HomeMy WebLinkAboutHunter Creek Hydroelectric Project Reconnaissance Study - Apr 2013 - REF Grant 7040060Prepared by
polarconsult alaska, inc.
1503 WEST 33
RD AVENUE, SUITE 310
ANCHORAGE, ALASKA 99503
HUNTER CREEK
HYDROELECTRIC RECONNAISSANCE STUDY
FINAL REPORT
APRIL 2013
Prepared for
EKLUTNA,INC.
16515 CENTERFIELD DRIVE, SUITE 201
EAGLE RIVER, ALASKA 99577
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April 2013 Final Report i
EXECUTIVE SUMMARY
In July 2011, the Alaska Energy Authority (AEA) granted Eklutna, Inc. (Eklutna) funds for a
hydroelectric reconnaissance study of Hunter Creek. The funds were awarded under the states
Renewable Energy Grant Program, which is administered by the AEA. In September 2011,
Eklutna hired Polarconsult Alaska, Inc. to perform the study. This report presents the findings
and recommendations of the completed study.
Hunter Creek drains an approximately 71.1 square mile basin in the Chugach Mountains
located between Eklutna Lake and Lake George (Figure ES 1). The creeks average annual flow
is approximately 311 cubic feet per second (cfs), with annual low flow in April of approximately
18 cfs and sustained high flows during the summer of approximately 1,200 cfs. Flood events
reach several thousand cfs.
Figure ES 1 Recommended Hunter Creek Hydroelectric Project Configuration
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This study considered a range of project configurations that included projects located only on
the east fork of Hunter Creek as well as projects located on both forks of Hunter Creek.
1
Installed generating capacity of these configurations ranged from 5.3 to 23 megawatts (MW),
with estimated annual energy generation of 21,000 to 80,900 megawatt hours (MWh). All
project configurations will require upgrade of approximately 14.7 miles of Matanuska Electric
Association (MEA)s existing distribution system to transmit electricity to railbelt utilities.
Based upon evaluation of technical, economic, environmental, and political factors,
Polarconsult has determined that a 7.7 MW run of river hydroelectric project on east fork
Hunter Creek appears to be the most favorable project configuration, and is recommended for
further study. This project would feature a diversion and intake structure on the east fork at
river mile (RM) 5.08, and a powerhouse at RM 2.67. The entire project footprint is located on
lands selected by Eklutna. The project would generate approximately 27,100 MWh annually
and would have a plant capacity factor of approximately 40.2%.
2 The estimated capital cost of
the project is $30 million. The estimated energy sales rate for the recommended project is
$0.11 per kilowatt hour (kWh), with a range of $0.064 to $0.162 per kWh under the full range
of capital cost, financing terms, and operating costs considered for this study.These rates are
competitive with the forecast avoided cost of energy for MEA over the 50 year project life. The
recommended project configuration is shown in Figure ES 1. Estimated technical and economic
parameters are listed in Table ES 1.
If Eklutna diligently advances the project and future analysis is favorable, a realistic operational
date is 2019. This depends in part on when the BLM conveys project lands to Eklutna, which
will determine whether the project requires a license from the Federal Energy Regulatory
Commission. If lands are conveyed by 2015, the project can avoid the FERC licensing process
and the project schedule could be accelerated by approximately one year.
Some other east fork project configurations are similarly favorable as the recommended
configuration, and it is possible that future additional information such as hydrology, fisheries,
or geotechnical data, may result in the selection of a different project configuration for
development.
Project configurations that included development of west fork Hunter Creek were determined
to not be viable for the following reasons:
1. The most economic west fork configurations are partially located within Chugach State
Park. Hydroelectric projects are not consistent with the current management goals of
this part of Chugach State Park. This is a significant political barrier for these project
configurations. West fork configurations that avoid Chugach State Park are not
economic under current and likely future southcentral energy market conditions.
1 This report refers to the two major forks of Hunter Creek as the east forkand west fork.These are not formal
names, and have therefore not been capitalized in this report.
2 Plant capacity factor is the amount of energy the plant produces in a year divided by the amount of energy the plant
would produce if it operated at 100% of its installed capacity for the entire year.
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2. The remoteness and rugged terrain of the west fork valley causes all west fork
configurations to be less economic than east fork configurations.
3. The cumulative impact of hydro projects on both forks of Hunter Creek is likely to result
in more severe permit terms, such as higher in stream flow reservations or required off
site mitigation for fish habitat, that will adversely affect overall project economics.
Table ES 1 Summary of Recommended Hydroelectric Project
ESTIMATED PROJECT PARAMETERS RECOMMENDED PROJECT
ESTIMATED TECHNICAL PARAMETERS (East Forkonly Configuration E2 48)
Design Flow (cfs)140 cfs
Diversion Location River mile 5.08
Intake Elevation (feet)1,150 feet
Powerhouse Elevation (feet) 270 feet (River mile 2.67)
Gross Head (feet)880 feet
Access Roads and Trails (feet) 18,800 feet
Power and Communication Line Upgrades and Extensions (feet)78,900 feet
Penstock Length (feet) and Diameter (inches) 11,600 ft./48 in.
Net Head at Full Flow (feet)793 feet
Reservoir Area (acres) None
Installed Capacity (MW)7.7 MW
Average Annual Net Energy Output (MWh) 27,100 MWh
Plant Capacity Factor 40.2%
ESTIMATED ECONOMIC PARAMETERS
1 Most Likely Value Estimated Range
ESTIMATED TOTAL INSTALLED COST $30M $23.7M $35.6M
Annual Debt Servicing Costs (Million 2013 $) $1.5M $0.9M $2.1M
Annual OMR & R Costs (Million 2013 $)$0.4M $0.4M $0.5M
Operating Margins (Million 2013 $) $1.1M $0.4M $1.8M
Total Annual Revenue Requirement (Million 2013 $)$3.0M $1.7M $4.4M
Estimated Range of Sales Rate for Energy ($ per kWh) $0.11 $0.064 $0.162
Estimated Range of Benefit Cost Ratio 2.0 1.49 3.06
1. Assumptions used to develop project economics are explained in Appendix G.
Field investigations of fish habitat confirm that the lower reaches of Hunter Creek, up as far as
approximately RM 3.1, are used by coho salmon and resident Dolly Varden. No evidence of
coho rearing was found in the lower canyon during field studies, and no fish were trapped or
observed in the general vicinity of the proposed east fork diversion site.
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Initial assessment of fish habitat along lower Hunter Creek indicates that the recommended
project configuration would likely not have a significant impact on resident or anadromous fish
habitat. If further study identifies significant unavoidable impacts, robust off site or in stream
mitigation opportunities are available along lower Hunter Creek or along the Knik River near the
project. Appropriate measures to avoid and/or minimize impacts to fish will depend on the
final project configuration that is developed and may include in stream flow reservations
and/or construction of off site habitat for impact mitigation.
Based on the findings of this study, further investigation of hydroelectric developments at
Hunter Creek should focus on the following information and analysis:
Collect additional hydrology data to better characterize resource hydrology. Conduct a
sediment transport study to quantify sediment transport rates.
Coordinate with MEA to complete a market analysis for determining a preferred project
configuration and the preferred route and configuration of the project transmission line.
Further evaluate site topography, surficial geology, and wetlands to refine penstock and
access routes. Perform topographic and geotechnical investigations of lower Hunter
Creek canyon to identify suitable powerhouse sites.
Conduct more detailed fisheries surveys to confirm the upper limit of fish habitat and
develop proposed permit terms for the preferred development configuration.
Hold meetings with regulatory agencies to determine the scope of environmental
studies, define potential mitigation requirements for fishery and wetland impacts, and
determine likely operational constraints on the project.
Generate refined estimates of electrical output and project costs to determine
economic feasibility.
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REPORT PURPOSE AND LIMITATIONS
Purpose of this Report
A reconnaissance study is the first stage of screening for a potential hydroelectric project, and
represents a limited effort, comprehensive review of relevant factors that pertain to the
technical, economic, environmental, and political viability of developing a hydroelectric project
at a given site or for a given power need. Depending on the available budget and the quality of
existing information, the reconnaissance study may include some field data collection for key
information, or may be limited solely to desk topreview of existing information.
This reconnaissance study provides Eklutna, Inc. (Eklutna) an initial assessment of the overall
viability of a hydroelectric project at Hunter Creek, and provides information on the advantages
and disadvantages associated with various project sites and configurations. This information is
intended for use by Eklutna to decide whether to continue with investigation of a project, and
to decide which project site(s) and configuration(s) warrant further investigation.
Limitations
In conducting our analysis and forming the opinions and recommendations summarized in this
report, Polarconsult has relied on information provided by others, and has assumed this
information is complete and correct. Also, Polarconsult has made certain assumptions with
regard to future events, conditions, and circumstances. Polarconsult does not guarantee the
accuracy of the information, data, or opinions contained herein. The methodologies employed
to perform the analysis and arrive at the conclusions in this report follow generally accepted
industry practice for this level of study. We believe that the assumptions and methodologies
used are reasonable and appropriate for meeting the objectives of this study. Future events
and information may result in outcomes materially different from those projected in this study.
Such events and information include, but are not limited to, future energy demand, supply, and
cost along the railbelt; actual site conditions such as ownership, topography, hydrology, and
geology; future trends in local construction, material, and labor costs; and national, state, or
local policies that may affect aspects of the project.
The contents and findings of this report are limited to potential development of a hydroelectric
project at Hunter Creek by Eklutna, and are suitable only for this intended purpose. Any use of
this report and the information contained therein constitutes agreement that (1) Polarconsult
makes no warranty, express or implied, relating to this report and its contents, (2) the user
accepts sole risk of any such use, and (3) the user waives any claim for damages of any kind
against Polarconsult. The benefit of such waivers, releases, and limitations of liability extend to
Polarconsult, its subcontractors, owners, employees, and agents.
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TABLE OF CONTENTS
EXECUTIVE SUMMARY..............................................................................................................I
ACRONYMS AND TERMINOLOGY.............................................................................................X
1.0 INTRODUCTION............................................................................................................1
1.1 PROJECT AUTHORIZATION AND PURPOSE ....................................................................................1
1.2 SUMMARY OF FINDINGS ...........................................................................................................1
1.3 PROJECT EVALUATION PROCESS .................................................................................................2
1.4 CURRENT AND PREVIOUS STUDIES ..............................................................................................2
2.0 COMMUNITY PROFILE..................................................................................................3
2.1 COMMUNITY OVERVIEW...........................................................................................................3
2.2 EXISTING ENERGY SYSTEM ........................................................................................................3
3.0 HYDROELECTRIC DEVELOPMENT OPTIONS................................................................... 7
3.1 RESOURCE DESCRIPTION ...........................................................................................................7
3.2 OVERVIEW OF PROJECT CONFIGURATIONS CONSIDERED ..............................................................13
3.3 RECOMMENDED PROJECT CONFIGURATION ...............................................................................17
3.4 ESTIMATED ENERGY GENERATION ............................................................................................19
3.5 DESCRIPTION OF FEATURES FOR RECOMMENDED PROJECT ...........................................................20
4.0 MARKET ANALYSIS AND OPPORTUNITIES................................................................... 25
4.1 POTENTIAL BUSINESS MODELS ................................................................................................25
4.2 POTENTIAL MARKETS .............................................................................................................28
5.0 CONCLUSIONS AND RECOMMENDATIONS................................................................. 33
5.1 DEVELOPMENT PLAN AND SCHEDULE ........................................................................................34
6.0 REFERENCES............................................................................................................... 35
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APPENDICES
APPENDIX A PROJECT MAPS
APPENDIX B SITE PHOTOGRAPHS
APPENDIX C HYDROLOGY DATA
C.1 Available Hydrology Data
C.2 Stream Gauge Station Information
C.3 Flow Measurements and Station Calibration
C.4 Hunter Creek Hydrology Data
C.5 Hunter Creek Hydrology Model
Attachment C 1: Hunter Creek Streamflow Analysis Report
Attachments C 2 and C 3: Additional Gauging Station Data, Main Stem and East Fork #2
APPENDIX D RESOURCE DATA AND ANALYSIS
D.1 Land Status
D.2 Hydrological Considerations
D.3 Geotechnical Considerations
APPENDIX E ENVIRONMENTAL CONSIDERATIONS
E.1 Threatened and Endangered Species
E.2 Fisheries and Wildlife
E.3 Water and Air Quality
E.4 Wetland and Protected Areas
E.5 Archaeological and Cultural Resources
E.6 Land Development Considerations
E.7 Telecommunications and Aviation Considerations
E.8 Visual and Aesthetic Resources
E.9 Mitigation Measures
Attachment E 1: Hunter Creek Fisheries Survey Report
APPENDIX F PERMITTING INFORMATION
F.1 Federal Permits
F.2 State of Alaska Permits
F.3 Local Permits
F.4 Other Permits and Authorizations
APPENDIX G ECONOMIC ANALYSIS ASSUMPTIONS
G.1 Introduction
G.2 Estimated Installed Cost
G.3 Estimated Annual Project Cost
G.4 Financing Terms
G.5 Operating Margins
G.6 Estimated Power Sales Rate
G.7 Estimated Benefit Cost Ratio
G.8 Environmental Attributes
G.9 Indirect and Non Monetary Benefits
APPENDIX H COMMENTS AND REVISIONS TO DRAFT REPORT, UTILITY SUPPORT LETTERX
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LIST OF TABLES
Table ES 1 Summary of Recommended Hydroelectric Project................................................iii
Table 3 1 Hunter Creek Subbasin Description........................................................................ 7
Table 3 2 Estimated Hunter Creek Subbasin Hydrology.........................................................9
Table 3 3 Overview of Hydroelectric Project Configurations Considered............................14
Table 3 4 Cost Estimates and Financial Analysis for East Fork Only Project
Configurations.......................................................................................................15
Table 3 5 Cost Estimates and Financial Analysis for East and West Fork Project
Configurations.......................................................................................................16
Table 4 1 Proposed Alternative Energy Supplies for MEA ...................................................30
Table 4 2 Selected Railbelt Transmission Grid Wheeling Costs ...........................................32
Table C 1 Summary of Hydrology Data for Hunter Creek....................................................C 3
Table C 2 Stream Flow and Water Stage Measurements at Hunter Creek.........................C 4
Table D 1 Maximum Probable Flood Flows at Hunter Creek and Tributaries.....................C 5
Table D 2 Estimated Sediment Load in East Fork Hunter Creek..........................................C 7
LIST OF FIGURES
Figure ES 1 Recommended Hunter Creek Hydroelectric Project Configuration........................ i
Figure 2 1 Monthly Peak and Average MEA System Demand and Load Factor......................5
Figure 2 2 Historical and Projected Future MEA System Demand.......................................... 6
Figure 3 1 Hunter Creek and Major Subbasins........................................................................ 8
Figure 3 2 Estimated Hunter Creek Hydrograph ..................................................................... 9
Figure 3 3 Explanation of Project Configuration Identifiers..................................................13
Figure 3 4 Map of Recommended Project Configuration......................................................18
Figure 3 5 Estimated Seasonal Energy Generation for Selected Project
Configurations.......................................................................................................19
Figure 4 1 MEAs Past and Projected Future Non Firm Avoided Cost of Energy ..................29
Figure 5 1 Project Development Schedule ............................................................................34
Figure A 1 Project Overview and Location Map ...................................................................A 3
Figure A 2 Map of Hunter Creek Subbasins..........................................................................A 4
Figure A 3 Land Status in Project Area..................................................................................A 5
Figure A 4 East Fork Hydroelectric Project Configurations...................................................A 6
Figure A 5 West Fork Hydroelectric Project Configurations.................................................A 7
Figure A 6 Conceptual Layout of East Fork Diversion and Intake.........................................A 8
Figure C 1 Estimated Daily Flow in Hunter Creek and Tributaries Based on Extended
Record..................................................................................................................C 9
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LIST OF PHOTOGRAPHS
Photograph B 1 Oblique North Aerial View of Lower Hunter Creek.................................B 3
Photograph B 2 Oblique North Northwest Aerial View of Lower Hunter Creek...............B 3
Photograph B 3 Oblique South Southwest Aerial View of West Fork Hunter Creek ........B 4
Photograph B 4 Oblique North Aerial View of West Fork Hunter Creek...........................B 4
Photograph B 5 Oblique Composite Aerial View of West Fork Hunter Creek...................B 5
Photograph B 6 Oblique Composite Aerial View of East Fork Hunter Creek.....................B 5
Photograph B 7 Oblique Southeast Aerial View of East Fork Hunter Creek......................B 7
Photograph B 8 Oblique Northwest Aerial View of East Fork Hunter Creek.....................B 7
Photograph B 9 Oblique Composite Southeast Aerial View of East Fork Hunter
Creek........................................................................................................B 8
Photograph B 10 East Fork Hunter Creek Looking Downstream (RM 4.42).......................B 8
Photograph B 11 East Fork Gauging Station #1 (RM 4.34)..................................................B 9
Photograph B 12 East Fork Gauging Station #1 (RM 4.34, Detailed View)..........................B 9
Photograph B 13 Typical Exposed Till Embankment along East Fork Hunter Creek .........B 10
Photograph B 14 Upstream View of East Fork Gauging Station #2 (RM 4.73)..................B 11
Photograph B 15 Trans Alaska Pipeline Bridge Over Tanana River near Delta
Junction..................................................................................................B 11
Photograph B 16 Upstream View of East Fork (RM 4.40)..................................................B 12
Photograph B 17 View of Till Embankment along East Fork Canyon (RM 3.83 to
4.02).......................................................................................................B 13
Photograph B 18 Upstream View of East Fork Canyon From North Rim Above RM
3.83 ........................................................................................................B 14
Photograph B 19 View of Active Slide Zone on North Side of East Fork Hunter Creek
(RM 4.15) ...............................................................................................B 15
Photograph B 20 Downstream View of West Fork Hunter Creek (RM 5.2).......................B 16
Photograph B 21 Upstream View of West Fork Hunter Creek (RM 5.2) ...........................B 17
Photograph B 22 Main Stem of Hunter Creek Gauging Station (Preflood).......................B 18
Photograph B 23 Main Stem of Hunter Creek at Flood Stage (Post Flood) ......................B 18
Photograph B 24 Main Stem of Hunter Creek at Flood Stage (RM 1.50)..........................B 19
Photograph B 25 Upstream View of the Main Stem of Hunter Creek (RM 2.22)..............B 20
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ACRONYMS AND TERMINOLOGY
C degrees Celsius
F degrees Fahrenheit
ABC Alaska Biological Consulting
ADCCED Alaska Department of Commerce, Community, and Economic Development
ADEC Alaska Department of Environmental Conservation
ADF&G Alaska Department of Fish and Game
ADNR Alaska Department of Natural Resources
AEA Alaska Energy Authority
AEP Alaska Environmental Power, LLC
AGDC Alaska Gasline Development Corporation
ANCSA Alaska Native Claims Settlement Act
AS Alaska Statute
ASAP Alaska Stand Alone Gas Pipeline
Aurora Aurora Energy, LLC
BHC Brailey Hydrological Consultants
Btu British thermal unit
CEA Chugach Electric Association, Inc.
cfs cubic feet per second
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CIRI Cook Inlet Region, Inc.
CPCN Certificate of Public Convenience and Necessity
DCRA Division of Community and Regional Affairs (organized under ADCCED).
DGGS Division of Geological and Geophysical Surveys (Alaska Department of Natural
Resources)
discharge A synonym for stream flow. Flow and discharge are used interchangeably in this
report.
DOPR ADNR Division of Parks and Recreation
EA environmental attributes. The term environmental attributesis used by the
utility industry to describe the desirable aspects of electricity that are generated
from environmentally benign and/or renewable sources. Environmental
attributes are tracked, marketed, bought, and sold separately from the physical
energy. Separating the environmental attributes from the physical energy allows
customers or ratepayers to elect to buy sustainable or greenenergy even if it is
physically unavailable from their electric utility.
EGS Eklutna Generation Station
Eklutna Eklutna, Inc.
FERC Federal Energy Regulatory Commission
FIW Fire Island Wind, LLC
firm energy Firm energy is energy that the utility depends on to meet the needs of its
customers. If the utility has a firm energy supply from an Independent Power
Producer (IPP), then it does not need to supply its own generating capacity to
meet customer demand.
ft foot, feet
GVEA Golden Valley Electric Association, Inc.
HEA Homer Electric Association, Inc.
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in. inch, inches
IPP Independent Power Producer
ISER Institute of Social and Economic Research (University of Alaska Anchorage)
ISFR in stream flow reservation. A minimum amount of flow that must be left in a
river or stream during all or certain times of the year.
isohyet A contour line delineating areas of equal precipitation.
JBER Joint Base Elmendorf Richardson
kV kilovolt, or 1,000 volts
kVA kilovolt ampere
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.
LFMC liquidtite flexible metal conduit
load factor Average load over a specified time period divided by the peak load for the same
time period.
MEA Matanuska Electric Association, Inc.
mi mile, miles
ML&P Municipal Light and Power
MOA Municipality of Anchorage
mmBtu Unit of energy produced. An abbreviation for million (10
6) British thermal units.
MW megawatt. Equal to 1,000 kW.
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MWh megawatt hour. Equal to 1,000 kWh.
NA not applicable
NALA North Anchorage Land Agreement
non firm energy
Non firm energy is energy that is available on an unpredictable, intermittent
basis, such as wind energy. Non firm energy is not scheduled or guaranteed, and
a utility that uses non firm energy supplies must maintain back up generating
capacity to meet the needs of its customers in the event the non firm energy
supply is unavailable at any given time.
Energy from run of river hydro projects falls somewhere between firm and non
firm energy definitions. A certain amount of power is predictably available at
any given time, but the amount of power varies seasonally. Utility pricing in
some other jurisdictions recognizes this distinction, but utilities on Alaskas
railbelt currently classify run of river hydro as a non firm energy supply.
avoided cost Avoided cost is the cost that a utility does not incur to generate a kWh of
electricity when it instead purchases the energy from another source (such as an
IPP). This cost typically includes the fuel that the utility would have purchased
and the operational and maintenance costs that the utility does not incur for the
generation equipment. Utilities have different avoided costs for firm and non
firm energy, with the avoided cost of firm energy normally higher than that of
non firm energy.
O&M operations and maintenance
P.E. Professional Engineer
Polarconsult Polarconsult Alaska, Inc.
PT pressure transducer
PTT pressure and temperature transducer
railbelt The railbelt electrical grid is defined as the service areas of six regulated public
utilities that extend from Fairbanks to Anchorage and the Kenai Peninsula.
These utilities are Golden Valley Electric Association, Inc. (GVEA), Chugach
Electric Association, Inc. (CEA), Matanuska Electric Association, Inc. (MEA),
Eklutna, Inc.
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Homer Electric Association, Inc. (HEA), Anchorage Municipal Light & Power
(ML&P, and the City of Seward Electric System (SES).
RCA Regulatory Commission of Alaska
REA Rural Electrification Administration (now known as Rural Utility Service)
RM river mile
SES Seward Electric System
SFH South Fork Hydro, LLC
sq. mi. square mile(s)
USACE U.S. Army Corps of Engineers
USGS U.S. Geological Survey
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1.0 INTRODUCTION
1.1 PROJECT AUTHORIZATION AND PURPOSE
In July 2011, the Alaska Energy Authority (AEA) granted Eklutna, Inc. (Eklutna) funds for a
hydroelectric reconnaissance study of Hunter Creek. The funds were awarded under the states
Renewable Energy Grant Program, which is administered by the AEA. In September 2011,
Eklutna hired Polarconsult Alaska, Inc. (Polarconsult) to conduct the study. This report presents
the study findings and recommendations.
1.2 SUMMARY OF FINDINGS
Reconnaissance level investigations of Hunter Creek find that a run of river hydroelectric
project on the east fork of Hunter Creek appears technically, economically, environmentally,
and politically viable.
3 Several project configurations are favorable, with a 7.7 megawatt (MW)
project generating an estimated 27,100 megawatt hours (MWh) annually recommended for
further study. Favorable east fork configurations range in installed capacity from 5.3 to 10.9
MW. The estimated power sales rates for energy from the recommended project is $0.11 per
kilowatt hour (kWh), with a probable range of $0.064 to $0.162 per kWh under the full range of
capital cost, financing terms, and operating costs considered for this study. These rates are
competitive with Matanuska Electric Association (MEA)s forecast avoided cost of energy over
the 50 year project life. Under the full range of costs and financing terms considered in this
study, project configurations have estimated benefit cost ratios ranging from of 0.74 to 3.06.
The recommended project configuration has an estimated benefit cost ratio of 2.0, ranging
from 1.49 to 3.06 under the full range of economic assumptions considered.
Projects that include development of west fork Hunter Creek were also considered, but these
were found to not be viable for the following reasons:
1. The most economic west fork configurations are partially located within Chugach State
Park. Hydroelectric projects are not consistent with the current management goals of
this part of Chugach State Park. This is a significant political barrier for these project
configurations. West fork configurations that avoid Chugach State Park are not
economic under current and likely future southcentral energy market conditions.
2. The remoteness and rugged terrain of the west fork valley cause all west fork
configurations to be less economic than east fork configurations.
3 This report refers to the two major forks of Hunter Creek as the east forkand west fork.These are not formal
names, and have therefore not been capitalized in this report. Similarly, the term Hunter Creek canyon,is not a
formal name and has not been capitalized in this report.
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3. The cumulative impact of hydroelectric projects on both forks of Hunter Creek are likely
to result in stricter permit terms, such as higher in stream flow reservations or
requirements for off site mitigation for fish habitat, that will adversely affect overall
project economics.
1.3 PROJECT EVALUATION PROCESS
Several hydroelectric project configurations at Hunter Creek were evaluated to define the range
of expected project output and development cost. Relevant resource data for Hunter Creek
were collected and analyzed to develop the project configurations. The resource data included
stream hydrology, fish surveys, site topography, and related information. Environmental and
regulatory factors were also considered in developing candidate project configurations.
Economic evaluations focused on wholesale purchase of the projects net electrical output by
Matanuska Electric Association, Inc. (MEA), the local electric utility.
The estimated electrical output for each project configuration was integrated with economic
data comprised of utility fuel costs, construction costs, operations and maintenance (O&M)
costs, and financing options to develop an estimated benefit cost ratio. Detailed discussion of
the assumptions used for economic analysis are available in Appendix G.
1.4 CURRENT AND PREVIOUS STUDIES
1.4.1 Previous Studies
Based on review of hydroelectric databases maintained by the AEA; Polarconsults archives; and
local, state, and university library databases, the hydroelectric potential of Hunter Creek has
not been previously investigated.
1.4.2 Current Reconnaissance Study
Polarconsult conducted the following field investigations to collect site specific information
about Hunter Creek for this reconnaissance study:
Installed stream gauges on the main stem of Hunter Creek upstream of Knik River Road
and on the east fork Hunter Creek in the vicinity of the proposed diversion site. These
data were analyzed to generate initial estimates of Hunter Creeks hydrology.
Performed topographic surveys to determine project head and terrain along prospective
penstock routes for various project configurations. These topographic surveys were
supplemented with existing data to generate contours of the project area.
Performed fish surveys in the powerhouse reach and east fork diversion reach to
provide initial information on the presence and distribution of fish in Hunter Creek.
Several field visits were completed in support of the above listed activities between September
2011 and November 2012. Field data collected from these trips have been used to complete a
reconnaissance study of Hunter Creek using the methodology described in Section 1.3.
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2.0 COMMUNITY PROFILE
2.1 COMMUNITY OVERVIEW
The community that would be served by a hydroelectric project at Hunter Creek is potentially
anywhere served by the railbelt utilities, which includes an area extending from the south side
of Kachemak Bay north to Nenana, Fairbanks, and Delta Junction. Approximately 540,000
people live within this area. The mostly likely community the project would serve is best
described as the service area of MEA, which extends from Eagle River to Talkeetna and includes
the population centers of the Mat Su Valley. Approximately 120,000 people live within MEAs
service territory (Alaska Department of Commerce, Community, and Economic Development
[ADCCED], 2012).
2.2 EXISTING ENERGY SYSTEM
2.2.1 Community Energy Overview
Electric service in the project area is provided by MEA. MEA is one of the six interconnected
electric utilities in Alaskas railbelt. This interconnected grid represents the largest utility grid in
the state in terms of population served. The hydro project would straddle the southern
boundary of MEAs certificated service area, with the transmission line and access roads
located within the service area and the powerhouse, penstock, and intake south of the service
area boundary.
2.2.2 Electric Utility Organization
MEA was incorporated in 1941 under the U.S. Department of Agricultures Rural Electrification
Administration (REA, now Rural Utility Service) regulations. MEA is an economically regulated
certificated public utility, holding Certificate of Convenience and Public Necessity (CPCN) No.
18, originally issued by the Alaska Public Utilities Commission, the predecessor to the
Regulatory Commission of Alaska (RCA).
2.2.3 Generation System
MEA currently purchases substantially all of its electricity from Chugach Electric Association,
Inc. (CEA) under an all requirements power supply contract. This supply includes a portion of
the output from two large hydroelectric projects: the 44 MW Eklutna Lake Hydroelectric
Project, and the 126 MW Bradley Lake Hydroelectric Project. The balance of power purchased
from CEA is generated with natural gas fired turbines. In addition to electricity supplied by CEA,
MEA also directly purchases a small amount of electricity from the 100 kilowatt (kW)
McRoberts Creek Hydroelectric Project located near Palmer.
MEAs existing all requirements supply contract with CEA expires at the end of 2014, and MEA
is currently constructing a new power plant, the Eklutna Generation Station (EGS), near the
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April 2013 Final Report 4
Native Village of Eklutna to supply electricity to its customers. The EGS will feature 10
reciprocating engines with a total generating capacity of 171 MW. The plant will likely be
fueled with natural gas, but will have the capability of operating on diesel fuel or other
hydrocarbon fuel supplies.
Starting in 2015, MEA will use the EGS to meet the electrical demands of its customers. MEA
will continue to purchase power from the Eklutna Lake, Bradley Lake, and McRoberts Creek
Hydroelectric projects, and has also contracted to purchase the full output of the 1.2 MW
Southfork Hydroelectric Project in Eagle River, which is expected to be operational in mid 2013.
There are several other prospective small hydroelectric and cogeneration projects located in
MEAs service area that may sell electricity to MEA in the coming years.
