HomeMy WebLinkAboutNushagak Area Hydroelectric Project Conceptual Design & Feasibility Study - Oct 2013 - REF Grant 2195419NUSHAGAK ELECTRIC AND TELEPHONE COOPERATIVE
DILLINGHAM AREA HYDROELECTRIC PROJECT
CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
October 2013
NUSHAGAK ELECTRIC AND TELEPHONE COOPERATIVE
DILLINGHAM AREA HYDROELECTRIC PROJECT
CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
Mark C. Storm, P.E.
AK Professional Engineer CE 8840
i DAHP CONCEPTUAL FEASIBILITY STUDY
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TABLE OF CONTENTS
EXECUTIVE SUMMARY .............................................................................................. 1
INTRODUCTION ........................................................................................................... 1
SUMMARY OF FINDINGS .......................................................................................... 1
BACKGROUND ............................................................................................................. 2
ALTERNATIVES DEVELOPMENT ............................................................................ 2
Alternatives Eliminated from Further Consideration .................................................. 3
GENERATION ALTERNATIVES EVALUATED ....................................................... 3
Grant Lake Project ....................................................................................................... 3
Lake Elva Project ......................................................................................................... 4
TRANSMISSION ALTERNATIVES ............................................................................ 5
Park Boundary Alternative .......................................................................................... 5
Glacial Moraine Alternative ........................................................................................ 6
ESTIMATED ENERGY PRODUCTION AND COSTS ............................................... 6
Installed Capacity and Generation ............................................................................... 6
ECONOMIC ANALYSIS PARAMETERS AND VALUES ......................................... 7
Benefit/Cost Ratios for Project Alternatives ............................................................... 7
Projected Energy Costs of Generation Alternatives .................................................... 8
PREFERRED ALTERNATIVES ................................................................................... 9
Grant Lake ................................................................................................................... 9
Lake Elva ................................................................................................................... 10
PROJECT SUMMARY DATA .................................................................................... 11
INTRODUCTION............................................................................................................. 1
OBJECTIVE .................................................................................................................... 1
PROJECT HISTORY and OTHER INFORMATION.................................................... 1
Study History ............................................................................................................... 1
NETC Study Involvement ........................................................................................... 3
Hydrologic and Environmental Studies ....................................................................... 3
Transmission Alternative Evaluations ......................................................................... 3
WORKSCOPE and METHODS ..................................................................................... 4
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GRANT LAKE AND LAKE ELVA PROJECTS
TASK 1. REVIEW EXISTING INFORMATION ........................................................ 4
TASK 2. SITE VISITS and EVALUATION ................................................................. 4
TASK 3. CONCEPTUAL DESIGN of ALTERNATIVE CONFIGURATIONS ......... 4
Dam Height and Location Alternatives ....................................................................... 5
Run-of-The-River vs. Storage Alternatives ................................................................. 5
Tunnel vs. Penstock Design Alternatives .................................................................... 5
Air vs. Land or Water Mobilization Alternatives ........................................................ 5
Transmission and Construction Access Road Routing Alternatives ........................... 5
TASK 4. DETERMINE FEASIBILITY BASED on ELECTRICAL GENERATION
and ENGINEERING CONSIDERATIONS ................................................................... 5
Hydrologic Data Collection and Analysis ................................................................... 6
Energy Calculations ..................................................................................................... 7
TASK 5. ECONOMIC ANALYSIS ............................................................................... 7
B/C Ratio Calculation .................................................................................................. 8
Cost of Energy to the Consumer................................................................................ 10
Sensitivity Analysis ................................................................................................... 11
RESULTS ........................................................................................................................ 12
TASK 1. REVIEW EXISTING INFORMATION ...................................................... 12
TASK 2. SITE VISIT and EVALUATION ................................................................. 12
TASK 3. CONCEPTUAL DESIGN of ALTERNATIVE CONFIGURATIONS ....... 12
Alternatives Eliminated From Further Consideration ............................................... 12
Generation Alternatives Analyzed ............................................................................. 14
TASK 4. DETERMINE FEASIBILITY BASED on ELECTRICAL GENERATION
and ENGINEERING CONSIDERATIONS ................................................................. 24
Operations and Electrical Generation ........................................................................ 24
Hydrologic Data Set Development ............................................................................ 26
Operations/Generation Model Results ....................................................................... 28
TASK 5. ECONOMIC ANALYSIS of ALTERNATIVES ......................................... 38
Construction and Finance Costs ................................................................................ 38
BENEFIT/COST ANALYSIS ...................................................................................... 44
Project Benefits.......................................................................................................... 44
iii DAHP CONCEPTUAL FEASIBILITY STUDY
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Benefit-Cost Ratios.................................................................................................... 46
Projected Cost of Project Debt Service ..................................................................... 47
Cost of Energy (At 2018 Startup) .............................................................................. 48
Sensitivity Analysis ................................................................................................... 50
ENVIRONMENTAL CONSIDERATIONS................................................................. 53
FISHERIES and AQUATIC RESOURCES ................................................................. 53
Grant Lake Project ..................................................................................................... 53
Lake Elva Project ....................................................................................................... 54
SCENIC/AESTHETIC RESOURCES .......................................................................... 54
WILDLIFE/BOTANICAL ............................................................................................ 54
Wildlife Resources ........................................................................................................ 54
Botanical Resources .................................................................................................. 55
CULTURAL RESOURCES ......................................................................................... 55
RECREATION RESOURCES ..................................................................................... 55
FERC LICENSING and STATE and FEDERAL PERMITTING ................................ 56
LAND USE ................................................................................................................... 56
SUMMARY of ENVIRONMENTAL CONSIDERATIONS....................................... 57
DISCUSSION .................................................................................................................. 57
GENERATION COMPONENTS and PROJECT ECONOMICS ................................ 57
GEOLOGIC and GEOTECHNICAL SURVEYS ......................................................... 59
TRANSMISSION and ACCESS ROUTING ............................................................... 59
ENVIRONMENTAL CONSIDERATIONS................................................................. 59
RECOMMENDATIONS ................................................................................................ 60
REFERENCES ................................................................................................................ 63
REFERENCES ................................................................................................................ 63
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APPENDICES
APPENDIX I. PROJECT SUMMARY DATA
APPENDIX II. TRANSMISSION FEASIBILITY STUDIES, DILLINGHAM
AREA HYDROPOWER PROJECT (DAHP) ‐ LAKE ELVA AND
GRANT LAKE SITES
APPENDIX III. HYDROLOGICAL SYNTHESIS, RESERVOIR ROUTING &
ENERGY GENERATION FORMULAE
APPENDIX IV. ECONOMIC FORMULAE
APPENDIX V. GEOTECHNICAL REPORT
APPENDIX VI. CAPITAL COST ESTIMATES
APPENDIX VII. MAJOR PERMITS REQUIRED FOR DAHP CONSTRUCTION
APPENDIX VIII. MAPS OF AFFECTED INHOLDINGS
LIST OF FIGURES
Figure ES-1. Project Location Map .......................................................................... ES-11
Figure ES-2. DAHP Alternative Transmission and Access Routes ......................... ES-12
Figure 1. Project Location Map ....................................................................................... 2
Figure 2 Alternatives G-1 & G-2 Project Features and Configuration ......................... 18
Figure 3. Alternatives E-1 & E-2 Project Configuration Map ....................................... 21
Figure 4. DAHP Alternative Transmission and Analysis .............................................. 25
Figure 5. Synthesized Monthly 20th, 50th, Average and 80th Percent Exceedance
Flows, Grant Lake Outlet Gaging Station.................................................... 27
Figure 6. Synthesized Monthly 20th, 50th, Average and 80th Percent Exceedance
Flows, Lake Elva Outlet Gaging Station. .................................................... 29
Figure 7. Grant Lake Project Alternative G-1 & Alternative G-2 Mean Monthly
Reservoir Levels .......................................................................................... 32
Figure 8. Lake Elva Project Alternative E-1 Mean Monthly Reservoir Levels. ......... 33
Figure 9. Lake Elva Alternative E-2 Monthly Reservoir Levels for Wet, Average and
Dry Years. .................................................................................................... 33
Figure 10. Mean Monthly Energy Generation and percent of Load Supplied by Grant
Lake Project Alternatives G-1 and G-2. ...................................................... 35
Figure 11. Mean Monthly Energy Generation and percent of Load Supplied by Lake
Elva Project Alternatives E-1 and E-2. ........................................................ 37
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LIST OF TABLES
Table ES-1. Estimated Installed Capacity, Annual Energy Generation and Annual
Diesel Avoidance for Grant Lake and Lake Elva Alternatives ............. ES-6
Table ES-2. B/C Ratios for Grant Lake and Lake Elva Project Alternatives ........... ES-7
Table ES-3. Projected Cost of Energy in $/kWh from NETC Generation Alternatives
at 2018 startup. ...................................................................................... ES-8
Table 1. Synthesized Monthly 20th, 50th, Average and 80th Percent Exceedance Flows,
Grant Lake Outlet Gaging Station. ................................................................. 27
Table 2. Synthesized Monthly 20th, 50th, Average and 80th Percent Exceedance Flows,
Lake Elva Outlet Gaging Station. ................................................................... 29
Table 3. Mean Monthly Reservoir Inflows in cfs for Grant Lake Project Alternatives
G-1 and G-2. ................................................................................................... 30
Table 4. Mean Monthly Reservoir Inflows in cfs for Lake Elva Project Alternatives E-
1 and E-2. ........................................................................................................ 31
Table 5. Mean Monthly and Mean Annual Energy Production for Grant Lake Project
Alternatives G-1 and G-2 and Current NETC Monthly Demand in kWh. ..... 34
Table 6. Mean Monthly and Mean Annual Energy Production for Lake Elva Project
Alternatives E-1 and E-2 and Current NETC Monthly Demand in kWh. ...... 36
Table 7. Annual Energy Production by DAHP Alternatives in kWh for Wet, Dry,
Median and Average Years. ............................................................................ 38
Table 8. Estimated Grant Lake Project Alternative Generation Facilities Construction
Costs (in $2013). ............................................................................................. 39
Table 9. Estimated Lake Elva Project Alternative Generation Facilities Construction
Costs (in $2013). ............................................................................................. 40
Table 10. Estimated Grant Lake Project Alternative Transmission System Pre-
Contingency Construction Costs (in $2013). .................................................. 41
Table 11. Estimated Lake Elva Project Alternative Transmission System Pre-
Contingency Construction Costs (in $2013). .................................................. 41
Table 12. Total Estimated Capital Costs for Project Alternatives. ................................. 42
Table 13. Annual O&M Costs for Grant Lake Alternative G-1. .................................... 43
Table 14. Annual O&M Costs for Lake Elva and Grant Lake Alternatives. .................. 43
Table 15. Grant Lake Project Annual Diesel Avoidance and Project Benefits at start-up.
......................................................................................................................... 45
Table 16. Lake Elva Project Diesel Avoidance and Annual Project Benefits at 2018
start-up. ........................................................................................................... 46
Table 17. B/C Ratios for Grant Lake and Lake Elva Project Alternatives. .................... 47
Table 18. Long-term Debt Service on Capital for Grant Lake and Lake Elva Project
Alternatives. .................................................................................................... 48
vi DAHP CONCEPTUAL FEASIBILITY STUDY
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Table 19. Estimated Cost of Energy per kWh at 2018 Startup. ...................................... 49
Table 20. Alternatives G-1 & G-2. Sensitivity Analysis of Selected Project Parameters.
......................................................................................................................... 51
Table 21. Alternative E-1 & E-2. Sensitivity Analysis of Selected Project Parameters. 51
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EXECUTIVE SUMMARY
INTRODUCTION
Nushagak Electric and Telephone Cooperative (NETC) holds a Preliminary Permit (PP)
from the Federal Energy Regulatory Commission (FERC) to study the feasibility of the
Dillingham Area Hydroelectric Project (DAHP, FERC No. 14356). The DAHP, or
"Project", consists of the Grant Lake and Lake Elva Hydroelectric Projects, described in
more detail in the following report. Both Projects are within the boundaries of Wood-
Tikchik State Park (WTSP) which is administered by the Alaska Department of Natural
Resources (ADNR) Division of Parks and Outdoor Recreation (DPOR).
The Grant Lake Project would be located approximately 52 miles N of Dillingham,
Alaska (Figure ES-1). The waters of Grant Lake flow through a smaller outlet lake,
referred to as Little Grant Lake, before flowing as Grant River. Grant River flows 7.5
miles before entering Lake Kulik at Stream Mile (SM) 0 of the stream.
The Lake Elva Project would be located approximately 45 miles NNW of Dillingham
(Figure ES-1). Elva Creek flows from Lake Elva at SM 3.5 before its confluence with
Lake Nerka (SM 0).
SUMMARY OF FINDINGS
Study results indicated that both of the Grant Lake Project Alternatives analyzed would
be economically feasible (Benefit/Cost Ratio > 1.0), under the economic conditions
analyzed. The Lake Elva Project, however, would not be economically feasible
(Benefit/Cost Ratio <1) under any of the base conditions analyzed
Sensitivity testing indicated that the Grant Lake Project would remain economically
feasible over a broad range of values for input variables such as capital cost, discount
rate, economic analysis period and load growth. The Lake Elva Project, using the same
sensitivity test, would be economically unfeasible under most values of the input
variables tested.
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At the currently-accepted NETC load growth forecast, Lake Elva Project energy might be
needed after approximately 20 years. This forecast greatly reduces the current need to
proceed with licensing for the Lake Elva Project.
Results of this analysis, then, rather strongly suggest that FERC licensing proceed for the
Grant Lake Project only at this time.
This study examined more environmental factors than have earlier studies.
Environmental issues such as instream flow requirements and Project consistency with
management objectives of WTSP might have significant effects on overall Project
feasibility.
BACKGROUND
Several earlier studies have addressed feasibility of the Lake Elva Project with lesser
emphasis on the Grant Lake Project. In 2009, EES Engineering conducted a
reconnaissance-level study based on existing data. That report concluded that the Grant
Lake Project would be economically feasible while the Lake Elva Project would not.
Hydrologic and fisheries data and information that have been obtained recently have
allowed the present report to evaluate both Projects under better-defined resource
conditions. Continuous streamflow and fisheries data from both Grant River and Elva
Creek allowed better inflow estimates on which to base installed capacity and to predict
operations in terms of reservoir elevations and downstream releases. Fisheries
information supported powerhouse locations at both Projects.
ALTERNATIVES DEVELOPMENT
In 2012, Civil Science Infrastructure (CSI) was tasked with conducting a new feasibility
study incorporating new fisheries, hydrology and topographic information. CSI
developed several alternative project configurations (dam heights, positions and
materials) and operations (run of the river and storage). In addition, CSI evaluated
various construction access alternatives such as access routes (summer, winter and
watercraft), materials airlift (helicopter and fixed-wing), power conduit types (penstocks
or tunnels) and intake locations.
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Alternatives Eliminated from Further Consideration
Initial analysis led to elimination of certain alternatives, including:
• Aircraft Access, based primarily on expense, but also on travel limitations due to
weather and environmental impacts (noise and visual aesthetics);
• Run of the River configuration and operations, based on optimal utilization of
inflow resources; and
• Power Conduit Tunnels, based on their lengthy construction periods, expense, and
risks for leakage and schedule delays.
• Ice road access for construction of generation facilities, based on shortened
construction seasons, increased time of construction and greatly increased risk for
delays and cost overruns because of weather.
After elimination of these factors, two separate generation alternatives for each Project
were developed, characterized by: 1) storage operations; 2) buried penstocks; 3) overland
(Grant Lake) or over-water (Lake Elva) construction access (as opposed to use of fixed-
wing or helicopter aircraft); and 4) different dam locations, heights, and materials.
GENERATION ALTERNATIVES EVALUATED
Access for construction of Generation Alternatives for the Grant Lake Project would be
via a surface roadway constructed along the Glacial Moraine just inside WTSP. The
following Generation Alternatives were carried forward for more detailed analysis:
Grant Lake Project
Grant Lake, Alternative G-1, Little Grant Lake Rockfill Dam with Powerhouse at SM
3.7 (Figure ES-1)
In detail, this alternative would consist of the following primary components:
• A 24-foot high by 640-foot long rockfill dam with auxiliary spillway on the left
bank located at SM 7.5 of Grant River, just below the outlet of Little Grant Lake;
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• A 66-in diameter buried pipe penstock approximately 16,100 feet in total length;
and
• A 40-ft x 60-ft steel-frame powerhouse at SM 3.7 at El 192 housing a 1.9
megawatt (MW) Francis turbine with associated controls and electro/mechanical
equipment. Total net head for this configuration would be 304 feet.
