11 glaci.ai flour 11 are
such that it remains in suspension for long periods of time.t
affecting the reliability of the model. In addition, the estimated
volume of sediment deposited in Watana Reservoir is Jess than 5% of
the total volume of the reservoir. · A large proportion of the
sediment will be deposited in the dead storage portions of the
reservoir due to the slow settling characteristics of the very fine
suspended sediments.
Turbidity could not be assessed on a quantitative basiso However.r
pre-project conditions were assessed, and ? qualitative analysis
conducted of probable turbidity patterns in the reservoirs and
downstream river.
susi10/x 1-1
2 .. SUMMARY OF RESERVOIR SEDIMENTATION
Trap efficiency estimates based on detention -storage time indicate
that 95-100 percent of sediment entering Watana Reservoir would
settle, even shortly after filling of the reservoir starts~ However,
data from Kamloops Lake, British Columbia, a 3 million acre-ft.
glacial lake confined in a narrow valley, indicates that up to
on~-third of the incoming sediment passes through it. Median
grain size at the lower end of Kamloops Lake is about 2 microns.
For the Susitna River near Cantwell, about 15 percent of the
susp~nded sediment is finer than 2 microns. Preliminary estimates
indicate that between 70-95 percent of incoming sediment would be
trapped in the reservoir, with particles smaller than 2 microns
possibly passing through the reservoir. As Watana Reservoir is
lons;er 1 deeper, and has a longer retention time than Kamloops
Lake, it is possible that even smaller particle sizes may settle in
the reservoir. Under the wcrst case sedimentation condition of
100% trap efficiency, an estimated 472 1 500 ac-ft. of sediment would
be deposited in Watana Reservoir i_n 100 years.
Devil Canyon Reservoir would have a slightly lower trap efficiency
than Watana due to its smaller volume. However, most sediment
will be_ deposited in Watana, the upstream reservoir. Assuming
that both reservoirs have a 70% trap efficiency, an estimated
109,000 ac. ft. of sediment would be deposited in bevil Canyon
Reservoh~ in 100 years.
Three interdependent but distinct sedimentation processes occur in
glacial lakes. These processes consist of: (a) delta progradation
into the lake; (b) sediment density surges down the steep uppet'
slope, depositing mclterial on the lake floor which had ·previously
been on the delta slope; and· (c) river plume dispersion, which
spreads the fine-grained material throughout the lake. The
serliment-laden streamflow will initially spread through the lake
either as surface flow, interflow, or underflow, depending on the
relative densities of the lake water and the stream water.
Tut'·bidity downstream of the reservoir will decrease sharply during
the summer months due to the sediment trapping characteristics of
the reservoirs. It is likely that the turbidity of water released in
the winter months will be near natural conditions, as suspendeci
sediment in near-surface waters should rapidly settle once the
r~servoir ice cover forms and essentially quiescent conditions
occur.
susi10/c 2-1
3 -TRAP EFFJCJ ENCY
Only a portion of the sediment. br~ought into a reservoir is normally
trapped and retained, with tr,e balance being transported through
and carried out of the reservoir by outflow water. The ability of
a reservoir to trap sediment is known as its trap efficiency, and is
expressed as the percent of sediment yield (incoming sediment)
which is retained in the reservoir.
3.1 -Factors Influencing Trap Efficiency
The trap efficiency of a reservoir depends on the sediment char-
acteristics and the rate of flow through the_ reservoir. As stream-
flow enters a reservoir, the cross-sectional area is increased,
resu,ting in a decrease in velocity with a consequent decrease in
sediment-transport capacity. The coarse-grained particles are
dropped immediately near the head of the back water,-with the
finer grains remaining in suspension until they are deposited
farther into the reservoir or carried out of the reservoir in the
outflow water.. The percent of total sediment trapped in the
reservoir depends on the fall velocity of particles and the rate at
which the particles are transported through the reservoir.
The fall velocity of particles in water depends on a number of
variables, including the size and shape of the particle, its chemical
composition and the viscosity of the water. Eiectrochemical pro-
cesses play an important role in determining the falJ velocity of
fine particles less than 10 microns in diameter, such as clays or
glacial flour. l n some areas, clays and colloids may aggregate into
cluste.rs which have settling properties similar to larger particles,
and conversely, highly dispersed particles may stay in suspension
for long periods of time and trar)sported out of the reservoir.
. -
Although no mineralogic analyses of ·suspended sediment from the
Susitna River are available, there are mineralogic analyses of
suspended sediment from a number of surrounding glacial rivers.
Clay minerals (montmorillonite) were absent from all samples except
from the Knik -Matanuska Rivers, where less than 2 percent clay
minerals were detected (Everts, 1979; Tice, et. al, 1972).
The rate of flow of water through a reservoir determines the
detention -storage time. The ratio of reservoir detention -
storage time is influenced by the inflow volume with respect to
reservoir storage capacity and the outflow rate. Watana Reservoir
has a storage voiume of 9,650,000 acre-feet, and Devil Canyon
Reservoir a volume of 1,092,000 acre-feet. Average annual inflow
at Watana and Devil Canyon RE.~servoirs is 5,880,000 acre-feet and
6,630,000 acre-feet, respectively. Watana Reservoir will release
approximately the average annual inflow each year, so that the
average annual inflow to Devil Canyon should not differ
susi10/d 3-1
significantly from pre-project conditions, The ratio of capacity to
infiow for 'the two reservoirs is 1.64 fOI" Watana and 0 .. 16 for Devi1
Canyon.
The size and location of reservoir outlets also influences the trap
efficiency, with bottom outlets more effective in removing the
higher sediment concentrations near the bottom~ Either multi-level
outlets or single outlets at a depth of about 200 feet will be used.
Neither type of outlet is near the reservoir bottom. Consequently,
the effects of the location of the reservoir outlets will not be
further considered in this study.
>
3. 2 -Trap Efficiency Estimates
Although several factors influence trap efficiency 1 the detention -
storage time appears to be the controlling factor in many
reservoirs. Brune (1953) developed the generalized trap efficiency
envelope curves shown in Figure 3. 1, which relate trap efficiency
to the storage capacity -inflow ratio. Using the Brune curve,
the following range of trap efficiencies were estimated.
Reservoir
Watana
Devil C~nyon
~pacity/ Inflow
1.64
0.16
Maximum
100
96
Minimum
95
84
Median
97
92
The Brune curve was developed on detention storage time ..
However, the variation due to differing reservoir shape, operation 1
and sediment cha:racteristics has not been determined ( Gottschal kr
1964). Using the Brune· curve 1 it would appear that about
97 percent of the sediment entering Watana Resarvoir would be
trapped. Devil Canyon Reservoir would trap .about 92 percent of
the sediment passing Watana Reservoir and any suspended sediment
picked up in the intervening river reach. Consequently 1 it would
appear that very little of the suspended sediment load entering
Watana Reservoir would eventually leave Devil Canyon Reservoir.
However, some concern has aeen expressed that the very fine
glacial flour would remain in suspension and pass through the
reservoir system. This may not be detrimental in the summer, but
if it remained in suspension throughout the winter months, winter
releases would be tur·bid instead of clear, as is the natural con-
dition. Consequently, a literature review of sedimentation
(App. B) in glacial lakes was conducted to estimate the trap
efficiency of glacial lakes·. Settling column studies of water
samples from the Susitna River were also· conducted to determine
the .sediment deposition rate under quiescent conditions (App. A}.
susi10/d 3-2
Estimates of sediment trap efficiency at two lakes immediately below
glaciers were on the order of 70-75% (Ziegler, 1973; ostrem, 1975).
Of more relevance is the estimate of trap efficiency for Kamloops
Lake by Pharo and Carmack (1979). Kamlcops Lake is somewhat
similar in morphometry to Devil Canyon Reservoir. lt is 15 miles
long by 1.6 miles wide, and has a volume of about 3 million
acre-feet. Mean annual flow of the Thompson River entering the
lake is about 25,000 cfs. This results In a capacity -inflow ratio
of about 0.16, very similar to that of Devil Canyon. Observations
of turbidity at the lake inlet and outlet (Figure 3.2)-led Pharo and
Carmack to estimate that nearly one-third of the incoming sediment
is carried througt) the lake and not depot~ited 1 resulting in a trap
efficiency of about 67%r
Use of the Brune curve on Kamloops Lake t"esults in trap
efficiencies ranging from 84 to 96 percent. This would see to
indicate that the sedimentation processes occurring in this deep
glaciar lake result in a lower sedimentation rate than in those
reservoirs analyzed by Brune.
For estimating the volume of sediment deposited in the reservoirs,
trap efficiency estimates were in the range of 70-100 percent. A
trap efficiency of 70 percent is considered the minimum efficiency,
and allows an estimate for the maximum amount of sediment passing
through Watana Reservoir and entering Devil Canyon Reservoir.
The trap efficiency of 100 percent allows an estimate of the
maximum amount of sediment deposited in Watana Resevoir. All
bedload is assumed to be deposited.
3.3 -Trap Efficiency during Reservoir Filling
The trap efficiency of a reservoir is· sometimes reduced during its
filling period due to the reduced storage capacity. An analysis
was conducted to estimate the effects at Watana Reservoir. It was
assumed that reservoir filling would begin in May. The increase
in reservoir storage was estimated using average monthly flows for
the Susitna River at Watana.
The Brune curve was used to estimate the trap efficiencies during
the filling period. The results are tabulated in Table 3.1. The
high flow in May and June fills the reservoir to such a level that
trap efficiency rapidly reaches the 95% level. The reservoir would
be about 30 miles long within 2 months after filling commences.
Consequently, it would appear that sediment deposition during the
filling period would be similar to that during fuJI pool.
susi10/d 3-3
TABLE 3.1
ESTIMATED TRAP EFFICIENCIES DUR~NG RESERVOIR FILLJNG
End oi Month Flow at Required Flow Trap Efficiency
(1st Year ) Watana (cfs) at Gold Creek (Brune Curve)
May 10,406 6,000 83
June 22,293 7,000 94
1-15 July 20,344 7,000 95
16-31 July 20,344 12,000 95
~August 18,012 12,000 96
1-'15 September 10,614 12,000 96
16-30 September 10,614 7,000 96
susi10/d 3-4
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3.1 -TRAP EFFICIENCY CURVES
3.2-INFLOW a OUTFLOW TURBIDITY LEVELS
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KAMLOOPS LAKE , B.C.
FIGURES 3~1,3.2 Nmm 1
4 -RESERVOIR SEDIMENTAT(ON
4.1 -Sediment Load
Suspended sediment -discharge relationships were established for
gaging sites on the Susitna River. The rating curves for stations
near the proposed reservoirs are illustrated on Figure 4. ·1.. Using
the flow-duration -sediment-rating curve method, the average
annual suspended sediment load was estimated for the following
four stations.
