HomeMy WebLinkAboutGrant Lake Hydroelectric Project Federal Energy Regulatory Commission application 1987Kenai Hydro,ihc.
Hydroelectric Planning S Deve1dp►pgfF(1,E OF THE St�f'.
1987 19AY I PH 2' 18
REGULATORY COMMISSION
May 6, 1987
Feeera'_ Energy Regulatory Commission
Office of Fv?ropower Licensing
825.North Capitol
Washington, D.C. 20126
Dear Sirs:
F.nclosee are agency comments and an instream flow study for
Grant Lake Hydroelectric Project 7633-002. These comments were
made on the draft study submirTtty 7?e. 17, 1987 to the agencies
as requested by your letter of August 19, 1986. The additional in-
formation supplements the Grant Lake License Application of December 20,
1984 and submissions after that date: Project Alternative I, developed
from studied and submitted project arrangements, provides for habitat
preservation in Grant Creek as requested by the Agencies and has been
submitted to the agencies for review. This Alternative provides for
equal consideration of power, fish and wildlife protection, recrea-
tion and other aspects of environmental quality.
Alternative I is within the scope of project material submitted
to FERC in previous submissions for the Grant Lake Project.
JMH/jP
Enc.
Si cerely,
r�
GJonathaAn M. Hanson President
FERC7 DOCKETED
P.O. Box 1776
Lummi Island, WA 98262
(206) 758-2252
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KENAI HYDRO, INC.
Grant Lake
Hydroelectric
Project
FERC No, 7633-002
Instream Flow Studies
and
Agency Responses
May 4, 1987
w
Kenai Hydro, Inc.
Hydroelectric Planning & Development
Dr. Robert McVey
U.S. Department
National Marine
P.O. Box 1688
Juneau, Alaska
Dear Dr. McVey:
of Commerce
Fisheries Service
May 4, 1987
Kenai Hydro has provided additional information to FERC and
the agencies for the Grant Lake Hydroelectric Project, 7633-002,
in accordance with the request of FERC of August 19, 1986. The
additional information supplements the Grant Lake License Appli-
cation of December 20, 1984 and additional information and sub-
missions after that date. Project Alternative I, developed from
studied and submitted project arrangements, provides for habitat
preservation in Grant Creek as requested by the agencies and has
been submitted to the agencies for review. This Alternative
provides for equal consideration of power, fish and wildlife
protection, recreation and other aspects of environmental quality.
The following is presented in reply to your letter of April 6,
1987. Information is drawn from the License application, addendum,
correspondence and recent surveys at Grant Creek referred to in
the presentations.
1. T!?e monthly operation curve shows one scenario by which
the plant may be operated. The demand and energy curves for the
area are relatively flat and the curve may be more of a straight
line than is projected, i.e. straight across at 200 cfs. The curve
presented is the most likely since the need for power is higher in
the winter in south-central Alaska (Seward has increased summer
activity making the curve flatter). The curve has made allowance
for summer spawning and appropriate flows are shown in June -August.
The reduced September flow would enhance the Coro spawning since
they like flows less than Chinook. Dumping and hedging are possible
in March -May and October since these months have no spawning activ-
ity or reduced activity. The reservoir management curve was left as
is since it represents an ideal curve.
P.O. Box 1776 Lumml Island, WA 98262 (206) 758.2252
NMFS
Page 2
Flows recorded by Cook Inlet Aquaculture ranged from 46 to
210 cfs in 1985 and 48 to 800 cfs in 1986 from August to October.
Coho spawning was essentially over by October 1, with peaks in
mid -September. According to the stream flow analysis the WUA does
not decrease more than 20 percent until we reach 200 cfs with the
maximum at 350 cfs. CIAA flow data shows less than 200 cfs is
regularly recorded under natural conditions (CIAA Grant Creek
Reports for 1985 and 1986). According to these reports, holding
the CFS above 100 may actually increase the WUA. The generated
curves represent the optimum condition. The high flow in 1986
actually blew the Coho right out of the creek.
2. The timing and collection of the field data was critical
due to several factors: (1) a bank full measurement provides the
optimum modeling condition; (2) Winter conditions were eminent and
the stream could fall extremely rapidly due to freezing conditions;
(3) Uncertain winter conditions i.e., long cold winter may cause
the collection of data to be put off until spring; (4) Uncertain
breakup and spring conditions would place the sampling in extreme
fluctuating conditions; (5) Project timing would be displaced by
more than a year if these conditions existed. The factors of
uncertainty and the need to proceed caused Kenai to act prudently
and sample the stream.
3. The paragraph concerning minimum instream flows reads:
"Minimum instream flow requirements have been developed for Grant
Creek (emphasis added) with provisions for Chinook etc." As pointed
out in the paragraph 1 above, plant management could actually
enhance Coho spawning with reduced flows. Rainbow trout have been
added to the affected species in Grant Creek in the instream flow
report. Chinook salmon was the target species according to our
previous discussion. Rainbow are found in Grant Creek in small
numbers and the size of fish found is small (less than 106mm).
4. Stranding area does not increase significantly until the
stream drops from 100 to 50 cfs. The curve is misleading since the
incremental plots were done on the average, not the range. The
model was run in 50 cfs increments, 200-150, 150-100, and 100-50 cfs.
The graph was plotted at the mid -point of the increment. The point
should have been placed at the lower value of the increment. Strand
able area would thus not show a significant increase until the water
is dropped from 100 to 50 cfs. The CIAA data shows how well the
stream holds up to 28.5 cfs.
5. The point of release'for the fish from the by-pass was
chosen for three reasons: (1) Economically this is the cheapest
place to release the fish (less pipe and construction). (2) The
fish would spend less time in a confined pipe and (3) The fish were
naturally required to emmigrate from the lake via this route. The
fow during the peak of migration would be 8 cfs (see Instream Flow
Graph). The out migration appears to be triggered by temperatures
NMFS
Page 3
and no migration was noted when temperatures were less than 40C:
Water could be concentrated during the out migration period June -
September, with flows during other periods through the turbines.
6. Emergency water is provided from two sources (Additional
Information, page 4) and shown in conceptual drawings IV-20A and
IV-22A. If the turbines and generators are shut down, flow is
continued through a by-pass valve at the powerhouse.. In the event
the penstock is shut down, water is drawn from the lake via the
fish by-pass pipe. These all supply water to the tailrace -
powerhouse discharge channel.
7. Enclosed is a conceptual plan for the powerhouse discharge
channel. The channel is designed for maximum use as a spawning area
u and will provide approximately 30,000 square feet of spawning area.
The long term maintenance and operation plan would depend only on
extreme damage to the system. Kenai does not propose any main-
tenance or operation other than normal plant operation and instream
flow maintenance. The channel represents a large increase in
spawning area and would require a catastrophic event to substantially
change the channel. A natural, self -maintaining system is proposed
similar to a natural stream.
B. The assumption that WUA will fall with project operation
assumes that the stream flow will always be 350 cfs as on the ideal
curve. As pointed out in paragraph 1 this is not true. The range
measured by CIAA is well below the ideal 350 cfs during August
when Chinook and Sockeye are spawning in Grant Creek. WUA would be
subject to the extreme fluctuations of the natural creek flows and
�.. not the ideal generated curve. The proposed flows are well within
the range of normally occurring flows and minimize the risk of lower
or higher flows. The fact that spawning may occur in 0.5 or 1.0
or 2.0 feet becomes mute when extreme fluctuation occurs. Modifi-
cation of the natural bed to reduce strandable areas and depth
fluctuations would reduce those impacts i.e., flattening of gravel
bars and placement of rock weirs.
9. The transects extend up the banks to a measured mark at
stations 2 and 3. At station 1 the bank disappeared into a morass
of roots well above the water. The bank at 2 and 3 was considered
representative of the bank in the sample area and measurements at
these stations was used to provide the profile at station 1. Out
of bank flows do not appear common at Grant Creek. Enclosed are
the data compiled from the field notes. Measurements at .2, .6
and .S of depth confirm the .32 and 6.62 fps readings referred to
in the additional information. The column labeled rFS should read
FPS. Figure 12 is given as water width, not total transect length,
and the widths should be 63, 613 and 75 not 63, 70 and 72 feet.
10. We too, are unable to accurately predict the effects of
NMFS
Page 4
w.-
oil and gas. A recent memorandum from the Office of the Governor
also demonstrates their flustration. Note, they too are tied to
.1981-1983 predictions. The bottom line of our economic analysis
is actual competition with existing rates and the prediction by
the utility of prices which it will have to pay in the future.
Summary
1. The WSP/IFG-2 model developed by ENVIRONSPHERE from data
provided by Kenai Hydro has been shown to preform from 50-400 cfs.
Data from CIAA confirmed the model was accurate to 30 cfs.
2. Strandable area does not increase substantially until
flows fall below 100 cfs.
3. Natural flows 48-800 cfs were recorded in 1985 and 1986
for the period August to October. WUA could actually be increased
by maintaining flows 100-350 cfs during spawning season.
4. Transects at stations 2 and 3 extend up the bank and pro-
vide profiles needed to permit the model to be extrapolated to
400 cfs, beyond projected impact.
5. Actual project flows may fluctuate from minimum stream
flow to maximum turbine flows of 377 cfs (both turbines running
at full gate). The best gate for the 1500 KW turbine is 80 cfs
and the 3500 KW is 216 cfs with a total of 296 cfs. When either
is running alone or in concert an effort will be made to obtain
maximum efficiency which will provide the most energy (bestgate).
When capacity is a target however, the maximum output will be up
to full gate. Under extreme conditions the turbines may be run
at low efficiencies to conserve water (see the turbine performance
curves). Project flows may thus be any combination of the turbines
to provide the needs and approximate the available water. To pre-
vent the spills during good water years there will be an increase
in turbine flow and during low flows the flows will decrease.
Monitoring of snowfall and rainfall will provide data to program
use. Figure 16 and 16A are both versions of the use of 200 cfs
annual flow. Figure 16A provides higher winter capacity with
summer spawning flows. The reduced size of the turbines (7 to 5 MW)
reduces the possible project- flows. project flows will protect
minimum flows and provide for maximum capacity and energy as pro-
jected in the material presented.
6. Enclosed are projections for Bradley Lake which incorporates
the most recent information for state oil and gas projections.
I-.
NMFS
Page 5
The material presented here should be incorporated in the
Grant Lake Hydroelectric Application 7633-002 in accordance with
the FERC letter of August 19, 1986. Alternative I, developed
from submitted and studied Alternatives is provided in compliance
with the Electric Consumers Protection Act of 1986 which requires
equal consideration of environment and power.
We would like to schedule an all day meeting in the next 20 days
to discuss the adequacy of data and a detailed request for any
additional data.
The revised instream flow report by Environsphere is attached
for your review.
Sincerely,
Richard Poole
RP/jp
Encl.
Kenai Hydro, Inc.
Hydroelectric Planning & Development
May 4, 1987
Mr. Robert Bowker
U.S. Fish and Wildlife Service
Sunshine Plaza, Suite 2B
411 West 4th Avenue
Anchorage, Alaska 99501
Dear Mr. Bowker:
Kenai Hydro has provided additional information to FERC and
the agencies for the Grant Lake Hydroelectric Project, 7633-002,
in accordance with the request of FFRC of August 19, 1986. The
additional information supplements the Grant Lake License Appli-
cation of December 90, 1984 and additional information and sub-
missions after that date. Project Alternative I, developed from
studied and submitted project arrangements, provides for habitat
preservation in Grant Creek as requested by the agencies and has
been submitted to the agencies for review. This Alternative
provides for equal consideration of power, fish and wildlife
protection, recreation and other aspects of environmental quality.
The following is presented in reply to your letter of April 6,
1987. Information is drawn from the License application, addendum,
correspondence and recent surveys at Grant Creek referred to in
the presentations.
1. The WSP model requires that data be collected during stable
flows is not entirely true. Data for the model can be collected
during other flow if the model can be calibrated. Methods for
adjusting flows are presented in the IFG manuals and allow the use
of data if it is mathematically correct. We cannot always be in
the field at the ideal time or predict the analysis of the data
in advance.
P.O. Box 1776 Lummi Island, WA 98262 (206) 758.2252
U.S.F&WS
Page 2
Proper field procedures compensate for unsteady flows. The
measurements were made downstream each time which would tend to
make the hydraulic gradient steeper. The progressive decrease
in flow shown by the Grant Creek measurements can be dealt with
by calibration of the model with each measured flow and comparing
the flow with the measured cross-section. The sections were compared
using a single "N" number which indicated a good match. The use
of the staff gage reading allowed the model to be calibrated as
indicated in the methodology of the report. The model preformed
well through the ranges indicated in the report from 50 to 400 cfs.
Even though the useful range of extrapolation is defined as 0.4
to 2.5 times the calibration (246 cfs) the model appeared to
easily preform to 50 cfs.
2. The accuracy of the model is confirmed by a stream flow
measurement made by Cook Inlet Aquaculture, February 24, 1987, at
station T1. Using a PVM-2A Montedora-Whitney current meter, the
stream velocities at one foot intervals was measured. The depth
was also measured at each station to provide an average mean column
flow. The measurements showed the stream flow to be 28.5 cfs.
The profile was compared with the measurements made by Kenai
Hydro on October 24, 1986 and found to be a reasonable match.
Comparison of model flows with the measured flow, indicate the
model flows to be somewhat conservative; i.e, predicted flows are
somewhat lower than actual.
The additional data collection by the Cook Inlet Biologist
Pat Markison, who has studied Grant Creek for the past three years,
confirms the validity of the Kenai Hydro data and its use to predict
the effects of plant operation. Attached is the data and comparisons.
During the field survey by the agencies and Kenai Hydro, the
stream was flowing in excess of the measurements made by Kenai. No
out of bank flows were noted during the visit and it appeared there
was considerable room for much larger flows within the normal bank.
The field data confirms those observations and bank measurements
made at stations 2 and 3 are considered representative of the banks
of Grant Creek in the study area. Observations during the field
surveys indicate that out of bank flows do not occur except in
extreme conditions (i.e. no gravel bars, marks on trees, brush piles
etc. are evident along Grant Creek).
As indicated in the methodology of the additional information,
three measurements were made at each station at .2, .6, and .8 of
depth (page 10, Paragraph 1 and paragraph 1). This data is present
Ilcre for YOM review. page 11, paragraph 1 indicates the average
U.S. F&WS
Page 3
column velocity was used to determine stream flow. The numbers in
Table 1-3 are the measurements at .6 of depth and were used in the
model. The columns are mislabeled and do represent FPS not CFS.
The total discharge is correctly computed.
3. The ends of the transects did not end at the waters edge.
At stations 2 and 3 measurement extended up the bank 2-4 feet. A
high bank exist on the north bank and a lower bank on the south
side of the creek. The profiles correctly show the bank to extend
.3 and 1.96 feet above the measured water surface 2-3 feet from the
waters edge. The measurements are consistent with the stream charact-
eristics of a straight tube with the stream confined to a relatively
stable bank.
Stream flows of 400 cfs do not represent over the bank flows
and due to the straight sides of the banks no stranding potential
is represented by the sides of the stream as shown by the profiles.
4. Extropolation to the limits of the model on the upper
end is not necessary to determine project effects. The penstock
will only carry 377 cfs maximum and project effects will normally
only extend to that limit. Higher flows would occur naturally
when the lake spilled. Note the natural. flows have exceeded 1500
cfs during extreme high water years. Stranding resulting from
natural occurrences is not the result of project activity. The
project would be operating normally during the high water period
and may be considered an additive effect, however, the flows
occurring during extreme high water periods exceed project flows
and will occur regardless of project activity. Normal reservoir
management would keep spills to a minimum and such occurrances
would be less than 3 percent of the time (See exceedance curves
and Table).
Additional discussion is added to the Instream Flow Report
concerning stranding and habitat analysis. The stranding analysis
is somewhat misleading due to the increments used and the Cook
Inlet data shows how well the stream holds up due to the increase
in "roughness" of the bottom. Strandable area does not increase
substantially until the water is dropped from 100 to 50 cfs. At
the 28 cfs, measured by Cook Inlet, the stream is bank to bank at
Station T-1. As previously stated, Kenai feels project impacts
between 100 and 400 cfs will. be minimal. Actual. project flows will
exceed 100 cfs most of the time and average 200 cfs.
5. Minimum instream flow maintenance is described on page 4
and shown in the conceptual drawings, Figures IV-20A and IV-22A.
Normally instream flow is maintained by discharge from the power-
house (50-377 cfs). The range of 50-377 is the maximum limits of
U.S.F&WS
Page 4
the turbines and operation will not normally be in this range.
The 1500 KW turbine operates most efficiently at 80-90 cfs and the
3500 KW turbine at 216 cfs. Efficient operation would call for
operations to exist between 80-300 cfs for maximum use of the water.
The 3500 KW generator would operate from 140-270 cfs. Average
monthly turbine flows are presented for low, medium and high flows
in Figure 1 in Instream Flow Report. These flows are projected
to occur once every 33 years (Table 5, page 16). The flows in the
license reflect the possibility of hedging or dumping to provide
for lake management in March and April and in October.
In the event the turbines shut down a valve in the power
house is actuated to provide flows to the tailrace. The 16 inch
valve utilizes water from the penstock and furnishes 100 cfs directly
at the power house (Figure IV-22A). In the event the penstock is
shut down the stream is supplied with water from the lake via an
18 inch pipe to the top of the falls (Figure IV-20A). This valve
is automatically actuated when the gates are closed. Water is
thus supplied to the head of the canyon. Since the tailrace is
in the streambed the water from any of these sources will insure
a supply of water is available for maintenance of stream flows as
required.
The penstock carries water directly from Grant Lake to the
powerhouse without falling through the canyon. The water discharged
from Grant Lake at the water ice interface is 2oC and with slight
increases due to depth of intake the temperature at the lake would
be approximately 30c, however, due to the time of passage through
the pipe of approximately 7 minute, the water would cool only slightly.