Grant Lake Alternative G-2, Concrete Dam at SM 6.5 with Powerhouse at SM 3.7 (See
Figure ES-1)
The primary difference between this alternative and Alternative G-1 would be the
position and structure of the dam, as described below:
• A 60-foot high by 120-foot long concrete dam constructed at the top of the
canyon at SM 6.7 of Grant River.
• A 66-in diameter buried pipe penstock approximately 16,100 feet in total length;
and
• A 40-ft x 60-ft steel-frame powerhouse at SM 3.7 at El 192 housing a 1.9
megawatt (MW) Francis turbine with associated controls and electro/mechanical
equipment. Total net head for this configuration would be 304 feet.
Under both alternatives, the project would operate as a storage facility and may suspend
operations during periods when reservoir storage is depleted. Such periods would usually
occur in March and/or April of certain low-water years.
Lake Elva Project
Lake Elva Alternative E-1, "High Dam" (or "Downstream Dam") Alternative (Figure
ES-1)
In detail, this alternative would consist of the following primary components:
• An approximately 110 ft-high, 620 ft-long rockfill dam at Stream SM 1.6 on Elva
Creek, 1.9 miles downstream from the outlet of Lake Elva (Figure ES-1).
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• A48-inch diameter buried penstock, approximately 7,800-ft in length located on
the left bank of Elva Creek. The penstock would be located within and along the
access road used to construct the dam. The alignment of the penstock would
generally parallel the course of the stream.
• A 40-ft x 60-ft steel-frame powerhouse at El 66, just upstream of Lake Nerka on
the left bank of lower Elva Creek at SM 0.2. The powerhouse would be situated
to be just upstream of the comparatively limited anadromous habitat in Elva
Creek that is located from the immediate vicinity of the lower stream gage and
downstream in the stream.
Lake Elva Alternative E-2, "Low Dam" (or "Lake Outlet Dam") Alternative (See
Figure ES-1)
In detail, this alternative would consist of the following primary components:
• A 38-ft high 362-ft long rock fill dam located at the outlet of Lake Elva.
• A 48-inch diameter buried penstock and access road approximately 15,200 feet in
length. The penstock would be located within the road corridor.
The powerhouse would be the same construction and at the same location as for
Alternative E-1.
Both Project Alternatives would operate throughout the year with occasional shutdowns
in late winter of certain low-flow years.
TRANSMISSION ALTERNATIVES
Additionally, CSI reviewed a report by Dryden and LaRue (D&L 2012) which evaluated
several potential transmission routes. CSI further analyzed the D&L transmission and
access routes and developed the following alternatives:
Park Boundary Alternative
This route of this alternative traveled east from the Lake Elva and Grant Lake generating
facilities to the east boundary of WTSP, where it traveled north to south outside the park
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to the existing transmission system at Aleknagik (Figure ES-2). The Park Boundary
Alternative is the recommended alternative from the D&L report.
Glacial Moraine Alternative
This Alternative’s route followed higher elevations and more stable subsurface material
near the terminus of a large glacial moraine, with much of the route inside WTSP (See
Figure ES-2). The Glacial Moraine Route was shown in earlier regional energy studies
(Retherford, 1980). This route was favored over the Park Boundary route which
followed lower-gradient, extensively muskeg ground with greater length outside WTSP.
To address environmental concerns, this route could be designed as a temporary feature
with revegetation of the route following the end of construction.
In both Transmission Alternatives, the construction access road for the generation
facilities would be a temporary feature, visible during construction but allowed to
revegetate afterwards with the objective of limited scenic resources impacts inside the
Park
ESTIMATED ENERGY PRODUCTION AND COSTS
Installed Capacity and Generation
Operations modeling suggested 1.9 MW installed capacity for Grant Lake Alternative
and 1.0 MW for Lake Elva Project Alternatives (Table ES-1). Annual energy output
from either Grant Lake Alternative would be approximately 15 gigawatt hours (GWh) in
an average year, equivalent to over 1 million gallons of diesel-based energy at current
NETC plant efficiency. Annual energy output from either Lake Elva Alternative would
be approximately 7 GWh in an average year, equivalent to approximately 0.5 million
gallons of diesel-electric energy at current NETC plant efficiency.
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Table ES-1. Estimated Installed Capacity, Annual Energy Generation and Annual
Diesel Avoidance for Grant Lake and Lake Elva Alternatives.
Project and
Alternative
Estimated Installed
Capacity (MW)
Estimated Annual
Energy Generation
(GWh)
Annual Diesel
Avoidance
(Millions of
Gallons)
Grant Lake Alt. G-1 1.90 14.3 0.97
Grant Lake Alt. G-2 1.95 14.7 1.00
Lake Elva Alt. E-1 1.0 7.4 0.50
Lake Elva Alt. E-2 1.0 6.9 0.47
ECONOMIC ANALYSIS PARAMETERS AND VALUES
Economic analyses of the Lake Elva Project envisioned that it would be developed as a
supplement to the Grant Lake Project. Under this concept, Lake Elva costs would be
reduced for such components as mobilization, access road and transmission line
construction and labor utilization.
Benefit/Cost Ratios for Project Alternatives
Project economics were calculated using a spreadsheet operations model based on the
following parameters and values:
Finance Rate/Discount Rate: 5.0%
Construction Finance Period: 3 years
Project Finance Period 30 years
Economic Analysis Period: 40 years
Current Diesel Fuel Price (2013): $3.42/gal.
Annual Fuel-oil Price Escalation Rate: 3.0%
Fuel Price @ 2018 startup: $3.96
Annual Escalation in Non-fuel-oil items: 1.5%
NETC Annual Load Growth: 0.5%
Estimated Startup Year: 2018
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Estimated total capital costs (construction and short-term finance) for the Grant Lake and
Lake Elva Project Alternatives, based on 2013 dollars ($2013) with a 2015-16
construction bid date are shown in (Table ES-2). There was very little difference
between the B/C ratios for each Project’s two Alternatives given the differences in
proposed dam locations and types.
Table ES-2. B/C Ratios for Grant Lake and Lake Elva Project Alternatives.
Alternative G-1 G-2 E-1* E-2*
Total Net Project
Benefits $89,848,579 $92,398,729 $42,882,929 $41,903,280
Total Capital
Costs $65,492,396 $68,683,832 $57,843,560 $51,305,451
B/C 1.37 1.35 0.74 0.82
Alternative G-1 used in this analysis. Results are similar using Alternative G-2.
*Supplemental to the Grant Lake Project
Projected Energy Costs of Generation Alternatives
The Grant Lake project was estimated to reduce 2018 electric rates that are
approximately the same as the projected 100% diesel-electric generation scenario at a
2018 startup (Table ES-3). The addition of the Lake Elva project increased rates over a
100% diesel-electric generation scenario by a significant amount (Table ES-3) for a
startup concurrent with the Grant Lake project. The cost increase for initial inclusion of
the Lake Elva Project Alternatives was due in large part to the lack of NETC load
projected for the time of Project start-up (2018). This situation would create a large
annual debt service without compensating generation revenue for several years into the
licensing period.
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Table ES-3. Projected Cost of Energy in $/kWh from NETC Generation
Alternatives at 2018 startup.
Generation
Alternative G-1 G-2 DAHP
G-1 & E-1
DAHP
G-1 & E-2
All Diesel
(Current
Condition)
Projected
Rate $0.4475 $0.4522 $0.5811* $0.5580* $0.4412
*Surplus Capacity exists at a 2018 startup with 0.5% annual load growth.
PREFERRED ALTERNATIVES
In the following sections, preferred alternatives are in bold type face on first reference.
Grant Lake
Generation Facilities
The Grant Lake Project Alternative G-1, the low dam located at Little Grant Lake, was
slightly less expensive to construct than Alternative G-2, which had essentially the same
energy generation and overall B/C ratio. Final selection of a preferred alternative will
require detailed surface and sub-surface geologic and geotechnical information. At the
time of this analysis, there are few decision factors on which to base confirmed selection
of one over the other Grant Lake Project Alternative.
Both Grant Lake Alternatives had the potential for environmental effects on project
feasibility. Instream flow releases and prescribed lake levels will be important factors
potentially reducing generation and overall feasibility. Both alternatives remained
economically feasible after application of a year-round instream flow requirement equal
to 17 percent of mean annual flow, but higher base flow requirements or differing flow
requirements during different seasons could have greater effects on feasibility.
Construction timing constraints to avoid wildlife disturbance could affect overall
schedule and budget. Costs of environmental studies and mitigation measures may
reduce B/C ratios.
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Transmission and Access
The Glacial Moraine Transmission Alternative was preferred because it was
significantly shorter in length, less expensive and offers better construction conditions
than the Park Boundary Alternative. The moraine landform this route follows offers
higher, more stable roadbed conditions than the extensive muskegs found to the east at
the park’s boundary. This transmission route for the Grant Lake Project was shown in
energy studies (Retherford, 1979, 1980) under discussion at the time of the creation of
WTSP. Consistency of this alternative with WTSP policies regarding such features
within the Park will be a major factor in determining its feasibility.
Lake Elva
Generation Facilities
The Lake Elva Project Alternative E-1, the downstream, higher dam alternative, while
more expensive to construct than Alternative E-1, had significantly greater energy
production with less potential for spill and late winter shutdown. As with the Grant Lake
Alternatives, final selection of a Lake Elva Project alternative will depend on surface and
subsurface information.
Environmental constraints on either Lake Elva Alternative are expected to be less
influential than those for the Grant Lake Project, but may still have significant effect on
project feasibility.
Transmission and Access
The Lake Elva Overland Transmission Alternative as opposed to submarine
transmission alternative was significantly cheaper and had fewer unknowns relative to
Lake Nerka lake bottom configuration. Visual effects of the overland route should be the
subject of consultation with WTSP to determine consistency with Park visual resources
policies.
Staged Development
Development of both Projects simultaneously would result in a substantial increase in
energy costs in the NETC service area. This cost increase for initial inclusion of either of
the Lake Elva Project Alternatives would be largely due to lack of NETC load at the time
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of project start-up. This situation would create a large annual debt service without
compensating revenue from energy sales for several years into the licensing period.
Under the current analysis, the Lake Elva Project would be feasible only if it were
brought on line at the time that NETC load was fully met by the combined Grant Lake-
Lake Elva projects. . This would require that Lake Elva Project licensing would begin
no less than about 7 years prior to expected need. During future licensing steps, NETC
will decide which Project or Projects to carry forward to the license application stage. It
is likely that licensing will involve only the Grant Lake Project.
PROJECT SUMMARY DATA
The analyses described above resulted in the summary data presented in Tables AI-1 and
AI-2 in Appendix I for the Grant Lake and Lake Elva Projects respectively. These data
are based on conceptual-level designs and are likely to change during the design
development process.
ES‐12 DRAFT DAHP CONCEPTUAL FEASIBILITY STUDY GRANT LAKE AND LAKE ELVA PROJECTS Figure ES-1. Project Location Map
ES‐13 DRAFT DAHP CONCEPTUAL FEASIBILITY STUDY GRANT LAKE AND LAKE ELVA PROJECTS Figure ES-2. DAHP Alternative Transmission and Access Routes
1 DRAFT DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
INTRODUCTION
Nushagak Electric and Telephone Cooperative (NETC) holds a Preliminary Permit (PP) from the
Federal Energy Regulatory Commission (FERC) to study the feasibility of the Dillingham Area
Hydroelectric Project (DAHP, FERC No. 14356). The DAHP, or "Project", consists of the Grant
Lake and Lake Elva Hydroelectric Projects, described in more detail in the following sections.
Both Projects are within the boundaries of Wood Tikchik State Park (WTSP) which is
administered by the Alaska Department of Natural Resources (ADNR), Division of Parks and
Outdoor Recreation (DPOR). DAHP project generation and transmission features are shown in
Figure 1.
OBJECTIVE
The objective of this study was to determine whether the Project, evaluated in terms of
engineering, environmental/regulatory and economics factors, would be feasible to construct and
operate. A primary factor would be the Project's ability to replace the expensive and volatile-
cost diesel generation on which NETC is wholly dependent at this time. The study would
employ newly available data for hydrology, fisheries, and land surface and lake bathymetric
mapping to supplement previous studies.
PROJECT HISTORY and OTHER INFORMATION
Study History
The Grant Lake and Lake Elva projects have been studied as potential energy sites for over half a
century. Several reconnaissance-level studies have resulted in design proposals for generating
and transmission facilities for both projects. The emphasis of earlier studies was on the Lake
Elva Project, shifting recently to the Grant Lake project. In legislation that created WTSP, the
Grant Lake and Lake Elva projects were deemed consistent with the park’s purposes.
2 DRAFT DAHP CONCEPTUAL FEASIBILITY STUDY GRANT LAKE AND LAKE ELVA PROJECTS Figure 1. Project Location Map
3 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
NETC Study Involvement
NETC began work on the DAHP in 2008 after a declaration of non-jurisdictionality was issued
by the Federal Energy Regulatory Commission (FERC). Later, NETC elected to proceed under
FERC jurisdiction to provide a structured licensing pathway and more formal consultation with
Stakeholders. During the early licensing phases, NETC retained EES Engineering of Kirkland,
Washington to prepare a preliminary feasibility report (EES, 2009). The EES study provided
conceptual-level analysis of the DAHP under both run-of-the-river and storage alternatives. The
study's conclusion was that the Grant Lake project would be feasible under both alternatives
while neither Lake Elva alternative would be feasible if developed on its own.
In 2012, NETC retained Civil Science Infrastructure (CSI) to conduct a second feasibility study
in which newly-acquired hydrologic and fisheries data could be used to improve the information
base for the assessment. In this second study, CSI was tasked with evaluating specific
generation facility designs and new transmission and access routes.
Hydrologic and Environmental Studies
In the EES report, no allowance was made for instream flow releases, minimum or maximum
reservoir elevation restrictions, or other environmental factors shown to have significant effects
on the feasibility of other hydro projects in Alaska. Further, the hydrologic data used in the EES
study were based on a rather short period of record from earlier studies. Newer and more
extensive stream gage data were available for the current assessment.
Similarly, the EES report did not have the benefit of fisheries study results to support project
design. In this report, detailed salmon spawning information was available to help determine
such features as powerhouse locations.
Finally, NETC obtained LIDAR imagery for the Project areas to more precisely determine
elevations, distances, areas and lake volumes relative to those used in earlier studies.
Transmission Alternative Evaluations
The EES study included a reconnaissance-level analysis of several transmission route
alternatives conducted by Dryden and LaRue (D&L). Among these alternatives was an
underwater route beneath the north arm of Lake Nerka. In 2012, NETC retained D&L to
evaluate a smaller set of alternative routes for both the Grant Lake and Lake Elva Projects (D&L,
4 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
2012). In this report, we have incorporated results from D&L (2012) and have developed new
routing alternatives based on the D&L results and more recent analyses. The D&L report is
included in this report in Appendix II.
WORKSCOPE and METHODS
The following section describes steps taken by CSI to conduct the feasibility analysis. Tasks are
those listed in the CSI contract with NETC with some modifications to facilitate report
organization.
TASK 1. REVIEW EXISTING INFORMATION
Previous studies were reviewed to summarize findings on construction alternatives and energy
generation estimates. Also reviewed were economic assumptions and historical hydrologic data.
Geologic reports for both the Project areas and the surrounding region were reviewed.
TASK 2. SITE VISITS and EVALUATION
Project team members visited the Project sites to perform resource studies and to evaluate
availability of construction materials and soil conditions.
TASK 3. CONCEPTUAL DESIGN of ALTERNATIVE CONFIGURATIONS
The conceptual design process proceeded in two steps: 1) development of a preliminary list of
both generation and transmission alternatives based on earlier studies and data collected in 2011
and 2012; and 2) elimination of certain alternatives through more detailed economic evaluation
and Benefit/Cost analysis. As a starting point, the project team focused on alternatives identified
in EES (2008) and earlier literature. Conceptual plan and profile drawings of several alternatives
were drafted, using available topographic data and LIDAR imagery collected in 2012.
