HomeMy WebLinkAboutTenakee Springs Small Hydropower and Related Purposes Letter Report 1984---
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NAKEE SPRINGS, ALASKA
SMALL HYDROPOWER
AND RELATED PURPOSES
LLETTER REPORT
r:'Pr.'I I.;.:!:.:.I -US Army Corps
of Engineers
Alaska Di~trict
APRil. 1984
Tenakee Springs, Alaska
Hydropower and Related Purposes
Interim Feasibility Study
and Environmental Assessment
LETTER REPORT
April 1984
Alaska District·
U.S. Army Corps of Engineers
Pouch 898 NPAEN-PL-P
Anchorage, Alaska 99506
PROPERTY OF:
Alaska Power Authority
334 W. 5th Ave.
Anchorage, Alaska 99501
OVERVIEW
The Alaska District conducted a study of small hydroelectric potential for
Tenakee Springs, Alaska. A Draft Interim Feasibility Report and
Environmental Assessment was completed in September 1983. The selected
hydropower plan was not economically feasible based upon an evaluation of
the anticipated power demand, the cost of diesel fuel, the expected
escalation of fuel prices, and the estimated cost of construction of a
265-kW project. This LETTER REPORT summarizes that evaluation and then
explains recent changes which make hydropower even less competitive with
diesel generation.
SUMMARY
The Alaska District, U.S. Army Corps of Engineers investigated the
feasibility of hydropower development for Tenakee Springs, Alaska, in
response to a United States Senate Resolution dated 1 October 1976. The
planning objective was to determine the technical and economic feasibility
of developing hydroelectric power generation facilities that would replace
the diesel power generators currently in use.
Various combinations for hydropower development of both Harley Creek
and Indian River were evaluated, including five different dam sites, four
different dam heights, and six different power house locations. All
alternatives were based on October 1983 price levels, an 8 1/8 percent
annual interest rate and a 50-year period of analysis.
Of the hydropower plans considered, the 265-kilowatt (kW) run-of-river
hydroelectric facility on the Indian River with an annual energy
capability of 1,870 megawatt-hours (MWh) was the most cost effective.
This plan also incorporated a provision for a needed water supply system
as well as fisheries mitigation.
The estimated investment cost of this project, including water supply
was $3,676,000. Potential benefits for the hydropower project included
the cost of diesel fuel avoided, the savings in future fuel price
increases, and the reduction in operations and maintenance costs. There
are also water supply, recreational, and employment benefits. The project
would not be economically feasible since the estimated costs exceeded the
potential benefits. Thus, electricity produced by hydropower would be
more expensive than electricity produced by a modernized diesel system.
1. Background
a. Authority. Evaluation of small hydroelectric systems was authorized
by a 1 October 1976 United States Senate Resolution, which directed the
U.S. Army Corps of Engineers to determine the feasibility of installing
small prepackaged hydroelectric units in isolated Alaskan communities.
b. Purpose and Objective. This letter report summarizes the plan
background, formulation, costs, benefit analyses, and conclusions and
recommendations of the Tenakee Springs Small Hydropower Study conducted by
the U.S. Army Corps of Engineers. The objective of the study was to
determine the technical and economic feasibility of hydroelectric pqwer
generation development for the city of Tenakee Springs.
c. Scope. Studies conducted for the evaluation of hydroelectric power
generation at Tenakee Springs reflect the level of detail required for
plan formulation evaluations of a general investigation feasibility
study. Design, cost, and economic analyses of all plans were
accomplished. Additionally, environmental evaluations of the two most
cost effective hydropower plans were made and coordinated with the U.S.
Fish and Wildlife Service and the U.S. Forest Service.
d. Area Location and Description. Tenakee Springs is located on
Chichagof Island, the second largest island in the Alexander Archipalego
of Southeast Alaska. Tenakee Springs is 50 air miles northeast of Sitka
and 45 air miles southwest of Juneau (see Figure l)and has a population of
approximately 141 people. Tenakee Springs is accessible by air or sea
only.
e. Coordination. Meetings and discussions were held with community
leaders to determine current and future electrical needs for Tenakee
Springs. Agency coordination with the U.S. Fish and Wildlife Service, the
Alaska Department of Fish and Game, and the U.S. Forest Service was
accomplishea. A U.S. Fish and Wildlife Service Planning Aid Letter and
final Coordination Act (CA) Report were prepared in accordance with the
provisions of the Fish and Wildlife Coordination Act. The CA report is
summarized in papagraph 4b.
f. Needs. Tenakee Springs currently receives electricity from two
90-kilowatt diesel generators owned and operated by the city. Fuel oil is
used for space heating, cooking and heating water. Several residents have
also installed wood heaters in response to the rising fuel oil costs.
Demand for electrical power is likely to increase in the near future due
to both the increased efficiency of the new distribution system and the
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TENAKEE SPRINGS
ALASKA
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projected increases in population. The population of Tenakee Springs is
estimated to increase by 6 to 8 percent annually for the remainder of the
decade, decreasing to between 1 and 2 percent for 20 years and remaining
stable thereafter. Because per capita electrical consumption in Tenakee
Springs is well below the average of the rest of the communities in the
Southeast Region, the opportunity for load growth in Tenakee Springs is
great. Provision of a cheaper source of electricity would probably induce
increased appliance use (e.g. washing machines and dryers). In addition,
loads will grow as more homes are built, a 6,500-square-foot addition to
the school is constructed, harbor improvements are made and reconstruction
of the cold storage plant occurs.
2. Formulation of Alternatives
a. General. Two nonstructural and nine structural energy alternatives
were formulated, evaluated, and compared. Of these, only hydropower was
reasonably competitive with continued reliance on diesel generation.
Hydroelectric plan configurations studied included five potential dam
locations, six potential powerhouse locations, nine different dam material
designs (including several variations on height and width), and over two
dozen combinations of hydroelectric plant capacity. This project was in
the unique position of having more than the typical hydrologic and
environmental data available for Alaskan studies, and less than the normal
amount of economic data with which to formulate the optimum plant for the
community. The Indian River gage provided 7 years of mean daily
discharge. Prior to 1983, the community was able to furnish only an
estimate of the total annual energy consumption but no monthly or daily
records because the city consumers were unmetered. Potential project
benefits were primarily based upon diesel fuel costs avoided and the
reduction in operation, maintenance, and replacement costs.
b. Hydropower. Harley Creek and Indian River were the drainages
evaluated. Although an abandoned pelton wheel system had generated
seasonal power, insufficient year-round flows ruled out economics of the
former. Indian River offered up to 150 feet of head and reliable
streamflows in excess of instream flow requirements for aquatic biota for
all but about 43 days annually on the basis of 7 years of streamgage
data. The 21.2-square mile drainage basin yields an estimated average
annual runoff of about 150 cubic feet per second. A plant sized to use
this much water would clearly exceed the anticipated needs of Tenakee
Springs.
c. Alternatives. The three prime development plans would take advantage
of one or more cascades which, depending on the combination, would provide
between 40 ana 100 feet of gross head and use up to 60 cubic feet per
second of the available streamflow. Indian River flows through a steep
canyon in the lower reaches where hydroelectric potential would be
realized. Access and civil works development through the rock canyon
would be very expensive and difficult for a small project. The sites
selected for detailed evaluation were in the upper part of the canyon
5
where these construction problems would be minimized. The uppermost site
would provide the most energy for the least cost. This plan would also
easi ly accommodate a water supply system and have the least impact on the
terrestrial and aquatic ecosystems.
3. Plan Selected
a. Plan Selected for Consideration. This plan consists of a rock filled
log crib diversion structure 7 feet tall and 90 feet wide located about
one mile upstream from tidewater. A 265-kW unit would be housed in a 20 X
20-foot wood frame building a half mile downriver. A 7.2 kV transmission
line about 3/4 mile long would connect with the 7.2 kV city distribution
system near the boat harbor (Figure 2).
b. Primary construction access would follow an existing heavy duty dirt
road which begins at a log dump about 2 miles east of the city. A short
spur from this road would lead to the dam. A penstock installation access
trail would be cut into the hillside rock along the opposite river bank.
The planned penstock would consist of 2000 feet of 42-inch diameter high
density polyethelene pipe and 400 feet of steel pipe. The plastic pipe
would be mounted above ground on railroad ties and about 250 feet of the
steel pipe would be buried. The powerhouse would be constructed using this
18-foot wide penstock trail and a 10-foot wide cat trail along side the
transmission line to the community.
c. The power potential and costs for this plan were developed based on
the selection of a single 265-kW horizontal francis type turbine. The low
available head (net = 71 feet) precludes use of an impulse type turbine.
Although other types of turbines would work, they were not evaluated in
detail when it became apparent that the structural costs were the critical
cost element and low demand was the critical economic constraint.
d. The hydroelectric plan would have the average annual potential to be
in operation all but 43 days. The hydroelectric system could operate at
design (52 cfs) a maximum of 250 days of the year. The remainder of the
year the plant would able to operate at less than the 265 kilowatt
capacity. The annual plant factor would be about 81 percent. Gross
maximum potential would be about 1,870,000 kWh and usable AAE energy would
be about 776,300 kWh annually. The total hydroelectric project cost
including interest during construction would be about $294,000 annually to
recover the initial capital investment.
e. Water supply plans were evaluated also. Gravity feed designs proved
infeasible so a pumped project was included taking advantage of an intake
near the tailrace and a pump inside the powerhouse operating off station
service. The limited needs of the town could be satisfied at a cost of
about $41,000 annually for a conduit which could follow the alignment of
the transmission line. The water supply system could operate year-round.
6
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4. Draft Interim Report Evaluation of the Selected Plan
a. During the study several load growth scenarios were formulated. The
mid-range scenario used for analysis assumed an average annual equivalent
(AAE) usable energy from the plant of 776,300 kWh. The average annual
equivalent demand was estimated to be 928,400 kWh indicating a need for
153,100 kWh of additional diesel generated power AAE. Usable energy is
less than the community demand because low streamflows during several
months of the year limit hydropower production.
b. The environmental cost associated with the plan could be mitigated for
about $5,000 annually. Indian River has minor salmon runs below the
project area, but has tremendous potential rearing habitat above the
project. The mitigation plan called for transplanting fry, hatchery
raised from eggs of silver salmon stripped at the mouth of the river, to
pools upstream of the diversion structure. There would be no significant
impacts on the rest of the project as long as eagle nests were avoided and
at least 10 cfs released below the diversion structure during low flow
periods.
c. Based on the cost estimated in Table 1, the project has a
hydroelectric benefit to cost ratio (BCR) of 0.71 and an overall BCR of
0.84 when water supply benefits and costs are included.
Table 1
Estimated Project Costs---Hydropower Only
Mobilization $ 260,000
Lands and Access 145,000
Diversion and Intake 281,000
Penstock 841,000
Powerhouse 513,000
Transmission 148,000
Contingencies 437,000
Engineering Design
Supervision & Administration 394,000
First Cost 3,019,000
Interest During Construction 240,000
Total Investment Cost $3,259,000
Annual cost $ 269,000
Mitigation 5,000
Operations, Maintenance,
and Replacement 20,000
Total Annual Cost $ 294,000
d. These costs could not be recovered by the displacement of fuel at
$1.37 per gallon escalated according to the 1982 Data Resources Institute
(DRI) rates of increase. Total energy benefits were estimated to be
7
$208,000 annually. This is the sum of fuel displacement benefits, the
avoidance of escalating fuel costs, and reduced operations, maintenance,
and replacements costs. Recreational use benefits and increased
employment benefits are additional non-energy credits. The benefit from
water is treated as equal to the cost of providing the water supply,
$41,000 annually. No fisheries enhancement benefits were claimed because
the hydroelectric plan was not justified, therefore no enhancement plan
was finalized, in accordance with current policy. Also, the fisheries
plan appears capable of implementation without a hydropower project, even
though each would mutually benefit the other.
Table 2
Project Benefit Categories
Diesel Costs Avoided
Fuel Cost Escalation
Reauced 0 & M and Extended Life
••• Subtotal
Water Supply
Employment
Fisheries Enhancement
Recreat ion
TOTAL
5. UPDATED EVALUATION
a. The following discussion, as stated in the
summarizes the changes and their consequences.
reflected in the Draft Report, but provide the
update.
$107,000
64,000
37,000
208,000
41,000
32,000
-zero-
1,000
281,000
overview, briefly
These changes are not
current study status
Upon completion of the study in September 1983, the Corps learned in
October and November:
.that 12 months of metered data compiled by the city
indicated lower than expected electricity use,
.that the community was paying a reduced rate for fuel,
.that the DRI fuel cost escalation rates changed.
b. Decrease in Oemand Estimate. A review of Figure 3 of this letter
report illustrates the effect of the change in energy demand estimates
between the time the Interim Draft Report load forecasts were prepared
(1981) and when the forecasts were revised upon receipt of meter records
of generation. The original demand estimate called for a requirement of
652,560 kWh in 1986 grOWing to 1,441,230 kWh by the end of period 2036.
The average annual equivalent (AAE) of this demand was about 928,400 kWh.
For this same period, the hydroelectric plan offered a potential usable
AAE energy of 776,300 kWh.
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1.5
ENERGY DEMAND ESTIMATES FOR TENAKEE SPRINGS
1980 -2036 POL 1986. 50 YR LIFE
---DEMAND USED IN THE DRAFT PREPARATION
----USABLE ENERGY OF THE DRAFT MODEL
1.25 -.. -NElLY REPORTED DEMAND
1
----------------------.. -------.. -
---------------
------------0.75
0.5
0.25
o
1980
I .. , .. -, ~ -" -"
1990
-.. --
-" -
2000
-" ------
2010
YEAR
------------
2020 2030
'.
1
0
0
0
~ K
C) U
H
140
120
100
80
60
40
20
o
ESTIMATED ANNUAL DISTRIBUTION BY MONTH
Old Scenario versus Current View or Growth
UPDATED DEMAND 1983 UPDATED DEMAND BY 2010
DRAFT DEMAND FOR 1983
DRAFT DEMAND BY 2010
JAN FEB MAR APR MAY JUH JUL AUG SEP OCT NOV DEC
The data received in November 1983 reduced the estimated AAE demand to
about 555,000 kWh. The projected 1983 power demand was 11 percent below
previous estimates. Also, fewer homes are being added to the system
and/or planned for construction in the near future than had been predicted
in the Draft Report. The anticipated expansion of the boat harbor has
been delayed and commericial demand is lagging that previously predicted.
Furthermore, the summer peak power demand anticipated during preparation
of the Draft Report does not appear to be materializing as shown in Figure
4. September now appears to be the peak month followed by December. This
decrease in expected summer demand makes hydropower less practical because
much of the available flow is not needed for power generation. The
combined effect of these factors and the compounding of projections for a
50-year period of analysis has reduced expected power demand by 30 percent
compared with that originally predicted for year 2036. This change is the
difference between the top and bottom curve of Figure 3.
Accordingly, the maximum usable energy for the newly reported demand
situation WOUld be the lower curve of Figure 3, or the demand itself. In
most years, the actual usable energy would be somewhat less because low
streamflows during dry periods limit hydroelectric'generation to less than
required by consumers. The decrease from 776,300 kWh to 555,000 kWh of
AAE energy production would make hydropower much less attractive than
diesel generation.
Savings in reduced diesel fuel use and lower operation and maintenance
costs would be less than previously estimated. Using the same estimated
construction cost, the benefit-to-cost ratio would be significantly below
the 0.84 reported in the Draft Report; which means the project as defined
is not economically feasible.
c. Decrease in Fuel. A 1982 diesel fuel cost of $1.37 per gallon was used
in the study. However, the cost to Tenakee Springs utility had decreased
to $1.21 in September 1983. This decreased the cost of diesel generation
about 3 cents per kilowatt-hour making hydropower even less attractive.
The table below shows how estimated fuel prices would change with the
updated fuel costs and the new escalation rates.
Table 3
Fuel Escalation Rates and Equivalent Costs
Updated Previously
Cost per Projected
Years DR! Rates Year Gallon Cost ~er ga 11 on
1983-1985 0.59 percent 1983 $1 .21 $1.37
1986-1990 6.12 percent 1990 1.65 1.66
1991-1995 3.98 percent 2000 2.31 2.27
1996-2000 2.86 percent 2013 2.65 3.33
2001-2013 1.07 percent
11
6. CONCLUSIONS
Based on the updated economic analysis the selected Federally-sponsored
hydropower projected as defined does not appear economically feasible for
Tenakee Springs at this time. The benefit-to-cost ratio would be
significantly below 0.8. Thus~ continued use of modernized diesel
generation appears to be the only reasonable option until demand increases
or a more innovative penstock installation technology is available. New
diesel generators with higher fuel efficiencies should be considered by
the city. Fisheries enhancement measures for Indian River should be
investigated. No further study by the Corps of Engineers appears
warranted at this time.
12
(A copy of the detailed Draft is available upon request~ if not attached.)
TENAKEE SPRINGS, ALASKA
SMALL HYDROPOWER
AND
RELATED PURPOSES
INTERIM FEASIBILITY STUDY
AND
DRAFT ENVIRONMENTAL ASSESSMENT
September 1983
SUMMARY
The development of alternative energy sources to replace the use of
nonrenewable resources, such as oil and gas, has assumed great importance
in recent years. In many isolated Alaskan communities, the reliance on
previously inexpensive diesel fuel for electrical generation has caused
electricity rates to more than double.
Tenakee Springs, located in southeast Alaska, currently receives
electricity from two 90-kilowatt (kW) diesel generators. Rising fuel
prices have more than tripled the cost of electricity in Tenakee Springs,
from 11.1 cents per kilowatt-hour (kWh) in July 1979 to 42 cents per kWh in
August 1983.
This study considered various alternatives to either supplement or replace
diesel generation. Of those, only hydropower appears to have the
capability to reduce Tenakee Springs· reliance on diesel for electrical
generation. However, hydropower would not totally eliminate the use of
diesel. During times of low streamflow, typically in January, February,
March, and August, diesel generation would be needed. The average cost of
a hydro-plus-diesel system is estimated to be greater than the cost of the
existing plant or the new diesel plant alone.
The plan studied consists of a new 265-kW run-of-river hydroelectric
facility on the Indian River with an annual energy capability of 1,870 MWh.
This plan incorporates a provision for a needed water supply as well as
fisheries mitigation. Overall annual project benefits of $281,000 yield a
benefit-to-cost ratio of 0.84 to one under the most reasonable assumptions.
Total project first cost including water supply is $3,676,000.
No further Corps of Engineers studies of Indian River hydroelectric
development at Tenakee Springs are planned at this time because cost of
construction and operation are not shown to be recoverable, and a project
would not be competitive with diesel generation.
GENERAL DATA
Installed Capacity
Number of Units
Type of Turbine
PERTINENT DATA SHEET
TENAKEE SPRINGS
Average Annual Energy (maximum)
Estimated Usable Energy (1986)
Estimated Usable Energy (2000)
Average Annual Equivalent Usab1~ Energy
Average Annual Equivalent Demand
Dependable Capa~ity
100-Year Flood
Design Flow
Gross Head
Des i gn Head
Penstock Diameter
Penstock Length
Dam Height
265 kW
one
Horizontal Francis
1,870,000 kWh
524,600 kWh
692,200 kWh
776,300 kWh
928,400 kWh
none
5,670 cfs
52 cfs
80 feet
71 feet
42 Inch
2,400 feet
7 feet
ECONOMIC DATA (October 1983 Price Level, 8-1/8 Percent Interest)
HYDROPOWER
Project First Cost
Project Investment Cost
Annual OM&R Cost
Annual Cost of Mitigation
Project Annual Cost
Project Annual Benefit
Net Annual Benefit
Benefit Cost Ratio
Total Estimated Energy Cost
WATER SUPPLY
Project First Cost
Project Investment Cost
Annual OM&R Cost
Project Annual Cost
Project Annual Benefit
Net Tangible Annual Benefit
Benefit Cost Ratio
Total First Cost
Total Investment Cost
Total Annual Project Cost
Total Annual Benefits
Total Annual Operation, Maintenance, and
Replacement and Mitigation Costs
i
$3,011 ,000
3,251,000
20,000
5,000
294,000
208,000
(86,000)
0.71 To 1.0
$0.38 per kWh
$301,000
425,000
5,000
41,000
41,000 o
1.0 to 1. 0
$3,312,000
$3,676,000
$335,000
249,000
30,000
TABLE OF CONTENTS
Summary
Pertinent Data Sheet
List of Figures
List of Tables
INTRODUCTION
1 • 1 AUTHOR ITY
1.2 SCOPE OF STUDY
1.3 STUDY PARTICIPANTS
1.4 STUDIES OF OTHERS
AREA PROFILE
2. 1 COMMUNITY PROFILE
2.2 REGIONAL ENVIRONMENTAL SETTING
2.3 ENERGY USE
PROBLEMS AND OPPORTUNITY STATEMENTS
3.1 LOCAL POWER SUPPLY
3.2 WATER SUPPLY .
3.3 FISHERIES OPPORTUNITIES
3.4 SUMMARY OF THE WITHOUT PROJECT CONDITIONS
PLAN FORMULATION
4. 1 OBJECTIVES
4.2 PLANNING ACCOUNTS
POSSIBLE ALTERNATIVES
5. 1 NONSTRUCTURAL
5.2 STRUCTURAL ENERGY ALTERNATIVES
5.3 WATER SUPPLY ALTERNATIVES
PLAN SELECTION
6. 1 COMPARISON OF PLANS
6.2 RATIONALE FOR SELECTING A PLAN
6.3 RATIONALE FOR DESIGNATION OF NED PLAN
7.1 Overview of the Tentatively Selected Plan
7.2 PLAN IMPLEMENTATION
7.3 PUBLIC INVOLVEMENT AND COORDINATION
CONCLUS IONS
ENVIRONMENTAL ASSESSMENT
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1
1
2
5
11
13
19
29
3()
31
35
35
36
37
45
46
49
52
53
59
59
62
TABLE OF NOMENCLATURE AND DEFINITIONS
APPENDIXES
APPENDIX A TECHNICAL ANALYSIS
APPENDIX B CULTURAL RESOURCES ASSESSMENT
APPENDIX C SECTION 404(b)(1) SUMMATION
APPENDIX D RELEVANT CORRESPONDENCE
APPENDIX E INDIAN RIVER FLOW DURATION CURVES
APPENDIX F INDIAN RIVER POWER DURATION CURVES
APPENDIX G USFWS COORDINATION ACT REPORT
; ; i
FIGURES
1. Location and Vicinity Map
2. Regional Employment
3. Indian River Basin
4. Residential Electrical Expenses
5. Energy Demand Plot
6. Preliminary Plant Size Optimization
7. Average Daily Streamflow of the Indian River
T-1. Indian River Suspended Sediment
T-2. Estimated Peak Annual Discharges
T-3. Probable Maximum Flood
T-4. Annual Power Duration and Demand Plot
T-5. Estimated Average Annual Energy Distribution
T-6. Energy Allocation in Tenakee Springs, Alaska
PLATES
1. Project Site Map
2. Geology
3. Dam Plan, Profile and Intake Structure
4. Penstock Plan and ·Profi1e
5. Powerhouse Plan, Profile and Section
6. Water Supply System
7. Transmission Line
8. Single Line Diagram
9. Schedule
TABLES
1. Population
2. Population Composition and Age Distribution
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Page
4
8
10
15
26
50
56
T-6
T-9
T-10
T-13
T-14
Page
5
5
TABLES (cont.)
3. 1980 Residential Energy Use in Various Alaskan Communities 16
4. Average Monthly Household Energy Consumption 16
5. Gross Generation and Estimated Distribution 21
6. Summary of Electrical Conditions 22
7. Diesel Generation Conversion Rates at Various Alaskan Towns 23
8. Load Scenarios for Power-On-Line 1986 25
9. Load Forecast Models for Tenakee Springs 30
10. Diesel Alternative Capacity Cost Analysis 33
11. Fuel Escalation R~tes 34
12. Preliminary Assessment of Hydropower Plans 49
13. Plant Size Optimization 50
14. Average Periods of Operation 56
15. A Partial Listing of Contacts and Coordination During Report 59
Preparation
16. Comparison of Alternatives 64
T-l Indian River Basin Characteristics T-2
T-2 Climatologic Records for Tenakee Springs T-4
T-3 Local Water Quality T-5
T-4 Indian River Flows Calculated from Forest Service Regression T-8
Fonnul ae
T-5 Usable Energy From A 265-kW Hydroelectric Unit T-15
T-6 Preliminary Comparison of Dam Designs T-22
T-7 Preliminary Penstock Materials Selection T-29
T-8 Water Supply Cost Estimate T-41
T-9 Separable Hydropower Project Costs T-47
T-10 Period Energy Sources
EA-l Relationship to Environmental Requirements
EA-2 Effects of the Preferred Plan on Resources of Principal
National Recognition
v
T-52
INTRODUCTION
1.1 AUTHORITY
The evaluation of small scale hydroelectric systems was authorized by a
United States Senate Resolution dated 1 October 1976. That resolution
directed the U.S. Army Corps of Engineers to determine the feasibility of
installing small prepackaged hydroelectric units in isolated communities
throughout Alaska. The full text of the resolution reads as follows:
RESOLVED BY THE COMMITTEE ON PUBLIC WORKS OF THE UNITED STATES SENATE,
that the Board of Engineers for Rivers and Harbors be, and is hereby
requested to review the reports of the Chief of Engineers on Rivers and
Harbors in Alaska, published as House Document Numbered 414, 83rd
Congress, 2nd Session; Southeastern Alaska, published as House Document
Numbered 501, 83rd Congress, 2nd Session; Cook Inlet and Tributaries,
Alaska, published as House Document Numbered 34, 85th Congress, 1st
Session; Copper River and Gulf Coast, Alaska, published as House
Document Numbered 182, 83rd Congress, 1st Session, Tanana River Basin,
Alaska, published as House Document Numbered 137, 84th Congress, 1st
Session; Southwestern Alaska, published as House Document Numbered 390,
84th Congress, 2nd Session; Northwestern Alaska, published as House
Document Numbered 99, 86th Congress, 1st Session, Yukon and Kuskokwim
River Basins, Alaska, published as House Document Numbered 218, 88th
Congress, 2nd Session; and other pertinent reports, with a view to
determining the advisability of modifying the existing plans with
particular reference to the feasibility of installing 5 MW or less
prepackaged hydroelectric plants to service isolated-communities.
1.2 SCOPE OF STUDY
Faced in April 1980 with an obsolete electrical system and high operating
costs, the community of Tenakee Springs requested the Corps of Engineers to
conduct a small hydroelectric feasibility study of Harley Creek and the
Indian River.
This report describes and evaluates the past, present, and future roles of
alternative energy sources in the social and economic structure of Tenakee
Springs. The study also includes evaluations of potential water supply and
salmonid fishery developments.
1.3 STUDY PARTICIPANTS
Responsibility for this study was shared by the Alaska District and North
Pacific Division of the Corps of Engineers. Pertinent drainage basin
information was contributed by the United States Fish and Wildlife Service,
Forest Service, and Geological Survey. The Alaska Division of Energy and
Power Development, the State Department of Fish and Game, and the State
Historical Preservation Office also provided assistance as did the Northern
Southeast Regional Aquaculture Association, the Alaska Power
Administration, the Bureau of Land Management, the Alaska Department of
Labor, and the Alaska Power Authority. Especially important was the
contribution of the residents of Tenakee Springs.
Coordination has been conducted with the USFS and will continue throughout
continued planning and engineering and project construction to insure that
a memorandum of understanding is prepared and followed regarding implemen-
tation of the plan on national forest land.
1.4 STUDIES OF OTHERS
The United States Geological Survey (USGS) Miscellaneous Geologic
Investigations MAP-I-388 (1963) "Reconnaissance Geology Map of Chichagof
Island and Northwestern Baranof Island, Alaskan and USGS Professional Paper
792 (1975) "Reconnaissance Geology of Chighagof, Baranof, and Kruzof
Islands, Southeastern Alaskan were used.
The Tongass National Forest Land Management Plan (LMP), prepared by the
U.S. Forest Service in 1979, is important to the community because part of
the Federal lands bordering the town were transferred to the State and the
City of Tenakee Springs according to the provisions of the Alaska Statehood
Act. This LMP covers the activities of the region which directly and
indirectly influence the economy of Tenakee Springs.
The State Department of Natural Resources (DNR) Division of Geology and
Geophysical Surveying has researched and mapped southeastern Alaska
hotsprings, including Tenakee Springs.
The State Divison of Energy and Power Development (DEPD) drilled test wells
at Tenakee Springs in 1981 in search of a geothermal heat source for space
heating of community buildings. Adequate reservoirs and temperatures were
not located.
A study by the Corps of Engineers evaluated the potential for construction
of a breakwater at Tenakee Springs. Another Corps' study concerned p
connecting Tenakee Inlet and Port Fredrick Narrows by cutting through
Chichagof Island. Neither of these studies, conducted between 1945 and
1975, proved feasible.
U.s. Fish and Wildlife Service and Forest Service surveys have identified
the upper Indian River to be one'of southeastern Alaska's best
unestablished salmon spawning and rearing habitats. Natural barriers
presently prohibit upstream migration of fish.
Tenakee Springs was included in a 1979 Corps report entitled Regional
Inventory and Reconnaissance Study for Small Hydropower Sites in Southeast
Alaska.
The Alaska Department of Transportation and Public Facilities' October 1981
Preliminary State Transportation Policy Plan assessed transportation needs
throughout the State. Improvements proposed at Tenakee Springs include a
$1,000,000 reconstruction of the breakwater and float facilities, a
$500,000 Alaska Marine Ferry transfer terminal, a $7,000,000 airport, and a
$1,000,000 seaplane float expansion and reconstruction project.
2
In February 1982, the Alaska Power Authority (APA) conducted an assessment
of the electrical distribution system at the request of the community and
the State Legislature prior to seeking funding for necessary improvements.
The first phase of a renovation plan was completed by a $200,000 grant.
Expansion of the system is anticipated by 1990. This and other APA studies
provided comparative information used to develop growth projections for
Tenakee Springs.
The Alaska Department of Community and Regional Affairs, Division of
Community Planning contracted the preparation of a photomosaic base map of
Tenakee Springs. Completed in September 1982, the map will be used to plat
subdivisions, rights-of-way, and other land lines for a community land use
plan.
The Tenakee Springs City Council hired Quadra Engineering, Inc., in
December 1982 to conduct a water supply feasibility study before filing for
a legislative or a Rural Development Agency (RDA) grant/loan.
3
o 100 210 300
5c ... , Mil ••
Sf( FIGUII(~ 1 AT RIGHT I
I
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TENAKEE __ .... , ..... -.:L.'
SPRINGS
PACIFIC OCEAN
..
o t
5<olol.WU ..
100
TENAKEE SPRINGS
ALASKA
location & Vlclnlt~
Map
AI ..... 0 .. " Ie I COtP, 0' Engln .....
FIGURE I
2. 1 COMMUNITY PROFILE
2. 1. 1 LOCATION
AREA PROFILE
Tenakee Springs is located on Chichagof Island, the second largest island
in the Alexander Archipa1ego of Southeast Alaska. Tenakee Springs is 50
air miles northeast of Sitka and 45 air miles southwest of Juneau
(Figure 1).
2.1.2 POPULATION
Historically, Tenakee Springs has grown about one percent a year except
during the cannery years when the population increased to 350. The 1982
permanent population was 141 as reported by the mayor in July. The Alaska
Department of Community and Regional Affairs provided the data contained in
Tables 1 and 2.
YEAR
1982"
1981
1980
1970
1960
1950
TABLE 1
popULATION
TOTAL
141
132
138
86
109
140
The permanent population has not changed significantly over the 30-year
period. However, the community experiences a seasonal increase in
population during the summer as summer residents, tourists and loggers
arrive. Population for this 3-month period may rise to 200. Since 1950,
the population has changed little in composition. Caucasions account for
92 percent of the total with the balance composed of Alaska Natives. The
male to female ratio has remained relatively constant.
1980
Pop.%
Total
138
100
1970 86
Pop.% 100
Male
72
52
49
57
TABLE 2
POPULATION COMPOSITION
AND
AGE DISTRIBUTION
Female
66
48
37
43
5
White
127
92
76
88
Black
1
1
o o
Alaskan Native
10
7
10
12
under 5 5-14 15-24 25-44 45-64 65 and over
1980 Total 5 20 14 49 19 31
Pop.% 4 14 10 36 14 22
--------------------------------------------------------------------------
1970 Total
Pop.%
3
3
7
8
4
5
16
19
33
38
23
27
Tenakee Springs is considered a retirement community. The 1980 median age
of 33 for the city's citizens is somewhat higher than the 1980 statewide
median of 26.1 years. However, comparing this figure to the 1970 median of
57 years, it is evident that the city's population has become considerably
younger. The most dramatic changes have been the tripling of the 15-44 age
group and the halving of the 45-64 age group. This change came about as a
result of an influx of younger families during the 1970's.
2.1.3 GOVERNMENT AND SERNICES
Tenakee Springs was incorporated as a second class Alaskan city in 1971.
The government is composed of a seven member city council and a five member
city planning commission. The city council holds public meetings on the
fourth Thursday of each month. Regular elections are held on the first
Tuesday in October of each year. The duties of the council generally
concern overseeing the local services, which are supported by State revenue
sharing entitlements, $24,743 in 1981, and a one percent sales tax on
tobacco, liquor and fuel.
Police
The city has a part-time Chief of Police and a full-time State funded
Village Public Safety Officer.
Fire
The community has a part-time Fire Chief and assistant Fire Chief. There
are no full-time fire-fighters, but, because the population is small, a
crisis effectively volunteers the entire town under the guidance of
department heads. The fire station is well equipped and is serviced by a
new pumper-tank truck that the city council recently purchased. There is
no hydrant system due to the lack of a community water system. Therefore,
the pumper truck draws water from surrounding creeks or, most often, from
hoses placed in the inlet.
Education
Tenakee Springs has two one-room school houses that are located next to
each other. The school is administered by the Regional Educational
Authority and serves 21 primary grade students, kindergarten through the
eighth grade. In addition, the township has four correspondent secondary
school students, tenth through twelfth grade. One full-time teacher is
present year-round and a second teacher is in the community for half of the
year. Both teachers stay in an apartment annexed on to the new school
building.
6
Health
The community has recently completed construction of a health care center.
The center is capable of handling regular and emergency medical care
needs. The facility is staffed by a full-time health aide; two public
nurses and a physical therapist visit the city twice monthly. The facility
is available to physicians and other medical practitioners staying in the
city during the summer fishing months. Cases that require treatment not
available in Tenakee Springs are flown to Juneau or to the native hospital
in Sitka.
Communications
The city has six telephones, one each located in the Snyder Mercantile
building, the school, the public service building, the bathhouse, city hall
and the health center. Television is relayed by satellite and the two
receivable radio stations are broadcast from Juneau and Sitka, respectively.
Transportation
Tenakee Springs joined the Alaska Marine Highway Ferry System in 1978. The
ferry picks up foot passengers going to Sitka once a week each Friday night
and returns for foot passengers traveling to Juneau each Saturday night.
The township has no roads or motor vehicles except for a few all terrain
vehicles, the small fire pumper, and one fuel oil delivery truck. Thus,
transportation to and from Tenakee Springs is restricted to air and water
modes. Small fishing and pleasure craft frequently dock or refuel at the
small boat harbor. A regularly scheduled mailplane on floats will carry
passengers who choose not to charter available small float planes.
Other
A Juneau attorney serves under contract as the city·s legal advisor. A
Juneau civil engineer, with a Tenakee home, is the city·s consulting
engineer. A full-time public works director manages a part-time staff to
provide snow removal, dock maintenance, building maintenance, and street
and trail improvements. An aluminum recycling program is sponsored by the
volunteer fire department. The city provides library service on weekends
and has two part-time librarians. The Senior Center is jointly sponsored
by the city and Catholic Community Services.
2.1.4 ECONOMY
Figure 2 illustrates the 1976 average proportions of employment for the
Chathanl area of Southeast Alaska. The Chatham area is described in the
1977 Tongass Land Management Plan (LMP) as including Haines, Skagway,
Yakutat, Tenakee, Sitka, Angoon, and the smaller communities in their
vicinities. Little specific census related or precise economic data is
available for the community of Tenakee Springs. The number in brackets
indicates the percent of the population dependent on a nonsubsistance
income. The 1980 Census indicates a regional per capita income of about
$8,400; the statewide average was $11,152 and the national average was
$8,781. A precise number is not available for Tenakee Springs but per
capita income is estimated at between $5,000 and $6,000.
7
OTHER
1776= 32.56~o
GOVERNMENT
OR GOVT.
INDUCED
1624 a 29.ncyo
Figure 2
Regional Employment
LOGGING
1055= 19.34%
TOURISM
2OO=3.67~o
Total Population 12,039
Total Employment 5,455
Projected 1990 change: Up 36 percent
Commercial fishing and fish processing constitute about 10 percent of the
total panhandle region's employment. In 1968, the Tenakee Springs docks
moored 26 fishing and commercial vessels and 40 pleasure craft. The Corps'
harbor study, cited in Section 1.4, noted that 100 transient craft refueled
or berthed for the fishing season. At that time, Totem Seafood crab cannery
and Panhandle Seafoods were the local purchasers (Figure 2). Prior to local
logging in the mid 1970's, crabbing and fishing followed retirement and
subsistance as predominant lifestyles. Fishing forecasts are closely keyed
to continued private and governmental enhancement efforts, maintenance of
the limited entry program, which places quotas on the number of fishing
vessels, and technologic improvements in the processing sector.
The natural beauty of the southeast draws thousands of international
tourists each year. Tourism accounts for three percent of the regional
employment. Many visit the Tenakee Springs hot springs and others
photograph, hunt, fish and hike on Chichagof Island. In 1978, 752
passengers traveled to Tenakee Springs from eight cities of origin in
Southeast Alaska; 640 were from Juneau and 88 from Sitka. Tourism will
continue to playa role in the regional economy if discretionary income and
leisure time are available. The Snyder Mercantile Company recently doubled
its overnight cabin space from three to six units and plans further
expansion.
8
Regionally, the logging industry employs 14 percent of the employees.
Ninety-five percent of the harvest is exported (1/2 to Japan) as either
pulp or cants. Provisions of the Tongass LMP call for a 50-year harvest of
4.97 billion board feet (Bbf) in the vicinity of Tenakee Springs, with 280
million board feet (Mbf) cut between 1976 and 1981. The first phase of
logging in the Indian River basin was completed 31 December 1981, and is
scheduled to resume 1 January 1996. The regional logging industry responds
to national construction new starts and import quotas set by other nations.
On 15 April 1982 the Japanese owned Alaska Lumber and Pulp Company (ALP)
closed five of its camps, including the Tenakee Springs-Corner Bay Camp
(Figure 3). The local impact of this closure has not yet been determined.
The camp is scheduled to resume operation in 1983 for work adjacent to
Tenakee Springs.
2.1.5 SOCIAL ENVIRONMENT
General
In 1975, the Alaska Department of Community and Regional Affairs reported
that over 40 percent of Tenakee Springs residents received Social Security
and that per capita income was much lower than the statewide average.
Despite this economic base, the majority of the residents have actively
chosen residence in Tenakee Springs and have sought its particular
lifestyle. Employment opportunities for those not living on retirement
income seem to have been erratic over the past decade with some
opportunities in timber, fishing and fish processing and the local retail
trade. Arts and crafts cottage industries have become increasingly
important as a means of support for the younger and highly educated
families. Subsistence pursuits are very important through both necessity
and choice. After the demise of the fishing industry, which was important
in the early half of the century, the recreation consumer remained the
town's most stable economic resource.
Tenakee Springs' residents frequently express preference for their present
lifestyle which depends on isolation, simplicity and enjoyment of their
natural surroundings. Activities, such as logging, which threaten
community cohesion and isolation through increased population and potential
danger to subsistence and commercial fishing, have intially induced strong
protest from Tenakee Springs residents. Key concerns of the residents
recorded in the Tongass LMP include limiting the sights and sounds of
further logging development, protection of key streams and estuaries, no
road connections to other communities, and no new logging camps. Some
Tenakee Springs residents do work in the timber industry, however, and the
camps do provide income to local retail business and children for the
school, so the timber industry has supplied some economic and social
stability to the community.
9
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Change
The residents of Tenakee Springs value the preservation of their
retirement, subsistence, and recreational lifestyle. They have expressed a
desire to reduce their dependency on foreign oil, conserve their local
resources, and preserve or improve their local economy. They acknowledge
the inevitable growth of the city on a personal level as they watch the
numbers of children grow. A decade ago there were only 6 children in
Tenakee Springs. As a community, they have recognized impending growth by
planning an efficient municipal generation system. They have encouraged
access to their town by constructing a public dock, heliport, urging small
boat harbor expansion, adding a ferry stop and by considering improvements
for air traffic. These and other actions are tangible evidence that
Tenakee Springs is a dynamic community, but one whose development is
actively guided by recognition of its quiet history.
There appears to be no objection by most residents to orderly development,
and the Planning and Zoning Commission plays an exceptionally strong role
in this community. There is objection, however, to any sharp increase in
development activity which would result in adverse social impacts.
Basically people desire a moderate, careful approach with emphasis on
maintaining the natural environment. Visual intrusion of industrial
development would depreciate peop1e 's enjoyment of their town. Sharp
population increases that would place a burden on local services, housing
and subsistence resources would be particularly worrisome.
Social change will accompany population, economic, and energy growth in
Tenakee Springs. Quite likely, a modest fishing industry will be revived.
The DOT-PF predicts the need for a 40-boat capacity harbor expansion.
Harbor designs sent to the Governor have prompted his recommendation to
include Tenakee in the next transportation bond plan. Crab, salmon, and
bottomfish harvests from adjacent waters will enhance the local economy.
Boats now traveling to Angoon, Hoonah, and Pelican could instead sell or
store their catches and purchase their supplies at Tenakee Springs. This
added income could induce the purchase of new appliances and amenities.
Installation of nonfossi1 fuel energy alternatives at Tenakee Springs could
reallocate fossil fuel to other productive portions of their economy and
lifestyle.
2.2 REGIONAL ENVIRONMENTAL SETTING
2.2.1 GEOGRAPHY
Tenakee Springs is located in southeastern Alaska. The region is dominated
by a large group of islands which parallels the mainland for 300 miles
between Dixon Entrance on the south and Icy Strait to the north.
Collectively the islands are the Alexander Archipelago. Six islands have
areas exceeding 1,000 square miles. Chichagof Island, the location of the
study area, is the second largest with an area of 2,062 square miles or the
size of Delaware.
11
2.2.2 CLIMATE
Southeastern Alaska is under the general influence of the cyclonic Alaska
Current, which creates maritime precipitation and temperature patterns east
of the Gulf of Alaska. Easterly moving moisture-laden air masses typically
cause about 80 inches of precipitation annually at sea level and more than
120 inches in the mountains. Yearly snowfalls total about 130 inches.
Persistant southeasterly breezes may develop into 40 knot storm winds with
5-to 6-foot seas. The mean diurnal tidal range is about 14 feet.
Significant variation in local weather patterns away from the coastline can
be attributed to orographic influences. Overall, temperatures average
about 62 degrees F in the summer and 33 degrees F in the winter.
2.2.3 REGIONAL GEOLOGY
The scenic rugged Alexander Archipelago reflects the convergence of the
North Pacific and Continental tectonic plates of the earth's crust. Major
fault zones create the Tenakee Inlet and Chatham Strait. Minor faults are
evidenced by smaller lineal features such as the Indian River basin
(Figure 3). Southwest of this fault, between the river and the community,
are ridges of igneous composition. The mountains to the northeast of the
river are quaternary limestones that were downthrust along this nearly
vertical fault. Pleistocene alpine glaciers enlarged the river basins of
the island and left a mantle of unconsolidated sediments over the
metamorphic marbles and gneisses along the faults. Geothermal aquifers are
captured in the disturbed porous formations along some faults and the beach
where marine deposits have sealed the fault breaks.
2.2.4 ~EGIONAL BIOLOGY
The continuous coastal temperate rainforest of Southeast Alaska is the most
dominating feature distinguishing Southeast from the rest of Alaska. This
old growth forest rises from sea level to 2,500 to 3,000 feet. Species
diversity is reduced with latitude; only 9 conifer and 22 broad1eaf species
attain tree size. Commercially harvested western hemlock, Alaska cedar,
and Sitka spruce forests located on well drained soils cover most of the
non-alpine island areas. In lower, less well drained areas, muskeg and
sedge meadows dot the landscape. A variety of understory species vegetate
slopes and low areas, dominated by ferns, berries, and devils club.
The forest provides habitat for b1acktai1 deer, varying hare, brown bear
and several bird species, including eagles, blue grouse, ptarmigan, and
songbirds. The fish and wildlife resouces of the area rivaled the forests
as inducement for settlement and exploitation. The abundant and easily
accessible salmon runs, fur bearing land and marine mammals, whales, and
bottomfish have been important in both native and contemporary cultures.
The five species of Pacific salmon found are: pink (humpback), chum (dog),
sockeye (red), chinook (king), and coho (silver). Halibut, rockfish, king
crab, dungeness crab, and several varieties of shrimp and clams are still
much sought by local residents, as well as by commercial fisherman.
Waterfowl are abundant throughout the area, particularly during the periods
of migration between northern nesting and southern wintering areas.
Hunters enjoy fine shooting in many bays and tidal flats. The Sitka
black-tailed deer and the brown bear are the major big-game species on
Chichagof Island.
12
The fish and wildlife resources of Southeast Alaska have gone through four
distinct phases of utilization (Federal Field Committee 1968): (1) the
aboriginal phase--oriented primarily toward marine resources, easily
harvested, with negligible drain on productivity; (2) the exploration and
colonization phase--the heavy hunting of sea otter, to the point of
extinction on Southeast Alaska; (3) the commercial fishery phase--from 1878
when the first salmon canneries were built to the dramatic exploitation and
depletion of the salmon resouce; and (4) the recent developmental
phase--hunting and fishing for recreational interests have become very
important, although commercial fishing and subsistence hunting still
continue.
2.2.5 REGIONAL ANTHROPOLOGY
Before the European American settlement of the town of Tenakee Springs in
the late nineteenth century, the Tenakee Inlet area was utilized by several
Tlingit Indian groups. The Hoonah people used to portage to the head of
Tenakee Inlet from Port Frederick to hunt seal and fish. The Angoon people
lived at the lower part of the Inlet and had smokehouses and houses there
at least during the early years of the cannery industry. Indications of
prehistoric settlement in Tenakee Inlet include a pictograph located at
Cannery Point, a petroglyph reported at the town of Tenakee Springs, and a
chert flake found near Kadashan Bay (Appendix B).
As one of Southeast Alaska's older communities, Tenakee Springs was
originally known to miners, prospectors, and hunters as Hooniah Hot
Springs. In 1899, steamboat travel was the only means of transportation.
When cold weather halted mining operations in Nome, Fairbanks, and Dawson,
the miners would journey to the coast. Many spent the winter awaiting
breakup in the "therapuetic" hot springs. About 25 people wintered over by
1894. In the 1890's a hole was blasted in the bedrock to provide a soaking
tub; other improvements including a concrete bathing pool and the concrete
structure which now completely encloses the pool, were built over the
years. Another mainstay of the town was Snyder Merchantile which was
started in 1899. The present Tenakee General Store building was
constructed by Snyder in 1905. The post office was established at that
time. The town of Tenakee Springs itself is listed as a historical
district on the Alaska Heritage Resource Survey file.
2.3 ENERGY USE
2.3.1 ELECTRICAL
From 1914 until 1953 the Superior Packing Company's cannery on Harley Creek
generated a small amount of hydropower for its own use. Tenakee Springs as
a community was electrified in 1954 when the general store installed a
small generator and a few hundred yards of distribution wire to serve the
store and a few households. Between 1954 and 1972 several different
generators were purchased. In 1972, Snyder Mercantile purchased two
Caterpillar 90-kW generators. The original distribution system was
replaced in November 1982 when the city formed a municipal utility.
13
Electrical use has always been limited and relatively constant. The annual
load shape is essentially uniform. The use by greater numbers of the
summer residents about equals winter use by fewer people. There has been
no significant change in spring and fall as has been noticed on regional,
statewide, and national levels. The peak demand pattern determines the
capacity requirements of a utility. Whereas most of the contiguous states
have a summer peak demand, Alaska generally has winter peaking. In 1981,
Tenakee Springs' peak load was about 80 kW with an average load of 30 kW
and 38 percent load factor. Because of the poor and unreliable condition
of the original distribution system, the generation system responded as if
the load factor were 60 percent. The average consumption was only 14,700
kWh per month, about 175 kWh per residence, or roughly one-quarter that of
an Anchorage residence and one-half that of a residence in the neighboring
community of Hoonah. Tables 3 and 4 compare electrical costs,
consumption, and market data compiled by Alaska Power Authority and the
Alaska Power Administration in several cities.
Tenakee Springs households averaged about 2,100 kWh/year (Figure 4). In
comparison, the statewide average was 10,500 kWh/yr and about 4,700 kWh/yr
for the smaller isolated communities primarily dependent on diesel power.
The 1979 national average residential electrical consumption was 8,800
kWh/year. Alaska's 1980 Statewide Energy Plan reports an average capacity
utilization factor of 29 percent compared to the nationwide average of
43 percent. Southeastern Alaska and the bush regions have a 24 percent
utilization factor. The low consumptions in Tenakee Springs and other
rural Southeast Alaskan communities are attributed to the lack of power
pool networks which normally allow utilities to meet their reliability
requirements more efficiently.
Because diesel can be flexibly sized to meet load demand, it remains
attractive to the small communities across Alaska. This is particularly
true in Southeast because of access to major fuel depots and barge routes.
However, electrical history in small communities such as Tenakee Springs is
not indicative of the potential consumption if constraints' to power use and
development were absent. There is opportunity for rate reduction if load
increases, but load growth requires capacity growth. Conversely, reduced
electrical use will increase rates due to increased operating costs unless
the number of customers dramatically increases.
14
11
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8
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0
RESIDENTIAL ELECTRICAL EXPENSES 1981
FROM DEPD COMMUNITY ENERGY SURVEY AND SNYDER MERCANTILE
14
12 10.9
10 rs;:S"SJ ELECTRICAL CONSUMPTION
8
6
4
2
0
05~--------------------------------------------------------------,
0.4. C·:·:·;·.·.·., ELECTRICAL PRICES
03-
0.2
0.1 •
0
1000
800
600
400
200 -
0
r •••••••...•...•••••••••••• .. . . . . . . . . . . . . . . ...• 5~
I· 1I·.·.·.·.·.·.·.·.·.·.·.·.·.·.:t!
I2S&S&$&l ELECTRICAL EXPENSES
655
390
SOU RAL SOUTH
EAST
40~
25~
.................... · .............. . . . . . . . . . . . . . . . . . . · .............. . . . . . . . . . . . . . . . . . . · .............. . · .............. . · .............. . · .............. . · .............. . · .............. . · .............. . · .............. . · .............. . · .............. . · .............. . · .............. . · .............. . · .............. . · .............. . · .............. . · .............. . · .............. . · .............. . · .............. . · . '.' ........... . · .............. . · .............. . · .............. .
