HomeMy WebLinkAboutCommunity of Elfin Cove Hydroelectric Project Reconnaissance Report - Jun 2010 - REF Grant 2195343HYDROELECTRIC RECONNAISSANCE STUDY
ELFIN COVE, ALASKA
FINAL REPORT
JUNE 2010
Prepared for
NON-PROFIT COMMUNITY OF ELFIN COVE
P.O. Box 1
ELFIN COVE, ALASKA 99825
-rr
THIS PROJECT WAS FINANCED BY THE DENALI
COMMISSION AND ITS PARTNERS, THE ALASKA
ENERGY AUTHORITY AND THE ELFIN COVE UTILITY
COMPANY.
E
/dan" ALASKA
ENERGY AUTHORITY
AS
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.Wg" *,
EXECUTIVE SUMMARY
The Non-profit Community of Elfin Cove (Elfin Cove) retained Polarconsult Alaska, Inc.,
(Polarconsult) to complete a reconnaissance study of hydroelectric resources for Elfin Cove.
Elfin Cove is interested in developing local hydroelectric resources to reduce the community's
current total dependence on diesel fuel for electrical generation.
The purpose of this report is to assist the community in evaluating potential hydroelectric
projects. Based on field investigations and analyses of resource suitability and community
needs, recommendations are provided for additional investigation and development activities.
Polarconsult evaluated six potential hydroelectric projects in the immediate vicinity of Elfin
Cove. These potential projects are:
➢ A run -of -river project on Crooked Creek;
➢ Three configurations of a storage project at Crooked Creek and Jim's Lake;
➢ A run -of -river project at Roy's Creek; and
➢ Simultaneous development of run -of -river projects at Roy's, Joe's and Ernie's Creek.
Each of these hydroelectric projects appears technically feasible. Projects at Crooked Creek,
Crooked Creek/Jim's Lake, and Roy's Creek appear to offer the greatest benefits to Elfin Cove
and have the highest estimated benefit -to -cost ratios. At the current level of study, it is not
possible to determine which of these projects would best suit the community. Continued
investigation of projects at all three resources is warranted.
Smaller projects at Joe's Creek and Ernie's Creek were considered in conjunction with a project
at Roy's Creek. Analysis of these projects determined that their projected incremental reduction
in diesel fuel usage did not justify their estimated costs.
Of the projects that warrant continued study, a project at Crooked Creek and Jim's Lake is
projected to achieve the greatest reduction in diesel fuel usage. That project also has the highest
estimated capital costs. A run -of -river project at Roy's Creek is projected to achieve the smallest
reduction in diesel fuel usage, but is estimated to have the lowest capital cost and highest
benefit -cost ratio. Findings for projects that warrant continued study are summarized below.
Attribute
Crooked Creek
(run -of -river)
Crooked Creek and
Jim's Lake (storage)
Roy's Creek
(run -of -river)
Conceptual Project Design Flow
5 cfs
9 cfs
4 cfs
Estimated Gross Head
450 ft
315 ft
450 ft
Maximum Probable Installed Capacity
120 kW
150 to 200 kW
100 kW
Estimated Installed Cost
$1.6 - 2.5M
$1.6 - 3.6M
$1.1-1.6M
Estimated Annual Diesel kWh Displaced
276,000 kWh
(79% of total)
313,000 - 344,000 kWh
(89-97% of total)
216,000 kWh
(62% of total)
Estimated Annual Diesel Fuel Displaced
22,100 gal
25,000 - 27,400 gal
17,300 gal
Estimated Annual Net Excess Energy
196,000 kWh
138,000 - 299,000 kWh
107,000 kWh
Estimated Benefit -Cost Ratio
0.7 -1.3
0.6 -1.4
0.8 -1.5
JUNE 2010 - FINAL REPORT
i
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.Wg" &,
Further investigation of hydroelectric resources for Elfin Cove should include:
➢ Continued hydrology data collection & analysis;
➢ Completion of topographic and geotechnical surveys;
➢ Consultation with resource agencies and the Federal Energy Regulatory Commission (FERC)
to investigate permitting issues, identify any necessary field studies, and decide on the best
FERC licensing process for the projects;
➢ Assessment of project sizing and integration with the community's existing energy
infrastructure to maximize utilization of energy produced by the projects;
➢ Completion of conceptual designs and investigate potential construction methods and costs;
➢ Development of project cost estimates;
➢ Refinement of project economics and determination of the preferred project; and
➢ Investigation of options for project financing.
These activities will be documented in a feasibility study for the preferred hydroelectric project
for the community.
A client review draft of this report was provided to Elfin Cove in March 2010. Elfin Cove met
on May 28, 2010 and voted to pursue the Jim's Lake Option 2C as presented in this study.
Option 2C is located approximately one mile south of Elfin Cove, and generally includes a run -
of -river hydroelectric project between Crooked Creek and Jim's Lake, and a second storage
hydroelectric project between Jim's Lake and tidewater. This project is projected to displace
97% of the community's diesel -fired electrical generation with renewable hydropower, at an
estimated capital cost of $2.5 to 3.6 million. Minutes of the community meeting are included in
Appendix G.
JUNE 2010 - FINAL REPORT 11
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.W4,1 *,
TABLE OF CONTENTS
ACRONYMS AND TERMINOLOGY..................................................................................................................V
1.0
INTRODUCTION.......................................................................................................................................1
1.1
PROJECT EVALUATION PROCESS
...............................................................................................................1
1.2
SUMMARY OF INVESTIGATIONS.................................................................................................................2
1.3
COMMUNITY BACKGROUND......................................................................................................................3
1.4
ELFIN COVE ENERGY PROFILE...................................................................................................................3
2.0
PREVIOUS STUDIES.................................................................................................................................7
2.1 CROOKED CREEK RUN -OF -RIVER PROJECT...............................................................................................7
2.2 CROOKED CREEK AND JIM'S LAKE DIVERSION AND STORAGE PROJECT.................................................7
2.3 ROY'S CREEK RUN -OF -RIVER PROJECT......................................................................................................8
2.4 JOE'S CREEK & ERNIE'S CREEK RUN -OF -RIVER PROJECTS........................................................................9
2.5 MARGRET CREEK RUN -OF -RIVER PROJECT...............................................................................................9
3.0 ANALYSIS OF PROJECTS......................................................................................................................10
3.1 COMMON PROJECT CONSIDERATIONS AND DATA.................................................................................12
3.2 CROOKED CREEK RUN -OF -RIVER PROJECT.............................................................................................13
3.3 CROOKED CREEK AND JIM'S LAKE DIVERSION AND STORAGE PROJECT...............................................16
3.4 ROY'S CREEK RUN -OF -RIVER PROJECT....................................................................................................21
3.5 SIMULTANEOUS DEVELOPMENT OF ROY'S, ERNIE'S AND JOE'S CREEK PROJECTS.................................22
4.0 ECONOMIC ANALYSIS.........................................................................................................................23
5.0 CONCLUSIONS AND RECOMMENDATIONS................................................................................25
5.1 REMAINING TECHNICAL CONSIDERATIONS...........................................................................................25
5.2 CONCLUSIONS..........................................................................................................................................27
5.3 DEVELOPMENT PLAN & SCHEDULE........................................................................................................27
APPENDICES
APPENDIX A — PROJECT MAPS
APPENDIX B — PHOTOGRAPHS
APPENDIX C — HYDROLOGY
APPENDIX D — ENVIRONMENTAL CONSIDERATIONS
APPENDIX E — PERMITTING
APPENDIX F — ASSUMPTIONS USED FOR ECONOMIC ANALYSIS
APPENDIX G — MINUTES OF ELFIN COVE COMMUNITY MEETING — MAY 28, 2010
LIST OF TABLES
Table 2-1: Existing Utility Generation Equipment............................................................................ 4
Table 3-1: Summary of Evaluated Hydro Projects..........................................................................11
Table 3-2: Effect of Jim's Lake Storage on Hydroelectric Generation............................................16
Table 4-1: Assumptions Used for Economic Analysis of Hydro Projects......................................23
Table 4-2: Summary of Estimated Economic Data for Evaluated Hydroelectric Projects ............ 24
Table C-1: Summary of Hydrology Data for Elfin Cove Hydroelectric Resources .................... C-1
Table C-2: Flow Measurements for Elfin Cove Hydroelectric Resources ................................... C-2
JUNE 2010 - FINAL REPORT III
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.Wg" &,
LIST OF FIGURES AND PHOTOGRAPHS
Figure 2-1: Recent Elfin Cove Power Generation Data.....................................................................5
Figure 2-2: Recent Elfin Cove Fuel Usage and Expenses.................................................................. 6
Figure 3-1: Estimated Average Monthly Energy Provided by Hydro Projects..............................10
Figure 5-1: Project Development Schedule......................................................................................28
Figure A-1: Project Overview and Location Map.........................................................................A-1
Figure A-2: Crooked Creek Run -of -River Project Map.................................................................A-2
Figure A-3: Crooked Creek -Jim s Lake Options A and B Project Map........................................A-3
Figure A-4: Crooked Creek-Jim's Lake Option C Project Map....................................................A-4
Figure A-5: Roy's Creek, Joe's Creek, and Ernie's Creek Project Map.........................................A-5
Photograph B-1: Aerial View of Small Sandy Beach, Jim's Lake, and Crooked Creek .............. B-1
Photograph B-2: Crooked Creek Gauging Station, Looking Upstream ...................................... B-1
Photograph B-3: Crooked Creek Gauging Station, Looking Downstream ................................. B-2
Photograph B-4: Crooked Creek 50 Yards Above Gauging Station, Looking Upstream ........... B-2
Photograph B-5: Site for Crooked Creek Diversion Outlet or Upper Powerhouse .................... B-3
Photograph B-6: Jim s Lake Looking West from Lake Outlet ...................................................... B-3
Photograph B-7: Jim's Lake Gauging Station................................................................................ B-3
Photograph B-8: Typical View of Power Line Route Between Jim s Lake and Elfin Cove .......
B-4
Photograph B-9: Soils Along Power Line Route Between Jim's Lake and Elfin Cove ............... B-4
Photograph B-10: Crooked Creek Gauging Station, Looking Upstream ..................................... B-4
Photograph B-11: Roy's Creek Running Over Bedrock Above Falls ...........................................
B-5
Photograph B-12: Roy's Creek Gauging Station........................................................................... B-5
Photograph B-13: Roy's Creek Waterfall ....................................................................................... B-5
Photograph B-14: Debris Field Upstream from Crooked Creek Intake Site ................................
B-6
Photograph B-15: Debris Field in Elfin Cove.................................................................................
B-6
Photograph B-16: Debris Field along Power Line Route..............................................................
B-6
Figure C-1: Jim's Lake Storage Curve............................................................................................
C-3
Figure C-2: 1984 -1985 Crooked Creek Recorded Stage and Calculated Flow Data ..................
C-7
Figure C-3: 2008 — 2009 Crooked Creek Recorded Stage and Calculated Flow Data .................
C-8
Figure C-4: Flow Duration Curves for Crooked Creek.................................................................
C-8
Figure C-5: 1984 -1985 Jim's Lake Outlet Recorded Stage and Calculated Flow Data .............
C-10
Figure C-6: 2008 - 2009 Jim's Lake Outlet Recorded Stage and Calculated Flow Data............
C-10
Figure C-7: Flow Duration Curves for Jim's Lake Outlet...........................................................
C-11
Figure C-8: 2009 Roy's Creek Recorded Stage and Calculated Flow Data .................................
C-13
JUNE 2010 - FINAL REPORT ry
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.Wg" &,
ACRONYMS AND TERMINOLOGY
ADCED Alaska Department of Community and Economic Development
ADEC Alaska Department of Environmental Conservation
ADFG Alaska Department of Fish and Game
ADNR Alaska Department of Natural Resources
AEA Alaska Energy Authority
AEA / REG Alaska Energy Authority Rural Energy Group
APA Alaska Power Authority (predecessor to AEA)
cfs cubic feet per second
COE U.S. Army Corps of Engineers
CPCN Certificate of Public Convenience and Necessity
ECUC Elfin Cove Utility Commission
Elfin Cove Non -Profit Community of Elfin Cove
Environmental attributes
The term environmental attributes is used by the green power industry to
describe the desirable aspects of electricity that is generated by environmentally
benign and/or renewable sources. Environmental attributes are tracked,
marketed, bought and sold separately from physical energy. Separating the
environmental attributes enables customers of a given utility system to elect to
buy sustainable or 'green' energy even if it is unavailable from their utility.
FERC Federal Energy Regulatory Commission
Flow duration curve
The flow duration curve is a curve that indicates how often a creek flows at or
greater than a given flow rate.
ft foot, feet
FY fiscal year
Hatch Hatch America, Inc.
HDPE high -density polyethylene
JUNE 2010 - FINAL REPORT v
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.Wg" *,
in inch, inches
Jim's Lake A small lake located approximately one mile south of Elfin Cove. Previous
studies refer to this lake as'Jim's Lake', and that name is used in this study. The
local name for the lake is'Elfin Lake'.
kV kilovolt, or 1,000 volts
kVA kilovolt -amp
kW kilowatt, or 1,000 watts. One kW is the power consumed by ten 100-watt
incandescent light bulbs.
kWh kilowatt-hour. The quantity of energy equal to one kilowatt (kW) expended for
one hour.
Mass wasting The geomorphic process by which soil and rock move down slope under the
force of gravity.
mi mile, miles
MW megawatt, or 1,000 kilowatts
NREL National Renewable Energy Laboratory
PCE Power Cost Equalization Program
Penstock A pipeline used to convey water to a hydropower turbine.
Polarconsult Polarconsult Alaska, Inc.
PLC programmable logic controller
RCA Regulatory Commission of Alaska
run -of -river A hydroelectric project that has little or no water storage capacity. The project
diverts the instantaneous flow of a river or creek for electrical generation. When
the river or creek is low, the project produces less electricity.
SWPPP stormwater pollution prevention plan
Tailrace The structure used to carry water away from a hydropower turbine and to the
receiving water body. The tailrace can be a pipe, ditch, flume, or other structure.
USGS U.S. Geological Survey
V volt
JUNE 2010 - FINAL REPORT yr
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.Wg" &,
1.0 INTRODUCTION
The community of Elfin Cove is evaluating hydroelectric projects in order to lower their
electricity costs. Electricity costs have risen in recent years due to increases in the cost of the
diesel fuel that the community uses for electricity generation. Through the use of a renewable
hydroelectric resource, the community will benefit from a reduced dependence on diesel fuel.