1'he projected discharge temperature in Figure 2-6A reflects the
lack of cooling that could occur in the canyon due to extreme tur-
bulence. Immediately upon discharge from the penstock, however,
the water will begin to cool and will be 0 0 C by the time it is
discharged in Trail Lake. The heat exchange effect created by the
rough bottom (turbulence) will be most extreme during very cold
weather and wind. The discharge temperature shown will not have
the effect which you project due to the rapid cooling which will
occur in the stream bed. The slight increase will probably be
beneficial since emergence at Grant Creek is normally June or July.
Minnow trapping did not produce young of year Chinook until August.
6. In order to recover lost head, due to moving the plant to
Grant Creek, Kenai will excavate a channel from the powerhouse 500
feet downstream (page 27 of Information). The channel will be lined
with 4-6" rock, 1.5 to 2.0 feet deep. Rock gabions will be placed
at 200 foot intervals to prevent rock from washing away during
extreme high weer. A conceptual drawing is presented.
U.S.F&WS
Page 5
The powerhouse discharge will provide 30,000 square feet of
spawning area, roughly 2 times what now exists. The low gradient
in the channel will maintain the gravel and the rock gabions will
stop rock from moving extensively. This will also insure that at
any flow the streambed will be wetted bank to bank (no slope bank
to bank). The depth and size of gravel will allow Sockeye or
Chinook to successfully use the area.
Since the channel represents extensive improvement to the
existing available area, Kenai does not propose any maintenance to
the channel except under extreme conditions. The flows normally
found during project operation should have no effect on the channel.
A very high natural flow may alter the channel and make repairs
necessary. This event is remote and according to records would
be a 50 year flood. Kenai does not feel extensive planning and
repair schedules are warranted due to the circumstances. Lake
management reduces the likelihood this event will ever occur.
7. The outlet for the fish bypass pipe is at elevation 650
near the falls. The pipe can exit in a relatively tranquill area
since we can construct such a setting, and then permit the fish to
exit to the natural stream bed. The discharge rate from the pipe
has been presented on several occasions to the agencies (See
Figure in Appendix, Instream Flow Maintenance). The releases would
be as follows: 5 cfs September to April, 7 cfs in May and 8 cfs
June to September. This could be adjusted to provide more water
June -October and less November to June. Fry migration during the
June to September period was the highest when water temperature
significantly increases. No smolts passed out of the lake when
temperatures were below 40C according to U.S. Forest Service
surveys. It may be more appropriate to concentrate the water
during the out migration period (if the enhancement project proves
feasible).
8. ENVIRONSPHERE is revising the Draft instream flow study
according to Agency comments. A .final report will be submitted to
you when it is completed. Your comments should make the report
more suitable for Grant Creek.
Summary
Kenai hydro is confident the data collected by Kenai provides
a model that will. analyses stream flows from 50-400 cfs. The data
is confirmed by comparison with stream flows taken in February 1987
by Cook Inlet Aquaculture. While CIAA data is inadequate to be
incorporated in the IFG-2 model, it does confirm the model produced
by data collected by Kenai in October is valid. Environsphere is
revising the draft according to your comment.
U.S. F&WS
Page 6
Details of the tailrace channel are provided to show the
conceptual design features. While the channel is simple, it
will greatly increase the spawning habitat in Grant Creek. A
roughness of the edge could provide some rearing habitat.
The material presented here should be incorporated in the
Grant Lake Hydroelectric Application 7633-002 in accordance with
the FERC letter of August 19, 1986. Alternative I, developed
from submitted and studied Alternatives is provided in compliance
with the Electric Consumers Protection Act of 1986 which requires
equal consideration of environment and power.
We would like to schedule an all day meeting in the next 20
days to discuss the adequacy of data and a detailed request for
any additional data.
The revised instream flow report by Environsphere is attached
for your review.
Sincerely,
Richard Poole
RP/jp
Encl.
Kenai Hydro, Inc.
Hydroelectric Planning & Development
May 4, 1987
Mr. Donald O. McKay
Alaska Department of Fish and Came
Habitat Division
333 Raspberry Road
Anchorage, Alaska 99518-1599
Dear Mr. McKay:
Kenai Hydro has provided additional information to FERC and
the agencies for the Grant Lake Hydroelectric Project, 7633-002,
in accordance with the request of FERC of August 19, 1986. The
additional information supplements the Grant Lake License Appli-
cation of December 20, 1984 and additional information and sub-
missions after that date. Project Alternative I, developed from
studied and submitted project arrangement, provides for habitat
preservation in Grant Creek as requested by the agencies and has
been submitted to the agencies for review. This Alternative
provides for equal consideration of power, fish and wildlife
protection, recreation and other aspects of environmental quality.
The following is presented in reply to your letter of April 1,
1987. Information is drawn from the License application, addendum,
correspondence and recent surveys at Grant Creek referred to in
the presentations.
1. Field data presented in the report represents a summary of
data from field notes. The description is correct in providing the
method of establishing the end of the transect prior to commencing
the actual measurements. This procedure is discussed in IFG methods
and reduces potential needs for data calibration. The data does
show measurements above the surface water measurements and provides
profiles needed to extrapolate flows above measured flows.
P.O. Box 1776 Lummi Island, WA 98262 (206) 758.2252
ADF&G
Page 2
While the data was collected during a drop in water flow it
calibrated and the model preforms well from 50 to 400 cfs. The
progressive drop in flows indicates correct measurements were made
at all stations.
The lower flows were confirmed by data collected by Cook Inlet
Aquaculture Association February 24, 1487. The profile of the
measurements made by CIAA corresponded reasonably well with Kenai's
measurements at station 1. The data shows the model to be somewhat
conservative i.e., model flows slightly lower than measured flows.
The data provided a valid modelwhich was used in the Instream Flow
Report.
2. The Tennant method was not used to support ramping, but to
support minimum instream flows. The Tennant method is used for
seasonal averages but is also commonly averaged on an annual basis.
The original license application provides a discussion of the negoti.-
ations using the Tennant method.
3. A conceptual drawing of the powerhouse discharge channel
is presented which updates the original presentation. Water to
the channel is normally provided by turbine flows from the power-
house. Emergency water is provided from two sources (Additional
information page 4) and shown in conceptual drawings IV-20A and
IV-22A. If the turbines and generators are shut down, flow is
continued through a by-pass valve at the powerhouse. In the event
the penstock is shutdown, flow is drawn from the lake via the fish -
bypass pipe. These all supply water to the tail -race -powerhouse
discharge channel. The channel will provide 30,000 square feet of
spawning and rearing habitat, nearly two times as much as now
exists in Grant Creek.
4. Long term maintenance and operation will depend only on
extreme damage to the system. The channel represents a large in-
crease in available spawning area and would require a catastrophic
event to reduce the available area. A natural, self-sustaining
system similar to a natural stream is proposed.
5. The stranding curve is misleading since the incremental
plots were done on the average, not the range. The model was run
in 50 cfs increments i.e., 200-150, 150-100 and 100-50 cfs. The
graph was plotted at the mid -point of the increment. The point
should have been placed at the lower valve of the increment.
Stranding potential thus does not increase substantially until the
flow rate drops below 100 cfs. The model demonstrates how well the
stream flows hold up at lower flows.
ADF&G
Page 3
6. Naturally occurring fluctuations in stream flow are
recorded by CIAA and presented in their reports in 1985 and 1986.
Flows in August to October ranged from 46-210 cfs in 1985 and 48-800
cfs in 1986. The WUA curve presented in the stream analysis shows
maximum spawning habitat at 350 cfs. However, it appears that flows
less than 100 cfs are regularily recorded in Grant Creek during
spawning season. Project flows from 50-377 cfs are within the range
of natural flows. The low flows would be eliminated and extreme
high flows would be reduced. The overall effect would be a
stabilization of flows and spawning habitat. Flows in 1986 of
800 cfs actually blew Coho out of Grant Creek.
The material presented here should be incorporated in the
Grant Lake Hydroelectric Application 7633-002 in accordance with
the FERC letter of August 19, 1986. Alternative I, developed
from submitted and studied Alternatives is provided in compliance
with the Electric Consumers Protection Act of 1986 which requires
equal consideration of environment and power.
We would like to schedule an all day meeting in the next 20
days to discuss the adequacy of data and a detailed request for any
additional data.
The revised instream flow report by Environsphere is attached
for your review.
Sincerely,
j�
R'chard Poole
RP/jp
Encl.
RESPONSE TO USFWS COMMENTS
Response to General Comment 4, Page 2
The habitat curves will be adjusted in the final report to more clearly reflect
comments made by the USFWS and to revise errors in the draft. We believe that the
description provided in the text (i.e., any substrate less than 12 inches in
diameter was considered spawnable [=1.0 suitability] for both chinook and sockeye)
is sufficient and that a curve does not need to be depicted.
Response to General Comment 5, Page 2
A reference is attached concerning the stranding analysis. This reference describes
the technique used to quantify potential effects of daily flow fluctuations at
Grant Creek on stranding of juvenile salmonids.
Response to Comment on Page 11, Paragraph 2
Change in discharge during a WSP measurement period is not uncommon. In fact, it
is truly rare to find discharges measured at successive cross -sections which do
not vary by 10 percent or more. This is largely because cross -sections for habitat
analysis are rarely consistent with respect to their bedform, substrate and
roughness and uniformity of flow. Stated another way, the actual discharge through
a measured reach could have no variation during the measurement period, and
discharge calculations at each cross-section could vary substantially, even if
they were measured as accurately as possible. Such discrepancies are impossible
to reconcile through mathematic proportionation because their source is complex
hydraulics, not simple change in discharge.
Detection of an unsteady flow event, then, should not be done by comparing discharge
measurements at different cross -sections through the day, but by measuring discharge
«- at the same (preferably the most uniform) cross-section at two or more times during
the day. This cross-section may not even be one of the IFIM cross -sections.
Further, these measurements should be made simultaneously with precise water
surface elevation measurements at the selected cross-section.
Regarding the Grant Creek data, it is not possible to determine the exact discharge
change during the day because sequential measurements were not taken at a discharge
measurement cross-section. Two points tend to support the hypothesis that the
measured flows reflected a reduction in discharge during the measurement period.
First, the calculated discharges at the three cross -sections descended in an
orderly fashion during the day (297, 261 and 246 cfs, respectively). Second, the
staff gage reading descended 0.21 ft during the measurement period, which proved
to be very near the model stage reduction when velocities were reduced proportional
to the difference in calculated discharges. (See methods section of our report.)
-2-
This does not eliminate the possibility that anomalous discharge variation existed,
it simply shows that some of the variation may be reconciled using simple
proportionation techniques.
Ultimately, the effects of discharge variation on reliability of the predictive
model must become a matter of mutual agreement among the parties enjoined in the
study. Neither the Instream Flow Group nor the USGS has published an exact level
of discharge variation above which all hydraulic simulation results become
unacceptable; nor will they comment consistently on the merits of correction
techniques.
The Grant Creek measurement discharge variation problem has been given minimal
collective analysis to determine: (1) actual source of the variation; (2) extent
to which the corrections resulted in a reasonable predictive model; and (3) ultimate
effects which the evaluation and corrections might have on the reliability of
habitat estimates.
The agencies should either state that 20 percent variation is too much and cite
the sources of their decision, or elect to convene a meeting to discuss an evaluation
process.
Response to Comment on Page 11, Paragraph 6
Comment noted. The final report will reflect these corrections.
Response to Comment on Page 21, Paragraph 3
The stranding analysis defines the potential for stranding based on gravel -bar
slope and substrate. The analysis does not establish ramping rates.
Response to Comment on Page 9, Paragraph 4
The revised report states that certain chinook and sockeye results may represent
habitat relationships for some life stages of coho, rainbow trout and Dolly Varden.
Generally, however, the actual instream flow study results for all target species
should be based on a detailed, final list of evaluation species provided by the
agencies along with any prioritization rankings they may have. It is not the
applicant's responsibility to determine evaluation species; the agencies should
provide a list of species and proposed analyses, preferably rior to seeing the
results of the instream flow studies.
Response to Comment on Paqe 10. Para4raohs 3 and 4
The development of values for suitable substrate for spawning chinook and sockeye
salmon were intended to cover a much wider range than might be found in the Grant
Creek system. This was none to assure that all possible substrate types that
might be used for spawning would be included.
Substrate suitability values for sockeye were derived from information in Estes
and Vincent -Lang (1984) which was generated from extensive studies on the Susitna
River, Alaska, by the Alaska Department of Fish and Game and literature review.
The values they used were:
-3-
Particle Size Suitability Index
Silt
0
Sand
0
1/8-1"
0.5
1-3"
1.0
3-5"
1.0
6-10"
0.25
> 10"
0
This implies that substrate up to nearly 10 inches could be suitable, but optimum
values are in the 3 to 5 inch range. As stated in the Envirosphere report,
observations of substrate sizes from Kenai Hydro were fairly broad in nature.
Therefore, to assure that all possible substrate lies suitable for spawning were
encompassed, all substrate less than 12 inches was considered suitable. Any
greater than 12 inches was considered unsuitable.
Estes and Vincent Lang (1984) developed substrate suitability curves for chinook
salmon, again from extensive studies by the Alaska Department of Fish and Game on
the Susitna River, Alaska, and literature review. The values they used were:
Particle Size Suitability Index
Silt
0
Sand
0
1/8-1"
0
1-3"
0.65
3-5"
1.00
5-10"
0.70
> 10"
0
Intermediate values also exist, but sizes less than 10 inches are potentially
suitable, whereas those greater than 10 inches are not. We have been unable to
locate the data referenced by the U.S. Fish and Wildlife in Estes and Vincent -Lang
(1984). Therefore, we request that the U.S. Fish and Wildlife Service send us
either the data or the specific reference (page, paragraph, and line) where the
USFWS found this data. This would greatly assist us in understanding the USFWS
comment.
In a manner similar to the analysis for sockeye, it was assumed that all substrate
sizes less than 12 inches are spawnable by chinook, and anything greater than that
is not utilized. This extra margin was considered to encompass most sizes that
were spawnable and to account for the fairly broad range of substrate sizes
described by Kenai Hydro.
Response to Comment on Page 21, Figure 2
Although Figure 2 indicates that a minimum depth of two feet is needed to obtain a
suitability of 1.0, the text (Page 11, lines 2-4) states that any depth over 1.0
foot is considered potentially spawnable (i.e., suitability=1.0). Therefore, the
figure (and any changes that might occur in the model) is in error and will be
revised in the final report.
-4-
Response to Comment on Page 13, Figure 3
The suitability curve depicted on Figure 3 is actually a curve developed by Bechtel
Civil and Minerals (1983) for a proposed project on the Chackachamna River, located
across Cook Inlet from the Kenai Peninsula. Therefore, it is incorrectly identified
in the figure. We will use the Burger et al. (1983) curve for the final report,
as it encompasses a wider range of velocities as being suitable.
Response to Comment on Page 15, Figure 4
Comment noted. These figures will be revised in the final report.
Response to ADFG Comment on ADFG Letter, Page 2, Paragraph 2
` The report text indicates that any depth greater than 1.0 foot were considered to
have a suitability value of 1.0. As correctly pointed out, the figure is in error
and will be corrected in the final report. Also, the modeling will be revised
accordingly.
Response to NMFS Comment on Page 21, Rampin<_Rates
Figure 2 of the draft report may be somewhat confusing. Although on a gross level
it appears that strandable area increases below about 125 cfs, this is not the
case. The stranding model was run in 50 cfs increments of flow change. These
were, for example, 200 to 150, 150 to 100, and 100 to 50 cfs. When the figure was
developed, the amount of strandable area was placed at the midpoint of the increment
(for example, 175, 125, and 75 cfs). A different graphic representation will be
included in the final report to clarify the results. These results will indicate
that strandable area does not show a dramatic increase until the discharge is
decreased in the increment of 100 to 50 cfs.
Response to NMFS Comment, Page 3, Page 10, Paragraph 4, Chinook Adults
The curves used for spawning chinook were derived from Estes and Vincent Lang
(1984). The text in the draft report reflects a 1.0 foot depth as having a
suitability value of 1.0. The accompanying figure (Figure 2) in the draft report
is incorrect and should reflect a habitat value of 1.0 at 1.0 foot depth. This
figure and any changes in the model results will he described in the final report.
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Instream Flow Chronicle
A. Training Announcement
January, 1986 Vol. II, No. 4 CSIJ Conference Services
A Technique for Quantifying Effects
of Daily Flow Fluctuations
On Stranding of Juvenile Salmonids
by
C. Mike Prewitt
Senior Aquatic Biologist
and
Cliff Whitmus
Associate Fishery Biologist
Envirosphere Co.
Bellevue, K'ashington
Backoround
Envionmenta? effects of fluctuating water discharge
levels below hydroelectric dams have been the subject
of considerable recent study. In many instances,
daily fluctuation impacts have been greater than
those fror, steady changes in weekly or monthly flow.
Daily flow fluctuations have had negative effects on
anadromous salmonids particularly during the spawning/
incubation period and during juvenile rearing and
smolt outmigration. In the case of spawning/incuba-
tion, impacts have resulted from flow fluctuations
which dewater redds located within the area dewatered
on a daily basis. Rearing and outmigrating salmonids
are typically affected through stranding during a
rapid water level drop (or "downramp"). Stranding,
either on large gravel bars or in isolated potholes,
has been shown to cause significant mortality on
certain salmon and steelhead stocks in Washington
State.
Abiotic factors which influence daily fluctuation
effects are generally related to channel morphology,
specifically depth, velocity and substrate for spawn-
ing/incubation effects and gravel -bar slope and
substrate for stranding. In the case of stranding,
there is good evidence to indicate that stranding
frequency increases with decreasing gravel -bar slope.
Expansive, flat bars are generally associated with
higher standing rate than are steeper -sided areas.
Conversely, stranding appears to increase with
increasing substrate size because of the tendency for
juvenile fish to seek cover in the larger substrate
interstices (Stober et al. 1981, 1982).