The alternative project features and processes included the following:
5 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
Dam Height and Location Alternatives
For both the Lake Elva and Grant Lake Projects, two different dam locations and construction
types (rockfill and concrete) were evaluated. For each Project, one dam option reflected low cost
considerations and the other reflected optimum storage given topographic restraints.
Run-of-The-River vs. Storage Alternatives
The Grant Lake and Lake Elva Projects were evaluated as both run-of-the-river and storage
projects. This was a general evaluation of the alternatives’ ability to meet NETC loads to the
greatest extent possible given inflow available for hydroelectric generation.
Tunnel vs. Penstock Design Alternatives
For the storage alternatives for both projects, we evaluated power conduits featuring both
tunneling and penstock designs. Evaluations of these conduit alternatives were based on
equipment and labor costs, risk of leakage, schedule and environmental considerations.
Air vs. Land or Water Mobilization Alternatives
Both fixed-wing and helicopter mobilization alternatives were evaluated against land and water
access in terms of cost, environmental effects, and aircraft load capabilities.
Transmission and Construction Access Road Routing Alternatives
Two transmission alternatives and two access alternatives were developed for each project. To
the extent possible, the access routes followed the transmission routes to take advantage of
existing soil and topographic conditions.
TASK 4. DETERMINE FEASIBILITY BASED on ELECTRICAL GENERATION and
ENGINEERING CONSIDERATIONS
Under this Task, CSI generally applied engineering and cost criteria to the broad array of
alternatives to eliminate certain alternatives from further consideration. Then, for the remaining
alternatives, CSI utilized a spreadsheet generation model to predict electrical generation based on
updated hydrologic data. Detailed methods for hydrologic synthesis and the energy generation
calculation processes are described in Appendix III.
6 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
Also under this Task, CSI reviewed earlier geotechnical results as well as surface and sub-
surface observations from recent field visits to determine reconnaissance-level feasibility of
constructability at the various dam locations.
The first step in developing the generation analysis was collection and analysis of hydrologic
data followed by use of the spreadsheet model to predict generation, as described in the
following:
Hydrologic Data Collection and Analysis
Hydrologic Data Collection
Hydrologic data were obtained from four separate sources including existing USGS gage records
and project-specific data collected by CSI during 2011 and 2012. These sources were:
1. Short-term data from USGS gages installed at the outlets of both Lake Elva and Grant Lake
("USGS Elva-USGS Grant"). USGS Grant was active from July 1959 through June, 1965.
USGS Elva was active between October 1979 through June, 1982;
2. Short-term data, collected by CSI in 2011 and 2012 at the same locations as the above-
described USGS sites ("CSI Elva, CSI Grant"); and
Long-term data collected by USGS on the Nuyakuk River ("USGS Nuyakuk") which was used
as the basis for synthesizing long-term streamflow forecasts for the outlets of Lake Elva and
Grant Lake. The USGS Nuyakuk gage was active from March, 1953 through September, 1996,
and from July 2002 through September, 2004. The Nuyakuk River gage was re-established in
July 2007 and has remained in operation since that date.
Hydrologic Data Analysis and Synthesis
To develop the long-term synthesized data set, CSI correlated data from the USGS Elva-Grant
sites and the CSI Elva-Grant sites with the corresponding data from the USGS Nuyakuk site.
Relationships from these comparisons were used to create long-term streamflow forecasts for
both the Lake Elva and Grant Lake outlet locations which were used as input to the operations
and generation model.
7 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
To evaluate the synthesized Grant-Elva data, CSI compared the short term data sets with the
respective USGS Nuyakuk data to determine whether the short-term data had been collected
during wet, dry or average years, and to adjust the forecast data accordingly.
Also, the synthesized Elva-Grant data sets were compared to the USGS Nuyakuk data to see
whether long-term trends from the measured data were in accord with those trends in the forecast
data.
Energy Calculations
Using the spreadsheet model, energy generation was calculated for alternative Project
configurations vs. monthly NETC loads. The model was also used to predict monthly reservoir
levels Reservoir levels were predicted relative to upper (reservoir at spill elevation) and lower
(bottom of active storage zone) limits.
Project energy was calculated using the standard “water to wire” formula. Generation losses
were estimated using manufacturer-provided efficiency values. Transmission losses were
estimated at 4.5% of generator output per consultation with D&L. Reservoir storage and energy
generation formulae are presented in Appendix III.
To simulate effects of a possible instream release requirement, a year-round release equal to 17
percent of mean annual flow was input to the model for both Projects. Since no detailed
instream flow requirements were available at this stage of project development, we used the
proposed quantity from the "Tenant Method" (Tenant 1975). In this study, salmonid flow needs
in mountain streams were found to be accommodated by 17 percent of mean annual flow.
Modifications of the Tenant method have been used in Alaska to make reconnaissance level
claims for instream flow needs. Energy generation results reflected the 17 percent of mean
annual flow instream release requirement.
TASK 5. ECONOMIC ANALYSIS
Economic analyses were conducted to predict two primary values for each Project Alternative:
1) Benefit/Cost (B/C) ratio; and 2) cost of electricity per kilowatt hour to NETC consumers. In
this section we describe the calculation processes for these values.
8 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
B/C Ratio Calculation
The B/C ratio in this analysis was defined as the Project’s total net benefits (B) divided by its
capital cost (C). The Project was assumed to be financed over a 30-year period. Annual
revenues from diesel avoidance benefits were discounted over a 40-year period (to reflect the
expected service life of the Project) to present-day values using a 5% discount rate.
Cost Calculation
The Project’s capital cost, C, was the sum the Project construction cost, including a 25%
contingency and the short-term finance costs, necessary to fund the Project’s construction
without impact or with minimal impact on rates before the project comes online. C was
annualized over the finance period and rate to calculate the Project’s annual debt service cost for
estimation of the projected cost of energy to NETC consumers. All Capital costs are in 2013
dollars ($2013) for a 2015/16 bid and operations to start-up in 2018.
Construction Costs
Construction costs were estimated for total quantities of the principal infrastructure components,
based on communications with specialty contractors, suppliers, logistics experts and
manufactures. Local businesses were contacted for lodging, transportation and aviation service
cost estimates. Costs for major infrastructure components, e.g., turbine, generator, transformers,
penstock, etc., were obtained through consultation with suppliers to estimate material and
shipping costs. Equipment and labor requirements were estimated based on logistics and
seasonal access constraints. The cost estimate also included construction management, testing
and certification and environmental monitoring during construction.
Transmission line and access road costs were calculated from estimates in D&L (2012). D&L
unit costs were preserved but quantities were adjusted to match the lengths of new transmission
line alignments developed by CSI. Ice road costs that were included in D&L estimates were
eliminated from the D&L costs where the transmission system would be constructed from the
Project access road.
All project alternatives were estimated to have a three year construction period, with the project
coming on line in the third year. This schedule was used to estimate the drawdown of
construction funds to calculate construction finance costs. Construction funding draws were
9 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
allocated at 25%, 50% and 25% of the total cost in the first, second and final years of
construction. The short-term financing would allow NETC to make payments to construct the
Project without an excessive burden on the ratepayers before the Project began producing
energy. Detailed descriptions of financial formulae are presented in Appendix IV.
Annual Operation and Maintenance (O&M) Costs
Operations costs included estimates for staffing, equipment, materials, supplies, transportation
and administration/insurance. Maintenance costs included those for project intake, SCADA
system, right of way, load controls, lines, roads and miscellaneous items. All O&M costs were
estimated in $2013 and escalated to a 2018 startup. O&M Costs were escalated at 1.5% per year
throughout the analysis period. Addition of the Lake Elva Project to the DAHP was assumed to
add an additional 50% to O&M costs on a kWh basis. This reduction was assumed to come from
economies of scale resulting from combined hydroelectric operations and that the Lake Elva
Project’s transmission line is approximately half the length of the Grant Lake transmission line.
Contingency
Estimated construction costs were based on conceptual-level engineering and associated
uncertainties due to lack of detail in geotechnical, environmental, and regulatory information.
To account for this uncertainty, a 25% contingency was included in the construction cost
estimate.
Inflation
No allowance for inflation was used in the capital cost estimates because of the short period (2-3
years) before short-term financing took effect. Fuel oil and O&M costs were escalated at 3%
and 1.5% per year, respectively.
Benefits Calculation
Benefits of the DAHP are derived from offsetting the costs of equivalent diesel generation since
all electricity within the NETC service area is currently diesel generated. Annual Net Project
Benefits (ANB) were calculated for each year of the 40-year analysis period as the Annual
Benefits (A) from diesel avoidance less the Project’s Annual O&M costs (O). In equation form:
10 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
ANB = A – O
Where:
ANB = Annual Net Benefits;
A = Annual Project Benefits; and
O = Annual O&M Costs
Annual Project benefits equaled the avoided costs of the diesel fuel required to produce the
projected annual energy sales from a given Project Alternative. Fuel costs included the costs of
purchase, shipping, delivery and storage of the volume of diesel fuel required to produce the
average annual energy generated by a given Project Alternative.
The avoided diesel volume was determined using NETC’s current plant efficiency of 14.8
kilowatt-hours (kWh) per gallon of diesel fuel consumed. Annual benefits in dollars were then
calculated using the price per-gallon (PPG) of diesel fuel at the NETC plant injectors multiplied
by the number of gallons of avoided diesel consumption, as shown in the following equation:
A = (E/14.8) x PPG
Where:
A = Annual Project Benefits, $
E = Average Estimated Annual Project Energy Sales in kWh;
PPG = Price per Gallon of diesel delivered to NETC plant injectors.
Annual Net Benefits (ANB) were calculated by subtracting annual O&M from the annual
benefits for each year of the analysis period. Each ANB in the 40-year analysis period series was
then discounted at an annual rate of 5% from the year it occurred to its present value. Total
benefits, B, were the sum of the discounted ANB series over the 40-year analysis period.
Cost of Energy to the Consumer
The cost of energy to the consumer was the cost per kWh of hydroelectric energy plus the cost
per kWh of supplemental diesel-generated energy for each Alternative. Hydroelectric energy
11 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
costs were the sum of annual costs for long-term debt service, O&M, distribution, and general
and administrative costs divided by the projected annual hydroelectric energy sales in kWh. For
cases where annual hydroelectric capacity exceeded annual demand, the diesel-electric
production was assumed to be 2% of the annual sales to cover peak loads. Hydroelectric energy
costs were the sum of annual costs for long-term debt service, O&M, distribution, and general
and administrative costs divided by the annual hydroelectric energy production in kWh. Annual
long-term debt service was calculated as the equivalent ordinary annuity payment for the
Project’s capital cost divided by the Project’s projected energy sales.
The supplemental diesel generation cost for the hydro-diesel generation scenario was the sum of
diesel fuel costs, as described above, divided by the annual supplemental diesel generation in
kWh. All cost components, except estimates for hydroelectric debt service and O&M, were from
NETC’s most recent accounting of their annual costs. These costs from NETC were escalated at
1.5% annually.
Energy costs for the 100% diesel generation scenario (for comparisons with costs per kWh under
the hydro-diesel scenario) were calculated in the same manner as was used for supplemental
diesel-electric energy. In this case, fuel storage costs were apportioned over the entire annual
energy sales rather than only the portion of the total load met by supplemental diesel generation
that would exist with hydroelectric generation in place.
For this analysis, the long-term interest rate was set at 5% and the finance term was 30 years.
The Project was assumed to be online in 2018 with annual NETC load growth set at 0.5%. As
with the B/C calculations, annual diesel costs were escalated at 3.0% and all non-fuel costs were
escalated at 1.5% per year.
Sensitivity Analysis
CSI evaluated the sensitivity of the Alternatives' B/C ratio to such variables as capital cost,
interest rates, annual fuel cost escalation, Annual O&M costs, economic analysis period and load
growth. These sensitivity analyses were projected over the 40-year economic analysis period to
depict a conservative estimate of the Project’s useful service life. All variables were kept at their
base rate and the selected parameter was varied to see its effect on the alternative’s B/C ratio.
12 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
RESULTS
TASK 1. REVIEW EXISTING INFORMATION
Studies of the Lake Elva project resulted in a recommendation by the Alaska Power Authority
(APA) [now Alaska Energy Authority (AEA)] leading to reconnaissance work by Retherford and
Associates (Retherford 1980) and a detailed feasibility study by R.W. Beck (1981). The Grant
Lake project has been mentioned in energy planning documents (UAF, 1976., US Dept. of
Energy, 1979) but interest in the Grant Lake project was lower than that in the Lake Elva project
until recently. Stream discharge data were collected at sites relative to both projects by the US
Geological Survey (USGS).
Geological information relating to topography was gathered and organized, along with
stratigraphy, geologic structures and seismicity via publications and teleconference
communications with the Alaska Geological Society, the USGS, Alaska Department of Natural
Resources, and the University of Alaska Fairbanks Geology Department. Topographic
information was obtained via LIDAR data acquired specifically for this project.
TASK 2. SITE VISIT and EVALUATION
American Geotechnics of Boise, Idaho, performed a geological site reconnaissance at both
Project sites in early July, 2012, to assess ground conditions relative to various Project features.
These surveys did not include subsurface investigations, but rather sought to: 1) generally
evaluate suitability of foundation and abutment conditions for major project features, including
dams, penstocks and powerhouses; 2) locate potential borrow sources for aggregates, blast rock,
and clay or silt materials; and 3) assess geologic benefits or constraints that would affect the
design and construction of the project. The geotechnical report is included as Appendix V.
TASK 3. CONCEPTUAL DESIGN of ALTERNATIVE CONFIGURATIONS
Alternatives Eliminated From Further Consideration
Air Mobilization
Air mobilization was deemed technically infeasible for either project for the following reasons:
13 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
• Aircraft load capacity would not be sufficient to transport large earth moving equipment
like scrapers, large dozers, off-highway trucks and heavy compaction equipment;
• The disturbance caused by multiple large aircraft flights through WTSP would be far
greater than that from lake barge operations on Lake Nerka or road access to Grant Lake;
and
• Weather and air traffic could jeopardize delivery schedules, often by days or weeks.
Run of the River Operations
Run of the river operations were eliminated from further consideration on both Projects because
energy generation would be significantly less than that produced using the advantages of
reservoir storage and release schedules. Energy generation resulting from even optimal storage
operation barely exceeded NETC load requirements. Further losses due to run of the river
operation would bring the Projects below acceptable ability to meet area loads.
Lake Nerka Project Submarine Transmission Alternative
The submarine transmission alternative (beneath the North Arm of Lake Nerka) was eliminated
from the Lake Elva Project on the basis of cost. Estimates for this transmission route in D&L
(2012) were nearly fifty million dollars, sufficient to eliminate this alternative from further
consideration.
Lake Elva Tunnel
A tunnel was considered as an option for the power conduit at the Lake Elva project. The tunnel
was initially attractive due to its low visual impacts and very long service life. The tunnel was
deemed unfeasible, however, due to lengthy construction periods resulting from low production
rates. The expected soft subsurface material added to the uncertainty of conditions which might
cause leakage and loss of generating efficiency. Even with extensive exploratory drilling, the
uncertainty of subsurface rock conditions would be a major factor reducing certainty of success
of the tunnel option.
Grant Lake Canal
The Grant Lake canal, generally following the route of an ancient glacial-fed river channel at the
northwest corner of Grant Lake, was envisioned as component of the power conduit in earlier
14 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
studies. It was eliminated from further consideration in this study because 1) an open channel
would be inoperable during winter and thus unsuited to storage project operations; 2) the canal
would require extensive excavation which would greatly increase construction costs, and, 3) the
canal’s alignment would traverse the terminal moraine at the northwest side of Grant Lake where
significant losses of water for power production could be reasonably expected due to leakage
from the canal into the porous moraine deposits.
Ice Road Access for Construction of Generation Facilities
The use of an ice road was eliminated from consideration for access to construct the generation
facilities at Grant Lake. An ice road would greatly increase the risk of costly delays and would
not provide sufficient capacity for transporting heavy generation and construction materials and
equipment.