4
2.2.4 Electrical Distribution System
MEA operates over 4,000 miles of transmission and distribution lines located throughout its
service area. These range from major 115 kilovolt (kV) transmission lines down to single phase
7,200 volt distribution circuits. The existing MEA distribution line in the project vicinity is a
single phase 7,200 volt overhead line typical of older REA construction. This line has
insufficient capacity to transmit energy from Hunter Creek to MEA load centers or other railbelt
markets. Upgrade options are discussed in Section 3.5.4.
2.2.5 Planned Upgrades
Aside from the new generation station currently under construction discussed in Section 2.2.3,
MEA does not have any planned upgrades that will affect the development of a hydroelectric
project at Hunter Creek.
4 Information on the EGS and MEA contracts is condensed from MEA Informational Packet Prepared Pursuant to 3 AAC
50.790(d).(MEA, August 2012a). Polarconsult principals have ownership interests in the McRoberts Creek and
Southfork hydroelectric projects, as well as other proposed small hydroelectric projects that may sell to MEA in the
future.
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April 2013 Final Report 5
0
20
40
60
80
100
120
140
160
2004 2005 2006 2007 2008 2009 2010 2011 2012
60%
70%
80%
90%
100%
110%
120%
130%
140%
Monthly Average MEA System Demand
Monthly Peak MEA System Demand
Monthly MEA System Load Factor
2.2.6 Existing Demand Profile
MEAs existing demand profile is significantly greater than the supply potential of Hunter Creek.
Over the past 5 years, MEAs average monthly system demand varied from 73 to 113 MW, with
highest demand in the winter months (November to February) and lowest demand in the
summer months (May to July). Peak system demand varied from 84 to 145 MW, and load
factor varied from 71% to 86%. Recent MEA system demand data are shown on Figure 2 1.
Figure 2 1 Monthly Peak and Average MEA System Demand and Load Factor
Chart is based on data provided in TA 423 18 (MEA, 2012b).
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650,000
700,000
750,000
800,000
850,000
900,000
Projected Future Annual System Demand
Historic Annual System Demand
2.2.7 Projected Future Demand Profile and Energy Market
MEAs past annual system demand and projected future annual demand is presented on Figure
2 2. MEA projects annual demand growth of 1.5% over the next 10 years, which is consistent
with the utilitys recent annual demand growth trends.
5
MEAs system demand is large enough to absorb the full output of any of the Hunter Creek
project configurations considered in this study. Market conditions will be determined by
economics rather than by system demand considerations. The energy market for Hunter Creek
is discussed in Section 4 of this report (Section 4.2.1 specifically discusses the MEA market).
Figure 2 2 Historical and Projected Future MEA System Demand
5 Past MEA system demand data compiled from MEA Tariff Advice letter TA 423 18 (MEA, 2012b). Projected future
MEA system demand data is from the MEA information packet dated August 23, 2012 (MEA, 2012a).
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3.0 HYDROELECTRIC DEVELOPMENT OPTIONS
3.1 RESOURCE DESCRIPTION
Hunter Creek is a major tributary of the Knik River, draining a 71.1 square mile basin in the
Chugach Mountains located between Eklutna Lake and Lake George (see Figure 3 1 and Figures
A 1 and A 2 in Appendix A). Hunter Creek discharges into the Knik River approximately 11 miles
upstream of the Old Glenn Highway bridge. The Hunter Creek project site is located at latitude
61 25 13north, longitude 148 48 47west, within USGS quadrangle map Anchorage B 5
northwest. The recommended project configuration is located within section 31 of township 16
north, range 4 east, and sections 6 and 7 of township 15 north, range 4 east (Seward Meridian).
The Hunter Creek basin is comprised of subalpine valleys, alpine valleys, glaciers, and barren
alpine terrain. The basin receives approximately 80 inches of precipitation annually.
6 The basin
is comprised of two major valleys: the west fork valley, which is oriented with a north facing
aspect; and the east fork valley, which is oriented with a northwest facing aspect. Both valleys
are surrounded by mountains, with the exception of an approximately 2 mile wide mountain
gap opening north to the Knik River valley through which Hunter Creek flows. The basin is
bounded to the west, east, and south by a series of peaks, valleys, and ridges at elevations from
4,900 to 8,005 feet. The northerly basin divide between Hunter Creek and Knik River is a lower
series of peaks, valleys, and ridges at elevations from 4,700 to 5,800 feet. The southern extents
of both the east fork and west fork valleys are extensively glaciated. Table 3 1 presents the
general land cover composition of the Hunter Creek basin and major subbasins.
Table 3 1 Hunter Creek Subbasin Description
Basin Land Cover
East Fork
Subbasin (above
Diversion Site)
West Fork
Subbasin (above
Diversion Site)
Subbasin
Downstream of
Diversion Sites
Total Hunter
Creek Drainage
Basin
Forested 12% 11% 55% 19%
Alpine Tundra 12% 25% 17% 19%
Glaciated 29% 18% 0% 19%
Barren Alpine and
Barren Floodplain
47% 46% 28% 43%
Subbasin Area in Square Miles
(Percentage of Total Basin)
22.8
(32%)
33.4
(47%)
14.9
(21%)
71.1
(100%)
Analysis of 2011 12 stream gauging data on the main stem of Hunter Creek at river mile (RM)
1.59 indicates that the annual average flow in the main stem is approximately 311 cubic feet
per second (cfs). Analysis of 2011 12 stream gauging data for east fork Hunter Creek indicates
6 Interpreted from U.S. Geological Survey (USGS) Water Resources Investigation Report 93 4179, Plate 2 (USGS, 1993).
The Hunter Creek basin is intersected by several isohyets, indicating precipitation of approximately 80 to 100 inches
per year in the glaciated southeast portion of the basin closest to Prince William Sound, decreasing to approximately
40 to 60 inches per year in the northwest portion of the basin near its outlet to Knik River.
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that flows in the east fork and west fork can be reasonably estimated by scaling main stem
flows by the ratio of subbasin areas. Table 3 2 and Figure 3 1 present estimated hydrology for
the main stem, east fork, and west fork of Hunter Creek. Detailed hydrology analysis of Hunter
Creek is presented in Appendix C.
Figure 3 1 Hunter Creek and Major Subbasins
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Table 3 2 Estimated Hunter Creek Subbasin Hydrology
Parameter
East Fork above
Diversion Site
(RM 5.08)
West Fork above
Diversion Site
(RM 6.14)
Main Stem at Gauging
Station
(RM 1.59)
Subbasin Area (square miles) 22.8 33.4 69.7
Average Annual Flow 100 cfs 150 cfs 311 cfs
Annual Minimum Flow
(late March / early April)
5.5 cfs 8 cfs 18 cfs
Sustained Summer Flow
(early June to late September)
130 to 390 cfs 190 to 580 cfs 400 to 1,200 cfs
Peak Sustained Summer Flow
(mid July to mid August)390 cfs 580 cfs 1,200 cfs
Range of Project Design Flows
Considered in this Study
90 to 210 cfs 260 cfs NA
NA: Not applicable.
Figure 3 2 Estimated Hunter Creek Hydrograph
0
500
1,000
1,500
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Maximum Daily Flow
Mean (Average) Daily Flow
Minimum Daily Flow
East Fork FlowWest Fork Flow
320 480
160 240
0 0
480 720
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The reach of Hunter Creek under consideration in this study for hydroelectric development
extends from approximately RM 1.3 upstream to RM 5.1 on the east fork and RM 6.2 on the
west fork (see Figure A 1).
3.1.1 East Fork and Main Stem of Hunter Creek (Headwaters to RM 0.0)
East fork Hunter Creek starts at the terminus of Hunter Creek Glacier at approximately RM 9.3.
From RM 9.3 to RM 7.4, east fork Hunter Creek traverses mostly barren terrain dropping
approximately 1,500 feet in 1.9 miles, including a drop of 400 feet from RM 8.0 to RM 7.7 (See
Figure 3 1). The reach from approximately RM 9.3 to RM 8.5 was still glaciated in the 1960s.
7
From approximately RM 7.4 down to RM 4.36, east fork Hunter Creek has eroded a channel into
deposits of glacial till along the bottom of the east fork valley. This channel is approximately
100 feet deep and typically 200 to 300 feet wide, with mostly vegetated banks at 60% to 120%
slopes. East fork Hunter Creek follows an actively meandering braided course down the floor of
this channel, actively eroding till embankments in some areas (see Photographs B 13, B 16, and
B 17 in Appendix B). The creek runs at a gradient of approximately 2% to 5% through this
reach. The creek bed is alluvial materials interspersed with large boulders (glacial erratics)
exposed as the creek cuts through and washes away finer constituents of the till.
At approximately RM 4.6, the grade of east fork Hunter Creek begins to increase, and the width
of the channel narrows. At RM 4.40, east fork Hunter Creek intersects bedrock and enters the
Hunter Creek canyon (Photograph B 16). The average gradient from RM 4.36 past the
confluence with the west fork (RM 3.48) and down to approximately RM 3.10 is 12%. The width
of the canyon floor through this reach is typically 20 to 50 feet, and the rock canyon is very
steeply incised, with near vertical rock walls rising approximately 50 to 150 feet above the
creek (Photograph B 18). There is an approximately 200 to 300 foot thick mantle of glacial till
overlying bedrock in this area, which forms the upper sides of the canyon. Many parts of the
canyon rim with favorable drainage patterns maintain vertical faces approximately 20 to 50 feet
tall at the top of the till layer, transitioning farther down to unvegetated or sparsely vegetated
slides at approximately 80% to 120% slopes (Photographs B 17 and B 18).
In the vicinity of RM 3.10, the canyon floor transitions from exposed bedrock and large
boulders to a more uniform floor of coarse alluvium (cobbles and gravels). From RM 3.10 down
to the canyon outlet at RM 1.35, the canyon is typically 50 to 250 feet wide at the floor, and
150 to 500 feet deep. The canyon walls are a combination of bedrock outcrops and vegetated
talus slopes. The walls have slopes varying from approximately 100% on talus slopes to vertical
rock faces approximately 10 to 50+ feet tall (Photographs B 16, B 17, and B 18).
Hunter Creek runs through the lower canyon (RM 3.10 to RM 1.35) at a grade of approximately
1.0% to 1.5%, actively meandering across the canyon floor. The canyon floor through this reach
is devoid of bedrock outcroppings and is covered in a mantle of alluvium ranging from large
7 Based on USGS 1: 63,360 scale quadrangle maps Anchorage A 5 and B 5 (USGS, 1969).
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boulders and cobbles down to sands and silts in backwater areas. Materials on the canyon floor
are actively replenished by ongoing erosion processes upstream and are redistributed by
frequent high flow events. The Alaska Department of Fish and Game (ADF&G) has designated
the upper end of this reach as the upstream limit of anadromous fish habitat at approximately
RM 3.13.
Hunter Creek exits the canyon at RM 1.35, at the Knik River Road bridge. From RM 1.35 to the
Knik River at RM 0.00, Hunter Creek actively meanders across an alluvial fan at a low gradient
and has no practical hydropower potential. The current channel runs down the easterly edge of
the fan, but U.S. Geological Survey (USGS) maps published in the late 1960s indicate that the
creek flowed down the center of the fan at that time.
8
Hunter Creek from RM 2.58 up to the east fork headwaters at Hunter Creek Glacier is entirely
within lands selected by Eklutna as part of its land entitlement under the Alaska Native Claims
Settlement Act (ANCSA).
3.1.2 West Fork Hunter Creek (Headwaters to RM 3.48 Confluence)
West fork Hunter Creek headwaters consist of several tributaries that emerge from glacier
termini at elevations of 3,000 to 4,000 feet. These tributaries drop approximately 1,000 to
2,000 feet in 2 miles, with the largest two tributaries joining at approximately RM 10.1 and an
elevation of 1,700 feet.
From RM 10.1 to RM 5.87, west fork Hunter Creek travels over a braided floodplain at a grade
of 1.5% to 2.5%. The floodplain is not significantly incised, typically 150 to 600 feet wide, and
covers most of the floor of the west fork Hunter Creek valley.
At RM 5.87, west fork Hunter Creek enters the west fork Hunter Creek canyon (Photographs B
20 and B 21). The creek runs at a grade of 3.5% to 6% from RM 5.87 down to approximately
RM 4.0, then steepens to a grade of 9% to 11% from approximately RM 4.0 down to the
confluence with the east fork at RM 3.48. Throughout this reach, west fork Hunter Creek is
steeply incised in bedrock, with the canyon typically 20 to 50 feet wide at the floor and 50 to
250 feet deep. The canyon is deepest near the confluence with the east fork and becomes
progressively shallower upstream. Based on surface topography and erosion patterns, the west
fork valley appears to lack the deep mantle of glacial till present in the east fork valley and
confluence area, so the unstable slopes associated with the till layer along the east fork canyon
are not as pronounced along the west fork, especially above approximately RM 4.15. Instead,
exposed and shallow bedrock appears to be more prevalent along west fork Hunter Creek, and
the sides of the west fork valley are generally steeper and more incised than in the east fork
valley.
8 USGS 1: 63,360 scale quadrangle map Anchorage B 5 (USGS, 1969).
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From approximately RM 4.71 up to RM 9.85, west fork Hunter Creek is within the boundary of
Chugach State Park. Land from RM 4.71 up to RM 8.08 is owned by Eklutna but is managed as
part of the park by the Alaska Department of Natural Resources (ADNR), Division of Parks and
Recreation (DPOR) and is designated for eventual transfer from Eklutna to the State of Alaska.
Hydroelectric development is not consistent with DOPRs management goals for Eklutna land
within the park.
9
3.1.3 Fisheries
The lower reach of Hunter Creek from RM 0.00 up to approximately 3.13 is designated as
anadromous fish habitat by the ADF&G. This reach is designated as habitat for coho salmon.
Field reconnaissance conducted for this study confirmed the presence of adult coho in
spawning condition in the creek up to RM 1.81. No juvenile coho were trapped on the main
stem. No coho were observed from RM 1.81 up to RM 2.22.
10
Resident Dolly Varden were also trapped along the main stem of Hunter Creek between RM
1.35 and RM 1.5. Resident Dolly Varden are estimated to occur up to the confluence of the east
and west forks at RM 3.48. Trapping at RM 4.5 on the east fork above the canyon did not yield
any fish, indicating that the velocities and falls in the Hunter Creek canyon are an effective fish
barrier on the east fork and likely on the west fork as well. Fisheries data are discussed in more
detail in Appendix E (Section E.2).
9 This land is subject to the 1982 North Anchorage Land Agreement (NALA) between Eklutna, the Municipality of
Anchorage, and the State of Alaska. See Appendix D, Section D.1 for discussion of the terms of the NALA.
10 Field observations on October 4, 2011; October 12, 2011; and October 19, 2012.
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E1-48
W1
Designates East Fork-Only Project
Powerhouse Site (1 through 3)
Penstock Diameter (42, 48, or 54-inch)
Designates East Fork & West Fork Project
Project Configuration Descriptor
1 = West Fork RM 6.14 Diversion, Penstock Routed Around East Fork Canyon
2 = West Fork RM 6.14 Diversion, Penstock Bridge Over East Fork Canyon
3 = West Fork RM 4.20 Dam, Penstock Bridge Over East Fork Canyon
3.2 OVERVIEW OF PROJECT CONFIGURATIONS CONSIDERED
Hydroelectric developments are technically possible on both forks of Hunter Creek, and this
study considered project configurations on both forks of Hunter Creek. Because of the
geography of the basins and the relative proximity to existing access corridors, a hydroelectric
project can be developed on the east fork without accessing the west fork valley. However, a
project on the west fork would require constructing many of the access roads and penstock
corridors also needed for an east fork project. Accordingly, this study considered east fork only
project configurations, west fork and east fork project configurations, but no west fork only
project configurations. The project configurations considered in this study are listed in Table 3
3 and shown on Figure A 4 (east fork only configurations) and Figure A 5 (east fork and west
fork configurations). Figure 3 3 explains the configuration identifiers, used in Table 3 3, Figures
in Appendix A, and elsewhere in this report.
Figure 3 3 Explanation of Project Configuration Identifiers
As shown in Table 3 3 and Figure A 4, all east fork project configurations feature a common
diversion/intake site at RM 5.08. Three different powerhouse sites and three different design
flows are considered for east fork only projects, resulting in a total of nine east fork only
project configurations that were evaluated for this study.
All west fork configurations include concurrent development of east fork configuration E2 48.
Two different diversion sites are considered for west fork projects. West fork configurations
W1 and W2 both feature a diversion at RM 6.14, within Chugach State Park. W1 routes the
west fork penstock directly across the east fork canyon with a 1,100 foot pipe bridge. This
would be a major bridge, comparable to the Trans Alaska Pipeline suspension bridge across the
Tanana River near Delta Junction (see Photograph B 15 in Appendix B). W2 routes the west
fork penstock on a longer route around the east fork canyon, avoiding the cost of this major
bridge. Configuration W3 features a dam/diversion at RM 4.20 to avoid Chugach State Park.
This configuration includes a shorter 800 foot pipe bridge across the east fork canyon. This
study did not include detailed technical evaluation of the proposed dam site at RM 4.20 or
proposed bridge crossings for configurations W1 and W3.
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Table 3 3 Overview of Hydroelectric Project Configurations Considered
Project
Configuration Diversion Site
Design Flow
(cfs)
Powerhouse
Site Notes
E1 42 East Fork, RM 5.08 110 RM 3.14
E1 48 East Fork, RM 5.08 160 RM 2.67
E1 54 East Fork, RM 5.08 210 RM 1.02
E2 42 East Fork, RM 5.08 100 RM 3.14
E2 48 East Fork, RM 5.08 140 RM 2.67
E2 54 East Fork, RM 5.08 200 RM 1.02
E2 42 East Fork, RM 5.08 90 RM 3.14
E3 48 East Fork, RM 5.08 130 RM 2.67
E2 54 East Fork, RM 5.08 175 RM 1.02
W1 1 West Fork, RM 6.14 260 RM 2.67
Penstock routed via bridge
over east fork canyon
W2 1 West Fork, RM 6.14 260 RM 2.67
Penstock routed on grade
around east fork canyon
W3 1 West Fork, RM 5.21 (dam) 260 RM 2.67
Penstock routed via bridge
over east fork canyon
1. All west fork configurations include concurrent development of east fork project E2 48.
Detailed technical parameters, costs, and economics of the nine east fork only project
configurations are summarized in Table 3 4. Detailed technical parameters, costs, and
economics of the three west fork and east fork project configurations are summarized in Table
3 5.
Eklutna, Inc.Hunter Creek Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.April 2013Final Report 15Table 34 Cost Estimates and Financial Analysis for East ForkOnly Project ConfigurationsPROJECT CONFIGURATIONEAST FORK PROJECT CONFIGURATIONSESTIMATED PROJECT PARAMETERSE142 E148 E154 E242 E248 E254 E342 E348 E354Design Flow (cfs)110 cfs160 cfs210 cfs100140 cfs20090130175Diversion Location (subbasin area in square miles) RM 5.08 (22.8) RM 5.08 (22.8) RM 5.08 (22.8) RM 5.08 (22.8) RM 5.08 (22.8) RM 5.08 (22.8) RM 5.08 (22.8) RM 5.08 (22.8) RM 5.08 (22.8)Intake Elevation (feet)1,150 feet1,150 feet1,150 feetPowerhouse Elevation (feet) 370 feet (RM 3.14) 270 feet (RM 2.67) 175 feet (RM 1.02)Gross Head (feet)780 feet880 feet975 feetAccess Roads and Trails (feet) 17,300 feet 18,800 feet 17,800 feetPower and Communication Line Upgrades and Extensions (feet)79,700 feet78,900 feet72,900 feetPenstock Length (feet) and Diameter (inches) 9,700 ft./42 in. 9,700 ft./48 in. 9,700 ft./54 in. 11,600 ft./48 in. 11,600 ft./48 in. 11,600 ft./48 in. 17,200 ft./48 in. 17,200 ft./48 in. 17,200 ft./48 in.Net Head at Full Flow (feet)700 feet696 feet701 feet791 feet793 feet786 feet880 feet876 feet880 feetReservoir Area (acres) NA NA NA NA NA NA NA NA NAActive Band of ReservoirNANANANANANANANANAActive Reservoir Volume (acrefeet) NA NA NA NA NA NA NA NA NAInstalled Capacity (MW)5.3 MW7.7 MW10.2 MW5.5 MW7.7 MW10.9 MW5.5 MW7.9 MW10.7 MWAverage Annual Net Energy Output (MWh) 21,000 MWh 26,500 MWh 29,200 MWh 22,400 MWh 27,100 MWh 32,100 MWh 23,400 MWh 28,800 MWh 33,600 MWhPlant Capacity Factor45.0%37.8%32.7%46.8%40.2%33.6%48.7%41.8%36.0%ESTIMATED TOTAL INSTALLED COST RANGE (2013 $, MILLIONS)Preconstruction (studies, permitting, design, site control, etc.)$0.9$1.3$0.9$1.3$0.9$1.3$0.9$1.3$0.9$1.3$0.9$1.3$0.9$1.3$0.9$1.3$0.9$1.3Power and Communication Lines $1.9$2.8 $2.0$3.0 $2.2$3.3 $1.9$2.8 $2.0$3.0 $2.2$3.2 $1.7$2.5 $1.8$2.7 $2.0$2.9Access Roads and Flood Protection$2.4$3.6$2.4$3.6$2.4$3.6$2.5$3.8$2.5$3.8$2.5$3.8$2.4$3.7$2.4$3.7$2.4$3.7Diversion and Intake Structure(s) $0.7$1.0 $0.7$1.0 $0.7$1.0 $0.7$1.0 $0.7$1.0 $0.7$1.0 $0.7$1.0 $0.7$1.0 $0.7$1.0Penstock(s)$3.0$4.5$3.5$5.3$5.0$7.5$3.5$5.3$3.4$5.1$6.1$9.1$6.0$9.0$6.8$10.2$10.0$15.1Powerhouse $5.9$8.8 $5.9$8.9 $7.0$10.5 $5.1$7.7 $6.0$9.0 $7.2$10.8 $3.0$4.4 $3.9$5.8 $5.0$7.5Construction Equipment$0.7$1.1$0.7$1.1$1.0$1.5$0.9$1.4$0.9$1.4$1.0$1.5$1.1$1.7$1.1$1.7$1.1$1.7Shipping $0.2$0.3 $0.2$0.3 $0.3$0.4 $0.2$0.4 $0.2$0.4 $0.4$0.6 $0.3$0.4 $0.3$0.4 $0.5$0.7Construction Engineering and Inspections$0.7$1.1$0.8$1.2$0.9$1.4$0.8$1.1$0.8$1.2$1.0$1.5$0.8$1.2$0.9$1.3$1.1$1.6Construction Management/Administration $0.7$1.1 $0.8$1.2 $0.9$1.4 $0.8$1.1 $0.8$1.2 $1.0$1.5 $0.8$1.2 $0.9$1.3 $1.1$1.6Contingency$5.1$7.7$5.4$8.1$6.4$9.6$5.2$7.8$5.5$8.2$6.9$10.3$5.3$7.9$5.9$8.8$7.4$11.1ESTIMATED TOTAL INSTALLED COST RANGE (2013 $, MILLIONS)$22.2$33.3 $23.3$35.0 $27.7$41.5 $22.5$33.7 $23.7$35.6 $29.9$44.6 $23.0$34.3 $25.6$38.2 $32.2$48.2ESTIMATED RANGE OF FINANCIAL PARAMETERS1Capital Cost Paid by Grants$85,000$8.0M$85,000$8.0M$85,000$8.0M$85,000$8.0M$85,000$8.0M$85,000$8.0M$85,000$8.0M$85,000$8.0M$85,000$8.0MOwner EquityPosition (Million $) $6.7$2.2 $7.0$2.3 $8.3$2.8 $6.7$2.3 $2.4$7.1 $3.0$8.9 $2.3$6.9 $2.6$7.6 $3.2$9.6Financed Capital Cost (Million $)$12.0$26.6$13.0$27.9$16.9$33.1$12.3$26.9$13.3$28.4$18.9$35.6$12.7$27.4$15.0$30.5$21.0$38.5Annual Debt Servicing Cost (Million $) $0.8$1.9 $0.8$2.0 $1.1$2.4 $0.8$2.0 $0.9$2.1 $1.2$2.6 $0.8$2.0 $1.0$2.2 $1.4$2.8Annual OMR & R Costs (Million $)$0.3$0.4$0.4$0.5$0.5$0.5$0.4$0.4$0.4$0.5$0.5$0.6$0.4$0.4$0.5$0.5$0.5$0.6Return on Equity (%) 12%18% 12%18% 12%18% 12%18% 12%18% 12%18% 12%18% 12%18% 12%18%Total Annual Revenue Requirement (Million $)$1.5$4.0$1.7$4.3$2.2$5.0$1.6$4.1$1.7$4.4$2.3$5.5$1.7$4.1$2.0$4.7$2.5$5.8Estimated Range of Sales Rate for Energy ($ per kWh) $0.072$0.192 $0.064$0.163 $0.074$0.172 $0.073$0.181 $0.064$0.162 $0.073$0.170 $0.072$0.176 $0.069$0.162 $0.075$0.174Estimated Range of BenefitCost Ratio1.232.531.483.041.372.821.302.661.493.061.412.881.332.721.473.011.362.801 SeeAppendix G for economic analysis assumptions.
Eklutna, Inc.Hunter Creek Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.April 2013Final Report 16Table 35 Cost Estimates and Financial Analysis for East and West Fork Project Configurations1. Technical and economic data for all west fork projectconfigurations include concurrent development of east fork project E248.2.See Appendix G for economic analysis assumptions.PROJECT CONFIGURATIONSWEST FORK PROJECT CONFIGURATIONS(1)ESTIMATED PROJECT PARAMETERSW1 W2 W3Design Flow (cfs)260 cfs260 cfs260 cfsDiversion Location (subbasin area in square miles) RM 6.14 (33.4) RM 6.14 (33.4) RM 4.20 (38.2)Intake Elevation (feet)1,250 feet1,250 feet920 feetPowerhouse Elevation (feet) 270 feet (RM 2.67) 270 feet (RM 2.67) 270 feet (RM 2.67)Gross Head (feet)980 feet980 feet650 feetAccess Roads and Trails (feet) 39,800 feet 32,800 feet 37,750 feetPower and Communication Line Upgrades and Extensions (feet)78,900 feet78,900 feet78,900 feetPenstock Length (feet) and Diameter (inches) 22,800 ft./72 in 26,000 ft./72 in 8,000 ft./60 inNet Head at Full Flow (feet)823 feet859 feet557 feetReservoir Area (acres) NA NA 12 acresActive Band of ReservoirNANA2 feetActive Reservoir Volume (acrefeet) NA NA 24 acrefeetInstalled Capacity (kW)22.3 MW23.0 MW18.7 MWAvg. Ann. Net Energy Output (MWh) 79,400 MWh 80,900 MWh 64,600 MWhPlant Capacity Factor40.6%40.2%39.4%ESTIMATED TOTAL INSTALLED COST RANGE (2013 $, MILLIONS)Preconstruction (studies, permitting, design, site control, etc.)$1.6$2.4$1.6$2.4$1.6$2.4Power and Communication Lines $3.3$4.9 $3.3$4.9 $3.1$4.7Access Roads and Flood Protection$6.8$10.1$6.9$10.3$6.0$9.0Diversion and Intake Structure(s) $1.4$2.0 $1.4$2.0 $33.1$49.4Penstock(s)$30.2$46.6$28.5$43.1$18.3$27.4Powerhouse $17.3$26.3 $17.7$26.5 $15.7$23.6Construction Equipment$1.8$2.8$1.8$2.7$1.8$2.7Shipping $0.5$0.8 $0.5$0.7 $0.3$0.5Construction Engineering and Inspections$3.1$4.7$3.0$4.5$3.9$5.9Construction Management/Administration $3.1$4.7 $3.0$4.5 $3.9$5.9Contingency$20.9$31.7$20.3$30.4$26.3$39.5ESTIMATED TOTAL INSTALLED COST RANGE$90$137 $88$132 $114$171ESTIMATED RANGE OF FINANCIAL PARAMETERS2Capital Cost Paid by Grants$85,000$8.0M$85,000$8.0M$85,000$8.0MOwner Equity Position (Million $) $9.1$27.4 $8.8$26.4 $11.4$34.2Financed Capital Cost (Million $)$74.3$109.7$71.3$105.4$94.5$136.9Annual Debt Servicing Cost (Million $) $4.8$8.0 $4.6$7.7 $6.1$9.9Annual OMR & R Costs (Million $)$1.3$1.5$1.3$1.4$1.0$1.2Return on Equity (%) 12%18% 12%18% 12%18%Total Annual Revenue Requirement (Million $)$8.1$16.4$7.8$15.8$9.6$19.7Estimated Range of Sales Rate for Energy($ per kWh) $0.100$0.202 $0.098$0.199 $0.148$0.305Estimated Range of BenefitCost Ratio1.202.471.132.330.741.52
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3.3 RECOMMENDED PROJECT CONFIGURATION
Several of the east fork project configurations evaluated in this study appear to be technically,
economically, environmentally, and politically viable. Based on currently available information
and the level of analysis performed for this study, project configuration E2 48 (see Figure 3 4) is
the most economic of the project configurations evaluated, providing the lowest cost electricity
and highest benefit cost ratio. East fork only project configurations E1 48 and E3 48 have
marginally less favorable economics than E2 48.
Project configurations E1 48 and E3 48 have similar economics as E2 48. Configuration E1 48
may have a lesser environmental impact than E2 48 or E3 48 because E1 48 is located entirely
upstream of anadromous fish habitat. Configuration E3 48 is more technically straightforward
than the others because it avoids the technical challenges associated with siting a powerhouse
within Hunter Creek canyon. Accordingly, it is possible that additional information collected
for a future feasibility study may result in the selection of a different project configuration for
development.
West fork and east fork project configurations W1 and W2 also have favorable economics but
less so than the east fork only project configurations. Configurations W1 and W2 both face a
significant political barrier since they would be partially located within a wilderness zone of
Chugach State Park. DOPRs management plans for the park designate hydroelectric projects as
inconsistent with the management goals for a wilderness zone (See Appendix D, Section D.1).
West fork and east fork project W3, which features a dam and small reservoir on the west fork
outside Chugach State Park, is not economically viable under current market conditions.