· .............. . · ............... . .:.: .:. :.:.:.:.:.:.:.:.:.:.:.:.:. · ............... . · .............. . · ............... . · .............. . ::::: ::::: :::::::::: :::: :::::::::
: :::::::: ::::::::: ::: ::::::::::::
-840
630
BUSH TEN ,KEE
REGIONS SPRINGS
TABLE 3
1980 RESIDENTIAL ENERGY USE IN VARIOUS COMMUNITIES
Name Plate 1/ Per Capita Unsubsidized
Conmunity Population Capacity Consumption
Tenakee Springs 138 180 kW 1,278 kWh
Angoon 465 575 kW 806 kWh
Cordova 1,879 8,400 kW 3,016 kWh
Craig 527 1,085 kW 3,000 kWh
Haines 993 4,270 kW 2,471 kWh
Hoonah 680 1,100 kW 1,173 kWh
Hydaburg 298 530 kW 2,200 kWh
Juneau 19,520 43,662 kW 2,655 kWh
Kake 555 800 kW 1,263 kWh
Kasaan 25 115 kW 1,461 kWh
Klawock 318 875 kW 2,350 kWh
Scal1'l11on Bay 250 345 kW 1,240 kWh
Sitka 7,800 16,600 kW 2,356 kWh
Skagway 768 3,885 kW 2,335 kWh
Valdez 3,079 10,173 kW N/A
Wrangell 2, 184 7,745 kW 1,705 kWh
Yakutat 449 2,025 kW 2,938 kWh
1/ Total installed capacity including backup units
2/ December 31,1981
TABLE 4
AVERAGE MONTHLY HOUSEHOLD ENERGY CONSUMPTION
AVEC
THREA
Craig
Pel ican
Sitka
168 kWh
343 kWh
700 kWh
498 kWh
706 kWh
Petersburg
Metlakatla
Hydaburg
Yakutat
Wrange~l
530 kWh
1,498 kWh
600 kWh
597 kWh
390 kWh
Cost/kWh
40¢
38¢
16¢
24¢
N/A
39¢
24i
6¢
N/A
N/A
N/A
48¢
6¢
18ft
23¢
14¢
26¢
1:./
As reported in the Corps I 1981 Nat i ona 1 Hydropower Study, about 45 percent ,"'
of the total statewide electrical production was al10ted for residential
electrical use in Alaska. In Tenakee Springs it was nearly 80 percent. As
of June 1983, the primary consumption was for incandescent lighting
followed by refrigeration, television, and radio. Although desired by
nearly all residents of the damp Southeast, there were only four electric
clothes dryers in town as of June 1981. There was one electric cook stove,
a few electric blankets, and very few of the appliances COl1'l11on to
metropolitan households. What little hot water is used domestically is
heated on stoves; segregated community bathing is done in the mineral hot
springs.
16
Excessive electrical use has been curtailed by exorbitant cost. Residents
on fixed incomes state that tney are nearing the threshold of willingness
to pay for diesel generated electricity. The 1983 price per kWh was 42¢
based on a wholesale fuel cost of $1.21 per gallon used with an efficiency
of 6.5 kWh/gallon. The nonfue1 operation, maintenance, service and
replacement costs during 1983 were about 10.4¢ per kWh. Distribution costs
and any earned surplus were about 13 cents. The entire situation prompted
the city council to initiate efforts to organize a municipal utility on
8 July 1982. Renovation of the distribution system started on
15 July 1982. A $200,000 grant was appropriated by the 1982 legislature
and the city has appropriated an additional $72,000 for thi~ project.
Construction of the first phase of the new distribution system was
completed in November 1982 (Table 6). By 1985 the existing units will be
fully taxed and will need replacement. A review of electrical use in
several similar communities shows that the demand for power will
significantly increase if additional energy is available. The city expects
a sUbstantial increase in demand between the new system and the State Power
Cost Assistance Program (PCA). The reduction of line losses from 28
percent to about 8 percent should cause an equal demand increase as
predicted by the APA and city officials. The PCA for 1984 will subsidize
up to 95 percent of the residential operational costs which exceed 14¢/kWh
and are less than 45t/kWh, with the lower limit increasing 1¢ each year
(providing funding for this program is continued).
There are 64 metered homes in town, 37 cottages, four commercial buildings,
a sawmill, a school, a firehouse, and a health clinic. On the west end of
town, six newer residences are not served, but will be added during the
next phase of expansion. The older residences are small and consume an
estimated 2,100 kWh/year each, 175 kWh per month (Table 5). The newer
homes are larger, better insulated, and contain more appliances and
amenities than the older homes and cottages. Served by independent
generators, each new home uses about 3,600 kWh/year or 300 kWh per month.
The 37 cottages are used most of the year by different parties. These
smaller units use about 150 kWh in April and September and 100 kWh per
month in the summer. Around 10 of these units are occupied in the spring
and fall, and all are occupied to some length in the summer.
2.3.2 OTHER SOURCES
There are no automobiles in Tenakee Springs, so gasoline consumption is
limited to a few "3 wheelers", service trucks, small engines, outboard
motors, and cruisers. Tenakee Springs consumes about 10,000 gallons of gas
annually and has a 20,OOO-ga110n storage facility. Diesel fuel is consumed
at a rate of 60,000 gallons per year from a 50,OOO-ga110n storage tank.
Fuel oil is relied upon for space heating, cooking, and heating water. The
typical residence consumes about 1,150 gallons annually. Snyder Mercantile
reports that 6,500 gallons are typically sold in December and 2,000 in
July. Some residents cook with propane, using about 10,000 pounds a year.
Residences are primarily small cabins of 300-to 350-square-feet each. The
total community residential floor space is about 42,000 square feet.
Because most of the buildings predate construction practices that
17
incorporated manufactured insulation (some are 75-year-old log cabins) only
15 to 20 percent have fiberglass insulation. Those that are more energy
efficient were built in the last few years. Several residents are also
installing wood heaters in response to rising fuel oil costs and an
abundant supply of wood. No estimate of the number or cords used per year
is yet available. At the present time, Tenakee Springs has no other
sources of energy. Some of the newer homes have passive solar
architechtura1 designs. The feasibility of geothermal space heating
utilizing heat pumps will not be determined unless legislative funding for
exploration is restored.
18
•
PROBLEM AND OPPORTUNITY STATEMENTS
3.1 LOCAL POWEH SUPPLY
3.1.1 GENERATING FACILITIES AT TENAKEE SPRINGS
At present, the municipal electrical capabilities are severely limited by
the age and reliability of the diesel generation system. The generators
themselves have had limited and infrequent maintenance while producing
about 176,400 kWh per year since their purchase in 1972.
Until October 1981, one generator (Table 5) operated 24 hours a day for
over a year after its companion unit broke down. An inspection sticker on
the operating generator indicated that the last maintenance took place 10
October 1978 after 18,977 hours. This implies that the unit had been
serviced and restored three times since its 1972 purchase and has now
logged over half its operational life and has exceeded its economic life.
Although the operational lives can be prolonged with periodic overhauls,
the repeated expenses of repairs decrease the economic efficiency of the
generators.
In October 1981, the two units were repaired and transferred to a new
powerhouse. Further major maintenance was completed in May 1982. Each
unit runs continuously for alternating periods of two weeks. The
maintenance should prolong the life of the units until 1985 or 1986,
presuming continued maintenance and efficient autosynchronous operation.
3.1.2 FUTURE ACTIVITIES
It is difficult to accurately predict the future electricity demand in
rural Alaskan villages because it is difficult to predict the economic
growth of an individual community. Economic growth depends on the
development opportunities that occur as a result of the Alaska Native
Claims Settlement Act (ANCSA), P.L. 96-487 Alaska National Interest Lands
Construction Act (ANILCA), the general economic development of the State
and region, and the availability of electricity to the community. In
addition, each village is a small isolated unit. A change in the habits of
a few households or the local school can have a dramatic effect on the
total level or composition of electricity demand in a community. Also, the
level of demand in any bush village largely depends on government decisions
made outside the control of the community. For instance, the defeat of the
capital move issue in the October 1982 election will insure a flow of
Juneau based people into Tenakee Springs for recreation. Because per
capita electrical consumption in Tenakee Springs is well below the regional
average, the opportunity for load growth is great.
3.1.3 LONG TERM OUTLOOK
The Power Authority has commonly reported 6 to 8 percent annual increases
in population in the southeastern cities that they have under study. They
project these rates to continue into 1986, increasing annually by 1 to 15
percent to the end of the century. The consulting firm CH2M-Hill has
19
TABLE 5
GROSS GENERATION IN TENAKEE SPRINGS
ESTIMATED DISTRIBUTION IN NOVEMBER 1982
(IN KILOWATT HOURS)
SI X NEW MONTHLY EXISTING FACILITIES ON LINE
HOMES DISTRIBUTION SCHOOL AND KESTAURANTS, STORE,
OFF SYSTEM PERCENTAGE 64 HOMES 37 COTTAGES TAVERNzTHEATRE
NET
MONTHLY 21
AVERAGE 300 8.33 175 100-2,963
USE
11
JANUARY 2,220 10.00-15,500 3,330
FEBRUARY 2,140 9.07 14,060 3,270
MARCH 1,720 7.77 12,040 3,270
APRIL 1,890 8.56 13,270 3,250
MAY 1,710 7.76 12,030 1,630 2,940
JUNE 1,660 7.53 11,670 4,040 3,380
JULY 1,740 7.89 12,230 4,040 3,510
AUGUST 1,850 8.39 13,000 4,040 3,520
SEPTEMBER 1,810 8.23 12,760 1,630 2,870
OCTOBER 1,920 8.71 13,500 820 2,850
NOVEMBER 1,690 7.68 11,900 3,160
DECEMBER 1 z850 8.41 13,040 3,350
TOTAL 22,200 100.00 155,000 16,200 38,700
Conmunity Total: 232 2 100 kWh per yearll
II Residential averages from the 5-vi11age T1ingit-Haida Electrical
Association monthly generation reported in 1980.
II Ten cottages using 150 kWh each in May and September, 5 using 150 kWh in
October, and all 37 using 100 kWh June-August.
31 Sum of the sales (176,000 kWh) in 1981, estimated use of four new homes and a sawmill added in 1982, 6 homes not on line, and estimated line losses.
Energy losses = Power Loss (%) (0.3LF + 0.7(LF2)) (net use), where LF = 0.5.
20
TABLE 6
SUMMARY OF ELECTRICAL CONDITIONS
OLD CONDITION RENOVATED CONDITION
GENERATION
Date on 1 ine 1972 1984-85
Fuel Diesel Diesel
Units Cat 0330/90 kW Two 150-kW units
Cat 03304/90 kW
Consumption 80 gpd 120 gpd
Voltage 120/208 three phase 120/240 three phase
House Next to store Next to school
waste heat recovery
DISTR IBUTION
Date on line 1954 November 1982
Poles 30 random dimension 50 treated
untreative native class 4-40 ft.
Crossarms Same 70-6 ft. treated
Insulators Glass Ceramic 7.2 kV
Transformers None 3-50 kVa service
8-25 kVa distribution
Wiring Unknown 17,200 ft. #2 ASCR
5,200 ft. #4/0
RES IDENTIAL
Random 32V 13,200 ft #2 triplex
Interior wiring Upgraded interiors
Meters Glass fuses Circuit breakers
Single phase Single phase
21
TABLE 7
DIESEL GENERATION CONVERSION RATES AT VARIOUS ALASKAN TOWNS
Annua 1 Fuel Energy 1981
Consumption Sold Rate
Location ~ga11ons} ~ Kilowatt-hours) (kWh/g)
Tenakee Springs 25,516 176,400 6.9
Angoon 107,630 819, 113 7.6
Cordova 1,321,000 17,049,600 12.9
Hoonah 200,421 1,972,342 9.8
Kake 179,083 1,496,976 8.4
Kasaan 19,901 69,080 3.5
Klawock 116,608 1,086,853 9.3
Old Harbor 34,100 274,000 8.0
Ouzinkie 19,800 158,000 8.0
Sand Point 141,625 1,770,000 12.5
Scammon Bay 31,000 269,300 8.7
Tanana 200,000 2,000,000 10.0
predicted a 1 percent per year population increase. The USFS Tongass LMP
forecasted changes in the four primary regional industries and then
computed population growth based upon employment growth. Using this
procedure, the population of Tenakee Springs would increase to 167 in 1985,
188 in 2000, 208 in 2010, and 253 in 2030. These figures are similar to
regional projections by the State APA and DEPD.
Three thousand acres for city expansion have been transferred to the city
from the State through land selection program. Some residents have
predicted at least six new year-round residences by 1983, several more
seasonal cottages, and a significant population increase as a result of city
land sales west of town and homesite disposals by the State east of Indian
River. A new school and gymnasium and conversion of the existing school
into apartments are being designed and a small seafood processing plant and
an airport are possibilities. Logging will continue to employ some
residents throughout the mid-to-late 1980's, depending on the future of
Alaska Lumber and Pulp operations. More residents will subsistence fish as
the young and middle age groups expand. The State DOT planning group
expects the harbor to double in 1984 and electricity would be needed for
lights, pumps, and hand tools. The city's purchase of a new municipal
generation and distribution system is evidence of Tenakee Springs'
intention to promote moderate growth and to meet the needs of that growth.
Although the growth in the 1980's will be great by local standards, growth
beyond the 1980's will be controlled by statewide management of oil,
natural gas, coal, and mineral wealth. Allocation of State revenues from
these sources will influence the futures of all isolated communities.
Community and individual lifestyle changes are keyed to the filtration of
this wealth to local levels, bringing with it energy demanding amenities
seen on TV and in catalogs.
22
3.1.4 LOAD FORECASTS
Prediction of load growth in small Alaskan communities is difficult because
adequate records of past use are unavailable.
Three electrical growth scenarios are suggested, each of which draws from a
number of specific studies and experiences reported by the State APA, the
Federal APA, DEPD, DOT-PF, USFS, and the Corps. Each of these is an
extent ion of the existing condition previously discussed in Section 2 and
Table 5. Models are graphed in Figure 5.
Each of the three load growth scenarios uses a common base value of 232,100
kWh. This figure represents the total estimated net consumption plus
anticipated line losses (Table 5). The community total of 232,100 kWh is
the sum of three user categories: those structures on line prior to
November 1982, those added in November 1982, and six homes not yet
connected. Table 8 presents the base figure escalated to the 1986
power-on-1ine date along the guidelines of each scenario.
All three scenarios synthesized reflect a burst of energy consumption for a
short period following the municipal upgrading of the electrical system.
The subsequent growth rates are less than the regional averages because
Tenakee Springs will remain a community in which the residential sector is
a greater consumer than planned commercial developments. Many other
communities of southeast are both larger and have some industrial base
which grows faster than the residential rate.
The scenarios assume the new distribution system improves the overall
system efficiency, and individual customers use their currently owned
appliances more frequently, and for longer periods. In the low growth
scenario residents would purchase few new appliances, but the opposite
holds for the other scenarios. Residents would replace 60 watt bulbs with
100 watt bulbs, buy clothes dryers, electric blankets, and other items that
were previously unreasonable to own because energy was unavailable. New
homes would use 360 kWh monthly. Consequently, energy demand would
dramatically increase as soon as the distribution and generation systems
are upgraded. The unsubsidized cost of electricity would drop because the
community base load would increase. The individual customer using more
energy would not notice a monthly cost reduction because the increased use
would offset any savings eliminated by replacing the distribution system.
Additionally, the peA program will encourage consumption because of lower
consumer rates.
All three scenarios are possible for Tenakee Springs and depend, in part,
on the regional and State economy. As a recreational/retirement community,
Tenakee Springs should continue to grow as long as the residents can afford
to purchase new amenities and nonresidents can purchase land, building
materials, and boats for recreational use.
In all three scenarios the rate of growth decreases substantially after the
turn of the century. The assumption is made that any fuel source used in
the early 21st century will be finite, and cost will react to laws of
23
N .p.
TABLE 8
KIlOWAll -~
The low Growth Scenario lhe HOst likely Scenario The Greatest load Scenario
Population -159 people !' Population -178 People !' Population -192 People l'
Pereent l' Cc.-or Annual Basic }/ Hal'bor ) New &asic l' New ,!, HarbOr il 9 New .reial §! 8asicl' New Y COIIIIIe re ia 1 and
Generation FacUlties E aosion ~s facll1Ues School E sion Houses Dewl nts FacilIties School HarbOr Devel
Jaruary 9.1 2),110 1,180 26,600 5,9110 ),520 11,8110 28,660 7,800 11,940
February 8.0 20,8)0 1,0lI0 2),380 5,940 ),090 11,)70 25,190 7,800 11,1160
March 7.9 20,570 1,020 2),090 5,940 ),060 4,8110 211,870 7,800 4,940
Apr11 7.6 19,790 4,)20 2,980 22,200 5,940 6,500 2,940 9,360 2),910 7,800 16,180
May 7.6 19,790 4,460 2,980 22,210 5,940 6,100 2,940 9,610 2),910 7,800 16,100
..A.Jne 8.6 22,iIOO 7,560 1,100 25,120 1,480 10,800 ),))0 46,800 27,070 ),900 58,750
.l.Jly 8.0 20,8110 7,810 1,0)0 2',)80 1,490 11,160 ',100 48,360 25,190 ',900 60,710
August 8.8 22,920 1,560 1,140 25,120 1,1190 10,800 ',iIOO 116,800 27,710 ',900 58,150
Septelltler 8.8 22,920 4,1160 1,140 25,720 5,940 6,100 ',400 9,360 27,110 1,800 16,l8O
October 8.8 22,920 4,120 1,140 25,120 5,940 6,500 ',1110 9,670 27,710 1,800 16,500
November 8.4 21,810 1,090 24,4)0 5,940 ',240 11,680 26,440 7,800 4,170
Oecellber J.:l 22,610 ...h!1!L 25,460 5,940 3,370 4.8110 27,400 7,800 4,940
Annual
Total 100.0 261,2)0 40,490 12,960 29),010 51,920 59,160 38,880 203,590 315,170 81,900 268,020
Grand Total 314.680 kilh 652.560 kilh 111,710 kWh
!~ IncreaSe 'rom 1982 population of 141 people -penranent residents only, )IIi growth In low scenario, 6tI In medii .. , 81 in high growth scenario •
.. , Eleven cOlll1U1ity average of monthly reSidential percentages as reported by the /!pAD for Pelican, TtflEA, Sitka, Wrangel}.
f.1 From Table 5 escalated from 1982 to 1986 according to the appropriate growth rate listed in Table 9.
.. )0 kill 9 hours per day, 22 days per month, 75$ reduction in s..-r. 5' 30 kill summer load factor .5, spring'fall .3.
61 Cola storage, meat locker, shop tools, welder, street lights, town improvements _ 65 kill loea load in summer, ~ sPrlng/fall, 10. wtnter. l' )0 kill, 10 hours per day, 26 aays per month 50lIl reCluCtion In SUlllllef.
~ greater than medium growth scenario (population growth rate).
19 New
Houses
2,720 7,450
2,400 6,550
2,360 6,460
2,270 6,220
2,210 6,220
2,570 1,040
2,400 6,550
2,6)0 7,200
2,6)0 7,200
2,6)0 1,200
2,510 6,870
2,610 7.120
)0,000 82,080
E
N
E
R
G
Y
~I D
E
M
A
N
0
I
N
K
W
H
..,.
(i') c :::u m
UI
MILLIONS
2.6
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
1975
ENERGY DEMAND PLOT FOR TENAKEE SPRINGS
1975 -2036 POL 1986. 50 YR LIFE
-CEPC REGIONAL MODEL RATES
-----AM HYDABURG MODEL RATES
_. -CORPS HIGH GROWTH RATES
+++ CORPS MEDtUM GROWTH RATES (SELECTED FOR PLANNING)
- -CORPS lOW GROWTH RATES
1980 1985 1990 1995 2000 2005 2010 2015 2020 2025 2030 2035
YEAR
supply and demand. Small communities such as Tenakee Springs will be
unable to compete on fuel markets for discount rates on small allotments of
fuel. There is no indication that energy growth would continue at a rate
greater than population growth and the U.S. Census Bureau forecasts a
nationwide stabilization. after the year 2000.
Low Growth
In the lowest probable growth scenario, very little change would take place
in Tenakee Springs. Several other studies have presented low growth
scenarios wherein Southeast Alaska communities would experience a 14
percent total increase in electrical demand between 1981 and 1986 as they
experience more of the conditions of modern cities. These are communities
with adequate generation and distribution systems serving residential,
small commercial, and public customers. In these communities, a 1.5
percent annual growth rate is commonly tendered until the end of the
century. By comparison, the low growth scenario for Tenakee Springs
predicts that the city remains a small. retirement community with no further
residential, commercial, or public development. Tenakee Springs would
experience a 3 percent annual energy growth between 1982 and 1986. After
1986 annual growth is estimated to hold at 1.0 percent until 2010 and be
zero thereafter.
This is based on a total of 73 year-round residences and 37 cottages by
1986. The six homes of modern construction not on line in 1982 are
included in the least growth scenario. Three additional homes would be
constructed and put on line by 1986. These nine homes would be larger and
contain more appliances.
Although well below the residential averages reported in Table 4, the
combined annual demand for these nine newer homes would be 38,950 kWh once
connected, or 360 kWh each per month. The city would also provide 40,490
kWh of service to the small boat harbor annually.
At the power-on-line date of 1986, the energy demand for this scenario
would be about 314,680 kWh, or 165 kWh per capita per month (Table 8). In
2010, technologic improvements, lack of available land, finite fuel
sources, and energy consciousness, should have slowed growth as shown in
Table 9.
The city regards this scenario as unlikely.
Most Probable Growth
This medium growth scenario predicts that Tenakee Springs' consumption
would more closely parallel that of its neighboring communities. Small
developments in the near term would be followed by a slower growth of
energy demand. Community lifestyle would be preserved but there would be a
slow shift away from the Uretirement" lifestyle as the number of children
increased. Births of new residents would slightly offset the number of
deaths from 1986 to 2006. Per capita consumption in the still residential
community would lag behind the regional average. By 1986, the prosperity
experienced in the more populated Alaskan cities should trickle down to
26
villages like Tenakee Springs. Appliance use would increase. This scenario
includes additional electrical energy demands of some intermittant1y used
small space heaters and a few domestic heat pumps for use in new energy
efficient homes (domestic heat pumps have been used successfully in the
Juneau climate) and public buildings constructed in town.
As indicated by local residents, several State and Federal agencies, and
studies on past regional development, several new buildings would be built
before 1986. These buildings would include a 6,500 square-foot addition to
the school, the nine homes of the low growth scenario as well as the six
additional homes. Harbor improvements and the reconstruction of the cold
storage plant would take place by POL 1986. Forty more boats would dock at
Tenakee Springs and could temporarily hold their catches, both commercial
and sport, before transporting a number of fish enmasse to Pelican or some
other regional facility. Development of a "safe water system" and the
resulting facilities, such as centralized showers and laundry, will make
Tenakee a more likely stop for the commercial and pleasure fleets.
Commercial and public demands would increase in response to the above
changes. The required capacity would be dispersed approximately as follows:
Residences - 1 kW per building
School - 4 kW per 1000 square feet
Commercial - 4 kW per building
Harbor expansion
Cold storage building, meat locker, shop tools,
street lights, domestic heat pumps, floor
heaters,centralized showers and laundry, and
miscellaneous improvements
1986 most likely scenario PEAK DEMAND
116 kW
30 kW
20 kW
30 kW
65 kW
261 kW
Historically, the APA and DEPD average residential, public, and small
commercial energy demand in isolated southeastern communities has increased
5 to 7 percent annually. As a smaller than average community, both
population and energy growth in Tenakee Springs will parallel this trend at
a lower rate, 6 percent annually until 1986. The 6 percent growth period
reflects community access to an upgraded power system in 1982. Reduced
growth rate beyond 1986 fo110ws,a burst of appliance purchases.
In 1986, per capita consumption should average 305 kWh monthly for each of
the predicted 178 permanent residents. The new distribution system would
encourage consumption,a1though not as dramatically as in Napakiak, where a
new transmission line induced a monthly per capita jump from 170-200 kWh to
800 kWh in one year. Most dramatic growth would occur between 1982 and
1986. Even as a small community, the combined affect of the new
distribution system and the PCA program should induce sustained energy
growth averaging 2.5 percent for 20 years.
A paced electrical expansion after 1986 would more closely match population
growth reflecting Tenakee Springs small size. A smaller town does not
develop the commercial base which would induce substantial energy demand.
With only cottage industry, energy consumption would be primarily
27
residential. The larger southeastern communities carry more weight in the
averaging process yielding the'7 percent figure used by DEPD for forecasts
to 2000. The 2.5 percent rate used in this scenario reflects continued
moderate lifestyle changes as the mean age decreases. This rate is similar
to the 3 percent rate used in the Hydaburg model (Table 9) until 2000.
Beyond 2006 the rate drops to 1.0 percent as the community stabilizes in
size and lifestyle. Both population growth and growth of an electrically
oriented population would stimulate small increases in electrical
consumption.
The city considers this scenario realistic, and the most probable. High
land values may impede housing construction, other than seasonal, for the
first few years after early land sales and before power on line in 1986.
The PCA Program will likely reduce rates and encourage increased
consumption to or above predicted levels.
High Growth
Tenakee Springs would remain a residential community in"this scenario, but
more emphasis is placed on the consequences of the recent lands transfer.
In the high growth scenario, the facilities listed in the medium growth
scenario are augmented by a 28-unit second home development three miles
east of the Indian River, as predicted by local and State officials
handling the lands transfer on Columbia Point. Separated from town, this
complex would be electrically interconnected in 1990. Ten new homes would
be built in town. There would be 89 year-round residences and 37 cottages
serviced in this scenario.
A subsidized senior citizens housing facility would be constructed. The
city has land available for the project, but has delayed proceeding,
preferring to await development of a safe water system and sewer
facilities. This facility could demand an average 2,500 kWh monthly.
Because of the influx of people, commercial facilities would be upgraded.
The school building would not be enlarged over the medium growth size but
would be used more often for community functions. By regional standards,
Tenakee Springs would remain a small community. The annual growth between
1982 and 1986 would be 8 percent. From 1986 to 2006 , energy demand would
rise at a rate of 3.5 percent annually, 1.5 percent thereafter. By
comparison, the State APA high growth scenarios used a 4.5 percent rate,
and DEPD used 7 percent to 2000 and 3 percent thereafter.
Table 8 shows the distribution of 777,770 kWh in 1986, which results in a
monthly average of 338 kWh per capita. Figure 5 graphs the growth of all
three scenarios from 1982 to 2036, showing a 67,125-kWh jump in consumption
in 1990 due to the residential housing complex and increased commercial
electrical use.
28
..
p,.
TABLE 9
LOAD FORECAST MODELS FOR TENAKEE SPRINGS
GROSS GENERATION {kWh~
Low Medium
Year
High DEPD Regional APA Hldaburg
1982 II 232, 100 232,100 232,100 232,100 232,100 .
1986 314,680 652,560 777,770 304,230 271 ,520
1990 327,450 720,310 959,630 1/ 398,790 308,560
1995 344,150 814,960 1,139,730 559,320 357,710
2000 361,710 922,060 1,353,640 784,470 414,680
2001 365,320 945,106 1,401,020 808,000 427,120
2006 383,960 1,069,300 1,663,970 936,700 427,120
2010 399,540 1,112,710 1,766,070 1,054,260 427,120
2036 399,540 1,441,230 2,600,900 2,273,580 427,120
Annua 1 1~ 1986-201 0 2.5~ 1986-2006 3.5~ 1986-2006 7"1. 1981-2000 4% 1981-1986
Rates 0% 2010-2036 1.0% 2007-2036 1.5~ 2007-2036 3~ 2001-2036 3"1. 1987-2000
O~ 2001-2036
11 Number derived in Table 5 and Section 3.1.5.
21 A 49,125 jump as a 28-unit recreational complex comes on-line and commercial
facilities use increases another 10 percent.
3.2 WATER SUPPLY
3.2.1 PRESENT FACILITIES
Hillside streams and seeps are tapped for the village water supply. Along
Tenakee Avenue, several 1-inch black plastic pipes and wooden troughs
collect water wherever a rivulet intersects the lane. In winter and dry
seasons, many of these sources are dry. Where these sources are not
sufficient or not available close to an individual home, water is carried
in buckets from a small stream on the edge of town. Potential
contamination is a constant problem. Water is conserved because of its
limited avai1ab1ity. Domestic water consumption in Tenakee Springs is less
than 10 gallons per day (gpd) per person whereas the typical American
residence averages 64 gpd per person. Nationally, municipalities estimate
a total daily use for residential, commercial, and industrial purposes to
be 125 gallons per person. The age and construction of the buildings in
Tenakee Springs makes fire a major concern. The community has one pump
truck in its volunteer fire department. Although equipped with salt water
pumps, a fire occuring at low tide would have ample time to engulf a great
deal of the town by the time hoses were coupled in sufficient length to
descend the warf and reach the inlet water. The seriousness of fire
potential is aggravated not only by the problem of pumping, but also from
the dryness of the wooden structures and organic soil materials and the
dependence on flame heating sources.
29
3.2.2 FUTURE NEEDS
Modest population growth is expected in Tenakee Springs. This growth would
also induce greater water demand. Regardless of the rate of growth, the
present water sources are insufficient. The U.S. Public Health Service
(PHS) water supply objective in bush villages is 50 1itres or 13.2 gpd per
person delivered to homes via a piped system for drinking, cooking,
bathing, and laundering. As recommended by the EPA Cold Climate Utilities
Delivery Design Manual, an upgraded system at Tenakee Springs would be
designed for a peak demand of 230 percent of the average demand. One cfs
would be required to meet projected demand. Commonly used nonstructura1
measures such as metering, recycling, pressure reduction, watershed
management, and leak detection and repair are clearly inapplicable to this
community until a system is created.
Any in-town housing expansion is limited to the hillside above Tenakee
Avenue. Development would eliminate many of the seeps, springs, and
rivulets currently used by the residents. The chance of surface water
contamination will increase with more sanitary and septic systems p1aced"on
the hillside. Residential and commercial development and expansion would
need new sources of water. These new sources must be sufficent to
accommodate the predicted gradual increases in population in future years.
Because of the potential for a major fire, a pressurized fresh water
reservoir would be an asset, not only for fire protection, but consumption
as well. A reserve water supply may also encourage commerical fish
processing development.
3.3 FISHERIES OPPORTUNITIES
After the closing of the Superior Cannery, the local commercial fishery
declined. Local commercial fishing opportunities are limited partly
because catches must be transported to other communities. The costs of
transportation discourage extensive local commercial fishing.
Opportunities are also limited in part because salmon populations within
Tenakee Inlet (Figure 1) are finite.
Some local streams support large fish populations while others, like Indian
iver, do not. Studies of the Indian River conducted in recent years by the
Forest Service and the Fish and Wildlife Service have determined that
nine-tenths of the river is used only by Dolly Varden.
These studies indicate that full utilization by salmon is naturally
prohibited by physical barriers to upstream migration. In similar
situations at other streams, man has helped migrating salmon bypass
obstacles.
Although Dolly Varden and some salmon are caught in the lower Indian River
by local subsistence and" recreational users, Indian River has little
commercial value. This interim feasibility study has the opportunity to
incorporate fisheries enhancement into the planning objectives. The USFS
and USFWS have projected commercial benefits of between $307,000 and
30
$438,000 annually, if the upstream habitat is fully utilized for coho,
pink, and chum salmon. Work on the overall plan can address potential
improvements in the commercial value of the Indian River fishery as part of
the evaluations of hydropower alternatives. There also exists an
opportunity for improved recreational and subsistence uses.
3.4 SUMMARY OF THE WITHOUT-PROJECT CONDITIONS
3.4.1 DESCRIPTION
The without-project condition is defined as the most likely condition
expected to exist in the future in the absence of a project, including any
known changes in law or public policy. The City of Tenakee Springs plans
to operate the two 90-kW units in service now for the near future. The
city will probably supplement these units with larger units by or in 1986.
Diesel generation will continue as the electrical source for the period of
analysis.
The without project condition for water supply and fisheries habitat does
not change. Surface water of limited quality and quantity will remain the
community's potable water source despite increased use because it appears
subsurface waters are inadequate sources. Limited potential exists for
expanding use of one or more intermittant streams closer to town providing
small dams are installed for storage. Resultant potential health hazards
will continue unless sewerage and water distribution plans are improved via
yet unknown state grants to the city which cannot afford such improvements
by itself. Salmon will continue to utilize the present habitat, which
includes only the first half-mile of the Indian River above tidewater.
The most significant impact of the future conditions described is
economic. Laws of supply and demand outside the control of the city would
continue to escalate fuel costs because diesel fuel is a finite resource in
high demand. Continued dependency would leave the city susceptable to fuel
shortages and potential service interruptions. Although the Power Cost
Assistance program will lower electricity costs for the consumer, it will
not lower the actual cost of diesel generation.
The environmental impacts of continued diesel generation are air and noise
pollution. Diesel generation has no impact on water supply or fisheries
unless a fuel spill occurs. Some potential exists for fire as a result of
continued fuel handling.
3.4.2 GENERATING FACILITIES -ECONOMIC LIFETIMES
Because diesel generators are reliable and flexible, they are the popular
choice for providing power to bush villages. But many villages install a
single large unit which is usually not optimally sized to match average
need. A diesel engine running at full power is relatively efficient, but,
the same engine running for a fraction of the rated power, will wear out
three times faster than necessary. Emerson Diesel representatives in
Anchorage estimate that the average lifetime of a medium capacity generator
operating under ideal conditions is 40,000 hours. (Other dealers have
31
reported shorter lifetimes). Assuming 12-hour switched operation, this
translates into nine years. With maintenance, a unit could last 20-25
years under ideal conditions where the rpm is constant and the unit is
closely matched to demand. With infrequent maintenance, generator life
expectancy is reduced to 4 or 5 years.
Economic evaluations of replacement diesel capacity generally reference a
20-year lifetime in an urban or military situation. Because Alaskan bush
community lifestyles are not urban or regimented, a shorter economic life
may more accurately represent the replacement diesel capacity of Alaskan
bush communities.
The life of a diesel generator in the bush is substantially reduced because
factory prescribed servicing rarely occurs. Parts are unavailable or cannot
be delivered in a reasonable time frame because of weather, distance or lack
of sCheduled transportation. Sometimes a trained mechanic is not available
and the local people may not have the expertise or the facilities to make
repairs. For these and other similar reasons, machinery in bush villages
is more often abandoned rather than repaired if the cost is not too great.
T1ingit Haida Regional Electric Association (THREA) reports that a unit
operating at a constant 1800 rpm will typically last 10 to 12 years while
the same unit operating at 1200 rpm lasts 20 years. However, small
communities usually own one large unit and a nearly equally sized backup
unit. Using a 100-kW unit to meet a 30-kW average demand with frequent
jumps to 80 or 90-kW peaks wears the unit out rapidly. Inadequate
dissipation of high temperatures, inefficient operations, and frequent
maintenance outages also reduce energy production.
Because Tenakee Springs is similar to THREA communities, a 15-year diesel
generator lifetime is used in our economic analysis.
3.4.3 COST, OF THE DIESEL ALTERNATIVE
Diesel generators have relatively low initial costs, but high operation,
maintenance t and replacement (OM&R) costs. High temperatures, which induce
wear, and the tendancy to use oversized units inefficiently, precipitate
early replacement. In 1983 the capital cost of a complete medium size
diesel generator system installed in Alaska was about $850.00/kW of
capacity. The first cost of a 500 kW (primary and reserve units combined)
system for Tenakee Springs would be $425,000. Assuming no salvage value
with replacement every 15 years (Table 10) the annual capacity cost is
about $50,000. This annual cost of the basic plant includes replacement
costs and is called the capacity value or cost. The capacity cost/kWh for
the system discribed would be $.059 based on the 1986 (POL) medium growth
projection of 653 t OOO kWh.
Table 10 demonstrates the annual cost of replacing and updating the diesel
system needed to meet area demand over the next 50 years. The estimated
cost/kWh is based on the average annual equivalent (AAE) demand of
mid-range projections shown in Table 9 or 928,400 kWh.
32
The cost per kWh of generating energy with the present diesel system is a
function of fuel cost per gallon and the efficiency of the unit. Table 7
shows an average of 9 kWh per gallon of fuel after eliminating the biases
of the very large efficient units and the very small inefficient units.
New units properly maintained by conscientious factory trained operators
may achieve a 12 kWh/g efficiency. Expecting bush villages to improve
their record, but not to be able to achieve top performance, a 10 kWh/g
efficiency is used in this study. Sensitivities to fuel efficiency are
discussed at the end of the Technical Appendix. An efficiency of 10 kWh
per gallon of fuel and a fuel price of $1.37 per gallon gives a fuel
cost/kWh of $.137. To this must be added the current O&M cost of 8 cents.
This rate is a typical representation from AVEC, THREA, and other reports
from small-system communities.
Structural modifications and/or enlargement of the diesel generation
building (excluding normal maintenance) would be needed when additional
units are required. As estimated 300 square feet would be affected at a
cost of $18,000 in each of the 15th and 45th years. This is an effective
$0.0129/kWh AAE in addition to the $0.080 fuel and normal operations and
maintenance costs. Tenakee Springs· fuel storage requirements would remain
unchanged by any capacity increases.
TABLE 10
COST ANALYSIS OF FUTURE DIESEL SYSTEMS
1986(POL) 2001{15th yr)
Units 2-250 2-325
Capacity (kW) 500 650
$/Unit 850 850
First Cost $425,000 $553,000
P.W. Factor 1 .31
P.W. $425,000 + $171,300 +
Combined P.W. $660,000
2016(30th yr)
2-350
700
850
$595,000
.096
$ 57,120
2031(45th yr)
2-400
800
850
$680,000 x 1/3
.030
+ $ 6,793
Annual Cost of Capacity, $660,000 x .08292 = $54,730
Capacity Cost/kWh = $54,730 + 928,400 = $.0590
Without Escalation With Escalation
Item $/kWh tscalation $/kWh
Capacity .0590 1 .0590
Fuel .137 1.6 .2192
O~ .0929 1 .0929
Total Cost/kWh .2889 .3711
Annual costs/kWh for diesel generation are estimated to be $.289 without
fuel cost escalation and $.371 when fuel cost escalation of 1.6 is allowed
as shown. The 1.6 is a mathematical condensation of the DRI rates shown
below.
Fuel costs escalation rates were used to determine future fuel costs. Fuel
prices in Tenakee Springs have jumped 328 percent between 1970 and 1981.
For the same period, the inflationary increase reported by the Bureau of
Labor Statistics for Anchorage (none is available for Tenakee Springs) was
134 percent, and 143 percent nationally.
33
For the purpose of this study, the fuel cost escalation rates, adopted by
Development Resources Incorporated (DRI) for 1982 are used. Both proposed
annual escalation rates and the prices that would result in Tenakee Springs
are shown in Table 11. (A diesel efficiency of 10 kWh/gal is used.)
YEAR
1983
1985
1990
1995
2000
2005
2010
TABLE 11
FUEL COST ESCALATION RATES
Year
1982-1985
1985-1989
1990-1994
1995-2000
2001-2012
DRI COST
PER kWh
$0.135/kWh
$0.166/kWh
$0.199/kWh
$0.227/kWh
$0.270/kWh
$0.333/kWh
34
DRI Rates
-0.53 Percent
4.23 Percent
3.71 Percent
2.65 Percent
3.53 Percent
PER GAL
$1.37/gal
$1. 35/gal
$1.66/gal
$1. 99/gal
$2.27/gal
$2.70/gal
$3.33/gal
,.
PLAN FORMULATION
4. 1 OBJECTIVES
4.1.1 PLANNING OBJECTIVES
Planning objectives summarize the primary concerns of the study area
residents. They are operational statements identifying the subject of
study, prescribing a general course of action, and setting the parameters
of land and water resource management used to enhance National Economic
Development and Environmental Quality. For this study these objectives are
to:
Stabilize or reduce the real cost of producing electricity at Tenakee
Springs, Alaska for the period of analysis from 1986 to 2036.
Provide a continuing supply of fresh water to the community of Tenakee
Springs, adequate in quality and quantity for drinking and living needs
during the period of analysis from 1986 "to 2036.
Preserve or enhance the commercial resource for pink, chum and coho
salmon in Tenakee Springs area during the period of analysis of 1986 to
2036.
Preserve, and if possible, enhance the terrestrial environment of the
region.
Preserve the archeological significance of any important sites
discovered within the Tenakee Springs project area.
4.1.2 NATIONAL OBJECTIVE
Congressional acts of the last decade directed Federal land and water
resource development studies to incorporate a mu1tiobjective planning
process. Those local needs that can address national objectives with the
goal of promoting the quality of life become the planning objectives.
These objectives are used to evaluate the alternatives on the basis of
equally weighted economic, social, and environmental assessments. The
Federal objective of water and related land resources planning is to
contribute to national economic development consistent with protecting the
Nation's environment pursuant to national environmental statutes,
applicable executive orders, and other Federal planning requirements.
4.2 PLANNING ACCOUNTS
Planning accounts are used to organize the information pertaining to the
effects of alternative plans to promote the quality of life. These
accounts are: National EconomiC Development (NED), Environmental Quality
(EQ), Regional Economic Development (RED), and Other Social Effects (OSE).
The Comparison of Alternatives (Table 15) indicates the degree to which
these criteria are satisfied by each alternative.
35
POSSIBLE ALTERNATIVES
5.1 NONSTRUCTURAL ALTERNATIVES
5.1.1 NO GROWTH, NO ACTION, LOAD MANAGEMENT
These plans essentially represent maintaining the status quo at Tenakee
Springs. Since the existing generation system would need replacement by
1985, and the water supply is unreliable, a plan of No Action is
unacceptable to local interests. A No Growth situation is unlikely because
as the population grows; the demand will increase. Even if a centralized
system were not developed, individual generators would be installed for new
housing.
Load management has value in a large community with a broad power base but
with limited supply. Large users of electricity can be encouraged to use
their allotment of power at an "off" time thereby reducing the peak load.
Tenakee Springs does not have the necessary power facility to utilize load
management; a 90-or l50-kW generator is not a sufficiently broad power
base. Similarly, a graduated rate schedule is not appropriate for such a
small community.
5.1.2 CONSERVATION
Description
This alternative requires the implementation of various methods that would
reduce or restrict the use of energy. Adding additional insulation,
installing storm windows, weather stripping, converting to flourescent from
incandescent lighting, replacement of worn out older appliances with newer
energy saving models, and construction of smaller volumed structures are
all solid conservation measures.
Impact Assessment
This alternative has virtually no negative environmental impact while
having very positive economic and social impacts. If implemented,
significant savings in heating costs could be realized by the community.
The DEPD has estimated that thermal losses in Alaskan structures can be
reduced by 10 percent, saving $180 annually if $300 worth of conservation
improvements are made. A $1,000 to $2,500 expenditure could yield a
30 percent or $500 per year savings on energy costs. The impact on
electrical use would be negligible because no electricity is used for
heating and the overall city energy use is minimal when compared to larger
communities. The cost of electricity is so high that minimizing its use
has become a way of life.
Evaluation
Energy conservation is probably the simplest method to reduce overall
energy consumption in the village. Insulation would greatly reduce space
heating costs. Implementation of this alternative is ongoing.
36
Implementation Responsibility
The basic responsibility for implementing this alternative lies with the
local residents, both individually and as a community. To aid in this
responsibility and to lessen the burden, various State and Federal programs
are available. The State offers energy auditing services, conservation
grants and low interest loans, and the Federal Government offers income tax
credits. These opportunities should be pursued to the maximum extent
possible by the community.
5.2 STRUCTURAL ALTERNATIVES
5.2. 1 ~ASTE HEAT RECOVERY
Description
Potential energy recovery from existing diesel generators may be possible.
One end use is direct waste heat recovery for hot water or building
heating. ~aste heat from the exhaust of the diesel generators heats
another fluid that is piped away. Direct waste heat recovery requires that
the generators be close to the building or water supply being heated,
otherwise heat is lost to the atmosphere.
A second end use is electrical generation using the Rankine Cycle. This
requires vaporization of fluid such as freon by the waste heat from the
diesels. The freon, which is under high pressure, is then used to drive a
turbine which will produce shaft horsepower to turn the generator for
additional electrical power. However, the Rankine Cycle energy recovery
systems are now in the development stage. ~hen they do become commercially
available it will probably only be for units above 1000 k~, too large for
consideration here.
Impact Assessment
The primary impact for this alternative is economic. The buildings in
Tenakee Springs are close together and several are near the generator
building. Such a system could benefit a few, but the rest would receive no
benefit. Currently, the investment in a waste heat recovery system most
likely would be the joint responsibility of Snyder Mercantile, the most
likely recipient of the extra energy because it owns the nearest building
to the generators, and the municip1e utility. The new generators would be
housed in a building to be constructed next to the existing school, or the
new school when it is constructed. In this case the school would be the
beneficiary.
Evaluation
Waste heat recovery may require the maintenance of a supply of water and a
degree of sophisticated engineering and plumbing not available locally.
The water at Tenakee Springs is in limited supply and is very high in
mineral content. Using local water would necessitate frequent maintenance
to remove the mineral scale. The use of distilled water or a special
chemical agent would add a discouraging degree of design complication and
expense.
37
Implementation
Implementation of a future waste heat recovery system would be the
responsibility of the City of Tenakee Springs perhaps with aid from the
State of Alaska.
5.2.2 WIND GENERATION
Description
A wind energy conversion system (WECS) transforms the force of wind moving
past a tower mounted generator into direct current (DC) electricity. DC
use is generally limited to lighting, resistance space heating, or water
heating. WECS commonly are used to charge battery banks in many remote
installations. Where batteries are not desired, a synchronous inverter is
required to transform DC into alternating current (AC) matching the voltage
requirements of most appliances. Expensive inverters are necessary if
conventional appliances are to be used or if the WECS is to be placed on
line with thermal or hydropower generators.
Wind is highly variable in velocity, duration, and direction. WECS are
designed to operate at velocities between 12 and 35 mph with relatively
constant direction and long duration. As the variability of each of the
wind vector components increases, WECS design complexity and cost
escalates. Relatively complicated maintenance requirements require
extensive operator training, and operation in subzero conditions may create
disruptions due to blade icing, lubrication freezeup, tower damage from
strong gusts, and other site specific conditions. WECS technology has
established an expanding market for units in the 1.5-to 15-kW range,
suitable for individual residences or farms and small industrial
complexes. Technology has not proven that larger units capable of meeting
the needs of small communities are competitively priced against thermal
generators.
Evaluation
Limited sustained wind observations are available for Tenakee Springs. The
community is subject to prevailing westerly breezes in the evenings and
strong east winds are common in the spring and fall. The city is wind
she1terd by the surrounding heavily forested mountains. WECS could not be
relied upon for base load generation; they would be limited to intermittent
use.
A WECS to serve the needs of Tenakee Springs would involve a concept called
wind farming. A large number of small (3-to 12-kW) units are constructed
on several acres of ideal terrain and interconnected by an electrical grid
intertied to a distribution system. Wind farms are not well established in
the marketplace probably because the operation and maintenance (O&M) costs
of wind farming creates noncompetitive costs. They must be added to an
existing thermal or hydropower backup electrical generation source. WECS
siting is the most crucial element in a successful installation. Offshore
floating units have not been proven in the United States.
38
In Tenakee Springs, acreage for development is not readily available.
Also, standard support towers are equal to or smaller than local tree
heights. Clearcut areas in the Tongass National Forest are distant from
town, and mountain tops are inaccessible. Further, development such as
this could not proceed without detailed wind records. No adequate
instrumentation is available at Tenakee Springs.
An inherent problem with Alaskan WECS development is that those who could
most profit from their potential are the individuals and small remote
communities least able to afford the high cost of installation, operation
and maintenance. A 10-kW WECS has a basic price in Alaska of about
$25,000. Installation and typical add-on equipment for improved operation
and the reduction of television and radio interference substantially
increase costs. Because reactive power problems limit induction systems
such as WECS to about 25 percent of the required capacity, wind could not
reasonably be expected to serve all community needs. Diesel backup would
be required. A state-of-the-art WECS on the marketplace does not appear to
be a competitive diesel alternative for Tenakee Springs.
Impact Assessment
The primary impact is economic as previously described. The residents of
Tenakee Springs are not likely to absorb the costs of a WECS on an
individual basis and the community does not appear capable of committing
itself to a large WECS and a required diesel system. Further, the
residents of Tenakee Springs place a high value on the aesthetics of their
surroundings. A large number of structures resembling very high voltage
transmission line towers would not be welcome on the local hillside rising
above the forest canopy.
Operational noise has become an issue at other WECS installations around
the country. Residents may not appreciate anything that disturbs their
lifestyle. A wind farm would take up much residential space and may
conflict with the planned expansion of the city. Aside from the loss of
available land, felling of trees or remodeling the landscape can alter WECS
performance. Zoning may be required.
Implementation
The implementation of this alternative would be the responsibility of the
city or individual, aided by the State of Alaska or the Department of
Energy. Various income tax credits, investment allowances, and grant
programs can assist a local WECS program. The responsibility for the
installation of recording instrumentation appears beyond the capability of
the city.
5.2.3 WOOD GENERATION
Uescription
Wood is used for space heating and cooking. Wood could be used to heat
water to steam in a pressurized vessel. Subsequently this steam could turn
a turbine producing electricity. Because coniferous wood is in great
supply in Southeast Alaska, its use as a fuel is an attractive option.
39
Evaluation
As identified in the Alaska Power Authority's March 1981 Hoonah Wood
Generation Feasibility Study, small scale plants are generally not
economical due to high O&M costs. Transportation, handling, and storage
costs generally remain dependent on oil costs. Despite its attractiveness
as a near future space heating fuel, long range use for electrical
generation is inhibited by a number of items.
Use of wood at Tenakee Springs would compete with higher priority
industrial pulp or lumber uses. Cutting restrictions on Tongass National
Forest lands may complicate acquistion of sufficient fuel reserves for the
project lifetime. Environmental concerns associated with logging
practices, necessary road networks, clearcutting, drainage and erosion,
dust, leachate, and changes in mature forests affecting wildlife
populations do not make wood as a base load fuel more attractive than the
established diesel generation system.
As noted in the discussion of waste heat recovery, the mineral water of
Tenakee Springs would be unsuitable in quality and quanity for a steam
plant. The large size particulate matter, creosote, gases, and ashes
associated with softwood combustion would have significant impact on the
air and water quality and accelerate the solid waste disposal burden of
Tenakee Springs. Sparks and creosote buildup would also add to the already
great fire hazard.
