HomeMy WebLinkAboutSmall-Scale Hydropower for Anaktuvuk Pass, Alaska Letter Report 1984-
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DEPARTMENT OF THE ARMY
.AL.ASKA DISTRICT CORPS OF ENGINEERS
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ANCMOIUGI AI. .ASK A tttOe
SMALL-SCALE HYDROPOWER FOR ANAKTUVUK PASS, ALASKA
LETTER REPORT
SEPTEMBER 1984
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DEPARTMENT OF THE ARMY
U.S. ARMY ENGINEER DISTRICT, ALASKA
POUCH 898
ANCHORAGE, ALASKA 99506-0898
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Plan Formulation Section
December 7, 1984
NOTICE OF COMPLETION OF NEGATIVE FEASIBILITY
REPORTS FOR HYDROELECTRIC POWER
AT FOUR ALASKA LOCATIONS
I am announcing completion of reports on potential hydroelectric
power generating facilities at four Alaska locations: Anaktuvuk
Pass, Kaktovik, Hope, and Seldovia. In all cases, after careful
investigation and evaluation, I found that Federal development of
the facilities is not feasible at this time.
All of these potential projects would require supplementation with
other sources of electricity during the winter, when flows of
Alaskan streams dwindle and when demand for electrical power is
greatest.
The four locations were studied pursuant to a resolution of the
U.S. Senate Committee on Public Works dated October 1, 1976,
directing the Corps of Engineers to determine the feasibility of
installing small hydroelectric plants in isolated Alaskan
communities. The studies evaluated future needs for electrical
power at each of the sites and alternatives available to meet those
needs. While the Corps had primary responsibi 1 ity for conducting
the studies, numerous other Federal, State, and local agencies and
groups contributed. A public involvement program was maintained.
All sites were identified in regional reconnaissance studies
performed by engineering firms under contract. The Corps conducted
followup field investigations. Each location is briefly described
below.
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Anak.tuvuk Pass: This community is in a mountain valley in the
centra 1 Brooks Range above the Arctic Ci rc 1 e, 250 miles
north-northwest of Fairbanks. The present diesel facilities for
electrical generation are owned and operated by the North Slope
Borough. The optimum project was found to be a run-of-river system
on Inukpasugruk Creek with a 22-foot-high rockfill dam and 3,250
feet of steel penstock. Its single turbine would have a total
cap-acity of 200 kilowatts (kW). The creek would have sufficient
streamflow to produce power during about 4 months of the year. The
project would cost about $6 million and would have a benefit-cost
ratio of 0.3 to 1. (A ratio of greater than 1 to 1 is required to
. ..
meet Federal economic evaluation criteria.) The total cost of
using this hydroelectric project in conjunction with the town
diesel system exceeds the cost of continuing to generate.power with
the diesel system alone.
Kaktovik: This village is located on Barter Island in the Beaufort
Sea just off the north coast of Alaska. The island is separated
from the coast by a narrow lagoon. A hydropower reconnaissance
study using existing topographic maps of northeastern Alaska found
that a site on the Okpilak river near Kaktovik might be marginally
feasible. Corps field investigation determined that this site is
founded on an alluvial deposit and the stream bank provides no
suitable dam or diversion site. The stream gradient is gradual,
approximately 25-40 feet per mile; thus an extremely long penstock
would be required. Due to the long winter season, sufficent
streamflow to produce power would be available only 4 months of the
year. Study of the site was terminated because of lack of
technical feasibility for hydropower development.
Hope: Hope is situated in Southcentral Alaska, on the south side
of Turnagain Arm about 25 air miles south of Anchorage. The
community currently receives single phase power produced by gas
turbines from Chugach Electric Association (CEA), which operates a
1 arge network that serves Anchorage and other towns in the area.
Tying the proposed hydropower plant into the existing CEA grid was
found to be more economical than using its output only for the
communities along the Hope feeder line, since the plant could not
meet the full feeder line demand in winter. Three dam sites on
Bear Creek near Hope were considered. The lowest one would be
optimum, due to considerably higher penstock and road improvement
costs for the upper sites. The run-of-river project evaluated for
this site would include a gabion diversion structure 6 feet high
and a polyethylene penstock 1,640 feet long. Six plant sizes were
considered; the one selected would have two turbines with a total
capacity of 150 kW. The project would cost about $1.5 million and
would have a benefit-cost ratio of 0.3 to 1. The costs would
exceed the benefits by $97,000 per year.
