HomeMy WebLinkAboutHumpback Creek Final Feasibility Report 1986· ,
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HUMPBACK CREEK
FINAL FEASIBILITY REPORT
January 1986
CORDOVA POWER COMPANY
Alaska Power Authority
LIBRARY COpy
''''1909 ~
L
CORDOVA ELECTRIC COOPERATIVE, INC.
HUMPBACK CREEK HYDROELECTRIC PROJECT
FEASIBILITY REPORT
FINAL REPORT
JANUARY 1986
PREPARED By:
CORDOVA ELECTRIC COOPERATIVE~ INC.
Q () k· !--'
OO-z.-.--
HUMPBACK CREEK HYDROELECTRIC PROJECT
FEASIBILITY REPORT
JANUARY 1986
TABLE OF CONTENTS
I. Summary
A. Technical
B. Financial
C. Environmental
II. Introduction
III. Cordova
A. General Data
B. Energy Balances
C. Energy Requirements
D. Existing Electrical System
E. General Information About Cordova
F. Potential Future Development
G. Power Cost Data
IV. Background
Page No.
1
1
2
3
5
7
8
9
10
15
24
27
A. Background 34
B. CEC Project Selection Process 37
C. Historical Background 39
D. Consideration of Archeological Aspects 43
V. Humpback Creek Hydro Facilities
A. Hydrologic Data
B. Geologic Data
C. Design & Construction Information
D. Comparison with Other Hydro Projects
E. Summary of Construction Costs
F. Accounting Treatment
Power Cost Equalization
G. Economic Analysis
sensitivity Analysis
Summary of Alternatives Investigated
VI. Construction Plan
A. Introduction
B. Construction Schedule
C. Time Frame for Access Clearing
D. Pipeline Right-of-Way Clearing
E. Pipeline
F. Power Plant
G. Transmission Line
47
51
53
67-1
68
79
88
90
93
95
102
102
107
107
114
116
119
Table of Contents (Continued)
VII. Environmental Analysis and
REA Borrower's Environmental Report
A. Vegetative Resources
B. Fisheries Resources
C. Mammal Resources
D. Birds
E. Marine Biota
F. Consideration of Impact of
Construction on Historical Value
VIII. Summary and Conclusions
A. Summary
B. License Considerations
C. Conclusions
APPENDIX
Appendix A Stream Flow Estimates
122
122
123
128
130
131
131
136
138
139
Appendix B Proposal from Turbine Manufacturuer
Appendix C
Appendix D
Appendix E
Power line Contacts by Eagles and
Other Large Birds
Power Cost Equalization Filing and
Letter from the Alaska Public
Utilities Commission
Comments Received on Draft Report
and Comments Thereon
I. SUMMARY
This report analyzes the feasibility of constructing a
hydro electric project on Humpback Creek, three miles
north of Cordova, Alaska.
The feasibility of this project was investigated in
three different areas:
A. Technical
B. Financial
C. Environmental
The project recommended by this study provides for an
850KW facility utilizing run-of-river flows in Humpback
Creek for a total annual generation of 3.5 million
kilowatt hours, approximately 20 percent of Cordova's
1984 generation.
A. TECHNICAL
Technical feasibility was straight forward. There
are no technical problems which could stop the
project. All of the construction techniques
require straight forward utilization of existing
technology in all areas and use construction
methods previously used in Cordova and known to
work. The technical risk of this project is
extremely small and should not hinder construction
of this project.
The project consists of an intake structure made
of rock filled gabians approximately nine feet
high and 25 feet wide. This intake structure is
designed to remove rocks and other gravel from the
stream flow before the water enters a pipe for
transport to the power plant. The pipeline is
2,000 feet from intake structure to power plant
and consists of two 32 1/2 inch polyethylene pipes
1
for a distance of 1,740 feet. The final 260 feet
will utilize thin wall steel pipe to accommodate
the higher hydraulic pressures anticipated in this
section of the pipeline. The use of two smaller
pipelines reduces the need for heavy construction
equipment and will allow the pipeline to be built
by hand utilizing helicopters to lift the
materials from the beach to their approximate
location of use.
The power plant is a 24 foot by 40 foot
pre-engineered metal building housing one 850KW
impulse type turbine and generator, generating
850KW at 12,470 volts, three phase. This plant is
designed to utilize maximum flows of 85 cfs.
Waters discharged from the turbine will reenter
Humpback Creek through an energy dissipating
tailrace and an energy absorbing structure within
the stream itself. The purpose of the energy
absorbing structure is to prevent scouring of the
stream while maintaining adequate flows for salmon
spawning in the stream. From the power plant an
overhead transmission line will carry the power
across Humpback Creek to the shores of Orca Inlet
where it will connect to the Cordova Electric
Cooperative distribution system.
B. FINANCIAL
Financial feasibility of this project was investi-
gated utilizing the following criteria:
1. Construction Cost of $3,250,000.00.
2. State Equity Investment of 40 percent
or $1,300,000.00.
3. Cordova Electric Cooperative Equity
Investment of 18 percent or $576,000.00.
2
4. The balance to be financed through a State
loan at five percent interest for 35 years.
5. Inflation for power cost purposes was assumed
to be three percent over the study period.
6. A discount rate of 3.5 percent for
benefit-to-cost analysis was used.
7. The Alaska Power Authorityts mean fuel
inflation scenario was used.
This provided a benefit-to-cost ratio of 2.05 with
energy generated by the project costing 6.5 cents
per kilowatt hour (kwh), or two cents per kwh
below an equivalent amount of energy generated by
diesel.
A sensitivity analysis was performed on each of
the assumptions to test their sensitivity to the
value of the assumptions. None of the assumptions
were of particular sensitivity. The project
maintained a benefit-to-cost above 1.0 in all
cases of State participation in the project.
Since the financing will be in place before
construction begins, it is anticipated that the
final project will not be significantly different
from that described above.
c. ENVIRONMENTAL
The environmental feasibility showed that there
were no major environmental risks that could not
be addressed. Two areas may possibly require
mitigation.
The first area concerns the historical value of an
existing dam and hydro electric site. The second
area concerns potential mitigation for dewatering
a portion of Humpback Creek that is used by
3
approximately 200 pink salmon for spawning (out of
a total 1985 run of 26,800 salmon).
The Feasibility Study recommends mitigation
measures in both of these areas. The cost
associated with this mitigation does not adversely
affect the feasibility of the project.
Construction of this project can provide long term
lowering of the cost of electric energy in Cordova
and should be undertaken as soon as financing can
be arranged.
The Draft Feasibility Report was mailed to those
agencies listed in Appendix E. Comments received
from those agencies are included in the Appendix
along with the response of Cordova Electric
Cooperative to each of the points raised. Some of
the points were addressed by rewording the report
and other comments are addressed in the response
provided to each letter. It is important to
realize that these letters brought up no
unforeseen problems with this project and in
general the letters are very supportive of the
Humpback Creek Hydroelectric Project.
4
II. INTRODUCTION
Cordova is a small fishing community located in the
eastern portion of Prince William Sound. Electric
power for the community of Cordova is provided by
Cordova Electric Cooperative, Inc. (CEC) utilizing
diesel fuel. The cost of electric energy in Cordova is
significantly above the cost of energy in surrounding
communities due, in part, to hydro electric
developments under the Energy Program for Alaska
(Four-Dam Pool).
The Board of Directors of Cordova Electric Cooperative
and the Cordova City Council have been actively seeking
alternatives to the non-renewable resources currently
used in generation. The Alaska Power Authority has
been studying long term solutions to Cordova's energy
problems. Silver Lake has been identified as a
possible long term solution but recent evidence
indicates it may not be financially feasible.
The Board of Directors of Cordova Electric Cooperative
decided in late 1984 to pursue smaller scale renewable
energy projects that could provide lower cost electric
energy for Cordova. In early 1985 a hydro electric
development on Humpback Creek was identified as having
the potential for lowering the cost of energy in
Cordova as well as reducing dependence on fossil fuel.
This report investigates the feasibility of a hydro
electric development on Humpback Creek.
This report was prepared by the staff of Cordova
Electric Cooperative. Many people within the
Cooperative and outside had a significant roll in
bringing this report to reality.
5
First we would like to thank Brent Petrie of the Alaska
Power Authority, without his support, knowledge and
willing assistance, we would still be bogged down
wondering what to do next. Many of the resource
agencies contacted were helpful in the development of
this project. We particularly appreciate the efforts
of the Alaska Department of Fish and Game in both their
Cordova office and the Anchorage Habitat Division. All
of the employees of Cordova Electric Cooperative
chipped in to help, some directly and others by
shouldering a portion of the job of those that were
directly involved in this project. Particular thanks
go out to Carl Burton for his ideas, strength and
willing assistance throughout the year, and Jim Roberts
who always got the jbos no one else wanted to do. Our
thanks also to Bill Corbus of Alaska Electric Light and
Power who lent us Corry Hildenbrand, a very smart
engineer, who got us started in the right direction on
the power plant.
6
III. CORDOVA
A. GENERAL DATA
Cordova Alaska is located on the southeast shore
of Orca Inlet near the eastern entrance to Prince
William Sound. The community is surrounded by the
Chugach National Forest, with most of its
development on the foothills of Mt. Eyak facing
across Orca Inlet toward Hawkins Island. Cordova
extends from the coast back to Eyak Lake across a
narrow divide between the slopes of Mt. Eyak to
the north and Mt. Eccles to the south. Five thin
lines of settlement radiate from the central
development, two extend around both sides of Eyak
Lake, one along Whiteshed Road, one along Orca
Road, and one along the Copper River Highway to
Mile 13 at the Cordova Airport. Elevation ranges
from sea level to 400 feet and the marine
influenced climate ranges from a January average
temperature of 26 degrees Fahrenheit to a July
average of 54 degrees Fahrenheit. Rainfall is
heavy, with an annual average precipitation of 177
inches.
Cordova is approximately 160 air miles southeast
of Anchorage and 410 miles northwest of Juneau,
while the nearest community, Valdez, lies 65 air
miles to the northwest. Presently, Cordova is
accessible only by air and water. Plans for the
construction of an overland connection to the
State Highway System have been delayed.
Cordova was founded in the early 1900's to ship
coal, oil and copper from the Wrangell Mountains.
Today, the fishing and fish processing industries
form the base of the community's seasonal economy.
7
•
At present, Cordova has a permanent population of
approximately 2,500 persons, but each summer an
influx of transient fishermen and cannery workers
double Cordova's population.
Cordova Electric Cooperative was formed in 1978
and on September 30, 1978 purchased all of the
electric utility assets of Cordova Public
Utilities, a municipally owned power system.
Cordova Public Utilities was not regulated by the
Alaska Public Utilities Commission, but at
transfer of assets, Cordova Electric Cooperative
was regulated. Since that time, in response to a
change in State Law, the members of Cordova
Electric Cooperative voted to become deregulated
on matters of rates and quality of service from
the Alaska Public Utilities Commission. At this
point, Cordova Electric Cooperative is regulated
solely as to service area.
B. ENERGY BALANCES
In understanding Cordova, it is important to
realize that the average price paid by consumers
for electricity in Cordova is approximately 21
cents per kwh. This price has prompted a
considerable amount of conservation and Cordova
Electric Cooperative, in conjunction with Alaska
Power Authority, has undertaken a study to
determine alternatives to diesel fuel. That study
is currently underway and while there are several
promising alternatives available, as a practical
matter, none will be available before the mid
1990's.
In order to establish a basic picture of energy
use in the Cordova area, an energy balance has
been compiled for the year 1979. No attempt has
8
been made to update these figures, but it is
doubtful that any significant changes have
occurred. Energy forms used are diesel fuel,
gasoline, heating oil#l, aviation gasoline, and
propane. It is recognized that coal, wood, wind
and natural gas are energy sources which have been
used on a small scale. While utilization data is
not available, it is estimated that 75 percent of
the dwelling units utilize wood for heat in
varying degrees.
Figure III-l summarizes the energy balance in
Cordova and the immediately surrounding area by
energy form and end-use category. This chart was
prepared by International Engineering Company as
part of their 1981 "Reconnaissance Study of Energy
Requirements and Alternatives for Cordova". Data
was obtained from several local sources and best
estimates were made for some aspects of the
breakdown shown in Figure III-i.
C. ENERGY REQUIREMENTS
The future energy needs of Cordova to the year
1999 have been projected based on the low
population growth scenario developed by Stone &
Webster. Figure III-2 shows the anticipated
population projections for three different growth
cases developed by International Engineering.
These population growth projections are based on
projections made for Outer Continental Shelf (OCS)
leasing impacts as follows:
Low = No impact scenario
Mean = Most probable impact scenario
High = Maximum probable impact scenario
9
EFFICIENCIES ASSUMED:
TRANSPORTATION 30,..
ELECTRIC GENERATION 30 %
INDUSTRY* a HEATING 70 %
* FISH PROCESSING
ENERGY AS
WASTE HEAT
~ rll!1
~ ~p~'m
.. ,..: :::: !::::
~ ::::::::::::: •...•......•.
~ :::::::::::::
/ .:.:::::::::
: :t~;~;t
/ :::::.:.:.:.: .: ::::::;:;:;:
Tr-~~~~~~~~~~~~~~~ o GASOLINE
T AV GAS 19.2".
A 1.3x106 GAL. L 1------.;.:.=.;..:.=.......;;;.;.;~-_4
E
N
E
R
G
Y
C o
N
S
U
M
E
D
DIESEL FUEL
1 HEATING FUEL
PROPANE
80.8%
5.2x106 GAL.
BOAT TRANSPORTATION 36.1 %
INDUSTRY 1.9%
E
N
E
R
G
Y
. ./ / ./ / /.' / / / / ./ .' / ./ . ./ .. / / .' / / / ... / / /.' ./ / / / / / ./ ./ ./ / / / ./ / ::::::::::::: / / / / / / ./ / 43.4 D/o U
./ .. ,o./ .. ./ / .' / / / / ... /. .' o'..'././ •• :.:.:.:.:.:. / / ./ / / / / ./ / ./ / ./ ./ ./ / T . " .... '7' ,..'/" ,/ / /',.. / .--/ / / ./ . ' / / -' / / / ,/ /./ / / ,/ ./ / ./ ./ ,/ .' ./ / :.:.:.:.:.:.:.-/././ / , . / / / / / / / / / 18 % / / I HE ATI NG 201. %././ ./ ./ .' / .. / ./ // ./ ./ / / ./ / / / / / / / / ; / / / / / / / / :::::::::::::::. / / / / / / / / / / / / / /. . . . " .. / / ./ ./ / ./ / ./ ./ / / / / / . / .' / .. ./ / / ./ / / ./ / .. / / / / / / / / / / / / / / / ..: .. :.:.:.:.:.:.:.. ./ / ./ .' / / / / / / / / ./ L
l~!!.!!~i!~:liiilii\~ii:~i~:~~~j~~:~:!~~~:!!~!~~;~~~:!liF / / / ,/ / / ~
CORDOVA PETROLEUM BASED ENERGY BALANCE IN 1979
FIGURE 111-1
Source: International Engineering Company
,--
5000 ------
-4S0~ --.
-HIGH
4 .... ..:= --_. -L -....----.a. "-----.. -..--, ---~ I'"""""" ""--MEAN ... -"""'" ~ .-~~ -S~~ ~ .. -~ LOW ~"""" _. --
25-,-
20_
1500 --,_._-
1000
500 ---
0
"80981 .1982 1983 198:4 198~ 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000
YEAR
Source: International Engineering Company
POPULATION PRO.ICTiONS
CITY OF CORDOVA
FIGURE 111-2
The growth in power needs for the last two decades
has greatly surpassed the growth in population for
the City of Cordova. This is consistent with the
increase in fishing and seafood processing
activities in the area and a general change from a
canned product to a frozen product. The seasonal
inflow of people is also a factor which does not
contribute to stable population increases.
D. EXISTING ELECTRICAL SYSTEM
Cordova Electric Cooperative operates and
maintains the power system Certificated, but not
regulated, by the Alaska Public Utilities
Commission. The power system extends from the
southwestern shore of Eyak Lake near Copper River
Highway, south to Three ~1ile Bay, north to the
Chugach Alaska Fisheries processing facility at
Orca, and east to Cordova Airport at Mile 13 of
the Copper River Highway.
Cordova Electric Cooperative maintains two diesel
engine driven power plants. The older, Eyak
Plant, is on standby during the winter period and
runs on base load during the summer. This plant
requires full time operators.
Generating Units In Eyak Power Plant:
Unit Age Capacity
#1 15 years 1900 KW
#2 12 years 2650 KW
#7 46 years 600 KW
#8 46 years 750 KW
Total Installed Capacity 5900 KW
10
The newer, Orca Plant, was placed in operation
during 1984 and is operated in an unattended mode
during the 10 p.m. to 6 a.m. period. During the
winter this plant is base loaded. During the
summer, the plant is used for peaking, operated by
remote control from the Eyak Plant.
Generating Units in Orca Power Plant:
Unit
#3
#4
Age
7 years
1 year
Total Installed Capacity
Capacity
2500 KW
2403 KW
4903 KW
Due to the age and unreliable condition of Units
#7 and #8, only one of them is considered when
determining firm and reliable capacity. On an
industry wide basis, "firm" power is defined as
the total generation capacity with the largest
unit out of service. Cordova Electric Cooperative
also uses the term "reliable" capacity which is
defined as the total generation capacity with the
largest unit out of service for overhaul and the
next largest unit also out of service due to
mechanical breakdown. These two separate
definitions of capacity are important for the
following reasons:
During the summer peak load periods, major
maintenance is not scheduled on any of the
engines. Thus they are all available for use
(except any mechanical breakdown). Thus, "firm
capacity" is used to determine our ability to meet
our summer peak loads.
11
Major maintenance (removing an engine from service
for several weeks) is scheduled during the winter.
The Cooperative must be able to reliably meet the
smaller, winter peak levels with one engine out of
service for maintenance and another engine down
with a mechanical problem. Thus the term
"reliable capacity" is used to determine the
ability to meet our winter loads.
Figures III-3 and III-4 show the estimated yearly
total electrical energy consumption and
corresponding peak power demands for the three
growth cases.
In making these projections, certain key factors
and assumptions influenced trends. These factors
are:
Actual population growth based on census
figures has historically been less than
projected figures. Use of the Outer
Continental Shelf leasing impact scenarios
discussed was used as the most realistic
basis of projection.
Employment will grow at an annual rate of
about 1.5 percent in the economic sectors of
trade services and fishing.
The trade and service sectors will increase
by about 4 percent per year as tourism and
recreation opportunities increase.
Manufacturing employment, primarily fish
processing, will increase by 1.5 percent per
12
8 0
7 5 ~V
7
/
./ '("'
/ /
5
/
'/
0 6
/ '"
5
V '\
~HIGH
0
l7 ./ r .....
5
V / "
./ V
5 ,
V ~ ~" ~
~ ./ -...........-0 V --" IlMEAN V ...---I----I----. --./ ~. -' 1-
5
V '" ---_L..--
[(LOW -----1.---~ -------P"""""
0 -----~~ ~ .. Hl----r~ b.. __ ,!:
FI" P" PROJECTED YEARLY I~P" ELECTRIC CONSUMPTION
2
2
CITY OF CORDOVA
FIGURE 111-3
1 0
1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000
Source: International Engineering Company YEAR Note: ~ Actual
,""~ 17
,IVV"> L
'~ V / IIVV"'o
'~ / / 000
/ / 000
/ /
,~
lX
,
1000
/ HIGH)
16
15
14
13
12
7
000 V ./ 0"" '-.,
..." V -----" ............ 000 V i-MEAN ,."",
,.-. l"""""'" i/ J-~.""... V ~~ ~-.
000 /" ,,/
,.,-
1-............
,.,...-
/ ~ ............. 00 -
V ~ ~----' ,.""",-~ ... (:"ow
~ -------",.-.------------500 r"~ ~ 1-~ . ---."..,. ...
tr [:1 ---PROJECTED YEARLY PEAK
000 f.t .-..Ii ~ --POWER DEMAND .-CITY OF CORDOVA .-.I r--
10
6
4
l !!"""" FIGU"EIII-4 .. ,.,..
1980 IMI 1982 "83 1.4 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1996 1999 2000
Source: International Engineering Company YEAR
Note: (!] Actual
year. The growth will keep pace with
estimated increases in fish harvests.
Surface transportation is assumed to increase
by 1 to 2 percent pet year. This employment
will result from increases in tourism and
recreation.
Government employment will grow at a rate of
only one percent per year.
Secondary employment estimates are based on
an employment multiplier of 1.47. This low
multiplier is reasonable in view of the
convenience to purchase goods and services in
Anchorage. As the trade and commercial
sectors of Cordova's economy grow, a higher
multiplier can be expected in the future.
Population estimates are based on a
population employment ratio of 2.0, the 1978
ratio. This ratio resulted in a forecasted
population growth of 1,320 from 1981 to the
year 2000 for the Cordova area.
The low-growth scenario is used as the basis
for change in the number of electric
customers and the use per customer for the
other growth scenarios.
No OCS leasing.
Half of the new growth for Cordova would come
from new developments and improvements in the
fish processing industry.
13
Half would come through development of the
local service sector.
Although no firm plans exist for new
commercial and industrial facilities in
excess of 350KVA, the City of Cordova is
currently developing two marine areas which
should be available for construction within
two years.
The south containment area consists of 12
acres immediately adjacent to the small boat
harbor. This area is to be leased to firms
requiring access to water. The loads in this
area are expected to be large commercial
users in the 25 to 250KW r~nge.
The north containment area consists of 17 .
acres immediately adj acent \.::0 the existing
fish processors. This area will be zoned
industrial and loads ranging from 150 to
1,000KW are anticipated whe~ the land becomes
available.
The rate of increase in per consumer
residential electric use has slowed in recent
years due to the rapid increase in the cost
of electricity. Since 1982, residential
electric rates have remained constant and
State of Alaska Power Cost Equalization has
actually reduced the cost to the consumer.
(See Figure III-5). Per residence
consumption is expected to increase slowly.
It is believed that the residential consumer
will pay the same amount for electric energy
in constant dollars. If the general
14
120
110
100
90
80
70
t; 60 0
U
50
40
30
20
10
0
IZZI
1979
Residential Electric Bill
(Per Month)
COST OF 500 KWH
AS OF' DECE~BER 31
1980 1981 1982 1983
COST TO CONSU~ER IS:sJ STATE ASSISTANCE
Figure 111-5
198 ..
inflation rate increases faster than the cost
of electricity, then consumption will tend to
increase. If the cost of electricity rises
faster than inflation, then consumption will
decrease.
E. GENERAL INFORMATION ABOUT THE CORDOVA AREA
Fishing and Fish Processing
Cordova's economy is presently dominated by
fishing and the fish processing industry.
However, there are several other existing and
potential sources of economic strength in the
Cordova area. Among the most notable are tourism,
which is actively being pursued by both the
Cordova Chamber of Commerce and the City Council,
wood products, oil, gas, coal and minerals.
Cordova is host to a considerable amount of
government facilities, including those of the U.s.
Coast Guard, Federal Aviation Administration, U.s.
Forest Service, and the Alaska Department of Fish
and Game.
The Federal Aviation Administration has announced
plans to automate the facilities at Mile 13
airport and remote the Cordova facilities from
Juneau. This would result in a reduction of FAA
Staffing in the Cordova area, however, the
electrical load would remain essentially constant.
In addition to the Coast Guard Cutter Station in
Cordova, the u.S. Coast Guard has established a
helicopter detachment in Cordova and is currently
constructing a bunkhouse and other facilities to
support the air crews. Coast Guard activity in
15
the Cordova area will increase significantly over
the next several years.
Although mining was the early basis of Cordova's
economy, fishing and fish processing have always
played a major role in the economy. Cordova is
the center of fishing and fish processing
operations for the Bering River, Copper River and
Prince William Sound areas.
The fisheries industry in Cordova diversified
considerably during the 1980's adding King,
Dungeness and Tanner Crab, shrimp, herring,
herring roe, herring roe-an-kelp, halibut and
razor clams. Some of these fisheries have seen
recent declines, although the long term outlook
for these alternative fisheries remains good.
Salmon continues to be the most important fishery,
accounting for 75 percent of the value of fish
caught in Prince William Sound.
Presently there are four major seafood processing
companies operating in the Cordova area. St.
Elias Ocean Products, North Pacific Processors and
Chugach Alaska Fisheries all have major facilities
capable of canning and freezing significant
amounts of salmon and other seafoods. The Copper
River Fishermen's Cooperative provides a large
scale freezing operation in the Cordova area but
no canning capacity. The Copper River Fishermen's
Cooperative has quadrupled their electrical load
within the past four years and is expected to
continue this growth rate for the next several
years.
16
There are also a number of other companies that
conduct highly specialized seasonal operations out
of Cordova, particularly in the processing of
herring and salmon egg products. Cordova also has
several small locally b~sed firms which produce
specialty salmon products. Included in these are
Odiak Smokeries, Blake's Canning and Glacier
Packing.
Climate
The Cordova area has a maritime climate
characterized by cool summers, mild winters and
heavy year-round precipitation. This type of
climate is typical of the southeastern and
southern coastal areas of Alaska where the ocean
exerts a modifying influence to cause relatively
low seasonal and diurnal temperature variations.
The nearness to the ocean, plus the frequent lows
which develop or move out of the Gulf of Alaska,
result in heavy precipitation. Precipitation
levels in the Cordova area are further exaggerated
by the rugged Chugach Mountains, while the steeply
rising slopes of Mount Eyak and Mount Eccles cause
still higher precipitation totals in the City
itself.
Cordova's winters are relatively mild. The
coldest month (January) averages about 26 degrees
Fahrenheit and, although temperatures as low as
minus 33 degrees Fahrenheit have been recorded,
extremely cold weather usually is of short
duration. On the other hand, summer temperatures
in the community tend to be on the cool side,
averaging between 50 degrees Fahrenheit and
55 degrees Fahrenheit, with daily maximums
reaching into the low 60's in July and August.
The record high temperature in Cordova is
17
84 degrees Fahrenheit, a mark set back in 1946.
As with extremely cold weather, however, lengthy
periods of high temperatures in Cordova are rare.
Heavy year-round precipitation is a dominant
feature of the climate of the Cordova area. Total
precipitation averages 81 inches per year at the
Cordova Airport and 177 inches annually in the
City itself. In winter, precipitation occurs as
snow, and since winter temperatures in Cordova are
relatively mild, the snow here has a high water
content and snow loading factors are very high.
According to the u.s. Army Corps of Engineers, the
design snow load factor for Cordova should be 100
pounds per square foot, the highest in the State.
In practical terms, it means that people have to
guard against excessive snow accumulations on
roofs, boats and light airplanes.
Cordova experiences strong winds in excess of 75
mph several times a year, predominantly in the
fall months. Fishermen in Prince William Sound
often encounter severe storms. Average annual
wind speed at Cordova is less than five miles per
hour, with easterlies being prevalent except in
April and May when winds shift to east southeast
and in June when the prevailing winds are from the
southwest. Occasionally, however, pressure
patterns cause cold air from the interior to flow
across the coastal ranges to the Pacific Ocean.
When this happens in the Cordova area, these winds
funnel down across two glaciers near the airport
to cause strong cross winds that sometimes prevent
aircraft from landing.
18
Vegetation and Wildlife
Cordova is surrounded by the Chugach National
Forest. The timber in this area is characterized
by overmature mixed stands of Sitka spruce and
western hemlock, with minor amounts of mountain
hemlock and black cottonwood. Pure Sitka spruce
stands usually only occur along river banks,
although this species does dominate stands on the
glacial flats in the Copper, Martin and Bering
River valleys.
The Copper River delta flats are a vast tidal
marsh with a vegetation cover of salt and
freshwater marsh grass and grasslike plants,
willow, alder, and a few scattered stands of Sitka
spruce and cottonwood. This is a major resting,
feeding and nesting area for migratory birds on
the Pacific flyway and is within the 330,000 acre
Copper Delta Game Management Area which was
jointly established by the u.S. Forest Service and
the Alaska Department of Fish and Game in 1962.
The productivity of the waterfowl habitat in the
area was greatly reduced by the 1964 earthquake
which uplifted the beach by about six feet and
converted productive brackish ponds into infertile
freshwater ponds. To some extent, this loss has
been offset by the uplifting of islands and
sandbars and their subsequent conversion to prime
wildlife habitat. The u.S. Forest Service has
expended a considerable effort to improve habitat.
Big game animals in the Cordova area include black
and brown bear, mountain goat, deer and moose,
while glacier bear have been observed in Port
Gravina. Moose, however, are not native to this
area and the present herd of 500 or so is
19
descended from 26 animals which were transplanted
here in 1949. Furbearers are also plentiful and
include wolf, wolverine, lynx, beaver, mink,
muskrat, marten, land otter, fox, weasel and
coyote.
While a number of big game hunters are attracted
to Cordova, the area is best known for its
waterfowl resources. The largest known
concentrations of Trumpeter Swans in North America
nest here, as well as 15,000 to 20,000 Dusky
Canada geese and a variety of ducks, geese,
cranes, shore birds and other sea birds. Bald
eagles are also numerous, although the highest
concentrations are in the Port Fidalgo area,
closer to Valdez.
Sea lion and seal inhabit several areas along the
coast, while the coastal waters and streams afford
a range of fishing opportunities to the sportsman.
The Copper, Bering and Eyak River systems contain
large king, red and coho salmon fisheries which
are used by commercial, subsistence, and sport
fishermen, with the Eyak River coho salmon fishery
and several small trout lakes being especially
popular with local sportsmen. Clam digging is a
popular pastime, while the waters of Prince
William Sound provide excellent fishing opportun-
ities for salmon, red snapper, flounder, halibut,
crab and shrimp.
Population
Since 1960, Cordova has experienced a period of
steady growth, due primarily to expansion within
the fishing and fish processing industry and the
resulting lessening of seasonality in that
20
industry. Between 1960 and 1970, Cordova's
population increased 28.6 percent and this rate
has been surpassed since 1970. The estimated
population of 2,000 in the Cordova area in 1975 is
32.2 percent above the 1 i 513 persons recorded as
living in Cordova and Meakerville by the 1970
census. However, some of this apparent increase
is due to the fact that the Cordova planning area
(Cordova and road-connected areas as far out as
the Cordova Airport) is larger than two census
enumeration districts.
The 1980 census indicates a population of 2,523.
Transportation
Cordova is presently accessible only by water and
by air. The rugged Chugach Mountains, with their
massive icefields and glaciers, have greatly
restricted access to Prince William Sound. Only
two land routes into the area are developed at
this time. One of these is via railroad tunnels
between Portage and Whittier and the second is via
the Richardson Highway south of Glennallen to
Valdez. No land routes connect any of the other
communities of Prince William Sound. The City
Council of the City of Cordova has recommended
completion of the Copper River Highway. Cordova
Chamber of Commerce plus other groups in the
community are also supporting connecting Cordova
with the rest of the State with an overland route.
Also under serious discussion is an overland road
to the Katalla area which would provide access to
the coal, oil, and gas resources of that area.
Whether the overland route out of Cordova is
constructed or not will not have a major impact on
21
power requirements during the period under
consideration of this study.
Even by Alaska standards, Cordova has exceptional
airport facilities and airline service for a town
of its size. The community has two State
airports. Cordova Airport, located at Mile 13 of
the Copper River Highway, has a 7,500 foot paved
runway capable of accommodating jet traffic. The
Eyak Lake Airstrip, located on the north shore of
Eyak Lake, has a 1,950 foot gravel runway which is
used by small planes weighing up to 12,500 pounds.
Two helicopter facilities are also located at this
airstrip although only one of these has a wooden
platform. Finally, Eyak Lake itself serves as a
seaplane base and has a 10,000 foot landing area
which is used by float planes or those equipped
with skis, depending upon the time of year.
Wood Products
The wood products industry has been a small, but
significant element in Cordova's economy since the
community was founded. In the early days, timber
was cut sporadically to meet demands for mine
timbers, railroad ties, fish traps, dock pilings,
and community needs.
Today, a small sawmill at Mile 13 cuts dimension
lumber primarily for use in the local area.
ro1ineral Development
Although mining played an important part in
Cordova's economy in the past, exploration and
development of metallic and non-metallic minerals
in the region is presently at a fairly low level.
This does not mean that the region has a low
22
mineral potential. Known occurrences of metallic
minerals include copper, gold, silver, molybdenum,
antimony, nickel, iron, lead and zinc and known
non-metallic minerals include coal, limestone,
sand and gravel.
Most of the copper produced in Alaska came from
the Kennicott mines in the Chitina River valley
between 1911 and 1938. Four mines in this area
yielded about 1.2 billion pounds of copper from
ore averaging an extremely high 12.4 percent
copper. The discovery of these deposits led to
the construction of the Copper River and
Northwestern Railroad and the development of port
facilities at Cordova. However, these deposits
are now believed to be largely depleted although
small scale operations are periodically
undertaken, such as a recent operation which was
engaged in hand sorting old tilings and flying out
the ore.
Gold and silver have been produced in the Cordova
region in the past, but no major gold rush
occurred here.
Coal
The Bering River Coal Fields, among the largest
undeveloped coal fields in the world, have been
receiving a considerable amount of attention
recently with the transfer of this area to the
Chugach Natives as part of the Alaska Land Claims
Settlement Act. Recent tests of the Bering River
Coal Fields found a particularly high quality
anthracite coal in the 13,000 to 14,000 BTU per
pound range which is unique in Alaska. The
bituminous coal in the area also has a very high
23
BTU content, as well as being a particularly dry
coal (low moisture content).
Development of the Bering River Coal Fields has
been hindered since the turn of the century by
lack of a suitable transportation mechanism to
remove this coal and bring it to market. Efforts
as long ago as 1906 to build a shipping port in
the area have failed.
Chugach Alaska Corporation has been actively
investigating the feasibility of developing the
Bering River coal resources. Recent estimates of
the energy required to operate a world class coal
mine in this area range upward of 50 megawatts,
with an annual energy requirement of 120 million
kwh. This is approximately ten times Cordova's
current demand and it is possible or probable
that, should such a coal mine be developed,
Cordova Electric Cooperative would enter into some
form of power purchase agreement with the
corporation developing the facilities.
F. POTENTIAL FUTURE DEVELOPMENT
Fishing
Over the next several years, the fishing industry
will see a significant change. Part of the change
will come about from increased marketing efforts
in the salmon industry, particularly in the frozen
salmon area where processors feel the most growth
will come.
There is also a growing market for Tanner or Snow
crab. This is a market which did not exist a few
years ago. Cordova will be one of the prime areas
for processing Tanner crab.
24
There have been many efforts toward development of
a bottom fish industry for Alaska. Although
Kodiak is the most likely site to support bottom
fish processing in the Gulf of Alaska, Cordova may
see significant impact.
A problem that Cordova faces is the extremely high
cost of electric energy
like Valdez (on hydro),
and Kodiak (on hydro).
compared with communities
Seward (on natural gas),
The State of Alaska has
made direct equity investments in the hydro
electric facilities in Kodiak and Valdez and
provided grants in aid of construction to Seward
to expand and improve their electric system.
Electric energy costs in these communities range
from 50 to 90 percent of the cost in Cordova.
The Governor of Alaska has appointed a task force
to examine the possibility of averaging wholesale
power costs around the State of Alaska. If such a
program is implemented, the cost of electricity to
the major industrial users in Cordova will drop by
almost 50 percent. This would provide a major
incentive for processors and other heavy
industrial loads to locate in Cordova. Without
Power Cost Averaging (or the State of Alaska
selling power from the hydro facilities in Kodiak
and Valdez at its true cost of production) any
major new processing growth will probably occur in
one of these other communities. That will not
prevent the existing processors in Cordova from
moving more and more into the fresh/frozen market.
25
Oil and Gas
Oil and gas developments played a role in
Cordova's economy in the early days and promise to
do so again in the future. The Katalla field,
discovered in 1902, was Alaska's first producing
oil field. Thirty-six shallow wells were drilled
here although only 18 produced oil in commercial
quantities and the most productive yielded a mere
20 barrels of crude oil per day. All told, the
entire Katalla field produced only about 154,000
barrels of oil in over 30 years of operation.
1985 and 1986 will see oil and gas exploration in
this area once again.
Upcoming oil and gas-related developments,
however, promise to have a much more substantial
and permanent impact on Cordova's economy.
The Gulf of Alaska is a major undeveloped
petroleum province although estimates of its
magnitude remain highly speculative. For example,
the Alaska Department of Natural Resources has
estimated the Gulf to have combined on-shore and
off-shore reserves in the vicinity of 8.8 billion
barrels of recoverable oil and 64.2 trillion cubic
feet of natural gas. The U.S. Geological Survey's
estimates are rather more conservative. That
agency estimated the scale of undiscovered
recoverable oil and gas resources of the entire
south coastal area of Alaska to be in the
neighborhood of .5 to 2 billion barrels of oil and
1 to 5 trillion cubic feet of natural gas from
on-shore lands and between 1 and 6 billion barrels
of oil and 2 and 17 trillion cubic feet of natural
gas from off-shore areas. The Bureau of Land
Management's estimates for the area between
26
Cordova and Yakutat which is scheduled to be
leased are the "high" estimates developed by the
u.s. Geological Survey, i.e. 2.8 billion barrels
of oil and 9 trillion cubic feet of natural gas.
Although the Trans-Alaska Pipeline route for
transporting North Slope oil has been established
and has been completed, the route for transporting
North Slope natural gas has yet to be determined.
Three major route proposals are under
consideration.
G. POWER COST DATA
Background
Cordova Electric Cooperative is not interconnected
with any other system and generates all of its
power with diesel engines. Since its formation in
1978, the Cooperative has purchased two new
generators and built a new power plant.
Both Cordova Electric Cooperative and the Alaska
Power Authority are investigating alternative
forms of energy to replace the high cost energy
generated with diesel fuel. There are many
possible alternatives, but none are considered of
high enough probability to be included in this
report other than the effect of the Humpback Creek
development. Of the possibilities under
consideration, it is not anticipated that any
major solution will be found and brought on line
within the next fifteen years.
27
Analysis of System Reguirements
1. outage Record.
The outage record of Cordova Electric Cooper-
ative has averaged above the REA guidelines
of five consumer hours per year. Figure
111-6 shows the cause of these outage hours
with the 15 minutes required to place an
engine on line, it is difficult to plan to
improve the outage record caused by
generation. The major source of outages is
dig-ins by contractors.
2. Future Capacity Requirements.
There have been many studies which have
attempted to determine the future population
and industrial composition of Cordova. These
were summarized by Stone & Webster in the
Cordova Power Supply Interim Feasibility
Assessment.
Recently, CEC solicited opinions from
employees, Board members and members of the
community as to their current views of
Cordova's future. In general, the views tend
to agree with Stone & Webster's analysis of
slow but steady growth.
Figure 111-7 shows the peak load projections
of Stone & Webster. This is the peak load
averaged over 15 minutes which was reached at
any time during the year. With the fishing
industry, the peak occurs during summer
months. Cordova Electric Cooperative must be
able to meet this load even with the largest
unit down for repairs. This is called the
28
Figure III-6
SERVICE INTERRUPTIONS
Average Consumer Hours Without Power
Year Plant Storm Prearranged All Other Total
1979 4.12 .15 11. 70 6.21 22.22
1980 2.79 .76 4.29 1. 30 9.14
1981 2.40 2.61 .57 2.12 7.70
1982 8.26 0 .11 3.58 11. 95
1983 .95 .14 .33 3.77 5.19
1984 .84 .98 .12 2.22 4.16
All Other categories:
Hours Without Power
Source 1983 1984
Fault .56 .95
Dig-In 2.51 .74
Unknown .70 .22
Overload 0 .31
Total 3.77 2.22
"firm" capacity. The firm capacity of our
total system (both power plants operating,
but the largest unit out of service) is 8153
KW. This is sufficient to meet our summer
loads until the 1990's. Individually, the
Orca Plant has a firm capacity of 2400 KW,
the Eyak Plant a firm capacity of 3250 KW.
Obviously, both power plants will meet the
peak load with a major unit out of service.
However, neither power plant alone can do
this.
Equally important is the winter load. During
the winter months, Cordova Electric
Cooperative must be able to meet the loads
with one unit out of service for an extended
period of time (such as for an overhaul) and
have another engine fail with a mechanical
problem. Since the maximum loads occur
during the summer months, Cordova Electric
Cooperative does not schedule any work on
engines that would have them out of service
during those months for an extended period of
time.
Figure 111-8 shows the peak winter loads.
There are several important points to
consider in the chart. First, during 1979
and earlier, the peak winter electrical loads
(due to the crab fishery) ran approximately
90% of the summer peak loads. Since 1980,
the winter loads have run 2/3 of the summer
peak. Figure 111-8 is based on 2/3 of the
summer peak load. If the winter crab
industry is expected to be reestablished, the
29
PEAK SYSTEM DEMAND
1985 POWER COST STUDY
12.0 ~----------------.---------------------------------------~
11.0 Firm Capacity
10.0
9.0
8.0
~ :; 7.0 :>-
------~ --------
""-'"
0 6.0 -"7 ~-.. t
'..:.: 5.0 -=-w
0
4.0
3.0
2.0
1.0 I
0.0 -+---,.-------,----,---~I ----r--..-1--,-..... -.----.-------r--l--I -1---r-----r-·-T---:·:-~
82 84 86 88 90 92 94 gc, 98 2(j~)O
YEAR
Figure III-7
WINl-ER PEAK DEMAND
1985 POWER COST STUDY
12.0
1 1 .0 -Reliable Capacity
10.0 -
9.0 -
8.0 -
~
> 7.0 :2 -
'-..../
0 6.0 z «
-
----------.... -
~ 5.0 LLJ
--
-----------------0 ~--
4.0 -
--~-----~ ---~
3.0 -C/
2.0 -
1 .0 -
0.0 1 I I I I I I [----1---1----I---T----r I I -----,-----r---;
82 84 86 88 90 92 94 96 98 2000
YEAR
Figure 111-8
winter peak loads would be considerably above
that shown.
For the purposes of this document, only the
"no winter fishing" case will be considered.
3. Fuel Supply.
All diesel fuel used by Cordova Electric
Cooperative is supplied by Chevron USA who
maintain bulk storage tanks near the Orca
Power Plant. Cordova Electric Cooperative
has investigated the feasibility of install-
ing its own bulk storage tanks on several
occasions. The current cost differential
between the wholesale price of diesel at the
Kenai Refinery and the price paid by Cordova
Electric Cooperative in Cordova does not
support installation of tanks by Cordova
Electric Cooperative. This option will
continue to be reviewed periodically in the
future.
Cordova Electric Cooperative currently
maintains a 10,000 gallon storage tank at the
Orca Power Plant. In addition, a 16,000
gallon fuel tank and 8,000 gallon bulk lube
oil storage tank are currently being
installed. These tanks will be well diked
and will meet all Environmental Protection
Agency requirements for pollution prevention
and control. During the winter months, this
tankage will provide approximately seven days
supply of fuel. During the summer, this will
provide a four day supply of fuel. Chevron
has recommended a four to seven day emergency
reserve supply.
30
The Eyak Power Plant currently has the
following tanks:
Size
130,000 gal.
10,000 gal.
4,000 gal.
1,000 gal.
4,000 gal.
300 gal.
Use
Bulk Storage
Not in Use
Fuel Storage for #7 & #8
Day Tank for #7 & #8
Enterprise Day Tank
#1 Intermediate Day Tank
In addition, two 10,000 gallon fuel oil tanks
are currently being installed and the 130,000
gallon bulk storage tank is to be retired. A
10,000 gallon waste oil storage tank is also
being installed that will hold waste
lubricating oils to be used to heat the Eyak
Power Plant during the periods it is not in
operation. Adequate diking is being
installed around these tanks to meet all
Environmental Protection Agency requirements
for pollution prevention and control.