5.2.4 COAL/PEAT
Use of coal/peat as a replacement for diesel at Tenakee Springs is not
feasible due to the small scale of the project and long distances from
these resources. Problems associated with establishing the infrastructure,
mining, transporting, and air quality standards would have adverse impacts
both locally and at some distance from the source. On a nonlocal level,
coal/peat use augments serious problems associated with acid rain, the
carbon-dioxide (greenhouse) effects, land and water contamination between
the mine and the source, and promotes technologic status-quo rather than
advancement and innovation. Adverse environmental impacts of this resource
favor continued use of diesel at Tenakee Springs.
5.2.5 NATURAL GAS
This alternative is not considerd feasible because no local supply exists
and one is not likely to be developed for Southeast Alaska.
5.2.6 SOLAR
The high latitude and cloudy maritime climate preclude serious
consideration of active solar electrical generation at Tenakee Springs.
Passive solar technology is far more advanced, less expensive, and
effective for water or space heating in conjunction with modern
conservation measures.
40
5.2.7 GEOTHERMAL
This alternative was considered to have some applicability for space
heating at Tenakee Springs. However, investigations conducted by the State
of Alaska have failed to locate an aquifer with sufficient quantity and
temperature to meet that purpose. Use of geothermally heated water to turn
steam turbines and produce electricity is not practical at Tenakee Springs
based upon DEPD drilling logs. This resource will more likely be developed
at other locations in the State of Alaska as the research continues and
technologies improve. In the event heat pumps were to be used on any
source developed locally, electrical demand would increase.
5.2.8 TRANSMISSION INTERTIE
Description
The Alaska Power Administration and the Alaska Power Authority have been
studying the potential for a 69-kV intertie between Hoonah and the
Snettisham Project near Juneau. Tenakee Springs could possibly pull power
off this system if it were constructed.
Evaluation
In this case, this is not an alternative but a potential alternative. Most
of the data collected to date is presented in the December 1981 Power
Administration Juneau -Hoonah Transmission Line Reconnaissance
Evaluation. The premise of an intertie is based upon sufficient demand
from the Tlingit Native community and a potential Noranda Exploration
mining operation near Hawk Inlet on Admiralty Island. Hoonah is located
approximately 25 miles north of Tenakee Springs on Chichagof Island.
Hoonah has about 1,000 permanent residents and has some light industry.
Hoonah has an average annual load of about 2000 MWh, which has been
projected to increase to 16,600 MWh before the end of the century. By
comparison the Tenakee Springs population has fluctuated between 140 and
200 people and has a load of only 176 MWh projected to increase to 790 MWh
by year 2000.
Costs for a small Tenakee Springs -Hoonah intertfe would be about $150,000
per mile for a total of about 30 miles. Total cost of this alternative
would be about $4.5 million. The variable annual per kilowatt hour rate
would be about 51 cents.
Two of the normally larger items associated with transmission line costs
are the required clearing and road construction. These two items have been
eliminated or reduced substantially in the course of ALP's operations
between the two communities. A line could be constructed at greatly
reduced cost in comparison to one requiring virgin right-of-way
construction.
The Power Administration's report concluded that service between only
Juneau and Hoonah is not economically justified. However, they also
indicated that if the Noranda Exploration mining operation is constructed,
an intertie between Juneau, Hoohah and Noranda may be economically
41
justified. In this case, the Power Administration feels that a feasibility
study would be warranted. The Power Authority is currently conducting a
feasibility study at Hoonah, but the results of that study, and how they
would affect a potential intertie between Hoonah and Tenakee Springs, are
not yet available. In response to a question from the ADF&G, the Power
Administration stated on 6 July 1981:
"There is no relation between this project and the small Indian
River project near Tenakee under investigation by the Corps of
Engineers. Certainly service to Admiralty and Chichagof Islands
leads to thoughts of service to other communities. However, a
transmission line is not justified on the basis of fairly large
loads for Hoonah alone, and very small loads elsewhere requiring
several miles of line are not viable under conventional financing
mechanisms. II
The State APA February 1982 Hoonah Load Forecasts working paper reiterated
the position that a line from Hoonah to Tenakee is unlikely. At this time,
construction of an intertie does not seem economically feasible.
Impact
A transmission intertie has unknown economic impacts at this time.
However, Tenakee Springs residents have repeatedly expressed that
preservation of the isolated, placid lifestyle at Tenakee Springs is very
important, and that they would not favor any alternative that includes a
possible road interconnection, such as a transmission corrider.
An intertie would have limited environmental effects, provided that
adequate controls were exercised during construction and restoration.
Water supply and fisheries benefits are unaffected by this potential
alternative.
5.2.9 HYDROPOWER
Description
Hydropower is one of man's oldest and proven technologies. Both Harley
Creek and the Indian River near Tenakee Springs have apparent hydroelec-
tric capabilities. Each of these streams have elevation drops sufficient
to transform the energy in water, descending from a diversion structure to
generators at a powerhouse below, into electricity. No sizable storage
potential is afforded by the terrain, so only run-of-river projects were
considered.
Evaluation
The Superior Cannery once used 3,000 feet of wood stave pipe to conduct
Harley Creek waters to a 10-kW generator (FPC minor license number 831,
original in 1927 as renewed in 1952.). However, the electrical demands of
Tenakee Springs exceed 10-kW. The streamflow of Harley Creek is about
one-fifth of that recorded in the Indian River (Table 12). Drainage basins
are 4.1 and 20.1 square miles, respectively. An examination of hydrologic
records reveals that Harley Creek would not have sustained flows capable of
42
meeting energy load projections for Tenakee Springs. Further, the expense
of transmitting power from Harley Creek renders that alternative
uneconomical. The Harley Creek site was therefore dropped from further
consideration.
Evaluation of hydroelectric development on the Indian River appears to hold
more potential for meeting Tenakee Springs' needs. At least three separate
damsites allow for several design options with different dam heights,
penstock lengths, and installed generator capacities. For instance, a
small dam about 0.8 river miles above tide water could divert sufficient
flows to a powerhouse at river mile 0.4 to produce 1,860,000 kWh annually.
Because streamflow decreases in the winter when demand is the greatest,
diesel standby power would also be required to meet the projected winter
demand.
This alternative could also incorporate a community water supply to meet
one of the local objectives. A diversion of water from the river to the
community would serve both local and national interests of improved quality
of life and health. A water source tap could be provided at either the dam
or the powerhouse. A small pipeline along the transmission line
right-of-way could feed a storage tank on the edge of town or an
impoundment developed in upper Kushtahini Creek with pumped assistance.
Impact Assessment
The primary impact of this alternative appears to be the stabilization of
energy costs. Social impact appears positive at this time. The community
has an avid interest in hydropower development as indicated by the
cooperation expressed during the study. Adverse environmental impacts
associated with this alternative are relatively minor. Temporary impacts
are likely during construction, but long term adverse impacts are
negligible compared with the potential benefits. No salmon are currently
able to utilize the 10 miles of river above the proposed diversion
structure. About 3,000 feet of the river environment between the diversion
pool and powerhouse would be affected by construction activities and
diversion of streamflows. The significant fisheries and aquatic resources
below the powerhouse site would not be significantly affected. An
excellent opportunity exists for combining fisheries enhancement with this
hydroelectric alternative. The utilization of habitat by salmon could be
expanded from 10 to 30 times. Projected benefits from increased salmon
production is under investigation.
The terrestrial environment would be temporarily disturbed during the
construction period. Some erosion and sedimentation potential exists but
can be controlled either by design or restricted seasonal work. Access
roads are, for the most part, existing as a consequence of prior logging
activities within the watershed. Some clearing will be required for the
project features. Edge effects created along transmission line and
penstock corridors will probably benefit the bird and small mammal
populations. Impacts on Sitka blacktail deer and brown bear movements are
not considered significant. Detailed analyses of this alternative are
provided in the Technical Analysis Appendix and Environmental Assessment of
this document.
43
Implementation
The responsibility for implementation of the hydroelectric portion of this
alternative would lie with the Federal Government, the State of Alaska. and
the city. The Corps of Engineers would require the assistance of the
USFWS, USFS. and ADF&G for planning, design. and implementation of
fisheries mitigation or enhancement measures at the hydroelectric facility.
The State Department of Environmental Conservation, Department of Health.
U.S. Public Health Service, or the community may assume responsibility for
the implementation of any water storage and distribution system if water
supply were incorporated. The first cost and annual costs would be 100
percent repaid by the users over a period not to exceed 50 years.
44
5.3 WATER SUPPLY ALTERNATIVES
Water supply alternatives are rather limited. The city apparently favors a
gravity system which would alleviate future O&M costs, particularly those
associated with running pumps. A city study is underway on SChoolhouse and
Kushtahini Creeks. These proposals have some attraction because a small
reservoir could be developed in lieu of a standpipe, and sufficient
pressure would be avai1abe for fire flows. There may be potential for a
small (10-15 feet) dam to impound up to 20 days supply. However, records
from the Indian River streamgage suggest that the probability of these
streams being essentially dry at two or more times during the year is
high. This study therefore focused investigation on the Indian River for
dependable water supply.
Desalinization of sea water is too costly for local application. Wells and
streamf10ws are the most reasonable options. A proposal for well sources
can consider the findings of the DEPD. Their geothermal investigation
indicated difficult drilling through dense, hard quartz diorite and dense
meta schists. Drilling rates tended to be very slow regardless of the
combinations of bits, speed, and pressure used. Flows described from six
test wells were less than 0.6 gallons per minute (gpm); a 7 to 15 gpm well
is desired for domestic use. The waters were noticeably high in mineral
content and were quite hard (Table T-3). Use of wells appears to be an
inadequate source of potable water for Tenakee Springs because of
inadequate flow and undesireable mineral content. The test holes by DEPD
indicated total dissolved solids are present in levels exceeding PHS
maximum limits.
Working with information provided by DEPD, PHS, several Juneau and
Anchorage well drillers, DEC, and local residents, it was determined that
the first cost of drilling wells, installing pumps, and operating them
would exceed $120,000, excluding desalinization and distribution costs.
Although it appears underground water quantity is no problem if enough
"wet" holes are drilled, reducing the objectionable taste and odor is a
costly problem. A desalinization unit used on the North Slope cost $47,000
in 1975, and required two 175-kW generators and support equipment (not
included in the $47,000) to produce 600 gallons of potable water a day.
Another system used in Barrow requires manned operation 24 hours a day.
Desalinization of well water is not a practical choice for Tenakee Springs.
A comparative review of a surface source cost estimate was made on the
Indian River because of the uncertainty of the quantity and quality of
water from a subsurface source. Three possible solutions were
investigated: (1) a strictly gravity fed ice proof conduit; (2) a conduit
from the proposed dam, along the penstock and transmission line corridors,
with pumped assistance; and (3) a conduit from the powerhouse tai1water
along the transmission line route with pumped assistance over the 130-foot
rise between the powerhouse and town.
In the first option, 6-inch diameter insulated underground polyethylene
pipe run 8,600 feet from the Indian River by qravity flow along the
shortest distance is estimated to cost about $1,236,250 or $107,509
annually. This is based on $100 per lineal foot of pipe including all
materials, valves, housings, and installation required; and 25 percent for
45
contingencies, 15 percent for engineering, design, supervlslon, and
administration evaluated at 8 1/8 percent interest. Five thousand dollars
annual operation and maintenance costs are assumed in all options.
In the second option, a pumped system 6,000 feet long from the hydropower
dam, along the penstock and transmission line routes to the edge of town
could cost $862,500 or $76,518 annually. Water would always be available
from the dam pondage. Although, this source would have adequate quality
and quantity for Tenakee Springs, a less expensive and probably more
practical system would pump water from the powerhouse tailrace and
eliminate the additional cost of 2,000 feet of pipe between the dam and the
powerhouse. This, the third option, would cost about $425,000 or $40,000
annually.
Federal, State and local interests are served by insuring a healthy
population. A separate water supply development on the lower Indian River
would duplicate many of the facilities needed for the hydroelectric plant.
Combining these saves about $12,000 annually.
For a separate system, no intake location holds any particular advantage.
A development near the footbridge (Plate 2) and along the trail would
require longer pipe length. The necessary intake or diversion structure
would be built on shifting fluvial deposits. A pump and pumphouse would be
needed, as would a power1ine from town. Access would have to be improved.
A french drain style intake in the riverbed could be constructed to act as
an inlet even during low water flows (when no water passes through the
penstock). A pump would be placed inside the relatively spacious
powerhouse without interfering with electrical generation. No separate
pumphouse is needed. The pump(s) would operate off the same electrical
system serving the hydroelectric plant. The maintenance trail along the
transmission line could be used to install the water supply conduit. No
additional clearing or road improvements would be necessary. Section T-8.3
of Technical Appendix explains these savings in greater detail.
Water filtration and chlorination would be necessary in any plan using
surface water supplies. These are associated project costs which must be
included in the evaluation, but are not Federally funded items.
6. 1 COMPARISON OF PLANS
The projected energy demand could be satisfied by several hydropower
options on the Indian River. All of the plans studied for power generation
on the Indian River take advantage of elevation differences between at
least 2 of the 5 cascades. The individual cascades are 8 to 15 feet high
and are numbered 1 through 5 upstream. Several dozen combinations of dam
and powerhouse locations, dam heights, installed capacities, and instream
flow releases were evaluated. Table 12 summarizes the options for decision
evaluation. The options with the lowest numerical impact ratings were
evaluated in more detail. This table is only a guide to show which plans
are the most promising.
46
6. 1. 1 OPTION 1
The first option considered a 15-foot-ta11 dam above Barrier 5 (Plate 2)
with a 350-kW powerp1ant below Barrier 1. The dam would have an overall
length of 108 feet with a 45-foot spillway 9.5 feet above the streambed.
Concrete was considered too expensive so gabions were proposed instead.
Gabions have a limited lifetime, are labor intensive, and would result in
high installation and maintenance costs. Rock filled timber cribs, rock
filled bin walls, and concrete weir and sheetpile dams may be competitive
alternatives.
About 600 feet of construction access road would be needed to reach the dam
from the Indian River logging road. Another three-quarters mile of access
is needed to reach the powerhouse from town along the proposed transmission
line.
This option would have a 36-inch diameter fiberglass penstock to divert 40
cfs over a distance of 6,800 feet, with a gross head of 130 feet. The
river would effectively be dewatered at times of low flow. At least three
important salmon pools would be destroyed as year-round habitat. Mitigation
would probably require at least five fish1adders and high instream flow
releases which could curtail plan operation. The estimated first cost in
October 1983 dollars is over $6 million, making this plan uneconomical.
6. 1.2 OPTION 2
Option 2 calls for a 55-foot-ta11 concrete gravity dam at Barrier 1
sufficient in height to flood Barrier 4. Fish ladders would be provided
over the dam. Regulation would be required to meet the energy demand of
Tenakee Springs, and would require enlargement of the dam to dampen
floods. Regulation would reduce the value of downstream fisheries habitat
during sustained releases.
A powerhouse below the dam would use 40 cfs and have a maximum capacity of
135 kW. The cost for this option is substantially greater than Option 1
because both the dam and powerhouse are located on highly faulted and
fractured weathered rock that would be impractical to stabilize to reduce
seepage and the prob.ability of failure. The value of benefits would be
considerably less than the costs of production.
6.1.3 OPTION 3
Option 3 places a 25-foot concrete gravity dam at Barrier 4 with a
powerhouse located about 1,100 feet downstream. The required flow would
dewater the river in this run-of-river option and capacity is limited to
about 150 kW with a net head of only about 50 feet. The expense of
concrete, excavation, and access exceeded the annual energy benefits in the
preliminary analysis.
6.1.4 OPTION 4
The fourth option explored three variations in dam height at Barrier 4.
The preliminary analyses suggested that a 15-foot dam optimized energy
47
production and minimized first cost. The optimization attempted to
determine the best combination of penstock length (the most expensive unit
item) versus powerhead which, in part, would dictate installed capacity.
Refinements of Option 4 included a powerhouse located just below Barrier 2
connected to the dam by 1,800 feet of 36-inch steel penstock on a gentle
uniform grade. An operating range of between 20 and 55 cfs over a net head
of 64 feet would allow an installed capacity of 250 kW. Other than minimal
impacts on one pool adjacent to the tailrace. no known salmon habitat would
be affected. A minor mitigation requirement would be imposed for Dolly
Varden habitat and potential salmon habitat.
A prefabricated dam of wood or sheetpi1e would be 160 feet wide and have a
75-foot spillway. About 1,400 feet of access road for construction would be
excavated west of the logging road. Minimal inspection access to the
powerhouse would be provided along the transmission line.
The preliminary annual cost of Option 4 slightly exceeded the annual
benefits.
6.1.5 OPTION 5
The fifth option includes a low rock filled timber crib dam 175 feet wide at
Barrier 5 with the powerhouse located just below Barrier 3. The net head is
72 feet with the spillway crest at 156 feet MSL and the tailrace at 75 feet
MSL. The range of operating flows and the installed capacity is essentially
the same as for Option 4.
The length of penstock is 2,500 feet, 700 feet longer than that of Option
4. The slopes the penstock crosses, however, are slightly less steep in the
upstream portion of the canyon. Total excavation quantities are similar.
Option 5 utilizes low pressure plastic pipe for an enclosed flume over most
of the penstock route. Only the last few hundred feet are 1/4-inch steel
pipe.
The tailrace is above any known salmon habitat. Because some sidecast
material excavated from the penstock route would be allowed to enter the
stream for cost effective disposal, the nonstructural mitigation plan of
Option 4 would also be applied in Option 5. This option would cost about
$300,000 annually and would have marginal net benefits.
The summary in Table 12 uses engineering constraints for a general
comparison. The impact of construction access subjectively rates the length,
amount of excavation, and time for installation. Maintenance access accounts
for the relative difficulty in getting to the site after construction. The
hydraulic design deals with the complexity of dam design to pass flood
requirements and to make enough water available for power. A medium rating
for installed capacity suggests that potential capacity is close to the
demand. A high or low rating indicates capacity and demand are poorly
matched in the particular option. Salmon impacts rate the amount of habitat
affected. Geology rates the acceptability of the site. Land ownership can
have a high rating if the city, the State, and Forest Service are all
represented whereas a low rating would have only one party involved. Dam
and penstock materials impacts reflect expensive items, or hard to obtain
and/or install items. The lowest total number of points indicate the least
relative impact of the project options.
48
TABLE 12
PRELIMINARY ASSESSMENT OF HYDROPOWER PLANS
Options
Decision Im2acts 2 3 4 5
Construction Access 2 3 3 2
Maintenance Access 2 2
Hydrau 1 i c Design 3 3 3 2 2
Salmonoid Impacts 3 4 2
Geology 3 4
Land Ownership 3 2 2 3
Dam Materials 3 4 4 2 2
Penstock Materials 2 2 4 3
Penstock Length 4 2 3 3
Preliminary Cost 3 4 2 3 3
Installed Capacity 2 4 2 2
Total 28 26 26 26 22
Degree of Impact *Impacts of aesthetic, archeological,
equipment, and streamflow variations
1 -Slight between options have been assumed to
2 -Moderate be equivalent.
3 -Considerable
4 -Severe
6.2 RATIONALE FOR SELECTING A PLAN
6.2.1 SITE SELECTION
The selection of a hydroelectric alternative to diesel generation was based
on the availability and accessibility of the resources available. Coal,
gas, solar, and wood fuels held no advantage over diesel fuel. By process
of elimination, only the water energy from either Harley Creek or Indian
River were found realistic. Harley Creek was soon eliminated from
contention because of limited flows and greater distance from the
community. Harley Creek would cost more to build per unit of energy
produced than would a project on Indian River.
49
In the ratings of Table 12, Option 5 appears to be the best candidate for
evaluation and Option 1, the worst. The high cost of Option 2 associated
with the poor geotechnical conditions caused it to be dropped in favor of
equally rated Option 3 or Option 4. But because Option 3 has insufficient
capacity in comparison with the needs of Tenakee Springs, Option 4 becomes
the second best choice.
Both Option 4 and Option 5 would be capable of producing sufficient energy
to meet a large portion of the demand projected in the most likely growth
scenario. (No hydroelectric scheme could meet all the annual demand due to
periodic low stream flows). The design of Option 4 would require longer
and more costly access features across steeper terrain than that of Option
5. The dam of Option 4 is more complex and costly than that of Option 5.
Impacts on fisheries near the powerhouse in Option 4 are likely to be more
of a concern than those of Option 5 because the pool at Barrier 2 is known
salmon habitat. The powerhouse site in Option 5 is above known salmon
habitat.
Option 5 is selected as the candidate for detailed technical analysis
because it appears to be more accessible, more constructable, less
complicated structurally, less aquatically disruptive, and less costly.
Option 5 best meets the objectives and criteria set forth in Section 4.
6.2.2 PRELIMINARY PLANT SIZE OPTIMIZATION
Preliminary annual power duration curves were created for 100, 200, 300,
and 400 kW. Projected annual demand curves for the years 1986, 1995, 2001,
2006, 2016, and 2036 were overlain on the power duration curves, using the
same scale. The areas common to both curves were digitized and converted
into estimated annual energy.
The energy values for the various plant sizes and the estimated annual
project costs were entered into the HPWRECON computer program for
preliminary annual benefits calculation. Net benefits are the annual
benefits less the annual costs. These are plotted on the left side of
Figure 6. The right side of Figure 6 shows the various usable energy
limits of each plant. Table 13 lists costs, benefits, net benefits and the
benefit to cost ratios for these plant sizes.
TABL~ 13
PRELIMINARY PLANT SIZE OPTIMIZATION
100-kW 200-kW 300-kW 400-kW
Annual Benefits $238,660 $290,140 $290,760 $291,370
Annual Costs 201,400 241,700 290,000 330,300
Net Benefits 37,260 48,440 760 [38,930J
B:C Ratio 1.18 1.003 1.00 0.88
50
N
E
T
B
E
N
E
F
I
T
S
I
THOUSANDS
4O-V
20 •
o .
-20 -
-40
*
I I ,
150 250 ~ 450
KILOWATTS
CAPACITY
U
S
E
A
B
L E
E
N
~
G
Y
K
W
H
1200 -
1000 -
800 •
800 -
,. ,
I
I ,
I • I ,
I
.-. ---
. --------------
I " I ,
I /
I ,
1/ 1/
,
, -1988
.• __ . 2006
---2038
I I I
150 250 380 450
KILOWATTS
CAPACITY
TENAKEE SPRINGSh~LASKA
SMALL HYDROnJWER
FEASIBI LlTY REPORT
PRELIMINARY
PLANT SIZE OPTIMIZATION
Alalka Dlltrlct, CarpI of En,ln .. ,.
FEBRUARY 1983
The projected demand at Tenakee Springs exceeds the output of a 100-kW unit,
and is less than the production of a 400-kW unit. Optimal plant size is
between 200 and 275 kW based on comparisons of projected demand, hydrologic
constraints, and costs. For this small range in capacity, most project
features and associated costs, remain the same. A study of multiple units
for this project yielded no improvements over the performance of a single
unit. Refinements are discussed in the technical appendix. Because the
range in size was small, marginal avoided costs methods and more elaborate
scoping analyses were inappropriate. The selected plant size may be
governed by available off-the-shelf standardized turbine units implied by
the authorization rather than the maximization of net benefits. (More
refined evaluations are presented later in the document.)
6.3 RATIONALE FOR DESIGNATION OF NED PLAN
The National Economic Development (NED) objectives are achieved by
increasing the value of the nation's output of goods and services and
improving the national economic efficiency. Based on these criteria,
hydropower Option 5 would be the NED Plan. This plan would allow the
displacement of expensive petroleum products, create a much needed reliable
community water supply, and/or maintain local fisheries.
52
THE SELECTED PLAN
7.1 OVERVIEW OF THE TENTATIVELY SELECTED PLAN
For Tenakee Springs, a hydroelectric system on Indian River is designated
as the tentatively selected plan. Since it provides the best over all
scheme to meet national and local objectives this hydroelectric plan also
includes measures that improve the value of the local salmonoid fishery and
can supply the community with needed domestic water. Net benefits are
maximized with this plan. It would reduce reliance upon imported fossil
fuels and use renewable resources. The selected plan also meets
Environmental Quality objectives by making a significant contribution to
the cultural and natural resources of the study area if the enhancement
option is exercised.
The selected plan provides a balance between demand, capacity, and cost and
satisfies the planning objectives of the study. The selected plan is close
to town and has reasonably good access.
The selected plan includes a 265-kW Francis turbine operating under 71 feet
of head. The system would operate reliably 7 months of the year and meet a
significant part of the demand for the remaining months of the year. It
could produce about 1,870,000 kWh of energy annually.
Local labor could be employed. The system could be placed in service in a
little more than one year from start of construction. A low weir would be
installed at river mile 1.0. A 39-inch inside diameter pipe would carry
water to a small powerhouse at river mile 0.4. About three-quarters of a
mile of 7,200 volt transmission line would connect directly with the city
distribution system.
The river features which make ideal damsites also make penstock routes and
construction difficult and costly. Reducing the length of the penstock and
the amount of excavation required, for both access and the penstock, became
the critical cost component of the study. The selected plan described in
Appendix A, Technical Analysis, best optimizes the costs and minimizes the
extent of environmental disruption of the project site. The selected plan
has the tentative acceptance and support of all environmental agencies
involved in the study.
7.1.1 POWER COMPONENTS
A rock filled timber crib diversion structure at river mile 1.0 would serve
this run-of-river project. The 39-inch inside diameter plastic penstock
would convey a maximum design flow of 52 cfs to a 265-kW horizontal Francis
turbine 2,400 feet downriver. Gross head is 80 feet with a 9-foot head
loss. This plan is capable of producing approximately 1,870,000 kWh of
energy per year on the average, of which 538,500 kWh would be usable the
first year of operation.
The connection to town would be made by 3,800 feet of 7.2-kV line. The
three phase system on wooden poles would be fully compatab1e with the new
city distribution system of the same voltage. A return line for station
service is also provided. The powerplant at Barrier 3 would be
53
unattended with automatic shutdown due to low flows. It would operate
synchronously with automatic diesel startup capability.
Diesel backup generation would be needed primarily in the months of
January, February, and August; intermittently in March, April, September,
November, and December due to reduced streamflow (Table 14). It is
anticipated that the two existing 90-kW units, now overhauled, and/or
additional 150-kW units should be capable of meeting total demand during
periods of reduced hydrogeneration.
The summaries of Table 14 show that had the unit already been installed, it
would have overaged 322 days of operation annually since 1976. There would
have been 43 days of total diesel reliance, and 73 days of partial reliance
if peak demand exceeded 104-kW. The unit would operate at capacity about
80 percent of the time, half capacity 85 percent of the year, and at
minimum capacity 87 percent of the time annually.
The purchase of any additional diesel capacity could be postponed
indefinitely by synchronously operating different sized diesel backup units
in parallel to closely match demand. Schedules could be derived based upon
streamflows and energy demand at given times across the calendar. A high
degree of efficiency could be attained because the generators could operate
at uniform speeds for fewer total hours using less fuel each year.
Hydroelectric power would meet the base load most of the time and the diesel
generators would come on line as needed to meet peak loads. Diesel
efficiency should increase and the lifetimes of the diesel units could be
extended due to their standby status. Standby 250-kW diesel units would
not be required when the more rugged and flexible hydroelectric development
is installed. Smaller multiple backup units could be operated more
efficiently than a single large diesel unit.
SUMMARY OF COSTS AND BENEFITS -POWER ONLY
Investment Cost
Annual Cost
OM&R and Mitigation Costs
Annual Energy Benefit
Annual Capacity Benefit
Annual Extended Life Credit
Annual Employment Benefit
Benefits -to -Costs Ratio: $240,000, $294,000
7.1.2 WATER SUPPLY COMPONENTS
$3,251,000
269,000
25,000
$170,000
Zero
38,000
32,000
0.82 to 1.0
Tenakee Springs has no developed sewer or water supply system. The
community is attempting to develop a Village Safe Water Program. In
conjunction with hydroelectric development of Indian River, the plan would
run an insulated 6-inch inside diameter polyethylene pipe along the
transmission line route from the powerhouse to the edge of town. Joint
hydro-water supply development appears to be most cost effective. The
community will need about 7,500 gpd for average daily residential use if
the population grows as outlined in the most likely scenario for energy
growth. About 15,000 gpd for peaks will be needed.
54
If the city develops a small resorvoir on Kushtanhini Creek prior to the
implementation of the Federal plan, the Federal plan can be modified to
intertie with the city development at little or no increase in cost.
Instead of continuing the pipe to the edge of town along the transmission
line, the same length of pipe would divert right at the 125 foot contour
and enter the Kushtahini resorvoir. The Federal system would pump upon
demand as the reservoir is drawn down.
The city has not expressed any option to construct at this time. Therefore
Federal plan assumes that at the edge of town, a filtration and
chlorination system, storage tank, laundry and shower complex, and/or valve
complex could be constructed by others. A pump at the powerhouse would run
off station service.
Water supply development has been a Corps project purpose in several
situations nationwide. Corps participation is limited to the development
of the source, its protection, and in some cases, its conveyance to (but
not the distribution to) the population center. In Tenakee, all costs of
Corps water supply projects must be recovered from the city within a period
of 50 years from first use. Costs equal benefits in this simple evaluation.
7.1.3 FISHERIES COMPONENTS
General
The major fisheries resources of Indian River consist of pink, chum, and
coho salmon, and Dolly Varden char. Pink and chum salmon use the Indian
River only for spawning and egg incubation (Figure 7). They spawn in late
summer to early fall. Fry emerge from late March to early April and
migrate to sea. After 1.5 to 3.5 years in the ocean the adults return to
the stream to spawn and die.
Escapement records from surveys conducted by the ADF&G are provided in the
USFS Coordination Act Report.
Coho salmon enter Indian River from late August through October (Figure
7). Fry emerge around December; however they remain in the stream for one
or two summers before migrating to sea. No escapement records are
available for coho salmon; however,it is estimated at a maximum of 100 fish
with less than 50 fish being probable. Coho would be the initial target
species for any mitigation and enhancement feature of the selected plan.
Resident and anadromous Dolly Varden char utilize Indian River. Resident
Do11ys would be principally affected in the reach of river between the dam
and powerhouse. Detailed information is provided in the EA and FONSI.
Mitigation
The USFWS recommended in their 1981 Planning Aid Letter a minimum flow
release between the dam and powerhouse of 27 cfs between December and
April, and 41 cfs during May through October.
55
ut en
""T1
(i)
C
::0
fTI
-J
,
£ o r
I
300
J50
JOO
INDIAN RIVER DISCHARGES AT THE USGS GAGE-TENAKEE SPRINGS
1976-1981
I
I
I
I
.I
! I
-"A. .....• IItIIUI IIA. 'Lor
_.-STA.DARD DIVIATlor
• 150
c ,
S 100
•
cO ~ -•
jJ ': .::.' •• '
• I ' ,. 1 ,." I
"',. J \" • :,': 'wI
o
o
OCT I
• If''': .:
50
NOV 19
tOO
JAN 8
150 200
FEB 27 APR 18
DAYS
Z50
JUN 7
STAY IN STREAM TWO SUMMERS a OUTMIGRATE
IMPRINT a OUTMIGRATE
300
JUL27
350
SEP 15
TABLE 14
AVERAGE PERIODS OF OPERATION
265 kW Francis Unit
, DAYS SHUTDOWN , DAYS BETWEEN 25 AND 52 CFS
QArrR YEAR j;JATE~ YEA~
RONTR 1976 1977 1 g711 . 1q7g 19S0 1981 19S2 AVG RONTH 1976 1977 1978 1979 1980 1981 1982 AVG
OCT 0 OCT 6 3 3 1.7
NOV 0 NOV 18 11 5 4.8
DEC 13 24 3 5.7 DEC 2 6 9 15 4.5
JAN 10 21 19 11 8.7 JAN 3 6 12 31 13 9.4
FEB 13 6 28 2 29 11.1 FEB 6 14 13 11 6.1
MAR 10 4 8 8 4 23 8.1 MAR 13 14 12 6 15 4 7 10.1
APR 8 1.1 APR 5 1 2 13 10 4.4
MAY 0 MAY 0
JUN O' JUN 6 11 2.4
JUL 8 1.1 JUL 1 20 8 13 16 14 10.2
AUG 3 3 6 11 8 23 7.8 AUG 10 26 23 16 8 3 5 13.0
~ SEP 6 9 1 6 3.1 SEP 2 9 4 9 8 1 8 5.8
TOTAL 49 9 70 39 22 7 1M 43.0 TOTAL 65 52 101 60 95 59 75 72 .4
POTENTIAL PLANT FACTORS AND GENERATION
MONTH 20 cfs-l04 kW 35 cfs-184 kW 52 cfs-265 kW
% 1000 kWh % 1000 kWh % 1000 kWh
JAN 71.8 54.8 66.7 90.2 59.4 117.6
FEB 61.0 43.1 5R.7 73.4 53.8 99.6
MAR 73.9 57.2 70.2 96.2 63.3 126.7
APR 96.2 72.0 94.4 125.0 91.3 177 .8
MAY 100.0 77.4 100.0 136.8 100.0 201.1
JUN 100.0 77.3 99.4 131.0 98.1 187.2
JUL 96.3 74.6 94.3 129.2 87.8 177 .9
AUG 74.7 57.9 67.8 92.9 58.8 118.4
SEPT 89.6 67.0 87.4 115.8 83.3 162.7
OCT 100.0 77 .4 100.0 136.1 9R.0 193.1
NOV 100.0 76.5 98.7 1?9.3 96.1 183.4
DEC 81.6 63.2 7Y.0 lOR.? 70,.6 151' .0
Annual 87.2 794.5 [fen 1,366.6 80.5 1,871.1
The minimum flows are desired to sustain the aquatic habitat of the river.
Upon consulation with the USFWS, an additional field survey was conducted.
It was determined that a minimum instream flow of 10 to 12 cfs would be
sufficient to sustain the aquatic resource for the 2,700 feet of river
above the powerhouse. Implementation of 27 and 41 cfs as minimum flows
would preclude the hydropower facility from being economically viable. A
mitigation program was proposed that could easily be expanded into an
enhancement program, with mutual hydropowe~water supply, and resource
benefits.
The most likely species of salmon to be impacted is coho. The coho
mitigation program would consist of an egg take during the late spawning
run in Indian River or adjacent watershed. The eggs would be fertilized on
site, packed in trays and sent to a fish hatchery in Juneau or Sitka. The
eggs would be incubated, hatched and raised until the finge~ling weighed
approximately 1 gram. Fingerlings would then be flown to Indian River for
release above the dam site. Approximately 25,000 fry per planting period
is targeted at a cost of about $12,500 per plant or $4,850 annually,
decreasing in future years as equipment is reused and a routine is
established.
A l-in-3-year planting program is planned with l-in-2 or 4-year programs
also to be considered, as well as additional species. A l-in-3-year
program would provide a split age of fish between 3 and 4 years old. An
estimated adult return and harvest of 250 coho salmon is reasonably
expected from a release of 25,000 fry. The 250 adult returns are based on
a 10 percent fry to smolt survival and 10 percent marine survival resulting
in a 1 percent survival rate. Turbine mortality to salmon smolts is
estimated at 2 to 12 percent. This estimate is based on the assumption
that less than 25 percent of the smolts would enter the penstock and
turbine which could produce 10 to 50 percent mortality. -
Spill would be the rule during each spring freshet. Presumably the
outmigrating juveniles concentrate on the top of the pool. Most would
bypass the turbine by traveling over the spillway or the through the
constant release notch in the spillway. Spillway mortality should be less
than 2 percent; overall system mortality should be 5 to 15 percent,
excluding avian and piscatorial predation. Table 14 gives an idea of the
timing and duration of the turbine inflows and the potential for turbine
mortality when there is little or no spill in excess of 10 cfs. The
penstock intake is hydraulically designed to have a lower velocity than
that of the constant release weir so few outmigrants should be attracted to
the penstock and turbine. The mitigation plan includes a turbine mortality
monitoring program because no studies have been made for small projects of
a similar nature.
A structural mitigation program using fish ladders was also considered but
was dropped from detailed consideration due to lack of support from various
resource agencies as well as not being engineeringly acceptable because of
high potential for damage by floods. The selected operational program
provided the more cost effective mitigation as compared to structural
alternatives.
58
7.2 PLAN IMPLEMENTATION
Various options are possible for the implementation of this plan. Under
the first two scenarios it is anticipated that the local utility would be
responsible for the operation of the plant by contracts with the State or
Federal agencies. The options available are listed below:
1. Construction by the Corps of Engineers with Federal funding.
2. Construction by the Corps of Engineers with State or local funding.
3. Construction by the Corps of Engineers with State of Alaska using
State grants or loans.
4. Cost shared State and Federal construction by the Corps of
Engineers.
5. Construction by a private firm with State or local funding.
6. Construction by a private firm with private funding.
7.3 PUBLIC INVOLVEMENT AND COORDINATION
Throughout the course of this study public involvement was accomplished
primarily through public meetings, individual discussions with community
leaders, utility owners, and telephone conversations and correspondence
with interested parties. The input from these sources early in the study
process helped to direct the study and provided data needed to develop a
plan. State and Federal agencies contacted directly or through the State
Clearinghouse reinforced the developing plan throughout the entire study
process. Some of the important contacts and coordination efforts are
listed below.
TABLE 15
A PARTIAL LISTING OF CONTACTS AND COORDINATION DURING REPORT PREPARATION
May 1980
August 1980
August 1980
thru March 1981
December 1980
Public Workshop
Public Workshop
North Pacific Division
U.S. Fish and Wildlife
Service
59
Notice of start and intent of the
study; initial data gathering
mission.
Additional scoping work and data
collection.
Plan formulation and design work
cooperation.
Initial coordination for
planning aid letter and instream
flow requirements.
December 1980
December 1980
January 1981
February 1981
June 1981
June 1981
October 1981
December 1981
December 1981
March 1982
March &
April 1982
u.s. Forest Service
Alaska Division of
Energy and Power
Development
u.S. Forest Service
Snyder Mercantile
Public Workshop
u.s. Forest Service,
Sitka and U.S. Fish
and Wildlife Service,
Sitka
Alaska Department
of Fish and Game
Snyder Mercantile
T1ingit-Haida REA
Alaska Department of
Transportation and
Public Facilities
Alaska Power Authority
60
Description of Indian River
cascades systems and potential
fisheries improvements possible in
conjunction with a hydropower
project.
Obtained data from their
geothermal drilling program
which could influence planning for
electrical and water supply in
town.
Basin hydrology, forestry, geology
interpretations.
Electrical load history, sales
records, general community history
and economic setting.
Progress report, discussions of
energy usage patterns,
alternatives to be evaluated and
potential hydropower site
descriptions.
Plan of study; sizing and
location of potential project;
coordination of involvements;
sharing of information; joint
field trip.
Obtained designs and plans for
possible installation of fish
ladders.
Preliminary description of planned
improvements in the local
electrical system.
Energy costs, usage patterns, and
equipment typical to small
Southeast Alaska villages.
Discussion of facilities and
improvements planned for Tenakee
which could influence energy
changes.
Evaluation of the electrical
distribution system and potential
future requirements; regional
forecasts applicable to Tenakee's
electrical growth rates.
•.
April 1982
May 1982
May &
June 1982
June 1982
June 1982
Nov 1982
January &
February 1983
u.s. Public Health
Service
Alaska Department
of Environmental
Conservation
City of Tenakee
Springs
Juneau Based Well
Dri 11 i ng Fi rms
Alaska Power
Administration
u.S. Fish and
Wildlife Service,
Anchorage
u • S. Fish and
Wildlife Service,
City of Tenakee
Springs
Discussion of potential designs,
problems, needs, and costs of
incorporating a water supply
into the hydropower project.
Received comments supporting
preliminary load forecasts and
and local descriptions to be used
in draft report.
Obtained costs, schedules,
anticipated difficulties for
installing a system at Tenakee.
A review of load projections.
Resolution of instream flow
requirements and mitigation
measures to include 10 cfs
constant release, controlled
low flow spillway, screened
low velocity intake, avian
protected transmission line
design, and strip-rear-release
fisheries program.
Received final CA report for
a prior draft plan at Barrier 4.
The recommendations are included
in this plan. An amendment to
the CA report -is attached to
the report.
Provided private consulting
firm with information relative
to a separate water supply
feasibility study.
4 October 1983 U. S. Fish and Wildlife All three agencies sign a
November 1983
Service, U.S. Forest letter of cooperative intent
Service, and Alaska to enhance fisheries benefits
Department of Fish in conjunction with a Corps
and Game hydropower projection Indian
River.
City of Tenakee
Springs
61
Reduced electrical demand
information is furnished
which forces termination
of the Federal-hydropower
study.
CONCLUSIONS
Continued use of diesel power generation appears to be the most economical
way to meet the electrical generation needs of Tenakee Springs. However,
the Indian River could provide a water supply source for Tenakee Springs.
Details of the hydropower alternative and the water supply system are
contained in the Technical Analysis. A detailed description of mitigation
measures and a potential fisheries enhancement program is outlined in the
Environmental Assessment.
By 1986 Tenakee Springs would need about 260 kW of peaking capacity. By
2031 the required capacity could be about 410 kW. Hydropower could meet a
significant portion of that demand, but not economically. Tenakee Springs
is currently upgrading their system and hydropower would help stabilize
electrical costs. During periods of low stream flow diesel generation
would be needed to meet the remainder of Tenakee's future energy demand.
Hydroelectric potential is sometimes advantageous because its cost per
kilowatt hour remains uniform while diesel fuel generation costs tend to
rise. The economic advantage of Indian River hydroelectric development
disappears at low energy consumption levels because of the high fixed costs
for construction of the facility. This is the present case in Tenakee
Springs. Potential production exceeds demand, so sales are insufficient
for cost recovery.
Indian River would provide a dependable source of water for domestic and
commercial use. An alternative water supply plan to withdraw water from
the river above the diversion site (Barrer No.5) would enable gravity flow
in the pipe. However, an additional mile of pipe would be needed and all
of the pipe would have to be a larger diameter due to the increased
frictlon losses in the longer pipeline. Also the amount of water diverted
through the water supply pipeline would not be available to produce
electrical energy. The city of Tenakee Springs retained a consultant to
prepare a water supply plan and a draft of the consu1tant 's report was
completed in July 1983. The findings of that report are being evaluated
the Tenakee Springs City Council.
The opportunity exists to greatly enhance the salmon resources of Indian
River. The five natural barriers to fish, completely block upstream
migration to the 10 miles of prime spawning and rearing habitat. A
potential enhancement measure would specify 1addering or physically
altering the configuration of the cascades which act as barriers to
movement. The proposed diversion structure is designed to be adaptable to
1addering if an enhancement program is selected. The sponsoring agency
would install ladders or modify the barriers. The expected commercial and
sport catches of not only coho but also pink and chum salmon would more
than offset the costs of enhancement program initiation and operation.
Because the enhancement program is not dependent upon the hydropower
project, could be implemented by any of several organizations.
62
An alternative commercial anadromous fisheries enhancement program could
involve expansion of the mitigation program by the frequency of fry
planting as well as the number of fry planted. This operational
enhancement program would evaluate planting of coho and king salmon for the
greatest economic return for the program. The ADF&G, USFS and USFWS have
expressed a preference to this type of program versus the structural
(ladder) alternative. In addition, this alternative when combined with the
mitigation program would reduce the cost per fish planted and would
increase the economic return.
A commitment to this development plan would require monitoring of flows,
detailed upstream habitat surveys and refinement ,of mortality estimates
both natural and project induced.
A means should be developed for continued operation of the USGS/USFS
cooperative streamgage. Additional hydrologic data would improve the-
reliability of design and plant sizing.
Current Federal guidance endorses the development of joint Federal and
State cost sharing or local sponsorship of Federal development through an
innovative financing agreement with a nonfederal interest. Unless totally
financed by nonfederal interests, it is anticipated that power marketed
from remote small hydroelectric facilities, such as this project, would be
allocated by the Alaska Power Administration. It appears likely that the
APA would contract with the local utility for operations and maintenance
services in remote communities. The cost of power and such services would
depend on how the project was financed. The consumers would be expected to
repay development costs of the project as part of their monthly bills.
The residents of Tenakee Springs have expressed an interest in helping to
building, operate, and maintain any hydroelectric facility built there.
Sufficient skills are available for the successful execution of at least
half of the construction and OMR phases. These skills are available for
less than Davis-Bacon Act wage rates. The use of simple design techniques
and the more basic the labor and equipment provided, the better chances of
operation of a facility as intended.
The benefit calculations included all categories which may be reasonable to
expect. Some of these, such as secondary energy benefits and intermittant
capacity credits, are supported by very weak arguments and are therefore,
excluded from the ultimate evaluation of the project to avoid being overly
optimistic in a project where so many variables are unknown or estimated
based on very limited data.
It is concluded that this project as defined and prepared according to
Federal criteria is infeasible and does not warrant further study by the
Corps of Engineers at this time.
63
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64
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ENVIRONMENTAL ASSESSMENT
SMALL HYDROELECTRIC POWER DEVELOPMENT
INTERIM FEASIBILITY STUDY
TENAKEE SPRINGS, ALASKA
U.S. Army Engineer District, Alaska
Anchorage, Alaska
September 1983
NEED FOR THE PROPOSED ACTION
The community of Tenakee Springs, faced with an obsolete electrical system and
hi gh opera ti ng cos t, reques ted the Corps of Engi neers to conduc t a small
hydroelectric study of Indian River and Harley Creek in April 1980. The
community also requested the Corps to investigate incorporation of a water
supply system to meet the residential cOlTlTlunity needs in conjunction with the
hydroelectric power study.
PROJECT SETTING
Tenakee Springs, located approximately 50 air miles from Juneau, is a small
cOlTlTlunityon the north shore of Tenakee Inlet on Chichagof Island, Alaska.
Chichagof Island is part of the Alexander Archipelago that comprises much of
Southeast Alaska. The townsite of Tenakee Springs consists of about 200 acres
located on a narrow strip of land near tidewater. The community has a
year-round population of 130, with a seasonal summer high of about 200
people. Tenakee Springs has 97 buildings that are connected to electric
power. Tenakee Springs households use an average of about 2,100 kWh per
year. Electric power is supplied by a 90-kW diesel generator. The community
has neither a centralized water supply nor sewage system.
Transportation to and from Tenakee Springs is restricted to water and air
modes. The cOlTlTlunity has no roads or motor vehicles except for a few all
terrain vehicles, fire equipment and one fuel oil delivery truck. Small
fishing and pleasure craft frequently dock or refuel at the small boat harbor.
Additional information concerning the general regional and project setting may
be found in the main report under section 2.2 Regional Environmental Setting.
Aquatic Resources
The watersheds of Indian River and Harley Creek are relatively long and
U-shaped as a result of previous glacial action. Indian River, located
approximately 1 mile east of Tenakee Springs, has a watershed area of
approximately 26 square miles, a main stream length of 11 miles, and a mean
annual flow of 156 cubic feet per second (cfs). Harley Creek, located
approximately 4 miles east of Tenakee Springs, has a watershed area of 4.3
square miles, a main stream length of 3 miles, and a mean annual flow of 29
cfs. The Harley Creek site is not a feasible site for producing hydroelectric
power for Tenakee Springs and is hot considered in this Environmental
Assessment.
The major fisheries resources in Indian River consist of pink salmon
(Oncorhynchus gorbuscha), chum salmon (0. ketal, coho salmon (0. kisutch) and
Dolly Varden char (Salvelinus malma).-Pink and chum salmon utilize the
freshwater habitat of Indian River only for spawning and subsequent egg
incubation. Spawning takes place in late summer and early fall, eggs hatch
generally from late November to January. After hatching, the fry emerge from
the streambed from late March to early May and migrate to sea. After 1.5 to
3.5 years in the ocean, the adults return to the stream of their.origin where
they spawn and die.
2
Salmon escapement records for pink and chum salmon are presented in Table 2 of
the Fish and Wildlife Coordination Act Report. In summary, pink salmon
escapement observations (1976 to 1980) varie'd between a low of 970 and a high
of 6,150 fish. Chum salmon escapement observation varied from a low of 20 to
a high of 1,OlD fish. No escapement records are available for coho salmon.
Coho escapement is estimated at less than 100 fish.
Coho salmon enter Indian River in late August through October. Their
activities and life requirements are somewhat similar to pink and chum salmon;
however, the young continue to use freshwater as rearing habitat, usually for
two surrrners, before migrating to sea. Comparatively, the coho salmon is the
strongest of three salmon and is able to migrate further upstream over natural
barriers in Indian River than pink and chum salmon. Analysis of river
features i ndi cate fi ve natural barri ers or di scouragements to fi sh passage
between river mile 0.4 and 0.9 (Plate 1). The five barriers are located below
the preferred dam site.
Barrier 1 is located at river mile 0.4 (elevation 30 feet mean sea level,
fmsl) and consists of two cascades. The upper cascade is a barrier to pink
and chum salmon, but not to coho salmon. The lower section of river (mile 0
to 0.4) provides excellent spawning and rearing habitat for pink, chum and
coho salmon.
The second barrier is located at mile 0.5 (elevation 50 fmsl) and consists of
a 12-foot-high falls and cascades. No coho fry were observed above this point
in 1980 and 1981. The falls is probably a barrier to coho passage; however,
coho passage may be possible at flows less than 150 cfs. The alternative
proposed powerhouse site is between barrier 2 and barrier 1.
Barrier 3 is located at mile 0.7 (elevation 80 fmsl) and is a velocity barrier
created by a hydraulic jump with a 2-foot vertical drop. It is believed that
coho could negotiate this barrier under certain flow conditions. The proposed
powerhouse is located between barrier 2 and barrier 3.
Barrier 4 (mile 0.8, elevation 113 fmsl) is a 15-to 17-foot-high falls and
cascade system and is considered a barrier to all fish. The alternative
damsite is located just upstream of this barrier.
Barrier 5 (mile 0.9, elevation 145 fmsl) consists of a 10-foot-high-cascade
system. The cascade would be a barrier to pink and chum salmon; however, it
is believed that coho salmon could negotiate the barrier under certain flow
conditions were they able to pass the downstream barriers. The preferred dam
site is located 50 feet upstream of this barrier.
Instream habitat between barrier 2 (mile 0.5) and barrier 5 (mile 0.9) is
considered poor to moderate due to the high stream gradient. A stream
gradient profile is provided in the Fish and Wildlife Coordination Act
Report. Only resident Dolly Varden were observed and captured above barrier
2. Good, but unutilized spawning habitat for salmon is located between mile
0.9 and mile 2.7. From mile 2.7 to mile 3.9, the stream gradient decreases
. and several beaver darns and backwater areas are located along the stream
course. There is little spawning habitat, but excellent potential rearing
habitat for coho salmon in this reach. From mile 3.9 to mile 11.6, the river
offers a variety of good to excellent salmonid spawning and rearing habitat.