Seldovia: Seldovia is located on the west coast of the Kenai
Peninsula, 16 miles southwest across Kachemak Bay from Homer.
Electrical power is currently supplied to Seldovia by Homer
Electric Association (HEA), which purchases the power from CEA. A
project site on Windy River was selected. The run-of-river project
analyzed for this site would have a rockfilled bin diversion
structure 8 to 10 feet high and 3,420 feet of penstock, part
polyethylene and part steel. The single turbine would have a
capacity of 590 kW. Failure of the transmission line from Homer
causes frequent power outages, especially in winter; the community
then uses diesel generators provided by HEA. Some of these power
losses may be avoided with a hydropower project, although low
stream flows during the winter would 1 imit potential hydropower
production available from the Windy River. The project would cost
2
about $5.2 million and would have a benefit-cost ratio of 0.6 to
1. It is not economically feasible for Federal construction at
this time.
Please pass this information on to others interested in these
reports who may not have received this notice.
Further information on any of the above studies may be
from my office or from Mr. Carl Barash, Chief of
Formulation Section, Post Office Box 898, Anchorage,
99506-0898. The telephone number is (90 75 2632.
Saling
Colonel, Corps of Engineers
District Engineer
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FOUR LOCATIONS INVESTIGATED FOR HYDROELECTRIC POWER
OECEMBER 1984
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SMALL-SCALE HYDROPOWER FOR ANAKTUVUK PASS, ALASKA
SUMMARY
The Alaska District, U.S. Army Corps of Engineers, investigated hydropower
potential for Anuktuvuk Pass, Alaska. A potential project about 2 miles
southeast of the town a long Inukpasugruk Creek was eva 1 uated. That
run-of-river project would feature a single turbine with a total capacity of
200 kilowatts (kW). Due to insufficient streamflows during about 8 months of
the year, it could not produce a dependable capacity year-round. An annual
average of 488,000 kilowatt-hours (kWh) could be fed into the existing diesel
electric system serving the town. The project would cost about $6 million and
deliver electricity for about $1.17 per kWh to the existing feeder line. The
total cost of using this hydroelectric project in conjunction with the town
diesel system exceeds the cost of continuing to generate power with the
existing diesel system alone. Therefore, no further studies by the Corps of
Engineers are planned at this time.
GENERAL DATA
ANAKTUVUK PASS ·
PERTINENT DATA SHEET
Project Installed Capacity (kW)
Number of Units
200
1
22 Dam Height (ft.)
Penstock Type
Penstock Length (ft.)
Welded Plate Steel
3,250
Penstock Diameter (in.)
Transmission Line Length (miles)
Access Road Length (miles)
Gross Head (ft.)
Design Net Head (ft.)
Average Annual Energy (MWh)
30
2
1. 5
97
68
540
ECONOMIC DATA (50 Years, 8-1/8 Percent Interest, 1984 Prices)
Project First Cost
Investment Cost
Total Annual Cost
Average Annual Equivalent Usable Energy (MWh)
Annual Benefits
Benefit-Cost Ratio
Cost per kWh
i i
$6,314,000
$6,554,000
$ 573,000
488
$ 150,000
0.26
$ 1.17
INTRODUCTION
~ALL-SCALE HYDROPOWER FOR ANAKTUVUK PASS, ALASKA
LETTER REPORT
The evaluation of small hydroelectric systems was authorized by a United
States Senate Resolution adopted in October 1976 which directed the U.S. Army
Corps of Engineers to determine the feasibility of installing small
prepackaged hydroelectric units in isolated Alaskan communities.
In 1981 a reconnaissance study of potential small hydropower projects in
Northwest Alaska was completed by Ott Water Engineers for the Alaska
District. This study indicated that a project at Anaktuvuk Pass (figure 1)
might be economically feasible based on preliminary information.
Observations and measurements from a July 1982 field trip were used to
select the project features evaluated in this study. The proposed sites for
the darn and powerhouse were located about 2 to 3 miles south of the town of
Anaktuvuk Pass. Access and transmission line corridors would lead from this
project area to the town.
Anaktuvuk Pass is located in a glaciated mountain valley in the central
Brooks Range above the Arctic Circle, 250 miles north-northwest of Fairbanks,
Alaska. The village economy and employment come primarily from limited
community services; community construction projects funded by the North Slope
Borough, and native arts and crafts manufacture. Access to Anaktuvuk Pass is
by air year-round. There is potential for travel by way of the Dalton Highway
{Trans-Alaska pipeline access road) during the winter.