Elfin Cove retained Polarconsult Alaska, Inc. (Polarconsult) to conduct a reconnaissance study
of hydroelectric resources that could provide economical electricity to Elfin Cove. This report
presents the findings of previous studies, new field investigations, analysis of potential project
configurations and resource availability, and a review of community power needs.
The initial project focus was on evaluation of a project at Crooked Creek and Jim's Lake.' This
was based on the recommendations of previous studies and the technical attributes of these
resources, specifically the storage and regulation offered by Jim's Lake and superior hydrology
at Crooked Creek. Field investigations in 2009 indicated that Roy's Creek also warranted
consideration, and this report analyzes both the Crooked Creek/Jim's Lake and Roy's Creek
resources. Recommendations are provided to guide future development of a hydroelectric
project to meet Elfin Cove's energy needs.
Polarconsult prepared this report under the June 22, 2009 contract with Elfin Cove. Funding for
this project is a combination of community funds and a grant from the Denali Commission. The
Denali Commission grant is administered by the Alaska Energy Authority (AEA).
1.1 PROJECT EVALUATION PROCESS
Prospective hydroelectric projects were evaluated through an iterative process that began with
review of existing data, previous reports, and new field investigations conducted in 2009.
Project evaluation criteria emphasized maximizing energy generation, technical feasibility, and
economic viability. Those projects that appeared technically feasible and economically
beneficial warrant further investigation. Prospective projects that failed to meet these criteria
have been eliminated through this process.
This process has determined that projects at Roy's Creek, Crooked Creek, and Crooked
Creek/Jim's Lake appear to be technically feasible, are estimated to provide substantial benefits
to Elfin Cove, and have favorable benefit -cost ratios. These projects warrant consideration for
further investigation.
A client review draft of this report was provided to Elfin Cove in March 2010. Elfin Cove met
on May 28, 2010 and voted to pursue the Jim's Lake Option 2C as presented in this study.
Minutes of the community meeting are included in Appendix G. Under its existing contract
with Elfin Cove, Polarconsult will conduct a feasibility study for this project configuration.
' Jim's Lake is a small lake located approximately one mile south of Elfin Cove. Previous studies called
this lake Jim's Lake and that name is used in this study. This lake is also known locally as 'Elfin Lake'.
JUNE 2010 - FINAL REPORT 1
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.Wg" *,
1.2 SUMMARY OF INVESTIGATIONS
Polarconsult's initial review and analysis of hydroelectric resources for Elfin Cove began in May
2009 with collection and review of past studies and other available resource information. This
included analysis of technical documentation on the recent electrical system upgrades, aerial
imagery of the project area, and available environmental and topographic data for the area.
Following review of this information, Polarconsult engineers Joel Groves, PE, and Dan Hertrich,
PE, visited Elfin Cove from July 6 to July 9, 2009 to conduct reconnaissance -level field
investigations of several local hydroelectric resources. Based on past studies and available data,
field investigations during this visit focused on the Crooked Creek/Jim's Lake resource.
Activities during this field trip included:
➢ gathering information on the existing electrical system and load profile;
➢ hiking the power line route from Elfin Cove to the Crooked Creek / Jim's Lake area;
➢ hiking from the tidewater powerhouse site to Jim's Lake;
➢ hiking from Jim s Lake to the Crooked Creek diversion site;
➢ measuring stream flows at the Crooked Creek diversion site and Jim's Lake outlet;
➢ measuring the bathymetry of Jim's Lake; and
➢ surveying the differential elevations between the Crooked Creek diversion site, Jims
Lake, and tidewater powerhouse site.
Mr. Groves later visited Elfin Cove from September 3 to September 5, 2009 to hold a community
meeting and present preliminary reconnaissance -level findings. During this visit, Mr. Groves
measured stream flow at Crooked Creek and Jim's Lake to continue calibration efforts at these
gauging stations. Mr. Groves also measured flow at Roy's Creek to ascertain whether this
resource warranted consideration. The community meeting was held on September 4. Based
on the presentation of Polarconsult's initial findings, the community passed a resolution
supporting the additional investigation of Roy's Creek.
Mr. Groves again visited Elfin Cove from October 7 to October 10, 2009 to upgrade the existing
stream -gauging installations at Crooked Creek and Jim's Lake and to install a stream gauge at
Roy's Creek. Flows were measured at all three sites to calibrate the gauging stations. Mr. Bob
Christensen of Living Systems Design, LLC in Gustavus was hired to assist with gauge
installations.
On December 9, 2009, Mr. Christensen and Ms. Jane Button, the Elfin Cove Utility Commission
(ECUC) manager for this project, visited all three gauging stations to measure flows and
download data.
The results of the 2009 field investigations, analysis of preliminary hydrology data,
reconnaissance level analyses, findings, and recommendations are presented in this report. In
May 2010, the Elfin Cove community met and selected option 2C at Jim's Lake for continued
study.
JUNE 2010 - FINAL REPORT 2
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.Wg" *,
1.3 COMMUNITY BACKGROUND
Elfin Cove is an unincorporated community located on the northern shore of Chichagof Island,
70 air miles west of Juneau and 33 air miles west of Hoonah. It is located at latitude 58' 19.44'
north, longitude 136' 34.33' west, which is approximately 520 air miles southwest of Anchorage.
Figure A-1 in Appendix A shows the location of Elfin Cove and its surroundings. The
community's population fluctuates seasonally. The winter population (September through
May) is 10 to 20, and the summer population (May through September) is approximately 100 to
200. There are several seasonally -operated fishing lodges in Elfin Cove that contribute to the
large increase in summer population.
Elfin Cove is located in a maritime climate, with relatively cool summers and mild winters.
Normal summer temperatures range from the lower 50s to mid 60s, and normal winter
temperatures range from the mid 20s to high 30s. Recorded temperature extremes are -10°F to
+85°F. Total average annual precipitation is 102 inches, with 96 inches of snowfall.
The community is accessible by seaplane or watercraft. Elfin Cove does not have road access or
an airport runway. Scheduled and charter air service is available from Juneau. Marine
transport is available from local operators. Elfin Cove is not currently served by the Alaska
Marine Highway System.
Elfin Cove is located in the Chatham School District, and has a local school/community
building. The community does not currently have enough students to receive state funding for
operating the school. Residents have formed a non-profit association to provide public services
within Elfin Cove, including the water system, a diesel power plant and electric distribution
system, bulk fuel facility, and harbor. There is no landfill or centralized sewer system in the
community. 2
1.4 ELFIN COVE ENERGY PROFILE
1.4.1 Community Energy Infrastructure
1.4.1.1 Electric Utility Organization
Electrical service in Elfin Cove is provided by the ECUC, which is owned by the Non -Profit
Community of Elfin Cove (NPCEC) 3 The ECUC holds Certificate of Public Convenience and
Necessity (CPCN) No. 701, issued by the Regulatory Commission of Alaska (RCA) in 2004,
authorizing it to operate as a public utility providing electrical service in and around Elfin Cove.
2 Compiled from the Alaska Department of Community and Economic Development (ADCED)
Community Profile for Elfin Cove.
3 Elfin Cove does not have a formally -organized local government. The NPCEC provides essential
government services to the community.
JUNE 2010 - FINAL REPORT 3
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
The RCA has exempted the ECUC from regulation other than certification on public interest
grounds as allowed by AS 42.05.711(d).
The ECUC participates in the State of Alaska's Power Cost Equalization (PCE) program, which
subsidizes electricity rates for residential and community facilities served by eligible rural
Alaska utilities.
Elfin Cove's energy infrastructure is relatively new. A new bulk -fuel facility was constructed in
2000, the diesel power plant was replaced in 2007, and the community's electrical distribution
system was upgraded in 2009. The diesel power plant provides waste heat to the adjacent
community building and shop.4
1.4.1.2 Electrical Generation System
ECUC's diesel power plant is located in the heart of the community. The plant has three
generators controlled by four sections of switchgear. The switchgear is fully automatic with
paralleling capability, and uses a programmable logic controller (PLC) to match the generator(s)
to system load. The plant generates three-phase electricity at 480 volts. Installed utility
generation equipment in Elfin Cove is listed in Table 2-1. Several of the lodges own and
maintain separate back-up generators. These private generators are not configured to parallel
with the utility system.
Table 2-1: Existing Utility Generation Equipment
Prime Power Commissioned
No. Equipment Designated Use
(kW) Date
1 John Deere 6081 179 kW 2007 Summer peak
2 John Deere 6068 101 kW 2007 Summer intermediate
3 John Deere 4045 67 kW 2007 Winter load
1.4.1.3 Electrical Distribution System
The ECUC electric distribution system was upgraded in 2009. The system is a 7,200-volt
grounded wye three-phase system without loop feed. Most of the system is run in shallow
burial or surface -laid cable in duct. Distribution along the west side of the cove is overhead on
wooden poles. The 480-volt power plant bus is stepped up to 7,200 volts using a single 225 kVA
pad -mount transformer.
4 Concept Design Report and Construction Cost Estimate for Energy Infrastructure Projects in the Community
of Elfin Cove, Report for the Alaska Energy Authority / Rural Energy Group (AEA/REG), Prepared by
Alaska Energy and Engineering, Inc. February 2006.
JUNE 2010 - FINAL REPORT 4
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.Wg" *,
1.4.2 Existing and Projected Future Electric Load Profile
ECUC electric demand varies significantly by season. Several lodges operate in the community
during the summer (May through September), creating an average load of 60 to 80 kilowatts
(kW) and peak loads up to 240 kW. During the winter (September through May), the lodges are
closed, and many residents leave town. Average wintertime load is 15 to 30 kW, with peak
loads up to 60 kW. The past seven years of load data are presented in Figure 2-1.
Elfin Cove's population has fluctuated in recent years between 10 to 60 full-time residents. The
summer population is consistently much higher due to fishing lodge clientele. Future load
trends are expected to be similar to recent experience. This report assumes no future growth in
ECUC load.
Elfin Cove's annual consumption of diesel fuel for electrical generation was generally uniform
from 2004 through 2008, varying from 30,000 to 33,000 gallons annually. Fuel consumption in
2009 was 14% lower than in earlier years at 26,413 gallons.
Figure 2-1: Recent Elfin Cove Power Generation Data
250
—Peak Monthly Power Demand
— Averaee Monthlv Power Demand
200
50
Jan-03 Jan-04 Jan-05 Jan-06 Jan-07 Jan-08 Jan-09 Jan-10
Potential hydroelectric projects were evaluated using a model of ECUC system loads. Monthly
and annual average and peak ECUC system load data was used to calibrate the 'Alaska Village
Electric Load Calculator', a program developed by the National Renewable Energy Laboratory
(NREL) 5
5 See NREL Technical Report #36824 at www.nret.gov/publications for documentation on this model.
JUNE 2010 — FINAL REPORT
Non -Profit Community of Elfin Cove -
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
Because of the large variance in ECUC's loads between summer and winter, the model was
calibrated to each season separately and these datasets were combined into a single dataset.
The resulting load model provides hourly system demand.
1.4.3 Energy Market
During the summer of 2009, the retail cost of electricity in Elfin Cove was $0.56 per kilowatt-
hour (kWh). PCE subsidies reduce the cost of electricity for residential customers (up to 500
kWh monthly) from $0.20 to 0.30 per kWh. Commercial customers receive no state subsidy, and
pay the full rate.
Fuel is delivered to Elfin Cove by barge. Historical fuel prices, costs, and consumption are
presented in Figure 2-2. Between 2003 and 2007, fuel prices roughly doubled from
approximately $2.00 per gallon to $4.00 per gallon. The cost of fuel in Elfin Cove reached a high
of $5.94 per gallon in the summer of 2008, and has since remained relatively stable at about
$4.00 per gallon.6
By developing the local hydroelectric project(s) considered in this study, Elfin Cove will reduce
its dependence on diesel fuel which is expected to remain expensive and volatilely-priced in the
future. This will strengthen the community's economy and long-term viability.
Figure 2-2: Recent Elfin Cove Fuel Usage and Expenses
-<)— Annual Cost of Fuel
$140,000
Annual Diesel Usage
Monthly Price of Fuel
w
w
° $120,000
y
0
U
$100,000
$80,000
1100
$60,000
v
+w
ro
H
40,000
d
w
X
C 20.000
F.
d Jan-03 Jan-04 Jan-05 Jan-06 Jan-07 Jan-08 Jan-09 Jan-10
6 ECUC system demand and fuel cost data obtained from ECUC reports and PCE program reports.
$6.00
$5.00
v
$4.00 w
0 0
$3.00
a
$2.00
�01
/-r
$1.00
$0.00
JUNE 2010 — FINAL REPORT 6
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.Wg" &,
2.0 PREVIOUS STUDIES
Several previous studies have reviewed a variety of hydroelectric resources for Elfin Cove:
❑ A 1979 regional reconnaissance study completed by CH2M Hill, Inc. for the U.S. Army
Corps of Engineers (COE) reviewed hydroelectric resources in the vicinity of Elfin Cove.
This study identified a 310-kW run -of -river hydroelectric project at Margret Creek, 6.4
miles from Elfin Cove.
❑ A 1984 reconnaissance study of energy alternatives and requirements for Elfin Cove
completed by Hatch America, Inc. (Hatch) for the Alaska Power Authority (APA). This
study considered the hydroelectric resources within Elfin Cove - Roy's Creek, Joe's
Creek and Ernie's Creek - and recommended further investigation of a 20 to 60 kW run -
of -river hydroelectric project at Roy's Creek in Elfin Cove.
❑ A 1984 APA supplement to the Hatch study considered the hydroelectric resources in
Elfin Cove - Roy's Creek, Joe's Creek and Ernie's Creek - to not be feasible and
recommended further investigation of a project about one mile south of Elfin Cove. This
project was an 80-kW hydroelectric project from Jim's Lake to tidewater with a diversion
from Crooked Creek to Jim's Lake.
The following is a summary of projects that have been previously considered for hydro power
development.
2.1 CROOKED CREEK RUN -OF -RIVER PROJECT
The 1984 APA supplemental report mentioned a stand-alone run -of -river hydroelectric project
at Crooked Creek. This alternative did not receive in-depth consideration in 1984 because the
combined Crooked Creek and Jim's Lake resource was considered to have the potential to
provide all of the community's projected electrical needs. By comparison, the Crooked Creek
watershed was judged to have no storage and to lack a suitable dam site to create storage, thus
presenting an inferior energy alternative.