Use of PHABSIM
To quantify the effects of daily fluctuations on
juvenile salmonid stranding, a variation on tradi-
tional use of the U.S. Fish and Wildlife Service
Physical Habitat Simulation (PHABSIM) system was
used. From information in the literature, it was
determined that gravel -bar slopes le•.s than four
percent were more likely to cause stranding (Sauers-
feld 1978); conversely, those greater than 9 percent
were felt to provide enough gradient to reduce strand-
ing (Bauersfeld 1977). Using these gradients as
general guidelines, a curve relating gradient and
stranding probability (or factor) could be drawn
(Figure 1).
Similarly, a curve relating substrate to stranding
probability (or factor) might appear as in Figure 1
(lower). Here, the substrate codes 1 through 15 are
associated with for example, sand (=2), gravel (=5),
cobble (=7), boulders (=10), etc.
The input to the PHABSIM hydraulic simulation computer
programs normally consists of channel cross-section
coordinates and substrate sizes. With respect to
slope only, Figure 2 illustrates a hypothetical
stream channel with various cross -sectional slope
conditions. If a daily downramp were from Q+ to Qi,
a relatively large, low slope area would be exposed,
with high risk of stranding. If discharge was reduced
from Qi to Qr in a daily downramp, a smaller area of
higher slope would be exposed, causing generally
lower concern for stranding. If substrate were also
of concern, the joint stranding factor (from multi-
plying slope stranding factor x substrate stranding
factor) could also be determined. To predict total
strandable area associated with any downramp incre-
ment, standard PHABSIM software provides all necessary
hydraulic simulation and habitat (or stranding)
calculations.
(See Figures 1, 2, and 3 on page 2)
Inside:
• Evaluation of Habitat Quality and Quantity
• What the IFIM User Must Know
• Instream Flow Information Systems
(IFIS)"STUDIES Data Base
• IFIS'STRATEGIES Data Set
• Publications in the Opportunity Series
• IFG Training
In actual use, it was necessary to make certain
modifications or additions to normal PHABSIM
processing in order to obtain results. These
included:
-Use of depth and velocity preference curves which
reflected preference of 1 for all depths and
velocities. This allowed depth and velocity to be
retained for hydraulic simulation purposes but negated
in the habitat analysis.
-Use of the PHABSIM cover code to incorporate slope/
substrate joint stranding factor.
-Use of a computer program to compute slope within
the individual cross -sectional cells, and to enter
those slopes in the substrate/cover space of an IFG-4
data deck.
Interpretation of Results
Recalling that the primary concern for stranding was
the difference between the peak afternoon discharge
and minimum after the evening downramp, (defined as
ramping amplitude), the analysis involved plotting
weighted stranding area vs. incremental decreases in
discharge as in Figure 3. In this example, it is
apparent that stranding area increases rapidly with
fluctuations in the 11,000 to 9,000 cfs range.
Fluctuations in the 12,000 to 15,000 and 4,000 to
7,000 cfs ranges appear to cause less stranding
concern. This relationship would be valuable to
hydropower planners to highlight discharge ranges
within which fluctuations would be especially likely
to cause stranding, as well as those within which
fluctuations might not be problematic.
A further analytic step would be determination of a
maximum permissible ramping amplitude given a fixed
average flow. Again, based on Figure 3, for example,
if the average flow was 12,000 cfs, a daily amplitude
of ± 1000 cfs would not cause concern for stranding.
Amplitudes of ± 2,000 or ± 3,000 cfs however, would
greatly increase stranding risk.
Such guidelines would be of obvious use in design and
feasibility studies of unconstructed hydroelectric
projects and could also be used to quantitatively
assess alternative operating regimes of existing
hydropower projects. This method addresses only the
stranding effects of flow fluctuations as they relate
to certain salmonid life stages. Comprehensive
assessment of flow fluctuation should include consid-
eration of egg dessicatlon as addressed using the
HABSP program described in the IFG Technical Note 15
and in Bovee (1985) or other techniques.
Although the stranding assessment technique has not
yet been formally applied, we feel that it has at
least two positive potentials:
First, it has illustrated that the PHABSIM software
system may be used in a variety of ways when basic
channel -related variables are considered. The ability
to use PHABSIM software allowed us to calculate an
area -weighted index using an accepted process, without
the need for extensive computer programming.
Second, the effort should encourage communications
between aquatic biologists and hydropower planners
which should help ensure that operating criteria with
respect to flo fluctuations will be incorporated in
the project feasibility studies and ultimately in
design and operation. Such coordinated efforts are
increasingly i.portant as hydropower projects must
meet more stringent environmental and economic
requirements.
9 P
r o
R T
R E
N N
T
I I
N A
0 L
T U
T
R E
N N
0 T
t i
N A
o L
SLOPE
SUBSTRATE 511t
Figure 1. Hypothetical relationships between stranding
potential and gravel -bar slope and substrate size
STREAM CHANNEL SLOPE
w.e c of
uoeE-,n
�� w.S.E.O SIOeE •S\
aoeE•,\
smarono anu
O4Mri M PSCMMOE
Figure 2. Representation of stream channel slope at
various water surface elevations, and potential stranding
areas
CHANGEIN 75
STRANDING
AREA
flit x 1000)
50
25
15 to 13 12 11 10 e 6 7 6 5 a 3
DISCHARGE N CFS a10G0
Figure 3. Discharge (as 1000 cfs downramp increments)
vs. change in stranding area relationship
Literature
Baunsfeld, K. 1977. Effects of peaking (stranding) of Columbia River dams
on juvenile anadtomous fishes below the Dalles Dam, 1974 and 1975.
Wash. Dept. Fuh., Tech. Rept. No. 31, 117 p.
Bauetsfeld, K. 1978. Stranding of juvenile salmon by flow reductions at
Mayfield Dam on the Cowlitz River, 1976. Wash. Dept. Fish., Tech. Rept.
No. 36. 36 pp.
Bovee, K.D. 1985. Evaluation of the effects of hydropeaking on aquatic
macroinvertebrates using PHASSIM. pp. 236-241. In Proceedings of the
Symposium on Small Hydropower and Fisheries, F.W. Olson, R.G. While,
and R.N Itamrq eck Amer. Fish Sur, Bethesda, MD,
Sinber, Q.1., S.C. Crumley, E.D. Fast, E.S. Killebrew, and R.M. Woodin.
Trial. the effects of hydroelectnc tinchatgr fluctuallnns on salmon and
steelhead survival in the Skagit River, Washington. FRE-UW-6127. 211 pp.
Stobeq Q.I. S.C. Crumley, D.E. Fast, LS. Killebrew, R.M. Wnodin, G. Eng-
man, and G. Tutmark. 1982. Effects of hydroelectric discharge fluctua-
tions on salmon and steelhead in the Skagit River, Washington, FRI-UW-
8216. final Report for Seattle City Light. 302 pp.
Evaluation of Habitat Quality and
Quantity
by
lean Baldridgee
In instream flow assessments using the Instream Flow
Incremental Methodology (IFIM), our evaluation is
based on a habitat index -- Weighted Usable Area
(WUA). WUA, a familiar term to all IFIM Users,
represents a measure of available habitat for a
particular species and life stage at a specific
streamflow. WUA represents the combination of both
habitat quality and quantity. In the habitat simula-
tion process, WUA is computed for each cell by muliti-
plying an area of the cell by a factor describing the
suitability of its physical microhabitat character-
istics called the composite suitability index. The
WUA's for all cells are su-.-red to get the total WUA
for each stream segment. A WL;A of 100 may represent
1,900 sq it with a lo.-level suitability of 0.1 or
Too sq ft of optimal habitat with a suitability of
I.C. The best interest of the fishery may not be
served by trading optimal habitat for a larger amount
of marginal habitat even though the WUA values may be
the same. The similarity in WUA indices for such
different habitat conditions has been a longstanding
criticism of the IFIM. In some assessments, decisions
regarding flow allocation or fisheries management may
be facilitated by evaluating the two components
(quality and quantity) of WUA separately. Both
habitat quality and quantity can be easily derived in
an IFIM anlysis.
Habitat area (HA) can be defined as the area having
positive WUA. It is the quantity component of habitat
and represents the actual area of the stream usable
by the species and life stage evaluated. It may be
derived by using binary criteria in a normally con-
figured HABITAT simulation. In binary criteria, the
usable habitat has a suitability of 1.0 and unusable
habitat has a suitability of 0.0. Thus, the WUA
output from binary criteria is no longer "weighted"
and portrays an actual area, the gross habitat area.
-Jean Baldridge is a project scientist with Entrix
Inc., Anchorage, AK.
HA derived in this fashion is expressed as sq it per
1000 lineal ft of stream and pertains to only one
life stage.'
Habitat quality in IFIM modeling is represented by
composite suitability indices. Composite suitability
indices are computed for each cell in the study site
by multiplying the habitat suitability indices for
each microhabitat variable (i.e., depth, velocity,
substrate and cover) together. Habitat quality can
be evaluated as a function of streamflow by calculat-
ing the average composite suitability index for each
species and life stage. This index is developed by
dividing the WUA value by the corresponding habitat
area (HA). The resultant ratio which ranges from 0
to 1 is termed the habitat quality index (IIQi).
Since WUA is computed by summing the products of the
composite suitability index of each cell and its
area, development of the HQI simply reverses the
process and divides WUA for the entire site by its
gross habitat area. HQI's can be used to compare
habitat quality between sites or between species and
life stages.
The mechanics used to develop these additional stream -
flow -specific indices can be used in other ways. The
quantity of optimal (suitability of 1.0) or good
(suitability of 0.5 or greater) habitat can be
evaluated by changing the binary criteria to reflect
the desired habitat range. Thus we can evaluate
gains and losses in higher quality habitat as flow
changes.
Development of both HA and HQI can benefit fisheries
resource managers and we routinely calculate them in
our IFIM assessments. These indices remove some of
the uncertainty associated with WUA values by iden-
tifying the component (quality or quantity) of WUA
that is sensitive to changes in flow. They can be
easily determined using IFIM software and simple
division.
'Composite habitat areas for all life stages of each
species evaluated in a HABTAT run are found on TAPER,
but habitat areas for specific life stages can be
evaluated only by making separate runs.
Seminar on Instream Flow Methodologies
(Contact: Maureen Lenihan, EPRI, (415)855-2127)
February 25, 1986, Crystal Gateway Marriott,
Arlington, VA
This seminar is based on a recent Electric Power
Research Institute study to evaluate techniques for
establishing instream flow releases. The study
reviewed over 50 methods, including the U.S. Fish and
Wildlife Service Instream Flow Incremental Methodology
(IFIM). Some of the methods were designed to estab-
lish biologically appropriate flow releases from dams
and diversions. Others developed functional relation-
ships between indices of habitat quality and instream
flows. Several used flow along with other input
variables to characterize stream habitat quality, and
a few were intended to predict measurable biological
responses, including fish standing crop and width of
riparian vegetation. Most aspects of model develop-
ment and verification were considered, and the results
of all available model testing and validation were
included. This seminar, presented by the authors of
the EPRI study, will describe the approach used in
the evaluation, the conclusions, and the recommenda-
tions for future research,
MEMORANDUM State of Alaska
office of the Governor
Division of Policy
TO: The Honorable Steve Cowper DATE: February 25, 1987
Governor
FROM: Mary Halloran W111� PHONE:465-3568
Director
Jack i
Seniorr Analystalyst(//`/� �
SUBJECT: Bradley Lake Hydroelectric Project
In April 1985, the Office of Management and Budget (OMB) determined
that the proposed Bradley Lake hydroelectric project was econom-
ically feasible and recommended to former governor Sheffield that
the project be approved. As you are aware, a number of factors
affecting the project have changed substantially in the nearly two
years since that recommendation was made. These factors, most of
which are linked to the recent sharp decline in petroleum prices,
include:
(1) the long-te
Inlet, with
(2) current and
(3) the State's
$218 millio
Legislature
:m outlook for prices of natural gas in Cook
which Bradley Lake power must compete;
forecast power demand in the Railbelt region;
fiscal position and ability to appropriate the
n equity investment originally approved by the
for Bradley Lake; and,
(4) the terms under which the Railbelt utilities will agree to
purchase power from the the project, especially the
provision which makes the revised power sales agreements
contingent on full State funding of the proposed Railbelt
transmission intertie system.
Because of these changes in key project parameters and the
magnitude of the State's financial commitment to the Bradley Lake
project, the Division of Policy has undertaken a thorough review of
the economic and financial feasibility of the project in light of
Governer Steve Cowper
Page 2
February 25, 1986
current conditions and the best available estimates of future
trends. This memorandum summarizes the results of our review and
discusses the options available for completing, delaying -and -
terminating the project.
Summary of Findings
• Our review indicates that the Bradley Lake hydroelectric
project is still economically feasible, although the
projected net benefits of the project are now substantially
lower than estimated in the 1983 project feasibility study.
This reduction in net benefits has resulted primarily from
the sharp decline in current and forecast Cook Inlet gas
prices during the last two years.
If construction of Bradley Lake had not already begun and
over $45 million been spent on the project, we would now
consider the project to be only marginally feasible and
would not endorse construction of the project without a more
comprehensive reevaluation of project design and
feasibility. However, when the sunk costs of the project
are considered, including additional expenses which would be
incurred if the project were terminated, completion of the
project becomes more attractive than if the project had not
entered the construction phase.
Other factors in addition to the project's sunk costs have
partially offset the negative impact of falling gas prices
on the feasibility of Bradley Lake. A construction
financing arrangement has been implemented which is expected
to reduce financing costs by about $30 million from the
level estimated in the 1983 project feasibility study. The
construction cost of the project is also expected to be
substantially lower than originally estimated because of
lower than projected inflation rates and a recent downward
trend in construction costs for major projects of this type,
both in Alaska and nationally. This downward cost trend is
supported by the experience of the federal Alaska Power
Administration, which is nearing completion of a major
generation addition to the Snettisham hydro project near
Juneau at an expected cost which is at least 15 percent less
than the original project cost estimate.
• Demand projections by Railbelt utilities are now much lower
than in 1983, but this change does not appear to affect the
feasibility or timing.of the Bradley Lake project. At 90
megawatts, Bradley Lake is a relatively small project in
comparison to total Southcentral or Railbelt power demand.
Even with no load growth over the next ten to fifteen years,
a large percentage of the existing gas generation capacity
Govern:>r Steve Cowper
Page 3
February 25, 1986
is expected to require replacement between 1988 and 1997.
Two years ago, utilities expected to install new gas
generation in the 1989-90 period, in addition to receiving
power from Bradley Lake. Now with lower demand projections,
it is expected that Bradley Lake power would forestall the
need for new gas generation until the mid-1990s, but utility
officials state that if Bradley Lake is not completed, an
equivalent amount of gas generation would have to be
installed by 1989-90.
The rate impacts of Bradley Lake depend on final financing
arrangements and the number of utilities participating in
the project. Although additional analysis is necessary, it
appears that relatively small increases in retail rates may
be required during the first years of project operation -- a
few percent at most. The potential for unacceptable rate
impacts is greatest for the Homer Electric Association,
because of the utility's small size, high debt load and the
possibility of major declines in the system's power sales.
over the life of the project, Bradley Lake will produce
power at substantially lower rates than gas generation, due
in part to the economic advantage of the project and in part
to the State's equity investment subsidy in the project.
• Economic feasibility is only one of several key issues
concerning Bradley Lake. The plan of finance for the
project and the status of power sales agreements are of
equal importance in the decision whether to continue project
construction. The revised power sales agreements which will
be submitted to the APA board for approval on February 27
are now contingent on full State funding of the Railbelt
intertie system. In essence, these proposed contracts merge
the Bradley Lake and intertie projects and invalidate the
Bradley Lake plan of finance which was approved by OMB, as
required by statute, in 1985. This issue is highly complex
and is discussed in detail in the body of this report.
On February 18, 1987, the Attorney General issued an opinion
which confirms that the Anchorage Municipal Light 6 Power
utility cannot commit to a power sales agreement for Bradley
Lake without advance approval of the agreement by the Alaska
Public Utilities Commission (APUC). The implications of
this ruling must be carefully considered before proceeding
with further contract awards for Bradley Lake.
a
Governor Steve Cowper
Page 4
February 25, 1986
Recommendations
• Although the projected net benefits of the Bradley Lake
project are now substantially lower than in 1985 when OMB
recommended approval of the project, our review indicates
that the project is still economically feasible and that
completing the project is likely to provide lower long term
power costs than alternative gas generation.
• However, we do not believe that additional construction or
procurement contracts for Bradley Lake should be awarded or
released for bid until final, unconditional power sales
agreements have been signed by the purchasing utilities.
The APA board is being asked to approve proposed power sales
agreements which are clearly conditional contracts, pending
legislative appropriation of funds for the Railbelt intertie
system. Obligating additional State funds for Bradley Lake
construction based on these conditional agreements appears
to violate both a legislative statement of intent which was
attached to a prior Bradley Lake appropriation, and the
formally adopted policy of the APA board of directors.
Although the APA staff has suggested that the existing
signed contracts with the Chugach and Homer Electric
Associations satisfy the requirement for unconditional
agreements, there is disagreement on the enforceability of
these contracts.
• If construction of Bradley Lake is to proceed, we feel ti re
are two basic options for the Alaska Power Authority:
(1) Negotiate with the Railbelt utilities to delete the
conditional link of the revised contracts to legislative
funding of the intertie system, and to develop a workable
power displacement agreement; or, (2) Delay the award and
bid of additional project contracts until the Legislature
acts, or fails to act, on an appropriation for the
interties. If the second option is pursued, consideration
should be given to reducing expenditures for work in
progress in order to reduce project termination costs in the
event that the Legislature fails to make the necessary
intertie appropriation and the utilities are unwilling to
accept Bradley Lake as a stand-alone project.