Gaging Station
Susitna River ·at Denali
Maclaren River near Paxson
Susitna River near Cantwell
Susitna River at Gold Creek
Average Annual Suspended
'Sediment Load (tons/year)
2 965 000 .I I
543.~000
6,898.~000
7,731,000
The suspended sediment load entering Watana Reservoir from the
Susitna River is assumed to be that at the gaging site. for the
Susitna River near Cantwell, or 6,898,000 tons/year. No bedload
data is available for this ·site. However, the channeJ is
well-armored, and little bedload movement appears poss.ible ..
Bedload at Susitna Rivero at Gold Creek is estimated to be
1 . 6 percent of suspended sediment load at 37,200 cfs. Bedload
movement in _,the Tanana River 1 a braided glacial river north of the
Susitna River.~ is about 1 percent of the suspended s.ediment load
at Fairbanks (Emmett.~ et.al, 1978). Consequently, bedload
entering Watana Reservoir was conservatively estimated as 3
percent of suspended sediment load, or. 207,000 tons/year.
The sediment contributed by the tributaries directly to the
reservoirs was estimated from the unit sediment runoff per square
mile between the gaging sites near Cantwell and at Gold Creek ...
The difference in annual suspended sediment loads at the two sites
was divided by the difference in d2ainage . areas, resulting in a
unit sediment load of 412.4 tons/mi. . Bedload is again assumed
to be 3 percent of suspended sediment load. The resulting
tributary sediment load is 429,000 tons/year of suspended sediment
and 13,000 tons/year of bedload at Watana Reservoir and
260,000 tons/year suspended sediment and 8,000 tons/year beci!-oad
at Devil Canyon. The total annual sediment load entering Watana
Reservoir is estimated as 7,547 .~000 tons/year. The estimated trap
efficiency of 70 percent for suspended sediment results in an
estimated 5,349,000 tons of sediment being deposited per yeat"1
with the full 7,547,000 tons/year deposited at 100% trap efficiency.
susilO/e 4-1
The total annual sediment load entering Devil Canyon Reservoir
consists of the sediment bypassing Watana at 70% trap efficiency,
2,198, 000 ton-s/year 1 plus the tributary sediment load of
268,000 tons/yeart for a total of 2,466,000 tons/year. Using trap
efficiencies of 70-100 percent for suspended sediment results in
1,729,000 -2,198 1 000 tons/year being trapped ln Devil Canyon
Reservoir ..
4. 2 -Unit Weight of Deposited Sediment
Estimates of the volume of sediment deposited in the reservoirs
require the unit weight of the deposited sediment. Published
values of 3 the unit weight of deposited sediment vary from 18 to
125 lb/ft. 1 depending on the sediment size, depth of deposit,
degree of subme.rgence or exposure of the deposit1 and length of
time the material has been deposited. The initial density for each
of seven sediment sizes was estimated using the Trask method.
The 50-year and 1 00-year unit weights were estimated using the
Lane and Koelzer method (1958) as modified by Miller (1963). The
sediment size analysis developed by the Corps of Engineers (1975)
for the Susitna River at Cantwell (Figure 4.2) was utilized to
estimate the percentage of each size range of suspanded sediment
entering Watana Reservoir. Th~ resulting average unit wei.ghts for
suspended sediment ajter 50 years and 100 years. were estimated at
71 .. 6 and 72.8 lb/ft. 1 respectively1 assuming the sediment was
always submerged or neariy su~merged.. The unit weight for
bedload was assumed to be 97 lb/ft •
4. 3 -Volume of Sediment Deeosits
I
Using the sediment loads and unit weight previously developed,
the following sedimentation volumes were estimated.
Watana
100% trap eff.
70% trap eff.
50-Year
240,000 ac -ft.
170, 000 ac -ft ..
100-Year
472, 500 ac-ft.
334,000 ac-ft.
Devil Canyon w/Watana at 70% Trap Efficiency
100% trap eff.
70% trap eff.
79,000 ac-ft.
55, 000 ac-ft.
155,000 ac-ft.
1 09, 000 a e-ft.
Devil Canyon w/Watana at 100% Trap Efficiency
1 00% trap eff.
70% trap eff.
susi10/e
8, 600 ac-ft.
6,100 ac-ft.
4-2
16,800 ac-ft.
6 1 000 ac-ft.
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SUSPENDED SEDIMENT DISCHARGE (TONS I DAY)
SUSPENDED SEDIMENT RATlNG CURVES
UPPER SUSITNA RIVER BASIN
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• ••• • •. • . 1 : I . . \ • .•. 'l . I '
0.. 5 --4 . .. r ·-r--·. . • ~·-· ---· --!-• l-..!-....! • .. -t-r:i,.li.· -:--;-·· ·;-; .. . .. .... .. . -:-:-:-.... o< .... •• '~ !!· .. . . r .. ! . t ;
i'i. ·;-:i ... .. .. :··· ··• ·1-i .. INTERIM REPORT
2 r-_··t·:-..•• :_:--__ .:. ~:; ::;. :::;l::: :~ .: ~-::::: ·:. .. -!--. . .. ···: ! SOUTHCENTRA.L RAILBELT ·-·· ... ·----.. ~-· ,.......,.._~ ~.-..' .. ~·· ,It::: :.~ I I t-:!"" .. t:.i..:: _;.::·: :::; ::.::::.~:~. ! :::· :::· :::. ' 1
0 '1 0.001 J Jll . .I
PARTICLE SIZE IN MILLIMETERS
SUSPENDED SEDIMENT SIZE ANALYSIS
SUSITNA RIVER
1.0
PREPARED FOR:
FIGURE 4.2
5 .. SEDIMENTATION PROCESSES AND SEDIMENT DISTRIBUTION
Sediment distribution within a Jake or reservoir is dependent on
-several_ factors, including sediment characteristics 1 inflow-outflow
relations, reservoir shape, and reservoir operation.. When a
stream enters a reservoir, its velocity drops sharply due to the
large increase in cross-sectional area, with a subsequent decrease
in the stream's sediment-transport capacity. As the velocity
decreases, the coarser particles are deposited initially, farming a
delta at the river1 s mouth. Much of the fine-grained suspended
sediment is carried past the delta to be deposited in the deeper-
parts of the lake.
5.1 -Delta Deposits
As a stream enters a standing water body the channel form and
process are altered in the backwater conditions. Bed aggradation
and .reduced flow velocities extend upstream some distance from the
lake. Although most of the fine-grained suspended sediment
passes through the backwater zone, much of the bed load is de-
posited, thus lowering the bed slope and raising the water surface
and stream bed elevations. As the delta builds, the front forms a
sharp slope break over which the remaining bedload is dumped~
As sedimentation continues, the river ·channel thanges to
accomodate the· changed profile so that sediment continues to be
carried to the delta front before being deposited. ExampJes from
Lake Mead on the Colorado River (Lara -and Sanders, 1970) and
glacial Lake Lillooet, e,ritish Columbia (Church and Gilbert, 1975)
iJJustrate the resulting morphology (Figure 5.1). A second
process 1 ·noted by Pharo and Carmacks (1979) in Kamloops Lake"
British Columbia, is that of ! episodic density surges which
redeposit material initially dumped on the-delta slope,. Sediment
density surges differ from the third process, that of river pfuroo
dispersion (as overflow 1 interflow 1 or underflow), in th~t density
surges are , episodic and relatively short-lived compared to the
relatively continnous nature of river plume dispersion; sediment.
density surges involve the redeposition of material aJready
deposited on ·the delta slope, rather than the uninterrupted
extension of river-borne sediment into the lake; and · sediment:
concentrations within sediment density surges dominate the fluid
density and dt"ive the downslope flow.
There will be considerable variation in the summer water levels ~t
Watana Reservoir, resulting in a complex delta formation at the.
head of the reservoir, with the bed elevation trying to re-establish·
equilibrium.
susi10/f
5 .. 2 -Glacial Lake-Floor Sedimentation
It has been noted by several authors (Embleton and King, 1975i
Bryan, 1974) that glacial lake-floor deposits beyond the area of
delta gro.wth are predominantly fine 1 becoming increasingly so ~s
the central or deepest parts of the Jake are approached. The
very fine material is the glacial rock flour which discolors the
water of glacial streams and lakes, and which often requires long
periods and quiet water conditions to settle (E. M. Kindle, 1930).
Deep lakes offer the best opportunities for the trapping and de-
positron of the finest material. In shaJiow glacial lakes, the ex is ...
tence of more powerful currents prevents the settling of fine
material, and often cause it to be washed towards and through the
lake outlet 1 resulting in its Joss from the fake.
Glacial lake ·floor deposits are often laminated, caused by sudden
C;hanges of grain size from finest mud to slightly coarser silt
between successive thin layers'· and often accompanied by a color
change between layers. These laminated deposits are known as
rhythmites, with an individual pair of one fine and one slightly
coarser layer known as a couplet. The thin dark layer of a
couplet consists of very fine and partly colloidal material, rept"'e.-
senting a period of slow deposition under very quiet water con•
ditions, such as when a Jake was frozen over in winter with little
or no meltwater entering.. The light-colored coarser layer indicates
a more rapid period of sediment; deposition under more disturbed
conditions, such as when meltwater is entering the lake and lake
currents are spreading sHt over the whole lake floor. Some
couplets form on an annual basis, and are known as varves. De
Geer (1912) indicated that the fine lamina of a couplet was the
result of deposition in winter wh~ri the lake was frozen and melt-
water limited. The abrupt break at the -top of the fine lamina.
represents the spring ·thaw when new coarser silt enters the lake.
Confirmation of this theory has come from pollen studies of rhyth-
mites, and from studies of modern glacial lake-floor deposits, such
as that made by W.A. Johnston (1922) on Lake Louise, Alberta ..