Sections 3.4 and 3.5 focus on project configuration E2 48, identified as the most favorable
configuration, to describe the performance and configuration of a hydroelectric project at
Hunter Creek.
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Figure 3 4 Map of Recommended Project Configuration
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3.4 ESTIMATED ENERGY GENERATION
Estimated average seasonal energy generation for the recommended project (E2 48) is
presented on Figure 3 5. For reference, Figure 3 5 also includes the estimated average daily
energy generation for the other project configurations considered in this study. Several sets of
project configurations have substantially similar energy generation profiles. For clarity, Figure
3 5 shows a single curve for each set rather than multiple overlapping curves.
All project configurations considered for Hunter Creek are effectively run of river projects since
the topography in the Hunter Creek basin is not conducive to economic construction of
significant volumes of reservoir storage. Even configuration W3, which includes a dam and
reservoir, does not provide significant storage and would operate as a run of river project. The
power generation of all project configurations would vary with stream flow in Hunter Creek.
Projects would typically generate full output from mid June to early September, decreasing
through the winter to approximately 5% of installed capacity in early April, and then increasing
through break up back to full output.
Figure 3 5 Estimated Seasonal Energy Generation for Selected Project Configurations
0
5,000
10,000
15,000
20,000
25,000
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Configurations
E1 42, E2 42, E3 42
Configurations
E1 54, E2 54, E3 54
Configurations
E1 48,E2 48, E3 48
Configuration W3
Configurations W1 & W2
Configuration E2 48
(Recommended Project)
Configuration E1 48, E3 48)
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Annual energy generation estimates for all Hunter Creek project configurations were developed
by:
1. Computing the average daily flow from the extended hydrology record for the main stem
Hunter Creek gauging station.
2. Scaling this daily flow by relative basin areas to the appropriate diversion location on the
east fork or west fork.
3. Calculating the gross energy generation for each day by considering the available flow;
hydraulic losses through the diversion, intake, and penstock; and turbine and generator
efficiencies at that particular operating point.
4. Subtracting losses for station service and step up transformer. The result is multiplied by
95%to provide an allowance for routine and unscheduled plant outages. The point of
delivery to the purchasing utility is assumed to be the high side of the transformer at the
hydro powerhouse.
This study has assumed that the project would be operated year round. It is possible that
operating costs through the winter season may exceed revenues, in which case it would be
cost effective to shut down the project during the winter season. More detailed analysis of the
economics of winter operations are warranted at the feasibility study stage of analysis. The
analysis should also evaluate spring start up considerations, such as management of icing in the
penstock during the spring start up sequence.
3.5 DESCRIPTION OF FEATURES FOR RECOMMENDED PROJECT
This study has identified project configuration E2 48 as the most favorable Hunter Creek
hydroelectric project configuration. This section describes major features of configuration E2
48 (see Figure 3 4).
3.5.1 Access and Staging
A new construction road will be built from Knik River Road to the project site, starting
approximately 0.4 miles east of the Hunter Creek bridge (see Figure 3 4). The recommended
project would require approximately 3.3 miles of new access roads up into the east fork Hunter
Creek valley. Heavy equipment may also access the in canyon powerhouse site by traveling up
the Hunter Creek canyon floor.
Equipment and material staging areas can be sited on Eklutna land in the project area or on
other privately owned land in the project vicinity.
3.5.2 Construction Schedule
Construction of the project is assumed to occur over two construction seasons.
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The first season would begin with upgrading the power line to the project and construction of
the access roads into the project work area. Once access roads are completed, one crew would
work on installing the penstock, power lines, and control lines; and a second crew would work
on site work for the in canyon powerhouse, including stabilizing and/or scaling the canyon wall
above the powerhouse in preparation for construction of the powerhouse and the portion of
the penstock that descends the canyon wall. Once water levels in Hunter Creek drop in late fall,
construction of the powerhouse foundations and diversion/intake structure would begin and
advance until winter shutdown. Long lead items such as the turbines and generators would
also be ordered during the first year of construction.
The second construction season would start in February or March, focusing on completion of
in water work at the powerhouse and diversion structure before the onset of higher summer
flows. Work on these structures would continue starting in May or June, finishing the
superstructure and furnishing the powerhouse with switchgear, controls, turbines, generators,
etc. Project testing and commissioning would occur in late summer or early fall.
3.5.3 Transmission Line
There are two MEA substations in the general project vicinity. The closest is located at the
intersection of the Old Glenn Highway and Bodenburg Loop Road, approximately 14.7 miles
from the proposed Hunter Creek powerhouse along existing utility easements. The Eklutna
Hydro Substation is 16.6 miles from Hunter Creek. The distribution circuit serving Hunter Creek
is three phase from the Bodenburg substation 0.3 miles to the intersection of the Old Glenn
Highway and East Our Road. From there, the circuit is single phase 1.6 miles to the south side
of the Knik River and an additional 10.6 miles to Hunter Creek along Knik River Road.
This existing distribution circuit will need to be bypassed or upgraded to deliver energy from
Hunter Creek to MEA load centers or other railbelt markets. For budgeting purposes, this study
assumes that this existing circuit will be upgraded to a three phase 34.5 kV circuit. Project
configurations over approximately 6 MW may require a higher voltage or a double circuit, likely
with a 7.2 kV underbuild to serve local customers.
3.5.4 Controls and System Integration
The project would include dedicated communications circuits between the intake and the
powerhouse to operate the project. A dedicated communications circuit would also be
provided between the powerhouse and the nearest MEA substation to integrate the project
with MEAs control systems. These circuits would allow for remote operation, monitoring, and
control of the project.
The control regime used to manage project operations would depend on the market for the
electricity. If the electricity was sold to MEA, the project could be configured to be
dispatchable by MEA to minimize MEAs fuel and purchased power costs, thereby maximizing
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the projects value. During system emergencies, MEA or Eklutna would have the capability of
shutting down the project and isolating it from the MEA grid.
3.5.5 Diversion and Intake
The east fork project diversion would be located at approximately RM 5.08. The bed of Hunter
Creek in this reach is alluvium, likely overlying glacial till and bedrock. The diversion structure
would be a dike approximately 200 feet long and 10 feet tall, spanning the full width of Hunter
Creeks floodplain in the diversion area. A concrete spillway would be sited at the existing main
channel of Hunter Creek to pass flow through the diversion and into the bypass reach. The
main spillway could be fitted with a bank of tainter gates to help regulate water elevation in the
diversion impoundment. This configuration would also help to preferentially pass bedload
downstream. A lateral intake structure would be located upstream of the diversion dike on the
north side of the creek to admit up to 140 cfs into the project intake works. Water would flow
from the intake into a stilling basin, where most suspended sediment would be removed from
the water column. Clarified water would then flow from the stilling basins over an inclined
plate intake screen to screen out small debris, and into a gallery for admittance to the
penstock. The intake works would be designed to allow for uninterrupted flow to the penstock
during stilling basin flushing operations. A conceptual site plan is shown in Figure A 6.
Initial estimates of sediment transport in east fork Hunter Creek, and issues surrounding
sediment management at the diversion and intake works, are discussed in more detail in
Section D.2.3 of Appendix D.
3.5.6 Penstock
The penstock would be an approximately 11,600 foot long, 48 inch diameter buried pipeline
co located with the access road to the diversion and intake site (see Figure 3 4). Most of the
penstock (approximately 9,800 feet) would be high density polyethylene (HDPE) pipe. The
1,800 feet of penstock nearest the powerhouse would operate at a higher pressure, requiring
the use of ductile iron, steel, or a similar pipe material.
The first 2,400 feet of the penstock/access road would be located along the edge of Hunter
Creeks active floodplain, set at a grade of approximately 5%.This portion would be armored
with riprap or sheet pile to prevent erosion by Hunter Creeks meandering action.
Approximately 2,400 feet downstream of the diversion, the penstock would sidehill along the
bank of Hunter Creeks incised channel for approximately 1,200 feet (station 24+00 to 36+00),
climbing approximately 70 feet at grades of up to +20%. A manual drain valve and automatic
air purge valve would be located at the bottom and top of this 1,100 foot section, respectively.
Once out of the incised channel, the penstock would continue downhill above the rim of the
channel and canyon for approximately 3,300 feet at a grade of approximately 0.5%to 1.0%
(station 36+00 to 69+00). This shallow grade is necessary to stay uphill of the canyon rim. Near
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the upstream end of this section (approximately 4,300 feet from the diversion), a 40 foot deep
cut or directional bore is necessary for approximately 300 feet to maintain grade. This section
is located approximately 70 to 100 feet from the top edge of an exposed embankment of glacial
till that forms the north side of the canyon at RM 4.15 (see Photographs B 7, B 9, and B 19).
The next 2,100 feet (station 69+00 to 90+00) of the penstock would sidehill at grades of 1 to
10%through upland terrain with cross slopes that vary from 2:1 to 4:1. There are several
small gullies in this area that would be crossed with culverts and fill.
The next 2,000 feet (station 90+00 to 110+00) of the penstock would cross relatively level land
away from the canyon rim at grades of 6%to 15%,ultimately returning to the canyon rim
directly above powerhouse site #2 at RM 2.67. The penstock would change from HDPE to
ductile iron or steel at approximately station 98+00. A significant portion of the land along the
penstock alignment in this area is wetland. Further field investigations may identify penstock
alignments that can avoid or minimize impacts to wetlands in this area.
The final 600 feet of the penstock (station 110+00 to 116+00) would descend the wall of the
canyon down to the powerhouse at a grade of 100%to 140%.The canyon wall would be
cleared and scaled to remove overburden and loose rock. The penstock would then be set on
reinforced concrete or steel piers secured with grouted rock bolts to the canyon wall. This
portion of the penstock would likely be 40 foot sections of steel pipe, minimizing the number of
intermediate piers built into the canyon wall. A permanent means of access to the powerhouse
would be integrated to the penstock structure descending the canyon wall. This would likely
include a covered staircase for four season pedestrian access and a railway or skid to move
machinery (generators, turbine, etc.) in and out of the powerhouse. The powerhouse site could
also be suitable for installation of a highline for this purpose.
3.5.7 Powerhouse
The powerhouse would be located in lower Hunter Creek canyon at approximately RM 2.67.
The exact powerhouse location would depend on site specific characteristics of the canyon
walls (rock stability, suitability for penstock installation, and construction access), and
environmental considerations (exact extent of fish habitat,mitigation options, etc.).
The powerhouse would be an approximately 30 by 50 foot building. The building footprint
may be formed by partially blasting an alcove into the canyon wall. Some or all of the building
footprint would occupy the canyon floor. The building foundation could use driven piling to
minimize obstructions to the flow of Hunter Creek. The general building design would
accommodate peak flood events, including the possibility of debris accumulating on the
powerhouse foundation and raising the local flood stage.
Routine access to the powerhouse would be via the overland project access road and then
down the canyon wall via the penstock structure. Heavy equipment for construction and
infrequent heavy maintenance would access the powerhouse site by driving up the canyon
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floor to the powerhouse. This activity would be weather and season dependent since most of
the canyon floor is inundated during peak flood events with few if any refuge areas for
equipment (see Photograph B 24). Such access would also need to be coordinated with
fisheries to avoid damage to fish habitat or possible redds along the creek bed.
3.5.8 Tailrace
The tailrace would be integrated into the powerhouse foundation, discharging directly to
Hunter Creek on the canyon floor.
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4.0 MARKET ANALYSIS AND OPPORTUNITIES
Based on current information and market conditions, the most accessible market for electricity
from a hydroelectric project at Hunter Creek would be wholesale purchase by MEA at its non
firm avoided cost of energy or a negotiated price. Under this business arrangement, Eklutna
would be operating as an Independent Power Producer (IPP). This and other potential business
models and markets are discussed in this section, as follows:
Section 4.1 discusses potential business models for a Hunter Creek Hydro Project.
Section 4.2 discusses potential markets for electricity from a Hunter Creek Hydro
Project.
4.1 POTENTIAL BUSINESS MODELS
Eklutna could adopt three business models as the owner of a hydro project at Hunter Creek:
Independent Power Producer (IPP),
Electric Utility, or
Non Utility Entity with Directed Sales.
4.1.1 Independent Power Producer
Eklutna could become an IPP. IPPs are non utility energy generators that output commercial
quantities of electricity to the electric grid on a wholesale basis. They are generally
distinguished from traditionalutilities in that they do not provide retail sales of electricity to
end users, and they do not own and maintain transmission or distribution systems beyond what
is necessary to deliver their electricity to the local grid.
IPPs are a well established market presence in the lower 48 states, but their role in Alaskas
(and the railbelts) electric industry is still relatively new and evolving. IPPs have been
operating on the railbelt grid for over 20 years, but until very recently their role has not been
fully recognized by most Alaska utility planning efforts or in the States regulatory framework.
11
This situation has started to change in the past few years, with increased recognition of the cost
savings, risk management benefits, supply diversification, and other benefits IPPs provide to
electric utilities and their ratepayers.
12
11 One of the earliest private sector IPPs on the railbelt grid was Enerdyne, LLC, operator of a 100 kW run of river hydro
project near Palmer that has sold wholesale energy to MEA since 1991. Enerdyne is owned by principals of
Polarconsult. Another early IPP is Aurora Energy, LLC, which started selling electricity to GVEA from its coal fired
plant in Fairbanks in 1995.
12 There are at least five commercial scale IPPs now operating on the railbelt, with several others in pre commercial
stages of project development. The Railbelt Integrated Resource Plan acknowledged the positive role IPPs can play in
the railbelt energy market (AEA, 2010).
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Under Alaskas existing regulations, many IPPs still fall under the definition of a utility and may
face varying levels of regulatory oversight or exemption by the RCA. Maintaining compliance
with full RCA regulation is expensive and is a significant cost for smaller IPPs. The RCA
recognizes this and has therefore exempted some IPPs from full RCA regulation under the
public interest criteria in Alaska Statute (AS) 42.05.711(d).
13 Some representative examples of
regulatory oversight exercised over IPPs operating on the railbelt are provided below:
Aurora Energy, LLC (Aurora)Aurora, an affiliate of Usibelli Coal Mine, Inc., operates a
coal fired power plant in Fairbanks and sells firm power to Golden Valley Electric
Association, Inc. (GVEA). Aurora is an economically regulated certificated public utility
operating under CPCN No. 520.
14
Fire Island Wind, LLC (FIW)FIW, a wholly owned subsidiary of Cook Inlet Region, Inc.,
operates a 17 MW wind farm on Fire Island that sells 100% of its output to CEA at a
fixed net price of $97 per MWh over a 25 year term. FIW was exempted from RCA
regulation by AS 42.05.711(r), and does not have a CPCN.
15
South Fork Hydro, LLC (SFH)SFH is a privately owned company currently developing a
1.2 MW run of river hydro project on the south fork of Eagle River near Anchorage. SFH
will sell 100% of its output to MEA at a fixed net price of $70 per MWh over a 30 year
term.16 SFH was granted exemption from RCA regulation under AS 42.05.711(d) and
does not have a CPCN.
17
Alaska Environmental Power, LLC (AEP)AEP is a privately owned company that
operates a wind farm with an installed capacity of 1.0 MW in Delta Junction, Alaska.
AEP sells 100% of its output to GVEA for a variable price equal to GVEAs system average
avoided energy cost reported in its tariff on a quarterly basis. AEP is a Qualified Facility
under federal regulations, which exempts it from state utility regulation. However,
because of conditions associated with a construction grant received from the AEA, AEP
is required to operate as a certificated public utility under CPCN No. 742.
18
4.1.2 Independent Electric Utility
Eklutna could form a new utility and provide retail electric service to developments in the
project vicinity outside of the MEA service area. In the project vicinity, this would generally
13 Some of the economic assumptions in this study include receipt of grant funds under the Renewable Energy Grant
Program for construction. Current program rules require the grant recipient to obtain a CPCN and submit to
economic regulation by the RCA or equivalent oversight by AEA. This is the case for Alaska Environmental Power,
LLC.
14 See Order No. 2 in RCA Docket U 97 139.
15 See Order No. 5 in RCA Docket U 11 100. AS 42.05.711(r) is a narrowly defined exemption criteria that does not
apply to Hunter Creek.
16 See AEA/AIDEA Board Resolution 2012 02. One of the members of SFH is a principal at Polarconsult.
17 See Order No. 2 in RCA Docket U 08 102.
18 See Order No. 2 in RCA Docket U 11 111.
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include Eklutna land in the east fork Hunter Creek valley and most of the west side of the west
fork valley (the MEA service area boundary is shown on Figure A 3).
This option presumes that Eklutna desires to develop these lands and that there is a market for
developed property in this area. Because of the seasonal variation in electrical output from
Hunter Creek, Eklutna would still need to sell surplus electricity to the railbelt during the
summer months, and either generate or purchase electricity during the winter months to meet
its customersdemand. Eklutna would also assume responsibility for building, operating, and
maintaining the distribution system, metering, billing, customer service, and related business
operations of a full electric utility.
While this business model is an option, it would involve significant cost, risk, and responsibility.
The relatively small size of the utility, and the continuing need to sell and purchase energy from
railbelt utilities to meet the needs of local customers, makes it questionable whether an
independent utility business model would be the least cost solution for providing electric
service in this area or would maximize the economic benefits of a hydroelectric project at
Hunter Creek.
If a specific development plan consistent with an independent utility model is envisioned for
these lands, the business case should be reviewed to see if it is competitive with more
conventional alternatives.
4.1.3 Non Utility Entity
If Eklutna identified a non utility market for electricity from a project at Hunter Creek, it may be
able to directly sell energy to that market. Some of the opportunities and restrictions for direct
sales to non utility entities are described below:
1. Sale to less than 10 independent end users that are not within an existing certificated
utility service area is not regulated by the RCA. Figure A 3 shows the extent of MEAs
existing certificated service territory in the project vicinity. Existing developed areas
along Knik River Road are all within MEAs certificated service area.
2. Potential examples of this market include mines, lodges, resorts, or similar businesses
operating in the immediate project vicinity. This business model would need to consider
the market demand for electricity and the supply capability of the selected hydro
project. Mismatches between demand and supply could potentially be met by sale or
purchase of energy from MEA, or other generation means. This business model would
require detailed analysis to verify a specific project business plan complied with existing
statutes and regulations.
3. Sale to affiliated interests of the hydro project owner. Under this structure, Eklutna (or
its subsidiary owning the hydro project) could sell electricity to affiliated interests
located within an existing utility service territory in certain limited situations. A specific
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business plan would require detailed analysis to determine if it complied with RCA
regulations.
4. Direct sale of electricity to unaffiliated entities within an existing utility service area is
not allowed under RCA regulations. Some electricity markets in the lower 48 states
have been deregulated to allow such direct sales, but Alaska remains a regulated market
where such activities are not allowed.
4.2 POTENTIAL MARKETS
4.2.1 Local Market Matanuska Electric Association, Inc.
Because Hunter Creek is located within MEAs service territory, MEA is the most logical
purchaser of electricity from Hunter Creek. The recommended project configuration, E2 48,
would supply approximately 8% of MEAs average load during the summer months.
Figure 4 1 presents MEAs past and projected future non firm avoided cost of energy. This, or a
similar negotiated price, is the most likely price that MEA would pay for the electrical output
from Hunter Creek. The greatest uncertainty in MEAs projected future non firm energy costs is
the price MEA will pay for the natural gas needed to run the EGS starting in 2014. Annual
shortages of natural gas are predicted in Cook Inlet in 2013 or 2014, and the pricing and
availability of natural gas from new discoveries or liquefied natural gas imports remains a
critical unknown. Developments over the next 2 years are expected to provide better guidance
for energy costs in 2018 and after, which is when Hunter Creek would become operational.
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$0.030
$0.040
$0.050
$0.060
$0.070
$0.080
$0.090
$0.100
Projected Future MEA Non Firm Energy Cost (Annual Average)
Historic Non Firm Energy Cost (Annual Average)
Historic Non Firm Energy Cost (Quarterly Cost)
Figure 4 1 MEAs Past and Projected Future Non Firm Avoided Cost of Energy
Chart sources:
1. Historic non firm energy costs are compiled from MEAs quarterly tariff advice filings with the RCA.
2. Projected future non firm energy costs for 2013 and 2014 are based on 80% of MEAs average annual
cost for 2012, escalated by 2% per year. The 80% factor reflects CEAs improved system heat rate
with the Southcentral Power Project operational. The Southcentral Power Project became fully
operational in January 2013.
3. Projected future non firm energy costs for 2015 to 2017 are from MEA (MEA, 2012a).
4. Projected future non firm energy costs for 2018 and after are escalated from MEAs 2017 forecast
cost at 2% per year.
There are several energy projects in various stages of development that could impact MEAs
energy costs, adversely affecting the market for a Hunter Creek project. Some of these projects
are listed in Table 4 1.
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Table 4 1 Proposed Alternative Energy Supplies for MEA
Resource/Project
Proposed
Operational
Date
Proposed
Energy Price
(2013 $)
Probable Impact on MEAs Non Firm Avoided Cost
Fire Island Wind Farm
(1)Fall 2012
$0.097 per
kWh
Neutral. Full output is purchased by CEA. This
slightly increases MEAs rates through 2014 but will
have no impact on MEA rates thereafter.
New Natural Gas
Supplies in Cook Inlet
2013 2016 NA
Neutral to increase. These new supplies are needed
to meet existing utility demand in southcentral
Alaska. Prices for gas from these new supplies will
likely be similar to or slightly higher than existing
natural gas prices, which is consistent withprojected
future MEA avoided cost.
Alaska Stand Alone Gas
Pipeline (ASAP)
2018 2019 $0.083 per
kWh
Neutral. Assumed to supplement existing natural
gas supplies. Projected cost of gasfrom the ASAP
project is similar to MEAs cost projections.
(2)
Susitna Watana
Hydroelectric Project
(4)2024 $0.138 per
kWh
Increase. The projected cost of energy from Susitna
Watana is approximately 30% higher than MEAs
projected energy costs in 2024.
(3)
Trans Canada Gas
Pipeline Unknown Unknown
Too many unknowns to speculate. Likely similar to
other gas supply projects listed in this table.
(1) Based on project information on FIW Web site: www.fireislandwind.com/news updates/
(2) Based on an assumed power plant heat rate of 9,000 British thermal units (Btu)/kWh and delivered natural gas
cost in Anchorage of $9.63 per MMBtu (million British thermal units) (ASAP Project Plan [AGDC, 2011]).
(3) Based on information in January 10, 2013 Project Update to Alaska Industrial Development and Export
Authority (AIDEA)/AEA Board (AEA, 2013).
All of these projects have some degree of risk and uncertainty. With the exceptions of the Fire
Island Wind Farm, which was completed in fall 2012 and is operational, it is unknown if or when
any of these projects will be built or whether the estimated budgets will be met and projected
energy costs will be realized.
4.2.2 Railbelt Market
The railbelt is the largest single electric market in Alaska and is capable of receiving the full
output of any Hunter Creek hydro project. The railbelt presents a variety of interesting market
opportunities and challenges for Eklutnas consideration.
While the railbelt is interconnected, it is not an integrated market. Different sections of the
railbelt transmission system are owned by different entities, and there are several technical and
contractual bottlenecks that restrict flow of power within the railbelt. Many of the utilities are
subject to all requirements or some requirements power supply contracts that limit the ability
of an IPP to sell electricity to utilities. The result is a very complicated technical and legal
patchwork.The railbelt electric utilities are currently in a cycle of capital reinvestment and
structural reform, which may simplify this patchwork over the next 5 to 10 years. By the time
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Hunter Creek is operational, it may be simpler to sell electricity to distant railbelt utilities than it
is at present.
Other Railbelt Utilities
Electricity from Hunter Creek could be sold to one or more of the other five railbelt utilities.
These are:
Chugach Electric Association, Inc. (southern Anchorage and northern Kenai Peninsula),
Anchorage Municipal Light and Power (ML&P) (northern Anchorage),
Golden Valley Electric Association, Inc. (GVEA) (Cantwell, Fairbanks, Delta Junction),
Homer Electric Association, Inc. (HEA) (southern Kenai Peninsula), and
Seward Electric System (SES) (City of Seward).
At this time, the railbelt transmission system is technically capable of transmitting electricity
from Hunter Creek to other railbelt utilities, but it is not legally or contractually configured for
use by IPPs. Assuming that Eklutna pays the cost of upgrading the distribution line from Hunter
Creek to MEAs substation, then Eklutna would only need to pay MEA wheeling charges from
that substation to the receiving utilitys (or intermediate utilitys) point of interconnection with
MEA. Wheeling agreements would need to be negotiated with MEA for use of its transmission
system and with the owners of specific transmission line segments between the MEA system
and purchasing utility. Wheeling to other utilities may be a practical option for Hunter Creek
depending on the expected costs and revenues associated with a specific proposal.
ML&P and CEA could take delivery of Hunter Creek electricity at the Eklutna Hydroelectric
Project Substation since they already receive electricity from this station and have existing
contractual transmission paths for this electricity.
GVEA could take delivery of Hunter Creek electricity at the Douglas Substation near Willow,
where it has existing wheeling agreements for delivery of electricity from CEA, ML&P, and the
Bradley Lake Hydroelectric Project.
SES and HEA do not have existing wheeling agreements with delivery points in the vicinity of
the project.
The four southern railbelt utilities all have generally similar projected future energy costs as
MEA and do not appear to present a superior market opportunity than direct sale to MEA.
GVEA currently has higher energy costs than MEA, and this trend is expected to continue until
GVEA secures a less costly energy supply.
19 For the present, sale to GVEA is a potentially
19 GVEAs system average non firm avoided energy cost is approximately 60% higher than MEAs, currently $0.1055 per
kWh compared to MEAs $0.062 per kWh (GVEA, 2012, MEA, 2012b).
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superior market than direct sale to MEA. It is unknown at this time if GVEAs relatively higher
energy costs will persist long enough to justify a long term power sales contract with GVEA over
MEA. It is also unknown if GVEA would be supportive of overcoming the mostly contractual
and regulatory challenges involved in wheeling IPP energy from Hunter Creek to GVEA.
Table 4 2 provides some examples of existing transmission wheeling rates on the railbelt grid. If
these rates applied to Hunter Creek energy being transmitted to GVEA, the total wheeling cost
is estimated at $0.005 to 0.007 per kWh.
Table 4 2 Selected Railbelt Transmission Grid Wheeling Costs
Energy
Customer
Transmission
Line Owner
Transmission Description and Location
Transmission
Line Length
Wheeling Cost
GVEA AEA
Wheeling Bradley Lake Energy over the Alaska
Intertie System
(MEAs Douglas Substation to Healy)
170 miles
$0.0257
per MWh mile
GVEA MEA
Wheeling Bradley Lake Energy over MEA System
(MEAs Teeland Substation to Douglas Substation)
19 miles
$0.0242
per MWh mile
GVEA CEA
Wheeling Bradley Lake Energy over CEA system
from Kenai Peninsula to Anchorage (Daves Creek
Substation to Rutherford Substation in
Anchorage)
98 miles
$0.0316
per MWh mile
Wheeling costs derived from GVEA filings in RCA Docket TA230 13.
Individual Customers
Sale to individual customers is possible if the total number of customers is less than 10 and they
are located outside of an existing utilitys certificated service area (the limits of MEAs service
area in the project vicinity are shown on Figure A 3). If the customers are located within the
utilitys certificated service area, direct sale is generally not allowed since it would violate the
terms of the certificate of public convenience and necessity granted to the utility by the RCA.
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5.0 CONCLUSIONS AND RECOMMENDATIONS
Reconnaissance level study of Hunter Creek has found that several run of river hydroelectric
project configurations on the east fork of Hunter Creek appear to be technically, economically,
environmentally, and politically viable. These configurations range in installed capacity from
5.3 to 10.7 MW. Of these, a 7.7 MW project (configuration E2 48) with a powerhouse located
at RM 2.67 in Hunter Creek canyon and a design flow of 140 cfs appears to be the most
favorable project configuration, and is recommended for further study. Project configurations
E1 48 and E3 48 are similarly favorable as E2 48. It is possible that additional information such
as hydrology, fisheries, or geotechnical data may result in the selection of a different project
configuration than E2 48 for development.
The most accessible market for the electric output of a hydro project at Hunter Creek is
wholesale purchase of the full electrical output of the project by MEA. Other railbelt utilities, in
particular GVEA in Fairbanks, have significantly higher avoided costs than MEA, and may
present a better market than direct sale to MEA. However, sale of energy to other utilities
requires navigating a more complex legal and regulatory framework that introduces greater
uncertainty and risk, at least partially offsetting these potential gains. These and similar market
opportunities should be monitored as project development continues. Project E2 48 has an
estimated benefit cost ratio of between 1.49nd 3.06 and estimated power sales rates of $0.064
to $0.162 per kWh. These are competitive with MEAs expected long term avoided cost of
energy.
Initial assessment of fish habitat along lower Hunter Creek indicates that the recommended
project configuration would likely not have a significant impact on anadromous fish habitat. If
further study identifies significant unavoidable impacts, robust off site or in stream mitigation
opportunities are available along lower Hunter Creek or along the Knik River near the project.
Based on the findings of this study, further investigation of hydroelectric development on
Hunter Creek should focus on the following information to determine if a hydroelectric project
at Hunter Creek is feasible:
Collect additional hydrology data to better characterize resource hydrology. Conduct a
sediment transport study to quantify sediment transport rates.
Coordinate with MEA to complete a market analysis to help determine a preferred
project configuration and the preferred route and configuration of the project
transmission line.
Refine site topography, surficial geology, and delineate wetlands to refine penstock and
access routes. Perform more detailed topographic and geotechnical investigations of
lower Hunter Creek canyon to identify suitable powerhouse sites.
Conduct more detailed fisheries surveys to confirm the upper limit of fish habitat and
develop proposed permit terms for the preferred development configuration.
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2011 2012 2013 2014 2015 2016 2017 2018 2019
ACTIVITY 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4
Reconnaissance Study
Feasibility Study
Conceptual Design
Permitting
Project Design
Construction Plan
Financing Plan
Construction
Project Commissioning
Construction Phase Close out
Hold meetings with regulatory agencies to outline the scope of environmental studies,
define likely mitigation requirements for fishery and wetland impacts, and determine
likely operational constraints on the project.
Generate refined estimates of electrical output and project costs to determine
economic feasibility.