3
The U.S. Forest Service (USFS), the U.S. Fish and Wildlife Service (USFWS),
the Corps of Engi neers (COE), and the Alaska Departmen t of Fi sh and Game
(ADFG) have acknowledged the fisheries enhancement potential for the Indian
River. At least 10 miles of good to excellent spawning and rearing habitat
for salmon is above the last upstream barrier at mile 0.9. The USFS conducted
a preliminary fisheries enhancement feasibility survey for Indian River, which
indicated that a commercial value of $437,700 per year could be realized if
fish passage above the natural barriers could be realized. This $437,000 in
commercial value is based on the harvestable population (adult returns)
increase of 30,000 chum salmon; 96,000 pink salmon and 3,300 coho salmon that
could occur based on stream surveys.
The above information was extracted from field investigations, reports by the
USFWS and Corps, meetings with various agencies and from the Fish and Wildlife
Coordination Act (FWCA) report prepared by the USFWS. Additional information
concerning the fisheries resource can be found in Appendix A, FWCA Report.
A summary of water quality data collected by the USFS, with a comparative
evaluation to acceptable drinking water standards of the State of Alaska, is
provided in Table 15. In general, the pH of Indian River is between 7 and 8
and the water quality meets drinking standards. Suspended sediments however,
vary from 0.1 mg/l at a flow of 15 cubic feet per second (cfs) to 500 mg/l at
1,000 cfs. A summary of suspended sediment data collected by the USFS is
presented in Figure T-l.
Terrestrial Resources
Sitka black-tailed deer (Odocoileus hemionus sitkensis) and brown bear (Ursus
arctos) are the two major big games species that inhabitat the project study
area. Both species are dependent on the coastal forest ecosystem. Preferred
spring and summer habitat for brown bear is along grassflats, tide-influenced
meadows, forest fringe, and anadromous fish streams such as Indian River.
Well used game trails are evident on both sides of the river from tidewater to
the headwater. During salmon migrations bear use may be concentrated in the
area below barrier one.
The riparian zone of Indian River provides habitat for mink (Mustela vision),
marten (Martes americana), river otter (Lutra canadensis), and beaver (Castor
canadensis). Various species of waterfowl occasionally use the upstream
muskeg and beaver pond areas for resting and feeding. Raven (Corvus corax)
and northwestern crow (Corvus caurinus) are common along the riparlan zone and
tidal grassf1ats. Shorebirds, gulls, waterfowl and other seabirds are found
in the marine waters of Tenakee Inlet. Bald eagles (Ha1iaeetus leucoceShalus)
are very common near tidewater areas within the study area. Nine bal eagle
nest trees have been identified between Tenakee Springs and Harley Creek.
Harbor seal (Phoca vitulina), Steller sea lion (Eumetopias jubatus), and the
humpback whale (Megaptera novaeangliae) are commonly observed in Tenakee Inlet.
Endangered Species
No known endangered terrestrial mammal or avian species are known to exist in
the project area. The humpback whale is listed as an endangered species
pursuant to the Endangered Species Act of 1969. Al though common to waters of
Tenakee Inlet, it is not anticipated that the project will effect the whale or
its habitat.
4
The bald eagle is not classified as an endangered species in Alaska. The bald
eagle is protected by the Bald Eagle Protection Act (16 USCC 668-668d) and the
Bird Treaty Act (16 USC 703-711). Bald eagles and their nest trees are
further protected through a cooperative agreement between the Fish and
Wildlife Service (FWS) and the U.S. Forest Service (USFS), which restricts all
disturbances within a 330-foot radius about each nest tree.
Additional information concerning the environmental resources of the Tenakee
Springs study area may be found in The Forest ECOStstem of Southeast Alaska,
1974,: Vol. 1, "The Setting"; Vol. 3, iiF,sh Aa hat"; Vol. 4, iiw,ldl,fe
Habitat"; Vol. 7, "Forest Ecology and Timber Management". The referenced
documents were prepared by the Pacific Northwest Forest and Range Experiment
Station, U.S. Department of Agriculture, Forest Service.
ALTERNATIVES
The following "action" alternatives to hydroelectric power were evaluated
during the course of the feasibility study: waste heat recovery; wind
generation; solar generation; alternative fuels (coal, peat, natural gas and
wood) ; geo thermal; and transmi ss i on in terti e (e 1 ec tri ca 1 transmi ss ion
interconnection with other utility systems). The above alternatives are
addressed in Section 5 of the main report. In summary, they were not
considered feasible alternatives in addressing study objectives relating to
corrmun ity needs. These study objec ti ves requ ired tha t a genera ti ng sys tem:
(a) be capable of generating sufficient electricity to meet projected demand,
(b) be socially and environmentally acceptable, (c) be of proven technology,
and (d) provide electrical power at the lowest cost convnensurate with other
project objectives.
Hydropower
Two sites were considered. Both sites, Indian River and Harley Creek have
apparent hydroelectric capabilities. However, Harley Creek does not have the
sustained flows capable of meeting projected energy loads for Tenakee Springs
and was dropped from further consideration.
Evaluation of hydroelectric power development on Indian River is feasible to
meet Tenakee Springs electrical needs. However, diesel standby power will
also be required to meet projected energy demands during low streamflows
during various periods of the year.
The Preferred Alternative
The preferred alternative consists of a diversion dam on Indian River, which
would divert between 20 to 52 cubic feet per second (cfs) of water through a
penstock to a powerhouse 2,440 feet downstream. The proposed locations of the
project features are shown in Plate 1. The alternative is a run-of-river
project and does not include water storage. A diesel power generator would
serve as a backup for electrical supply during periods when flows were
insufficent to meet electrical power demand.
The dam would be located approximately 50 feet upstream of barrier 5 (river
mile 0.9). Crest height of the dam would vary from 5 feet to 16 feet above
the streambed. The dam width (length across the river) is 84.5 feet with a
5
length of 22 feet. The structure would be constructed of timbers and rock
salvaged from the project area. The upstream face of the dam would be planked
to reduce seepage. Left of center (facing downstream), between two
rock-filled sections of the dam, would be a timber bulkhead spillway. Under
normal conditions flows would flow over the bulkhead spillway and/or the
bulkhead notch. A narrow vertical notch (1.35 feet wide and 3.9 feet deep) is
incorporated into the bulkhead spillway to provide a minimum instream flow
release of 10 cfs during periods of hydropower operation. The bulkhead
spillway is deSigned to pivot at flood flows in excess of 4,200 cfs. A flow
of 92 cfs is required before flows pass over the bulkhead spillway and 132 cfs
before flows pass over the rock crib spillway (157 fmsl) during maximum
hydropower operations. A 10-foot non-overflow section (16 feet in height) on
the right side of the dam would protect the penstock below the intake
structure.
The intake structure has a crest height of 165 fmsl and would be constructed
into the riverbank. Twenty feet upstream of the intake structure, a l6-foot-
long weir would be built with a crest elevation of 153.1 fmsl to protect the
water intake for the penstock. The center height of the penstock at the
intake structure is 148 fmsl.
The penstock would be about 2,440 feet in length and follow the right
(southwest) bank of the river (Plate 4). The first 250 feet would be steel
pipe with an inside diameter of 42 inches and would lie in a rock cut. A
39-inch diameter plastic pipe would compose the middle section, 2,040 feet in
length. This section would be above ground supported by rail road ties every
10 feet. The last 150 feet of penstock above the powerhouse would be steel
and laid above ground.
The powerhouse (Plate 5) is a wood frame structure 20 by 20 feet and would
house a single 265-kW turbine unit. The proposed unit is standardized
horizontal shaft Francis type with a throat diameter of 1.78 feet. The
powerhouse tailrace is 50 feet in length traversing a cut section to the
stream edge. The downstream end of the tailrace would be riprapped to protect
the streambed and form the water supply intake.
The water supply intake would consist of a cross channel trench cut into the
streambed to a depth of at least 64 fmsl (approximately 2 feet below
streambed). Gravel would fill the trench creating a French drain. A buried
6-inch plastic pipe would transport water to the conmunity of Tenakee Springs
following the route of the transmission line right of way.
Construction of the preferred alternative.
The primary access to the project would be over an existing Forest Service
logging road east of Indian River and 3 miles from Tenakee Springs. This road
runs from the logging camp at sea level through the eastern Indian River
drai nage. A permanent 700-foot access road woul d be cons tructed from the
Forest Service road to the dam site. The access road would be unpaved and of
single-lane construction (12-foot travel width and 2-foot shoulders)
constructed to standards adequate for construction access and maintenance of
the project.
6
The access road would traverse through a Forest Service c1earcut area.
Approximately 0.28 acre of clearing (400 feet by 30 feet) would be required
near the river. An estimated 210 cubic yards of excavation and 625 cubic
yards of select fill (gravel-rock) is required for road construction. Minimal
grubbing is anticipated. The road would be cu1verted and/or constructed so
that natural drainage would not be adversely affected. Coarse gravel or rock
water bars placed within the road would provide cross drainage and minimize
erosion. The existing forest Service quarries would provide fill material
required for road construction on a pennit basis.
The access road to the dam would have a grade of 11 percent dropping from 225
ms1 to 150 fms1 (Plate 1). A 10-foot high bank would be cut to a maximum 20
percent grade for the river crossing approach on both sides of the river.
Materials excavated for the river crossing would be used for a diversion
structure during construction of the dam and spillway and within other project
areas. The stream crossing would require excavation of approximately 480
cubic yards of rock and 240 cubic yards of cOl1lTlon material. Vehicular access
across the river would probably be a native log stringer bridge unless
c1earence is given by the Forest Service and Alaska Department of Fish and
Game to cross the bedrock streambed. An alternative stream crossing approach
would be evaluated in the refined engineering design phase of the project to
include use of the dam surface for the purpose of small construction vehicle
crossing. However, large equipment would still be required to use the
stringer bridge or bedrock crossing. Dam installation would occur during the
summer when flows are generally less than 150 cfs. Flows would be directed
away from the dam section being installed through the use of the diversion
struture. The diversion structure would consist of logs and approximately 50
cubic yards of rock. Construction of the rock and timber dam and intake
structure would require excavation of 110 cubic yards of rock 320 cubic yards
of rock fill, 11 cubic yards concrete, and 100 cubic feet of grout and about
9,000 board feed of lumber. Approximately 0.8 acres of clearing would be
required to accolTlTlodate a 50-year flood. Primarily the area to be cleared
would be to elevation 160 fms1, a distance upstream of 500 feet. Clearing of
vegetation would preceed construction and would occur in late fall or early
winter.
Construction of the penstock route would follow the right bank because rock
banks are less fractured and are cabab1e of holding a 1 horizontal to 4
vertical cut. The penstock would be installed on a bench cut from the river
bank. The route would require excavation of 9,000 cubic yards of rock and
1,500 cubic yards of cOlTlTlon material. Excavated material would be sidecast on
the downside, on a 3 horizontal to 1 vertical slope. Cleared trees would be
salvaged and used as retaining walls for fill sections where needed. Lost
fill below the embankment should be limited to less than 100 cubic yards. A
30-to 50-foot wide corridor would be cleared for the penstock route, about 2.3
acres. Excavation and terracing of the dam site and penstock corridor would
occur between May and July.
The powerhouse site would be created primari 1y by rock excavation. Estimated
excavation amounts to 1,100 cubic yards of rock and 125 cubic yards of common
material. Vegetation clearing would be within a 0.1 acre area. Access to the
powerhouse would be along the transmission line corridor. The trail along the
transmission line would require only those improvements necessary to
7
facilitate passage of equipment to construct the transmission line and the
powerhouse. A two track trail would remain to provide a low use maintenance
trail for the powerhouse.
Construction of the transmission corridor would require a 30 to 50-foot wide
right-of-way (ROW) below 175 fmsl. The route would avoid terrain involving
extensive surface modification. The access road would consist of a bladed and
graded bulldozer trail with minimal upgrading done only as necessary to permit
passage of construction and maintenance vehicles. Vegetation clearing would
generaly be within the 50-foot corridor. However, selective clearing of
danger trees (diseased, leaning, or dead trees) within a 300-foot area would
als9 be cleared for a safe conductor zone. A water supply conduit would be
placed within the transmission corridor.
The conduit would be 3,800 feet of 6-inch polyethylene pipe with a preformed
1.4-inch thick insulation layer. The pipe would be buried in a shallow trench
excavated by backhoe or trenching tool. Additional loose earth for the
transmission line access road would be mounded on top of the buried pipe for
additional insulation.
The water supply conduit intake would be sited in the lower half of the
tailrace. A cross channel trench would be blasted into the bedrock streambed
about 2 feet in depth. The trench would be fill with gravel creating a French
type drain.
Other Hydroelectric Alternatives
Variations of the preferred plan were considered.
were evaluated and included various dam heights,
locations.
Two additional dam sites
powerhouse and penstock
Dams having overflow weir crest heights up to 25 feet were found to be less
cost effective. A tall concrete dam, in excess of 80 feet at river mile 0.4
near barrier one, which would have included a fish ladder system and
eliminated the natural fish barriers behind the dam by flooding, was
recommended by the USFS for evaluation. This option was determined infeasible
as a result of geological and power analysis. The next best alternative dam
site to the preferred plan is at river mile 0.8, just upstream of barrier 4.
This option has the advantages of less penstock, but the disadvantage of the
added road construction, increased cost, and greater potential effect to
fisheries resource due to the powerhouse location near active salmon spawning
areas. The environmental effects are considered to be basically the same as
for the preferred plan. Similarly, a dam at barrier 5 could divert water to a
powerhouse at barrier 3.
A powerhouse location on the east bank of the river would require greater
foundation cost and would increase construction disturbances to the
environment. Turbine choice could be modified prior to construction as more
instream flow data and data regarding potential for fish mortal ity (as a
result of mechanical damage from the turbine) becomes available. A crossflow
turbine as compared to the Francis type turbine is an alternative choice.
Crossflow turbines are less efficient, but can operate at reduced flows. A
crossflow turbine would require greater diversion of water during maximum
operation of the hydropower facility.
8
.'
Additional information concerning project feature alternatives is discussed in
the technical appendices and the main report.
ENVIRONMENTAL CONSEQUENCES
Aquatic Resources
The proposed run-of-the-river hydropower facility with a water diversion
structure would not include any major water storage. The normal operating
pool (elevation 156 fms1) would flood a total of 1.4 acres of which 1.1 acres
is currently inundated by Indian River. Due to the steep slopes on the river
bank, 0.3 acres of stream bank would be inundated. A 50-year flood would
result in a total of 1.9 acres being flooded and 4.5 acres for a 100-year
flood. The flooding of the limited operation pool could cover and destroy
some spawning habitat for Dolly Varden. However, the pool would probably
increase rearing habitat and overall adverse impact should be minimal. During
periods of operation, the project would diivert between 20 and 52 cfs of water
from the dam site near barrier 5 to the powerhouse located between barrier 2
and 3. The diversion would reduce the flows proportionat1y in the 2,700-foot
distance between the dam and powerhou~)e. During periods of nonoperation
(streamf10ws less than 32 cfs), the water would flow unobstructed from the dam
to tidewater.
At various times during the year, when stream flows are less than 64 cfs and
greater than 31 cfs the project could divert all but 10 to 12 cfs from this
reach. The 10 to 12 cfs discharge has been established as a minimum instream
flow for the affected reach (see FWCA report) and would be provided by a notch
1.35 feet wide and 3.9 feet deep in the bulkhead section of the dam. It is
expec ted tha t mi nor seepage through the~ stream and i nfi ltra ti on downs tream
will produce another 2 cfs for a minimum total of 12 cfs. An average worst
case analysis resulted in 73 days per year in which only minimum instream
flows (10'-12 cfs) would be discharged in the affected (2,700 feet) reach of
river. The average worst case is based on a hydroelectric power facility that
would have been operating constantly at maximum operation during the 6 years
of recorded data wi th the yearly freqU4~ncy of minimum flows averaged. In
addition, the facility would not have beE~n operating an average of 43 days per
year (range 9 to 105 days) requiring total diesel generator backup, and
supplemental diesel power up to 160 days per year. Additional information
concerning minimum flow release data is presented in Table 14 of the main
report.
During field surveys conducted by the USFWS and Corps, only resident Dolly
Varden char were captured or observed between barri ers 2 and 5. Coho sa 1mon
could util ize the addi tiona1 but 1 imi ted spawning habi tat between barrier 2
and 4 during certain reduced flow periods. However, this habitat potential is
not considered significant because of the bedrock substrate, although some
pools with gravel substrate do exist.
The diversion flows would return to the r'iver below the powerhouse and project
operation would not affect downstream aquatic resources below the powerhouse.
Supersaturation of water by atmospheric gases and/or significant changes in
wa ter temperatures are no t expec ted to occur as a resu 1 t of projec t opera ti on.
9
USFWS recommended in their January 1981 Planning Aid letter that to mitigate
potential adverse impacts and to sustain winter flows for rearing habitat
associated with water diversion in the 2,700 feet of river, a base flow of 27
cfs be maintained during the months of December through April. The USFWS did
not anticipate water use conflicts during the summer, however they recommended
41 cfs minimum flow releases for the months of May through October. Upon
consulation with USFWS, who conducted an additional field survey in July 1981,
it was determined that a reduced minimum flow could be incorporated into the
plan design to satisfy hydropower and fisheries requirements. It was
concluded that a minimum flow of 7 to 12 cfs would be sufficient to sustain an
adequate aquatic resource for the affected reach of river above the natural
fish barrier, provided that a mitigation program is incorporated into the
proposed project. .
The mi ti ga ti on program cons i dered by the Corps and Fi sh and Wi 1 d 1 i fe Servi ce
would compensate for the reduction of flow through the 2,700 feet of river.
The reduction in flow could affect the fisheries habitat for resident Dolly
Varden char and the potential habitat for coho salmon. The preferred
mitigation program would consist of a basic operational program, which could
be expanded to a commercial anadromous fisheries (salmon) enhancement program.
In addition to streamflow maintenance, the operational mitigation program
would consist of 1 year in a 3-year program of capturing 10 to 20 coho salmon
during the mid-to late-spawning run in Indian River or adjacent watersheds
(e.g. Kadashan River). The fish would be stripped and the eggs fertilized on
site, packed in trays, and sent to a fish hatchery (probably in Juneau or
Sitka). The eggs would be incubated, hatched, and raised until the
fingerlings weighed approximately 1 gram. Fingerlings would then be flown
back to Indian River for release above the dam to the previously unutilized
but good salmon rearing habitat. Approximately 25,000 fingerlings would be
released every 3 years at Indian River. Release of fingerlings every 2 to 4
years would reduce intraspecies competition and should improve survival
rates. The coho fry release program could easi ly be expanded beyond the
mitigation program provided that a cost-sharing commitment can be obtained by
USFS, ADFG, or other agencies, subject to ADFG approval. Additional
information concerning the operational mitigation and enhancement program is
presented in Section 6.1.3 of the main report.
A moni tori ng program to eva 1 ua te the mi ti ga ti on program is inc 1 uded in the
preferred plan. The monitoring program also would estimate the percent of
smolt migration entering the penstock and evaluate mortality to outmigrating
smo 1 ts caused by passage through the pens tock and turbi ne. The moni tori ng
study would also provide information on turbine mortality for other small
hydropower plants in Alaska. An additional mitigation feature conSisting of a
intake wall and optional screening has been included in the proposed plan to
prevent or discourage fish from entering the water intake for the
hydroelectric power facilities.
When incoming streamflow is less than 32 cfs, a penstock valve would close
causing streamf10ws to pass over the bulkhead spillway and/or through the
. bulkhead notch. When streamflow is between 21 and 64 cfs, the intake weir
would allow passage of operational water (20 to 52 cfs) and maintain a minimum
of 10 cfs discharge through the bulkhead notch. It is expected that coho
salmon smolts, resulting from the mititation plant program, would travel near
10
the surface of the stream and be attracted by the faster current of the notch
and spillway. The estimated velocity over the intake crest is 3 fps while 7
fps would occur at the bulkhead during a minimum flow release. During times
of salmon smo1t migration, average streamf10ws are greater than 90 cfs
resulting in flows over the a-foot bulkhead spillway in addition to the
spillway notch.
Aquatic resources would also be affected during construction activities.
Construction activities for the dam, powerhouse, tailrace and penstock routes
cou1 din troduce s i 1 t and soi 1 sin to the! ri ver affec ti ng the aqua ti c resource
downstream. However, the predominant material to be excavated would be rock.
Those activities that could introduce slignificant silt and soils in the river
would be restricted to a construction window of 20 May to 15 July as
recommended by the U.S. Fish and Wildlife Service. Those activities that
would involve the use of explosives in or near the stream would also be
restricted to this time period. In addition, instream sediment control
measures would be incorporated in the construction plan as necessary to reduce
potenti a1 impacts resulti ng from i ncreasE!d turbidi ty and sedimentati on.
Construction of the 2,440-foot penstock route would involve excavation of
about 9,000 cubic yards of rock and 1,500 cubic yards of common material.
Basically the penstock would be installed on a bench cut from the river bank.
Most excavated materials would be retained in 3 horizontal to 1 vertical
(3H:1V) embankments on the river side of the bench, cut above the river high
water mark. However, some of the excavated (rock) material and shot rock
(resulting from the use of explosives) may enter the river. A maximum
estimate of 100 cubic yards of rock is predicted with 50 cubic yards as being
the most probable estimate. This quantity of rock is not anticipated to
affect water quality or Significantly alter downstream habitat provided that
mitigation measures to limit the rock quamties are implemented.
Construction of the dam would require the temporary construction of a
diversion structure. The diversion structure would divert water away from the
current area of dam construction. The diversion structure would be
constructed of rock (50· to 200 cubic yards) and logs. Inwater and related
construction activities of the powerhouse and tailrace that could
Significantly effect salmon migration and egg incubation, would also be
confined by a construction timing restrictions.
Terrestrial Resources
Effects to the terrestrial environment \~ou1d result from construction of the
proposed action. Short term or minor impacts would occur as a result of
cons truc ti on ac ti vi ti es and long term i mpac t wou 1 d occur as a resu 1 t of
habitat alteration. Although impacts would occur, no significant impacts have
been identified for the proposed action.
Habitat alteration would occur as a resLl1t of vegetation clearing, excavation
and fill material placement, placement of structures and maintenance of
facilities. Approximately 8.9 acres of clearing forest could be required as
follows: Access road (0.3 acres); dam, including intake structure and work
area (2.0 acres), penstock (2.3 acres), transmission corridor (4.2 acres) and
powerhouse (0.1 acres). The largest area to be cleared, the transmission
corridor, would transect primarily through a western hemlock (Tsuga
11
hetero~h~lla) and Sitka spruce (Picea sitchensis) forest. Revegetation of
dlstur e sltes along the transmisslon llne corrldor has been included in the
preferred alternative. Revegetation species considered would be sod-producing
species that would reduce long term maintenance as well as for erosion
protection. Natural revegetation would also be considered where feasible.
Earthwork required for the proposed project would involve the excavation of
about 11 ,000 cubic yards of rock and 4,000 cubic yards of soil. The dam,
including the left bank work area and stream crossing, would require about 590
cubic yards of rock and 630 cubic yards of common excavation; the access road,
1,300 cubic yards of common material; the penstock route, 9,000 cubic yards of
rock and 1,500 cubic yards of common material; the powerhouse and tailrace,
1,100 cubic yards rock and 125 cubic yards common material; and the
transmission corridor with maintenance trail, 700 cubic yards rock and 1,300
cubic yards common material. Approximately 2,300 cubic yards of select fill
rna ter i a 1 for road cons truc ti on wou 1 d be ob ta i ned from the ex is ti ng quarry
located near the project.
Construction activities at or near the powerhouse during the summer and fall
salmon runs could discourage or prevent brown bear from using the lower
sec ti on of the ri ver as a feed i ng area. Cons truc ti on of the pens tock rou te
and transmission line corridors would cross some established game trails and
cou 1 d alter natura 1 movemen t and mi gra ti on patterns. Human-bear encounters
and conflicts can be anticipated during construction phase of the project.
Although short term effects during the construction phase of the project may
be severe for individual animals, the long term effects to the population
should not be significant. The introduction of a transmission line could
increase the probability of electrocution to large birds such as the bald
eagle and raven and line strike mortality to all birds flying through the
corridor. However, the transmission line would be designed in coordination
with the U.s. Fish and Wildlife Services to minimi.ze this potential. In
addtion, the transmission line and all other project features would be aligned
as to maintain or exceed a minimum 330-foot undisturbed buffer around any
eagle nest tree.
The small pool area created by the dam would destroy some existing riparian
habitat for some furbearers, microtines and birds. However, a new riparian
zone should develop around the edge of the pool. The pool is estimated to
hold 5.2-acre-feet during normal operations. The pool may also attract
waterfowl as a resting and feeding area. The potential benefits and adverse
impacts of the pool are minor.
A breakdown of acreage to be utilized for project purposes within the 13,888
acre Indian River watershed basin is presented in Table EA-l.
12
Table EA-1.
Land Ownership Within Project Study Area
Involving Project Features
FEATURE
1. Dam and pool
2. Roads
3. Penstock
4. Powerhouse
5. Transmission corridor
including maintenance
trail to powerhouse
6. Moorage
7. Borrow pits
TOTAL
LAND O~NERSHIP (ACRES)
FEDERAL
1.8
2.2
0.8
o
o
o
O. 1
4.4
STATE
o
8.5
1.8
1.0
4 " .j;.
0.2
0.3
16.iJ
TOTAL
1.8
10.7
12.6
1.0
4.2
0.2
0.4
20.4
TOTAL ACRES REQUIRING
DEVELOPMENT
1.8
0.8
2.6
1.0
4.2
o o
10.4
An estimated 11.4 acres of the 20.4 acres needed for hydropower development
have been developed for logging. Therefore 10.4 acres of unimproved lands
would be developed.
Impacts resulting from operation of the hydropower facility, although not
considered significant in magnitude, are generally long term in nature.
Primary impacts activities include reduction in flow in the 2,700 feet of
effected reach of river removal of sediment build-up behind the dam, and
transmission corridor maintenance.
Reduction of flows in the affected reach of river results from diversion of 20
to 52 cfs of water from dam to the powerhouse a di stance of 2,700 feet.
Fisheries habitat conditions are not considered significant in this reach of
river due to limited pools and bedrock conditions of the stream bed. natural
barriers below the powerhouse prevents pink and chum salmon from utilizing the
upstream reaches. Coho salmon, a stronger swinrner may be able to utilize the
affected reach of river from the powerhouse to barrier 4 (river mile 0.8)
during certain flow conditions. However, sampling conducted (1981 and 1982)
resulted in coho fingerlings observed or captured only below barrier 2. Only
Dolly Varden char were captured above barrier 2.
In order to maintain a viable aquatic system a minimum instream flow
requi rement was estab 1 i shed at 10 cfs for release duri ng hydropower operat i on
during times of low flow. The 10 cfs flow requirement was a reduction from
that first recolTlTlended by the USBtJS provided that a mitigation program was
included in the operational program, as previously defined. Further
information on the program and rationale is presented in the Fish and Wildlife
Coordination Act Report prepared by the USFWS. It also should be noted that
the 30-day winter low flow (November-April) is estimated at 10 cfs with a 7
day sUlTlTler low flow of 19 cfs.
The proposed dam designs does not include a seperate sluice gate. The
operational plan calls for sediment removal to occur about one every three
years during periods of non hydropower operation (low flows). The bulkhead
13
would be pivoted or removed and sediment worked through the opening. Rising
waters subsequent to maintenance 'would carry sediment downstream. Although
turbidity would occur for a short time during low stream flows, material
should settle out before reaching its powerhouse. The USFS has collected
several years of Indian River sediment information, and is in the process of
completing their analysis. Interim data analysis has been included within
this studies report.
The actual timing of sediment removal behind the dam would be coordinated with
the USFWS, USFS and ADF&G. Coordination with these agencies in determining
timing of sediment removal behind time should mitigate aquactic impacts.
Transmission corridor maintenance would result in maintaining a low height
growth area the length of transmission like primarly through an old growth
western hemlock and Sitka spruce forest. The corridor, 30-to 50-feet wide,
would be hand cleared of larger trees. In addition, due to the height of
mature trees through which the corridor passes selective clearing of danger
trees (diseased, leaning, or dead trees) within 300 feet of the corridor would
also be cut.
The typical transmission line under the recolTll1ended plan is of an armless
configuration. The armless configuration (plate 8) minimizes raptor
electrocution by limiting potential raptor perching primarily to the top of
the insulators and placement of conductors alternately on the sides of the
pole. Raptor collision with power lines is not considered a significant
mortality factor due to the type of surround habitat, prey availability and
high visual acuity of raptors.
Social Resources
Most of the socio-economic effects of this project will be posi tive. The
major long term effect will be the stabilization of electrical costs to the
commun i ty, bo th in terms of cos t per k i 1 owa tt hour and in terms of a more
reliable power flow. Present fluctuations in power leave lights dim in houses
near the end of lines and cause damage to appliances and loss of refrigerated
goods. Residents have suggested that a more reliable source of electricity
will enable construction of other amenities such as a marina, a welding shop,
a centralized shower and laundry.
Residents feel that a more reliable electrical system may attract some new
services and businesses of the type they find compatible with the Tenakee
Springs way of life. It is unlikely that a project of this scale would
attract any large industrial development that would be undesirable in terms of
environmental or social effects.
Lifestyles and incomes in the community suggest that energy conservation would
continue to be the rule, rather than the exception, even with a new system on
line. The implications of this are that, in general, there would be no major
changes in the pattern of appliance use or associated lifestyle changes with
this project. An exception is that residents frequently conmented on the
difficulty of washing and drying clothes with the present electric and water
distribution system. This situation could improve in the future if this
project is constructed and thereby improve the perceived quality of life.
14
Expans i on of the present system to servi ce the new construct i on expected on
the city land selections would be difficult. The proposed project would
enable reasonable and orderly extension of service to new buildings and be
less intrusive visually and audibly than a series of individually owned
generators.
The lands within the project area are government owned and excluded from
assessment and taxation. There would be no tax loss as a result of this
project.
Temporary impacts wou ld occur to the soci a 1 resources duri ng constructi on.
However, they are considered minor due to the short term duration and minor
magnitude (e.g. noise from required blasting and temporary increase in
population).
There would be no relocation of families, structures of personal property as a
result of this project. No relocation of roads, footpaths, or utilities are
expected.
Historical and Archaeological Resources
An archaeological field survey indicated that hydropower development on Indian
River and power transmission to the town of Tenakee Springs would have no
effect on cultural resources. Although there are several potentially eligible
sites near the project area described in the main report, no known potential
National Register sites will be impacted by the project as currently designed.
A copy of the Corps' Tenakee Spring Cultural Resource Assessment (appendix B)
was provided to the State Historic Preservation Officer who concurs with the
above. findings.
Coastal Zone Management Consistency Determination
The proposed hydroe 1 ect ri c power deve 1 opment wi 11 be undertaken ina manner
consistent to the maximum extent practicable with the Alaska Coastal
Management Program. This determination is based upon the description of the
proposed project and its effects, and upon an evaluation of the relevant
provisions of the management program.
SUMMARY/CONCLUSION
The Environmental Assessment
the National Environmental
Environmental Quality. The
impact.
was prepared under the procedural prOV1Slons of
Policy Act as established by the Council on
assessment indicates a finding of no adverse
15
Table EA-2
Federal Policies
Relationship to Environmental Requirements
Preferred Alternative
Archaeological and Historic Preservation Act
Clean Air Act
Clean Water Act
Coastal Zone Management Act of 1972
Endangered Species Act of 1973
Estuary Protection Act
Federal Water Project Recreation Act
Fish and Wildlife Coordination Act
Land and Water Conservation Fund Act of 1965
Marine Protection, Research and Sanctuaries
Act of 1972
National Environmental Policy Act of 1969
National Historic Preservation Act of 1966
River and Harbors Appropriation Action
of 1899
Watershed Protection and Flood Prevention
Act
Water Resource Planning Act of 1966
Wild and Scenic Rivers Act
Flood Plain Management E.O. 11988
Protection of Wetlands E.O. 11990
Full Compliance
Partial Compliance
Partial Compliance
Partial Compliance
Full Compliance
Fu 11 Comp 1 i ance
Fu 11 Comp 1 i ance
Fu 11 Comp 1 i ance
Full Compliance
Not Applicable
Partial Compliance
Fu 11 Comp 1 i ance
Fu 11 Comp 1 i ance
Not Appl icable
Fu 11 Comp 1 i ance
Not Appl icable
Fu 11 Comp 1 i ance
Fu 11 Comp 1 i ance
The compliance categories used in this table were assigned based on the
following definitions:
a. Full compliance --all requirements of the policy and related
regulations have been met.
b. Partial compliance --some requirements of the policy and related
regulations remain to be met.
c. Noncompliance --none of the requirements of the policy and related
regulations have been met.
Partial compliance would be changed to full compliance upon review of comments
received, signing of the Finding of No Significant Impact and authorization by
Congress.
16
Table EA - 3
EFFECTS OF THE PREFERRED PLAN ON RESOURCES OF PRINCIPAL NATIONAL RECOGNITION
Types of Resources
Air qual i ty
Areas of particular
concern within the
Coastal Zone.
Endangered and
threatened species
critical habitat
Fish and wildlife
habi ta t
Floodplains
Historic and cultural
properties
Prime & unique farmland
water qual i ty
Principal Sources
of National Recognition
Clean Air Act as ammended
Coastal Zone Management
Act of 1972, as amended
Endangered Species Act
of 1973 as amended
Fish and Wildlife
Coordination Act
Executive Order 11988
Floodplain Management
National Historic Preser-
vation Act of 1966
as arrmended
CEQ memorandum of August
1, 1980. Analysis of
Impacts on Prime or
Unique Agricultural
Lands in Implementing
the National Environmental
Pol icy Act
Clean water Act of 1977
17
Measurement of Effects
No effec t
No effect
No effect
Temporary disruption
during construction;
reduction of flow in
2,700 feet of river
would reduce the
quality of fisheries
habitat. Inclusion
of the mi tigation
program makes available
10 miles of salmon
rearing habitat
100 year floodplain in-
creased immediatey up-
stream of dam by 3.4
acres.
No effect
Not present in
planning area
Increase in turbidity
during construction,
no long term impacts
anticipated with
exception of reduced
(24-60 cfs) flows in
2,700 feet of river
Types of Resources
Wetlands
Wild and Scenic Rivers
Table EA-3 continued
Principal Sources
of National Recognition
Executive Order 11990,
Protection of Wetlands
Cl ean Wa ter Ac t of 1977
Wild and Scenic Rivers
Act as amended
18
Measurement of Effects
No significant effect
Not present in
planning area
APPENDIX A
TECHNICAL A~A[YSIS
APPENDIX A
TECHNICAL ANALYSIS
Page
Ll HYDROLOGY T-1
L2 GEOLOGY T -17
T.3 PROJECT LANDS AND PERMITS T-18
T.4 DAM, SPILLWAY, AND INTAKES T-20
T.5 PENSTOCK T-28
T.6 POWERHOUSE T-36
L? TRANSMISSION LINE T-38
T.8 WATER SUPPLY T-39
T.9 PROJECT OPERATION AND MAINTENANCE T-43
T. 10 CONSTRUCTION PROCEDURES AND SCHEDULING T-45
T.11 CONSTRUCTION CAMP AND LABOR T-46
L 12 PROJECT COSTS T-4?
T.13 PROJECT BENEF ITS
T.1 HYDROLOGY
T. 1. 1 BASIN DESCRIPTION
The Indian River follows a fault trace through a glacially enlarged
valley. The maximum elevation within the 21.7-square-mile drainage basin
(Figure 3) is 3,909 feet MSL. Other pertinent data is presented in Table
T-l. Alpine ecosystems comprise most of the basin above 1,500 feet and
represent about 33 percent of the basin. The forest, on gentler terrain
below, covers 65 percent of the basin and muskeg covers 2 percent.
The lower valley overburden consists of undulating well drained young
granular soils, 2 to 4 feet deep, underlain by impervious marine alluvium
and bedrock. Runoff is relatively rapid through this porous medium with
limited storage in the organic horizon and moss/fern complexes. Soil
storage capabilities or precipitation runoff lag times appear not to have
been impacted by the limited amount of clear cutting within the basin.
The length of the main channel is about 12 miles. The stream gradient
above river mile 8 is quite steep. From river mile 1 to 8, the stream
gradient decreases to about 36 feet per mile. Below river mile 1 to sea
level, the gradient increases, dropping about 130 feet over several
cascades. I"n general, the lateral gradient changes from a broad valley
floor into steep valley walls at about the SOO-foot contour. Most of the
muskeg and organic soils are adjacent to the meandering channel below
elevation 400 feet.
It is this elevation that generally receives 110 inches of precipitation
annually, as indicated by the Water Resources Atlas for USDA Forest Service
-Region X. The greatest depths of snow (estimated 9.5 feet) occur at the
higher elevations on the lee sides of the mountains. The accumulations
persist longest in the shaded pockets and beneath the coniferous
vegetation. Snow usually begins to fall in October, ceases in April, and
persists on the valley floor in measurable depths until May, lingering
until June at the higher elevations.
TABLE T-l
INDIAN RIVER BASIN CHARACTERISTICS
RIVER POINT ELEVATION AREA % OF AREA % DISCHARGE
(FEET) (SQ. MILES) ABOVE 500 FT. RELATIVE TO GAUGE
USGS GAUGE 330 12.90 86.7 100
Tributary 1 118 0.83 88.0 N/A
Tributary 2 220 1.54 92.9 N/A
Tributary 3 325 1.24 94.4 N/A
Tributary 4 335 1.04 84.6 N/A
Tributary 5 450 1.26 92.9 N/A
Tributary 6 450 1.46 95.2 N/A
Tri butary 7 425 2.34 97.9 N/A
Tributary 8 375 0.97 90.7 N/A
Barrier #5 145 20.46 80.3 160
Barrier #4 113 20.71 79.8 162
Barrier #3 80 21. 66 80.0 170
Barrier #2 50 21 .71 79.8 170
Barrier #1 30 21.76 79.6 170
Bridge 10 21.80 79.2 170
T. 1.2 STREAMFLOWS
The USGS and USFS have cooperatively measured streamflow at two locations
on the Indian River. One gauge, at elevation 500 feet on the southwest
headwater tributary, was installed primarily for water quality analyses.
The gauged area is 1.16 square miles, adequate for only intermittent
records. A second gauge, at elevation 330 on the main channel, has
provided daily records beginning with water-year 1976. It measures 12.9
square miles. Figure 7 is a plot of average mean daily flows at gauge
#15107920. These gauges have been discontinued pursuant to USFS soils and
watershed research program funding reductions.
High flows generally occur from mid-April to June and from September to
November. Generally, the greatest sustained discharge is in the spring
when rains and snowmelt combine. Over 44 percent of the total annual flow
occurs from 1 April through 31 August as a result of this combination and
latent percolation. The average mean daily discharge at the gauge, from
December to April, is 87.4 cfs while the average June to October flow is
74.8 cfs. Peak discharges occur in the fall as a result of intense rains.
The instantaneous maximum discharge of 1,900 cfs took place on 15 September
1976 and the minimum of record was 5 cfs on 19 and 20 February 1979.
T.1.3 SMALL SAMPLE STATISTICAL VALIDITY
It was necessary to determine if the years of record on the Indian River
presented an unbiased, representative statistical sample of long term
characteristics. Using the long term records of the adjacent Pavlov River
(Figure 1) and nearby Kadashan River for regional correlation, it was
T-2
determined that the Indian River record is not biased toward wet or dry
years. The Student's t-test of the means of each sample streamflows, and
the F-test of the variances of sample streamflows were both upheld at the
10 percent level of significance.
The USGS computer data file WATSTOR was obtained for the referenced gage
site. This data file, containing 7 years of record, was corrected for
damsite location relative to the gage and used to calculate potential
hydroelectric plant capacities and energy productions as described in
Section T.l.8.
T.l.4 WATER QUALITY AND SEDIMENTATION
A 'summary of water quality and sedimentation rates monitored by the USFS
are presented in Table 7 and Figure T-l and compared with drinking water
standards for the State of Alaska, Department of Environmental
Conservation. Valley shape and stream configuration appear to cause the
waters to have a high organic material content. In the steep reach, river
mile 8, rainfall quickly washes material into the stream. Below mile 7,
the stream channel meanders through mature forest and muskeg. Fallen trees
and overhanging alders and sedges contribute much organic material,
particularly during high flows.
Normally a high organic content causes waters to be tea colored and
acidic. Rain water normally has as pH of 7 or slightly lower. In the case
of Indian River waters, calcareous rocks appear to adequately buffer any
acid contributions of precipitation and rotting vegetation. Indian River
waters have pH of between 7 and 8.
Indian River waters meet acceptable drinking water standards as specified
by the State of Alaska. Standard treatment of surface waters used as a
community water supply requires sand filtration and chlorination.
Treatment would be necessary if the intake would entrap salmon carcasses or
if Giardia spp. are present.
Indian River sediments are generally cobble size or smaller. The gentle
gradient above river mile 1.0 (Barrier #S) causes most gravel or larger
sized sediments to settle out. Immediately upstream of Barrier #5, the
gradient and velocity increase. Cobbles cover the streambed as finer
particles are carried downstream to below Barrier #1. The streambed below
river mile 1.1 is predominantly bedrock and the cobble armor is generally
thin except where fissures or meanders lower streamflow velocities and
induce settlement of bedload.
Gravel bars and cobbles, with occasional boulders probably derived from the
collapse of the riverbank's glacial soils, are most evident above river
mile 1.1. Below mile 1.0 cobbles and rocks cover the streambed. Waters
are turbulent down to river mile 0.2 as the valley gradient increases.
Several cascades (Appendix B) occur at minor fault strikes. In mile 0.4 to
0.8 some rock debris falls from canyon like walls covered with dense
herbaceous growth. At the mouth of the river, a history of sediment
transport is displayed by a moderately sized cobble and gravel delta.
T-3
-I
I
~
TABLE T-2
.CLIMATOLOGICAL SUMMARY STATION NUMBER
9121 (!)I) IDlN<EI SPRII'KJS J t\l..ASKA LAT. 5JO ll7' LONG 135° 13'
TEMPERATURE (OF.) PRECIPITATION TOTALS ( INCHES) WIND
MEANS EXTREMES SNOW AND SLEET ~~ ~~ (/);:
I-~o
I :E ~ (f)>-~~ I~ ! O:::E O....J
:E .... n::: :l __
u..W I-::> .... Z a::: a::: I-Z a::: ~t a:: <n a:: W-l Z :J I <noo ~~ om ~ ::> I (/) <! <:! <! W>-Z ~ oW <! OW <! 1--<! ~I-<! W z <! 0 X r a:::I: 0::3 W <!<! W ~-l .... ;:x::l 0::0
G~ Z z oC!> W 0 0 W W Xz W W 41-0 W zW ~~ w Z
~ >--~ WO >-<!O 4n.. cn 4 ....J:E 0 or >-0....J >-~ >-w<! >-Wn..O:: >-~ ct w n:: ~~ 0::0 O::W(!) W(/) g:o ~o W :::IN
0 0 ~ 0:: 0:: 19 19 (!)o ::!! zlO
JAN )I) 124 2h 148 1942 -3 19'3) -6 :i l!}YB 12-26 199) -5 19L14 - --E 31 --.
FEB ZJ ?f) 31 50 1945 -I, [958 5 1 19115 15 41 1q-X) 14 : 191!3 ---E Z2
MAR 41 28 .35 52 19L19 13 9L13 5 1 19lQ B 27 1943 J2 19113 ---E 25
APR 47 33 lj() 65 1943 14 91Jl1 4 1 19!3 2 11 l<¥!Lt 8 1944 - --E 11
MAY S7 39 Lj6 79 l~ 25 9116 q 1 191~1 --E 4 ---- --
JUN E3 4ft 52 83 19£il1 33 9sa 3 1 1947 ---E a -----
JUL 64 qB )7 82 1950 36 ~943 II '} 1~2 --E 0 ------
AUG 65 l~ 57 82 19113 )J a9l17 5 2 19117 ------ --E 0
SEP 59 ltS 51 78 19112 33 ~942 8 ~. 1943 -E 0 -------
OC1 49 3R '13 ff) 1950 19 ~9115 12 5 19119 0 2 19119 20 1949 ---E 6
NOV 39 2G 32 ~ 19119 8 [l95f} 8 3 19119 12 211 19113 8 1942 - --HE 19
DEC 35 26 2..q 44 1941 2 ~9L'9 7 2 1Yl!9 19 301 19119 8 19111 ---mE 27
NOT E S: 1B1lPATIlRE MID PrJIIPITI\TIIJI MTA KEPT BEJVffN 1941-1950. mTA KEPT Bffi£EN 1970-1900 IlIS t()T mCLUDE r'v\xI~u'SJ
MItmU~J OR Dl\JLY PHORDS. r.o RECORD KEPT (f EXTRF1[ SfDJ OCPTII.OR HINDSPEED.
MISCEllAN-
-EOUS DATA
DE PO
TESTS
'" ~ ~ ~ o::~
VlW:£ ~I-~ f4:8 < -' <3. ~~ VI ~~~ < 0 ...
~~ l!l l!l l!l ~~~ z: :z: ~ ~ ~ ~~I-R5 '" /l.. 0.. "-VlCVI "'..., VI VI VI
INORGANICS Mg/l
Alwninwn None ----Arsenic 0.05 ----Barium 1.0 ----Bicarbonate I None JO.O -Il1.1! 18.1
Cadllli ",n 0.1 --0.01 0.01
Calcium ugll None 6.9 ---
Chromium 10.05 --~6~~ 0.01
Chloride None 3.6 3.40 60.5
Fluoride 2.40 0.1 -5.4 4.2
Iron u.1 - -
--Lead 0.05 --0.01 0.01
Maqnesiwn None 1.1 - --Manganese lJ.O~ --U.Ul 0.1
Mercury 0.002 ----Total Nitrates 10.0 0.3 -0.5 0,:>
Total Phosphates None --~:~ 0.1
Potassium None 0.2 0.8 -Selenium 0.01 --0.1 10.1
Silica ROne 1.1 40.Z 54.0 42
Silver 0.U5 ----
Sodium 250 -120.0 205 -
'SUlTate "orie u.u 1~4.U JJJ.J 1':411.~
Tdnnin None -- - -
Tin None --0.1 0.1
,jljY~L M911
Alka Ii nity None -8.7 2.25 -Color 15 75.0 ---
Conductivity (uMHO) tiQpe 163.0 -O~~ 798.0
Oissolved solids None 39.0 -704.0 560.0
Hardness NOlie 22.0 -- -
Suseended solids fiOOle -3.0 13.0
pll None 7 -9.4 8.8
Turbidi ty 1.0 - -
--Q..RGANill M9/1
Elldrin 0.000
Lindane 0.000
Methoxychlor 0.1
TQX~Jlh~ne 0.005
2.4.-D 0.1
2.4.5-TP Sl1vex 0.01
Tota 1 Trihalolllethanes Q"J Max. Trihalolllethane Pot. 0.1
HAD I OACT I V lTV pCifl
Gross Alpha 15
RddiulII 226 & 228 5
I~r·{)f., f., ~~QJ~._ ~f1 ----,-,--
iUIll-91
co ....
~
.n
w z ::> ...,
0.5 --------111.7 ---
2.24 -'0 ---
.5 -----
.O~ -
01: -
.631 -
--
1. 929 -
IABLE T-3
LOCAL WATER QUALITY
USFS TESTS ON THE INDIAN RIVER
~
~ OJ ~
OJ Ch OJ '''' '" 0>
'" ... '" ... OJ :;; ~ ... co co '" co ~; OJ .... Q) .... !:"~ .... en en en >
'" .... ~ ~ .-< .-< en .... '" ~ ~ §~ .... ~ .-:-t! ~ en'" ;; ~! .... ~ .... a. M N .n ",0.
N ID .-< ~~ ~ .-:-~E
:I: -' '" W >-l>-I-Ll ~ W ;--oIl :z: -' --' l!l 0.. O! >-Z --' ::> ::> ::> ~!:! W ~.:! ~ ~ ::> =>N ..., ..., ..., VI ..., ...,~
-.08 .03 -.03 .10 .07 .02 -.08 --- -
--- ---------- --- -
----- - ---------1:>1; 21.Ji. -112.68 116.3 14.2 11 A _1 II I?n R ------ -----2.01 1. 97 -2.21 12.4 5.54 5.15 2.75 3.64 -----------0 .113 -.027 0 0 .005 -.Oll --------11.6 1.4 -.728 11.6 0 In "I :n 1 1~ ------ ----- ---- ---141 no -.093 ,146 14Q o~? Mn 12Ji -.054 .0323 -.037 .014 .01 .024 .016 .032 -.804 .828 -.456 .607 .322 .407 16.71 .479 ----------
~
OJ ~ Ch
'" ~ ...
OJ en> .D .... '" en N
"'QJ :-~~ "" <~ co'" ~., ° oil '" I-'" uw '" o~ "-
.02 0.4 -------
13.2 18.3
--
3.13 4.72 --
.0213 .UU6 --
2.095 1.3 ----
,110 .225
.052 .UtU
.486 .473
-----2.871 2.Y36 -1.348 1.602 .663 0 1.859 2.246 1. 78410
-----------
1.543 --?127 2.104 -2.664 4.093 lRQ3 11,7R? 11 17R ~t 12.095 2.049
.Il --JZ.J 2.401 -1.163 3.41 1.82 .97 .SO 1. (J82 1.85
-1.0 - --1.0 -1.0 --1.0 0.2 .20 .20 .16 .10 .55 .31
-- ------------
8.76 --13.34 14.70 -8.34 8.56 5.88 .120 7.01 12.95 8.52 11.53
0.0 --10.0 15.7 10.0 69.0 20.0 15.0 25.0 20.0 12.5 55 25
73 0 --~30cLL W~L Ilg.,L Z9.~_ lH~§" 21h*-m,-~ ~2. 152.8 Ill. I 148.96
-1.0 --69.3 60.0 35.4 93.0 74.0 120.0 61.0 'YD)-:071 ~oii-
31. 67 --72.35 ---I~ ~ -
8.2 --7.5 7.4 7.4 7.5 7.6 7.3 7.6 7.2 7.0
------ --- -----
State of Alaska requires tes ts for Pesticides. Radioactive Isotopes. lIeavy
meta Is. & Co Ii fon" BdC teri a. These tes ts were Hot perfonlll~d Of} lhe specific
State Standards generally oa"nJdte SdllJ fillralioll field salllples shown here.
of surface waters tOI' JOllies tic con::,ulllpll on.
W I I I .~. I.~ I I ~-I --, ------
I . 1
~.
'" 0>
° '" ...