Nonannual rhythmites may also form from sudden fluctuations in
discharge, such as from the bursting of an ice-dammed lake
upstream, unseasonal warm or cold spells, or periodic storms. ·
The deposition of the coarser laminae is attributed to turbid
underflows and interflows of dens.er sediment-laden water from
glacial meltwater streams. The phenomena of underflow and
interflow have been noted in numerous studies of sedimentation in
glacial lakes (Emerson, 1898; Kuenen, 1951; Mathews 1 1956;
Gilbert, 1973; Bryan, 1974 a 1 b; Theakstone, 1976; Ziegler, 1973;
Qfstream, 1975; Gustavson, 1975; Pharo and Carmack, 1979). The
frequency, duration, and intensity of the underflows and
interflows have been attributed to stream temperature and sediment
load, temperature and suspended (.sediment distribution in the lake,
and lake bathymetry, especially near the stream mouth.
susi10/f S-2
The uninterrupted downlake transport of the silt and clay -sized
material was noted as being due to the interflow process in
KamJoops Lake {Pharo and. Carmack, 1979). During summer the
lake surface waters warm more r"apidly than those of the incoming
river. The river water first moves to the plunge line, where it
sinks and flows down along the slope of the delta as a turbulent
gravity current. The plume entrains take water as it sinks,
causing convergence at the lake surface and resulting in a coJ.or
change at the plunge line., When the plume reaches a depth where
its density is approximately equal to that of the lake water, the
river plume with its large suspended load leaves the bottom slope
and spreads horizontally along lines of equal density (tempera-
ture), as illustrated in Figure 5. 2. The interflow is indicated by
the tongue of turbid water extending from the face of the river
de1ta at a depth of about 20 m. The flow parallels isothermal
surfacesr and' is modified by the Coriolis force so that the river
plume is directed towards the right hand shoreline in the direction
of flow. The preferential movement to the right-hand side was
evidenced by both higher turbidity readings and coarser sediments
along the right-hand shore of the lake. A schematic of the three
interdependent but distinct processes controlling sediment t!~ans
port and deposition within Kamloops Lake is shown in Figure 5.3.
As · previously noted r glacial lake-floor sediments become
increasingly fine as the central· or deepest parts of the lake are
reached. Grain size distribution in Kamloops Lake varied from
0.5 mm near the lake inlet to 0. 002 mm (2 microns) near th.e Jake
outlet. Accumulation rate.s decreased with distance from the delta,
with rates of 8. 00 em/year . adjacent to the delta decreasing to
0.35 em/year· near the lake outlet. Not all sediment was deposited
in Kamloops Lake. Measurement of inflow and outflow turbidity
levels indicated that nearly one third of the incoming sediment was
not deposited, with the percentage varying with time. As
illustrated in Figure 3.2, turbidity at the lake outlet increased
following periods of very high turbidity levels at the inlet.
5.3 -Glacial Lake Temperatures
Deep glacial lakes commonly show temperature stratification
(Mathews 1 1956; Gilbert, 1973; Pharo and Carmack, 1979 1
Gustavson 1 1975), although stratification is often relatively weak ..
Bradley Lake, Alaska, (Figure 5.4) demonstrated a weak
thermocline in late July, 1980, but was virtually isothermal by late
September, and demonstrated a reverse thermocline during winter
months (Corps of Engineers, unpublished data). Temperature data
for Kluane Lake (Bryanr 1974b) are also illustrated in Figure 5 .. 4.
Selected thermal profiles from Malaspina Lake, Alaska, are Hlust-
r·ated in Figure 5.5 (Gustavson, 1975), as are bathythermograrns
showin the destruction and reforming of the thermocline in Lillooet
Lake (Gilbert, 1973) during periods of strong underfJow ~
Garibaldi Lake, British Columbia, also demonstrates a thermocline
in the summer months, as seen on Figure 5.6 (Mathews, 1956).
susi10/f 5-3
4oo A
Hoover Oam
-e3oo
c·
0 -0 >
Cl)
w
---
.... .. ~
~ ...... -.. _ ...
• .. •
; 1ss3-s4;
/ • _,
.~'' . ,'
,
I ,
Distance ~m)
Original Colorado
River profile
Profiles of (A) Colorado River at Lake Mead (after Lara and Sanders, 1970, p. 155) andl I!B)
Lillooct River at Lillooct Lake, showing that the greatest accumulation on an established delta occurs a.t the
delta f.ront and on the forcset beds. Luke :\lead dat.,_, reproduced by courtesy of the Cnited States Bztre~ of
Reclamation. .··
(Church and Gilbert, 1975)
PREPARED BY : OREPARED FOR:
DELTA FORMATION
RAM CONSULTANTS, INC~ LAKE MEAD .AND LlLLOOET LAKE
FIGURE 5.1
,,
22
-------5------5 ---------t
-------..... -----------------4 5----------..... ,,...._ ......
TEMPERATURE (°C)
...
' ... ...... ..
: 29 JULY, 1974
140 ~~0----------~5~--------~10~--------~,5~--------~20 __________ 2~5~
0
e .....
DISTANCE {ltm)
,.,-----....... ... ... ---... 1.5 ..... , '1 5 _... ...., ,' • • l\IIIIJW---~ '
I \
I \
I " \ I \
' ' \
'< \
\
' ' \
\
\
\
\
, ' I
--1.5-----------~ TURBIDITY ( J.T.U.)
29 JULY, 1974
•
~Plan and Carmachs, 1979)
PREPARED BY:
R&M CONSULTANTS, INC.
TEMPERATURE S TURBIDITY ISOLINES
KAMLOOPS LAKE
DREPAREO FOR~
FIGURE 5~2
PREPARED BY ' ·
NOTE:
DELTA
PROGRADATION
SlACK ARROWS DENOTE SEOIMENTATtON~ "'
LIGHT AF\ROWS DENOTE FlUlO MOTION =>
I
Schematic illustration of sediment -transp~rt and deposition me:::hanisms associated w!!i:T. a
river ent~ring a lake assumed to be temperature stratified. The equilibrium depth is that at which 11he
irtlo'' ing river \\ater has the same density a~ the lake water. and at which the river water tl~Jl":.'\'S
dnwn the la.kc.
(Pharo and Carmachs, 1979}
DREPARED FOR:
R&M CONSULTANTS, INC.
SCHEMATIC OF SEDIMENTATION PROCESSES
KAMLOORS LAKE
FiGURE 5.3
--1 C~ORPS OF ~NGlNEE{BS,.._,..._._.t t=~==:!.=·='-=-':.~~:_-:_ ....... ·~..,..._+J .. -::•::-=·:::!~~·~~~t= .. =.=.=-=t'·~::-.--:_.-_-~U-~-P~~B_H+f11...,..s....,...HED_,-..}r-tf---'.....,:-:'"--:-. ·it
so.L---~---·-·~ ··-----~1 ----~----~--~----~----'~--~----~1
WATER TEMPERATURE, °C
0 2 4 6 10
Pre ared by: Prepared for:
WATER TEMPERATURE PROFILES
R&M CONSULTANTS. INC. BRADL'EY LAKE, ALASKA AND ~~~~~ KLUANE LAKE, YUKON TERRITORY . I
FIGURE 54
PREPARED BY:
:r:
..
1
401 401
MALASPiNA LAKE
SELECTED THERMAL
PROfiLES
Or· • 2!0 4.0 .
!
'
20~
40~
.
'
60 ..
l.9
WATER TEMPERATURE iN oc
• ~\".ttl'r lmlfli'T:ttnrc 1ht(•m:l:ont )faJ,.;t•m, T.·,b· .t, · rr.1·t'' wid .. ·1'1 1h .'\ ~. • • ·:·::('r,, ..• :.•' •·' ~ p ... t .,l•lt•.tH\ 1r '(rtUllCUt 'l.ltl1ltl J IAJ! ,t} ,\ liCre t)wrn~.,l t~rut·i.t \\-' ~ t't"~•r l--•l *i ~· 1l f!·~·","l' !' ..... ! .. ~t· ~a"t ..:~
ttlm:uu::·J Ly d.ttc 17,'.!1) <>n \\JUdi they \\l'te tl'· ordt•l Pmhle ... mt•t,,n,.! u. 1'•;11
2
80·
(Gustavson, 1975)
Temperature (°C)
12 14 ts sr-,..._.;,r::--,.....:..;:=--,.~=t"~
Ol
/I August
1971
:.
Bathythermograms sho\'l'lng the dcstruc:ti<'n an!! rcfonn1n~
of the thermal structure of Lillooct Lake a:.z::oci nted
with tt.;o periods of strong intcrflow nnd un;lcrflOI-'.
Numbers refer to dates of the observations in July :mJ
August 1971.
"'
(Gilbert, 1973)
PREPARED FOR:
R&M CONSULTANTS, INC.
TEMPERATURE PROFILES, MALASPINA LAKE ,ALASKA, M~m· .
8 DURING STRONG UNDERFLOW, LILLOOET tAKE, B.C. . . . ·
' .
FIGURE 5.5
-...
i
-E -
:r:
~ a.
w a
100
R&M Cor..:SULTANTS. tNC.
<
' i
.I
l
Prepared for:
.
WATER TEMPERATURE PROFILES
GARIBALDI LAKE, BRITISH COLUMBIA ~PD[Q FIGURE5~6 tlUU[O
-n
6 -RESERVOIR AND DOWNSTREAM TUR~31DITY
M~ . .
The reservoirs will have a significant impact on the turbidity of
the Susltna River b~tween Devil Canyon and the Susitna-Chulitna
confluence, with the river being considerably less turh!d in the
summer and possibly more turbid ln the win'2er-. A rigid
quant1tative analysis is not possible with the available data ..
However, a qualitative analysis discussing the interrelated factors
will shed some light on the probable post-project turbidity in the
reservoir and downstream of Devil Canyon ..
6.1 -Pre-Project Turbidity
•
Turbidity data for the Susitna River were reviewed for the Gold
Creek and Vee Canyon sites. The U.S. Geological Survey
gathered turbidity data during 1974, 1975 and 1976, with turbid1ty
Visually measured in Jackson Turbidity Units (JTU). R&M
Consultants measured turbidity using photoelectric detectors
during 1980 and 1981 at both the Gold Creek and Vee Canyon
sites, with the data presented in nephelometric turbidity units
(NTU). The units are approximately equivalent, but due to the
subjective nature of visual observations, nephelometric means are
generally considered more accurate, especially in the lower ranges
of turbidity (less than 40 NTUls).
The nephelometric turbidity data was logarithmically plotted agajnst
vertically integrc:1ted samples of suspended sediment concentration
for the Gold Creek and Vee Canyon sites. The plots, regression
equations and correlation coefficients for both sites are shown on
Figure 6 .1. Best f~ts for the data were obtained by the general
equation T = a [ss] , where T is turbidity, ss is suspended
sediment concentration ·'in mg/1, and a and b are coefficients ..
Sediment concentration and turbidity _have -a very high correlation.
Available USGS data were also analyzed to obtain relationships for
discharge and suspended sediment concentration for the above two
gaging sites. The following relationships were derived for
turbidity, suspended sediment concentration, and discharge.