The climate of Anaktuvuk Pass is strongly continental, in contrast to the
maritime climates of .other villages in the North Slope Borough. Due to its
high elevation, temperatures are relatively cold in the winter and warm in the
summer comparee to the foothills to the north. Temperatures range from an
average minimum of about -22F in January to an average maximum of about 61F in
July. The lowest recorded temperature was -56F in January 1957 and the
highest was 91F in July 1967. Temperatures are below freezing most of the
year. (Arctic Environmental Information and Data Center, University of Alaska)
The area is underlain by continuous permafrost and has a seasonal depth of
thaw of 3 to 5 feet. The total generating season for potential hydropower is
heavily dependent on the weather, but is generally from June to September.
The village of Anaktuvuk Pass (population 260 in 1983) has about 15
col11llunity and coi11Jlercial buildings and about 70 homes that are served by
coi11Jlunity electricity generation. Some new buildings and improvements are
planned. The present electrical generation, owned and operated by the North
Slope Borough, uses four 210-kW diesel units and one 90-kW diesel unit. The
fuel supply is shipped by air from Fairbanks. The generators are serviced
monthly by technicians flown in from Fairbanks. In 1984 the local utility
produced and distributed electricity at a cost of about $1.10 per kWh. The
consumer paid $0.15 per kWh for each of the first 600 kWh and $0.35 for each
additional kWh. The North Slope Borough and the State made up the difference
in cost with subsidies.
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ANAKTUVUK~ PASS
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RIGHT
FAIRBANKS •
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I 0 100 200 300
\ SCALE IN MILES
10 10 :so 40 10 -.-un
ANAKTUVUK PASS, ALASKA
SMALL HYDROPOWER FEASIBILITY
STUDY
VICINITY AND LOCATION MAP
Flgur. ·1 leple•ller 1884
ENVIRONMENTAL SYNOPSIS
The proposed project in lnukpasugruk Creek would have only minimal impacts
if care were taken in construction. However, approximately one quarter-mile
of good adult grayling summer habitat would be degraded considerably if
minimum streamflows are not allowed below the diversion dam. The portion of
the stream which flows through the small canyon is characterized by pools
connected by cascading water. The cascades are small enough to allow adult
grayling and char passage for almost the entire length of the canyon. It does
not appear that fish are able to move above the proposed diversion site. The
Centra 1 A 1 ask a caribou herd passes the project area in both fa 11 and spring.
It does not appear that the caribou would cross the creek in the canyon area;
however, there are some places where passage may occur. The caribou migration
could conflict with an aboveground penstock in these places. If the project
were to continue, care in the design and timing of construction would minimize
any impact.
Erosion from moving vehicles across the tundra underlain with permafrost
could constitute a major impact. Vehicle disturbance of the vegetation mat
and subsequent erosion are well documented. Means to transport equipment and
materials to all project features must be established to eliminate any
destruction of the vegetative mat.
The esthetic quality of the project area is extremely high. The project
should be designed to be as inconspicuous as possible.
Additional studies are needed to establish species composition
distribution and timing of fish activities in Inukpasugruk Creek. If the
project study were to cant i nue, measures shou 1 d be taken to determine and
provide minimum stream flows for fish species in the affected stretch of the
creek.
HYDROLOGY
Description of Area. The Inukpasugruk Creek (680 05' N latitude, 1510
40' W longitude) basin consists of a tundra covered valley 1 to 2 miles in
diameter, surrounded by rugged mountains up to 6,032 feet high. From the base
of the far mountains to the proposed diversion site, a distance of
approximately 10 miles, the stream drops 800 feet. At a point about 2 miles
upstream from the proposed damsite the creek flows out of the valley onto a
high, flat plateau where it becomes braided in gravel channels. At the
proposed damsite it enters a rock walled gorge. The gorge is approximately 1
mile long, and the river drops about 100 feet over a series of falls and
cascading rapids along its length. At the base of the gorge the stream enters
the John River Valley, where it flows for a quarter-mile in a well graded
gravel channel before entering the John River. The stream is typically clear
and fast moving. There is evidence that floods overtop the stream banks.
Design Flows. No known stream gage records exist for Inukpasugruk Creek.
Monthly mean flows for the stream were synthesized. from 5 y_ears of records/or
Atigun Tributary Station No. 15904900 (680 22 N lat1tude_,. 149° 19 W
longitude near Galbraith) which is believed to have s1m1lar average
precipitation to Anaktuvuk Pass. The mean monthly flows estimated in
Inukpasugruk Creek at the proposed dam site are shown in table 1.