Because Elfin Cove now has a modern diesel power plant, a run -of -river hydro project at
Crooked Creek warrants review and is considered as a part of this reconnaissance study.
2.2 CROOKED CREEK AND JIM'S LAKE DIVERSION AND STORAGE PROJECT
The 1984 APA supplemental report recommended a project at Crooked Creek and Jim's Lake,
approximately one mile south of Elfin Cove.
As conceptualized by APA, this would be a storage project with a 1,650-foot long by 18-inch
diameter diversion pipeline from Crooked Creek to Jim's Lake. A small weir and/or siphon
would be installed at Jim's Lake. A 2,400-foot long by 12-inch diameter penstock would run
from the lake to a powerhouse located at tidewater at 'Small Sandy Beach' (local name). The
project has 330 feet of net head, a design flow of 4.5 cubic feet per second (cfs), and an installed
JUNE 2010 - FINAL REPORT
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
capacity of 80 kW. Electricity was to be transmitted from the powerhouse to Elfin Cove via a
surface -laid 6,700 foot single-phase 7,200 volt cable in flexible duct. The annual energy output
of the project was estimated at 141,000 kWh. APA also estimated that the project could meet all
of the community's electricity needs and eliminate the need for a central diesel power plant.
APA estimated a project capital cost of $400,000 (1984 dollars). This cost estimate assumed use
of local labor and materials, and minimal use of heavy equipment for construction. Materials
would be staged by helicopter or obtained locally and the project would largely be built by
manual labor.
Based on the APA recommendations, the Alaska Department of Natural Resources (ADNR)
installed stream gauges at the proposed Crooked Creek diversion site and Jim's Lake outlet in
1984. Data from these gauges is available from August 1984 through February 1985. More
recently, ECUC installed new stream gauges at these same locations in 2008 and Polarconsult
upgraded these installations in 2009. These stream gauges remain in service.
Analysis of this hydroelectric resource indicates that it is too small to provide all of the
community's current electrical demand, but it does have the potential to significantly reduce the
community's diesel fuel usage, and therefore warrants consideration in this study.
2.3 Roy's CREEK RUN -OF -RIVER PROJECT
The 1984 Hatch reconnaissance study recommended a 20 to 60 kW run -of -river project at Roy's
Creek in Elfin Cove.
As conceptualized by Hatch, this would be a run -of -river project with a penstock running from
a diversion at an elevation of 320 feet to a powerhouse at tidewater. The project would use the
320 feet of head and a design flow of 1 to 3 cfs to generate 20 to 60 kW. Because the powerhouse
would be located within the community, electricity would be fed into the local distribution
system. The project was estimated to reduce the community's diesel fuel demand at a
centralized power plant by 60%.
Hatch estimated the capital cost of a 40-kW project at Roy's Creek to be $200,000 (1984 dollars).
APA's 1984 supplemental report concluded that a project at Roy's Creek was likely not feasible
due to reports that the creek experiences extended periods of low or no flows and frequent
dangerous floods. These findings were based on daily qualitative observations of flows in
Roy's Creek at the footbridge near tidewater.
While the observed flows at the footbridge in Elfin Cove support the conclusions in the 1984
APA study, flows at the elevation where an intake would be located appear more favorable for
a hydroelectric project. On September 3, 2009, Polarconsult measured 1.06 cfs just above the
waterfall at an elevation of 300 to 350 feet. Concurrent flows at the footbridge appeared much
JUNE 2010 - FINAL REPORT 8
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
lower. This measured flow would be sufficient to generate approximately 20 kW of power from
Roy's Creek.
Roy's Creek runs over exposed bedrock in the intake vicinity, and is expected to have very little
subsurface flow. In the vicinity of the footbridge, there is a significant deposit of coarse alluvial
material, and it is likely that much of the creek's flow is subsurface by the time it reaches the
footbridge. This would be most pronounced during low flow periods — such as on September
3ra.
Based on these observations, this study considered development of a run -of -river project on
Roy's Creek. A stream gauge was installed in October 2009 to quantify flows at Roy's Creek
and guide future investigation of this resource.
2.4 JOE'S CREEK & ERNIE'S CREEK RUN -OF -RIVER PROJECTS
The 1984 Hatch reconnaissance study mentions run -of -river hydro projects at Joe's Creek and
Ernie's Creek, but does not provide any detail on the conceptual development of these
resources. The 1984 APA supplemental report dismissed development of these two creeks for
the same reasons it dismissed development at Roy's Creek.
These two creeks are smaller than Roy's Creek, but appear to be technically viable run -of -river
hydro projects. This study considered developing these creeks simultaneously with Roy's
Creek, but found that this approach was not as beneficial as the other hydro projects available
to the community.
2.5 MARGRET CREEK RUN -OF -RIVER PROJECT
The 1979 COE study considered development of a 310-kW run -of -river project at Margret
Creek, at the abandoned site of Port Althorp, about six miles south of Elfin Cove.
As conceptualized by the COE study, the Margret Creek project would be a run -of -river project
with a 2,600-foot long by 18-inch diameter penstock generating 310 kW of power from 270 feet
of net head and a design flow of 16 cfs. Electricity would be transmitted to Elfin Cove via 6.4
miles of submarine cable and 2.0 miles of overland or overhead power line. The estimated
capital cost of this project was $2.0 million (1979 dollars). Estimated annual energy output of
the project is 538,000 kWh.
The high cost of the transmission line alone is expected to result in this project not being
economically viable compared to the other projects. For this reason, this project is not
considered further in this report.
JUNE 2010 - FINAL REPORT 9
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.Wg" &
3.0 ANALYSIS OF PROJECTS
Six hydroelectric project options were identified for further analysis as projects that had the
potential to meet the electrical needs of Elfin Cove. The projects considered are:
Project 1. Crooked Creek (stand-alone run -of -river project)
Project 2a. Crooked Creek and Jim's Lake Option A (diversion of water from Crooked Creek
to Jim's Lake and a siphon intake at Jims Lake for a hydro project between Jim's
Lake and tidewater)
Project 2b. Crooked Creek and Jims Lake Option B (diversion of water from Crooked Creek
to Jim's Lake with a siphon intake and dam at Jims Lake for a hydro project
between Jim's Lake and tidewater)
Project 2c. Crooked Creek and Jim's Lake Option C (A run -of -river hydro project between
Crooked Creek and Jims Lake, and a second hydro project between Jim's Lake
and tidewater)
Project 3. Roy's Creek (stand-alone run -of -river project)
Project 4. Roy's Creek, Joe's Creek, and Ernie's Creek (simultaneous development of run -
of -river projects on all three creeks)
Figure 3-1 presents the estimated average monthly electrical supply each project would provide
for the community. Each of these projects is described in the following sections. The
hydrology, permitting, and environmental data used to arrive at the study conclusions are
presented in the Appendix.
Figure 3-1: Estimated Average Monthly Energy Provided by Hydro Projects
50,000
40,000
a
0
¢ 30,000
v
en
20,000
� I
10,000 F
0
TOTAL SYSTEM DEMAND
-I�L-Option 1 - Crooked Creek ROR
-41- Option 2A - Jim's Lake (no dam)
f Option 2B - Jim's Lake (with dam)
f Option 2C - Jim's Lake (with Crooked Creek Power Recovery)
Option 3 - Roy's Creek ROR
$Option 4 - Roy's, Ernie's & Joe's Creek
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
JUNE 2010 - FINAL REPORT
Month
10
m
r
v
O
O a
O
o
rn
d!
ad_i
d_i
�
O
o
�
�
�
�
i• Y
ti��
s
Cn
o
O N
.o.
.°.•
p
IfI
O
z
��_i
Z
��_i
Z
��_i
z
z
N
N
��_i ��_i
Z z
��_i
Z
Z.
�
Obi
O
w
U o
Z
Z
'r
Z
N z
z
W
Efl
d ^
O
G!
�_Q_
N
`O
o0
IR
0
0
00
L\
Z
Z
'i
Z
Z
z
O
'-i
o
N
N z
z
N
�
N
W
W
O
Efl
In
i ^
O
•�
O
N
Itf
�
i0i N
O
.Yi ^
Xi
O D
e-i
�••i
N
N
O
�
O
O
O
O
T
O
O
rl
O
0p
O
O
di
d+
~
N 'z
z
EA
cm,
o
$
$
M
N$
rn
w
y
�O
ii
N
•
Xi
O
O u1
M
O
O�
O
p
00
y
N
Ol
v
O
O
O
d
C4 � •O
�
N
N Q`
�
O
M
� �
w
L�
w0
oD
O
(M')
N
O
M
N
�.
O
�
.'�i
'O ..i
••>y
fA
U
o
F
N
M
N
M
N
OM
N
N
O 00
M
m
a.6
a Xi
OMO
W
Oi
OD
� �
O d�
..N.•
�
rl
f»
I
ti N
~
v
O
O
M
LnpOp
p
ry
N
O
00
00
O
N
L
m
O
Lo
�
I
0
3
bc
bp
:°
v
V]
v
xev
FA
a
z
u
e.
cc5a+
3
and
u�a�Z
�Aa¢
o
u
E~u
0
W
a.
z
ti
z
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
3.1 COMMON PROJECT CONSIDERATIONS AND DATA
This section summarizes considerations and data common to all of the hydroelectric project
options investigated in this study. Considerations unique to the various projects are discussed
in sections 3.2 through 3.5.
3.1.1 Hydrology
Estimated stream hydrology and conceptual project design flows are based on data from
ADNR's 1984 to 1985 stream -gauging efforts and preliminary data from the current gauging
efforts that began in 2008. The projects considered in this study are the largest developments
considered practical at these sites based upon current information. Future analysis of these
projects may find that larger or smaller projects are superior based on additional hydrology
data and a more refined technical and economic analysis. Hydrology data used to develop the
conceptual project design flows in this study are presented in Appendix C.
3.1.2 Geotechnical and Geomorphological Considerations
The country around Elfin Cove is steep and mountainous, with bedrock often found at or near
the surface. Tectonic activity and recent glaciation have created a steep terrain prone in many
areas to spawning significant mass wasting events. Debris fields from avalanches, alluvial
cones, and mass wasting events are common at the base of cliffs and mountain slopes. Three
noteworthy mass wasting events are apparent in the project area: one in Elfin Cove that
occurred after 1990, one approximately 1/2 mile south of Elfin Cove that occurred after 2002, and
one older event near the conceptual intake site on Crooked Creek? Future project selection and
design will consider risks associated with mass wasting hazards.
At elevations below 600 feet (the area of interest for projects considered in this study), terrain
exhibiting grades of approximately 40% to 100% is typically vegetated with forests dominated
by large conifers. These forests typically grow in shallow soils overlaying weathered and
fractured rock. Terrain with grades less than 40% appears to have thicker soil layers and a
mixed conifer and deciduous forest. Terrain with grades under 30% tends to feature terraced
peat bogs vegetated by grasses and a few trees.
Because of the prevalence of shallow or exposed bedrock, trenching for burial of pipelines or
power cables is expected to be prohibitively costly. Because of Elfin Cove's temperate maritime
climate, partial burial, on -grade, and/or above -grade pipelines are viable options for all of the
hydro projects considered in this study. Similarly, on -grade or shallow burial cables are
practical options for power and communications.
7 Photographs of these mass wasting events are presented in Appendix B. Event locations are
indicated on the project maps in Appendix A.
JUNE 2010 - FINAL REPORT 12
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
3.1.3 Permitting
All of the projects considered in this study would fall under the jurisdiction of the Federal
Energy Regulatory Commission (FERC). With the exception of projects 2b and 2c that would
raise Jim's Lake for storage, the projects considered in this study appear to meet the general
eligibility criteria for exemption from the FERC licensing process. FERC exemption
proceedings can be completed in as little as one year if there are no complex or controversial
permitting issues. Obtaining a FERC license can take from 3 to 5 years at substantial cost.
Permitting considerations are discussed in greater detail in Appendix E.
3.1.4 Environmental Considerations
Field investigations and review of existing available information do not indicate any
environmental conditions that are incompatible with the considered hydro projects. None of
the creeks or lakes is known to be fish habitat, and no fish have been observed or reported in the
course of field work. Environmental considerations are discussed in greater detail in Appendix
D.
3.1.5 Land Status
All of the projects considered in this study are located in the Tongass National Forest. They
would all require utility and access easements across private property within Elfin Cove, and
they all may have powerhouses located on state tidelands which would require tidelands leases.
A project at Roy's Creek would cross state Mental Health Trust lands within USS 2949. Land
ownership is indicated on the maps of each project in Appendix A.
3.2 CROOKED CREEK RUN -OF -RIVER PROJECT
A run -of -river project located on Crooked Creek would be located on U.S. Forest Service land
approximately one mile south of Elfin Cove. This project would divert up to 5 cfs of the
instantaneous flow in Crooked Creek to a tidewater powerhouse at Small Sandy Beach for
energy generation. The project is sized at an installed capacity of 120 kW and is estimated to
reduce Elfin Cove's annual diesel fuel consumption by approximately 79%.
The configuration described here is based on aerial imagery, existing mapping products,
available hydrology data, differential elevation surveys to establish gross head, and field
reconnaissance of the project area on foot and by air. Additional investigations would be
necessary to determine resource hydrology, characterize geotechnical issues, characterize
environmental considerations, and establish specific alignments and locations of project
features. A map of this project is presented in Figure A-2 of Appendix A.
There are technical concerns with the preferred intake site at Crooked Creek. Other aspects of
this project appear technically straightforward. Construction methods would have a significant
impact on the cost of this project. Conventional construction methods utilizing heavy
JUNE 2010 - FINAL REPORT 13
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
equipment and building access roads or trails to project sites may make this project
uneconomical. The use of helicopters for material staging and manual labor for the
construction, as suggested by APA in the 1984 supplemental study, appears to be a viable
approach for this project. The following provides a detailed discussion of the project features.
3.2.1 Intake
The existing stream -gauging station appears to be the best location along Crooked Creek for an
intake structure. This intake site is in a steep -walled valley less than 100 yards wide. The valley
is oriented on a southeast -northwest axis, with the creek flowing along the southerly side of the
valley to the northwest. The valley floor appears to be a combination of mass wasting debris,
large woody debris, and stream -borne deposits. Bedrock is not visible along the valley floor.
The gauging station and proposed intake site is shown in Photographs B-2 through B-4 in
Appendix B.
The creek flows through a debris field consisting of large boulders. This debris field
complicates access and penstock construction for an intake at this location. Crooked Creek
flows at a shallow gradient of 2 to 5% in this reach. Below the gauging station, the creek
descends at grades of 15 to 40%. Siting the intake downstream would sacrifice head and reduce
the generation capacity of the project.