• Feasibility studies on the Railbelt intertie system are now
in progress and will be completed in late April. Although
the Legislature is free to appropriate funds for the
construction of the interties at any time, we do not believe
the APA should endorse or support the intertie projects
nnt.il the feasibility studies have been completed and
reviewed by the board. ro do otherwise would be to lgnoro�
Governor Steve Cowper
Page 5
February 2', 1986
the systematic project approval process which is required
under AS 43.83.177-44.83.185 and APA regulations.
Project Overview
proigct History. The Bradley Lake hydroelectric project was first
studied by the U.S. Army Corps of Engineers, beginning in the late
1950's. Although the project was authorized for construction by
Congress in 1962, no appropriations for project construction were
ever made. After efforts by the State of Alaska to develop a joint
construction arrangement with the federal government proved
unsuccessful, the Alaska Legislature approved transfer of the
project to State control in 1982.
A Bradley Lake feasibility study was completed for the Alaska Power
Authority (APA) in 1983. The study concluded that the project was
economically feasible. In 1984, the Legislature authorized
construction of the project at a cost of $300 million (in 1983
dollars). The Legislature also appropriated $50 million for
project design and construction as part 'of a four-year, $200
million appropriation later struck down by a court ruling. In
prior years, $18 million had been appropriated for project design
and licensing.
In 1985, the Federal Energy Regulatory Commission (FERC) issued a
construction license to the APA. In June 1985, conditional power
sales agreements for Bradley Lake were signed by the Chugach
Electric Association and the Homer electric Association. The
Legislature appropriated an additional $50 million for the project,
raising the total amount of project appropriations to $118 million.
In 1986, an additional $50 million was appropriated by the
Legislature, but was subsequently restricted by former governor
Sheffield in August to limit the State's growing deficit. A
contract for site preparation for the project valued at $22.9
million was awarded by the APA, with onsite work begun in June,
1986.
Cmrrent project Status.. Approximately 16 percent of the overall
pr.nject construction has been completed. The site preparation
contract is about 80 percent complete; most of the project access
roads and the airstrip have been finished; the Bradley River
diversion tunnel is nearing completion; the powerhouse site is
being excavated, and permanent project housing and offices are more
than half finished.
Bids for the turbine/generator procurement contract were opened by
the APA on January 29, but have not been awarded pending approval
by the APA board of directors and revision of certain bid elements.
Governor Steve Cowper
Page 6
February 25, 1986 a
Apparent low bid was $12 million, which is $2.5 million or 17
percent less than the project budget amount of $14.5 million.
Under the current project schedule, the main general civil
construction contract is slated to be released for bid in March and
awarded by June, with onsite work to begin in July.
Proiect Exuenditurea nd eudq�. As of January 31, 1987,
expenditures on the Bradley Lake project totalled $45,377,000. If
site preparation and project design work continues as scheduled, a
total of about $55 million will be expended by May, 1987.
The current official construction cost estimate for the project is
$356 million, in nominal or as -built dollars. The APA does not
intend to formally modify this estimate until after bids are
received for the main construction contract. However, the APA
staff believes that the official cost estimate is probably high,
for three reasons:
(1) The estimate is based on July 1983 prices escalated at
inflation factors ranging from 5.5 percent to 6.5 percent
over the course of project development and construction.
Actual inflation during 1986 was less than 2 percent and has
not exceeded 4 percent during the last four years. Even if
inflation returns to the 5.5 to 6.5 percent range during the
next several years, the completed cost of the project should
be lower than the estimate because of the low inflation
rates from 1983 to 1986.
(2) The current construction market for major projects such as
Bradley Lake is currently depressed both in Alaska and
nationally. As a result of increased competition for the
fewer projects under development, construction and equipment
procurement bids have shown a distinctly lower trend during
the last two to three years. For example, the federal
Alaska Power Administration is nearing completion of the
Crater Lake addition to the Snettisham hydro project near
Juneau, and expects to complete the project for at least 15
percent less than the original project cost estimate. Also,
the Bradley Lake site preparation contract was bid at $23
million, compared to the engineer's estimate of $33 million.
As mentioned earlier, the low turbine/generator procurement
bid was $2.5 million under the estimated cost of $14.5
million.
(3) The current project budget includes a contingency allowance
of approximately $59 million, or 17 percent of the total
project cost of $356 million. The original project budget
was based on a contingency amount of $48.7 million (14
percent); however, the amounts saved through lower than
Governor Steve Cowper
Page 7
February 25, 1986
estimated bids on the site preparation, design, and
construction management contracts have been shifted into the
project contingency for accounting purposes. Additional
reserves are still being held for the remaining work on
these contracts, but the actual savings for work completed
to date total about $10.4 million. The project contingency
allowance could conservatively be reduced to the originally
budgeted amount of $48.7 million to reflect these savings,
as this would preserve the original contingency with over 16
percent of the project completed.
Based on these three considerations, the APA project staff believe
it should be possible to reduce the total cost of the Bradley Lake
project to approximately $328 million. Our review of the staff
analysis generally supports this conclusion. However, we do not
believe that power sales agreements and legislative appropriations
emu. should be based on this lower cost estimate until it is supported
by the bids for the main construction contract.
Economic Feasibility
The key factors which determine the economic feasibility of the
Bradley Lake project, now that construction has already commenced,
are:
• The marginal cost of completing the project;
• The initial cost, escalation rate, and availability of gas
supplies in Cook Inlet; and,
• The need for new generation capacity in the Railbelt, which is
a function of trends in power demand and the requirement to
replace existing generators as they wear out or become
uneconomic to operate.
In the limited time available for this review, we have focused our
efforts on evaluating the effects of recent changes in these three
key parameters on Bradley Lake. Thus, our analysis is based
largely on previous Bradley Lake studies, with adjustments made to
account for differences in these three factors. A brief summary of
previous economic studies of Bradley Lake is necessary to provide a
basis for comparison with our analysis and conclusions.
7983 rea•ibility Study• The 1985 review by OMB of the economic
feasibility of the Bradley Lake project was based primarily on the
L983 project feasibility study prepared by the engineering firm of
Stone and Webster. This study used a sophisticated generation
planning model which calculated the relative costs of Bradley Lake
and other generation alternatives for both the Railbelt region as a
Governor Steve Cowper
Page 8
February 25, 1986
whole and the Kenai Peninsula alone. The 1983 study used the
following major assumptions in the base case analysis:
Bradley Lake Cost: $300 million (1983 dollars). Construction
financing was assumed to be obtained through the issuance of
long-term bonds at the outset of construction, with an interest
during construction cost in real terms of 3.5 percent per year.
The project construction cost was estimated to increase through
inflation at 5.5 percent to 6.5 percent per year.
Natural Gas Prices: The base case assumed that Cook Inlet natural
gas prices would increase at the following rates, starting with a
1983 price of $2.77 per thousand cubic feet (mcf). A pipeline
delivery charge of 30 cents/mcf was included in the projected gas
prices.
1985-1988 0.0%
1989-2010 3.0%
2011-2020 2.5%
2021-2030 1.5%
2031-2040 1.0%
Power Demand Forecast: The demand forecast in the base case
projected an average annual compound load growth rate of 2.8
percent from 1983 through 2010. This growth rate resulted in
projected Anchorage -Kenai Peninsula peak demand doubling from 469
MW in 1983 to 961 MW in 2010.
E.., The reference or base case economic analysis in the 1983
feasibility concluded that the net benefits of the 90 megawatt
Bradley Lake configuration for the Kenai Peninsula were $305
million, with the thermal generation alternative expected to cost
1.51 times as much as the Bradley Lake alternative. Project
benefits were discounted at a real rate of 3.5 percent and no State
subsidy was included in the benefit calculations.
8y �� 1Q86 Uy�atG• Stone and Webster conducted an additional
economic analysis of Bradley Lake in August, 1986 in order to
clarify the effect of varying natural gas prices on the feasibility
of the project. This analysis was based on a simple comparison of
Bradley Lake with a 90 MW gas turbine and did not incorporate the
complex generation planning model used in the 1983 feasibility
study.
The A gust update was based on the 'original project cost estimate
and financing method, and did not reflect the less costly variable
rate bond financing that was in effect at the time. Gas turbine
Governor Steve Cowper
Page 9
February 25, 1986
capital costs were based on a recently installed unit on the Kenai
Peninsula. The study did not consider the effect of changes in
power demand on Bradley Lake benefits.
This economic analysis compared the effect of three gas price
escalation rates: no escalation, 3 percent per year escalation, and
a breakeven escalation case of about 2 percent per year. In all
cases, the 1986 wellhead value was assumed to be $1.60/mcf. A
delivery fee of 40 cents/mcf was added to produce an expected
delivered price of $2.00 in 1986.
The analysis concluded that with 3 percent annual escalation in
real gas prices, the Bradley Lake project would produce a net
benefit of $72 million. At zero escalation, Bradley Lake would be
$87 million more expensive than gas generation. An annual increase
of 2 percent in real gas prices produced a breakeven result over
the 50 year period.
The August analysis produced much lower net benefits for the
Bradley Lake project, in comparison to the 1983 feasibility study,
because of the lower starting gas price. Even at the 3 percent
escalation rate, real gas prices projected for the year 2000 in the
August update were $2.82/mcf, compared to $3.99/mcf in the
feasibility study, or 29 percent lower.
Our Analysis. Based on data supplied by Railbelt utilities and APA
staff, we have revised Stone and Webster's August 1986 feasibility
update to incorporate different assumptions for the cost of the
Bradley Lake project and for natural gas prices.
The most important adjustment we have made in our analysis is
deducting the already committed or sunk costs of Bradley Lake from
the calculation of net benefits. While an analysis based on total
project costs is useful in that it suggests whether the project
would be undertaken now if construction had not already begun, the
real decision today is whether to complete the Bradley Lake project
at its marginal cost -- defined as the total project cost less
costs incurred or obligated to date -- or to suspend or abandon the
project and pursue gas generation or other alternatives. This type
of marginal cost analysis is appropriate because if Bradley Lake
were terminated, the projectes sunk costs could not be applied to
new gas generation; the gas plant would have to be built from
scratch at its full cost of construction and operation.
over $45 million has already been spent on Bradley Lake design,
licensing and construction. Current estimates of total sunk costs
for Bradley Lake range from $60 to $90 million, depending on the
extent of site restoration which would be required by FERC if the
project. were terminated. Using a mid -point figure of. $75 mi.]1ion,
over 20 percent of the total project cost has already been spent or
Governor Steve Cowper.
Page 10
February 25, 1986
committed, and the marginal cost of completing the project is about
$281 million ($356 - $75).
These sunk costs increase the net benefits of completing Bradley
Lake by an equivalent amount, so that from today's perspective, the
economic benefit of completing Bradley Lake is about roughly $75
million higher relative to the gas alternative than it would be if
project design and construction had not been initiated. Accounting
for the sunk costs of the project in this manner partially offsets
the effect of lower gas prices on Bradley Lake feasibility and the
decision whether to complete the project.
The second major adjustment made to the August 1986 Stone and
Webster study was to incorporate the APA's preliminary revised cost
estimate of $328 million, for a savings of $28 million (356-328).
For the reasons discussed earlier, we believe that this cost
reduction is credible and very likely to be realized if the project
is continued.
An additional adjustment which must be made pertains to fact that
financing costs for the project are now expected to be about $30
million less than was assumed in the 1983 feasibility study. The
feasibility study assumed that the construction of Bradley Lake
would be financed through the issuance of long-term revenue bonds
issued at the start of project construction. This assumption meant
that the project was expected to accumulate $21.6 million in
interest during construction charges (IDC).
When developing the plan of finance for Bradley Lake, the APA was
able to implement a much more favorable financing approach based on
the use of short-term, variable rate notes, coupled with arbitrage
earnings on the reinvestment of the borrowed funds. The net result
is that instead of paying out $21.6 million for IDC, the APA is
expected to receive about $10 million in arbitrage earnings.
Higher issuance costs reduce the net savings over the standard
bonding approach to about $30 million.
The feasibility study was correct in basing its analysis on the
standard bonding approach, because the variable rate financing
approach had not yet been approved or implemented. However, now
that this less costly financing is in place, it is necessary to
account for the resulting savings in the cost of the Bradley Lake
project. It does not appear that a similar financing arrangement
could be arranged for the alternative gas generation plant.
However, to maintain comparability, we have excluded interest
during construction costs from the calculation of gas generation
costs. Construction financing costs are a relatively minor concern
for gas generation because of its low capital cost and short
construct Lon perir)d. "'
Governor Steve Cowper
Page 11
February 25, 1986 a
Combining the $75 million estimate for Bradley Lake costs with the
additional $28 million reduction in construction costs and $30 -
million in financing costs produces a total reduction in the
marginal cost of completing Bradley Lake of $133 million.
Financing costs for Bradley Lake have always been budgeted in
addition to the $356 million construction cost estimate, so that it
is incorrect to deduct the $30 million savings in financing costs
from the $356 million construction cost estimate. The original
total cost of the project was estimated at $408.3 million ($356
million construction + $52.4 million financing cost).
The net effect of these three adjustments is therefore to reduce
the total marginal cost of completing Bradley Lake from
$408 million to $275 million, a reduction of almost one third.
Natural Gas Prices. The 1983 APA Bradley Lake feasibility study
was based on a forecast of natural gas prices prepared by Sherman
H. Clark Associates. The reference case used the following real
escalation rates:
1985-1988
0.0%
1989-2010
3.0%
2011-2020
2.5%
2021-2030
1.5%
2031-2040
1.0%
The base 1983 gas price used was $2.47/mcf, plus a 30C/mcf pipeline
transportation charge. The $2.47 figure was derived from a netback
value calculation based on the export market for liquified natural
gas (LNG).
There is widespread agreement among both the Railbelt utilities and
the Cook Inlet gas producers that both the escalation rates, in
particular the 3 percent real escalation rate from 1989 to 2010,
and the base gas prices assumed in the Sherman Clark forecasts are
too high for today's Cook Inlet gas outlook.
Views on gas escalation rates vary considerably; however, there is
a general consensus that an upper limit for the base price of new
gas supplies is about $1.70/mcf. This is the price paid by Chugach
Electric in its 1986 short-term contracts for peaking gas supplies
from the Beluga field producers. Chugach officials are confident
that they will be able to secure new long-term gas supplies at a
price of $1.70 or less.
'rhe key questions are: (1.) Is new Cook Inlcft gas likely to he
priced substantially lower than this upper limit price; and
Governor Steve Cowper
Page 12
February 25, 1986
(2) What is the most probable rate, or range of rates, at which
Cook Inlet gas prices will increase during the 50 year economic
life of the Bradley Lake project.
Figure 1 summarizes our projections of the net benefits of the
Bradley Lake project in comparison to gas -fired generation at
various prices for new gas and real escalation rates. This chart
incorporates the adjustments to Bradley Lake costs which have been
discussed: (1) the reflection of the $75 million in sunk costs in
the marginal cost of completing the project; (2) the reduction of
project financing costs based on the current variable rate
financing and arbitrage earnings; and (3) the reduction in total
project construction cost from $356 million to $328 million.
An additional important assumption incorporated in Figure 1 is that
no delivery charge is added to the wellhead price of gas; in other
words, it assumes that all new generation will be located at a
producing field. This assumption differs from both the 1983
feasibility study and the Stone and Webster August 1986 feasibility
update, which assumed that delivery charges of 30 cents/mcf and 40
cents/mcf, respectively would be added to the wellhead price of
gas. The justification for adding the delivery charge is that both
the Bernice Lake and Soldotna it generating stations now pay a
delivery charge of about 60 cents/mcf to Enstar for their gas
supplies. Chugach Electric officials believe, however, that t::ey
will be able to buy new gas supplies at a wellhead price, with no
delivery fee. For this reason, and to be conservative, we have not
included a delivery charge in the analysis summarized in Figure 1.
Figure 1 shows that at a real gas escalation rate of 2 percent and
a price for new gas of $1.40/mcf or more, Bradley Lake power would
be substantially less expensive than gas -fired generation over the
period of analysis (50 years). Net benefits range from about $50
million at a new gas price of $1.40/mcf to $100 million at a gas
price of $1.70/mcf. However, at lower escalation rates and/or
.lower base gas prices, Bradley net benefits become marginal or
negative. Each 10 cent/mcf change in base gas prices increases or
reduces Bradley net benefits by about $15 million.
The results shown in Figure 1 can be compared to Stone and
Webster's August 1986 feasibility update. The Stone and Webster
analysis concluded that at a base gas price of $1.60/mcf, plus a
40 cents/mcf delivery charge, a real escalation rate of 2 percent
annually produced a breakeven result for Bradley Lake net benefits.
Figure 1 shows that when sunk costs, reduced construction costs,
and financing savings are incorporated into the analysis, a gas
price of $1.60/mcf results in a breakeven escalation rate of about
0.3 percent per year. If the 40 cent delivery charge were added to
the gas prices shown in Figure 1, the breakeven escalation rate at
$1.60/mcf would be about negative 1.0 percent. Put another way,
Governor Steve Cowper
Page 13
February 25, 1986
Lake by about $65 million.
A sample printout of the model used to determine the net benefits
shown in Figure 1 is included in Appendix A. Because Figure 1 is
based on 24 runs of this model, we have not included the detailed
printout for each run. This model was developed by APA staff and
modified to incorporate our own assumptions on gas prices and
escalation rates.
Cook Inlet producers claim that new gas is likely to be sold at
prices which would render'Bradley Lake infeasible, but these
producers have no recent contracts to support their contention and
have an obvious interest in the termination of Bradley Lake in
order to improve the market for their gas. As a result, the
producers' point of view must be considered in light of their clear
financial interest in the fate of the Bradley Lake project.
A more objective index of the value of new Cook Inlet gas is the
gas contract negotiated in 1982 by Enstar (Alaska Pipeline
Company), which supplies gas to Chugach Electric, Anchorage
Municipal Light and Power, and the Alaska Electric Generation and
Transmission cooperative, which operates the 39 MW Soldotna it gas
turbine unit. Although the base price of the contract in 1982 was
$2.32/mcf, future gas prices under the contract were tied to the
price of fuel oil at the Tesoro refinery on the Kenai Peninsula.