4. Real Estate and Zoning.
The location of the Orca Power Plant is
currently unzoned, but the use of the entire
area is heavy industrial. Within a short
distance of the Power Plant is the Morpac
Fish Processing facility, the Chevron fuel
tank farm, the municipal dock and an
industrial staging area. If this area is
later zoned, our use of the area for power
production will be protected.
The property of the Eyak Power Plant is
within the Eyak Lake AMSA (Area Meriting
Special Attention). This area is under study
for inclusion in a special restrictive use
zoning to protect and improve the water
31
quality of Eyak Lake. The use of the Eyak
Power Plant site for power production is a
non-conforming use. Cordova Electric
Cooperative will be allowed to continue the
present use of the site, but expansion or
additions will not be permitted.
5. Warehousing.
Under cover, out of the weather storage is
very limited. The line materials building
consists of an open faced storage shed used
for storing line hardware, such as bolts,
insulators, fused cutouts, etc. Steel and
PVC conduit, pipe and riser guard are stored
on the ground under the open faced warehouse.
There is no security for these items, but
vandalism and theft do not appear to be a
problem.
The "line shed" is an old two story building
left over from Copper River Highway construc-
tion days. This building provides storage
for underground construction materials,
meters, and street light parts. This
building is heated by electric heat. The
building provides the only secure storage for
line materials.
6. Power Plant Automation.
The Orca Power Plant was designed to run
unattended. The control system is a
straight-forward relay operated system that
contains the following capabilities:
32
a. Remote start/stop of each engine
from the Eyak Power Plant. Future
improvements will allow the Eyak
Power Plant to control the specific
load on each unit.
b. Selection of a "first unit" by
manual switch. The first unit is
the unit that will remain running
if two engines are no longer
required.
c. Automatic start/stop of the standby
unit by the "first unit". Load
sharing automatically provides that
each engine take one-half the load
when both are on line.
d. Automatic Black Start. If the
power goes off, both engines will
try to start. The first engine up
to speed will automatically place
itself on line and take the load.
This feature is normally not used
since the initial cold load pickup
is usually above the capacity of
either engine by itself and would
result in a shutdown of that unit
on overload.
Note that the system does not have
the capability to be expanded to
handle the involved decision making
if a third unit is added to the
power plant at a later time.
33
IV. BACKGROUND
A. BACKGROUND
Cordova has a long history of hydro electric
investigations in addition to the operating hydro
facility that was constructed on Humpback Creek in
1908. A development began on Power Creek in the
1920's but technical problems forced abandonment
and, other than numerous studies, there have been
no specific efforts to build any hydro electric
development on Power Creek.
Other investigations of hydro electric facilities
in the Cordova area include a 1968-69 plan by
Cordova Public Utilities to place a major storage
hydro project on Power Creek. An application was
prepared for submission to the Federal Energy
Regulatory Commission, but was ultimately not
submitted. This plan called for three turbines of
1,250 KW each for a total installed capacity of
3,750 KW. Although no cost data is available for
this project, personal communications have
informed us that the project was not submitted to
FERC because it became obvious that construction
was going to be much more expensive than
originally anticipated and was not economically
feasible with the price of diesel fuel at that
time. There were also serious questions
concerning the technical aspects of this
construction.
In September 1977 Marks Engineering prepared a
document for Cordova Public Utilities entitled
"1977 Power Cost Study Supplement A Hydro Electric
Run Of River Alternative--Power Creek". The
options offered in this document included a 5MW
34
run of river development with an installed
capacity of 5,000 KW and total annual generation
of 14,200,000 kwh per year. It was projected that
this development would meet 60 percent of
Cordova's energy needs at a construction cost of
$8,000,000.00. This cost estimate was reviewed by
independent sources and felt to be unreasonably
low and the project was not pursued.
In 1979 the u.s. Army Corps of Engineers
commissioned a "Reconnaissance Study of Hydro
Electric Alternatives in the Cordova, Alaska
Area". As part of this study, the Corps of
Engineers engaged CH2M Hill to investigate several
of the potential hydro sites. Among the sites
identified by CH2M Hill in their Reconnaissance
Study was a run of river development on Power
Creek, a run of river development on Humpback
Creek and another site on Crater Lake. Of the
sites that CH2M Hill investigated, only these
three had positive benefit to cost ratios. The
Corps of Engineers elected not to pursue the study
of Humpback Creek and Crater Lake, instead
concentrating their efforts on Power Creek. The
Corps felt that of the three streams only Power
Creek could make a significant impact on the cost
of energy in Cordova. The Corps of Engineers'
final determination on Power Creek recommended
that it not be pursued. Their study showed a
construction cost on Power Creek of $62,000,000.00
for an annual cost, including operations and
maintenance, of $6,224,000.00. The benefits to be
achieved were $5,400,000.00 a year yielding a
benefit to cost ratio of .87. As a portion of the
work for the Corps of Engineers, the Fish and
Wildlife Service investigated the environmental
35
concerns of Crater Lake, Humpback Creek and Power
Creek, the results of this study will be discussed
later under the environmental portion of this
report.
In 1981 the City of Cordova, in conjunction with
the Alaska Power Authority, hired International
Engineering Company to perform a second
Reconnaissance Study of the Cordova area which
broadened the scope to include other energy
sources besides hydro electric. Investigated were
coal developments in the Bering River area, oil
and gas in the Katalla area and several other
energy conservation and alternative measures such
as wind power, burning wood for power generation,
and so on. This study was not conclusive in
finding alternatives, but recommended areas for
additional study.
In 1982 Stone and Webster Engineering Corporation
was hired by the Alaska Power Authority in
conjunction with the City of Cordova and Cordova
Electric Cooperative to perform a preliminary
Feasibility Assessment of several alternatives for
Cordova. This study identified Silver Lake as
having the potential of meeting all of Cordova's
electrical energy needs until beyond the year 2000
at a construction cost of $110,000,000.00 (1985
dollars). Even though this project is technically
feasible and offers a positive benefit to cost
ratio, it is currently believed to be
unfinanceable for a community of 2,500 people.
This study also looked at Power Creek, Humpback
Creek, as well as several smaller hydro projects.
These projects were again ruled out since
individually they only meet a small portion of
36
Cordova's energy needs and require continued use
of diesel, making them more expensive over a life
cycle than the Silver Lake alternative.
Figure IV-1 tabulates the major alternatives
investigated by Stone and Webster. Since each of
the Stone and Webster alternatives provide a total
energy solution, it is not possible to directly
compare them with Humpback Creek which will
generate only a small portion of Cordova's needs.
Stone and Webster determined the peak loads and
total generation for Cordova Electric Cooperative
based on 1982 projections. Since that time
changes in the fishing industry and energy
conservation measures have reduced our projection
of total kilowatt hour generation. The 1985 Power
Requirements Study, prepared by Cordova Electric
Cooperative and approved by the Rural Electrifi-
cation Administration contains the peak generation
and total generation figures as shown in Figure
IV-2. The projections from the 1985 Power
Requirements Study are used in this document.
B. CEC PROJECT SELECTION PROCESS
Cordova Electric Cooperative has for many years
actively pursued alternatives to lower the price
of electrical energy. The results of all of the
studies outlined in the previous section indicate
that there is not a single project that will solve
all of Cordova's energy needs for a reasonable
cost. To this end, CEC has investigated and
undertaken projects each of which will lower the
cost of energy by a small amount, but when taken
37
Option
Figure IV-1
LIFE CYCLE COSTS OF ALTERNATE
ENERGY SOURCES FOR CORDOVA
(From Stone & Webster)
Capital Cost Life Cycle Costs
Existing Diesel $14.0 Million $181.4 Million
Coal
Katalla Plant 59.2 Million 153.0 Million
Local Coal 48.0 Million 138.3 Million
Hydro
Silver Lake 85.4 Million 103.4 Million
*Crater Lake 11. 2 Million
*Sheep River Lake 33.0 Million 112.3 Million
*Lake 1488 33.0 Million
Transmission
*Cordova to Valdez 35.2 Million
*Teeland to Glenallen 61.6 Million 160.0 Million
Cordova to Katalla 28.6 Million
Note: *A combination of these alternatives is required to
meet long term energy needs.
1985
1990
1995
2000
Figure IV-2
COMPARISON OF PEAK LOADS AND TOTAL GENERATION
Peak in Megawatts
Annual Generation in Million KWH
Per CEC Power
Per Stone & Webster Requirements Study
Peak Annual Peak Annual
5.0 22.0 4.9 18.9
5.8 24.7 5.8 21.7
7.4 30.1 7.4 27.1
8.6 35.8 8.6 32.8
together have the possibility of making
significant reductions in the cost of energy_
For example, in 1983, CEC investigated the
feasibility of installing a waste heat system to
make use of heat from the diesel generators. It
was pointed out at that time that the waste heat
system could reduce energy costs by as much as ten
percent. This waste heat system is still under
investigation by the Alaska Power Authority and
may, in fact, be implemented in future years.
In 1983 CEC received a grant in the amount of
$250,000.00 from the Legislature which was put
towards construction of CEC's new power plant.
This grant resulted in annual savings of
approximately 2 percent on electric bills.
In 1984 CEC sought to obtain a lower cost level of
financing for its debt. Depending on the interest
rate that could be achieved, the cost of
electricity could have been reduced by as much as
17 percent. Due to political considerations,
refinancing of CEC's debt was not considered
during the 1985 Legislature, but a grant in the
amount of $150,000.00 to help CEC offset the high
cost of debt was received from the Legislature.
This grant has enabled CEC to keep rates stable
and avoid an increase of about five percent in
electric rates.
During the spring of 1985, CEC reviewed possible
hydro electric sites that could reduce the cost of
electrical energy in Cordova. Among those sites
that were identified were Power Creek, Crater
38
~ake, Humpback Creek, Sheep River Lake and Lake
1488. Crater Lake was ruled out early in the
selection process due to the fact that it is being
used as a major source of water for the City of
Cordova and the community needs for water would
have reduced the amount of energy to be obtained
from the Crater Lake site after the City water
needs were met. The remaining water would have
generated less than 1,000,000 kwh per year. A
combined water/power facility at Crater Lake was
investigated by the City of Cordova in 1980 and
1981. At that time it was felt that the hydraulic
head required for water transmission would reduce
kwh generation below the break even point. Power
Creek was investigated, but it was felt that a
minimum of $10,000,000.00 to $15,000,000.00 would
be required for any significant construction and
the studies necessary would take several years
delaying the net benefit. Humpback Creek was
identified as the primary site for efforts during
1985 since it had sustained an existing hydro
facility on it and presented a fairly straight
forward construction project. It was felt that
the project could be constructed and on line
within two years. This report is a summary of the
investigations undertaken on Humpback Creek.
C. HISTORICAL BACKGROUND
On December 12, 1907, T. R. Carpenter, o. Roberts
and Leon Giroux filed the following notice:
WATER LOCATION NOTICE
That we the undersigned, citizens of the
United States of America, and of the town of
Cordova, Alaska, have this the 12th day of
December, 1907, located (1,000) one-thousand
39
inches of water of the stream or creek called
Power Creek formerly known as Humpback Creek
situated in Cordova Bay, Mining District, and
emptying in Cordova Bay, about two miles in a
northerly direction from the Orca Cannery of
Cordova Bay all of the Cordova Mining
District of Alaska, and recorded in the
Cordova Recording District of Alaska. The
said water mentioned in this notice to be
used for generating power for the purpose of
mining, milling, townsite lighting and
commercial purposes (electrical power) and it
is further understood that said water to be
used for transmitting power to the town of
Cordova and the surrounding vicinity where
mining, milling, and lighting operations are
carried on.
1907.
Located this 12th day of December,
Locators:
T. R. Carpenter
o. Roberts
Leon Giroux
Sometime between then and November 9, 1908, these
three individuals, assigned their water rights for
this site to Henry Bratnober. On November 9,
1908, Henry Bratnober sold his rights to this site
to the Cordova Power Company.
In October and November of 1908, A. Judson Adams
performed a survey of the pipeline and
transmission line of the Humpback Creek power
plant. This survey has badly deteriorated with
use and has been photographed by CEC to save the
data.
On May 17, 1909, the hydro power site was placed
in commercial operation and the community of
Cordova had electric power (and a movie theater).
40
In the fall of 1910, C. H. Kiehl, an engineer from
Seattle, Washington, was hired to prepare a
"Report on the Water Supply and Water Power
Propositions for the Cordova Power Company,
Cordova, Alaska". This is the first reference to
an operating hydro site on Humpback Creek.
According to this report, the facilities consisted
of a 60 foot high wood crib dam, a 1,350 foot 30
inch wood stave pipeline, and a double nozzle
pelton wheel with a direct connected generator.
The hydro had an effective head of 175 feet and
125 KW power output. A coal fired boiler driving
a 250 HP engine was used for winter power when the
stream stopped running.
Shortly after 1910, the assets of the Cordova
Power Company were sold to the Alaska Public
Utilities Company.
The facility at Humpback Creek consisted of living
quarters and a power plant. Figures IV-3 and IV-4
are photographs of the Humpback Creek facilities
furnished by Virginia Mesman.
There is no specific record as to when the hydro
plant was shut down. It is known that the plant
was not in operation in 1952 when the City of
Cordova bought the electric, water and telephone
utilities from Alaska Public Utilities Company.
A local rumor reports that the power plant burned
down.
The next reference to Humpback Creek is in the mid
1970's when the Alaska Department of Fish and Game
considered building a fish hatchery in the lower
41
Figure IV-3
Figure IV-4
':ii
..
reaches of Humpback Creek. This hatchery was not
built.
The U.S.G.S. maintained stream flow data on
Humpback Creek for the period of October 1973 to
September 1975.
In 1979 the U.S. Army Corps of Engineers (Alaska
District) commissioned CH2M Hill to perform a
"Reconnaissance Study of Hydro Power Sites Near
Cordova Alaska".
The CH2M Hill report called for a much more
extensive development of Humpback Creek. The CH2M
Hill plan (developed without a site visit) called
for a concrete diversion dam, 6,625 foot flume,
700 foot penstock (both 30 inches in diameter) and
1,010 KW Power Plant .
The July 1979 issue of the Alaska Journal
contained an article by Virginia Messman about
life at the power plant on Humpback Creek.
There are three dams on Humpback Creek called
Humpback 1, 2 and 3 with Humpback 3 being the
lowest and by far the largest. These dams were
inspected by the State of Alaska Department of
Natural Resources in June 1980, and all three were
considered unsafe and unusable. Their report
recommends destruction of the Humpback 3 dam.
Local legend reports that the Forest Service
attempted to destroy the dam several years ago and
succeeded only in creating a small breach in the
west abutment which allows the water to escape.
There are hundreds of ~housands of cubic yards of
gravel held back by this dam. Destruction of this
42
D.
/'''"
dam would result in a major scouring of the
downstream drainage, possibly even causing the
river to change course in the lower reaches. Dams
1 and 2 were used for trash removal during periods
of high flow.
The Eyak Corporation has received conveyance of
the land in the Humpback Creek area under the
ANCSA. The City of Cordova has indicated a desire
to obtain these lands under Section l4(c)(3) which
allows municipal selections from Native
allotments.
There are no recorded easements in the area under
consideration for the hydro electric project.
CONSIDERATION OF ARCHEOLOGICAL ASPECTS
A review by Douglas Reger, Regional Archeologist,
u.S. Forest Service, in 1974 of the Humpback Creek
drainage area has indicated that there are no
archeological values in this area. This letter is
attached as Figure IV-5. Several people have
documented the historical value of the remains of
the old hydro electric site. These have been
reviewed and a discussion of each follows:
1) Pelton Wheel and Generator.
The power plant building from the original
hydro electric site on Humpback Creek was
removed several years ago. The pelton wheel,
governor, generator and other items are badly
rusted. One of the buckets on the pelton
wheel is broken, but the overall condition of
the equipment is good considering its age.
The hydro electric project proposed for
43
--UNITED STATES DEPARTMENT OF AGRICULTURE
FOREST SERVICE
REPLY TO: 2360 Special Interest Areas
SUBJECT: Archeological ~sance,
Hmpback Creek
R-10
,", .. : v l: I " :~ 'I
TO: Forest Supervisor, ~U;ach National Fo.rest
~ 30, 1974
An archeological reconnaissance was candlx:ted at the ItDUt:h of Hurpback
Creek by the Regional Archeologist on October 22, 1974. 'l1le area is
~5 miles oor+=beast of COrdova! Rena.ins of a historic ~ " are
pmsent on the south bank of the Creek rrouth. concrete~,
Pelton water wheel ~ generator ~ misO!lIaneous npgem
remaliiS 'We%e fOund. t Service Sl'ii<i these remains to be fran
the CO;dcya Power co. powm:house licensed under FPC pemit 11931. The
pexmit was applied tOr in NOViiibei' 1924.
'Dle incubation beds proposed by ADF&G should not dist.uIb the site.
'Dlis is actually a respc:IlSil:xi.lity of the State of Alaska as the. land
is tenative1y awroved for transfer to them. Included in the ADF&G
p.rcposal, mwever, is the possibility of destJ:u::tion ~dam assccfated
wlJ;b the alxJw pgwerlDuse. b d@..,site is on Forest_ ._~ ~
should be c:onsidexed an integral part of the total site. I suggest the
State be contacted about their feelings oonceming the pcMe.rhouse.
If they regard it as historic then the dam w::>uld also be historic and
Im.lSt be tl:eated acoording1y.
Enclosure
Figure IV-5
construction on Humpback Creek will not be
located within 500 feet of the existing
pelton wheel and generator.
2) Building Foundations.
The foundations for two buildings currently
exist and the tin roofing for one of the
buildings has collapsed within the
foundation. There is no structure to the
buildings remaining and there are very few
remnants of people that lived there. The
area is strewn with old pieces of pipe,
valves, generator stators, etc. The hydro
electric development proposed for Humpback
Creek will not be located within 500 feet of •
the building remnants.
3) Pipeline.
The pipeline serving the original hydro
electric facility was approximately 1,350
feet long and consisted of a 30 inch outside
diameter wood stave pipeline. There are four
separate areas of this pipe that have to be
considered separately. The highest elevation
pipe ran from the old dam site along a notch
cut in the east bank of Humpback Creek at an
elevation ranging from 10 to 60 feet above
the Creek bed. Approximately one-half of the
pipe in this area has washed away and there
are no remnants of pipe rings or any other
construction. An additional 25 percent of
the pipe in this area has been covered with
rock slides from the east abutment. It is
impossible to tell the condition of the
pipeline in these areas although the size and
weight of rocks indicates that any remains
44
would be crushed. The remaining 25 percent
of the pipe in this area is visible and
consists of metal rings and a few badly
rotted boards from the wood stave pipeline.
The hydro electric development proposed would
necessitate the removal of all remains of
this portion of the pipeline.
The second area of interest is the overhead
span across Humpback Creek. There is
currently one cable span still in existence
across the Creek and remnants of a second
cable can be found on the east abutment.
There is no pipe left across the Creek and
there are no other fastenings on the existing
cable to indicate how the pipe was supported
in this area. The new pipe will cross the
Creek in essentially the same location, but
the existing cable will not be disturbed.
A third area of interest is on the west bank
of Humpback Creek Canyon at elevations
ranging from 60 to 100 feet above stream
level. Approximately 50 percent of the pipe
in this area is covered by rock slides and
the condition is unknown. The remaining 50
percent is visible with approximately 70
percent of the wood stave rotted away, and
the remaining 30 percent is badly
deteriorated and cannot be moved without
crumbling. The remains of the pipe in this
area would be removed for the new pipeline.
The last 500 feet of the existing pipe turns
away from Humpback Creek Canyon and proceeds
due west down the hill to the existing pelton
wheel and generator. The pipe in this area
45
is covered with moss and some gravel. In
several places the remains of the existing
pipe can be seen. The wood still remains and
the pipe retains its original shaping.
Approximately ten percent of the pipe in this
area is missing and an additional 25 percent
is covered by dirt or other overburden and
the remaining 65 percent is visible in
varying degrees of decay. This portion of
the pipe would not be disturbed by the
proposed construction.
4) Dams.
Three dams were constructed on Humpback
Creek. These have been labeled dams #1, #2
and #3 by the Alaska Department of Natural
Resources. Dams #1 and #2 are a considerable
distance up river from the proposed project
and consist of small structures to remove
trash from the stream before they entered the
main portion of the old hydro project.
Sketches of Dams #1, #2 and #3 as prepared by
the Department of Natural Resources are
included as Figures IV-6 through IV-10.
Dam #3 is approximately 500 feet down stream
of the proposed intake structure and will be
impacted by the proposed hydro electric
development. The impacts and potential
mitigation are discussed in Chapter VII--
Environmental Analysis.
46
TDP
~ I ' ~\ \ \
\ \' ,
I
L .\
\ " '.(/
J
Humpbo.c..K Creck
., t 1 .1
t1" TO .scc-.I"
# I.
I
FRONt
" " • l~-,. ---11'-~ :====------~~ ~. \-----------~---.------------~ -.. -.. ~-~~---~ .. ~~=----=.-=-.
\\ \\
\ ! \ !
\ I i J,// J V /
T
1 _.__---"-J
Figure IV-6
,\
I-,I
+
l
t·
J
\:i
" 1
\
\
-lor
6--1' ------"II..! ;;III
\
\ ')
1 11
I
./
i
) FR 0 wT
'<:--' I';: -------;J.? ---~
,
~--s -".\
1
Figure IV-7
I
I .
\')-
I _'V'_
H'unvl P b Or d< Cr~e ~ +=I-~
nv+ fo sc.C\./~
FRO tvl
I
II/.J ---------_._----------_._------.... ---.----.~ ._-------------------
-··\ .. \_--O~~ __ ----(J----i-( ~-----
\
Figure IV-8 \. (] -----r) ---··----·----0· -'-"--'--
", '-.. ----------~~--.------. -----_ .. ---'----".-
,
~.-----.., -.. --~ .. _.-.-_ .. _ .. --.-.-.. ------.-
~--'-------~---"'-'-._--
\ 1 \ ~ \ \ / .?
\ /"
\ 1/
'v. Y / I _t: /' _/ -_,
/
k / _·-----:1--
)
-1/0'--
T . ,1;\
L
lof
, rl
L/
I
I
I
I
I .
. I
\
I
\
'.
Figure IV-9
------
t\
r! + I I h 0 ot-Q sCC>. C.
I
/
I
I
/
/ ,
/
;'
.I
/
;'
i
f
/
/
./
/1)
\ //I\~
~~ oJ
/
/
!
/
/
c-_· -----
r---(0
I /-----~----____ _
-< _---1-
~----~-------.'------------.. ---.-------'----)
----
Figure IV-IO
v. HUMPBACK CREEK HYDRO FACILITIES
A. HYDROLOGIC DATA
The amount of energy from a hydro electric project
is dependent on many factors. The limiting factor
being the amount of water available for the
generation of power. Humpback Creek has the
advantage of a stream gauge which was installed in
the stream from the fall of 1973 and remained
operational until it was removed in the fall of
1975. Daily stream flow data is available for
these two years. The Alaska Power Authority, in
conjunction with the Department of Natural
Resources, Division of Geological and Geophysical
Surveys (DGGS), developed flow estimates for
Humpback Creek based on available information.
Appendix A is a copy of the report prepared by the
Division of Geological and Geophysical Surveys.
Cordova is characterized by a wide variation in
precipitation levels. The local radio station in
Cordova served as a voluntary observer for the
u.S. Weather Service for many years and
information from this station was used in
calculating the mean flow. Information developed
by DGGS indicates a mean annual flow of
approximately 48 cubic feet per second (cfs) with
a summer month mean of 78 cfs. This is based on
an annual precipitation of 170 inches. The 170
inch annual precipitation is supported by
information obtained at radio station KLAM which
observed an annual average of 177 inches of
precipitation.
The drainage basin of Humpback Creek is very near
the drainage basin of Power Creek. They are
separated by a very narrow mountain ridge. Power
47
Creek has had stream flow information recorded for
many years and it is possible to correlate the
data on Humpback Creek to the data on Power Creek.
Figure V-1 shows the average flow on Power Creek
on an annual basis compared to the long term
average flow. From this table it can be seen that
water year 1975 was six percent above the long
term average water flow. This may not be exactly
correct for Humpback Creek since the Power Creek
drainage basin has a larger percentage glacier
coverage than does the Humpback Creek basin. Thus
in dry years we can expect the Humpback Creek flow
to drop off more rapidly than the Power Creek
flow.
To determine the amount of kwh available from
Humpback Creek, several alternatives were
considered. First, two different size installa-
tions were investigated, one based on a 65 cfs
maximum design flow and the other based on 85 cfs
maximum design flow. Manufacturers were contacted
to determine equipment efficiency at various flow
rates within the anticipated range. The proposal
from one of these manufacturers is included as
Appendix B. Figures V-2A and V-2B show turbine
output and kwh output for various flow rates for
both the 65 cfs and 85 cfs maximum design flow
rates.
DGGS has provided mean monthly flows for Humpback
Creek based on the u.s. Forest Service regression
formulas and local precipitation. Two different
precipitation levels were used (140 inches and
170 inches per year). These monthly mean flows
can be multiplied by turbine generator efficiency
to obtain annual kilowatt hour production. Use of
48
these mean flows tends to overstate the annual
kilowatt hour production by 10 to 25 percent
depending on the flow characteristics of the
individual stream. Figures V-3 through V-6 show
the annual kilowatt hour production for precipi-
tation levels of 140 inches and 170 inches per
year with turbine maximum design flows of 65 cfs
and 85 cfs.
A more accurate method of determining the annual
kilowatt hour production is to use the stream data
obtained in 1975 and correcting it for the long
term deviation in a known stream such as Power
creek. As seen in Figure V-1, Power Creek mean
stream flow in 1975 was 106 percent of the long
term average. Thus we can expect Humpback Creek
to have been slightly above average in 1975. As
mentioned above, 40 percent of the Power creek
flow is provided by glacier run off. This keeps
the flow higher during dry years. DGGS indicates
that the 1975 data from Humpback Creek may be 5 to
15 percent above long term average.
The observed flow rates on Humpback Creek for 1975
were then reduced by varying amounts and daily kwh
productions were calculated based on anticipated
flow, and turbine/generator efficiency. Figures
V-7 through V-14 show the total kilowatt hours
available from Humpback Creek given various water
flows. As can be seen from these tables, the kwh
production for the 65 cfs design water flow ranges
from 3.3 million kwh per year to 3.6 million kwh
per year and for the 85 cfs water flow from
3.5 million kwh per year to 3.9 million kwh per
year. For the purpose of this study, an
anticipated kwh production of 3.2 million kwh per
49
year based on 65 cfs design flow and 3.5 million
kwh per year for 85 cfs design flows will be used.
Selection of Turbine Size
The selection of the optimum turbine generator
size depends on available flow and net head
available at the turbine. There is a range of
design water flows that can be used to estimate
the design output of a run of river hydro electric
plant. In general these estimates run from 15
percent to 25 percent flow exceedence. That is,
the predicted stream flow will exceed the design
flow 15 to 25 percent of the time. Twelve month
flow data takes into consideration the low flow
periods during the winter months when for all
practical purposes there is not flow available in
the Creek. If flows during nine months of the
year are considered and the months of January,
February and March are not included in the
calculation, a higher flow is obtained. Figures
V-IS and V-16 show the 9 and 12 month flow
duration curve that was obtained based on 85
percent and 95 percent of water year 1975 flows.
Figure V-17 shows the range of design flows
available based on the considerations above. The
selection of the actual design flow is based on
cost benefit analysis evaluating the construction
costs of various size plants and pipeline and
intake structures and will be discussed in greater
detail in the next section.
50
Figure V-1
POWER CREEK FLOW CORRELATION
FOR HUMPBACK CREEK
Percent Of
Main Stream Average Annual
Year Flow Rank Stream Flow
1948 274.0 7 111
1949 247.0 16 100
1950 263.0 12 106
1951 231. 0 23 94
1952 245.0 18 99
1953 300.0 3 121
1954 233.0 22 94
1955 246.0 17 100
1956 220.0 26 89
1957 260.0 13 105
1958 321. 0 2 130
1959 219.0 27 89
1960 264.0 10 107
1961 259.0 14 105
1962 205.0 30 83
1963 250.0 15 101
1964 223.0 25 90
1965 236.0 19 96
1966 235.0 21 95
1967 265.0 8 107
1968 228.0 24 92
1969 181. 0 32 73
1970 288.0 5 117
1971 236.0 20 96
1972 211. 0 28 85
1973 195.0 31 79
1974 180.0 33 73
1975 263.0 11 106
1976 292.0 4 118
1977 336.0 1 136
1978 210.0 29 85
1979 264.0 9 107
1980 284.0 6 115
Figure V-2-A
OUTPUT DATA SHEET
For recommended 28 inch MID Twin Jet High Capacity Turgo
Impulse Turbine.
Note: The net heads are based on 175 ft. gross and 160 ft.
net at 66 cfs.
TURBINE
FLOW HEAD OUTPUT KW KWH I
(cfs) ( ft. ) (BHP) OUTPUT DAY
5 174 68 48 1,152
10 174 156 111 2,664
15 174 250 177 4,248
20 173 338 240 5,760
25 173 426 302 7,248
30 172 511 362 8,688
35 172 582 412 9,888
40 171 668 473 11,352
45 170 753 534 12,816
50 170 832 593 14,232
55 169 919 651 15,624
60 168 995 705 16,920
65 167 1,061 752 18,048
66 167 1,110 787 18,888
Figure V-2-B
OUTPUT DATA SHEET
For recommended 31 inch M/D Twin Jet High Capacity Turgo
Impulse Turbine.
Note: The net heads are based on 175 ft. gross and 163 ft.
net at 85 cfs.
TURBINE
FLOW HEAD OUTPUT KW KWH/
(cfs) ( ft. ) (BHP) OUTPUT DAY
6 174 77 55 1,320
10 174 144 102 2,448
15 174 232 164 3,936
20 173 324 230 5,520
25 173 413 293 7,032
30 172 497 352 8,448
35 172 583 413 9,912
40 171 655 464 11,136
45 170 723 512 1,288
50 170 809 573 13,752
55 169 888 629 15,096
60 168 967 685 16,440
65 167 1,043 739 17,736
70 166 1,116 791 18,984
75 165 1,187 841 20,184
80 164 1,237 877 21,048
85 163 1,276 904 21,696
Figure V-3
ANNUAL GENERATION BASED ON MONTHLY
MEAN STREAM FLOW DATA
65 cfs Maximum Flow
170 Inches Annual Precipitation
Mean Mean HP KWH KWH
Month Flow Output Output Generated
January 10.4 163.4 115.85 86,156
February 7.6 113.8 80.6 54,197
March 9.5 147.2 104.3 77,615
April 15.7 261. 3 185.2 133,332
May 109.7 1110.0* 786.7 585,578
June 85.7 1110.0* 786.7 566,640
July 106.8 1110.0* 786~7 585,528
August 68.2 1110.0* 786.7 585,528
September 65.8 1110.0* 786.7 566,640
October 68.8 1110.0* 786.7 585,528
November 43.1 706.0 500.3 360,246
December 18.3 307.1 217.6 161,925
Total 4,348,913
*Flow exceeds rated output of turbine.
Figure V-4
ANNUAL GENERATION BASED ON MONTHLY
MEAN STREAM FLOW DATA
85 cfs Maximum Flow
170 Inches Annual Precipitation
Mean Mean HP KWH KWH
Month Flow Output Output Generated
January 10.4 151. 0 107.0 79,608
February 7.6 103.8 73.6 49,459
March 9.5 135.6 96.1 71,498
April 15.7 244.9 173.6 124,992
May 109.7 1,276.0 904.3 672,799
June 85.7 1,276.0 904.3 651,096
July 106.8 1,276.0 904.3 672,799
August 68.2 1,089.7 772.3 574,591
September 65.81 1,054.7 747.5 538,200
October 68.8 1,098.5 778.5 579,204
November 43.1 697.2 494.1 355,752
December 18.3 292.7 207.4 154£305
Total 4,524,303.
Figure V-5
ANNUAL GENERATION BASED ON MONTHLY
MEAN STREAM FLOW DATA
65 cfs Maximum Flow
140 Inches Annual Precipitation
Mean Mean HP KWH KWH
Month Flow Output Output Generated
January 7.6 113.8 80.7 60,041
February 4.9 66.6 47.2 31,718
March 6.9 101. 4 71.9 53,494
April 13.9 228.5 161. 9 116,568
May 87.4 1110.0* 786.7 585,528
June 61.6 969.3 686.9 494,568
July 88.9 1110.0* 786.7 585,528
August 54.8 884.1 626.6 466,190
September 53.8 869.5 616.2 443,664
October 54.1 873.9 619.3 460,759
November 32.8 544.1 385.6 277,632
December 12.4 200.6 142.2 105,797
Total 3,681,487.
*Flow exceeds rated output of turbine
Figure V-6
ANNUAL GENERATION BASED ON MONTHLY
MEAN STREAM FLOW DATA
85 cfs Maximum Flow
140 Inches Annual Precipitation
Mean Mean HP KWH KWH
Month Flow Output Output Generated
January 7.6 103.8 73.6 54,758
February 4.9 62.9 44.6 29,971
March 6.9 92.1 65.3 48,583
April 13.9 212.6 150.7 108,504
May 87.4 1,276.0* 904.3 672,799
June 61.6 991. 3 702.5 505,800
July 88.9 1,276.0* 904.3 672,799
August 54.8 884.8 627.1 666,562
September 53.8 870.4 581. 4 418,608
October 54.1 873.8 619.3 460,759
November 32.8 545.2 386.4 278,208
December 12.4 186.2 132.0 98 1 208
Total 4,015,559
HUMPBACK CREEK HYDRO ELECTRIC PROJECT
FIGURE V-7
KILOWATT HOUR GENERATION
BASED ON 85% OF 1975
65 CFS MAXIMUM DESIGN FLOW
12 MONTH DATA
FLOW RANGE # OF DAYS KWH PER DAY KWH PER YEAR
2.5 30 0 0
7.5 55 1152 63360
12.5 33 2664 87912
17.5 33 4248 140184
22.5 13 5760 74880
27.5 19 7248 137712
32.5 7 8688 60816
37.5 17 9888 168096
42.5 18 11352 204336
47.5 9 12816 115344
52.5 10 14232 142,320
57.5 13 15624 203112
62.5 15 16920 253800
67.5 7 18048 126336
72.5 21 18048 379008
77.5 7 18048 126336
82.5 3 18048 54144
87.5 13 18048 234624
92.5 6 18048 108288
97.5 7 18048 126336
102.5 6 18048 108288
107.5 2 18048 36096
112.5 4 18048 72192
117.5 0 18048 0
122.5 2 18048 36096
127.5 1 18048 18048
132.5 1 18048 18048
13 18048 234624
365 3330336
HUMPBACK CREEK HYDRO ELECTRIC PROJECT
FIGURE V-8
KILOWATT HOUR GENERATION
BASED ON 90% OF 1975
65 CFS MAXIMUM DESIGN FLOW
12 MONTH DATA
FLOW RANGE # OF DAYS KWH PER DAY KWH PER YEAR
2.5 28 0 0
7.5 57 1152 65664
12.5 23 2664 61272
17.5 36 4248 152928
22.5 19 5760 109440
27.5 15 7248 108720
32.5 12 8688 104256
37.5 13 9888 128544
42.5 14 11352 158928
47.5 14 12816 179424
52.5 7 14232 99624
57.5 10 15624 156240
62.5 14 16920 236880
67.5 11 18048 198528
72.5 13 18048 234624
77.5 14 18048 252672
82.5 7 18048 126336
87.5 3 18048 54144
92.5 13 18048 234624
97.5 6 18048 108288
102.5 7 18048 126336
107.5 3 18048 54144
112.5 5 18048 90240
117.5 2 18048 36096
122.5 2 18048 36096
127.5 1 18048 18048
132.5 1 18048 18048
15 18048 270720
365.0 3420864
HUMPBACK CREEK HYDRO ELECTRIC PROJECT
FLOW RANGE
2.5
7.5
12.5
17.5
22.5
27.5
32.5
37.5
42.5
47.5
52.5
57.5
62.5
67.5
72.5
77.5
82.5
87.5
92.5
97.5
102.5
107.5
112.5
117.5
122.5
127.5
132.5
FIGURE V-9
KILOWATT HOUR GENERATION
BASED ON 95% OF 1975
65 CFS MAXIMUM DESIGN FLOW
12 MONTH DATA
# OF DAYS KWH PER DAY
28 0
51 1152
29 2664
31 4248
21 5760
10 7248
14 8688
9 9888
14 11352
18 12816
9 14232
9 15624
7 16920
15 18048
8 18048
13 18048
14 18048
7 18048
3 18048
13 18048
6 18048
7 18048
1 18048
7 18048
1 18048
3 18048
o 18048
17 18048
365
KWH PER YEAR
o
58752
77256
131688
120960
72480
121632
88992
158928
230688
12'8088
140616
118440
270720
144384
234624
252672
126336
54144
234624
108288
126336
18048
126336
18048
54144
o
306816
3524040
HUMPBACK CREEK HYDRO ELECTRIC PROJECT
FIGURE V-l0
KILOWATT HOUR GENERATION
BASED ON 100% OF 1975
65 CFS MAXIMUM DESIGN FLOW
12 MONTH DATA
FLOW RANGE # OF DAYS KWH PER DAY KWH PER YEAR
2.5 22 0 0
7.5 57 1152 65664
12.5 28 2664 74592
17.5 26 4248 110448
22.5 25 5760 144000
27.5 7 7248 50736
32.5 18 8688 156384
37.5 7 9888 69216
42.5 17 11352 192984
47.5 10 12816 128160
52.5 14 14232 199248
57.5 5 15624 78120
62.5 12 16920 203040
67.5 9 18048 162432
72.5 10 18048 180480
77.5 8 18048 144384
82.5 14 18048 252672
87.5 14 18048 252672
92.5 4 18048 72192
97.5 3 18048 54144
102.5 13 18048 234624
107.5 6 18048 108288
112.5 5 18048 90240
117.5 3 18048 54144
122.5 6 18048 108288
127.5 1 18048 18048
132.5 4 18048 72192
17 18048 306816
365 3584208
HUMPBACK CREEK HYDRO ELECTRIC PROJECT
FIGURE V-11
KILOWATT HOUR GENERATION
BASED ON 100% OF 1975
85 CFS MAXIMUM DESIGN FLOW
12 MONTH DATA
FLOW RANGE # OF DAYS KWH PER DAY KWH PER YEAR
2.5 22 0 0
7.5 57 1100 62700
12.5 28 2448 68544
17.5 26 3936 102336
22.5 25 5520 138000
27.5 7 7032 49224
32.5 18 8448 152064
37.5 7 9912 69384
42.5 17 11136 189312
47.5 10 12888 128880
52.5 14 13752 192528
57.5 5 15096 75480
62.5 12 16440 197280
67.5 9 17736 159624
72.5 10 18984 189840
77.5 8 20184 161472
82.5 14 21048 294672
87.5 14 21696 303744
92.5 4 21696 86784
97.5 3 21696 65088
102.5 13 21696 282048
107.5 6 21696 130176
112.5 5 21696 108480
117.5 3 21696 65088
122.5 6 21696 130176
127.5 1 21696 21696
132.5 4 21696 86784
17 21696 368832
365 3880236
HUMPBACK CREEK HYDRO ELECTRIC PROJECT
FIGURE V-12
KILOWATT HOUR GENERATION
BASED ON .95% OF 1975
85 CFS MAXIMUM DESIGN FLOW
12 MONTH DATA
FLOW RANGE # OF DAYS KWH PER DAY KWH PER YEAR
2.5 28 0 0
7.5 51 1100 56100
12.5 29 2448 70992
17.5 31 3936 122016
22.5 21 5520 115920
27.5 10 7032 70320
32.5 14 8448 118272
37.5 9 9912 89208
42.5 14 11136 155904
47.5 18 12888 231984
52.5 9 13752 123768
57.5 9 15096 135864
62.5 7 16440 115080
67.5 15 17736 266040
72.5 8 18984 151872
77.5 13 20184 262392
82.5 14 21048 294672
87.5 7 21696 151872
92.5 3 21696 65088
97.5 13 21696 282048
102.5 6 21696 130176
107.5 7 21696 151872
112.5 1 21696 21696
117.5 7 21696 151872
122.5 1 21696 21696
127.5 3 21696 65088
132.5 0 21696 0
17 21696 368832
365 3790644
HUMPBACK CREEK HYDRO ELECTRIC PROJECT
FIGURE V-13
KILOWATT HOUR GENERATION
BASED ON 90% OF 1975
85 CFS MAXIMUM DESIGN FLOW
12 MONTH DATA
FLOW RANGE # OF DAYS KWH PER DAY KWH PER YEAR
2.5 28 0 0
7.5 57 1100 62700
12.5 23 2448 56304
17.5 36 3936 141696
22.5 19 5520 104880
27.5 15 7032 105480
32.5 12 8448 101376
37.5 13 9912 128856
42.5 14 11136 155904
47.5 14 12888 180432
52.5 7 13752 96264
57.5 10 15096 150960
62.5 14 16440 230160
67.5 11 17736 195096
72.5 13 18984 246792
77.5 14 20184 282576
82.5 7 21048 147336
87.5 3 21696 65088
92.5 13 21696 282048
97.5 6 21696 130176
102.5 7 21696 151872
107.5 3 21696 65088
112.5 5 21696 108480
117.5 2 21696 43392
122.5 2 21696 43392
127.5 1 21696 21696
132.5 1 21696 21696
15 21696 325440
365 3645180
HUMPBACK CREEK HYDRO ELECTRIC PROJECT
FLOW RANGE
2.5
7.5
12.5
17.5
22.5
27.5
32.5
37.5
42.5
47.5
52.5
57.5
62.5
67.5
72.5
77.5
82.5
87.5
92.5
97.5
102.5
107.5
112.5
117.5
122.5
127.5
132.5
FIGURE V-14
KILOWATT HOUR GENERATION
BASED ON 85% OF 1975
85 CFS MAXIMUM DESIGN FLOW
12 MONTH DATA
# OF DAYS KWH PER DAY
30 0
55 1100
33 2448
33 3936
13 5520
19 7032
7 8448
17 9912
18 11136
9 12888
10 13752
13 15096
15 16440
7 17736
21 18984
7 20184
3 21048
13 21696
6 21696
7 21696
6 21696
2 21696
4 21696
o 21696
2 21696
1 21696
1 21696
13 21696
365
KWH PER YEAR
o
60500
80784
129888
71760
133608
59136
168504
200448
115992
137520
196248
246600
124152
398664
141288
63144
282048
130176
151872
130176
43392
86784
o
43392
21696
21696
282048
3521516
FLOW DURATION CURVE
9M! OF' 1 975 F'lOWS
180
150
14-0
0 130 z
0 120 0
La.I en 110
~ 100 La.I
A-
t:; 90
La.I 80 ~
0 70 iii
:::) 80 0
~ 50
~ .t.O
30 ~
20
10
0
0 10 20 30 50 80 70 80 90 100
PERCENT or TIME now EXCEEDS
c 9 MONTH + 12 MONTH
Figure V-1S
FLOW DURATION CURVE
89 OF' 1 975 F'LOWS
180
150
141·0
c 130 ~ 120 0
I&J
'" 110
15 100
A.
ti 90
I&J 80 LI..