Generation Alternatives Analyzed
After preliminary evaluation of numerous alternative project configurations, including dam type
and location, power conduit material and alignment, powerhouse locations and transmission line
and access road routing, the following alternatives for both the Lake Elva and Grant Lake
projects were further analyzed.
In the following project descriptions, elevations are denoted using "El" as the height above the
North American Vertical Datum of 1988 (NAVD 88), as in "El 255" or "El 458". Stream bank
locations were as seen looking downstream. Locations on Grant River are noted in Stream Miles
(SM) upstream from the confluence of Grant River with Lake Kulik. SM on Elva Creek are in
miles upstream from Elva Creek's confluence with Lake Nerka.
Grant Lake Project Generation Alternatives
Grant Lake Alternatives were developed based on differences in two primary project features:
1. Dam Location and Type; and
2. Transmission Line and Access Road Routing.
Dam Location and Type Alternatives
The two Grant Lake Alternatives would differ only in terms of dam size and location. The
project under both alternatives would operate as a storage project with operations occurring
15 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
throughout the year with occasional shutdowns, usually in March and/or April of certain low
water years, when operations would exhaust reservoir storage before spring runoff.
Alternative G-1. Little Grant Lake Rockfill Dam with Powerhouse at SM 3.7
Alternative G-1 would consist of a 24-foot high rockfill dam at the outlet of Little Grant Lake
(Figure 2) at Grant River SM 7.5. The penstock would run to a powerhouse at SM 3.7, at El 192
feet. Total gross head of this configuration would be 316 feet.
In detail, this alternative would consist of the following primary components:
A 24-foot high rockfill dam with impervious membrane liner and auxiliary spillway to pass peak
flood events. The dam would be located at SM 7.5 of Grant River, at a location just below the
outlet of Little Grant Lake. The dam would have a crest at El 514 and would be approximately
636 feet long. The dam would impound Grant Lake to a maximum elevation of 508 feet (20 feet
impoundment) and provide 44,000 acre feet of active storage. The dam would increase Grant
Lake's surface area to 2,558 acres at 508, an increase of 645 acres over the Grant and Little Grant
Lake’s existing combined surface area.
• A gated outlet works, controlled to provide instream flow release to upper Grant River or
drain the reservoir if needed.
• A submerged intake in the northwest corner of Grant Lake. The intake would be situated
at a depth sufficient to minimize the probability of entraining floating debris and/or
ice/slush at the low pool levels experienced during late winter and early spring.
• A 66-in diameter buried pipe penstock approximately 16,100 feet in total length. The
penstock would follow the alignment of the ancient glacial-fed river channel from the
northwest corner of Grant Lake. From near the old channel’s confluence with Grant
River, the penstock would continue further downstream along the right bank of Grant
River, generally approaching the stream until terminating at the powerhouse at SM 3.7.
• A 40-ft x 60-ft steel-frame powerhouse with reinforced concrete foundation and tailrace
which would house the turbine/generator unit(s) and all associated mechanical and
electrical equipment located on the right bank of Grant River at SM 3.7. A reinforced
concrete tailrace structure would control tailwater levels with a riprap-lined transition
16 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
channel providing for the water’s re-entrance to Grant River. Total net head for this
configuration would be 304 feet.
Alternative G-2. Concrete Dam at SM 6.7 with Powerhouse at SM 3.7
Alternative G-2 would feature a concrete gravity dam located at SM 6.7 instead of the rockfill
dam in Alternative 1 (Figure 2). This Alternative’s powerhouse, power conduit, intake and
transmission facilities would be identical to the respective components in Alternative G-1. The
primary difference between this alternative and Alternative G-1 would be the position and
structure of the dam, as described below:
• A 60-foot high concrete dam would be constructed at the top of the canyon (SM 6.7) of
Grant River. The dam would have a crest at El 508 with a length of 400 feet. It would
impound approximately 47,000 acre feet of storage in Grant Lake. Surface area of the
new reservoir would be 2,659 acres, an increase of 746 acres (about 1 square mile) over
Grant Lake's existing surface area.
• An integral spillway would convey peak flood events and a gated outlet works would be
used to release flows to upper Grant River for instream flow maintenance.
• A submerged intake in the northwest corner of Grant Lake. The intake would be situated
at a depth sufficient to minimize the probability of entraining floating debris and/or
ice/slush at the low pool levels experienced during late winter and early spring.
• A 66-in diameter buried pipe penstock approximately 16,100 feet in total length. The
penstock would follow the alignment of the ancient glacial-fed river channel from the
northwest corner of Grant Lake. From near the old channel’s confluence with Grant
River, the penstock would continue further downstream along the right bank of Grant
River, generally approaching the stream until terminating at the powerhouse at SM 3.7.
• A 40-ft x 60-ft steel-frame powerhouse with reinforced concrete foundation and tailrace
which would house the turbine/generator unit(s) and all associated mechanical and
electrical equipment located on the right bank of Grant River at SM 3.7. A reinforced
concrete tailrace structure would control tailwater levels with a riprap-lined transition
17 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
channel providing for the water’s re-entrance to Grant River. Total net head for this
configuration would be 304 feet.
Under Alternative G-2, the project would operate as a storage facility and would suspend
operations during March and/or April of certain low-water years, or when operations reduced the
reservoir to below critical levels prior to spring runoff. Operations modeling has shown that,
under Alternative G-2, these operations suspensions would be only slightly less frequent than
they would under Alternative G-1. 17% of average annual flows at the dam site would be
released to Grant River for instream flow maintenance.
18 DRAFT DAHP CONCEPTUAL FEASIBILITY STUDY GRANT LAKE AND LAKE ELVA PROJECTS Figure 2 Alternatives G-1 & G-2 Project Features and Configuration
19 DRAFT DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
Lake Elva Project Generation Alternatives
After analysis of various Lake Elva Project generation features, two configurations were
developed, the "High Dam" and "Low Dam" Alternatives, as described in the following:
Alternative E-1: "High Dam" (or "Downstream Dam") Alternative
Alternative E-1 was characterized by a relatively high rockfill dam located somewhat
downstream of the Lake Elva outlet. This Alternative provided the greater storage of the two
Alternatives by tapping inflow from greater watershed area in a significantly larger capacity
reservoir. Construction cost of the higher dam would be a factor in the Alternative's economic
analysis.
In detail, this alternative would consist of the following primary components:
• An approximately 110 ft-high rockfill dam with impervious core at SM 1.6 on Elva
Creek, 1.9 miles downstream of the outlet of Lake Elva at SM 3.5 (Figure 3). The dam
crest elevation would be at approximately El 380 and the dam's length would be
approximately 620 feet. The dam would impound approximately 27,000 acre feet of
active storage in the new Lake Elva reservoir. Surface area of the new reservoir would
be 775 acres, an increase of 487 acres over the existing area of Lake Elva.
• An auxiliary uncontrolled spillway, excavated in an old channel of Elva Creek to the left
of the dam.
• A 7,760-ft long, 48-inch diameter penstock located on the left bank of Elva Creek
generally paralleling the path of the creek.
• A 40-ft x 60-ft steel-frame powerhouse at El 66 housing the turbine/generator(s) and
associated mechanical and electrical equipment, including switchgear and transformer, on
the left bank of Elva Creek at SM 0.2. A reinforced concrete tailrace, integral with the
powerhouse/turbine foundation, would reintroduce flows to the stream. Total net head
for this alternative would be 297 feet.
Access to the powerhouse, penstock and dam from the shore of Lake Elva would be via a road
developed along the penstock route.
20 DRAFT DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
Alternative E-2. "Low Dam" (or "Lake Outlet Dam") Alternative
Under Alternative E-2, a lower rockfill dam would be located near the existing Lake Elva outlet.
This Alternative would provide less storage than Alternative E-1, but the cost of dam
construction would be significantly less.
In detail, Alternative E-2 would consist of the following primary components:
• A 38-ft high rockfill dam with impervious membrane at Elva Creek SM 3.2, at the outlet
of Lake Elva. The dam crest elevation would be approximately 362 feet. This dam
would raise Lake Elva by 28 feet and impound approximately 11,000 acre feet of water.
Surface area of the new reservoir would be 488 acres, an increase in 200 acres over the
existing Lake Elva surface area.
• A 48-inch diameter buried penstock and access road 15,200 feet in length located on the
right bank and generally paralleling the course of Elva Creek. The penstock would cross
the stream to the left bank of the Elva Creek at SM 1.7 at slightly less than half (7,000
feet) the distance to Lake Nerka. After crossing the stream, the penstock would continue
for another 8,200 feet downstream to the powerhouse site.
• The powerhouse would be the same construction and at the same location as for
Alternative E-1. Total net head for this alternative would be 274 feet.
Access for both Alternatives from Dillingham would be first via the selected access road route to
a point near the east end of the lower (South) arm of Lake Nerka. From there, a short spur road
would lead to Lake Nerka, from which point watercraft would carry material to a location near
the mouth of Elva Creek. From this point, access to the powerhouse, penstock and dam from
would be via a road developed along the penstock route located on the left of, and generally
paralleling, the stream.
22 DRAFT DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
Under both Alternatives, the Project would operate as a storage facility with infrequent
shutdowns during March and/or April of certain low-water years, or when operations reduced
reservoir elevation below the minimum level prior to spring runoff. Instream maintenance flows
of 17% average annual flow would be released from the E-1 reservoir. The E-2 Alternative
would rely on natural accretion in the watershed below the dam to provide instream flows in the
anadromous reaches of lower Elva Creek with no instream release from the dam site.
Transmission Line and Access Road Routing Alternatives
At the Grant Lake project, two transmission line/access road routing alternatives were evaluated:
1. The Park Boundary Alternative; and
2. The Glacial Moraine Alternative; as described in the following
The Park Boundary Alternative
Transmission Line Routing
This is the preferred alternative from the D&L report. Under this alternative’s routing, a 34.5 kV
overhead line would follow a direct west to east routing from the Grant Lake powerhouse 8.7
miles to the eastern boundary of WTSP (Figure 4). From the intersection with the park
boundary, the route would continue south 22.3 miles along the park boundary to the southeast
corner of the park, where it would angle southwest for 13.2 miles to its interconnection with
existing transmission facilities Aleknagik. This line would be a total of 44.2 miles long with 8.7
miles of its length inside WTSP.
From Aleknagik, the existing 12.5 kV overhead line would be upgraded to a new 15.5-mile long
34.5 kV transmission line to a new substation at Waskey Road. A new 5.6-mile long 12.5 kV
distribution line would be routed along Waskey Road to provide power delivery from the
hydroelectric projects to the NETC’s existing main powerhouse substation in Dillingham.
Access Road Routing
Transmission line construction access under this alternative would be via an ice road which
would follow the transmission route (Figure 4). Use of the ice road would restrict construction
to winter months. Consequently, this access route would not be used for construction access to
for the generation facilities for the Grant Lake Project. A separate access route would be needed
23 DRAFT DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
for the generation facilities. The access route for the generation facilities would follow the
glacial moraine landform separate from the transmission route (See Figure 4).
Construction access to the Lake Elva Project site would be via a short (approximately 0.5 mile)
all-season spur from the main access road constructed for the Grant Lake project to the eastern
shore of Lake Nerka. From there, construction access would be via watercraft across Lake
Nerka during the open water period.
Glacial Moraine Alternative
Transmission Routing
Under this routing Alternative, a 34.5 kV overhead transmission line would be routed to the east
of Grant Lake then generally south near the park’s eastern boundary along the terminal moraine
which forms the drainage divide between the Wood and Nushagak Rivers (Figure 4). This
transmission route would continue southerly along the divide to Aleknagik following the original
design concept in effect when the Grant Lake Project was being considered with the creation of
WTSP (Retherford, 1980). The total length of the new 34.5 kV overhead transmission line from
the powerhouse to Aleknagik would be 41.5 miles, with 26.6 miles located inside WTSP.
Access Road Routing
Under this routing alternative, access to the Grant Lake project site as well as access for
construction of the transmission line would be via a road which would be generally congruent
with the transmission line routing (Figure 4). Preliminary reconnaissance of this route indicates
more suitable soil conditions than those along the Park Boundary route, particularly in the
segment of the Park Boundary route east of the park boundary.
The access road in this alternative would be developed under the concept of a temporary feature
with restoration of the vegetation in the developed area conducted as part of the mitigation
package for the feature.
Lake Elva Transmission Facilities
Transmission facilities would include a 2.3 mile long 35 kV submarine crossing at the “elbow”
of Lake Nerka followed by a 21.9 mile long 35 kV overhead line routed along upper Lake
Nerka’s north shore to a junction with the Grant Lake transmission line near the park’s eastern
24 DRAFT DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
boundary. From the Junction, a 34.5 kV overhead line would continue to Aleknagik following
the terminal moraine for a total length of 22 miles. This transmission segment would be
congruent with the "Glacial Moraine" transmission alternative described for the Grant Lake
project in the following section.
From Aleknagik, the existing 12.5 kV overhead line would be upgraded to a new 15.5-mile long
34.5 kV transmission line to a new substation at Waskey Road. A new 5.6-mile long 12.5 kV
distribution line would be routed along Waskey Road to provide power delivery to the existing
main powerhouse substation in Dillingham
TASK 4. DETERMINE FEASIBILITY BASED on ELECTRICAL GENERATION and
ENGINEERING CONSIDERATIONS
Operations and Electrical Generation
As described above, economic analysis of the four major alternatives was the result of a series of
steps involving:
1. Development of hydrology data sets to represent monthly streamflow available for
energy generation at both projects;
2. Use of a reservoir operations model to translate monthly reservoir inflow into: 1) forecast
reservoir elevations and corresponding storage volumes resulting from operations; and 2)
forecast monthly energy generation time series noting percent of time NETC load would
be met;
3. Evaluation of the generation time series to determine two decision factors:
• Benefit/Cost (B/C) ratio expressing Benefits divided by Costs, as described in the
Methods section; and
• Cost per kWh to compare unit energy costs to those for NETC diesel generation.
25 DRAFT DAHP CONCEPTUAL FEASIBILITY STUDY GRANT LAKE AND LAKE ELVA PROJECTS Figure 4 DAHP Alternative Transmission and Analysis
26 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
In the following sections we present results of 1) the hydrologic analysis; 2) summarized output
of the operations/generation model; and 3) results in terms of B/C and cost per kWh.
Hydrologic Data Set Development
Annual Runoff Cycle Analysis
The USGS Grant gage operated during a period (1959-1965) when the Nuyakuk River flowed at
92% of its long-term average while USGS Elva gage operated during a period (1979-1982) when
the Nuyakuk flowed at 116% of its long-term average. The USGS Grant gage average flow was
93.7 cubic feet per second (cfs) and the USGS Elva gage averaged 56.6 cfs during their
respective periods of stream gaging. Given similar runoff trends in the region, the Elva-Grant
annual runoff averages in cfs and cfs per square mile of watershed (csm) would be:
Grant Lake gage: 1/92% x 93.7 cfs = 102 cfs or 2.97 csm
Lake Elva gage: 1/116% x 56.6 cfs = 48.9 cfs or 5.43 csm
Synthesized Long-Term Hydrologic Time Series
Results of flow synthesis for both Grant Lake outlet and Lake Elva outlet locations compared
well with the results found by comparison with Nuyakuk flow ratios above. The long-term
average flow for the synthesized record was found to be 101 cfs for the Grant Lake outlet station.
The long term average calculated from the USGS Nuyakuk station’s annual flow ratios was 102
cfs, resulting in a difference of less than 1 percent. The long-term average synthesized flow for
the Lake Elva outlet station was 46.2 cfs which compared reasonably well (-5.8%) with the value
of 48.9 cfs calculated from annual flow ratios from the USGS Nuyakuk gage.
Grant Lake Synthesized Flows
The long-term synthesis results for Grant Lake shown in Figure 5 and Table 1 resembled a
typical Alaskan flow pattern characterized by yearly low flows in winter followed by peak flows
during the spring snowmelt cycle and a secondary high flow period in early fall related to high
rainfall. Peak monthly flows of over 200 cfs were forecast to occur in May and June with lower
monthly peaks over 150 cfs were forecast for August and September. Yearly lows of all
exceedance intervals were forecast to occur in March and April. The annual average flow for the
33-year forecast was 101 cfs.