This tie to current oil prices has reduced the price of gas under
this contract from $2.32 to $1.47/mcf (as of January 1, 1987).
Based on this contract, a price for new gas of $1.50/mcf appears to
be a reasonable mid -range figure. At a real escalation rate of 2
percent per year, this gas price produces net benefits for Bradley
Lake of about $70 million.
with respect to future trends in gas prices, we have referred to
forecasts by the Department of Revenue (DOR) and Chugach Electric.
DOR states in the January, 1987 petroleum revenue forecast that
Cook Inlet gas prices are expected to track crude oil prices.
DOR's projections of average crude oil prices assume average real
escalation between 1987 and 2003 of about 2.01.
DOR also makes an explicit forecast of average Cook Inlet gas
prices. This forecast, as well as that of Chugach Electric, is
shown in Figure 2. The gas prices shown in this chart are not
comparable to those included in Figure 1, because Figure 2 is in
nominal dollars and includes melded prices for all gas, not just
new gas. However, Figure 2 does indicate a fairly close
correlation between the forecasts by DOR and Chugach Electric.
In summary, the economic feasibility of the Bradley Lake project
continues to remai.n very sensitive to prices of new gas supplies
and future price trends. Although these factors are subject to a
Governor Steve Cowper
Page 14
February 25, 1986
and future price trends. Although these factors are subject to a
high level of uncertainty, current gas price forecasts by the
Department of Revenue and Chugach Electric suggest that Bradley _
Lake is still likely to be less expensive than gas generation over
the 50 year period of analysis.
Railbelt Power Demand. The decline in oil prices and resulting
slowdown in Alaska's economy has resulted in a major reduction in
demand forecasts by Railbelt utilities. For example, the Chugach
Electric Association, which two years ago was projecting load
growth of 5-6 percent per year, is now estimating that demand will
increase by an average of only 0.55 percent per year from now to
the year 2000. Similar reductions in load forecasts have been made
by other Railbelt utilities.
These lower load forecasts mean that much less additional
N generation capacity will be needed in the Railbelt over the next
ten to fifteen years than was expected two or more years ago. The
obvious question is whether Bradley Lake's power is still needed,
given the lower demand forecasts. Our research indicates that even
with flat or slightly declining demand, new generation will be
required in Southcentral Alaska in the 1990-95 period.
Because of time constraints, we focused our review of the demand
issue on Chugach Electric, which would be the major purchaser of
Bradley Lake power if the project is completed. Even with the
basically flat load forecast cited above, Chugach expects to
require at least 45 MW of new capacity by 1990. A planned
retirement of an 8 MW unit at the Bernice Lake plant accounts for a
portion of this capacity requirement. Chugach now has a contract
with Anchorage Municipal Light and Power for the purchase of 40 MW.
This contract will decline by 10 MW per year and terminate in 1990.
Chugach now plans to replace this capacity with 45 MW from Bradley
Lake, but if Bradley is not completed, gas generation would be
installed instead. Over the longer term, Chugach expects to retire
over 250 MW of existing capacity by 1997.
The effect of Chugach's lower load forecast on planned capacity
requirements is that two years ago, Chugach was expecting to need a
new. 87 MW gas plant in addition to 72 MW from Bradley Lake. Now
the utility expects Bradley Lake power to delay the need for new
gas generation until the mid-1990s.
Figure 3 shows current and projected peak demand and installed
capacity for Chugach Electric. The dotted line shows the effect of
plant retirements on total installed capacity if the plants are not
replaced.
'fwo additional points are relevant concerning the demand issue.
First, gas generation capacity is inexpensive compared to the cost
Governor Steve Cowper
Page 15
February 25, 1986 a
of fuel to run the plant. Thus, the question of excess capacity is
less important than gas price trends.
Second, the effect of demand trends on the Bradley Lake project is
much different from the hydro projects in the 4-dam pool. These
projects, with the exception of Solomon Gulch, were intentionally
constructed with generation capacities much larger than the total
demand of their service area, in order to allow for load growth.
For these projects, a decline in forecast demand produces an equal
decline in project revenues and requires higher power rates to
recover the revenue shortfall. Bradley Lake, by contrast, would be
a small portion of the demand in Southcentral Alaska and the
Railbelt, so that declining demand does not create the revenue
reduction.and rate problem that the 4-dam pool projects could face.
Power Sales Agreements
In June 1985, the Chugach Electric Association and Homer Electric
Association signed conditional power sales agreements for the
purchase of Bradley Lake power. At the time, these agreements were
presented to the APA board as binding documents, but controversy
has developed over the enforceability of the contracts and their
current legal status is unclear.
At the request of the Railbelt utilities, the APA staff has
v,. negotiated revised agreements which the board is being asked to
approve on February 27. The revised agreements have certain
favorable features, such as the inclusion of all seven Railbelt
utilities and a provision for equal sharing of project costs
between the State and the utilities, up to $350 million ($175
million each).
However, final approval of the revised agreements by the utilities
is now contingent on full State financing of the Anchorage -Kenai
and Anchorage -Fairbanks transmission interties, at a cost of up to
$200 million. This linking of the Bradley Lake power sales
agreements to funding of the interties raises two major policy
issues. First, the conditional agreements, if approved by the APA
board, would once again put the State in the position of proceeding
with project construction without final, unconditional agreements
for the sale of the project output. This situation clearly puts
the State at risk for project costs and adversely affects the
bargaining position of the State in negotiating final contracts.
Both the Legislature and the APA board have required final, binding
power sales agreements to be in place before proceeding with
project construction.
A second concern is that in accepting the revised Bradley
agreements, the Board would effectively be endorsing funding and
construction of the intertie systems before the feasibility studies
Governor Steve Cowper
Page 16
February 25, 1986 a
on the interties are completed. Such a position would conflict
„ with the APA's statutory and regulatory requirements to follow a
prescribed project approval process for any new project.
The utilities' responses to these policy concerns have been that
the intertie systems are the only way that all seven Railbelt
utilities can receive firm Bradley Lake power. We believe that a
feasible power displacement agreement could be developed which
would provide most of the benefits of the intertie systems at much
lower cost. While it is true that the existing Kenai intertie
cannot provide firm power,' the cost of maintaining reserve
generation must be balanced against the cost of the interties.
Although a displacement agreement would be a complex undertaking,
it is clearthat this option has not been adequately explored by
the utilities, because they would prefer to take advantage of $200
million in State funds for the interties. Displacement agreements
are commonly used in lower 48 grid systems, and we have seen no
firm evidence that similar arrangements could not be used in the
Railbelt.
Delaying the Project
Delaying additional work on Bradley Lake may be unavoidable,
depending on the APA board's actions and the responses of the
utilities and the Legislature. However, it does not appear that an
intentional delay in project construction of a year or more would
be cost effective. APA staff has estimated that a one year delay
would increase project costs by about $10 million, including the
expense of a FERC license amendment, escalation in construction
costs, site maintenance and other costs.
Delaying the project could also increase financing costs. The
Bradley Lake project was granted a special tax-exempt status in the
recent federal tax legislation. This exemption expires in December
1990. If the project were delayed longer than one year, long-term
bonds would have to be issued prior to project completion, rather
than after completion as planned. By placing some completion and
cost overrun risk on the bond holders, this earlier issuance of
bonds could result in higher interest rates.
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IN REPLY REFER TO:
ANC-FWE
United States Department of the Interior
Fish and Wildlife Service
Anchorage Fish and Wildlife Enhancement
Sunshine Plaza, Siute 2B
411 West 4th Avenue
Anchorage, Alaska 99501
Richard Poole
Vice President
Kenai Hydro, Inc.
P.O. Box 1776
Lummi Island, Washington 98262
— hear Mr. Poole:
MAR 2 Z MOT
Re: Grant Lake Hydroelectric Project
FERC Project No. 7633-002
The U.S. Fish and Wildife Service (FWS) has reviewed the Additional
Information and Instream Flow and Fish Habitat Analysis, both dated February,
1987. The following comments are intended to facilitate your project
planning, and supplement our previous letters on this project.
General Comments
We appreciate the efforts of Kenai Hydro, Inc., in quantifying the habitat
losses and gains attributable to the proposed project. However, as detailed
in our specific comments, we believe that additional data collection and
analysis is warranted. We have identified the following five major concerns
related to the analysis which should receive your specific attention prior to
submittal of your license application to the Federal Energy Regulatory
Commission (FERO :
1. A major assumption of the Water Surface Profile (WSP) model is that the
flows were stable during the collection of the data. When the field
measurements were taken flows were not stable, varying by 51.5 cubic feet
per second (cfs) (20.7 percent change).
2. The field data cannot be extrapolated below 98 cfs (0.4 x 246 cfs),
assurring the data are good (see S1 above). This does not allow for an
analysis of habitat at the proposed minimum flows. Also, since we are
concerned with the acceptability of the data collected, our confidence in
the modeling and stranding analysis at the lower extrapolation extreme is
low.
We are not certain of the upper limits for data extrapolation since it is
unclear where the transects begin and end. If the transects were taken
from water's edge to water's edge as indicated in the discussion (see
Additional Information page 10, paragraph 2), then the model cannot
estimate available habitat above 246 cfs. However, the data (see Appendix
A Tables 1 through 3) indicate that the transects were initiated and ended
at some point on the streambank, out of the water.
3. The data presented in Appendix A is questionable. The greatest velocity
in the field data is 5.95 feet per second (fps). However, the discussion
reports velocities ranging from 0.32 to 6.62 fps (see Additional
Information page 11, paragraph 6).
4. The habitat suitability curves are questionable. Detailed comments are
provided in our Specific Comments section.' These curves, and curves which
are not presented (e.g., substrate) are the basis for all habitat values
analysis and, with the noted errors, the habitat values are unreliable.
5. The stranding analysis is not clear. The reference cited is unpublished,
and the methodology is thus essentially unknown. A detailed explanation
of the methodology should be provided, or the reference attached.
Specific Comments on: Grant Lake Hydroelectric Project Additional
Information, dated February 15, 1987.
Page 1; paragraph 3: Salmon spawning and rearing were identified above the
outlet of the proposed tailrace facility during the 1981-1982 studies (see
page E-3-21 of the Grant Lake Hydroelectric Project license application). A
properly designed tailrace facility and acceptable instream flow regime should
mitigate for the loss of this habitat.
Reference is made to maintaining flows, . by alternate means " in
the event of a shutdown. The design of this bypass device and its design
-- capacity should be provided. The outlet should be into the tailrace facility
to maintain the habitat provided.
Page 3; paragraph 4: This is a misrepresentation of the Tenants Method.`
What is not indicated is that different flow rates are set for different
seasons. The Tennants Method could be used to support instream flow
recommendations of 200 cfa and 100 cfs for this project.
Page 4; paragraph 4: To evaluate the adequacy of the bypass pipe it would be
useful to know the discharge rate and the situation the fish would be released
to (i.e., would the fish have to survive a 100-foot free fall, or would they
be released into a relatively tranquil setting). Flows need to be provided to
the tailrace to maintain the habitat created. Consideration should be given
to having one bypass structure, releasing into the tailrace channel.
Page 5; paragraph 1: The referenced meeting minutes were not attached.
Please provide a copy of these minutes.
Page 7; paragraph 7: The study would have more credibility if the data had
been collected when the discharge was 100 cfs to 125 cfs as recommended by the
agency personnel at the October 21, 1986, meeting and on October 23, 1986, at
the site survey. Kenai Hydro, Inc., was informed on site that the water was
too high to model the lower instream flows being proposed.
Page 10; paragraph 2: It is indicated that the ends of the transects were
located at the water's edge. If this is true then the WSP model cannot
estimate habitat for flows greater than those that were measured. The model
has no information of a higher streambank to spread water over during higher
w discharge amounts. This deficiency in data collection limits the
applicability of the model to the range of 246 cfs to 98 cfs (0.4 x 246 cfs).
This limitation means that the WSP model will not be able to model habitat
availability under average winter flows, average summer flows, project
proposed winter minimum flows and high with —project operating flows. However,
Appendix A Tables 1 through 3 and the cross —sectional profiles (page 20)
indicate that the transects did extend shoreward from the water surface. This
apparent discrepancy should be clarified. We strongly recommend that a second
set of data be obtained to verify the original data set, extend the landward
ends of the original transects to allow modeling of higher flows (up to the
extrapo limits of 615 cfs), and to extend the modeling limits down to the
proposed 50 cfs winter minimum flows.
Page 11; paragraph 2: It is stated that the flows dropped from 297.3 cfs to
245.868 cfs, a decline of approximately 21 percent during the data collection
period. This violated a major assumption of the WSP model, that the data be
collected during stable flows. Although unstable flow data can be
mathematically corrected, the magnitude of the change in the flow measurements
decreases our confidence in it, and further justifies an additional set of
data.
Page 11; paragraph 6: The velocities are reported as ranging from 0.32 to
6.62 fps. However, the greatest velocity shown in the field data (Appendix A
Table 1) is 5.95 fps. We have assumed that the FLOW READING column of
Appendix A Table 1 is mislabeled and is velocities (fps) and not discharge
(cfs). If this assumption is incorrect than the total discharge is only about
50 cfs rather than 246 cfs as reported.
Page 13; paragraph 6: Please provide a reference for the statement, "During
this period egg incubation is occurring and for the four month period the eggs
-ire essentially in a holding phase due to the low temperatures which limit
`--development."
Page 21; paragraph 1: It is stated that March is a low target energy and
capacity month. However, projected discharges (see Figure IV 16—A) are shown
as approximately 200 percent higher than what was proposed in the license
application. Please discuss these discrepancies.
Page 21; paragraph 3: In consideration of the lack of confidence that could
be placed on the data collected we cannot concur with the conclusion that
proposed project flow changes would not result in stranding. Additional
discussion should be provided relating the stranding analysis in the instream
flow report (page 24) to the proposed ramping rates.
Page 23; paragraph 1: Additional discussion should be provided concerning
temperature —related project impacts.. Based upon accumulated temperature units
with the project versus natural temperature regimes (without project), time to
hatching of chinook enbryos would be nearly unaffected (October 23 with
project versus October 29 without project). However, the amount of time for
fry to reach the button —up stage would he greatly affected (March 27 with
project versus May 28 without project). These estimates of hatching and
button —up times were calculated from the temperature curves, Figure 2-6A, and
assumes a spawning date of August 21.
Page 25; paragraph 5: We consider the tailrace channel as mitigation for the
loss of habitat upstream of the tailrace outfall. As such, spawning and
incubation conditions must be maintained throughout the life of the project.
That is, gravels lost during flood flows would have to be replaced, weirs
maintained, and an instream flow regime would need to be provided. The
channel should be designed so that a minimum depth of one foot is maintained
during the spawning period and sufficient flow'is provided during incubation
to wet the spawning gravels and prevent freezing. In addition, an emergency
water source to this channel would be required to maintain flows in the event
of project shutdown.
Page 27; paragraph 5: Please reference our comments immediately above. We
consider the habitat provided by the tailrace channel to be a mitigation
feature.
Specific Comments on: Instream Flow and Fish Habitat Analysis for Grant
Creek, Alaska in Relation to a Proposed Hydroelectric Facility, dated
Februarv. 1987.
Page 1; paragraph 1: The Grant Creek weir intercepted 1,113 coho salmon
during the 1985 season. Of these, 73 percent (812 fish) were attributed to
the release of fry into Grant Lake. The remaining 300 fish may be either
natural Grant Creek stocks or strays from adjacent systems. However, in
consideration of the number encountered it should be assumed that these fish
encompass a natural Grant Creek stock.
Page 3; Figure 1: The anticipated occurrence of the "High" and "Low" flows
should be indicated (e.g., one -in -ten-year events).
Page 9; paragraph 4: We disagree that an analysis based upon the requirements
of chinook and sockeye salmon would be representative for rainbow trout.
Rainbow trout spawn in the spring under different flow conditions and are not
at all represented by the discharge/habitat relationships of chinook or
-' sockeye salmon. It would be appropriate, therefore, to add rainbow trout to
the list of species for evaluation.
Page 10; paragraphs 3 and 4: Habitat suitability curves for substrate should
be provided. It is stated that all substrate less than 12 inches is
suitable. This is not true for sockeye salmon and may not be true for chinook
salmon in Grant Creek. Studies of the tributaries of the middle Susitna River
(Estes and Vincent -Lang 1984) assumed a curve for chinook based upon the
following:
6.5
inches
0.1
index
rating
8.5
inches
1.0
index
rating
12.5
inches
0.15
index
rating
13.5
inches
0.0
index
rating
It is recommended that the suitability criteria used in this study be
re-examined and verified with a biologist familiar with the fisheries in the
Grant Creek drainage.
Page 12; Figure 2: The habitat suitability curve for depth developed for
tributaries of the middle Susitna River (Estes and Vincent -Lang 1984) uses a
rating of 1.0 at a depth of one foot. Please discuss why a depth of two feet
is used for attaining an index rating of 1.0 in Figure 2. Curves should be
validated with the assistance of a field biologist familiar with the Grant
Creek drainage.
Page 13; Figure 3: The habitat suitability curve for chinook fry (juveniles)
51 to 100 mm does not agree with Burger et al. (1983). Please provide a more
accurate rendition or discuss why a curve which is radically different from
the data referenced was used.
Page 15; Figure 4: The suitability curves appear to be mislabeled. Please
review and correct the curves.
Page 17; Table 1: Although the periodicity table shows the "Egg Incubation
and Early Intragravel" life stage for chinook and sockeye salmon, no analysis
is presented for this stage for either species. This table should show all
species and life stages to show that those included in this study represent
all other species and life stages utilizing the drainage system. Please
provide these analyses and information.
Page 18; paragraph 1: Please refer to our comments on the Additional
Information page 10, paragraph 2. Depending upon the extent of the transects
away from the water's edge, the extrapolation limits of the data gathered may
be as narrow as 246 cfs to 98 cfs.