0 70 iii
~ 80 0
! 50
~ .0
30 LI..
20
10
0
0 10 20 30 50 60 70 80 90 100
PERCENT OF' TI~E FLOW EXCEEDS
c 9 ~ONTH + 12 ~ONTH
Figure V-16
Percent
Of 1975
85
95
Percent
Of 1975
85
95
Figure V-17
MAXIMUM WATER FLOW FOR TURBINE SIZING
BASED ON TWELVE MONTH FLOWS
25 Percent
Excedence
65 cfs
70 cfs
15 Percent
Excedence
81 cfs
90 cfs
MAXIMUM WATER FLOW FOR TURBINE SIZING
BASED ON NINE MONTH FLOWS
25 Percent
Excedence
72 cfs
80 cfs
15 Percent
Excedence
88 cfs
98 cfs
B. GEOLOGIC DATA
No specific geological reconnaissance was made of
the Humpback Creek site. The following regional
geological summary was prepared by Stone and
Webster in their Interim Feasibility Assessment
(June 1982). The Stone and Webster assessment was
general in nature and applies to the entire region
including the Humpback Creek area.
a) Geomorphology
The study area is characterized by active
glaciation and associated landforms. Due to
the dynamic tectonic environment and active
glaciation, the area is undergoing regional
uplift, local rapid downcutting by streams,
local slope instability in the form of major
landslides, local rockfalls, local debris
flows, and avalanches in areas of major snow
accumulation. The coastline is characterized
by a sequence of northeast trending major
fjords, which are deep, long, narrow,
steep-sided valleys formed by a more weakly
developed set of topographic lows: northwest
trending valleys including Jack Bay, Sawmill
Bay, Silver Lake, Galena Bay, Two Moon Bay,
and Eyak Lake. These gross regional
geomorphic trends are probably related to
regional fracture patterns and major
structural features resulting from the
ter.tonic history of the area.
b) Stratigraphy
The rocks in the study area have been divided
into two groups: the Valdez Group and the
Orca Group. The division is based on slight
51
variations in metamorphic facies and
lithology.
The Valdez Group rocks cover the general
study area from Valdez south to Port Fidalgo,
and the Orca Group extends from Port Fidalgo
to south of Cordova beyond the southern limit
of the study area. The Valdez Group is a
metamorphosed sedimentary series including
bluish-gray and dark gray quartzites,
graywackes, arkoses, and quartz-schists
interbedded with generally thin beds of dark
blue or black slate, shale, mica-schist, and
occasionally some conglomerate. The Orca
Group exhibits a slightly lower grade of
metamorphism then the Valdez Group and
consists of thick bedded brown and gray
sandstones, black limestones, arkoses with
thin zones of slate, and occasional
conglomerate greenstones associated with
highly mafic basalt flows. The rocks in both
the Valdez and Orca Groups are highly
deformed and fractured. Extensive secondary
quartz emplacement has occurred along the
fractures. The thickness of these quartz
veins ranges from a fraction of an inch to
several feet.
c) Structure
The structural geology of the area is
characterized by highly deformed rocks,
tightly folded and faulted along two dominant
structural orientations: northwest and
northeast. These structural features result
from the active subduction of the Pacific
plate which is occurring along the southern
52
coast of Alaska and ex ten:i. I :"'q \4(!stward along
the Aleutian Island ar"c. Numerous thrust
faults have been inferred in the study area,
the largest is named the Contact Fault. Other
smaller thrust faults include the Jack Bay
Fault, the Landlocked Bay Thrust, and the
Galena Bay Thrust. Many other folds and
faults trending predominantly northwest and
northeast have been inferred from aerial
photographs and satellite imagery.
C. DESIGN AND CONSTRUCTION INFORMATION
Dam and Intake Structure
The purpose of the intake structure is to divert
the water in Humpback Creek into the pipeline so
that it can be delivered efficiently to the
turbines for the generation of electric energy.
This project does not envision a dam for the
purpose of storing water. This is a run of river
project and the dam is a part of the intake
structure. As used in this discussion, the word
dam and intake structure are interchangeable since
the purpose of either is to direct the water in
the stream into the pipeline.
The flows in Humpback Creek range from a low of no
surface flow during the winter to a maximum record
of over 600 cfs. The preliminary design of this
project is to utilize flows up to 100 cfs. It is
known from visual inspection of the area that
Humpback Creek carries a considerable stream
sediment load consisting of small gravel up to
large rocks. The intake structure must keep the
sand, gravel and rocks out of the pipeline while
offering the minimum amount of impedance to the
flow of the water into the pipeline. There are
53
many possible designs to accomplish this. None
are totally satisfactory; all allow some sand and
gravel to enter the pipeline. The design of the
intake structure has not been finalized and will
receive additional review during the final design
phase. We do believe, however, that the basic
concept of the preliminary design will be utilized
in final design. Efforts to remove the stream
sediment are discussed in two separate areas.
The first involves the use of a stilling pond
upstream from the intake structure. The purpose
of a stilling pond is to reduce the rate of flow
of water in the stream to allow the larger gravel
and sediment to settle out of the stream. It is
anticipated that this gravel will settle out just
upstream of the diversion structure. A sluice
gate will be installed in the diversion dam that
can be open during high flow periods to allow the
gravel collected behind the dam to flow down
stream. Gravel that does not settle out will flow
over the dam on to a metal grating on the down
stream side of the dam.
The second area of design will be the intake
structure. This structure will consist of grates
and a metal tank on the down stream side of the
weir. The grating will be sloped down stream to
encourage rocks and gravel to roll off the grating
down river of the intake structure. Water would
fall through this grating and then enter the
intake pipe. A method would be provided to clean
the intake structure as it is anticipated that
rocks will become trapped in the screen area and
leaves, twigs and other small organic material may
go through the grating and become wedged in the
54
screens. Sheet 3 of Figure V-18 shows the intake
structure in more detail.
Pipeline
The selection of pipe to carry the water from the
intake structure to the power plant depends on
many factors. The two prime considerations are
the amount of water to be carried under maximum
flows, in other words, the design flow of the
power plant, and the amount of head loss that can
be accepted. Utilizing the design flow for the
power plant of 65 to 85 cfs, our plan is to
minimize the net head loss since the power
generated is proportional to the rate of flow and
the effective head or water pressure at the power
plant. For an 85 cfs flow rate, a 48 inch
diameter pipe would provide adequate volume with
minimal head loss.
Since much of the pipeline will be built by hand
utilizing helicopters to carry the materials to
the site, the construction weight of the pipe also
must be considered. Of the materials available
for the pipe, those that would be suitable include
steel, polyethylene and fiberglass reinforced
epoxy (FRE). It is possible that water will
freeze in the pipe during winter months and the
pipe selected must be able to withstand the
pressures caused by this freezing. Steel pipe is
not considered a practical alternative for the
entire pipeline due to its weight, cost, and cost
of construction. Polyethylene and FRE are
considered prime candidates for this pipeline.
The pipe selected will have a maximum design
working pressure of approximately 100 pounds per
square inch. This pressure is difficult to
55
achieve in large diameter polyethylene pipe.
Polyethylene pipe 48 inches in diameter in this
pressure range weighs over 100 pounds per foot
making a 40 foot length weigh over two tons. This
would require a larger helicopter than is locally
available or reducing the joint lengths to 20
feet. Suppliers of polyethylene pipe recommend
against shortening the joint length due to the
time and expense involved in making fusion butt
welds.
Polyethylene pipe, on the other hand, has the
advantage that it does not need to be restrained
and can be laid on the ground and allowed to move
with changing pressures in the pipe. Connecting
joints of polyethylene together uses a special
thermal welding technique that results in no
additlonal roughness within the pipe. Between the
intake structure and the old dam, the polyethylene
pipe will be laid on the gravel trapped by the
existing dam. During periods of high flows, water
may cover the pipe and it is necessary to restrain
the pipe to prevent scouring of the gravel under
the pipe. Figure V-19 shows one method of
securing the pipe using gabions.
This method may allow scouring during heavy flows.
The scour depth has not been determined, but may
be as much as five to seven feet. Routing the
pipeline near the east bank will remove the pipe
from the main portion of the flow at all except
high flow periods. The pipe can be buried below
the scoured depth to reduce the possibility of
damage due to scouring during heavy flow periods.
It is estimated that this burial would be below
the water level behind the dam and the material
56
floatation of this pipe would tend to make it rise
to the surface. This area will not be accessible
to mechanical equipment and the pipe will have to
be buried by hand. With the round nature of the
gravel and cobbles in the area, it is possible
that a burial depth of five to seven feet is more
than can be expected to be accomplished by hand
digging methods. Wing dikes could be installed
over the pipeline which would be gabions laid
perpendicular to the axis of the pipeline. These
wing dikes would encourage siltation and
depositing of small gravel over the pipeline
during most flows. Theoretically this gravel
would then be available to protect the pipe during
heavy flows.
FRE pipe uses mechanical joints that are bolted or
strapped on to the pipe. FRE pipe must be
restrained and is mounted in saddles at intervals
of 15 to 20 feet to keep thrusts and other forces
from separating the pipe at the joints. Polyethy-
lene pipe is flexible and can be bent without
kinking in a radius of 30 times diameter. FRE
pipe is straight and bends are accomplished by
pre-manufactured elbows. Slight bends are allowed
by misalignment of the pipe joints. In general,
FRE pipe is lighter than the polyethylene pipe for
the same structural strength.
For the purpose of this project, prices and flows
have been developed around utilizing two 32 1/2
inch polyethylene pipes. These two pipes give the
same flow as a 48 inch diameter pipe and
approximately the same head loss. The smaller
diameter results in a pipe that weighs
approximately 40 pounds per foot or 1,600 pounds
57
for a 40 foot length. This weight can be handled
by helicopters and can be manhandled by
construction crews. The use of this polyethylene
pipe will allow gradual bends to be made as shown
on the attached drawings. Sharp bends such as the
dam crossing would utilize pre-manufactured
polyethylene elbows.
The notch carved into the east abutment ranges
between four and five feet in width. This area is
not wide enough to accept the two 32 1/2 inch
pipes side by side. Alternatives include mounting
the pipes vertically one above the other,
attaching them to the rock bluff with saddles or
clamps, or removing additional rock from the bluff
to increase the width to six or eight feet. It
may also be possible to combine the two 32 1/2
inch pipes into one 48 inch pipe for this area.
Trestles would have to be constructed to support
the 48 inch polyethylene pipe in the area where
there is no natural support. FRE pipe 48 inches
in diameter could also be used in this area. The
FRE pipe has the advantage that it can be
supported on saddles at intervals and that can
span most of the notches and other non-supported
areas. The route along the east abutment may turn
more rapidly than is allowed with fiberglass pipe
and thus require a large number of
pre-manufactured elbows which would add to the
cost and complexity of the project.
In discussions with manufacturers of polyethylene
pipe, transitions from 32 inch to 48 inch pipe
would have a small but measurable head loss. No
specific figures are available on the amount of
this head loss. The use of one 48 inch diameter
58
of polyethylene pipe long the east abutment may
prove to be more desirable during final
engineering and pipeline optimization.
Construction plans provide for the use of
polyethylene pipe over a distance of 1,740 feet
from the intake structure to just above the power
plant. As can be seen on the attached figures,
the elevation drops very rapidly near the power
plant site. It is anticipated that steel pipe
would be used (either two 32 inch pipes or one
48 inch pipe) for this last run before the power
plant. Two steel pipes 32 inches in diameter
again are lighter than one 48 inch pipe and would
be easier to handle, but require more welding and
an adapter at the power plant to combine the two
pipes into one pipe for powering the turbine.
Sheets 1 and 2 of Figure 18 show the routing and
preliminary design of the pipeline utilizing two
32 inch polyethylene pipes.
Figure V-20 shows the load loss as a function of
flow for the proposed pipe.
As mentioned above, during final design the size,
type and number of pipes will be optimized to
minimize construction costs and provide the
maximum flow and minimum head loss.
Turbines and Generators
(a) Design Considerations
There are several designs of turbines available
for recovering the energy from water and turning
it into electrical power. Designs that are
currently in use include Francis, Kaplan, Pelton,
Crossflow, Turgo, etc.
59
Each of these is unique in some aspect, but in
general hydro power turbines can be broken into
two classes, impulse turbines and reaction
turbines.
Impulse turbines achieve their energy through the
force of water hitting the blades. This would be
akin to squirting a garden hose at a fan. Impulse
turbines are characterized by the water impacting
the blades or cups at a small number of points,
usually one or two nozzles per device.
Reaction turbines, on the other hand, derive their
energy from the water stream by turning in the
flow as a propeller. The Francis and Kaplan
Turbines are particular examples of reaction
turbines. These are normally situated so that the
entire mass of water flows around and through the
device and all of the blades are in contact with
the water all of the time. In general reaction
turbines are used for high flow situations and
impulse turbines are used in high head situations.
Figure V-21 shows the combination of flows and
heads where each type of turbine is applicable.
(b) Alternatives Considered
The application under consideration for Humpback
Creek includes a maximum flow of approximately 70
to 90 cubic feet of water per second at an
effective head of 165 to 175 feet. This
particular head height would be most effectively
served by a Francis, Crossflow or Turgo turbine.
Figure V-22 shows the efficiencies of each of
these turbine types as a function of percent of
rated capacity. It can be seen that the Francis
turbine is very efficient at very high loads, but
60
that efficiency drops off quite rapidly for lower
flows. The Francis turbine is particularly well
suited for an application with a constant flow of
water where maximum efficiency at the specific
operating point is the prime consideration. Both
the Crossflow and Turgo turbines operate over a
much broader range of input flows although their
peak efficiencies do not approach the high
efficiency of the Francis. Figure V-23 shows the
efficiency of a Turgo turbine over the range of
flows expected on Humpback Creek.
The Crossflow and Turgo turbines are very
different in their construction and operating
mode.
The Crossflow turbine is usually of welded
construction and resembles a squirrel cage fan.
Since the water strikes the turbine tangentially,
no axial thrusts are produced. The Crossflow
turbine is efficient over a wide range of flows.
Its design is such that it does not respond well
to abrupt changes in load. For example, if the
load on the generator was suddenly reduced
drastically, the water flow in the penstock could
not be altered rapidly without causing undue
hydraulic pressures in the penstock. As a result,
the operating speed of the Cross Flow turbine
increases significantly. It is not unusual for
turbines of this type to reach two to four times
rated rpm in response to a drastic load reduction.
It is obviously necessary that all loads be
dropped before a generator is allowed to
significantly increase speed which further
compounds the problem. Large load swings are not
anticipated in the application on Humpback Creek
61
although it is possible for the circuit breaker to
open, dumping all loads and allowing the turbine
to overspeed. The generators purchased to operate
with the turbines are usually specified to be
capable of physically withstanding the magnitude
of overspeed which can be expected. Crossflow
turbine outputs range up to several hundred
kilowatts (KW). Ossberg Company has produced
Crossflow turbines in the 1,000 KW range but they
have been used in lower heads than that considered
for this project. Thus the use of Crossflow
turbines would necessitate the installation of two
units.
The Turgo impulse turbine has a cast runner or
blade assembly that water is directed to through
one or two nozzles. These nozzles are at an angle
to the axis of the turbine and result in a
considerable amount of end thrust that must be
absorbed in bearings. It is possible to very
rapidly deflect this stream of water and overspeed
problems are not normally observed although
generators purchased to operate with these are
also specified to operate in the overspeed
situation.
(c) Selection of Turbine
Selection of the specific turbine to be used for
this project will be accomplished during final
engineering based on efficiency curves of each
unit. It is anticipated that proposals will be
received for both the Crossflow and Turgo impulse
turbines.
62
(d) Selection of Generator
Generators to be connected to the turbines can be
either induction (asynchronous) or synchronous.
Induction generators are little more than AC
motors connected to a device that turns them
faster than they would normally run with the
voltage applied to them. Induction generators are
very simple in that voltage regulation and
frequency regulation is not required but is
established by the utility system. Induction
generators have a particularly poor power factor
and are not able to provide reactive power to the
system. Induction generators can not operate
independently; they require the presence of
utility power to establish voltage and frequency
references.
The total amount of induction generation allowed
on a utility system is subject to some discussion,
but there seems to be general agreement that it
should not exceed 15 to 20 percent of minimum
system load. Beyond this point voltage and
frequency instability problems can cause
inadequate electrical service for all customers
served by the utility. Figure V-24 shows the hour
by hour loads expected by CEC during the peak
summer season and the minimum winter season. Also
shown on the chart is the 15 percent practical
limit that can be allowed in induction generators.
As a practical matter, even during the peak summer
months, the Humpback Creek hydro project will put
out more power than would be allowed for induction
generators and a synchronous generator must be
used.
63
Synchronous generators have voltage and frequency
regulators to allow them to precisely maintain
operating voltage and frequency. Synchronous
generators are able to provide reactive power
needed by the system and are capable of operating
in an isolated mode separate from the utility
system. For example, a cable failure between the
Humpback Creek hydro plant and town could result
in the Humpback Creek project providing power just
for itself or itself and other loads without any
help from the diesel power plants. Being able to
operate independently would allow generation of
power necessary to prevent freezing of the
building, and it would keep telemetry and control
batteries charged until repairs could be made.
Synchronous generators can be purchased in several
voltage ranges. The two most probable voltage
ranges for consideration for this project would be
4,160 (4KV) volts or 12,470 (12KV) volts. 4,160
volts is a standard voltage and is utilized by
some of CEC's existing generators, and by many
other utilities in the State of Alaska. This
voltage must go through a transformer to be raised
voltage back up to 12,470 volts for transmission
back to town. 12,470 volts would be required to
match with the existing CEC distribution system.
The reason for the step-up transformer is to
reduce the current required and consequently the
conductor size. The 4KV generator would produce
130 amps per phase for 750KW. A 12KV generator
would produce 44 amps. A 4KV generator is
significantly cheaper than a 12KV generator. The
cost differential amounts to approximately
$30,000.00 for a 800KW generator. However, a 4KV
generator would require a step-up transformer
64
which would cost approximately $18,000.00 and
would have core and winding losses amounting to
over 30,000 kwh per year. Since kwh lost in the
transformer will not be available to the utility's
system, they must be made up by diesel at a cost
of 8 cents per kwh (based on 1985 fuel prices
which would increase with the cost of diesel) for
a 1985 cost of $2,500.00. The 12KV generator will
have a simple payback period of five years. Based
on the above, it is recommended that we utilize a
12,470 volt three phase generator.
Building and Tailrace
An arctic insulated metal building approximately
24 ft. by 40 ft. will be constructed to house the
power plant. A concrete footing will be installed
for the building. The building will be of metal
construction with 16 ft. eave height. It will be
constructed to withstand 200 pounds per square
foot ~now loads and 100 mph winds. It is
anticipated that over the life of the building
heavy snow years may completely bury the building
and ventilation pipes will be run through the roof
of the building to provide ventilation during
periods when the building may be totally buried.
For planning purposes it is anticipated that the
building will be approximately 40 ft. by 24 ft.
Figure V-25 shows the proposed layout of the
building. Figure V-26 shows a cross section of
the building showing elevations of the generator
and tailrace. Figure V-27 shows the site
arrangement of the power plant site.
65
~
\
SEE INTAKE
STRUCTURE DETAILS
CREEK
SCALE: I"e 40' HORZ.
I"' 10' VERT.
35 LF. ~ (2) 32-QJ
20 LF.:!: (2) 32" QJ
SOR 32.5 PE. PIPE
20 LF. :t (2) 32· "
150 LF. f SOR 32.5 P.E. PIP~ .. (ISOR 32.5 PE. PIPE
~~ ____________________ ~4~8~0~L~F.~±-2~~)~32~·~0~S~O~R~3~2~.5~P.~E~.~P~IP~E~ ____________________ ~+i~ I 410 LF. ± (2) 32" QJ SOR 32.5 PE. PIPE (2) 32-" SOR 32.5 P.E. PI ~ __
. ~oo
190
180
170
160
150
TOP OF
..... "'u ;!~
~It;
SPILLWlY 20~ 0· ...
10
. .. c
!
~--.-------------------':7-__________ ,../
INV. 196.0'.1
Figure V-18
Sheet #1
II 12 13
DATE "01S'ONI AND RECORD Of ISSUE
14
TOP EXIST. DAM
194.0'&
15 IG
DESIGNED .....,C",-L",,"' __ _
CORDOVA ELECTRIC 0"''''0 -,C=C-,<-C __ _
CHECKED -,C'-".L=,.. __ _
COOPERATIVE. INC. "'.OV'D __ D=L=,.. __ _
DATE JULY 198~
.. .. ; ....
e-.• >
OJ -.. .. >
\.
CONSTRUCT TlN~ER /\
SUPPORT SYSTE~
ACROSS GULLT
PHOTOGRAPHIC
17 18
:\lEl~I{ELL & ASSOC.
DESIG:'\.' SEH.VICE
SUPPORTED ON CABLE
\
\
\
\
. -\
REDUCTION \
\
19 20
HUMPBACK CREEK
HYDRO PROJECT
PIPE LINE -PLAN -PROFILE
21
I
I
I
I
I
I
ILl z
::::i
:I:
U
I-
~
:::E
190
16o __
150 __
SHEET
I OF 3
160
~O
_130
-'20
110
100
o
IP .
N
22 23
OAT[
HUMPBACK
SCALE: 1"= 40' HORZ.
1"= 10' VERT.
625 LF. t (2) 32" 0 SDR 32.5 P. E. PI PE
Figure V-IS
Sheet #2
24
R£V1SIONS A ... O I'IECOIilO 0' ISSU[
2~ 26
CORDOVA ELECTRIC
COOPERATIVE, INC.
HO •• aT I C'-:' "'P
27
DESIGPoiED DU"
DETAILED ~
CHEC"ED DlM
APPRovED ~lM
CATE JULY 1985
TRAN SITION FITTINGS
P E -STEEL
125 LF.t (2) 32"0
WELDED STEEL PIPE
25 LF t (2) 32"0
LOED STEEL PIPE
150 80
90 20
28 29
20"-Z PIECE
STEEL ELIla.¥S
;
~ ..
MERRELL & ASSOC.
DESIG;\J SERVICE
30
bJ PLANT ,
SITE
.. 1,.
~ ~
~ ~ ~
\
j
---~ __ --r--
PHOTOGRAPHIC REDUCTION
31
HUMPBACK CREEK
HYDRO PROJECT
PIPE LINE -PLAN -PROFILE
90
80
70
60
40
30
20
SHEET
2 OF 3
HIIMPBACK
~
CREEK
I
5 1/2 11 CONCRETE
BACKING BEHIND
GAB10fIS
APPROX. LOCATION
OF SAOINO STATION
ELEV. 197.9'
Figure V-18
Sheet #3
CONC WEIR ,SPILLWAY) f"w nm .. ." " .. ~ .,,"
/ P. E PENSTOCKS (2)
/ /
/ /
/' ~ ." C.L DRAIN fOR INTAKE STRUCTURE :;-:-". / /
INTAKE STRUCTURE
SITE PLAN
SCALE: I "e 10'
fABRICATED
STEEL INTAKE
STRUCTURE
36". SLUICE GATE
12'-0"
CONe. WEIR
,SPILLWAV)
ELEV. 20S't
UPSTREAM VIEW-INTAKE STRUCTURE AND GASION WALL
SCALE, 1"= 4'-0"
HEAVV GALV. STEEL
GRATING ,TRASH RACK)
2" RAD. STEEL
CORNER
ROUND R.T.
i
!
~I
~I it:
'!i!
TOP ELEV. WEIR
/ 205'~
/ 5112" CONC.
//
/6'-6"'
:-/, ?, (I I~ I-r-
...J ... ... ... .,
r-------R.R. STL. tP 8'-0" O.C.
/------GABION WALL // r fASTEN NARINE PLYWOOD TO SIDES
ABOVE STEEL TAIIK
/. HEAVY GALV STEEL GRATING
/ !' _ FOR TRASH RACK
'~... ,//
·0" RINGS
/STEEL STUDS
STEEL FLANGE ADAPTERS
2 -32". P.E. PENSTOCKS
J
---....I ...,!~""-,..,.0Yr.7-='=-cif=" _=-. -,;-!----
i r : 1fII;' ; 11f1Ci=
JET IN R.R. STL ~-Jrlll -- - --~.---
M/ft. 8' INTO GRAVEL I
uj
SECTION A-A
SCALE' 1/2"= I'-O",APPROX.)
PHOTOGRAPHIC REDUCTION
DESIGNE:..:: _~o,-,'",," __ _
CORDQVI>, ELECTRIC I D"m" _--', .... ,~ __
---------------~---+-----------------------PROJECT NO.
:\IEHRELL & ASSOC.
HUMPBACK CREEK
HYDRO PROJECT
DESIG:".' SEr~VICE -----+---_____________________ .:J~~ ~E.~ATIV=:. IN:. I ~;:~~~:: ~~~ __ lNTAK~ STRUCTURE 3sro=cE~3
--l _____________________ ~tL·D~A~~~~==J=J'=Y=='9=~=-.===_~ __________________________ -l __________ -L __________________________________________ ~ ______________ L_ ________ _ QM4, IWtIIitOtl:, aIUlIlU:.Q&D Q' ISSUE ___ . __ .. ~_~~:~~::~ _
----------------------------------'""1
EXISTING Gf{AVEL
G~ADE----'
PLACED IG"BELOW
FINAL GRADE FOR
LATE~AL SUPPORT
Figure V-19
LOOKING UPRIVE~
-
I I I ~--3X3X6 GABIO!'!
I . 'I
. I . '.' I . . . J . L ____ . __ .
. . .
LARGE BOULDERS PLACED--"-
AGAlt,IST GABIONS FOf\
ADDITIONAL SUPPOR.T .
• AND PROTECTION _
PROTECTION OF POLYETHYLENE PIPES
ABOVE OLD DAM
CORDOVA ELECTRIC COOPERATIVF SCALI~:t
HUMPBACK Cf\EEK HYDRO PROJECT DESIGN: w6a---
DRI\WING NO. DRAWN GFTlJr(l(
Figure V-20
FLOW RATE VS. HEAD LOSS FOR TWO POLYETHYLENE
PIPES 32 1/2 INCHES O.D.
EACH 1720 FEET LONG PLUS 270 FEET OF 32 INCH O.D. STEEL PIPE
Flow Rate Head Loss
cfs ft.
5 0.1
10 0.2
15 0.5
20 0.8
25 1.2
30 1.7
35 2.2
40 2.8
45 3.5
50 4.2
55 5.0
60 5.9
65 6.8
70 7.9
75 8.9
80 10.1
85 11.2
90 12.5
95 13.8
100 15.2
Assume Hazen-Williams "c" of 150 Polyethylene Pipe and
130 for mortar lined steel pipe.
Byron Jackson Division BORG)(WARNER
® Section 2-190
Eft. Sept. 1983
BORG-WARNER CORPORATION Page 2-190-15
HYDRO TURBINE APPLICATION RANGE
(ft)
1000r-~--~--------~--~--~------~----~--~----~
500
200~ ____ -+ __ ~~ __ ~~ __ __
c
<100~~ __ ~ __ __ w
J:
50~~ __ -4~~ ____ -4 ______ ~~~ ____ ~~ ____ ~ ______ ~
201--__ __+_
10~ ____ ~ ________ ~~--__ ~~ ____ ~ ________ ~~--~
10 20 50 100
DISCHARGE
Figure V-21
200 500 1000
(cfs)
TURBINE EFFICIENCIES
100~------------------------------------------~
90
>-80 u z
UJ
U
L;:
~
UJ 70
60
o 10 20 30 40 50 60 70 80 90 100
FLOW IN PERCENT OF RATED FLOW
o FRANCIS + CROSSFLOW 0 TURGO
Figure V-22
IMP U L SET U RBI NEE F F I C lEN C·I E S
100~-----------------------------------------------,
90
>-80 u z w
U
u.. u.. w 70
60
o 10 20 30 40 50 60 70 80
FLOW IN CFS
o 65 CFS MAX + 85 CFS MAX
Figure V-23
,-tn
~-I--
..:(
~
~ c:>
L.&J
~ ..........,
a
~
0
.....J
LOAD DURATION CURVE
For 1984 AND 1985
4~------------------------------------------------------~
3.5
3
2.5
2
1 .5
1
MID 2am 4am 6am 8am lOam noon 2pm 4pm 6pm 8pm 10pm mid
TIME OF DAY
o Winter + Summer
TAILR,ACE
Figure V-25
" 36 SUPPLY
f/
MCC ST 001 I SWITCH-
GEAF\ PANEL SE~V. B8
'" ''----STANDBy GEN.
I3ATTER.Y BANK
STORAGE A~EA
.----800 KW GENERATOR
LIVING QTRS.
BUNK BEDS
28 TURGO IMPULSE TURBINE
OVE~HEAD 000 F\ESTF\OOM
POWERJ-iOUSE GENERAL ARPANGEMENT
CORDOVA ELtCTRJC COOPERATIVE SCALE: 1."= (Oil
HUMPBACK CF\EEK HYDRO PROJECT:.....-I ___ 4 -------1
DR,~Vvlf\JG ~~(). I DESIGN BY: WD.B.
i D PA VII r~ G BY: G.F. TIJ RY,.
r-.. /""'\, I '~n r--. , ..... ", -B LJ I: :--! '\ ,'--' '1 \ \ 1\ r-+-i I I '. \ ' i I! ' !' ~_
rV '.! J L K I L;-'\ I \I I I '-~ I " ~
\
34--
TU RBINE CENTER--+-----+---.
I
32--
30~ __ ~F~LO~O~R~L=E~V~EL~_,
A
I 28--I
3
I
26·--
I
24--
NOTE:
TUR.BINE/GENERf.TOR. FOUNDATION
ISOLATED FR.OM 13UILbiNG FLOOF\
AT POINTS A 4 B
Insulated 6 inch pipe to be
buried under stream to insure
flows during freezing weather.
Figure V-26
f-o-----------13U 1 L DIN G W ~ L L
~G·FOUNDATION WALL
..------1i----1-----T UR BIN E I G ENE RATO R
FOUNDATION 13LOCK
TAILR,ACE
DETAIL OF
TU~8INE/GENERATOR ISOLATION
AND TAIL~ACE
~-EXISTING GROUND LEVEL
STREAM
r-LEVEL
CORDOVA ELECTRIC COOPERATIVE SCALE: 1/~2/0·
HUM P BAC K CREE K HYDRO PRO J ECT ~-=-:-:--=-:"""'-------:-=---------1
DO/\WING NO. DESIGN BY: W.O.B.
r'(\ D AWING BY: G.F.TI.J K
z ....
Figure V-27
.-TBM~
Note:
-
•
Bridge across creek
to be perpendicular
to creek.
'''1 ,. '
! •
SCALE
(. 20'
! .' --.. ........ ,-. -~, --~ -i. ; ~: ..... '. _ ~ -, _ _ _ ,-.
connection to CEC's Distribution System
Cordova Electric Cooperative's distribution system
consists of approximately 20 miles of 12,470/7,200
Volt primary conductor and approximately four
miles of 2,400 Volt primary. Cordova Electric
Cooperative is currently developing a Long Range
Plan and Two-Year Construction Work Plan with the
engineering firm of Dryden and LaRue to determine
long range growth patterns for the Cooperative.
The Eyak Corporation is currently in the final
stages of negotiating a contract with a firm for
the sale of timber from Native Corporation lands
in the Cordova vicinity. This timber sale
provides for construction of a road from Cordova
to a marine terminal site at Shepard Point.
The CEC Long Range Plan anticipates the
requirement for power at Shepard Point over the
next several years. While the design of the line
has not been finalized at this point, it is
anticipated that an underwater cable energized at
12,470 volts will be run from the existing CEC
substation at Orca to Shepard Point. This line
will be brought ashore at a minimum of three
points north of Cordova. Point 1 will be
approximately one mile north of Orca, Point 2 just
north of the mouth of Humpback Creek and Point 3
at Shepard Point. The design considerations for
this distribution line are outside the scope of
this study. It is anticipated that by 1987
distribution voltage will be available on the
north side of Humpback Creek above the high water
mark. As part of the Long Range Plan and Two-Year
Construction Work Plan being prepared by CEC, a
Borrower's Environmental Report is being prepared
66
which will separately assess the environmental
impacts of this proposed line. The construction
of this line is not considered part of this hydro
electric development and will occur independently
of the hydro electric development. From the
switchgear located inside the power plant, 15KV
wire will be run to a termination pole located
just north of the power plant. Overhead
construction will be used from this point
utilizing the REA recommended Raptor Construction
Standards (See Appendix C). Vertical construction
will be used for all turns and angles above five
degrees. Horizontal construction will be used in
all other places. The ruling span will be
approximately 200 feet which is a standard CEC
construction spacing providing resistance to wind
slap and the resulting strain on the lines. It
also provides additional strength required for the
heavy snow expected in the area. The poles on
either side of Humpback Creek will be at least
40 feet from the stream bank and will be
independently guyed so that a failure on either
side of these poles will not affect their support
capability. The transition from overhead to the
existing CEC distribution system will utilize
normal REA construction standards. See
Figure V-28 for the location of this overhead to
underground transition.
67
/
j
" \
\
I
I
I
/
/
/
I
'~ i, if
/~ i
)
~--------~-----------------
~""'-CREEK CROSSING
_......_-175 ____ -------------
"3-
i
I
!
!
CORDOVA ELECTRIC COOPERATIVE
HUMPBACK CPEEK HYDRO PROJECT
TOPOGRAPHICAL DETAIL
ORCA
INLET
Figure V-28
SCALE: ( = 100'
PLAN BY,
OESI0NBY,
DRAWING BY, G.FTU~~
REVISION NO.
DATE EXPlANATiO N
D. COMPARISON WITH OTHER RECENT HYDRO PROJECTS
Tabulated on the next page are other recent
hydroelectric projects around the State of Alaska.
In addition to the cost of each of these projects,
the installed cost per kilowatt of capacity is
included and the cost of power (when fully loaded)
is included. This chart can be used for relative
comparison of the various projects.
67-1
COMPARISON WITH OTHER RECENT HYDRO ELECTRIC PROJECTS
Average Installed
Date In Installed Annual Cost Cost
Name Operation Capacity Production Cost Per KW Per KWH
Humpback 1987 850 KW 3,500,000 $ 3,200,000. $3,765. $ .91
Creek
Solomon 3/82 12 MW 36,000,000. 53,000,000. 4,417. 1. 47
Gulch
Tyee 1/82 20 MW 133,000,000. 126,000,000. 6,300. .95
Terror 11/84 20 MW 139,100,000. 190,000,000. 9,500. 1. 36
Lake
Swan Lake 1983 22 MW 88,000,000. 96,000,000. 4,364. 1. 09
Seward
Bradley 1990 90 MW 369,200,000. 355,900,000. 3,954. .96
Lake
Susitna* 1620 MW 6,910,000,000. 5,300,000,000.** 3,272. .78
Salmon
Creek
Snettisham
Ek1utna
*Staged Construction **1982 Costs, others are actual or estimated.
Note: Installed cost per kwh is installed cost divided by average annual
production and does not relate to cost of power from the project.
E. SUMMARY OF CONSTRUCTION COSTS
This cost estimate is for the Humpback Creek pipeline
and intake structure.
PIPELINE
1. Pipe material.
a) SDR 32.5 P.E. Pipe
3440 L.F. 32" Diameter
SDR @ $43.26/ft.
Shipping and Freight
@ $15/ft
b) SCR 32.5 Fittings
6 ea. 60 0 Fabricated Elbows
@ $2,000/ea.
12 ea. Flange Adapters
@ $l,OOO/ea.
2 ea. Transition Fittings
@ $2,500/ea
c) 32" Dia. Welded Steel Pipe
(3/8" Wall Thickness)
540 L.F. @ $85/ft.
Shipping @ $20/ft.
2 ea. 45 0 2 pc. elbows
@ $2,300/ea.
2 ea. 30 0 2 pc. elbows
@ $2,300/ea.
2 ea. 20 0 2 pc. elbows
@ $2,300/ea.
d) Thrust Blocks
(Pre-cast Concrete)
L.S. $200/ea x 8
Sub-Total Pipe Material
68
$ 148,815.
51,600.
12,000.
12,000.
5,000.
45,900.
10,800.
4,600.
4,600.
4,600.
1,600.
$ 301,515.
2. Miscellaneous Other Materials
a) Permanent Timber Support & Gully
4 x 12 Stringers
(Est. 200 L.F. x 4 x $1)
6 x 6 Posts
(Est. 280 L.F. x 3 x $1)
3 x 12 Deck
(Est. 600 L.F. x 3 x $1)
2 x 6 Handrail
(Est. 400 L.F. x 1 x $1)
Misc. Fasteners and Hardware
sub-Total
b) Temporary Work Bridge For
Pipe Cable Suspension System
3 x 12 Decking
(Est. 800 L.F. x 3 x $.60)
3 x 12 Stringers
(Est. 400 L.F. x 3 x $.60)
2 x 6 Handrails
(Est. 1200 L.F. x 1 x $.60)
Steel Cable (7/8")
(500 L.F. @ $2.50)
Misc. Hardware & Fasteners
sub-Total
c) Permanent Cable Suspension
for Creek Crossing (7/8" Dia.)
(Assume one cable for each pipe)
1,000 L.F. @ $3.50
Misc. Fasteners, Rock Anchors
and Clips
Pipe Saddle
sub-Total
Sub-Total Misc. Other Materials
3. Equipment
Portable Air Compressor and Hoses
Portable Welder (300 amps)
4" Diesel Pump
Gasoline Driven Donkey Engine
Butt Fusion Welder
Misc. Portable Tools (Lump Sum)
Helicopter (Max. Pick 3,500 lbs.)
Helicopter (Max. pick 800 lbs.)
69
800.
840.
1,800.
400.
300.
4,140.
1,440.
720.
720.
1,250.
1,500.
5,630.
3,500.
3,000.
4,500.
11,000.
175./day
85. /day
20,770.
275./day
1,500./month
6,700./month
2,000./L.S.
900./hr.
485./hr.
a) Helicopter
b)
c)
d)
e)
f )
P.E. Pipe
(Est. 25 hrs. @ $900)
Steel Pipe
(Est. 7 hrs. @ $900)
Misc. Mobilization and
Demobilization of Pipe Equip-
ment (Est. 12 hrs. @ $900.)
Cable Suspension System
at Creek Crossing
(Est. 10 hrs. @ $900.)
Sub-Total
Portable Air Compressor
(Est. 15 days @ $175.)
Portable Welder (300 amps)
(Est. 15 days @ $85.)
Gasoline Driven Donkey Engine
(Est. 3 months @ $1,500.)
Butt Fusion Welder
(Est. 3 months @ $6,700.)
Misc. Small Handtools
Sub-Total Equipment Costs
4. Labor
Labor Rates (Assume 30% Markup
for Employee Cost)
Supervision: Use $30/hr. x 1.30
General Labor: Use $15/hr. x 1.30
Pipe Welder: Use $25/hr. x 1.30)
Assume 10 hour days
a) Clearing and Grubbing
Pipeline Route
Est. 10 days (4 man crew)
(1) 10 days x 10 hrs. x $39.
(3) 10 days x 10 hrs. x $19.50
Sub-Total
70
22,500.
6,300.
10,800.
9,000.
48,600.
2,625.
1,275.
4,500.
20,100.
2,000.
39.00/hr.
19.50/hr.
32.50/hr.
3,900.
5,850.
9,750.
79,100.
b) Pipe Laying (P.E. Pipe)
Est. 1 joint/hr
@ 100 joints = 100 hrs.
Add 80 hrs. for mobilization
and demobilization
Total = 180 hrs.
Est. 8 man crew
(1) x 180 hrs. x $39.
(7) x 180 hrs. x $19.50
Sub-Total
c) Pipe Laying (Steel Pipe)
Est. 1 joint/hr.
@ 30 joints = 30 hrs.
Add 40 hrs. for mobilization
and demobilization
Total = 70 hrs.
Est. 6 man crew
(1) x 70 hrs. x $39.00
(1) x 70 hrs. x $32.50
(4) x 70 hrs. x $19.50
Sub-Total
d) Cable Suspension System
Across Creek
Est. 4 wks. (200 hrs.)
Est. 8 man crew
(1) x 200 hrs. x $39.00
(7) x 200 hrs. x $19.50
e) Timber Support for Pipeline
Est. 50 hrs.
Est. 4 man crew
(1) x 50 hrs. x $39.00
(3) x 50 hrs. x $19.50
Sub-Total
Sub-Total Labor Costs
71
7,020.
24,570.
31,590.
2,730.
2,275.
5,460.
10,465.
7,800.
27,300.
35,100.
1,950.
2,925.
4,875.
91,780.
INTAKE STRUCTURE
1. Material
a) Gabions (PVC Coated)
(Assume rock available at site
wino blasting required)
6 ft. x 3 ft. x 3 ft. = $75./ea. (Quote)
b)
c)
d)
e)
f)
g)
h)
i)
j )
Total Volume = 3,500 cubic feet
$75. divided by 54 times 3,500
Sluice Gate (Low Pressure)
(Quote) $2,600. plus freight
Concrete Wall and Weir
Est. 12 cubic yds. @ $250.
Trash Rock and Screens
Est. 10 ea. sections
Pre-Fabricated @ $750.
Pre-Fabricated Steel Tank
Est (L.S.) $8,500.
R.R. Steel
Est. (L.S.) $500.
Plywood Forms
Est. 20 pcs. @ $25.
Steel Flange Adapters
for P.E. Pipe
2 ea. @ $ 2 , 000 .
36" Dia. Steel Pipe
Est. 20 L.F. @ $140./ft.
4" C.I. Pipe for Drain and
Valve and Box
Est. 200 L.F. @ $4.50
Est. L.S. $150.00
Sub-Total Material Cost
72
4,860.
3,500.
3,000.
7,500.
8,500.
500.
500.
4,000.
2,800.
1,050.
36,210.
2. Equipment
a) Helicopter
Est. 18 hrs. @ $485./hr. 8,730.
Est. 4 hrs. @ $900./hr. 3£600.
Sub-Total 12,330.
b) Air Compressor
Est. 20 days @ $175. 3,500.
c) Portable Welder
Est. 10 days @ 85. 850.
d) 4" Portable Pump
Est. 45 days @ $275. 12£375.
Sub-Total Equipment Costs 29,055.
3. Labor
Est. 8 man crew -45 days
( 1 ) x 45 days x 10 x $39.00 17,550.
( 7 ) x 45 days x 10 x $19.50 61£425.
Sub-Total Labor Costs 78,975.
73
COST SUMMARY FOR PIPELINE AND INTAKE STRUCTURE
A. Pipeline
1. Pipe Material
2. Misc. Other Materials
3. Equipment
4. Labor
Sub-Total Pipeline
B. Intake Structure
1. Material
2. Equipment
3. Labor
Sub-Total for Intake Structure
$301,515.
20,770.
79,100.
91,780.
$ 36,210.
29,055.
78,975.
Sub-Total for Pipeline & Intake Structure
Add 15% for Contingencies
Total Estimated Cost
74
$ 493,165.
$ 144,240.
$ 637,405.
95,610.
$ 733,015.
This cost estimate on the Humpback Creek Power Plant
is based on 850 KW installed capacity.
1. Mobilization, demobilization,
site preparation and finish
grading.
2. Foundations:
Buildings (30 yds. @ $l,OOO/yd.)
Tailrace (40 yds. @ $l,OOO/yd.)
Turbine/Generator
(40 yds. @ $l,OOO/yd.)
Pilings under turbine generator,
if needed. (20 @ $1,000 each)
Total Foundations
3. Flexible coupling, isolation valve.
Flexible couplings (2)
Isolation Valve
Welding (1 man for 50 hrs.)
Total
4. Turbine/Generator
Includes Governor, Control System
Freight (25 tons)
Total
5. Switchgear, motor control center
Includes freight
6. System batteries/battery charger/
AC Inverter/Preferred AC System
7. Building (24' x 40')
8.
9.
Includes doors, vents, windows
Bridge Crane (10 ton)
Manual Bridge and Main Lift
Small Electric 5 Ton Hook
Intake Structure Water and Gravel
Level Sensors Includes
Cable to Power Plant
75
$
30,000.