5.1 DEVELOPMENT PLAN AND SCHEDULE
The next step in the development of a hydro project at Hunter Creek is to perform a feasibility
study to collected more detailed site information, refine the preferred project configuration,
and develop a detailed conceptual design. The feasibility study would focus on collecting more
field data to better define the hydroelectric resource and potential technical, environmental
and regulatory constraints that may be imposed on the projects operations. Once these
parameters are better defined, a more detailed economic analysis can be performed to
evaluate the projects economic feasibility.
The proposed development schedule for the project is presented on Figure 5 1. A key variable
in the development schedule is when the project lands are conveyed to Eklutna by BLM. If
lands have not been conveyed to Eklutna by the time the project is ready to begin the
permitting process (in 2015), then Eklutna will have to either license the project with the
Federal Energy Regulatory Commission (FERC) or postpone permitting until conveyance is
completed. The schedule in Figure 5 1 has assumed that land conveyance is not completed and
the FERC licensing process is completed in approximately 30 months. Conveyance of the lands
before 2015 would likely result in a faster permitting process,possibly accelerating project
commissioning from 2019 to 2018.
Figure 5 1 Project Development Schedule
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6.0 REFERENCES
Alaska Department of Commerce, Community, and Economic Development (ADCCED). 2012.
Community profiles. Web site:
http://www.commerce.state.ak.us/dca/commdb/CF_COMDB.htm
ADCCED, Division of Energy and Power Development. 1977.Alaska Regional Energy Resources
Planning Project, Phase I, Volume II: Inventory of Oil, Gas, Coal, Hydroelectric, and
Uranium Resources, Final Report. October
ADCCED, Division of Energy and Power Development. 1980.Alaska Regional Energy Resources
Planning Project, Phase II: Coal, Hydroelectric, and Energy Alternatives Volume II:
Hydroelectric Development.
ADCCED, Statewide Digital Mapping Initiative. 2012. Web site:
http://www.alaskamapped.org/sdmi
Alaska Department of Natural Resources (ADNR), Division of Geological and Geophysical
Surveys (DGGS). 1977. Geological Report 55: Short Notes on Alaska Geology. Tectonic
Significance of the Knik River Schist Terrane, Southcentral Alaska. By Carden, J. R. and
Decker, J.E.
ADNR, Division of Parks and Recreation (DOPR). 2011.Chugach State Park Management Plan,
Public Review Draft. May. Web site:
http://dnr.alaska.gov/parks/units/chugach/chugachmanageplan/cspmp_prd_complete.
pdf.
Alaska Energy Authority (AEA). 2010.Railbelt Integrated Resource Plan. Prepared by Black &
Veatch, Inc.
AEA. 2011. Amended and Restated Alaska Intertie Agreement. November 18.
AEA. 2012a. Renewable Energy Fund Round 6. Web site:
http://www.akenergyauthority.org/RE_Fund 6.html. July.
AEA. 2012b. Susitna Watana Hydroelectric Project Website:http://www.susitna watanaydro.org
AEA. 2012c. Board Resolution 2012 02.
AEA. 2012d. PCE Program Statistical Report for Fiscal Year 2011.
AEA. 2013. Project Update to Alaska Industrial Development and Export Authority
(AIDEA)/AEA Board. January 10.
Alaska Gasline Development Corporation (AGDC). 2011. Alaska Stand Alone Gas
Pipeline/ASAP: Project Plan. July 1. Web site:http://www.agdc.us/wp
content/uploads/2011/07/ASAP Project Plan_1July2011_WEB1.pdf.
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Golden Valley Electric Association (GVEA). 2012. GVEA Tariff Advice letters in Dockets TA222
13, TA224 13, TA231 13, and TA230 13.
Institute of Social and Economic Research (ISER), University of Alaska Anchorage. 2012b.
Alaska Fuel Price Projections 2012 2035. ISER Working Paper 2012.1 and Microsoft
Excel Spreadsheet Price Model. July.
Matanuska Electric Association, Inc. (MEA). 2012a. Informational Packet Prepared Pursuant to
3 AAC 50.790(d). Projected future avoidable firm and non firm energy costs, capacity
additions, firm power purchases, and tariff and special contract purchases. August 23.
MEA. 2012b. Tariff Advice letter TA423 18, Filed with the RCA on October 4, 2012.
Municipality of Anchorage (MOA). 1982.North Anchorage Land Agreement Informational
Pamphlet.
Regulatory Commission of Alaska (RCA). 1997. Docket U 97 139, Order No. 2.
RCA. 2008. Docket U 08 102. Order No. 2.
RCA. 2011a. Docket U11 100. Order No. 5.
RCA. 2011b. Docket U11 111. Order No. 2.
RCA. 2011c. Docket U11 127.
U.S. Department of the Interior, Bureau of Land Management (BLM). 2008.Ring of Fire Record
of Decision and Approved Management Plan.March.
U.S. Geological Survey (USGS), 1969. USGS 1: 63,360 scale quadrangle map Anchorage B 5.
USGS. 1973.The McHugh Complex of Southcentral Alaska: Contributions to Stratigraphy.
USGS Bulletin 1372 D. By Clark, Sandra H. B.
USGS. 1993. Plate 2: Map Showing Mean Annual Precipitation for Alaska and Conterminous
Basins of Canada. Magnitude and Frequency of Floods in Alaska and Conterminous
Basins in Canada: Water Resources Investigations Report 93 4179. By Jones, S.H. and
Fahl, C.B.
USGS. 1992. Glacier Runoff and Sediment Transport and Deposition Eklutna Lake Basin, Alaska.
Water Resources Investigations Report 92 4132.By Brabets, Timothy P.
USGS. 2003.Estimating the Magnitude and Frequency of Peak Streamflows for Ungaged Sites
on Streams in Alaska and Conterminous Basins in Canada: Water Resources
Investigations Report 2003 4188.By Curran, Janet H.; Meyer, David F.; and Tasker, Gary
D.
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APPENDIX A PROJECT MAPS
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Figure Title Page Nos.
Figure A 1 Project Overview and Location Map ........................................................A 3
Figure A 2 Map of Hunter Creek Subbasins ..............................................................A 4
Figure A 3 Land Status in Project Area ......................................................................A 5
Figure A 4 East Fork Hydroelectric Project Configurations........................................A 6
Figure A 5 West Fork Hydroelectric Project Configurations.......................................A 7
Figure A 6 Conceptual Layout of East Fork Diversion and Intake...............................A 8
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Figure A 1 Project Overview and Location Map
HH
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Figure A 2 Map of Hunter Creek Subbasins
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Figure A 3 Land Status in Project Area
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Figure A 4 East Fork Hydroelectric Project Configurations
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Figure A 5 West Fork Hydroelectric Project Configurations
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Figure A 6 Conceptual Layout of East Fork Diversion and Intake
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APPENDIX B SITE PHOTOGRAPHS
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Photograph Title Page Nos.
Photograph B 1 Oblique North Aerial View of Lower Hunter Creek.................................B 3
Photograph B 2 Oblique North Northwest Aerial View of Lower Hunter Creek...............B 3
Photograph B 3 Oblique South Southwest Aerial View of West Fork Hunter Creek ........B 4
Photograph B 4 Oblique North Aerial View of West Fork Hunter Creek...........................B 4
Photograph B 5 Oblique Composite Aerial View of West Fork Hunter Creek...................B 5
Photograph B 6 Oblique Composite Aerial View of East Fork Hunter Creek.....................B 5
Photograph B 7 Oblique Southeast Aerial View of East Fork Hunter Creek......................B 7
Photograph B 8 Oblique Northwest Aerial View of East Fork Hunter Creek.....................B 7
Photograph B 9 Oblique Composite Southeast Aerial View of East Fork Hunter
Creek........................................................................................................B 8
Photograph B 10 East Fork Hunter Creek Looking Downstream (RM 4.42).......................B 8
Photograph B 11 East Fork Gauging Station #1 (RM 4.34)..................................................B 9
Photograph B 12 East Fork Gauging Station #1 (RM 4.34, Detailed View)..........................B 9
Photograph B 13 Typical Exposed Till Embankment along East Fork Hunter Creek .........B 10
Photograph B 14 Upstream View of East Fork Gauging Station #2 (RM 4.73)..................B 11
Photograph B 15 Trans Alaska Pipeline Bridge Over Tanana River near Delta
Junction..................................................................................................B 11
Photograph B 16 Upstream View of East Fork (RM 4.40)..................................................B 12
Photograph B 17 View of Till Embankment along East Fork Canyon (RM 3.83 to
4.02).......................................................................................................B 13
Photograph B 18 Upstream View of East Fork Canyon From North Rim Above RM
3.83 ........................................................................................................B 14
Photograph B 19 View of Active Slide Zone on North Side of East Fork Hunter Creek
(RM 4.15) ...............................................................................................B 15
Photograph B 20 Downstream View of West Fork Hunter Creek (RM 5.2).......................B 16
Photograph B 21 Upstream View of West Fork Hunter Creek (RM 5.2) ...........................B 17
Photograph B 22 Main Stem of Hunter Creek Gauging Station (Preflood).......................B 18
Photograph B 23 Main Stem of Hunter Creek at Flood Stage (Post Flood) ......................B 18
Photograph B 24 Main Stem of Hunter Creek at Flood Stage (RM 1.50)..........................B 19
Photograph B 25 Upstream View of the Main Stem of Hunter Creek (RM 2.22)..............B 20
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Photograph B 1 Oblique North Aerial View of Lower Hunter Creek
Oblique aerial view of Hunter Creek canyon looking north northwest. The lower east fork (right) and west fork
(left) canyons are visible in the foreground. The Knik River is visible in the far distance. Approximate locations of
some project features are shown.
Polarconsult, October 19, 2011.
Photograph B 2 Oblique North Northwest Aerial View of Lower Hunter Creek
Oblique aerial view of Hunter Creek canyon looking northwest. The east fork is visible in the foreground, and the
confluence with the west fork is visible at middle left. Approximate locations of some project features are shown.
Polarconsult, October 19, 2011.
Powerhouse Site 1
Powerhouse Site 2
Powerhouse Site 3
Penstock Route for
West Fork
Configuration W1
Penstock Route for
West Fork
Configuration W3
Penstock Routes for East
Fork only Project
Configurations
N
Powerhouse Site 1
Powerhouse Site 2
Powerhouse Site 3
Penstock Route for
West Fork
Configuration W3
Penstock Routes for East
Fork only Project
Configurations
Penstock Route for West
Fork Configuration W1
Penstock Route for West
Fork Configuration W2
W3 Dam site
N
Eklutna, Inc.
Hunter Creek Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
April 2013 Final Report B 4
Photograph B 3 Oblique South Southwest Aerial View of West Fork Hunter Creek
Oblique aerial view of west fork Hunter Creek looking south southwest (upstream). Approximate locations of
some west fork project features are shown.
Polarconsult, October 19, 2011.
Photograph B 4 Oblique North Aerial View of West Fork Hunter Creek
Oblique aerial view of west fork Hunter Creek valley looking north (downstream). The approximate location of the
proposed west fork diversion site is shown. The Knik River valley is visible in the far distance.
Polarconsult, October 19, 2011.
Penstock Route
RM 6.14 Diversion Site
(Configurations W1 and W2)
N
RM 4.20 Dam Site
RM 6.14 Diversion Site
(Configurations W1 and W2)
Penstock Route for West
Fork Configuration W1
Penstock Route for West
Fork Configuration W3
Penstock Route for West
Fork Configuration W2
W2 Penstock Route
(Continued)
N
Eklutna, Inc.Hunter Creek Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.April 2013Final ReportB5Photograph B5 Oblique Composite Aerial View of West Fork Hunter CreekOblique composite aerial view of west fork Hunter Creek. Approximate locations of some west fork and east fork project features are shown.Polarconsult, October 19, 2011.Photograph B6 Oblique Composite Aerial View of East Fork Hunter CreekOblique composite aerial view of east fork Hunter Creek valley extending from approximately RM 5.3 downstream to RM 4.4. Approximate locations of some east fork and west fork project features are shown.Polarconsult, October 19, 2011.RM 5.08 Diversion Site(All East Fork Project Configurations)Access Route for All Project Configurations,Penstock Route for all East Fork Project Configurations and West Fork Configuration W2(Generallyobscured bybluff in this view where dotted)RM 4.5RM 5.3Access Route for All West Fork Project ConfigurationsPenstock Route for Configuration W2RM 4.73East Fork Gauging Station #2NPowerhouse Site 3Penstock and AccessRoutes for East ForkonlyProject ConfigurationsRM 5.3Penstock and Access Route,Configurations W1 and W2RM 4.20 Dam Site(Configuration W3)Penstock Route,Configuration W3Powerhouse Site 1Powerhouse Site 2800Penstock Bridge(Configuration W3)1,100Penstock Bridge(Configuration W1)Penstock Route (Configuration W2)and Access Route (all WestFork Project Configurations)RM 4.72Upstream Extent of Reservoir(Configuration W3)NN
Eklutna, Inc.Hunter Creek Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.April 2013Final ReportB6This page intentionally blank.
Eklutna, Inc.
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April 2013 Final Report B 7
Photograph B 7 Oblique Southeast Aerial View of East Fork Hunter Creek
Photograph B 8 Oblique Northwest Aerial View of East Fork Hunter Creek
Oblique aerial view of east fork Hunter Creek valley looking northwest (downstream). The creek is visible from
approximately RM 5.0 down to RM 4.4. Approximate locations of some project features are shown.
Polarconsult, October 19, 2011.
Oblique aerial view of east fork Hunter Creek looking southeast (upstream). The creek is visible at right from
approximately RM 3.6 up to RM 4.5. Approximate locations of some east fork project features are shown.
Polarconsult, October 19, 2011.
East Fork Access and Penstock Route
(All Project Configurations)RM 4.15
Slide Zone
N
East Fork Penstock and Access
Route (All Project Configurations)
West Fork Access (All Configurations)
West Fork Penstock Route (Configuration W2)
N
Eklutna, Inc.
Hunter Creek Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
April 2013 Final Report B 8
Photograph B 9 Oblique Composite Southeast Aerial View of East Fork Hunter Creek
Photograph B 10 East Fork Hunter Creek Looking Downstream (RM 4.42)
Downstream view of east fork Hunter Creekat RM 4.42. The creek is running over alluvial material and exposed
glacial erratics in this reach, but the creek bed transitions to bedrock shortly downstream. Exposed embankments
of glacial till are visible at upper left. These embankments are also shown in Photograph B 13. Flow is 125 cfs.
Polarconsult, October 4, 2011.
Oblique composite aerial view of east fork Hunter Creek looking southeast (upstream). The creek is visible at right
from approximately RM 3.6 up to RM 4.5. Approximate locations of some project features are shown.
Polarconsult, October 19, 2011.
West Fork Penstock Route (Configuration W2)
West Fork Access Route (All Configurations)
RM 4.15 Slide Zone
East Fork Gauging
Station #2 (RM 4.73)
East Fork Penstock and Access
Route (All Project Configurations)
East Fork Gauging
Station #1 (RM 4.34)
1,100West Fork Penstock Bridge (Configuration W1)
800West Fork Penstock Bridge (Configuration W3)
N
Approximate Bedrock/Till Interface
Eklutna, Inc.
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April 2013 Final Report B 9
Photograph B 11 East Fork Gauging Station #1 (RM 4.34)
Photograph B 12 East Fork Gauging Station #1 (RM 4.34, Detailed View)
Detailed view of East Fork Gauging Station #1 at RM 4.34. The pool outlet is a rock sill extending from the middle
of the photograph to the lower right. Hydrologist David Brailey is measuring stage. Flow is 125 cfs.
Polarconsult, October 4, 2011.
Downstream view of East Fork Gauging Station #1 at RM 4.34. The creek bed in this reach is bedrock with
numerous glacial erratics. This area has large (10+ feet) boulders; most boulders smaller than 12 inches are
swept downstream. Hunter Creek descends into the canyon below this location. Flow is 125 cfs.
Polarconsult, October 4, 2011.
Eklutna, Inc.
Hunter Creek Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
April 2013 Final Report B 10
Photograph B 13 Typical Exposed Till Embankment along East Fork Hunter Creek
Exposed embankment of glacial till along the south side of east fork Hunter Creek at RM 4.43. A minor drainage or
local groundwater seep is causing accelerated erosion at the center of the photograph. The till maintains near
vertical faces where protected from erosion by local drainage patterns.
Polarconsult, October 4,2011.
Eklutna, Inc.
Hunter Creek Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
April 2013 Final Report B 11
Photograph B 14 Upstream View of East Fork Gauging Station #2 (RM 4.73)
Upstream view of East Fork Gauging Station #2 at RM 4.73. The west fork access road and configuration W2
penstock would cross the east fork just upstream of this location.
Polarconsult, November 16, 2012.
Photograph B 15 Trans Alaska Pipeline Bridge Over Tanana River near Delta Junction
View from south bank of the Trans Alaska Pipeline bridge over the Tanana River near Delta Junction. The 48 inch
pipe and approximately 1,200 foot main span of this bridge are similar to the pipe bridges required for west fork
project configurations W1 and W3.
Wikipedia, December 14, 2012
Eklutna, Inc.
Hunter Creek Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
April 2013 Final Report B 12
Photograph B 16 Upstream View of East Fork (RM 4.40)
Upstream view of East Fork Hunter Creek at RM 4.40. The bedrock visible in the foreground is the first
presentation of bedrock in the creek bed downstream of the proposed intake site at RM 5.08. The abundance of
large glacial erratics and large woody debris is typical of this reach and indicates the intensity of high flow events
through this channel. Eroding glacial till embankments are visible to the right of the creek (also see Photographs B
10 and B 13). Flow is 125 cfs.
Polarconsult, October 4, 2011.
Eklutna, Inc.
Hunter Creek Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
April 2013 Final Report B 13
Photograph B 17 View of Till Embankment along East Fork Canyon (RM 3.83 to 4.02)
Detailed view of glacial till embankment on south side of east fork Hunter Creek from approximately RM 3.83 to
4.02. This bank and the debris field below it extend for approximately 300 vertical feet down to east fork Hunter
Creek. Note the 20 to 40 foot tall vertical faces at the top of the bank and partially exposed glacial erratics.
Polarconsult, October 4, 2011.
Eklutna, Inc.
Hunter Creek Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
April 2013 Final Report B 14
Photograph B 18 Upstream View of East Fork Canyon From North Rim Above RM 3.83
Upstream view of east fork canyon from north rim above RM 3.83. The lower portion of the slide zone shown in
Photograph B 15 is visible on the south side of the creek (photograph right). This reach of the canyon is
inaccessible due to the steep and unstable terrain.
Polarconsult, August 27, 2012.
Eklutna, Inc.Hunter Creek Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.April 2013Final ReportB15Photograph B19 View of Active Slide Zone on North Side of East Fork Hunter Creek (RM 4.15)View of active slide zone on north side of east fork Hunter Creek canyon at RM 4.15. The slide is stable enough for mature cottonwoods to grow along the lowerflanks, but the growth patterns of the tree trunks indicate the entire slide face is active. Large partially exposed erratics and vertical faces occur along the top of theactive slide area. The proposed penstock route is uphill of this slide area (also see Photographs B7 and B9).Polarconsult, October 12, 2011.East Fork Penstock and Access Route(All Project Configurations)(Generally obscured by terrain where dotted)NApproximate bedrock/till interfaceActive Slide Area
Eklutna, Inc.
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April 2013 Final Report B 16
Photograph B 20 Downstream View of West Fork Hunter Creek (RM 5.2)
Downstream view of west fork Hunter Creek at RM 5.2 showing the narrow rock canyon typical of this reach.
Polarconsult, April 3, 2012.
Eklutna, Inc.
Hunter Creek Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
April 2013 Final Report B 17
Photograph B 21 Upstream View of West Fork Hunter Creek (RM 5.2)
Upstream view of west fork Hunter Creek at RM 5.2 showing the rock canyon typical of this reach. Flow is 11 cfs.
Polarconsult, April 3, 2012.
Eklutna, Inc.
Hunter Creek Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
April 2013 Final Report B 18
Photograph B 22 Main Stem of Hunter Creek Gauging Station (Preflood)
Upstream view of main stem gauging station. The PT is buried in the right edge of the streambed at the right edge
of the photograph. This gauging station remained stable from October 2011 through September 2012 but was
buried by sediment in the floods of late September 2012. The PT survived the flood, but the main channel shifted
to the far side of the canyon approximately 150 feet away (See Photograph B 23). Flow is 88 cfs.
Polarconsult, October 28, 2011.
Photograph B 23 Main Stem of Hunter Creek at Flood Stage (Post Flood)
View upstream of main stem gauging station after September 22 24, 2012, flood event. Data logger is located in alder bush at
left. Red arrows point to same features in Photographs B 22 and B 23, illustrating sedimentation of the former creek channel.
Polarconsult, September 23, 2012.
Eklutna, Inc.Hunter Creek Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.April 2013Final ReportB19Photograph B24 Main Stem of Hunter Creek at Flood Stage (RM 1.50)Upstream view of the main stem of Hunter Creek from Knik River Road during flood event. Estimated flow is 3,300 cfs. This storm event resulted in significantflooding in several areas of the MatSu Borough.Polarconsult, September 23, 2012.
Eklutna, Inc.Hunter Creek Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.April 2013Final ReportB20Photograph B25 Upstream View of the Main Stem of Hunter Creek (RM 2.22)Upstream view of the main stem of Hunter Creek at RM 2.22. The canyon floor in this reach is approximately 80 to 100 feet wide, and the creek is confined bythe canyon to a single channel. The creek runs as a nearcontinuous riffle at a grade of approximately 1.5%, and the creek bed is large cobbles (6 to 18 inches)with few very backwater areas or pools with finer bed materials. Flow is approximately 88 cfs.Polarconsult, October 12, 2011.
Eklutna, Inc.
Hunter Creek Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
April 2013 Final Report C 1
APPENDIX C HYDROLOGY DATA
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April 2013 Final Report
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Eklutna, Inc.
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April 2013 Final Report C 2
Section Title Page Nos.
C.1 Available Hydrology Data......................................................................... C 3
C.2 Stream Gauge Station Information.......................................................... C 5
C.3 Flow Measurements and Station Calibration .......................................... C 8
C.4 Hunter Creek Hydrology Data ................................................................. C 8
C.5 Hunter Creek Hydrology Model............................................................... C 8
Attachment C 1 Hunter Creek Streamflow Analysis Report
Attachment C 2 Additional Gauging Station Data, East Fork Hunter Creek Station #2
Attachment C 3 Additional Gauging Station Data, Main Stem Hunter Creek Station
Tables
Table C 1 Summary of Hydrology Data for Hunter Creek.........................................C 3
Table C 2 Stream Flow and Water Stage Measurements at Hunter Creek...............C 4
Figures
Figure C 1 Estimated Daily Flow in Hunter Creek and Tributaries Based on Extended
Record.....................................................................................................C 9
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April 2013 Final Report
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Eklutna, Inc.
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April 2013 Final Report C 3
C.1 AVAILABLE HYDROLOGY DATA
Approximately 12 months of usable hydrology data have been collected at Hunter Creek. Two
gauging stations are currently installed at Hunter Creek; these are described in Section C.2. This
appendix summarizes the hydrology data and analysis used for this study. Daily stage and
calculated flow data for both gauging stations is included at the end of Attachment C 1.
Existing hydrology data are summarized in Table C 1. Flow measurements at the Hunter Creek
gauging stations are summarized in Table C 2. Hydrographs, stage discharge curves, flow
duration curves, and station notes for both gauges are included in this appendix.
Table C 1 Summary of Hydrology Data for Hunter Creek
Location on
Hunter Creek
Basin Size
(square
miles)
Site
Elevation
(ft)(1)
Latitude(1)Longitude(1)Begin
Date
End
Date
Number of
Daily Records
Main Stem
Gauging Station
(RM 1.59)
69.7 210
61
26.37
148
48.8610/28/11 1/26/13 456
(2)
East Fork Gauging
Station #1 (RM
4.34)
23.6 950
61
24.32
148
48.2911/14/11 5/8/12 176
(3)
East Fork Gauging
Station #2
(RM 4.73)
24.5 1,060
61
24.07
148
47.9411/16/12 12/1/12 15
(4)
West Fork Hunter
Creek
(RM 5.21)
37.2 1,000
61
23.53
148
49.57
4/3/12
(single
measurement)
1 (5)
NOTES:
(1) Coordinates are in North American Datum (NAD) 83. Gauging station elevations are orthometric height in feet, Geoid 12A.
(2) Count of available daily records through power failure on January 26, 2013. The PT failed, presumably due to freezing, by
the time the power supply was replaced on March 5, 2013. The gauge was removed on March 21, 2013.
(3) Gauge destroyed by landslide on May 8, 2012.
(4) The station datalogger entered a low power mode on January 27, 2013 due to low voltage. The datalogger is believed to be
intact but is not currently transmitting. The station pressure transducer (PT) stopped working on December 1, 2012,
presumably due to freezing.
(5) Individual flow measurement only. No datalogger was deployed at this location.
Eklutna, Inc.Hunter Creek Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.April 2013Final ReportC4Table C2 Stream Flow and Water Stage Measurements at Hunter CreekDate/TimeLocationPartyFlow (cfs)Stage (ft)Flow MethodCommentsMAIN STEM HUNTER CREEK STAGE AND FLOW MEASUREMENTS10/12/11 10:45 Main Stem (RM1.59) Brailey/Groves 88.3 +/2RP5: +0.14Stage: 1.83CurrentVelocity Not ice affected.10/28/11 15:30 Main Stem (RM1.59) Brailey 77.3 +/2RP5: +0.08Stage: 1.77CurrentVelocity Not ice affected.12/16/11 15:30 Main Stem (RM1.55) Groves/Paulus 34.7 +/2RP7:3.56Stage: 1.44Salt Injection Not ice affected.2/28/12 15:00 Main Stem (RM1.55) Brailey 22.2 +/8RP8:4.89Stage: 1.30Salt InjectionNot ice affected, poormeasurement repeatability.3/7/12 15:00 Main Stem (RM1.55) Brailey 19.2 +/2RP8:4.02Stage: 1.28Salt Injection andCurrentVelocityStage affected by ice.See Attachment C14/13/12 17:35 Main Stem (RM1.55) Brailey 22.5 +/0.5RP7:3.71Stage: 1.29Salt Injection Not ice affected.5/9/12 11:45 Main Stem (RM1.59) Groves 116.8 +/2RP7:2.98Stage: 2.02CurrentVelocity Not ice affected.8/29/12 13:30 Main Stem (RM1.55) Brailey 395 +/50RP8:3.77Stage: 2.72Acoustic CurrentDoppler ProfilerNot ice affected.EAST FORK HUNTER CREEK STAGE AND FLOW MEASUREMENTS10/4/11 16:00 East Fork (RM 4.73) Brailey/Groves 125 +/3RP2:5.45Stage: 2.75CurrentVelocity Not ice affected.10/12/11 15:00 East Fork (RM 4.73) Brailey/Groves 29.5 +/1RP2:5.84Stage: 2.36CurrentVelocity Not ice affected.11/14/11 16:00 East Fork (RM 4.35) Brailey 13.6 +/0.4RP6:0.08Stage: 2.20Salt Injection See Attachment C12/28/12 15:45 East Fork (RM 4.35) Brailey 8 +/0.6 Stage: 1.87 Salt Injection See Attachment C14/3/12 13:40 East Fork (RM 4.35) Brailey 5.7 +/0.3 Stage: 1.70 Salt Injection See Attachment C14/13/12 14:15 East Fork (RM 4.35) Brailey 7.6 +/1.4RP2:6.40Stage: 1.80Salt InjectionSee Attachment C19/13/12 15:30 East Fork (RM 4.73) Groves/Paulus 43 +/1.5 RP3B:0.25 CurrentVelocity Not ice affected.WEST FORK HUNTER CREEK STAGE AND FLOW MEASUREMENTS4/3/12 15:30 West Fork (RM 5.21) Brailey 11.1 +/0.1 NM Salt Injection See Attachment C1NM: Not measured. RP: vertical reference point from which stage is measured from.
Eklutna, Inc.
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April 2013 Final Report C 5
C.2 STREAM GAUGE STATION INFORMATION
The main stem and both east fork gauging station sites were identified in October 2011. On the
main stem, site criteria included a deep pool to protect the pressure and temperature
transducer (PTT) from freezing, a stable outlet control, a protected location for the PTT from
flood events, and a low visual profile to discourage vandalism. These same criteria apply on the
east fork, except that vandalism is less of a concern due to the sites remoteness. All three
stations are described in detail in this section.
C.2.1 Main Stem Gauging Station
On October 28, 2011, Polarconsult subconsultant Brailey Hydrological Consultants (BHC)
installed a gauging station (Main Stem Gauging Station)at RM 1.59 on Hunter Creek,
approximately 400 yards upstream of Knik River Road (see Figure A 2). This station was
selected based on the presence of a deep pool with a riffle outlet control at lower flows,
perceived stability of the creek bed in the immediate station vicinity, relative protection from
flood debris and velocities behind a rock outcrop, and proximity to Knik River Road for
download and maintenance.
At the time of installation, the gauging station was located on the right bank of the main
channel of Hunter Creek in an area where the creek flows along the east wall of the canyon
(Photograph B 22). The main channel in this area is approximately 35 feet wide and is incised
approximately 3 feet into the alluvial field that covers the 200 foot wide canyon floor. At low
flows, the creek is well confined to this channel, but at high flows, the creek can meander
across the entire canyon floor. The creek bed in this channel consists mainly of cobbles 4 to 8
inches in diameter. The gauging station is in a scour pool behind a rock outcrop. At low flows,
the site is a pool with a riffle outlet formed by a low cobble bar. At higher flows, the site is
relatively uniform subcritical open channel flow, eventually developing significant vortices and
turbulence in the PTT vicinity at flows over approximately 500 cfs.
The PTT was buried under cobbles at the toe of the canyon wall/right bank of the creek
approximately 20 feet downstream of the rock outcrop, and the data logger was tied to an
alder bush approximately 10 feet above the creek and 5 feet above the ordinary high water
line. The vented PTT cable was routed in liquidtite flexible metallic conduit (LFMC) under
cobbles and up to the data logger.