Susitna River near Cantwell
T = 0.3568(ss)o 8;~J0 n =_9, r 2 2 0.98
ss = 0. 0000553 Q 1 n -37, r = 0. 703
Susitna River at Gold Creek
T = 0. 2496(ss) · ;~~~1 n = 6, r 2 = 2· 95
ss = 0.000673 Q -, n = 332, r = 0.585
The poor correlation coefficients between suspended sediment
concentration and discharge are to be expected on glacial rivers,
where glaciers contribute irregular amounts of sediment ..
susi10/s 6-1
Ev~n though the determine coefficients are · rather poor, the
regression equations are stiiJ useful in determining the seasonal
variation in turbidity. The turbidity..,suspended sediment
concentration equations and the suspended sediment
concentration -discharge euqations were used together w~th the
mean daily flow summary hydrographs for the two sites to estimate
the monthly pattern of turbidity. The summary hydrographs used
ar·e found in the Corps of Engineers Interim Feasibility Report
(1975). The resulting estimated average ~nnual turbidity patterns
are shown on Figure 6.2. The actual turbidity patterns show
much greater variation in a single year due to the larger
variations in suspended sediment concentration.
6.2 -Factors Effecti_ng Turbidity
Reservoir sedimentation processes described in Section 5.2 are the
main proce.sses affecting reservoir turbidity.. The sediment-laden
river will enter the reservoir as either overflow1 Interflow, or
underflow, depending on its density relative to that of the
reservt~ir waters. Once it reaches its equHibrium density level,
the inflowing river plume spreads horizontally ?long lines of equal
density. The flow parallels isothermal surfaces, and is modified
by the Coriolis force so that the river plume is directed towards
. the right hand shoreline In th~ direction of flow.
The turbidity at the reservoir outlet is also dependent on the
residence time of inflowing waters hi the reservoirs.. Watana
Reservoir has mean annual bulk residence time (volume/mean
annual streamflow) of 600 days, with Devil Canyon having a mean
annual buJk residence time of 60 days. However1 the bulk
residence time varies with· flow, with the bulk residence t!me
decreasing to ;;Jbout 110· days for the mean annual f!ood entering
Watana. The residence times for summer .fJows are affected by the
relative reservoir level. As the reservo~rs will be filling during
the early high flow periods, the residence time would be somewhat
increased above 110 days ·far the breakup flood.
. '
The !ong residence times indicate that an ice cover would form
be.fore much of the late summer flew passes through the
.reser"vairs. Settling column studies (Appendix A) indicated that
suspended sediment rapidly settled out under quiescent conditions 1
with tu-rbidity also rapidly decreasing (Figure 6.3). Once an ice
cover forms, essentially quiescent conditions will exist in the
reservoirs, with wind action no Jonger disturbing the surface, and
inflow dropping to minimal levels. Consequently, relatively rapid
sedimentation should commence once an ice cover forms, with
surface waters rapidly clearing beneath the lee. The turbidity of
inflowing waters is also quite low during this period, thus
contributing little additional sediment.
susi10/s 6-2
6 .. 3 -.Post-Project Turbidity
A discussion of the timing of certain events occurring within the
reservoirs and Upper Susitna River will serve to help describe the
changes in the turbidity pattern. Breakup normally occurs in late
Apdl or-early May on the Susitna River. Suspended sediment
concentrations and turbidity sharply increase in May 1 and remain
high into September 1 as the glaciers are contributing significant
amounts of sediment during their melt period. However 1 the ice
cover on the reservoirs will remain longer than ice now remains on
the river 1 as the lake ice will not be flushed out of the system by
breakup but will instead melt in place. Consequently 1 relatively
quiescent conditions will occur through most of the lake until the
ice cover has significantly decreased 1 which will probably not
occur until late May or early June. Even though turbid water will
enter the reservoir in early May 1 an increase in turbidity in outlet
waters should not occur until early to mid-June.
During the summer months.r turbidity will increase as suspended
sediment concentrations increase at the reservoir inlet. Pulses of
sediment may pass through the reservoir when very large sediment
concentrations enter the reservoir 1 such as during a large flood ,c
but they will be sharply dampered. The pattern will probably be
similar to that shown 'at Kanloops Lake on Figure 3. 2, except that
the decrease should be even larger in the Susitna River system
due to relatively larger size of the reservoirs (longer' residence
time).
Downstream turbidity can not be accurately quanti tied 1 but
tentative estimates indicate that is possible that it will not exceed
maximum values of 35-45 NTU during peak flows, and will normally
be in the. 10-20 NTU range during summer months, based on
cursory estimates from flow suspended sedimen.t concentrations 1
trap efficiency 1 and reservoir outflow. Reservoir turbidity will
decrease in the downstream direction as the larger sediment sizes
settle out.
In September and October, inflowing turbidity levels to the
reservoir are significantly less than summer values, as the glaciers
contribute less meltwater and sediment. Ice cover on the
reservoirs will normally start to form about the third week in
October. Once the ice cover forms, essentially quiescent
conditions occur 1 and turbidity in the upper levels of the
reservoir should rapidly decrease.
susi10/s 6-3
r----------~--------------------------------------~~------------------------~
". ,, ·-~~· .V/
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' 10 '2
PREPARED BY I
R&M CONSULTANTS, INC.
3 ' ' ' ~ 4 5 6 7 8 9 i
100
I .
' 2 3
SUSPENDED SEDIMENT CONCENTRATION
( mg I I)
TURBIDITY vs.
l
I
4 5 7 8 9
PREPAREO FOR~
SUSPENDED SE0.1tv1ENT
CONCENTRATION FIGURE 6 .. 1
c:. A
r-----------------~----------------------------------------------··~---------------------------------.
-
-
>-.....
0
--~----------~--~-._....,__....._~ ... _.,....,~ ,,........._ ... ,,._.._. ------·--""' ~ ... ,-."-
!
• t -2~+-:.------:.--.,.._~ ............ -~_.;.,..~---......__._.__""' ~~~~------,.ot..,... ________ _ ---.....-...... .. ~---
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1
~ .. -·--·--,-...... . "' ---· .. -'"
'-~·-··-!-JAN· -FEB-l MAR· ~:-:-..:::-_-::-;-.:~-=-~-----~:-~ :·.=--:r-----
... ,._---~ ~ .. -""---··--·--· L'-... -·~ " ·~-. . -.... 1 --.. ~·-· -~· .... ·---' --':
'"APR ·1 MAY ---JUN-~t-JUL ·AUG-; SEP· , .. oe;·~-NOV ! DE-c-:·
·--·-·-i"" ---. .!.. ··-·· -.: •• _ . ·-·j ... -------.-----1·--·-· .. i. --~ 1-·. ----l ···----···j-·----.. ---~--------~----. ···· ..... ·---~· ··----..:..:.i ____ -t'"'"""-....... --~--t
I . ..____,. ..
TIME OF YEAR
* curves are estimates based on the mean daily flow summary hydrographs and
from regression equations relating discharge, suspended sediment
concentration, and tllrbidity. Turbidity in a single year displays greater
daily variation ..
PREPARED BY ; PREPARED FOR~
AVERAGE ANNUAL TURBIDITY PATTERN
SUS1TNA RIVER
FIGURE 6.2
PREPARED BY • PREPARED FOR~
TURSI DITY V.S TIME·
R&M CONSULTANTS. INC.
SUSITNA RIVER
SETTLING COLUMN STUDY FI.GURE 6.3
7 -PROJECTED RESERVOIR SEDIMENTATION
Trap efficiency estimates using the Brune curve indicate
90-100 percent of the incoming sediment will be trapped in the
reservoirs, even shortly after reservoir filling, but sedimentation
studies at glacial lakes indicate that fine glacial sediment may pass
through the take. Delta formation at the head of the reservoir will
be constantly adjusting to the changing water leveJ. Sediment
passes through the channels on the delta to be deposited over the
lip of the delta. Depending on the relative densities of the lake
water and the river, the sediment-laden water will either enter the
lake as overflow, interflow, or underflow (turbidity current),. It
is probable that the turbid summer flows of the Susitna River will
initially dive below the surface, seeking an equi!ibrium density
layer. The settling process will then commence somewhere below
the surface.
Estimates of the total amount of deposition of fine flacial sediment
in the reservoirs are somewhat uncertain. Glacial lakes
immediately below glaciers have trap efficiencies of 70-75%.
Kamloops Lake, B.C. r retains about 66% of the incoming sediment.
Sediment concentration at the outlet of Kamloops Lake increased
during periods of high sediment Inflow, which would correspond to
high stream fJows. Kamloops Lake is a natural lake, so retention
time of high f!ows decreases to about 20 days during the spring
freshet. However, Watana Reservoir has significant active storage
capacity o During the May .. July period the reservoir will normally
be filling, so that outflow will be much less than inflow. The
increased residence time due to refilling of the reservoir would
tend to allow more of the sediment to settle. Once the reservoir is
full, there may be periods of increased turbidity downstream
following periods of very high streamflow, similar to that evidenced
at Kamloops Lake on Figure. 3.2. The .median grain size at the
lower end of Kamloops Lake was 0.002 mm, and appeared to be
uniformly distributed across the lower end of the lake. The
suspended sediment size analysis for stations on the upper Susitna
River (Corps of Engineers, 1975), shown on Figure .4.2, indicates
that about 15 percent of the suspended sediment entering Watarta
Reservoir (Susitna River near Cantwell gaging station) is smaller
than 2 microns (. 002 mm). The trap efficiency of Watana
Reservoir is estimated be between 70 -"97 percent, with only the
material finer than 2 microns possibly passing through the
reservoir.
The minimum assumed trap efficiency for Devil Canyon Reservoir is
70 percent, based on data from other Ia kes. However 1 it is
possible that the trap efficiency may be. much lower 1 as only fine
material with very slow settling rates would pass through Watana
Reservoir.
susi10/h 7-1
Based on the results of the settling column studies, (App. A)
much of the suspended sediment s~ill in suspension when an ice
cover forms would settle, as quiescent conditions would soon be
prevalent.
susi10/h 7-2
REFERENCES
Brune, G.M. 1953. Trap efficiency of reservoirs. Trans. Am.
Geophys. Union, June. U.S. Dept. Agr. Misc. Publ .. 970,
p. 884.
Bryan, M. L. 1974a. Sedimentation in Kluane Lake. Pages 151-154
in V .C. Bushnell and M.G. Marcus, eds. Ice Field Ranges
Research Project Scientific Results, Vol. 4. American
Geographical Society, New York NY, and Arctic Institute of
North American 1 Montreal, Canada.
Bryan, M. L. 1974b. _Sublacustrine morphology and deposition,
Kluane Lake, Yukon Territory. Pages 171-187 in V.C.