40,000.
40,000.
20,000.
6,000.
30,000.
2,000.
350,000.
10,000.
75,000.
130,000.
38,000.
360,000.
100,000.
10,000.
48,000.
25,000.
5,000.
10. Control System to Interface to
Orca Power Plant
Hardware
Transducers
Wire to Town
11. Electrical
30,000.
5,000.
15,000.
Materials (Includes 10KW
Standby Generator
Control Labor
(2 men x 3 wks. x $50 x 11 hrs.)
To install conduit in concrete
pull wire)
House Labor
(2 men x 3 wks. x $50 x 11 hrs.)
Includes lighting, outlets,
battery charger, inverter, S B
generator, preferred AC System)
Power Labor
(2 men x 1 wk. x $50 x 11 hrs.)
Includes pulling high
voltage cables.
Terminating Labor
(2 men x 3 wks. x $50 x 11 hrs.)
Includes control wiring, switch-
gear wiring, and field wiring.
Total Electrical
12. Mechanical
Materials (Includes heating,
ventilation, restroom,
10,000.
16,000.
16,000.
5,000.
16,000.
potable water, backup cooling. 9,000.
Labor (Includes setting turbine
and generator alignment, grouting,
piping potable and power water
systems, installing governors
and linkage.
(2 men x 12 wks. x $50 x 11 hrs.) 64,000.
50,000.
63,000.
Total Mechanical 73,000.
13. High Voltage Electrical
Terminate high voltage cable
generator and install station
service.
(3 men x 2 wks. x $50 x 11 hrs.)
Materials
Total High Voltage Electrical
76
16,000.
2,000":'..
18,000.
14. Connect to CEC Distribution System
Five spans overhead construction
raptor construction standards
Total Connect to CEC
15. Start up and Checkout
Factory Representative
1 man x 15 days
Switchgear Representative
1 man x 5 days
Miscellaneous Other Services
Total Start up and Checkout
Sub-Total
Engineering @ 8%
General and Administrative @ 10%
Contingency @ 20%
TOTAL
77
10,000.
25,000.
6,000.
10,000.
10,000.
41,000.
$1,046,000.
84,000.
105,000.
209,000.
$1,444,000.
HUMPBACK CREEK HYDRO COST ESTIMATE
Pipeline and Intake Structure
Estimate Per Dave Merrill
Rock Work East Abutment
Not Force Account Work
Sub-Total
Contingency @ 20%
Engineering @ 8%
General and Administrative @ 10%
Total Pipeline and Intake Structure
Power Plant and Line to Town
Estimate per C. Hildenbrand
Connect to CEC System
Sub-Total
Contingency @ 20%
Engineering @ 8%
General and Administrative @ 10%
Total Power Plant and Line to Town
Interest During Construction
Bridge at Creek Crossing
Preliminary Costs
Mitigation
Micsellaneous
PROJECT TOTAL
ROUND UP
78
$ 640,000.
100,000.
260,000.
$1,000,000.
$ 200,000.
80,000.
100,000.
$1,380,000.
$1,036,000.
10,000.
$1,046,000.
$ 209,000.
84,000.
105,000.
$1,444,000.
$ 100,000.
75,000.
50,000.
25,000.
100,000.
$3,174,000.
$3,250,000.
F. ACCOUNTING TREATMENT
The financial feasibility analysis determines, on
a long term basis, whether the benefits of a
project outweigh the costs. As long as the
benefit to cost ratio remains above one, the
benefits outweigh the costs and the project will
provide a long term benefit to the electric
consumer.
Financial feasibility must also address the actual
cost of electric energy from a project or the end
price paid by a user of electricity. In some
cases (such as the Tyee project), early year
electrical loads will not provide sufficient
revenues to cover the costs of the facility.
Either electric rates must be raised above the
non-hydro alternative, a subsidy must be found to
lower rates to an acceptable level, or costs can
be deferred to the future when kwh sales and
revenues from the project will have increased to
support the higher costs.
As a borrower of the Rural Electrification
Administration (REA), CEC must follow the
accounting standards set forth by the Federal
Energy Regulatory Commission as amended by the
REA. Since CEC will own this project, the
associated costs will be incorporated in the
existing financial statements prepared by CEC on a
monthly basis. Figure V-29 contains the plant
account numbers and descriptions under which
elements of this project will be carried on the
Cooperative's books. Figure V-30 contains the
expense accounts that will be charged during
operation of the project.
79
Assignment of project costs to plant accounts is
accomplished at the end of a project when all
costs are known. For the purpose of this
analysis, the assignment of costs shown in
Figure V-31 will be used. The only portion of
these costs that will appear on the Cooperative's
books is that portion that the Cooperative has
invested in, either through equity or debt. The
portion of State equity investment will not appear
on the Cooperative's books and thus will not form
a portion of the Cooperative's rate base.
Figure V-31 also shows the total costs, State
equity investment, and CEC's investment by general
ledger number. This table also shows the life in
years of equipment in each plant account group.
Thus under the financing plan discussed in the
previous section, CEC anticipates an annual
depreciation cost of $63,700.00.
Cordova Electric Cooperative, as all businesses,
financ0s a portion of plant investment with its
own funds (equity) and a portion through borrowed
funds (debt). As of June 30, 1985, CEC had a
capitalization of $8,597,855.00 of which
$7,005,592.00 is debt and $1,592,263.00 is equity
for an equity to debt ratio of 18 percent. Thus
it is anticipated that of the $1,950,000.00
investment that CEC will make in this project, 18
percent or $576,000.00 will be equity investment
and $1,324,000.00 will be debt.
Although this investment will be retired in equal
installments over the 35 year period of the loan,
REA accounting standards require that CEC's
financial statements show the actual interest
80
accrued on the average balance. The portion of
cost of power from this project due to debt
service will then decrease each year.
CEC has mortgaged the assets of the Cooperative
with the Rural Electrification Administration and
the National Rural Utilities Cooperative Finance
Corporation (CFC) to secure loans with each of
these entities. Both of these mortgages require
CEC to maintain a minimum Times Interest Earned
Ratio (TIER) of 1.5. A discussion of TIER is
outside the scope of this study, but in general it
requires a minimum profit or margin level based on
interest payments. On a business wide level, a
TIER of 1.5 is very low and recognizes the capital
intensive nature of the electric utility industry.
From other considerations, the Board of Directors
has established a TIER goal for CEC of 1.85. We
can then establish the margins that the
Cooperative must maintain based on the level of
debt.
Other expenses to be charged to this project
include insurance, maintenance, and property lease
charges. Other Cooperative charges such as
general and administrative, accounting, consumer
billing, etc. will not change significantly due to
this project and will not be considered in this
analysis.
Maintenance is estimated at one cent per kwh
generated. This is also expected to increase at
the general inflation rate.
CEC maintains replacement cost insurance on all
major facilities. The insurance industry is
81
undergoing severe financial stress and insurance
rates are very volatile. 1984 insurance rates
were 7.5 cents per hundred dollar value. In 1985
these rates have increased to 22 cents per
hundred. We have been given a preliminary quote
of 95 cents per hundred for 1986. For the purpose
of this study, an insurance rate of $.50 per
$100.00 of value will be used.
Figure V-32 shows the total annual cost of this
hydro electric project as it will appear on the
accounting records of the Cooperative for years 1,
5 and 10.
With the exception of maintenance and interest
which is recorded on the Cooperative's books as
incurred, all of the remaining expenses will be
recorded on a prorated basis monthly.
Savings associated with operation of the hydro
electric project will be reduced diesel
consumption and reduced maintenance on the
engines. These savings will be realized only
during months the project generates energy.
Figure V-33 shows the average monthly hydro
electric power production from the project as
developed in the chapter. This figure also shows
the monthly savings expected based on operation of
the project.
It can be seen from an accounting point of view
that on a month-by-month basis the revenue from
the project will not coincide with the expenses.
82
There are several options available to the
Cooperative in adjusting consumers' rates to show
savings and expenses associated with operation of
the project.
83
OPTION I
Estimate savings and expenses from the project and
calculate as per kwh surcharge as a credit to be
applied to each consumer's bill all year long.
Advantages:
1. Benefits accrue to consumers all year long.
2. Easily calculated based on budgeted items.
3. Can be adjusted as needed.
4. Consumer can see exact benefits on his bill
from this project.
Disadvantages:
1. Requires a "trueing up" at end of year if
actual amounts do not equal budgeted amounts.
2. Large power users who pay a lower per kwh
charge would receive a larger percent
benefit.
3. Benefits are received by consumers during
CEC's low cash flow period (winter), further
reducing cash flow.
84
OPTION II
Expense the cost of the project on a monthly
basis, but only credit consumers during month that
power is actually generated.
Advantages:
1. No "trueing up" at the end of the year since
savings are known exactly before being passed
on to the consumer.
2. Benefits canneries and other summer power
users.
3. Easily calculated and applied to bill.
4. Benefits would be received by consumers
during CEC's high cash flow period.
Disadvantages:
1. Benefits not given to all consumers equally.
2. Summer only users doubly benefit since they
share all savings while winter only users pay
higher rates to cover project expenses, but
receive no benefits.
3. will increase bills during the period when
hydro power is not available.
85
OPTION III
Incorporate all savings and expenses within the
rate base. All electric rates would be changed by
an equal percentage.
Advantages:
1. All consumers receive an equal share of
benefits based on electricity usage.
2. Simplified accounting treatment since hydro
costs would not be maintained separately.
Disadvantages:
1. Consumer would not see benefit on their bills
and consequently would not be aware of
savings realized from hydro.
86
OPTION IV
Accumulate hydro expense charges in a deferred
account and expense them only as power is produced
from the project.
Advantages:
1. Hydro expenses show up only when savings are
present to offset them.
2. Consumers do not pay expenses when no savings
are present.
3. Does not show costs associated with hydro
during months when not running.
Disadvantages:
1. Requires "trueing up" at end of year if
savings and expenses do not meet
expectations.
2. Consumers using power during periods with no
hydro production will not receive any
benefit.
3. Most benefit would be achieved by those users
using power during spring, summer and early
fall months.
4. Tends to distort financial statement since
Cooperative would be incurring expenses that
would not show up on financial statement.
87
Alc
Figure V-29
LIST OF PLANT ACCOUNTS ASSOCIATED WITH
HYDRO ELECTRIC POWER PRODUCTION
No. Description
330 Land and Land Rights.
Includes the cost of land and land rights used in
connection with hydraulic power generation. It
shall also include the cost of land and land
rights used in connection with the conservation of
fish and wildlife, and recreation. Separate
subaccounts shall be maintained for each of the
abqve.
331 Structures and Improvements.
Includes the cost in place of structures and
improvements used in connection with hydraulic
power generation. Also includes the qost in place
of structures and improvements used in connection
with the conservation of fish and wildlife and
recreation. Separate subaccounts shall be
maintained for each of the above.
332 Reservoirs, Dams and Waterways.
Includes the c6st in place of facilities used for
impounding, collecting, storage, diversion,
regulation, and delivery of water used primarily
for generating electricity. Also includes the
cost in place of facilities used in connection
with the conservation of fish and wildlife, and
recreation. Separate subaccounts shall be
maintained for each of the above.
333 Water Wheels, Turbines and Generators.
Includes the cost installed of water wheels and
hydraulic turbines (from connection with penstock
or flume to tailrace) and generators driven
thereby devoted to the production of electricity
·by water power or for the production of power for
industrial or other purposes, if the equipment
used for such purposes is a part of the hydraulic
power plant works.
334 Accessory Electric Equipment.
Includes the cost installed of auxiliary
generating apparatus, conversion equipment, and
equipment used primarily in connection with the
control and switching of electric energy produced
by hydraulic power and the protection of electric
circuits and equipment, except electric motors
used to drive equipment included in other
accounts, such motors being included in the
account in which the equipment with which they are
associated is included.
335 Miscellaneous Power Plant Equipment.
Includes the cost installed of miscellaneous
equipment in and above the hydro electric
generating plant which is devoted to general
station use and is not properly includible in
other hydraulic production accounts. Also
includes the cost of equipment used in connection
with the conservation of fish and wildlife, and
recreation. Separate subaccounts shall be
maintained for each of the above.
336 Roads, Railroads, and Bridges.
Includes the cost of roads, railroads, trails,
bridges, and trestles used primarily as production
facilities. Also includes those roads, etc.,
necessary to connect the plant with highway
transportation systems, except when such roads are
dedicated to public use and maintained by public
authorities.
353 Station Equipment
Includes the cost installed of transforming,
conversion, and switching equipment used for the
purpose of changing the characteristics of
electricity in connection with its transmission or
for controlling transmission.
355 Poles & Fixtu'res
Includes the cost installed of transmission line
poles, wood, steel, concrete, or other material,
together with appurtenant fixtures used for
supporting overhead transmission conductors.
356 Overhead Conductors and Devices
Includes the cost installed of overhead conductors
and devices used for transmission purposes.
Alc
Figure V-30
SUMMARY OF EXPENSE ACCOUNTS
ASSOCIATED WITH HYDRO ELECTRIC
POWER PRODUCTION
No. Description
535 Operation Supervision and Engineering.
Includes the cost of labor and expenses incurred
in the general supervision and direction fo the
operation of hydraulic power generating stations.
Direct supervision of specific activities, such as
hydraulic operation, generator operation, etc.
shall be charged to the appropriate account.
536 Water for Power.
Includes the cost of water used for hydraulic
power generation. Cost of water purchased from
others, including water tolls paid reservoir
companies. Periodic payments for licenses or
permits from any governmental agency for water
rights, or payments based on the use of the water.
Periodic payments for riparian rights. Periodic
payments for headwater benefits or for detriments
to others. Cloud seeding.
537 Hydraulic Expenses.
Includes the cost of labor, materials used and
expenses incurred in operating hydraulic works
including reservoirs, dams, and waterways, and in
activities directly relating to the hydroelectric
development outside the generating station. It
shall also include the cost of labor, materials
used and other expenses incurred in connection
with the operation of fish and wildlife, and
recreation facilities.
538 Electric Expenses.
Includes the cost of labor, materials used and
.expenses incurred in operating prime movers,
generators, and their auxiliary apparatus,
switchgear, and other electric equipment to the
point where electricity leaves for conversion for
transmission or distribution.
539 Miscellaneous Hydraulic Power Generation Expenses.
Includes the cost of labor, materials used and
expenses incurred which are not specifically
provided for or are not readily assignable to
other hydraulic generation operation expense
accounts.
540 Rents.
Includes all rents of property of others used,
occupied or operated in connection with hydraulic
power generation, including amounts payable to the
United States for the occupancy of public lands
and reservations for reservoirs, dams, flumes,
forebays, penstocks, power houses, etc., but not
including transmission right of way.
541 Maintenance Supervision and Engineering.
Includes the cost of labor and expenses incurred
in the general supervision and direction of the
maintenance of hydraulic power generating
stations. Direct field supervision of specific
jobs shall be charged to the appropriate
maintenance account.
542 Maintenance of Structures.
Includes the cost of labor, materials used, and
expenses incurred in maintenance of hydraulic
strucutres, the book cost of which is includible
in Account 331, Structures and Improvements.
However, the cost of labor, materials used and
expenses incurred in the maintenance of fish and
wildlife, and recreation facilities, the book cost
of which is includible in Account 331, Structures
and Improvements, shall be charged to Account 545,
Maintenance of Miscellaneous Hydraulic Plant.
543 Maintenance of Reservoirs, Dams and Waterways.
Includes the cost of labor, materials used, and
expenses incurred in maintenance of plant
includible in Account 332, Reservoirs, Dams and
Waterways. However, the cost of labor, materials
used and expenses incurred in the maintenance of
fish and wildlife, and recreation facilities, the
book cost of which is includible in Account 332,
Reservoirs, Dams and Waterways, shall be charged
to Account 545, Maintenance of Miscellaneous
Hydraulic Plant.
544 Maintenance of Electric Plant.
-Includes the cost of labor, materials used and
expenses incurred in maintenance of plant
includible in Account 333, Water Wheels, Turbines,
and Generators and Account 334, Accessory Electric
Equipment.
545 Maintenance of Miscellaneous Hydraulic Plant.
Includes the cost of labor, materials used, and
expenses incurred in maintenance of plant, the
book cost of which is includible in Account 335,
Miscellaneous Power Plant Equipment, and Account
336, Roads, Railroads and Bridges. Also includes
the cost of labor, materials used and other
expenses incurred in the maintenance of fish and
wildlife, and recreation facilities. Separate
accounts shall be maintained for each of the
above.
Figure V-31
APPORTIONMENT OF HUMPBACK CREEK
HYDRO ELECTRIC PROJECT COSTS
G.L. Total State CEC Annual
No. Description Cost Equity Investment Life Depreciation
331 Structures and $ 300,000. $ 120,000. $ 180,000. 20 $ 9,000.
Improvements
332 Reservoirs, 1,500,000. 600,000. 900,000. 35 25,700.
Dams & Waterways
333 Turbines and 1,050,000. 420,000. 630,000. 33 19,000.
Generators
334 Accessory 150,000. 60,000. 90,000. 30 3,000.
Elec. Equipment
335 Misc. Power 50,000. 20,000. 30,000. 10 3,000.
Plant Equipment
353 Station Equipment 50,000. 20,000. 30,000. 30 1,000.
355 Poles & Fixtures 25,000. 10,000. 15,000. 30 500.
356 Overhead Conductors 25,000. 10,000. 15,000. 30 500.
and Devices
336 Roads & Trails 100,000. 40,000. 60,000. 2,000.
Totals $3,250,000. $1,300,000. $1,950,000. $ 63,700.
Composite Depreciation Rate .0327
G.L.
No.
403.3
427.2
540
408.6
924
925
535
to
545
Figure V-32
SUMMARY OF ANNUAL EXPENSES ASSOCIATED
WITH HUMPBACK CREEK HYDRO PLANT
Annual Amounts
Description Year 1
Depreciation $ 63,700.
Interest 68,250.
TIER (Margins) 34,100.
Property Lease 10,000.
Taxes and 16,700.
Insurance
Operations &
Maintenance 36£100.
Total Cost $228,850.
Note: 3% Inflation Assumed
1. 50 TIER
Year 5
$ 63,700.
64,064.
32,000.
11,500.
19,300.
41£800.
$232,364.
Year 10
$ 63,700.
58,722.
29,400.
13,400.
22,400.
48£500.
$236,122.
Figure V-33
MONTHLY KWH PRODUCTION, COSTS AND SAVINGS
BASED ON 3.5 MILLION KWH ANNUAL GENERATION
1987
Net
KWH Fixed Variable Savings
Month Generated Costs Costs Savings (Cost)
Oct. 478,900 $ 16,063. $ 4,94l. $ 40,99l. $ 19,987.
Nov. 330,005 16,063. 3,405. 28,247. 8,779.
Dec. 169,578 16,063. 1,750. 14,515. (3,298.)
Jan. 48,339. 16,063. 500. 4,138. (12,425.)
Feb. 6,123. 16,063. 63. 524. (15,602.)
March 2,313. 16,063. 24. 198. (15,889.)
April 119,266 16,063. 1,230. 10,209. (7,084.)
May 452,213 16,063. 4,666. 38,707. 17,978.
June 567,516 16,063. 5,855. 48,577. 26,659.
July 555,218 16,063. 5,728. 47,524. 25,733.
Aug. 331,280 16,063. 3,418. 28,356. 8,875.
Sept. 438,283 16,063. 4,522. 37,515. 16,930.
Total 3,499,034 $192,756. $36,102. $299,50l. $70,643.
POWER COST EQUALIZATION
CEC receives payments from the State of Alaska
Power Cost Equalization Program. Payments under
this program are based on the utility's cost of
producing energy and not (subject to some
limitations) on the sale price of this energy.
The Alaska Public Utilities Commission has
determined that the average cost of producing
power in Cordova is 19.01 cents per kwh (based on
1984 test year). See Appendix D. Ninety-five
(95) percent of the amount over 8.5 cents per kwh
is eligible for power cost equalization. Thus CEC
passes a credit on to our consumers amounting to
9.98 cents per kwh on the first 750 kwh. Note
that these figures are based on the cost of
energy, not the price paid by the consumer.
Figure V-34 shows the amount actually paid per kwh
for various classes of consumers. As would be
expected, the canneries pay the least amount per
kwh when operating due to the economies of scale.
Also, as expected, the canneries receive the least
assistance from Power Cost Equalization since PCE
is applied only to the first 750 kwh.
As discussed above, the amount of PCE is based on
the cost of providing energy. Then, if the cost
of producing energy over a 12 month period is
reduced, the amount of Power Cost Equalization is
reduced. It is through this mechanism that the
State of Alaska will directly benefit from this
hydro electric project. CEC has adopted Tariff
revisions that automatically adjust the consumers'
bill as Power Cost Equalization changes so that
the bill will remain constant (for equal usage).
88
It is through the PCE adjustment that the State of
Alaska will benefit. As stated above, any cost
reduction for consumers using less than 750 kwh
per month will be passed on to the State. Savings
for larger users will be passed on to the user.
It should be noted in passing that, even with
State PCE reducing the cost of electric energy by
9.98 cents per kwh, electricity remains a more
expensive form of energy than alternatives for
heating and cooking.
During 1985 Cordova Electric Cooperative expects
kwh sales eligible for Power Cost Equalization to
amount to 7,350,000 kwh. The per kwh amount of
PCE is established by law to be 95 percent of the
utility's cost of producing power above 8.5 cents
per kwh. Cordova Electric Cooperative currently
receives 9.98 cents per kwh eligible for state
power cost equalization. Figure V-35 shows the
total amount of Power Cost Equalization received
from the State of Alaska under this program over
the thirty year study period. Construction of the
Humpback Creek hydro project will save the State
of Alaska $4,300,000.00 over the thirty year
period.
89
Rate Class
Residential
Small
Commercial
Large Power
Cannery
(Winter)
Cannery
(Summer)
Cannery
(Year Average)
Figure V-34
AVERAGE COST PER KWH PAID BY
VARIOUS RATE CLASSES
(Based on 1984 Data)
Kwh Cost Per Kwh
Usage Without PCE
500 23.00
2,000 19.18
30,000 17.13
50KW
11,000 19.64
50KW
200,000 16.74
600KW
18.26
~In cents!
With PCE
13.02
15.44
16.88
18.96
16.70
18.16
SAVINGS TO THE STATE OF ALASKA
THROUGH THE POWER COST EQUALIZATION PROGRAM
------NO HYDRO---------WITH HYDRO---
KWH ELIGIBLE PCE PCE COST PCE PCE COST SAVINGS
FOR PCE TO STATE
1987 7554167 10.06 $759,949 10.06 $759,949 $0
1988 7880833 10.20 $803,845 9.88 $778,626 $25;2 1
:':
1989 8289167 10.27 $851,297 9.93 $823,114 $28,ldj
1990 8493333 10.75 $913,033 10.35 $879,060 $33,973
1991 8860833 11. 08 $981,780 10.64 $942,793 $38,988
1992 9391667 11. 29 $1,060,319 10.81 $1,015,239 $45,080
1993 10085833 13.19 $1,330,321 12.68 $1,278,884 $51,438
1994 10575833 13.48 $1,425,622 12.93 $1,367,455 $58,167
1995 10861667 14.01 $1,521,720 13.41 $1,456,550 $65,170
1996 11065833 14.64 $1,620,038 13.99 $1,548,110 $71,928
1997 11433333 15.17 $1,734,437 14.47 $1,654,403 $80,033
1998 11760000 15.77 $1,854,552 15.02 $1,766,352 $88,200
1999 12250000 16.27 $1,993,075 15.48 $1,896,300 $96,775
2000 12862500 16.73 $2,151,896 15.91 $2,046,424 $105,473
2001 13393333 17.32 $2,319,725 16.45 $2,203,203 $116,522
2002 13393333 18.33 $2,454,998 17.39 $2,329,101 $125,897
2003 13393333 19.38 $2,595,628 18.36 $2,459,016 $136,612
2004 13393333 20.48 $2,742,955 19.38 $2,595,628 $147,327
2005 13393333 21. 63 $2,896,978 20.45 $2,738,937 $158,041
2006 13393333 22.83 $3,057,698 21. 55 $2,886,263 $171,435
2007 13393333 23.73 $3,178,238 22.40 $3,000,107 $178,131
2008 13393333 24.66 $3,302,796 23.28 $3,117,968 $184,828
2009 13393333 25.62 $3,431,372 24.18 $3,238,508 $192,864
2010 13393333 26.62 $3,565,305 25.11 $3,363,066 $202,239
2011 13393333 27.64 $3,701,917 26.06 $3,490,303 $211,615
2012 13393333 28.70 $3,843,887 27.05 $3,622,897 $220,990
2013 13393333 29.79 $3,989,874 28.07 $3,759,509 $230,365
2014 13393333 30.91 $4,139,879 29.12 $3,900,139 $239,741
2015 13393333 32.07 $4,295,242 30.20 $4,044,787 $250,455
2016 13393333 33.26 $4,454,623 31. 32 $4,194,792 $259,831
2017 13393333 34.49 $4,619,361 32.47 $4,348,815 $270,545
2018 13393333 35.76 $4,789,456 33.66 $4,508,196 $281,260
TOTAL 382444993 $82,381,816 $78,014,491 $4,367,325
PRESENT VALUE $41,774,323 $39,653,473 $2,120,849
Figure V-35
G. ECONOMIC ANALYSIS
The decision to construct a hydro electric project
depends on many factors. Among them is the
benefits to be achieved by building and operating
the project over a 20, 30 or 50 year life,
compared to the cost to construct and operate
another project over the same period.
Another factor is the effect of the project on the
cost of power in the community. For example, a
project in which the benefits exceed the cost but
significantly increases the cost of power in early
years may not be as desirable as another project
with less total benefits but which consistently
decreases the cost of power over the life of the
project. To evaluate the financial feasibility of
Humpback Creek hydro electric project, the
following base case was developed:
1) Construction cost of $3,200,000.00 made
up as follows:
State Equity Investment 40 percent
or $1.3 million.
CEC Equity Investment 18 percent
or $576,000.00.
Thirty year loan for the balance in
the amount of $1,324,000.00.
2) For the benefit-to-cost analysis, a
discount rate of 3.5 percent was used.
3) Generation and load growth as
established by the Power Requirements
Study which is summarized in Section
III.
4) Generation from the hydro electric
project was assumed at 3.5 million kwh
per year.
5) A basic fuel inflation rate above the
nominal inflation rate of minus four
90
."'
percent decrease for 1986, no increase
for 1987 and 1988, two percent increase
between 1989 and 2005 and no increase
for the remainder of the thirty year
study period.
6) An inflation rate of three percent was
assumed for power cost purposes.
7) For the benefit-to-cost analysis, a
period of thirty years was used.
8) A TIER of 1.85 on existing Cordova
Electric Cooperative debt was assumed
and a TIER of 1.5 on the debt portion of
the Humpback Creek hydro project.
For the power cost portion of the analysis,
generation increments recommended by the 1985
Power Requirements Study were assumed to be
installed on schedule. The possibility of
delaying the acquisition of additional generating
capacity was not evaluated as part of this
investigation. A financial model of Cordova
Electric Cooperative based on 1984 actual
operating costs was developed and used as a base
line in determining power cost projections. The
"no hydro development" base line is included as
Figure V-36. The base case with hydro development
as described above was evaluated and a sample
print-out is included as Figure V-37. A separate
analysis of the cost and savings from the hydro
project was developed. A sample of the base case
is included as Figure V-38. The base case shows a
cost of generation of power in Humpback Creek
ranging from 6.5 cents per kwh in 1987 to 6.8
cents per kwh in 2002. Savings over generating
the same number of kilowatt hours with diesel
91
range from 2.02 cents per kwh in 1987 to 10.24
cents per kwh in 2002.
Under the base case, the average retail power rate
in Cordova would decrease from 19.24 cents per kwh
to 18.90 cents per kwh in 1987. By the year 2002,
the cost of power would decrease from 28.90 cents
per kwh to 27.83 cents per kwh with the Humpback
Creek hydro electric project.
92
Figure V-36
Sheet #1
HUMPBACK CREEK HYDROELECTRIC DEVELOPMENT--ECONOMIC ANALYSIS
CASE O--NO HYDRO
ASSUMPTIONS: YEAR-----1986 1987
HYDRO CONSTRUCTION COST 0
STATE EQUITY INVESTMENT 0%
CEC EQUITY INVESTMENT 0%
COMPOSITE DEPRECIATION RATE--HYDRO 3.27%
COMPOSITE DEPRECIATION RATE--GENERATION 3.74%
COMPOSITE DEPRECIATION RATE--DISTRIBUTION 3.18%
LOAN INTEREST RATE 5%
INFLATION 3% 3%
FUEL COST ABOVE INFLATION -4% 0%
TOTAL GENERATION 18.5 19.3
PEAK LOAD 5100 5300
HYDRO GENERATION 0 0
FUEL COST 0.950 0.979
DISCOUNT RATE 3.5%
NET GEN EFFICIENCY (KWH/GAL) 13 13
OPERATING MARGIN (TIER) TARGET 1. 85 1. 85
OPERATING MARGIN (TIER) TARGET (HYDRO) 1.5 1.5
GENERATION PLANT ADDITIONS 10000
DISTRIBUTION PLANT ADDITIONS 300000
INSTALLED CAPACITY:
ORCA PLANT 4903 4903
EYAK PLANT 5900 5900
HUMPY CREEK 0 0
TOTAL 10803 10803
OPERATING COSTS: (FIXED)
PRODUCTION PLANT DEPRECIATION 234000 234400
HYDRO PLANT DEPRECIATION 0 0
DISTRIBUTION PLANT DEPRECIATION 120500 130000
OTHER DEPRECIATION 15500 15500
INTEREST ON PRODUCTION PLANT 285000 285487
INTEREST ON HYDRO PLANT 0 0
INTEREST ON DISTRIBUTION PLANT 160000 172600
INTEREST ON OTHER PLANT 7000 7000
RENT OF PRODUCTION PLANT PROPERTY 4000 4000
RENT OF HYDRO PLANT PROPERTY 0 0
OPERATING COSTS (VARIABLE)
PRODUCTION PLANT OPERATIONS 225000 231800
PRODUCTION PLANT MAINTENANCE 145000 155800
DIESEL FUEL 1351900 1452700
HYDRO PLANT 0 & M 0 0
DISTRIBUTION PLANT 0 & M 181000 194500
CONSUMER COSTS 51000 52500
GENERAL AND ADMINISTRATIVE COSTS 286000 294600
TAXES AND INSURANCE 82000 86700
REQUIRED OPERATING MARGINS 384200 395300
TOTAL OPERATING COSTS 3532000 3713000
COST PER KWH (CENTS) 19.09 19.24
1988
3%
0%
20.3
5400
0
1. 008
13
1. 85
1.5
10300
309000
4903
5900
0
10803
234800
0
139900
15500
286000
0
185700
7000
4000
0
238800
168800
1573800
0
210700
54100
303400
91700
406900
3921000
19.32
1989 1990 1991 1992 1993 1994
3% 3% 3% 3% 3% 39" . 0
2% 2% 2% 2% 2% .... 0 "::'0
20.8 21. 7 23 24.7 25.9 26.6
5600 5800 6000 6800 7000 7200
0 0 0 0 0 0
1. 059 1.112 1.169 1. 228 1. 290 1. 355
13 13 13 13 13 13
1. 85 1. 85 1. 85 1. 85 1. 85 1. 85
1.5 1.5 1.5 1.5 1.5 1.5
10600 10900 11200 3505100 11900 12300
318300 327800 337600 347700 358100 368800
4903 4903 4903 9903 9903 9903
4550 4550 4550 4550 4550 4550
0 0 0 0 0 0
9453 9453 9453 14453 14453 14453
235200 235600 236000 367200 367700 368100
0 0 0 0 0 0
150000 160400 171100 182200 193600 205300
15500 15500 15500 15500 15500 15500
286500 287000 287500 447300 447900 448400
0 0 0 0 0 0
199100 212900 227100 241800 256900 272400
7000 7000 7000 7000 7000 7000
4000 4000 4000 4000 4000 4000
0 0 0 0 0 0
246000 253400 261000 268800 276900 285200
178100 191400 209000 231200 249700 264100
1694200 1856900 2067700 2332900 2570000' 2773100
0 0 0 0 0 0
222400 239000 260900 288600 311700 329700
55700 57400 59100 60900 62700 64600
312500 321900 331600 341500 351700 362300
97000 102600 108500 149400 157100 165200
418700 430900 443400 591700 605000 618600
4122000 4376000 4689000 5530000 5877000 6184000
19.82 20.17 20.39 22.39 22.69 23.25
1995 1996 1997
3% 3% 3%
)9-~O 2% 2%
27.1 28 28.8
7400 7600 7900
0 0 0
1. 424 1. 496 1. 572
13 13 13
1. 85 1. 85 1. 85
1.5 1.5 1.5
12700 11100 13500
379900 391300 403000
9903 9903 9903
4550 4550 4550
0 0 0
14453 14453 14453
368600 369100 369600
0 0 0
217400 229800 242700
15500 15500 15500
449000 449600 450200
0 0 0
288500 305000 322100
7000 7000 7000
4000 4000 4000
0 0 0
293800 302600 311700
277100 294900 312400
2968100 3221900 3481600
0 0 0
346000 368200 390100
66500 68500 70600
373200 384400 395900
173800 182900 192500
632800 647400 662400
6481000 6851000 7228000
*' ,"4' 23.92 24.47 25.10
Figure V-36
Sheet #2
1998 1999
3% 3%
2% 2%
30 31. 5
8100 8300
0 0
1. 651 1. 735
13 13
1.85 1. 85
1.5 1.5
13900 14300
415100 427600
9903 9903
4550 4550
0 0
14453 14453
370100 370600
0 0
255900 269500
15500 15500
450800 451400
0 0
339600 357600
7000 7000
4000 4000
0 0
321100 330700
335200 362500
3810200 4203200
0 0
418500 452600
72700 74900
407800 420000
202600 213300
677800 693600
7689000 8226000
25.63 26.11
2000 2001 2002
3% 3% 3%
2% 2% 2%
32.8 32.8 32.8
8600 8600 8600
0 0 0
1. 822 1. 915 2.012
13 13 13
1. 85 1. 85 1. 85
1.5 1.5 1.5
14700 15100 15600
440400 453600 467200
9903 9903 9903
4550 4550 4550
0 0 0
14453 14453 14453
371200 371800 372300
0 0 0
283500 297900 312700
15500 15500 15500
452100 452800 453400
0 0 0
376200 395300 414900
7000 7000 7000
4000 4000 4000
0 0 0
340600 350800 361300
388800 400500 412500
4598100 4830800 5075200
0 0 0
485400 500000 515000
77100 79400 81800
432600 445600 459000
224600 236500 249000
710000 726800 744000
8767000 9115000 9478000
26.73 27.79 28.90
2003 2004 2005 2006 2007 2008
3% 3% 3% 3" ii 3% 3%
2% 2% 2% 0% 0% 0%
32.8 32.8 32.8 32.8 32.8 32.8
8600 8600 8600 8600 8600 8600
0 0 0 0 0 0
2.113 2.220 2.333 2.403 2.475 2.549
13 13 13 13 13 13
1. 85 1. 85 1. 85 1. 85 1. 85 1. 85
1.5 1.5 1.5 1.5 1.5 1.5
16100 16600 17100 17600 18100 18600
481200 495600 510500 525800 541600 557800
9903 9903 9903 9903 9903 9903
4550 4550 4550 4550 4550 4550
0 0 0 0 0 0
14453 14453 14453 14453 14453 14453
373000 373600 374200 374900 375500 376200
0 0 0 0 0 0
328000 343800 360000 376800 394000 411700
15500 15500 15500 15500 15500 15500
454300 455000 455700 456600 457300 458200
0 0 0 0 0 0
435200 456200 477700 500000 522800 546300
7000 7000 7000 7000 7000 7000
4000 4000 4000 4000 4000 4000
0 0 0 0 0 0
372100 383300 394800 406600 418800 431400
424900 437600 450700 464200 478100 492400
5332000 5601800 5885200 6061800 6243700 6431000
0 0 0 0 0 0
530500 546400 562800 579700 597100 615000
84300 86800 89400 92100 94900 97700
472800 487000 501600 516600 532100 548100
262300 276400 291200 306900 323400 340900
762000 780500 799300 819100 839000 859800
9858000 10255000 10669000 10982000 11303000 11635000
30.05 31. 27 32.53 33.48 34.46 35.47
2009 2010 2011
3% 3% 3%
0% 0% 0%
32.8 32.8 32.8
8600 8600 8600
0 0 0
2.625 2.704 2.785
13 13 13
1. 85 1. 85 1. 85
1.5 1.5 1.5
19200 19800 20400
574500 591700 609500
9903 9903 9903
4550 4550 4550
0 0 0
14453 14453 14453
377000 377700 378500
0 0 0
430000 448800 468200
15500 15500 15500
459200 460100 461100
0 0 0
570600 595500 621200
7000 7000 7000
4000 4000 4000
0 0 0
444300 457600 471300
507200 522400 538100
6623900 6822600 7027300
0 0 0
633500 652500 672100
100600 103600 106700
564500 581400 598800
359500 379100 399800
881300 903200 925900
11978000 12331000 12696000
36.52 37.59 38.71
Figure V-36
Sheet # 3
2012 2013
3% 3%
0% 0%
32.8 32.8
8600 8600
0 0
2.869 2.955
13 13
1. 85 1. 85
1.5 1.5
21000 21600
627800 646600
9903 9903
4550 4550
0 0
14453 14453
379300 380100
0 0
488200 508700
15500 15500
462100 463100
0 0
647700 674900
7000 7000
4000 4000
0 0
485400 500000
554200 570800
7238100 7455200
0 0
692300 713100
109900 113200
616800 635300
421700 444800
949300 973300
13072000 13459000
39.85 41. 03
2014 2015 2016 2017
3% 3% 3% 3%
0% 0% 0% 0%
32.8 32.8 32.8 32.8
8600 8600 8600 8600
0 0 0 0
3.043 3.135 3.229 3.326
13 13 13 13
1. 85 1. 85 1. 85 1. 85
1.5 1.5 1.5 1.5
22200 22900 23600 24300
666000 686000 706600 727800
9903 9903 9903 9903
4550 4550 4550 4550
0 0 0 0
14453 14453 14453 14453
380900 381800 382600 383500
0 0 0 0
529900 551700 574200 597300
15500 15500 15500 15500
464100 465200 466200 467300
0 0 0 0
703000 731900 761700 792300
7000 7000 7000 7000
4000 4000 4000 4000
0 0 0 0
515000 530500 546400 562800
587900 605500 623700 642400
7678900 7909300 8146600 8390900
0 0 0 0
734500 756500 779200 802600
116600 120100 123700 127400
654400 674000 694200 715000
469300 495200 522600 551600
998000 1023500 1049700 1076600
13859000 14272000 14697000 15136000
42.25 43.51 44.81 46.15
Figure V-37
Sheet #1
HUMPBACK CREEK HYDROELECTRIC DEVELOPMENT--ECONOMIC ANALYSIS
CASE 1--BASE CASE
ASSUMPTIONS: YEAR-----1986 1987
HYDRO CONSTRUCTION COST 3250000
STATE EQUITY INVESTMENT 40%
CEC EQUITY INVESTMENT 18%
COMPOSITE DEPRECIATION RATE--HYDRO 3.27%
COMPOSITE DEPRECIATION RATE--GENERATION 3.74%
COMPOSITE DEPRECIATION RATE--DISTRIBUTION 3.18%
LOAN INTEREST RATE 5%
INFLATION 32-. ° 3%
FUEL COST ABOVE INFLATION -4% 0%
TOTAL GENERATION 18.5 19.3
PEAK LOAD 5100 5300
HYDRO GENERATION 0 3.5
FUEL COST 0.950 0.979
DISCOUNT RATE 3.5%
NET GEN EFFICIENCY (KWH/GAL) 13 13
OPERATING MARGIN (TIER) TARGET 1. 85 1. 85
OPERATING MARGIN (TIER) TARGET (HYDRO) 1.5 1.5
GENERATION PLANT ADDITIONS 10000
DISTRIBUTION PLANT ADDITIONS 300000
INSTALLED CAPACITY:
ORCA PLANT 4903 4903
EYAK PLANT 5900 5900
HUMPY CREEK 0 850
TOTAL 10803 11653
OPERATING COSTS: (FIXED)
PRODUCTION PLANT DEPRECIATION 234000 234400
HYDRO PLANT DEPRECIATION 0 63700
DISTRIBUTION PLANT DEPRECIATION 120500 130000
OTHER DEPRECIATION 15500 15500
INTEREST ON PRODUCTION PLANT 285000 285487
INTEREST ON HYDRO PLANT 0 68250
INTEREST ON DISTRIBUTION PLANT 160000 172600
INTEREST ON OTHER PLANT 7000 7000
RENT OF PRODUCTION PLANT PROPERTY 4000 4000
RENT OF HYDRO PLANT PROPERTY 0 10000
OPERATING COSTS (VARIABLE)
PRODUCTION PLANT OPERATIONS 225000 231800
PRODUCTION PLANT MAINTENANCE 145000 127600
DIESEL FUEL 1351900 1189300
HYDRO PLANT 0 & M 0 36100
DISTRIBUTION PLANT 0 & M 181000 194500
CONSUMER COSTS 51000 52500
GENERAL AND ADMINISTRATIVE COSTS 286000 294600
TAXES AND INSURANCE 82000 101300
REQUIRED OPERATING MARGINS 384200 429400
TOTAL OPERATING COSTS 3532000 3648000
COST PER KWH (CENTS) 19.09 18.90
1988
3%
0%
20.3
5400
3.5
1. 008
13
1. 85
1.5
10300
309000
4903
5900
850
11653
234800
63700
139900
15500
286000
67493
185700
7000
4000
10300
238800
139700
1302500
37200
210700
54100
303400
106800
440600
3848000
18.96
1989 1990 1991 1992 1993 1994
3% 3% 3% 3° '0 3% 3%
2% 2% 2% 2% 2° '0 2%
20.8 21. 7 23 24.7 25.9 26.6
5600 5800 6000 6800 7000 7200
3.5 3.5 3.5 3.5 3.5 3.5
1. 059 1.112 1.169 1. 228 1. 290 1. 355
13 13 13 13 13 13
1. 85 1. 85 1. 85 1. 85 1. 85 1. 85
1.5 1.5 1.5 1.5 1.5 1.5
10600 10900 11200 3505100 11900 12300
318300 327800 337600 347700 358100 368800
4903 4903 4903 9903 9903 9903
4550 4550 4550 4550 4550 4550
850 850 850 850 850 850
10303 10303 10303 15303 15303 15303
235200 235600 236000 367200 367700 368100
63700 63700 63700 63700 63700 63700
150000 160400 171100 182200 193600 205300
15500 15500 15500 15500 15500 15500
286500 287000 287500 447300 447900 448400
66697 65862 64985 64064 63098 62082
199100 212900 227100 241800 256900 272400
7000 7000 7000 7000 7000 7000
4000 4000 4000 4000 4000 4000
10600 10900 11200 11500 11800 12200
246000 253400 261000 268800 276900 285200
148200 160600 177200 198400 215900 229300
1409100 1557400 1753100 2002400 2222700 2408200
38300 39400 40600 41800 43100 44400
222400 239000 260900 288600 311700 329700
55700 57400 59100 60900 62700 64600
312500 321900 331600 341500 351700 362300
112500 118600 125000 166400 174600 183200
452100 463800 475900 623700 636600 649700
4035000 4274000 4572000 5397000 5727000 6015000
19.40 19.70 19.88 21. 85 22.11 22.61
1995 1996
3% 3%
-'0 <::-6 2%
27.1 28
7400 7600
1.5 3.5
1. 424 1. 496
13 13
1. 85 1. 85
1.5 1.5
12700 13100
379900 391300
9903 9903
4550 4550
850 850
15303 15303
368600 369100
63700 63700
217400 229800
15500 15500
449000 449600
61017 59897
288500 305000
7000 7000
4000 4000
12600 13000
293800 302600
241300 258000
2584800 2819200
45700 47100
346000 368200
66500 68500
373200 384400
192300 201900
663300 677300
6294000 6644000
23.23 23.73
Figure V-37
Sheet #2
1997 1998
3% 3%
2% 2%
28.8 30
7900 8100
3. 5 3.5
1. 572 1. 651
13 13
1. 85 1. 85
1.5 1.5
13500 13900
403000 415100
9903 9903
4550 4550
850 850