Page 18; paragraph 2: The stranding analysis is not clear. The methodology
is essentially unknown. Please provide additional discussion on this
methodology and its underlying assumptions.
Summary
During the discussions held on October 21, 1986, between representatives of
Kenai Hydro, Inc., and the FWS, Alaska Department of Fish and Game, and the
National Marine Fisheries Service it was concluded that one set of transects
may be adequate to model the habitat contained in Grant Creek and evaluate
project related impacts to that habitat. The probability of additional
transects being needed to adequately accomplish the modeling was also
discussed at that time (see Additional Information page 5, paragraph 2; page
7, paragraphs 1 and 5; page 9, paragraph 2; and Instream Flow and Fish Habitat
Analysis page 4, paragraph 2). We have concluded that, based upon the
concerns expressed in this letter, a second set of data is needed to extend
the transects out from the water's edge, allowing quantification of habitat
availability during average summer flows and high with -project flows, and to
validate the model for the lower flow conditions. Actual depths and
velocities, as measured in the field, for a discharge of 50 to 125 cfs should
be compared to the estimates from the model for the same discharge.
Additional details should be provided on the tailrace channel. Instream flow
requirements for Grant Creek should also be appropriate for maintaining the
tailrace channel habitat for spawning and incubation. The mitigation plan
should provide for monitoring, and maintenance of this feature throughout the
project life.
Thank you for the opportunity to comment on the Grant Lake Hydroelectric
Project Additional Information and the Instream Flow and Fish Habitat
Analysis. Please provide this office with a copy of the complete draft
license application prior to its submittal to the FERC. If you wish to
discuss our comments, you may contact Mr. Leonard P. Corin, of my staff, at
(907) 271-4575.
Sincerely, �JJ���� v r� "
Field Supervisor
cc: The Honorable Kenneth F. Plumb - FERC - Washington, D.C.
Mr. Robert LaResche - APA - Anchorage, AK
Mr. Eric Eisen, Esq. - Birch, Horton, Bittner, Pestinger & Anderson -
Washington, D.C.
Mr. Russ Redick - Alaska Sport Fishing Assoc. - Anchorage, AK
Mr. Robert Alder, Esq. - Trustees for Alaska - Anchorage, AK
Mr. Geoffrey Y. Parker, Esq. - Anchorage, AK
Ms. Catherine Dennerlein - Wildlife Federation of Alaska - Anchorage, AK
Mr. Ron Morris - NMFS - Anchorage, AK
Mr. Ben Rosenthal - WS - Juneau, AK
Mr. Dan Wilkerson - ADEC - Anchorage, AK
Mr. Don McKay - ADF&G/Habitat - Anchorage, AK
Mr. Gary Prokosch - ADNR/SCRO Water - Anchorage, AK
Mr. Tom Mears - CIAA - Soldotna, AK
USDI - Office of the Solicitor - Washington, D.C.
FWS - Office of the Director - Washington, D.C.
FWS - Regional Director - Anchorage, AK
I STEVE COWPER, GOVERNOR
/I"ADA&U 1'MEWT O FISH AND GAME
319 HASI'ULHIIY IILIA H
ANCHORAGE, ALASKA 995181599
PHONE: (907) 344-0541
April 1, 1987
Mr. Richard Poole
Kenai Hydro lnc.
P. O, Box 1776
Lummi Island, Washington 98262
Dear Mr. Poole:
The Alaska Department of Fish and Game (ADF&G) has reviewed
the information submitted to the Federal Energy Regulatory
Commission on 17 February 1987 for the Grant Lake
Hydroelectric Project (Project No. 7633-002).
Our primary concern is the instream flow report. The
document is difficult to evaluate due to incomplete and or
lack of documentation to support the analyses. It had been
originally suggested that you use data from one low flow
measurement to run their WSP model and collect additional
data to test the validity of using the WSP analysis. The
additional flow data were to be collected to test the
calibration range of their model. From the data presented,
it appears the calibration data were collected during a
period of higher flows than suggested and during a period of
higher flow variation than is recommended by the IFG.
Therefore, a major assumption of the WSP model appears to
have been violated because field data were collected during
a period of unstable flow conditions.
The discussion of methods on page 10 suggests that
measurements along transects were initiated at the waters
edge. However, field data in Appendix A and plotted in
Figure 5 (Instream Flow Report) suggests that some
elevations were measured above the water level. These two
concerns cause the validity of the data and the analysis to
be questionable. The analysis of flows cannot be
extrapolated for flows above the elevation of the stream
cross sections that were measured. These basic problems
need to be clarified. Additional field data may need to be
collected to support the analysis.
The Tennant analysis was not presented properly, nor is it
clear why or how it fits into this report. It should be
Mr. Richard Poole -2- 4/1/87
stressed that the Tennant analysis is a good method when
adjusted to regional hydrological conditions, but it does
not provide a basis for evaluating ramping effects.
Habitat suitability curves used in the analysis need to be
evaluated and revised. Some curves are mislabled. The
depth suitability curve to chinook spawning should be
revised. Estes and Vincent -Lang (1984) report a depth of
1.0 ft. to have a suitability value of 1.0 for tributaries
of the Middle Susitna River. These streams are similar in
size to Grant Creek.
Once these problems have been addressed we recommend that an
additional set of data be collected for a discharge of 50 to
100 cfs and that these be compared to estimates from the
model at the same discharge. This would indicate how well
the model predicts below 100 cfs.
A more complete description of project design is required so
that mitigation requirements can be more completely
addressed. Perhaps this could be addressed by combining the
instream flow report into the license application. We are ✓
particularly interested in the design of the tailrace to
evaluate the quantity of spawning and rearing habitat that
this project feature will provide. We are also interested
in how water will be maintained in the tailrace during
periods when the plant is not operating.
The discussion of ramping rates needs to be revised to
include an analysis of the change of flow on fish habitat.
Although it is stated that flow would change at a rate of
not greater than 100 cfs per hour, there is no discussion of
the effects of this change on habitat and fish.
The following specific questions and comments are provided
for your consideration.
Page 4 - Does the project design include a bypass around the,,
turbines to the tailrace?
Page 10 - It is stated that "The ends of the transect were
established by measuring water level at each end of the
tag line prior to commencing the measurements across i
the stream." However, the field data in Appendix A
indicates some measurements were collected beyond the
waters edge.
Page 11 - It is stated that the stream flow dropped 46 cfs
during the period measurements were taken. This
appears to violate an assumption of stable flow for the
WSP model.
Mr. Richard Poole -3- 4/1/87
Page 19 - The information on the return of coho salmon to
Grant Creek in 1986 is incomplete. Cook Inlet
Aquaculture Association estimated that 846 coho
returned in 1986. Therefore the number of fish that
were estimated to have returned from the stocking of
fry in Grant Lake in 1984 is 79 percent of 846 or 668.
The remainder of the escapement is thought to be fish
naturally produced or from the lake stocking in 1983.
Page 25 - Based on more complete analysis of project impacts
that will occur in the future, it may be necessary to
plan Lo maintain spawning and rearing Habitat In the
tailrace.
Should you wish to discuss these comments, please contact me
in Anchorage at (907) 267-2284.
Sincerely,
\\ V"-J �
'm C �c ..--)
Donald O. McKay
Habitat Biologist
Habitat Division
267-2284
cc: B. Deibel, FERC
C. Estes, ADF&G
B. Hauser, ADF&G
L. Corin, USFWS
B. Smith, NMFS
S. Lyons, USFWS
UNITED STATES DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
�.,�,•''7 National Marine Fisheries Service
P.O. Box 1668
Juneau, Alaska 99802
April 6, 1987
Mr. Richard Poole
Kenai Hydro, Inc.
P.O. Box 1776
Lummi Island, WA. 98262
Dear Mr. Poole:
We have received the Additional. Information - Grant Lake
Hydroelectric Project, February 1987. We assume materials
presented here will be incorporated into the project application
as an amendment as outlined in your letter dated July 23, 1986.
Having reviewed this document, we offer the following comments.
General
The report on habitat/flow relationships for chinook and sockeye
salmon provides valuable information on project impacts. The
quality of these data and the confidence which can be applied to
its extrapolation are limited, however. These failings appear
to be due to a significantly reduced streamflow which occurred
during the time of recording, and to the limits of the hydraulic
model itself, given one data point. Considering these limita-
tions and the fact that habitat suitability curves used were
developed on other systems, some error in the WUA projections is
expected. The information quality could be improved, however,
if additional measurements are taken at other flows, as previ-
ously recommended by our agency and others.
Cross -sectional profiles themselves might provide the most
useful available information. These profiles indicate that
project flows would reduce the area available to adult chinook
salmon during spawning periods. On the benefit side, it is
likely the effective spawning area would be less diminished, as
the extreme minimum winter flows would be avoided. To allow a
more informed view of actual project impacts from salmon
spawning to egg survival, it would be useful to generate an
incubation curve to quantify any change with respect to egg
survival.
S eci.fic Comments
page 3, para. 4.
How has increasing stream flow to optimize spawning requirements
been considered in the monthly operational scheme? We note th
K
August, September, and October powerhouse releases have been
reduced from those previously presented (Figure IV-16 of the
December 1984 FERC license application). September flows are
less than one half that originally proposed.
page 5, para. 1.
We cannot locate the referenced minutes from the subject meeting
within the appendix.
page 7, para. 7.
We question the statement that "Due to the timing, Kenai Hydro
collected stream data October 2.7, 1986 at approximately stations
5 and 6". Kenai hydro was repeatedly informed of the need to
gather flow data in a valid manner, including taking measure-
ments after flows had stabilized. These measurements were not
made during steady flow and have therefore violated a major
assumption of the WSP model.
page 21, para. 1.
March is described as being a low target energy and capacity
month; however, project flows (fig. IV 16-A) show high March
releases, a 200 percent increase above the flow originally
proposed. Why is this flow so high?
page 21, para. 2.
It is misleading to state that minimum flow requirements have
been developed for these species. Although it is appropriate to
select chinook and sockeye salmon as flow (IFG) evaluation
species, consideration of other species, including rainbow
trout, must also occur. We anticipate any revisions to the
proposed release schedule necessitated by this evaluation would
be done during the latter stages of licensing.
page 21, Ramping rates.
Changes in powerhouse flow must not adversely impact spawning,
rearing, incubation, or migration. Based on the stranding
information provided, we have some concern for flow changes when
powerhouse releases are at or below 120 cfs. It may be prudent
to limit the maximum rate of change to 10 cfs per hour for any
decreases from powerhouse flows at or below 120 cfs. More
discussion is necessary to relate the information in this
section to the stranding analysis.
page 24, Project Discharge Temperatures.
The revised temperature data are significantly changed from that
presented in the original license application. We are pleased
you have incorporated the multi -level intake feature into the
revised plan and believe it should lessen adverse impacts to
downstream fisheries.
page 2.7, para. 1.
The collection and release of juvenile fish through the by-pass
system/fish egress facility by means of an inclined screen is
acceptable. It may not be advisable, however, to release these
3
fish at the suggested point in the canyon. Would 5.8 cfs be
sufficient flow to pass these fish downstream from this point?
Additionally, if the powerhouse tailrace is designed as a
mitigation feature by providing spawning habitat, it will he
necessary to provide an emergency water source to this channel.
In this case, it may be possible to combine the fish by-pass and
emergency flow systems.
page 27, para. 7.
We strongly support plans to develop the tailrace to accommodate
chinook salmon spawning. Detailed plans for this feature should
be developed and should include provisions for emergency flow
during shut -down, energy dissipation to minimize erosion, and a
long-term operation and maintenance plan.
Instream Flow and Fish Habitat Analysis
page 3 - flows The low and high flows presented should be
one -in -ten statistical events.
page 10, para. 4. Chinook Adults.
The assumptions regarding spawning depths used in this report
serve to minimize project impacts to chinook spawning habitat.
It does not seem conservative to consider 0.5 feet the minimum
depth for spawning. Based the research discussed here, it would
be more conservative to set 1.0 feet as the minimum spawning
depth. It is apparent from the cross -sections in figure 5 that
post project WUA would fall considerably if the 1.0 foot, rather
than 0.5 foot minimum depth was used.
page 16, para. 3.
In scaling the downstream transect to meet the data gathered
from transect 1 and 2, were the depths as well as velocities
scaled by the 246/297 ratio?
< Appendix
Fig. IV - 16A
The proposed project flows should be depicted as a range of
monthly or weekly flows within the limits bounded by 1 in 10
events and/or recommended minimum flows. It will be necessary
for a project flow regime to be developed which considers the
results of the fisheries analysis. The proposed August and
September flows are significantly lower than the original flow
releases as shown in fig. IV-16 of the December 1984 License
Application. This lowered flow will also decrease the WUA
values for chinook salmon, as spawning habitat will be reduced.
Similarly, flow decreases in October may not benefit spawning
coho salmon. How can the regulated reservoir operation ele-
vation remain exactly the same as the original application even
though significant flow changes have been made? In summary, we
question the accuracy of the projected discharges, and recommend
that further discussion be presented on this important issue.
0
Appendix A. Field Data from Kenai. Hvdro.. Inc.
The data presented appear questionable and the recording
procedures improper. on table one, no figure is given as to the
date or time of measurement. No scale is presented for the
DISTANCE column. The FLOW READING column is listed as being
CFS; however we would think these figures should be in feet per
second. Also, the transect seems to have begun at water's edge.
Without extending measurements beyond the stream channel, it is
impossible for the WSP model to predict flows above that
measured. Because of this discrepancy, we are unable to
understand how these data could be used to generate the cross -
sectional profiles for flows of 300 cfs (page 20). The velocity
range presented on page 11 (0.32 to 6.62 fps) does not seem to
agree with figures in the FLOW READING column; i.e., these
figures do not appear. The total transect lengths of 65, 70,
and 86 feet differ from figure 2 (page 12) which depicts lengths
of 63, 70, and 72 feet.
Summary
We find the additional information presented furthers our
understanding of the potential impacts resulting from the Grant
Lake Project. We believe that confidence in the hydraulic model
might be improved through additional data gathering and updated
runs through the existing model. This would allow verification
of the model and perhaps, improve its applicability to lower
flows. Specifically, we recommend additional measurements be
made at the existing transects at flows between 100 and 150 cfs.
Using this information and a detailed projection of proposed
powerhouse flows, a project flow regime should be developed
which accommodates evaluation species. It appears that minimum
flows of 50 to 100 cfs would only be experienced during
shut -downs. Thus it is important to evaluate actual project
flows. We feel this project has the potential to benefit some
species through flow regulation, (moderating extremes), through
thermal changes, and through structural means. While the
revised plan to locate the powerhouse release into Grant Creek
has greatly reduced potential. impact, it is important to
quantify all habitat gains or losses and prepare a plan to
mitigate adverse impact. The development of a chinook spawning
channel within the tailrace looks to be a very promising
mitigation feature. A detailed mitigation plan, incorporating
this feature and describing monitoring and mai-ntenance efforts
should be presented in the revised application amendment to
FERC.
We appreciate Kenai Hydro's effort to address our original
comments on the economic feasibility analysis. Significant
aLrldes have been made with respect to the use of a more
appropriate interest rate for debt service estimation, the
provision of a financial plan, and clarification of differential
transmission loss rates utilized in calculating the relative
J
performance of the several alternative sources of electrical
power considered in that analysis. However, we continue to have
serious concerns about the economic feasibility analysis. As we
pointed out in our original remarks, dated necemhnr 1, 198fi, the
continued reliance upon 1981-1982 data for development of
assumptions on oil and gas price trends, which are clearly
inappropriate given market performance over the period 1982-1987
and current industry projections, place the entire resultant
"comparative economic analysis" in doubt. We urge you to review
our original comments on the economic feasibility analysis and
incorporate the most recent information available in reexamining
the comparative economics of the Grant Lake project.
We hope these comments will assist you in your licensing
efforts. Please call us if we can answer any questions. We.
request a copy of the complete draft License Application be
provided for our review prior to submittal to FERC.
Sincerely,
Y � �
i
tl� RcSbezt W. McVey c/
J irector, Alaska Region
Instream Flow and Habitat Analysis
Grant Lake Hydroelectric Project
Kenai Hydro, Inc.
Prepared by
nvirosphere Company '
0900 N.E. 8th Street'
......................................:
...........................................
vue, Washington 98004
(206) 451-4600
April 1987
INSTREAM FLOW AND
FISH HABITAT ANALYSIS
GRANT LAKE, HYDROELECTRIC PROJECT
PREPARED FOR
KENAI HYDRO, INC.
BY
ENVIROSPHERE COMPANY
10900 NE 8TH STREET
BELLEVUE, WASHINGTON 98004
APRIL 1987
5192a
TABLE OF CONTENTS
1.0 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . .
1.1 BACKGROUND . . . . . . . . . . . . . . . . . . . . . .
1.2 OBJECTIVES . . . . . . . . . . . . . . . . . . . . . .
1.3 SCOPE OF STUDY . . . . . . . . . . . . . . . . . . . .
2.0 APPROACH . . . . . . . . . . . . . . . . . . . . . . . . .
2.1 EXISTING DATA . . . . . . . . . . . . . . . . . . . .
2.1 .l Discharge . . . . . . . . . . . . . . . . . . .
2.1 .2 Habitat . . . . . . . . . . . . . . . . . . . .
2.1.3 Fish . . . . . . . . . . . . . . . . . . . . .
2.2 FIELD DATA COLLECTION . . . . . . . . . . . . . . . . .
2.3 FISH HABITAT SUITABILITY CURVES . . . . . . . . . . . .
2.3.1 Chinook . . . . . . . . . . . . . . . . . . . .
2.3.2 Sockeye . . . . . . . . . . . . . . . . . . . .
2.4 TIMING OF LIFE HISTORY STAGES OF
CHINOOK AND SOCKEYE SALMON IN GRANT CREEK . . . . . . .