Three factors at the preferred intake site on Crooked Creek are cause for concern.
1. Cliffs above the intake site appear capable of significant mass wasting events. Large
boulders at the intake site and the debris field upstream of the intake site appear to be
from past mass wasting events originating from these cliffs. A mass wasting event
impacting the intake site could render the intake inoperable and very costly to repair.
2. The valley floor to the north of the intake site is approximately 5 to 10 feet lower than
the floor where the creek is currently located. Although remnants of the 1980s stream -
gauging hardware at the current gauging station/intake site suggest that this reach of the
creek has been relatively stable for at least 25 years, a major flood could shift the creek to
the north side of the valley, stranding the intake. A larger intake or diversion structure
could be built to prevent the creek from shifting course at this location, but that would
increase project costs above the estimates provided in this study.
3. The materials composing the valley floor at the intake site may render collecting water
from Crooked Creek difficult. The apparent jumble of woody debris, sand, gravel,
cobbles, and large boulders may have a high permeability, allowing water to flow
beneath a small impoundment structure. Preventing this subsurface flow is often
difficult and would increase project costs beyond the estimates provided in this study.
The intake structure would use a screen or grate to keep harmful debris present in the creek
from entering the penstock and damaging the turbine. Keeping these screens or grates clear
could be accomplished by automated machinery or by manual labor. Cost estimates assume
automated equipment to keep the intake clear of debris. Power and controls would be run in
JUNE 2010 - FINAL REPORT 14
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
duct parallel to the penstock from the powerhouse to the intake to run and control this
apparatus.
3.2.2 Penstock
A specific penstock route has not been determined for this project. The terrain that the penstock
would cross does not appear to present any unusual concerns for design or construction.
Future investigation of this project would further consider construction methods and materials,
as these will significantly impact project costs. The methods described in APA's 1984
supplemental study, using high -density polyethylene (HDPE) pipe, relying heavily on manual
labor, and using minimal heavy equipment, appear feasible for penstock construction.
3.2.3 Powerhouse
A specific powerhouse site has not been selected for this project, but the powerhouse would
generally be located at Small Sandy Beach. Small Sandy Beach is a cobble and gravel beach
with an approximate grade of 15%. There is a bedrock outcrop near the low tide line, and
stepped rock cliffs rising about 100 feet starting about 50 feet inland from the head of the beach.
The powerhouse could be located on piling in the intertidal zone or built on grade above the
high water line. It would house a 120 kW turbine and generator, switchgear, controls, and
associated equipment. After passing through the turbine, water would flow down the beach
and into the waters of Port Althorp.
3.2.4 Power Line
A specific power line route has not been determined for this project. The terrain that the power
line would cross does not appear to present any unusual concerns for design or construction.
An overhead line would be subject to hazards from falling trees and limbs, which would
increase maintenance costs and reduce reliability. A conventional buried cable is not
considered cost effective due to the presence of shallow bedrock throughout in the project area.
A surface laid or shallow -burial cable in duct, as proposed in APA's 1984 supplemental study,
appears to be a favorable approach and is used to develop the cost estimates in this study.
Further investigation of this project would consider construction methods and materials, as
these would have a significant impact on project costs.
JUNE 2010 - FINAL REPORT 15
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
3.3 CROOKED CREEK AND JIM's LAKE DIVERSION AND STORAGE PROJECT
A project that diverts water from Crooked Creek into Jim's Lake and then develops the
hydroelectric potential between Jims Lake and tidewater at Small Sandy Beach was considered
in the 1984 APA supplemental study.
The major differences between the run -of -river Crooked Creek project described in Section 3.2
and the combined Crooked Creek and Jim's Lake project (hereinafter referred to as the 'Jim's
Lake' project(s)) are:
➢ A Jims Lake project sacrifices approximately 140 feet of head between Crooked Creek
and Jim's Lake. This is about 30% of the energy potential between the Crooked Creek
diversion site and tidewater. Jim's Lake Option C (described below) would recover this
energy with a second powerhouse at Jims Lake.
➢ A Jim's Lake project picks up an estimated additional 0.7 cfs of flow from the Jim's Lake
drainage. This is estimated to be about 15 to 30% of the available average flow at
Crooked Creek. This additional flow partially offsets the lost head between Jim's Lake
and Crooked Creek.
➢ A Jim's Lake project is able to use Jim's Lake to store water and regulate power
generation. This allows a Jim's Lake project to follow ECUC's loads, saving water so the
project can provide more energy during droughts or cold spells than a comparable run -
of -river project could. The approximate length of time that a Jim's Lake project could
supply ECUC loads under drought conditions is presented in Table 3-2.
Table 3-2: Effect of Jim's Lake Storage on Hydroelectric Generation
Parameter (Estimates) Typical Summer Typical Winter
Conditions Conditions
Average ECUC System Load 80 kW 30 kW
Project Flow 4.4 cfs 1.7 cfs
Inflow to Reservoir
0.6 cfs 0.6 cfs
(Drought Conditions)
Reservoir Drawdown 3.8 cfs 1.1 cfs
7.6 ac-ft per day 2.1 ac-ft per day
Days of Hydro Operation with Small Reservoir
4 15
(32 ac ft of storage using only siphon)
Days of Hydro Operation with Large Reservoir
12 45
(95 ac ft using siphon and a dam)
Three project configurations for this resource are considered in this study.
Option A: The project originally envisioned by APA, with a diversion from Crooked Creek
to Jim's Lake and a hydro plant between Jim's Lake and tidewater. A siphon is
used to access storage in the lake. This option is described in Section 3.3.1.
JUNE 2010 - FINAL REPORT 16
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
Option B: The same as Option A, but with a 12-foot tall dam at the Jim's Lake outlet to
maximize the lake's storage potential. The key differences between Option A
and Option B are detailed in Section 3.3.2
Option C: The same as Option B, but with a second powerhouse at the bottom of the
Crooked Creek pipeline to recover the energy otherwise lost along this diversion.
The key differences between Options B and Option C are detailed in Section 3.3.3
Attributes of these three project options are summarized in Table 3-1 on page 11.
3.3.1 Crooked Creek and Jim's Lake Option A (Non -Power Diversion and Lake Siphon)
In 1984, APA considered a project that diverts Crooked Creek flows into Jim's Lake and uses a
siphon intake for a hydro project between Jim's Lake and tidewater. This same project
configuration is considered here as 'Option A'. The Option A project is sized at 150 kW and is
estimated to reduce Elfin Cove's annual diesel fuel consumption by approximately 89%. The
conceptual project layout for Option A is shown in Figure A-3 in Appendix A.
3.3.1.1 Crooked Creek Diversion
The Crooked Creek diversion would be located at an elevation of approximately 480 feet. The
diversion would be at the same location as the intake for the Crooked Creek run -of -river project
discussed in Section 3.2.1. The technical concerns regarding this site discussed in 3.2.1 also
apply to the diversion structure for this project and for all three of the Jim's Lake project
options.
Unlike the intake structure described in Section 3.2.1, this diversion structure would only need a
coarse grate to keep large debris out of the pipeline. This grate could be cleaned manually as
necessary.
3.3.1.2 Diversion Pipeline
The diversion would direct up to seven cfs from Crooked Creek into a 10-inch pipeline
approximately 800 to 1,400 feet long. A specific route has not been identified for this pipeline.
The shorter pipeline option would discharge water into a peat bog approximately 600 feet from
the lake, allowing the water to follow a natural low -gradient course into the lake (see
Photograph B-5). The terrain that this pipeline would cross does not appear to present any
unusual concerns for design or construction. Future investigation of this project would further
consider construction methods and materials, as these would have a significant impact on
project costs. The methods described in APA's 1984 supplemental study — using HDPE pipe,
relying heavily on manual labor, and using minimal heavy equipment — appears feasible for
diversion pipeline construction.
JUNE 2010 - FINAL REPORT 17
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
3.3.1.3 Jim's Lake Intake and Penstock
A siphon would be placed into Jim's Lake allowing the project to draw the lake down eight feet
below its natural level of 338 feet. This would provide approximately 32 acre-feet of storage.
The siphon would extend approximately 300 feet into the lake from the outlet to reach the
required depth.
Water from the Jim's Lake siphon would enter a 2,000 foot long 16-inch diameter penstock sized
to handle up to nine cfs of water. A specific route has not been identified for this penstock. The
size of this penstock would make construction using manual labor and hand tools challenging.
The penstock would end at a powerhouse located at tidewater at Small Sandy Beach. Power
and controls would be installed adjacent to the penstock from the powerhouse up to the intake
siphon at Jim's Lake.
3.3.1.4 Powerhouse
The powerhouse for this project option would be similar to the powerhouse for the run -of -river
Crooked Creek project as described in Section 3.2.3. It would house a 150 kW turbine and
generator, switchgear, controls, and associated equipment.
3.3.1.5 Power Line
The power line back to Elfin Cove would be similar to the power line described for the run -of -
river Crooked Creek project in Section 3.2.4.
3.3.1.6 Access Trails
This project would require approximately 8,200 feet of access trails for construction and
operations. Specific access routes have not been identified. The size and type of trails necessary
would depend on the design and construction methods used to build the project.
3.3.2 Crooked Creek and Jim's Lake Option B (Option A with 12-foot Tall Dam)
This option is identical to Option A, only with the addition of an approximately 12-foot tall dam
at the outlet of Jim's Lake to maximize the lake's storage capacity. Based on the topography
around Jim's Lake, an approximately 12-foot tall dam is the maximum dam height that is
considered practical. This dam would increase the available storage in Jims Lake from
approximately 32 to 95 acre-feet, and would also increase the maximum lake level to 350 feet
and the maximum project head to 330 feet. Figure A-3 in Appendix A shows the layout of the
Jim's Lake Option B project. Photographs B-6 and B-7 show Jim's Lake and the gauging station
at the lake outlet.
Aside from the addition of the dam and possible trail upgrades needed to construct the dam,
the infrastructure required for this project is identical to that for Option A.
JUNE 2010 - FINAL REPORT 18
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
Increasing the amount of available storage in Jims Lake is estimated to further decrease the
average annual ECUC diesel fuel consumption by another 3% from the Option A project
configuration, for a total estimated reduction of 92% from existing conditions.
In a typical year, the 32 ac-ft of storage available with just a siphon at Jim's Lake appears
sufficient to meet nearly all of ECUC's electrical demand during the winter months. During
long dry spells during the summer months, the 32 ac-ft of storage at Jims Lake would be
drained over the course of a few weeks. Once drained, ECUC would operate its diesel
generators in parallel with or instead of the hydro project. Maximizing the storage volume of
Jim's Lake with a dam would delay starting the diesels for another few weeks. This increased
delay in running the diesels during summer dry spells is the typical annual benefit of
maximizing the storage at Jim's Lake under project Option B.
3.3.3 Crooked Creek and Jim's Lake Option C (Option B with Power Recovery)
This option is identical to Option B as discussed in Section 3.3.2, only with the addition of a
second powerhouse to recover energy from the Crooked Creek diversion pipeline. This'upper'
powerhouse would be located adjacent to the Jim's Lake reservoir shoreline and would operate
as a low -head run -of -river hydro project. The additional energy generated from this upper
powerhouse would reduce the volume of water that had to be released from Jims Lake to meet
ECUC system demand. This would increase the ability of the Jim's Lake reservoir to span
summer -time droughts without needing to run the diesel generators.
The addition of this second powerhouse is estimated to further decrease the average annual
ECUC diesel fuel consumption by another 5% from the Option B project configuration, for a
total estimated reduction of 97% from existing conditions.
The configuration of the Jim's Lake Option C project is shown on Figure A-4 in Appendix A.
This project would be identical to Option B with modifications as described below.
3.3.3.1 Crooked Creek Diversion
An intake structure at Crooked Creek would be similar to the structure described for the run -of -
river Crooked Creek project described in Section 3.2.1.
3.3.3.2 Diversion Pipeline
The diameter of the diversion pipeline would be increased to approximately 14 inches to
minimize friction losses in the pipeline.
3.3.3.3 Powerhouse
The second powerhouse would be located near the northerly shoreline of the raised lake at an
elevation of approximately 355 feet. This upper powerhouse would house an approximately 50
kW turbine and generator, switchgear, controls and associated equipment. After passing
through the turbine, water would discharge into the Jim's Lake reservoir or onto its shores
depending on the reservoir level.
JUNE 2010 - FINAL REPORT 19
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
3.3.3.4 Power Line
A power line would be installed connecting the upper powerhouse to the power line between
Elfin Cove and the 'lower' powerhouse at tidewater. Communications would also be extended
to the upper powerhouse. Power and controls would be run in conduit from the upper
powerhouse at Jim's Lake to the Crooked Creek intake.
3.3.3.5 Access
An additional access trail would be extended to the upper powerhouse site.
JUNE 2010 - FINAL REPORT 20
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
3.4 Roy's CREEK RUN -OF -RIVER PROJECT
A run -of -river project on Roy's Creek would be located on U.S. Forest Service land east of Elfin
Cove, with a powerhouse located within Elfin Cove. The configuration described here is based
on aerial imagery, existing mapping products, estimated elevations of gross head, and field
reconnaissance of the project area on foot. Additional investigations would be necessary to
establish resource hydrology and gross head, characterize environmental considerations, and
specify alignments and locations of project features. As envisioned here, this project would
divert up to 4 cfs of the instantaneous flow in Roy's Creek to a tidewater powerhouse in Elfin
Cove for energy generation. The project is sized at 100 kW and is estimated to reduce Elfin
Cove's annual diesel fuel consumption by approximately 62%. This project is shown in Figure
A-5 in Appendix A.
All aspects of this project appear technically viable. Conventional construction methods
utilizing heavy equipment are not feasible on this project due to the steep slopes present.
Construction could use helicopters for material staging at the intake and manual labor for most
construction activities. The detailed project features are as follows.
3.4.1 Intake
An intake at Roy's Creek would be located below the confluence of two major tributaries and
above the large falls on Roy's Creek at an elevation of approximately 350 to 450 feet above sea
level. The creek in this reach flows in a shallow valley approximately 20 to 50 feet deep and
oriented roughly east -west. The creek bed along this reach varies from exposed bedrock to
cobbles to very large boulders, and flows along a gradient of approximately 10 to 25%. (See
Photographs B-11 through B-13 in Appendix B). The north side of this valley is steeper than the
south side, and rises several hundred feet above the creek to a mountain ridge. This side of the
valley is generally vegetated by mature old -growth conifer forest growing directly upon thin
mineral soils and broken rock. The south side of this valley is less steep and appears to have a
thicker soil and organic layer. The terrain within a few hundred feet of the creek valley is
vegetated by a mixed conifer and deciduous forest, alpine meadows, and peat bogs.