Instrumentation at this gauging station is an Acculevel vented PTT manufactured by Keller
America, Inc. and a MONITOR 1 data logger manufactured by Sutron, Inc. The data logger is
powered by a primary lithium battery pack. The data logger was configured to record water
depth at 15 minute intervals. The PTT is mounted in LFMC and buried under cobbles on the
right bank of the creek. At annual low flow conditions, the PTT is immersed in approximately
1.4 feet of water. The battery pack is sufficient for 12 to 14 months of operation.
Eklutna, Inc.
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April 2013 Final Report C 6
Several vertical datums were established for this site. The primary vertical datum is the top of a
¼inch rock bolt drilled into the upstream face of the rock outcrop upstream of the PTT. Other
datums were natural rock outcroppings. The top of the rock bolt is +5.00 feet in the station
datum. The point of zero flow for the pool outlet control is 0.00 feet in this datum.
This hardware remained in service at this station without problems from October 28, 2011,
through January 26, 2013, when the power supply was depleted. A new power supply was
installed on March 5, 2013, but the PTT was no longer working at that time. The PTT is
presumed to have failed due to freezing action. The station was removed on March 22, 2013.
A flood event from September 21 to 24, 2012, significantly changed the creek section at the
gauging station (Photographs B 22, 23, and 24 in Appendix B). The existing channel was filled
in, and the creek shifted to the opposite side of the canyon. The creeks new channel is not
significantly incised into the alluvial plain, and as a result local water elevation is approximately
2 to 3 feet higher than before the flood. This new channel appears susceptible to continued
shifting under high water conditions in 2013.
The data logger and PTT survived this flood event and remained in working order through
January 26, 2013. The rating curve developed for the 2011 12 water year was invalidated by
this flood event, and a new rating curve will be needed to convert stage data recorded after
September 22, 2012 to flow.
There are a handful of other sites along the lower canyon that are similar to the existing
gauging station. None of these offer a particular advantage to the existing station, and superior
sites are unlikely downstream of approximately RM 3.0 that will be immune to frequent
channel shifting and flood hazards. Gauging sites above RM 3.0 would be extremely difficult to
access and are impractical. Future stream gauging efforts on the main stem of Hunter Creek
should plan for frequent channel changes, flood events, and high risk of equipment loss.
C.2.2 East Fork Gauging Station #1
On November 14, 2011, Polarconsult subconsultant BHC installed a gauging station (East Fork
Gauging Station #1)at RM 4.34 on east fork Hunter Creek, at the head of the east fork canyon
(see Figure A 4). This station was selected based on the presence of a deep pool with a rock sill
for outlet control at lower flows. One of the 3/8 inch rock bolts used to secure the PTT to the
rock sill was used as a vertical datum. The top of the bolt has an elevation of +2.28 feet in the
station vertical datum. The approximate point of zero flow for the station is 0.00 feet.
The main channel at the gauging station is approximately 30 feet wide and is cut approximately
12 feet into bedrock on the left side and confined by a jumble of 10 foot (and larger) boulders
on the right side (Photograph B 11 and Figure A 4). The creek bed at the gauging station is
bedrock, with a rock weir controlling stage in a pool at low flows. At higher flows, the pool is
overwhelmed by water jets from upstream, and the entire reach becomes turbulent. The creek
is well confined to this channel at all flows.
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April 2013 Final Report C 7
The PTT was installed buried in a gravel deposit immediately upstream of the rock weir. The
vented PTT cable was routed in a section of electrical metallic conduit bolted to the rock sill,
then routed through LFMC up to a data logger on top of the bedrock outcrop.
Instrumentation at this gauging station was an Acculevel vented PTT manufactured by Keller
America, Inc. and a MONITOR 1 data logger manufactured by Sutron, Inc. The data logger was
powered by a primary lithium battery pack. The data logger was configured to record water
depth at 15 minute intervals. At annual low flow conditions, the PTT was immersed in
approximately 0.4 feet of water. The battery pack is sufficient for 12 to 14 months of
operation.
This station performed well through the winter months. The site channels flows into a single
chute, minimizing the potential for freezing. In addition, the site is carved from bedrock, and is
expected to be stable unless blocked by flood debris. However, the station is exposed to debris
slides and extreme flow velocities during the summer months. The PTT installation was torn
away by summer flows, and the data logger was destroyed by a boulder slide on May 8.In
addition, this station is difficult to access during the summer months due to high flows and
dense brush. The station hardware was located on the south (far) side of Hunter Creek, which
cannot be safely crossed on foot at typical summer flows.
Future gauging efforts on the east fork should consider this station for winter only gauging or
year round gauging if the PTT and instrumentation can be mounted on the north side of the
creek. The north side is not as exposed to landslides and can be accessed on foot without
crossing east fork Hunter Creek. The PTT installation will need to be very robust to survive
summer flow conditions.
C.2.2 East Fork Gauging Station #2
On November 11, 2012, Polarconsult installed a replacement gauging station (East Fork
Gauging Station #2)at RM 4.73 on the east fork of Hunter Creek (see Figure A 4). East Fork
Gauging Station #1 was not safely accessible at the time. This station was identified in fall 2011
as one of the better locations for current velocity flow measurements in the reach from RM
4.34 to 5.10.
The main channel at the gauging station is approximately 30 feet wide and is incised
approximately 2 feet into the alluvial plain. The left (south) bank abuts the edge of the
currently active floodplain, which is an approximately 6 foot tall bank vegetated by alders. An
older floodplain bench is present south of this bank. The right (north) bank is part of the active
floodplain and is only sparsely vegetated (Photographs B 14 and B 15). The creek bed at the
gauging station is alluvium, generally gravels and cobbles with sand in backwater areas. The
creek bed forms a shallow pool, which becomes a riffle at typical summer flows. The creek is
not confined to this channel at higher flows. A new channel formed on the north side of the
valley floor during the September 22 24, 2012, flood event, although low flows remain confined
to the original channel where the PTT was installed.
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April 2013 Final Report C 8
The PTT was installed in gravels at the thalweg of the main channel. The vented PTT cable was
routed in a section of electrical metallic conduit buried in the creek bed, then laid exposed on
the ground back to the data logger.
Instrumentation at this gauging station is an Acculevel vented PTT manufactured by Keller
America, Inc. and a DataGarrison SolarStream data logger manufactured by Upward
Innovations, Inc. The data logger is powered by a 7 amp hour lead acid battery and a five watt
amorphous solar panel. The data logger includes an Iridium satellite transceiver and uploads
data at programmed intervals.
The PTT at this station failed on December 1, 2012, only 2 weeks after installation. The failure
mode was consistent with freezing of the PTT although this has not been confirmed. This
station is subject to frequent channel shifting and is generally inferior to East Fork Gauging
Station #1, provided that instrumentation can be installed on the north side of the creek and
can be armored to survive summer flows. The data logger went into a low power mode on
January 27, 2013 and has not transmitted data as of March 25, 2013. The data logger should
automatically resume normal operation once the battery is recharged.
Future gauging efforts on the east fork should focus on improving gauging station #1 as this site
performed well in through the 2011 12 winter season.
C.3 FLOW MEASUREMENTS AND STATION CALIBRATION
The stage discharge curve for the Main Stem Gauging Station and East Fork Gauging Station #1
has been developed by measuring flow in Hunter Creek multiple times between October 2011
and September 2012 (Table C 2). Development of stage discharge curves and the resulting
curves for each station are discussed in Attachment C 1.
C.4 HUNTER CREEK HYDROLOGY DATA
Hydrology data for the period of record at the Main Stem Gauging Station and East Fork
Gauging Station #1 was compared against existing nearby USGS gauging stations to develop
initial estimates of the long term hydrology at Hunter Creek. The analysis and resulting
estimated long term hydrology are presented in Attachment C 1.
C.5 HUNTER CREEK HYDROLOGY MODEL
The hydrology model for Hunter Creek is developed in Attachment C 1. Estimated average and
extreme flows in Hunter Creek are shown on Figure C 1.
Eklutna, Inc.
Hunter Creek Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
April 2013 Final Report C 9
Figure C 1 Estimated Daily Flow in Hunter Creek and Tributaries Based on Extended
Record
East Fork FlowWest Fork Flow
960 1,440
480 720
0 0
1,440 2,160
0
500
1,000
1,500
2,000
2,500
3,000
3,500
4,000
4,500
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Maximum Daily Flow
Mean (Average) Daily Flow
Minimum Daily Flow
Eklutna, Inc.
Hunter Creek Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
April 2013 Final Report C 10
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Eklutna, Inc.
Hunter Creek Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
April 2013 Final Report C 11
ATTACHMENT C 1
HUNTER CREEK STREAMFLOW ANALYSIS REPORT
Eklutna, Inc.
Hunter Creek Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
April 2013 Final Report C 12
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December12, 2012
Polarconsult Alaska,Inc.
1503W. 33
rd Avenue, Suite 310
Anchorage, Alaska 99503
Attn: Mr. Joel Groves,P.E.
Subject: HunterCreek 2011 12 streamflow analyses
Dear Joel:
As per your request, this letter provides the results of streamflow analyses for gaging stations
on the east fork and the main stem of Hunter Creek near Knik, Alaska. The main stem
gaging station was installed October 28, 2011, and the east fork gaging station was installed
on November 14, 2011. The main stem gaging station remains in operation, but the east fork
gage was struck by a landslide on May 8, 2012. The landslide crushed the datalogger and
interrupted the power supply, but the streamflow data was recovered.
Stage hydrographs for both gaging stations are shown on Figure 1. The main stem stage
hydrograph shows three large peaks during the winter months that are attributed to ice
effects. Although the east fork hydrograph displaysa smooth recession, photographs during
Figure 1. Hunter Creek RawStageHydrographs
Brailey Hydrologic
Consultants
3527 North Point Drive
Anchorage, AK 99502
907 248 0058 phone
dbrailey@alaska.net
Mr.Joel Groves,P.E.
December 12,2012
Page2
installation and subsequent rating measurements suggest that the entire winter record is
affected by ice.
A corrected winter stage hydrograph for the main stem gaging station was created by
honoring ice free rating measurements in October and April, and periods of baseline
recession in December and February (Figure 2). The corrected winter stage record for the
east fork gaging station is more tenuous, relying on ice free measurements in October and an
annual minimum in April (Figure 3).
Figure 2. Winter StageCorrections,Hunter Creek Main Stem
For the main stem gaging station, the ice free measurements define a linear relationship in
bilogarithmic space, when gage height is transformed using an offset of 0.25 feet (Figure 4).
Assuming that flow is linearly related to hydraulic head, the offset indicates a point of zero
head slightly above the streambed. The exponent of the rating equation is at the upper limit
of the acceptable range for steady, uniform flow. As a result, the rating equation is probably
not valid forextrapolation to high flow conditions.
For the east fork gage, a linear relationship is evident for the low flow measurements, but no
single linear fit could be obtained that includes the highest measurement (Figure 5). This
may indicate a change in flow conditions at higher stages. Although the gage pool showed
only slight turbulence and aeration at 29.5 cfs (Figure 6), these effects would be more
pronounced at higher flows. This is consistent with the exponent for the upper segment of
the rating curve, which exceeds the limit forsteady,uniform flow conditions.
Mr.Joel Groves,P.E.
December 12,2012
Page3
Figure3. Winter StageCorrections, East Fork Hunter Creek
Figure 4. Preliminary Rating Curve,Main Stem Hunter Creek
Mr.Joel Groves,P.E.
December 12,2012
Page4
Figure 5. Tentative Rating Curve, East Fork Hunter Creek
Figure 5. East Fork Gage Pool, October 12,2011 (Q = 29.5 cfs)
Mr.Joel Groves,P.E.
December 12,2012
Page5
The preliminary rating curves were used to compute mean daily flows using the Aquarius
Workstation software (Tables 1 and 2). To evaluate long term streamflow characteristics, a
synthetic streamflow record was generated by correlating mean daily flows at the main stem
gaging station against provisional online flow data for the Knik River USGS station (no.
15281000). The Knik River station has 28 years of continuous flow data from 1959 to 1987, 2.6
yearsof continuous flow data from 2001to 2003, and 7years ofopen water flow records from
2004 to 2011. Although only provisional data are available after October 1, 2011, mean daily
flows for the concurrent period of record were computed using 15 minute provisional flow
data. Minor corrections of the provisional data were needed to remove some spurious
values.
Although a reasonable correlation between flows at the main stem of Hunter Creek and the
Knik River was obtained using linear regression (r squared = 0.86), a better correlation was
obtained using an adaptive neuro fuzzy interference (ANFIS) model (r squared = 0.89). The
ANFIS modelalso produced more realistic winter flow estimates.
Eliminating prior Knik River flows affected by glacial outburst floods, the ANFIS model was
used to generate a synthetic streamflow record from 1967 to the present. Results are shown
on Figure 6, indicating that measured 2012 flows are consistent with the long term record
during the open water season, but winter flows correspond to long term daily minimums.
Consideringthat the concurrent record is limitedto May 1 through October20, 2012, it is
Figure 6. Hunter Creek Main Stem ExtendedRecord
Mr.Joel Groves,P.E.
December 12,2012
Page6
apparent that the ANFIS model overestimates winter flows, and the synthetic winter flows
are probably inaccurate.
To avoid overestimating winter flows, measured flows from October 29, 2011 through April
30, 2012 were substituted for the corresponding part of the average synthetic hydrograph.
Results were used to prepare an averageflow duration curve (Figure 7). This curve
presumes that the measured winter flows are representative of averageconditions, which
seems reasonable based on the 2011and 2012 open water record (Figure 6).
Figure7.AverageFlow DurationCurve,Hunter CreekMain Stem
Similar analyses were performed for the east fork gage, except that synthetic east fork flows
were generated using synthetic main stem flows rather than the Knik River. This is because
there are only 8 days of concurrent flow data for the Knik River and the east fork gaging
station (May 1 9, 2012). Using the slightly longer ice free concurrent flow record for the main
stem and east fork gaging stations, the ANFIS model provides a good correlation (r squared
= 0.94), but the model overestimates summer flows (Figure 8). Because it is based on the
main stem synthetic flow record,it also overestimates winter flows.
Mr.Joel Groves,P.E.
December 12,2012
Page7
Figure 8. Hunter Creek East Fork Attempted Record Extension
Lacking a valid extended flow record for the east fork gage, an estimated annual hydrograph
could be generated by scaling the main stem hydrograph using basin areas. Studies in the
adjacent Eklutna watershed show that the proportion of glacial coverage also affects annual
flows (Figures 9 and 10; Larquier 2011). Based on 2009 and 2010 Eklutna streamflow data,
the unit discharge for glaciatedareas ranged from 2.6 to 3.1 times greater than forunglaciated
areas. However, because both forks of Hunter Creek have similar proportions of glaciated
area, the glacial component causes only a small change (<1 percent) in estimated flows. Scale
factors for the east fork gage and the west fork intake location are provided on Table 3.
Table 3. Scale Factors and DrainageAreas
Location Drainage Area,mi
2 GlaciatedArea,mi2 Main Stem Scale Factor
East Fork Gage 23.6 6.3 0.53
WestFork Intake 36.2 6.4 0.32
Main Stem Gage 69.7 12.7 1.0
Using the main stem annual hydrograph and the scale factors provided on Table 1, flow
duration curves for the east fork gage and the basin and glacier areas provided on Figure 11.
Mr.Joel Groves,P.E.
December 12,2012
Page8
Figure9. EklutnaEast and West Fork Streamflow Data (Larquier 2011)
Figure 10. Eklutna and Hunter Creek Subbasins& GlaciatedAreas
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Table 1. Mean Daily Flows (cfs), Hunter Creek Main Stem Gage, Page 1 of 2Year: 2011 Average: Maximum MinimumDay Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec1 75.5 E 41.2 E2 68.7 E 40.6 E3 69.9 E 40.0 E4 68.0 E 39.4 E5 61.5 E 38.8 E6 64.0 E 38.2 E7 59.6 E 37.7 E8 55.0 E 37.1 E9 60.3 E 36.8 E10 59.2 E 35.8 E11 58.2 E 35.1 E12 57.1 E 34.7 E13 56.0 E 34.2 E14 55.0 E 33.7 E15 54.0 E 33.5 E16 53.0 E 33.1 E17 52.0 E 32.9 E18 51.0 E 32.5 E19 50.0 E 32.4 E20 49.1 E 32.2 E21 48.1 E 31.9 E22 47.2 E 31.5 E23 46.3 E 31.2 E24 45.6 E 31.0 E25 44.9 E 30.7 E26 44.3 E 30.5 E27 43.6 E 30.2 E28 43.0 E 30.0 E29 80.6 E 42.4 E 29.7 E30 79.3 E 41.8 E 29.5 E31 70.3 E 29.2 EAverage 76.7 54.1 34.0Maximum 80.6 75.5 41.2Minimum 70.3 41.8 29.2E = estimated due to ice effects55.0 80.6 29.2
Table 1. Mean Daily Flows (cfs), Hunter Creek Main Stem Gage, Page 2 of 2Year: 2012 Average: Maximum MinimumDay Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec1 29.0 E 23.8 E 20.4 E 18.0 E 118.8 206.6 738.6 813.8 T 468.4 172.32 28.7 E 23.7 E 20.3 E 17.7 E 104.3 211.0 714.0 1066.3 T 287.0 159.73 28.5 E 23.6 E 20.0 E 17.6 94.1 223.7 712.8 797.1 387.9 153.84 28.3 E 23.4 E 19.8 E 17.5 84.7 222.5 683.4 599.1 318.0 206.25 28.0 E 23.3 E 19.7 E 17.6 81.3 247.9 626.4 489.5 322.8 272.06 27.8 E 23.1 E 19.6 E 17.9 84.4 273.1 598.1 428.7 216.6 945.9 T7 27.6 E 23.0 E 19.5 E 18.2 95.7 280.9 561.9 459.8 154.7 777.38 27.5 E 22.9 E 19.4 E 18.1 111.7 295.6 534.4 449.1 120.9 688.49 27.3 E 22.7 E 19.3 E 18.1 129.4 314.0 487.4 506.7 103.9 585.410 27.2 E 22.6 E 19.2 E 18.3 134.7 324.4 440.7 562.5 90.9 493.511 27.0 E 22.4 E 19.1 E 18.9 139.1 312.0 424.2 645.7 82.3 428.012 26.8 E 22.3 E 19.0 E 20.1 122.2 348.3 396.9 737.1 79.6 388.813 26.7 E 22.2 E 18.9 E 22.0 109.6 375.7 389.3 790.6 76.7 361.114 26.5 E 22.0 E 18.8 E 24.0 103.6 362.7 411.5 859.4 T 76.5 337.815 26.4 E 22.2 E 18.7 E 26.4 105.7 346.9 457.7 928.4 T 143.2 318.416 26.2 E 22.0 E 18.7 E 32.0 114.1 340.8 447.1 852.8 T 1165.0 T 301.417 26.1 E 21.8 E 18.6 E 37.2 130.6 362.3 449.9 647.3 615.4 286.418 25.9 E 21.6 E 18.5 E 40.1 153.3 437.7 506.9 530.6 267.9 276.719 25.8 E 22.5 E 18.4 E 47.0 165.9 708.8 551.3 626.1 557.220 25.6 E 21.5 E 18.3 E 53.5 159.4 1066.0 T 710.1 679.5 2271.4 T21 25.5 E 21.4 E 18.2 E 62.1 168.5 1286.6 T 1380.3 T 508.8 2193.4 T22 25.3 E 21.1 E 18.1 E 67.9 202.2 1748.9 T 2120.8 T 445.9 3300.5 T23 25.2 E 21.0 E 18.0 E 74.2 237.8 2036.5 T 2082.0 T 489.024 25.0 E 20.8 E 17.9 E 77.9 271.4 2126.2 T 1468.5 T 383.3 1430.9 T25 24.9 E 20.8 E 17.8 E 82.5 286.4 1766.5 T 1130.5 T 393.9 1654.2 T26 24.7 E 20.7 E 17.7 E 94.8 268.7 1268.0 T 1131.2 T 386.8 661.327 24.6 E 20.6 E 17.6 E 107.5 253.1 927.6 T 1197.9 T 964.6 T 268.428 24.4 E 20.5 E 17.5 E 110.8 237.4 772.1 1326.9 T 696.1 248.129 24.3 E 20.3 E 17.8 E 107.2 231.9 741.2 1395.9 T 460.7 227.230 24.1 E 17.8 E 114.1 215.1 758.2 1165.1 T 492.6 193.231 24.0 E 17.9 E 208.8 834.9 T 440.6Average 26.3 22.1 18.7 46.6 158.8 689.7 841.2 617.2 620.1 397.4Maximum 29.0 23.8 20.4 114.1 286.4 2126.2 2120.8 1066.3 3300.5 945.9Minimum 24.0 20.3 17.5 17.5 81.3 206.6 389.3 383.3 76.5 153.8E = estimated due to ice effectsT = rating tentative above 800 cfs343.8 3300.5 17.5
Table 2. Mean Daily Flows (cfs), Hunter Creek East Fork Gage, Page 1 of 2Year: 2011 Average: Maximum MinimumDay Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec1 17.7 E 11.2 E2 17.4 E 11.1 E3 17.1 E 11.0 E4 16.8 E 11.6 E5 102.8 T 16.6 E 11.0 E6 87.6 T 16.3 E 10.4 E7 74.1 T 16.1 E 10.7 E8 62.2 T 15.8 E 10.6 E9 51.9 T 15.6 E 10.4 E10 44.0 T 15.3 E 10.4 E11 36.4 T 15.1 E 10.5 E12 30.2 T 14.8 E 10.8 E13 28.1 E 14.6 E 10.5 E14 27.1 E 14.4 E 10.2 E15 26.1 E 14.2 E 10.1 E16 25.1 E 14.0 E 9.9 E17 24.2 E 13.8 E 9.8 E18 23.5 E 13.6 E 9.8 E19 22.9 E 13.4 E 9.7 E20 22.3 E 13.2 E 9.7 E21 21.8 E 13.0 E 9.7 E22 21.3 E 12.8 E 9.6 E23 20.9 E 12.7 E 9.5 E24 20.5 E 12.3 E 9.4 E25 20.1 E 12.1 E 9.4 E26 19.7 E 11.8 E 9.3 E27 19.3 E 11.7 E 9.2 E28 19.0 E 11.5 E 9.1 E29 18.7 E 11.2 E 9.1 E30 18.4 E 11.4 E 9.0 E31 18.0 E 8.9 EAverage 33.6 14.2 10.0Maximum 102.8 17.7 11.6Minimum 18.0 11.2 8.9E = estimated due to ice effectsT = rating tentative above 30 cfs19.3 102.8 8.9
Table 2. Mean Daily Flows (cfs), Hunter Creek East Fork Gage, Page 2 of 2Year: 2012 Average: Maximum MinimumDay Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec1 8.7 E 7.3 E 6.4 E 5.7 E 69.3 T2 8.6 E 7.4 E 6.4 E 5.6 E 52.7 T3 8.5 E 7.3 E 6.4 E 5.6 42.2 T4 8.6 E 7.4 E 6.3 E 5.6 30.4 T5 8.7 E 7.3 E 6.3 E 5.6 28.56 8.5 E 7.1 E 6.3 E 5.5 29.07 8.5 E 7.1 E 6.2 E 5.5 37.1 T8 8.5 E 7.0 E 6.1 E 5.59 8.4 E 6.9 E 6.3 E 5.610 8.2 E 7.0 E 6.2 E 5.711 8.2 E 6.9 E 6.1 E 6.112 8.4 E 6.9 E 6.1 E 6.813 8.2 E 6.9 E 6.1 E 7.514 8.1 E 6.9 E 6.1 E 8.415 8.2 E 6.8 E 6.0 E 9.116 8.0 E 6.8 E 5.9 E 10.717 7.8 E 6.8 E 5.9 E 12.718 7.8 E 6.8 E 5.9 E 14.919 7.8 E 6.8 E 5.9 E 17.820 7.9 E 6.8 E 5.8 E 21.321 7.9 E 6.7 E 5.8 E 25.022 7.8 E 6.7 E 5.7 E 28.623 7.7 E 6.6 E 5.8 E 36.7 T24 7.7 E 6.6 E 5.7 E 42.5 T25 7.7 E 6.5 E 5.7 E 46.7 T26 7.6 E 6.6 E 5.7 E 60.2 T27 7.5 E 6.6 E 5.6 E 74.1 T28 7.4 E 6.5 E 5.6 E 72.6 T29 7.3 E 6.4 E 5.6 E 62.1 T30 7.3 E 5.7 E 65.9 T31 7.3 E 5.7 EAverage 8.0 6.9 6.0 22.8Maximum 8.7 7.4 6.4 74.1Minimum 7.3 6.4 5.6 5.5E = estimated due to ice effectsT = rating tentative above 30 cfs10.9 74.1 5.5
Eklutna, Inc.
Hunter Creek Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
April 2013 Final Report
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Eklutna, Inc.
Hunter Creek Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
April 2013 Final Report C 13
ATTACHMENT C 2
ADDITIONAL GAUGING STATION DATA, EAST FORK HUNTER CREEK STATION #2
Eklutna, Inc.
Hunter Creek Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
April 2013 Final Report C 14
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Hunter Creek Hydroelectric Reconnaissance Study
Eklutna, Inc.
Polarconsult Alaska, Inc.
EAST FORK HUNTER CREEK GAUGING STATION #2. STATION DATA
Record Water Stage (Site Datum, feet) Water Temperature (F) Air Temperature (F)
Date Count Minimum Average Maximum Minimum Average Maximum Minimum Average Maximum Comments
11/16/2012 97 0.03 1.01 1.27 13.57 29.13 31.83 6.02 10.40 25.63
11/17/2012 36 1.20 1.21 1.24 31.70 31.73 31.79 4.45 9.54 14.95 station installed approx 14:00h
11/18/2012 22 1.17 1.20 1.24 31.66 31.73 31.78 6.86 11.47 16.53 sample rate reduced to every 2h
11/19/2012 12 1.17 1.17 1.17 31.68 31.73 31.80 1.48 4.87 6.93
11/20/2012 12 1.14 1.18 1.20 31.70 31.73 31.76 0.71 3.90 11.68
11/21/2012 12 1.17 1.19 1.20 31.68 31.71 31.76 0.56 1.96 3.13
11/22/2012 12 1.20 1.22 1.24 31.68 31.73 31.79 2.54 5.49 8.03
11/23/2012 12 1.20 1.24 1.24 31.66 31.73 31.79 6.16 10.60 17.95
11/24/2012 12 1.24 1.24 1.27 31.68 31.74 31.79 5.53 7.50 9.18
11/25/2012 12 1.24 1.27 1.30 31.73 31.75 31.77 5.88 7.07 8.24
11/26/2012 12 1.30 1.39 1.47 31.67 31.71 31.73 6.45 7.98 10.38
11/27/2012 12 1.47 1.60 1.67 31.65 31.72 31.77 5.46 7.15 9.18
11/28/2012 12 1.67 1.71 1.77 31.67 31.71 31.74 3.13 6.70 9.58
11/29/2012 12 1.77 1.87 1.94 31.67 31.71 31.76 1.94 6.40 16.35
11/30/2012 12 1.94 2.04 2.11 31.66 31.70 31.75 2.84 4.74 7.35
12/1/2012 12 1.51 2.13 2.24 2.17 24.49 31.67 2.01 4.53 6.30
Apparent freeze and failure of PT between
17:10 and 19:10h
12/2/2012 12 0.14 0.68 1.75 3.13 0.64 1.10
Water temperatures after PT failure are
suspect.
12/3/2012 12 2.08 2.98 3.50 3.63 1.44 8.65
12/4/2012 12 3.59 3.91 4.15 11.00 8.48 4.64
12/5/2012 12 1.58 2.79 3.94 11.00 7.63 3.96
12/6/2012 12 0.62 0.99 1.41 2.96 0.02 2.01
12/7/2012 12 0.07 0.32 0.64 1.66 1.93 5.88
12/8/2012 12 1.40 0.46 0.03 5.17 17.41 26.22
12/9/2012 12 1.59 1.17 0.60 22.64 25.93 27.54
12/10/2012 12 0.48 0.01 0.43 19.47 23.60 25.42
12/11/2012 12 0.53 0.83 1.14 13.02 20.12 24.17
12/12/2012 12 1.23 1.40 1.64 24.61 27.15 29.61
12/13/2012 12 1.69 1.92 2.13 17.78 21.91 25.69
12/14/2012 12 2.21 2.38 2.52 0.48 6.43 12.57
12/15/2012 12 2.54 2.62 2.67 5.16 4.23 9.58
12/16/2012 12 2.59 2.64 2.67 11.78 8.60 3.96
12/17/2012 12 2.40 2.52 2.65 14.62 13.20 11.00
12/18/2012 12 2.27 2.35 2.44 7.99 1.06 6.65
12/19/2012 12 2.04 2.11 2.21 11.00 6.52 1.86
12/20/2012 12 2.06 2.10 2.15 7.45 2.71 0.06
12/21/2012 12 1.96 2.01 2.08 4.81 2.85 1.66
12/22/2012 12 2.00 2.08 2.23 6.38 3.23 0.40
12/23/2012 13 2.25 2.34 2.44 5.59 0.21 4.09
PT temperature channel turned off to
conserve battery power, bandwidth.
12/24/2012 12 6.79 22.60 30.94
12/25/2012 12 20.79 25.83 29.92
12/26/2012 12 22.02 28.00 31.49
12/27/2012 12 25.31 29.34 32.24
12/28/2012 12 22.91 27.35 37.32
12/29/2012 12 30.58 33.79 35.54
12/30/2012 12 33.19 34.03 36.94
12/31/2012 12 24.93 29.43 33.73
1/1/2013 12 29.20 31.77 34.03
1/2/2013 12 26.59 29.60 31.64
1/3/2013 12 26.01 30.53 34.22
1/4/2013 12 25.31 26.64 27.96
1/5/2013 12 24.77 29.19 32.09
1/6/2013 12 26.38 30.30 32.04
1/7/2013 12 17.24 20.56 28.58
1/8/2013 12 13.83 22.75 27.43
1/9/2013 12 5.67 11.71 20.22
1/10/2013 12 11.03 17.56 23.46
1/11/2013 12 18.48 24.25 28.01
1/12/2013 12 25.15 31.57 34.13
1/13/2013 12 33.53 34.50 36.70
1/14/2013 12 28.48 34.56 38.65
1/15/2013 12 15.50 19.70 30.99
1/16/2013 12 17.95 21.05 27.80
April 2013 Final Report Appendix C, Attachment C2, Page C2 1
Hunter Creek Hydroelectric Reconnaissance Study
Eklutna, Inc.