27 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
Figure 5. Synthesized Monthly 20th, 50th, Average and 80th Percent Exceedance Flows,
Grant Lake Outlet Gaging Station
Table 1. Synthesized Monthly 20th, 50th, Average and 80th Percent Exceedance Flows,
Grant Lake Outlet Gaging Station.
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Q20 46.3 43.3 30.2 30.3 123 192 94.9 70.9 85.0 102 59.1 48.2
Q50 58.2 53.2 35.3 36.0 162 202 104 87.6 112 137 84.4 52.3
QAverage 60.9 54.9 35.2 35.9 198 203 108 94.5 125 144 93.1 55.1
Q80 73.8 68.6 39.7 42.9 277 216 121 117 173 215 117 60.9
0
50
100
150
200
250
300
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DecMonthly Discharge, cfs20th Percentile Monthly Flow
50th Percentile Monthly Flow
Average Monthly Flow
80th Percentile Monthly Flow
28 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
Lake Elva Synthesized Flows
The long-term synthesis results for Lake Elva shown in Figure 6 and Table 2, as with the Grant
Lake forecast flows, also resembled a typical Alaskan flow pattern characterized by yearly low
flows in winter followed by peak flows during the spring snowmelt cycle and a secondary high
flow period in early fall related to high rainfall. As expected based on its significantly smaller
watershed area, Lake Elva inflows was lower throughout the year than inflow to Grant Lake.
Peak monthly flows of over 120 cfs were forecast to occur in June and July, somewhat later than
at Grant Lake. This was probably due to the steeper topography within the watershed and
increased shading of slopes, resulting in later runoff. A secondary set of high flows, averaging
from 60 to 80 cfs occurred in July through September. Yearly low flows of all exceedance
intervals were forecast to occur in January through April. The annual average flow for the 33-
year forecast was 46.2cfs.
Reservoir Inflows
The synthesized streamflow data was adjusted to match the drainage area of the project
alternatives. Alternatives G-1 (Table 3) and E-2 (Table 4) both had their respective dam located
at the respective system’s gaging station location. The drainage area was 34.3 square miles for
Grant Lake outlet and 9.0 square miles for Lake Elva outlet respectively. Alternative G-2’s
drainage area was 35.3 square miles and thus had reservoir inflows 2.9% larger (Table 3).
Alternative E-1 had a drainage area of 10.3 square miles, with flows 14.4% larger than the flow
measured at the gage (Table 4).
Operations/Generation Model Results
Reservoir Levels
Predicted reservoir levels for both projects were graphed relative to the projects' maximum
reservoir level (the spill level) and the minimum level which was in both cases the lowest
elevation of active storage.
29 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
Figure 6. Synthesized Monthly 20th, 50th, Average and 80th Percent Exceedance Flows,
Lake Elva Outlet Gaging Station.
Table 2. Synthesized Monthly 20th, 50th, Average and 80th Percent Exceedance Flows, Lake
Elva Outlet Gaging Station.
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Q20 13.1 12.6 12.2 12.1 15.8 94.8 80.1 55.1 49.6 46.7 16.2 0.25
Q50
14.0
13.3
12.9
12.8
17.3
111
96.5
66.3
60.5
72.6
33.8
8.75
QAverage
14.2
13.4
12.9
12.8
18.5
112
101
70.2
63.8
77.1
39.1
13.7
Q80
15.1
14.1
13.4
13.5
21.2
131
116
82.8
76.6
120.7
54.0
21.1
0
20
40
60
80
100
120
140
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DecDischarge, cfs20th Percentile Monthly Flow
50th Percentile Monthly Flow
Average Monthly Flow
80th Percentile Monthly Flow
30 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
Table 3. Average Monthly Reservoir Inflows in cfs for Grant Lake Project
Alternatives G-1 and G-2.
Month Alternative G-1 Alternative G-2
Jan 60.9 62.6
Feb 54.9 56.5
Mar 35.2 36.2
Apr 35.9 37.0
May 198 203
Jun 203 209
Jul 108 111
Aug 94.5 97.3
Sep 125 128
Oct 144 148
Nov 93.1 95.8
Dec 55.1 56.7
Annual Average 101 104
31 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
Table 4. Average Monthly Reservoir Inflows in cfs for Lake Elva Project
Alternatives E-1 and E-2.
Month Alternative E-1 Alternative E-2
Jan 16.2 14.2
Feb 15.3 13.4
Mar 14.8 12.9
Apr 14.6 12.8
May 21.2 18.5
Jun 129 112
Jul 115 101
Aug 80.3 70.2
Sep 73.0 63.8
Oct 88.2 77.1
Nov 44.8 39.1
Dec 15.7 13.7
Annual Average 52.4 46.2
Grant Lake
Reservoir operations modeling revealed essentially identical water levels for operation of both
Grant Lake Project Alternatives (Figure 7). There was about a 3% chance of spilling and about
the same odds of shutting down due to lack of water over the 33 year analysis period.
32 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
Figure 7. Grant Lake Project Alternative G-1 & Alternative G-2 Mean
Monthly Reservoir Levels
Lake Elva
There was a significant difference in the performance of the two Lake Elva Project Alternatives
with Alternative E-2's smaller reservoir spilling much more frequently and also depleting storage
more frequently than Alternative E-1 (Figures 8 and 9). This is directly attributable to the large
difference in storage capacity afforded by Alternative E-1's higher downstream dam.
480
485
490
495
500
505
510
DJFMAMJJASONDJ
Wet Year
Average Year
Dry Year
Min. Reservoir Level
Max. Reservoir Level
33 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
Figure 8. Lake Elva Project Alternative E-1 Mean Monthly Reservoir Levels.
Figure 9. Lake Elva Alternative E-2 Monthly Reservoir Levels for Wet, Average
and Dry Years.
315
325
335
345
355
365
375
DJFMAMJJASONDJReservoir WaterSurface Elevation, Feet NAVD 88Average Year
Wet year
Max. Reservoir Level
Dry Year
Min. Reservoir Level
320
325
330
335
340
345
350
355
360
365
370
DJFMAMJJASONDJReservoir WaterSurface Elevation, Feet NAVD 88Average Year
Wet Year
Dry Year
Max. Reservoir Level
Min. Reservoir Level
34 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
Energy Generation
Output of the operations/generation model was averaged over the analysis period to determine
mean monthly energy output. Formulae used to estimate losses for the hydraulic (power
conduit), electro-mechanical (turbine/generator) and transmission systems are included in
Appendix III for reference.
Grant Lake
Both Grant Lake Project Alternatives met more than 80 percent of NETC load during the
September-December period (Table 5, Figure 10). Both alternatives met between 60 and 80
percent of NETC load during the remaining months of the year, with the lowest percentages
occurring between April and August.
Table 5. Mean Monthly and Mean Annual Energy Production1 for Grant Lake Project
Alternatives G-1 and G-2 and Current NETC Monthly Demand in kWh.
Month Current (2011)
Demand
Alternative G-1 Alternative G-2
Jan 1,583,256 1,251,194 1,259,841
Feb 1,359,060 1,085,087 1,090,690
Mar 1,530,960 1,169,716 1,109,125
Apr 1,454,390 984,607 933,170
May 1,516,040 1,071,182 1,015,212
Jun 1,657,720 1,194,065 1,186,908
Jul 2,018,020 1,310,923 1,337,556
Aug 1,591,640 1,310,755 1,337,753
Sep 1,364,340 1,267,205 1,293,422
Oct 1,474,975 1,303,896 1,338,933
Nov 1,456,621 1,258,547 1,282,715
Dec 1,585,790 1,281,020 1,290,325
Annual 18,592,812 14,320,762 14,727,225
1. Energy production values are net after instream flow releases.
35 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
Figure 10. Mean Monthly Energy Generation and percent of Load Supplied by Grant
Lake Project Alternatives G-1 and G-2.
Lake Elva
Energy generation from both Lake Elva Alternatives fell short of meeting NETC loads in all
months by virtue of the limited installed capacity of the alternatives (Table 6, Figure 11). Of the
two alternatives, Alternative E-1 provided the largest generation relative to load, especially
during the May through August period.
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
600,000
700,000
800,000
900,000
1,000,000
1,100,000
1,200,000
1,300,000
1,400,000
1,500,000
1,600,000
DJFMAMJJASONDJ % of Current Load Available from AlternativeMean Monthly Energy Generation, kwhAlternative G‐1
Alternative G‐2
% of Load G‐1
% of Load G‐2
36 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
Table 6. Mean Monthly and Mean Annual Energy Production1 for Lake Elva Project
Alternatives E-1 and E-2 and Current NETC Monthly Demand in kWh.
Month Current (2011)
Demand
Alternative E-1 Alternative E-2
Jan 1,583,256 637,603 640,526
Feb 1,359,060 587,589 573,081
Mar 1,530,960 591,454 569,885
Apr 1,454,390 593,715 507,276
May 1,516,040 526,731 384,437
Jun 1,657,720 521,912 284,518
Jul 2,018,020 636,145 650,181
Aug 1,591,640 651,968 668,195
Sep 1,364,340 635,835 649,729
Oct 1,474,975 660,231 673,144
Nov 1,456,621 643,089 652,268
Dec 1,585,790 646,139 668,816
Annual 18,592,812 7,442,284 6,947,626
1. Energy production values are net after instream flow releases.
37 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
Figure 11. Mean Monthly Energy Generation and percent of Load Supplied by
Lake Elva Project Alternatives E-1 and E-2.
To better depict energy generation across a range of potential inflows, we calculated energy
generation during wet, average and dry years (Table 7). For this analysis, the annual energy
production from a wet year was defined as the value having a 20 percent annual probability of
being equaled or exceeded while a dry year was defined as the amount of annual energy
production that had an 80 percent annual probability of being equaled or exceeded.
Lake Elva alternatives E-1 and E-2 showed 18% and 11% energy increases, respectively,
between wet and dry years (See Table 7). Grant Lake alternatives G-1 and G-2 showed 25% and
25% energy increases, respectively between wet and dry years. This could indicate that the
Grant Lake alternatives would benefit more from any future precipitation increases such as those
possibly associated with climate change.
0%
10%
20%
30%
40%
50%
60%
‐
100,000
200,000
300,000
400,000
500,000
600,000
700,000
800,000
DJFMAMJJASONDJ % of Current Load available from AlternativeMean Monthly Energy Generation, kwhAlternative E‐1
Alternative E‐2
% Load E‐1
% Load E‐2
38 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
Table 7. Annual Energy Production by DAHP Alternatives in kWh for Wet, Dry, Median
and Average Years.
Project
Alternative
Wet Year Median Year Average Year
(exceedance %)
Dry Year
Grant Lake G-1 15,682,871 15,248,641 14,320,762
(33.8%)
12,590,182
Grant Lake G-2 16,147,613 15,676,275 14,727,225
(33.7%)
12,884,794
Lake Elva E-1 7,997,354 7,749,430 7,442,284
(30.9%)
6,788,666
Lake Elva E-2 7,153,396 7,064,208 6,947,626
(30.0%)
6,461,763
TASK 5. ECONOMIC ANALYSIS of ALTERNATIVES
Construction and Finance Costs
Generation Facilities Construction Costs
Construction costs shown in this section are for generation facilities only. Construction costs for
the transmission alternatives are in the following section.
Grant Lake Project Generation Alternatives
Grant Lake project Alternatives G-1 and G-2 were identical in configuration with the exception
of the dam type and location. Alternative G-2 featured a concrete gravity dam versus the smaller
embankment dam used in Alternative G-1. As such, the difference in cost between the two
alternatives was almost entirely due to the difference between the different dam configurations.
Cost differences among all other principal project features were negligible (Table 8).
39 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
Table 8. Estimated Grant Lake Project Alternative Generation Facilities Construction
Costs (in $2013).
PROJECT FEATURE ALTERNATIVE G-1 ALTERNATE G-2
Mobilization, Camp and
Construction
Management.
$7,227,340
$7,230,844
Access Road $4,155,000 $4,155,000
Dam; including Diversion,
Foundation. Prep., Outlet
works & Spillway
$3,329,100
$5,640,000
Penstock, Intake &
Appurtenant structures,
incl. roadway
$12,511,200
$12,511,200
Powerhouse and
Switchgear $4,266,000 $4,266,000
Total Pre-contingency
Generation System Cost $31,488,640 $33,803,044
Lake Elva Project Generation Alternatives
Costs for Lake Elva Project alternatives E-1 and E-2 were essentially the same for all the major
project features except for the dams and penstocks. The E-1 alternative’s large dam [225,000
cubic yards (CY) in volume] contributed significantly to the cost for this Alternative. The
Alternative E-2 dam was an order of magnitude smaller (25,900 CY), but its penstock and access
road were much longer (15,200 feet) than the penstock/access road for Alternative E-1. The
longer penstock and access road for Alternative E-2 were significantly more costly than those for
Alternative E-1. Even with this difference, however, Alternative E-1 remained significantly
more costly than Alternative E-2, because of its much larger dam (Table 9).
40 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
Table 9. Estimated Lake Elva Project Alternative Generation Facilities
Construction Costs (in $2013).
PROJECT FEATURE ALTERNATIVE E-1 ALTERNATIVE E-2
Mobilization, Camp and
Construction
Management.
$7,011,680
$7,159,040
Access
Road/ferry/landings $1,832,500 $1,832,500
Dam; incl. Diversion,
Foundation. Prep., Outlet
works & Spillway
$11,010,000
$3,133,300
Penstock, Intake &
Appurtenant structures,
incl. roadway
$6,589,902
$9,740,358
Powerhouse and
Switchgear $3,626,000 $3,463,500
Total Pre-contingency
Generation System Cost $30,070,082 $25,328,698
Transmission Alternative Costs
Costs for the alternative transmission systems for the Grant Lake project differed primarily due
to the differing lengths of the two routes. However, the Glacial Moraine Route would be
constructed using the same construction access road used for construction of the generation
components of the Grant Lake Project eliminating the need for an ice road. The elimination of
the ice road costs and the Glacial Moraine Route’s shorter alignment results in a cost reduction
of approximately $5.3M from the Park Boundary Route (Table 10). These Glacial Moraine
Routes costs do not take into account the higher efficiency that would occur with a construction
in summer instead of winter construction via an ice road; therefore, the stated cost reduction is
conservative.
41 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
Table 10. Estimated Grant Lake Project Alternative Transmission System Pre-
Contingency Construction Costs (in $2013).
Transmission Alternative Glacial Moraine
Alternative
Park Boundary
Alternative
T-Line to Aleknagik &
upgrade existing line to 35
kV
$16,005,916
$21,339,200
Costs for the alternative transmission systems for the Lake Elva project differed greatly due to
the high cost of the submarine cable. Lengths of the two routes were similar but the submarine
cable added nearly 27 million dollars in additional cost over the overhead route with no
contingency applied (Table 11).
Table 11. Estimated Lake Elva Project Alternative Transmission System Pre-Contingency
Construction Costs (in $2013).
Transmission Alternative Overland Route Submarine Route
T-Line to Grant Lake
Junction $11,877,600 $39,533,600
Total Capital Costs
Total Project alternative capital costs were estimated as the sum of the costs of generation
facilities with the cost of the preferred transmission system plus contingencies and short-term
(construction) finance costs (Table 12). Detailed cost estimates which include unit costs and
quantities are included in Appendix VI.
42 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
Table 12. Total Estimated Capital Costs for Project Alternatives.
Alternative
G-1
Alternative
G-2
Alternative
E-1
Alternative
E-2
Generation
Facilities $31,488,640 $33,803,044 $30,070,082 $25,328,698
Transmission
System $16,005,916 $16,005,916 $11,877,600 $11,877,600
Subtotal $47,494,556 $49,808,960 $41,947,682 $37,206,298
Contingency
(25%) $11,873,639 $12,452,240 $10,486,921 $9,301,575
Construction
Subtotal $59,368,195 $62,261,200 $52,434,603 $46,507,873
Short-term
Finance Cost $6,124,200 $6,422,632 $5,408,957 $4,797,578
Total
Estimated
Capital Cost
$65,492,396
$68,683,832
$57,843,560
$51,305,451
The Park Boundary Transmission Alternative would add an estimated $7,354,306 if it were used
instead of the Glacial Moraine Alternative for either the Grant Lake Project Generation
Alternatives G-1 or G-2. The use of the Park Boundary Alternative would result in Total
Estimated Capital Costs of $72,846,702 and $76,038,139 for Generation Alternatives G-1 and G-
2 respectively (See Appendix VI). The use of the Park Boundary Transmission Alternative
would not affect the cost of either Lake Elva Project Alternative because the location of the
Grant Lake-Lake Elva Transmission junction would be the same for either transmission
alternative.