Bushnell and M. B,. Marcus, eds. lcefield Ranges Research
Project Scientific Results, Vol. 4. American Geographical
Society, New York, NY, and Arctic Institute of North
American, Montreal, Canada.
Church, M., and R. Gilbert. 1975. Preglacial fluvial and
lacustrine environments. Pages 22-100 in A. V. Jopl.ing and
B.C. McDonald, eds. Glaciofluvial and glacialacustrlne
sedimentation. Society of Economic Paleontologists and
Mineralogists. Tulsa, 0-K. Special Publication 23. ·
Embleton, c., and C.A.M. King. 1975. Glacial geomorphology~
John Wiley and Sons, New York, NY. pp .. 532-558.
Emerson, B. K. 1898. Geology of Old Hampshire County 1
Survey Monogr·aph 29, Massachusetts. U. 5. Geological
790 pp.
Emmett, W. W. ,
transport
Geological
Alaska.
Burrows, R.L., and B. Parks. 1978. Sediment
in the vicinity of Fairbanks, Alaska, 1977. U.S.
Survey, Open-File Report 78-290 1 Anchorage,
""
Everts, C. H. 1976. Sediment discharge of glacier-fed rivers in
Alaska. Pages 907-923 in Rivers '76. Vol. 2. Symposium on
inland Waterways far Navigations, Flood Control and Water
Diversions. 3rd ·Annual Symposium, Colorado State
University 1 Fort Collins, CO. Waterways, Harbors and
Coastal Engineering Div., American Society of Civil
Engineers, New York, NY.
Geer, G. De. 1912. A geochronology of the-last 12,000 years.
Cr. 11th lnternation Geological Congress, Stochholm, 1910, 1,
p. 241-258.
susi10/i
Gilbert, R. 1973. Processes of underflow and sediment transport
ln a British Columbia mountain lake. Pages 493-507 in Fluvial
Processes and Sedimentation. Proceedings of the 9th
Hydrology Sympasuim, University of Alberta, Edmenton.
Canada, May 8-9. Subcommittee on Hydrology, Associate
Committee on Geodesy and Geophysics, National Research
Council of Canada.
Gottschalk, L.C. 1964. Reservoir sedimentation, in Chow, V.T.
(ed.) Handbook of Applied Hydrology. McGraw-HiJI; New
York.
_Gustavson, T. C. 1975. Sedimentation and physical limnology in
preglacial Malaspina Lake 1 southeastern Alaska. Pages
249-263 in A.. V. Jopling and B.C. McDonald, eds.
Glaciofluvial and glaciolacustrine sedimentation. Society of
Economic Paleontologists and ·Mineralogists, Tulsa, OK.
Special Publication 23.
Johnston 1 W.A. 1922. Sedimentation in Lake Louise.r Alberta,
American Journal of Science 2041 pp. 376-336.
Kindle, E. M. 1930. Sedimentation in a glacial Jake, Journal of
Geology 38, p. 81-87.
Kuenen, P. H. 1951. Mechanics of varve formation and the action
of turbidity currents, Geol. for Stockh. Forh~6, 149-162.
Lare, E.W., Koelzer, V.A. and J.M. Lara. 1958. Density and
compaction rates of deposited sediments. Proceedings ASCE,
Journal of Hydraulics Division, Paper 1603, April.
Lava, J.M. and J.l. Sanders. 1970. The 1963-64 Lake Mead
Survey, U.S. Department of Interior, Bureau of Reclamation
Repqrt REC-OCE-70-21, 172p.
Mathews, W. H. 1956. Physical limnology and sedimentation in a
glacial lake. Bulletin of the Geological Society of America,
67:537-552.
Miller 1 C. R. 1963. De!termination of the unit weight of sediment
<" for use in sediment volume computation, U.S. Bureau of
Reclamation Memorandum, February 17.
Ostrem, G. 1975. Sediment transport in glacial meltwater
streams. Pages 101-122 in A. V. Jopling and B.C. McDonald,
eds. Glaciofluvial and glaciolacustrine sedimentation. Society
of Economic Paleontologists and Mineralogists, Tulsa, OK.
Special Publication 23.
susi10/i
Pharo, · c. H. , and E .. D. Carmack. 1979. Sedimentation processes
in a short residence-time intermontane lake, Kamloops Lake 1
British Columbia. Sedimentology. 26:523-541.
Theakstone 1 W.H. 1976. Glada! lake sedimentation,
Austerdalsisen 1 Norway. Sedimentology. 23(5):671-688.
Tice, A.R.1 L.W. Gatto, and D.M. Anderson. 1972. The
mineralogy of suspended sediment in some Alaskan glacial
streams and Jakes. Cold Regions Research and Engineering
Laboratory. Corps of Engineers, U.S. Army, Hanover, NH ..
Research Report 305. 10 pp.
Trask, P. (undated). Compaction of sediments. Bull, Am.
Assoc. Petrol. Geologists, 15, 271-276.
U.S. Army, Corps of Engineers 1 Alaska, District. 1975.
Southcentrai Railbelt Area, Alaska Upper Susitna River Basin,
Interim Feasibility Report: Appendix 1, Part 1, Hydroelectric
Power and Related Purposes.
Ziegler 1 T. 1973. Material Transportundersokelser
bre-elver 1971: Rept. No. 41/73, Hydrologisk
Norges, vassdrags -og elecktrisitetsvesen, 91 p.
summary).
susi10/i
i norske
avdeling,
(English
APPENDIX A
SETTLING COLUMN STUDIES
SETTLING COLUMN STUDIES •
Settling column studies were conducted to obtain data on the
settling rates of suspended sediment and on time based turbidity
levels of Susitna River water after it enters standing water.
Procedure
Twc' 55 gallon water samples were obtained from the Sus;tna Rivel!'
neat~ Watana damsite. These samples were taken in an area of
turbulent flow using a pump whose inlet depth was varied to allow
depth integrated sampling. The samples were retrieved at the\
following flow rates and water temperatures.
Sample #1
Sample #2
July 29, 198 .. t at 3:00 p.m.
Sept. 3, 1981 at 5:00 p.m.
28,000 c.f.s.
17,200 c.f.s.
The samples ware placed in the settling columns, thoroughly mixed
and initial (time zero) samples taken from ports which were located
at 0.5 1 2.5 1 4.5, 6.5 and 8.5 feet from the bottom of the column.
The depth of water in the columns varied during testing as water
was removed for testing. In column 1 the average depth of watetr
was 9.2 feet and in column 2 the.average depth was 8. 9 feet.
Samples were taken at 0, 0.5, 1, 3, 6, 12, 24, 48 and 72 hour
intervals and analyzed for turbidity (N. T. U.) and total suspended
solids (T.S.S. in mg./litel"). Air and water temperatures at these
times wet .. e also recorded.
Results
Results of the settling column studies are illustrated for suspended
solids in Figures A.1 and A.2. In 72 hours 1 total suspend~d
sediment concentration decr·eased by 93% in the 28,000 cfs sample
and by 98% in the 17,200 cfs sample. Little density stratification
was noted in the 28,000 cfs sample dur"ing the settling period, but
was more noticeable in the 1-6 hour period for the 17,200 cfs
sample.
Turbidity levels showed a similar decrease. The composite average
for each time period is shown on Figure 6.3. There was little
variation in turbidity with depth. As would be expected from the
suspended sediment results, turbidity decreased significantly, with
reductions of 85 percent for· the 28,000 cfs sample and 94 percent
for the 17,200 cfs sample.
susi10/g A-1
SUSPENDED SEDIMENT CONCENTRATION ( mg /I)
SAMPLE COLLECTED ON 29 JULY 1981, I MILE ABOVE WATANA DAM SITE
PREPARED BYt WATER TEMPERATURE (7/29/81) :so•F
R & M CONSULTANTS, lNC.
SUSPENDED SEDIMENT CONCENTRATION VS TIME 8c DEPTH
'·SETTLiNG COLUMN STUDY
28,000 CFS SAMPLE FIGURE A-1
PREPARED FORt
-t-!
LL -
PREPARED BY t
SUSPENDED SEDIMENT CONCENTRATION (mg/1)
SAMPLE COLLECTED ON 3 SEPT. 1981, I MILE ABOVE WATANA DAM SITE
WATER TEMPERATURE (9/3/81) = 46°F
VS TIME a DEPTH
R&M CONSULTANT.$,. INC.
SUSPENDED SEDIMENT CONCENTRATION
SETTLING COLUMN STU.DY
17,200 CFS SAMPLE
I
I
I
l
I
' . I
I
I
; .
! ' !
PREPARED FORt
FIGURE A-2
APPENDIX B
ANNOTATED BIBLIOGRAPHY
OF
SEDIMENTATION PROCESSES
IN
GLACIAL LAKES AND RIVERS
INT.RODUCTION
A literature search was conducted to obtain information on glacial
lake trap efficiency of suspended sediments 1 with emphasis on
materials smaller than 50 microns. Relevant information will
provide a basis for predicting the fate of suspended sediments
entering the reservoirs of the proposed Susltna Hydroelectric
Project.
The bibliography contains annotations for 36 references with
relevant information and a listing of 31 additional references with
no specific information. There is information on depositional
processes when preglacial rivers enter standing water bodies
(Church and Gilbert 1975; Carmack, Gray, Pharo, and Daley 1979i
Embleton and King 1975; Gilbert 1973, 1975; GHbert and Shaw
1981; Hamlin and Carmack 1978; Pharo and Carmac.\< 1979; Smith
1978; Sturm and Matter 1978), with details on particle size dis-
tribution for two ancient lake environments (Ashley 1975; Shaw
1975). However 1 research reveals that reconstructing modern
depositional environments from analyses of ancient environments
may be misleading, as distance-from source and shore and depth of
lake are not as significant as density 1 wind-induced curr~nts, and
stratification (Bryan 1974a, b). Furthermore, misinterpretation of
depositional events can lead to overestimation of the time involved
in deposition (Shaw r Gilbert, . and Archer 1978). A method is
presented fot"' determining sedimentation rates by radioactive fallout
(Ashley 1979). One study on a modern lake shows that suspended
sediment concentrations affect density stratification (Gustavson
1975b). Two studies (Ostrem 1975; Theakstone 1976) address lake
trap efficiency and distance of deposition from the source.
The literature search included ~ review of University of Alaska
theses and publications of the University -of Alaska 1s Institute of
Water Resources and Geophysical Institute, the U.S. Geologica!
Survey, and the U .5. Army Corps of Engineers• Cold Regions
Research and Eng~neering Laboratory (CRREL}. A · computar
search was conducted on the CRREL Bibliography and on Selected
Water Resources Abstracts.
susi8/h B-1
PART J -RELEVANT INF.ORMATION
1 . Arnborg 1 L., H.J. Walker, and J. Peippo .. 1967.
load in the Colville River 1 Alaska, 1962 ..