'" 0", 0 0> co> ,D
~ ~'" ~
.D '" ~n ~ N
NE: ~
:I: '" U ~oIl >-'" 3N --' ~ ::::>
...,~ ...,
.10 --------
---
---
15.1 17.663 -
---
3.72 3.38 ----
.015 ----
1.4 1.144 --
--
.033 .090 .080
. UII .013 .O,O(
.632 .824
.261 .316
t 2.494 .949 --1. 74 1. 58
. III .13
--
61.71 14.2fi
20 10
138.48 119. fl9 :06-7 --~0a7--
F----7.2 7.4
--
I'~ --
-~ -
f---.
- -
1 I
7 •
"T1
(i)
C :::u
fTI
--i
_.
en
&I-
0 -3:
0
-1
lL.
SUSPENDED SEDIMENT (mg/I)
.1 .5 1.0 5 10 50 100 500 IPOO I.OOCH-____ -JL-_...L-____ ---II __ ........ ____ ......... __ ..L-_ ....... ---:.-----& __ .....
500
100
o
•
• •
•
•
•
• •
•
• ..
•
NOTE: (I) DATA MEASURED BY U.S. FOREST SERVICE
IN 1977.
(2) mg/I = ppm"' 8.345 Ib •. /mlllion gollon.
= 1.11513 IIO-6Ib •. /clI.f •.
• • •
• •
TENAKEE SPRINGS I ALASKA
SMALL HYDROPOWER
FEASIBILITY STUDY
INDIAN RIVER
SUSPENDED SEDIMENT
ALASKA DISTRICT, CORPS OF ENGINEERS
I~--------------------------------------------------~----------------------------.-.
T.1.5 DESIGN FLOODS
Prior to beginning design of a structure. it was first necessary to
determine the most severe combination of meteorologic and hydrologic
conditions anticipated for the Indian River. Because streamflow records
are limited. two methods for developing peak discharges were investigated.
The first method used regression equations developed by the USFS for Alaska
National Forest regions. These general equations provide quite
satisfactory results. They are based on exponentially weighted values for
precipitation. drainage area. percent of lakes in the channel. and
elevation. Table T-4 provides results of these equations for comparison.
The Corps developed a second method, a computer program,'HEC-1, designed to
simulate the surface runoff response of a river basin to precipitation.
This method was selected for design use. The reconstitution/optimization
option allows for input of observed precipftation and runoff data and,
using these, will calculate basin runoff coefficients. The coefficients
can then be used in subsequent runs as input along with observed
precipitation to generate corresponding flood hydrographs.
The Probable Maximum Precipitation (PMP) was estimated prior to calculating
the Probable Maximum Flood (PMF). Usually the National Weather Service
prepares the PMP for a basin when requested. Because no PMP was available
for the study area, the one for Takatz Creek/Lake Grace near Takatz,
Alaska, located 50 miles south of Tenakee Springs, was used. The basins
are very similar in all climatological respects. The result of the PMP
input was a peak PMF of 9,685 cfs at the proposed Indian River dam site.
Eleven years of climatological records were available at Tenakee Springs
for determination of the precipitations for the 10-, 25-, 50-, and 100-year
floods (Figure T-2). Using the recorded maximum 24-hour precipitation
weighted for elevation differences by 1.25, a frequency curve was
prepared. The curve was calculated using the Log-Pearson Type III method
as described in the Water Resources Council Bulletin 17A. The 10-, 25-,
50-, and 100-year peak events were distributed over 24 hours and input to
the calibrated HEC-1 model. Additional input was a base flow of 80 cfs and
a drainage area of 21.1 square mile for the study site. The computed peak
discharges are presented in Figure T-2 and Figure T-3.
T.1.6 SPILLWAY DESIGN FLOOD
The structures proposed are classified as small, having a height of less
than 40 feet and storage of less than 1,000 acre-feet. The hazard
potential classification is low with no permanent structures for human
habitation downstream of the dam and minimal potential for economic loss.
Normally, the COE recommends a spillway design for the 50-year or 100-year
flood under these conditions. However, preliminary designs which would
pass these floods while sustaining no damage proved too costly to yield
positive projects. The selected plan will pass the 25-year flood without
structural damage. Floods up to the 100-year event would be safely passed
with only minor and easily repairable damage as discussed in Section T.4,
T.9, and T.13.
T-7
10-Year Peak Flow
TABLE T-4
INDIAN RIVER FLOWS
CALCULATED USING
FOREST SERVICE REGRESSION FORMULAE
Q = 19.8 Pl.15 A.898 L-.352 E-.417
Q = 19.8 (112)1.15 (21.1 .898 (1)-.352 (1110)-.417 = 1585 cfs
Q-25 Year Peak Flow
Q = 23.7 pl. 12 A.905 L-.355 E-.403
Q = 23.7 (112)1.12 (21.1)·905 (1)-.355 (1110)-·403 = 4375 cfs
50-Year Peak Flow
Q = 26.2 P1.09 A.903 L-.356 E-.384
Q = 26.2 (112)1.09 (21.1).903 (1)-.356 (1110)-.384 = 4770 cfs
100-Year Peak Flow
Q = 30.3 p1.06 A.904 L-.359 E-.371
Q = 30.3 (112)1.06 (21.1).904 (1)-.359 (1110)-.371 = 5260 cfs
Mean Annual Flow = 0.0312 (112)1.13 (21.1)1.03 = 150 cfs
50% Exceedance Flow
Q = .00391 p.991 A1.02 L.0692 E.343
Q = .00391 (112).991 (21.1)1.02 (1).0692 (1110).343 = 105 cfs
Where:
P = Mean Annual Precipitation in inches
A = Drainage Area in square miles
L = Percent of main channel in lakes
E = Mean Basin Elevation in feet
T-8
7
~
.."
G)
C
::0
fT1
-i
I
N
F
L
0
LJ
•
C
F
S
X
1
0
0 e
12
10
8
6
4
2
o
-10 -----25
I---50 -160
10.25,50 & 100 YR. PEAK DISCHARGES AT DA"
INDIAN RIVER NEAR TENAKEE SPRINGS, AK
VR (33 (;3 • ~FS )
VR (41 52 4 ~FS)
VR (48 is ~ ~FS )
VR (56 11 C ~FS ..
J " I .....
\ I \ I ...... , \ I I
1/ \ ,
I • , ,
)1 , , ,
I ' . r\ " , . , " I , " \ \ I • ,
,." I. """ .: , .. ,
/// ;11 "-'\' ~ ,,~ y ',~, ,
/~ ".( " ~ ~ '.~ ~
#
2 4 6 3 10 12 14 16 1S 20 22 24 26 28 30 32 34 36
HOURS
-f
I
(5
"'TJ
G)
c:
::0
fT1
-i
I
()J
F
L
0
lJ
#
C
F
5
)(
1
9
" 9
12
19
8
6
4
2
o
f"
V ~
o 24
PROBABLE ftAXIHUA FLOOD AT DAH INDIAN RIUER_ TENAKEE SPRINGS_ AK
~-~ PPIF 9685
/ ~
/
7 \ \. \
~ /
~ ~
CFS
'--
72 96 120 144 168 192 216 240
HOURS
T.l.7 ICE
No record of the frequency of ice accumulation on structures at Tenakee
Springs exists that could be indicative of future effects on project
facilities. Expected loading, frequency, and control measures will be
addressed in future design memoranda. Surface ice thicknesses based upon
freezing degree day calculations should not exceed 12 inches. Because
full-time operation is not anticipated, frazil ice will rarely be a
problem. During cold ice prone periods water levels are expected to be
below turbine limits.
The nearby Pelican Cold Storage hydroelectric system experiences minor
lClng inconveniences. The plant is generally inoperable in December and
January because of insufficient inflow. When cold enough, the pond has 1
to 4 inches of ice cover, and with buildup at the penstock intake, and
icicles form from leaks in the old wood stave penstock.
A period of subzero temperatures would have to exceed a length of 9 days
before the insulated water supply line would freeze solid. After 11 hours
of QOF temperature, dendritic ice could be a problem if the water was
stagnant the entire time. The record low temperature at Tenakee Springs is
-3°F. If flow is induced in the water supply system twice daily, 2 inches
of insulation on aboveground pipe and 1 inch on be10wground pipe should
prevent freezing.
T.1.8 PLANT SIZING
Energy Calculation
The Power Duration Plot Program (JPOWDURR) was used to optimize power plant
capacity. Designed by the North Pacific Division for use in specialized
small hydropower studies, this routine uses mean daily discharge and
turbine head, flow and, efficiency limitations to calculate the frequency
of operation of various selected plant sizes. The power potential is based
on the formula:
Average Power in kilowatts = Head x Flow x Unit Efficiency
Conversion factor
All studies were made using an assumed average turbine-generator efficiency
of 85 percent. The minimum net head was taken as the difference between
the spillway crest and the tailwater, less penstock friction loss; both
head and head loss were assumed constant.
The flow of the Indian River is quite variable and there is no appreciable
regulating storage. Therefore, the generating capacity at the sites could
not be considered firm or dependable and energy generated would be
classified as fuel-saver. Although the energy from the sites would not be
firm, such generation would be seasonally dependable and could, therefore,
be seasonally relied upon in the planned operation of an integrated diesel
system. That seasonally dependable energy is called usable energy.
T-11
Usable Energy
The primary goal in selecting a plant size was to create the maximum amount
of usable energy. Repetitive trials of JPOWDUR for different sized units
performed much like a sensitivity analysis of capacity versus available
streamflow. Varying the operational limits of different turbine sizes
caused the energy producton to change. The study optimized on the usable
energy from a 265-kW unit.
The calculation of usable energy is simplified when a utility can supply
hourly or daily consumption records from which a demand duration curve can
be synthesized. This plot can then be superimposed on the power duration
curve when common scales are selected. The area beneath and common to both
curves gives a good approximation of usable energy for that month or year.
Figure T-4 illustrates this method. Using the sum of monthly duration
curves avoids the slight overestimation of energy from the use of annual
curves. However, this method can introduce small errors due to the
underlying assumption that the timing of demand and production are
coincident. Since energy use records were not available until 1983 at
Tenakee Springs, power forecasts were compiled using other communities as
models.
The average annual energy capabilities of Indian River are graphed in
Figure T-4. The power duration curve (line p) represents the gross annual
power potential, that is if all generation were usable from the system.
This amounts to 1,870,000 kWh annually. Line D could approximate the
expected demand in 1986. The stippled area beneath and common to both
curves would be an estimate of usable energy. Secondary energy is the
shaded area above line D. This is energy which could be produced, but for
which there is no present market. Line P would remain essentially constant
from year to year, but line D would rise as energy demand grows.
Consequently, usable energy also grows, capturing secondary energy, until
the area under line D exceeds the area under line P. Diesel power would be
used for peaking demand above line P and for the unshaded area on the right
beneath the demand curve.
If demand is high at a time when streamflow (therefore energy produced) is
high, there is a large amount of usable energy. If demand and streamflow
do not coincide, less energy produced by the system is usable. Over the
long term it is expected that demand and available energy will not always
coincide. Neither will the two be totally asynchronous. A relatively flat
demand curve shape is typical of small communities which use electricity
primarily for residential purposes. Several small Alaskan communities were
studied to develop a reliable load curve shape. Communities with a
substantial industrial or commercial base have a sigmoid shape with a large
range in capacity and attenuated ends. Tenakee Springs lacks, and probably
will not develop a sizable commercial and industrial base. The flat shape
used for Tenakee Springs is a reasonable approximation of the average
condition over the 50-year period of analysis.
T-12
The flat demand curve shape was used because the Tenakee Springs utility
could not supply the information from which a load shape could be
prepared. Therefore, another community of 200 people with a similarly
sized utility, serving mostly small residences, in a maritime climate at
similar latitude (similar daylight hours) was used as a model because its
utility records were available and reliable. This curve was used to shape
the block of energy presented by the most likely scenario of Table 8.
The expected energy demand in 1986 is about 6S2,S60 kWh. Figure Sand
Table 9 show the escalation over the period of analysis. The demand curves
for 1986, 1995, 2001, 2006, 2016, and 2036 are shown on Figure T-4.
The monthly distribution of available energy and demand is shown in Figure
T-S. The sum of the monthly usable energies is the annual usable energy.
Table T-S provides a breakdown of the estimated usable energy.
Installed Capacity
The selection of installed capacity was made by using estimated annual
energy needs and probable load factors to calculate peak capacity demands
(Tables T-S and T-6). Initially separated in Section 3.1.S, monthly energy
needs were easier to predict than the minimum, maximum, and average
capacities. The monthly curves were re-synthesized for the annual energy
values and fitted to the flat load shape. The results conform well with
the description of Section 3.1.5. The 26s-kW unit selected satisfies more
monthly scenarios and hydrologic capabilities than substantially larger or
smaller units. A larger unit requires more water, therefore, operates
fewer days (Table 14). More diesel would be required for either a larger
or smaller unit as suggested by Figure T-s.
In the description of the most likely growth scenario (Section 3.1.S), an
expected peak capacity of 261 kW was projected for 1986. The 261 kW is the
total of all electrical devices. It is unlikely that all would be on-line,
at maximum use, at the same instant for a long duration; thus the narrow
"spike" of Figure T-4. In June, the month of greatest projected demand,
the school is not always in use, fewer light bulbs are on because of longer
daylight hours, and the recreational season is just beginning so all
commercial facilities to serve patrons are not drawing their full load.
For instance, patrons inside the store are not using appliances at home
while in the store. Therefore, the peak demand is unlikely to equal the
peak installed capacity early in the project life.
The review of this small scale study should not place great importance on
the peak intercept of Figure T-4. While the figure would be of critical
significance in a study of large plants, it is less demonstrative for the
study of Tenakee Springs. For this study, a 2S-kW change in peak capacity
demand would not significantly alter the final conclusion of the study or
the cost of the project. Energy production from this small capacity plant
would be used in effect as a self-fulfilling prophesy: whatever the
capacity, its energy would be used.
T-13
Multiple units are not of value in this project. The flow duration curve
(T-4) shows that very little energy tan be picked up by decreasing the
lower turbine limits. Most flows not used by a single 265-kW unit are
single digit values; too low to be of value even ;n a small unit. These
flows are also reserved for instream flow needs. Reducing the capacity
deprives the plan of more energy at the peak (more valuable) than ;s gained
at the base end (less valuable) over the life of the project. Also two or
more units would probably increase the operations and maintenance cost.
T-14
TABLE T-5
USABLE ENERGY
FROM A 265 kW HYDROELECTRIC UNIT
YEAR
MONTH 1986 1995 2001 2006 2016 2036
JAN 28,207 36,360 41,064 46,260 51,026 62,520
FEB 23,993 30,319 45,490 39,816 44,294 53,846
MAR 25,355 31,651 37,015 41,947 46,142 56,515
APR 41,832 52,070 60,329 68,832 75,910 92,357
MAY 42,286 54,691 61,200 69,487 76,716 93,611
JUN 82,000 103,421 119,533 135,252 148,529 171,425
JUL 77,962 97, 121 112,788 126,554 139,846 160,610
AUG 64,706 76,697 89,539 97,826 109,627 109,483
SEP 43,031 54,533 63,048 71 ,366 78,703 96,077
OCT 45, 180 61,344 65,754 74,398 82,692 100,474
NOV 34,344 42,696 49,943 56,398 62,474 76,172
DEC 29 2 570 36 2 655 42 z768 48 z 154 53 z489 65 2 095
TOTAL 538,466 677,558 788,471 876,290 969,448 1,138,185
in
(1,000 kW-hr) 538.5 677.6 788.5 876.3 969.5 1,138.2
DEMAND 652.6 815.0 945. 1 1,069.3 1,181.2 1,441. 2
SECONDARY
ENERGY 1,331. 5 1,192.4 1,081. 5 993.7 900.5 731.8
TABLE T-6
ESTIMATED GROWTH
YEAR PEAK DEMAND LOAD FACTOR ENERGY DEMAND
(kW l (%) (1 2 000 kWh)
1980 80 25 174.4
1986 261 28.5 652.6
1995 310 30 815.0
2001 327 33 945. 1
2006 349 35 1,069.3
2016 355 38 1,181.2
2036 411 40 1,441.2
T-15
TENAKEE SPRINGS I
ANNUAL POWER DURATION AND DEMAND PLOT • 4~ ------------------------~
400
3!50 •
300 •
D
E , II ~ 2S0 ~ 200.1
K w
100
so
o
o
LINE P
----.. ~ -----.----
2036
2016
2006
2001
1995
1986
::::::::::'
;;;;;: :J!llllll!l!l!!l!!!l!
r r
20 40 60 80
PERCENT OF TI ME
EQUALLED OR EXCEEDED
'",
100
TENAKEE SPRINGSl..~LASKA
I
I
I
I
I
I
I
I
I
I
I
I
I
SMALL HYOROt"UWER
FEASIBILITY REPORT
DURATION a DEMAND PLO~ ~
Alaska District, Corps of Engineers
FE8RUARY 1983 J
FIGURE T-4
o o
2
ESTIMATED AVERAGE ENERGY DISTRIBUTION IN TENAKEE SPRINGS
INDIAN RIVER BARRIER e FOR 2Se kW PLANT
2~~------------------------------------------~
AVERAGE
MAXIMUM
200 HYDROELECTRI
ISO
100
PRODUCTION r,.,.,.:.:.:.:.:,
AVERAGE USABLE
HYDROELECTRIC PRODUCTION
O~------~----------~----------------------~ JAN FEB MAR APR MAY JUN JUL AUG SEP OCT ~ DEC
FOR YEAR 2006
-r -17
TENAKEE SPRINGS, ALASKA
SMALL HYDROPOWER
FEASIBILITY REPORT
ENERGY DISTRIBUTION
Alaska District, Corps of Engineers
FEBRUARY 1983
FIGURE T-5
Tenakee Springs, like most small bush villages, is under-energized by
conventional standards. When an "un1imited" power supply is made avai1a~le
at a competitive or stable cost, its energy will be used. This was the case
in Napakiak when a transmission line intertie from Bethel was created. Per
capita consumption tripled. The optimum plant size in Tenakee Springs is
clearly more than 100 kW and less than 400 kW. Although Indian River is
capable of producing over a megawatt at times, the practical limit is
substantially less.
For the small sized units under consideration the overall plan changes very
little in design or cost. Essentially only the size of the penstocks, intake
valves, and turbine-generator units changes with capacity. The dams,
excavations, roads, powerhouse buildings, transmission connections, and
mobilization and percentages of contingencies, engineering and design, and
supervision and administration remain the same.
Optimum plant size at Tenakee Springs is, at present, dictated by hydrology,
community energy demand, and instream flow requirements for salmon. The
range of unit size is very small. Increasing turbine size above about 265 KW
requires greater stream flow diversion. Diversion of more than 20 to 52 cfs
deprives fish of needed water at critical times. Instream flow requirements
would then be raised if the hydropower plan threatened to dewater signficant
portions of the river. The net affect would be reduced periods of
operation. Consequently, a larger unit would not produce significantly more
usable energy, and a smaller unit would produce less usable energy.
Figure 6 indicated optimum plant size near 200 kW. The large 265 kW size was
selected partly because it more closely matches anticipated peaks. Fish
mortality is reportedly reduced if turbines are run at 70 percent of maximum
capacity~ A larger unit running below capacity could yield the same energy
as a smaller one running at full capacity, and have a less detrimental impact
on any outmigrating smo1t passing the fish screens. The larger amounts of
secondary energy produced could be used for off-peak heat storage, heat
pumps, to run water supply pumps, electric hydro10sis for development of any
oxygen and hydrogen production plant, an off-peak sawmill, and any other
potential source of employment and income that Tenakee may add in the
future. Also, the selection of a larger unit offsets some of the uncertainty
regarding sizing based upon the flow duration curve without regard to the
sequence of the loads and flows. Because the flow duration curve may not be
timed synchronously with demand, the secondary energy of a 265-kW plant would
partially compensate when the relative curves shift position.
Although a 265 kW appears to be the optimum size unit at this time the choice
between a 225-kW, 250-kW, 265-kW, or similarly sized unit will depend upon
what is in stock or can be most rapidly fabricated. The authorization (1.1)
of the Alaskan small hydro studies specifically intends for the rapid
deployment of small prepackaged hydroelectric units for projects indicating
feasibility. Thus, some flexibility in selecting the plant size during final
design studies is appropriate for this small scale, remote project.
T-18
T.2 GEOLOGY
The Indian River lies near the contact (Plate 2) between the Kennel Creek
Limestone formation, and older, igneous intrusive rocks (chiefly biotite
trondhjemite) which resemble granite. This contact is the result of
several kilometers of right-lateral movement along the Indian River fault
zone, which influences the a1inement of the Indian River, for which it is
named. Unconsolidated sediments originating from both the limestone and
the igneous rocks fill the stream channel and the valley floor upstream of
river mile 1.1, and form the delta at the mouth of the Indian River.
Several minor fault strikes cross the Indian River in the first mile above
tidewater. Each of these create small cascades of between 2 and 15 feet.
The five largest cascades are referred to e1swhere in this report as fish
barriers, designated in numbers ascending upstream. Hydroelectric
alternatives on the Indian River would take advantage of these cascades.
Barrier #1 at river mile 0.4 consists of two cascades. At this point the
river passes through a narrow canyon with banks rising abruptly for 50 to
85 feet. The banks are covered with herbaceous growth rooted into highly
faulted and fractured igneous intrusives. There is no consistant joint
pattern and the riverbanks are porous and unstable. The right wall above
the lower pool is suggestive of a locally large collapse 100 feet across.
Ascending upstream from Barrier #1 to Barrier #2 at river mile 0.5, the
walls are steep with signs of local failure. Faulting and fracturing
patterns are not as severe as downstream. Barrier #2 is a 10-foot
cascade. Geologic conditions are less severe but similar to Barrier #1.
Upstream of Barrier #2 to Barrier #4, river bank walls rise less steeply
and are stable enough to support large trees with straight trunks. Bank
failure is less than noticed below. Barrier #4 is a series of cascades
rising over 20 feet in 100 feet. Rock at this point is granitic and
displays a consistant joint pattern. Joints are random and blocky but
tight. Solid abutments to the stream rise about 30 feet at a pOint where
the channel is about 45 feet wide.
The riverbanks open considerably between Barrier #4 and #5 and have about a
lV to 3H slope. They are densely vegetated and appear stable. Barrier #5
at river mile 1.0 and elevation 150 exhibits minor fracturing and a
consistent joint patterns in granitic rock. The major joint strikes N 75° E
dipping 29° S; the minor joint strikes N 35° Wand dips 51° S. The cascade
at barrier #5 is about 10 feet high and 125 feet wide. River banks rise
sharply about 5 feet and level off in mature forest. Upstream of Barrier
#5 the river valley opens and the stream meanders gently over deep gravels.
Outcrops are noticed in the streambanks below elevation 150 feet. The
overburden in the valley masks rock until it is exposed next in the quarries
at elevation 700 or above. All quarries are in limestone/dolomite/marble
rock. Several quarries are open and accessible over heavy duty logging
roads installed by ALP under the auspices of the USFS. The closest is
about 4,000 lf below the project and others are located more than a mile
above the project. The State (city) now controls the closest quarry; one
which contains a large quantity of road quality material. as well as rock.
T-19
T.3 PROJECT LANDS AND PtRMITS
Three primary ownership parties have interests in the proposed project:
the city of Tenakee Springs, the State of Alaska, and the U.S. Government.
The State has selected 3,000 acres in the vicinity of Tenakee Springs which
encompass most of the area under study. Most of the lands have been
conveyed to the State and are administered by the State. Any unconveyed
lands are tentatively administered by the Forest Service.
According to information provided the Corps by the U.S. Bureau of Land
Management (BLM), State lands begin 200 feet downstream of Barrier 4
(Plate 1). BLM Master Title Plat T.47S., R.63E., Copper River Meridian
suggests that the boundary with Tongass National Forest lies along
N2179,000. However, the USFS indicates that the line is along N2179,640.
If the USFS line is accurate, all of an alternative development at Barrier
4, except for a little of the access road, would be on State lands. The
proposed selected plan development at Barrier 5 would straddle both the
State and Federal lands. The dam, access road, and about 1,000 feet of the
flume would lie on Federal lands. The remaining 1,700 feet of
flume-penstock, powerhouse, quarry, and most of the transmission line and
water supply conduit would lie on State land. The planned substation and
lower end of the transmission line and water conduit fall within city
limits. The Alaska DNK requested additional lands selection to include all
parts of the Indian River basin which might be affected or included by any
potential hydroelectric development. As of August 1983 no action had been
taken on this proposal.
Prior to the initiation of construction, developers of the tentatively
selected plan would have to secure several permits. Corps development
would preclude the need for a Federal Energy Regulatory Commission
license. Alaska ADFG would require a stream crossing permit and a habitat
protection permit; a State tidelands permit may be needed; Alaska DEC would
require a water quality permit; the city would need to pass a zoning
ordinance; the USFS would require an Exceptional Use Permit; and the Alaska
DNR would require a quarry permit, a clearing permit, and a water rights
permit.
The pool behind the dam is estimated to hold 5.2 acre feet at normal pool.
The average annual fluctuation is about 2 feet in head or 4 acre feet. The
existing area of the river bed that would be flooded is about 1.1 acres.
At normal operating pool about 1.4 acres would be flooded; the 100-year
flood would cover about 4 acres. The 50-year flood pool area (elevation
160 fms1, 1.9 acres) would be cleared of potentially hazardous vegetation
as preventive maintenance and to provide materials for the dam construction.
Decomposing vegetation could impair the water quality, damage or corrode
machinery, or physically impede free water movement.
A breakdown of acreage to be utilized for project purpose follows, but note
that much of the road network, moorage area, yards and pits already
exists. The total development would amount to only about 20 acres.
T-20
Feature:
Watershed
Pond age (Normal)
Transmission
Roads
Penstock
Powerhouse
Moorage
Yards and Pits
Total
Federal
13,248
1.3
o
2.2
0.8
o o
O. 1
13,252.4
Land Area
Acres
State
640 o
4.2
8.5
1.8
1.0
O. 1
0.3
655.9
Total
13,888
1.3
4.2
10.7
2.6
1.0
O. 1
0.4
13,908.3
The proposed construction should have minimal fish and wildlife impacts.
No additional lands are to be acquired for mitigation.
The lands are essentially unimproved and unzoned. Use status is as timber,
watershed, wildlife habitat, and recreational. Terrain and remoteness
preclude high density development.
The lands within the project area are government owned and excluded from
assessment and taxation. There would be no tax loss as a result of this
project.
There would be no relocation of families, structures, or personal property
as a result of this project under PL 91-646. No relocations of roads,
footpaths, or utilities are expected.
There are no known outstanding mineral or water rights or block ownership
within the project area. There is harvestable timer that could be salvaged
or used by the contractor. Timber values and land values would be
discussed in future project studies. Rights for construction and
maintenance of the project features across State and Federal lands would
require a perpetual (50-year) utility easement.
T-21
T.4 DAM, SPILLWAY, AND INTAKES
T.4.1 ACCESS
The primary construction access to the dam and intake facilities would be
over the existing USFS haul road. This heavy duty gravel road runs from a
log boom and staging area at the sea level through the entire Indian River
drainage basin (Plate 2). ALP upgraded the road from the USFS 14-foot
specification to about 20 feet. A permanent 700-foot spur road (Plate 1)
would be constructed from this road to the damsite. The travel width would
be 16 feet with 2-foot shoulders. A work and staging area near the stream
and a widened section along the access road would allow 2-vehicle passage.
The construction access road would be primarily a 2-foot thick fill section
traversing a clear cut area. Only 400 feet of the access road would be
cleared to 30 feet wide (0.28 acre). Stumps would be cut flush with the
ground surface and the root systems would be left in place.
The material for the spur road construction would be obtained from local
sources as permitted by onsite material inspection. Where the excavated
material is deemed unsuitable, select borrow for embankment and surface
courses will be obtained by permit from existing USFS quarries. A quarry
is located about 4,000 feet from the intersection of the haul road and the
dam access road. A typical section is shown in Plate T-l. Waste material
would be stockpiled and graded onsite where possible.
Minimal grubbing is anticipated although the clear cut area would require
some work to dispose of slash and tall stumps. Uepending on USFS or State
preferences at the time of construction, grubbed material could be stacked,
stacked and burned, stacked and buried, stacked in windrows, or transported
to a specified disposal area, probably near the quarry.
The road to the dam would have a grade of 11 percent dropping from 225 fmsl
to 150 fmsl. Coarse gravel or rock water bars would provide cross drainage
to minimize erosion. The 10-foot high bank would be cut to a maximum 20
percent grade for the river crossing approach. The radius of curvature and
any upgrading of the specifications would remain the contractor's option,
to suit the dimensions of the largest equipment chosen. The access across
the river would also involve a bank cut of similar dimensions and another
work area, primarily for stockpiling of penstock materials.
T.4.2 DESCRIPTION
The sole purpose of the small hydroelectric dam is to divert water into the
penstock intake. The diversion structure dimensions for this plan are held
to a minimum. Downstream safety is not a critical issue, so a massive
structure is not needed. A small structure would require the importation
of few costly materials to the site, and have fewer local ecologic impacts
than a larger dam. This structure is designed to function for the project
life of 50 years. Its simple features are designed to accommodate the
passage of floods by controlled collapse of the structure.
T-22
As shown on Plate 3 the dam is a low rock filled timber crib. The upstream
face is planked to reduce seepage and to help control overtopping. The
deck of the cribs at 155 fms1 is planked to retain core rock during
overtopping. Also the decking will provide a surface for equipment access
when the bulkhead is repositioned. Left of the center is a 8-foot wide
bulkhead section which incorporates a specialized opening for fisheries
purposes. The overall width of the structure is 90 feet. Crest height
varies from 7 feet to 15 feet. The penstock exits from beneath the right
side of the structure and follows the right riverbank to the powerhouse.
The bulkhead section generally overlies and takes advantage of a natural
flume on the left of the cascades at Barrier 5. This section is designed
to pass most of the expected annual flows. For events exceeding the
25-year flood or about 4,200 cfs, the bulkhead would pivot downstream when
Indian River stages reached elevation 162.5 fms1.
If flows and stages continue to increase, the short plank extensions of the
upstream dam facing would shear when the flow reached 4,750 cfs under a
stage of 163 fms1. This event would have a frequency of about 43 years.
The 100-year event would have a stage of about 164 feet keeping the waters
within the natural channel as a result of the folding of the fisheries
bulkhead and the loss of the plank extensions. These extensions and the
bulkhead would be replaced after flows receeded. The remainder of the
structure would be undamaged.
Successive yielding of components according to flood stage maintains the
basic integrity and function of the hydroelectric diversion structure. The
operations, maintenance, and replacement (OM&R) costs of this design are
greater than a conventional design of no-failure, but the overall combined
. annual cost of initial and OM&R costs is lower. Risks and costs are
explained in Section T-9 and Section T-13
T.4.3 MATERIALS AND INSTALLATION
Most materials for the dam would be salvaged. Trees felled along the
access trail, dam site and pondage area, and the penstock corridor are to
be cut into logs for the cribs, stream crossing protection, and diversion
during construction. The rock fill for the dam core and diversion during
construction is to be salvaged and selected from onsite excavation.
The planned dam construction will take place during the low flow (less than
150 cfs) summer periods. Nevertheless, installation will involve working
in shallow water. Temporary diversion berms around particular features
would be built on an as needed basis by placing a log in the stream and
adding fill around the log. This method' should be quite effective as
evidenced by trees now jammed at top of the barrier.
Once the concrete cutoff sill and the first log of a crib is in place, no
diversion would be necessary since the normal inflow will pass through the
bulkhead. Once all the cribs are constructed, the bulkhead would be
installed and raised into position to effect operation of the structure.
T-23
The small amounts of concrete required are expected to be mixed onsite.
The decking, planking, and bulkhead timbers would be untreated tongue and
groove lumber. This should provide better quality control and better fit
for seepage control than would rough hewn local lumber. All steel
components would be precut and formed by the offsite supplier(s).
T.4.4 INTAKE STRUCTURE
The right side of the diversion structure houses the penstock intake. The
structure with its crest at elevation 164 fmsl is designed not be
overtopped. The intake is a 16 x 6-foot box constructed into the granitic
riverbank. A 16-foot long weir with crest elevation of 153.1 fmsl is built
above the stream bed 20 feet upstream of the dam. This weir operates in
conjunction with the bulkhead notch to pass the instream flows as described
in Section T.4.5.
Low velocity water entering the intake box flows through a trashrack into
the penstock gate valve. Because the intake box is recessed into the
riverbank, logs and large debris are unlikely to impact the trashrack. The
weir is above the riverbed so most fine sediment should be trapped outside
the intake box. Larger sediment particles would be dropped farther
upstream in the pool area.
The gate valve operated from atop the non-overflow structure is accompanied
by an air vent to prevent penstock collapse in case of sudden unscheduled
dewatering. The penstock below the valve is incised and incased in the dam
structure to provide protection from high water in floods.
T.4.5 FISHERY FEATURES
To reduce potential mortality rates of the outmigrant smolt a few design
features are added to the planned hydropower design. The bulkhead section
shown on Plate 3 has a notch 1.35 feet wide and 3.9 feet deep designed to
always pass a minimum of 10 cfs, the minimum instream flow release. It is
expected that minor seepage through the structure and infiltration
downstream will produce another 2 cfs for a total of 12 cfs minimum
instream flow between the dam and the powerhouse.
When incoming streamflow (inflow) is less than 30 cfs insufficient water
will pass over the intake weir crest to operate the turbines. When inflow
is between 30 and 62 cfs the weir will allow passage of operational water
(20 to 52 cfs) and maintain the 10 cfs minimum flow through the bulkhead
notch. Salmon smolts are expected to travel near the surface of the stream
and be attracted to the faster current of the notch and spillway. The low
velocity over the intake weir crest (because of its larger dimensions)
should reduce the attraction of smo1ts significantly thereby reducing
potential entrainment and turbine mortality. The anticipated velocity
through the notch is about 7 fps and over the intake weir crest is about 3
fps at average April through June discharges.
T-24
The mitigation program of this plan includes monitoring turbine mortality
of coho smolt. If these studies reveal significant losses provisions can
be made to mount a 1/2-inch mesh screen between the trashrack and the gate
valve. If this screen were needed, it would probably be installed for
about a month during the spring outmigrant period. The screen is not
incorporated at this time because the other mitigation measures are
believed adequate.
The low dam height should cause no nitrogen supersaturation of passed
waters.
The dam facilities could accommodate the installation of a fish ladder if
future conditions warrant. At this time, a local sponsor for fisheries
enhancement is not available and mitigation requirements do not mandate a
ladder at the dam. These measures are addressed in the Environmental
Assessmment (EA), and the Coordination Act Report, Appendix G.
T.4.6 SLUICING
No separate sluice gate is provided in this plan. Hydroelectric operation
is expected to cease for one or more weeks during the year (Table 14). As
explained in Section T-9 removal of sediment would take place during those
months of non-operation on the average once every three years. The
bulkhead would be pivoted or removed and sediment worked through the
opening using a locally available backhoe or similar equipment. Rising
waters subsequent to maintenance would carry the sediment downstream and
renew spawning sands and gravels. The actual timing would be coordinated
with the USFWS, USFS, and ADF&G to mitigate downstream impacts on the
fisheries.
Although siltation downstream may be critical for a short period when
streamflow is low, this is felt to be the best economical alternative. A
sluice gate is not used because it will be hydraulically incapable, under
only 7 feet of head, of moving enough sediment without mechanical
manipulation. Earthmoving equipment cannot realistically operate in deep
water to remove sediment; and removal of the sediment from the stream
altogether would interrupt transport of gravels needed for downstream
spawning redds.
Captured floating debris would be periodically removed by hand and
machine. The clearing of the pondage area to the anticipated high water
mark of a 50-year flood should reduce this problem.
The U.S. Forest Service has collected several years of Indian River
sediment information, and is in the process of completing their analyses.
Continued planning and engineering of the selected plan will use the
updated information when the USFS report is completed. The preliminary
sediment and bed load data suggest that 2.S-inch rocks are the largest
normally expected to move as bed load above the planned damsite.
It is expected that the largest of the bed load materials will settle out
200 feet above the dam as they enter the planned pond age area. Only the
finest of bed load materials and a portion of the suspended load would
accumulate in the deepest and calmest waters adjacent to the dam.
T-2S
Although the penstock invert would be 3 feet below the bottom of the dam. a
weir (Plate 3) at the mouth of the intake channel would block debris from
entering the intake structure.
T.4.7 OPERATION
The intake structure is designed to operate year-round regardless of flow.
During the warmer months. with streamf10ws in excess of power requirements.
some water would flow over the intake weir into the penstock with the
excess passing over the dam. When flows drop below the combined turbine
minimum and consumption uses. the hydropower system would not operate. All
flows would then be diverted over the fish bulkhead.
Turbine operation requires flows between 20 and 52 cfs and instream flow
needs are 10 cfs. When the penstock flow drops below 20 cfs the plant
would shut down and the diesel plants would start. If the plant is shut
down for an extended period during the winter. the intake valve at the dam
would be closed and the system drained to prevent freezing.
The hydroelectric and diesel plants would interface automatically if demand
exceeded the power capability of the natural inflow, and/or if streamflow
decreases below 30 cfs. Automatic shutoff of the system at a power output
of less than 110 kW (20 cfs) would be designed into the turbine/generator
unit. Diesel units would switch on line, if demand has not already called
for capacity above 110 kW. An alternate set of pressure controls would
automatically switch on backup diesel units if loads suddenly increase or
if heads diminish below minimum operational levels. A simple floating
remote sensor would be installed to signal turbine shutdown if the pond is
drawn below the minimum operational level.
Manual operation would also be designed into the plant. Depending on the
energy demand at the time. some portion of flows in excess of the turbine
minimum could be diverted for other instream or consumptive needs. If for
example, the community electrical and water supply needs were such that 40
cfs were needed, and the streamflow at that time was 55 cfs. it would be
possible to operate the plant and release 15 cfs for fisheries downstream,
5 cfs above the minimum instream flow needs. The full-flow turbine
capacity would not be met if the demand were greater than 215 kW (40 cfs).
but all three needs would be met to some degree. On the average. diesel
supplements may be needed 160 days per year. Of these, total diesel
reliance is expected 43 days annually. Statistics indicate that. for
instance, 250 kW of hydropower would be available 51 days in the critical
low flow months of December, January, February. March. and August (Table
14). During this same period, there would be sufficient water for at least
a minimum production of 104-kW on at least 40 days.
T-26
T.5 PENSTOCK
T.5.1 DESCRIPTION
Development of the tentatively selected plan calls for about 2,400 feet of
penstock. The first 250 feet of pipe below the intake would be below the
original ground surface. The remaining 2,150 feet would be placed above
ground on supports. The route (Plate 4) would follow the right or
southwest bank. The pipe would drop approximately (0.5 percent slope) from
elevation 146 at station 0+00 to elevation 135 at station 22+50. From this
point to the powerhouse at station 24+00 the penstock would drop
approximately 21 percent to elevation 78 feet.
The design startup time is 20 to 60 seconds. Because the plant is to be
used for supplementary base load (rather than peaking) the longer-than-
normal (5 seconds) time allows more design flexibility. The pressure
downsurge is reduced and the need for a surge tank is eliminated. No water
hammer problems are anticipated. The maximum water hammer pressure
calculated was 145 feet or 63 1b/in2g. Under 80 feet of gross head the
rated flow (52 cfs) would have a velocity of 6 fps and a head loss of 5
feet. The penstock would be placed above the 100-year flood stage to
reduce the probability of damage.
T.5.2 Material Selection
Five materials available are: concrete, high density polyethylene, steel,
ductile iron and wood stave. Concrete was dropped because of the excessive
weights. Shipping and handling would be expensive and would entail too
much heavy equipment. Ductile iron pipe was dropped for similar reasons.
Plastic, wood,'and steel all compete for combined weight, handling,
corrosion, and durability advantages.
Because the first 250 feet of pipe below the dam is to lie in a rock cut
1/4-inch thick coated steel pipe with a 42-inch outside diameter (0.0.) was
chosen. Because of 63 psi pressures near the powerhouse, steel was
selected for use in the 150 feet of conduit above the turbine valve.
The steep terrain between the dam and powerhouse would require either a
flexible conduit to fallow the contours, or a steel penstock requiring
massive side slope cuts to provide a constant alignment. To minimize the
amount of excavation, woad and high density polyethylene pipe were compared
for use in the middle 2,000 feet. •
Wood stave pipe has performed adequately in many Alaskan water projects.
Wood stave pipe can be installed with unskilled labor using small
handtoo1s. Little heavy equipment, hence minimal access, is needed for its
installation. However, shipping and handling costs are high. Additionally
wood pipe was rejected for this plan because any pipe selected must be
dewatered during winter low flow months. Annual maintenance costs would be
high to repair joints after repeated differential shrinkage and swelling of
the wood stave pipe.
T-27
Plastic pipe was selected because it is relatively lightweight and requires
only a small crew and a few pieces of machinery to install. It can follow
the terrain with only relatively minor site preparation. Although it has a
high coefficient of thermal expansion, polyethylene goes into tension as
temperature drops and becomes a stronger material. Temperature induced
movement should be alleviated by installation during the warmer surmner
period, following natural contors with slight curves, and strategically
placing blocks and pylons. The overall material (weight) and shipping
costs of steel and plastiC pipe of the same diameter are comparable.
Plastic should require less labor and time to install because it does not
have to be welded. Plastic is also smoother than steel, so a smaller
diameter p"ipe can be selected. A steel or wood penstock of 42 or 45 inch
1.0. would be needed for comparable head losses and performance; therefore
the additional weight would add more costs than those of the selected
42 inch 0.0. polyethylene pipe.
T.5.3 ROUTE PREPARATION
The selected penstock route essentially follows the contours of the river.
Bedrock underlies shallow soils under the entire route. The right bank is
favored over the left because the rock tends to be less fractured and
competent enough to hold a 1H to 4V cut.
Clearing will be kept to a minimum. The timber volume in this mature
forest is too great to clear a right-of-way of sufficient width to insure
that no massive tree would fallon the penstock. Further, full-width
clearing could induce undesirable soil creep on the steep slope. Only a
30-to 50-foot wide corridor would be cleared. Leaning, rotten, dead, or
diseased trees on the edge of the right-of-way would be culled, and 1imbing
used where desirable. As built dimensions would vary from station to
station.
Basically the penstock would be installed on a bench cut from the river
bank. Because the construction period is short, and the penstock route is
not intended to perform as a road (there would be no vehicular traffic
after the pipe is installed), exception is taken to both the Corps access
standards and the USFS l4-foot minimum travel width for light duty single
lane forest roads. The estimate was prepared assuming the penstock
platform to be about 14 feet wide or the minimum needed to accommodate the
contractor's equipment, and composed of sidecast fill from the cuts where
possible.
Construction of the access route would conserve and salvage native material
as much as possible. Clearing would remove only that vegetation within or
overhanging the work area. Larger trees could be felled and used in
conjunction with steel cable, and/or welded wire baskets to form retaining
walls for the fill sections on an "as needed" basis, particularly where
sidecast material could be eroded in floods. Most of the excavated
materials would be retained in the planned 3H:1V embankments. In this
manner, "10st" fill material below the embankments should be limited to
less than 100 cubic yards. Gravity would take only the largest of the
110st" excavated pieces to water level, posing a minor and temporary
sedimentation problem. The contractors could be required to install
additional sediment control devices or to rescu1pture the rock entering the
T-28
stream into fisheries habitat, or to otherwise mitigate for deterimental
impacts. The bench created would essentially follow a 0.5 percent gradient
for most of its length. The last 250 feet would drop to the powerhouse
along a 21.4 percent grade, steep but negotiable by a bulldozer using a
winch and tag line if necessary. Because the plastic pipe is somewhat
flexible, minor variations within the hydraulic grade line were considered
to make installation easier. The pipe will rest on railroad ties and
anchored down with steel straps rock bolted as diagrammed on Plate 4.
The trenched sections near the dam and powerhouse are also held to minimum
dimensions for economy. These sections call for steel pipe and burial is
not necessary. The pipe near the dam will be the last to be installed.
The area where the trench is to be dug would be graded for downstream
access first, and excavated just prior to pipe placement.
A foot trail would remain along the penstock route after pipe placement.
T-29
T.6 POWERHOUSE
T.6.1 POWERHOUSE GENERAL
Installation of a single 265-kW capacity unit is proposed, which will be
housed in a wood frame structure measuring 20-by 20-feet in plan. The
penstock rock-cut and transmission line cut will lead to the powerhouse
door. A work area, a powerhouse site, and access routes in and out of the
work area would be created primarily by rock excavation.
The building would be framed on bedrock and then leveled by placing a
grout/concrete pad. The floor would be at elevation 75 fms1, above the
100-year flood stage. The draft tube would empty into a concrete-lined
drop box. The tailrace weir would be wood timbers held in place by channel
iron rock bolted to the excavated and grouted walls of the excavated drop
box. A 4-ton rolling hoist would be provided to install and remove
equipment and tools. Plan view and sections of the powerhouse are shown on
Plate 5.
The tailrace would be about 50 feet long fully traversing the cut section
to the stream edge. A timber weir would control the level at elevation 73
fms1. The walls of the tailrace would be 0.5 feet above the weir. The
bottom of the tailrace would be at elevation 67 fms1. There would be 3
feet of clearance beneath the draft tube providing 3 feet of submergence.
The downstream end of the tailrace would be riprapped to protect the stream
bed and to form the water supply French drain intake. The river water
level at the outlet of the tailrace is about elevation 66 fms1.
T.6.2 ACCESS TO THE POWERHOUSE
Two options are available for powerhouse construction, helicopter or
overland. Because a large helicopter would be required to lift and place
the machinery in a forested canyon, the difficulty would precipitate great
expense. Therefore, the overland road option was selected in this level of
study.
The transmission line associated with this plan would require only a
minimal access trail. Within the limits of the designated cleared area,
only a light duty cat trail would be constructed. Grubbing of the tree
stumps and a minor amount of fill would be needed along the trail. This
trail would require only those improvements necessary to facilitate
transmission line construction equipment passage and that required to
construct the powerhouse.
All powerhouse materials and equipment, the steel penstock pipe and valves
used at the powerhouse, and the water supply pipe materials would be off
loaded at the beach between Kushtahini Creek and the Tenakee Springs boat
harbor. From this point they would be transported to the powerhouse site
along the improved transmission line trail. Very few improvements are
expected to be needed along most of the route. Only the last few hundred
feet descending the canyon to the powerhouse will entail heavy earthwork.
T-30
From the powerhouse (Station 24+50) to the crest of the river canyon
(Station 29+00) the transmission line would follow a cut and fill access
trail. This would be only about 10 feet wide, and excavated material would
be sidecast. This cut would have a 18 percent grade; steep but negotiable.
About 700 cubic yards of rock would be excavated.
T.6.3 POWERHOUSE MECHANICAL
The reaction turbine originally selected for estimating in this study is a
standardized horizontal shaft Francis type with adjustable guide vanes and
a throat diameter of 24 inches. The runner is rigidly attached to the
generator shaft. A butterfly shut-off valve is provided in the inlet
pipe. The turbine would be rated to produce 356 HP while operating under a
net head of 71 feet at 85 percent efficiency. At full load the unit would
discharge 52 cubic feet per second. Intake and penstock losses are
approximately 10 feet. Rated generator output would be approximately 265
kW, which corresponds to 85 percent turbine and 95 percent generator
efficiencies. The speed of the turbine is estimated to be 900 RPM. A
hydraulic power unit would provide power to the guide vane adjusting
servo~tor and the butterfly valve cylinder actuator. An accumulator
would be provided for emergency shutdown of the turbine.
The advanced engineering work on this study suggests that other turbine
packages are or will be marketed in the next few years which could be used
to advantage here. A turgo type unit may perform nearly as well for less
expense. Pumps used as turbines may also perform well. A large capacity
(150) and small capacity (75 kW) pump combination would more fully utilize
the flow duration curve. Although pumps have narrower efficieny ranges,
they are less expensive and less sophisticated -an advantage for rural
area maintenance techniques. The point in this discussion is that although
costs and designs were presented around a 265-kW horizontal Francis, other
units could be adopted for no significant change in cost. Each of these
has specific sets of advantage and disadvantages inappropriate for
discussion now since the overall project is not significantly altered.
T.6.4 GENERATOR AND BREAKER
The generator would be a horizontal shaft synchronous type with the shaft
directly connected to the turbine. The generator would be rated 265 kW
(325 KVA @ 0.8PF), 3-phase, 60 Hz, 0.40 kV. A drip-proof enclosure would
be provided for the generator. The generator would be open ventilated with
an 80°C rise Class B insulation system without provisions for overload.
The generator would have full run-away speed capability.
The governor would be of the oil pressure, distributing valve, actuator
type with mechanically driven, speed responsive elements designed for
regulating the generator speed by controlling the wicket gates. The
governor unit would consist of an actuator, restoring mechanism, motor
driven pumping unit, pressure or accumulator tank, sump tank, oil piping,
and accessories. In addition, an automatic gate limit control would be
provided for positively limiting turbine gate opening. On load rejection,
the governor would first allow the generator to go to overspeed, then open
the bypass valve, and lastly close the wicket gates shutting down the unit.
T-3l
The connection between the generator and breaker would be with cable. The
generator and station service breakers would be metal enclosed switchgear
type. The breakers would be combined in a common switchgear lineup along
with instrument transformers. The excitation system would be specified to
be the generator manufacturer's standard. This could be either a direct
connected brushless exciter or a bus-fed power potential source static
excitation system. Solid-state continuously acting dynamic type voltage
regulators would be used and would be incorporated in the unit switchgear.
T.6.5 UNIT CONTROL AND PROTECTIVE EQUIPMENT
A complete complement of generator protective relays (differential,
overvoltage, overcurrent, etc.), start-up and shut-down controls, and other
unit control relays would be provided in the metal-clad switchgear lineup
containing the generator circuit breaker. Synchronizing would be
accomplished by speed switches. The generator breaker would close at
95 percent speed, with the static excitation system being energized at
98 percent speed. The generator would be provided with a connected
amortisseur winding to facilitate pull-in with the system. The unit would
be a package type unit and would have electrical and mechanical protective
devices as indicated on the one-line diagram.
T.6.6 STATION SERVICE
The station service equipment would consist of a 480-volt panel board, a
480-208Y120-volt lighting transformer and lighting panel. A pump, lights,
outlets and a 4-kW heater would run off station service. The station
service transformer connection would be made in the powerhouse and as shown
on the one-line diagram (Plate T-8). A 125 volt battery would be provided
for unit control. Station service would also be available during periods
of shutdown by in-town diesel sources.
T.6.7 CONNECTION TO LOAD
A single pole-mounted 7.2/0.48 kV, delta-grounded Wye, 3-phase, AA Class,
500 kVA transformer with the minimum nonpremium impedance specified would
be connected by about 3,800 feet of transmission line. The 7,200-volt
winding would be connected to the existing distribution system.