Previous studies described flood events at Roy's Creek that can mobilize large boulders.
Observations along the creek support this conclusion. The creek is well -incised along the intake
reach, and floods have scoured vegetation and soil from the valley sides to a height of five to 10
feet above the creek bed. Boulders two to four feet across are common in this reach of the creek,
and these are likely to move downstream during major floods. The lower reach of Roy's Creek,
between about 30 and 100 feet above sea level, is choked with boulders of this size.
An intake on Roy's Creek would likely be constructed directly on bedrock, and would need to
be designed to withstand the flood events and bed load evident at Roy's Creek. This is possible
using a helicopter to stage light equipment and material at the intake site.
JUNE 2010 - FINAL REPORT 21
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
3.4.2 Penstock
A specific penstock route has not been determined for this project. The terrain that the penstock
would cross does not allow for construction of a road or the use of heavy equipment for access
or construction. The penstock for this project could be partially buried, laid on the ground, or
built above grade on supports. A gravity penstock installed along the south side of Roy's Creek
could likely exit the creek's flood hazard zone within 100 feet of the intake. Once out of the
creek valley, the intake would descend at a 10 to 25% grade for several hundred feet. At an
elevation of about 300 feet, the penstock would begin a steep descent to tidewater at grades of
80 to 100%.
3.4.3 Powerhouse
The powerhouse for this project would be located at tidewater in Elfin Cove. It could be
located on piling in the inter -tidal zone or built on grade above the high water line. A specific
powerhouse site has not been selected for this project, and would be located based on the
penstock route and land availability.
3.5 SIMULTANEOUS DEVELOPMENT OF Roy's, ERNIE'S AND JOE'S CREEK PROJECTS
The hydroelectric resources at Ernie's Creek and Joe's Creek were presented in the two 1984
reconnaissance reports, but neither report discussed these resources or their development
potential in detail. Both creeks are similar to Roy's Creek, only they have smaller drainages and
are therefore expected to have lower flows. Projects on these creeks are expected to be generally
similar to the project at Roy's Creek as described in Section 3.4, adjusted for lower design flows.
The locations and configurations of the Ernie's and Joe's Creek projects are shown on Figure A-
5 in Appendix A.
Because of their smaller size, these projects are expected to have higher unit costs relative to
Roy's Creek. To reduce these costs, simultaneous development of all three creeks was
considered. This would allow the three projects to share certain costs such as resource and
technical studies, permitting, mobilization, and construction costs. The parameters of these
three projects are summarized in Table 3-1.
The combined development of these creeks is only estimated to displace approximately 7%
more diesel fuel than development of Roy's Creek alone. This is due to the fact that all three of
these projects are expected to have very similar hydrology, and will tend to experience the same
drought and flood timing. Most of the energy from Ernie's Creek and Joe's Creek is available at
times when Roy's Creek is already serving the entire ECUC system load, hence they displace
relatively little additional diesel fuel.
This combined project configuration does provide a significant amount of excess energy, and
may warrant further consideration if Elfin Cove develops a market for this energy on an
interruptible service basis or if the community's base load increases significantly. This project
configuration does not warrant further consideration for reducing ECUC's current reliance on
diesel fuel for electricity generation, which is the primary focus of this reconnaissance study.
JUNE 2010 - FINAL REPORT 22
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
4.0 ECONOMIC ANALYSIS
A comparative analysis of the project alternatives considered in this study was made against
projected diesel generation costs. The analysis considered the differential costs and savings
associated with each hydro project compared to continued sole reliance on diesel for electrical
generation.
The analysis annualized capital costs on an assumed 100% debt basis, and considered annual
costs for repair, operation, and maintenance of the hydro project(s) and savings from reduced
fuel costs and diesel operations and maintenance costs. Costs such as ECUC's general and
administrative costs were held constant.
Based on this comparison, the Crooked Creek project, Jim's Lake projects, and Roy's Creek
project all appear cost effective. Simultaneous development of Roy's Creek, Ernie's Creek and
Joe's Creek does not appear to be cost effective. There is insufficient information presently
available to determine which of the favorable projects is best for the community to pursue.
Key assumptions used to conduct this analysis are detailed below in Table 4-1. These
assumptions are discussed in greater detail in Appendix F. Economic summaries for the
projects are presented in Table 4-2. Table 4-2 presents estimated electricity rates for both debt -
financed and grant -financed projects. The figures in Table 4-2 have not been adjusted to reflect
PCE subsidy of electric rates.
Table 4-1: Assumptions Used for Economic Analysis of Hydro Projects
Parameter
Value
Annual ECUC Electric Generation
351,000 kWh
ECUC Fuel Efficiency
12.5 kWh generated per gallon
Annual ECUC Fuel Usage for Electricity Generation
28,100 gallons
Per Gallon Fuel Cost to ECUC (annual cost)
$4.00 per gallon (2010 dollars)
Total Annual ECUC Fuel Costs
$112,400 (2010 dollars)
Load Projections
Flat growth for all analyses
Project Financing
Percent of Project Financed with Debt
100%
Debt term
30 years
Debt rate
Real discount rate
5%
3%
JUNE 2010 - FINAL REPORT
23
c
O
a
ME
m m
O
o
p
o
o
O
p
o
0 0
CD
V
v cn
M
N
O
O
o
G
O
N
i
p
Lr
O
.N
n
vi
O
U)
O O
EA
N
fA
O '�
r
ER
EALO
U)-
`p
EA
fA
fA
U w
O
Lf)
N
C-I
O
O
Oi
O
N
O
O
o
CDCDery-I
Om
ti
CDO
O
O
C)
S
��-'�
0 3
0
.v
4�
rn O
I
O
d3
I
N
CD
O
�
�
N
�
�
O
M
v
�
�
.�
fAl
�
S
o
U
O
O
Om
°
a,
o
c
o
S
'd�
a4
O
O
p
ti
°O 4
0 3
� 4
0 3
�
S
�
.0�
S
S
S
00ON
O CO 3
�
�
it?
�
�
N
O1
V
O
N
°°
cn
�
Cif)
it? Q1
14
r"! v
o
el
�
�CD
V
O
r
�
�
a
\�
O
P�
O
l�
N
GO
CD
O
S
O
0
ON
eqL�
OI
c
OI
O
d�
O
o
O�
0
NCD
O
O
p
m
01
N
V)
C
U
O o
ci
ull
EA
N
O
O
U
Q
O
o
ON
p
N
r
N
Mr
SS
N�SO
co
r
M
G:
,141
�1
Q
r-I
A
O
N
A
41
6
u
O
�
z"' 9
O
�O
O
O
O
�''�
Q
O
O
[7
�2'"
Oj
Oj
M
ti
CD
CO
O
o
O�
M
O
O
✓
✓
.O
1y O
I
di
p
-
1.
N
n
N
Go
N
O
�
O
L'i
N
N�
Vi
p
p
c
C�
U
�
N
N
rye
W
0
o
m
`�
p
6A
b��o
v
d
r.
cu
o
o
0
0
o
v
U
~
p0
W
o
v
p
O
w
I
I
+�
c
�✓
�t
u
5
o
w
p
o
w
bop
o
�
v
U
w
3
tv
w d
.'
M
w
v
*'
u
u
O
O
(D w
u
v
a
*�
UI
O
Q>
M
-a
41
++
-o
41
fC
m
V
C>
d
M O
m y
w
w
v������
� N
zz
N
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
5.0 CONCLUSIONS AND RECOMMENDATIONS
5.1 REMAINING TECHNICAL CONSIDERATIONS
Major remaining technical considerations are summarized below. These items should be
addressed in a feasibility study of the hydroelectric resource selected by Elfin Cove for
continued investigation.
5.1.1 Hydrology
Collection of hydrology data necessary to complete feasibility analysis of these hydro power
resources is in progress. Measurements to determine the stage -discharge curves at the three
installed gauges need to be continued and a longer period of record collected and analyzed.
This process is already in progress.
5.1.2 Installed Capacity
This reconnaissance study considered projects at each of the hydroelectric resources that fully
utilize the estimated resource potential at each site, thereby providing the greatest benefits for
Elfin Cove. Once the hydrology study is completed, the optimal installed capacity of each
resource should be reevaluated in the feasibility study. This will be influenced by:
➢ Community demand. A higher capacity hydro project is justified only if the community
can pay for and use all or most of the energy the project produces.
➢ Resource availability. This will be determined by the hydrology study.
➢ Project cost. Many costs associated with a small hydro project are independent of
installed capacity. As a result, project capacity can often be increased with a
comparatively modest increase in construction or maintenance costs.
5.1.3 Existing Electric System Constraints
Based on available information, ECUC's existing electric generation and distribution systems
are generally adequate to interface with a hydroelectric project. Controls at the diesel power
plant would need to be modified to allow paralleling and backup capabilities with the hydro.
Depending on the final size and characteristics of the preferred hydro project, different diesel
gen-sets may be more efficient than the current gen-sets for paralleling with the hydro.
5.1.4 Financing
The basic financing options include grants, capital financing, and debt financing.
➢ There are a variety of federal and state grant programs that could provide complete or
partial funding for project construction.
JUNE 2010 - FINAL REPORT 25
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
➢ Capital financing would be possible if ECUC has the funds necessary to build the project
out-of-pocket. If ECUC did have construction funds, it would likely require a return on
its investment, which would affect the revenue structure and electric rates for the utility.
➢ Debt financing could be achieved through either private sector or public sector
financing. There are state or federal financing programs such as the state's Power
Project Fund that could be used for project financing. Some of these programs offer
below -market interest rates. There are also government loan guarantee programs that
can help reduce the interest rates for debt financing.
5.1.5 Geotechnical / Topographic Considerations
A topographic and geotechnical site survey is necessary to determine the specific intake
location, penstock alignment, powerhouse site, and access route for the hydro project.
5.1.6 Permits
All of the projects considered in this study are located on federal lands, and will require FERC
licensing or FERC exemptions.
There may be other unknown permitting issues - such as the presence of significant
archeological resources in the project footprint - that would affect project feasibility. Resource
agencies should be consulted in the feasibility phase in an effort to identify any such issues.
5.1.7 Feasibility Study
Once the additional data described above is collected, a more detailed study of project
feasibility is necessary. The feasibility study would focus on technical, permitting, and
economic issues to confirm project feasibility and identify which of the projects considered in
this study should be advanced.
JUNE 2010 - FINAL REPORT 26
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc. M, W-.'
5.2 CONCLUSIONS
This reconnaissance study has identified hydroelectric resources at Crooked Creek, Jim's Lake,
Roy's Creek, and the smaller creeks within Elfin Cove as which development appears
technically feasible. Development of the larger resources at Crooked Creek, Jim's Lake, or Roy's
Creek offers the potential to supply a significant portion of Elfin Cove's electrical demand.
Development of the smaller resources within Elfin Cove - Joe's Creek and Ernie's Creek -
appears technically viable, but does not warrant further study at this time because of their
relatively high cost and modest benefits to the community.
Projects at Crooked Creek, Jim's Lake and Roy's Creek warrant continued investigation because
they offer the greatest potential benefits to the community and have favorable estimated
benefit -cost ratios. The Elfin Cove community met in May 2010 and decided to focus on
developing a project at Jim's Lake and Crooked Creek (Option 2C as presented in this study).
Based on the community's review of this report and feedback on the findings in this report, the
next step in the journey towards a community hydroelectric project is to complete a feasibility
study. The feasibility study will include review of technical, environmental, regulatory, and
cost considerations to assess the feasibility of the selected project. Design and permitting of the
selected project can then begin after the favorable completion of the feasibility study.
5.3 DEVELOPMENT PLAN & SCHEDULE
The major steps to advance the hydroelectric project are:
1. Continued maintenance of existing stream gauges at Crooked Creek and Jim's Lake;
2. Collection of additional field data;
3. Consultation with resource agencies on key permits required for the projects;
4. Completion of a feasibility study of the projects;
5. Application for permits required for the preferred project - completion of permitting
process;
6. Completion of engineering designs;
7. The securing of construction funding; and
8. Construction.
Based on current information and assuming no complex resource issues emerge, any of the
favorable hydroelectric projects can be ready for construction in 2013. A project schedule is
presented in Figure 5-1.
JUNE 2010 - FINAL REPORT 27
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
Figure 5-1: Project Development Schedule
2009
1 2010
2011
2012
2013
Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4
Q1 Q2 Q3 Q4
ACTIVITY
Feasibility Study Activities
Hydrology
Add'l Field Investigations
Agency Consultations
Feasibility Study and Report
Permitting
FERC Licensing
Resource Studies
License Issuance
Project Design
Conceptual Design
100% Design
Construction Plan
Arrange Financing
Construction
Post Construction Activities
As -Built Survey
Finalize Property Documents
JUNE 2010 — FINAL REPORT 28
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
APPENDIX A - MAPS AND FIGURES
JUNE 2010- FINAL REPORT
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
Figure A-1: Project Overview and Location Map
STATE INDEX MAP LOCATION MAP
0 25 50
a xsa soa ELFIN
BARROW JUNEAU ""
�� a COVE
z L.' � �9
FNRBANKS .�; Ilooral3
ANCHORAGE ro� PELICAN IENAKEL. �
�c SP RING
JUNEAU r pP�C;uC?N
,. SEE � -4�'f,� FAKE
LOCATION
�r MAP SITKA
PROJECT VICINITY MAP
SokPA
r FEET
r co
Ll
r J�
CREEK <; f
` Nit
+rig a1 4F �' 4 � I�TM1ti�
CREEK
CREEK
Gd CROCK D
.0 EEK i♦ ��
i JIMS.
LAKE
D AINAGE BASIN
<B UNDARY (TYP.)
�iPhr>rp Nk v., - 1
JUNE 2010 — FINAL REPORT A-1
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
Hizure A-2: Crooked Creek Run -of -River Proiect Map
RECENT SLIDE 0 1/8 1/4
ROY'S CREEK MILES
&INTAKE LOCATION
POWERHOUSE LOCATION
��1•1 �'jr
` 1'.:;,�.� PENSTOCK ROUTE
CREEK
Ad
JOE'S CREEK` ACCESS / POWER LINE
O It �P- ' NOTES:
..� . t .,.