Annaler. 49A (2-4):131-14';t.
Suspended
Geografiska
Discussion of suspended sediment data collected during one
year (1962) for hydrologic-morphologic study of the Colville
River ·delta. Three aspects of suspended load considered
were~ quantity transported in water; size of particles in
suspension; and total quantity transported in a given period
of time. As unit volume increases, median grain size and
total Joad carried increases. Grain size analyses. for samples
representative of selected locations, depths, and times are
presented. The amount and size of suspended material
increased with depth at one location.
2. Ashley 1 G.l'vL 1975. Rhythmic sedimentation in glacial Lake
Hitchcock, Massachusetts-Connecticut. Pages 304-320 in A. V ..
Jopling and 8. C. McDonald, e6Is. Glaciofluvial and glacio-
lacustrine sedimentation. Society of Economic Paleontologists
and Mineralogists, Tulsa, OK. Special Publication 23.
Discussion of seasonal silt and clay deposition {varves) Jn an
ancient environment. Suspended sediment concentration
affects water density far more than temperature in glacial
lakes. The settling velocity of a 60 silt grain· in 4°C water
undisturbed by currents is 0.05 em/second. Therefore 1 such
a grain would settle 50 m in 1.15 days. However, silt was
found in all winter clay layers, and could indicate that lake
currents were present 1 preventing settling,· or sediment was
introduced year-round. Mean grain size of silt layers de-
pends on location in the lake whereas-grain size distribution
of clay layers is uniform. Grain size analyses are presented,
but there is no specific information on the distance traveled
across the lake prior to deposition.
3. Ashley, G.M. 1979. Sedimentology of a tidal lake, Pitt Lake;
British Columbia, Canada. Pages 327-345 in Ch., Schluchter,.
ed. Moraines and Varves. Proceedings of an I NQUA
Symposium of Genesis and Lithology of Quaternary Deposits,
.curich, September 10-20 1 1978. A.A. Balkema, Rotterdam.
Sedimentation rates were determined by 137 Cs dating
techniques. Grain size analyses were determined for
190 samples . and mean grain size distribution was3 mapped ..
Annual sediment accumulation equalled 150± 20 x 10 tons, of
which SO% was coarser than 50.
susi8/h B-2
4. Ashfey, G.M .. , and L .. E. Moritz. 1979. Determinaf~ of
lacustrine sedimentation rates by radioactive faHout ( · Cs) 1
Pitt Lake, British Columbra. Canadian Journal of Earth
Sciences. 16( 4): 965-970.
5 ..
Discussion of techryiques · for determining modern lacustrinf~
sedimentation rat~s.
Borland, W. M. 1961 ~
streams in Alaska.
66(10):3347-3350.
Sediment transport of
Journal of Geophysical
glacier-fed
Research.
Developed empirical formula for sediment yield rates for
glacial drainage basins based on glacie~ area, total dr'ainage
area, and length of watercourse.' No differentiation by
particle size.. Used. five years of U.S. Geological Survey
suspended sediment data from Denali and Gold Creek stations
to test formula.
6. Bryan 1 M. L.. 1974a. Sedimentation in Kluane Lake. Pages
151-154 in V.C. Bushnell and M.G .. Marcus, eds. lee Field
Ranges Research Project Scientific Results, Vol 4. American
Geographical Society, New York, NY L and Arctic Institute of
North America 1 Montreal, Canada.
Study of bathymetry, thermal structure, and sediment·
distribution ln Kluane Lake, 1968. A weak thermocline
developed in July and August, which was occasionally
destroyed by storm ... induced mixing. The lake is ice-covered
for eight months, and receives sediment from the Slims River
for four months. Statistical parameters of grain size analyses
are presented. Sedimentption is affected by density, by
wind-induced lake currents, and by. stratification as well as
by bathymetry 1 distance from shore and input, point and
sediment composition. Highly turbid, cold glacial waters may
be sufficiently dense to flow across the lake bottom regardless
of thermal stratification v When the Slims River warms, it
flows over the lake.
7. Bryan, M. L. 1974b. Sublacustrine morphology and
deposition, Kluane Lake, Yukon Territory. Pages 171-187 in
V .. C. Bushnell and M.B.. Marcus, eds.· lcef.ield Ranges
Research Project Scientific Results t Vol 4. American
Geographical Sq~iety 1 New Yorkr NY, and Arctic Institute of
North American, Montreal 1 Canada.
Discussion of processes affecting sedimentation in lakes from
glacial streams. Bathymetric mapping of Kiuane Lake in 1968
and 1970 revealed growth of the Slims River delta.
Cartographic and statistical analyses of bottom sediments are
p~esented. Finest sediments far:thest from the Slims River
susi8/h B-3
were not in the deepest portion of the lake,. Distance from
source, depth of lake, and distance from shore are not signif-
icant in controlling deposition. Reconstructing depositional
environments based on sediment size analysis may be mis·
leading.
8. Carmack, E.C., C.B.J. Gray, C.H. Pharo, and R.J .. Daley~
1979. Importance" of lakerfver interaction on the physical
limnology of the Kamloops Lake/Thompson River system
Limnology and Oceangraphy. 24(4):634-644.
Discussion of physical effects of large fiver entering a deep 1
intermontane lake. No information of particle size analysis.
9. Church, M .. , and R. Gilbert. 1975. Preglacial fluvial and
lacustrine environments. Pages 22-100 in A. V. Jopling and
B.c. McDonald, eds. Glaciofluvial and glaciolacustrine sedi-
mentation. Society of Economic Paleontologists and
Mineralogists. Tulsa, OK. Special Publication 23"
Discussion of deposition when preglacial rivers enter standing
water bodies. Significant events are: aggradation -on the
bed due to deposition of bed load extends upstream from the
lake, along with reduced flow velocities; development of a
high angle delta, with transport .of sediment to the delta lip~
movement of coarse material over the lip and. down into the
lake in turbidity flows (bottom flow); movement of river water
down the delta front to Jake water of equal density (inter-
flow); movement of river water onto the surface of the 'lake if
denstty is Jess than the take (surface flow}; deposition of
fine-grained material and formation of varves, of which the.
silt (summer) portion is deposited by turbidity currents, and
the clay (winter) portion by ·the turbidity current after
stagnation, and then by slow, continuous settling from
suspension. Turbidity underflow is not a continuous event in
the melt season. Varve formation cannot be directly
correlated to mean annual discharge, because a single large
flood can create a turbidity flow. Turbidity flows resulting
in more rapid deposition depend on discharge, river and lake
water temperature, thermal structure of the lake, quantity of
sediment suspended in the lake from previous events, and
river and Jake dissolved sediment concentrations. No specific
information on particle size is presented.
10. Embleton, c .. , and C.A.M. King. 1975. Glacial geomor ...
phology. John Wiley and Sons, New York, NY. pp. 532-558.
Review of general principles affecting sediment deposition in
lacustrine environments with examples.. lake floor deposits
become increasingly fine toward center or deepest parts of
sus18/h. B-4
takes, requiring quiet . water and long settling periods.
Turbidity currents formed by cold, silt-laden stream water
are important Jn distributing sediment across the Jake ftoor.
Rhythmites (!aminated deposits) develop in_ cold freshwater
Jakes receiving intermittent streamflow, and ln some cases
form on an annual basis (varves). They can aJso form from
sudden fluctuations in discharge (bursting of an ice-dammed
lake upstream), unseasonal warm or cold spells, or periodic
storms.
11 ~ Everts, C. H .. 1976. Sediment discharge by glacier-fed rivers
in Alaska. Pages 907--923 in Rivers '76. Vol.. 2. Symposium
on J nfand Waterways for Navigation, Flood Control and Water
Diversions~ 3rd Annual Symposium, Colorado State
Universlty, Fort Collins, CO. Waterwaysr Harbors and
Coastal Engineering Div., American Society of Civil
Engineers, New York, NY.
Investigation of glacial sediments discharged into the coastal
zone (Knlk, Matanuska). Size distribution, composition, and
settllng characteristics of glacial sediment are important
characteristics in determining where the sediment will be
transported and deposited when it reaches the marine en-
vironment. Based on particle size distribution analyses 1 it
appears that fine-grained · particles pass completely through
the river system. Ice margin Jakes fringing glaciers are
depositories for coarse sediments. Clay minerals were absent,
which is significant because clay particles form aggregates
with other fine-grained particles and settle more rapidly.
This absence may be common in other glacial areas because of
negligible chemical weathering in the source areas.
i
12. Fahnestock, R. K. 1963. Morphology and hydrology of a
glacial stream: White River, Mount Rainier, Washington.
U.S. Geological Survey. Professional Paper 422A. 70; pp.
Investigation of formation of a valley train by .a preglacial
stream. Particle size analyses of deposited material showed
si Its and clays were washed out of stream deposits.. Analysis
cf suspended load indicated that silt and clay stay ih suspen-
sion and are carried out of the study area into Puget Sound ..
13. Fahnestock, R .. K. 1969. ·Morphology of the Slims River.
Pages 161-172 in V.C. Bushnell and R.H .. Ragle 1 eds. Ice
Field Ranges Research Project Scientific Results, Vol. 1 ..
American Geographical Society 1 New York, NY, and Arctic
Institute of North America, Montreal, Canada ..
Investigation of the Slims River, a prog!acial stream flowing
14 miles from Kasfawulsh Glacier to Kluane Lake.. The river
is modifying a valley train deposited when the glacier was up
susiS/h
against a terminal moraine. -It ls regrading, ie 1 adjusting to
a decrease in load at the source by cutting in the upper
reaches and depositing in the tower reaches. The Slims River
is also affected by downstream changes in the base· level,
which is controlled by the extension of the defta into Kluane
Lake and the variation in lake level.. As the volume arowth
rate of the delta is not known, the sediment transport rate
cannot be estimated. Suspended sediment is p.redominantly
silt and clay. No data on partide size distribution ..
14. Gaddis, B. 1974. Suspended-sediment transport relation-
ships for four Alaskan glacier streams. M.S. Thesis.
University of Alaska, Fairbanks, AK. 102 pp.
Investigation of suspended sediment transport relationships in
glacial streams at Gulkana, Maclaren, Eklutna, and Wolverine
glaciers. Data on mean particle size is presented for four
glaciaJ streams for one season at sites near the terminus.
Sediment availability depends on amount of sediment, distance
travelled downstream, and mechanical nature of sediment
entrainment (no specific information on entrainment).