T-32
T.7 TRANSMISSION LINE
Approximately 3,800 feet of 7.2 kV transmission line would run from the
powerhouse to the edge of town. The three phase #2 ASCR line would be
mounted on single 30-to 50-foot tall wood pole (Plate 6). The connection
at the harbor would consist of a set of fuse gear and jumper loops to
connect with the planned community distribution system. This design would
be fully compatible with the new distribution system. There would be no
associated costs in this plan.
The proposed corridor would enclose a 30-to 50-foot wide right-of-way
(ROW) below elevation 175 feet. The ROW would avoid terrain involving
extensive surface modification. The access road is envisioned as a bladed
and graded bulldozer trail with minimal upgrading.
The heights of the mature trees through which the corridor passes would
require an impractical clearcut of 300 feet, so selective ROW edge clearing
of diseased, leaning, or dead (danger) trees and selective trimming of
borderline trees is anticipated to complement the SO-foot clearcut for a
safe conductor zone. Felled trees would be limbed and salvageable logs
piled at designated points along the edge of the right of way. Slash would
be chipped, piled and burned, or compacted by bulldozer to provide small
animal habitat. Site restoration along the transmission line, access
roads, and penstock route may consist of grading, seeding, and mulching as
appropriate.
T-33
T.B WATER SUPPLY SYSTEM
T.B.l GENERAL
Three design options for the water supply system (Plate 7) from the Indian
River are possible: (1) combined use of the penstock with a tap taken off
above the powerhouse, (2) a separate conduit from the dam for each purpose,
or (3) a tap from a pool in or near the tailrace. No supply system in
association with the hydropower plan could rely solely on gravity feed; all
would require pumping.
A tap taken off the penstock at some point above the powerhouse would
ensure water virtually all year because of the pool above the penstock
intake. However, with a full penstock in winter, when the power plant is
inoperative, cold temperatures and icing could rupture the penstock.
Restarts of the turbine could endanger the units if loose ice chunks were
trapped in the penstock. Maintenance costs an associated problems delete
this option.
A separate conduit from the dam would insure water even when the penstock
is empty. However, a smaller cost is involved when the conduit begins at
the powerhouse rather than the dam 2,500 feet upstream. A water supply
using the powerhouse is the tentatively selected plan because it is simple,
lower cost, and dependable.
T.B.2 DESIGN
T.B.2.1 Intake/Outlet
The water supply conduit intake would be sited in an infiltration gallery
in the river channel below the tailrace. A cross-channel trench would be
-excavated into the streambed to elevation 64 fmsl. This trench would
capture instream water during low flow periods when the powerplant is shut
down. Captured water would percolate into a sump for the village water
supply. To insure flow and reduce any surface ice problems, the water
supply intake would be submerged in the sump below the stream bed. A pump
located inside the powerhouse would operate off station service from the
diesel/hydro sources.
The community would have the responsibility for design construction, and
operation and maintenance of all facilities at the end of the Federally
supplied conduit. The outlet system could consist of a series of valves
possibly in a treatment facility housed in a small wooden structure with a
passive solar roof. The community has the option of improving this outlet
with a distribution system and/or a storage tank. Also the community could
direct the water to a Kushtahini Creek development if that option (Section
5.3) is independently developed.
T.B.2.2 Conduit
The conduit would be 3,BOO feet of 6-inch polyethylene pipe with a
preformed 1.4 inch insulation layer. The EPA Cold Climate Utilities
Delivery Design Manual states that insulation achieved by burying a foam
board above the pipe is less expensive but has a greater installation cost
T-34
and is a less effective insulator. The pipe would be buried in a shallow
trench excavated by backhoe or trenching tool. Additional loose earth and,
peat waste from the transmission line access road would be placed on top of
the buried pipe. Although the pipe would not shatter if frozen under
pressure, the extra material would offer additional insulation and
protection from vandalism and bears.
Burial would help control the expansion and contraction of the pipe by
increasing wall friction. A 6-inch diameter water supply pipe with 2
inches of insulation above ground and 1 inch of insulation where it is
buried 1 foot would be adequate if water is flowing on an hourly basis. If
water is stagnant for long periods of time, more insulation and/or larger
diameter pipe would be needed. The water outlet system in the village
would be designed with a small constant discharge valve to prevent
freezing.
T.8.3 COST ANALYSIS
Several concepts for single purpose water supply development other than the
tentatively selected plan appear to be more costly than the multiple
objective plan. The terrain conditions are such that gravity would not
feed to the village from the nearest point on the Indian River. The cost
of pipeline clearing, excavation, and installation is over $600,000. A
system pumping water from the tailrace could not guarantee the water supply
that a system diverting from a dam could insure.
The separable cost for a water supply system incorporated into the
hydropower project is presented below. Right-of-way features are about 20
percent the dimensions of the transmission line features presented in Table
T-9.
T-35
Table T-7
WATER SUPPLY COST ESTIMATE
Feature Units Unit Cost Total Cost
Pumphouse
Intake and Valve Structure
Pipe Materials and Installation
Access Cut Between Sta 24+00 and 28+00
Clearing, Disposal, and Uozer Trail
SChedule 40 pipe and fittings
Valves, flanges, fittings
Excavation, Burial, and Restoration
Outlet House 11
Outlet Valve TI
Filtration Housing 11
Chlorinator 11 -
Pump -
Powerl i ne
Sub Total
Contingencies (20%)
100 sf
1 @
3,800 lf
700 cy
3,800 1
1 job
1 job
730 cy
100 sf
3,800 1f
Engineering, Design Supervision, and Administration
Interest During Construction
Total Cost
Annual Cost (8 1/8%)
O&M Cost 21
TOTAL ANNUAL CO~
45
$5,500
$ 65
$ 30
job 1 s
$ 20
$ 25
$ 17
( 13%)
$ 4,500
$ 5,500
$247,000
$ 21,000
$14,000
$ 3,200
$ 6,700
$ 14,600
$ 2,500
$ 2,500
$ 3,000
$ 5,000
$ 11,500
$64,600
$406,100
$ 81,200
$ 63,200
$ 23, 100
$573,600
$ 47,600
$ 5,400
$ 53,000
11 Cost sharing to be arranged by non-Corps authority. II Labor, materials, chlorine, replacement equipment, electricity.
Savings if constructed in conjunction with the hydropower plan would
eliminate the duplication of:
1. The pumphouse
2. Access excavation between Sta 24+00 and Sta 28+00;
3. Clearing and disposal between Sta 24+00 and 61+00;
4. The dozer trail between Sta 28+00 and 61+00;
5. Restoration, and;
6. The powerline
T-36
7. Shipping charges, because all the water supply pipe could be
nested inside the penstock pipe.
The sUb-total for water supply would be reduced to $301,500.
The total first cost would be $425,900
The total annual cost would be $35,300 plus O&M of $5,450, or $40,750.
T-37
T.9 PROJECT OPERATION AND MAINTENANCE
If constructed as a Federal project, the Federal APA would own and
operate this project. The APA would probably. contract with the local
utility for operation and maintenance in conjunction with the backup
diesel generators. It would be the responsibility of the city to
maintain the intake works, penstock, powerhouse, transmission line,
substation, distribution system, and water supply system. Spring startup
and winter shutdown, including penstock bleeding, would be required. The
water supply tap would require extra observation and maintenance during
the winter.
The hydropower unit would be capable of matching the necessary load
during the times of the year when flows equal or exceed demand, less
instream flow and water supply releases. During the periods of
insufficient flow, usually December through March, the hydropower unit
would operate at a base load mode or shut down temporarily while diesel
assumes primary status. Automatic and mechanical sensors at the intake
and in the powerhouse would start/stop diesel units to pick up/drop as
loads and hydroelectric output changes with available streamflow.
If a major powerhouse overhaul is ever required, a backhoe or similarly
sized machine would be brought up the transmission line trail from the
beach. To cross the tailrace to get to the powerhouse door, fill
material from the disposal area (Plate 5) would be placed in the tailrace
for a temporary crossing while the plant is shut down and the tailrace is
dry. The in-house portable hoist would move the dismantled equipment to
the door where the backhoe or bulldozer would transport the part(s) back
to town and the shipping dock on skids.
The operations and maintenance of the combined diesel and hydroelectric
generation and distribution system would require one permanent, part time
person all year. Two additional people would be required for an
estimated 2 weeks every third year for hydroelectric plant maintenance,
primarily sediment and trash removal. The year-round duties associated
with the hydroelectric system are primarily inspection walks of the
substation-transmission line, penstock and dam, and the cleaning and
lubrication of the valves, gates, and powerhouse equipment.
The permanent, part-time employee would distribute half his time to the
hydroelectric system (because it is further from town) and half to the
distribution and diesel systems. The basic time allotted to
hydroelectric O&M is 520 hours annually. Every 3 years, he would spend
another 100 hours supervising two co-workers in repairs, overhauls, and
debris removal. There are additional O&M allotments for periodic repairs
of a substantial nature (for example, trash rack replacement), equipment
rental, and small tool purchases. The estimated annual O&M cost is:
T-38
Basic Annual Cost:
Labor - 2 hours X 5 days X 52 weeks X $25 per 11
Grease -20 tubes X $5 per
Misc. Hardware and Tool Allowance
Additional Costs Every Third Year:
Labor -30 mandays X 10 hours X $25 per
Backhoe -50 hours X $50 per
Combined fuels (chainsaw, backhoe, generator)
Sub total
Effective Annual Cost
Sub total
= $ 7,500
= 2,500 = 500
= $1O~00
(8 11 )
Estimated Total Annual O&M Cost
= $13,000
= 100
= 200
$13,300
$ 3,220
$16,520
Replacement costs are an additional category to consider. In this plan it
is expected·that certain replacement costs will be incurred by the dam
design, intake arrangement, and access features. The diversion structure
is designed to withstand and pass the 25-year flood with negligible
damage. Controlled damage will occur in larger events. The repairable
damage is associated with the risk of the damaging event occurring within
the 50-year project life. Risk analysis permits reduction of the high
initial cost of a dam built to withstand the 100-year flood, a cost
determined to exceed the limits for a feasible project. The probability
that flooding will not occur for n successive years ;s equal to:
~ _ +) n
Where T equals the return period of the flood.
The probability R, called risk, that flooding will occur at least once in
n successive years is equal to:
R= 1-{ -! ~
The figures below summarize the risks of occurance of floods greater than
the 25-year design flood, the value of repairs for anticipated damage to
the plan features, and the equivalent annual cost of repairs and
rep 1 acement •
FLOOD EVENT RISK ESTIMATED COST OF DAMAGE PRODUCT
12-year 0.5811 X 0 = 0
15-year 0.4984 X 0 = 0
17-year 0.4546 X 0 = 0
20-year 0.4013 X 0 = 0
25-year 0.3352 X $3,700 = $ 1,257
30-year 0.2875 X 4,700 = 1,350
T-39
35-year 0.2516 X 6,000 = 1,510
40-year 0.2237 X 7,500 = 1,680
45-year 0.2013 X 10,000 = 2,013
50-year 0.1829 X 20,000 = 3,660
75-year 0.1256 X 30,000 = 3,770
100-year 0.0956 X 45,000 = 4z300
SUM $19,540
A 25 percent contingency factor is applied to compensate for uncertainty,
and to aproximate intergration of all years, then an effective annual cost
calculated.
1.25 x $19,540 = $24,525.
$24,425 x 0.08292 is the effective annual cost of $2,025.
Aside from flood damage, normal wear and tear is expected to add to
replacement costs. Assume that normal costs can be approximated by the
values below if every 16 years there is a need to
Replace a complete ,transmission pole assembly
Replace trashrack
Replace powerhouse roofing and siding
Replace/repair 20 lineal feet of penstock
Sub total
$ 500
10,000
12,100
12,000
$34,600
Effective Annual Cost (8 1/8%) $ 1,125
In summary the estimated annual cost of operations, maintenance, repair,
and replacement is:
Annual OM&R
The rounded cost of $20,000 is used in Section T.12
$13,300
$ 3,220
2,025
$ 1,125
$19,670
This estimate is substantiated by results of a survey of small
hydroelectric installations across the Nation. Findings suggested that
annual replacement costs average 23 to 24 percent of the annual operations
and maintenance costs.
An additional mitigation cost of $4,850 annually is explained and used
elsewhere in the report.
T-40
T. 10 CONSTRUCTION PROCEDURES ANU SCHEDULING
Access to the project features presents the most difficulty. Any needed
gravel and borrow material could be prepared, stockpiled, and protected in
the Forest Service quarries or work areas in the late summer or autumn
preceding construction (Plate 9). Surveying and clearing of vegetation
would be planned to precede the construction season, taking place around
October or November. Timber salvages for on site use, lumber, pulp, or
fuel would be incorporated. Pioneer access roads could be built the
following spring, incorporating the appropriate cross drainage and sediment
retention features. The stream crossing and dam and intake rock could be
drilled and blasted in late spring.
Excavation and terracing of the damsite and penstock corridor between May
and July would not coincide with the incubation of eggs or the outmigration
of pink, chum, and coho salmon (Figure 7). Construction activities causing
sedimentation during this period would have the least impact on the
riparian ecosystem. The streamflows would be relatively high and no eggs
would be incubating. Later in the summer, the fish would fan away any
settled silts prior to spawning,. Some excavated rock would be placed in
deSignated areas along the margin of the cut and in a few low areas where
fill is required. The remainder would be used in/or near the dam or
disposed in existing quarries. Rock debris should include little soil.
Flows diminish in August, at which time construction of the dam would be
scheduled. At this time, the pink and chum' redd are incubating. Instream
sediment control measures would be used and should be effective during this
low flow period. Powerhouse installation would be well underway at this
time also. Instream activity would be less at the powerhouse (primarily
inside work), but sediment control would be closely monitored because of
the proximity to the Indian River1s largest spawning and rearing areas
downstream of the pool at Barrier #1.
The installation of the penstock would begin as soon as heavy equipment is
no longer needed at the powerhouse. After the penstock is placed, travel
width along the penstock cut would be reduced to about 3 feet. Some small
equipment could travel the access route on the transmission line or along
the penstock.
Transmission line and substation construction could be scheduled either the
preceding autumn or in July. Installation of any water supply features
would also take place in July. Finishing details beyond September would be
held to a minimum to avoid weather problems. Cleanup and restoration would
be completed by October.
T-41
T.ll CONSTRUCTION CAMP AND LABOR
Many residents of Tenakee Springs are accomplished laborers having skills
in surveying, logging, earthwork, distribution system construction,
carpentry, equipment operation and maintenance. If these residents are
employed during construction of this project, camp requirements are
substantially reduced. Only housing for supervisory and administrative
personnel would be needed. Rental of some of the existing 37 cottages
could easily satisfy their needs. Office trailers could be moved to
on-site work areas.
All construction materials are assumed barged in from Seattle or Portland.
Pelican Cold Storage operates a direct barge line serving Pelican and
Tenakee Springs. Dock and shelterd moorage is available at or adjacent to
the eXisting ALP/USFS log dock and rafting area. Only limited improvements
would be required. No dredging is expected. Because logging is not
scheduled to resume until 1990, no conflict is anticipated for use of the
dock, road, and storage areas during project construction. The contractor
would be required to maintain user agreements with ALP/USFS.
Equipment and materials needed for the transmission line, water supply
line, and powerhouse could be (all or in part) delivered to the hard beach
between the small boat harbor and Kushtahini Creek. Landing craft have
beached hera before to offload heavy equipment. This is adjacent to the
planned switchyard and water supply outlet, so a small staging area should
be easily arranged.
Equipment and materials storage areas would be provided at the project.
Waste material from road, damsite, river crossing and penstock excavations
would be graded to create work areas. A batching and storage area would be
built adjacent to the dam access road near the 17S-foot contour. Another
longer and narrower staging area would be created along the intake and
upstream portion of the penstock.
T-42
T.12 HYDROPOWER PROJECT COSTS
Estimated project costs are detailed below. Listed items include all costs
associated with furnishing, shipping, and installing the items.
Operations, maintenance, and replacement costs are estimated at $20,000 per
year. The expected project life is 50 years. Annual costs are computed
using a 8 1/8 percent discount rate as anticipated for Fiscal Year 1984.
Costs are given in October 1983 price levels.
No plan considered in this study had any associated historical and
archeological salvage operation costs, relocation costs, nor hand water and
mineral rights costs. Remaining costs are shown in the table below. Fish
and wildlife mitigation costs are inherent to the proposed design.
The estimated costs for this and other similar small, remote hydroelectric
developments will be high. The economy of scale is missing. Aggregates
must be imported from afar because onsite materials are unavailable or
insufficient in volume to make crushing and screening plants economical.
The use and installation of items like steel penstock concrete and heavy or
specialized equipment drastically increases project costs due to rough
terrain and distance from established ports and markets.
At this level of study all selected fill, aggregate, sand and cement are
expected to be barged in from Juneau, Seattle or Portland. No local
sources are available. Later phases of study may find cost savings if the
contractor were to import a crusher and screener.
Project costs include all line items and materials used in project
construction plus Engineering and Design (E&D) and Supervision and
Administration (S&A) and a contingency factor to cover unforseeable
changes. To this cost must be added the cost of using money during the 18
month construction phase of the project when no product or a service is
being realized. By considering these phases a project investment cost is
developed.
The following table shows project costs, investment costs, and the
hydropower development of annual costs associated with the Tenakee Springs
Project. The costs developed in this study represent busbar costs
excluding additional expenses to the consumer associated with distribution,
administration, taxes, insurance, or depreciation.
T-43
TABLE T-8
SEPARABLE HYDROPOWER PROJECT COSTS
(October 1983 Prices)
FEATURE:
LANDS: Government owned;
USFS (dam)
State (powerhouse)
UNIT
3.5
5.5
MOBILIZATION AND DEMOBILIZATION
PONDAGE AND SPILL AREAS:
Clearing and Disposal 0.8 acres
ACCESS TO THE DAM: (700 1f)
AND LEFT BANK WORK AREA:
Clearing
Grubbing and Disposal
Excavation (common)
Fill (select)
(common)
(75 X 110 1f)
0.8 acres
1.2 acres
1,300 cy
2,300 cy
1,800 cy
UNIT COST
$5,000
$5,000
$ 3,000
1,000
2,000
15
25
10
STREAM CROSSING, DIVERSION, DAM, AND INTAKE STRUCTURE
Clearing and Disposal
Excavation (Rock)
(Common)
Fill (Diverson) (Mixed)
(Crib Dam) (Rock)
Concrete
Log Dam
2"x12" Planking
2"x12" Decking
Trashrack
Penstock intake gate
Penstock reducer (6 l to
1 acre
590 cy
630 cy
200 cy
420 cy
50 cy
1 job
2.6 MBM
3.8 MBM
1 ea
1 ea
3.5 1 )1 ea
T-44
3,000
50
15
8
10
1,200
L.S.
2,500
1,850
L.S.
L.S.
L.S.
LINE TOTAL
$44,500
$ 17,500
$ 27,000
$260,000
$ 2,400
$ 98,000
800
2,400
19,500
57,500
18,000
$281,280
3,000
29,500
9,450
1.600
4,200
60,000
134,000
6,500
7,030
5,000
12,000
9,000
PENSTOCK: 42 inch outside diameter
Clearing and Disposal
Excavation (rock)
(common)
Concrete
Anchor Assemblies
Wood (RR ties) Supports
Steel pipe 42"
Ring Stiffners
Plastic Pipe 42"
Pipe Transition
2.3 acres
9,000 cy
1,500 cy
10 cy
230
230
45,000 1bs
2,300 1bs
2,000 1f
2@
2,340 ft
3,000
30
15
1,200
253
110
2.00
1.80
168
3,600
TRANSMISSION LINE (3,750 1f, 7,200 kV 3 phase)
Clearing and Access
Wood Pole Line
POWERHOUSE WOOD ENCLOSURE
Work area
4 acres
0.8 mile
Clearing, Disposal, Stripping
Building
1 job
400 S.F.
Powerp1ant
5,000
160,000
L.S.
60
Turbine, Governors, Intake valve, Installation, Shipping, Duty
Generator and Cooling System
Accessory Electrical Equipment
Auxilary Systems and Equipment
Mobile A-frame and 4-ton Chain Hoist and Frame
42" diameter gate valve
Foundation and Tailrace
Excavation (Rock)
Concrete
Contingencies (2~)
1,100 cy
10 cy
Engineering and Design (~)
Supervision and Administration (7~)
TOTAL FIRST COST
Interest During Construction (18 months)
TOTAL INVESTMENT COST
Annual Interest and Amortization
50
1,000
Annual Operations of Maintenance, and Replacement Cost
Annual Environmental Mitigation Cost
TOTAL ANNUAL COST (rounded)
T-45
$840,630
6,900
270,000
22,500
12, 000
58,190
25,300
90,000
4,140
344,400
7,200
$148,000
20,000
128,000
$512,800
3,000
24,000
170,000
75,000
130,000
25,000
10,500
10,300
55,000
10,000
$ 433,390
208,000
182,000
3, all, 000
240,000
$3 2 251 z000
269,000
20,000
5,000
$294 z000
T.13 PROJECT BENEFITS
T. 13. 1 INTERMITTANT CAPACITY BENEFITS (ICB)
The capacity value and benefit is the cost to recover the investment cost,
operation and maintenance (O&M) costs, and major repairs to a thermal
(diesel) alternative plant. Traditionally capacity credit has been given
to a hydroelectric project for only the capacity considered to be fully
dependable. That is the load carring capacity of the project under the
most adverse combination of system loads, hydrologic conditions, and plant
capabilities. Federal evaluations now recognize that this results in a
very conservative estimate of the hydroelectric project's dependable
capacity, which is completely unrelated to the dependable capacity of the
thermal alternative and which gives no credit for capacity which may be
available for a substantial percent of the time.
In Tenakee Springs demand is estimated to grow from 652,560 kWh in 1986 to
1,441,200 kWh in 2036. The AAE is 928,400 kWh. The hydrologic record of
Indian River suggest that the proposed plant could supply much of the
required energy 7 months of the year. This amount could delay the purchase
of smaller diesel units providing the plant operates during peak summer
(July) months when demand is greater than that of winter months. This
claim assumes summer demand curves rise at a greater rate than winter
demand as the community base expands ov~r the next 50 years.
The recently revised Water Resources Council (WPC) procedures (adopted by
the Federal Energy Regulatory Commission,FERC) state that when
intermittant capacity is available, a credit should be taken. The credit
is approximated by computing the ratio of the expected availability of the
hydroelectric plant during peak load to the expected availability of the
thermal alternative during the same period. The anticipated peak demand
period in Tenakee Springs is expected to be July.
Additionally the expected period of availability and hydroelectric
operation is about a 300 day block of time, not the full calendar year.
This hydroelectric plant will shut down during several days in the winter
and a few days in late summer. The actual availability period may average
(Table 14) 322 days annually, but will coincide with water year, not
ca1andar year characteristics. The intermittant capacity credit benefit
calculation for Tenakee Spring is based on this period (cautiously reduced
due to limited records) of a 300 day "year".
A redefinition of the "year" which acknowledges a summertime critical
period may allow a small ICB because the summertime peak demand is less
than the anticipated winter peak demand.
T-46
The dependable capacity benefit (DCB) is computed as follows:
DCB = IC X HA X HMA/TMA X CV X (HF)
Where: IC = installed capacity in kilowatts;
HA = hydrologic availability, the same as critical period
plant factor;
HMA = hydropower mechanical availability, 97.5 percent as
suggested by FERC;
TMA = thermal plant mechanical availability, 93.5 percent for
diesel as suggested by WPC;
CV = The annual capacity value per kilowatt of diesel at
8 1/8 percent financing.
F = Additional flexibility factor for hydropower, zero for a
run-of-river project as stated by FERC.
For simplicity in calculation the July Power Duration Curve (Appendix F) is
segmented at 110-kW, 184-kW, and 265-kW. The annual capacity value of
hydropower on Indian River is:
110 X 0.963 X 97.5/93.5 X $71 X 1.00 = $ 7,843
74 X 0.943 X 1.0428 X 71 X 1.00 =
81 X 0.886 X 1.0428 X 71 X 1.00 =
The 265-kW Intermittant Dependable Capacity
$ 5,166
$ 5,313
Benefit equals each year $18,322
Traditionally the capacity benefit computed for a hydropower project is
intended to reflect the capacity costs saved by not constructing
alternative power generating facilities. This credit has usually been
applied to large interconnected systems with several sources of generation.
In the case of the remote, isolated, small system such as proposed in
Tenakee Springs, the intermittant dependable capacity benefit is taken to
reflect the delayed purchase of smaller reserve diesel generators.
The installation of a dependable hydroelectric plant would require
supplemental power during periods of low flow. When the hydroelectric
plant operates at less than rated capacity and when demand is greater than
the hydroelectric capacity, small increments of diesel are required.
Because the increments are small, diesel reserve generators can be
purchased in smaller size, at lower total cost to the community, and would
operate near the maximum efficiency because they would be closely matched
to incremenal load. Operating at a constant rpm, the lifetime of the units
would be extended, and operations and maintenance costs reduced.
On the days when there is not hydroelectric generation available due to
adverse flow conditions, demand is generally significantly lower than that
of the peak demand month, September. Again because demand is lower, the
required diesel capacity is also smaller. One or more small diesel units
(parallel connected) would suffice in lieu of significantly larger thermal
units.
T-47
This approach in allowing intermittent capacity benefits is analogous to
derating or complete shutdown of the thermal unit due to a forced outage.
Unlike a diesel unit which can be represented as either on, off, or at
discrete levels of partial output, the hydropower plant has capacity
availability in a wide range of outputs on a nearly continuous
distribution. The FERC and WPC modeling has accepted the average
hydrologic availability of the plant's capacity as the most easily derived
and comparable value to thermal capacity value. In the case of Tenakee
Springs, $18,300 (rounded) of average annual benefits represent the best
estimate of intermittant capacity value for periods of greater value versus
periods of no hydroelectric value, i.e., greater availability versus
insufficient str~amf10w.
Other benefits associated with the project are water supply, fisheries
enhancement, and employment. Each benefit category is defined and assessed
and includes a description of the methodology used to determine the benefit
value. At the end of the section a summary of the benefits is presented.
T.13.2 ENERGY BENEFIT
The primary benefit value for hydropower is measured by the cost of the
next least expensive alternative. In the study area, the most likely
alternative energy source is diesel powered generators. The energy benefit
that could result from the proposed hydro project on the Indian River is
the cost of diesel fuel displaced by hydropower in meeting the projected
future demand for energy.
The hydropower plant at Tenakee Springs is expected to generate in 1986
538,000 kWh of a total demand of 652,560 kWh for the area. By the end of
the project life area demand will be 1,441,230 kWh and the proposed
hydrop1ant will supply 1,138,200 kWh of projected demand (Table T-5). The
annual equivalent output of the project is 776,300 kWh over the project
life.
FUEL COST
Specifically, the energy benefit is derived by assigning each marketable
kWh of hydro output a value equal to the cost of fuel used in producing a
unit of energy (kWh) by diesel. Figure T-6 graphically shows how the
Indian River hydro project is expected to contribute to the area demand on
a annual basis over the project life.
To determine the value that can be assigned to the hydroproject, it is
necessary to identify the current and estimated future diesel cost per kwh
that can be eliminated by the hydropower alternative. The hydrop1ant being
considered has the potential of eliminating the use of diesel fuel during
the months of high water flows in the area.
Fuel Cost Escalation
Fuel cost escalation is calculated to demonstrate the savings realized by
avoiding the use of fuel source for which the real costs are increasing
faster than the inflation rate associated with general construction costs.
T-48
FIGURE T-6
ENERGY ALLOCATION IN TENAKEE SPRINGS, ALASKA
MILLIONS
1.4
1.3
K 1.2
I
L 1.1 TOTAL DEMAND DIESEL
0
W
A
--t T ,
T ~
1.0
0.9
H 0.8
0
U 0.7
R
S
0.6
0.5
0.4
0.3
1975 1980 1985 1990 1995 2000 2005 2010 2015 2020 2025 2030 2035
YEAR OF THE ANALYSIS PERIOD
By directive, escalation rates associated with diesel fuel have been
assigned by Development Resources Incorporated (DRI) to estimate future
fuel prices that exceed average inflation levels (Table 11).
These growth rates are applied undiscounted to the power-on-line (POL) date
then discounted to the end of the 30 year escolation period and held
constant through the remaining years of project life to 2036. This process
(Section 3.4.2) gives a multiplier of 1.6 which is used to adjust the fuel
portion of diesel the next least costly alternative generation costs. The
savings that can be eliminated is $0.1370/kwh without escalation and
$0.2192/kWh with escalation.
The net energy benefit is $0.2192/kWh X 776,300 kWh = $170,160.
T.13.3 EXTENDED DIESEL PLANT LIFE
The introduction of a hydroelectric plant would allow the diesel system to
be used more as a peaking plant for fewer total hours of annual usage.
Also the unit would be used when flows are restricted. Local dealers
estimate that a direct relationship exists between reduced operation and
extended life.
By decreasing the hours of use the diesel plant has an extended life and a
reduction in O&M costs which can be claimed as a diesel cost prevented.
The 1983 price of diesel at Tenakee Springs was $1.37/gallon. The
generator efficiency of current and future plants is estimated to be 10 kWh
per gallon giving a diesel fuel cost per kwh of $.137. The average O&M
cost reported in 1982 is $0.08/kWh. By assigning the diesel unit to a
standby statues plant life expectancy will increase allowing an extended
use life. This extended use and with the associated O&M prevented has been
estimated to be worth only $0.048/kwh. Full credit cannot be taken because
the diesel plant is not totally replaced.
The net operations, maintenance, and extended life benefit is $0.048/kWh X
776,300 kWh = $37,260.
Uther benefits associated with hydro development at Tenakee Springs are
water supply, fisheries enhancement, and employment.
T.13.4 SECONDARY ENERGY BENEFITS
As shown on Figures T-4 and T-5 the proposed hydroelectric plant is capable
of producing more energy than is required at certain times. This is energy
for which thare is no specific use now, but were the energy available, a
market would likely arise by laws of supply and demand. This is secondary
energy, and it is traditionally marketed during off peak hours at a reduced
rate.
AS shown in Table T-5 about 1,331,500 kWh of surplus energy could be
generated in 1986, decreasing to 731,000 kWh over the years as demand
increases. Most of this potential secondary energy is available early in
the period when demand is lowest. There would be little secondary energy
T-50
marketed in the early years. It is assumed that 7.5 percent of the
available secondary would be marketed in 1986 (about 66 kWh per building).
Secondary energy sales would increase until all available secondary is
consumed in 2036. The effective annual sales of secondary energy is
estimated to be 116,000 kWh.
Because Tenakee Springs is small, and so is the estimated volume of
secondary energy sales, it is not likely that a rate structure would be
devised. All sales of electricity would be at the same flat rate.
However, because the surplus secondary energy creates a market which
probably would not exist if the town relied solely on diesel, no reduced
O&M and extended life of the diesel plant is claimed for the sales of
secondary energy. The benefit claimed is 116,000 kWh x $0.2192 = $25,427
annually.
T.13.5 NED EMPLOYMENT BENEFITS
A hydropower project is credited with an employment benefit to show the
impact of the project construction phase on the local economy. The Tenakee
Springs area meets the criteria for an employment benefit since it
experiences substantial and persistent unemployment.
The benefit is attributed to the amount unemployed labor of the region that
would contribute to the construction of the project.The total amount
claimed is amortized and expressed as an annual benefit for project
construction. Computation of the NED employment benefit is detailed below.
Employment opportunities for local nonski11ed labor exist for this
project. The clearing and disposal of trees and brush on the project
features, and the brushing associated with surveying work could employ
Tenakee Springs residents. Some, if not all, timber could be salvaged by
the residents for use as fuel or sawtimber.
Manual labor such as materials handling, camp construction, culvert
installation, carpentry, and restoration work could also employ several
individuals (See T.13). As mentioned in T.6. 1. 1, all materials would be
imported. Local employment benefits could be reaped if a crusher and
screening plant were delivered on site the season before most construction
were to take place. Local residents could operate the plant and stockpile
needed material.
Local labor would also be used in the annual operation and maintenance of
the hydroelectric and water supply facility, including the mitigation/
enhancement program.
T-51
NED Employment Benefit Computation
Project Construction Cost (less E&D, S&A, IDC) = $2,601,000
Labor Cost (55%) = $1,430,550
Skilled
Labor
Amount =
Local
Amount =
Cost (60%)
$858,330
Contribution
$309,000
(36%)
Percent Claimed (43%)
Amount = $132,900
Unskilled
Labor Cost (40%)
$572,220
Local Contribution
$429,200
Percent Claimed (58%)
$249,000
Combined Amount = $381,900
(75%)
Annual Benefit $381,900 X 0.08292 = $31,660 (rounded to $32,000)
T.13.6 BENEFITS WATER SUPPLY
The assessment of health benefits that would
supply is difficult to monetarily quantify.
estimated from sick time 10sse~ to commerce.
type are kept in Tenakee Springs, the values
estimate.
result from an improved water
The time value can be
Because few records of any
are most difficult to
Studies conducted by health agencies have shown that the incidences of
diarrheal disease morbidity, Shingel1a bacterial infections, Ascaris round
worm infections, tape worm infections, and chemical reactions have been
reduced when an adequate central treated source ;s introduced to
communities provious1y relying on unprotected and untreated sources.
Because no lesser cost alternative appears possible, Federal guidance
suggests that the benefits of the proposed conduit would be exactly equal
to the costs. The advantage of the proposed project is that the water
supply installation would be less costly if executed simultaneously with
the hydropower installation.
Because no comparable water supply system for the project area can be
constructed more efficiently, the annual cost of meeting these needs as a
development phase of the hydrop1ant is taken as a benefit to hydro
deve1pment. This estimated water supply system has a first cost of
$425,900 or an annual cost including O&M equalling the benefit value of
$40,750 for a ratio of 1.0 to 1.0.
T.13.7 BENEFITS RECREATION
The average Tenakee Springs household income has been documented to be
largely subsistance reliant. Approximately 1.5 deer are harvested per
household. The transmission cooridor not only only would provide easy
access to the Indian River watershed but also would create a small edge
effect which may make deer more accessible. Assume that 10 hunters per
T-52
year make 3 trips each along this corridor. Engineering Pamphlet 116S-2-1,
Chapter 16 suggests that a hunting user day has a value of $20. A hunting
benefit of $600 is claimed annually.
Recreational hiking, photography, picnicking, and fishing using project
created features such as the transmission corridor and dam pool are
expected. An estimated 10 people a month each making 2 trips during May
through September assign a benefit of $SOO annually to the project. Total
recreational benefits of $1,100 annually are claimed.
T.13.8 ENHANCEMENT COST ANALYSIS
The mitigation program of this plan consists of an operational fish
planting program and a monitoring program. About 2,SOO smo1t (coho only)
are targeted at a cost of about ~4,8S0 annually or $12,SOO every 3 years.
This migation program can be easily expanded to increase the number of
smo1t above the 2,SOO mitigation level. Returns exceeding the 2S0 adult
cohoes could be claimed as enhancement for a benefit, because most of the
operational costs would be borne by mitigation.
A $4,000 increment above the $12,SOO assigned for a 1-in-3 year plant
program could produce $2,000 in annual benefits if the number of coho fry
is tripled for an incremental BCR of 1.2S the overall BCR is 1.17. The BCR
could be substantially improved by going to a 1-in-2 year program
considered viable by the USFWS. These benefits again are considered only
for commercial harvest and ignore the sport fisheries aspects, value of
nonadu1ts, and excess value o·f program fish as compared with costs of
hatchery raised adults.
Another enhancement program that could be implemented independently of the
hydropower and water supply project has been evaluated by the USFS.
Laddering or dynamiting rock pools to act as 1addering in the Cascade
system could cost about $1,000,000 or $82,920 annually on a SO-year period
of analysis at 8 1/8 percent interest. The cost would be distributed over
returns of not only coho, but also pink and chum salmon. An annual return
is estimated worth about $430,000 for a BCR of S.2 to one. It is likely
that the BCR could rise if the enhancement and hydropower plans are
developed simultaneously through interagency agreements because some
construction costs could be shared and reduced.
For instances, the major item common to development of both power and
fisheries is adequate access provisions for equipment needed to construct
the penstock and to modify or excavate the natural barrier to fish
passage. If the penstock route proposed in Section T.S were moved
downslope, a hydraulically preferrab1e a1inement would be created. A trail
would generally follow the river just above flood level. More excavation
costs would be incurred with this a1inement, however it appears that costs
could be separable for enhancement purposes as well.
Removal of rock from the natural barriers would probably be the best
structural modification measure. Drill rigs and excavation equipment could
not travel the riverbed in its present ·state to accomplish this work. This
T-S3
equipment could travel a route prepared for the penstock installation. Only
minor changes would be needed to permit access to the barriers themselves.
Additional information regarding potential fisheries enhancement is
presented in the EA and CA report and its amendment of 20 September 1983
later in this report.
Under present guidance a Corps-sponsored project for fishery enhancement
cannot be recommended unless the primary reporting purpose (hydropower)
demonstrates feasiblity. Because Indian River hydroelectric potential is
shown (in the next subsection) not to be cost effective by present Federal
standards, no benefits are claimed for enhancement.
Similarly, no credits are taken for intangible benefits from decreased
(albeit minor) air and noise pollution from decreased diesel use. No
credits are taken for saltwater sport fishing. No credits are taken for
community self-reliance and independence of a locally operated hydro plant.
T.13.9 TOTAL PROJECT BENEFITS
Project benefits are made up of power supplied by the hydroplant, water
supply benefits, fisheries enhancement benefits, and employment benefits.
Power benefits are shown as the current effects of diesel fuel costs
eliminated, the effect of escalation costs and other associated costs
prevented.
Power benefits
1. Present Diesel Costs Eliminated
776,300 kWh X $0.137 = $106,350
2. Fuel Cost Escalation
776,300 kWh X $0.0822 = $63,810
3. Reduced O&M and Extended Life
776,300 kWh X $0.0480 = $37,260
4. Secondary Energy Available
116,000 kWh X $0.2192 = $25,425
5. Intermittant Capacity Benefit
= $18,300
Water Supply Benefits
Fisheries Enhancement Benefit
Employment Benefit
Recreation Benefit
Annual Project Benefit
Power Costs
Mitigation Costs
T-54
Subtotal
$250,000 (rounded)
$41,000 o
32,000
1,000
$324,000
$289,000
5,000
$294,000
Water Supply Costs
B/C Analysis:
$324,000 t 335,000 = 0.97
T.13.10 SENSITIVITY ANALYSIS
41,000
$335,000
If no secondary energy is claimed the overall BCR becomes 0.89 to one. The
hydro-only BCR is 0.77.
If no intermittant capacity benefit is claimed the overall BCR becomes 0.91
to one. The hydro-only BCR is 0.79.
If neither secondary energy nor ICB are claimed the BCR is 0.84 to one.
This is the most likely case and is the basis for recommendations. The
power only BCR is 0.71 to one.
If a 25 percent contingency is used, the BCR becomes 0.92 to one.
If the 20 percent contingency is used but the direct labor and materials
costs have been overestimated by $260,000, the total annual project cost
drops to $306,000. Including secondary energy benefits the BCR becomes
(306 t 306) 1.00 to one.
The state-of-the-art new diesel plant in the bush may have a fuel
efficiency of 11 kWh per gallon. The BCR drops to 0.90 to one.
A 9 kWh/g efficiency shows a BCR of 1.00 to one.
If mitigation were deleted the BCR would be 0.99. Mitigation may be
required for the EQ plan, but not for the NtrrlPran.
If the useable energy and/or demand is overestimated the BCR drops to 0.87
to one if 600,000 kWh/yr is used. --
If use is underestimated, an 850,000 kWh/yr use creates a 1.10 to one BCR.
If the project is financed with 3 percent money the net benefits are
$125,000 for a 1.85 to one BCR.
But 12 percent money yields a BCR 0.73 to one.
If 50-50 cost shared at a 3 percent State rate and eight and one-eighth
Federal rate the BCR is 1.02 to one.
Changing the POL to 1996 moves the BCR to 1.10 to one.
Evaluation using a 35 year payback period at 3 percent interest results in
a cost of $0.235 per kilowatt hour; and at 8 percent $0.41 per kWh. This
is essentially the Alaska Power Authority test.
T-55
ADF&G
ALP
ANCSA
ANLICA
AVEC
CVEA
Capacity
Capac i ty Factor
Capacity Utilization
Factor
cfs
Demand
DEPD
TABLE OF NOMENCLATURE AND DEFINITIONS,
Alaska Department of Fish and Game
Alaska Lumber and Pulp Company
Alaska Native Claims Settlement Act
Alaska National Lands Interest
Conservation Act
Alaska Village Electrical Cooperative
Copper Valley Electrical Association
The maximum power output or load for which
a machine, apparatus, station or system is
rated.
The ratio of the average load supplied to
the capacity rating of a machine or
equipment for the period of time
considered.
The percentage of generation over a given
time period relative to full use of the
system equals(actual generation x
lOO)/(installed capacity x hours)
Cubic feet per second -the rate of
streamflow
The rate at which electric energy is
delivered to or by a system, part of a
system, or to a piece of equipment
expressed in kilowatts, kilovolt-
amperes, or other suitable unit at a given
instant or averaged over any designated
period of time.
Alaska Department of Commerce and Economic
Development Division of Energy and Power
Development
T-56
TABLE OF NOMENCLATURE AND DEFINITIONS (cont)
Dependable
Capacity
DNR
DOT-PF
Energy
EPA
Fi nn Power
Francis-Type Unit
GVEC
·Head
kW, Kilowatt
kWh, Kilowatt-hour
LMP
Load
Load Factor
The capacity, which for specified time interval
and period, can be relied upon to carry system
load, provide assured reserve and meet firm power
obligations, taking into account unit operating
variables, hydrologic conditions, and seasonal or
other characteristics of the load to be supplied.
Alaska Department of Natural Resources
State of Alaska Department of Transportation and
Public Facilities
Energy is defined as the ability or capability to
do work.
United States Environmental Protection Agency
Power intended to have assured availability to
the customer to meet his load requirements.
A reaction-type turbine which uses the combined
action of pressure and velocity of the water to
drive generating equipment. Water enters the
unit radially and leaves axially.
Golden Valley Electrical Cooperative
The elevation between the headwater surfaces
above and the tailwater surface below a
hydroelectric powerp1ant.
One thousand (1,000) watts, 1.341 horsepower,
3412.9 BTU's.
A measure of ENERGY. A 1,000 watt light bulb
left on for one hour would use one ki10watt-
hour of energy.
Land Management Plan
The amount of power needed to be delivered at a
given point on an electric system. The rate
at which electric energy is delivered to or
by a system or to a piece of equipment
expressed in kilowatts, kilovolt-amperes, or
other suitable unit at a given instant or
average over any designated period of time.
The ratio of average load supplied during a
designated period to the maximum peak load
occuring in the same period.
T-57
TABLE OF NOMENCLATURE ANU DEFINITIONS (cont)
Mbf
MBF
MW, Megawatt
MWH, Megawatt-hour
FMSL
PCAP
Peak load
Penstock
Pond age
Power
Power Factor
rpm
Run-Of-River Plant
PMF
SDF
Million board feet; also B (billion)-bbf
b-bf=1"x12"x12"
Thousand board feet measure
One million (1,000,000) watts.
One thousand kilowatt-hours.
Feet Mean Sea Level
Alaska's Power Cost Assistance Program. A program
which subsidizes diesel generation costs in bush
villages. This program is politically and
economically uncertain because it appears to
encourage consumption while other major programs and
ethics encourage conservation.
The greatest of all load demands of the load
under consideration which has occurred during a
specified period of time.
A conduit or pipe for conducting water to an
electric powerhouse.
Storage of water of sufficient magnitude for
daily or weekend regulation of flow, generally
applies to storage at run-of-river plants.
Power is defined as the rate at which energy ;s
used, i.e. the amount of energy used per time.
The ratio of the amount of power, measured in
kilowatts, used by a consuming electric facility
to the apparent power measured in kilovolt-
amperes.
Revolutions per minute
A hydroelectric powerplant using the flow of a
stream as it occurs and having little or no
reservoir capacity for storage.
Probable Maximum Flood
Spillway Design Flood
T-58
THREA
USFS
USGS
USFWS
W, Watt
WECS
TABLE OF NOMENCLATURE AND DEFINITIONS (cont)
Tlingit -Haida Regional Electrical Authority,
cooperative based in Juneau for Angoon, Hoonah,
Kake, Kasaan, Klawock.
United States Forest Service
United States Geological Survey
United States Fish and Wildlife Service
A measure of POWER. A watt is def; ned as one
joule per second.
Wind Energy Conversion System
T-59
CORPS Of ENGINHRS
~
i
E2384paa f
Tl)POGRAPHIC PLAN
~~.~Ifi,""
'CO"., .. " I
"1 ", .. pro
I
b
i
ACCESS ROAD TO TENAKEE SPRINGS DAM
\: Y· 5l~=NG'" ,
ON 8EDROCK "'~)(,E"".'50·
GRA,OE: NT[ 2O"JI.
AQ ... ow ... v
...... TER1 ... L
STREAM CROSSING PROFILE
U. S AI,,",Y
. I ~L+-,,-.. t~-,·=---=+----;-l I [lUSTING ORClI.MO ~E _
'I~_=-----==-__ ~,
ACCESS TRAIL
TYPICAL SECTKlN
TEN"'KEE SPIUNOS .... L ... SX,l
SMALL HYDROPOWER FEASI81L1TY STUDY
TOPOGRAPHIC PLAN 6 ACCESS TRAIL
PROFILE AND SECTIONS
ALASKA DISTRICT, CORPS OF ENGINEERS
PlATE 1
+-
_ ACCESS ROAD
PENSTOCK
~~UNE
S'i
INTRUSIVE IGNEOUS ROCKS
=::~~ONTACT BETWEEN KiNEOUS
JUNE t9EM FIELD ~kS OBSERVED ClJRlNG
TENAKEE SPfIINGS. SMALL ALASKA
HYDROPOWER FEASIBILITY STUDY
SITE GEOLOGY MAP
PLATE 2
coos Of II!NGINlI!fRS
,,,,'
,,"
,oc'
,.,'
140'
....
t u 1----lL .... _ ··1
'~~--rf'.::..a:~"'-. 1 .... ~OT ... _T'l..-rtMID __ .D
SEyTION ,A-A.
mah
,---,---~---,----,'---'----'I---'----'---'----'---'----,,---,---,
0' . . ~ ---
DAM PR9Fl.E
I
,eo'
I
Il10'
U.S. ".MY
----------------_"'!?_'!"'!!'_-
~tC-C
Il10'
,,,,'
",,'
,.,'
I I
""" ".' ",,'
aMALL HYDROPOWER FEASI BILITY STUDY
DAM PLAN, PROFILE, a SECTIONS
.... ASKA DISTRICT, CORPS OF ENGINEEMI
PLATE 3
CORPS OF ENGINEERS
___ ";II'!':-----
~-EXISTIiIG GROtJNJ
~-PENST()Q(
_____ ~EXISTIIfQ RIVEIIIIIED
--DAM SITE
}w:-
~ ~
TOPOGRAPHIC PLAN
? 100 m
!ll:Al£,""ffT
STAT'O'N~~ IN Hu'NMrOS OF' ' .. 00
PENSTOCK PROFILE FEET
POWERHOUSE
WOOD P(""
TRANSMISSION LINE
SMALL H~~~~:~ SPRINGS. AlASKA WER FEASIBiLITY STUDY
PENSTOCK
PLAN 8 PROFILE
ALASKA DISTRICT, CORPS OF ENGINEERS
PLATE 4
CORPS OF ENGINEERS
""l
14d1
..
TDiAlln .,;n'::A:~~:~Y STUDy SMAll HYDROPOWE
POWERHOUSE
PLAN a PROFILE
ALASkA DISTRICT, CORPS (JiF ENGINEERS
U. 5. ARMY
PLATE 5
ALONG
TRANSMISSION
LINE
STORAH.
'ILTRATION. ~-.,
AND
CHLORINATION
BY PASS
REDUCER
OUTLET
HOUSE
FRENCH DRAIN INTO
IV'-L----CREEK TO PREVENT
FREEZING
LIMIT OF CORPS'
RESPONSIBILITY
-
TENAKEE SP~NG~ALASKA
SMALL HYDRO POWER
FEASIBILITY STUDY
Water Supply Schematic
AI •• II. District. Cor.,. of Engln •• rs
PLATE 6
I •
•
LIGHT ANGLE IN LINE CROSSARM
E SPECI FIC A J"ER NATE CONDU
ir---------50'(TYPICAL) --------~
40' (TYPICAL)
T -61 .
BURIED WATER
SUPPLY LINE
----",-
TENAKEE SPRINGS, ALASKA
SMALL HYDROPOWER
FEASIBILITY STUDY
Typical Transmission Line
AI .. k. District. Corp. 01 Eqln..,.
FEBRUARY 1883
PLATE 7
GENERATOR
BEARING
TEMP.
DEVICE
I TRANSMISSION LINE (7.2 kV)
500 kVA
7.2/0.48 kV
STEP UP
TRANSFORMER
STATION SERVICE
GENERATOR STATOR
TEMP. DEVICE r---------,
r~
325 kVA
STATIC EXCIT.
SYSTEM a
V.R. EQUIP.
0.8 P. F., 480V.
60 HZ, 900 RPM
TURBINE BEARING
TEMPERATURE DEVICE
STATIC
EXCITOR '==~ POTENTIAL
TRANSF.
r-------------------------* TENAKEE SPRINGS,ALASKA
SMALL HYDROPOWER
FEASIBILITY STUDY
HYDRO UNIT
ONE-LI NE DIAGRAM
ALASKA DISTRICT, CORPS OF ENGINEER
~-------------------T-_6-2----------------------P~LA~~~E~8 ',..
CONSTRUCTION ~EDULE
DESCRIPTION 1984 1985 1986
oj A S 0 N I:t J f M A M ., J A • 0 N 0 J F M A M J J A S 0 N 0
CONTRACT DOCUMENTS
MOBILIZATION:
CAMP CONSTRUCTION
SURVEY
QUARRY AND STOCKPILE
CLEARING
MATERIALS DELlYERY
ACCESS ROAD:
EXCAYATION AND SURfACING ~-
RESTORATION
DAM:
COffERDAM CONSTRUCTION
EXCAYATION -•
CONCRETE WORK
STEEL WORK
I RESTORATION
I , PENSTOCK:
£XCAYATION -PIPE INSTALLATION a fAB
RESTORATION
POWERHOUSE:
TAILRACE EXCAYATION -fOUNDATION WORK -~
STRUCTURE EflECTION -~
TURBINE MANUfACTURE
TURBINE INSTALLATION -~
RESTORATION ~ -TRANSMISSION LINE:
ACCESS GRADING
EXCAYATION -~-r-------- -----
POLE SETTING • ~ --~----- -----
WIRE STRING ------------- -
PUNCHLIST ~.