15303 15303
369600 370100
63700 63700
242700 255900
15500 15500
450200 450800
58722 57488
322100 339600
7000 7000
4000 4000
13400 13800
311700 321100
274400 296000
3058500 3365700
48500 50000
390100 418500
70600 72700
395900 407800
212100 222800
691800 706500
7001000 7439000
24.31 24.80
1999 2000 2001
3% 3% 3%
2% 2% 2%
31.5 32.8 32.8
8300 8600 8600
3.5 3.5 3.5
1.735 1. 822 1. 915
13 13 13
1. 85 1. 85 1. 85
1.5 1.5 1.5
14300 14700 15100
427600 440400 453600
9903 9903 9903
4550 4550 4550
850 850 850
15303 15303 15303
370600 371200 371800
63700 63700 63700
269500 283500 297900
15500 15500 15500
451400 452100 452800
56193 54832 S3404
357600 376200 395300
7000 7000 7000
4000 4000 4000
14200 14600 15000
330700 340600 350800
322100 347200 357600
3736100 4107400 4315300
51500 53000 54600
452600 485400 500000
74900 77100 79400
420000 432600 445600
234100 246000 258600
721700 737400 753500
7953000 8469000 8792000
25.25 25.82 26.80
2002 2003 2004 2005 2006 2007 2008
3% 3% 3% 3% 3% 3% 3%
2% 2% 2% 2% 0% 0% 0%
32.8 32.8 32.8 32.8 32.8 32.8 32.8
8600 8600 8600 8600 8600 8600 8600
3.5 3.5 3.5 3.5 3.5 3.5 3.5
2.012 2.113 2.220 2.333 2.403 2.475 2.549
13 13 13 13 13 13 13
1. 85 1. 85 1. 85 1. 85 1. 85 1. 85 1. 85
1.5 1.5 1.5 1.5 1.5 1.5 1.5
15600 16100 16600 17100 17600 18100 18600
467200 481200 495600 510500 525800 541600 557800
9903 9903 9903 9903 9903 9903 9903
4550 4550 4550 4550 4550 4550 4550
850 850 850 850 850 850 850
15303 15303 15303 15303 15303 15303 15303
372300 373000 373600 374200 374900 375500 376200
63700 63700 63700 63700 63700 63700 63700
312700 328000 343800 360000 376800 394000 411700
15500 15500 15500 15500 15500 15500 15500
453400 454300 455000 455700 456600 457300 458200
51904 50329 48676 46940 45117 43203 41193
414900 435200 456200 477700 500000 522800 546300
7000 7000 7000 7000 7000 7000 7000
4000 4000 4000 4000 4000 4000 4000
15500 16000 16500 17000 17500 18000 18500
361300 372100 383300 394800 406600 418800 431400
368300 379300 390700 402400 414500 426900 439700
4533600 4763000 5004000 5257200 5415000 5577400 5744700
56200 57900 59600 61400 63200 65100 67100
515000 530500 546400 562800 579700 597100 615000
81800 84300 86800 89400 92100 94900 97700
459000 472800 487000 501600 516600 532100 548100
271800 285800 300600 316100 332600 349900 368200
770000 787200 804800 822800 841600 860600 880400
9128000 9480000 9847000 10230000 10523000 10824000 11135000
27.83 28.90 30.02 31.19 32.08 33.00 33.95
2009 2010
3% 3%
0% 0%
32.8 32.8
8600 8600
3.5 3.5
2.625 2.704
13 13
1. 85 1. 85
1.5 1.5
19200 19800
574500 591700
9903 9903
4550 4550
850 850
15303 15303
377000 377700
63700 63700
430000 448800
15500 15500
459200 460100
39082 36866
570600 595500
7000 7000
4000 4000
19100 19700
444300 457600
452900 466500
5917100 6094600
69100 71200
633500 652500
100600 103600
564500 581400
387600 408000
900800 921600
11456000 11786000
34.93 35.93
Figure V-37
Sheet #3
2011 2012
3% 3%
0% 0%
32.8 32.8
8600 8600
3.5 3.5
2.785 2.869
13 13
1. 85 1. 85
1.5 1.5
20400 21000
609500 627800
9903 9903
4550 4550
850 850
15303 15303
378500 379300
63700 63700
468200 488200
15500 15500
461100 462100
34540 32097
621200 647700
7000 7000
4000 4000
20300 20900
471300 485400
480500 494900
6277400 6465700
73300 75500
672100 692300
106700 109900
598800 616800
429600 452400
943200 965300
12127000 12479000
36.97 38.05
2013
3%
0%
32.8
8600
3.5
2.955
13
1. 85
1.5
21600
646600
9903
4550
850
15303
380100
63700
508700
15500
463100
29532
674900
7000
4000
21500
500000
509700
6659700
77800
713100
113200
635300
476500
988000
12841000
39.15
2014 2015 2016 2017
3% 3% 3% 3%
0% 0% 0% 0%
32.8 32.8 32.8 32.8
8600 8600 8600 8600
3.5 3.5 3.5 3.5
3.043 3.135 3.229 3.326
13 13 13 13
1. 85 1. 85 1. 85 1. 85
1.5 1.5 1.5 1.5
22200 22900 23600 24300
666000 686000 706600 727800
9903 9903 9903 9903
4550 4550 4550 4550
850 850 850 850
15303 15303 15303 15303
380900 381800 382600 383500
63700 63700 63700 63700
529900 551700 574200 597300
15500 15500 15500 15500
464100 465200 466200 467300
26838 24010 21041 17923
703000 731900 761700 792300
7000 7000 7000 7000
4000 4000 4000 4000
22100 22800 23500 24200
515000 530500 546400 562800
525000 540800 557000 573700
6859500 7065300 7277300 7495600
80100 82500 85000 87600
734500 756500 779200 802600
116600 120100 123700 127400
654400 674000 694200 715000
501900 528800 557200 587200
1011400 1035500 1060200 1085600
13215000 13602000 14000000 14410000
40.29 41. 47 42.68 43.93
Figure V-38
Sheet #1
HUMPBACK CREEK HYDROELECTRIC DEVELOPMENT--ECONOMIC ANALYSIS
CASE 1--BASE CASE
ASSUMPTIONS: YEAR-----1986 1987 1988 1989 1990 1991 1992 1993
HYDRO CONSTRUCTION COST 3250000
STATE EQUITY INVESTMENT 40%
CEC EQUITY INVESTMENT 18%
COMPOSITE DEPRECIATION RATE--HYDRO 3.27%
LOAN INTEREST RATE 5.0%
INFLATION 3% 3% 3% 3% 3% 3% 3% 3%
FUEL COST ABOVE INFLATION -4% 0% 0% 2.0% 2.0% 2.0% 2.0% 2.0%
TOTAL GENERATION 18.5 19.3 20.3 20.8 21.7 23 24.7 25.9
PEAK LOAD 5100 5300 5400 5600 5800 6000 6800 7000
HYDRO GENERATION 0 3.5 3.5 3.5 3.5 3.5 3.5 3.5
FUEL COST 0.950 0.979 1.008 1. 059 1.112 1.169 1. 228 1. 290
DISCOUNT RATE 3.5%
NET GEN EFFICIENCY (KWH/GAL) 13 13 13 13 13 13 13 13
OPERATING MARGIN (TIER) TARGET (HYDRO) 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5
OPERATING COSTS: (FIXED)
HYDRO PLANT DEPRECIATION 0 63700 63700 63700 63700 63700 63700 63700
INTEREST ON HYDRO PLANT 0 68250 67493 66697 65862 64985 64064 63098
RENT OF HYDRO PLANT PROPERTY 0 10000 10300 10600 10900 11200 11500 11800
OPERATING COSTS (VARIABLE)
HYDRO PLANT 0 & M 0 36100 37200 38300 39400 40600 41800 43100
TAXES AND INSURANCE 0 16700 17200 17700 18200 18700 19300 19900
REQUIRED OPERATING MARGINS 0 34100 33700 33300 32900 32500 32000 31500
TOTAL OPERATING COSTS 0 228900 229600 230300 231000 231700 232400 233100
SAVINGS
FUEL 0 263400 271300 285100 299500 314700 330600 347300
MAINT 0 36100 37200 38300 39400 40600 41800 43100
TOTAL SAVINGS 0 299500 308500 323400 338900 355300 372400 390400
NET COST (SAVINGS) 0 -70600 -78900 -93100 -107900 -123600 -140000 -157300
COST PER KWH (CENTS) 0.00 6.54 6.56 6.58 6.60 6.62 6.64 6.66
SAVINGS OVER DIESEL POWER 0.00 2.02 2.25 2.66 3.08 3.53 4.00 4.49
NET PRESENT VALUE OF COSTS 4829899
NET PRESENT VALUE OF SAVINGS 9905912
BENEFIT TO COST RATIO 2.05
1994 1995
3% 3%
2.0% 2.0%
26.6 27.1
7200 7400
3.5 3.5
1. 355 1. 424
13 13
1.5 1.5
63700 63700
62082 61017
12200 12600
44400 45700
20500 21100
31000 30500
233900 234600
364900 383300
44400 45700
409300 429000
-175400 -194400
6.68 6.70
5.01 5.55
Figure V-38
Sheet #2
1996 1997
3% 3%
2.0% 2.0%
28 28.8
7600 7900
3.5 3.5
1. 496 1.572
13 13
1.5 1.5
63700 63700
59897 58722
13000 13400
47100 48500
21700 22400
29900 29400
235300 236100
402700 423100
47100 48500
449800 471600
-214500 -235500
6.72 6.75
6.13 6.73
1998 1999 2000
3% 3% 3%
2.0% 2.0% 2.0%
30 31. 5 32.8
8100 8300 8600
3.5 3.5 3.5
1.651 1. 735 1. 822
13 13 13
1.5 1.5 1.5
63700 63700 63700
57488 56193 54832
13800 14200 14600
50000 51500 53000
23100 23800 24500
28700 28100 27400
236800 237500 238000
444500 467000 490600
50000 51500 53000
494500 518500 543600
-257700 -281000 -305600
6.77 6.79 6.80
7.36 8.03 8.73
2001 2002 2003 2004 2005 2006 2007
3% 3% 3% 3% 3% 3% 3%
2.0% 2.0% 2.0% 2.0% 2.0% 0.0% 0.0%
32.8 32.8 32.8 32.8 32.8 32.8 32.8
8600 8600 8600 8600 8600 8600 8600
3.5 3.5 3.5 3.5 3.5 3.5 3.5
1. 915 2.012 2.113 2.220 2.333 2.403 2.475
13 13 13 13 13 13 13
1.5 1.5 1.5 1.5 1.5 1.5 1.5
63700 63700 63700 63700 63700 63700 63700
53404 51904 50329 48676 46940 45117 43203
15000 15500 16000 16500 17000 17500 18000
54600 56200 57900 59600 61400 63200 65100
25200 26000 26800 27600 28400 29300 30200
26700 26000 25200 24300 23500 22600 21600
238600 239300 239900 240400 240900 241400 241800
515500 541600 569000 597800 628000 646800 666200
54600 56200 37900 59600 61400 63200 65100
570100 597800 626900 657400 689400 710000 731300
-331500 -358500 -387000 -417000 -448500 -468600 -489500
6.82 6.84 6.85 6.87 6.88 6.90 6.91
9.47 10.24 11. 06 11. 91 12.81 13.39 13.99
2008 2009
3% 3%
0.0% 0.0%
32.8 32.8
8600 8600
3.5 3.5
2.549 2.625
13 13
1.5 1.5
63700 63700
41193 39082
18500 19100
67100 69100
31100 32000
20600 19500
242200 242500
686200 706800
67100 69100
753300 775900
-511100 -533400
6.92 6.93
14.60 15.24
Figure V-38
Sheet ~D
2010 2011
3% 3%
0.0% 0.0%
32.8 32.8
8600 8600
3.5 3.5
2.704 2.785
13 13
1.5 1.5
63700 63700
36866 34540
19700 20300
71200 73300
33000 34000
18400 17300
242900 243100
728000 749900
71200 73300
799200 823200
-556300 -580100
6.94 6.95
15.89 16.57
2012
3%
0.0%
32.8
8600
3.5
2.869
13
1.5
63700
32097
20900
75500
35000
16000
243200
772400
75500
847900
-604700
6.95
17.28
2013 2014 2015 2016 2017
3% 3% 3% 3% 3%
0.0% 0.0% 0.0% 0.0% 0.0%
32.8 32.8 32.8 32.8 32.8
8600 8600 8600 8600 8600
3.5 3.5 3.5 3.5 3.5
2.955 3.043 3.135 3.229 3.326
13 13 13 13 13
1.5 1.5 1.5 1.5 1.5
63700 63700 63700 63700 63700
29532 26838 24010 21041 17923
21500 22100 22800 23500 24200
77800 80100 82500 85000 87600
36100 37200 38300 39400 40600
14800 13400 12000 10500 9000
243400 243300 243300 243100 243000
795500 819400 844000 869300 895400
77800 80100 82500 85000 87600
873300 899500 926500 954300 983000
-629900 -656200 -683200 -711200 -740000
6.95 6.95 6.95 6.95 6.94
18.00 18.75 19.52 20.32 21.14
Sensitivity Analysis
To test the sensitivity of the various assumptions
discussed in the previous section on the
feasibility of the project, a series of
alternatives were evaluated. Each of these
alternatives evaluated three specific areas:
1) Cost of power from the project and the
resulting savings over generating an
equivalent amount of power utilizing diesel.
2) The cost of power in Cordova with and without
the hydro electric project.
3) The resulting benefit-to-cost ratio of the
project.
The benefit-to-cost analysis normally utilizes
actual construction cash flows. That is, the cost
of the project is incurred as funds are expended
on the project. This benefit-to-cost ratio is
shown in Figure V-39 and labelled "Actual Cash
Flows". The only items considered in this
benefit-to-cost ratio are the construction costs,
operations and maintenance costs, taxes, insurance
and the land lease costs. Benefits include only
fuel and diesel maintenance savings.
While this method properly evaluates the
benefit-to-cost ratio of the project, it does not
take into account other costs that Cordova
Electric Cooperative will incur. These costs are
discussed further in accounting treatment. Since
the rates for electric energy that Cordova
Electric Cooperative will charge its consumers is
93
set on the accounting treatment of the project, a
second benefit-to-cost ratio was established.
This second ratio is called the Cordova Electric
cooperative cash flow, and does not consider
construction costs per se, but rather considers
interest charges, depreciation and required
margins on the debt portion of the project. These
three items are treated as a continuing series of
cash flows. Since State equity investment in the
project will not be part of the Cordova Electric
cooperative rate base, it is not included in this
benefit-to-cost ratio. Figure V-39 shows the
second benefit-to-cost ratio and is labelled
"Cordova Electric Cooperative Cash Flow".
Figure V-40 shows the cost of power from this
project under each of the alternatives discussed
below. Figure V-41 shows the overall cost of
energy in Cordova from each of these alternatives.
94
Summary of Alternatives Investigated
Case #2--Low Construction Cost
This alternative assumes a construction cost of
$500,000.00 below our estimate. This alternative
considers that the State equity investment remains
constant at $1.3 million. Thus the State equity
contribution has increased from 40 percent to
47 percent. The lower construction cost increases
the benefit-to-cost ratio and reduces both the
cost of power from the project and the cost of
power in Cordova.
Case #3--High Construction Costs
This alternative assumes that the final
construction cost of the project will be
$500,000.00 more than estimated. It also assumes
that the State equity investment remains constant
at $1.3 million. This alternative provides a
lower benefit-to-cost ratio although still
significantly above one. The cost of power from
the project in the early years is very close to
the cost of diesel generated power, but becomes
significantly less expensive in later years. In
early years this option does not reduce the cost
of power in Cordova significantly but by the year
2002 will result in a cost of power in Cordova of
one cent per kwh lower than the diesel
alternative.
Case #4--Low Inflation
To test the sensitivity of the project to the
overall inflation rate, an inflation rate of zero
was tested. Since the price paid for diesel fuel
is tied by formula to the inflation rate, this
reduces the overall diesel alternative costs while
95
the hydro power costs remain fairly constant.
This significantly reduces the benefit-to-cost
ratio, but the benefit-to-cost ratio still remains
significantly above one. This alternative
provides lower electric costs with hydro electric
power over the study period.
Case #S--High Inflation
This alternative assumes that inflation increases
at an average rate of six percent. The high
inflation drives the cost of diesel generated
power up much more rapidly and makes the hydro
electric project more attractive in all cases.
Case #6--TIER of 1.0
As discussed previously, Cordova Electric
Cooperative is required by mortgage with our
lenders, to maintain a Times Interest Earned Ratio
(TIER) of 1.5. That is our operating margins plus
interest divided by interest must be 1.5. These
margins are available to the Cooperative for other
projects and usually provide Cordova Electric
Cooperative equity investment for other projects.
These operating margins are also the source of the
Cordova Electric Cooperative equity investment
that will be made in this project. A TIER of 1.0
means that the project breaks even and does not
generate any operating margins. This alternative
provides lower cost power to Cordova although it
is outside the scope of this study; a reduction in
operating margins tends to increase future debt
financing and increases future cost of power.
Case #7--TIER of 1.85
The Board of Directors of Cordova Electric
Cooperative has set a TIER goal of 1.85. This
96
provides the Cooperative with slightly more cash
flow than a TIER of 1.5 which enables the
Cooperative to build equity in the system and
reduces the need for future borrowing. If the
TIER on the debt portion of this project is
increased to 1.85, it increases the cost of power
from the project and the cost of power in Cordova
and reduces the benefit-to-cost ratio. However,
the cost of power still remains less than it would
be without this project, and the benefit-to-cost
ratio still remains significantly above one.
Case #8--Low Generation
Although we have used an annual generation of
3.5 million kwh for this project throughout the
feasibility analysis, the sensitivity of the
feasibility of this project to generation was
investigated. This alternative assumes that the
project generates a low of 2.5 million kwh. This
is 30 percent below our estimate of generation for
this project. The benefit-to-cost ratio at this
generation level is still 1.77. The cost of power
in the first year, 1987, is slightly higher than
an equivalent amount of power generated with
diesel fuel. However, the cross over point occurs
in 1988 and after that reduces the cost of
electric energy in Cordova.
Case #9--High Generation
This alternative investigates the feasibility of
the project if it generated 4.5 million kwh per
year, or 30 percent above our projected genera-
tion. As would be expected, the benefit-to-cost
ratio increases significantly and the cost of
power from this project is significantly below the
base case. This alternative would provide power
97
in 1987 at three cents per kwh below an equivalent
diesel generation and would reduce the cost of
power in Cordova by 3/4 of a cent per kwh.
Case #10--Low Interest
The feasibility of this project has been evaluated
utilizing an interest rate for the debt portion of
the project of five percent. The effect of a two
percent loan on the cost of power was evaluated.
This alternative provides power almost four cents
per kwh below the cost of equivalent diesel
generation and provides significant savings to the
Cordova consumer.
Case #ll--High Interest
This alternative considered the effect on the cost
of power if a State loan were not available.
Cordova Electric Cooperative has access to
alternative financing at an interest rate of
approximately ten percent. While this alternative
still has a benefit-to-cost ratio above one, the
cost of power from this project in early years is
nearly one cent per kwh above the cost of
generating an equivalent amount of power with
diesel. By 1992 the cost has crossed over and the
power generated from the hydro electric project
is lower than diesel generated power.
Case #12--Low Fuel Costs
The feasibility of the project was evaluated
utilizing the Alaska Power Authority mean fuel
price projections of minus four percent in 1986,
no change in 1987 and 1988, and an increase of two
percent per year from 1989 to 2005. This fuel
escalation figure is above the base line
inflation. The Alaska Power Authority's low fuel
98
price scenario calls for the price of diesel fuel
to dec~ease four percent per year from 1986 to
1988 and then no increase for the remainder of
this study period. The effect of this low fuel
cost on the project was investigated. In the
early years very little change in the feasibility
of the project is seen. The benefits still are
approximately two cents per kwh although in future
years the benefits do not increase as rapidly as
the base case since the price of diesel fuel does
not climb as rapidly.
Case #13--High Fuel Costs
A high fuel cost projection figure which calls for
no change in the price of fuel between 1986 and
1988, and then an annual price increase of
3.5 percent from 1989 through 2005. In this case
the first year savings are very similar to the
base case, but future savings are much more
significant due to the rapidly rising price of
diesel fuel.
Case #14--Best Possible Case
As a test of the best that we anticipate could
occur during this project, the following scenario
was developed. The State equity investment would
remain at $1.3 million, but the project could be
built for $2.5 million. Cordova Electric
Cooperative would be able to generate the
remaining funding for this project internally and
no borrowing would be required. It should be
noted that this is not a probable case and should
not be considered as an alternative to the base
case. This alternative was prepared at the
request of individuals who wanted to know what the
best possible outcome of this project could be and
99
its effect on the cost of electric energy. This
alternative would provide for energy from Humpback
Creek at less than three cents per kwh and would
result in an immediate decrease of the cost of
energy in Cordova of one cent per kwh increasing
to 1.S cents per kwh by the year 2002.
Case #lS--Worst Case
The worst case was investigated which provides no
State investment, a Cordova Electric Cooperative
equity investment of 18 percent and the remainder
of the project financed at 10 percent. While this
alternative still provides a benefit-to-cost ratio
above one on the actual cash flow, the discounted
Cordova Electric Cooperative cash flow benefit-
to-cost ratio is exactly one indicating that the
benefits of the project equal exactly the cost of
the project. This alternative significantly
increases the cost of power in Cordova until 2001
at which time the hydro electric project power
falls below diesel power. In the early years
power from this project would be 1.S cents per kwh
above the cost of diesel. It should be noted that
before construction is started, we will be aware
of the financing available to us to determine
whether or not this case applies and a decision on
whether to pursue the project could be made.
Case #16--Worst Probable Case
The worst probable case is a slightly better
scenario than Case #lS. In this case it is
assumed that Cordova Electric Cooperative would be
able to invest approximately $1,000,000.00 of its
own funds in the project over the project
construction period. The remaining portion of the
project would be financed at 10 percent interest
100
and no operating margins would be generated by
this project. Although this project does provide
more expensive power in the early years, in 1994
power becomes less expensive than the diesel
alternative. This alternative has a benefit-to-
cost ratio above one. As with Case #15, before
construction is started, the sources of financing
will be known and a decision whether to pursue the
project can be made at that time.
Summary of Alternatives Investigated
With the exception of the two worst case
scenarios, all of the other alternatives
investigated still provide benefit-to-cost ratios
significantly above one, and even if the cost of
power from the project in early years is more than
diesel, it is not significantly above diesel and
the cross over point occurs fairly early on.
Combinations of alternatives were not investigated
since the number of permutations tends to increase
quite rapidly. It should also be pointed out that
it is believed that the base case is the case that
will be seen by this project. The purpose of the
sensitivity analysis is solely to ensure that
there are no assumptions made on the project which
can drastically alter the feasibility of the
project if the assumption is an error.
101
Figure V-39
HUMPBACK CREEK HYDRO--SUMMARY OF ALTERNATIVE FINANCIN6 METHODS
BENEFIT TO COST RATIO
CASE DESCRIPTION CONSTRUCTION STATE CEC INTEREST INFLATION HYDRO SEN KNH CEC ACTUAL
COST EQUITY EQUITY RATE RATE TIER "ILLIONS CASH FLON CASH FLON
BASE CASE 3,250,000 401 181 51 31 1. 50 3.5 2.31 2.05
2 LON CONST COST 2,750,000 471 181 51 n 1.50 3.5 2.84 2.31
3 HI6H CONST COST 3,750,000 351 181 51 31 1.50 3.5 1.95 I.B4
4 LOtI INFLATION 3,250,000 401 181 51 01 1.50 3.5 1.70 1.48
5 HI6H INFLATION 3,250,000 401 181 51 n 1.50 3.5 3.0B 2.BO
6 TIER OF 1.0 3,250,000 401 lBI 51 31 1.00 3.5 2.60 2.05
7 TIER OF I.B5 3,250,000 401 lBI 51 31 1.85 3.5 2.14 2.05
8 LOtI 6EN£RATION 3,250,000 401 181 51 31 1.50 2.5 1.77 1.55
9 HI6H 6ENERATION 3,250,000 401 181 51 31 1.50 4.5 2.79 2.49
10 LON INTEREST 3,250,000 401 181 21 31 1.50 3.5 2.94 2.05
11 HI6H INTEREST 3,250,000 401 181 101 31 1.50 3.5 1.63 2.05
12 LOW FUEL COST 3,250,000 401 lBI 51 31 1.50 3.5 1.9B 1.56
13 HI6H FUEL COST 3,250,000 401 lBI 51 31 1.50 3.5 3.06 2.41
14 BEST P06S CASE 2,500,000 521 461 51 31 1.50 3.5 4.31 2.4B
15 NORST CASE 3,250,000 01 181 10.01 31 1.50 3.5 1.00 2.05
16 NORST PROB CASE 3,250,000 01 301 10.01 n 1.00 3.5 1.3B 2.05
f" W
,,~
HUMPBACK CREEK HYDRO--SUMMARY OF ALTERNATIVE FINANCING METHODS
CASE DESCR I P Tl ON CONSTRUCTION STATE CEC INTEREST INFLATION HYDRO GEN KWH POWER COST FROM HUMPBACK CREEK AND SAVINGS OVER DIESEL GENERATION
COST EQUITY EQUITY RATE RATE TIER MILLIONS 1987 1992 1997 2002
BASE CASE 3,250,000 401 18X 5X 3X 1. 50 3.5 COST 6.54 6.64 6.75 b.84
SAVINGS 2.02 4.00 6.73 10.24
2 LOW CONST COST 2,750,000 477. 18X 51 3X 1. 50 3.5 5.13 5.27 5.43 5.59
3.43 5.37 8.04 11. 49
3 HIGH CONST COST 3,750,000 351 18X 5X 31 1. 50 3.5 7.96 8.02 8.07 8.09
0.60 2.62 5.40 B.99
4 LOW INFLATION 3,250,000 401 18X 5X OX 1. 50 3.5 6.50 6.32 6.09 5.80
1.81 2.59 3.b5 4.85
5 HIGH INFLATION 3,250,000 401 18X 5X 6X 1. 50 3.5 6.58 7.03 7.64 8.47
2.22 5.61 10.84 18.57
6 TIER OF 1.0 3,250,000 401 18X 51 3X 1. 00 3.5 5.57 5.73 5.91 6.09
2.99 4.91 7.57 10.99
7 TIER OF 1.85 3,250,000 40X 18X 5X 3X 1. 85 3.5 7.22 7.28 7.33 7.35
1.33 3.36 b.14 9.73
8 LOll GENERATION 3,250,000 401 18X 5X 3X 1. 50 2.5 8.74 8.82 8.89 8.93
-0.18 1. 82 4.58 8.15
9 HIGH GENERATION 3,250,000 401 18X 5X 3X 1. 50 4.5 5.32 5.43 5.56 5.68
3.24 5.21 7.92 11.40
10 LOll INTEREST 3,250,000 401 181 2X 3X 1. 50 3.5 4.79 4.94 5.14 5.38
3.77 5.70 8.33 11.70
11 HIGH INTEREST 3,250,000 401 18X 101 3X 1. 50 3.5 9.47 9.61 9.74 9.78
-0.91 1. 03 3.74 7.30
12 LOll FUEL COST 3,250,000 40% 18X 5X 3X 1. 50 3.5 6.54 6.64 6.75 6.84
1.72 2.60 3.96 5.58
13 HIGH FUEL COST 3,250,000 40X 18X 51 3X 1. 50 3.5 6.54 6.64 6.75 b.84
2.02 4.57 8.43 13.75
14 BEST POSS CASE 2,500,000 521 48X 5X 3X 1. 50 3.5 2.81 3.07 3.38 3.74
5.75 7.57 10.09 13.34
15 WORST CASE 3,250,000 OX 18X 10.0X 31 1. 50 3.5 16.25 16.27 16.19 15.91
-7.69 -5.63 -2.72 1.17
16 WORST PROB CASE 3,250,000 OX 30X 10.0X 3X 1. 00 3.5 11.33 11.46 11.56 11.56
-2. i7 -0.82 1. 91 5.52
Figure V-40
f;~
HUMPBAC~ CREEK HYDRO--SUMMARV OF ALTERNATIVE FINANCING METHODS
CASE DESCRiPTION CONS TRUCTI ON STATE eEC INTEREST INFLATION HYDRO GEN KWH AVERAGE RETAIL RATE IN CENTS PER KWH
COST EQUITY EQU ITY RATE RATE TIER MILLIONS 1987 1992 1997 2002
BASE CASE 3.250,000 40% 18i: 5% 31. 1. 50 3.5 WO/HYDRO 19.24 22.39 25. 10 28.'10
IiI/HYDRD 18.90 21. 85 24.31 27.83
2 LOW [ONST COST 2,750,000 m; 18% 51. 3% 1. 50 3.5 i/O/HYDRO 19.24 22.39 25.10 28.90
II/HYDRO 18.59 21. 47 23.75 27.16
3 HIGH CONST C051 3,750,000 35;; 181. 51. 3% 1.50 3.5 iIIO/HYDRO 19.24 22.39 25.10 28.90
W/HYDRO 19.17 22.05 24.48 27.97
4 LOW INFLATION 3,250,000 40i. 18% 51. 0% 1. 50 3.5 liD/HYDRO IB.92 19.60 19.64 19.99
II/HYDRO 18.56 19.21 19.18 19.46
5 HIGH INFLATION 3,250,000 407-18:4 51. 6:4 1. 50 3.5 liD/HYDRO 19.66 25.74 32.47 42.70
ill/HYDRO 19.24 24.92 31.13 40.69
6 TIER OF 1. (I 3,250,000 40% 18:4 5% 31. 1. 00 3.5 NO/HYDRO 19.24 22.39 25.10 28.90
II/HYDRO 18.73 21.72 24.20 27.75
7 TIER OF l.85 3,250,000 401. 181. 5% 31 1. 85 3.5 NO/HYDRO 19.24 22.39 25.10 28.90
ill/HYDRO 19.03 21. 94 24.38 27.88
8 LOW GENERATION 3,250,000 40X 18% 51. 31. 1. 50 2.5 liD/HYDRO 19.24 22.39 25.10 28.90
II/HYDRO 19.28 22.22 24.72 28.29
9 HIGH GENERATION 3,250,000 40X 18% 5% 3Y. 1. 50 4.5 i/O/HYDRO 19.24 22.39 25.10 28.90
II/HYDRO 18.52 21.48 23.90 27.37
10 LON INTEREST 3,250,000 401. 181. 2% 3X 1. 50 3.5 NO/HYDRO 19.24 22.39 25.10 28.90
II/HYDRO 18.59 21.61 24.11 27.67
11 HIGH INTEREST 3,250,000 401. 181. 10% 3X 1. 50 3.5 liD/HYDRO 19.24 22.39 25.10 28.90
II/HYDRO 19.43 22.27 24.67 28.14
12 LON FUEL COST 3,250,000 40% 181. 51. 31. 1. 50 3.5 NO/HYDRO 18.99 21.03 22.38 24.28
II/HYDRO 18.65 20.64 21.88 23.66
13 HIGH FUEL COST 3,250,000 40~ 18l 5% 31. 1. 50 3.5 NO/HYDRO 19.29 23.00 26.84 32.45
II/HYDRO 18.90 22.34 25.80 30.96
14 BEST POSS CASE 2,500,000 52l 481. 5% 31. 1. 50 3.5 NO/HYDRO 19.24 22.39 25.10 28.90
Ii/HYDRO 18.22 21.34 23.89 27.49
15 WORST CASE 3,250,000 OX 181. 10.0% 31 1. 50 3.5 IIO/HYDRO 19.24 22.39 25.10 28.90
W/HYDRO 20.72 23.26 25.50 28.84
16 NORST PROS CASE 3,250,000 0% 30'1. 10.0'1. 3~ 1. 00 3.5 NO/HYDRO 19.24 22.39 25.10 28.90
Ii/HYDRO 19.82 22.58 24.94 28.38
Figure V-41
VI. CONSTRUCTION PLAN
A. INTRODUCTION
Construction of the Humpback Creek hydro electric
project will take place over two years beginning
in early 1986 with project completion scheduled
for the fall of 1987. For construction of this
project, Cordova Electric Cooperative will act as
the general contractor. Individual portions of
the work will be subcontracted out or accomplished
by local crews hired by CEC (force account crews).
Figure VI-1 lists those portions of the project
that will be contracted out. Figure VI-2 lists
those portions that will be accomplished with
locally hired crews.
B. CONSTRUCTION SCHEDULE
The construction phase of the project has been
broken down into six separate areas of work
effort:
1. Access roads and trails.
2. Bridge construction.
3. Right-of-way clearing.
4. Intake structure.
5. Pipeline.
6. Power plant and tailrace.
7. Connect to CEC Distribution System.
Access Roads and Trails
Two separate access areas will be used during
construction of the project. The first area
indicated as Trail #1 on the attached drawing
(Figure VI-3) will be used for personnel access
only. This trail will provide access to the
intake structure and a major portion of the
pipeline route.
102
Figure VI-l
HUMPBACK CREEK
LIST OF SUBCONTRACTED WORK
1. Rock clearing of east wall, including blasting and
erection of safety railing.
2. Installation of rock anchors over Creek span (two on
each side).
3. Footings and concrete work at power plant site,
including concrete portions of tailrace. Also includes
site excavation as needed.
4. Furnish and erect building at power plant site,
including inside wall partitions and overhead crane.
5. Furnish and install turbines and generators, including
governors, switchgear, shutoff valves and safety
devices.
6. Provide labor, equipment and supplies to weld steel
portions of pipe.
7. Provide helicopter time to haul pipe material to site.
Back haul rings to selected site. (3,000 pound lift).
8. Provide helicopter time for personnel support during
construction. Transport equipment as needed.
(500 pound lift).
9. Provide poles and pole line hardware for overhead
portion of transmission line.
10. Provide labor and materials to wire power plant
building, includes high voltage wiring, station service
wiring and control wiring.
11. Provide labor and materials for plplng and plumbing of
power plant building, includes domestic hot and cold
water, sanitary system within the building, and all
piping, except water piping used to generate power.
12. Provide labor and materials to complete interior of
building, includes painting, appliances, fixtures,
bunks, etc.
13. Provide barge service to haul equipment and freight to
and from Cordova to the site, includes loading and
unloading as necessary.
14. Fabricate and install gravel separator at power plant,
includes pressure water piping from end of pipeline to
turbine inlet fittings.
15. Fabricate grates and steel tank for impoundment
structure.
16. Purchase work boat.
17. Purchase tools.
18. Purchase station service transformer (25 KVA).
Figure VI-2
HUMPBACK CREEK
LIST OF FORCE ACCOUNT WORK
1. Right-of-way clearing west bank, includes removal of
rings.
2. Remove rings on east bank.
3. Right-of-way clearing intersection to power plant,
includes stump removal.
4. Right-of-way clearing of access trail to power plant
site.
5. Right-of-way clearing of transmission line route.
6. Place and weld P.E. pipe along whole project.
7. Site clearance on power plant site.
8. Site clearance on staging areas.
9. Aerial cables across Creek to support pipe.
10. Construction of impoundment structure.
11. Construction of an overhead transmission line to
connect to CEC's distribution system.
12. Construction of non-concrete portions of tailrace.
NEW DAM-~
OLD DA M ----\-------\----1.....&
/ \
,/
250-------
~-------------
CREEK CROSSING
~ --------------
i ~;::C' -"J' - -
___ ., \..... t..:. =-_==-::,1,--..,......,........, ....... ,-
ORCA
INLET
Figure VI-3
I REVI SION N0·1 DA-=
-!
EX~LA.NA-I()N
Right-of-Way Clearing for Trail #1
The right-of-way clearing will consist of removal
of alder, small fir trees and undergrowth (mostly
ferns and devils club) from an area approximately
ten (10) feet wide beginning at the high water
mark and extending to the base of the hill, a
distance of approximately 500 feet. Other than
removal of small stumps and large rocks, no
surface disturbance is anticipated. This area
appears to have a gravel surface and will heal
rapidly when the trail is no longer used for
access. Due to this stable gravel substrate, no
erosion problems are anticipated during clearing
or use of the trail. No grading or other surface
disturbance of the trail is anticipated. The
rapid rate of growth of alder trees in the area
will ensure that no visible disturbance will
remain in this portion of the trail after a couple
of years. Alder and other organic material
removed as part of the right-of-way clearing will
be stacked on the beach above high tide line and
burned at a time agreeable with the Department of
Environmental Conservation. No standing trees
larger than six inches in diameter will be removed
during right-of-way clearing. Fallen trees in the
area that will be cut include four trees six to
twelve inches in diameter and one tree larger than
twelve inches in diameter.
Trail #1 will continue east up the slope to the
Creek canyon. (See Figure VI-3). The only
clearing anticipated for this area is the hand
removal of portions of fallen logs that block the
trail and undergrowth such as devils club. Slash
and debris thus removed will be scattered adjacent
to the trail for natural disposal by rotting. No
103
surface disturbance is anticipated as part of this
right-of-way clearing. The predominant ground
cover is primarily fern and moss covering a
relatively stable soil and small gravel base. In
some areas, rain run-off down gentle to moderate
slopes has saturated the soil and created muddy
areas. To the maximum extent possible, the access
trail will be routed around these areas and where
not possible, gravel will be hand placed in these
less stable areas to stabilize the trail and
minimize erosion. This portion of the trail up
the slope has a total distance of approximately
500 feet.
Once the trail reaches Humpback Creek Canyon, it
will branch north and south with the south leg
continuing over the crest of the hill to provide
access to the site of the intake structure, old
dam site, and pipeline route up stream of the
existing cable crossing. The same clearing
criteria as used on the previous portion of the
pipeline will be used in this area although the
elevation and topography is such that there will
not be many, if any, soft areas. Several small
gullies will be crossed, but these areas can be
crossed by walking and will not require any fill,
constructed walkways, or other ground disturbance.
The portion of trail #1 that branches to the west
will be used for access to portions of the
pipeline to be constructed downstream from the
cable crossing. (See Figure VI-3.) This trail
will traverse an area called the intersection
where the proposed pipeline alignment intersects
with the old wood stave pipeline route that
continues downhill to the existing pelton wheel
104
and generator. A collapsed building and debris
situated in this area will be removed by stacking
to allow it to dry and burning it in its current
location. Ashes and non-combustible materials
remaining will be buried at the site in accordance
with provisions of a Department of Environmental
Conservation authorization. With the speed at
which moss and ferns grow over disturbed soil, it
is anticipated that the area now covered by the
collapsed building will completely heal itself
within two years.
Trail #2 will be on the north side of Humpback
Creek and will extend from mean high water
upstream along the Creek as shown on the attached
drawing. This trail will be used during
construction for the movement of heavy equipment
and supplies and will be used for access and
maintenance on a continuing basis. This area
consists of alluvial gravel deposited along the
stream which currently supports alders and small
Sitka spruce and western hemlock. Undergrowth is
sparse and consists primarily of moss.
Within the Trail #2 right-of-way from the high
tide mark of Orca Inlet to the edge of Humpback
Creek, an approximate twelve (12) foot width will
be cleared of all the trees and brush. No trees
larger than six inches in diameter will be removed
in this area. Trees and slash removed will be
stockpiled on the gravel beach above high tide
line near the start of the trail and burned at a
time and manner acceptable to the Department of
Environmental Conservation.
105
This trail will be used by construction equipment
moving to and from the power plant and steel
portions of the pipeline. Equipment to be used
includes large tracked backhoe, wheeled loaders,
boom trucks, concrete mixer truck, and miscell-
aneous small equipment such as welders, air
compressors, pumps, etc. This trail will be
bladed flat by a tracked dozer.
A 40-ton temporary gluelam bridge will be erected
across the creek. This bridge will rest on gravel
pads and will be full span thus not requiring any
support within the stream bed. There will be a
minimum of five feet clearance above the stream
level. The bridge will be erected during the
month of June. The bridge will remain in place
for two years after completion of construction.
At that time a decision will be made to remove the
bridge or make it permanent. This decision will
be based on the number of times it is necessary to
visit the site on foot and with equipment.
From the far side of Humpback Creek to the power
plant site, the right-of-way clearing will entail
removal of several trees ranging from one (1) inch
to 15 inches in diameter, as well as the minimal
amount of surface cover, such as devils club,
fern, and small spruce and hemlock trees. Eight
to ten trees six to twelve inches in diameter will
be removed. Five trees twelve to eighteen inches
in diameter and three trees over eighteen inches
in diameter will be removed. All brush and trees
removed will be stacked on site near the
transmission line route and burned at a time and
in a manner acceptable to the Department of
Environmental Conservation.
106
C. TIME FRAME FOR ACCESS CLEARING
It is difficult to determine exactly when
right-of-way clearing can commence. The items
that must be accomplished prior to right-of-way
clearing include obtaining the necessary licenses
and permits from agencies, including the Federal
Regulatory Commission, as well as obtaining
surveys, subsurface and water rights for the
project. Weather or other circumstances can
prevent access to the site until mid-June. For
project scheduling purposes, we have assumbed that
right-of-way clearing can commence on May 15,
1986. This work will be accomplished by crews
hired from the local work force.
D. PIPELINE RIGHT-OF-WAY CLEARING
This project will include removal of rock, trees,
brush and other organic matter in the area to be
used for the pipeline. Since the pipeline will
simply rest on the ground surface for most of its
alignment, minimal preparation of the surface is
required. Right-of-way clearing for the pipeline
will be broken into two separate areas.
107
The area upstream of the cable crossing will be
cleared by a combination of construction work and
force account work. CEC crews will enter this
area as soon as possible in the spring to remove
all of the existing iron rings from the old wood
stave pipeline. The rings on this portion of the
pipeline will be stacked in the area indicated on
the attached drawing. They will be made available
to the Eyak Corporation at this location.
Portions of the rings from the old pipeline are
buried under rock slides and will not be
accessible to our crews. Where necessary, work
crews will remove rock in the slide area along the
alignment and dispose of it into the canyon of the
upper reaches of Humpback Creek. The material to
be removed in this area consist of rocks and
cobble without any fine material. This rock
disposal area is a considerable distance upstream
from the salmon spawning area and well above the
limits of fish access in the stream. Total rock
to be removed in this area is between 20 and
40 cubic yards. Decomposed pieces of the wood
stave pipeline that are not large enough or stable
enough to remove, will likely be disposed of with
the rock. Large chunks of wood that are
sufficiently stable to be carried will be removed
from the right-of-way to a site upstream and
burned. It is estimated that only a small
fraction of the wood stave pipeline debris will be
sufficiently stable to remove.
Once CEC crews have done the preliminary clearing,
a contractor will clear the right-of-way to a
width of six (6) feet. Right-of-way clearing will
consist of removing the rock abutment, widening
the existing area, removing loose rocks that may,
108
over time, weather and falloff the abutment, and
building trestles as necessary to ensure a six (6)
foot wide right-of-way for installation of the
pipe. It is not possible at this time to estimate
the amount of rock to be removed during this
phase. The contractor will also be responsible
for installing a safety rail on the Creek side of
this area for personnel safety. No right-of-way
clearing will be required between the base of the
existing dam and the new intake structure. (See
Pipeline Design details for a discussion of the
means of running the pipeline up the face of the
existing dam.)