3
Jan
Feb
Mar
Apr
Table 1
MEAN MONTHLY FLOWS IN INUKPASUGRUK CREEK
(cfs)
0
0
4
0
May 10
Jun 155
Ju 1 172
Aug 127
Sep
Oct
Nov
Dec
28
2
0
0
Seillway Design Flood. Based on a low hazard potential and the use of a
relat1vely small dam, the Corps of Engineers Feasibility Studies for Small
Scale Hydropower Additions recommends designing the spillway for the 100-year
event. Using the methodology described in the USGS publication, "Flood
Characteristics of Alaskan Streams", this flow was computed to be 3,600 cubic
feet per second.
ENERGY ANALYSIS
Demand. A 1979 stuay by Robert W. Retherford Associates for the North
Slope Borough predicted a 1983 energy production of 1,356 megawatt-hours
(M~h). This prediction fell 6 percent short of the actual production.
However, this projection was considered to be fairly accurate given the
tremencous increase· from the approximately 342 MWh produced in 1978.
Electricity production actually increased an average of 28 percent a year from
1978 to 1983. The Retherford analysis was based on growth patterns and
planned capital improvements in the town. It allowed for a tremendous growth
rate in the first four years with much smaller growth in later years until its
last projected year, 1990. The study noted that the single most significant
item affecting the growth appeared to be the North Slope Borough Capital
Improvements Program (CIP). Oil revenues from the North Slope are the
keystone of the borough • s economy. 0 i 1 revenues cou 1 d begin fa 11 i ng in the
1980•s and are very likely to decline substantially in the late 1990•s as
known oil reserves are expected to dwindle.
The 1, 452 MWh produced by the North Slope Borough ut i1 ity at Anaktuvuk
Pass in 1983 was used as the base for the forecast in this study. A 3. 7
percent annual growth rate was assumed between 1983 and 1990. This is the
same growth assumed by the 1979 study. The growth rate is assumed to decline
to 2 percent annually between 1990 and 2000, then to 1 percent from 2000 until
2040. The energy forecast presented in the 1979 study, together with the 1983
actual production and the forecast assumed by this study, are presented in
table 2.
4
Year
1978
1983
1990
2000
2040
Table 2
HISTORIC AND FORECASTED ENERGY DEMAND
1979 Retherford Study
Annual Growth Rate Demand
(%) (MWh)
26.0
3.7
427*
1 '356
1,745
1984 Project Forecast
Annual Growth Rate
(%)
3.7
2.0
1.0
* 427 MWh and 1,452 MWh were the actual amounts of energy
produced in 1978 and 1983 respectively.
Demand
(MWh)
1,452*
1 t 869
2,278
3,392
The approximate electrical energy demand for each month in 1983 and its
percentage of the total year are presented in table 3. The study assumed that
the monthly demand percentages would remain constant for the foreseeable
future.
Table 3
1983 MONTHLY ENERGY DEMAND
MONTH
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
·kWh PERCENT OF YEAR TOTAL
162
135
141
120
97
82
84
98
110
133
130
160
1~
11.2
9.3
9.7
8.3
6.7
5.6
5.8
6.7
7.6
9.2
8.9
11.0
100.0
Hydropower. Monthly power routings for various plant sizes ranging from
100 to 350 kW were made based upon the standard energy equation:
kWh=E x Q x H x 0/11.8
kWh =plant output in kilowatt-hours.
E = Efficiency of conversion, which was assumed to equal 0.83.
Q = Mean monthly flow through penstock in cubic feet per second.
H = Net energy head in feet at the turbine, which is 97 feet
gross head minus head losses associated with the flow in
the penstock. D = 7L0 hours of flow, a typical month•s duration.
5
The computations assumed that each plant capacity would be developed by a
single turbine. Each alternative capacity project analyzed would develop
power during four months, except the 350-kw plant, which would cease to
operate during September since the flow is too small. Figure 2 compares the
expected electrical demand in the years 1990 and 2040 with the potential
supply from the 200-kw capacity plant.
Marketable Energy. The hydropower analysis predicted potential monthly
average kilowatt-hours of electrical energy for each alternative capacity
project. However, much of this potential energy was not considered marketable
since it exceeded the demand. Therefore, the potential production was
compared with the forecasted demand during the project 1 ife to predict the
marketable energy. All expected marketable energy during the project life was
aiscountea to the 1990 POL date. An annual equivalent value of marketable
energy was then determined using an 8-1/8 percent interest rate.