POWER ON LINE -~
DE MOBILIZATION -~
PLATE T-9
APPENDIX B
TENAKEE SPRINGS CULTURAL RESOURCES ASSESSMENT
Appendix B
Tenakee Springs Cultural Resources Assessment
The Alaska District U.S. Army Corps of Engineers is studying the feasibility
of a hydroelectric dam on Indian River to provide power to the nearby town of
Tenakee Springs. The project is located on Chichagof Island (see map).
Aboriginal Background
Before the European American settlement of the town of Tenakee Springs in the
late nineteenth century, the Tenakee Inlet area was utilized by several
Tlingit Indian groups. The Hoonah people used to portage to the head of
Tenakee Inlet from Port Frederick to hunt seal and fish (Goldschmidt & Haas
1946:101-102). In the past, houses, smokehouses and cabins, were located near
the portage. The Angoon people lived at the lower part of the Inlet and had
smokehouses and houses there at least during the early years of the cannery
industry. (Goldschmidt and Haas 1946: 118-119).
Other possible indications of prehistoric settlement in Tenakee Inlet include
a pictograph located at Cannery Point, a petroglyph reported at the town of
Tenakee Springs, and a chert flake found near Kadashan Bay (Ackerman, n.d.).
Historical Background
A bit more is known about Tenakee Inlet and the town of Tenakee Springs during
the historic period.
Tenakee Springs was established as a resort for miners, fishermen and
prospectors shortly after the establishment of Juneau. It was first called
Hoonah Hot Springs and had about 25 people overwintering by 1894, attracted by
the therapeutic water of the spring. In the 1890's a hole was blasted in the
bedrock to provide a soaking tub; other improvements inlcuding a concrete
bathing pool and the concrete structure, which now completely incloses the
pool, were built over the years.
Another mainstay of the town was Snyder Merchantile which was started in
1899. The present Tenakee General Store building was constructed by Snyder in
1905. The post office was also established at that time.
Several canneries were built near the town around 1918 and the population
climbed to approximately 400. The population began to decline when these
canneries closed down in the 1930's and 1940's (Roppel 1978).
Known Cultural Resources of Tenakee Springs Area
The town of Tenakee Springs itself is listed as a historical district on the
Alaska Heritage Resource Survey file. The AHRS number is SIT 084.
Besides the well preserved historic structures near the spring, field
investigation established that the beach area between the present small boat
harbor and the town was the site of the Indian section of town during the
cannery period. The ruins of several poorly preserved structures can be seen
along the footpath along with a fairly well preserved smokehouse.
SIT 167 is the Indian River Burial ground. This is located on both sides of
the footpath just to the west of the mouth of Indian River, about a third of a
mile east of the boat docks (Sealaska 1975:594-595).
The site was used from the 1930·s on, after the graveyard on Indian Islana
became full.
SIT 048 is the reported Tenakee petroglyph. This is supposedly located on one
of two points that jut out from Tenakee Springs (AHRS file: Sealaska 1975:594).
SIT 181 is the Grave Island or Indian Island Burial ground. A small wooden
gravehouse in a state of disrepair is located here as well as many marble
headstones dating to the turn of the century (AHRS file; Sealaska 1975:686).
Field Investigation
My investigation focused on the coastal strip between the town of Tenakee
Spri ngs and Indi an Ri ver and on the area at the mouth of Indi an Ri ver si nce
these were high probability areas of finding remains and mign.t be indirectly
impacted by construction activities, although there should be no direct impact
in these areas.
The banks of Indian River at the dam, penstock, and powerhouse sites were also
investigated as were the less steep portions of the powerline alignment (see
inclosed map) although the likelihood of finding cultural remains in these
areas seemed low. Three person days were spent in visual inspection. Shovel
test pits were excavated in areas judged to have a probability of cultural
remains, and natural exposures were closely inspected in hopes of locating the
reported petroglyph. This was done at two different times of the day, so the
1 i ghting on the rocks was different. No petroglyphs were found, however.
The mouth of the ri ver was scruti ni zed from shore and from a boat for the
presence of fish weirs or other cultural features. None were noted.
Overa 11, no prev i ous ly unknown cu 1 tura 1 resources were discovered. The two
historic cemeteries were located and it was ascertained that the project would
have no impact on them. Further, the project wi 11 have no impact on the
standing structures that comprise the Tenakee Springs Historical District, or
on the ruined historic Indian section of town.
Recorrmendations
Hydropower development on Indian River and power transmission to the town of
Tenakee Springs should have no effect on cultural resources. Should the
project design change, or unexpected resources be uncovered in the course of
further study or construction, the Alaska State Historic Preservation Officer
should be contacted irrmediately.
2
Bibliography
Ackerman, Report to the U.S. Forest Service: Archaeological
for Five Year Cutt;n Pro osal, A.L.P.
Goldschmidt, W.R. and Theodore H. Haas, 1946, possesorl Rights of the Natives
of Southeastern Alaska. A Report to the Commissioner 0 Indian Affairs.
Roppe1 P., 1978, Vacationing at Tenakee Springs Alaska Magazine, June 1978.
Sea1aska Corporation, 1975, Native Cemeteries and Historic Sites of SE Alaska.
3
APPENDIX C
SUMMATIOO
Section 404 (b) (1) Preliminary Evaluation
APPENDIX C
SUMMATION
Section 404 (b)(l) Preliminary Evaluation
Small Hydropower and Water Supply Project
Interim Survey Study
Tenakee Springs, Alaska
I. PROJECT DESCRIPTION
Tenakee Springs is located on Chichagof Island, the second largest
in the Alexander Archipalego of Southeast Alaska. Tenakee Springs
air miles northeast of Sitka and 45 air miles southwest of Juneau.
River is located approximately one mile east of Tenakee springs.
island
is 50
Indian
The U.S. Army Corps of Engineers, Alaska District has conducted a
feasibility study for the purpose of developing a hydroelectric power
facility and a water supply system for the cOlTlTlunity of Tenakee Springs.
The project would require development of 10.4 acres of Federal and State
1 ands. The total project woul d requi re approximately 20.4 acres, however
11.4 acres have previously been developed for logging activities. (roads,
mooring facilities and borrow pits). In sUlTlTlary, a 16-foot high dam with a
8-foot high spillway would divert 20 'to 52 cubic feet per second of water
from Indian River to a powerhouse site approximately 2,700 feet
downstream. The powerhouse would be equipped with a 264,-kW turbine and
generator. Diverted water would be returned to Indian River above the
natural barriers for anadromous fish migration. A minimum instream flow
requirement of 10 cfs has been established with an operational mitigation
program. The water supply system would divert approximately 1 cfs of water
from the tailrace area along the transmission corridor by the buried pipe
to the powerhouse substation near the city dock. For additional
information, refer to the Environment Assessment (EA), and the main survey
report.
II. FACTUAL DETERMINATIONS
The following determinations have been made with a finding of no
significant impacts, based on the evaluation process and on information
presented in the Environmental Consequences section of the EA:
a. Physical Substrate Determination
b. Water Circulation, Fluctuation and Salinity Determinations
c. Suspended Particulate/Turbidity Determinations
d. Contaminant Determinations
e. Aquatic Ecosystem and Organism Determinztions
f. Proposed Disposal Site Determinations
g. Determination of Cumulative Effects on the Aquatic Ecosystem
h. Determination of Secondary Effects on the Aquatic Ecosystem
III. FINDING OF COMPLIANCE FOR TENAKEE SPRINGS SMALL HYDROPOWER AND WATER
SUPPLY PROJECT
1. No significant adaptations of the guidelines were made relative to
this evaluation.
2. Structural alternatives included a variety of locations for project
features as well as varying sizes, as discussed under the alternative
section of the survey report and EA.
3. The proposed action will not violate any applicable State water
quality standards. The action will not violate the Toxic Effluent
Standards of Section 307 of the Clean Water Act.
4. The proposed action will not affect any endangered species or their
critical habitat.
5. The proposed action will not result in any significant adverse
effects to human health and welfare, including municipal and private water
supplies, recreational and conmercial fishing, plankton, fish, shellfish,
wildlife and special aquatic sites. The various life stages of aquatic
organisms and wildlife will not be significantly affected. Significant
adverse impacts to aquatic ecosystem diversity, productivity and stability,
and recreational, aesthetic and economic values will not occur.
6. Appropriate steps have been taken in project design to minimize
potential impacts. These include site location for the dam, powerhouse,
and transmission corridor; engineer design of the diversion dam to
incorporate a minimum flow release, establishment of an instream flow
requirement; an operational fisheries egg take and transplant program for
an estimated adult salmon return of 250 fish; establishment of a
construction window for in water or near water activities that could
introduce material into the river between 20 May and 15 July; restoration
of disturbed sites with potential for erosion with vegetation; and, a
reduction in quantity of vegetation clearing required for project features.
7. On the basis of the guidelines the proposed disposal sites for the
discharge of fill material is specified as complying with the requirements
of the guidelines as specified in 40 CFR part 230.
APPENDIX D
RELEVANT CORRESPONDENCE
)
~ V
:lefore
CO;'·L.1s:;ioners:
.1n t:~~ }.;ltter or
u;a'ri':; ST,\Tc.5 I.J: ':'J.S~j r ..
Ff!.:::f,,·,.L r-,j'."jEit clJ~s:;rr.;;
.J, rc:-,. t:. K:,:-·k':IIG'lll., CL ... im.·.:l; ~'-:l ... r., uet;;
Cl :'J~':-I.. l/r·lpo.-!'" t
)
)
)
....
. 1 ••
.. ~ , .
Applic~tl~n ~as tiled ~ctoter 20, 1~52 by Superior Packine -C~~)~nj~
ot Seattlt', Wash1n~..on. tor a ne; 11=er.se IlnCer the I-'e~eral i'o't;er Act
(bereir.a!ter re!'er!'ed to as the Act) tor construct.ed cinor ~jc~t. ~jo.
8)1 locat<..d.;.-:Cout L CJ!.l!.s ear.st of 'l'e.la.kee .sprine;.s on a cree.k of Chichagof
Island flo .. d~1g into TE:na~8 I:lle:t, First Jw!icial Divis!O:/ Alas!r.a, and.
affect;.ing l .. r!<is of t!le ~ttitecl Slates ",1 thin Tor.gass :;a tio:"_l rorest.
or-be or1g1 • .al license !-')r t.he project ~os b3uec1, 71ithout c.'largG, to
the licensee on :io"e:!l~ er 26, 1:'"27 tor' a pe:-io..!. or 25 yo!ar:J t.h~2 e!'":r-oo~ and
e.'t?!re-:1 en (:oveClber 25, 15152. . . . '.-. I
The proje_~tc~nsi~ta of:
(a) All lar.u:c co:-.stit· .. ting the pr:>ject C!.r~, tne l.bits -~f
'1Jhich are 50 Ic:et on each side of the ct'nt.t:r line· or . the
wood-stave pl1le~, da::1 and or. eacn site of t.he er:e" or
a:r..j
(b) All project "";)1'0.:.3; cc~r1s1ng a 10. dive':Jion ca.";!, 24
..
teet loot: ar4 6 teet. h1~bj a sh.:l:-t :strate.): 1.'[ 'I'I-')OQ Ili.1 ... ,e;
·~o 1tOo..l-:'i ..... ve pi}1e:J, Oi.e b inchd:J £.nd the ether 12 1nc~s
in d1A.:lf:ttt:r, eac!l ilbout. ),0iXl feet in leJ".gth~ three_ .. Pe!-:
t.7n to:.tcr -:o:beels, O:le 24-incn a.Jd tl'fo J6-1nchj ~a(.d 009 _·/t-{.:
10-1C.f g~ne:-a tar 1:1 the C3:lr.er,r bil.::initJ:-
(c) Ail other :strJctures, tixt.o.res, e .. ~ulp!:)E!:lt, oi" faciliUes
\.:!Ie~ or U$:.t'ul 1."1 tr.e na1:lt.e:uocs &II(! operation of th~
P~Je<;t. and loca~d on t.he PT'Oj~ct at'ea, n(l~ all ri,;ht.3
and interesta, tae possession of ~;tich-1s nac~s~~rj or
appropria.te in the ::a1ntenance a~d ·operat.ion '~r th.f proj-
f!ct.., -rbe proj~ct lar.ci5 a..:..ct prvjE:ct -;roi'ie3""'C'O' i::oro Bpeci!i-
call,y' 3ha:7n and descrl~d ~)" a ce:-tG1n r::.ap' '"hich fOr=;1~ '"
part ot t;le ar.plication tOl' llcE:-..,e by reJ.·e~t'~e· the:-eto,
ar.d "Meh ilS t!!scri~ed ::.~=
..... . --·_c~
t.
(
~ '. v·,".-!\.-_ .. ,~,
;'.LkS ... -.
March 13, 1980
[·Iir. Lee R.. Nunn
Colenel, Corps of Engineers
Dept. of the Aroy
P. O. Box 7002
Anchorage, Ak. 99510
Dear r·II!'. Nun..'1.:
Your letter and report were disc~ssed at length at ~lr rec~~~
Ci t;y Council m.eeting. The Co· .. ,;.ncil is very i:'1"Cer2s"':~;·,,:, i:-~
al terna ti ve energy sources J 3.::1.d is prese:ltly i::1.ves '~':.:..g2.. -:L·.;
geothermal possibili ties vii th respect to Oi.i.r :'cc s)r':'::--.gs.
tve wccid also like to have a. -;; ..... c:..ic ;-r,ee ti:-:g a::lci/cr -;·-::-ks:-.:~..;
vlith your sta=f, at ycur ccnvsr..:"e::--~cs, ~':a ~~2.v= ..::.i2. ____ :::,=:~
hyd-f"Q"r"'\cv'er dev"':loD~e:1~ \'~i t h -~ .. ~" ~a-Y" ~on";--:.'~ .. :. -:--....... ,. .. .:. --"--": .. • _ ~. ~ ...... " w ., "' .... _ •• !-.... <::_ .... "~ ........ _<c __ •• _ .•• ___ -=_-....
and also wi"t!:. t!1.6 Ce:partrr_er~:: 0= :':a "'c-v.ral ~es()·~.:::·,:>~::;, ':,.'-'-.,_
intel~ested irJ. furthering cur k:--;J·-;/:t:;~5e; as \. ""':.:.. 8.3 .-~ -':l~~-:.' "_
rnetilccis of fur:d.in@; suer. a P:'1;:,j2C·;:;.
If possible, a meeti~g sc~adule~ fer late d~:::~_
would be good, as there are ~3v6~a:" ~oi.i.~ci~ =2~~~r
out ef "tovrr... \~e would wa:1.i: ::... 1\,;.11 CG'J.Dci2. fo::.. .... S-";'C.·.
..... .:;..
Please contact r:.e and advise as -:0 vf!".en sue!. :=. ~.:a·-,,' ---:'6 (;.: .:~
take place. ~har_~ yeu.
Sin~erely,
San~ra L •. Andersor.
City Clerk
..
..
t·
t·
,.
.,
II'
•
'~
CITY OF POST OFFICE BOX 52
TfnAHff SPRinGS
May 16, '1980
Mr. Loran R. Baxter
U.S. Army Corps of Engineers
P. O. Box 7002
Anchorage, Ak. 99510
Dear Mr. Baxters
TENAKEE SPRINGS
ALASKA 99841
The City of Tenakee Springs wishes to express our sincere
thanks to you and your department for your continuing
interest and assistance to our community. Your recent .
visit was very informative, and many of the citizens
have expressed their support for continuing study of
the development of hydro-electric power for our town.
Enclosed is a resolutl.on passed by the City Council
at a special meeting last night, requesting the Army
Corps of Engineers conduct a feasib~lity study of the
sites near Tenakee Springs. We look forward to hearing
from you on this, and will offer any assistance we can
give to aid in this endeavor.
Sincerely,
p£-r,d-za .. ;( a'u-b~
Sandra L. Anderson
City Clerk
cc: Rep. Ernie Haugen
SLA/aw •
.. '. .:.. • &
& •• r -
I
i
1
I CITY OF TENAKEE SPRINGS
RESOLUTIOr; aO-2
In the Council
May 15, 1980
Introdueed by
C ouncil l~ reside"nt
WHEREAS
WHEREAS
WHEREAS
A'RESOLUTION REQUESTING THE ARMY CORPS OF
ENGINEERS CONDUCT A FEASIBILITY STUDY OF
POTENTIAL HYDRO-ELECTRIC ENERGY NEAR TENAKEE
SPRINGS, ALASKA.
preliminary studies of Harley Creek and Indian River
for potential hydro-electric sites have been COffilllcted,
and,
funding is available for feasibility studies to be done
in potentially favorable areas, and,
the City of Tenakee Springs is interested in developing
alternative sources of energy, to become less dependent
on increasingly scarce and expensive fossil fuels for
heat and energy, then t therefore,
BE IT RESOLVED by the Council of the City of Tenakee Springs,
.. ~
------
.r' : r .. '. :' ~l', ,. ,', ,,'J,
-/ t '" , ' '. ,(.,
.ft '; ... ~ :. t ,-,'! •..•. ! .. '.'
" " "" . ) ... ' (~~;TTES~I ' ..
I, .~,\' ,
) ", ,I , ','. :.~, "'", ~ ..
. l ,
" • '\.. ;:. I'~ ', ••
that it respectfully request the Army Corps of
Engineers conduct a feasibility study of the potential
hydro-electric sites near Tenakee Springs.
1"-,") DAY OF
,
~i/;.;.'~' ,1980.
j
Council Preside)1f •
ex officio MaY6r
Sandra L~a Anderson, City Clerk
· , ~.
, . (.
June 10, 1980
Re: 1130-2-1
Harlan E. Moore, Chief
Engineering Division
Corps of Engineers
Box 7002
Anchorage, Alaska 99510
---_ ..... _-_ ... -,--....-..--.. -~-------------
(
DIVISION OF PARKS
JAY S. HAMMOND, GOVERNOR
619 Warehouse Dr., Suite 210
Anchorage, Alaska 99501
274-4676
Subject: Tenakee Springs Hydro Project
Dear Mr. Moore:
We have revie\"ed the subject proposal and \'JOuld I ike to offer the following
comments:
STATE HISTORIC PRESERVATION OFFICER
The proposed work may adversly impact AHRS site # SIT-084, Tenakee Springs
Historic District. This site may be eligible for the National Register of
Historic Places. In addition, sites SIT-048 (Tenakee Petroglyph) and SIT-167
(Indian River Burial) may also be impacted. Therefore, per 33 CFR 325.2{e)
(draft), a survey is recommended. ~' t II ~"
, "" ...L <:" L1 y.J L ..... ~ '4' "-oJ ,Ce1"I?A t J-L.l ~1, 1 .J / v I
~WilJiam s. HanabJe
(I . State Historic Preservation Officer
STATE PARK PLANNING
This office has strong concerns over any construction activity \o/hich \o/ould
alter the natural scenic qualities of the area and result in a deragation of
the recreational and scenic enjoyment of this area.
LWCF
No comnent.
Sincerely,
./
IN REPL V REFER TO:
.---.----.--.. ~ ... _------
(
United States Department of the lnteri.
FISH AND WILDLIFE SERVICE
1011 E. TUDOR RD.
ANCHORAGE~ ALASKA 99503
(90l) 276-3800
flPAPO
Colonel lee R. Nunn
District Engineer
6 fL ....... .!l
Alaska District, Corps af Engineers
P.O. Box 7002 .
Anchorage, Alaska 99510
Dear Colonel Nunn:
Re: Tenakee Springs proposed
Hydropower Development
'rhis letter transmits copies of U.S. Forest Service correspondence con-
cerning fishery enhancement opportunities at. Indian River near Tenakee
Springs, Alaska. (Ref. Kanen ~o Vaught, USDA memo dated 12/15/80 and
Fish, USDA, to Hughes, FWS, letter dated 1/16/81). The alternative
proposed would involve construction of a dam with sufficient crest
height to flood all the natural barriers to upstream fish passage.
The facility would be designed to assure fish passage to upstream
spawning and rearing habitat.
We are not necessarily advocating this proposal, but we believe that
it is a viable alternative that could be considered in your feasibility
studies for the Tenakee project.
Sincerely,
Regional Director
Attachment
Ed Ob
.. I
r
Bi 11 Hugh2s
(. (
UNITED STATES DEPARTMENT OF AGRICULTURE
FOREST SERVICE
Sitka Ranger District
Post Office Box 504
Sitka, Alaska 99835
U.S. Fish and Wildlife Service
P. O. Box 810
Sitka, Alaska 99835
L
Dear Bill:
7500
2630
January 16, 1981
. r 6 FEB i~i
~ ".
Since we are aware of the Corps of Engineers interest in looking at
Indian River as a potential hydroelectric site for Tenakee Springs,
1 thought you might be interested in the enclosed letter from Dale
Kanen, our fisheries engineer. Dale visited Indian River last summer
in the normal course of our annual pc;>tential fish\1ay investigations.
Further field investigations are necessary of course to detennine how
usable Dale's suggestion is. .
If we can be of any help in the course of the project, please let us
know.
Sincerely,
·£-y3"~~
ROBERT B. FISH
District Ranger
Enclosure
.~, (1/69)
• " .J 1} ~, ... ..u ,;:Uc:lll::=:S R~~jl Department of ~ Agriculture
Forest
(-ViCe
TI\'F -Ct-'A " '
. (
Reply 10: 7500 \'/ater storage and Transmission
2600 \"lildli fe and Fish t.1anagement
December 15, 1980
Su::.jec:: Indian River Fish Ladder 6 FEb I~bl
To:
•
Robert Vaught Sitka Ranger District
This is in response to your request for in formatio;'"", concerning Indian River.
On Aug:..!st 1, 1979, r·latt Longenbaugh and I hiked up the Indian River gorge from
Salt \':ater. It was our main intent at the time to inventory any barriers to
the upstream mmigration of coho salmon. The following is an excerpt from my
field notes:" ••• sa\,1 ten small falls ranging from 2' to 5' in height. There
was one eight foot falls and one 10' falls. Banks of stream are sheer for
100' above stream bottom. This stretch is approximately 112 mile long and
full of rapids \"Ii th good resting pools in between". ,There also follo...,s a .
comment by biologist Matt Longenbaugh that none of the falls observed would be
a complete barrier to coho migration by itself. Most of the barriers had a
ramped face (instead of a vertical drop) thus creating a high velocity zone
for the fish to negotiate. Immediately bela~ these, the standing waves on the
leading edge of the hydraulic junp tend to be too far downstream from the
falls. I would expect this to cause disoriented leaping behavior in salmonids.
This survey was incomplete in that forward progress up the river \'las halted by
a lack of good hand holds and foot holds. We traversed roughly a 1/4 mile of
~orge area in our survey and it appeared that roughly a 1/4 mile of high
energy gradient remained before a fish reached the spa~~ing and-rearing
habitat above.
Due to the extreme difficulty we had traversing this stretch of stream above
the foot bridge, all plans to engineer a passage solution appeared impractical
for the near future. A separate structure at each falls would be cost
prohibitive. The 100'+ high vertical walls of th~ canyon make logistics all
but impossible. Extreme stage fluctuations in this confined stretch of stream
would jepardize work schedules, equipment and personnel safety.
Construction of a dam with ladder works might be feasible at the lower end of
the gorge. A dam could possibly be constructed such that the crest height
would flood out the existing rapids and barriers upstream. Such a structure
might take advantage of the low width to height ratio of the canyon. Access
for heavy equipment coul~e relatively easy, needing only to traverse the
intertidal zone and the relatively flat alluvial slopes to the canyon
entrance. The cost of such a project simply to utilize the upstream habitats
would probably not be economical. If sufficient demand could be found for the
potential hydroelectric paner available a dual purpose project might be
desired. The to\'tnS of Tenekee Springs and Hoonah both need an inexpen~ive
source of hydroelectric prn1er. This dam could also serve as a reservoir for
the Tenel<ee ~/ater source. Tenekee now has a critical shortage of good water.
--_ .... ".
i would be very interested in updates as ~tudies continue on this praject. If
we may be of further help., please let us Knao'i.
IJ~ ,f Jra,--~
O.o.!..E VJ\r-.=:N
Civil Engineer
. .. _-' .
;: -:C'ITY OF e
I TEnAKEE" SPRinGS
J '--
POST OFFICE BOX ~
.... jut'!
I
,-
.....
Department of the Army
Alaska District Corps of Engineers
P.O. Box 7002 .
Anchorage, Alaska 99510
Att: Harlan E. Moore
Dear Mr. Moore:
TENAKEE SPRINC
March 2, 1981
RE: NPAEN-PL-R
In your letter of January 28 to Mrs. Sandra Anderson, former city clerk, you re-
quested additional information on the Indian River site in connection with the hydro-
'electric feasibility study you are conducting. In a phone conversation with Mr. Shoup, h
. suggested that we outline a history of Tenakee Springs. I will start with the history
and then attempt to answer your questions.
Tenakee Springs is one of Southeast Alaska's older communities. Shortly after the
founding of Juneau, prospectors and hunters came to know the place as Hooniah Hot Springs
It was a halfway point betweeB Juneau and Sitka for boat trave1--the only transportation
at that time. In 1899, Ed Snyder started a general merchandise business which is 'sti11 i
existence. The main hot spring was enclosed by a log bu~lding and Mr. Snyder built a
number of cabins to accomodate visitors who soon learned of the therapeutic value of the
mineral baths. A post office was estab1i.shed in 1903 and the name "Tenakee" was adopted.
It became a favorite wintering resort for miners and fishermen. When cold weather
halted mining operations in the fall in such places as Nome, Fairbanks, Dawson etc. the
miners would journey by dog team to the coast, take a steamer to Juneau, thence by mail
boat to Tenakee where many of them would spend the winter until breakup time in the
north. About 1918 two large salmon canneries were built four and five miles east of the
helping to boost the summer time economy. By 1930 there were slightly more ~han 300
permanent residents. One cannery ceased operations in the 1930's; the othe~fina11y
shut down in· the late 1940's. A drastic population decline could be attributed to (a)
lack of industry to support the permanent residents and (b) convenient plane transportatic
became conmonplace enabl ing the fonner northern visitors to fly "outside" for the winter .
A small crab cannery kept the town alive from 1948 to 1974 when it too closed down.
Currently, logging and fishing are the mainstays of the economy. The present population
is 1 54. • I . ! "", .. " .• . _. '1. ",.'~ ~·(,,"'.i'-· \.0, 'It!'! \. .' ~ . ' .. 'I'. £-(1,-1.1 t··1 _ . ,"" ;.:.J ._ ~ •. j , ~...' ,I.. '.
Prior to 1952, there was no community electric system. The crab cannery required an
increase in power for some new machinery that was installed and it was decided to expand
the e1ectrie system to include the entire community. Currently, two 100 kw diesel
generators, one of them a standby, are used for local power. Both are in need of comp1et
overhaul which, at today's prices, is extremely costly. Rates for electricity must
necessarily reflect these expenses which when cougled with ipnstaotly rising fuel costs
creates a hardship for the consumer. The present owners of the electric system cannot
afford to upgrade the system and have indicated that in the event of plant failure, they
would have to cease operations. The most logical alternative is hydro power.
The Indian River site which you favor seems to be the most logical selection.
It lies about 1~ miles east of the tm'ln of Tenakee Springs and within a few hundred
yards of a log dump which marks the beginning of a logging road that courses some 10
or 11 miles along the Indian River valley. Heavy equipment could be brought in over
C'tTY OF i
TfnAHff SPRinGS
POST OFFICE BOX 52 :.
TENAKEE
ALASKA
SPRINC"
99841 I
the logging road. There are no indications of archeological or historical sites in f,
this area. As for concerns about the salmon, the State Dept of Fish & Game voiced no Ii •
opposition to logging, stating that Indian River was not considered an important corrmercial.~
salmon stream. {here should be no problem with eagle nests. ! ~
I •
~
The present cost of electricity is 30¢ kwh and it has been announced that an increase .~.:
to 35¢ will take effect on the first of April. Since decontrol of oil prices there have •
been several fuel price increases making it more costly to operate the generators. Diesel I
fuel is now $1.40 per gallon. The generators use about 75 or 80 gallons per day.
Due to the high cost of electricity, residential consumers restrict themselves to
what they consider necessities. There is only one electric range in use-in the community. ~.'
Almost all cook stoves are oil burning. There are some who cook with propane. The ~
average home uses a few 1 i ghts. Many have refri gerators and freezers and numerous small I
apP],i_ances. No home is electrically heated.
Since the closure of the crab cannery, there is no cOlllTlercial machinery on line
except for limited commercial refrigeration. However, it is anticipated that in the very
near future=-probably this year--a seafood processing plant will be established and \>';11 ~
undoubtedly require considerable power for cold storage equipment, pumps, compressors, etc. ~.
Residences, for the most part, are small cabins. Average size would be about 300 or
350 square feet. Total floor space of the community, about 42,000 square feet: About 15 _
or 20% of the buildings are insulated with 5ibreglass blanket type insulation. The .
typical small residence consumes about 1150 gals of fuel per year for both heating and ~
cooki ng. Some propane is used for cooki ng, probably about 10,000 1 bs per year. More and ..
more homes are using wood for fuel but statistics as to the number of cords is unavailable. ~,
There is no community water system. The residents obtain water from numerous small .'
surface streams. The city has a new tank type fire truck and some portable sdlt water
Construction equipment is limited to one dump truck and one front end loader and
back hoe owned by the city. Local labor is available.
Our community is on the verge of unprecedented expansion, having finally received its ~.~.
long awaited land selection. Final conveyance is expected to take place in July, 1981
and invoi1ves about 3000 acres. It is expected there will be quite a bit of building activi
and resu1tant1y, a demand for electricity. The city's corporate limits extend 11 miles E.
along the shoreline of Tenakee Inlet. Tenakee's lifestyle, unique as it is, would under-.~
go some changes if an unlimited supply of electricity were available at a reasonable rate,
e.g. 6 to 8¢ kw--not 27¢ or higher. Additional power will be required for contemplated
expansion of heliport and also, an airport is planned for 1986. A new school and
gymnasium is being planned for construction within a couple of years. All in all, we
can expect a greatly increased demand for electricity in the very near future.
I
Mayor
I.
DEPARTMENT OF HEALTH 8c HUMAN SERVICES
PUBLIC HEALTH SERVICE
Refer to: A-D (A-EHB)
Colonel Lee R. Nunn
District Engineer
December 2, 1981
Alaska District, Corps of Engineers
P.O. Box 7002
Anchorage, Alaska 99510
Dear Co~onel Nunn:
ALASKA AREA NAT IV. H.ALTH S."VICE
80x 7·7.1
ANCHORAG •• ALASKA 1111510
This responds to your request dated November 20, 1981 for any information
that we have that might be useful for the interim hydroelectric feasibility
study being conducted for Tenakee Springs, Alaska.
No sanitation facilities projects have ever been provided to Tenakee Springs
under the auspices of the Indian Health Service (IHS). Therefore, we do not
have any information in our files that would be useful to the Corps.
According to the 1981 U.S. Census, Tenakee Springs has a population of 138,
95 percent of whom are non-Native. Since IHS can only build sanitation
facilities for communities in which a significant portion of the community
is Native, it is. doubtful whe.ther the IHS will ever be involved in a future
sanitation facilities project at Tenakee Springs.
I regret that we are not able to provide you with the information and data
you requested. Also, since none of our engineers have any familiarity with
the area, we are not in a position to comment on any of the hydropower
options.
If I can be of assistance in other matters, please contact me.
Sincerely,
t'·~4~..L
,~;' G: H. Ivey P Dl.rector
Alaska Area Native Health Service
Department Of Energy
Alaska Power Administration
j~~~~~.x~~ska 99802 .: ~<~--;' .. -. _.
--~-.::::--.:~;_:~:~::~ ~;~-;0-~~=--=-~ ·::·~··=·:~I;'~~·:~.~:~· ... ;~~~~, -~ ::~~~-2:-~'~'~~;J~~
-:--. ::.~.:~-,~":".-. . '--..-:.-_ .. -~ -" -
.. , ... -,-
Colonel LeeNunn :.,., . -, .-'~ . .:,
Distiic-t-Engineel;' , .... -_::-:.
Alaska. -District. .,-','.~-.::~'-:~:::.} ~
. _. _corps~£Engirieers--.. -.-:-:~~~-:;.~---
···:-···o:../;;..:-·p~o. Bo-x::]002-' .. -::-;:., -:~--
.--~Ar1chorage, AK 99510 _ .
", ......
Dear Col~' Nunn:
... ~
. -'--. . '-.,:.------.--.
-;'-...... -. . '.: :. -' ..
-... '.-
_ .. _ . December '19, 1981
".' . " ~~
",''';. '7":-' ,' •• . ---.-. '.
..,..... -
--:-~'-. _.-, .,. ::-~""-'-''-.-'.
. -'
'Thank you for the information on the progress of t.he Corps' investigation
of hydropower for Tenakee as explained in your November 20 letter.
Since we have not had an opportunity to review your plans, we do not
have specific information to provide. This is particularly true for the
fisheries aspects, construction access.and floods. However, in your
project design planning you may want to consider an additional parameter.
In our recent c!icu!?sionswith the Forest Service, it was determined that
long range Forest. Service plans include a road system from Hoonah to a
point near Tenakee. This of course, raises the possibility of electrically
interconriecting Hoonah and Tenakee. If a larger project (that which
exceeds projected Tenakee loads) could be developed, excess power could
possibly be market.ed in Hoonah. To reflect the interconnection possibility
~e are including a rough estimate of Tenakee loads in our update of the
Hoonah load forecasts. The3e s:H:mld be L.---ompleted in about two weeks and
a copy will be furnished to you.
We would be willing to make a brief power market analysis of the Tenakee
area early next spring to assist the Corps analysis. This would include
better load estimat.es, effect.s of land acquisition by the cOIlb-uunit.y
under P.L. 96-487, commercial developments reported to be under consider-
ation, and transmission alternat.ives bet. ... een Hoonah and Tenakee. This
, ' ... -'-'
'~-'-
-.analysis~would_be closely. coordinated and_scheduled so as ."to provide:._ :.::: __ -:o::-;::·_~'::::.
': ::~--:." t~~~~f.:in.p~t .. fo~_. ~~_~r'''f:~~~; .. ~~e~~~,~~~~7,~:~-.·.~:'-:'-~: :-:'_ ;~ .. :-:-:.--'.: __ :.' __ ...... -~:.:.~" -.' ._.:.!~~:;,._ : .. ~ .-;.~~~~
. -:_ :::;:;-~e ~w~cf:-6a-gl,icI. 'io" :dI~cuss-thrs::~a:~irYoU'~-to~:'-~('-ordillate-~u~-~f-fort's~:-. ''1"--~_ ;::-., -:.--.~:?~~
. --.". ~":"": .. " --_." . . --. . --:. "--. . -
':<:·":·~:~;:?::-:'"7~;:_.::--~~.sj\{Cu·~_el;"~: ::"'~ .:' .',
... . A?-f ~/Y.J-
Robert J. Cross
Administrator
--
• ". r '.' ...... _ .
tJORTHERN _.
(
REGIONAL AQUACULTURE ASSOCIATION, INC.
w .... --
p. 0_ BOX 781
17 December 1981
Hr. Hod Moore
Chief, Engineering Division us Army Engineer District
P. O. Box 7002
Anchorage, Alaska 99510
Dear Hr. Moore:
SITKA. ALASKA 99135 (IU) 147-U50
Northern Southeast Regional Aquaculture Association (NSRAA)
wishes to express its interest in working with the Corps
of Engineers in developing a cost-sharing salmon enhance-
ment project at Indian River (Tenakee springs) to benefit
commercial fishermen in the area. As you may be aware,
NSRAA is a regional, nonprofit association supported by
commercial fishermen. The primary purpose of this organ-
ization is to increase the production of salmon in
northern Southeast Alaska. .
\ve have discussed several enhancement projects with Bill
Hughes of the US Fish and ~Nildlife Service and we \Olere
able to visit the si te.. ~ie would welcome the opportunity
to develop these ideas with your staff.
If you see potential benefit in our involvement with
the enhancement aspects of your hydroelectric project
at Indian River, could you so indicate in a reply? It
\OlOuld also be helpful to knm'T of the time constraints
under which a project would be developed.
Sincerely,
/.1 -/' /.-/7 .4 ~t ':',L!':-e'( u .... --=-r,. C::-. {-r+ -,'-"-----
Bruce Bachen
operations Manager
BB/pd
Colonel Lee R. Nuun
District Engineer
BUREAU OF LAND MANAGEMENT
Alaska State Office
701 C Street, Box 13
Auchorage. Alaska 99513
Alaska District, Corps of Engineers
P.O. Box 7002
Anchorage, Alaska 99510
Your Reference: NPAEN-PL-R
Dear Colonel Nunn:
IN •• PI.Y Il&.I •
2013 (932"
DEC 2 1 31
The enclosed copy of our Master Title Plat for T.47S., R.63E., Copper
River Meridian illustrates the land status in the Tenakee Springs area.
The area under study for hydroelectric feasibility on Indian River lies
within the longass National Forest, and most of the area has been
selected by and tentatively approved to the State of Alaska.
" "
The" lands couveyed to the State are now administered by the State and
the unconveyed lands within the national forest are administered by the
US Forest Service.
As the lands are not UDder the jurisdiction of the Bureau of Land
Managemen~ we do not have any spetial stipulations to place on UlnU use.
Sincerely yours,
/J /-0ft~) =a.J -l,':i·~r ...
Curtis V. i~cVe "
State Director
ED~osure
/
CITY OF
T£nAH£f SPRlnHS·
Decabar 31, 1981
La. L l\Tuzm
Coloaal, Corpa of 1D11 n _ra
DepublBt of. the ArtaJ
P.O. Boz 7002
ADchoras., ~ 99510
Dear Hr. BUDIl:
POST OFFle! Box
TENAKE SPRIN
AlASKA 99~
I apolosU. for the clelay in oar reply aDd &l.o·for tba substance of it..
lJDfortullauly. .. jut dAm't hna the raaourcu to. raspcmd. with accuracy
to-your quast1aaa.Baw •• c, 1 have c:ouuJ.t8f1rith UDy people aDd c:oma
up . rim the fol.l.awm& 1Dfcmaadoll. . . . .
1 bel1 ... Hr. Shape .,aka rith Doll p .... of Snyder HEc:&Iltile i_ed 1 a tely
before va rKa1vecl yom: lat~ar aDd .... h1a my 1Dfcmu.d.oll .".11 able ra-
prcl1Da CiUxat loads, .te. W. wou.ld atimat. that the l"aad:"'1Dc:ruaas in.
q&a. ... n1Da·1Iou .... ad:--u·-~y· a:U'··duriDl th.··ught: AI: pr .. ant. the
11.Du clo DOt H1:'ft ~ .houM 1D tCNII. LaDA title baa DOt p .... d from ehe
Stat. to' cha .. City yet. BeN •• ar. a Stat. ci1spoaal 1a sc:haduled for ll~
fall of 1982 in ColUlibia Cove, ... t of t ... tee aDd beyOl1d Indian It1ver.
ther. vill b •• ."rmd.matel,...ZQ····tr&et. :La. ~_subcliviaiou. the Ci1:y u-
pnaHd tha1J: cl .. ire that DO road lJ.Dk the aUbcl1v1aiOll with the City
proper; hovwvar, 1t 18' poaa1lile that power at lDcliall It:1v.r or wat.r would
be 1:1m to the subcl1.v1a:1all. tba Stat. baa _t1aatacl that half of the .
trK" wauld be ~1t .. aDd half lott.ry, ao yCN can ap.ct that:'·tan.-
-of'. ~l0~~~ .... C" • .lau1:.:b·]f~ City. laDcl. after
traDaf.rof title, w1ll probably b. cl1.apoHd of 011 the vut ancl of town
but it 18 cloabeful that such cl1apoaal vill taka plac. th1a year. !!y
eazol1eat _t1mat. wou.1cl be ill twa ,.us.
tba City 18 ill the proe ... of acq1d.r1Da DeW ,eDenton and baa purchased
utility pol .. for 1Da1:&llat1Oll -puhapa tlU.a ." .... r. Our teDcative plans
are to ruD pcNU' f1'Ola the "'!V..J'.O&t.P.,~~;t.~_.~~~.,· Again, though.
thes. plaDa are v.ry taud.ve aDd have DOt bUD authoriz.d officially
'by the CotJDC11 Dar have va had all 4IDIiDaer devis. my proc:.aclure to follow.
w~ do apac~ populad.oll to iDer .... but ita barcl to say how that w1lJ.
affact our p0W8r or . vatu ___ • Moat laDd chat will b. available will
b. sm. clia1:allc. out of the Ci~ itsalf but' within the City limits. It
is 'po .. %blaal.dla~""~ari~t:h.·-h1ll -f~TeDaai(' Aveniie -wurbe
op __ ~~~.~ but DO lalla us. plan DDr disposal ordinanc:.e has
yet. bHD writt_.
w. have begun discu.sions with the O.partmanc of EDv~ronmencal Conservation
regarding vat.r and/or sewer systems for the City. A survey is being
_ .. ..:--::;~ ••• J
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... ,.' e····
Lee R. Nunn December 31, 1981 2-2-2-2
developed which should be circulated in January which will ascertain the
community's feelings on a feasibility study fora water and/or sewer
system. If the community feels a study is in its best interest. we will
ask for funding from the legislature to conduct it. The study ~hould
produce-the information on water use a~d needs and project such need for
several years as well as identify potential sources.
Currently, though, water use per household is very small. Most ()eople
haul their water, have outhouses and bath! at the hot springs so household
use would be for washing dishes or clothing. Should the populat:lon swell
to any degree, though, bathing at the hot springs might become l~ss
prevalent. A1~o, if water were available, many people would install flush
toilets. I think you would find that here, population would follow devel-
-opment rather than the reverse •
Our year round population in 1980, according to the U.S. census, was
138. In 19S1, the State determined our population to be 112. With demand
for land here as high as it is, prices have skyrocketed. In many cases,
these prices have squeezed out the local resident in favor of the part-time
resident who holds a higher paying job in nearby population centers such
as Juneau and Sitka. I would imagine this trend will continue.
As I promised earlier. the substance of our reply is disappointing. However,
we are in hopes that we will hAve a feasibility study conducted on our
water' audsewer'nHas and that information will dovetail nicely with the
study being'conducted by the Corps. In addition, we are asking for a
highschoo1._ facility.' for Tenakee as the number of school-age children will
soon require it. More school facilities will also attract more people.
Please let me know if we can be of further help. For your information, the
mayor is DOW Robert Pegues.
Sincerely,
TERESSA C. MOE3
City Clerk/Treasurer
UNITED STATES DEPARTMENT OF AGRICULTURE
FOREST SERVICE
Sitka Ranger District
Post Office Box 504
Sitka, Alaska 99835
2630
January n~ 1.982
Mr. Harlan E. Moore
Chief, Engineering Division
Department of the Army
Alaska District Corps of Engineers
P. O. Box 7002
~nchorage, Alaska 99510
Dear Mr. Moore:
This letter and corresponding enclosures refers to your request
dated 23 November 1981, and concerns information related to the
Corps' hydropower study at Tenakee Springs. ~/e trust this infor-
mation will be helpful to your evaluation of alternatives.
The enclosure letter dated 14 December 1981 relates to requests
c,f, g and h of your letter and the enclosed binder contains all
our available soil and water resource data (requests a, b and e).
With regard to your request (d), the amount of timber salvage
on National Forest land tied with any of your proposed options
would be either negligeable or non-existant, depending on the
option selected. Most of the proposed work would occur on State
lands. At this time I do not foresee timber salvage on the
National Forest portion as a major issue in the scope of the
proposed project. Although disposal of salvable material must
be considered we would prefer to discuss this item after the
proposal is well defined and specific detail is required.
There could be some very definite conflict regarding your request
item (i), depending upon your scheduling of this project, planned
Forest Service use and resolution of ROW on the lower Indian
Ri ver road system through State ownersh"j p.
We realize that some unknowns remain pertaining to your request,
but .hopefully the included information will pennit maintenance
of your study schedule.
Si nc'ere 1y,
. i , ,././' , ,;/£---_.
~~l-' I. l 7 ./";' ';;;;//' ;p~~:,'ttr'l
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/ JERRY-S. HAmL TON
Acting District Ranger
Enclosures
UO~l1 (1,6t)
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cITy OF
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TEnAKEE SPRinGS
April 30, 1982
Lee R~ Nunn
Colonel, Corps of Engineers
Department of the Army
P.O. Box 7002
Anchorage, AK 99510
Dear Colonel Nunn:
POST OFFICE BOX 52
TENAKEE SPRINr~
ALASKA 99841
The City of'Tenakee Springs is in the process of applying
for a rural development assistance grant for the purpose of
conducting a feasibility study for a water distribution
system within the areas of our community encompassed by the
outer boundaries of USS 1418.
One of the requirements in applying for this grant is to
obtain the promise of cooperation from agencies that will be
involved in the project. To the extent that the Corps of
Engineers is simultaneously conducting a feasibility study
for the hydro potential of Indian River, your agency will
be involved in our water feasibility study. I believe I
mentioned the possibility of this study in my letter to you
dated December 31, 1981.
At this time, I would appreciate it if you could write a
letter to the City of Tenakee Springs describing your
ongoing study at Indian River and offering to cooperate with
and endorse a water feasibility study for the community.
That letter would become a part of our grant package.
I am enclosing a copy of the survey we used to ascertain the
wishes of the local citizenry and a resolution passed by the
City Council in response to that survey. These may give you
an idea of the scope of the study we wish conducted.
Certainly it seems that the water feasibility study would
take into consideration the various options the Corps is
eXam1n1ng in relation to Indian River -particularly those
options that would provide a year-round consistent supply
of water.
I hope you will be able to help us as I requested. Please
let me know if you need further information.
Sincerely,
V(!r)~~
TERESSA C. MOEN
City Clerk/Treasurer
p'
In the Council
March 25, 1982
(
CITY OF TENAKEE SPRINGS
Resolution 82-11
(
Introduced by
Council President
A RESOLUTION SUPPORTING THE CITY'S REQUEST FOR STATE FUNDINC FOR
A .WATER FEASIBILITY STUDY TO BE CONDUCTED IN THE CITY OF
TENAKEE SPRINGS.
WHEREAS, The first step in obtaining a city water system is a fe:lsibility
study, and
WHEREAS, a water feasibility study will indicate what sources of water are
~vailab1e and the quality of each source, and
WHEREAS, such a study would indic'ate various methods of construction and
operating costs as well as suggest options available to the
community for sewer systems and waste treatment facilities, and
WHEREAS, a poll taken of the citizens of Tenakee Springs was taken and
the majority are in favor of such a feasibility study, then
THEREFORE BE IT RESOLVED that the Cit'y of Tenakee Springs formally requests
the State of Alaska to provide funding for a water feasibility
study to be conducted to provide safe water service for residents
of U.S.S. 1418. .
. , .1./1) /;
ADOPTED THIS ___ ..... ..:--_. _, _.5 ________ DAY of_'-:;;''ln~if ..... {...:..C.=..l.:.,,rt_,,,,,,j ______ , 1982.
ATTEST:
' . ., ." ""/Ii ~. ( . vli.¥~ (. t.
CITY CLERK
c __ _
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POST OFFICE BOX 52 CIty OF
TEnAKEE SPRinGS TENAKEE SPRINC
ALASKA 9:
December 21, 1 ~
PUBLIC OPINION SURVEY
To the residents of Tenakee Springs:
At the City Council meeting of November 24, a representative of the
State Department of Environmental Conservation spoke to the Council
and citizens of Tenakee Springs describing various types of sewer
and water systems available with total or partial State funding.
The first step in obtaining such a system is conducting a fcasibilit~
study. This feasibility study would cost bet1-reen $30-40,000 and
wO'lld provide the community with the following preliminary engineering
information:
1. Sources of water available to the community.
2. Quality of each available water source and costs and methods of
treatment necessary to insure a safe water supply from each sourL~
3. Various methods and~construction costs in bringing water from
each source to the community.·
-.
4. Costs of operating and maintaining a continuous, quality ,-rater
distribution system;
s. The options available to the community for selier systems and was!€
treatment facilities including costs of both construction and
operation of each option. Treatment facilities may not be requi.~
6. The total costs and scheduled time needed for completion for eac·
option.
The study will take into account legal responsibilities connected wi~~
the operation of each optional system. Public hearings will be con-
ducted to determine what the community's opinions and needs arc in
relation to a water and/or sewer system. The feasibility ~tuJj riculd
obligate the City to construct either a sewer or water system but
would outline options to choose from so that the community may
make an educated choice. The community would be able to choose any
one option, a combination of options, or none of the options named i"
the study.
TO HELP THE CITY COUNCIL MAKE A DECISION ON THE FEASIBILITY STUDY,
DO YOU THINK THE CITY SHOULD SEEK FUNDING FROM THE STATE TO HAVE
·SUCH A FEASIBILITY STUDY CONDUCTED? YES
NO ---
Please return this survey to the City Clerk or drop into the boxes
provided at Snyder Mercantile or the Shamrock.
f .
May 20, 1982
File No: 1130-2-1
Harl an E. Moore
Chief, Engineering Division
USDA, Army Corps of Engineers
P.O. Box 7002
Anchorage, AK 99510
Dear Mr. Moore:
DIVISION OF PAR;CS
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i)L-EAJ
JAY S. HAMMOND, GOVERNOR
619 WAREHOUSE DR .• SUITE 210
ANCHORAGE. ALASKA 99501
PHONE: 274-4616
We have revie\'ied the "Tenakee Springs Cultural Resource Assessment"
report submitted to this office. We concur with all conclusions and
recon~endations of the Corps archaeologist. Should there be any changes
in the project plans, we would like the opportunity to review them. If
any cultural resources are discovered during the course of the work, we
request that the project engineer halt all work which may disturb such
resources and contact us immediately ..
Sincerely,
Dan Robinson
Acting Director
T~a~,[)/5Pv"Y sHl'o
By: Ty L. Oil'! i plane .
~.,,: State HistOl~ic Preservation Officer
OR/jdg
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CITY OF POST OFFICE BOX 52 .,
TfnRKff SPRinGS TENAKEE . SPRINGS
ALASKA 99841 '
June 16, 1982
Major Michael R. Foster
Acting District Engineer
Alaska District
U.S. Army Corps of Engineers
P.O. Box 7002
Anchorage, AK 99510
Attn: NPAEN-PL-H
Dear Major Foster:
Thank you for affording me the opportunity to review the Corps' energy
growth projections for Tenakee Springs.
The preliminary draft was one of the best of these types of documents
that I have seen in some time. Th~ draft was circulated to various
individuals locally, generating a number of suggestions which I hope
will prove. to be useful.
The draft I received was apparently missing a page and appeared to be
out of sequence at one point. Never the less, this did not hamper our
review.
The comments offered on the attached pages summarize the suggestions
of myself; T.C. Moen, City Clerk; Mr. Don Pegues, current electric
utility operator; and Mr. A. Dermott O'Toole, long-time resident and
the former utility operator.
The comments are offered in response to statements in the preliminary
draft and may add some helpful clarification for preparing the final
report.