O&M Costs
Annual O&M costs estimated as the total of the cost components and factors presented above in
the methods section totaled approximately $580,000 ($2013) for the Grant Lake Alternative G-1
(Table 13). This cost equated to $0.04/kWh and was assumed to apply to the Grant Lake
Alternative G-2. The inclusion of the Lake Elva Project added an additional 50% ($0.02/kWh)
43 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
in annual O&M costs to the Grant Lake Project which results in a total annual O&M cost of
$0.06/kWh for the combined DAHP (Table 14). These O&M costs were assumed to be
applicable to either the Glacial Moraine or Park Boundary Transmission Alternatives.
Table 13. Annual O&M Costs for Grant Lake Alternative G-1.
Operations Alternative G-1
Labor (1 FTE) $250,000
Transportation (24 trips) $72,000
Equipment, materials and supplies $25,000
Insurance $98,000
Subtotal $445,000
Maintenance
Intake $20,000
SCADA System $10,000
T-Line (Plant to Aleknagik) $75,000
Misc. $30,000
Subtotal $135,000
TOTAL Annual O & M $580,000 ($0.04/kWh)
44 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
Table 14. Annual O&M Costs for Grant Lake and Lake Elva Project Alternatives.
Alternative Average Annual
Energy
Production, kWh
O & M Cost,
$2013/kWh
Annual O&M
Costs, $2013/kWh
Grant Lake G-1 14,320,762 $0.04 $580k
Grant Lake G-2 14,727,225 $0.04 $590k
Lake Elva E-1 7,458,848 $0.02* $150k*
Lake Elva E-2 6,989,552 $0.02* $140k*
*Incremental O&M cost when combined with Grant Lake Project operations.
BENEFIT/COST ANALYSIS
Project economic analysis was completed with the following base economic parameters.
Finance Rate/Discount Rate: 5.0%
Project Finance Period; 30 years
Economic Analysis Period (Service life): 40 years
Current Diesel Fuel Price (2013): $3.42/gal.
Annual Fuel-oil Price Escalation Rate: 3.0%
Fuel Price @ 2018 start-up: $3.96
Annual Escalation Rate on Non-fuel-oil items: 1.5%
NETC Annual Load Growth: 0.5%
Estimated Startup Year: 2018
Project Benefits
Annual Net Benefits and Total Net Benefits over the analysis period for the Grant Lake Project
Alternatives were nearly equal due to the two projects nearly-identical average annual energy
output and O&M costs (Table 15).
45 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
Table 15. Grant Lake Project Annual Diesel Avoidance and Project Benefits at start-up.
Item Alternative G-1 Alternative G-2
Annual Diesel Avoidance
(Gallons) 967,619 995,083
Annual Diesel Avoidance
Benefits at 2018 Start-up $3,836,336 $3,945,222
Annual O&M Costs at
2018 Start-up $617,101 $634,616
Annual Net Benefits at
2018 Start-up $3,219,235 $3,310,606
Total Net Project Benefits
at Start-up* $89,848,579 $92,398,729
*Total Net Project Benefits over analysis period discounted to start-up.
Annual net benefits for the Lake Elva Project alternatives were similar to each other with the
larger, more expensive Alternative E-1 producing approximately 7% more annual net benefits
than Alternative E-2 (Table 16). Both Lake Elva Alternatives were burdened with significant
excess capacity in 2018 which reduced Project Benefits.
46 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
Table 16. Lake Elva Project Diesel Avoidance and Annual Project Benefits
at 2018 start-up.
Item Alternative E-1 Alternative E-2
Annual Diesel Avoidance
at full utilization (gallons) 502,857 469,434
Annual Diesel-equivalent
Excess Energy at 2018
Start-up (gallons)
169,570 136,148
Annual Diesel-equivalent
Energy Sales at 2018
Start-up (gallons)
333,287 333,287
Annual Diesel Avoidance
Benefits at 2018 Start-up $1,321,387 $1,321,387
Annual Supplemental
O&M Costs at 2018 Start-
up
$160,349 $149,691
Annual Net Benefits $1,161,038 $1,171,696
Total Project Benefits* $42,882,929 $41,903,280
*Total Net Project Benefits over analysis period discounted to start-up.
Benefit-Cost Ratios
Benefit-Cost ratios provide an index of economic feasibility for the conditions analyzed. Both
Grant Lake project alternatives show a positive B/C indicating benefits exceed costs. The
addition of the Lake Elva project appears economically infeasible for the economic conditions
analyzed (Table 17).
47 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
Table 17. B/C Ratios for Grant Lake and Lake Elva Project Alternatives.
Alternative G-1 G-2 E-1* E-2*
Total Net Project
Benefits $89,848,579 $92,398,729 $42,882,929 $41,903,280
Total Project
Costs $65,492,396 $68,683,832 $57,843,560 $51,305,451
B/C 1.37 1.35 0.74 0.82
Alternative G-1 used in this analysis. Results are similar using Alternative G-2.
*Supplemental to the Grant Lake Project.
The use of the Park Boundary Alternative would reduce B/Cs to 1.23 and 1.18 for Generation
Alternatives G-1 and G-2 respectively. This indicates that the Grant Lake Project would still be
economically feasible for the more expensive Park Boundary Transmission Alternative under the
conditions analyzed. The use of the Park Boundary Transmission Alternative would not affect
the cost of either Lake Elva Project Alternative and therefore have no effect on the B/Cs of those
Alternatives.
Projected Cost of Project Debt Service
The cost of energy generation was estimated for the Grant Lake Project alternatives with
supplemental diesel-electric generation and for the combined DAHP with alternatives E-1 and E-
2 as a cost per kWh. Annual debt service costs, which are substituted for fuel costs, for the Grant
Lake Alternatives are projected to be approximately $4.3 to $4.5M at 2018 start-up. The
addition of the Lake Elva Alternatives at that time would add another $3.3 to $3.8M in annual
debt service depending on the alternative. Total debt service on a kWh basis is approximately 30
cents for either Grant Lake Alternative. The addition of the Lake Elva Project raises DAHP debt
service cost to about 40 to 42 cents per kWh for the combined DAHP Project depending on the
Alternative (Table 18).
48 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
Table 18. Long-term Debt Service on Capital for Grant Lake and
Lake Elva Project Alternatives.
Alternative G-1 G-2 DAHP
G-1 & E-1*
DAHP
G-1 & E-2*
Total Capital
Cost $65,492,396 $68,683,832 $57,843,560 $41,903,280
Annual Debt
Service at start-
up
$4,260,374 $4,467,982 $3,762,807 $3,337,493
Combined
DAHP Debt
Service at start-
up
$4,260,374 $4,467,982 $8,023,181 $7,597,867
Projected
Hydroelectric
Sales* at start-
up, kWh
14,320,762 14,727,225 18,494,226 18,494,226
Projected Debt
Service Cost at
Startup*, $/kWh
$0.2975 $0.3034 $0.4338 $0.4108
* Projected 2018 Load of 18,871,659 kWh. Diesel Electric estimated to provide 2% of
annual load for peak demands with combined DAHP.
Cost of Energy (At 2018 Startup)
The Grant Lake Project was projected to have electric costs at start-up that are approximately
equal to the projected 100% diesel-electric generation scenario for the first year of operation.
The addition of the Lake Elva Project was found to increase costs by approximately 30%
compared to the projected diesel-electric generation scenario (Table 19) for a 2018 start-up
concurrent with the Grant Lake Project.
49 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
Table 19. Estimated Cost of Energy per kWh at 2018 Startup.
Alternative
Component
Cost
G-1 G-2 DAHP
G-1 & E-1
DAHP
G-1 & E-2
Long-term
Debt service $0.2975 $0.3034 $0.4338 $0.4108
O&M $0.0431 $0.0431 $0.0647 $0.0647
Distribution $0.0215 $0.0215 $0.0215 $0.0215
General &
Administrative $0.0794 $0.0794 $0.0794 $0.0794
Cost of
Hydroelectric
Energy
$0.4415 $0.4474 $0.5768 $0.5532
Cost of
Supplemental
Diesel-Electric
Energy**
$0.4663 $0.4692 $0.7902 $0.7902
% Load by
Hydro (2018) 75.9% 78.0% 98%# 98%#
Cost of
Blended
Hydro-Diesel
Energy
$0.4475 $0.4522 $0.5811 $0.5580
Cost for 100%
Diesel-electric
Energy**
$0.4441 $0.4441 $0.4441 $0.4441
Change from
100% Diesel-
Electric
+0.77% +1.8% +31%* +26%*
* Surplus Capacity exists at 2018 start-up assuming 0.5% load growth.
** Supplemental Diesel-electric exceeds 100% Diesel-electric due to constant storage costs
apportioned over lower diesel-electric sales.
# 2% of Annual demand estimated from diesel-electric to meet peak loads.
50 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
The large increase in rates for the Lake Elva project is reflective of both Alternatives’ high
development costs, their small watersheds and the excess capacity that would be brought to the
NETC market as a supplemental energy source to the Grant Lake project.
Energy generation from hydroelectric production has a stabilizing effect on electric rates when
compared to diesel generation, because the cost of Project debt service is substituted for fuel oil
costs as the major component in the cost of energy generation. Diesel fuel costs currently make
up approximately 80% of NETC’s generation outlays, and are subject to sometimes large price
swings over yearly or even monthly timeframes. These volatile diesel costs would be largely
replaced by the fixed cost of debt service.
Sensitivity Analysis
Inputs to the energy generation and economic analysis were varied independently to assess their
effect on the overall economic feasibility of the project. Input parameters analyzed included
total project costs, discount rate, annual fuel escalation rate and annual load growth.
Grant Lake Project
Grant Lake Project Alternatives G-1 and G-2 had positive B/C ratios for all variables considered
within the ranges examined with the exception of high discount rates (> 7%). Marginal capital
costs, $90M and $92 for Alternatives G-1 and G-2 respectively, exceeded these Alternative’s
respective estimated capital costs by over 37% for both alternatives (Table 20).
51 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
Table 20. Alternatives G-1 & G-2. Sensitivity Analysis of Selected Project Parameters.
Parameter
Base Value
(G-1 / G-2)
Range
Evaluated
Resulting
B/C Range
(G-1 / G-2)
Marginal Value
(B/C = 1)
(G-1 / G-2)
Total Capital Cost $65,492,396 /
$68,683,832 ±30% 1.06 to 1.96 /
1.03 to 1.92
$89,848,579 /
$92,398,729
Annual Discount
Rate 5.0% 1.5% to
8.0%
2.75 to 0.86 /
2.69 to 0.85
6.95% /
6.8%
Annual Fuel
Escalation Rate 3.0% 0 to 6.0% 0.67 to 2.92 /
0.65 to 2.86
1.6 % /
1.7%
Annual O&M
$0.04/kWh $0.02 to
$0.10/kWh
1.47 to 1.07/
1.40 to 1.05
$0.1140/kWh /
$0.1100/kWh
Benefits Period 40 years 30 to 50 1.11 to 1.44 /
1.09 to 1.56
26 years /
27 years
Annual Load
Growth 0.5% N/A* N/A* N/A*
* No excess capacity.
Both Lake Elva project alternatives were found to have a marginal B/C only with substantial
variance of their input parameters from their base condition.
For Alternative E-1 to be marginal, i.e., B/C = 1.0, the project’s Total Capital Costs would have
to be over 25% less than estimated. Similarly, other parameters would need to be at very high
levels, e.g., annual fuel escalation at approximately 4%, etc. in order to make marginal economic
conditions for the project at a 2018 start-up (Table 21).
52 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
Table 21. Alternative E-1 & E-2. Sensitivity Analysis of Selected Project Parameters.
Parameter
Base Value
(E-1 / E-2)
Range
Evaluated
Resulting B/C
Range
(E-1 / E-2)
Marginal Value
(B/C = 1)
(E-1 / E-2)
Total Capital
Cost
$57,843,560/
$51,305,451 ±30% 0.57 to 1.06 /
0.63 to 1.17
$42,882,929/
$41,903,280
Annual Discount
Rate 5.0% 1.5% to 8.0% 0.45 to 1.56 /
0.45 to 1.69
0.50% /
1.15%
Annual Fuel
Escalation Rate 3.0% 0 to 6.0% 0.36 to 1.60 /
0.41 to 1.74
3.8% /
4.2%
Annual O&M* $0.02/kWh $0.01 -
$0.10/kWh
0.51 to 0.77/
0.57 to 0.85
N/A /
N/A
Benefits Period 40 years 30 to 50 0.58 to 0.88 /
0.65 to 0.96
61 years /
54 years
Annual Load
Growth 0.5% 0 to 4% 0.47 to 0.87/
0.54 to 0.91
N/A /
N/A
Alternative G-1 used in this analysis. Results are similar using Alternative G-2.
*O&M costs are supplemental to the Grant Lake Project O&M.
The lower B/C ratios of the Lake Elva project are in large part due to the excess capacity that this
project brings to the system at the current demand forecast of 0.5% annual load growth.
53 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
ENVIRONMENTAL CONSIDERATIONS
In addition to engineering and economic factors, there are several environmental issues which
might influence feasibility. Experience in Alaska has shown that resource-related issues can
affect both project configuration and operation. Following is a list of resource-specific
considerations as known at this time. Further consultation with resource agencies will better
define these issues, and likely add to the list as well.
FISHERIES and AQUATIC RESOURCES
Grant Lake Project
Of the two Projects, the Grant Lake Project has the greater fisheries resource impact potential,
related primarily to the value of Grant River as a sockeye spawning location. Two years of
detailed study has shown that Grant River supports spawning for as many as 10,000 sockeye
salmon each year. At this time, the two most likely sockeye salmon issues are:
1. Instream flow related to the amount of habitat available for various salmon life stages
under the with-project flow regimes, both above and below the powerhouse location.
Determination of final instream flow requirements is a critical factor in project feasibility
because of the potential for lost revenue due to instream flow release requirements which
conflict with optimal generation.
2. Powerhouse location, related to the need to place the powerhouse at a point which
impacts the fewest spawning or incubating fish. Powerhouse location affects feasibility
through potential loss of head and length of the penstock.
In addition to Grant River impacts, there are some concerns for aquatic resources in Grant Lake.
These include water quality impacts related to 1) water temperature at the intake which in turn
affects Grant River water temperature below the powerhouse and 2) potential for disruption of
the mercury compounds in the bottom of Grant Lake. This second issue has been deemed
unlikely because no methyl mercury was found in sampling during 2011. Neither of the Grant
Lake issues are likely to influence overall project feasibility, but this will not be known until
after consultation with resource agencies.
54 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
Lake Elva Project
Lake Elva and Elva Creek, based on studies conducted in 2012, have far less potential for salmon
impacts and resultant effects on project feasibility. Salmon were shown to ascend Elva Creek
only a few hundred feet until reaching impassable stream conditions. Studies at Lake Elva
showed only minimal fish populations with no salmonid or other game species.
SCENIC/AESTHETIC RESOURCES
Scenic values in WTSP are exceptionally high and represent one of the major attributes of the
park purpose. Scenic and aesthetic values are high at both projects and along the
transmission/access routes. Because of this, it will be necessary to consult with DPOR on details
of all project features, both permanent and temporary. Of particular concern are access roads,
transmission lines and dams. If these features are to be approved by DPOR, extensive
consultation will be required to determine their exact locations and final appearance as well as
the management plans necessary to maintain these attributes.
WILDLIFE/BOTANICAL
Wildlife Resources
Grant Lake Project
Grant Lake wildlife resources are diverse and range from effects on aquatic mammals to effects
on large game animals, particularly moose. The primary potential for impact would be during
the construction period, and would relate to disturbance from equipment movement, human
activity and blasting. These actions would likely disturb the moose hunting activity from various
lakeside camps which are established each year. This might cause suspension of construction or
access during a portion of the critical snow-free construction period.
Water level fluctuation might also affect aquatic mammals such as beavers and otters, with
potential for limitation lake level fluctuation primarily during the open water season.