COST ANALYSIS
Table 4 develops the annual costs for various alternatives. Construction
was assumed to take a year. The project was amortized over a 50-year (1990 to
2040) project life at 8-1/8 percent interest. An annual $30,000 operations
and maintenance cost was added to obtain total annual costs. All costs were
estimated based on 1984 price levels.
Table 4
ANNUAL COSTS DEVELOPED FOR VARIOUS CAPACITY ALTERNATIVES
Plant Size (kW) 100 160 200 250 350
First Cost ($1,000) 6,064 6, 211 6,313 6,496 6,659
Interest During Construction 230 237 241 248 253
(1 year) ($1,000)
Investment Cost ($1,000) 6,259 6,448 6,554 6,744 6,912
Annual Interest and 522 535 543 559 573
Amortization (50 years
at 8-1/8%, 1990 POL)
($1,000)
30 Operations & Maintenance 30 30 30 30
($1,000)
Total Annual Cost ($1,000) 552 565 573 589 603
BENEFIT ANALYSIS
The fuel cost of energy per kilowatt-hour is taken as a benefit to
hydropower development, and each kilowatt-hour produced is credited with that
amount as a cost prevented. By using an area fuel cost of $2.25 per gallon
and a generating efficiency of 12 kWh per gallon, a fuel savings of $.188 per
kWh can be realized.
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Comparison of Project Supply
YS.
Forecasted Demand
The cost of diesel fuel is expected to increase faster than construction
costs. This st_udy accounted for this by using escalation factors determined
by Data Resource, Inc. (July 1984). This escalation was projected
undiscounted from the present (1984) to the 1990 power-on-line (POL) date and
discounted to POL for the remaining years of the project life. Escalation
accounted for a benefit of $0.099 for each k~h of hydroelectricity produced.
No benefits for replaced capacity have been considered in this analysis
because the hydropower facility would not produce any power during the winter
peak season due to insufficient streamflow. A diesel system would supplement
the hydro system in meeting the electrical demands of Anaktuvuk Pass. Although
no capacity benefits have been claimed, there would be some reduction in costs
of the di ese 1 system due to an expected extended 1 ife and reduced operations
and maintenance (0 & M). This benefit was given a value of $0.021 per k~h
based on past studies.
The total value of each kWh produced by the project hydropower is $0.308,
as shown in table 5. The annual equivalent marketable energy for each
alternative capacity project and the resulting benefits are shown in table 6.
Table 5
BENEFITS OF THE HYDROPOWER PROJECT
Category
Fuel Saved
Fuel Escalation
Replaced Capacity
Extended Life and Reduced
Operations and Maintenance
Dollars per k~h
0. 188
0.099
0.0
0.021
0.308
The annual equivalent marketable energy for each alternative capacity
project and the resulting benefits are shown in table 6.
EVALUATION
To derive the optimum project size and the benefit/cost ratio, aMual
benefits were compared with annual costs. In addition, a payback cost per k~h
was derived by dividing the project annual cost by the annual equivalent
usable energy. The optimum capacity alternative project was ~elected by
maximizing net benefits (in this case minimizing net negative benef1ts).
8
Table 6
ECONO~IC SUMMARY FOR VARIOUS ALTERNATIVE CAPACITY PROJECTS -
Average Benefit/ Power Cost
Marketable Annual Annual Net Cost Associated
Plant Size EnergJ Benefits Costs Benefits Ratio with Pro,ect · ( kw) (MWh ($1,000) ($1,000) ($1,000) ($/kwh
100 288 89 552 -463 0.16 1. 92
160 445 137 565 -428 0.24 1.27
200 488 150 573 -423 0.26 1.17
250 535 165 589 -424 0.28 1.10
350 408 126 603 -477 0.21 1.48
The above analysis indicates that none of the turbine sizes evaluated is
economically feasible. Based on the assu~ptions of the study, a project with
an approximate capacity of 200 kW would be the optimum alternative, but even
this project would be expected to show annual losses of some $423,000 and have
a benefit/cost ratio of about 0.3. Table 7 presents a detailed cost estimate
for the 200-klrJ project, which was identified as the optimum project although
it was found economically infeasible.