Downstream of the cable crossing, right-of-way
clearing will be accomplished by CEC force account
crews. Right-of-way clearing in this area
consists of two distinct phases. Upstream of the
intersection point, CEC crews will remove the
existing iron rings and stable pieces of wood from
the existing pipeline and will store them at the
intersection in the area which currently has the
collapsed building that will be burned under
Access Right-of-way Clearing. In addition to ring
removal, a considerable amount of rock removal
will be accomplished. In this area much of the
rock can be recovered and used elsewhere. The
material to be removed in this area consist of
rocks and cobble without any fine material. Total
rock to be removed in this area is between 50 and
75 yards. Approximately 25 to 30 yards of this
rock will be recovered and used in other areas.
The rock that cannot be recovered will be disposed
of in the canyon of Humpback Creek. This area is
also a considerable distance above the salmon
109
spawning area, and well upstream from the limit of
fish access.
From the point of intersection to the new power
plant site, right-of-way clearing will consist of
removal of trees ranging from small spruce,
hemlock, alder and blueberry bushes to large trees
15 to 20 inches in diameter. Approximately 15
trees between six and twelve inches in diameter
will be removed, and between five and ten trees
from twelve to eighteen inches in diameter will
be removed. All brush and slash removed will be
stacked near the right-of-way and burned. Large
tree trunks will be segmented and allowed to
decompose naturally. Ground disturbance will be
limited to stump and root removal and a minor
amount of surface gravel removal to make a bed for
the pipeline. All stump and root removal in this
area will be by hand. It should be noted that the
pipeline will not be buried but will rest in a
shallow depression in the ground along the
pipeline right-of-way. Right-of-way clearing on
the steep part of the hill just before the power
plant will include removal of some large rocks and
may entail a minor amount of blasting. Rock
removal in this area will be between five and ten
yards. Since this area is near the salmon
spawning reaches of Humpback Creek, particular
care will be taken to ensure that no rock, gravel,
or organic matter is allowed to enter the Creek.
Necessary blasting will also comply with the
conditions and timing stipulated by Alaska
Department of Fish and game Title 16 permit for
activities near Humpback Creek. It is anticipated
that right-of-way clearing will begin as soon as
the snow is gone and should be accomplished within
110
three months. The majority of the work near the
Creek will be accomplished early on in the season.
See Figure VI-4 for a construction schedule for
1986.
Three staging areas will be used for this project.
One staging area will be just north of Humpback
Creek near the barge off-loading area on Orca
Inlet. This staging area will be used to store
materials and supplies before being hauled to the
project. The second staging area will be at the
intersection point. This staging area will be
used to store polyethylene-pipe and materials to
be used for the overhead cable crossing. The
third staging area will be in the vicinity of the
intake structure and will consist of materials to
be used in the intake structure, polyethylene
pipe, and the gabion baskets before they are used.
Materials will be moved from the barge off-loading
area to staging areas #2 and #3 by helicopter.
Minimal ground disturbance will be necessary in
each of these staging areas since they are
currently clear of all but small undergrowth.
Materials will be transported from the City of
Cordova staging area in Cordova to the project by
non-powered barges. These barges will be taken in
at high tide and left to rest on the bottom as the
tides goes out. Planks will be used for
off-loading equipment from these barges on to the
beach and no surface disturbance below the high
water mark is anticipated.
111
Intake Structure
The intake structure will be constructed by force
account crews hired by CEC. This structure will
consist primarily of gabions, a steel tank, and
necessary grates and screens to remove the rock
and gravel from the water. The intake structure
will be located in an area of deep, fast moving
water where the depth of the gravel is not known.
Railroad rails will be driven down into the gravel
bed to support and restrain the gabions to be
installed. This will prevent their washing out
during high flow periods. Gravel for filling the
gabions will be taken from the surface gravel
behind the existing dam. Gravel will be extracted
by hand. No mechanical equipment will be used for
rock removal. Due to the large amount of gravel
inlpounded behind the existing dam, large gravel
for the gabions will be taken from the east side
of the stream bed. This portion of the stream bed
does not become wet except at maximum flows.
Minimum railroad rail penetration will be five (5)
feet. If bed rock is reached at a depth of less
than five (5) feet, the area will be drilled, and
reinforcing steel will be grouted in. The gabions
will be filled with gravel taken from the site and
will be set over the steel. The first level of
gabions will be dug down approximately one and
one-half (1~) feet into the gravel to provide
additional lateral support. The gravel located
below the gabion structures will be sealed with
Bentonite or equivalent sealer. Equipment to be
used during construction of the intake structure
will be portable welders, air compressors and pile
drivers. Spare fuel and lubricating oils will be
stored on the hill above the site to prevent
contamination of the stream in the event of a
112
spill or major storm resulting in unexpected high
flows. Storage of spare fuel and lube oil will be
minimal and will not exceed 50 gallons at any
time. The location of fuel and lube oil storage
is shown on Figure VI-3.
Figure V-18, Sheet #3 contains a sketch of the
intake structure. The steel tank will be flown in
by helicopter and set in place after installation
of the gabions. Construction will be such that
there will be no altering of the stream flow while
the gabions are being installed. Gravel water
diversion dams may be temporarily constructed, and
these will be removed after the intake structure
is complete.
The temperature of the water in the stream will be
between 35°F and 45°F. This will pose serious
productivity problems for the crews working in the
water on the gabions. It is probable that CEC
will have to provide wet or dry suits for the
crews. It may also be possible to span the Creek
at the point of the intake structure with 30 foot
long gluelam beams. This will provide a working
platform and these beams could be raised or
removed during high flow periods.
The intake structure will have a concrete face.
Cement will be flown in by helicopter and mixed
with on-site sand and gravel. Gravel will be
obtained by screening operations within the flood
plain but no washing of this gravel will occur.
The concrete will be poured during low stream flow
periods although the purpose of the concrete is to
provide protection for the gabions and is not
structurally part of the intake structure.
113
E. PIPELINE
The pipeline will be constructed by our own crews.
A thermal plastic welding machine will be leased
for the two months estimated for pulling of the
pipe. The welding machine makes use of a butt
welding process whereby the pipe is pulled through
the welding machine and the welding machine
remains stationary. The welding machine would
first be placed at the top of the existing dam,
and the polyethylene pipe would be pulled to the
new intake structure. Large rollers will be
necessary to prevent kinking of the pipe as the
polyethylene pipe is pulled around the corner
between the old dam and the intake structure. As
discussed in the previous section, three alterna-
tives are being evaluated to secure the pipe
during high flow periods. A final decision among
the three options will be made during detailed
engineering. See Figure V-19 for a detail of the
pipe and gabions for one of the proposed
alternatives. Since the pipe will be installed
parallel to the stream flow scouring action will
be minimized. Location of the pipe near the east
bank of the stream above the old dam will keep it
out of the main flow further reducing the tendency
for scouring. See Figure V-18, Sheet #1 and #2
for preliminary pipeline alignment.
The pipe would be laid on the northeast side of
the existing gravel area above the old dam to
provide better protection during high flow
periods.
The welder would then be relocated by helicopter
to the base of the old dam and the polyethylene
114
pipe would be pulled to the cable crossing area.
Elbows would be placed on the polyethylene pipe to
allow the portion of the pipe that traverses the
face of the dam to be installed by hand. For a
discussion of the dam crossing, see Section VII F
"Historical Considerations".
The pipe welding machine would then be relocated
by helicopter to the intersection point on the
west side of Humpback Creek. From there the pipe
would first be pulled to the south to the cable
crossing point then north to the area where the
steel pipe would begin. The steel pipe would be
brought across the access road to the new power
plant site on flat bed trucks and would be winched
into position by hand assisted by the backhoe that
would be on site for construction of the power
plant. The steel pipe would be welded by hand in
sections as necessary.
Installing the pipe across Humpback Creek as shown
in Figure V-18, Sheet #1 will involve winching
cables across the Creek, securing them to rock
anchors and using a winch to tension the cables.
Premeasured clips would be hung from each of the
two cables across the Creek. The length of these
premeasured clips would be such that the
polyethylene pipe would be horizontal when loaded
with water. After the support clips are
installed, polyethylene pipe would be pulled
across the Creek utilizing the supports one pipe
at a time. The use of polyethylene pipe reduces
the need for thrust blocks. Concrete for thrust
blocks that are required for the polyethylene pipe
plus the steel pipe in the lower portions would be
115
mixed on-site above the old dam and transported as
needed by helicopter.
F. POWER PLANT
Construction of the power plant would begin as
soon as snow has left the site and permission is
received from the Alaska Department of Fish and
Game to install the temporary bridge. Power plant
construction will continue over the two
construction seasons.
The portions of the building and heavy equipment
would be transported to the site by barge from
Cordova. The equipment will consist of a large
tracked backhoe, a ten (10) yard cement mixing
truck, and one or two semi-trailers of building
materials, steel pipe and cement. The large
tracked backhoe would have the advantage of being
able to serve many purposes during construction of
the building and tailrace. It would serve as a
crane to lift portions of the building and steel
pipe into place. The tracks will do less surface
damage than a wheeled vehicle and the longer reach
of the large backhoe will assist in installing the
steel pipe portions of the pipeline. The backhoe
will also be used to install the gravel pads for
the bridge and the beams that make up the bridge
to minimize instream activity.
A spoil disposal area in the vicinity of the
transmission line will be established for disposal
of over burden and excess soil removed where the
footings and tailrace are installed. See Figure
V-27 for location of the spoil area.
116
The tailrace will consist of a concrete trough as
shown in Figure V-27. Where the tailrace enters
Humpback Creek, an energy absorbing structure will
be built. The location where the tailrace enters
Humpback Creek will be located as far upstream as
possible. A steep cliff limits the distance
upstream where water can be returned to Humpback
Creek. The approximate location of the tailrace
is shown in Figure V-27. The exact location where
the tailrace enters the Creek as well as the
physical design of the energy absorbing structure
will be determined during the final engineering
phase. We have contacted the National Marine
Fishery Service and received some preliminary data
from them on the design of the tailrace structure.
Final design of the tailrace and energy absorbing
structure will be furnished to the Alaska
Department of Fish and Game for approval before
construction.
It is possible that during construction of the
tailrace in the stream, a diversion berm will have
to be constructed to contain silty water. This
temporary berm will be constructed of larger
in-stream boulders upstream of the tailrace
structure and will be removed upon completion of
the tailrace. The final design will incorporate a
design system which will keep pink salmon from
entering the tailrace. The National Marine
Fisheries Service has provided preliminary
information to assist in this design effort. The
gravel for the gabions to be used in the tailrace
energy absorbing structure will be obtained from
the gravel bed on the north side of the stream
plus larger boulders and rocks in the stream bed
above the tailrace area. This is the area that
117
will be partially dewatered by construction of
this hydro electric project.
Although the design for this energy absorbing
structure is not complete, it is anticipated that
the structure will be made of gabions filled with
rock from Humpback Creek. It will also be
necessary to drive some railroad iron or
reinforcing steel in the Creek bed underneath the
gabions to provide support for them during high
flow periods. As with the intake structure, if
the depth of the gravel is less than five (5)
feet, the railroad iron cannot be installed and
reinforcing steel will be drilled and grouted to
provide lateral support for the gabions.
Preliminary estimates show the requirement for
approximately 50 yards of concrete for power plant
footings, generator support and tailrace. Gravel
for this concrete will be taken from gravel banks
located away from Humpback Creek. During the
spring of 1986 tests will be made of potential
gravel sites and the selection of the final gravel
borrow area will be coordinated with Alaska
Department of Fish and Game. The gravel borrow
area will be removed from Humpback Creek so that
there will be no adverse affect on the salmon
resource of Humpback Creek. The gravel will be
taken in such a manner as to minimize disturbance
to the stream and the borrow area will be returned
to a smooth grade upon completion of the gravel
removal efforts.
Emergency living quarters will be provided in the
power plant although it is not planned that anyone
will live at the site on a regular basis. All
maintenance will be performed on a "day work"
118
basis with employees going to the site in the
morning and returning to town in the evening. Due
to the possibility of storms or other unforeseen
circumstances requiring overnight accommodations,
a small bunk room will be built. Bathroom
facilities will be furnished by a chemical toilet
and a sink and stove will be installed to allow
washing and minimal cooking. Gray water from the
sink will be stored in a 100 gallon holding tank
inside the building. This gray water will be
transported to Cordova in 55 gallon drums on an
"as needed" basis. It is anticipated that the
overnight facilities will be used less than five
(5) days per year.
G. TRANSMISSION LINE
The transmission line construction will be
overhead from the power plant to the north side of
Humpback Creek. Construction will use the REA
recommended construction standards for Protection
of Large Birds (see Appendix C).
The routing of the transmission line is shown on
Figure V-28. The length of this transmission line
is 1,000 feet.
The overhead transmission line from the power
plant to the water's edge will utilize relatively
short spans of approximately 200 feet each. These
short spans will prevent wind related line slaps
and similar problems. The short spans also have
proven effective in the heavy snow expected in
this area. The right-of-way clearance for this
overhead line will be 20 feet wide and all small
brush will be removed from the right-of-way.
Danger trees (trees outside the right-of-way which
119
will damage the transmission line if they fall
over) will be removed for an additional 20 feet
outside the right-of-way. This transmission line
will cross an area vegetated primarily with moss,
fern and gravel. The poles erected on either side
of Humpback Creek will be guyed and have double
dead ends so that a failure of a pole on either
side of Humpback Creek would not take down the
poles on the bank of Humpback Creek. Pole spacing
will be adjusted so that no pole is located within
40 feet of the bank of Humpback Creek.
The backhoe on site for construction of the power
plant will be used to dig the holes. The poles
will be erected by CEC line crews.
Power generation will be at 12,470 volts so that
no step-up transformer will be necessary.
Secondary voltage (120/240) will be provided by an
REA approved pad mount transformer during
construction. A dry transformer will be installed
for permanent power.
Construction crews will be expected to return to
Cordova from the work site each evening. There
are no plans for any overnight work. Each day the
returning crews will carry out all garbage
accumulated during the day so that there will be
no storage of putrescible materials. During the
day the garbage will be stored in metal
containers. Sanitary facilities will be provided
by three portable outhouses; disposal of septic
materials will be in accordance with Department of
Environmental Conservation requirements.
120
Before working on this project each employee will
be given an indoctrination course explaining
safety precautions to be taken on the job,
particularly relating to any potential bear
problems. Non-supervisory employees working on
this project will not be allowed to carry weapons.
121
Key
IIII = CEC Hired Laborers
\\\\ = Contractor : : :: = CEC Line Crew
1986 CONSTRUCTION SCHEDULE
Figure VI-4
Sheet #1
May June July August September October
5 12 19 26 2 9 16 23 30 7 14 21 28 4 11 18 25 1 8 15 22 29 6 23 20 27
Clear Access Trail
North Bank
Construct Bridge
Abutments
Build Bridge
Clear Access Trail
Rock Clearing
East Notch
Right-of-way Clearing
West Side
Right-of-way Clearing
New Pipeline Route
Rock Excavation
East Notch
Bail Gravel for Concrete
Excavation for Foundations
And Tailrace
IIII
\\\\\\\\
\\\\
IIIIIII
IIII
IIIIIIII
IIIIIIIIIII
\\\\\\\\\\\\\\\
\\\\
\\\\\\\
Key
Figure VI-4
Sheet #2
IIII = CEC Hired Laborers
\\\\ = Contractor
1986 Construction Schedule (Continued)
: I : I = CEC Line Crew
Form and Pour Foundation
And Tailrace
Build Intake Structure
Build Tailrace Gabian
Structure in Creek
Install Sectionalizer
At Orca
Build Pole Line At
Humpback Creek
Install In-Water Line
To Town
Install Service At
Humpback Creek
May June July August September
5 12 19 26 2 9 16 23 30 7 14 21 28 4 11 18 25 1 8 15 22 29
\\\\\\\\\\\\\\\\\\\\\\\\\
IIIIIIIIIIIIIIIIIIIIII
111111111111111/11111
I I I I I I I
II I I I I I
I " I I I I I II I I I I
I I I I I I I I I
I I I I I I I I I
I I I I I
I I I I I
I I I I
I I I I
October
6 23 20 27
VII. ENVIRONMENTAL ANALYSIS AND REA BORROWER'S ENVIRONMENTAL
REPORT
This portion of the report is based on the 1980 Draft
Coordination Act Report submitted to Alaska District
U.S. Army Corps of Engineers by the U.S. Fish and
Wildlife Service.
A. VEGETATIVE RESOURCES
The primary vegetative type in the project area is
a coastal western hemlock-Sitka spruce forest. A
narrow band of riparian species occupies the
Humpback Creek floodplain and marine flora typical
of Prince William Sound inhabit the terminus of
the Humpback Creek delta where it enters Orca
Inlet.
The western hemlock-Sitka spruce vegetation type
is well represented. Sitka spruce and western
hemlock are the dominant members of the community.
Blueberries, devilsclub, and several species of
ericaceous shrubs make up the understory. Because
of the high rainfall and resulting high humidity,
mosses grow in great profusion on the ground, on
fallen logs, and on the lower branches of trees,
as well as in forest openings.
Alders and willows occupy a narrow band along the
stream channel primarily near the mouth and above
the canyon area. The creek has formed a small
gravel delta into Orca Inlet. A portion of the
delta is being colonized by willows, grasses and
forbs. The rest is barren. The intertidal and
subtidal areas off the delta appear to be quite
productive in terms of marine flora. Rockweed,
122
sea lettuce, wrack, and a species of red algae are
all abundant.
B. FISHERIES RESOURCES
Prince William Sound pink salmon stocks are
particularly adapted to heavy use of the
intertidal zone and Humpback Creek is no
exception. Pink runs typically display an
even-odd year cyclicity and those stocks returning
to Humpback Creek tend to dominate on odd years.
Spawning activity usually takes place from early
July through early September and peaks during late
July to early August. Escapement counts conducted
by the Alaska Department of Fish and Game are
shown in the following table. Dolly Varden are
found in lower Humpback Creek and are probably
seasonally attracted following migrating pink
salmon. Sport fishing effort for pinks and Dolly
Varden is low.
Pink Salmon Escapement Counts
Humpback Creek 1960-1985
Year
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
No.
2,390
16,010
7,200
9,860
3,560
1,200
310
420
550
4,730
540
8,230
1,740
Year
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
No.
2,510
70
6,800
840
13,920
360
11,940
2,140
5,340
1,860
13,540
20,560
26,800
As previously mentioned, Humpback Creek flows into
a canyon approximately one mile before it enters
Orca Inlet. The canyon area is estimated to be
between 0.5 to 0.75 miles long. A series of three
123
old log dams, constructed for power generation in
the early 1900's are situated approximately 0.25
miles apart beginning with where the creek first
enters the canyon. The uppermost dam is about 12
feet high and is situated where the creek enters
the canyon. Downstream about 0.25 miles in the
steepest part of the canyon is another small dam
about 10 to 12 feet high. About 0.25 miles below
the second dam is a large dam about 80 to 100 feet
high. The big dam was constructed of log cribbing
and is slowly deteriorating. The Alaska
Department of Fish and Game estimates that 50,000
to 60,000 cubic yards of gravel are backed up
behind the structure. During periods of high
flow, gravel movement throughout the stream scours
the lower creek channel decr.easing the survival of
pink salmon eggs.
The big dam does not block salmon migration.
Natural velocity barriers occur downstream.
However, if the dam collapses, a tremendous amount
of gravel would be released and it could take
several years for the creek to flush all the
gravel out of the system. Pink salmon eggs in the
lower end of the creek could be physically damaged
or buried limiting the adult returns in future
years until the lower end of the creek and the
expanded delta are eventually stabilized.
The spawning escapement in Humpback Creek during
1985 approximated 26,800 pink salmon.
Approximately 200 fish of this salmon return
utilized the area above the proposed power plant
and tailrace, and the portion of the Creek in
which they spawned would be partially dewatered by
this project. Since this project is based on
124
utilizing stream flows from zero to 85 cfs, the
spawning area utilized by these salmon would be
dewatered over a major portion of the year,
particularly during the critical winter months.
The habitat in this area has been classified as
marginal by the Alaska Department of Fish and
Game. During the winter of 1985-1986, Cordova
Electric Cooperative will test the gravel in the
spawning area above the power plant tailrace to
determine the winter survival of eggs and fry. If
there is no survival in this area, it will not be
necessary for Cordova Electric Cooperative to take
any mitigation measures for the dewatering of this
portion of the stream. If fry survival is found
in the area to be dewatered, then Cordova Electric
Coope~ative will make mitigation efforts
acceptable to the Alaska Department of Fish and
Game.
Cordova Electric Cooperative, the Alaska
Department of Fish and Game and the Prince William
Sound Aquaculture Corporation have met to discuss
possible range of mitigation efforts for the
salmon impact in Humpback Creek. Several areas of
mitigation were investigated including:
1) Stocking a barren stream in Prince William
Sound selected by the Alaska Department of
Fish and Game with pink salmon fry produced
by Prince William Sound Aquaculture
Corporation. This stream stocking would be
accomplished for two years (a complete
cycle of one odd year and one even year).
2) Stocking streams in Prince William Sound that
have an even/odd year return disparity. Many
125
streams in Prince William Sound have good
pink salmon returns on either the odd or even
years, but the other years have little or no
return. These streams have suitable habitat
as evidenced by the existing even or odd year
runs in these streams, but for unknown
reasons part of the run is missing. The
Alaska Department of Fish and Game would
identify two such streams, one having no odd
year returns and the other having no even
year returns. Cordova Electric Cooperative
would then contract with the Prince William
Sound Aquaculture Corporation to stock these
streams for two complete cycles for each
stream.
3) Performing a fisheries rehabilitation project
in the eastern Prince William Sound area.
This project could include such areas as
stream bank stabilization, stream diversion
work or other efforts to improve the habitat
for a specific area. Previous efforts by the
City of Cordova, while successful, have not
shown the expected level of habitat
improvement and salmon runs compared with the
funds invested.
4) Performing a fishery rehabilitation project
to install a silver salmon rearing area north
of the CEC power plant. The selected area is
approximately 7/10 of a mile from Cordova
Electric's source of heat and would require
an investment of over $300,000.00 for the hot
water system for the rearing area. This is
not considered to be an economical
alternative.
126
5) Sponsoring a silver salmon smolt imprinting
program in the Cordova small boat harbor to
improve the silver salmon return for the
Cordova Silver Salmon Derby. Cost estimates
for this by Prince William Sound Aquaculture
Corporation indicate a cost of approximately
ten times a pink salmon stocking project.
Costs for this program could range upward of
$50,000.00 per year over a four year period
and would not be economically feasible.
In discussions with the Alaska Department of Fish
and Game and the Prince William Sound Aquaculture
Corporation, Option II has tentatively been
identified as a feasible option. Budgetary
estimates of $5,000.00 per year for four years
have been established and are included in the cost
estimates.
Information on the occurrence of fish species in
Humpback Creek above the canyon area is not well
documented. The Alaska Department of Fish and
Game states that fish are probably absent.
Information provided by CH2M Hill indicates that
winter flows in Humpback Creek can get as low as
two cubic feet per second (cfs) and have been
known to cease. This makes the presence of a
resident fish population highly unlikely. On
June 6, 1980, biologists sampled upper Humpback
Creek with minnow traps and traditional sport
fishing gear. No fish were captured. The creek
was visually estimated to be flowing over 150 cfs.
Abundant stream bank cover and a favorable
pool-riffle ratio would make the upper stretch a
good Dolly Varden stream if the winter flows did
not disappear. Casual observations by biologists
127
during August 1985 did not observe any fish
presence above Dam #3.
C. MAMMAL RESOURCES
Game species present in Humpback Creek include
Sitka black-tailed deer, brown bear, black bear,
and mountain goat. Mountain goats are usually
found above the timberline inhabiting the most
rugged, inaccessible terrain. On June 6, 1980, no
goats were observed in Humpback Creek during a
brief helicopter flight although suitable habitat
is available. A 1980 Alaska Fish and Game
estimate stated that no more than 20 goats were
found in the Humpback Creek and Power Creek
drainages at anyone time. Goats use the ridges
overlooking Humpback Creek, but their distribution
varies greatly by season. For purposes of this
report, goat habitat in Humpback Creek is
considered to be above the 500 foot contour line.
Since the highest elevation used in this project
is just over 200 feet, no goat impact is
anticipated.
Black bear prefer forested habitat, but are
commonly seen foraging in open meadows, tidal
flats, brush fields, and alpine areas. Although
no black bear were seen during 1985 field
investigations, Humpback Creek contains excellent
bear habitat. Many bear signs can be seen in the
area. No critical denning habitat for black bear
has been identified in the Humpback Creek
drainage.
The Alaska Department of Fish and Game has
documented that the salmon spawning area on lower
Humpback Creek contains seasonal concentrations of
128
brown bear attracted by the readily available food
source. Clumps of brown bear hair were found in
the brush near the uppermost dam during field
investigations by the Alaska Department of Fish
and Game in 1980. Skeletal remains of pink salmon
were found scattered on the bank along the
spawning reach. Biologists assumed that the fish
remains were evidence of brown bear use during the
1979 spawning season. No critical denning habitat
has been identified for brown bear in Humpback
Creek by the Alaska Department of Fish and Game.
Their 1980 estimate stated that there were
probably six brown bear using the drainage.
Biologists encountered frequent evidence of Sitka
black-tailed deer while traversing the area from
above the canyon to the delta. Deer tracks were
present in the sand along the creek above the
canyon area and on the delta. Numerous tracks and
pellet groups were observed around small bogs in
the forest parallel to the creek. During the
winter, deep snows force deer down to the beach
fringe throughout Prince William Sound and when
populations are high, almost all these fringe
areas can become critical winter range. According
to the Alaska Department of Fish and Game,
mainland deer populations in Prince William Sound
are low and the eastern shore of Orca Inlet is not
considered to be an important winter range. Even
though direct documentation is lacking, there is
enough evidence of deer in the Humpback Creek area
to suggest that portions of the beach fringe on
the eastern shore of Orca Inlet, including the
Humpback Creek delta, may be winter range for a
few animals.
129
D. BIRDS
The Humpback Creek delta provides feeding and
nesting habitat for waterfowl and shorebirds.
During Alaska Department of Fish and Game's survey
in 1980, twenty Canada geese were observed on the
delta. Close investigation revealed that the
geese were feeding on forbs growing on the higher,
dry areas of the delta where permanent vegetation
has become established. There was no evidence of
goose nesting. Several species of shorebirds nest
on the delta although not in great numbers.
Species that were displaying protective behavior
indicating that they had nests nearby were: two
pair of spotted sandpipers, two pair of semi-
palmated plovers, and one pair of black oyster-
catchers. Other birds observed in the area were
glaucous-winged gulls, mew gulls, black-legged
kittiwakes, ravens, scoters, water pipits,
harlequins, northern bald eagles, and savannah
sparrows.
Northern bald eagles are frequent visitors all
along Orca Inlet. Undoubtedly they feed on
spawning salmon in Humpback Creek. During 1980
field investigations, biologists used a helicopter
to search the shores of Orca Inlet for several
miles in either direction from the mouth of
Humpback Creek and the lower five miles of
Humpback Creek looking for bald eagle nests. None
were located in spite of the fact that a dozen
adult birds were seen in the area. Since 1980,
several visits by the Alaska Department of Fish
and Game, Fish and Wildlife Service and Cordova
Electric Cooperative personnel as well as regular
fish count overflights have failed to locate any
eagle nests in the Humpback Creek drainage. 1985
130
reconnaissance along pipeline route, across
Trail #1 and power plant site did not note any
bald eagle nests.
E. MARINE BIOTA
Besides the abundance of seaweed, the intertidal
and subtidal habitats off the delta appear to be
productive in terms of marine organisms as well.
Profuse amounts of barnacles cover all the exposed
rocks and cobble. Mollusk shells windrowed by the
surf are abundant as are mussels, horse, butter
and littleneck clams, and cockles. In addition,
sea otters were observed feeding a short distance
offshore.
F. CONSIDERATION OF IMPACT OF CONSTRUCTION ON
HISTORICAL VALUES
The proposed hydro electric development will not
be near or have any impact on historical values of
the pelton wheel and generator, buildings, and the
pipe running down the hill from Humpback Creek to
the pelton wheel. The pipe on the east and west
banks of the Creek will be removed. The rings are
the property of the Eyak Corporation and will be
stored nearby for their eventual use. The
remaining pipe from Humpback Creek to the old
power plant is representative of the construction
used throughout the project and is available to
show the construction used in the areas removed.
By the installation of the pipeline for the
proposed hydro electric project, the historical
use of the pipeline right-of-way on the east and
west banks will be re-established. Rather than
using wood stave pipeline as the original hydro
project did, this project will utilize
polyethylene pipe.
131
There will be no impact on Dams #1 and #2. The
water level increase caused by the intake
structure to be proposed will not significantly
alter the level of water and will not have any
effect on Dams #1 and #2.
Dam #3 is representative of wood dam construction
throughout Alaska. the Alaska Department of
Natural Resources has provided a sample list of
similar dams throughout the State. This list is
included as Figure VII-I.
The major historical impact will be in the area of
Dam #3. The proposed pipeline must cross this
area to connect the intake structure with the
proposed power plant. A picture of Dam #3 is
included as Figure VII-2 showing the settling on
the dam, particularly on the right or west end.
In order to keep the level of the pipe below the
level of the intake structure, it will be
necessary to cross Dam #3 at an elevation lower
than the top of the dam on the right or east side.
There are three alternatives available to cross
this dam.
Option #1 would be to tunnel around the dam. This
tunnel would be constructed in the west abutment
and would start approximately 50 feet upstream
from the dam and would tunnel for a distance of
500 to 600 feet through the rock and emerge at the
west end of the cable crossing. If this approach
was utilized, it would not be necessary to disturb
the existing pipeline on the east bank nor would
it be necessary to cross the Creek on cables. An
estimated construction cost of $800.00 to
$1,000.00 per foot results in an estimated
132
construction cost of ~400,000.00 to $600,000.00
for this portion of the pipeline. There are
considerable questions as to the suitability of
the rock for tunnelling. It is possible that the
rock is badly fractured and would not be suitable
for tunnelling without the continued risk of
collapse which could remove support for the west
end of the dam and result in extensive damage to
the existing dam.
The second alternative would be to route the pipe
over the west or right (facing upstream) edge of
the dam. The elevation in this area is below the
intake structure and no structural changes would
be necessary in the dam. A cable would be
stretched from the west abutment across the face
of the dam down to the rock at the bottom of the
east side of the dam. The polyethylene pipes
would then be clamped to this cable. The cost of
this portion of the construction would be
approximately $150,000.00 to $250,000.00. While
this alternative has a minimal structural impact
on the dam, it would have a considerable visual
impact. Even if the pipeline was painted the
approximate color of the dam, there would be two
large pipes that cross the face of the dam and
would block the view of this dam. Figure VII-3
shows the relative size of the pipeline and the
dam.
The third alternative would be to route the
proposed pipe through the dam near the east
abutment three or four logs down from the top.
This would be accomplished by removing a six-foot
portion of one log to allow the pipe to come
through the dam. The cost of this option is
133
estimated to be $25,000.00. While this would
physically affect the structure, there would be a
minimal visual impact as shown in Figure VII-4.
Figures VII-5 through VII-7 show the method that
would be used to support the dam structure where
the log was removed.
It is recommended that the third option be
adopted, due to the minimal construction costs and
the minimal visual impact on the dam. It is
believed that with the pipe painted brown and
routed to the left edge of the dam, it would not
offer a significant impact to anyone desiring to
view the dam. To protect the historical values in
the area, a professional photographer will be
employed by CEC to record on film the current
condition of Dam #3 and the pipeline on the east
and west bank that will be removed. This
photographic history will also include photographs
of the pipeline to be left in place and the pelton
wheel, generator and buildings. Prior to
photographing the pelton wheel, generator and
buildings, brush will be removed and the area
generally cleaned up so that adequate pictures can
be obtained. The pictures thus taken along with a
narrative description of each picture will be
included in booklet form and copies will be
provided to the Eyak Corporation, the Cordova
Historical Society, Cordova Museum, the City of
Cordova, the State Historical Preservation
Officer, the Alaska State Museum and others
identified as desiring copies.
134
Figure VII-8 shows the portions of the old hydro
electric project and indicates those portions
which will be affected by the proposed hydro
electric development.
135
Figure VII-l
WOOD CRIB DAMS IN ALASKA SIMILAR TO
HUMPBACK CREEK
Provided by Department of Natural Resources
Crest Height Year
Dam Name Dam No. (Feet) (Feet) Constructed Notes
Humpback
Creek #3 1000048 110 47 1953(?)
Annex
Lakes Dam 1000003 190 25 1915 (Juneau)
In use for
hydro
production.
Bettinger A 1000022 251 36 1959 (Kodiak)
Drained for
repairs.
Pelican
Creek 1000038 153 22 1941 (Pelican)
In use for
hydro
production.
Bettinger B 1000040 245 32 1959 (Kodiak)
Drained.
Nugget
Creek 1000046 434 25 1916 Treadwell.
Figure VII-2
Figure VII -3
Figure VII-4
, >
.------. ----.--. -'
ii, .. .... ~ L-----------------1 r; ~=-~~--.--.-=-~~~------=--.. ---.. --.. -..... --==~
1'1---------1 -
'. -_._---------
""---STEEL BANDS
-
Le----32 ~/_--,'---32 :i'--I ~ 1----------------------
I~---CHANNEL
/--THR.U BOLT
~11,).~i(.·; ------..::-~ L------------I.-------!: J-'7 _______ ----
fl-• I-----------~-----I IJ
I 'f 1-------------J-" -.-'---... -
)
F~ONT VIEW Figure VII-S
DAM FACE CROSSI NG DE TAIL ~t=-------...l
~: Ii
·~~I,....~·---~~~~~-~~'--~ICO~DOVA ELECT~IC COOPER.AT I VE SCALE: (= 2/
\.II:: .... ~·rr HUMPBACKCf:\EEK HYDR,O P~OJECT DESIGNey: W.D.B.
EXISTING WOOD-CRIB DAM DRAWING BY: ~F.ruR.K
-------60 D ELBOW --", .....
I \
I \~ ____ ~~
\ I PO~TION
, I
'-_/
SIDEVIEW
SECTION 88
DAM FACE C~OSSI NG
Figure VII-6
CO~DOVA .ELECTRIC COOPE~ATIVE SCALE: (':: 21
HUMPBACK CREEK HYDJ30 PROJECT DESIGN BY: w.O.S,
EXISTING WOOD-CRIB DAM D~AWING BY: G.F.T:
.--------6'CHANNEL IRON
~-----8~X 1/4" TWO-PIECE STEEL I3ANOS
ARpUND EACH LOG
'---------3/4-NUT WITHIN CHANNEL
~
'---------~ TH F\U 130 L T
SIDE VIEW
SECTION AA
DAM C~OSSING SUPPO~T STR,UCTUR.E
Figure VII-7
CORDOVA ELECT81C COOPEJiATIVE SCALE: (= 2/
HUMPBACKCliEEK HYD~O Pf=(OJECT t-O-E-S-'G-N-B-Y-: -W-.O-.B-,--
EXISTING WOOD-C~IB DAM DJ?AWING BY.-GFI.
NEW DAM-~
~
OL D DA M -\----\----\--h.i_
~-CREEK CROSSING
~ --------~----~-------
150-------
) CORDOVA ELECTRIC COOPEqATI
HUMPE,:'CK r<, HYDRO PROJECT
DES!GN BY:
DRAWING BY, G,FTURI<
ORCA
INLET
Figure VII-8
~EVISION NO.
DATE E XP1.ANATIO N
.
'1,' I~
11
"
VIII. SUMMARY AND CONCLUSIONS
A. SUMMARY
This project has reviewed the feasibility of
constructing a hydro electric project on Humpback
Creek. Three areas were considered:
1. Technical
2. Financial
3. Environmental
4. Economic
Technical
There are no major technical problems involved in
the construction of Humpback Creek that could
prevent the project from proceeding. All of the
technology to be used is readily available, it is
not "exotic" and the construction methods proposed
have been used successfully in Cordova many times
over the past years.
Final engineering will optimize the design of the
project. We are confident that the design put
forth in this document will work and provide a
viable project. We believe that the system
proposed in this document can be improved upon.
Financial
The financial feasibility of this project is
assured as long as there is State participation.
A benefit-to-cost ratio above two was found for
the base case and a benefit-to-cost ratio above
one was seen for all cases. without State
financial participation, the project has a
benefit-to-cost ratio of exactly one, but the cost
of electric energy in Cordova in the early years
of the project rises significantly and thus the
136
project would not be acceptable to the members of
the Cooperative. The State equity investment in
this project is significantly less than the State
investment in other hydro electric projects around
Alaska. The direct savings in Power Cost
Equalization payments to Cordova far exceed the
State equity investment in the project, thus it
has a positive benefit-to-cost ratio for the State
of Alaska. The net present value of the benefits
to the State of Alaska for the State equity
investment is anticipated to be $2,100,000.00.
Compared with the State equity investment in this
project of $1.3 million, it shows a direct
benefit-to-cost ratio of 1.63 for the State of
Alaska. Thus it is anticipated that this project
will more than return the State investment through
lower future Power Cost Equalization payments.
Environmental
No major environmental concerns were identified
which could halt the project. Mitigation of
adverse environmental impacts may be required in
two areas. First, the project will be built in
the vicinity of an existing dam and an existing
pipeline for a historic hydro electric site which
was placed in operation in 1909. During the
design phase it was decided to minimize the visual
impact on the existing historical facilities.
Mitigation of the adverse effects on the
historical project is proposed. This mitigation
will consist of hiring a professional photographer
and creating a photographic history of the
pipeline and dam facilities including portions of
the old hydro project that will not be affected by
this proposed development. The location of the
existing dam and pipeline remnants is such that
137
they are not readily accessible to tourists or
other visitors who might wish to view them. The
photographic record combined with minimum visual
impact on the structure will provide more detailed
information to the people of Cordova on the old
hydro electric facility that was constructed
there.
During 1985, 26,800 pink salmon returned to
Humpback Creek to spawn. During reconnaissance
surveys in 1985 approximately 200 of these salmon
were observed in an area of the stream above the
tailrace which will be partially dewatered by this
project. The area used by these 200 fish is
classified as marginal habitat. During the winter
of 1985-1986, Cordova Electric Cooperative and the
Alaska Department of Fish and Game will test this
area for fry survival. If fry survival is found
in this area, Cordova Electric Cooperative, in
conjunction with the Alaska Department of Fish and
Game and Prince William Sound Aquaculture
Corpotation will undertake suitable mitigation
measures ~hrough a pink salmon restocking program
in other streams in Prince William Sound.
Economic
In determining the economic feasibility of the
project, the project is investigated on a
benefit-to-cost ratio without any subsidy.
Subsidies come in many forms. If it is assumed
that there will be no State participation in the
project, then the benefit-to-cost ratio is exactly
one. However, if the cost to the State of Alaska
through the PCE Program is included, then the
project has a positive benefit-to-cost ratio. For
the most part, this project was evaluated with a
138
State equity investment of $1.3 million. As
indicated under the financial comments, the State
will receive a benefit-to-cost ratio of 1.63 for
this investment. Therefore, it is not considered
to be a subsidy per se~ Under all scenarios with
State participation in the project (which we feel
is reasonable considering the future benefits to
the State), the benefit-to-cost ratio is above
one. In most of the alternatives it was above
two. Thus this project will provide significant
savings in the future to the State of Alaska and
the electric consumers of Cordova.
B. LICENSE CONSIDERATIONS
There are three avenues through which licensing of
this project can be obtained. First is the full
submission for a major licensed project, second is
a small project exemption and the third is a
determination of non-jurisdiction.
These three options each have their desirable and
undesirable qualities. The final decision on
which of these three alternatives to pursue will
be made based on the comments and concerns of the
agencies in reply to this document.
C. CONCLUSION
The Humpback Creek hydro electric project can
provide significantly reduced energy costs in
Cordova far into the future. This project by
itself does not solve all of the energy problems
in Cordova, but is a necessary step in the right
direction. It is feasible from all areas
evaluated and it is recommended that construction
of this project be undertaken as early as
possible.
139
APPENDIX A
PUBL1( DATA F1LE 85-46
STREAMFLO~ ESTIMATES FOR HUMPBACK CREEK, CORDOVA (C-5) QUADRANGLE, ALASKA
by Stan Carrick and William E. Long
Alaska Division of Geological & Geophysical Surveys
September 1985
THIS REPORT HAS NOT BEEN READ BY THE DIRECTOR,
HAS NOT RECEIVED OFFICIAL DGGS PUBLICATION STATUS,
AND SHOULD NOT BE QUOTED AS SUCH.
State of Alaska
Department of Natural Resources
Division of Geological and Geophysical Surveys
P.O. Box 772116
Eagle River, Alaska 99577
Weather records for the Cordova area (AEIDC, 1985) are available for two
stations, the Cordova airport, 10 mi southeast of town, and radio station
KLAM, downtown. The airport averages 90 in. of precipitation a year, with
September being the wettest month and January and June the driest months. In
Cordova, yearly precipitation is almost double and averages 170 in., with
October being the wettest month and June the driest month.
The Humpback Creek watershed should receive as much or more precipitation
as downtown Cordova because of orographic effects, but no site specific data
are available for the creek. However, runoff for Humpback Creek during the
water year 1975 was 152 in. (USGS, 1975), and this figure can be used to
back-calculate basin precipitation. Precipitation and streamflow were about
10 percent above normal for the 1975 ~vater year; therefore, "normal" runoff
might equal 137 in. a year. Add to runoff 20 in. of yearly evapotranspiration
for Cordova (Patric and Black, 1968) and another 20 in. of estimated ground
water, lake, and soil moisture losses, and that results in 177 in. of annual
precipitation for the Humpback Creek watershed. This later precipitation
estimate tends to confirm annual rain and snowfall amounts comparable with
downtown Cordova, not the airport.
RESULTS
DGGS performed four tasks for this study after discussions with APA and
Cordova Electric Cooperative staff. In addition, hydrologists Carrick and
Long visited Humpback Creek on August 19, 1985. inspected the facilities
sites, and took streamflow discharge measurements at three locations. The
four tasks and findings follow.
Humpback Creek Report - 2
Task 1: How representative is the discontinued USGS gaging station to
the proposed intake weir site?
The old USGS gage station is located 0.5 mi downstream of the intake
site, with a drainage basin area of 4.37 sq mi compared to 4.25 sq mi for the
intake site. A bedrock gorge consisting of metasedimentary and metamorphic
rocks separates the USGS station from the intake site. The bedrock, though
exhibiting tight crenulations and cleavage, does not appear highly fractured
or permeable.
The streambed ~t the intake site is made up of gravel and cobbles of
undetermined thickness deposited behind an old log crib dam. This bed
material is somewhat thicker than what normally might be the case because of
sediment trapping by the dam. Downstream at the USGS station, the bed is
composed of gravel, cobbles, some boulders, and bedrock.
Weather patterns at the two locations should be similar, if not the same,
and no significant tributaries exist between the intake and USGS sites.
The above evidence suggests that streamflow at the proposed intake site
and the USGS gaging station will be nearly the same. Some streamflow probably
moves through the gravels behind the log crib dam, but reappears as surface
flow immediately downstream of the structure. Discharge measurements taken on
two different occasions this summer showed flows at both sites within 1-5 cfs
of each other, i.e. discharges approximately equal considering allowable
measurement limits of error. It is our opinion that streamflow data from the
Humpback Creek Report - 3
~iscontinued USGS gage station are representativE of flow conditions at the
upstream intake weir site.