1. DRAWING IS FOR PLANNING
PURPOSES ONLY. ALL FEATURES
ARE APPROXIMATE.
it
r AERIAL IMAGERY DATED AUGUST 11,
1990. OBTAINED FROM ELFIN COVE
FILES, COLLECTED BY USFS.
[`'n "�
r �
F� uj Lj
LO fD
POWER LINE AND
ACCESS ROUTE
TIDEWATER
POWERHOUSE SITE
EL: 20
LL SMASANDY BEACH
— SECTION 7
•ru 3
RECENT SLIDE
ONFELr480'
PENSTOCK
POWER / CONTROLS
S LAKE
JUNE 2010 — FINAL REPORT A-2
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
Figure A-3: Crooked Creek-Jim's Lake Options A and B Project Map
MILES
INTAKE/DIVERSION LOCATION
CREEK :ii
��� ,•1` t�ti►' t 0 POWERHOUSE LOCATION
PENSTOCK ROUTE
,t
CREEK
ACCESS / POWER LINE
;> • w NOTES:
-.� 1. DRAWING IS FOR PLANNING
PURPOSES ONLY. ALL FEATURES
2. T ARE APPROXIMATE.
o, o
AERIAL IMAGERY DATED AUGUST 11,
v�i •' LJ
1990. OBTAINED FROM ELFIN COVE
"' ti t► FILES. COLLECTED BY USFS.
Ln
POWER LINE AND��
ACCESS ROUTE
RECENT SLIDE '
I' a' •�.�
IN
CROOKED CREEK -
DIVERSION SITE 4
CROOKED CREEK EL: 480'
TIDEWATER
POWERHOUSE SITE..
SMALL SANDY BEACH '
T42S --SECTION 36
T43S — SECTION 7 POWER AND CONTROLS
� j PENSTOCK
ti..
SIPHON DAM SITE
M
_a,
DIVERSION
PIPELINE
OVERLAND
FLOW
JIM'S LAKE
EL: 350'
JIM'S LAKE
EL: 338'
JIM'S LAKE
JUNE 2010 — FINAL REPORT
A-3
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
Figure A-4: Crooked Creek-Jim's Lake Option C Project Map
0 1 /8 11'4
& INTAKE/DIVERSION LOCATION
JOE S CREEK
POWERHOUSE LOCATION
5
PENSTOCK ROUTE
GREEK
ACCESS / POWER LINE
NOTES:
1. DRAWING IS FOR PLANNING
.• = PURPOSES ONLY, ALL FEATURES
Z`bz ARE APPROXIMATE.
o. 0 1
w; AERIAL IMAGERY DATED AUGUST 11,
1990. OBTAINED FROM ELFIN COVE
FILES COLLECTED BY USFS
POWER LINE AND
ACCESS ROUTE
CROOKED
CREEK
)EWATER \ LOWER
POWERHOUSE SITE
SMALL SANDY BEACH
- SECTION
LO
RECENT SLIDE
' CROOKED CREEK
INTAKE SITE 5--s
EL: 480� .�,.r,
LOWER PENSTOCK
UPPER
PENSTOCK_,
UPPER
POWERHOUSE
EL: 355'
OVERLAND
FLOW
JIM'S LAKE
MAX EL: 350'
JIM'S LAKE
Ulki CI . -4-4n'
JUNE 2010 - FINAL REPORT A4
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
Figure A-5: Roy's Creek, Joe's Creek, and Ernie's Creek Project Map
;J.'! ,',.
ERNIE'S'
CREEK
EXISTING DIESEL
POWERHOUSE
0 500 1000
FEET
4& INTAKE LOCATION
0 POWERHOUSE LOCATION
PENSTOCK ROUTE
(AND POWER/CONTROLS)
CREEK
STATE OF AK MENTAL HEALT
TRUST LAND
NOTES:
1. DRAWING IS LOCATED WITHIN
T42S, R55E, COPPER RIVER MER.
2. DRAWING IS FOR PLANNING
PURPOSES ONLY. ALL FEATURES
ARE APPROXIMATE.
' ZW P� :. fir•► f +� •
i i RECENT f ''
•f•t
SLIDE ,
i4x"
SECTION�35' ��� ROY'S
GREEK
+#...#; SECTION 36 i r ¢ INTAKE
-
17
♦:
v ? s {
• � f,
ROY'S CREEK
PENSTOCK/ ACCESS
ROY'S CREEK e*
POWERHOUSE,
AERIAL IMAGERY BY AERO-METRIC, INC
DATED SEPT. 4, 2002.
{-.
JUNE 2010- FINAL REPORT A-5
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
APPENDIX B - PICTURES
JUNE 2010- FINAL REPORT
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
Photograph B-1: Aerial View of Small Sandy Beach, Jim's Lake, and Crooked Creek
Aerial view of the Crooked Creek and Jim's Lake project area.
July 6, 2009. Polarconsult.
JUNE 2010 - FINAL REPORT B-1
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
Photograph B-2: Crooked Creek
Gauging Station, Looking
Upstream
Note large boulders in background
(covered in vegetation). These are part of
a larger boulder field (see Photograph
14) believed to be from a mass wasting
event spawned from cliffs to the left in
this view. Similar cliffs are adjacent to
this intake site.
Crooked Creek is flowing at 3.71 cfs
October 9, 2009. Polarconsult.
Photograph B-3: Crooked Creek
Gauging Station, Looking
Downstream
The log in the foreground is the outlet
control for the pool where the stream
gauge is located. Crooked Creek's
gradient increases to 1540% below the
gauging station.
Crooked Creek is flowing at 3.71 cfs.
October 9, 2009. Polarconsult.
Photograph B-4: Crooked Creek
SO Yards Above Gauging Station,
Looking Upstream
Crooked Creek runs at a gradient of 2%
to 5% for approximately 1/4 mile above
the gauging station / intake site.
Crooked Creek is flowing at 1.0 cfs
July 8, 2009. Polarconsult.
JUNE 2010- FINAL REPORT B-2
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
Photograph B-5: Site for Crooked
Creek Diversion Outlet or Upper
Powerhouse
Peat bog north of Jim's Lake, looking
towards the lake. If a shorter diversion
pipeline was built from Crooked Creek,
(Jim s Lake Options A or B) the water would
flow through these wetlands approximately
600 feet to Jim's Lake. For Jim's Lake Option
C, the upper powerhouse would be located
in this vicinity. The terrain in this
photograph is at an elevation of 350 to 360
feet. The estimated maximum Jim's Lake
spillway elevation is 350 feet.
September 3, 2009. Polarconsult.
Photograph B-6: Jim's Lake
Looking West from Lake Outlet
View of Jim's Lake looking west from
outlet.
July 7, 2009. Polarconsult.
Photograph B-7: Jim's Lake
Gauging Station
September 3, 2009. Polarconsult.
JUNE 2010- FINAL REPORT B-3
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc. q1:-_, WqW
Photograph B-8: Typical View of
Power Line Route Between Jim's
Lake and Elfin Cove
Terrain is typically moderate slopes of
less than 15% and vegetated by mature
conifer forest.
July 7, 2009. Polarconsult.
Photograph B-9: Soils Along Power
Line Route Between Jim's Lake and
Elfin Cove
This uprooted tree reveals a shallow
organic soil layer overlaying mineral soil
dominated by angular rocks up to
approximately 12 to 18 inches in size.
July 7, 2009. Polarconsult.
Photograph B-10: Crooked Creek
Gauging Station, Looking
Upstream
Typical peat bog. This peat bog is
located at an elevation of about 120 to
150 feet between tidewater and Jim s
Lake. Brown areas in the foreground are
normally ponds, but were dry due to a
prolonged period of sunny weather.
July 8, 2009. Polarconsult.
JUNE 2010- FINAL REPORT B-4
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
Photograph B-11: Roy's Creek
Running Over Bedrock Above Falls
Roy's Creek running over exposed
bedrock above the waterfall. Roy's
Creek runs over a combination of
exposed bedrock, gravel, cobbles, and
boulders for at least 1/4 mile above the
waterfall.
September 3, 2009. Polarconsult.
Photograph B-12: Roy's Creek
Gauging Station
Stream gauging station at Roy's Creek.
Gauge is located in a pool with bedrock
and 3- to 6-foot boulders forming the
outlet control. The gauge is bolted to a
15- to 20-foot tall boulder.
October 8, 2009. Polarconsult.
Photograph B-13: Roy's Creek Waterfall
View of the waterfall on Roy's Creek.
The top of this waterfall is at an elevation
of approximately 300 feet.
Roy's Creek is flowing at 1.06 cfs.
September 3, 2009. Polarconsult.
JUNE 2010 - FINAL REPORT B-5
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc. q1:-_, WqW
Photograph B-14: Debris Field Upstream
from Crooked Creek Intake Site
This debris field extends to the proposed intake site
on Crooked Creek. Polarconsult engineer Dan
Hertrich, in the foreground, is sitting on a 20-foot
boulder.
July 8, 2009. Polarconsult.
Cove
This debris field is from a mass wasting event that
occurred sometime after 1990.
October 10, 2009. Polarconsult.
4
Photograph B-16: Debris Field along Power
Line Route
This debris field, located along the proposed power
line route between Jim's Lake and Elfin Cove, is
from a mass wasting event that occurred sometime
after 2002. July 7, 2009. Polarconsult.
JUNE 2010 - FINAL REPORT B-6
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
APPENDIX C - HYDROLOGY
JUNE 2010- FINAL REPORT
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
HYDROLOGY
Approximately two years of hydrology data have been collected at Crooked Creek and Jim's
Lake. Less than a year of data has been collected at Roy's Creek. The hydrology of the
identified hydroelectric resources needs to be further refined in order to more accurately
estimate how much energy the resources can provide. This information is also necessary to
properly design the hydroelectric project so it is not damaged by flood events. Also, hydrology
information is necessary to assess the effect the project may have on the natural environment.
CA AVAILABLE HYDROLOGY DATA
Existing hydrology data is summarized in Table C-1. Flow measurements at the gauging
stations near Elfin Cove are summarized in Table C-2. Hydrographs, stage -discharge curves,
flow duration curves, and station notes for the three gauges are included on pages C-7 through
C-13. For some of these stations, data is still preliminary as stage -discharge curves are not fully
developed.
Table C-1: Summary of Hydrology Data for Elfin Cove Hydroelectric Resources
Basin
Site
Number of
USGS
Latitude
Longitude
Begin
End
Location
Size
Elevation
Dail
Gauge ID (sq mi)
(ft)
(DMS) 1
(DMS)'
Date
Date
Records 2
Crooked Creek
7/6/84
2/13/85
202
_ 0.56
480
58°10'40"
136°19'16"
intake site
8/22/08
Current
232
7/6/84
2/11/85
201
Jim's Lake outlet
- 0.09
338
58°10'34"
136°19'32"
8/22/08
Current
310
Roy's Creek
- 0.62 480 (est.) 58°11'29" 136°20'03" 10/9/09 Current 60
intake site
Tonalite Creek 15106980 14.5 50 57°40'42" 135°13'17" 6/1/68 9/30/88 7,426
1. Coordinates for U.S. Geological Survey gauges are in NAD 27. All other coordinates are in NAD 83.
2. Record count for current gauges reflects data through December 9, 2009.
JUNE 2010 - FINAL REPORT C-1
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
Table C-2: Flow Measurements for Elfin Cove Hydroelectric Resources
Date Party Flow Stage Method / Equipment
(cfs) (ft)
Crooked Creek Intake Site (1984 to 1985)
7/6/198413:30 Ireland/Collazzi 0.8 0.71 Marsh McBirney 1
11/20/198410:15 2.72 0.84 "
3/2/198510:15 2.29 0.7 "
3/11/198611.47 1.47 0.6 "
Crooked Creek Intake Site (2008 to 2010)
7/26/2008 15:15 Button/ Christensen 2.33 7.7 Pygmy Meter 2
7/27/2008 16:20 Button/ Christensen 4.35 7.76 "
8/22/2008 14.30 Button/ Christensen 5.38 7.92 "
6/1/200911:39 Button/ Christensen 4.17 7.73 "
6/28/200916.40 Button/ Christensen 1.3 7.6 "
7/9/200910:55 Groves/ Hertrich 0.98 7.53 Hanna Meter 3
7/9/200911:20 Groves/ Hertrich 0.94 7.54 "
9/4/200911:40 Groves/ Glendoing 0.93 7.54 "
10/9/200912.50 Groves/ Christensen 3.71 7.68 "
12/9/200913.45 Button/ Christensen 1.07 7.52 "
Jim's Lake Outlet (1984 to 1985)
7/6/198411:15 Ireland/Collazzi/Wild 0.23 - Marsh McBirney
11/20/1984 9:00 Ireland/Collazzi 0.93 0.57 "
3/2/1985 9:30 Ireland/Collazzi 0.25 0.125 "
3/11/198610:00 Ireland/Collazzi 0.75 0.35 "
Jim's Lake Outlet (2008 to 2009)
7/25/2008 12.30 Button/Christensen 3.42 4.18 Pygmy Meter
7/26/200810.45 Button/Christensen 1.3 3.82 "
8/22/200812.45 Button/Christensen 0.11 3.7 "
6/1/200910:00 Button/Christensen 0.54 3.73 "
6/28/200918:00 Button/Christensen 0.04 3.61 "
7/9/200912:15 Groves/Hertrich 0.0911 3.56 Hanna Meter
7/9/200912:30 Groves/Hertrich 0.0910 3.56 "
9/4/200910:00 Groves/Glendoing 0.219 3.52 "
9/4/200910:15 Groves/Glendoing 0.217 3.51 "
10/9/200913.45 Groves/Christensen 0.44 3.62 "
Jim's Lake Outlet (2009 to 2010) 4
10/9/200914:05 Groves/Christensen 0.44 3.69 Hanna Meter
12/9/200914:15 Button/Christensen 0.219 3.68 "
Roy's Creek Intake Site (2009 to 2010)
9/3/0917:00 Groves 1.06 - Hanna Meter
10/8/200916.45 Groves/Christensen 2.39 1.27 "
12/9/200911.45 Button/Christensen 0.66 1.09 "
1. Current velocity stream flow method with March McBirney current velocity meter.
2. Current velocity stream flow method with Pygmy current velocity meter.
3. Sudden dose salt integration stream flow method with Hanna HI 9828 conductivity meter.
4. A small weir was installed on October 9, 2009 to stabilize and improve the section at the gauge.
JUNE 2010 - FINAL REPORT C-2
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
C.2 JIM'S LAKE BATHYMETRY
The storage curve for Jim's Lake was calculated from bathymetry data collected in July 2009.