Lake Elva Project
Lake Elva also supports a good population of moose although it is not known to be used as much
as Grant Lake as a base for hunting. Previous studies (Dames & Moore, 1980) identified moose
and brown bear habitat in the upper Elva Creek above Lake Elva and the reach below the lake.
Current wildlife surveys at or near Lake Elva/Elva Creek have not been as extensive as those
55 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
around Grant Lake, and it remains for more detailed studies and consultation with agencies to
determine a current list of wildlife related impacts at the Lake Elva Project.
Transmission/Access Roads
Wildlife impacts might also be associated with the building and operation of the access roads to
both Lake Elva and Grant Lake. Activity on the roads or waterways might disturb animal
movements and/or migrations. Transmission line routes might intersect areas of important
wildlife habitat or life history requirements, necessitating re-routing the lines.
Botanical Resources
Botanical resources in all construction areas, potentially-inundated areas, and along the
transmission/access routes may include rare, endangered or sensitive plants. Prior to
construction of any project feature, a detailed plant survey will be required, results of which
might require repositioning of project features or realignment of a transmission line or access
road. If such plants are found in a potentially-inundated area, it may be necessary to re-establish
them in a suitable area.
CULTURAL RESOURCES
Similar to botanical resources, prior to any ground-disturbance, it will be necessary to conduct a
detailed survey for cultural or historical resources. Preliminary cultural resources surveys
conducted in 2011 and 2012 have shown low likelihood of encountering such resources. A
detailed cultural resources management plan will be required prior to construction, and, as with
botanical resources, actions may be necessary to avoid loss of important cultural resources.
RECREATION RESOURCES
Although overall numbers of visitors are small relative to more accessible state and federal parks
in Alaska, WTSP is known to offer some of the highest value recreation in the state. Among the
attributes sought by visitors to WTSP are the largely unspoiled setting and lack of disturbance
from other recreationists and commercial interests.
For these reasons, disturbance associated with construction of the DAHP is expected to have a
major effect on the recreation experience near the projects. These and other recreation impacts
might affect feasibility through the need to limit construction or access during certain high-use
56 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
periods of the summer, reducing an already short construction season. As with all other resource
issues, consultation with resource agencies will be required before decisions may be made.
FERC LICENSING and STATE and FEDERAL PERMITTING
Because the project is proceeding under FERC jurisdiction, development of the DAHP will
require a federal license to be issued. The FERC license in turn requires completion of the
National Environmental Policy Act (NEPA) process. The NEPA process is based on either and
Environmental Assessment (EA) or an Environmental Impact Statement (EIS) for both of which
FERC is the federal lead agency. Both EA's and EIS's developed under FERC guidance contain
a list of proposed mitigation measures which, after approval through resource agency
consultation, become Articles to the FERC license. These mitigation measures and license
Articles may impose significant constraints on construction and operation of the project, all of
which may affect project feasibility.
In addition, several state and federal permits, including those from ADNR, US Army Corps of
Engineers (USACOE), ADF&G, and the State Historic Preservation Office will impose more
constraints in addition or similar to those in the FERC license. A list of anticipated permits
required to develop the DAHP is included in Appendix VII.
LAND USE
A private inholding (USS 12063) exists at the outlet of Grant Lake which will require landowner
coordination for construction and operation of the Grant Lake project. An easement from the
landowner or outright land acquisition will be necessary to construct and operate the Grant Lake
project.
The Lake Elva project is burdened by the presence of a conservation easement on two parcels
(Lots 1 & 2, USS 12016) owned by the state of Alaska that are located at the mouth of the Elva
Creek. Limited land records research suggests that this conservation easement may be able to
be vacated through compensation or exchange for lands of a “reasonably equivalent location
with public purposes which meet or exceed those of the Property;”
Maps showing the two parcels at the mouth of Elva Creek and the parcel at Little Grant Lake
outlet are provided in Appendix VIII.
57 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
SUMMARY of ENVIRONMENTAL CONSIDERATIONS
At this time, the environmental considerations deemed most likely to affect Project feasibility
are:
• DPOR policy regarding construction of an access road and transmission line in the Park
under the Glacial Moraine Alternative;
• Effects of instream flow requirements in Grant River as they affect sockeye salmon
spawning, incubation and early rearing;
• The presence of conservation easements on state lands at the powerhouse site at mouth of
Elva Creek and of private inholdings at Grant Lake outlet. The Grant Lake inholding
which will require negotiated agreement or acquisition to construct and operate the
project. The lots at the mouth of Elva Creek will require a land exchange, vacation of the
easements or other mechanism to allow development of the project.
• Effects of construction activity and permanent features of both projects on wildlife
movement and migration;
• Potential existence of botanical species of concern and significant cultural resources
within the area of potential effect, or all potential ground disturbance areas;
• Effects, related to all of the above, of FERC license Articles and other permit conditions
on construction and operation of the Project.
DISCUSSION
GENERATION COMPONENTS and PROJECT ECONOMICS
The following discussion reflects results of conceptual-level engineering and economic analyses,
and represents general guidelines. More extensive data and information will be necessary in
most analysis areas, as suggested in the following recommendations.
58 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
Currently available data and analyses demonstrate that both Grant Lake Project Alternatives G-1
and G-2 would be economically feasible with either transmission alternative while neither Lake
Elva Project Alternative would be feasible for 2018 development.
Total capital costs, including a 25% contingency and short-term financing to avoid a rate-shock
during the construction period before power production, for the various alternatives were:
G-1: $65,492,396
G-2: $68,683,832
E-1: $57,843,560
E-2: $51,305,451
Costs were considered insignificantly different between the Grant Lake Alternatives; cost for
Lake Elva Alternative E-2 was considerably less than for Alternative E-1 due to the much
smaller dam. This smaller dam, however, left the Project much more susceptible to both spilling
and suspension of operation because of the reduced reservoir active storage capacity.
Annual energy output from the Grant Lake Alternatives was approximately 14.5 GWh during an
average precipitation year. This energy would annually displace approximately 1 million gallons
of diesel fuel consumption at current NETC plant efficiency. This diesel avoidance would be
valued at $3.5M per year at current NETC delivered diesel prices. Annual energy output from
Lake Elva Alternates E-1 and E-2 were approximately 7.4 and 6.9 GWh, respectively. This
energy would annually displace about 0.48- 0.5 million gallons of diesel fuel at an avoided cost
of about $1.7M per year at current prices.
B/C ratios for both Grant Lake Alternatives were essentially equal at about 1.36 under
established conditions. Similarly, B/C Ratios for Lake Elva Alternatives E-1 and E-2 were quite
close in value at about 0.74 and 0.82, respectively. These values reflected development of the
Lake Elva Project supplemental to the Grant Lake Project. This supplemental nature results in
savings from "piggy-backing" the Lake Elva Project’s costs for access roads, upgrades to the
existing system as well as a portion of the Project’s transmission system on those from the Grant
Lake Project.
59 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
Sensitivity analysis showed that the Grant Lake project B/C ratio generally remained at or above
1.0 even under rather extreme values of tested parameters.
The Lake Elva Project would result in a moderate increase in NETC electric rates if it were
developed at the same time as the Grant Lake project. This rate increase would result from the
need to service the additional debt that the Lake Elva Project would bring without compensating
generation revenue for several years into the project life.
Rates would increase over time but at a much lower and more predictable rate than they would
with all diesel-electric generation. This would be due to the substitution of non-escalating debt
service (fixed interest payments) for the highly-volatile diesel fuel outlay for the largest
component of the generation cost.
GEOLOGIC and GEOTECHNICAL SURVEYS
Final selection of dam location and type at both the Grant Lake and Lake Elva sites will depend
heavily on surface and sub-surface conditions. For the Grant Lake project, if suitable conditions
were found near the lake outlet, it would facilitate construction of a significantly lower cost dam
at the outlet of Little Grant Lake (Alternative G-1). Similarly, for the Lake Elva Project, the
feasibility of the more cost-effective downstream high dam (Alternative E-1) would be highly
dependent on geotechnical conditions suitable for the large gravity-type dam.
TRANSMISSION and ACCESS ROUTING
The proposed Glacial Moraine transmission/access route occupies relatively high ground on a
series of terminal moraines just inside WTSP and largely avoids problematic muskeg areas found
along the park’s eastern boundary. The overland (as opposed to submarine) transmission route
to Lake Elva generating facilities would offer a substantial cost savings. Consistency of the
various transmission elements with DPOR policies will be a major factor in final feasibility of
the both the Glacial Moraine and Lake Elva overland transmission routes.
ENVIRONMENTAL CONSIDERATIONS
Due to the high fisheries, scenic and recreational values in the potentially-affected area,
environmental constraints may well become the most influential factors determining Project
feasibility. The FERC licensing process requires extensive consultation with state and federal
60 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
resource agencies and affected Indian tribes to determine studies, impacts and mitigation
measures.
Costs associated with further studies and mitigation measures must be added to overall project
cost and may, at a certain point, significantly influence feasibility. Consultation and negotiation
of mitigation measures and other conditions will proceed over the next two years, after which
time it will be possible to more precisely estimate their effect on Project feasibility.
The Projects are far enough apart geographically that studies on each Project would be largely
independent. Therefore, it is expected that licensing of the two Projects at the same time would
realize few cost savings relative to overlapping travel and study team efficiency.
RECOMMENDATIONS
• Conduct a load growth and rate study to assess in more detail the effects of load growth
and fuel escalation on the feasibility of the Grant Lake Project.
• Conduct a study assessing joint operations of wind and DAHP generation. At least one
study (Marsh Creek et al., 2013) has examined this topic, but a future study should
examine the wind-hydro relationship using Alternatives from this report and the most
recent wind energy proposals.
• Determine during the next licensing phase, whether to proceed with the Grant Lake
Project only or to include the Lake Elva Project in licensing efforts. The current analysis
suggests that the Lake Elva Project would be feasible only if and when NETC load grows
to the point at which that Project's generation could be fully utilized. The decision to
proceed with the Grant Lake Project only would focus resources on that Project and
expedite the licensing process.
• Continue the FERC licensing process beginning with Preferred Alternative for the Grant
Lake Project from this report or others developed during the licensing process. FERC
license application requirements will advance the design and operations proposals for the
Project including both generation and transmission facilities. Licensing should also
61 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
require detailed analysis of staged development and the potential for a joint wind-DAHP
system.
• Consult with DPOR on the Park’s requirements for restoration of the Glacial Moraine
access road and mitigation measures necessary for construction and operation of the
transmission line in WTSP from the Grant Lake Project powerhouse for either the Glacial
Moraine or Park Boundary Transmission Alternatives. Both of these Transmission
Alternatives feature some length of their respective alignments within WTSP.
• Conduct more extensive geotechnical surveys, particularly at the dam, penstock and
powerhouse location(s) of preferred Alternatives. Such investigations will necessarily
require special use permits from DPOR. More invasive investigation, e.g., drilling and/or
test pits, will likely have to be conducted under strict constraints. Planning for this study
will need to be comprehensive and timely.
• Conduct field verification of past soils and shallow subsurface work, to investigate the
availability of suitable materials for dam construction in the vicinity of dam sites and
along all proposed generation features of the project as well as along the proposed access
road.
• Increase efforts of hydrologic studies during winter to better understand and quantify low
flows particularly at times critical to salmonid incubation and emergence.
• Analyze the potential for seepage that might result from raising lake levels, particularly
through the glacial moraine along Grant Lake’s northwestern shore. Such a seepage
analysis may require piezometers or other field measurements of subsurface conditions to
determine the potential for lost energy generation.
• Continue environmental studies in support of the licensing and permitting processes.
Fisheries studies, particularly those addressing instream flows for salmon in Grant River,
should be conducted as soon as possible. Studies already underway, such as those for
cultural, wildlife, water quality and hydrology should be completed while studies of
recreation and aesthetics should begin as soon as possible.
62 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
• Investigate land ownership restrictions to further review and assess potential impacts as it
relates to project development. Right-of-Way or easements will be required from the
property owner at Grant Lake outlet for project construction and operation of either
Alternatives G-1 or G-2.
• Develop an outreach program, with informational materials and public presentations to
educate project stakeholders, potential financiers, and the general public about the
project. Such an effort should include a project web site. Such a program can help to
improve public awareness of the project’s economic and environmental benefits, increase
public support and help secure financing for the project.
63 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
REFERENCES
Alaska Power Authority. Findings and Recommendations: Bristol Bay Power Plan. 1986.
Alaska Power Authority. Lake Elva Hydroelectric Project Feasibility Study. Findings and
Recommendations. 1981. http://akenergyinventory.org/hyd/SSH-1981-0422.pdf
R.W. Beck & Associates, Inc., Lake Elva Project Detailed Feasibility Analysis. Alaska Power
Authority. April 1981. http://akenergyinventory.org/hyd/SSH‐1981‐0127.pdf
Robert W. Retherford Associates, A Division of International Engineering Company, Inc.
Reconnaissance Study of the Lake Elva and Other Hydroelectric Power Potential in the
Dillingham Area. Supplemental Report. Anchorage, Alaska. Alaska Power Authority.
June 1980. http://akenergyinventory.org/hyd/SSH-1980-0186.pdf
Robert W. Retherford Associates, A Division of International Engineering Company, Inc.
Reconnaissance Study of the Lake Elva and Alternate Hydroelectric Power Potentials in
the Dillingham Area. Anchorage, Alaska. Alaska Power Authority. January 1980.
http://akenergyinventory.org/hyd/SSH-1980-0188.pdf
Robert W. Retherford Associates, A Division of International Engineering Company, Inc.,
Bristol Bay Energy and Electric Power Potential. Prepared for United States Department
of Energy. December 1979. http://akenergyinventory.org/hyd/SSH-1979-0075.pdf
Alaska Power and Telephone, Inc. Klawock, Alaska, Conversation with Prince of Wales
Division Electric Production Manager re: Black Bear Lake Project O&M costs and
factors. April 2013.
Cordova Electric Cooperative. Cordova, Alaska, Conversation with General Manager Re:
Humpback Creek project O&M costs and factors. April 2013.
EES Consulting. Review of Dillingham Area Hydro Projects. Nushagak Area Hydroelectric
Project Feasibility Draft Report. Nushagak Electric and Telephone Cooperative
(NETC). 2009.
Marsh Creek, LLC and Coffman Engineers, Inc. Wind, Hydro & Heat Recovery Analysis
Report. NETC. May 2013.
HDR Engineering, Inc. Tazimina River Hydroelectric Project Feasibility Study. Iliamna-
Newhalen-Nondalton Electrical Co-Op (INNEC). May 1991.
http://akenergyinventory.org/hyd/SSH‐1991‐0190.pdf
64 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
Nushagak Electric and Telephone Cooperative. Information Document. Nushagak Area
Hydroelectric Project Lake Elva and Grant Lake Projects Near Dillingham, Alaska. April
2009.
NETC. “Region 5 Dillingham, Snake Lake, Nushagak Bay Summary of Resources and Uses in
the Region” Chapter 3 – Region 5: Dillingham, Snake Lake, Nushagak Bay, Bristol Bay
Area Plan. April 2005.
Nushagak Electric Cooperative, Inc. (now NETC). Demand Management Project. Before the
Federal Energy Administration. Feb 1975. http://akenergyinventory.org/hyd/SSH‐1975‐
0187.pdf
Sachin Mishra, S. K. Singal, and D. K. Khatod. Costing of a Small Hydropower Projects.
IACSIT International Journal of Engineering and Technology, Vol. 4, No. 3, June 2013.
www.ijetch.org/papers/357‐P013.pdf
Stone & Webster Engineering Corporation. Feasibility Report Tazimina River Hydroelectric
Project. Alaska Power Authority. Mar 1987. http://akenergyinventory.org/hyd/SSH‐1991‐
0190.pdf
Tennant, D. L., 1975. Instream flow regimens for fish, wildlife, recreation and related
environmental resources. U.S. Fish and Wildlife Service, Billings, Mont.
University of Alaska, Institute of Social and Economic Research. Electric Power in Alaska,
1976-1995, 1976. http://akenergyinventory.org/hyd/SSH‐1976‐0393.pdf
United States Geological Survey (USGS) Gaging Station Records. “USGS 15302800 Grant LK
Outlet NR Aleknagik AK” National Water Information System: Web Interface.
http://waterdata.usgs.gov/nwis/nwisman/?site_no=15302800&agency_cd=USGS.