Task 2~ How indicative of Humpback Creek long term streamflow
conditions are the two years of USGS gaging records?
The USGS (1985) has gaging data for three other small basins in the
Cordova area: Power, Dick, and West Fork Olsen Bay Creeks. Streamflow in all
three creeks was at record low levels, averaging 35 percent below normal,
during water year 1974 (Oct. 73 -Sept. 74). The following water year 1975
(Oct. 74 -Sept. 75), streamflow was about typical, averaging 8 percent above
normal. Cordova precipitation during the same periods was 35 percent below
and 9 percent above normal, respectively. Based on the above information, we
Cin say that USGS gaging records for water year 1974 would not be indicative
of long term streamflow for Humpback Creek. But, area streamflow and
precipitation during water year 1975 are so close to normal that it would be
safe to conclude that USGS gaging data on Humpback Creek for the same year
could be indicative of long term conditions.
Pertinent streamflow data for Humpback Creek published by USGS (1975) for
water year 1975 is as follows:
Mean Annual Flow -48.9 cfs
Maximum Daily Flow -416 cfs
Peak Flow -638 cfs
Winter Minimum Daily Flow - 2 cfs
Summer Minimum Daily Flow -17 cfs
Mean Annual Runoff -152 in.
Humpback Creek Report - 4
If it is assumed that streamflow in Humpback Creek was, like the other
creeks, about 8 percent above normal for 1975, then an adjusted mean annual
flow would be 45 cfs. Breakup on the creek occurs in April, while freezeup
probably takes place in November or December. Power generation would
therefore be done from May to November when mean monthly flow would be
approximately 58 to 68 cfs based on the USGS records.
To complement and confirm the two years of published flow records, the
USDA Forest Service Water Resources Atlas (1979) was used to estimate
additional streamflow data. The Atlas provides numerous regression equations
for use in estimating streamflow characteristics for ungaged watersheds in the
Tongass and Chugach National Forests. Each equation contains easily obtained
precipitation and physiographic variables that are significant for the
particular streamflow characteristic. Each equation does have a certain amount
of error unique to the calculation. For instance, average annual and some
mean monthly flows have the lowest error, while low flow equations, especially
winter low flow, have considerably greater error.
Table 1 lists various calculated flow characteristics for Humpback Creek.
Because precipitation is one of the most significant variables used in the
equations, two different mean annual precipitation amounts were utilized to
account for any uncertainties in rain and snowfall estimations. The 140 in.
figure is derived from precipitation maps in the Atlas, and the 170 in. figure
is taken from previously described sources in the background section of this
report. Other variables used to make the flow calculations are as follows:
Basin area -4.25 sq mi (from the intake site upstream)
Proportion of basin above treeline -60 percent
Humpback Creek Report - 5
Proportion of basin in main channel lakes - 1 percent
Slope of main channel -146.8 ft/1000 ft
Mean elevation of basin -1237 ft
Miles south to Gulf of Alaska -12 mi
Task 3: Construct a monthly streamflow hydrograph and flow duration
curve to illustrate timing and magnitude of flows.
The U.S. Forest Service Water Resources Atlas and USGS gaging records
were used to derive the graphs. See figure 1 and 2. The total flow
represented by the hydrograph agrees with published records, though the timing
of the flows may not. In particular, June would typically have a higher flow
than July, and the flows in September and October would generally be higher
than depicted.
Task 4: Calculate monthly and annual energy projections using measured
and estimated flow figures.
The energy or power available is taken from the formula: Energy
(Kilowatt hours or KWH) = Discharge (cfs) X Head (ft) X Generation System
Efficiency X .0847 (Conversion Factor) X 24 hours. Table 2 gives the results
of the calculations using the following variables taken from Loeffler and
Denig-Chakroff (1985): Head = 175 ft, Efficiency = 80 %.
CONCLUSION
Inspection of USGS gaging records for Humpback Creek and other Cordova
area streams indicates that data from water year 1975 represents near normal
Humpback Creek Report - 6
streamflow conditions. We believe that mean annual flow for the creek falls
somewhere between 40 and 50 cfs, with discharge during the ice free generating
months of May -November averaging 58 -68 cfs. The energy projections given
in Table 2 are estim3tes that don't take into account the design limitations
of the turbine/penstock system. However, if we use a seven month average flow
of 58 cfs (a lower rate than the Water Resources Atlas estimates but
equivalent to the lowest USGS figures) then the iotal annual energy available
would be 3.53 million KWH, a conservative amount that, nonetheless, should not
render the project hydrologically unfeasible at this time . ..
REFERENCES CITED
AEIDC (Arctic Environmental Information and Data Center), 1985, Climate
Summaries for Cordova, Alaska: Personal Commun., 2 p.
Loeffler, B., and Denig-Chakroff, D., 1985, DRAFT: Humpback Creek
Reconnaissance Report: Alaska Power Authority, 21 p.
Patric, J., and Black, P., 1968, Potential evapotranspiration and climate in
Alaska by classification: PNW Forest and Range Experiment Station, USDA
Forest Service Research Paper PNW-71, p. 8.
USDA Forest Service, 1979, Water Resources Atlas for USDA Forest Service
Region X, Juneau, Alaska: prepared by Ott Water Engineers, Redding,
California, 7 p, ~ plus Appendix.
U.S. Geological Survey" ~jater Resources Data, Alaska, Water Years 1974,1975:
U.S. Geological Survey Water Data Report AK-74-1, AK-75-1.
U.S.G.S, 1985, Streamflow summaries for Power, Dick, and West Fork Olsen Bay
Creeks: computer printout from personal commun. with R.D. Lamke, U.S.
Geological Survey, Anchorage, Alaska.
Humpback Creek Report - 7
Table 1. Humpback Creek Flow Estimates. Based on U.S. Forest Service Water
Resources Atlas Regression Equations.
Mean Annual Flow
Mean JAN Flow
Mean FEB Flow
Mean MAR Flow
Mean APR Flow
Mean MAY Flow
Mean JUN Flow
Mean JUL Flow
Mean AUG Flow
Mean SEP Flow
Mean OCT Flow
Mean NOV Flow
Mean DEC F1 ow
MAY -NOV Mean
7 Day 10 Year Winter
Low Flow
7 Day 10 Year Summer
Low Flow
30 Day 10 Year Winter
Low Fl ow
30 Day 10 Year Summer
Low Flow
5 Year Peak Flow
10 Year Peak Flow
100 Year Peak Flow
Using 140 in.
mean annual PPT
( cfs)
38.2
7.6
4.9
6.9
13.9
87.4
61.6
88.9
54.8
53.8
54.1
32.8
12.4
61.9
1.2
3.6
1.0
10.9
850.5
1002.7
1496.0
Humpback Creek Report - 8
Using 170 in.
mean annual PPT
(cfs)
47.9
10.4
7.6
9.5
15.7
109.7
85.7
106.8
68.2
65.8
68.8
4.3.1
18.3
78.3
1.5
4.7
1.3
13.8
1129.3
1315.9
1892.2
Table 2. Humpback Creek Energy ProJ2ctions.
Using estimated discharges from Table 1.
Mean Annual Production
140 in. Mean Annual PPT
lrWH )
(based on mean annual flow) 3,968,066
JAN Production 67,050
FEB Production 39,046
MAR Production 60,874
APR Production 118,675
MAY Production 771,074
JUN Production 525,926
JUL Production 784,307
AUG Production 483,465
SEP Production 459,331
OCT Production 477 ,289
NOV Production 280,038
DEC Production 109,397
MAY-NOV Production
(based on monthly figures) 3,769,876
* * * * * *
Using USGS Gaging Records:
Mean Annual Production (based on 45 cfs mean
annua 1 fl ow)
MAY-NOV Production (based on 63 cfs average)
Humpback Creek Report - 9
170 in. Mean Annual
(KWH)
4,975,664
91,752
60,561
83,812
134,043
967,812
731,686
942,227
601,684
561,785
606,978
367,977
161,449
4,768,680
4,674,424 KWH
3,836,869 KWH
PPT
F-igure 1 M U N I Ii l... ~ I Ii L /\ ii I l U 'ti II Y U II U u I ( 1\ I 11
120-
110~----4_----~-----+----~----~~----+-----~-----+------~----+_----~-----+-4l
I' t~
I \ / \ 100 1---------II-----+----+------I---/+--4\r-,-+--/-#---+---L-,----1--__
I \ ,/ ,
90~----+------r-----+----~-----~~--~~~---r~~-+----~------+_----4_----~ :;~ W J\ \.
8 Ol-------+-----+------+-----+--------t-: ,-+t--/ +-\--+--j---+-----+---\-\----+-\--+--, ----+--+---+---_____+____
,'/ \( \ ~~ -~~ --\ 7 0
C/) -u
-6 0
~
0 -u..
5 0
____ Ihl~;r'rt on 14[J I fl.
ITI f~ n n ~l Il III 1;1 I Jl r f' (' I I' .
_IlQ~;pd (1111711 III.
m f' in 1 a II IllJ rl I p r (' (' I P •
i
!/ \ \ 40r-----+-----~----~-----+~IH/~~r-----+-----~----~----_4------~--~\-+~--~-~ :'. 30~----+_----~----~-----+~--~------+-----~----~----_4------~----~~ __ ~
;' \(',-
-""11-. ./ ...... ;: ~,
10~-----~~~~--~~~~-+----~r-----+_----~-----r----_;------r_----+_----~"
--.,-----4 ....... --:V--\
20
" \ \ ! I \ '\
\
.,,.
o~----~----~----~----~----~~----~----~----~----~------~----~----~
Jan Feb Mar Apr May Jun Jut Aug Sep Oct Nov Oec
Month
w
> a::
::>
0
Z en
0 -(.) .... -< ~ , 0
-~
0
?;
0
...J
~
.
N
CD ..
:l
01 .-
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10U
90
60
70
60
50
40
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u
0
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200
100
90
80
70
60
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40
30
20
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9
8
7
6
5
4
3
2
1
----~--- i _ J _______________
~ --"-" f----------------------- -------------------._--------------
--f-------------------------------
---r-----
i
Based on 1LJO 1 rl . ~ me arl annu&J prf'C'lp.
\ Based 170 In. ---on
\ mean annuaJ preclp.
~\
"" ~
"-\..
'\' ,,,
~ "
'" , .. """ , '" ""'" ,
~ "" ~' " " " ~ I"-, ,'\
~
\\
\,
\.
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\',
\
.,. " .. " o 1\ .. ,\t,
APPENDIX B
Gilkes Inc.,
P.o. Box 628,
Seabrook,
Texas 77586
October 21, 1985
Cordova Electric Co-op
P. O. Box 20
Cordova, Alaska 99574
Attention: Mr. Doug Bechtel,
General Manager
GPI 1109
GILKES
HUMPBACK CREEK HYDRO-ELECTRIC PROJECT
Dear Mr. Bechtel:
I refer to our letter of September 10 to Corry Hildenbrand of
Alaska Electric Light & Power and to our meeting at waterpower '85.
We have rerun the turbine outputs based on your latest penstock
data. Our 28" Twin Jet High Capacity Turgo Impulse Turbine would
have the following turbine output:
Flow Head Efficiency Power (Turbine)
(CFS) (FT) (%) BHP
5 174.9 68.7 68.3
10 174.8 78.8 156.
15 174.5 84. 250.
20 174.2 85.6 338.
25 173.8 86.4 426.
30 173.3 86.7 51lo
35 172.8 84.8 582.
40 172.2 85.5 668.
45 171.5 86. 753.
50 170.8 86.4 837.
55 170. 86.6 919.
60 169.1 86.5 995.
65 168.2 85.6 1061.
69.3 167.1 84.5 1110.
Analyzing the turbine performance against the Flow Duration
Curve shows the turbine is ideally sized. Using the conventional
rule of selecting a turbine based on the 25% exceedance equivalent
flow, confirms this observation.
Continued ..... .
Cordova Electric Co-op
Humpback Creek Project
Page Two
october 21, 1985
We tru~t this information will meet your immediate require-
ments.
Should you require any fUrther details to assist you with this
project, please do not hesitate to contact us.
YOu~~ very truly, 2 c?-
/ N1~/~.?/
a ond J. ~ngelly, /'
~ce Presr5ent ,
RJP/djb
APPENDIX C
UNITED STATES DEPARTMENT OF AGRICULTURE
Rural Electrification Administration
March 9, 1979
REVISION OF REA BULLETIN 61-10
SUBJECT: Powerline Contacts by Eagles and Other Large Birds
State and Federal agencies concerned with the protection of wildlife
have requested that REA and its borrowers cooperate in reducing the
loss of eagles and other large birds due to accidental electrocution
by powerlines.
Reports indicate that this problem exists primarily on distribution
lines in localized areas of the western and southwestern states.
However, it may exist to a lesser extent in other parts of the country.
Because of greater clearances, transmission lines apparently do not
present a significant threat to large birds.
Since the bald eagle is in danger of extinction and other large birds
may be in trouble also, we are asking you to cooperate to the fullest
extent with state and Federal agencies to minimize accidental electro-
cution of these birds. The attached bulletin discusses the causes of
electrocution on distribution lines of REA standard designs and offers
suggestions for modifying existing structures and constructing new
lines in areas where eagle electrocutions have occurred.
This bulletin has been revised to incorporate knowledge gained from
research performed since the issuance of the original bulletin.
Changes include revised interphase clearances.
This bulletin replaces REA Bulletin 61-10 dated March 1972, and its
supplements.
o~ .,j ~stan
Attachment
UNITED STATES DEPARTMENT OF AGRICULTURE
Rural Electrification Administration
REA BULLETIN 61-10
March 9, 1979
Supersedes 3/27/72
SUBJECT: Powerline Contacts by Eagles and Other Large Birds
I. Introduction: Power poles are often favorite perches for eagles
and other large birds of prey, such as herons and pelicans.
Occasionally, these birds are electrocuted by contact with the
wiring devices on distribution line poles. Such contact also
causes momentary or sustained outage of the power line. Both of
these incidents are undesirable and may be minimized by
relatively inexpensive modifications in distribution structure
design and devices by the power supplier. Transmission line
structures do not present a significant hazard to either small or
large birds because of their greater interconductor clearances.
II. The Problem: Powerline contacts by large raptors, such as eagles
and red-tailed hawks, in general, are limited to localized areas
where these birds hunt and nest. On any given system, it appears
that remedial modification to frequently used power poles, within
relatively short stretches of line, will greatly reduce the
incidence of electrocution. It is probable that linemen and other
operating personnel, after a short orientation, can readily identify
the poles potentially most hazardous to birds. State and Federal
wildlife authorities are available to conduct these orientations.
REA borrowers with distribution lines in areas inhabited or
frequented by bald and golden eagles are urged to patrol such lines
prior to and at the end of the winter migratory season for any
indications of past eagle electrocutions. Where dead birds are
found at the base of power poles, remedial measures should be taken
as described in this bulletin.
The Bald Eagle Protection Act as amended (76 Stat. 1246; 86 Stat.-
1064; 16 U.S.C. 668) provides that where a bald or golden eagle is
taken knowingly, or with wanton disregard for the Act, it is
punishable by both civil and criminal penalties. "Take" includes
the wounding, killing, molesting, or disturbing of one of the subject
eagles. The Act further prohibits the transport of either live or
dead bald or golden eagles. Consequently, any dead birds which are
found should not be moved from the site without the specific
authorization of the U. S. Fish and Wildlife Service or its designa-
ted representative.
Bulletin 61-10
Page 2
Managers of REA borrower systems with lines in areas frequented by
eagles should consult with their attorney for other provisions of
the Bald Eagle Protection Act. These systems should adopt an
operational procedure to deal with raptor problems and make sure
that all employees likely to find dead eagles or eagle eggs or
nests are fully informed of the contents of the Act.
III. Behavior of Large Birds of Prey: In general, predatory birds
select for perching those poles that give them the best view of the
habitat of their quarry. Therefore, the poles selected often are
the most elevated poles in areas heavily populated by ground
squirrels, other rodents, and game within reasonable flying distance
of the nest, or within the wintering habitat of the raptor. Reports
indicate that the birds are most likely to make contact between
energized parts and ground wire on transformer poles. However,
kills have occurred on single-phase and three-phase tangent poles
as well. Favorite perch poles can be specifically determined by
examining the area just below the pole for mutes or droppings of
the birds and for their castings. Since birds of prey cannot digest
the fur, feathers or bones of their quarry, they cast or disgorge
these in the form of a pellet called a casting. These castings are
as large as 1.5 inches in diameter and 5.0 inches in length.
IV. Suggested Remedial Measures: The illustrations and the text that
follow: (1) identify those details of standard construction that
seem to contribute to eagle electrocution; and (2) offer suggestions
for relatively inexpensive modifications which will make the various
structures less hazardous to large birds. Only the most commonly
used structures are discussed, but an understanding of how these
structures can cause electrocution and how they may be modified for
greater safety will permit similar corrections to other less
commonly used structures that may be involved in eagle electrocution.
In addition to the measures that follow, insulating extension links
may be adcied to primary deadends. This will allow safe perching at
the poletop or on the crossarm.
Shock
Ground
Wire
Figure I
---~-
'4--4" <Jap
" ~4 gap
Fi <Jure 2
Bulletin 61-10
page 3
Single-Phase Poles ~.;ri thout Equipment
This structure is potentially hazardous
to large birds only when the pole grou~d
wire is extended above the neutral as
shown in Figure 1. In such a case,
contact could be made simultaneously
between the phase conductor and pole
ground wire when the bird landed on
the poletop. Actually, the poletop
does not seem to be a geed perch because
of the obstruction of the phase con-
ductor. It is probable, therefore, that
relatively few electrocutions will be
experienced at these structures.
When electrocuted birds have been found
at the base of single-phase structures,
it is recanmended that the ground wire
be cut back to the neutral. If this
is not feasible because of lightning
considerations, the pole ground wire
above the neutral should be double
gapped as shown in Figure 2. A total
of 8 inches of clear wood is believed
to provide safety to large birds. On
guyed structures, an insulating link
may be used to isolate the upper portion
of the guy from ground.
Bulletin 61-10
Page 4
-'5"'i"'---
Covered
Jumper
Covered
Bushings
Figure 3
Fig ure 4
Shock
Hazard
Single-Phase Transformer Poles
On single-phase poles with trans-
formers or other equipment, raptors
may land on the grounded equipment
tank and contact energized parts such
as jumpers, open fuse links or bushing
terminals. (See Figure 3.)
Depending on the type of transformer,
it may be possible to cover all primary
and secondary energized parts with which
a bird is likely to make contact. The
use of bird guards, transformers with
internal fuses, isolated arresters, and
insulated conductors for primary jumpers
should provide effective protection.
(See Figure 4.) However, in some cases,
it may not be practical to cover all
energized parts.
Figure 5
Phase to Phase
Contact
Old C-I
.. -.
Old sin~I'-Q'm assemblies
Figure 6
Braces
Bulletin 61-10
Page 5
Where the nature of the equipment
installation is such that it is not
feasible to cover exposed energized
parts, a perch similar to the one
shown in Figure 5 could be installed.
The perch, made of two-2f~ sections
of treated 2" x 4" lumber or of used
3 5/8" x 4 5/B",crossarms, is mounted
on a vertical B ft. crossarm. Eagles
normally use such a perch in preference
to the equipment tank. Alternatively,
the transformer could be changed to a
self-protecting type which would
permit covering the primary energized
parts as in Figure 4.
TOP VIEW
Three-Phase Tangent Construction
Of all REA poles in common use, pre-
1962 REA standard construction is
potentially the most hazardous to
large birds because
o its crossarm construction is
particularly attractive as a
perch.
a its relatively flat construc-
tion permits phase-to-phase
contact as the bird approaches
the crossarm.
a the use of steel crossarm braces
in close proximity to the pole
ground wire facilitates phaSe-
to-ground contact.
Both of these types of contact are
illustrated in Figure 6.
Bulletin 61-10
Page 6
Old C-I
FiCJur. 7
60"
.. " p
Old C-I
FiQur. 8
wood braces
60"
Connector) "p"
Bird electrocutions may be
minimized on pre-1962 three-
phase structures by adding the
perch to the pole as shown in
Figure 5, or by changing the
steel braces to wood braces as shown
shown in Figure 7 and by cover-
ing the center phase for about
60 inches on either side of the
insulator as shown in Figure 8.
Any material used for covering
the conductor need provide for
only momentary contacts. However,
it should not have any seams,
cracks, or openings on its top or
sides through which a spark may
jump. Several manufacturers pro-
vide "tree guards" which seem
adequate for this purpose. The
guards may be restrained from
moving into the span by the use
of a connector or other obstruction.
Where feasible and ground clearances
permit, the crossarm may be lowered
so that the center line of the cross-
arm is 43 inches below the top of the
pole as shown in Figure 10 instead of
covering the center-phase conductor as
mentioned above.
New C-I
Figure 9
Proposed three -phase line
assembly for eagle areas.
Other New Construction
Bulletin 61-10
Page 7
Figure 9 shows the post-1962 REA
standard three-phase construction.
The use of wood braces and the lowered
crossarm should make this structure
relatively safe for large birds.
However, in the event electrocutions
are experienced, the center phase
should be covered as described in
the preceding paragraphs to avoid
phase-to-phase contacts, or the cross-
arm should be lowered even more as
shown in Figure 10 if ground clearances
permit.
New Three-Phase Construction
For new construction in areas frequented
by eagles and other large birds, it is
recommended that the crossarm and
neutral conductor be lowered as shown
in Figure 10. All other features of
standard construction including
positioning of the ground wire and the
use of wood crossarm braces should be
as shown in REA standard drawings. The
borrower should maintain ground clearances
as required by the National Electrical
Safety Code or local regulations, which-
ever is the more stringent.
Single-phase construction should be in accordanr.e with Figure 2.
Single-phase transformer installations should make use of transformers
which permit covering of energized parts and jumpers.
APPENDIX D
REA AIC No.
428
411. 7
Cordova Electric Cooperative, Inc.
, .
CORDOVA ELECTRIC COOPERATIVE PC 16 -OlD
Other Deductions Detail Schedule
Test Year 1984
Appendix 2, Schedule A, Page 3
Description
Amortization of Debt Discount
and Expense
Amortization of Loss from
Disposal of Utility Plant
Amount
$ 606.00
3,056.76
$3,662.76
08·H6LH
ALASKA PUBLIC UTILITIES COMMISSION
DEPARTMENT OF COMMERCE AND ECONOMIC DEVELOPMENT
May 31, 1985
In reply refer to:
Mr. W.O. Bechtel, General Manager
Cordova Electric Cooperative, Inc.
Cordova, Alaska 99574
Dear Mr. Bechtel:
File:
BILL SHEFFIELD, GOVERNOR
420 "L" STREET
SUITE 100
ANCHORAGE, ALASKA 99501
(907) 276-6222
Finance
PCE PC15.02D
As Meera Kohler was notified by telephone on May 28, 1985, the
Alaska Public Utilities Commission has approved a permanent Power
Cost Equalization level of 9.98 cents/KWH for Cordova Electric'
Cooperative, Inc. for bills rendered on or after May 25, 1985.
The Commission reminds Cordova of its continuing obligation under
the PCE legislation to provide its customers with the notice
specified in AS 44.83.162(k) or a similar notice approved by the
Alaska Power Authority.
Should you have any questions regarding the contents of this
letter, please feel free to contact Carolyn Evans of the Com-
mission Staff.
BY DIRECTION OF THE COMMISSION
Enclosure
Very truly yours,
ALASKA PUBL~C UTI~TIES COMMISSION
H. 7~/~~:~ .. ~
John B~ Far1eigh
Executive Director
APPENDIX E
DISTRIBUTION LIST FOR DRAFT FEASIBILITY REPORT
ON HUMPBACK CREEK HYDROELECTRIC PROJECT
Mr. Kurt Dzinich
Senior Advisor
Senate Advisory Council
Pouch V
Juneau, AK 99811
Mr. Corry V. Hildenbrand
Generation Engineer
Alaska Electric Light & Power
134 N. Franklin Street
Juneau, AK 99801
Mr. Kurt Nelson
Cordova District Ranger
U.S. Forest Service
P.O. Box 280
Cordova, AK 99574
Mr. Richard Randall
Alaska Dept. of Fish & Game
P.O. Box 669
Cordova, AK 99574
Mr. Luke Borer
Chief Executive Officer
Eyak corporation
P.O. Box 340
Cordova, AK 99574
Mr. Brent Petrie
Director of Project Evaluation
Alaska Power Authority
334 West 5th Avenue
Anchorage, AK 99501
Mr. Remy Williams
Alaska Power Authority
334 West 5th Avenue
Anchorage, AK 99501
Mr. Gary J. Prokosch
Dept. of Natural Resources
Div. of Land & Water Mgmt.
Pouch 7-005
Anchorage, AK 99510
Mr. Don McKay
Alaska Dept. of Fish & Game
Habitat Division
333 Raspberry Road
Anchorage, AK 99502
Appendix E
Mr. Brad Smith
National Marine Fisheries Svc.
701 C Street, Box 43
Anchorage, AK 99513
Mr .. Leonard P. Corin
U.S. Fish & Wildlife Service
Sunshine Plaza, Suite 2B
411 West 4th Avenue
Anchorage, AK 99501
Mr. Larry Wright
National Park Service
2525 Gambell
Anchorage, AK 99503
Ms. Patty Bielawski
Project Coordinator
Div. of Governmental Coord.
2600 Denali Street, Suite 700
Anchorage, AK 99503
Ms. Diana Rigg
Dept. of Natural Resources
Div. Parks & Recreation
Pouch 7001
Anchorage, AK 99510
Mr. Don Rice
Permits Section
U.S. Army Corps of Engineers
P.O. Box 898
Anchorage, AK 99506-0898
Mr. Dave Hutchens
Executive Director
A.R.E.C.A.
237 E. Fireweed Lane, suite 301
Anchorage, AK 99503
Mr. Bob Dryden
Dryden & LaRue
Consulting Engineers
P.O. Box 111008
Anchorage, AK 99511-1008
Mr. Alan Yost
REA Field Representative
13621 Venus Way
Anchorage, AK 99515
Mr. Martin Seipel, Director
Western States Division
R.E.A.--U.S.D.A.
Washington, D.C. 20250
Mr. Charles B. Gill, Governor
National Rural Utilities
Cooperative Finance Corp.
1115 30th Street, N.W.
Washington, D.C. 20007
Mr. George Turk
77 West First Street
Rexburg, ID 83440
Mr. Dalton DuLac, Supervisor
Chugach National Forest
U.S.D.A. Forest Service
201 E. 9th Avenue, Suite 206
Anchorage, AK 99501
Environmental Impact Review Off.
Environmental Protection Agency
Region X
1200 Sixth Avenue
Seattle, WA 98101
Regional Environmental Officer
Department of Interior
P.O. Box 120
Anchorage, AK 99510
Director
Bureau of Indian Affairs
Department of Interior
P.O. Box 3-8000
Juneau, AK 99802
State of Alaska
Dept. of Environmental Conserve
Div. of Water Programs
Pouch 0
Juneau, AK 99811
State of Alaska
Dept. of Natural Resources
Division of Parks
Pouch M
Juneau, AK 99811
Coastal Program Coordinator
Office of Coastal Management
Pouch AP
Juneau, AK 99801
Mr. Ronald O. Goqdrich, President
Cordova Electric Cooperative, Inc.
P.O. Box 2247
Cordova, AK 99574
Mr. Robert E. Cunningham, Vice President
Cordova Electric Cooperative, Inc.
P.O. Box 22
Cordova, AK 99574
Mr. John R. Wilson
Secretary/Treasurer
Cordova Electric Cooperative, Inc.
P.O. Box 813
Cordova, AK 99574
Mr. Scott Novak~ Director
Cordova Electric Cooperative, Inc.
P.O. Box 157
Cordova, AK 99574
Ms. Carly Kritchen, Director
Cordova Electric Cooperative, Inc.
P.O. Box 1255
Cordova, AK 99574
Mr. Ron Bowen, Director
Cordova Electric Cooperative, Inc.
P.O. Box 161
Cordova, AK 99574
Mr. Harry Curran, Director
Cordova Electric Cooperative, Inc.
P.O. Box 35
Cordova, AK 99574
Cordova Times
P.O. Box ~OO
Cordova, AK 99574
Mr. Rick Leland
City Manger
City of Cordova
P.O. Box 1210
Cordova, AK 99574
Mr. Roger Kemppel
Kemppel, Huffman & Ginder
Suite 200
225 E. Fireweed Lane
Anchorage, AK 99503
KLAM Radio Station
P.O. Box 60
Cordova, AK 99574
APPENDIX E
HUMPBACK CREEK FEASIBILITY STUDY
On each letter the paragraphs are numbered as necessary so
the response can be related to the specific paragraph.
DEPARTMENT OF FISH AND GAME
COMMERCIAL FISHERIES DIVISION
December 5, 1985
Mr. W. D. Bechtel, General Manager
Cordova Electric Cooperative, Inc.
P.O. Box 20
Cordova, Alaska 99574
Dear Doug,
BILL SHEFFIELD, GOVERNOR
P.O. BOX 669
CORDOVA, ALASKA 99574-0669
After reviewing the IIFisheries Resources ll section of the draft form of the
Humpback Creek Hydro Electric Project Feasibility Report I have the following
convnents:
I. The section does not put sufficient emphasis on upstream pink salmon
spawners, i.e. those fish that spawn above the twelve (12) foot high
tide mark (A 12 foot high tide represents the average high tide in
Prince William Sound). This upstream spawning is especially important
in the odd-year cycle when, on the average, 50% of the spawners utilize
spawning gravels above the average high tide level (Even year cycles
average 25% upstream spawners).
The point of all of the above is that a major spawning riffle exists
next to the proposed hydro 5 ite. As 5 uch a 11 necessary efforts mus t
be made to ensure year round waterflow be made available to this
spawning area.
II. The proposed mitigation efforts for the 200 fish observed above the
aforementioned spawning riffle sound sufficient.
II I. Proposed Hydro Site outfa"1 1 (Reference Fi gures V-26 and V-27) --
The gabion structure regulating the ultimate return of outfall water
to the streambed should extend far enough upstream so as to ensure:
1) A 11 of the spawn; ng r'i ffl e) 1 oca ted next to and ups tream of the
proposed hydro site, recei Vt the total amount of outfall water.
w. D. Bechtel -2-December 5. 1985
Judging from the three (3) foot elevation differential between the
top of the tailrace and stream level (Fig. V-26) and the streamside
elevations shown on Figure V-27 this should be easily accomplished.
5i ncerel;,. (1fM~mc4
Michael L. McCurdy
Research Project Leader
Paragraph #1
LETTER FROM MIKE McCURDY
ALASKA DEPARTf1ENT OF FISH & GAME
DATED DECEMBER 5, 1985
The area from the power plant upstream has very
and large boulders. This is a non-tidal area.
of concerns about the maintenance of year round
steep sides
We are aWare
water flows
to the spawning area. During our preliminary
investigations, the problem of water freezing within the
tailrace was uncovered. We feel that it will not be
possible to make the intake structure completely water
tight; there will always be a certain amount of seepage
around the intake structure. During low flow periods, such
as the winter, it is possible that all of the water in the
stream will leak around the intake structure. We have also
called for the insta~lation of a six inch (6") insulated
pipe from the power plant directly into Humpback Creek.
This six inch (6") pipe will be buried at a depth so that it
will not freeze and will be provided to ensure winter flows
in the event that the tailrace freezes.
We are aware of salmon spawning above the high water area.
All potential spawn~ng areas will be protected whether above
the mean high water mark or not.
Paragraph #2
The tailrace structure will be designed to extend as far
upstream as practical. The stream bed rises very rapidly in
this area and it will be necessary to do a stream bed survey
to determine how far upstream the tailrace can extend.
Extending the tailrace also provides an additional energy
absorbing mechanism to reduce any potential scouring from
the project. We will submit the design of the proposed
tailrace structure to the Alaska Department of Fish and Game
for their review prior to finalizing it. We will continue
our dialogue with the Alaska Department of Fish and Game and
others interested in the fisheries aspect of this project.
The pink salmon return to Humpback Creek is the major
concern of the entire project.
United States Department of the Interior
IN REPL V REFER TO:
WAES
Western Alaska Ecological Services
Sunshine Plaza, Suite 2B
411 W. 4th Ave.
Anchorage, Alaska 99501
W. D. Bechtel» General Manager
Cordova Electric Cooperative, Inc.
P.O. Box 20
11 DEC f985
Cordova, Alaska 99574
Dear Mr. Bechtel:
Re: Humpback Creek Hydroelectric Project
Draft Feasibility Report.
FERC 118889
The U.S. Fish and Wildlife Service (FWS) has reviewed the subject report
dated November 1985. The proposed project would be an 850 kW facility
utilizing run-of-the-river flows in Humpback Creek, near Cordova, Alaska.
We found that the draft report adequately describes the proposal. If the
project is constructed in the manner described, and with the mitigation
proposed, adverse environmental impacts will be minimized to an acceptable
level. The following comments are provided to facilitate your project
planning.
Specific Comments
Page 107, first paragraph: We strongly recommend that work not be initiated
prior to receipt of any necessary license and/or permits, and appropriation
of sufficient funding. Although the proposed early clearing would result in
only minor terrestrial impacts, without full assurance that the project will
be constructed, even these impacts are unnecessary.
Page 108, first paragraph: Although this stream reach does not provide
salmon spawning habitat, disposal of rock and decomposing wood here would
not be desirable. High flows would result in this material moving
downstream, and thus into salmon spawning habitat. We recommend that no
disposal occur in Humpback Creek.
Page 117, first paragraph: Please provide this office with the preliminary
plans for the tailrace and energy absorbing structure. When the final
design plans are available, we would appreciate receiving them for review.
Page 118, paragraph 3: It is stated that gravel would not be removed from
Humpback Creek. The last sentence, however, refers to gravel removal
methods from streams. Please clarify where and how gravel would be obtained.
®
®
Page 121, first paragraph: The FWS developed a film on bear safety for the
Terror Lake Hydroelectric Project. This film is available in a video
cassette through the FWS Office of Public Affairs in Anchorage. For
additional information you may contact Bob Olendorff, the FWS Audio/Video
Production Officer~ at (907) 786-3309.
Pages 122 through 131: We recommend the addition of a section specifically
~ddressing threatened or endangered species. The presence or absence of
listed or proposed threatened or endangered species under the jurisdiction
of the FWS and the National Marine Fisheries Service should be discussed.
Historical and current harvest levels, in addition to subsistence use data,
should be discussed in this portion of the report.
Page 125, first paragraph: Please provide this office with the results of
the salmon eggs and fry winter survival study.
Page 127, second paragraph: The FWS concurs with the mitigation option
selected.
Page 138, second paragraph: Although the proposed mitigation is closely
tied to the project's potential adverse impacts to pink salmon, the FWS has
considered it as sufficient to mitigate for both in-kind adverse impacts (to
pink salmon) and out-of-kind adverse impacts (to terrestrial resources). As
such, we recommend that the mitigation proposed be pursued,irregardless of
the results of the winter survival study. If the current study shows no
winter survival, then the scope of the proposed mitigation could be reduced.
Summary Comments
Assuming that our specific comments will be adequately addressed in the
final feasibility report and that the proposed mitigation will be adopted as
a project feature, the FWS, in consideration of the area's fish and wildlife
resources, finds the proposed project to be environmentally sound. If you
wish to discuss these comments, please contact Leonard Corin of this field
office (271-4575).
Sincerely,
Field Supervisor
cc: FERC, Washington D.C.
ADF&G, ADEC, NMFS, NPS, EPA, Anchorage, Alaska
Paragraph #1
LETTER FROM ROBERT BOWKE
U.S. DEPARTMENT OF THE INTERIOR
DATED DECEMBER 11, 1985
We agree with the recommendation that right-of-way clearings
not begin until the project is assured. In addition to the
cost of clearing this area, there will be the significant
cost of restoration should the project not go forward.
Paragraph #2
We have reviewed means of keeping rock and wood from the
stream bed. This can be minimized, but it will not be
possible to totally prevent all rock and decomposing wood
from entering the stream. We will take efforts to minimize
the amount of rock disposed of in the creek bed, but there
are areas, particularly on the east abutment, where the only
alternative would be to remove the rock by helicopter which
would be prohibitively expensive. We are aware of the
concerns of the Department of the Interior in this area and
will keep this in mind during design and construction of the
project.
Paragraph #3
We will provide the Department of the Interior with the
design for the tailrace and energy absorbing structure for
review prior to being finalized.
paragraph #4
The study has been revised to make it clear that no gravel
will be removed from Humpback Creek. As indicated on the
drawings, a borrow bed will be established away from the
stream bed in an area agreeable with Chugach Alaska
Corporation, The Eyak Corporation, Alaska Department of Fish
& Game and Cordova Electric Cooperative.
Paragraph #5
Cordova Electric cooperative will make use of the film on
bear safety developed by the Fish and Wildlife Service.
Paragraph #6
As indicated in the study, much of the information on
wildlife resources in the area was taken from work done by
the Fish and Wildlife Service in 1980. At that time the
Fish and Wildlife Service indicated that there were no
endangered species in the area. This area has since been
visited by numerous biologists and no indication of any
change from the 1980 findings of the Fish and wildlife
Service were observed. Unless there is some reason to
believe that the habitat patterns of endangered species have
changed since 1980, we believe that the study has adequately
addressed the issue of threatened or endangered species.
Letter from Robert Bowke
Department of the Interior (Continued)
paragraph #7
Specific harvest data is not available for Humpback Creek.
Discussions with the Alaska Department of Fish and Game
indicate light sport and subsistence use of this area.
Commercial fishing is not allowed within several miles of
Humpback Creek. It is estimated that the Prince William
Sound commercial fishery catch is 70 percent of the Humpback
Creek return.
Paragraph #8
The Department of the Interior will be furnished a copy of
the salmon egg and winter fry survival study to be
accomplished this winter.
Paragraph #9
The winter salmon egg and fry survival study will take into
account the weather conditions which may have an effect on
the current year which would not normally be found. A
review of the salmon escapement for Humpback Creek indicates
that there are occasional winters that are so severe that
very little fry survival is evidenced. It then takes a
number of years for the return to build back up to full
strength. When the winter fry survival study is
accomplished this winter, unique weather conditions will be
considered prior to deciding what mitigation measures are
required for this project.
STREAMFLOW ESTIMATES FOR HUMPBACK CREEK. CORDOVA (C-5) QUADRANGLE, ALASKA
A Report Submitted to the Alaska Power Authority
by
The State of Alaska Department of Natural Resources
Division of Geological and Geophysical Surveys (DGGS)
Water Resources Section
September 25, 1985
INTRODUCTION
Humpback Creek, a small stream five miles northeast of Cordova, Alaska,
is being considered for a run-of-river hydroelectric project by the Cordova
Electric Cooperative, Inc. and the Alaska Power Authority (APA). The Water
Resources Section of DGGS was contracted by APA to analyze and estimate
streamflow conditions for Humpback Creek; this information will be used to
evaluate the hydrologic feasibility of the project and to aid in future SY$tem
planning and design.
BACKGROUND
Humpback Creek flows four miles on a generally westward course to Orca
Inlet northeast of Cordova. The drainage basin encompasses approximately 4.4
S4 mi, with a basin high elevation of nearly 3500 ft and a low elevation at
sea level. Two small snowfields are located in the basin along with two small
lakes.
The U.S. Geological Survey gaged the creek 800 ft upstream of the mouth
from October 1973 to September 1975 (U.S.G.S., 1974-75). These two years of
record are the only published discharge data available, and are not
necessarily indicative of long-term flow conditions.
DEPART~IENT OF NATURAl, RESOURCES
DIVISION OF PARKS AND OUTDOOR RECREATION
December 13, 1985
Re: 1130-13
Subject: Feasibility Report: Humpback Creek
W.D. Bechtel
General Manager
CEC
P.O. Box 20
Cordova, A I aska '99574
Dear Mr. Bechtel:
BiLL SHEFFIELD, GOVERNOR
225A CORDOVA STREET
ANCHORAGE, ALASKA 99501
PHONE: (907) 276·2653
MAILING ADDRESS:
POUCH 7001
ANCHORAGE, ALASKA 99510
Thank you for the subject report. You have put a lot of thought into consider-
ation of the historic remains in the project area and we appreciate the work
you have do,,~,
However, determining whether something is significant and if there is to be an
effect is a formal process set up in 36 CFR 800 that involves consultation
between the agency (or its representative), this office, and the Advisory
Council on Historic Preservation (ACHP). It is called the Section 106
process. In this case, the agency is FERC and CEC is its representative. As
the representative, you must determine whether the resources are significant
and under which criteria they are important (National Register criteria are
enclosed). This information is submitted for our review and concurrance. If
it is determined that the resource is el igible for the National Register, we
then consult to determine the project1s effect.
This part of the process involves you, as FERC's representative, deciding how
the project wil I affect the resource and determining mitigation measures to
alleviate those affects. This office reviews that decision, and if we concur,
the whole package is sent to the ACHP for their review and concurrance.
The information you supplied in the feasibi I ity report goes a long way towards
the consultation process. It was also our understanding that the Chugach
National Forest archaeologist, John Mattson was going to do part of the
determination of el igibil ity. Perhaps we should meet with Dr. Mattson some-
time this winter when you have an opportunity to be in Anchorage to discuss
this Section 106 process. As we said, much of the information you have is
appl icable to the process, it simply needs to be reworked and eventually
submitted to the ACHP for their review.
December 16, 1985
Page 2
If you have any questions or would I ike to set up a meeting, please contact
Diana Rigg at 762-4139.
Sincerely,
Neil C. Johannsen
Director
Judith E. Bittner
State Historic Preservation Officer
cc: John Mattson, CNF
Larry Wright, NPS
enclosure
DR:tls
I. Criteria of Evaluation
Th. quality of .ignificance in AMerican
hi.tory. architecture. archaeology. and
culture i. present in di.trict ••• ite ••
building ••• tructure •• and object. that
po •• e •• integrity of location. de.ign •
• etting. mat.rial •• workman.hip. f.eling.
and a •• ociation. and:
A. th.t .re a •• ociated with event. that
have m.d. a .ignific.nt contribution
to the bro.d pattern. of our history: or
8. th.t are a •• ociated with the live. of
per.on •• ignific.nt in our p •• t: or
C. that embody the di~tinctive char.c-
teri.tic. of a type. period. or ~ethod
of con.truction. or th.t repre.ent the
verk of a ma.t.r. or that po ••••• high
.rti.tic valu ••• or th.t repre.ent a
.ignificant and di.tingui.habl. entity
who •• compon.nt. m.y lack individual
di.tinction, or
D. ~nat hav. yi.lded. or may b. likely to
yi.ld. information important in pre-
hi.tory or hi. tory.
II. Crit.ri. Con.ideration.
ordinarily c.met.ri ••• birthplac ••• or grav ••
of hi.tor cal figure •• prop.rti •• owned by
r.ligiou. in.titution. or u •• d tor religious
purpo ••••• tructur •• th.t h.ve been moved from
th.ir origin.l location •• r.con.tructed hi.-
toric building •• properti •• prim.rily commem-
or.tiv. in natur.. and prop.rti •• that have
achi.ved .ignific.nc. within the pa.t fifty
y.ar •• hall not b. con.ider.d .ligibl. for the
NATIONAL REGISTER. Hov.v.r •• uch properti ••
will qualify it th.y ar. int.gral part. of
di.trict. th.t do ~ •• t the criteria or if they
fall within the following categorie.:
A. a religou. property deriving primary
.ignificanc. from archit.ctur.l Or
arti.tic dietinction Or hietoric.l
illlportanc., Or
•• • building or .tructure removed from
it. original loc.tion but which i •
• ignific.nt primarily for architectural
valu •• or which i. the .urviving .truc-
tur. mo.t importantly a •• ociat.d with
a hi.toric per.on Or ev.nt: ~.