Polarconsult Alaska, Inc.
EAST FORK HUNTER CREEK GAUGING STATION #2. STATION DATA
Record Water Stage (Site Datum, feet) Water Temperature (F) Air Temperature (F)
Date Count Minimum Average Maximum Minimum Average Maximum Minimum Average Maximum Comments
1/17/2013 12 10.38 14.29 17.72
1/18/2013 12 1.41 6.43 12.38
1/19/2013 12 11.61 21.58 27.70
1/20/2013 12 20.10 27.28 32.64
1/21/2013 12 18.77 23.43 30.48
1/22/2013 12 25.90 29.49 32.39
1/23/2013 12 20.96 27.32 32.14
1/24/2013 12 21.86 24.25 26.59
1/25/2013 12 2.69 14.68 26.91
1/26/2013 12 17.21 9.78 0.40
1/27/2013 12 20.66 18.80 17.21 Station entered low power mode 11:10h,
stopped transmitting data.
1/28/2013 12
1/29/2013 12
1/30/2013 12
1/31/2013 12
April 2013 Final Report Appendix C, Attachment C2, Page C2 2
Eklutna, Inc.
Hunter Creek Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
April 2013 Final Report C 15
ATTACHMENT C 3
ADDITIONAL GAUGING STATION DATA, MAIN STEM HUNTER CREEK STATION
Eklutna, Inc.
Hunter Creek Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
April 2013 Final Report C 16
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Hunter Creek Hydroelectric Reconnaissance Study
Eklutna, Inc.
Polarconsult Alaska, Inc.
MAIN STEM HUNTER CREEK GAUGING STATION STATION DATA (note 1)
Record Water Stage (Site Datum, feet) Data Logger Temp. (F) (note 2) Battery Voltage
Date Count Minimum Average Maximum Minimum Average Maximum Minimum Average Maximum Comments
10/19/2012 96 2.43 2.44 2.46 21.26 23.38 25.98 12.81 12.85 12.92 download by J Groves at 18:15h
10/20/2012 96 2.42 2.42 2.45 19.81 22.15 25.76 12.78 12.81 12.84
10/21/2012 96 2.41 2.42 2.43 20.17 21.35 23.32 12.76 12.78 12.80
10/22/2012 96 2.42 2.43 2.44 16.67 18.73 20.72 12.73 12.76 12.78
10/23/2012 96 2.44 2.44 2.45 15.16 17.04 19.43 12.71 12.74 12.77
10/24/2012 96 2.45 2.45 2.46 17.12 19.02 21.89 12.73 12.76 12.80
10/25/2012 96 2.45 2.46 2.48 18.26 19.64 21.95 12.75 12.77 12.80
10/26/2012 96 2.47 2.54 2.67 16.55 18.13 20.06 12.73 12.75 12.77
10/27/2012 96 2.67 2.72 2.75 15.06 17.21 20.07 12.71 12.74 12.78
10/28/2012 96 2.74 3.08 3.31 16.59 18.49 21.35 12.73 12.76 12.79
10/29/2012 96 3.27 3.49 3.59 18.02 20.59 24.91 12.75 12.78 12.84
10/30/2012 96 2.47 3.33 3.99 19.91 23.92 25.39 12.77 12.82 12.84
10/31/2012 96 2.42 2.48 2.62 15.87 17.89 20.01 12.71 12.74 12.76
11/1/2012 96 2.42 2.52 2.70 15.20 16.24 17.90 12.70 12.72 12.74
11/2/2012 96 2.40 2.40 2.42 16.15 20.98 27.00 12.72 12.78 12.86
11/3/2012 96 2.40 2.40 2.40 19.36 21.55 25.39 12.75 12.79 12.84
11/4/2012 96 2.39 2.39 2.40 16.25 18.18 21.01 12.71 12.74 12.78
11/5/2012 96 2.39 2.39 2.40 16.19 17.98 19.77 12.72 12.74 12.76
11/6/2012 96 2.39 2.39 2.40 18.02 19.92 21.43 12.73 12.76 12.78
11/7/2012 96 2.39 2.41 2.44 9.09 12.81 18.99 12.63 12.67 12.75
11/8/2012 96 2.44 2.46 2.48 8.72 12.61 18.10 12.62 12.67 12.75
11/9/2012 96 2.39 2.40 2.45 18.19 25.39 29.44 12.74 12.83 12.88
11/10/2012 96 2.39 2.39 2.40 25.37 26.92 28.29 12.83 12.85 12.87
11/11/2012 96 2.39 2.40 2.40 25.03 26.40 28.13 12.81 12.83 12.85
11/12/2012 96 2.39 2.39 2.40 27.99 28.87 30.39 12.84 12.86 12.88
11/13/2012 96 2.39 2.39 2.40 23.30 25.92 28.86 12.78 12.82 12.86
11/14/2012 96 2.39 2.43 2.49 22.78 27.24 29.65 12.77 12.83 12.86
11/15/2012 96 2.48 2.50 2.51 19.69 21.69 24.41 12.73 12.76 12.79
11/16/2012 96 2.50 2.51 2.52 14.10 19.31 23.36 12.66 12.73 12.78
11/17/2012 96 2.52 2.55 2.57 13.11 14.74 16.76 12.65 12.68 12.70
11/18/2012 96 2.56 2.58 2.61 11.74 13.69 16.02 12.64 12.66 12.69
11/19/2012 96 2.60 2.63 2.67 8.05 10.01 11.70 12.60 12.63 12.64
11/20/2012 96 2.67 2.84 3.04 7.28 8.58 10.04 12.59 12.61 12.63
11/21/2012 96 3.04 3.48 4.06 5.86 6.52 7.23 12.58 12.59 12.61
11/22/2012 96 4.08 4.74 5.36 6.18 6.62 7.14 12.58 12.59 12.60
11/23/2012 96 5.37 5.59 5.72 7.15 11.50 14.90 12.60 12.65 12.70
11/24/2012 96 5.70 5.75 5.79 10.49 12.22 13.69 12.63 12.66 12.68
11/25/2012 96 5.72 5.78 5.81 7.19 9.09 10.55 12.59 12.61 12.63
11/26/2012 96 5.62 5.70 5.78 6.31 7.08 8.02 12.57 12.59 12.60
11/27/2012 96 5.61 5.69 5.76 2.85 4.68 6.43 12.53 12.56 12.58
11/28/2012 96 5.62 5.75 5.81 3.80 5.28 7.50 12.54 12.57 12.60
11/29/2012 96 5.21 5.37 5.61 6.81 9.95 14.66 12.58 12.63 12.69
11/30/2012 96 4.95 5.03 5.21 9.24 11.05 13.87 12.61 12.63 12.67
12/1/2012 96 4.74 4.82 4.95 8.58 11.22 15.97 12.59 12.63 12.69
12/2/2012 96 4.54 4.64 4.75 7.52 8.84 10.04 12.58 12.60 12.62
12/3/2012 96 4.17 4.36 4.54 5.91 7.50 9.00 12.56 12.58 12.60
12/4/2012 96 4.06 4.18 4.25 2.37 1.40 6.97 12.44 12.50 12.58
12/5/2012 96 3.93 4.01 4.09 5.11 4.09 2.15 12.40 12.42 12.45
12/6/2012 96 3.59 3.76 3.93 4.45 2.04 0.94 12.41 12.45 12.47
12/7/2012 96 3.33 3.45 3.59 2.49 1.53 0.19 12.38 12.44 12.48
12/8/2012 96 3.27 3.30 3.33 2.46 9.33 20.52 12.38 12.57 12.74
12/9/2012 96 3.23 3.26 3.30 17.21 18.43 20.55 12.68 12.70 12.72
12/10/2012 96 3.13 3.19 3.23 18.59 21.20 22.49 12.68 12.72 12.74
12/11/2012 96 3.07 3.11 3.14 18.71 21.85 22.98 12.67 12.72 12.75
12/12/2012 96 3.06 3.08 3.09 21.97 25.13 26.39 12.72 12.76 12.78
12/13/2012 96 2.99 3.05 3.07 23.41 24.35 25.03 12.73 12.75 12.76
12/14/2012 96 2.70 2.80 3.01 15.69 18.89 23.28 12.63 12.67 12.74
12/15/2012 96 2.64 2.67 2.70 11.10 14.76 16.93 12.55 12.61 12.65
12/16/2012 96 2.61 2.62 2.63 4.37 7.82 10.98 12.44 12.50 12.56
12/17/2012 96 2.60 2.61 2.61 6.66 2.71 4.26 12.24 12.32 12.44
12/18/2012 96 2.60 2.61 2.63 6.98 3.94 0.30 12.23 12.27 12.35
12/19/2012 96 2.59 2.60 2.61 0.70 0.68 1.49 12.32 12.34 12.37
12/20/2012 96 2.59 2.60 2.61 1.97 0.23 2.15 12.29 12.32 12.35
12/21/2012 96 2.60 2.60 2.60 1.14 3.25 5.28 12.32 12.36 12.39
12/22/2012 96 2.60 2.60 2.61 3.50 4.45 4.95 12.34 12.36 12.38
12/23/2012 96 2.61 2.62 2.63 0.48 1.03 3.52 12.25 12.29 12.35
12/24/2012 96 2.63 2.63 2.64 0.26 10.91 21.22 12.25 12.44 12.62
12/25/2012 96 2.62 2.63 2.63 21.19 22.18 23.61 12.62 12.63 12.66
12/26/2012 96 2.62 2.62 2.63 19.97 22.50 25.22 12.60 12.64 12.67
12/27/2012 96 2.59 2.61 2.62 24.99 25.61 26.09 12.66 12.68 12.69
12/28/2012 96 2.57 2.57 2.59 25.24 25.79 26.59 12.66 12.67 12.69
April 2013 - Final Report Appendix C, Attachment C3, Page C3-1
Hunter Creek Hydroelectric Reconnaissance Study
Eklutna, Inc.
Polarconsult Alaska, Inc.
MAIN STEM HUNTER CREEK GAUGING STATION STATION DATA (note 1)
Record Water Stage (Site Datum, feet) Data Logger Temp. (F) (note 2) Battery Voltage
Date Count Minimum Average Maximum Minimum Average Maximum Minimum Average Maximum Comments
12/29/2012 96 2.55 2.56 2.57 26.62 29.74 30.93 12.67 12.72 12.73
12/30/2012 96 2.55 2.55 2.56 30.17 31.10 31.62 12.71 12.72 12.73
12/31/2012 96 2.54 2.54 2.55 29.59 30.50 31.41 12.68 12.70 12.72
1/1/2013 96 2.54 2.54 2.55 31.04 31.16 31.44 12.66 12.68 12.70
1/2/2013 96 2.53 2.54 2.54 30.85 31.02 31.17 12.63 12.65 12.67
1/3/2013 96 2.54 2.54 2.54 29.99 30.69 31.12 12.60 12.63 12.65
1/4/2013 96 2.54 2.54 2.54 29.58 29.85 30.01 12.53 12.58 12.62
1/5/2013 96 2.53 2.54 2.57 29.25 30.02 30.60 12.48 12.51 12.57
1/6/2013 96 2.54 2.54 2.54 29.49 30.31 30.69 12.45 12.48 12.55
1/7/2013 96 2.54 2.54 2.54 26.06 27.68 30.58 12.37 12.42 12.50
1/8/2013 96 2.54 2.55 2.55 22.98 25.91 26.87 12.29 12.36 12.44
1/9/2013 96 2.55 2.55 2.55 19.32 20.84 22.91 12.17 12.22 12.29
1/10/2013 96 2.55 2.55 2.55 18.48 20.65 23.28 12.12 12.18 12.23
1/11/2013 96 2.55 2.55 2.55 18.90 22.30 24.40 12.12 12.17 12.21
1/12/2013 96 2.54 2.55 2.55 23.37 27.23 31.82 12.17 12.23 12.29
1/13/2013 96 2.54 2.55 2.56 31.65 32.79 34.78 12.27 12.29 12.33
1/14/2013 96 2.54 2.55 2.55 31.05 33.10 34.81 12.23 12.28 12.31
1/15/2013 96 2.54 2.54 2.55 26.69 28.24 31.05 12.12 12.16 12.23
1/16/2013 96 2.53 2.54 2.54 23.32 25.51 27.45 12.04 12.09 12.13
1/17/2013 96 2.53 2.53 2.54 20.52 22.06 23.36 11.96 12.01 12.05
1/18/2013 96 2.54 2.56 2.58 12.25 16.27 20.63 11.75 11.86 11.97
1/19/2013 96 2.58 2.59 2.61 12.45 16.19 20.66 11.74 11.79 11.86
1/20/2013 96 2.54 2.58 2.61 20.67 23.27 26.10 11.82 11.88 11.94
1/21/2013 96 2.54 2.55 2.55 19.67 20.94 23.54 11.73 11.77 11.82
1/22/2013 96 2.53 2.54 2.54 23.15 24.08 25.14 11.76 11.78 11.80
1/23/2013 96 2.52 2.53 2.53 24.89 26.12 27.97 11.70 11.77 11.79
1/24/2013 96 2.52 2.52 2.52 24.10 26.46 27.67 11.57 11.61 11.73
1/25/2013 96 2.44 2.93 6.43 16.95 23.69 27.69 11.31 11.48 11.58
1/26/2013 58 2.55 5.78 6.78 6.29 11.14 16.71 10.98 11.14 11.31 batteries depleted, power failure at 14:00h
1/27/2013 0
1/28/2013 0
1/29/2013 0
1/30/2013 0
1/31/2013 0
2/1/2013 0
2/2/2013 0
2/3/2013 0
2/4/2013 0
2/5/2013 0
2/6/2013 0
2/7/2013 0
2/8/2013 0
2/9/2013 0
2/10/2013 0
2/11/2013 0
2/12/2013 0
2/13/2013 0
2/14/2013 0
2/15/2013 0
2/16/2013 0
2/17/2013 0
2/18/2013 0
2/19/2013 0
2/20/2013 0
2/21/2013 0
2/22/2013 0
2/23/2013 0
2/24/2013 0
2/25/2013 0
2/26/2013 0
2/27/2013 0
2/28/2013 0
3/1/2013 0
3/2/2013 0
3/3/2013 0
3/4/2013 0
3/5/2013 21 24.66 26.38 29.94 12.37 13.04 13.24
Batteries replaced at 18:30h. PT not functional.
3/6/2013 96 23.68 25.42 28.52 12.97 12.98 13.01
3/7/2013 96 25.56 28.54 31.39 12.96 12.97 12.99
3/8/2013 96 31.04 31.50 32.34 12.95 12.96 12.99
April 2013 - Final Report Appendix C, Attachment C3, Page C3-2
Hunter Creek Hydroelectric Reconnaissance Study
Eklutna, Inc.
Polarconsult Alaska, Inc.
MAIN STEM HUNTER CREEK GAUGING STATION STATION DATA (note 1)
Record Water Stage (Site Datum, feet) Data Logger Temp. (F) (note 2) Battery Voltage
Date Count Minimum Average Maximum Minimum Average Maximum Minimum Average Maximum Comments
3/9/2013 96 30.63 31.42 33.18 12.92 12.94 12.95
3/10/2013 96 28.59 30.24 31.85 12.90 12.91 12.93
3/11/2013 96 24.47 28.40 29.94 12.85 12.88 12.91
3/12/2013 96 19.99 22.56 25.45 12.81 12.84 12.86
3/13/2013 96 15.96 18.72 22.92 12.79 12.81 12.85
3/14/2013 96 17.40 21.44 28.04 12.80 12.84 12.89
3/15/2013 96 16.00 18.64 22.04 12.78 12.81 12.83
3/16/2013 96 14.19 18.25 22.77 12.77 12.81 12.85
3/17/2013 96 14.27 17.00 21.02 12.77 12.80 12.83
3/18/2013 96 12.81 16.00 21.02 12.76 12.79 12.83
3/19/2013 96 12.79 15.48 19.93 12.76 12.79 12.82
3/20/2013 96 9.31 13.00 18.84 12.73 12.77 12.81
3/21/2013 80 8.72 12.72 Station hardware removed at 13:00h
GENERAL NOTES:
1. NO STAGE DISCHARGE MEASUREMENTS COLLECTED FOR THE PERIOD OF RECORD SHOWN. PRIOR STAGE DISCHARGE CURVE DEVELOPED FOR 2011 12 SEASON
WAS INVALIDATED BY FLOOD EVENT OF SEPTEMBER 21 TO 25, 2012.
2. DATA LOGGER TEMPERATURE SENSOR IS MOUNTED ON THE LOGGER PRINTED CIRCUIT BOARD, AND IS SUBJECT TO THERMAL ANOMALIES FROM LOGGER POWER DISSIPATION.
THE LOGGER HOUSING IS ALSO SUBJECT TO THERMAL ANOMALIES FROM EXPOSURE TO DIRECT SUNLIGHT OR BURIAL IN SNOWPACK. ACCORDINGLY, THIS DATA IS INDICATIVE
OF AMBIENT TEMPERATURES AT THE GAUGING STATION, BUT SHOULD NOT BE USED AS AN ACCURATE AIR TEMPERATURE RECORD.
April 2013 - Final Report Appendix C, Attachment C3, Page C3-3
Eklutna, Inc.
Hunter Creek Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
April 2013 Final Report
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Eklutna, Inc.
Hunter Creek Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
April 2013 Final Report D 1
APPENDIX D RESOURCE DATA AND ANALYSIS
Eklutna, Inc.
Hunter Creek Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
April 2013 Final Report
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Eklutna, Inc.
Hunter Creek Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
April 2013 Final Report D 2
Section Title Page Nos.
D.1 Land Status.............................................................................................. D 3
D.2 Hydrological Considerations.................................................................... D 5
D.3 Geotechnical Considerations................................................................... D 8
Tables
Table D 1 Maximum Probable Flood Flows at Hunter Creek and Tributaries...........D 5
Table D 2 Estimated Sediment Loads in East Fork Hunter Creek..............................D 7
Eklutna, Inc.
Hunter Creek Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
April 2013 Final Report
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Eklutna, Inc.
Hunter Creek Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
April 2013 Final Report D 3
D.1 LAND STATUS
Land status in the project area is shown on Figure A 3. Most of the land in the project area has
been selected by Eklutna, Inc. (Eklutna) as part of its land entitlement from the Bureau of Land
Management (BLM) under the Alaska Native Claims Settlement Act (ANCSA). Eklutna selected
land in the project area does not have any competing land selections, so these lands should be
conveyed to Eklutna over the next several years. The entire footprint of the recommended
project configuration is located on lands that have been selected by Eklutna. No development
restrictions were identified on land needed for any of the east fork project configurations or
west fork configuration W3.
Conveyance of lands needed for the recommended project is currently waiting for the State of
Alaska to make its requests for ANCSA 17(b) easements so the BLM can continue processing the
lands. There is not a definite schedule for when the State will make its formal 17(b) easement
requests, or when the conveyance process for these lands will be completed, but conveyance is
expected within the next five years.
Eklutna owns land along west fork Hunter Creek needed for project configurations W1 and W2
(sections 13 and 24 of Township 15 North, Range 3 East, Seward meridian). This land is subject
to the 1982 North Anchorage Land Agreement (NALA) between Eklutna, the Municipality of
Anchorage (MOA), and State of Alaska (SOA), and is managed by the Alaska Department of
Natural Resources (ADNR) Division of Parks and Recreation (DOPR) as part of Chugach State
Park. This land is designated as wilderness zonein the 2011 public review draft of the
Chugach State Park Management Plan. The management plan states that hydroelectric
development is not compatible with this management designation.
20
For west fork project configurations occupying lands within Chugach State Park to be
authorized, it appears that the NALA would have to be modified, or DOPRs management
objectives for the project footprint would need to be changed. Hydroelectric developments are
allowed in both other park land management designations:recreation development zoneand
natural environment zone.
If Eklutna chooses to pursue hydroelectric development of west fork Hunter Creek within
Chugach State Park, more detailed review of the NALA and DOPR management objectives will
be necessary to determine development constraints and a strategy for developing an
acceptable hydroelectric project configuration that is compatible with the various management
objectives for the project area.
20 Table 5.4 (Facilities: Alternative Power Development, page 56) and Table 5.5 (Commercial Uses: Commercial Power
Development, page 58) (ADNR, 2011).
Eklutna, Inc.
Hunter Creek Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
April 2013 Final Report D 4
D.1.1 Ownership
21
The proposed project is located within the sections listed below, all within the Seward
Meridian. Land ownership is shown on Figure A 3.
Township 16 North, Range 4 East, Section 31 (powerhouse, lower penstock, and access)
Current land ownership of this section is a patchwork of native selected federal land and
private land. Both Cook Inlet Region, Inc. (CIRI) and Eklutna have selected federal lands
within this section. These selections do not have any competing selections from the SOA or
other entities. Eklutna ANCSA selections within this section are ranked 4
th for conveyance
priority.22 No impediments to the eventual conveyance of these lands to Eklutna were
identified. Powerhouse site #3 at RM 1.02 of Hunter Creek is located on CIRI selected land,
and would be accessed by crossing CIRI selected land north of Knik River Road.
Township 15 North, Range 4 East, Sections 6, 7, and 8 (east fork penstock, diversion)
These three sections are part of Eklutnas ANCSA selections. Neither the SOA or CIRI have
filed competing selections for these sections. Eklutna has ranked these selections 8
th, 37
th,
41st, and 48
th, for section 6, section 7, section 8 W½, and section 8 E½, respectively, for
conveyance priority.
23 No impediments to the eventual conveyance of these lands to
Eklutna were identified.
Township 15 North, Range 3 East, Sections 12, 13, and 24 (west fork penstock, diversion)
These three sections are owned by Eklutna, and are located within the boundary of Chugach
State Parks Eklutna Peters Creek Planning Unit.
24,25 All three sections are subject to the
NALA, a 1982 agreement between Eklutna, the MOA, and the SOA. The NALA settled
litigation relating to a number of land issues in north Anchorage. It provides for transfer of
future excess military land associated with Joint Base Elmendorf Richardson (JBER) to the
MOA and Eklutna, in exchange for concurrent transfer of certain Eklutna lands to the SOA.
Under the NALA, most Eklutna lands within Chugach State Park are managed by DOPR as
part of the park. This includes sections 12, 13 and 24. All Eklutna lands subject to the NALA
have been ranked in the order that they will be transferred to the SOA. These sections are
near the bottom of the transfer priority list (sections 12, 13, and 24 are 54
th, 53
rd, and 52
nd
priority, respectively, out of 57 total tracts subject to the NALA).
26
21 Land ownership and status in the project area is based on review of land records on federal Master Title Plats, State
of Alaska Status Plat Maps, State Recorders Office records, the BLMs Spatial Data Management System, and
summary information regarding the NALA.
22 ANSCA conveyance ranking sets the order in which the BLM processes ANSCA conveyances. Also, in the event an
ANSCA native corporation selects lands in excess of its ANCSA entitlement, the overage will be withheld from the
lowest priority land selection(s),
23 E mail from Christy Favorite, BLM ANCSA Coordinator. December 7, 2012.
24 This land was conveyed from BLM to Eklutna by Patent 50 93 0565.
25 The boundary of Chugach State Park is established by AS 41.21.120.
26 North Anchorage Land Agreement, Informational Pamphlet. MOA, 1982.
Eklutna, Inc.
Hunter Creek Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
April 2013 Final Report D 5
D.2 HYDROLOGICAL CONSIDERATIONS
D.2.1 Maximum Probable Flood
Determining the maximum probable flood for Hunter Creek is important for (1) designing the
in stream diversion structure(s) at Hunter Creek to withstand flood flows, and (2) designing the
creek crossing(s), powerhouse, and other project features so they are not damaged by flood
events. Existing data from the gauging station are compared with statistical models for
southcentral Alaska streams to develop initial estimates of the 100 year and 500 year flood
flows for Hunter Creek and its tributaries.
The USGS has developed statistical models to estimate the maximum probable floods for
streams in southcentral Alaska. These models are developed based on stream gauging data
throughout the region and specific parameters for the drainage basin of the stream of
interest.27 The USGS model input parameters and estimated flood flows are summarized in
Table D 1. The highest calculated flow estimate in the extended record (4,170 cfs on August 16,
1979) is approximately 75% of the estimated 30 year flood flow based on the USGS model. This
is reasonable agreement, given the accuracy of the USGS estimation method, the accuracy of
the extended record at higher flows, and the length of record at these gauging stations.
Table D 1 Maximum Probable Flood Flows at Hunter Creek and Tributaries
Parameter
Main Stem Gauging
Station
(RM 1.59)
1
East Fork Gauging
Station #1
(RM 4.34)
2
West Fork Dam
Site
(RM 4.20)
3
Basin Area (square miles) 69.7 23.6 38.2
Mean Annual Precipitation (inches)
4 70 80 80
Percentage of Basin as Storage (lakes, ponds) 0% 0% 0%
Estimated 500 year flood 9,100 cfs 4,300 cfs 6,400 cfs
Estimated 100 year flood 7,000 cfs 3,300 cfs 4,900 cfs
Estimated 30 year flood 5,500 cfs 2,500 cfs 3,900 cfs
Estimated 10 year flood 4,200 cfs 1,900 cfs 2,900 cfs
Maximum Flow in Extended Record
(approximately 30 years)
4,170 cfs
(8/16/1979)
NA NA
NOTES:
1. At this level of study, these estimated flood flows are suitable for all main stem structures.
2. At this level of study, these estimated flood flows are suitable for all east fork structures.
3. At this level of study, these estimated flood flows are suitable for all west fork structures.
4. Data are from source maps specified in the USGS Water Resources Investigation Report 2003 4188 (USGS, 2003).
27 See USGS Water Resources Investigation Report 2003 4188 (USGS, 2003).
Eklutna, Inc.
Hunter Creek Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
April 2013 Final Report D 6
D.2.2 Flood Hazards
Flood hazards at Hunter Creek are limited to well defined floodplains in the creek canyons and
valleys.
On the east fork of Hunter Creek, the diversion structure, upper approximately 2,000 feet of
penstock/access road, and (for west fork project configuration W2) penstock/access road creek
crossing would all be designed to survive flood hazards along east fork Hunter Creek. These
flood hazards, such as inundation, scour, and channel shifting, occur within a flood hazard area
that is well defined by topography and is generally limited to a corridor along the creek
approximately 100 to 300 feet wide.
The diversion structure would span the active meander area of the creek and would confine
flow to engineered channels to provide continuous flow to the project. The diversion would be
engineered to prevent scour or undercutting from flood flows. The access road and penstock
alignment would be armored by rip rap or sheetpile where exposed to scour from creek
meandering.
On the west fork of Hunter Creek, for project configurations W1 and W2, the diversion
structure and upper approximately 1,000 feet of penstock/access road would all be designed to
survive flood hazards along west fork Hunter Creek. These flood hazards occur within a flood
hazard area that is well defined by topography and is generally limited to a corridor along the
creek approximately 300 feet wide.
On the main stem of Hunter Creek, the powerhouse site would be designed to survive flood
hazards along Hunter Creek such as inundation, channel shifting, debris, or sedimentation.
These flood hazards would be confined to the canyon floor, with the maximum flood stage
dependent on location within the canyon and the powerhouse configuration. Any in canyon
access routes would likely be left unimproved and would be reestablished after flood events.
D.2.3 Sediment Management
The sediment load in Hunter Creek has not been measured, but it is apparent from field
observations and the geologic setting that Hunter Creek carries a significant sediment load.
Both forks of Hunter Creek drain basins that are significantly glaciated. Additionally, the east
fork is actively degrading through glacial till, increasing the sediment load. During the summer
months, the east fork is turbid, with visibility under one inch. Main stem turbidity in the winter
months is variable, with visibility varying from six inches to clear. Winter time turbidity may be
influenced by the condition of individual slide areas and erosion zones.
Sediment transport in east fork Hunter Creek is estimated to be between 6,900 and 37,000 tons
per year, based on measurements on the east and west forks of Eklutna River from the 1980s
Eklutna, Inc.
Hunter Creek Hydroelectric Reconnaissance Study Polarconsult Alaska, Inc.
April 2013 Final Report D 7
(see Table D 2).28 The Eklutna River basin is immediately southwest of the Hunter Creek basin,
and is similar in aspect, area, topography, geology, climate, and glaciation (See Figure 10 in
Attachment C 1 for relative locations of project basins to Eklutna basins).
Table D 2 Estimated Sediment Load in East Fork Hunter Creek
Parameter
Estimate Based on
East Fork Eklutna
Creek
Estimate Based
on West Fork
Eklutna Creek
Estimate Adjusted
for Percentage of
Glaciated Basin Area
Suspended Sediment Transport (tons per year) 8,100 38,200 17,200
Bedload Transport (tons per year) 3,300 3,000 3,200
Total Sediment Transport (tons per year) 11,400 41,200 18,400
Average Daily Total Sediment Transport
(tons per day)
180 600 310
NOTES: Estimates are based on data and relationships reported in WRIR 92 4132 adjusted by basin area and percentage of
glaciated basin area to the subject site.
Sediment is a key issue in project design and operations. Improper design of the diversion and
intake works can lead to rapid sedimentation and blockage of these structures, resulting in
excessive downtime and operations and maintenance costs to clear the sediment. Excessive
sediment entering the project can cause a variety of operational problems, such as scour and
damage to the penstock (accelerated erosion of plastic pipe walls and steel pipe coatings, etc.)
and accelerated wear of the turbine.
To minimize accelerated wear of project infrastructure, the intake structure will need to be
designed to remove most of the sediment from the water before admitting it to the penstock.
The conceptual intake design described in Section 3.5.5 of the main narrative is one of many
ways that sediment can be removed from the water and returned to Hunter Creek. Sediment
loads need to be quantified before development of a more detailed conceptual design is
warranted. Future studies at Hunter Creek should include sediment measurements to quantify
the sediment transport and guide intake structure design.
28 USGS, 1992.Glacier Runoff and Sediment Transport and Deposition Eklutna Lake Basin, Alaska. WRIR 92 4132.
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D.3 GEOTECHNICAL CONSIDERATIONS
D.3.1 Bedrock Geology
The Hunter Creek basin is largely located within the Valdez Group, with the southwestern
portion of the basin (upper west fork subbasin) located in the McHugh Complex.