2.5 DATA ANALYSIS . . . . . . . . . . . . . . . . . . . . .
3.0 RESULTS . . . . . . . . . . . . . . . . . . . . . . . . . .
4.0 CONCLUSIONS . . . . . . . . . . . . . . . . . . . . . . . .
5.0 REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . .
APPENDIX A - SUMMARIZED FIELD DATA FROM KENAI HYDRO INC.
APPENDIX B - MODEL INPUT DATA
5192a
ii
Page
1
1
2
4
6
6
6
6
7
11
11
11
14
17
19
22
35
37
LIST OF FIGURES
Page
Figure
No.
1
NATURAL (AVERAGE) AND WITH PROJECT FLOWS (WITH
PROJECT "HIGH," "AVERAGE," OR "LOW" REFER TO THE
TYPE OF WATFR YEAR THAT TIIE BASIN IS EXPERIENCING)
3
I2
HABITAT SUITABILITY FOR CHINOOK ADULTS
12
3
HABITAT SUITABILITY FOR CHINOOK JUVENILES
15
4
HABITAT SUITABILIIY IOR S(ILKLYL ADULTS
16
5
CROSS -SECTIONAL PROFILES FOR GRANT CREEK TRANSECTS.
STATION 0+00 = DOWNSTREAM TRANSECT, 0+33 = MIDDLE
TRANSECT, AND 0+52 = UPSTREAM TRANSECT
23
6
WEIGHTED USABLE AREA (WUA) FOR SPAWNING CHINOOK
SALMON
24
I7
WEIGTHED USABLE AREA (WUA) FOR REARING JUVENILE
CHINOOK (35-50 mm) IN GRANT CREEK
25
8
WEIGHTED USABLE AREA (WUA) FOR REARING JUVENILE
N
CHINOOK (50-100 mm) IN GRANT CREEK
26
9
WEIGHTED USABLE AREA (WUA) FOR SPAWNING SOCKEYE
SALMON
28
10
POSSIBLE COMPARISON OF KENAI HYDRO DATA TO CIAA
DATA AT TRANSECT 1 (3 FIGURES - A, B, and C)
29
11
CHANGE IN STRANDING AREA FOR GRANT CREEK
CHINOOK FRY (35-50 mm)
33
12
INCREMENTAL CHANGES IN STRANDING AREA FOR GRANT
CREEK (INITIAL DISCHARGE IS 450 CFS. THE
FLUCTUATION AMPLITUDE IS THE DECREASE IN CFS
FROM 450 CFS)
34
5192a
iii
LIST OF TABLES
Table
No.
1 LIFE fIISIURY PIWA LS UI CHINOOK AND SOCKEYE SALMON
IN GRANT CREEK,
5192a
iv
Page
f7
1.0 INTRODUCTION
1.1 BACKGROUND
Grant Lake is located in the central part of the Kenai Peninsula,
Alaska approximately 1.5 miles due east of Moose Pass and 27 miles
northeast of Seward. This lake is drained by Grant Creek, which flows
for about one mile from the outlet of Grant Lake to the Trail Lakes
system. The upper portion, approximately one-half mile, of Grant Creek
flows through a narrow canyon. The steep gradient and falls within the
canyon are a complete barrier to upstream migration of fish into Grant
Lake. Lower Grant Creek is utilized, to a limited extent, by chinook
(Oncorhynchus tshawytscha) and sockeye (0. nerka) salmon. Rainbow
trout (Salmo gairdneri) and Dolly Varden (Salvelinus malma) char have
also been noted to exist (Alaska Power Authority (APA) 1984).
Evaluations are currently underway by the Cook Inlet Aquaculture
Association (CIAA) to determine if a coho planting program is viable
for this site. In recent years, artificial introduction of coho
(0. kisutch) fry in Grant Lake has resulted in returns to the lower
portion of Grant Creek. The objective of these plantings has been to
utilize the potential rearing capacity of Grant Lake to supplement
existing runs in the Kenai River system.
Kenai Hydro, Inc. has proposed to develop a hydroelectric project at
this site. The project would take advantage of the head that could be
created by the sharp drop in elevation between Grant Lake and the Trail
Lakes system. The intake for the project would be on Grant Lake. The
water would be conveyed to a powerhouse on Grant Creek. The discharge
from the powerhouse would be upstream of the area most utilized by fish
in Grant Creek.
This general site has been studied previously for potential hydropower
development. In 1980, the City of Seward examined the site. For this
5192a
feasibility stud), fish habitat in Grant Creek was only briefly
considered, primarily because with the preferred alternative, most of
the water would be conve)ed to a powerhouse on Upper Trail Lake,
thereby leaving Grant Creek mostly dewatered.
The Alaska Power Authority (1984) also examined the site and performed
extensive environmental and engineering field investigations. The
Power Authority's preferred alternative was similar to that for the
City of Seward in that a powerhouse would be sited on Upper Trail Lake,
thus significantly reducing flows or dewatering Grant Creek. The Power
Authority study examined the resources of Grant Creek and performed
some general instream flow analyses, primarily those of Tennant
(1976). This methodology provides a habitat quality designation based
on given percentages of the average monthly discharge.
1.2 OBJECTIVES
Kenai Hydro's project differs from previous preferred alternatives in
that the powerhouse will be on Grant Creek. Thus, under this proposed
siting, water would not be removed from Grant Creek. However, the
existing flow regime would be altered. Figure 1 shows the average
natural discharge over the 33 years of record (11.5 years of USGS
records at Grant Creek and 22 years of synthesized data from the Power
Authority studies (1984)). This figure also shows anticipated average
with -project discharges for years when low, average, and high amounts
of water are available in the watershed.
The natural flow regime has peak flows in the summer with June, July,
and August being the peak months. The highest discharge occurs in
July, with an average of 504 cfs. In contrast to these high flows,
winter discharges are very low, ranging down to 27 to 41 cfs (averaged
from January to April).
5192a
2
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With -project flows would decrease the summer flows and increase the
winter flows. Minimum flows of 50 cfs from October through April and
100 cfs from June through September have been proposed by Kenai Hydro
(and di;ru,,rl with Ilir rr.ouiIV I(IVn( inf.) a, providinq adrvpntr, fi'.h
habitat in Grant Creek.
The U.S. Federal Energy Regulatory Commission (FERC) has requested that
an instream flow study be performed for, this project. The study is to
encompass a quantification of the relationship between the amount of
suitable habitat and flow for each life history stage of salmon and
trout present in Grant Creek. In addition, the FERC requested that an
identification be made of the physical habitat type that is limiting
production in Grant Creek.
In initial consultations between Kenai Hydro and resource agencies (the
National Marine Fisheries Service (NMFS), Alaska Department of Fish and
Game (ADF&G), U.S. Fish and Wildlife Service (USFWS), and U.S. Forest
Service) concerning the FERC request, daily fluctuation of discharges
in the area downstream of the powerhouse was also identified as a
potential area of concern and in need of analysis.
As a result of the above requests or consultations, it was decided to
1) quantify the relationship between suitable habitat and flow for each
life history stage of key fish species in Grant Creek, and 2) develop
the relationship between daily fluctuations and potential fry
stranding. Both analyses were to be conducted based on data collected
for the Instream Flow Incremented Methodology (IFIM, Bovee and Milhous,
1978).
1.3 SCOPE OF STUDY
Kenai Hydro conducted the initial consultations with the resource
agencies and performed the field investigations related to the IFIM
study. Envirosphere Company was contracted to analyze the field data
5192a
4
and provide results cf the ccmputer analysis for fish Weighted Usable
Area (WUA) and stranding. Results presented in this report are
considered provisional pending agency review and comment.
5192a
5
2.0 APPROACH
2.1 EXISTING DATA
A considerable amount of data is available on the physical, chemical,
and biological attributes of the the Grant Lake/Grant Creek system. A
major portion of this information was developed during the Power
Authority's feasibility analysis of the site (APA 1984) and in
association with recent evaluations by the Cook Inlet Aquaculture
Association (CIAA) concerning the introduction of coho salmon to the
Grant Lake system. In addition, the U.S. Geological Survey maintained
a stream gage on Grant Creek for 11.5 years starting in 1948.
i
Following is a brief sketch of information available from past studies.
2.1.1 Discharge
In addition to the 11.5 years of USGS records, the Power Authority
synthesized an additional 22 years of data using the HEC-4 Monthly
Streamflow Simulation Model. This modeling effort incorporated
streamflow information from other, nearby systems. The Power Authority
also installed continuous recording gaging stations during their
feasibility studies.
2.1.2 Habitat
The Power Authority aquatic studies of Grant Creek involved collection
of information on the presence and distribution of fish species,
periphyton, and macroinvertebrates. Particular attention was given to
spawner surveys for adult salmon and abundance of juvenile salmonids.
In general, fish habitat studies in relation to instream flow were
restricted to a brief examination of optimum flows based on Tennant's
Method (1976). As previously mentioned, the reason that more extensive
5192a
11
studies were not undertaken was that discharge from the Power
Authority's preferred project would be into Upper Trail Lake; thus,
Grant Creek would essentially be dewatered and the existing habitat
lost. The Power Authorlty planned to mitigate this loss by several
means described in the feasibility report (APA 1984).
2.1.3 Fish
The Power Authority's studies did establish information about the
existing fish resources of Grant Creek. Important information for the
salmon and trout (including char) can be summarized as follows:
Chinook
1. Adults
a. Spawn during August and September
b. Based on surveys by ADF&G (1952 to 1981)'and the Power
Authority in 1982 (APA 1984), the average peak salmon spawning
ground count for the creek over these years was 19 fish. Weir
counts by the CIAA indicate that this number may be somewhat
larger, but generally indicate that there are less than 50
adult chinook that return each year.
2. Juveniles
a. Juveniles (age 1+) have been observed throughout the year
(APA 1984); however, the low numbers observed during March,
May, and June suggest that they are either very inactive
during these months or they have left the system to rear
elsewhere prior to downstream migration.
5192a
7
Ib. Natural emergence of age zero chinook may be later than June
because none were observed (in minnow traps) until August
during the Power Authority studies (APA 1984). However, some
were observed in May during electrofishing, but these appeared
to have been stimulated out of the gravel from the
Ielectrofishing activities.
Sockeye
1. Adults
a. Spawn during August and September.
b. The combined average peak salmon spawning count by ADF&G from
1952 to 1981 and the Power Authority (1984) was about 61
fish. Weir counts by the CIAA show higher numbers at
approximately 400 fish in 1985 and 675 in 1986 (Marcuson
1986a, 1986b).
2. Juveniles
a. Previous observations indicate that sockeye juveniles do not
rear in Grant Creek. Juvenile sockeye typically rear in a
lake habitat. Therefore, Grant Creek juvenile sockeye
probably rear in one of the many lakes in the Kenai River
System.
Coho Salmon
1. Adults
a. No adult coho were observed either during previous spawning
ground surveys by ADF&G from 1952 to 1981 or by the Power
Authority (1984).
5192a
8
b. The artificial introduction of coho fry to Grant Lake has
produced a return of approximately 1,000 fish (based on weir
counts by the CIAA in 1985 and 1986). Some of these appear to
be native fish; however, none were observed in previous
studies (see No. 1).
C. Peak returns occur in August and September, with a few
returning in October.
2. Juveniles
a. Previous studies showed that some coho rear in the lower
reaches of Grant Creek but are less abundant and were not as
widely distributed as juvenile chinook (APA 1984).
b. The fact that some extremely small juvenile (less than 40 mm)
coho were trapped in August 1982 (APA 1984) in Grant Creek
strongly indicates that some natural spawning does occur.
Rainbow Trout
1. Adults
a. No spawning adults have been observed; however, small
young -of -the -year (45-50 mm) were observed in October 19829
which suggests that spring spawning may occur (APA 1984).
2. Juveniles/Adults
a. Rainbow trout appear to be evenly distributed in Grant Creek
and are found in most habitat types. Rainbow captured during
1982 studies by APA (1984) ranged from 43 to 106 mm in length.
5192a
9
Dolly Varden Char
1. Adults
a. No spawning adults have been observed (APA 1984).
b. Larger fish may move into Grant Creek during late summer to
feed and to avoid the high turbidity of the Trail Lakes System.
2. Juveniles
a. Sizes observed during the Power Authority studies ranged from
55 mm to 30 cm.
The above species are found throughout the Kenai River system. In
terms of commercial and sport value, the most important of these
species in this system are the Chinook and sockeye salmon. Coho salmon
are also very important. The numbers of chinook, sockeye and coho in
Grant Creek represent a relatively small portion of the total
escapement to the Kenai system.
The continued existence of a coho planting program in Grant Lake is
currently being evaluated. Therefore, it is uncertain if this run will
be maintained. Rainbow trout and Dolly Varden char represent a small
local sport fishery in Grant Creek. Due to its inaccessibility and
often high turbidity during the fishing season, angling pressure is
considered relatively light for these species (APA 1984). Based on
these considerations, the key species selected for habitat analysis in
Grant Creek were chinook and sockeye salmon.
In summary, the evaluation species and their life stage selected for
habitat analysis were:
o Chinook - spawning and rearing
o Sockeye - spawning
5192a
10
2.2 FIELD DATA COLLECTION
All field data for the instream flow habitat analysis were collected on
October 24, 1986, by personnel from Kenai Hydro. Three transects were
placed across the stream. Depth, velocity, and substrate were
recorded. Measurement for bed elevations were made at intervals of 2
to 4 feet apart at each transect and velocities were measured at 0.2,
0.6, and 0.8 of the depth (R. Poole, Kenai Hydro, personal
communication 1987). Appendix A contains a summary of the original
field notes.
2.3 FISH HABITAT SUITABILITY CURVES
Suitability curves for the various life stages of chinook and sockeye
were developed from information found in the literature. This was
believed to be a reasonable approach because a considerable amount of
information is available in Alaska on suitability of habitat for
certain species with some information directly derived from the Kenai
River system (e.g., Burger et al. 1983) Following is a brief
description of the sources or the rationale for each curve.
2.3.1 Chinook
Adults
Burger et al. (1983) found that velocities measured in Kenai River
tributaries at 0.6 of total depth had mean values of about 1.5 to
3.0 feet per second (fps) in the pit of chinook redds and 2.3 to 3.7
fps in the tailspill. Burger et al. (1983) also suggested that Kenai
mainstem spawners may utilize velocities of 0.9 to 4.6 fps (measured at
0.2 total depth). Collins et al. (1972) found a preferred range of 1.0
to 2.25 fps. From this information, a suitability curve was developed
with ranges from 0 (not suitable) to 1 (entirely suitable). A broad
range of velocities was established for the suitability analysis. This
curve is shown in Figure 2.
5192a
11
0
1.0
0.8
'' 0.6
a
m
0.4
N
0.2
0.0
0 1 2 3 4
depth (feet)
FIGURE 2. HABITAT SUITABILITY FOR CHINOOK ADULTS
Habitat Suitability
Chinook - Adults
Velocity
Velocity
Suitability
0.0
0.0
0.5
0.0
0.8
1.0
3.6
1.0
4.6
0.0
1 2 3 4 5
velocity (fps)
Depth (Estes and Vincent -Lang 1984a)
Depth
Suitability
0.0
0.0
0.5
0.0
1.0
1.0
4.0
1.0
12
Burger et al. (1983) found chinook redds in a tributary of the Kenai
River to be at a depth of 2 to 2.3 feet. Other researchers elsewhere
(Collins et al. 1972) indicated that a preferred range is from 1.0 to
1.75 feet. A multitude of other ranges have been described in the
literature (Reiser and Bjornn 1979); however, they are all quite
similar. To encompass a wide range in the habitat analysis, it was
assumed that no spawning would occur at depths of less than 0.5 feet.
Also, because maximum depths of 6.5 feet have been reported
(Smith 1973) and the maximum depth in the Grant Creek is in this
general range, any depth over 1.0 foot was considered to be entirely
suitable for spawning. The resultant curve (Figure 2) is the same
curve as that reported by Estes and Vincent -Lang (1984a). That curve
was developed from studies on the Susitna River Basin, Alaska and from
professional judgment of the authors. Again, this curve is believed to
encompass a wide range of possible values.
Successful growth and incubation of chinook eggs and alevins can occur
over a wide range of substrate sizes and particle size distributions.
The substrate observations taken by Kenai Hydro were fairly broad in
their description (see Appendix A). This makes it somewhat difficult
to define precise suitability curves for Grant Creek. Studies by Estes
and Vincent -Lang (1984a) resulted in suitability values of:
Size (inches) Suitability Index
Silt
0
Sand
0
1/8-1
0
1 to 3
0.65
3to5
1.0
5 to 10
0.70
greater than 10
0
5192a
13
Therefore, it was assumed that substrate sizes 12 inches or larger in
diameter were not suitable (equal to 0) while sizes less than 12 inches
in diameter were usable (equal to 1). Again, this is believed to be a
wide range because the optimum sizes for chinook range from 0.5 to 4
inches in diameter (Reiser and Bjornn 1979).
Juveniles
Burger et al. (1983) examined the depth and velocity preferences for
chinook juveniles in the Kenai River system. Figure 3 shows the curves
developed from their data. These were adapted for use in the habitat
analysis for Grant Creek. There are some differences noted in velocity
suitabilities in fish at 35 to 50 mm and those from 51 to 100 mm. For
depth, the curves are the same.
Substrate for chinook juveniles was primarily considered for the
stranding analysis. The field results from Kenai Hydro indicated that
most of the material observed was fairly large (greater than 2 inches
in diameter). Therefore, all of the substrate in the study section was
considered to have the potential for stranding. The potential for
stranding was only considered for chinook less than 50 mm. The
rationale for this is that juveniles greater than 50 mm would be much
more capable of escaping potential stranding situations (Prewitt and
Whitmus 1986).
2.3.2 Sockeye
Adults
The depth, velocity, and substrate suitability curves for spawning by
sockeye were adapted from studies by Estes and Vincent -Lang (1984b).