Figure 3 shows the 1 ayout of the major project features. The design is
based on field measurements and observations. The powerhouse lump sum cost,
exc 1 uding tail race and powerhouse excavation costs, is based on estimated
costs of other A 1 ask an small hydropower powerhouses which were more c 1 ose ly
calculated. The cost estimates include the following items: a 22-foot-high
rockfill dam and related features including a 40-foot-wide spillway
constructeo in the rock bank alongside the dam (the excavated rock would be
used to fill the dam), an intake structure, and a temporary diversion during
·construction; a powerhouse, including a single 200 kW turbine, electrical
components, and tailrace; a 12-foot-wide gravel access road; a 2-mile
aboveground 3-phase transmission line and in-towh transformer and poles
required to connect the project to the existing diesel powerhouse; 3,250 feet
of 30-inch diameter steel penstock which would be constructed with the use of
a helicopter; 6 months use of a helicopter including associated costs (the
helicopter would be required to deliver equipment and workers required to
construct the dam, spillway and penstock); mob and demob; lands and damages; a
20% contingency; a 15% allowance for engineering, designing,. supervision and
administration; and interest during construction based on a 1-year
construct ion period. Investment costs were amortized for a 50-year project
(1990 to 2040) at 8-1/8 percent, and an annual $30,000 operations and
maintenance cost was added to obtain total annual costs. All cost estimates
were based on 1984 price levels.
No road was considered along the penstock route because the field
evaluators determined that road construction along the rugged penstock
corridor would be unacceptable in this area, which lies within the Gates to
the Arctic National Park. Therefore, a helicopter would be utilized.
Furthermore, the proposed aboveground transmission line would be subject to
review by the National Park Service. If the project were to be con.side~ed
further, an underground transmission line should be considered de~p1te 1ts
probable higher cost. The "Pertinent Data Sheet" at the front of th1s report
summarizes the 200-kw optimum project.
9
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AN'AKTUVUK
SOUTH BASE LY263
10
Figure 3
PROJECT SITE MAP
ANAKTUVUK PASS, ALASKA
CONCLUSIONS
A hydropower project would not be economically feasible at this time based
on Federal evaluation criteria. The major factor responsible for keeping the
benefits much lower than they might otherwise be is the lack of an adequate
streamflow for most of the year. The stream has good flows during the June to
September period, but has a low flow for May and practically no flow for all
the other months. If the flows did not drop off to such an extent, multiple
turbines could adapt to the varying flows by utilizing small turbines for low
flows. The analysis conducted in this study is based on a simplified
assumption that both monthly streamflows and monthly power demands remain
constant and do not vary during each month. This assumption tends to
overestimate the amount of actual marketable energy available.
RECOMMENDATION
It is recommended that no further Corps of Engineers studies of hydropower
development in the Anaktuvuk Pass be undertaken at this time.
11
Table 7
ANAKTUVUK PASS SMALL-SCALE HYDROPOWER
ITEM/DESCRIPTION QUANTITY UNIT -UNIT PRICE TOTAL
Mob & Demob 1. s. $600,000
Lands & Right of Way 1. s. 30,000
Dam 2 Intake & S~illw~
Rockfill Dam (22ft. high with 1,480 c.y. $15.00 22,200
rock from spillway)
Anchored Plywood Facing 1,700 s.f. 3.00 5, 100
Spillway Rock Excavation 1,600 c.y. 50.00 80,000
Intake (including gate, trash 1 1. s. 30,000
rack & misc. equipment)
Cutoff (excavation & grout) 80 ft. 50.00 4 2 000
$141,300
Penstock
~elded Steel Pipe (1/4" thickness, 260,000 lb. 3.00 $780,000
30" diam., 80 lb/ft.)
Wood Supports (along 2,350 ft. of 9,750 b.f. 3.00 29,250
penstock)
Rock Excavation (along 900 ft. 500 c.y. 50.00 25 2000
of penstock) $834,250
Power Plant
Building, Turbine/Generator, 1 l.s. $705,000
Accessory Equipment & Switches
Gravel Work Pad 1,230 c.y. 15.00 18,450
Riprap for Tailrace 100 c.y. 30.00 3,000
Tailrace {gravel excavation) 200 c.y. 15.00 32000
$729,450
Transmission Line
3-Phase Aerial Line
Between Project Powerhouse 200,000 $400,000 and Diesel Powerhouse 2 mi.
Transformer (in town) 20 2000
$420,000
Access Road $600,000 Gravel ( 1. 5 mi.) 40,000 c .y. 15.00
2" Rigid Insulation 320,000 s. f. 1.00 320 2 000
$920,000
Helicof!ter (6 months of use) 1 1. s. $900 2 000
Subtotal $4,575,000
12