29 Rock in the
project area is generally a heavily folded complex of shales, argillites, slates, greywackes, and
conglomerates. Bedrock is present throughout the Hunter Creek canyon, predominantly as
outcrops along the walls of the canyon and the floor at the head of the east fork canyon.
D.3.2 Surficial Geology
Surficial geology of the project area is characterized by past glaciation events. Exposed bedrock
generally occurs within Hunter Creek canyon and in alpine areas above the project. A few areas
of exposed rock occur on the crests of the rolling topography east of the main stem of Hunter
Creek between 300 and 800 foot elevation. Most other areas are covered by a mantle of
glacial till, with some talus and rubble cone deposits at the base of mountain slopes, more
commonly along the west fork. The soils are generally poorly drained, with wetlands typically
present in areas with slopes of 10% or less if they have significant upstream catchment areas.
Upland vegetation is typically present in areas with slopes over 10% or along hilltops and
ridgelines.
Hunter Creek canyon is formed where Hunter Creek has cut through a layer of glacial till and
then further cut 100 to 200 feet down into bedrock depending on location. Generally, the till
layer is deepest in the east fork canyon (100 to 200+ feet thick), above the confluence of the
east and west forks, progressively thinning to less than 100 feet where the canyon ends
immediately upstream of Knik River Road. Where exposed, the glacial till maintains near
vertical faces from approximately 10 to 50+ feet tall where protected from surface runoff.
Where more exposed to erosion, the till generally maintains slopes of 1:1. Approximately half
of the eroding till embankments along the canyon is covered by mature vegetation, generally
consisting of cottonwood, birch, alder, and willow. The balance is exposed till with limited
woody vegetation. It appears that vegetation is able to establish itself on these slopes over the
course of decades, but massive failures of the resulting vegetative mat commonly occur on
these faces, perhaps due to low frequency events such as extremely heavy rains or large
earthquakes.
D.3.3 Seismic Considerations
Several known faults are located within the project vicinity, and other unknown faults are likely
present as well. Major fault systems in the vicinity of the project include:
29 The McHugh Complex of Southcentral Alaska: Contributions to Stratigraphy. USGS Bulletin 1372 D (USGS, 1973).
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The Castle Mountain fault system, trending southwest northeast approximately 25 miles
to the northwest of the project area north of Palmer;
The Border Ranges fault system, also trending southwest northeast approximately 10
miles north northwest of the project area near the Knik River bridge on the Old Glenn
Highway;
The Contact fault system, trending southwest northeast approximately 50 miles to the
southeast of the project area in Prince William Sound; and
The Eagle River thrust fault, located approximately 5 miles southwest of the project
area.30
The region is seismically active, and the above listed or other unknown faults in the project
vicinity can be expected to produce major earthquakes that will affect the project. Design of
project features in accordance with building codes and accepted engineering practice is
adequate to address general seismic hazards of the region. More detailed analysis of the site
geology is warranted to characterize seismic hazards and appropriate design criteria for specific
development concepts. In particular, developments on or near the oversteepened slopes of
rock and glacial till in the vicinity of the Hunter Creek canyon warrant analysis to evaluate the
risk of seismically induced slope failures and appropriate design practices to mitigate these
risks.
D.3.4 Mass Wasting Events
Mass wasting events are evident in the general vicinity of the project. Two forms of mass
wasting are indicated in the project area:
1. Failure of vegetated layer along the till bluffs overlooking east fork Hunter Creek. The
apparent failure sequence is the progressive growth of vegetation and quasi stabilization of
a marginal slide face, followed by eventual failure of the vegetation layer due to some
discrete event such as high rainfall or earthquake. Evidence of such events is apparent
along the till slopes of the east fork canyon. The penstock route (in particular from
approximately station 24+00 to 36+00) may traverse slopes susceptible to this type of mass
wasting. In such areas, the penstock should be buried in intact till along the inside cut of
the bench to reduce the likelihood of damage in the event of a mass wasting failure.
2. The actively eroding banks of glacial till strata generate mass wasting events as the banks
are directly undercut by Hunter Creek or undergo uneven erosion. There are several
oversteepened faces of glacial till strata evident along Hunter Creek that may produce
future mass wasting events (see Photographs B 10, B 13, B 16, B 17, B 18, B 19). These
areas are generally confined to the reach between approximately RM 3.5 (east west
confluence) and RM 4.2 (top of east fork canyon).
30 Geological Report 55: Short Notes on Alaska Geology (ADNR, DGGS, 1977).
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The only such feature that could directly affect the recommended project is the exposed
slope adjacent to the penstock alignment from approximately station 42+00 to 48+00
shown in Photograph B 19. The penstock is proposed to be routed approximately 100 feet
laterally behind the lip of this exposed slope. A mass wasting event would reduce this
setback. Based on the angle of repose on this slope, it is unlikely that a mass wasting event
would jeopardize the penstock at this location. More detailed investigation of this area
would be warranted in the final design phase of the project. A greater setback is possible if
warranted, but may require increased excavation to maintain the penstock grade or other
design changes to accommodate this setback.
Failure of some of these features could indirectly affect the project by temporarily damming
east fork Hunter Creek in the bypass reach. This could result in a dam burst flood at the
powerhouse when the dam was breached. The design of the powerhouse site should
consider the potential magnitude of flooding due to such an event.
D.3.5 Avalanche Hazards
While avalanche hazards generally exist within the mountainous terrain of the Hunter Creek
basin, no prominent avalanche chutes are evident in the development corridors identified for
the proposed project configuration. Terrain slopes and vegetation patterns indicate that no
avalanche hazards exist for the access road corridor from Knik River Road to the powerhouse
site, or the penstock corridor from station 70+00 to 116+00. The penstock corridor from
approximately station 50+00 to 70+00 traverses terrain that could generate avalanches,
however vegetation in the corridor suggests avalanches are uncommon in this area. The
powerhouse site, diversion structure site, and upper 2,000 feet of the penstock corridor could
be subject to small avalanches originating on the approximately 200 to 400 foot tall slopes
above these project features.
The penstock would not be susceptible to avalanches as it is buried in all areas at depths and in
materials that would protect it from damage. The access road that is co located with the
penstock could be blocked by avalanches should they occur along this route. The significance
of such blockages to project operations would depend on (1) how often the intake requires on
site personnel during the winter months, (2) what type of equipment is used to access the
intake during the winter months, and (3) whether the project is operated year round. It is likely
that winter access to the intake (and powerhouse) by means of a snow cat or similar vehicle will
be more economic than plowing the road to the intake through the winter season.
The potential for small avalanches at the diversion and powerhouse locations would depend on
the final sites selected for these features. It is expected that avalanche hazards at these
locations can be mitigated through appropriate design of these structures.
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APPENDIX E ENVIRONMENTAL CONSIDERATIONS
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Section Title Page Nos.
E.1 THREATENED AND ENDANGERED SPECIES......................................................................E 3
E.2 FISHERIES AND WILDLIFE.................................................................................................E 3
E.3 WATER AND AIR QUALITY................................................................................................E 4
E.4 WETLAND AND PROTECTED AREAS.................................................................................E 4
E.5 ARCHAEOLOGICAL AND CULTURAL RESOURCES.............................................................E 4
E.6 LAND DEVELOPMENT CONSIDERATIONS.........................................................................E 4
E.7 TELECOMMUNICATIONS AND AVIATION CONSIDERATIONS ..........................................E 5
E.8 VISUAL AND AESTHETIC RESOURCES...............................................................................E 5
E.9 MITIGATION MEASURES..................................................................................................E 5
Attachment E 1 Fisheries Survey Report .................................................................E 7
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E.1 THREATENED AND ENDANGERED SPECIES
The U.S. Fish and Wildlife Service and National Marine Fisheries Service were contacted about
this project. Both agencies confirmed that the project area is not listed as critical habitat for
any threatened or endangered species.
E.2 FISHERIES AND WILDLIFE
Wooded areas in the project footprint provide calving, rutting, and wintering habitat for moose,
and the general project area provides habitat for mammals typical of southcentral Alaska such
as black bear, brown bear, wolves, lynx, and wolverines. Alpine areas in the Hunter Creek
basin, above the project, are habitat for mountain goats.
31 The project would not significantly
affect these habitat areas, so no wildlife impacts are expected.
Polarconsult contracted with Alaska Biological Consulting, Inc. (ABC) to complete an assessment
of fisheries resources in Hunter Creek that may be affected by the hydro project. ABCs full
report is included at the end of this section as Attachment E 1.
The lower portion of Hunter Creek up to approximately RM 3.1 is anadromous habitat for coho
salmon and is also habitat for resident Dolly Varden. No fish were trapped in the vicinity of the
proposed intake site on east fork Hunter Creek. Trapping was not conducted along the west
fork for this study. Based on the similarity of conditions on the west fork and east fork, no fish
are expected to occur along west fork Hunter Creek above the canyon.
Preliminary analysis of environmental impacts of project configurations indicates that
hydroelectric development of only the east fork Hunter Creek is not likely to have a significant
adverse impact on fish habitat in Hunter Creek. Reasonable mitigation measures can likely
address any impacts that do occur. If further study identified significant impacts to fish habitat,
several mitigation strategies can be considered:
1. Siting the powerhouse upstream of fish habitat.Siting the powerhouse within Hunter
Creek canyon presents some technical challenges but appears technically feasible and was
identified as a more cost effective configuration than siting the powerhouse downstream of
the canyon. Reconnaissance level economic analysis indicates that the higher costs of siting
the powerhouse downstream of the canyon (powerhouse site 3) are not quite offset by the
increased electrical output gained from the increased project head. Siting the powerhouse
upstream of significant fish habitat appears to be a good avoidance option.
2. Developing only the east fork of Hunter Creek.The relative remoteness of west fork
Hunter Creek makes hydroelectric development of this fork less economical than
development of the east fork. Additionally, some west fork land is subject to the NALA, and
is managed by the DOPR as part of Chugach State Park. Current management plans for the
31 Chugach State Park Management Plan, Public Review Draft. May 2011.
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park do not allow hydroelectric development in this area. While this does not absolutely
preclude hydroelectric development on the west fork, it is a formidable barrier to an
economically marginal project. Because of the land status and economics of the west fork,
it is likely beneficial to forego development of the west fork, allowing the west fork to
maintain in stream flows throughout fish habitat reaches of Hunter Creek and reducing or
avoiding impacts to fish habitat.
3. Maintaining minimum in stream flows in Hunter Creek.The relatively low flows that occur
in Hunter Creek in late winter may present technical challenges for year round project
operation or may be uneconomic, with operating costs in these months exceeding project
revenue. If either or both of these are the case, it may be advantageous to shut down the
project during these months, allowing flow to remain in the creek and avoiding impacts to
fish. In stream flow reservations while the project is operational would have an adverse
economic impact on the project, especially during the fall, winter, and spring seasons.
E.3 WATER AND AIR QUALITY
The project will not negatively impact water or air quality. By reducing natural gas or diesel
combustion in southcentral Alaska, the project will improve regional air quality.
E.4 WETLAND AND PROTECTED AREAS
The diversion, intake, tailrace, and possibly powerhouse structures are by necessity located
within the ordinary high water mark of Hunter Creek. The creek bed at these proposed
features is a combination of exposed bedrock, boulders, cobbles, and/or gravels.
The penstock and access routes will likely cross some wetland areas, and may have some
unavoidable wetland impacts. Other project features do not pass through significant wetland
areas although some small unidentified wetlands may exist along the proposed routes. Many
of these small wetland areas can likely be avoided in final design once they are identified.
E.5 ARCHAEOLOGICAL AND CULTURAL RESOURCES
No archeological or historical resources are known to exist in the project area. No cultural
resource surveys or consultations were conducted as part of this study.
E.6 LAND DEVELOPMENT CONSIDERATIONS
The diversion/intake structures and upper portion of the access roads and penstock for project
configurations W1 and W2 would be located on Eklutna land located within Chugach State Park.
This land is subject to the 1982 North Anchorage Land Agreement (See Section D.1), and is
managed by ADNR Division of Parks and Recreation (DOPR) as part of Chugach State Park. This
land is designated as wilderness zonein the 2011 Public Review Draft of the Chugach State
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Park Management Plan. Hydroelectric development is not compatible with this management
designation.
For the west fork project to be authorized, the NALA would have to be modified, or DOPRs
management objectives for the project footprint would need to be changed. Hydroelectric
developments are allowed in both other parkland management designations:recreation
development zoneand natural environment zone.
Project lands needed for west fork configuration W3 and all east fork only configurations are
entirely outside of Chugach State Park and not subject to DOPR management.
The project access corridors will improve access to portions of the Hunter Creek basin that are
currently only accessible by primitive foot trails. This will likely increase use of the area by the
public. Use of these access corridors should be controlled consistent with the interests of the
owners of land in the Hunter Creek basin (BLM, Eklutna, CIRI, State of Alaska, and private
owners).
E.7 TELECOMMUNICATIONS AND AVIATION CONSIDERATIONS
The project will not affect telecommunications. Penstock bridges across the east fork canyon
proposed in project configurations W1 and W3 would be a hazard to extremely low flying
aircraft.
E.8 VISUAL AND AESTHETIC RESOURCES
The project will not be visible from widely accessible vantage points on the ground. Project
features would be generally visible from the air and from remote alpine areas in and near the
Hunter Creek basin.
E.9 MITIGATION MEASURES
Mitigation measures would depend on the final project configuration proposed. Mitigation
may be appropriate for affected wetland areas, and for affected fish habitat.
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ATTACHMENT E 1
FISHERIES SURVEY REPORT
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Technical Report No. 12-012
__________________________________________________________
A Fisheries Survey of Hunter Creek, a Knik River tributary near Palmer AK,
Associated with Potential Hydroelectric Development
by
Bruce M Barrett
October 2012
________________________________________________________________________________
Alaska Biological Consulting
PO Box 322
Lakeside, MT 59922-0322
Tel: 406-844-3453
E-mail: alaskabiol@yahoo.com
1
INTRODUCTION
Hunter Creek, a south tributary of the Knik River near Palmer, Alaska, is a designated anadromous fish
stream under Alaska Statute 16.05.871. The stream is being considered for hydroelectric development by
Eklutna, Inc. Polarconsult Alaska, Inc. is handling the reconnaissance study, project design, and
permitting.
The main stem of Hunter Creek is occupied by two species of anadromous fish based on the Alaska
ADF&G) Catalog of Waters Important for Spawning, Rearing, and
Migration of Anadromous Fishes (2012). An October 15, 2011 survey by ADF&G confirmed juvenile
and adult sockeye salmon (Oncorhynchus nerka) and adult Coho salmon (O. kisutch) downstream of East
Knik River Road near interface with the Knik River floodplain. The reported upper limit of
anadromous fish habitat in Hunter Creek is river-mile (RM) 3.13, which is about 1.8 miles upstream of
the East Knik River Road bridge.
At approximately RM 3.5, Hunter Creek divides into the east and west forks (Figure 1). The
reconnaissance study is assessing the hydroelectric potential of both forks of Hunter Creek. The full run-
of-river hydroelectric development scheme under consideration is for a diversion at about RM 5.6 of the
west fork (Elv. 1150 ft.), a pipeline to RM 4.5 of the east fork (Elv. 1050 ft.), and a penstock transporting
the water from both forks to a powerhouse sited between RM 1.0 and RM 2.0 of the main stem of Hunter
Creek. Diverted waters would be returned to Hunter Creek at the powerhouse site.
Based on similar characteristics of the east and west forks above their confluence through the canyon
reach at RM 3.5, it is reasonable to assume that fish presence and habitat in the area of the west fork
diversion site are likely similar to conditions at the east fork diversion site. Should the reconnaissance
study conclude that development of the west fork is viable, this will need to be verified in the field with
fish trapping and habitat assessment. Diverting both forks for hydroelectric would significantly reduce
in-stream flows in the anadromous fish reach from RM 3.13 to the powerhouse site, and expectedly
demand fisheries mitigation either onsite or off-location or both.
This report summarizes fisheries work conducted in the area of the proposed intake on the east fork of
Hunter Creek and on the main stem of Hunter Creek upstream of the Knik River Road bridge in late
August 2012. It also addresses potential fish impacts and mitigation alternatives.
OBJECTIVES
The objectives of this study were:
1. Determine fish presence by species and their relative abundance in the east fork of Hunter Creek
from a potential hydroelectric water intake site at RM 4.5 downstream to the west fork confluence
at RM 3.5, and whether there are any apparent fish impediments or barriers within that reach.
2. Evaluate whether minnow traps and salmon roe bait are suitable for evaluating fish occurrence in
Hunter Creek at the time of the August survey.
3. Determine average fish size by species of any resident and juvenile salmon caught.
4. Classify the general stream characteristics of the east fork of Hunter Creek, and evaluate the
sport-fishing potential.
5. Identify major fish impacts and potential mitigation alternatives.
METHODS
A total of six standard minnow traps were deployed in two reaches of Hunter Creek upstream of the Knik
River Road bridge (RM 1.3). Three were sited in the area of the east fork gauging station near RM 4.5
2
and another three in the area of RM 1.5. Average fishing time per trap was 23.9 h (range: 23.4-24.2h) for
the east fork traps and 7.5 h (range: 7.1-7.8 h) for the main stem traps fished upstream of the bridge. The
trap baits consisted of sockeye salmon roe disinfected by a 10-m soak time in a 1/100 Betadyne solution.
Two sections of roe (approx. 20 g/each) individually secured in a cheesecloth wrap were placed in each
trap along with one or two medium-sized cobble for weight. The traps were set in relatively low velocity
areas, typically behind boulders or a similar flow obstruction along the stream bank, and secured by a line
attached to the shore. Trap locations were identified by GPS and flagged for visual identification.
Fish captured were confirmed by species in accordance with Pacific Fisheries of Canada (Hart 1973). A
total of 129 trap-caught Dolly Varden (Salvelinus malma) were measured for FL (tip of snout to fork-of
tail, mm). One larger length Dolly Varden (DV) was examined for maturity.
Fish sampling was conducted in compliance with an ADF&G-issued collection permit (SF2012-256), and
field assistance was provided by Joel Groves, PE of Polarconsult Alaska, Inc.
RESULTS
EAST FORK HUNTER CREEK
A limited number of suitable gear placement sites were found in the vicinity of the proposed east fork
intake at RM 4.5, and the most optimum for fish occurrence were the three locations fished. In 72 h of
total fishing time, no resident or other fish were caught in the three traps (Tables 1-2).
On both days sampled there was no visible evidence of fish presence,
transport of glacier silt which limited visibly to a depth of less than one-inch. Figures 2-3 are illustrative
of the conditions.
The east fork flow was estimated at 300-400 cfs on both days (August 27-28/12) based on observed
channel width, depth, and velocity of the main channel. A minor surface drop in water elevation occurred
overnight after the traps were set amounting to approximately 3 to 4 inches. The change was not
considered substantial to alter trapping efficiency.
Surface velocity in the mid-channel was estimated to be in the 10 ft/sec range on both days, and stream
gradient was estimated at 4-8% in the reach where the minnow traps were deployed with 4% in the area
of traps #1 and #2 and 8% just below trap #3 (Figures 2-3). As illustrated in Figure 3, flow was limited
to a single channel, and with the exception of log debris on the right side of the creek at trap site #3, no
other large woody materials were noted except for wood debris on exposed bars below the OHW line
deposited by floods. On both sampled days, relatively heavy materials (cobbles and other) were being
moved by stream forces as evidenced by a persistent sound of rocks tumbling in the main channel.
The east fork stream temperature was 38F, and the corresponding air temperature was 53F on August 27,
2012 at 1340hrs.
An attempt to reach the Hunter Creek east fork-west fork confluence at RM 3.5 was aborted. Safety
issues associated with steep terrain precluded a successful decent. However, the confluence vicinity was
photographed as shown in Figure 5. From observation of the stream channel downstream of trap site #3
at RM 4.4 to the RM 3.5 confluence, it is apparent that the reach is unsuitable for fish passage and
occupancy due to the lack of rearing habitat from steep gradient, velocity, incised channel, and absence of
any suitable fish resting, cover, and holding areas.
Irrespective of minnow traps catches, there is no evidence that the east fork has any sport-fishing potential
as: (1) stream access is restricted due to steep terrain; (2) the stream cannot be forded safely from spring
3
to mid to late fall; (3) there are no fishable pools nor turbid free flow until a hard freeze-up occurs in the
glacial fields upstream and; (4) water velocities are excessive (10+ft/sec).
WEST FORK HUNTER CREEK
The west fork intake site was inaccessible by foot on August 27 and 28, 2012. Likely the west fork
upstream of RM 3.5 does not support fish life due to flow conditions including gradient and turbidity.
This is based on the physical similarity of the east and west forks and the absence of any fish being taken
in the three east-fork minnow traps (Table 1). Should Polarconsult reconnaissance survey conclude that
development of the west fork is economically feasible then these preliminary findings need to be field-
verified.
MAIN STEM HUNTER CREEK
Three minnow traps were set in the main stem of Hunter Creek, upstream of East Knik River Road from
approximately RM 1.5 to RM 1.8, for a combined total of 22.5 hours (Figure 6, Tables 1-2). Each trap
produced fish, and all 27 fish caught were positively identified as DV. Trap #2 produced the highest
catch at 17 DV and was located off the downstream end of an exposed gravel bar. Likely the catch would
have been greater had an 18.8 cm FL DV not been lodged in the downstream end of the trap
opening (Figure 7).
Average FL of the 27 DV taken in the three traps was 14.7 cm and the median was nearly the same
at 14.5mm , Tables 3-4). The range was 11.9 18.8 cm (4.7-
A single DV sampled for maturity was determined to be a non-anadromous gravid female. This fish
would have spawned about mid fall (Figure 8, Hart 1973)
Interestingly, no salmon fry were trapped near RM 1.5. With Coho salmon known to spawn upstream to
about RM 3.1, expectedly some fry would have been taken. The absence is indication that Coho fry may
well prefer rearing habitat elsewhere, likely in non-turbid waters downstream in the Knik River floodplain
among spring-fed ponds and confluences of clear-water tributaries. Alternatively, the relatively high DV
abundance suggests that the species may be more adapted for rearing in highly turbid waters than Coho
fry or DV were too much of a predator base in the main stem of Hunter Creek. The literature indicates
that DV can be a major component of the mortality suffered by Coho fry. Logan (1968) reported that
31% of the DV stomachs examined from an Alaskan coastal stream contained juvenile Coho salmon.
In the RM 1.5-1.8 reach of the main stem of Hunter Creek, there was no visible sign of fish presence. As
encountered in the east fork, turbidity levels were high due to the transport of glacier silt limiting visibly
to a depth of about two inches.
Water temperature in Hunter Creek was recorded at 38F and the air at 44F on August 28, 2012 at
1000hrs.
From the main-stem Hunter Creek catch data, it is apparent that the minnow traps, salmon roe, and site
selectivity standards were appropriate for sampling fish presence and relative abundance in the east fork
of Hunter Creek.
IMPACT ASSESSMENT and MITIGATION
EAST FORK DIVERSION ONLY
The main stem of Hunter Creek supports anadromous and resident fishes downstream of RM 3.5.
Evidence is that the east fork of Hunter Creek upstream of RM 3.5 is not fisheries habitat and neither is
the west fork. Diversion of flow only from the east fork for hydroelectric use could improve summer and
4
early fall water quality conditions and, correspondingly, fisheries habitat in the main stem of Hunter
Creek downstream of RM 3.5 to about RM 1.5 or the powerhouse site. This is probable as the east fork
transports substantial amounts of glacier silt much more so than the west fork by about a factor of about 2
(Joel Groves, Polarconsult, pers. com.). Further, main-stem velocities would be reduced from less water
from the east fork entering the main channel of Hunter Creek at RM 3.5. However from late fall through
early spring, an east fork flow diversion would reduce main-stem Hunter Creek flow by about a third at a
time when resident DV and salmon egg-incubation is occurring, and when the east fork would be
contributing less volume (than in the summer) but higher quality water due to less glacial input. The
question of whether a net impact on Coho salmon production to smolt stage would result is debatable. It
would be unlikely that all main-stem spawning would be impacted because expectedly about 2/3 of the
main stem flow would be maintained from the west fork and the sub-basin reach between RM 3.13 and
the RM 5.6 at the west fork diversion site (Tables 5-6). Further, numerous studies indicate that Coho
salmon production is more dependent on rearing habitat availability than spawning habitat (Groot and
Margolis 1991). Nevertheless if deemed necessary, mitigation could be provided by constructing a Coho
salmon spawning channel using the flow discharge from the powerhouse. Additionally a pond could be
built off the spawning channel to serve as a ripening area for adult salmon and rearing area for salmon fry
and resident fish. Land suitable for such developments exists below the bridge on the East Knik River
Road.
EAST AND WEST FORKS DIVERSION COMBINED
If both the east and west forks are developed for hydroelectric power, the DV rearing habitat upstream of
the powerhouse site on Hunter Creek would be seriously reduced and as well as the Coho salmon
spawning habitat extending to RM 3.13. However, replacement spawning habitat for Coho salmon could
be provided by using the tailrace discharge, and the reduction of winter rearing habitat for DV could be
partially if not completely mitigated by constructing one or more ponds using water from the tailrace
discharge.
An alternative mitigation proposal would be for Eklutna, Inc. to provide an agreed level of annual funding
to the Eklutna Salmon Hatchery (Cook Inlet Aquaculture Association facility) which currently is a
standby facility for the Upper Trail Lakes Hatchery. A provision for such is provided in A.S 16.05.851.
LITERATURE CITED
Alaska Department of Fish and Game (ADF&G) 2008, updated 2012. Catalog of waters important for
spawning, rearing, and migration of anadromous fishes. ADF&G, Sport Fish Div., Juneau, AK.
Groot, C. and Margolis L. 1991. Pacific salmon life histories. UBC Press, Vancouver, BC.
Hart, J.L. 1973. Pacific fishes of Canada. Bull. 180; Fish. Res. Bd. Canada.
Logan, S.M. 1968. Silver salmon studies in the Resurrection Bay area. Prog. Rep. ADF&G Sport Fish
Div. 9(1967-68):117 -134. In Groot and Margolis 1991.
5
6
Figure 1. Map of Hunter Creek with the proposed hydroelectric reach defined and the locations where
fish traps were set.
Figure 2. East Fork of Hunter Creek upstream of RM 4.5 and below trap site #1, August 28, 2012.
7
Figure 3. East Fork of Hunter Creek above RM 4.5 in the general area of trap site #2, August 27, 2012.
Figure 4. East Fork of Hunter Creek at trap site #3 in the immediate area of the proposed hydroelectric
intake at RM 4.5, August 27, 2012.
8
Figure 5. East Fork of Hunter Creek at RM 3.6, immediately upstream of West Fork confluence, August
27, 2012.
9
Figure 6. Hunter Creek upstream of East Knik River Road in the area of RM 1.8, and trap site #T-3,
August 28, 2012.
Figure 7. Minnow trap catch of 17 DV with an 18.8 cm DV lodged in the trap opening, trap #T-2, Hunter
Creek, August 28, 2012.
10
Figure 8. Dolly Varden, 18.8cm FL, gravid female from Trap #T-2 catch, Hunter Creek, August 27, 2012.
11
Table 1. Summary of minnow trapping catch results in total number of fish, and average
hourly catch by locaƟon, date, and species, Hunter Creek, near Palmer, AK, 2012.
TRAP Dates Total TOTAL CATCH Avg. Hourly
# LOCATION Fished Hours DOLLY other Catch
VARDEN Dolly Varden
East Fork #1 N 61 24.129 8/27-28/2012 24.2 0 0 0.0
W 148 48. 009
East Fork #2 N 61 24.156 8/27-28/2012 23.4 0 0 0.0
W 148 48. 055
East Fork #3 N 61 24.231 8/27-28/2012 24.2 0 0 0.0
W 148 48. 185
Hunter Cr. N 61 26.416 8/28/2012 7.6 6 0 0.8
# T-1 W 148 48. 776
Hunter Cr. N 61 26.391 8/28/2012 7.1 17 0 2.4
# T-2 W 148 48. 791
Hunter Cr. N 61 26.318 8/28/2012 7.8 4 0 0.5
# T-3 W 148 48. 920
12
Table 2. Fish catch numbers by species using a standard minnow trap by location in Hunter Creek, a Knik River
tributary near Palmer AK, August 27- 28, 2012.
TRAP CATCH
# LOCATION DATE TIME DOLLY other Notes
VARDEN
East Fork #1 N 61 24.129 8/27/2012 1334 hrs Elv. 1053 ft.
W 148 48. 009 Rt bank set behind 2 boulders
Bank veg. 60% alder, 40% willow
Water temp. 38F; air 53F
Trap fished at 15"depth
main-stem flow vel. approx 10ft/sec
Glac. flow; poor water clarity, 1" vis. max.
8/28/2012 1343 hrs. 0 0 Flow: approx. 350-400 cfs & 4% slope
East Fork #2 N 61 24.156 8/27/2012 1356 hrs Elv. 1036 ft.
W 148 48. 055 Rt bank set in side-channel confluence
with mainstem
Trap depth: 16"; approx. 4% slope
8/28/2012 1330 hrs. 0 0 River ht. down approx. 3-4" from previous day
East Fork #3 N 61 24.231 8/27/2012 1356 hrs Elv. 1012 ft.
W 148 48. 185 Rt bank set behind log jam
Trap depth: 14"; approx 8% slope below trap
8/28/2012 1405 hrs. 0 0 Last suitable trap site
above canyon
Hunter Cr. N 61 26.416 8/28/2012 0931 hrs Elv. 218 ft.
# T-1 W 148 48. 776 Cobble bed predominatly
Left bank set; 18" trap depth
bank veg. 90% alder (1-5yds);
8/28/2012 1705 hrs 6 0 40%willow, 40% alder, 10% cottonwood
(5-10yds); approx 3% stream grade
turbid water; 2" visibility max.
trap in left bank eddy
(field book #1)
Hunter Cr. N 61 26.391 8/28/2012 1012 hrs Elv. 219 ft.
# T-2 W 148 48. 791 Left side set
immed. below pt. bar
in mainstem; cobble bed
8/28/2012 1717 hrs 17 0 Trap depth: 12-14"
(field book #3; relabled site 2)
Hunter Cr. N 61 26.318 8/28/2012 0950 hrs Elv. 228
# T-3 W 148 48. 920 Left bank set above rock slide
Trap set behind boulder in eddy
w/alder overhanging
8/28/2012 1740 hrs 4 0 Water temp: 38F; air: 44F (1000hrs)
Trap depth: 18" approx.