The study area was the Susitna River, Alaska. Figure 4 shows the
curves for depth and velocity. The suitability that Estes and
Vincent -Lang used for substrate was:
5192a
14
tm
N
Habitat .Suitability
Chinook - Juveniles
Velocity - Fry: 35 to 50 mm (Bu(gor et al. 1983)
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
velocity (fps)
Velocity - Fry: 51 to 100 mm (Burger et al. 1983)
1.0
0.8
T
y
0.6
m
0.4
N
0.2
0.0
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4
velocity (fps)
1
Depth - Fry: (Burger et al. 1983)
Velocity
Suitability
0.0
0.5
0.2
1.0
0.3
1.0
0.5
0.5
1.6
0.1
2.0
0.0
Velocity
Suitability
0.0
1.0
0.5
1.0
0.6
0.8
2.25
0.0
Depth
Suitability
0.0
0.0
0.1
0.0
0.2
1.0
1.0
1.0
0.0 0.2 0.4 0.6 0.8 1.0
depth (feet)
FIGURE 3. HABITAT SUITABILITY FOR CHINOOK JUVENILES
15
Habitat Suitability
Sockeye - Adults
Velocity (Estes and Vincent -Lang 1984b)
1.0
0.8
0.6
a
A
0.4
N
a...
0.2
0.0
0
�_.. 1.0
0.8
'' 0.6
z
0.4
N
0.2
0.0
0.0
1 2 3 4 5
velocity (fps)
Depth (Estes and Vincent -Lang 1984b)
0.2 0.4 0.6 0.8 1.0
depth (feet)
FIGURE 4. HABITAT SUITABILITY FOR SOCKEYE ADULTS
16
Velocity
Suitability
0.0
1.0
1.0
1.0
2.0
0.5
3.0
0.1
4.5
0.0
Depth
Suitability
0.0
0.0
0.2
0.0
0.3
0.2
0.5
0.9
0.75
1.0
1.0
1.0
Size (inches) Suitability Index
Silt 0.0
Sand 0.0
1/8 to 1 0.5
1 to 3 1.0
3 to 5 1.0
6 to 10 0.25
greater than 10 0.0
As with the chinook suitability curves, any substrate less than
12 inches in diameter was considered suitable (equal to a suitability
of 1). Any 12 inches or larger was considered unsuitable (equal to
�.
0). This assumption was believed to encompass a wide range of possible
values.
Juveniles
Juvenile sockeye were not considered in the habitat analysis because
ILI previous studies of Grant Creek generally indicate that the juveniles
rear in downstream areas and not in Grant Creek (APA 1984).
1
2.4 TIMING OF LIFE HISTORY STAGES OF CHINOOK AND SOCKEYE SALMON IN
GRANT CREEK
Table 1 summarizes the general life history stages of chinook and
sockeye salmon in Grant Creek. In general, the adult phase is easily
defined through previous studies by the Power Authority, ADF&G, and the
CIAA. The incubation phase is somewhat more difficult; however,
inferences have been made from observations of the appearance of small
juveniles (less than 50 mm) in the summer. Rearing by juveniles is
fairly well defined with juvenile chinook apparently present year-round
and juvenile sockeye moving rapidly downstream.
Ir5192a
17
TABLE 1
LIFE HISTORY PHASES OF CHINOOK AND SOCKEYE SALMON IN GRANT CREEK
Stage
Chinook
o Adults
o Egg Incubation and Early Intragravel
o Juveniles
Sockeye
o Adults
o Egg Incubation and Early Intragravel
o Juveniles
5192a
18
When Present
August -September
August-May/June
All Year
August -September
August-May/June
Move Downstream and
Rear Elsewhere
2.5 DATA ANALYSIS
The analysis of habitat was performed in a stepwise manner as follows:
1. A summary of the field data (submitted to Envirosphere by
Kenai Hydro) was reviewed (Appendix A).
2. Minor adjustments or corrections were made to the basic Kenai
data so that the data would conform to modeling inputs. These
changes were:
Transect 1
a. The staff reading for the "surface" was changed from
7.86 to 6.86. This would appear to be a reasonable
correction because the surface on the opposite bank
was 6.86. It appears that a 1.0 foot error was made
by Kenai Hydro in the field data. The measurement
for distance at this station was considered to be 0.
b. A "distance" of 65 feet for station number 18 was
inserted into the data base. No distance was
originally provided, however, a staff reading of
5.05 was taken. It was assumed that because other
distance measurements between stations ranged from
2 to 4 feet, a distance of 2 feet would be a
reasonable number to use.
C. The stage level decrease recorded at the end of the
day was change from 0.25 to 0.21. The rationale for
this change was that a subtraction error was made in
the original data (6.86 - 6.65 does not equal 0.25,
it equals 0.21).
5192a
19
M
Transects 2 and 3
No adjustments were made at these transects except a
distance of 0 was inserted at the stake for Transect 3.
3. Envirosphere transformed the resultant data to develop input
for the WSP model. This process consisted of scaling the
water surface elevation (WSEL) at Transect 1 to 100.0 feet
elevation (see Appendix B), calculating depths, and utilizing
the 0.6 foot depth velocities from the original data.
4. Codes were assigned to the Kenai Hydro substrate data. If the
average of the substrate range was less than 12 inches in
diameter, a value of 3 (unsuitable) was assigned to this
substrate. If the average was equal to or greater than 12, a
code of 4 (unsuitable) was assigned. This designation was for
the habitat analysis. For the stranding analysis, all
substrate was considered strandable.
The adjusted data from Kenai Hydro (Appendix Tables B-1 through B-3)
were analyzed by calibrating a standard Water Surface Profile (WSP)
program (Bovee and Milhous 1978). The Manning's N was adjusted at the
three cross -sections to calibrate to the water surface elevation (WSEL)
using a calibration flow of 246 cfs. This step required four runs with
WSEL's calibrating to 0.01 foot. The model calibrated well for the
lower and middle transects; however, some adjustment was needed for the
upstream transect. The reason for this was that the model was
calibrated to 246 cfs, but the WSEL at the upstream cross-section was
obtained at 297 cfs. Two steps were taken to evaluate this
discrepancy. First, calibration velocities were scaled down
proportionally (246/297) to represent what measured velocities might
5192a
20
M
have been at the lower discharge. The model was then calibrated to the
adjusted velocities. Next, the predicted water surface elevation for
246 cfs modeled discharge was compared to a WSEL adjusted by
subtracting the total daily stage differential (0.21 feet measured at
the staff gage) from the WSEL measured at 297 cfs (100.00). The
resulting WSEL (99.79) was .02 ft less than the predicted WSEL after
the velocity adjustment.
Once the WSP model was calibrated, the HABTAT model was run to
determine weighted usable area (WUA) for the various life history
stages (for additional details about this methodology see Bovee and
Milhous 1978). The flow range examined was from 50 cfs to 450.
One set of field measurements (taken on October 24, 1986) was provided
by Kenai Hydro for the analysis. A supplemental set of field
measurements were taken by the CIAA on February 24, 1987. These
measurements were taken at Transect 1. The discharge was 28 cfs. The
field notes on this data were provided to Envirosphere by Kenai Hydro.
This information was not used to supplement the WSP model because the
data were taken for discharge calculations and not for habitat analysis
(the procedures and measurements are not the same). However, to
provide a check on the WSP model, the data were examined.
Stranding potential was analyzed by the methodology described by
Prewitt and Whitrtus (1986). In general, this methodology uses
information on the slope (of the transect across the stream),
substrate, and discharge to determine stranding potential. In the
situation for Grant Creek, chinook juveniles less than 50 mm were the
key species for investigation. However, the analysis would generally
apply to all salmonid species less than 50 mm (e.g., sockeye, rainbow,
or Dolly Varden).
5192a
21
3.0 RESULTS
Cross -Sectional Profiles
Figure 5 presents the cross -sectional profiles at each of the
transects. Station 0+00 represents the downstream transect, Station
0+33 is in the middle of the study reach, and Station 0+52 is the
upstream transect. Also shown on this figure are WSEL for discharges
of 50, 100, 300, and 400 cfs. In general, the major portion of the
streambed at each transect is covered at about 100 cfs.
Habitat Relationships
Figures 6 through 8 show the relationship between WUA and discharge for:
o Adult Chinook Spawning (Figure 6)
o Juvenile Chinook Rearing
- less than 50 mm (Figure 7)
- greater than 50 mm (Figure 8)
The WUA applies to this study site and represents the amount of area
(in square feet) per 1,000 ft of stream. The discharges encompass most
of the average discharge levels measured in Grant Creek; however,
extrapolations to higher or lower discharges were not done because
these were felt to possibly be beyond the range of good predictions for
the WSP model.
The adult Chinook spawning curve shows that WUA increases with
discharge up to about 350 cfs. It then begins to decline. The
probable reason for this is that at the higher flows, velocities
increase beyond those preferred for spawning. (It should be noted that
the curves are considered to encompass a wide range of possible
spawning habitat, i.e., if suitable substrate sizes were less than
5192a
22
('R011e-5ECTIONAL PROFILE
104
103
102
f01
100
it •
•7
0 10 40 •o •o
01•TANct Cm
CROSS -SECTIONAL PROFILE
104
100
102
101
100
•
••
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DISTANc[ (FT)
CROSS -SECTIONAL PROFILE
STATION 0402
$04
103
102
101
100
QQQ111 •
••
•7
O 20 40 •o
DISTANcz cm
FIGURE 5. CROSS SECTIONAL PROFILES FOR GRANT CREEK TRANSECTS. STATION 0+00 IS
THE DOWNSTREAM TRANSECT, 0+33 = MIDDLE, AND 0452 = UPSTREAM TRANSECT.
23
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6 inches in diameter rather than the 12 inches used in this analysis or
suitable velocities were less, the WUA would have been less also.)
The WUA (Figure 7) for Juvenile chinook less than 50 ami shows a peak at
about 150 cfs and decreases at both higher and lower discharges. The
curve for juvenile chinook greater (Figure 8) than 50 mm also shows a
similar peak at about 150 cfs.
Sockeye
Figure 9 shows the WUA for adult sockeye. In general, the WUA is
similar between 50 and 250 cfs. However, at discharges greater than
200 cfs, the WUA decreases significantly. This most likely occurs
because higher velocities are associated with the increased discharge.
rison of Kenai Hydro Data to the CIAA Data at Low Flow
In examining the CIAA data, the first problem encountered was the
missing water surface elevations and the tie-in, by leveling, to the
Kenai Hydro benchmark. This causes difficulty in matching the CIAA
data points to the original data and therefore does not provide
sufficient data to use it for habitat modelling. Thus, the CIAA data
do not add substantially to the capabilities for prediction of habitat
at low flow. However, a cross-section bed profile was developed to see
if the CIAA's profile matched the Kenai Hydro data. Figures 10A, 10B,
and IOC show the Kenai Hydro profile for T1 and CIAA's profile. The
two are reasonably similar. These also show possible matchups of the
bottom profile with the CIAA water surface elevation at 28 cfs and the
model's water surface at 30 cfs. The matching of the model to the CIAA
data or vice versa does show some potentially important features. For
example, the model generated is considered to be conservative for low
flows; i.e., water surface elevations would be expected to be slightly
lower than actual values. This is probably because at lower
discharges, the "roughness" increases. The model does not account for
this because a single "N" value was used for all flows. Therefore, for
5192a
27
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analyses such as stranding, the "strandable area" developed from the
model would be expected to be somewhat larger than it is in reality.
Because the CIAA data show a water surface elevation higher than that
predicted in the model, the model confirms what should happen at lower
flows given the single Manning's value used in the simulation.
Stranding
Figure 11 shows the stranding area associated with various incremental
changes in discharge from Grant Creek. In general, the changes are
similar from 450 cfs to about 10U cfs. At flows less than 100 cfs, the
stranding area increases significantly. The changes apparent in this
figure are a function of the bottom configuration at each
cross-section. At discharges greater than about 100 cfs, the change in
wetted perimeter is much less than for changes at 100 cfs or less.
Figure 12 shows the relationship of potential stranding to flow
fluctuation. This figure assumes an initial flow of 450 cfs. From
this flow, the graph shows how the physical area (stranding area) would
change as the flow is decreased in 50 cfs increments. For example,
changes from 450 cfs to any other flow from 50 to 350 cfs less result
in a small change in stranding area. However, a decrease in flow by
any incremental change of 350 cfs or greater results in a significant
.... increase in stranding area.
5192a
32
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■ 34
4.0 CONCLUSIONS
The analyses contained in this report are sufficient to discuss a
negotiated flow regime for the Grant Creek Project. However, the
modeling is considered potentially unreliable at flows below about
100 cfs. This is mainly important in considering the low winter flows
under natural conditions. With -project flows will not approach these.
The following preliminary conclusions can be made based on the
information provided by Kenai Hydro:
1. High natural flows in August and September can affect WUA for
spawning chinook, particularly at flows greater than about
350 cfs, where WUA begins to decrease from its maximum.
2. High natural flows in August and September result in
significantly lower WUA's for sockeye spawning than for flows
less than 200 cfs. Therefore, with -project flows will
potentially result in a significant increase in WUA for
sockeye spawners.
3. The WUA for juvenile chinook less than 50 mm shows that an
optimum occurs at about 150 cfs. If fish of this size are
present during the summer months, then the high natural flows
also result in WUA's that are much lower than optimum.
Project flows will generally approach the optimum much more
consistently than natural flows. Winter conditions were
generally not considered for these small fish because they
were expected to remain within the gravel and would not be in
the water column.
5192a
35
4. The shape of the WUA curve for juveniles greater than 50 mm is
similar to that for the smaller juveniles. Under natural
conditions, the low winter flows would severely affect habitat
whereas under with -project conditions for this period, the WUA
would be larger. During the summer period, the WUA under
with -project conditions may demonstrate an improvement over
natural conditions.
5. The comparison of predictions made by the model using Kenai
Hydro data and the data taken at low flow (28 cfs) by CIAA
shows that the model may predict reasonably well even for low
flows.
Measurements should be taken using methods developed for
habitat analysis (e.g., differential leveling) and not for
discharge, as was done by the CIAA.
6. When considering potential stranding, it is apparent that at
this study site, the potential for stranding increases
significantly when flows are decreased below about 100 cfs.
For fluctuations greater than this, little effect is apparent.
i 5192a
36
5.0 REFERENCES
Alaska Dept. of Fish and Game. 1952/1980. Escapement count surveys,
Grant Creek. Unpublished. (On file at Alaska Dept. of Fish and
Game, Soldotna, Alaska.)
Alaska Power Authority (APA). 1984. Grant Lake Hydroelectric Project
detailed feasibility analysis - Volume 2 - Environmental Report.
Prepared for the Power Authority by Ebasco Services.
Bovee, K.D. and R. Milhous. 1978. Hydraulic simulation in instream
flow studies: Theory and techniques. Instream Flow Information
Paper No. 5. USFWS Cooperative. 131 pp.
Burger, C.U., D.B. Wangaard, R.L. Wilmot, and A.N. Palmisano. 1983.
Salmon investigations in the Kenai River, Alaska, 1979-1981.
USFWS, Nat. Fish. Res. Center, Seattle, Alaska Field Station.
Anchorage, AK. 178 pp.
Collings, M.R., R.W. Smith, and G.T. Higgins. 1972. Hydrology of four
streams in western Washington as related to several Pacific salmon
species: Humptulips, Elochoman, Green, and Wynoochee Rivers. U.S.
Geological Survey. Tacoma, Washington, 1972.
Estes, C., and D.S. Vincent -Lang, eds. 1984a. Report No. 3. Aquatic
habitat and instream flow investigations (May -October 1983).
Chapter 9: Habitat suitability criteria for chinook, coho, and
pink salmon spawning in tributaries of the middle Susitna River.
Susitna Hydro Aquatic Studies, Alaska Dept. of Fish and Game.
Report to the Alaska Power Authority. Anchorage, AK. Doc. 1938.
Estes, C., and D.S. Vincent -Lang, eds. 1984b. Report No. 3. Aquatic
habitat and instream flow investigations (May -October 1983).
5192a
37
Chapter 7: an evaluation of chum and sockeye salmon spawning
habitat and sloughs and side channels of the middle Susitna River.
Susitna Hydro Aquatic Studies, Alaska Dept. of Fish and Game.
Report to the Alaska Power Authority. Anchorage, AK. Doc. 1936.
Marcuson, P. 1986a. Grant Creek Project - Progress Report: First
Coho Salmon Returns From Fry Stocking. Cook Inlet Aquaculture
Association, Soldotna, Alaska. 10 pp.
Marcuson, P. 1986b. Grant Creek Project - Progress Report: Coho
Salmon Returns From Fry Stocking. Cook Inlet Aquaculture
Association, Soldotna, Alaska. 11 pp.
Prewitt, C.M., and C.J. Whitmus. 1986. A technique for quantifying
effects of daily flow fluctuations on stranding of juvenile
salmonids. In: Instream Flow Chronicle, Vol. II, No. 4 Colorado
State University Conference Services. Pages 1 to 3.
Reiser, D.W. and T.C. Bjornn. 1979. Influence of forest and rangeland
management on anadromous fish habitat in western North America:
habitat requirements of anadromous salmonids. U.S. Dept. of Ag.,
Forest Service. 54 pp.
Seward, City of. 1980. Feasibility assessment. Hydropower
development at Grant Lake. Prepared for the City of Seward by
CH M Hill Company.
Smith, A.K. 1973. Development and application of spawning velocity
and depth criteria for Oregon salmonids. Trans. Am. Fish. Soc.
10(2):312-316.
Tennant, D.C. 1976. Instream flow regimes for fish, wildlife, and
recreation and related environmental resources. Page 359 to 373 In
Instream Flow Needs, American Fisheries Society.
5192a
38
U.S. Geological Survey. 1981. Surface water quality records,
southcentral Alaska, 1949-1974. Unpublished computer printout.
5192a
39
APPENDIX A
SUMMARIZED FIELD DATA FROM
KENAI HYDRO, INC.
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MODEL INPUT DATA
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