15. Gilbert, R. 1973. Processes of underflow and sediment
16.
transport in a British Columbia mountain lake. Pages 493-507
in Fluvial Processes and Sedimentation. Proceedings of the
9th Hydrology Sympasuim, University of Alberta, Edmanton,..
Canada, May 8-9.. Subcommittee on Hydrology, Associate
Committee on Geodesy and Geophysics, National Research
Council of Canada.
Description of processes involved in formation of varved
sediment deposits. in preglacial Jakes, primarily underflow and
interflow. Underflow increases . with -increa·se of water and
suspended sediment inflow. Cores obtained to determine
thickness and corr.parision of varves. No information on
particle size distribution.
Gilbert, R. 1975. Sedimentation
Columbia. Canadian Journal
12(10):1697-1711.
in Lillooet Lake, British
of Earth Sciences ..
LHiooet Lake receives sediment from a 3,580 sq km drainage
basin, of which 7% is glacier-covered. lnterflow and under-
flow distribute sediment through the lake in summer when the
lake is stratified. Factors affecting distribution are: density
characteristics of the lake and inflowing water, as determined
by temperature and suspended sediment concentrations;
currents induced by wind and inflow i thermal structure of
the lake water, which determines the nature of circulation
patterns and allows interflow along the thermocline; diurnal
and seasonal fJuctuations in infJowing waters and sediment;
•
susi8/h B•S
and the large annual volume of inflow (4.5 times greater than
the lake volutne on the average).. I nt.erflow carries sediment
at the base of the epilimnion to the distal end of the lt,~te in
one to two days. No specific. information on particle siz~~
17. Gilbert, R ~ 1 and J. Shaw. 1981. Sedimentation in pr•oglacial
Sunwapta Lake, Alberta. Canadian Journal of Earth Sctences.
18(1):81-93.
Examination of hydrologic and limnologic condition,~ of
Sunwapta Lake 1 a small, preglacial lake ln the Canadian
Rockies. Sediment input was measured and sedimentation
rates were calculated. Sediments of small, shallow lakes with
large and highly variable inflows are expecte~d to demonstrate
lateral and vertical variability, whereas those in large pro-
glacial lakes are more predictable dUe! to modification by
large, stable water masses.
18. Gustavson, T .c. 1975a. Bathymetry and sediment distribu-
tion in preglacial Malaspina Lake, Alaska. Journal of
Sedimentary Petrology. 45:450-461.
See next abstract
19. Gustavson, T .C. 1975b. Sedimentation and physical limnology
in preglacial Malaspina Lake,
249-263 in A~. v.. Jopling and
ofluvial and glaciolacustrine
Economic Paleontologists and
Special Publi~ation 23.
southeastern Alaska. Pages a. c. McDonald I eds. Glaci-
sedimentation. Society of
Mineralogists, Tulsa, OK.
UndArfJow, lnterflow, anc;i over'flow water entered Malaspina
Lake, and the type of flow is dependent on the relative
suspended s~diment content of the lake water e1nd the in-
flowing melt water. The 18-km lor~ lake is density stratifr~d
(increasing suspended sedim~nt concentration with depth) but
not thermally stratified. No specific information. on particle.
size or trap effrciency is presented.
20. Guymon, G. L. 1974. Regional sediment yield analysis of
21.
Ai3ska streams. Journal of the Hydraulics Div. of the·
American Society of Civi·l Engineers. 1 OO(HY1): 41-51.
Analyzed Borland's (.,'161) formula. ConsicJ~ c;p,d particle size,
but used an averaQ1~ particle size in ",ij1e fo~'mUL1. However 1
concluded that particle size affects application of the formula.
Hamblin, . P. F., and E .. C.
currents in a fjord lake ..
8~l{ C2): 885-889 ..
Carmack. 1978. River-induced
Journal of G·:aophysical Research.
susi8/h
Discussion of dynamics of strong ·flowing river entering a
long, narrow lake ( Kamloops Lake, B.C.). River .... induced
currents influence circulation patterns in a fjord lake.. No
specific information on sedimentation rates or particle size
analysis.
22.. Hobbie, J. E. 1973. Arctic limnology~ a review.
23.
Pages 127-168 in M .. E. Britton, ed. Alaskan arctic tundra.
Arctic Institute of North America. Technica·t Paper 25 ~
Review of properties of lake in northern tundra regions.
Thermal cycle of deep arctic lakes is highly variabJe 1 and
stratification is uncommon, occurring only in warm, calm
weather after lake waters rise to 4°C. Deep Jakes maintain
" circulation even when ice covered. Deeper lakes are re-
latively turbid as a result of glacial flour from streams drain-
ing active glaciers. Lake Peters is fed by gfaclal streams and
drains via a 1-km long, 15-m deep channel into Lake Schrader·
in the Brooks Range. Both are 50 ... 60 m deep. Lake Peters
acts as a settling basin. When dense glacial \=Vater enters
Lake Peters in -~June, it sinks to the bottom, and the lake fills
upward with turbid water. ·
Mathews, W. H.. 1956. Physical limnology and sedim~ntation
in a glacial lake. Bulletin of the Geolo~icaJ Society of
America. 67:537-552.
Garibaldi Lake, British Columbia, receives sediment frorn two
glacial streams with relatively low sediment cont~,nt. Particle
size and composition of bottom deposit analyses rev~.aled slow
transport to site of depositfon and slow rate of deposition for
clays. No information on amount of sediment passing through
system.
24. Ostrem, G. 1975. Sediment tran.sport in glacial .meltwater
streams. Pages 101-122 in A .. V. Jopling and B.C .. McDonald 1
eds. . Glaciofluvial and glaciolacustrine sedimentation. Society
of Econornic Paleontoiogists and Miheraloglsts, Tulsa, OK~
Sped a I Public"~tion .23.
Recognized problems of utilizing glacial waters for hydro-
electric pi"Oj~cts, speciflcalty in reservoirs and turbines ..
Grain size analyses of cores of varved sediments showed that
summer layers consisted of coarser material than winter layers
(based on 20 micron grain size variation). X-ray diffraction
analyses showed that summer deposits contained mere quartz
(rapid sedimentation), and winter deposits 1 more mica (slower
sedimen'tation). For one 1 ,800-m long progladal fake over
29 years, about 70 percent of the total suspended sediment
input was deposited.
susi8/h B-8
25. Ostrem, G .. , T. Ziegler, and S.R~ Ekman. 1970. A study of
sediment transport in Norwegian glacial rivers, 1969 ..
Institute of Water Resources, Dept,. of Hydrology 1 Oslo 1
Norway. Report 6/70. Report for Norwegian Water
Resources and Electricity Board. Translated from Norwegian
by H. Carstens. 1973. Institute of Water Resources,
University of Alaska, Fairbanks, AK. Report 35. 1 vol.
Investigations were conducted on water discharge and sedi-
ment volume measurements in glacial rivers above and at the
outlet of giacial lakes to calculate the sedimentation of fine
material on the bottom of the lakes.. Volume of material
available for transport is probably largest at the beginning of
the season. No data on particie size.
26. Pha·ro, C.H., and E.D. Carmack. 1979. Sedimentation
processes in a short re-sidence-time intermontane lake,
Kamloops Lake, British Columbia. Sedimentology.
26:523-541.
Sediment transport and deposit~on in the lake is controlled by
three interdependent pr,ocesses: delta progradation at the
lake-river confluencai sediment density surge~ originating
along the deita face, which result in turbicHte sequences
lakeward from the bate of the delta; and dispersal by the
interflowing river plume, which, due to Coriolis effects 1
results in a higher sedimentation rate and greater fraction of
coarser material along the right-hand of the Jake in the
direction of flow. Suspended sediment concentrations are
high above the thermocline where higher turbulence, main-
tained by wind mixing and river inter interflow, r.educes
settling velocities. Particles settle rapidly once they enter
the hypolimnion.
27. Ritchie, J.C., J.R. McHenry, and A.C. GilL 1973. Dating
recent reservoir sediments. Limnology and Oceanography.
18:254-283.
Discussion of radioactive 137 Cs dating~ Method could be used
to date sediment in reserviors that have not been surveyed.
28., Shaw, J. 1975. Sedimentary successions in Pleistocene
ice-marginal lakes. Pages 281-302 in A. V. Jopling and Be C.
McDonald, eds. Glaciofluvial and glaciolacustrine sedimenta-
tion. Society of Economic Paleontologists and Mineralogists,
Tulsa, OK. Special Publication 23.
Discussion of sedimentatlon in proximal portion of a glacial
lake based on interpretation on the ancient environment.
Mean grain size values were determined for sections of each
facies from o to 80. No information on transport of fine
materials.
susi8/h B-9
29. Shaw, J. 1977. Sedimentation in an alpine fake during de-
glaciation, Okanagan Valley 1 British Columbia, Canada.
Geografiska Anna let,. 59(A) :221-240.
Ancient lake sediments wer~ examined to develop a model of
alpine lake sedimentation based on changing depositional
processes with time and distance from the ice margin.
30. Shaw, J. 1 R. Gilbert 1 and J,.J.J. Archer. 1978. Preglacial
lacustrine sedimentation during winter·. Arctic and Alpine
Rasaarch. 1 0( 4): 689-699.
Discussion of deposition of coarse-grained sediments during
winter in Lillooet Lake. Misinterpretation can lead to over-
estimation of time seqences of deposition.
31. Slatt, R.M. 1970.. Sedimentological and geochemical aspects of
sediment and water from ten Alaskan vaHey glaciers., Ph. D.
Thesis. University of Alaska, Fairbanks, AK. 125 pp.
Studied five groups c;f glaciers with different bedrock lith-
ologies; Worthington and Matanuska; Castner and Fels;
Gulkana and College; Rendu and Reed; and Carroll and
Norris. Particle size analyses and mineralogy of superglacial
and suspended stream . sediments are presented. The
environment of transport has a much greater effect on grain
size than the nat~Jre of the starting material.
32. Slatt, R.M. 1971. Texture of ice-cored deposits from ten
Alaskan valley glaciers. Journal of Sedimentary Petrology ...
41(3):828-834~
Revised and condensed por.tions of Ph.D. thesis (see above) ..
33. Smith 1 N . D. 1978. Sedimentation processes and patterns in
a glacier-fed lake with low sediment input. Canadian Journal
of Earth Sciences. 15(5):714-756e Snow malt and gia.cial melt
waters carrying relatively low suspended sediment concentra-
tions enter Hector Lake in the eastern Rocky Mountains,
Alberta. When stratified 1 water and fine sediments enter the
lake as interflow and overflow. Grain size analyses were
conducted on 42 cores. Depositron varies left to right as wen
as distally due to katabatic winds 9enerating dovvnlake
currents in the epilimnion that are deflected $OUthward
(rightward) by the Coriolis force.