The storage curve is presented in Figure C-1.
355
350
345
335
330
325
Figure C-1: Jim's Lake Storage Curve
0 10 20 30 40 50 60 70 80 90 100
Available Storage (ac-ft)
The storage curve for Jim's Lake was used to model reservoir status against inflows and the
ECUC system load model. The reservoir model was configured to meet 100% of ECUC
demands until the reservoir reached its minimum level. Inflows to the reservoir were first
dispatched to meet ECUC demands. Any excess inflows were dispatched to refill the reservoir.
When the reservoir is full and the hydro is meeting 100% of ECUC demand, then excess inflows
and idle hydro capacity are dispatched to interruptible loads on the ECUC system. Any
residual inflows are spilled.
C.3 HYDROLOGY ANALYSIS
The accuracy of a hydrological resource assessment is improved with a longer period of direct
flow records. Several years of continuous data is ideal; however, this data is seldom available in
Alaska, and it is not available in Elfin Cove.
JUNE 2010 - FINAL REPORT C-3
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc. M1:-_, wqw
When direct flow data are unavailable, another approach is to find a suitable water resource
with a long period of record and similar discharge characteristics to the water resource of
interest, and establish a correlation relationship between the two. The discharge characteristics
of the resource of interest can then be estimated using the correlation relationship. This method
requires a common period of record for the two resources to establish the correlation.
USGS stream gauge #15106980 at Tonalite Creek, across from Tenakee Springs and
approximately 50 miles southeast of Elfin Cove, has 20 years of flow records and is the nearest
suitable candidate to Elfin Cove for this correlation approach. The correlation coefficient
between Tonalite Creek and Crooked Creek for the 1984 to 1985 Crooked Creek data set is 0.64.8
For reconnaissance -level analysis, this method and correlation is adequate.
Crooked Creek flows were modeled using the 20-year record at Tonalite Creek, linearly scaled
using the common period of record with Crooked Creek. This Crooked Creek model was then
scaled by basin area to model project flows at Roy's Creek and the other smaller creeks within
Elfin Cove.
The 20-year long Tonalite Creek dataset was used to model flows and power generation at
Crooked Creek, Roy's Creek, Ernie's Creek, and Joe's Creek.
The 1984 to 1985 flow data at the outlet of Jim's Lake has a correlation coefficient of 0.11 with
the concurrent Tonalite Creek data set. This is a very poor correlation coefficient.
Because the hydroelectric projects considered for Jim's Lake all would use the lake for storage,
the instantaneous outflow from the lake is less important for hydroelectric analysis than the
average outflow because the lake's storage volume will be used to regulate discharges.
Both the 1984 to 1985 and 2008 to 2009 stream gauging data indicate that outflows from Jim's
Lake outlet exceed 0.7 cfs 50% of the time. Natural outflows from Jim's Lake are modeled as a
constant 0.7 cfs for hydroelectric analysis in this study.
8 A correlation coefficient of one indicates a perfect linear relationship between the two data sets, and a
correlation coefficient of zero indicates no relationship between the data sets.
JUNE 2010 - FINAL REPORT C4
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
CA STREAM GAUGE STATION HISTORIES
C.4.1 1984-86 Installations
According to ADNR personnel, the 1984 - 1986 Crooked Creek stage data was measured with
vented pressure transducers and recorded on data loggers manufactured by Bob Dryden. 9 The
only data recovered from the 1984 - 1986 stream gauging efforts at Crooked Creek and Jim s
Lake was a sheaf of dot matrix printouts covering the period July 1984 through February 1985
and ADNR's flow measurement data for both sites. The printouts include date, stage, and
calculated discharge.
The calculated discharges on the printouts for both gauging stations were developed using a
weir equation, but the flows did not correlate well with the field measurements in the ADNR
database. Because only four flow measurements are available at each site, a linear fit is used to
estimate flows from the stage data for each gauging station. These data are presented in Figures
C-2 and C-5 for Crooked Creek and Jim's Lake outlet, respectively.
C.4.2 Current Installations (2008 - 2009)
In August 2008, ECUC installed new gauging stations in the vicinity of the original Crooked
Creek and Jim's Lake gauging stations. From August 24, 2008 through October 9, 2009,
Crooked Creek and Jim's Lake outlet stage data was measured and recorded with a sealed
Hobo level logger manufactured by Onset, Inc. Atmospheric pressure fluctuations were
measured with a Hobo atmospheric pressure logger ('barologgee) installed in the immediate
vicinity of the Crooked Creek gauge site. The Crooked Creek barologger was used to correct for
atmospheric fluctuations at the Jim's Lake site.
The barologger experienced data quality problems during cold weather during the winter of
2008-09. Data gaps in November, December and January are due to these problems. The data
gap from early February 2009 thru the end of June 2009 is due to the data logger memory being
full and overwriting older records. The lack of a second barologger at Jim's Lake outlet
introduced additional noise into the stage data at this station due to transient pressure gradients
(windy conditions) between the Crooked Creek and Jim's Lake gauging stations.
The gauging station at Crooked Creek is in a deep pool. The outlet of this pool is controlled by
a large log lying at a slight angle to the water's surface and nearly perpendicular to the direction
of flow (See Photographs B-2 and B-3).
The gauging station at Jim's Lake outlet is about 10 feet downstream of the lake outlet in a
shallow pool formed by loose rocks sitting on a weathered bedrock stream bed. After several
measurements in the summer of 2009, it was determined that this section was not stable. A
9 Roy Ireland, ADNR hydrologist, personal communication. 2009.
JUNE 2010 - FINAL REPORT C-5
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
small weir was built of local materials in an effort to stabilize and improve the stage discharge
curve at this location (See photographs B-6 and B-7).
ECUC conducted several flow measurements at both stations during 2008 and 2009 using a
pygmy current velocity meter to calibrate these gauging stations. These data, combined with
additional flow measurements performed by Polarconsult and ECUC personnel in the summer
and fall of 2009, are used to develop stage -discharge curves for these stations. These data are
presented in Figures C-3 and C-6 for Crooked Creek and Jim's Lake outlet, respectively.
C.4.3 Current Installations (2009 - Current)
On October 9, 2009, the Hobo hardware at Crooked Creek was replaced with an Acculevel
vented pressure transducer manufactured by Keller America, Inc., fitted to a MONITOR data
logger manufactured by Sutron, Inc.
On this same date, the Hobo barologger was moved to Jim's Lake outlet to improve
atmospheric correction at this station and mounted in a large desiccant canister to improve cold
weather performance. The Hobo sealed pressure transducer installed in 2008 remains in service
at the Jim s Lake outlet station.
Identical Keller America, Inc. and Sutron, Inc. data logging hardware was installed at a new
gauging station at an approximate elevation of 350 feet above the falls on Roy's Creek to collect
quantitative flow data for hydroelectric assessment. The Roy's Creek gauge is located in a
small plunge pool in a series of cascading falls on Roy's Creek. The outlet control for this pool
is a series of very large boulders interlocked with smaller bed materials and resting on bedrock
(See Photograph B-12).
Two discharge measurements have been collected at Roy's Creek to date. This is sufficient for a
preliminary stage -discharge curve, but additional flow data will be collected in 2010 to
complete calibrating this station and recalibration of the Jim's Lake outlet station. The
preliminary Roy's Creek hydrograph is presented in Figure C-8.
JUNE 2010 - FINAL REPORT C-6
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
C.5 CROOKED CREEK HYDROLOGY DATA
Figure C-2: 1984 -1985 Crooked Creek Recorded Stage and Calculated Flow Data
7/1/84 7/29/84 8/26/84 9/23/84 10/21/84 11/18/84 12/16/84 1/13/85
Date
1984-86 Crooked Creek Stage Discharge Curve
p All Row Measurements
p Row Measurements used for S D Curve
—Linear (Row Measurements used for S D Curve)
2
m
rn
t 1.5
w y= 5.0711 x- 1 .4574
p 1 R2 = 0.9267
0.5
0
0 0.1 0.2 0.3
0.4 0.5 0.6 0.7 0.8 0.9
Stage
7
0
W
S
4 u
a
aj
Q
2
1
0
2/10/85
JUNE 2010 - FINAL REPORT C-7
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
Figure C-3: 2008 — 2009 Crooked Creek Recorded Stage and Calculated Flow Data
Ro f_F;r o.,,, H— !7 Fl........,o
9.00
+^� 8.75
v
v
*" 8.50
cn
8.25
v
8.00
7.75
7.50
7.25
18
17
16
15
14
13
12
11
10
9
8
7
m
w
6
5 a
v
4
3 m
2 Q
1
0
8/15/08 9/19/08 10/24/08 11/28/08 1/2/09 2/6/09 3/13/09 4/17/09 5/22/09 6/26/09 7/31/09 9/4/09 10/9/09 11/13/09
Note 1: Weir equation for broad crested weir with rounded section used for flows above highest measurement. H = 5 - 7.92
2008-10 Crooked Creek Stage -Discharge Curve
6
:1
4 '
a\
y = - 24.707x2 + 392.87x - 1556.3
3 R2 = 0.9965
N
2 All Row Measurements
Row Measurements Used for SD Curve
1
—Poly. (Flow Measurements Used for S-D Curve
o'
7.5 7.55 7.6 7.65 7.7 7.75 7.8 7.85 7.9 7.95
Stage
JUNE 2010 — FINAL REPORT C-8
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
Figure C-4: Flow Duration Curves for Crooked Creek
Preliminary Stage -Discharge Curve for Crooked Creek
8
7
— Crooked Creek Flow Duration (2008-2009)
— Crooked Creek Flow Duration (1984-1985)
6
5
w.
u
34
0
w
3
2
1
0
0% 10% 20% 30°0 40% 50% 60% 70% 80% 90% 100%
Percent of Time Flow is Equalled or Exceeded
The flow duration curves for the two Crooked Creek data sets are significantly different. This
can most likely be attributed to the short period of record for both gauges. This short period of
data can give a certain season (such as fall and winter in the 1984-85 data set) disproportionate
weight, and can also result in unusual weather influencing the resulting hydrograph.
The cause of these effects has not been investigated as part of this reconnaissance study. The
1984-85 data set was satisfactorily correlated to concurrent flow data at Tonalite Creek, and the
Tonalite Creek data set, adjusted to Crooked Creek by a linear fit, is used for reconnaissance -
level flow estimates for power generation.
JUNE 2010 — FINAL REPORT C-9
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
C.6 JIM's LAKE OUTLET HYDROLOGY DATA
Figure C-5:1984 -1985 Jim's Lake Outlet Recorded Stage and Calculated Flow Data
3
2.5
^. 2
v
d
w
1.5
v
1
cn
0.5
0
7/1/84 7/29/84 8/26/84 9/23/84 10/21/84 11/18/84 12/16/84 1/13/85 2/10,
Date
1984-86 Jim's Lake Outlet Stage Discharge Curve
p All Flow Measurements
1.2 —
o Flow Measurements Used for S- D Curve
1 —Linear (Flow Measurements Used for S- D
0.8
y = 1.5307x + 0.1101CM
0
W = 0.9345
0.6
0.4
0.2
O
0
0 0.1 0.2 0.3 0.4 0.5 0.6
Stage
1.75 ,A
1.00 to
0.75
0.50
'85
JUNE 2010 — FINAL REPORT C-10
Non -Profit Community of Elfin Cove
Wirk
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
Figure C-6: 2008 - 2009 Jim's Lake Outlet Recorded Stage and Calculated Flow Data
5.00
4.80
+ 4.60
d
w 4.40
4.20
4.00
3.80
3.60
3.40
3.20
3.00
8/15/08 9/19/08 10/24/08 11/28/08 1/2/09 2/6/09 3/13/09 4/17/09 5/22/09 6/26/09 7/31/09 9/4/09 10/9/09 11/13/09
2008-09 Jim's Lake Outlet Stage Discharge Curve
4
All 20 08- 09 Flow Measurements
3.5
2009-2010 Flow Measurements
3
0 Flow Measurements Used for S D Curve
—Poly. (Flow Measurements Used for S D Curve)
2.5
rn
r
2
U
1.5
O
1
y =
5.109x2 -
34.455x + 58.19
Rz =
0.9899
0.5
0
3.4
3.5 3.6 3.7 3.8 3.9 4 4.1 4.2 4.3
Stage
10
9
8
7
6
5
4
�n
w
u
WIPWA
0
JUNE 2010 — FINAL REPORT C-11
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
Figure C-7: Flow Duration Curves for Jim's Lake Outlet
5.0
4.5
Preliminary Stage -Discharge Curve for Jim's Lake Outlet
— Jim's Lake Flow Duration (2008-2009)
—Jim's Lake Flow Duration (1984-1985)
4.0
3.5
3.0
V
2.5
3
0
w
2.0
1.5
1.0
0.5
0.0
0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
Percent of Time Flow is Equalled or Exceeded
The flow duration curves for the two Jim s Lake outlet data sets are significantly different. As
for the Crooked Creek data sets, this can most likely be attributed to the short period of record
for both gauges. This short period of data can give a certain season (such as fall and winter in
the 1984-85 data set) disproportionate weight, and can also result in unusual weather
influencing the resulting hydrograph.
Another potential cause for the discrepancy in the Jim's Lake outlet data is the stage -discharge
curves applied to the different data sets. Because stage -discharge curves are typically a power
function over a sufficiently large range of flows, the use of a linear fit for the 1984-85 data will
tend to underestimate higher flows, which is consistent with the observed discrepancy.
This matter has not been explored to resolution as part of the reconnaissance study. Both
datasets exhibit a 50% flow exceedance value of approximately 0.7 cfs. This flow is within the
range of field measurements for both periods of record, so both models can be expected to be
reasonably accurate at a flow of 0.7 cfs.