Please extend my thanks and compliments to Mr. Shupe and to all those
others in the District whose di11igence and dedication are reflected
by the Draft Report. Their effort and skill is commendable, and very
much appreciated.
Please let me know if I may be of further assistance.
Again, thanks!
Sincerely,
~~~
MAYOR
RAP/tcm
Enclosure
APPENOIX E
INDIAN RIVER FLOW DURATION CURVES
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°0.00 2 oc~o
DF.RCF.NT OF r[M[ F.aUALLF.O OR F.XCCF.OED
APPENDIX G"
USFWS COORDINATION ACT REPORT
United States Department of the Interior
IN REPLY REFER TO:
Colonel Neil E. Sa1i~g
District Engineer
FISH AND WILDLIFE SER VICE
IOIl E. TUDOR RD.
ANCHORAGE, ALASKA 99503
(907) 276-3800
1 a OCT 1982
Alaska District, Corps of Engineers
P.O. Box 7002
Anchorage, Alaska 99510 Re: Coordination Act Report
Tenakee Springs Small Hydropower
Dear Colonel Saling:
This letter transmits the attached Coordination Act (CA) Report under the
authority of the Fish and Wildlife Coordination Act (48 Stat. 401 as amended:
16 U.S.C .• 661 et seq.) for the proposed hydroelectric development on
Indian River at Tenakee Springs. Alaska. We support the Corps' basic
preferred alternati've hydropower development plan. However. we recorrunend
that measures to mitigate adverse effects to fish and wildlife resources.
as outlined in the attached CA Report. be incorporated into the development
plan. If a ,decision is made to initiate an operational fishery management
program on Indian River. then additional interagency consultation with our
agency as well as the Alaska Department of Fish and Game. U.S. Forest
Service, National Marine Fishertes Service, and other interested agencies
will be required to develop and finalize an appropriate management plan.
In that event. we will submtt an amendment to our CA Report whi ch wi 11
address the speciftcs of the program.
We appreciate the opportuntty to cOl1111ent and advise on matters regarding
fish and wildlife resources associated with the proposed hydropower develop-
ment plan.
Attachment
cc: ADF&G. Juneau. Sitka
USFS, Sitka
FWS. ROES, Juneau, Si'tka
FWS, Federal Projects, woe
NMFS, Juneau
Sincerely yours •
• f('~. '/ P %v~ <)~ I~l /"'-~/ Regional Director
Northern SE Regional Aquaculture Assn.
Tenakee Springs Proposed Small Hydropower Development
Coordination,Act Report
Prepared By
William A. Hughes, Fish and Wildlife Biologist
Sitka Substation
Southeast Alaska Ecological Services
U. S. Fish and Wildlife Service
Juneau, Alaska
September 1982
TAB L E
Introduction. .
Project Description •
Project Alternatives.
Description of Resources.
Fishery Resources •.•
o F CON TEN T S
Fishery Enhancement Opportunities .•
Wildlife Resources
Endangered Species
Discussion of Potential Impacts and Recommendations .
Instream Flow Needs. . . • . •
Mitigation Options •..•••
Future Fishery Enhancement Efforts
Turbine Mortalities ••.
Construction Impacts ••••
Gass Bubble Disease. • •
Loss of Spawning Habitat •
Bald Eagles. • • • • •
Brown Bear • • • • . .
Right-of-Way Clearing. .
. . . . . .
Summary • .
References.
. . . . . . .
i
1
1
4
5
5
9
9
9
11
11
11
13
13
14
14
14
14
15
15
15
16
Figures
Figure 1
Figure 2
Tables
Table 1
Table 2
Table 3
Appendices
-List of Tables, Figures, and Appendices -
Proposed Alternative Hydropower Development Facility
Sites and Eagle Nest Tree Locations at Tenakee Springs,
Alaska .......................... .
Location of Proposed Project Features on Indian River,
Tenakee Springs, Alaska ............... .
Fish Sampling Catch Results for Indian River Near Tena-
2
3
kee Springs, Alaska. . . . . . . . . . . . ... . . .6,7&8
Salmon Escapement Observations in Indian River and Har-
1 ey Creek. . . . . . . . . . . . . . . . . . . . . . 9
Selected Stream Discharge Parameters at Proposed Dam
Site on Indian River Near Tenakee Springs, Alaska .. 10
Appendix A Fishery Mitigation/Enhancement Proposal for Indian
River Near Tenakee Springs, Alaska .......... . . A-I
_, Appendix B Stream Survey Results for Indian River Near Tenakee
Springs, Alaska .•.•..........••...... A-2&3
Appendix C Enhancement Opportunity Estimates of Habitat-Area and
Potential Commercial Fishery Values for Pink, Chum and
Coho Salmon. • • . . . . . . . • . . . . . . . . • . . . . A-4
ii
INTRODUCTION
The following is a Coordination Act Report to the U. S. Army Corps of
Engineers (Corps) under the authority of the Fish and Wildlife Coordina-
tion Act (48 Stat., 401 as amended: 16 U.S.C. 661 et seq.) for a proposed
hydroelectric power development project on Indian River near Tenakee Springs,
Alaska.
The project area is located on the north shore of Tenakee Inlet on Chichagof
Island, Alaska (Fig. 1). Chichagof Island is part of the Alexander Archipel-
ago that comprises southeast Alaska. The climate is maritime with small
temperature variations, high humidity and high precipitation. Annual preci-
pitation in the project area var~~s from about 80 inches near tidewater to
120 inches at higher elevations.~ Although there are no permanent snow fields
or glaciers on Chichagof Island, the major landscape features have been formed
by recent glaciation. The lower elevations are forested with western hemlock,
Sitka spruce and some Alaska cedar. Timberline occurs at about 1,500 to
2,000 feet elevation. The valley floors are interspaced with forest openings
occupied by muskeg-type vegetation. Alder and devil's club are common along
the river banks and disturbed areas. The Indian River watershed drainage
area is approximately 22 sq. miles with a main stream length of 12 miles.
Mean 1i?nual discharge of the drainage basin at the proposed dam site is 118
cfs.-,
Most of the forest lands in Tenakee Inlet vicinity are under U. S. Forest
Service (USFS) management as part of the Tongass National Forest. For manage-
ment purposes the USFS has classified the federal lands within the project
area as LUD (land use designation) III. LUD III units are managed to provide
a combination of both amenity and commodity values. The Indian River water-
shed has been recently logged as part of a USFS timber sale to Alaska Lumber
and Pulp Company.
The current population of Tenakee Springs is approximately 132. The actual
townsite consists of about 200 acres of private and State lands located on
a narrow strip of land near tidewater on the north shore of Tenakee Inlet.
The State of Alaska has selected about 3,000 additional acres of adjacent
National Forest Lands for transfer to the City of Tenakee Springs and for
public land sales and homesite disposal. Some additional population growth
can be anticipated in the future.
Electrical power is currently provided to Tenakee Springs by a 90-kW diesel
generator owned and operated by Snyder r1ercanti 1 e.
PROJECT DESCRIPTION
The preferred development plan would involve construction of a 21-foot high
concrete and steel sheet pile dam with a IS-foot high spillway at River Mile
0.8 (Fish Barrier 4).* The dam would divert water for hydropower generation
* Barriers 1 through 5 in this report refer to natural waterfalls or cascades
located between Mile 0.4 and Mile 0.9 on Indian River. The barriers are pro-
bable barriers or discouragements to upstream passage of anadromous fish.
-1-
I
N
I
Figure 1. Proposed Alternative Hydropower Development Facility Sites and Eagle Nest
Tree Locations at Tenakee Springs, Alaska.
LEGEND
1 • propo8ed powerhou8e
~ propo8ed dcun
propo8ed pen8toak
• • • propo8ed tran8mi88i
® eagle ne8t tree
~ ~I'&-ALTERNATIVE #l
~ ~
TENAKEE
SPRINGS
CHICHAGOF ISLAND
unnamed fish stream
ADF&G #112-42-008
Columbia Pt.
o Grave I. Cannery Pt.
TENAKEE INLET
1 inch = 4000 ft
-. -1 , ... ,
"
Figure 2. Location of Proposed Project Features on Indian River,
Tenakee Springs, Alaska.
LEGEND
eagl.e nest tree
possibl.e fish barrier
trail.
'::'::::'~:;'::'= intertidal. area ....
......
':\ Map redrawn from uSPS col.or aerial. phot
Scal.e: 1 inch ~ 1320 ft "', " , , , ...
" " " " " " " .... , .... ,
" , , .... , .... ,
" , .... , ,
.... " .... , , , , ....
" "" .... ,
" arri~ 5 ... ' .:-~
\\
\\ , ,
Barrie~:4 I S LAN D
" rri er 3''... ... .:..... U'('
-3-
..... ::... ..Jps , .. ... Ii. ..... ::;: ..... afJI
..... ~ .... ROad "~' ........ '~ 1 " .... .... ~"
~ .... , .. .. , -'~ ..... .... .,..,...,...--.--.-..-........ :~
TENAKEE I N L E'T
to a steel 42-inch diameter penstock. The penstock would transport water
1,926 feet downstream to a powerhouse located at Mile 0.4 midway between
Barriers 1 and 2. Electrical power would be generated by a Francis-type
turbine with a rated output of approximately 200 to 250 kW. Electricity
would be transmitted 3,700 feet to the community of Tenakee Springs via
an above ground transmission line. After the diversion water has passed
through the powerhouse, it would be returned to the natural stream channel
below Barrier 1. The turbine would operate at diversion flows of between
19 and 48 cfs. Streamflows in excess or below hydropower operational re-
quirements levels would flow over or through the dam to the natural stream
channel. A 6-inch diameter tap and separate pipeline carrying approximately
1 cfs of water to the community for domestic use would be incorporated into
the design of the penstock intake works. A valve or pipe would be imbedded
in the dam to provide required instream flows. A manually operated gate
and sluice system would provide the capability to flush debris and sediment
from the upstream reservoir pool. Diesel backup generation capacity would
be required when turbine flow capacity cannot be met due to reduced natural
flows. An existing logging road parallels the river valley and would pro-
vide access to the dam site from tidewater. Construction ofa ~-mile spur
road to the dam site would be necessary.
PROJECT ALTERNATIVES
A concrete dam, in excess of 80 feet high, at River Mile 0.4 was proposed
by the USFS and evaluated by the Corps. The dam would inundate the natural
upstream fish passage barriers and provide a single fish ladder at the dam
site to access the upstream spawning and rearing areas for anadromous fish.
This option was determined to be infeasible as a result of geotechnical,
economic and power analysis.
Another alternative dam site was considered at River Mile 0.9. This alterna-
tive would have involved the construction of an additional 1,800 feet of
penstock and was eliminated because of economic consideration.
An alternative powerhouse location on the west bank of the river was evaluated
by the Corps and found to have significantly greater foundation cost and was
eliminated for economic reasons.
Turbine choice has not been finalized and could be modified prior to construc-
tion pending refined project flow requirements. A crossflow turbine is a
possible alternative to the proposed Francis-type turbine. Crossflow turbines
are less efficient, but can operate at reduced flows.
An alternative hydropower development site on Harley Creek located about four
miles east of Tenakee Springs was considered during the early planning stages
of the project. However, this alternative has been discounted as techni-
cally infeasible by the Corps because of insufficient sustained flows to meet
project energy requirements.
-4-
DESCRIPTION OF RESOURCES
Fishery Resources: The major fishery resources in the project area consist
of pink, chum and coho salmon and Dolly Varden char. In early July, pink and
chum salmon adults return to freshwater to spawn. Spawning takes place from
early summer to late fall with the eggs hatching from November to January.
After hatching,' the resultant fry emerge from the streambed from late March
to early May and migrate to sea. Peak oU~ligration periods for pink and
chum salmon fry from the Kadashan River in Tenakee Inlet occurs during the
third week of April. After 1.5 to 3.5 years in the ocean, the adults return
to the stream of their origin where they spawn and die. Coho salmon enter
freshwater somewhat later (late AUgust through October) than pink and chum
salmon. Their activities and life requirements are somewhat similar to
pinks and chums, however, the young continue to use freshwater as rearing
habitat, usually ~Qr two summers and two winters, before smoltifying and
migrating to sea.-1 After one or more years (usually two summers) at sea,
the adults return to the stream of their origin where they spawn and die.
Dolly Varden char have both resident and anadromous populations. Dolly
Varden spawn in the fall, however, unlike pacific salmon, they do not nec-
essarily die after spawning. Anadromous adults return to the sea, while
resident adults remain in the stream.
Indian River and several of its major tributaries were surveyed by FWS bio-
logists from tidewater to a point about 11 miles upstream. Survey results
and descriptions of fish barriers and habitat quality are given in Appendix
B. In summary, the lower section of the river (Mile 0.0 to Mile 0.4) pro-
vides good to excellent spawning and rearing habitat for pink and chum sal-
mon and Dolly Varden char. Cottids (COttu8 aZeuticu8) were present in this
section. A series of five barriers or discouragements to upstream fish pas-
sa~~ exist between Mile 0.4 and Mile 0.9 (Fig. 2). The presence of coho
salmon fry indicate that adults are able to negotiate upstream at least to
the base of the second barrier at Mile 0.5. The habitat was judged to be
moderate to poor quality due to the relatively high stream gradient. A set
of 13 fry traps captured 67 juvenile Dolly Varden and 13 coho salmon fry in
this section of the river. Good but inaccessible spawning habitat for pink
and chum salmon is located between Mile 0.9 and Mile 2.7. From Mile 2.7 to
Mile 3.9 the stream gradient decreases with several beaver dams and back-
water areas located along the stream course. Dolly Varden were abundant.
There is little spawning habitat in this section, but there is excellent
potential rearing habitat for coho salmon. Mile 3.9 to Mile 11.6 provides
a variety of good to excellent salmonid spawning and rearing habitats for
coho, pink and chum salmon. However, Dolly Varden were the only species
observed or captured. There ara unconfirmed reports of the presence of
cutthroat trout in this section of the river. A steep falls at Mile 11.6
prohibits any upstream fish passage. Fishery habitat upstream of the falls
is judged to be poor due to the steep gradient. Catch results from fish
sampling efforts are listed in Table 1.
There are three streams within the project area that arylisted by the Alaska
Department of Fish and Game as anadromous fish streams. Catalog number and
selected salmon escapement reports are listed in Table 2.
-5-
Table 1 . Fish Sampling Catch Results for Indian River Near Tenakee Springs, Alaska. Unless otherwise noted, samp-
ling was done with Gee-Type Minnow Traps.
Sampling No. Time Fi shed
Location** Date Species Captured Fork Length (em) (Hours)
Mile 0.1 7/25/80 Dolly Varden (D.V.) 13 5.0 -7.4 5.8
coho salmon 26 2.5 -7.4
Cottid (c. aleutious) 1 7.6
Mile 0.4 6/16/81 D. V. 19 5.0 -9.0* 1.2
150' upstream
of Barri er 1.
7.5* coho 10 6.5 -
~1il e 0.4 6/16/81 D. V. 2 6.5 -9.0* 1.2
170' upstream
of Barri er 1.
Mile 0.4 6/16/81 D. V. 3 5.0 -6.5* 25.5
300' upstream
• of Barri er 1.
0\ 7.5* I 6/17 /81 coho 2
Mile 0.4 6/16/81 D. V. 2 7.5 -11.5* 0.9
400' upstream
of Barrier 1.
r~il e 0.4 6/17/81 D. V. 13 2.5* (1/8-i neh mesh
450' downstream minnow seine)
of Barrier 2.
Mile 0.5 6/17/81 D. V. 4 7.5 -9.0* 22.0
200' upstream 6/18/81
of Barrier 2.
Mile 0.5 6/17 /81 D. V. 25 6.5 -15.0 * 22.0
350' upstream 6/18/81
of Barrier 2.
Table .1 (continued). Fish Sampling Catch Results for Indian River Near Tenakee Springs, Alaska. Unless otherwise
noted, sampling was done with Gee-Type Minnow Traps.
Sampling** No. Time Fished
Location Date S(!ecies Ca(!tured Fork Length (cm) (Hours)
Mile 0.5 6/17/81 D. V. 8 6.5 -11.5 * 21. 9
400' upstream 6/18/81
of Barrier 2.
Mile 0.8 6/17/81 No Catch 0.7
400' downstream
of Barrier 4.
Mil e 0.9 6/17 /81 D. V. 4 10.0 -14.0 * 1.5
350' downstream
of Bard er 5.
Mile 0.9 6/17/81 No Catch 1.5
300' downstream
of Barrier 5.
Mile 0.9 6/17 /81 No Catch 1.3 ,
200' downstream "'-J
I of Barrier 5.
Mile 1. 5 7/25/80 D. V. 5 11.0 -13.0 2.0
D. V. 1 14.5
Mile 2.4 7/25/80 D. V. 1 12.0 2.0
Mile 2.8 7/25/80 No Catch 2.0
Mile 4.0 7/24/80 D. V. 7 10.0 -11.9 19.7
16 12.0 -14.9
25 15.0 -16.9
3 17.0 -17.9
Mile 4.7 7/24/80 D. V. 5 5.0 -6.9 20.3
3 7.0 -8.9
I co ,
Table 1 (continued). Fish Sampling Catch Results for Indian River Near Tenakee Springs, Alaska. Unless otherwise
noted. sampling was done with Gee-Type Minnow Traps.
Sampling**
Location
Mile 7.3
Mile 10.2
*Total Length
Date
7/24/80
7/24/80
**Miles upstream from tidewater
Species
D. V.
D. V.
No.
Captured
3
20
22
13
4
13
Fork Length (cm)
5.0 -6.9
7.0 -8.9
9.0 -10.9
1l.0 -13.9
5.0 -7.9
8.0 -9.9
Time Fi shed
(Hours)
3.5
Table 2. Salmon escapement observations in Indian River and Harley Creek.
(Personal communication with Jim Dangle, ADF&G, 7/30/82)
1970 1976 1977 1978 1979 1980
Indian River
(cat. #112-42-008)
Pink salmon 970 6150 1500 4703 4410
Chum salmon 20 123 1010 430 460
Harley Creek
(cat. #112-41-010)
Pink salmon 550
Fishery Enhancement Opportunities: Indian River has definite upstream fish-
ery enhancement potential. The USFS has identified the river as a potential
enhancement opportunity if fish passage facilities ,ere constructed over the
natural barriers in the lower section of the river.-1 There are at least 10
miles of good to excellent spawning and rearing habitat for anadromous fish
upstream of Barrier 5 at Mile 0.9. Estimates of habitat area and potential
commercial fishery values for pink, chum and coho salmon are given in Appendix
C.
Wildlife Resources: Two species of ,big game inhabit the project area--Sitka
black-tailed deer (OdocoiZeus hemionus sitkensis) and brown bear (Ursus arctos).
Both species are dependent on the coastal forest ecosystem. Preferred spring
and summer habitat for brown bear is along grassflats, tide-influenced meadows,
forest fringe, and anadromous fish streams such as Indian River. Four brown
bear were observed feeding on salmon in the lower portion of Indian River dur-
ing the 1980 stream survey. Well used game trails are evident on both sides
of the river from tidewater to headwater areas. Habitat for mink (MusteZa vis-
ion), marten (MartesamePicana), river otter (Lutra canadensis) and beaver
(Castor canadensis) is found along the riparian zone. Various species of water-
fowl will occasionally use the upstream muskeg and beaver pond areas for rest-
ing and feeding. Raven (Corvus corax) and northwestern crow (C. caurinus) are
common along the riparian zone and tidal grassflats. Shorebirds, gulls, water-
fowl and other seabirds are found in the marine waters of Tenakee Inlet. Bald
eagle (HaZiaectus ZeuaocephaZus) are very common near tidewater areas. Nine
bald eagle nest trees have been identified between Tenakee Springs and Harley
Creek (Fig. 1). Harbor seal (Phoca vituZina), steller sea lion (EUmetopias
jubata) and humpback whale (Megaptera novaeangZiae) are commonly observed in
Tenakee Inlet.
Endangered Species·: There are no known endangered terrestrial mammal or avian
species known to exist in the project area, The humpback whale, Megaptera
novaeangZiae, is listed as an endangered species pursuant to the Endangered
Species Act of 1969. Although common to waters of Tenakee Inlet it is not
anticipated that the project as proposed will affect the habitat of the species.
The bald eagle and brown bear, while threatened or endangered in other parts
of North America, are not so designated in Southeast Alaska. Two species of
peregrin falcon (FaZco peregrinus anatum and F.p. tundrensis) could migrate
through the project area; both are on the Federal Threatened and Endangered
Species List.
-9-
Table 3. Selected stream discharge parameters at proposed dam site on
Indian River near Tenakee Springs, Alaska.*
Mean annual flow (at proposed dam site)
7-day winter low flow (November-April)
7-day summer low flow (may-October)
30-day winter low flow (November-April)
Mean January flow
Mean February flow
Mean March flow
Mean April flow
Mean May flow
Mean June flow
Mean July flow
Mean August flow
Mean September flow
Mean October flow
Mean November flow
Mean December flow
Peak Flow (Recorded 9/15/76)
Low flow of record (Recorded 2/79)
118 cfs
8 cfs
19 cfs
10 cfs
86 cfs
66 cfs
61 cfs
114 cfs
194 cfs
150 cfs
85 cfs
54 cfs
135 cfs
254 cfs
136 cfs
86 cfs
3040 cfs
5 cfs
*Six-year data average (1976-81) from USGS-USFS stream guage on \~~ian River
and adjusted by a factor of xl.6 for proposed dam site location.--
-10-
DISCUSSION OF POTENTIAL IMPACTS AND RECOMMENDATIONS
Instream Flow Needs ~ Since the proposed project is essentially a run-of-the-
river design it is not anticipated that pink and chum spawning habitat be-
·low the pO\,/erhouse outfall would be significantly affected by upstream water
useage (i.e., the limited storage capacity of the low-head dam would not
affect the downstream flow regime). However, we anticipate that water use
conflicts would occur during periods of low flow in that section of river
between the proposed dam and the powerhouse outfall. Diversion of all or a
significant portion of the natural flows for hydropower needs could reduce
or eliminate about 1,950 ft and 500 ft of instream habitat respectively for
Dolly Varden char and coho salmon. There are no tributaries that would sign-
ificantly supplement the flow within the affected stream reach. Calculated
mean monthly flows and selected discharge parameters are listed in Table 3.
According to the predicted flow duration curves, natural instream flows at
the dam site would exceed the t~rbine's upper operational flow requirement
of 48 cfs only 72% of the time.--' When flows are less than 48 cfs, the only
water that would be available for instream use would come from leakage around
the dam. One cfs for domestic water supply would be withdrawn under all
flow conditions.
Different methodologies with varying degrees of resolution and required ef-
for~ §qn be used to detenmine instream flow requirements for aquatic resourc-
es.~ In consideration of the scope of the propos~d project, the method-
ology developed by Tennant was used, for this report.-' Tennant states that
various percentages of the average annual flow for a stream can be used to
detenmine the quality of instream habitat that can be maintained under those
minimum flow releases. With an average annual flow of 118 cfs at the dam
site, the calculated instream flow requirements for the following habitat
quality would be:
Excellent
Good
Fair
Poor (minimum)
30-50% of 118 cfs = 35 to 59 cfs
20-40% of 118 cfs = 24 to 47 cfs
10-30% of 118 cfs = 12 to 35 cfs
10% of 118 cfs = 12 cfs
The Corps has proposed that a constant flow release valve or pipe could be
incorporated in the dam to provide required instream base flows. When nat-
ural flows would drop below the lower operational limit (1.e., 19 cfs), all
stream flow could be passed through or over the dam for instream aquatic
habitat uses.
Recommendations: To prevent or mitigate the loss or degradation of fishery
nabltat due to water withdrawl from the affected stream reach we recoomend
that the Corps incorporate either of the two following options into the
design and operation of the proposed hydropower facility:
Option I--Maintenance of Adequate Instream Flows
Minimum instream flows needed to support fish and other aquatic life below
the diversion dam should be assured. To sustain adequate flows during the
winter periods, we recommend that a base flow of 24 cfs (fair habitat qual-
ity) be required during the months of November through April. During the
summer growing season, we recommend an increased base flow minimum of 35
cfs (good habitat quality). In either case, downstream flows should not be
less than inflow to the dam if operations cannot provide the specified flow
requirements. Option I is FWS preferred option.
-11-
Option IInMinimum Instream Flow Requirements with Mitigation
If adequate minimum instream base flows for fishery concerns as described
in Option I above cannot be provided within the technical and economic
feasibility of the project, a reduced instream base flow regimen of 7 to
12 cfs could be implemented along with additional measures to mitigate for
the loss/and degradation of aquatic habitat due to the reduced flows.
Tennan~ states that instream flows below 10% of the average annual flow
(i.e., 12 cfs for Indian River) would significantly reduce width, depth,
and velocities and degrade the aquatic habitat. Although this base flow
regimen would severely reduce the quality of the aquatic habitat, some
fishery habitat could be maintained in the pools. Under this option, two
alternative mitigation alternatives are proposed and would be required
only if the recommended flows under Option I cannot be provided.
Mitigation Alternative A: Fish ladders or step-pool passage fac-
ilities over the dam and natural barriers would be constructed.
These facilities would provide passage for anadromous fish to the 10
miles of rearing habitat above Barrier 5. The target species would
be coho salmon. Design criteria would be easier to meet for coho
than for either pink or chum salmon. At present only Barriers 2
and 4 are considered impassable to coho. The proposed dam would
present an additional barrier and would have to be laddered as
well. Additional field studies would be required to determine if
construction of fish passage facilities are technically and econ-
omically feasible within the scope of the project. Annual main-
tenance of the passage facilities would be required and would be
included as a cost of the project. Preliminary indications are
-' that construction and maintenance cost may be too high to justify
this alternative.
Mitigation Alternative B: Alternative B would be an operational
management plan with no physical structures required on the river.
It is the FWS preferred mitigation alternative. Adult coho salmon
would be captured downstream of the first barrier; the eggs stripped
from the females and fertilized in the field; transported to rear-
ing facilities in Juneau or Sitka; raised to fry stage; transported
back to Indian River and stocked in the upper reaches of the river.
The fry would disperse in the river and pond systems, rear to smolt
size, and outmigrate naturally to the ocean. Returning adults
would be captured to repeat'the operational cycle. Initially, there
may not be sufficient numbers of adult coho in Indian River to pro-
vide the required numbers of eggs and fry for a saturation stocking
program. Implementation may require the capture of brood stock from
another watershed in Tenakee Inlet such as Kadashan River. A min-
imal stocking program to mitigate only the loss of Dolly Varden
char and coho salmon habitat would require a target number of 2,500
coho smo1ts--the estimated number of smo1ts that could be produced
in a stream reach of comparable size with good rearing habitat for
coho. Species for species mitigation for Dolly Varden char is imprac-
tical since proposed upstream rearing areas are already utilized by
that species. Mitigation target numbers were derived as follow:
-12-
Affected stream area
Potential smolt production
(1000 smolt/acre x 2.5 acre)
Number of fry to produce 2500 smolt
(assume 10% survival fry to smolt)
Number of eggs to produce 25,000 fry
(assume 85% survival of egg to fry)
Number of adults to yield 30,000 eggs
(assume 3,000 eggs per female)
2.5 acres
2,500 smolt
25,000 fry
29,412 ( 30,000)
10 adult female coho
For efficiency of operations, we suggest that egg-take and fry stocking
operati2?s be conducted every other year. Since the Sashin Creek
studie~ show that most coho salmon in that area spent two summers
and two winters in fresh water and two summers and one winter in the
ocean, a once every two-year program may reduce competition between
year classes of juvenile salmon. Expanding the egg-take operations
to a three-year cycle may not coincide with the maximum adult returns
for a year class to the river. The numbers of fry stocked could
be increased to compensate for off years and to mitigate for other
project impacts such as turbine mortality and downstream siltation
of pink and chum salmon spawning areas from construction and oper-
ation of the hydroproject. A proposal to fully utilize the upstream
rearing habitat for production, of coho salmon is attached (see Appen~
dix A). Potential cooperators include Alaska Department of Fish &
Game, the U. S. Forest Service, and the Northern Southeast Regional
Aquaculture Association.
Future Fishery Enhancement Efforts -The U. S. Forest Servic 7/has identified
Indian River as a potential fishery enhancement opportunity.-The laddering
of the barriers or initiation of an upstream fry stocking program may be a
viable fishery enhancement opportunity with'in the life of the hydroproject.
The construction of a dam upstre~ of Barrier 4 without fish passage provi-
sions would present another obstacle to fish passage and possibly preempt
future fishery enhancement programs for the river.
Recommendations: Project design should provide the option for upstream pas-
sage of adult salmon and assure that the dam would accommodate passage fac-
ilities at a reasonable cost if a decision were made at a later date to breach
the natural barriers. Unless fish passage is considered as a mitigation
or enhancement measure for this project, the construction of passage facili-
ties would not be required at this time. This concern could also be met by
making a commitment to provide passage over the dam should a future enhance-
ment project be implemented.
Turbine Mortalities -If upstream fishery enhancement programs are initiated,
the proposed dam and penstock could entrap outmigrant salmon smolts in the
power generating equipment. Significant mortalities could occur.
Recommendations: If fishery enhancement of mitigation efforts are initiated,
project design of the diversion flume and turbine should assure that signi-
ficant numbers of outmigrant smolts are not passed through the generating
equipment and killed or injured. The Corps has proposed construction of a
diversion wall and screening device to prevent or discourage fish from enter-
ing the water intake for the generating facilities.
-13-
Construction Impacts -Instream constructicin activities, rock waste disposal
from penstock installation, vehicular and heavy equipment access across
the stream, and flushing of sediments from the reservoir would all intro-
duce considerable quantities of sediments into the river system. These in-
troduced sediments may settle out in d~wnstream spawning gravels, cause
mortalities to rearing fish, and lower the quality of the spawning areas.
Recommendation: State-of-the-art erosion and siltation control efforts
should be maintained throughout the construction phase of the project. Major
instream construction activities should be scheduled for the time period of
20 May through 15 July--the time when pink and chum salmon adults or fry
would not be present in the river system. Indiscriminant side casting of
spoil or rock waste into the river as a result of penstock construction act-
ivities should be prohibited. The penstock should be aligned so as to mini-
mize encroachment on the stream and river banks. Excess rock or spoil should
be disposed of in an approved site. We would recommend that vehicular access
across the river at the dam site should be by bridge built to USFS specifica-
tions--probably a native log stringer bridge.
Gas Bubble Disease-Depending upon the effective head and amount of air
entrainment at the powerhouse outlet, supersaturated dissolved atmospheric
gas (particularly nitrogen) may cause gas bubble disease to fish exposed to
the discharge water. Large numbers of pink, chum, and coho salmon congre-
gate in a pool immediately below Barrier 1. A critical level of 110% satur-
ation has been identified for fish confined to waters of one meter or less
in depth.~
Recommendation: The design of the flume, penstock and powerhouse must assure
that air entrainment and the resulting supersaturation of discharge water
with atmospheric gases will be minimized and not exceed 110% saturation at
the powerhouse outfall.
Loss of Spawning Habitat and Riparian Vegetation to Reservoir Pool -The
flooding of the limited reservoir pool could cover and destroy some spawning
habitat for Dolly Varden. However, the reservoir would probably increase
rearing habitat and the ~verall adverse effects should be insignificant.
Likewise, the loss of riparian vegetation to the reservoir pool should not
be significant. A new riparian zone would develop around the edge of the
new pool.
Bald Eagle Nest Trees -The bald eagle is classified as endangered in the
contlguous Onlted States, but it is not on the endangered Jist for Alaska.
The bald eagle is protected by the Bald Eagle Protection Act of June 8, 1940,
as amended (16 USC 668-668d) and the Migratory Bird Treaty Act (16 USC 703-711).
Bald eagles and their nest trees are further protected through a cooperative
agreement between the FWS and the USFS which restricts all disturbance within
a 33Q-ft radius about each nest tree. A bald eagle nest tree is located in
the vicinity of the proposed transmission line to Tenakee Springs about 300
feet north of the Tenakee Small Boat Harbor. The nest was active and con-
tained two eaglets during the 1982 nesting season. Construction activities
in the vicinity of eagle nest trees may cause abandonment or destruction of
the nest. Improper transmission line and support pole design can cause elect-
rocution of large birds such as bald eagles. -
-14-
Recommendations: The transmission line· (or any other project feature)
should be aligned so as to maintain a minimum 330-foot undisturbed buffer
around any eagle nest tree. Pole design should assure that the possibility
of accidental electrocution of bald eagles is minimized. Design suggestions
for minimizing this potential can be obtained from the Edison Electric In-
stitute Raptor Research Foundation·pub1ication, Suggested Practices for Rap-
tor Protection on Power Lines, the State of the Art in 1981, Raptor Re-
search Report #4, University of Minnesota. A copy of this report has been
submitted to the Corps under separate cover. Additional design criteria
can be found in REA Bulletin #61-10 (attached).
Brown Bear Conflicts -Construction activities at or near the powerhouse
during the summer and fall salmon runs could discourage or prevent brown
bear from traditional use of the lower section of the river as a feeding
area. Construction of the penstock route and transmission corridors would
cross some established game trails and could alter natural movement and
migration patterns. Human-bear encounters and conflicts can be anticipated
during the construction phase of the project. Although short term effects
during construction of the project may be severe for individual animals,
the long term effects to the populations should not be significant.
Right-of-Way Clearing -Clearing of old-growth climax forest conditions
could reduce habitat for wildlife species dependent on these conditions
(i.e., deer, marten, etc.). Approximately 12 acres of forest would be
cleared for project features.
Recommendation: Although overall project impacts from clearing are consider-
ed minor, the amount of ROW clearing should be minimized to prevent the pos-
s'i bi 1 ity of unwanted blowdown of the adjacent forest.
Summary
The FWS would support the Corps' basic preferred alternative hydropower de-
velopment plan for Indian River. We recommend that the fish and wildlife
mitigation measures contained in this report should be incorporated into
the plan. If our recommended minimum instream base flows (i.e., 24 cfs for
the time period November 1 through April 30 and 35 cfs for the period May 1
through October 31.) can be met then no direct mitigation for fishery con-
cerns would be required. If additional water withdraw1 below our recommended
base flows are necessary for the technical and economic feasibility of the
project, then we would accept severely reduced base flows (e.g., 7-12 cfs)
with an appropriate operational fishery management program such as described
in this report. Any fishery management or enhancement plan must have the
full concurrance of the Alaska Department of Fish and Game.
-15-
References
1. Alaska Department of Fish and Game, 1975 Catalog of Waters Important for
Spawning and Migration of Anadromous Fish. Juneau, Alaska.
2. Crone & Bond. 1976. Life History of Coho Salmon in Sashin Creek, South-
east Alaska. Fishery Bulletin: Vol. 74, No.4, pp 897-923.
3. Sheridan, Wm. 1979.
Enhancement Projects.
Production of Salmon in Relation to Fishery Habitat
Unpublished USFS Report, March 1, 1979, Juneau, Alaska.
4. Tennant. 1975. Instream Flow Regimens for Fish and Wildlife, Recreational
and Related Environmental Resource. USFWS, Billings, Montana.
5. U.S. Department of Agriculture. 1979. Water Resource Atlas for Region 10,
Juneau, Alaska.
6.
7.
USFWS (OBS). 1976.
Flow Requirements:
Methodologies for Determination of Stream Resource
An Assessment. Utah State University.
Vaught, R. 1980. Biological Enhancement Feasibility Survey.
USFS Report. Sitka, Alaska.
Unpublished
8. Weitkamp and Katz. 1977. Dissolved Atmospheric Gas Supersaturation of
Water and Gas Bubble Disease of'Fish. Water Res. Sci. Info. Center, USDI,
10/77.
9. -' Bayha, K. 1981. Instream Flow Information Paper #13 (In process).
10. U.S. Fish & Wil'dlife Service. 1981. Planning Aid Report--Tenakee Springs
Proposed Hydropower Development. Unpublished FWS Report, Juneau, Alaska.
11. U.S. Army Corps of Engineers. 1982. Personal communication with Lloyd
Fanter, Project Biologist, Anchorage, Alaska.
-16-
Appendix A. Fishery Mitigation/Enhancement Proposal for Indian River near
Tenakee Springs, Alaska.
Proposal: Stock ten-mile portion of Indian River above barrier falls with coho
salmon fry. All available rearing habitat would be utilized. Fry would rear
under natural instream conditions in the river and associated ponds and side
channels. Stocks would be maintained by yearly (or two-year interval) stocking
of coho fry obtained from returning adult fish for the life of the proposed hydro-
power project. Survival estimates are conservative and probably represent mini-
mal returns and benefits to the fishery.
Project Components:
1. Stream length
2. Estimated available rearing habitat
3. Potential number of coho smolts produced ~n
available habitat (assume 10 smolts/100 m
of habi tat) .
4. Number of catchable size adult coho produced
(assume 8% marine survival)
16,000 m
160,000 m2
16,000
1,280
5. Number of fry req~ired to saturate available rearing 160,000
habitat (based on a 10% survival of fry to smolt)
6. Number of eggs required to produce target number of 190,000
fry (assume 15% hatchery mortality of egg to fry)
7. Number of adult female coho required to produce 63
target number of eggs (assume a fecundity of
3,000 eggs/female)*
*This number of adult female coho salmon probably would not be available for
egg-take until the first returns from the initial stocking efforts are realized.
Therefore, a saturation stocking program probably would require brood stock from
adjacent watersheds in Tenakee Inlet such as Kadashan River or Corner Creek.
A-I
Appendix B Stream survey results for Indian River near Tenakee Springs,
Alaska.
Stream Reach Comments
Mile 0 to Mile 0.3
Mile 0.4 to 0.9
Mile 0.4
(Barrier 1)
Mi 1 e--0.5
(Barrier 2)
Mile 0.7
(Barrier 3)
Mile 0.8
(Barrier 4)
Mile 0.9
(Barrier 5)
Mile 0.9 :. Mile 2.7
Exceptionally good salmonid spawning habitat. Pink
and chum salmon abundant. Dolly Varden char, coho
salmon and sculpin (Cottus aZeutiaus) present.
Fairly high stream gradient (2 0 -50) with five falls
or cascade systems that are barriers or discourage-
ments to upstream fish passage. Poor to moderate
instream habitat for resident Dolly Varden and coho
salmon.
First upstream barrier (Barrier 1) or discouragement
to fish passage. Barrier 1 is actually a series of tw,o
separate cascades separated by a 60-ft. long run of
high velocity flow. The first cascade is a 2-ft. high
vertical step-falls and is a significant discouragement
to most of pink and chum salmon. The second cascade .
is a high gradient chute dropping about five feet in
40 feet. Although no adult salmon were observed above
Barrier 1, adult chum salmon were observed in the run
between the two cascades. Juvenile coho salmon' were c
tured in fry traps set in the 900-ft. stream reach be-
tween Barriers 1 and 2.
Second upstream barrier--12-ft high falls/cascade.
Probably a 'barrier to coho salmon, but may be passable
under certain flow conditions.
Third barrier or discouragement. Possible velocity
barrier under some flow conditions. However, salmon
should be able to negotiate under most conditions.
Fourth barrier. 15-17-ft high falls/cascade system.
Probable barrier to all salmon species. Possible
steep-pass fish passage construction opportunity at
left hand side (looking upstream) of falls.
Fifth barrier. Ten-ft high cascade. Barrier to pink
salmon, but should be negotiable by coho salmon. This
is last barrier to fish passage until the large falls
at Mile 11.5.
Moderate stream gradient (1 0 -30 ); good spawning hab-
itat in gravel-cobbl e substrate. Dolly Varden capture'
in pools and side channels. Poor to moderate rearing
habitat. No salmon observed.
A-2
Appendix B (cont.). Stream survey results for Indian River near Tenakee
Springs, Alaska.
Stream Reach
Mile 2.7 -Mile 3.9
Mile 3.9 -Mile 9.5
Mile 9.5 -Mile 10.2
Mile 9.6
MUe 10.2 -11.6
Mile 11.6
COlTlllents
Low gradient (<:1 0 ); slow meandering stream flow;
muskeg ponds, beaver dams, silty substrate. Ex-
cellent rearing habitat for salmonids.
Undercut, unstable stream banks; gsavel-sand sub-
strate with moderate gradient « 1 ). Good rearing
habitat in pools and side channels; good spawning
habitat in riffle areas.
Depositional alluvial area from confluence of two
major tributaries; unstable stream channel with
cobble-gravel substrate. Braided stream channels;
alder bank cover. Good rearing and spawning hab-
itat.
A major tributary enters main stream from northeast.
Tributary appears intermittent in the alluvial area;
however, about 0.5 miles of moderately good rearing
habitat exists in the upstream portion of the drain-
age.
Stream gradient increase (1 0 -30 ); cobble-gravel
substrate; steep side slopes; moderately good hab-
itat.
Steep falls (50 ft. high). Fish passageoimpossible.
Stream gradient above falls too great (5 ) to sup-
port significant fish habitat.
A .. 3
Appendix C. Enhancement Opportunity Estimates of Habitat Area and Potential
Commercial Fishery Values for Pink. Chum. and Coho Salmon.
Chum Salmon
Stream length
Stream width
Stream area
Usable spawning area
Commercial fishery value
Net commercial value
Pink Salmon
Stream area
Usable spawning area
Commercial fishery value
-' Net commercial value
Coho Salmon
Stream length
Stream width
Habitat area
No. of smolts/100 sq. m
No. of smolts produced
Marine survival (8%)
Required escapement
Harvestable fish
Commercial value @ $10/fish
A-4
5.100 meters
10 meters
51.000 sq. meters
40% x 51,000 m2 = 20.400 m2 = 5.0 acres
$48,000/acre/yea~
5 acres x $48,000/acre/year = $240,000/yr
51,000 sq. meters
30% x 51,000 m2 = 15,300 m2 = 3.8 acres
$15,000/acre/yea~
3.8 acres x $15,aOO/acre/year = $58,000/yr
16,000 meters (10 miles)
10 meters
16,000 m x 10 m = 160,000 sq. meters
10 smoltsY
10 x 160,000/100 = 16,000 smolts
.08 x 16,000 smolts = 1,280 adults coho
200 adults
1,280 less 200 = 1,080 adult coho
$10 x 1,080 fish = $10,800/yr
United States pepartment of the Interior
IN REPLY AEPER TO:
SEES
Colonel Neil E. Saling
District Engineer
o
FISH AND WILDLIFE SERVICE
1011 E. TUDOR RD.
ANCHORAGE, A1.ASKA 99'03
(907) 276-3800
2 0 SfP 19B3
Corps of Engineers, Alaska District
Pouch 898 Re: Amended Coordination Act Report
Tenakee Springs Sma,' Hydropower Anchorage, Alaska 99506
Dear Colonel Saling:
The enclosed .. terial constitutes. an ~ndment to our September 1982 Fish and
Wl1 dl1fe Coordination Act (CA) report dated Septlllber 1982 regarding the Corps
of Engineers Interill Small Hydropower Feasibility study at Tenakee Springs,
Alaska. Since sublrission of our final 1982 CA report, your agency has
incorporated several design Changes. into the recoaaended alternative. The
preferred dam site would now be located at river llile 0.9 and the powerhouse
site woul~ be IIOved to river mile 0.5.· The new prefel"1'"ed alternative is
described in your recent cornspondence (ref. Moore to Bayha letter dated 26
July 1983). The attached _nciDent evaluates the recent design ·changes and
provides additional rationale and justification for the proposed mitigation
program.
We commend the Corps of Engineers for their preparation of a hydropower
develor:-nt plan that fully incorporates envirollllllntal concerns into the
project design and llitigates unavoidable adve"e impacts to inst1"e1lD fishery
resources. We believe that the Tenakee project is an excellent example of how
small hydropower projects in Alaska can be developed in a IIInner that meets
the power and water needs of small rural c~nities and also lritigates and
minimizes adverse effects to fish and wildlife resources and their habitat.
Attachment
cc: ADF&G, Juneau, Sitka
USFS, Sitka
NMFS, Juneau
Northern SE Regional Aquaculture Assn.
FWS-ROES, Juneau, S1 tta
FWS-Federal Projects, woe
• Amended Fish & Wildlife Coordination Act Report for
Tenakee Springs Hydropower Study, September 1983
The anticipated impacts to fish and wildlife resources resulting from the·
Corps of Engineers 1983 alternative development plan are similar to those
described and evaluated in our September 1982 Coordination Act report. The
proposed dam and powerhouse locations in the 1983 plan would increase the
stream length and corresponding amount of aquatic habitat which would be
affected by water withdrawals as described below.
1982 Al ternative
1983 Alternative
Stream
Length (Ft.)
1,900
2,700
Area
(Acres)
2.5
3.5
Coho Habitat
(Acres)
0.6
0.0
Dolly Varden
Habitat (Acres)
2.5
3.5
However, the 1983 alternative would. locate the powerhouse outfall upstream of
Barrier 2 and thus, eliminate out-of-stream project water use in the 500 feet
of coho habitat between Barrier 2 and the 1982 powerhouse site. We consider
the 1983 plan to be environmentally preferable to the other action
alternatives.
We still anticipate adverse effects to Dolly Varden char and other aquatic
habitats in the 2,700 feet of stream that would be affected by hydropower
water withdrawal. The Corps has calculated that the average worst case
analysis of stream flows resulted in 73 days per year in which minimum
instream flows of 10-12 cfs (10% of average annual flows) would be discharged
in the affected stream reach. Tennant!! states that a discharge of 10% of
average annual flow is a minimum short-time survival flow at best, and is a
minimum instantaneous flow which will sustain short-term survival habitat for
most aquatic life forms. Kraf~ reported that the total number of brook
trout age I and older in three runs of a Montana stream was reduced
approximately 62% when 90% of the normal flow was diverted for 3 months. We,
therefore, continue to recommend that our mitigation proposals as described in
our 1982 CA report (see Mitigation Alternative B, page 12) and in the Corps'
Draft Environmental Assessment dated August 1983, be incorporated into the
Tenakee Springs Hydropower Development Plan.
1/ Tennant. 1975. Instream Flow Regiments for Fish and Wildlife, recreational
-and related environmental resources. USFWS, Billings, Montana.
2/ Kraft. 1972. Effects of controlled flow reduction on a trout stream.
-J. Fish. Res. Bd. Canada 29:1405-11.
,
On-s1te species-for-species mitigation for Dolly Varden char is impractical
since available habitat areas in Indian River are already utilized by that
species. Therefore, coho salmon, which ara also indigenous to Indian River
and have similar but not necessarily competing habitat requirements, are
considered the best species choice for the management mitigation proposal.
The amount of mitigation required would be based on an approximate 60%
reduction in habitat qua1ity~~ in the 3.5 acres of affected riverine
habitat over the 50-year life of the project. Mitigation would be provided by
stocking coho salmon fry in the upper reaches of Indian River, which has
excellent habitat for coho salmon that is presently inaccessible to that
species because of natural barriers in the river. Calculations and rationale
for determination of the amount of mitigation required are presented in
Appendix I.
Since the habitat value of the area proposed for mitigation management is
greater than that in the stream reach affected by the project~ the area or
management effort required to adequately mitigate project impacts would be
correspondingly reduced. Also, one coho fry stocking effort will utilize the
new stream habitat for two years (i.e., the average freshwater residency of
presmo1t coho salmon). Therefore, each stocking effort would be equivalent to
two years of mitigation effort. The number of years of mitigation management
could be varied in any manner such that the 325 habitat units (see Appendix I)
required for mitigation could be achieved. However, obtaining sufficient
numbers of broodstock female coho salmon for the program may be a limiting
factor--especially in the first few years of the program. We therefore .
recommend a 10-year management program that would require five alternate year
stocking efforts to mitigate for the 325 habitat units lost over the 50-year
life of the project. The logistics of the management plan are outlined in our
1982 CA report. We anticipate that the Alaska Department of Fish and Game,
the U. S. Forest Service, the Army Corps of Engineers and the U. S. Fish and
Wildlife Service would be active cooperators in the mitigation program.
3/ Personal observation indicates the reduction in habitat quality will be
very similar to that found by Kraft.
J •
t
1
~ .
!
.J
f
l
j
I
l
i
1
• APPENDIX I
Comparison of riverine aquatic habitat valu.es with and without the proposed
hydropower .project on Indian River, Tenakee Springs, Alaska.
without with Project
Project Project Mitigation
Target Years 1-50 1-50 1-10.v
Area (Acres tV 3.5 3.5 3.6
Habitat Unit Value (HUV)2/ 3 1.14 9
Percent Change in HUV 0 -62!1 +125
Total Annualized Habitat Unit~ 10.5 4.0 32.5
Life-of-Project Habitat Units 525 200 325~
1/ Acres of aquatic habitat affected (stream reach is 2,700 feet long by
57 feet wide = 3.5 acres.
2/ Based on subjective rating scale of 1 to 10, with 10 being optimum habitat
value. Ratings were jointly agreed to by FWS and Corps biologists familiar
with the project.
3/ One acre of aquatic habitat of a HUV of 1.
4/ 62% reduction in habitat value from: Kraft,1972. Effects of controlled
flow reduction on a trout stream. J. Fish. Res. Bd. Canada 29:1405-11.
5/ Total required mitigation habitat units (325) divided by annualized
mitigation habitat units (32.5).
6/ The number of habitat units necessary to mitigate project impacts due to
stream flow reductions over the life of the 50-year project.
Without Project (525 HU) = With Project (200 HU) + Mitigation (325).
,
Forest
Service
'/\'Sitka Ranqer District
Box' 1866
Sitka, Alaska 99835
-_ .. _--------
Reply 10 2600
j :! Date: October 4, 1983
1
I
Lloyd Fanter
Environmental Resources Section
Alaska District, Corps of Engineers
P.O. Box 7002
Anchorage, AK 99510
L
Dear Mr. Fanter:
The proposed Tenakee Springs Hydroelectric project involving the damming
and diverting of water from Indian River has brought to light both concerns
over potential impacts on anadromous fish and possible opportunities to
improve natural runs. Investigations and discussions to date appear to
indicate that adverse impacts to salmonids can successfully be minimized
through design and operation specifications, and compensated for through
mitigation measures. .
Habitat surveys above the proposed construction sites have shown a large
amount of 900d anadromous spawning and rearing area that is presently not
utilized due to a series of barriers in the first mile of stream. We ~re
in favor of considering cost effective ways to make this habitat available
to anadromous species.
We feel that there is some real potential for expanding whatever mitigation
program is proposed along with the hydroelectric project -to t~e realm of
enhancement. Our agencies are interested in cooperating in any mitigation
or enhancement program which may be developed as a result of this project.
~ If ~ct4uGHb.t.v ~:~~-H~RDY ~-:"'1
Fish and Wildlife Biologist Area Habitat Bi010g;s
U.S. Fish & Wildlife Alaska Dept. of Fish &
Service Game
P~O. Box 810 P.O. Box 510
Sitka, AK 99835 Sitka, AK 99835
FS-6200·"o 1716 ~ I