34. Sturm, M. 1 ·and A. Matter. 1978.. Turbidites and varves in
Lake Brienz (Switzerland): deposition of clastic dPtritus by
density currents. Pages 147-168 in A. Matter and M.E ..
Tucker, eds. Modern and ancient lake sediments. Inter-
national Association of Sedimentologists.. Speciai
Publication 2 .
•
susi81h e-10
Discussion of sed1ment transport and deposition by overflow 1
interflow~ and underflow in a Jong 1 narrow 1 deep basin with
rivers entering at each end. Fjne ... grained sediments supplied
by overflows and interflows settle continuously during summer
thermal stratification. Most of the fine-grained particles
remain in suspension at the thermocline because the vertical
density gradient is more dependent on temperature than on an
increase in density due to suspended particles. Durlng fall
turnover, the remaining sediment trapped at the thermocline
settles~
35. Theakstone, W. H. 1976. Glacial lake sedimentation,
Austerdalsisen, Norway~ Sedimentology. 23(5):671-688.
A lake completely filled with glacial sediments, over which
braided stream deposits formed. A new progJacial lake then
formed. Discussion of bedding and composition of ancient
lake sediments. Initially 1 deposition was very slow in deep
(80 m) water. In another lake 300 m from a glacier 1 about
75 percent of the sediment transported in suspension is
retained in the basin, but the amount retained in one day is
highly variable.. The daily summer values exceeded the
minimum by 200 times (data not presented)~
36. Tice, A. R., L. W. Gatto, and D.M .. Anderson. 1972. The
mine~a!ogy of suspended sediment in some Alaskan glacial
streams and takes. Cold Regions .Research and Engineering
Laboratory Corps .of Engineers 1 u.s. Army, Hanover, NH ..
Research Report 305. 10 pp.
Investigation of the role of chemical weathering of bedrock in
cold regions determined tl)at no chsmical changes occurred in
fine suspended material. Suspended -sediment samples were
obtained for X-ray diffraction analyses from galciaL outwash
str-eams and 'Jakes in seven areas (Chackachamna, Pafmer-
Mataouska, Moose Pass-Portage, Valdez, Juneau, Mt .. McKinley
National Park, and Black Rapids):
susi8/h B-11
PART II-NO SPECIFiC INFORMATION
1. Agterberg. F.P., and 1.. Banerjee. 1969. Stochastic modet
for the deposition of varves in glacial Lake Barlow-Ojibway,
Ontario, Canada. Canadian Journal of Earth Sciences.
6:625-652
2. Banerjee, L, and B.C. McDonald. 1975. Nature of esker
sedimentation. Pages 132-154 in A.V. Jopling and B.C.
McDonald, eds. Glaciofluvial and glaciolacustrine sedimenta-
tion. Society a of Economic Paleontologists and Mineralogists,
Tulsa, OK. Special, Publication 23.
3. Boothroyd, J.C. and G.M Ashley.. 1975. Processesr bar
morphology, and sedimentary structures on braided outwash
fans, northeastern Gulf of Alaska. Pages 193-222 in A.V.
Jopling and B.C. McDonald, eds. Glaciofluvial and
glaciolacustrine sedimentation. Society of Economic
Paleontologists and Mineralogists, Tulsa, OK. Special
Publication 23.
4. Bradley, W. H. 1965.. Vertical density currents. Science~
15({3702):1423-1428.
5. Claguer J.J. 1975.. Sedimentology and paleohydrology of !ate
Wisconsinan outwashr Rocky Mountain trench, southeastern
British Columbia. Pages 223-237 in A. V. Jopling and B. C,.
McDonald, eds. Glaciofluvial and glaciolacustrine sedimen..,.
tation. Society of Economic Paleontologists and Mineralogists.,
Tulsa 1 OK, Special Publication 23. o
6. Everts, C. H. and H. E. Moore. 1976. Shoaling rates and
related data fr,:>m Knik Arm· near Anchorage, Alaska. Coastal
Engineering Research Center, Corps of Engineers, U .. S ...
Army, Fort Belvoir, VA. Technical Paper 76-1. 84 pp.
7. Gilbert, R. 1971. Observations on ice-dammed· Summit Lakett
British Columbia, Canada. Journal of Glaciology ..
10(60) :351-356. ,
8. Gustavason, T.C., G .. M. Ashley, and J.C. Boothroyd. 1975 ..
Depositional sequences in glaciolacustrine deltas.
Pages 264-280 in A. V. Jopling and B. C. McDonald, eds.
Glaciofluvial and glaciolacustrine sedimentation. Society of
Economic Paleontologists and Mineralogists, Tulsa1 OK ..
Special Publication 23.
9. Guymon, G. L. 1974. Sediment relations of selected Alaskan
glacier-fed streams. Institute of Water Res!>Urces, University
of Alaska, Fairbanks, AK.. Report 51. 17 pp.
susi8/h
10. Hobbie, J. E., ed~ 1980. Limnology of tundra ponds:
Barrow, Alaska~ Dowden, Hutchinson and Ross, Inc;;
Stroudsburg, PA. US/IBP Synthesis Series 13. 514 pp.
11. Howarth, P.J .. , and R.J. Price. 1969. The preglacial lakes
of Breidamerdurjokull and Fjallsjokull, I eel and.. Geographical
Journal. 135:573-581.
12. Jopling, A.V. 1975. Early studies on stratified
4-21 in A. V. Jopling and B.C. McDonald, eds.
and glaciolacustrine sedimentation. Society
Paleontologists and Mineralogists, Tulsa,
Publication 23.
drift. Pages
Glaciofluvial
of Economic
OK. Special
13. Kindle, E.M. 1930. Sedimentation in a glacial lake. Journal
of Geology. 38( 1): 81-87.
14. Lawson, D. E. 1~77. Sedimentation in the terminus re'gion of
the Matanuska Glacier, Alaska. Ph.D. Thesis. University of
Illinois, Urbana-Champaign 1 IL. 287 pp.
15.. Long, W.E. 1972. Glacial processes arid their relationship to
streamflow; Flute Glacier, Alaska. Institute of Water
Resources, University of Alaska, Fairbanks, AK.. Report 18 ..
1 vol.
16. Ludlam, S.D. 1967. Sedimentation in Cayuga Lake, New
York. Limnology and Oceanography. 12(4):618-632.
17. Mcuonald 1 B.C. 1 and W. W ~ Shilts. 1975. .Interpretation of
faults in glaciofluvial sediments. Pages 123-131 in A. V,.
Jopling and B.C. McDonald, eds. Glaciofluvial and glacio-
lacustrine sedimentation. Society of Economic Paleontologists
and Mineralogists, Tulsa, OK. Special Publication 23.
'
18. Moores, E.A. 1962. Configuration of the surface velocity
profile of Gulkana Glacier 1 central Alaska Range, Alaska.
M.S. Thesis. University of Alaska, Fairbanks, AK. 47pp •
•
19. Moravek, J. R. 1973. Some further observations on the be-
havior of an ice-dammed self-draining ·· lake, Glacier Bay r
Alaska, USA. Journai of Glaciology. 12(66) :505-507.
20. Reger, R~D. 1964. Recent glacial history of Gulkana and
Col.lege Glaciers, central Alaska Range, Alaska. M.S. Thesis.
University of Alaska, Fairbanks 1 AK. 75 PP~
21. Rust, Be R. 1975. Fabric and structure in glaciofluvial
gravels. Pages 238-248 in A. V. JopHng and B.C. McDonald,
eds.. Glaciofluvial and glaciolacustrine sedimentation. Society
of Economic PC1Ieontologists and Mineralogists 1 Tulsa, OK ..
Special Publication 23 ..
susi8/h .B-13
22. Rust, B. R... and R.. Romanelli'" 1975. Late quaternary
subaqueous outwash deposits near Ottawa, Canada.
Pages 177-192 in A. V. Jopling and B.C. McDonald, eds.
Glaciofluvial and glaciolacustrine sedimentation. Society of
Economic Paleontologists and Mineralogists, Tulsa, OK.
Special Publication 23.
23. Ryder .. , J.M., and M. Church. 1972. Paraglacial sedimenta-
tion: consideration of fluvial processes conditioned by glacia-
tion. Bulletion of the Geological Society of America.
83:3059-3072.
24. Saunderson, H. C. 1975. Sedimentology of the Brampton
esker and its associated deposits: an empirical test of
theory. Pages 155-176 in A. V.. Jopling and B.C. McDonald,
eds. Glaciofluvial and glaciolacustrine sedimentation. Society
of Economic Paleontologists and Mineralogists 1 Tulsa, OK.
Specia1 Publication 23.
25. Sellmann, P.V. 1962. Flow and ablation of GuJkana Glacier,
central Alaska Range, Alaska. M.S. Thesis University of
Alaska, Fairbanks, AK. 36 pp.
26. Shira, o. L. 1978.. Hydroelectric powerplant siting in glacial
areas of Alaska. Pages 59 .. 76 in Applied Techniques for Cold
Environments 1 Vol. 1. Proceedings of the Cold Regions
Specialty Conference, Anchorage, AK, May 17-19. American
Society of Civil Engineers, New Vorl<, NY.
27. Slatt, R.M., and C.M. Hoskin. 1968. Water and sediment in
the Norris Glacier outwash area, upper Taku !nlet, south-
eastern Alaska. Journal of Sedimentary Petrology,.
38(2):434-456.
28. Stone, K. H. 1963. Alaskan ice-dammed lakes. Association
of American Geographers: Annals. 52:332-349.
29. St. Onge, D.A. 1980. Glacial Lake Coppermine~
north-central District of MacKenzie, Northwest Territories ..
Canadian Journal of Earth Sciences. 17(9):1310-1315.
30. Williams, P.F., and B.R. Rust. 1972. The sedimentology of
a braided river. Pages 183-210 in V.C. Bushnell and R.H ..
Ragle, eds. lcefield Ranges Research Project Scientific
Results 1 Vol. 3.. American Geographjc Society, New Yor·k,
NY, and Arctic Institute of North America, Montreal, Canada~
31 .. Yould, E.P., and T. Osterkamp. 1978. Cold regions con-
siderations relative to development of ·the Susitna hydro•
electric project. Pages 887-895 in Applied Techniques for
susi8/h B-14
Cold Environments, Vof .2. Proceedings of the Cold Regions
Specialty Conference, Anchorage, AK, May 17-19.. American
Society of Civil Engineers, New York, NY.
susi8/h B-15