C. • birthpl.ce Or grav. of a hi.torical
figure of out.tanding importance if
th.r. i. no appropri.te .it. or building
dir.ctly a •• ociated with hi. productiv.
lU., Or
D. a cem.tery which derive. it. primary
.ignificance fro/ll grav •• of p.r.on.
of tranacend.nt importanc •• from ag.,
fro. di.tinctive d •• ign f.atur •• , or
fro. a •• ociatioft vit~ hi.toric event., or
E. • r.con.tructed building when .ccurately
.xecut.d in a .uitable environm.nt and
pre.ented in a dignified manner a. p.rt
of a r •• toration ma.ter plan. and when
no oth.r building or .tructur. with the
.am. a •• ociation has .urvived, or
F. a property primarily commemorative in
intent if de.ign. ag •• tradition. or
.ymbolic value ha. inve.ted it wi~h it.
own hi.torical .ignificanc., or
G. a property achi.ving .ignificanc. within
the pa.t fifty year. if it i. of .xc.ption-
al importance.
LETTER FROM JUDITH E. BITTNER
DEPARTMENT OF NATURAL RESOURCES
DIVISION OF PARKS
DATED DECEMBER 13, 1985
We have met twice with representatives of the State
Historical Preservation Officer on this project. As can be
inferred from the effort expended on the historical portion
of this report, Cordova Electric Cooperative is particularly
interested and concerned about the historical values of the
old facilities. Of particular question is the suitability
of the existing dam Humpback Creek #3 for inclusion in thE.;
National Register of Historical Places or other appropri.3'.
national register. The Eyak Corporation has not granted
permission for us to visit the site with an archeologist or
historian. For the purpose of this study, we have assumed
that the existing dam is eligible for inclusion in the
National Register. Mitigation efforts proposed were based
on this assumption.
Cordova Electric Cooperative is well aware of the historical
values in the area and will take suitable efforts to
minimize any adverse effect on these resources. Cordova
Electric Cooeprative has relied on the survey done by r0~~
Reger of the U. S. Forest Service which has been included .,
the study. This survey done by Mr. Reger is in the exact
area where the power plant would be located. This is
exactly the same area proposed by Alaska Department of Fish
and Game for a fish hatchery. If any artifacts are revealed
during construction, construction in the area will be
immediately halted until the value of the artifacts can be
determined and a mutually agreeable approach taken to
preserve the archeological values in the area.
United States Department of the Interior
NATIONAL PARK SERVICE
IN REPLY REFER TO:
L7427 (ARO-ONR)
ALASKA REGIONAL OFFICE
2525 GJmbel1 Street, Room 107
Anchorage, Alaski1 99503 -2892
Mr. W.D. Bechtel, General Manager
Cordova Electric Cooperative, Inc.
P.O. Box 20
Cordova, Alaska 99504
Dear Mr. Bechtel:
1 6 DEC 1985
As you have requested, we have reviewed the proposed Humpback Creek Hydroelectric
Project Draft Preliminary Feasibility Report. We have the following carment.
Cultural resources impacts are discussed, however there is no evidence of
coordination with the state Historic preservation Officer (SHPO). Since we
understand the project has received direction from the SHPO, the report should
document the coordination and identify whether the proposed mitigative action is
in accord with the SHPO's recammendations.
Let us know if we can be of further assistance.
Sincerely,
$tt~
Acting Regiona: ;i~ec~rr
cc:
State Historic Preservation Officer
LETTER FROM M. V. FINLEY
U.S. DEPARTMENT OF THE INTERIOR
NATIONAL PARK SERVICE
DATED DECEMBER 16, 1985
This letter, as the previous letter, indicates concern over
the historical values in the area. Representatives of the
State Historical Preservation Office have been invited to
all meetings and presentations organized by Cordova Electric
Cooperative but have not been able to attend. On two
occasions they have been invited to visit the site, but were
unable to attend. We have met twice with them separately to
review their concerns on this project. We have visited the
site with an archeologist from the U.S. Forest Service. See
comments to prior letter for a full discuss'ion of the
historical aspects of this project.
STATE OF ALASKA
Division of Commercial Fisheries
Mr. Doug Bechtel, General Manager
Cordova Electrical Cooperative
P.O. Box 20
Cordova, Alaska 99574
Dear Doug:
December 19,1985
Thank you foc the opportunity to comment on the Feasibility Report for
the proposed Humpback Creek hydroelectric project. Since we have had
prior discussions with you relative to this project and members of our
Cordova staff have participated in field trips to the proposed site I
think your feasibility report incorporates most of our concerns over
potential impacts on the fisheries resources in the area.
To further assist you in refining your feasibility analysis for this
project we have made a few comments directly on your review draft
(attached). Although the specific construction guidelines and any
possible mitigation measures would have to be worked out through the
formal permit process I wanted to identify a few of the likely timing
and construction constraints that we would eventually need to address
and will hopefully be of assistance to you in developing work
schedules. Of primary concern relative to fish is the possible loss
of productive spawning area upstream of the tailrace along with the
potential impact as a result of instream crossings, bridge
construction, powerline construction, trails, etc. Until we are able
to fUrther evaluate the potential survival of pink salmon fry in that
portion of the stream dewatered by diverting the creek it will not be
possible to recommend reasonable mitigation measures, if any, related
to this loss. We have tentatively identified a potential loss of 200
pink salmon spawners and if a real loss can be verified by the
presence oflive fry In this stretch of the stream, the most reasonable
mitigation may simply involve a two year program of releasing pink
salmon fry at another barren stream. With respect to any stream
crossings, bridge construction, blasting or other activity that could
directly or indirectly impact spawning fish or live eggs, the best
time window for this would be during the May-June period with some
flexibility in either direction depending on the observed timing of
the ['un.
It didn't
impact on
specify the likely size of any powder
eggs and fish would need to at least be
charges but
identified.
t hi s
Any
(i)
close blasting would again ha~e the least possible impact during the
May and June window during which most of the fry have outmigrated and
the adults would not normally be present in the stream.
Although there is no reservoir construction or any significant
impoundment of water in this type of run of river hydro project, is
there any likelihood of a significant change in water temperature as
a result of the trip through the penstock and the plant? This isn't
mentioned anyplace in the report and I would be interested in any
information that may be available from evaluation of similar run of
river proJects at other sites.
I also notice that the upper' section of the penstock is to be
supported by a portion of the creek t ha t has been built up by gra ve 1
deposited above one of the older' log crib dams. Since this design
depends somewhat on the long term stability of tt)is dam have the
engineers evaluated the i ntegr'i ty of t hi s structure?
I also
some of
didn" t notice any reference to a likely need for gravel for
the road and pad construction. If there is any need for local
gr'avel has a potential SOUt'Cf> been identified?
Most other comments relative to the fisheries resources have been made
directly on your draft copy but the local area game biologist, Herman
Griese, had the following comments relative to mammal and bird
resour'ces:
C. Hammal RtlSOUt'Ces
A September 1985 goat survey revealed 20 goats proximate to Humpback
Cr'eek and Powee Creek. There is a high likelihood that up to 30 goats
may now b,~ using Humpback Cr'eek during the year. F'acilities and
construction activities outlined in the report are unlikely to affect
the goats; however improved access to the Humpback drainage to huntet's
may reduce that number or displace them periodically during fall or
winter.
Facilities described in the report indicate personnel will reside at
the site, Because brown and black bear will continue to use the salmon
spawning in the ceeek, interaction between man and bears is
inevitable. Every precaution should be taken to reduce conflicts,
Those precautions include 1) fencing work areas to keep bears out, 2)
not having on site garbage storage and 3) continually removing brush
near work areas \ 30-S0 meter's) to allow high visibility of bears.
D, Birds
Corr'ect "new" gull to mew gull.
Bald eagles, gt'eat blue her-ons, gulls, ravens and Ct'OWS are the large
blC'ds likely to be attracted t.o Humpback Creek salmon. Many of these
bil'd~; will land on man rnadp st.t'uctures not ldentified in REA Bulletin
6 1 -1 I) . The d e ~; 1 9 n 0 [' t ran s m i s ~ ion t. 0 w e r s ~'\ tl d s tat ion fix t u t' e s s h 0 u 1 d
reducp possibIlitIes of ele~trocution, Chugach Electric in Anchorage
lIla.y be (1\)1,) t.o i.dent.lf:," de::::lqns that have allo~H~d electrocution of
[. a veil t: d n d it" sub s f"~ IJ e n t. I. 0 5 S 0 f ~:; e t' \' 1 C e .
If you have furt.her questions nl' h;:lv~ new lnformation to pass
please contact our office.
Sincerely,
Jb ~~ ~d Randall
Area Flsheries Blologist
co: Gary Liepitz, Habitat DIvision, Anchorage
attachment
along
Paragraph #1
LETTER FROM RICHARD RANDALL
ALASKA DEPARTMENT OF FISH & GAME
DATED DECEMBER 19, 1985
The attached comments were incorporated within the study,
they are not included in this Appendix. We have agreed to
limit our instream activities to the months of May and June
as permitted by the Department of Fish and Game when
construction actually begins. It is possible that due to
weather variations this period may be expanded or
contracted.
Paragraph #2
Until final decisions are undertaken, the size
of any blasting charges cannot be determined.
of Fish and Game's concerns on blasting and we
coordinate any blasting activities with them.
amount of blasting will be very minor and will
the area behind the powerplant building, which
very light charges.
Paragraph #3
and placement
We are aware
will
Hopefully the
be limited to
would entail
During the summer months temperature change in the water in
the pipeline will be insignificant. The velocity of the
water in the pipeline is such that the water will not be
exposed to the warmer outside air for a long period of time.
Any temperature increase would be further diluted when the
water is put back into the stream where it will mix with a
large quantity of water that has not been through the
pipeline.
During the winter there will be a slight cooling of the
water, however, the temperatures in Cordova are such that
there will not be a significant temperature differential
between the water and air temperatures. There is concern
that water may be flowing in the Creek that is supercooled,
that is temperature below 32 degrees Fahrenheit. This water
does not freeze since it is moving but a reduced velocity
can cause a rapid freezing. This problem is addressed by a
six inch pipe that will be heated to ensure that the water
temperature remains above the freezing point for re-entry to
the stream.
Maximum temperature change from the project would be in the
neighborhood of one to two degrees which should not affect
salmon fry development.
Letter from Richard Randall
Dated Decenber 19, 1985 (Continued)
Paragraph #4
The log crib dam has been reviewed by several engineers and
all agree that the amount of gravel built up behind the dam
is a concern. The concensus of the engineers is that it
will not fail catastrophically but will continue to sag in
the future. It has been pointed out that by transporting a
portion of the water around the dam, hydraulic pressures on
the dam will be reduced and may serve to extend the life of
the dam.
Paragraph #5
There are no plans for any personnel to reside at the site,
other than on an emergency basis. We agree with the
precautions recommended. As indicated in comments to a
prior letter, we will be using the film developed for the
Terror Lake Hydro Project concerning bear safety.
Paragraph #6
We will work with Chugach Electric Association during final
design to identify designs to minimize electrocution hazards
for large birds. We consider this to be a relatively minor
problem since it can be addressed at the time of design of
the fixtures.
Advisory Council Members
Senator Bennett, Chairman
Senator Kerttula
Senator Abood
Senator Sackett
•""' .. :, ..
.... " . Pouch V
State capitol
Juneau. Alaska 99811
Phone; (907) 465-3114
SENATE ADVISORY COUNCn
~J. D. Bechtel
Genera 1 ~1anager
December 23, 1985
Cordova Electric Cooperative, Inc.
P.O. Box 20
Cordova, AK 99574
Dear Doug,
In response to your letter of November 26, 1985, I have had a chance
to review your draft Prel iminary Feasibil ity Reporton tbe Humpback Creek
hydroelectric project.
Before proceeding into specifics, let me commend you all for taking
the initiative and spending the necessary resources to put together a good
and well thought out report. In the context of decreaSing state oil
revenues, I believe that it is essential for the communities to be willing
to spend their own funds and resources and thereby considerably enhance
their chances of obtaining matching state grants and/or loans for essential
projects such as this.
Mow to some specifics.
was that APA had tentatively
solution to Cordova's energy
and changed economic factors
findings.
Reference page 5, paragraph 2, my impreSSion
identified Silver Lake as the best long-term
needs, and that due to the high capital cost
it was going to revaluate these initial
Reference page 8, paragraph B1, the quoted price of electricity should
be identified as retail or wholesale. At the bottom of the page reference
is made to a 1979 energy balance. I would suggest using one more up to
date if available.
Reference figures 1II-3 and 111-4, it would be better to break the
data into actual (1980-1985) and projected (1986 onward).
®
®
w.o. Bechtel
December 23, 1985
Page 2
Reference figure V-I8, sheet #3, I would recommend leaving more space
for sediment in the steel intake structure with provisions for easy
cleaning of it.
Reference page 79, paragraph FI, the economic feasibility is the term
normally used when referring to benefit/cost analysis and normally
accomplished on the basis of no subsidies. The term financial feasibility
normally refers to the analysis and preparation of a plan of finance such
that the energy from the project will be marketable, i.e., the consumers
would be willing to buy from day one. This does not preclude the
possibility that enlightened consumers would be willing to pay somewhat
higher prices in the short-term in order to obtain lower prices over the
long-term. Clearly there are various ways to finance a project and still
have marketable rates.
Reference page 88, paragraph 2, last two sentences seem to imply that
only users of 750 KWH per month or more would benefit, i.e., encouraging
consumption when a better strategy would be to encourage conservation.
Reference page 39, this is an excellent selling point for the project.
Reference page 90, paragraph 2, I don't believe that the idea conveyed
is the one intended. Ideally, the project with the highest benefits would
be the most desirable provided that it can be financed in such a way as to
preclude rate shock in early years. The inherent danger is that financial
obstacles can lead a utility to select a costlier short-term option over a
more cost effective long-term option. I would also recommend that whenever
benefit/cost analysis is discussed, that it be noted whether the results
are based on subsidized or nonsubsidized data.
Reference page 136, I would add the economic area to the three you
have considered. As noted earlier the economic feasibility of the project
should be determined on the basis of a benefit/cost analysis based on
unsubsidized costs. If the project is feasible, i.e., B/C greater than 1,
then the financiability of it is determined as discussed earlier.
In terms of choosing the appropriate turbine and generator, I believe
that you are on the right track by consulting with the manufacturers and
utilizing off-the-shelf items to the greatest extent possible. In
addition, the manufacturers might be able to help you with other relevant
portions of the design such as foundations, powerhouse layout, etc.
In order to accomplish this project as expeditiously as you desire,
the licensing and financing aspects will have to be accomplished pretty
fast. I noted that there is $1.3 million for your project in the
Governor's proposed FY 87 capital budget. I would also encourage you to
coordinate with and take advantage of the Alaska Power Authority's
expertise in this area.
W.D. Bechtel
December 23, 1985
Page 3
In summary, r believe that you have a good small hydropower project
that deserves support by all concerned. The project's strong points are
that:
it will utilize a clean and renewable energy resource.
it will payback state's investment through decreased power
cost equalization.
it will utilize local labor as much as possible.
it will lower energy costs over the life of the project.
it is being accomplished by the local utility with the active
support. of the community.
Please let me know if I can be of further assistance. Best wishes for
the holiday season.
Sin~Y~, ~ lJ~s~;Uc)
Senior AdViso7
Paragraph #1
LETTER FROM KURT S. DZINICH
SENATE ADVISORY COUNCIL
ALASKA STATE LEGISLATURE
DATED DECEMBER 23, 1985
The Alaska Power Authority has tentatively identified Sil, ~
Lake as the best long term solution to Cordova's energy
needs. The Alaska Power Authority is still continuing the~~
investigation of this project although at a much reduced
scope. The major problem we see with Silver Lake is whether
or not a $100,000,000.00 project is realistic for a
community of 2,500 people.
Paragraph #2
We have attempted to obtain more recent data to update the
energy balance. The accumulation of this data is outside
what we currently have time for although it will be pursued
in the future. The study has been modified to indicate that
retail prices of energy are used.
Paragraph #3
Done.
Paragraph #4
It now appears that the design of the intake structure wiil
include a much larger steel "tank" to make water intake more
efficient as well as providing more room for accumulation of
sediment between cleanings.
Paragraph #5
The last sentence on Page 88 has been deleted to prevent the
misinterpretation. Those users who utilize less than 750
kwh a month will not see a direct reduction in their
electric bill. The savings will be passed on to the State
of Alaska through reduced PCE payments. It should be noted,
however, that even with PCE the cost of electric energy for
heating and cooking is still above available alternatives
such as stove oil and propane.
Paragraph #6
We agree that the project with the highest benefits would be
the most desirable long term solution for Cordova's energy
needs. However, those benefits must be weighed against the
financial feasibility of the project. The Silver Lake hydro
project is the case in point which provides much more
benefit to Cordova over the next fifty years yet is probably
not financially feasible for a community of this size. The
Study indicates where State investment is included in the
calculations. It should be noted that the State will
receive a benefit from their investment through reduced PCE
payments in the future and as indicated in the Study, the
Letter from Kurt S. Dzinich
Senate Advisory Council (Continued)
benefit-to-cost ratio for the State of Alaska for this
investment is 1.6.
Paragraph #7
The Study has been modified to include economic feasibility
as well as financial feasibility.
Paragraph #8
Manufacturers of equipment that could be used for this
project have been very helpful in providing equipment
efficiencies and preliminary design information. We intend
to work with these people closely in the future to take
advantage of their expertise in this area.
Paragraph #9
As indicated in a Foreword to this Study, the Alaska Power
Authority has been very helpful in this project and we
continue to make use of their knowledge and efforts to keep
this project going.
December 26, 1985
W.D. Bechtel, General Manager
Cordova Electric Cooperative, Inc.
P.O. Box 20
Cordova, Alaska 99574
Dear Mr. Bechtel:
UNITED STATES DEPARTMENT OF COMMERCE
National Ocaanic and Atmospharic Administration
NationaL Marine Fisheries Service
P.O. Box 1668
Juneau, ALaska 99802
The National Marine Fisheries Service has reviewed the Humpback Creek Hydro-
electric Project Draft Feasibility Report, November 1985. Our review found
the Report to be quite thorough in describing the proposed run-of-the-river
project, and in establishing mitigative opportunities for certain environ-
mental impacts. We concur with the analyses and conclusions presented in the
Report and look forward to continued participation in project planning as
the licensing efforts continue. As mentioned in the Report, we have parti-
cular interest in the design of the powerhouse and tailrace facilities and
would appreciate the opportunity to review these plans when they become
available. We would also like to receive the results of the 1985-86 fisher-
ies investigations referred to on page 125.
We appreciate this opportunity to comment.
Si nce~79v~:7l C' ~:
Rober W. McVey f/;1;7~
Direc or, Alaska R~
, .. -",
tETTER FROM ROBERT W. McVEY
DEPARTMENT OF COMMERCE
NATIONAL MARINE FISHERIES
DATED DECEMBER 26, 1985
We will submit preliminary designs of the power plant and
tailrace facilities to the National Marine Fisheries Service
for their review prior to finalizing these plans. We will
also provide all interested parties a copy of the 1985-1986
pink salmon survival studies when complete.
;'-:-":",
Ll1~S.\
United States
Department of
Agriculture
Forest
Service
Mr. W. D. Bechtel, General Manager
Cordova Electric Cooperative, Inc.
P.O. Box 20
Cordova, Alaska 99574
Chugach NF 201 E. 9th Ave.
Suite 206
Anchorage, AK 99501
Reply to: 2510-4
Date: December 26, 1985
This letter is in response to your request for comment and review of the
Preliminary Feasibility Report on the Humpback Creek hydroelectric project. Our
comments are limited to the potential resource impacts from the proposed
project. We have not addressed the report's economic analysis.
We are pleased to have the opportunity to review this report, and like seeing
investigation being done on this sort of small scale power development project.
We do not forsee major or insurmountable problems with the development of the
project, however, we would like to provide several comments in the areas of
hydrology, historic/archeologic values, and fisheries. Also, as a general
comment, it would be useful to the report to provide a good vicinity map of the
project site and where it lies in relation to the City of Cordova. Specific
comments are as follows:
1. Hydrology. You have addressed briefly the problem of sediment buildup
behind the old crib dam, and the danger of this sediment releasing as the
dam deteriorates. Is there the possibility of modifying the crib dam during
construction of the power plant such that it could work to release sediment
at a moderate rate rather than in a large "blowout" at some point in the
future? The latter event would obviously have negative impacts to the
channel morphology and to the salmon population in Humpback Creek. A more
measured release of the sediment load could help to lessen these impacts.
2. Historic/Archeological Values.
a. The general background history of the old hydro-power installation is
good.
b. The plans for construction provide reasonable alternatives for
mitigating impacts to potentially significant historic features.
c. FERC will probably still need to see official clearance from the State
Historic Preservation Officer and if need be, the National Advisory
Council on Historic Preservation. This need should be antiCipated by
CEC regardless of the archeological assessment work done to date.
d. Subsurface testing of the new power generating site and access road
should be seriously considered as part of the clearance program.
.:1 \ .
Mr. W. D. Bechtel Page 2
3. Fisheries. Impacts to the fisheries resource by this project appear to be
slight. It further appears that your proposed mitigation efforts should
amply make up for pink salmon losses on Humpback Creek due to installation
of the power project. As mentioned previously, we see the sediment load
perched behind the old crib dam as a potential problem to the fisheries.
Perhaps reduction of this danger could in fact be considered a mitigating
measure for the Humpback Creek fisheries.
We appreciate the opportunity to comment on this report. If you have additional
questions please contact myself or our hydrologist, Dave Blanchet at 261-2500.
Sincerely,
DAL~?dr;, Fo~~;;rv~ r
cc: CRD
112685 1018 msw 2510-4 db
FS·6200·28(7·82)
Paragraph #1
LETTER FROM DALTON DULAC
U.S. FOREST SERVICE
DATED DECEMBER 26, 1985
We will review the possibility of a gradual release of the
sediment load behind the existing dam. However, we feel
that this is outside the scope of the hydro electric project
that we are currently undertaking, but since we will have
people on site over the next few years, this is something
that could be worked out. It is the general concensus of
engineers that have visited the site that the dam will not
fail in a catastrophic manner, but will continue to sag as
it is currently doing for the foreseeable future.
Paragraph #2
See comments to prior letters concerning the historical
value of the existing dam and hydro site. Subsurface soils
testing of the power plant and access road will be
undertaken in early 1986.
Paragraph #3
We agree that the sediment load behind the existing crib dam
is a potential problem. As mentioned previously, we will
work on this with the Alaska Department of Fish and Game.
DEPARTMENT OF FISH AND GAME
January 9, 1986
Mr. W. D. Bechtel, General Manager
Cordova Electric Cooperative, Inc.
P.O. Box 20
Cordova, Alaska 99574
Dear Mr. Bechtel:
BILL SHEFFIELD, GOVERNOR
333 RASPBERRY ROAD
ANCHORAGE, ALASKA 99518·1599
Re: Humpback Creek Hydroelectric Project Draft Feasibility Report,
November 1985
The Alaska Department of Fish and Game (ADF&G) has reviewed the referenced
report. We understand that Cordova Electric Cooperative proposes to
construct an 850 kw run-of-the-river project on Humpback Creek, near
Cordova.
Based on the information contaioed in the draft report, the ADF&G believes
that the project, including mitigating measures, can be constructed without
significant impact to the fish and wildlife resources of the project area.
Our primary concerns with the project are with maintaining the existing
productive pink salmon spawning habitat in Humpback Creek through proper
location and design of the tailrace; avoiding activities that will alter
spawning gravels such as sedimentation and downstream transportation of wood
and rock materials; and minimizing the potential for human/bear conflicts
through worker orientation and proper storage and disposal of refuse.
Please keep us informed of project developments. As you are aware, this
project will require authorization from the ADF&G pursuant to A.S. Title
16.05.870.
The following specific comments are provided for your consideration:
Page 107, para. 1: We recommend that the initiation of right-of-way
clearing be delayed until the appropriate project approvals are
received.
Page 108, para. 1: We request that the potential for hydraulic
transportation of 20 to 40 cubic yards of rock downstream to the
spawning reach of Humpback Creek be addressed in future project
analyses.
(3)
®
Mr. W. D. Bechtel -2-January 9, 1986
Page 110: When more specific plans are developed regarding the need for
blasting for right-of-way preparation we will need to know charge size
and the distances to Humpback Creek to develop timing stipulations for
Title 16 permits.
Page 117, para. 1: The tailrace should be located as far upstream as
possible to assure a water supply to the salmon spawning habitat.
Also, please provide plans for the design of the tailrace and energy
dissipating structures for our review when they are available.
Page 117, para. 2: Timing of construction of the tailrace and other
instream activities should be planned for May and June.
Page 125, para. 1: The ADF&G should be consulted regarding the overwinter
survival study of pink salmon eggs and fry. Please provide the
opportunity to review the study design prior to initiation. If egg and
fry survival is found to be low or nonexistent then we need to first
determine and evaluate the factors that are responsible before
concluding that no mitigation is necessary.
Page 125-127, Fishery Mitigation Alternatives: The ADF&G supports the
evaluation of these mitigation alternatives. Because the potential
adverse impact is to the population of pink salmon in Humpback Creek,
we prefer mitigation options 1 and 2. If these prove to be infeasible,
then additional alternatives can be considered.
Should you wish to discuss these comments, please contact me in Anchorage at
(907) 267-2284.
Sincerely,
~~~~ G· 'N'~ \.<-\
Donald O. McKay
Habitat Biologist
Habitat Division
267-2284
cc: G. Bos, ADF&G
R. Randall, ADF&G
M. McCurdy, ADF&G
H. Griese, ADF&G
R. Bowker, USFWS/WAES
B. Smith, NMFS
G. Prokosch, ADNR
P. Bielawski, DGC
LETTER FROM DONALD O. McKAY
HABITAT DIVISION
ALASKA DEPARTMENT OF FISH & GAME
DATED JANUARY 9, 1986
Paragraph #1
We concur, see our response to prior letters.
Paragraph #2
We will address the impact on rock disposal in the stream
when we apply for our Title 16 permit. We agree that it
does pose a potential problem, but as indicated in our
response to the Department of Interior's letter, we do not
see a readily available alternative.
Paragraph #3
As soon as we are able to determine
blasting for right-of-way clearing,
Alaska Department of Fish and Game.
will form a portion of our Title 16
Paragraph #4
our requirements for
we will inform the
We realize that this
permit application.
We agree. See our response to Mike McCurdy's letter of
December 5, 1985.
Paragraph #5
We agree. The wording of the Study has been modified to
indicate this timing constraint for instream work
activities.
Paragraph #6
We are currently working with local Fish and Game personnel
on the pink salmon fry survival study. We agree that
weather conditions this winter have to be taken into account
before any opinions can be reached concerning long term fry
survival in the area near the tailrace.
I
DEPT. OF ENl-'IRONMENTAL CONSERVATION I ! January 17, 1986
Division of Environmental Qualit.Y
43'7 IIEII St.
Anchorage, AK., 99501
Mr. W.D. Bechtel
General Manager
Cordova Electric Cooperative Inc.
P.O. Box 10
Cordova, AK., 99574
Dear Mr. Bechtel:
,
! BILL SHEFFlfLD, GOVERNOR
Havi ng revi ewed the draft IIHumpback Creek Hydroel ectri c Project
Feasibility Reportll, dated November, 1985, prepared by the Cordova
El ectri c Cooperative, the Department of Envi ronmental Conservati on
fi nds no major envi ronmental concerns wi th the proposed project.
As the contractor has noted, a permit to burn will be necessary in
conjunction with planned clearing activities. Also, a solid waste
disposal permit will be required for any disposal of construction
debris. Application for the respective permits should be filed as
soon as final details are known. We have no further comments at
this time; thank you for the opportunity to review the project.
cc: Commissioner Ross
Keith Kelton, Director
Dan Lawn, DEC/Valdez
Bob Bowker, USF&WS
Cordi ally,
~~-<-... -
Boh Martin, P.E.
Deputy Director
ApDendix 2
Schedule A
Page 1
:;cm:OUI.E or E!.1 GI IjI.E 1'01.'F.R COSTS
Cordova Electric Cooperative
PC16 -010 1984
UTlI.ITY NAtI£ -CEHTlrICATE NO. ItEI'OllT I NG l'!::IOOI)
(Test Year)
ACCOm<'T NmmER REFERENCE
FPC/FERC REA OTHER
CLASS AlB Co-op (INDICATE)
500 500
502 502
503 503
504 504
505 505
506 506
507 507
510 510
511 511
512 512
513 513
514 514
535 535
536 536
537 537
538 538
539 539
540 540
541 541
542 542
543 543
544 544
545 545
546 546
548 548
549 549
550 550
551 551
552 552
553 553
554 554
556 556
557 557
560 560
561 561
562 562
563 563
564 5610
565 565
566 566
567 567
.568 568
569 569
EXPE1\SE C,\TEGOR'{
1. PWER PRODUCTION EXPF:NSES
A. STEAtI POwr:R GENERATION
Operation supervlslon & engineering
Steam expenses
Steam Crom other sources
Steam transferred -Credit
Electric expenses
Misc. steam power expenses
Rents
Maintenance supervision & engineering
tlaintenance of structures
Maintenance of boiler plant
MainteDance of electric plant
Maintenance of misc. steam plant
B. HYDRAULIC POWER GENERATION
Operation supervision & engineering
Water for power
Hydraulic expenses
Electric expenses
Misc. hydraulic power gen. expenses
Rents
MainteDance of supervision & engineering
MaiDtenance of structures
MaiDtenance of reservoirs, dams & waterways
Maintenance of electric plant
Maintenance of misc. hydraulic plant
c. OTHER POWER GENERATION
Operation superVision & engineering
Generation Expenses
Misc. other po"'er gener:ltion expenses
Rents
tlaintenan,te supervision & engineering
Maintenance of structures
Maintenance oC generating & electric plant
M:lintenance of misc. other power
generation plant
D. OT)~R POwLR SUPPLY EXPENSES
System control and load dispatching
Othe r expenses
2. TRANStlISSION EXPEt-.'SES
Operalion superVision & engineering
Load dispatching
Slalion expenses
Overhead line expenses
Underground line expenses
Tran~mission oC eleclricily by olhers
Misc. lr:lnsmission exprnses
Rents
Maintenance supervi~ion & en~ineering
Maintenance of structure5
~!otr:r PAGE I;
$·21,891.23
250,364.02
31,687.79
2,333.39
21,912.46
34,206.01
94,859.64
53.60
$457,308.16
,\prend i x 2
Sch~Jule A
P.Jge 2
SCHEDULE OF El.IGI!lLE POI."ER COSTS
CORDOVA ELECTRIC COOPERATIVE
PC16 -010
UTI Ll T\' NA,'I" -CWTI f" I C,\"I'I: ~O.
ACCOIJXT NUl'IBl;R REFERE~CE
FPC/fERC REA OIlIER
CLASS AlB Co-op (I:-1lIC,\TE)
570
571
572
573
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
901
902
903
904
905
907
908
909
910
911
912
913
916
570
571
572
573
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
901
902
903
904
90S
907
908
909
910
911
912
913
916
EXP"NSE C~TCGORY A/'IOlr.IT PA G
2. TRANsmSSION EXPENSES CONT'D
tla intenance of station equipment
tla intenance of overhead lines
Maintenance of underground lines
tla intenance of misc. transmission equipment
3. DISTRIBUTION EXPENSES
Operation supervision & engineering $
Load dispatching
2,897.44
Station expenses
Overhe3d line expenses
Underground line expenses
Street lighting and signal system expenses
l1eter expenses
Customer installation expenses
Misc. distribution expenses
Rents
Maintenance supervision & engineering
Maintenance of structures
Maintenance of station equipment
Maintenance of overhead lines
Maintenance of underground lines
Maintenance of line transformers
Maintenance of street lighting
and signal system
Maintenance of meters
Maintenance of misc. distribution plant
4. CUSTO~~R ACCOUNTS EXPENSES
Supervision
Meter reading expenses
Customer records and collection expenses
Uncollectible accounts
Misc. customer accounts expenses
5.
, ..
CUSTmlER SERVICE &
lNFOIU-IATIONI\L EXPENSES
Supervision
Customer assistance expenses
Informational & instructional
advertising expenses
Misc. customer service &
informational expcnses
6. SALES EXPE~SES
Supervision
D~mon~tr.1Ling & selling eXl'e"s~s
~<Iv~'rtisinc expenses
Misc. sales expenses
556.06
10,564.23
8,650.62
10,,253.26
39,114.86
1,497.81
546.26
2,897.42
1,097.58
11,094.73
21,864.20
2,344.14
2,942.27
220.40
112.49
$116,653.77
10,607.91
46,099.47
3,000.00
$59,707.38
SUlmARY
P'):H:R COST EOUt\LIZ,\TIOII PRO:::I\A~I
Utility Name Cordova Electric Cooperative
Certificate "u~ber PC16 -010
A:>oendix 5
I'.l-:lc .!.
Address ____ p_,_O_, __ B_O_x __ 20 __________________________________________ ------
Cordova, AK 99574
1984
Reporting Period (Tes~ Year)
lS,253,189
Total KWH Sold or de~era~ed (circle one) During Reportin; Pe~iod
A, Total KWH Gener5te~
B. Total KHH ~etered to
Customers
C. Total Allowable Costs
(except return on e~uity
and fuel costs) ?er KWH
based upon financial
documents submitted
D. Total.fuel costs per KWH
based upon docu~ents submitted
E. Total System Avera;e Costs
per KIlH C + 0 -S.5¢/KWH
F. The lesser of E or 44¢/KUH
(to and includin; 750 KWH) .
G. Average Class Rate (from Appen-
dix 7, Page 3) -8,5~/KWH
1. Residential
2. Cornmercial
3. Public Lighting
4. Large Power
S. Industr ial
6. Etc. Boat Harbor
Utility
Reouest
17, 155,96~1"lH
1 S, 253, 18!%mH
7,94 ¢/KIolH
10.54 ¢/KHH
10. 54 ¢/l\i~H
12.632 ~/K;"H
13.432 ¢/KUH
10.232 ¢/KUH
10.232 ¢/KI"lH
¢lKI·IH
10.232 ¢/Ki"lH
Commission
Determination
17 • 155.960 KIm
15.253,189 Kim
11. 07 ¢/Ki~H
7.94 ¢/KI·IH
10.54 ¢/K;m
10.54 ¢/K;·m
12.632 ¢/Ki:ij 13.43~ ¢/KIlH
10.232 t/i(lm
10.232 s:!!i<~1H
t/Kim
10.232 t/Ki~iJ
----------------------------------------------------------------------
Class Power Cost Equa1izatio~
per KilH Payable by Alaska
Power Authority
H. Lesser of: (ll f' x .95: or (2) ::;
1. Residential 9.98 ¢/i<llH
2. Commercial 9.98 t/KiIH
3. Public Lightin; 9,98 ¢/KI"IH
4. Large Power 9.98 ¢/KUH
S. Industrial ¢/KIlH
6. Etc, Boat Harbor 9.98 ¢/KIlH
9,28 I!/KllH
2 28 s:!/i<ilH
9.9t;l ¢/i<:lH
9,9~ ¢/Kim
¢/i\;m
9.<)8 ¢!i<iIIt
AMENDMENT TO
POI1ER COST EQUALIZATION CONPUTATION
WITII FUEL COST RATE ADJUSTNENT
Utility Name: Cordova Electric Cooperative
TA Number: PC16 -OlD
Prior Updated
Commission Utility
Determination Request
A. Non-Fuel Power
Costs/KWH (Line C,
Appendix 7, page 4) 10.42 ¢/KWH 11. 07 ¢/KWH
(A) (A)
B. Fuel Power Costs/
KWH (Line G,
Appendix 7, page 4) + 7.88 ¢/KWH + 7.94 ¢/KWH
(B) (B)
C. Total Power
Costs/KWH 18.30 ¢/KWH 19.01 ¢/KWH
(MB) (A+B)
0, Total Power Costs/
KWH less B.5¢/KWH 9.80 ¢/KWH 10.51 ¢/KWH
(D) (D)
E. 95\ of 0 9.31 ¢/KWH 9.98 ¢/KWH
(E) (E)
F. Statutory Maximum
Eligible Power
Cost Equalization
.95 (52.5¢/KWH -
8.5¢/KWH) 41.8¢/KWH 41.8¢/KWH
G. Lesser of E or F 9.31 ¢/KI"IH 2·9~ ¢/KWH
(G) (G)
Customer/class
H. Hate (from Appendix
7, page 3, column 7)
Residential 10.232 ¢/KWH 12.632 ¢/KWH
Small Commercial 10.232 ¢/KWH 13.432 ¢/KWII
Large Power 10.232 ¢/KWH 1Q.232 ¢/KWH
Boat Harbor 10.232 ¢/KWH 10.232 ¢/KWH
Street Lights 10.232¢/KWH 1Q.232 ¢/KWH
¢/KWH ¢/Klm
Power cost Egualization
1. For Each Class, the
Lesser of H (for that
class) or G
Residential 9 3l ¢/Kl~1l 9.98 ¢/KWIl
Small Commercial 9.31 ¢/KNII 9.98 ¢/Kl~1I
Large Power 9.31 ¢/KI"IH 9.98 ¢/Klm
Boat Harbor 9.31 ¢/KWH 9.98 ¢/KWH
Street Lights 9.31 ¢/KWII 9.98 ¢/KWIl
¢/KWH ¢/KWH
I\ppcndl.x 7
rage 2
Updated
Commission
Determination
..
(A)
+
(B)
(A+B)
(D)
(E)
4L8¢/K'.-IH
(G)
¢/'f
¢/K
¢/I
¢/I
¢/r
¢,
¢.
¢,
¢,
¢,
¢,
¢
<-
¢
(
¢
¢
¢
Appendix 2
Schedule A
hge 3
SCI~DULE Of ELIGIBLE POWER COSTS
CORDOVA ELECTRIC COOPERATIVE
PCl6 -010
UTlLIT¥ N,\tLE -CERTlFlC,\TE NO.
ACCOUNT miSER REfERENCE EXPENSE CATEGOR¥
FPCI fERC REA OIlIER
CLASS AlB Co-op (INDICATE)
920 920
921 921
922 922
923 923
924 924
925 925
926 926
927 927
928 928
929 929
930.1 930.1
. 930.2 930.2
931 . 931
932 932
7. ADI1INISTRATIVE & GENERAL
EXPENSES
Administrative & general salaries $124,067.66
Office supplies & expenses 23,019.73
Administrative expenses
transferred -Cr.
Outside Services employed 25,621.50
Property Insurance 17,328.09
Injuries & damages 22,858.03
Employee pensions & benefits 348.33
Franchise requirements
Regulatory commission expenses
Duplicate charges -Cr. 462.02 General adVertiSing eXpenses 18,007.42
Misc. general expenses
Rents 13,164.00 Maintenance of general plant $244,876.78
8. ALLOWABLE FIXED COSTS (to the extent expensed)
Depreciation
Taxes
Interest on debt
Other Deducations
$270,629.93
7,626.59
377,444.15
(Schedule attached) 3,662.76
$659,363.43
Total Expenses, Excluding Fuel Costs
$1,537,909.52
NOTE:
Staff.
An adjustment for current fuel costs will be made by Commission
The follOWing information is therefore required:
a. Regulated utilities with surcharges in effect
1. Current price per gallon of fuel shown in most
recent surcharge calculation approved by the Commission.
2. Yearly gallons consumed and Kh1' sales shown in most
recent surcharge calculation approved by the Commission.
b .. Utilities with no surcharge i'O effect or :unregulated
1. fuel storage c:spacity 133,500
* 2. Actual price per gallon of fuel on hand, assuming
that latest purchases are sold last (Le. FIFO) .935
Attach schedule showing components of total. 5ch. Ref.
3. Latest invoiced price of fuel per gallon .935
~bt:~~o~PIn'lfotg~o~~: 47 36iifha ti!.eic!hed.
*Fuel price has not changed for over a yea~. Refer to our 5/31/84
filing based on 1983 as a test year. Cop~es of FCRA consumptions
attached in lieu of Fuel usage Schedule.
Total Expenses excluding fuel
Extraordinary loss: Chase Avenue Overhead Retirement**
Fuel Cartage
Lubricating Oil
Antifreeze, Fuel Tests
$14,589.80
24,038.63
1,984.25
**See Appendix 8 for REA Approval of Accounting
treatment of this item.
$1,537,909.52
110,487.61
40,612.68
$1,689,009.81
CC:~PUT,\TIO:I OF ".VERAGE CLASS RATE PER K .. 11
UTILITY Cordova Electric Cooperative
RATE SCHEDULE R-Residential
1 2 3 4 5 KWH _TOt~1. Rate Total
Rate Surcharge (S/KVlH) (S) By Block (S/KWH) (S/KWH) (2 + 3) (1 x 4)
0 $lB.OO $lB.OO
750 .19 .00268-.18732 140.49
(A) Total 750 (El $158 .49
RATE SCHEDULE GS-1 Small Commercial
1 2 3 4 5
KWH Total Rate Total
Rata Surcharge (S/KWH) (S)
_By Block (S/KWH) . l$/KWH) (2 + 3) (1 x 4) .. .. . ' .. . 0 . $24.00 ~24.00
750 .19 .00268-:18732 140.49
, -. ' .. -
(A) Total 750 (E) 164.49
RATE SCHEDULE GS-3 Large Power & Boat Harbs>r
1 2 3 4 5
lCWH Total Rate Total
Rate Surcharge ($/KWH) (S)
By Block (S/KWH) ($/KWH) (2 + 3) (1 x 4)
*750 .12 .00268-lR712 t-WJJ......4...9....
*Does not nclude vari ~ble demanc charqes as iessed
(A) Total 750 (E) $140.49
RATE SCHEDULE Street Lights & Signals
.L :l .j 4 5
lCWH TOtal Rate Total
Rate Surcharge (S/KI-;1I) (S)
By Block (S/KI-;1!) IS/KIm) (2 + 3) (1 x 4)
750 .19 .00268-.18732 $140.49
(A) Total 750 (E)$140.49
Appendix 7
Page ).
6
Avg. Rate
(S/K',rn)
(E) .:. (A)
.21132
6
Avq. Rata
7
Avg. R
(s/n·n!)
S.085/
.12632
7
Avq. Ra
(S/KWH) ($/KWH) ;
(E) ~ (A) S.085/~
.21Q12 .1141
6 7
Avg. Rate Avg. P
($/K'fni) (S/KHIi)
(E) .:. (1\) $.085/
.18732 .102 c
6 7
Avg. Rate Avg. R
(S/KWII) (S/KHIi)
(E) .:. (A) S.085/
.18732 .1023
AMENDMENT TO ALLOWABLE POWER COST
EQUALIZATION FOR REGULATED UTILITIES
WITH FUEL COST RATE ADJUSTMENT
Utility Name: Cordova Electric Cooperative
TA Number: PC16 -010
Non-Fuel Costs
Approved Total Allowable
Costs--Less Return on
Equity and Fuel Costs
Source: REA Form 7
12 Month total KWH sales
from surcharge filing
Total non-fuel power costs (A~B)
Fuel Costs
Current fuel price used in most recent
surcharge filing
12 Month total fuel consumption from
surcharge filing
12 Month total KWH sales from
surcharge filing
Total fuel power costs (0 x E~F)
$
$
$
$
Arpclldix 7
Pa'lC 4
1,689,002.111
(A)
15,253,189 KWH
(B)
11.07¢ /KWH
(C)
.935 /ga1.
(0)
1,295,563 gal.
(E)
15!253,182
(F)
KWH
7.94¢ /KW!I
(G)