(field book #2; relabeled site 3)
13
Table 3. Sampled fork lengths (mm) of Dolly Varden
by minnow trap, in lower Hunter Creek, a Knik
River tributary near Palmer, AK, 8/28/2012.
Hunter Creek mainstem traps
Specimen Trap # 1 Trap # 2 Trap #3
#
1 15.7 15.0 14.0
2 14.7 13.7 13.0
3 14.0 15.5 14.5
4 13.5 13.7 15.7
5 14.5 16.0
6 14.2 13.2
7 16.0
8 11.9
9 16.5
10 15.7
11 16.8
12 14.5
13 15.7
14 14.7
15 13.5
16 18.8
17 12.2
Table 4. Selected length (FL) statistics on Dolly Varden sampled from lower Hunter
Creek, a Knik River tributary near Palmer, AK, August 28, 2012.
Sample Size Mean Median Range Standard
(n) mm inches mm inches mm inches deviation
(mm)
27 14.7 5.8 14.5 5.7 11.9-18.8 4.7 - 7.4 0.5
14
Table 5. Hunter Creek watershed area by selected reach (source: Polarconsult Alaska (10/12)).
AREA
Sub-Basin
Area (square
miles)
Percent of
Sub-basin
Above Main
Stem Gauging
Station
East Fork Sub-basin above RM 4.5 Diversion Site 23.5 34%
West Fork Sub-basin above RM 5.6 Diversion Site 36.2 52%
RM 3.13 (Anadromous Limit) upstream to Both Diversions 8 11%
RM 1.7 (Gauging Stat.) upstream to RM 3.13 (Anadromous Limit) 1.9 3%
TOTAL ABOVE RM 1.7 (Gauging Station) 69.6 100%
Table 6. Water flow (cfs) measurements by date at selected locations in the Hunter Creek drainage
(source: Polarconsult Alaska (10/12)).
October 12,
2011
February 28,
2012
April 13,
2012
AREA Flow
(cfs)
% of
Main
Stem
Flow
Flow
(cfs)
% of
Main
Stem
Flow
Flow
(cfs)
% of
Main
Stem
Flow
East Fork Sub-basin at RM 4.5 Diversion Site 29.5 33% 7.7 35% 8.1 34%
West Fork Sub-basin at RM 5.6 Diversion Site - - - - - -
TOTAL at Main Stem Gauging Site (RM 1.7) 88.3 100% 21.8 100% 23.5 100%
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APPENDIX F PERMITTING INFORMATION
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Section Title Page Nos.
F.1 Federal Permits........................................................................................ F 3
F.2 State of Alaska Permits............................................................................ F 4
F.3 Local Permits............................................................................................ F 6
F.4 Other Permits and Authorizations........................................................... F 6
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F.1 FEDERAL PERMITS
F.1.1 Federal Energy Regulatory Commission (FERC)
The Federal Energy Regulatory Commission (FERC) has jurisdiction over hydroelectric projects
that meet certain criteria. Generally, these criteria include:
(1) The project is located on navigable waters,
(2) The project is located on federal land,
(3) The project affects interstate commerce, or
(4) The project is part of an interstate electrical grid.
Once project lands are conveyed to Eklutna, none of these criteria are expected to apply to the
proposed project. Accordingly, the project should not fall under FERC jurisdiction. A
Declaration of Intention will need to be filed with the FERC in the permitting phase of the
project to verify this jurisdictional analysis.
F.1.3 U.S. Army Corps of Engineers (USACE) Permits
The diversion structure, intake structure, tailrace, and other features of the recommended
project will be located within waters of the United States; therefore, permits from the USACE
will be required under Section 10 of the Rivers and Harbors Act. In addition, some project
features or project mitigation efforts may impact wetlands, which will also require a USACE
permit under Section 404 of the Clean Water Act. The project may be eligible for a Nationwide
Permit #17 for hydro projects. Otherwise, an individual permit will need to be obtained for the
project.
F.1.4 U.S. Environmental Protection Agency
A stormwater pollution prevention plan will be required for construction of the project.
F.1.5 Federal Aviation Administration
The recommended project will not have any features likely to present a hazard to aviation.
The penstock bridges included in west fork configurations W1 and W3 would be more than 200
feet over the floor of the east fork canyon, and would require consultation with the FAA.
F.1.6 BLM Land Use
Aside from private land near Knik River Road, land in the project area is currently managed by
the BLM or DOPR.
BLMs current management plan for southcentral Alaska calls for implementation of a
Knik River Special Management Area (SMA) that would include the entire project area.
BLM does not anticipate implementing this SMA until existing state and native land
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selections are adjudicated, and the SMA designation would not carry forward if lands
are transferred out of BLM ownership.
32
Land managed by DOPR as part of Chugach State Park (upper portions of west fork
configurations W1 and W2) is designated as wilderness zonein the 2011 Public Review Draft
of the Chugach State Park Management Plan. Hydroelectric development is not compatible
with this management designation.
F.2 STATE OF ALASKA PERMITS
F.2.1 Alaska Department of Natural Resources (ADNR) Permits
F.2.1.1 Coastal Zone Consistency Review
The State of Alaska does not currently have a Coastal Zone Management Program.
F.2.1.2 Land Authorizations
None of the recommended project area is on state land. However, the diversion/intake
structures and upper portion of the access roads and penstock for project configurations W1
and W2 would be located on Eklutna land located within Chugach State Park. This land is
subject to the 1982 North Anchorage Land Agreement (See Section D.1), and is managed by
ADNR Division of Parks and Recreation (DOPR) as part of Chugach State Park. This land is
designated as wilderness zonein the 2011 Public Review Draft of the Chugach State Park
Management Plan. Hydroelectric development is not compatible with this management
designation.
For the west fork project to be authorized, the NALA would have to be modified, or DOPRs
management objectives for the project footprint would need to be changed. Hydroelectric
developments are allowed in both other park land management designations:recreation
development zoneand natural environment zone.
F.2.1.3 Tidelands Permits
No tidelands permits are needed for the project.
F.2.1.4 Material Sale Agreement
Not applicable. Material sources likely to be used for this project are not state owned.
32 Ring of Fire Record of Decision and Approved Management Plan, March 2008. Appendix F and Figure 2.3 7.
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F.2.1.5 Water Use Permit/Water Rights
The project will need to obtain water rights from the Alaska Department of Natural Resources
(ADNR). No existing water rights were identified in the project footprint that would affect the
project.
F.2.1.6 State Historical Preservation Office (SHPO)
Section 106 of the federal National Historic Preservation Act requires federal agencies and
federal actions (such as issuance of a federal permit) to take into account the effects of their
actions on historic properties. Eklutna can either directly consult with the SHPO, or relevant
federal agencies will consult with SHPO directly in consideration of issuing permits for the
project.
It is likely that a cultural resources survey will be required to determine if the project would
disturb any significant items. The survey should be conducted once a specific project
configuration and road, penstock, and power line alignments have been selected.
F.2.1.7 Dam Safety Program Permit or Finding
Consultation with ADNRs Dam Safety Program will be required to determine if the diversion
structure requires a dam safety permit. The jurisdictional criteria for dam safety permits are:
1. Structure greater than 10 feet tall and impounds more than 50 acre feet of water, or
2. Structure greater than 20 feet tall, or
3. Would threaten lives and property if it failed.
The Dam Safety Program has interpreted potentially vulnerable downstream fish habitat as
property that can trigger dam safety jurisdiction.
Alaskas Dam Safety Program does not have jurisdiction if the project is under the jurisdiction of
the Federal Energy Regulatory Commission.
F.2.2 Alaska Department of Fish and Game (ADF&G) Permits
F.2.2.1 Fish Habitat Permit
Title 16 of the Alaska Statutes requires that the project will need to obtain a fish habitat permit
from the ADF&G.
F.2.3 Alaska Department of Transportation and Public Facilities Permits
A driveway permit will be needed for the intersection of the project access road(s) and Knik
River Road.
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F.2.4 Alaska Department of Environmental Conservation (ADEC) Permits
F.2.4.1 ADEC Wastewater or Potable Water Permits
Not applicable.
F.2.4.2 Solid Waste Disposal Permit
Not applicable.
F.2.4.3 Air Quality Permit and Bulk Fuel Permit
Not applicable.
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F.3 LOCAL PERMITS
The project area is located within both the Matanuska Susitna Borough (MSB) and the
Municipality of Anchorage (MOA). Figure A 3 shows the boundary between the two local
jurisdictions, which in the project vicinity runs east west along the boundary between Township
15 North and 16 North. Generally, major improvements for the recommended project
(diversion/intake structure, penstock, and powerhouse) are all located within the MOA, and
most of the transmission line and a portion of the access road are located within the MSB.
Some other project configurations may have the powerhouse and a portion of the penstock
located within the MSB as well.
Local permitting processes would need to be completed for the portions of the project located
within each jurisdiction.
F.4 OTHER PERMITS AND AUTHORIZATIONS
F.4.1 Material Sales
Locally sourced aggregate material for the project will need to be purchased from the
appropriate land owner. There are a number of existing material sources in the project vicinity
on state and private land, or a new quarry could be developed on Eklutna land within the
project footprint.
F.4.2 Site Access
All project access corridors shown on Figures A 4 and A 5 have been routed on land selected by
Eklutna when possible (land ownership is shown on Figure A 3). Significant exceptions are
listed below. Land owners were not contacted regarding potential use of their property in
conjunction with hydroelectric developments as part of this project.
33
Powerhouse Site 3 (Figure A 4) and the access corridor from Knik River Road is sited
on BLM land selected by CIRI. An alternate route and site located on adjacent
private land to the east appears to be a viable alternative.
In some instances, use of non Eklutna land may result in cost savings relative to the costs
presented in this study through the use of more direct or easier routes. These potential savings
are not considered significant with regard to the overall findings of this study.
33 Private land owners were contacted for permission to cross their property to conduct fieldwork necessary to
complete this reconnaissance study.
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APPENDIX G ECONOMIC ANALYSIS ASSUMPTIONS
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Section Title Page Nos.
G.1 Introduction............................................................................................. G 3
G.2 Estimated Installed Cost .......................................................................... G 3
G.3 Estimated Annual Project Cost ................................................................ G 3
G.4 Financing Terms....................................................................................... G 3
G.5 Operating Margins................................................................................... G 4
G.6 Estimated Power Sale Rate...................................................................... G 4
G.7 Estimated Benefit Cost Ratio................................................................... G 4
G.8 Environmental Attributes ........................................................................ G 5
G.9 Indirect and Non Monetary Benefits....................................................... G 5
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G.1 INTRODUCTION
The economic analysis of the project configurations considered in this study used a range of
estimated capital costs and related financial parameters to develop a range of estimated energy
costs for each configuration and a range of estimated benefit cost ratios for each configuration.
This appendix explains the ranges used for each parameter.
To avoid confusion over the intent of the range of parameters used,
lowvalues always correspond to more favorable project economics, and
highvalues always correspond to less favorable project economics.
In some instances, this convention results in the lowvalue being numerically greater than the
highvalue. These terms are kept in quotes to emphasize their special definition in this
section.
G.2 ESTIMATED INSTALLED COST
Reconnaissance level cost estimates were developed for each project configuration by
estimating unit quantities and volumes of project components and applying estimated unit
costs to each component line item. An approximate 30% contingency was then applied to the
result. The resulting estimated cost was multiplied by a range of +/20% to develop a range of
probable cost.
G.3 ESTIMATED ANNUAL PROJECT COSTS
G.3.1 General, Administrative, Operation, Maintenance, Repair, and Replacement Expenses
All operating costs of the projects are assumed to cost between $0.013 (lowcase) and $0.018
(highcase) per kWh. This term includes general, administrative, operation, maintenance,
repair, and replacement expenses associated with the project.
G.4 FINANCING TERMS
G.4.1 LowCase Assumptions
For the lowcase, capital project costs are assumed to be financed with $8 million in grants, a
10% owner equity position, and the balance financed at a 5% interest rate and 30 year
term.34,35 A 3% surcharge is added to the financed amount to cover loan origination fees,
underwriting, and guarantee fees. Return on equity is assumed to be 12%.
34 $4 million is the maximum construction grant currently allowed under the Renewable Energy Grant Program. Under
current program rules, acceptance of a construction grant would require Eklutna to become a certificated
economically regulated utility. The economic assumptions used in the lowcase are believed to be consistent with
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G.4.2 HighCase Assumptions
For the highcase, capital project costs are assumed to be financed with $85,000 in grants (the
grant award received for this reconnaissance study), a 20% equity position, and the balance
financed at a 6% interest rate and 30 year term. Loan origination costs of 3% are assumed for
items such as application fees, loan guarantee fees, and other origination fees. Return on
equity is assumed to be 18%.
G.5 OPERATING MARGINS
Operating margins of 12% of gross revenue (lowcase) and 14% of gross revenue (high
case) are assumed.
G.6 ESTIMATED POWER SALES RATE
Annualized estimated costs as described above are totaled and then divided by the estimated
net energy output of the project to calculate an estimated power sales rate for energy from the
project. High and low range estimated annual costs are divided by the same estimated total
energy output.
G.7 ESTIMATED BENEFIT COST RATIO
Benefit cost ratios for project configurations were calculated using the economic model
developed for the Alaska Energy Authority (AEA)s Renewable Energy Grant Program Round 6
by the Institute of Social and Economic Research (ISER) at the University of Alaska Anchorage.
Before being used for economic analysis of Hunter Creek project configurations, the power
plant heat rate in the ISER economic model was reduced approximately 10% to match MEAs
future projected avoided cost of energy from 2013 to 2022 (Figure 4 1). This modified heat rate
was used over the full model period (2010 to 2070).
For the lowcase (more favorable) economic assumptions, the modified ISER model was used
to calculate the project benefit cost ratio.Lowcase capital cost and O&M cost were input to
the ISER model.
For the highcase (less favorable) economic assumptions, the ISER model was further
modified by zeroing out a social cost of carbonterm from years 2010 to 2070. This
modification has the effect of reducing the cost of fuel for MEA. While the merits and
probability of future manifestation of this carbon cost are debatable, the cost is not
represented in current railbelt electric utility economics, and therefore is zeroed out for the
the financial constraints typical associated with RCA economic regulation.
35 The ability of the project to obtain grant funds will depend on what state and federal grant programs exist, whether
the project meets specific program eligibility criteria, and whether the project successfully competes for grant funds
if and when the project is ready to pursue construction funding.
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highcase. This modification assumes the railbelt utilities do not adopt a carbon pricing
mechanism during the 50 year economic life of the project.
Highcase capital and O&M costs were input to the modified ISER model to compute the
estimated highcase benefit cost ratio.
G.8 ENVIRONMENTAL ATTRIBUTES
No revenue from sale of the projects environmental attributes is explicitly considered in the
reconnaissance study. The ISER energy prices used to calculate the benefit cost ratios includes
a monetary value for the social cost of carbon,which is functionally similar to the value of the
projects environmental attributes (See G.7 for details of how this was handled in the lowand
highcases).
G.9 INDIRECT AND NON MONETARY BENEFITS
The recommended hydroelectric project offers 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 natural gas fired power plants in the Cook Inlet region.
More stable energy prices. Hunter Creek would incrementally help to stabilize MEAs
energy rates.
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APPENDIX H DRAFT REPORT REVIEW COMMENTS AND RESPONSES
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polarconsult alaska, inc.
1503 West 33rd Avenue, Suite 310
Anchorage, Alaska 99503-3638
Phone: (907) 258-2420
FAX: (907) 258-2419
M E M O R A N D U M
130422-HUNTERCKREPORT_AEACOMMENTS.DOC
DATE: April 22, 2013
TO: Erin Ealum, Corporate Lands Project Assistant, Eklutna, Inc.
FROM: Joel Groves, Project Manager, Polarconsult
SUBJECT: Response to AEA Review Comments on Hunter Creek Hydroelectric
Reconnaissance Study and Summary of Other Major Revisions to Final Report
CC: Final Report Appendix H
The Client Review Draft of the Hunter Creek Hydroelectric Reconnaissance Study Final Report
was provided to the Alaska Energy Authority (AEA) on February 13, 2012. The AEA provided
comments on February 25, 2013. Upon review of the revised final report, AEA issued a second
series of review comments on April 17,2013.
AEA comments and Polarconsult responses are summarized below. As appropriate, AEAs
comments have been incorporated into the final release of the Hunter Creek Hydroelectric
Reconnaissance Study Final Report,dated April 2013.
AEA Comments Received February 25, 2013 (Polarconsult responses in BLUE)
1. The estimated unit construction costs for the recommended scheme found in this report
are approximately one third to one half of that for a nearby hydro project on another Knik
River tributary. A recently completed study of a seasonal, run of river hydroelectric plant on
Glacier Fork of the Knik River estimated the cost of plant at approximately $9 M per MW. The
most favorable Hunter Creek scheme is estimated at $3 4.5 M per MW. Review and confirm
the construction cost data provided in this report.
The line item cost estimates for the Hunter Creek and Glacier Fork run of river schemes were
reviewed to determine the cause of the disparity in estimated per kW costs for these two
projects. Most of the cost difference can be attributed to:
1. The Glacier Fork project requires a significantly more expensive four mile power tunnel than the
two mile buried penstock at Hunter Creek.
2. The Glacier Fork project requires a significantly longer access road than the Hunter Creek project.
3. The Glacier Fork project requires a significantly longer transmission line than the Hunter Creek
project.
When Glacier Fork costs for these three items are adjusted for conditions at the Hunter Creek
site, the per kW cost of the Glacier Fork project falls from $9,219 to $4,044 per kW. This is
consistent with the cost range of $3,078 to $4,623 per kW in the Hunter Creek
Reconnaissance Study for the recommended project configuration. Based on this review, the
per kW cost estimates in the Hunter Creek and Glacier Fork studies are comparable, and
there is no cause to adjust the construction cost estimates in the reconnaissance study. The
following table explains how the Glacier Fork costs were adjusted.
POLARCONSULTMEMORANDUMApril 22, 2013Cost ItemGlacier ForkCost Estimate1AdjustmentsAdjustedEstimated Cost2NotesLand and Land Rights $0 $0 $0 No adjustmentStructures and Improvements $8,300,000 $0 $8,300,000 No adjustmentReservoir, Dams, and Waterways $272,700,000$194,000,000+ $39,440,000$118,140,000Subtract all tunnel and penstock costs, replace with cost of11,600 foot long buried 12foot diameter penstock at averageinstalled cost of $3,400 per foot.3Waterwheels, Turbines, andGenerators$46,000,000 $0 $46,000,000 No adjustmentAccessory Electrical/MechanicalEquipment$5,400,000 $0 $5,400,000 No adjustmentRoads and Bridges $135,000,000$104,145,000$13,236,000$17,619,000Subtract cost of 18mile access road to site, prorate cost of onsite roads by 0.429 (ratio of roads needed at Hunter Creek toroads needed at Glacier Fork, 15,000 LF / 35,000 LF).Transmission Plant $36,700,000$11,010,000 $25,690,000Prorate cost of transmission line by 0.70 (ratio of line needed atHunter Creek to line needed at Glacier Fork, 14.7 mi / 21.0 mi).SUBTOTAL $504,100,000$282,951,000 $221,149,000Contingency (30%) $151,230,000$66,345,000 Percentage of cost basis held constant.SUBTOTAL $655,330,000$287,494,000Engineering, Environmental,Regulatory (3.0%)$19,659,900$8,625,000 Percentage of cost basis held constant.Construction Management (1.0%) $6,553,300$2,875,000 Percentage of cost basis held constant.Administrative and GeneralExpenses (2.0%)$13,106,600$5,750,000 Percentage of cost basis held constant.SUBTOTAL $694,649,800$304,744,000Interest During Construction $89,000,000$39,038,000 Percentage of cost basis held constant at 12.81%.TOTAL PROJECT COST $783,649,800$343,782,000Installed Capacity (kW) 85,00085,000Estimated Cost per Installed kW $9,219$4,0441.Values taken fromGlacier Fork Reconnaissance Hydropower Study, Palmer, Alaska. March 2013. U.S. Army Corps of Engineers, Alaska District. Appendix D, first table.2.Values are rounded to nearest $1,000.3.A 12foot diameter penstock is permissible instead of the 14foot diameter tunnel due to the higher gross head (880 ft. vs. 710 ft.) and shorter water conveyance route(11,600 ft. vs. 19,760 ft.) at the Hunter Creek site.
P OLARCONSULT M EMORANDUM
April 22, 2013 Page 3 of 6
2. The most recent history of a power purchase agreement between MEA and South Fork
Hydro in Eagle River has provided for 7 cents/kWh with no escalator for 30 years. It is unlikely a
power sales rate exceeding this will be available to an IPP from MEA in the near term.
The terms of a power sales contract for the Hunter Creek project will depend on the
prevailing market conditions and utility forecasts that exist when Eklutna is ready to
negotiate a contract, which will not be for several years. Recent IPP power sales contract
examples on the southern railbelt include the Southfork contract, at a fixed $0.07 per kWh for
30 years, and the Fire Island Wind (FIW) contract with Chugach Electric Association, Inc. (CEA)
at a gross price of $0.10785 per kWh for 25 years.
1
Future avoided costs of energy on the southern railbelt are subject to considerable
uncertainty, primarily surrounding the availability and cost of local natural gas and alternate
supplies. This uncertainty is expected to be resolved before the Hunter Creek project would
be ready to begin contract negotiations, which will help determine if Hunter Creek is an
economic generation option for railbelt utilities.
3. Table ES 1 indicates Annual OMR & R costs for the project at $0.4 0.5 M in 2013 dollars.
Provide a paragraph to describe how this number was arrived at.
This range is based on a range of assumed OMR & R costs of $0.013 to $0.018 per kWh, which
is explained in Section G.4.1 of Appendix G. A footnote has been added to Table ES 1
referring the reader to Appendix G for more explanation of the assumptions used in the
economic analysis.
4. Appendix D The report fails to describe the potential risks of sedimentation issues and
woody debris collection at the proposed intake structure during high flow events. Loss of
generation and expense of clearing and debris removal do not appear to be accounted for in
the operational budget of the project.
A narrative has been added to Section D.2.3 of Appendix D estimating sediment loads in east
fork Hunter Creek and generally discussing some of the operational issues associated with
sediment and debris management. The description of the diversion and intake structure at
Section 3.5.5 of the main narrative has been expanded to conceptually explain how the
diversion and intake might be configured to manage sediment.
The main narrative at Section 3.4 has been revised to provide more detail about how energy
generation estimates were developed. All power generation estimates in this study are
discounted by an assumed plant reliability of 95%, which addresses interruptions due to
unusual debris or sediment issues at the diversion and intake structures.
1 The CEA FIW contract includes a wind integration cost to FIW of $0.01085 per kWh, so the net price for FIW
energy is $0.097 per kWh. This integration cost would not apply to a run of river hydro source, so the gross
price is most appropriate for contract comparison.
P OLARCONSULT M EMORANDUM
April 22, 2013 Page 4 of 6
5. Appendix D The report fails to address other potential risks to project structures and
operations reliability from extreme events, such as landslides, channel changes, flood events
and avalanches.
Extreme event hazards are addressed as applicable throughout the report narrative. An
expanded discussion of extreme event hazards has been added to Appendix D.
6. Page 33 Almost all of the lands for the selected project scheme E2 48 are currently owned
by BLM. Land ownership directly influences the licensing jurisdiction of the project. Until the
land is transferred out of federal hands, any hydropower licensing activity at Hunter Creek will
be under FERC jurisdiction. Due to the licensing jurisdiction impacts, AEA recommends Eklutna
Inc. to take steps to secure land ownership from BLM before seeking any additional grant
funding for additional studies or to further advance a project at this site.
The narrative explaining the current status of land conveyance in the project area in Section
D.1 of Appendix D has been expanded. Land status will not significantly affect site
investigations until the project has advanced to the permitting stage. If Eklutna were to
decide to commence permitting prior to land conveyance, the project would fall under FERC
jurisdiction and would require a FERC license or license exemption.
7. The grant scope (Page 13 of 24) was to include a letter from prospective utilities affirming
their interest in an opportunity to purchase power from this site. No letter of this nature (from
MEA) has been included in the study.
Eklutna and Polarconsult met with MEA staff on March 21, 2013 to review the report findings.
MEA staff affirmed that they believe the project may have merits and are interested in the
opportunity to purchase electricity from the project. A letter fulfilling this requirement was
requested from MEA and will be included after this memo when received.
8. Page 3, Section 2.1:Kachemak Bay has been miss spelled.
This has been corrected in the final report.
9. Page 11, Section 3.1.1:ANCSA has been miss spelled
This has been corrected in the final report.
10. Page 15, Table 3 4: Under ESTIMATED RANGE OF FINANCIAL PARAMETERS, Capital Cost
paid by Grants is listed for each of the nine schemes as $85,000 $8.0M. However, the
maximum eligible REF grant funding for construction of this railbelt project is limited to $4M.
Accordingly, the financial parameters found in this section need to be revised, as well as those
shown for the Estimated Ranges of Sales Rate for Energy and Benefit Cost Ratios, to reflect the
lower amount of grant funds available.
The source of grant funding for this project is not limited to the Renewable Energy Fund (REF)
Grant Program. The ability of the project to obtain grant funds will depend on what state and
federal grant programs exist, whether the project meets specific program eligibility criteria,
and whether the project successfully competes for those grant funds, if and when the project
is ready to pursue construction funding. If Eklutna diligently advances the project, this would
not occur until 2016 or 2017.
P OLARCONSULT M EMORANDUM
April 22, 2013 Page 5 of 6
11. Page G 3, G.4.1: The maximum RE Fund grant a construction project at Hunter Creek would
be eligible for is $4 M (not $8 M). Revise this section and footnote 33 accordingly.
The footnote on page G 3 has been corrected. See response to AEA comment #10 regarding
general grant funding limits. The narrative in Appendix G has been revised to clarify the
range of grants for which the project may be eligible.
12. Page 28, Figure 4 1: Provide citation for source of data for the Projected Future MEA Non
Firm Energy Cost.
A footnote has been added to Figure 4 1 explaining the source of the past and projected
future MEA non firm energy costs.
13. Page 33, Section 5.1: Indicate the expected date of land transfer from BLM to Eklutna, Inc.
and adjust the project development schedule accordingly.
The expected date of land transfer from BLM to Eklutna is unknown. The narrative in Section
D.1 has been expanded to explain the current status of land conveyance in the project area.
The project development schedule allows two years for land conveyance to be completed
before the formal permitting process would begin. If land conveyance is not completed at
that time, Eklutna would have to proceed with the FERC licensing process or wait for final
conveyance before permitting the project. Figure 5 1 has been revised to reflect this
scenario, and the accompanying narrative has been revised to explain these assumptions.
AEA Followup Comments Received April 17, 2013 (Polarconsult responses in BLUE)
1. The original AEA review comments and their responses were received by AEA on April 15
and have now been bound in the report in Appendix H.
AEAs followup comments have also been included in Appendix H of the final report.
2. The size of the West Fork Subbasin has been changed from 36.2 to 33.4 sq mile in Figure 3
1, while the same subbasin remains at 36.2 sq mile in Figure A 2. Reconcile and modify as
needed for consistency.
The area of the west fork subbasin is 33.4 square miles. Figure A 2 has been corrected.
3. The revised discussion of the Diversion and Intake for the favored scheme A2 48 in Section
3.2.2 now includes stilling basins where suspended sediment would be dropped out before
entering the penstock. The terrain upstream from the proposed intake is a narrow canyon, not
conducive for large flat basin areas constructed below intake grade of sufficient size to collect
the annual deposition of hundreds (thousands?) of tons of creek sediment and still avoid
damage from storm and break up flood surges. I am not convinced this is a feasible option for
this location. Given the significance of arriving at a workable solution, there needs to be further
effort put into ideas that can effectively cope with this problem in this location.
The narrow canyon along east fork Hunter Creek is downstream of the proposed intake
location, outside the footprint of the intake works. There is sufficient area adjacent to the
creek for the conceptual intake configuration. While beyond the customary level of analysis
appropriate for a reconnaissance study, Polarconsult has prepared a new Figure A 6 to show
the existing topography at the proposed intake site and a conceptual layout of the intake
configuration described in Section 3.5.5 of the report. The conceptual stilling basin shown in
P OLARCONSULT M EMORANDUM
April 22, 2013 Page 6 of 6
Figure A 6 provides for an approximately 1 foot per second average velocity and 2 minute
residence time which, depending on several factors, can be expected to remove suspended
sediments larger than approximately 0.1 to 0.4 mils in diameter. A significantly larger stilling
basin appears feasible at the site if necessary. A reference to Figure A 6 has been added to
Section 3.5.5 of the report.
4. When it becomes available, the letter from MEA acknowledging their support for the
project as a future energy source remains to be provided to AEA. It should also be bound in the
final report.
MEA provided a letter indicating their support for the project on April 17, 2013. The letter is
included in Appendix H of the final report.
5. Newly included in the revised report is page V, which provides for statement of project
Purpose, Limitations and Copyright. Per Provision 28 of Appendix A of the Award Document for
Grant 7040060, the following has been agreed to:
28. Ownership of Documents and Products
All designs, drawings, specifications, notes, artwork, computer programs, reports and other work
developed with grant funds in the performance of this agreement are public domain and will be used
by the Authority and/or public without notice or compensation to the Grantee. The Grantee agrees not
to assert any rights and not to establish any claim under the design patent or copyright laws. Except
as otherwise specifically agreed, and without limiting any Intellectual Property requirements of a
federal funding agency, the Authority shall have unlimited rights to use and to disseminate any data
produced or delivered in the performance of the contract.
Accordingly, this copyright notice must be removed from this document.
Polarconsult has removed the copyright notice included on Page V.
OTHER SIGNIFICANT REVISIONS FROM DRAFT REPORT
1. The executive summary was expanded to include the estimated development schedule for
the recommended project configuration.
2. The first paragraph of Section 3.1 was expanded to include a geographic description of the
project site.
3. Appendix C was updated to reflect the current status of stream gauging stations installed at
Hunter Creek.
4. Section F.2.1.7 was added to Appendix F detailing the requirements of ADNRs Dam Safety
Program.