JUNE 2010 — FINAL REPORT C-12
3.50
3.00
v
v
w
2.50
v
2.00
to
1.50
1.00
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
C.7 Roy's CREEK HYDROLOGY DATA
Figure C-8: 2009 Roy's Creek Recorded Stage and Calculated Flow Data
Recorded Stage (feet)
-Calculated Discharge (cfs) 1
� M I M MM
Best -Fit Equation
= 9.611 S - 9.8161 (preliminary)
16
14
12
10
m
yr
8
a
6
4
A
2
0
10/8/09 10/15/09 10/22/09 10/29/09 11/5/09 11/12/09 11/19/09 11/26/09 12/3/09 12/10/09
2009-10 Roy's Creek Stage Discharge Curve (Preliminary)
3
2.5
2
a�
z 1.5
_N
1
0.5
0
1.05 1.1 1.15 1.2 1.25 1.3
Stage
JUNE 2010 - FINAL REPORT
C-13
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
APPENDIX D - ENVIRONMENTAL CONSIDERATIONS
JUNE 2010- FINAL REPORT
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
D.1 THREATENED AND ENDANGERED SPECIES
The U.S. Fish and Wildlife Service's online consultation guide indicates that there are no species
listed as threatened or endangered within the vicinity of the projects. 10
D.2 FISHERIES AND WILDLIFE
Development of the recommended project has the potential to affect fisheries and wildlife
resources. Significant effects to wildlife are considered unlikely.
The Alaska Department of Fish and Game (ADFG)'s Atlas of Waters Important for the Spawning,
Rearing or Migration of Anadromous Fishes does not indicate that Crooked Creek, Jim's Lake,
Roy's Creek or the other small streams in Elfin Cove are habitat for anadromous species.
Existing information and field reconnaissance have not identified fish in any of the project
waters. The steep stream gradients and waterfalls present on all of the streams investigated in
this study are almost certainly barriers to fish passage.
D.3 WATER AND AIR QUALITY
None of the projects would have any significant negative impacts on water or air quality. By
reducing diesel combustion within Elfin Cove, all of the projects would improve air quality.
DA WETLAND AND PROTECTED AREAS
All of the projects will require filling wetlands areas, such as for the diversion structure located
in the creek. Some of the penstock or access routes for the various projects could also cross
wetlands. If Jim's Lake is used for storage, that entire water body would be affected.
D.5 ARCHAEOLOGICAL AND HISTORICAL RESOURCES
None known. The state historical preservation office would be consulted to determine if any
historical or cultural resources are present in the project area.
D.6 LAND DEVELOPMENT CONSIDERATIONS
None.
D.7 TELECOMMUNICATIONS AND AVIATION CONSIDERATIONS
The project will not affect telecommunications or aviation.
10 http://alaska.fws.gov/fisheries/endangered/pdf/consultation_guide/70_consult_guide_map_llxl7.pdf
JUNE 2010 — FINAL REPORT D-1
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
D.8 VISUAL AND AESTHETIC RESOURCES
Due to the dense conifer vegetation present around Elfin Cove, none of the projects would have
a large visual impact. Most of the disturbed areas, such as transmission, access, and penstock
alignments, would be mostly concealed from view from sea or the air.
Tidewater powerhouses at Small Sandy Beach (for the Jim's Lake projects) would be visible
from sea and air. These would be small structures consistent with the many isolated
outbuildings found at tidewater throughout Southeast Alaska, and they could be finished in
materials and colors that would blend with their surroundings.
Tidewater powerhouses within Elfin Cove (for Roy's Creek or the smaller in -cove resources)
would be visible from throughout the community, but would not be distinct from the many
other buildings present within the community.
A project on Roy's Creek would reduce the amount of water flowing over the waterfall that is
located at an elevation of about 300 feet. Depending on the size of this project, these falls would
be mostly or completely dewatered for a significant portion of the time. Similarly, development
of the other small creeks within Elfin Cove would also dewater any water features downstream
of the diversion points on these streams.
D.9 MITIGATION MEASURES
No impacts warranting mitigation are known at this time.
JUNE 2010 - FINAL REPORT D-2
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
APPENDIX E - PERMITTING INFORMATION
JUNE 2010- FINAL REPORT
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
E.1 FEDERAL PERMITS
E.1.1 Federal Energy Regulatory Commission
The Federal Energy Regulatory Commission (FERC) has jurisdiction over hydroelectric projects
that meet certain criteria. One of these criteria is whether the project would occupy federal
land. All of the projects considered in this study are located in whole or part within the
Tongass National Forest, and therefore would fall under FERC jurisdiction.
For projects that require a FERC license, all state and federal permitting efforts are managed
through the FERC licensing process. Small hydroelectric projects meeting certain criteria can be
exempted from FERC licensing requirements, in which case the normal state and federal
licensing processes must be used.
The main eligibility criteria for exemption from FERC licensing are:
➢ The project must use a 'natural water feature'. All of the run -of -river projects
considered in this study are expected to qualify under this criteria. It is unclear if FERC
would accept a siphon at Jim's Lake under the 'natural water feature' rule. A dam at
Jim's Lake would not qualify.
➢ The project owner must have control over all non-federal project lands. This would
include private lands and state lands (tidelands) that the projects may occupy. Private
lands could be secured by easements or leases, and state tidelands could be secured with
leases as well.
E.1.2 U.S. Forest Service
All of the projects considered in this study are located in whole or part within the Tongass
National Forest, and would require land leases and permits from the U.S. Forest Service for the
specific development proposal(s).
E.1.3 U.S. Army Corps of Engineers Permits
The diversion structures and tailraces of all the projects considered in this study would be
located within wetlands, therefore a wetlands permit from the COE will be required. Other
project features, such as access, transmission, and penstock routes may also be located in
wetlands. With the exception of projects that use Jim's Lake, these projects would likely be
eligible for a Nationwide Permit #17 for small hydroelectric development. A project at Jim's
Lake may require an individual permit from the COE.
If any of the projects use a powerhouse built on piling in tidelands or other permanent tidelands
structures, additional COE permits will be required under the COE's marine navigation
authority.
JUNE 2010 - FINAL REPORT E-1
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
E.1.4 U.S. Environmental Protection Agency
A stormwater pollution prevention plan will be required for construction of the projects
considered in this study.
E.1.5 Federal Aviation Administration
None of the projects considered in this study would have any features likely to present a hazard
to aviation.
E.2 STATE OF ALASKA PERMITS
E.2.1 Alaska Department of Natural Resources Permits
E.2.1.1 Coastal Zone Consistency Review
All of the projects considered in this study are located within the state's coastal zone, and will
have to go through consistency review by ADNR's Division of Coastal and Ocean Management
for consistency with the statewide coastal management plan. The projects are not located
within a local coastal management program.
E.2.1.2 Land Authorizations
A project on Roy's Creek would require an easement on and possibly a lease of State of Alaska
Mental Health Trust land.
E.2.1.3 Tidelands Permits
If any of the projects included temporary or permanent structures within state tidelands,
tidelands permits may be required.
E.2.1.4 Material Sale Agreement
Not applicable.
E.2.1.5 Water Use Permit / Water Rights
Any of the projects would need to obtain water rights from the ADNR.
E.2.2 Alaska Department of Fish and Game Permits
E.2.2.1 Fish Habitat Permit
Any of the projects would need to obtain either a fish habitat permit or a finding that a permit is
not required from the ADFG.
JUNE 2010 - FINAL REPORT E-2
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
E.2.3 Alaska Department of Transportation Permits
Not applicable.
E.2.4 Alaska Department of Environmental Conservation (ADEC) Permits
E.2.4.1 ADEC Wastewater or Potable Water Permits
Not applicable.
E.2.4.2 Solid Waste Disposal Pennit
Not applicable.
E.2.4.3 Air Quality Permit & Bulk Fuel Permit
Not applicable.
E.3 LOCAL PERMITS
The project is not located within an organized borough or city, so no local permits would be
required.
JUNE 2010- FINAL REPORT E-3
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
APPENDIX F - ASSUMPTIONS FOR ECONOMIC ANALYSIS
JUNE 2010- FINAL REPORT
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
ECONOMIC ANALYSIS ASSUMPTIONS
FA ESTIMATED ANNUAL PROJECT COSTS
F.1.1 General, Administrative, Operation and Maintenance Expenses
Typical general and administrative costs for a utility like ECUC range from $20,000 to $40,000
per year. This annual expense includes activities such as meter reading, customer service,
managing the utility's business affairs, etc. These costs will not change if the means of energy
generation changes from diesel to hydroelectric or a combination.
Typical non -fuel operation and maintenance (O&M) expenses for a utility like ECUC are about
$20,000 per year. This annual expense includes the costs of lube oils, filters, and other
consumables for the diesel generators, maintenance labor, and similar costs that are related to
the running time of the diesel engines. A significant portion of these costs will be avoided with
any of the recommended hydroelectric projects.
The hydroelectric projects will have additional operation and maintenance costs. This includes
additional labor costs for monitoring and maintaining the hydro as well as direct expenses for
parts and consumables. Based on experience with similar projects, annual O&M costs for Roy's
Creek are estimated to be $11,400 annually. Costs for other configurations are higher. The
Crooked Creek and Jim's Lake options would have higher transmission line, penstock, and trail
maintenance costs. There would also be more travel time and reduced project reliability due to
the greater distance to these projects. Any of the three Jim s Lake projects would have two
intake structures to maintain, and the Jim's Lake project Option C would have two
powerhouses to maintain.
F.1.2 Repair and Replacement
Most of the hydroelectric project systems and components have a very long useful life. The
intake, penstock, powerhouse, switchgear, turbine/generator, and power line all are expected to
have useful lives of 30 years. Some portions of the project will require periodic repair or
replacement. Some minor components, such as minor pumps, actuators, control sensors, and
similar devices, are assumed to have a useful life of five years. The water turbine would need
an overhaul after about 15 to 25 years. The average annual expense for repair and replacement
is estimated at $4,300 for Roy's Creek. As for O&M costs, more complex and more distant
project configurations have higher repair and replacement costs.
F.1.3 Taxes
No tax liability is considered.
JUNE 2010 - FINAL REPORT F-1
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
F.1.4 Insurance
It is assumed that the ECUC's existing insurance policies would be adequate for the
hydroelectric project. No additional annual costs are allocated for insurance.
F.1.5 Financing
The costs of financing will depend on how the project is financed.
Commercial finance for the project is assumed to consist of a 30-year debt at a nominal interest
rate of 5%. Adjusted for inflation (assumed at 3% average over 30 years), this is a real interest
rate of approximately 2%. In addition, the cost of originating the debt is assumed to be 3% of
the debt amount (for items such as application fees, loan guarantee fees, origination fees, etc).
F.2 ESTIMATED PROJECT REVENUES AND SAVINGS
F.2.1 Direct Fuel Displacement
All of the hydro projects would significantly reduce (62% to 97%) the amount of diesel fuel
ECUC consumes for electricity generation. Fuel savings are based on a diesel plant efficiency of
13.0 kWh per gallon, and a fuel price of $4.00 per gallon.
F.2.2 Excess Energy
In addition to reducing diesel fuel usage at the power plant, the hydroelectric projects also
generate a significant amount of excess energy that is available to the community. For
economic analysis purposes, 10% of the gross excess energy is assumed to be consumed by the
hydro load governor system and/or station service, and 90% is assumed to be made available to
utility customer loads such as space heating and water heating applications. Of this 90%, 12% is
assumed to be consumed by losses on ECUC's distribution system. The balance (79% of gross
excess energy generation) can be metered to ECUC's accounts on an interruptible basis at a
special rate.
All of this excess energy is assumed to be directed to space and water heating applications,
displacing heating oil that is consumed with an assumed average efficiency of 70%. Because the
community building and shop currently receive waste heat from the power plant, 75,000 kWh
of the excess energy is assumed to be allocated to these buildings at no cost in all economic
analyses.
F.2.3 Environmental Attributes
As small, low -impact, hydroelectric projects, all of these hydro projects would have the ability
to market their environmental attributes nation-wide. The market for environmental attributes
is still developing, and as a result is subject to considerable uncertainty. There is federal and
state legislation pending that could influence this market, transforming it from the existing
JUNE 2010 - FINAL REPORT F-2
Non -Profit Community of Elfin Cove
AIIIM�11 `-
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc. ml:.—, wqw
patchwork of state compliance markets and national and regional voluntary markets into a
more uniform and regulated national market. A reasonable range for the value of the
environmental attributes from this project is $0.001 to 0.020 per kWh on the voluntary market.
Elfin Cove has the potential to market its unique Alaska setting to command a premium for its
environmental attributes. For the economic analysis, no revenue from sale of environmental
attributes is assumed.
F.2.4 Indirect and Non -Monetary Benefits
The studied hydroelectric projects offer significant indirect and non -monetary benefits in
addition to direct economic benefits. These other benefits include:
➢ Reduced air pollution (NOx, SOx, particulates, and hydrocarbons) due to decreased
operation of the diesel power plant
➢ Reduced noise when the diesel plant is turned off.
➢ Reduced risk of oil spills due to decreased throughput and handling of fuel.
➢ More stable energy prices. With a hydro, ECUC's electricity rates will be largely
insulated from increasingly volatile world oil prices.
➢ Secondary benefits arising from the availability of plentiful hydroelectity with a stable
price. This will increase the affordability of living and doing business in Elfin Cove and
will increase the long-term viability of the community. Secondary benefits could
include an increase in the population of school -age children, ensuring that school
enrollment exceeds district and state thresholds for state funding year-to-year.
➢ Economic multipliers due to the fact that a greater percentage of the utility's revenues
will be retained in the local community for labor instead of paying external entities such
as fuel suppliers.
Local training and experience with small hydroelectric projects. To the extent that locals choose
to be involved in construction, maintenance, and operation of the hydroelectric project, they
will learn a unique set of skills. These skills will become increasingly useful as Alaska continues
to develop local hydroelectric resources.
JUNE 2010 - FINAL REPORT F-3
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
APPENDIX G - EXCERPT FROM COMMUNITY MEETING MINUTES
MAY 28, 2010
JUNE 2010- FINAL REPORT G-1
Non -Profit Community of Elfin Cove
Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
Community of Elfin Cove Non -Profit
Corporation
Board Meeting Minutes
May 28, 2010, 7:00 p.m.
Call to Order: Members present: David Abel, Jim Wild, Patti Lewis,
Gordy Wrobel, Shirley Perkins, Lane Ply, Karen Nemacek
Board Members Present: Susan Abel, Dennis Meier, Joe Kulavik,
Travis Lewis, Mike Nelson, Steve Alexander, Debbie Hemenway
Dennis Meier presiding; Susan Abel, Secretary
Agenda Item 2. Hydropower Decision- Mike Nelson moved that Elfin Cove
select Hydropower Option #2C. Travis Lewis seconded it. Board
Member Vote: Mike Nelson: yes; Steve Alexander: yes; Joe Kulavik:
yes; Travis Lewis: yes; Debbie Hemenway: yes; Dennis Meier: yes;
Susan Abel: yes.
JUNE 2010- FINAL REPORT G-2