United States Geological Survey (USGS) Gaging Station Records. USGS Station No. 15302800.
Elva Lake Outlet near Aleknagik, Alaska. National Water Information System: Web
Interface. http://waterdata.usgs.gov/nwis/nwisman/?site_no=15302840&agency_cd=USGS
United States Geological Survey (USGS) Gaging Station Records. USGS Station No. 15302000
Nuyakuk River near Dillingham, Alaska. National Water Information System: Web
Interface. http://waterdata.usgs.gov/nwis/nwisman/?site_no=15302000&agency_cd=USGS
United States Geological Survey (USGS) Streamflow Measurement Records. USGS Station No.
15302800. Grant Lake Outlet near Aleknagik, Alaska. National Water Information
System: Web Interface. http://waterdata.usgs.gov/nwis/measurements/?site_no=15302800
65 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
United States Geological Survey (USGS) Streamflow Measurement Records. USGS Station No.
15302800. Elva Lake Outlet near Aleknagik, Alaska. National Water Information
System: Web Interface. http://waterdata.usgs.gov/nwis/measurements/?site_no=15302840.
Walsh, Patrick, Kaufman, Darrell, and Liedberg, Paul. Inventory of the Ahklun Mountain
Glaciers, Southwest Alaska. Alaska Refuges Report 07-004. Dillingham, Alaska. U.S.
Fish & Wildlife Service.Togiak National Wildlife Refuge. May 2007.
Western Regional Climate Center for the Lake Nerka, Alaska Station 505374 Period of Record
Monthly Climate Summary, Period of Record : 1/ 9/1952 to 5/31/1965.
http://www.wrcc.dri.edu/cgi‐bin/cliMAIN.pl?ak5374.
Zaheer, Syed H., Eng, P. and Fallows, Craig. Document Project Readiness by Estimate Class
Using PDRI.2011 AACE International Transactions, EST. 604.
Appendix I‐1 DRAFT DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
APPENDIX I
PROJECT SUMMARY DATA
TABLE AI-1. Grant Lake Project Summary Data.Grant Lake Project Alternative G-1 (SM 7.5 Dam) Grant Lake Alternative G-2 (SM 6.5 Dam)HydrologyHydrologyWatershed 35.5 Square miles Watershed 36.5 Square milesAverage Annual Runoff 101 cfs Average Annual Runoff 104.3 cfsAverage Annual Runoff per square mile 2.85 csm Average Annual Runoff per square mile 2.85 csmAverage Annual Net Precipitation 38.6 inches Average Annual Net Precipitation 38.6 inchesReservoirReservoirActive Storage Capacity 43.4 1000 AF Active Storage Capacity 46.8 1000 AFFull Reservoir Water Surface Elevation 508 feet NAVD 88 Full Reservoir Water Surface Elevation 508 feet NAVD 88Full Reservoir Water Surface Area 2,558 Acres Full Reservoir Water Surface Area 2,659 AcresMinimum Water Surface Elevation 488 feet NAVD 88 Minimum Water Surface Elevation 488 feet NAVD 88Average Water Surface Elevation 498.2 feet NAVD 88 Average Water Surface Elevation 498.1 feet NAVD 88Average Annual Reservoir Inflow 101.2 cfs Average Annual Reservoir Inflow 104.3 cfsAverage Instream Maintenance Release 17.2 cfs Average Instream Maintenance Release 17.7 cfsDam & SpillwayDam & SpillwayDam Location SM 7.5 Dam Location SM 6.7Dam Type Rockfill with impermeable membrane liner Dam Type Concrete GravityDam Height 24feetDam Height 60feetCrest Elevation 514 feet NAVD 88 Crest Elevation 508 feet NAVD 88Crest Length600feet Crest Length120feetSpillway Uncontrolled. Auxiliary on left bank of dam Spillway Type/Location Uncontrolled. Integral with Dam (Ogee)PowerhousePowerhousePowerhouse Location, Stream mile (SM) above Lake Kulik (SM 0) 3.7 SM Powerhouse Location, Stream mile (SM) above Lake Kulik (SM 0)3.7 SMPowerhouse Elevation 192 feet NAVD 88 Powerhouse Elevation 192 feet NAVD 88Installed Capacity 1.89 MW Installed Capacity 1.95 MWTurbine TypeFrancis or Turgo Turbine TypeFrancis or TurgoProject Power Flow 84.0 cfs Project Power Flow 86.7 cfsInstream Flow Maintenance Release 17.0 cfs Instream Flow Maintenance Release 17.7 cfsStatic Head 316.0 feet Static Head 316.0 feetNet Head 304.0 feet Net Head 304.0 feetTransmission LineTransmission LineType 34.5 kilovolt 3-Phase ACSR Single-pole Overhead Type 34.5 kilovolt 3-Phase ACSR Single-pole OverheadLength, Powerhouse to Aleknagik 38.0 miles Length, Powerhouse to Aleknagik 38.0 milesUpgrade, Existing System, 34.5 kV 3Ø to Waskey Rd. 15.5 miles Upgrade, Existing System, 34.5 kV 3Ø to Waskey Rd. 15.5 milesUpgrade, Existing System, 12.5 kV 1Ø Waskey Rd. to Plant 5.6 miles Upgrade, Existing System, 12.5 kV 1Ø Waskey Rd. to Plant 5.6 milesEnergy ProductionEnergy ProductionAverage Annual Net Energy Output114,320,762 kWhAverage Annual Net Energy Output114,727,225 kWhAnnual Net Energy Output (Wet Year) Exceeds 80% of years 15,682,871 kWh Annual Net Energy Output (Wet Year) Exceeds 80% of years16,147,613 kWhAnnual Net Energy Output (Wet Year) Exceeds 20% of years 12,590,182 kWh Annual Net Energy Output (Wet Year) Exceeds 20% of years12,884,794 kWhAverage Annual Diesel Avoidance 967,619 Gallons Average Annual Diesel Avoidance 995,083 Gallons1 Net Energy after instream flow maintenance release.Appendix I‐2DAHP CONCEPTUAL FEASIBILITY STUDYGRANT LAKE AND LAKE ELVA PROJECTS
TABLE AI-2. Lake Elva Project Summary Data.Lake Elva Project Alternative E-1 (SM 1.6 Dam)Lake Elva Project Alternative E-2 (SM 3.3 Dam)HydrologyHydrologyWatershed10.3 Square miles Watershed9.0 Square milesAverage Annual Runoff 52.9 cfs Average Annual Runoff 46.2 cfsAverage Annual Runoff per square mile 5.13 csm Average Annual Runoff per square mile 5.13 csmAverage Annual Net Precipitation 69.7 inches Average Annual Net Precipitation 69.7 inchesReservoirReservoirActive Storage Capacity 28.1 1000 AF Active Storage Capacity 10.9 1000 AFFull Reservoir Water Surface Elevation 370 feet NAVD 88 Full Reservoir Water Surface Elevation 356 feet NAVD 88Full Reservoir Water Surface Area 775 Acres Full Reservoir Water Surface Area 488 AcresMinimum Water Surface Elevation 320 feet NAVD 88 Min Water Surface Elevation 328 feet NAVD 88Average Water Surface Elevation 350.2 feet NAVD 88 Average Water Surface Elevation 344.5 feet NAVD 88Average Annual Reservoir Inflow 53.5 cfs Average Annual Reservoir Inflow 46.2 cfsAverage Instream Maintenance Release 9.00 cfs Average Instream Maintenance Release 0* cfsDam & SpillwayDam & SpillwayDam Location SM 1.6Dam Location SM 3.3Dam TypeRockfill with impervious coreDam TypeRockfill with impervious core or membraneDam Height108 feetDam Height38 feetCrest Elevation380 feet NAVD 88Crest Elevation362 feet NAVD 88Crest Length620 feetCrest Length620 feetSpillwayUncontrolled. Auxiliary spillway to left of dam via old channelSpillwayUncontrolled. Auxiliary spillway to right of dam via excavated channelPowerhousePowerhouse Location, Stream mile (SM) above Lake Nerka (SM 0) 0.2 SM Powerhouse Location, Stream mile (SM) above Lake Nerka (SM 0)0.2 SMPowerhouse Elevation 66 feet NAVD 88 Powerhouse Elevation feet NAVD 88Installed Capacity 1.0 MW Installed Capacity 0.96 MWTurbine TypeFrancis or Turgo Turbine TypeFrancis or TurgoProject Power Flow 44 cfs Project Flow 46.2 cfsInstream Flow Maintenance Release 9 cfsInstream Flow Maintenance Release20 cfsStatic Head304 feet Static Head 290 feetNet Head297 feet Net Head 273.8 feetTransmission LineTransmission LineSegment 1 Type:34.5 kilovolt 3-Phase SubmarineSegment 1 Type:34.5 kilovolt 3-Phase SubmarineLength, Elbow Point to Grant Lake Transmision Line 2.3 miles Length, Elbow Point to Grant Lake Transmision Line 2.3 milesSegment 2 Type:34.5 kilovolt 3-Phase ACSR Single-pole OverheadSegment 2 Type:34.5 kilovolt 3-Phase ACSR Single-pole OverheadLength, Elbow Point to Grant Lake Transmision Line 21.9 miles Length, Elbow Point to Grant Lake Transmision Line 21.9 milesEnergy ProductionEnergy ProductionAverage Annual Net Energy Output17,442,284 kWh Average Annual Net Energy Output 6,947,626 kWhAnnual Net Energy Output (Wet Year) Exceeds 80% of years 7,997,354 kWh Annual Net Energy Output (Wet Year) Exceeds 80% of years 7,153,396 kWhAnnual Net Energy Output (Wet Year) Exceeds 20% of years 6,788,666 kWh Annual Net Energy Output (Wet Year) Exceeds 20% of years 6,461,763 kWhAverage Annual Diesel Avoidance (full utilization) 502,857 Gallons Average Annual Diesel Avoidance (full utilization) 469,434 Gallons1 Net Energy after instream flow maintenance release.2Instream flows in anadromous reach assumed provided by accretion in bypass reach.Appendix I‐3DAHP CONCEPTUAL FEASIBILITY STUDYGRANT LAKE AND LAKE ELVA PROJECTS
Appendix II‐1 DRAFT DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
APPENDIX II
TRANSMISSION FEASIBILITY STUDIES, DILLINGHAM AREA
HYDROPOWER PROJECT (DAHP) ‐ LAKE ELVA AND GRANT LAKE
SITES
Dryden & LaRue Draft Study, November 2012
TRANSMISSION FEASIBILITY STUDIES,
DILLINGHAM AREA HYDROPOWER
PROJECT (DAHP) ‐ LAKE ELVA AND
GRANT LAKE SITES
November 5, 2012
Page i
SUMMARY OF CHANGES
Revision Number Revision Date Revision Description
A 11/05/2012 Review Draft
Page ii
TABLE OF CONTENTS
1. Introduction ............................................................................................................................. 1
2. Right of Way and Land Use ..................................................................................................... 1
3. Environmental ......................................................................................................................... 2
4. Transmission Line Alignments ................................................................................................. 2
5. Preliminary Transmission Design ............................................................................................ 4
6. Construction Cost Estimate ..................................................................................................... 5
APPENDIX
A – Land Use and Status Maps
B – Environmental Report
C – Transmission Line Alignments
D – Basis of Design Memorandum
E – Voltage Profiles
Transmission Facilities Feasibility Studies, DAHP, Lake Elva and Grant Lake Sites
Page 1
1. INTRODUCTION
Development of the Dillingham Area Hydropower Project (DAHP), Lake Elva and Grant Lake,
requires the construction of electrical transmission facilities from the hydro sites to Dillingham.
Estimated generation capacities are 1.5 MW from Lake Elva and 3.0 MW from Grant Lake.
Dryden & LaRue, Inc. (D&L) was contracted by Nushagak Cooperative, Inc. (Nushagak) to
complete a Transmission Line Facilities Feasibility Study for the DAHP. The scope of the study is
to evaluate and refine transmission alignments developed in previous studies from the two
hydro sites to the Nushagak Power House Substation. The final transmission alignments shall
consider land use, environmental, constructability, operational and economic factors. A cost
estimate for the transmission line and interconnecting facilities will also be completed.
2. RIGHT OF WAY AND LAND USE
Right of way and land use for the transmission line alignments was reviewed by the D&L Right
of Way Department. Land use and status maps are located in Appendix A. The following are
their findings:
Lands crossed by the proposed transmission line corridor include ANCSA Native Corporation
lands owned by Bristol Bay Native Corporation and Aleknagik Natives, Limited, State of Alaska
patented and tentatively approved lands and City of Aleknagik property. The bulk of the State
of Alaska owned lands are within the Wood‐Tikchik State Park.
Wood‐Tikchik State Park
The Wood‐Tikchik State Park Management Plan at page 5‐7 contains the following statement:
Hydropower Development
When Wood‐Tikchik State Park was established, all state‐owned lands and waters within
the park were withdrawn from the public domain and designated for special purpose
management. The enabling legislation gives the Division of Parks and Outdoor
Recreation a clearly defined management purpose, which it cannot exceed without
specific legislative action.
The Legislature made a special finding that two potential hydro projects, at Lake Elva
and Grant Lake, were compatible with park purposes. Both projects have since been
determined unfeasible and dismissed from further consideration.
Chikuminuk Lake has also been considered in the past for hydroelectric development,
although it has not received the legislative recognition of Lake Elva and Grant Lake.
Hydroelectric development at sites other than Lake Elva and Grant Lake is incompatible
with the special park purpose management mandated by the Legislature and therefore
already prohibited by law. The park enabling legislation must be amended to specifically
allow hydroelectric development at Chikuminuk Lake.
Section 41.21.167 of the Alaska Statutes addresses incompatible uses within the park.
Paragraph (c) specifies that hydropower development at Lake Elva and Grant Lake are not
incompatible uses of the park.
Transmission Facilities Feasibility Studies, DAHP, Lake Elva and Grant Lake Sites
Page 2
(c) Development and operation of a hydroelectric site at Lake Elva or Grant Lake is not
considered an incompatible use.
Although the Wood‐Tikchik State Park Management Plan states the projects are unfeasible and
dismissed from further consideration, the legislative declaration takes precedence over the
management plan.
Development of the hydropower facilities authorized by AS 41.21.167(c) are subject to
reasonable stipulations to protect park values and resources. Page 8‐12 of the Wood‐Tikchik
State Park Management Plan.
A Land Use Permit will be required for the preliminary project research; leases and rights of way
for project facilities, power house and switchyard, transmission line and access roads will need
to be obtained through the State of Alaska Department of Natural Resources, Division of Parks
and Outdoor Recreation.
State Lands Outside Wood‐Tikchik State Park
For the State of Alaska owned lands outside of the Wood‐Tikchik Park, a right of way grant will
be required for transmission line and access easements. Removal of gravel from State lands
outside of the park will require a material sale application. These permits will be issued by the
State of Alaska Department of Natural Resources, Division of Mining, Land and Water.
ANCSA Corporate Lands
Easements for the transmission and access for the transmission line and to the project area will
need to be acquired from Bristol Bay Native Corporation and Aleknagik Natives, Limited.
City of Aleknagik
Easements for the transmission and access for the transmission line to connect to existing
easements will need to be acquired from the City of Aleknagik.
3. ENVIRONMENTAL
Environmental issues which may be realized along the proposed alignments were addressed by
Travis and Peterson Environmental Consultants, Inc. An environmental report addressing
potential environmental issues, potential permits and approvals is included in Appendix B.
4. TRANSMISSION LINE ALIGNMENTS
A site visit was performed on August 8th, 2012 to visually inspect and photographically record
alignments established after review of the previous hydro studies, ROW, land use and
environmental factors. Final transmission line alignments were then refined utilizing the field
collected data, satellite aerial photography and USGS topographical maps.
Lake Elva and Grant Lake Hydro Sites are both located within the Wood –Tikchik Alaska State
Park. The required transmission facilities shall be minimized in the park by establishing
alignments following construction favorable terrain which will allow the most direct route to
the park boundary. The alignments were optimized to maximize constructability and reduce
environmental impact.
Transmission Facilities Feasibility Studies, DAHP, Lake Elva and Grant Lake Sites
Page 3
The transmission of power from the Grant Lake Hydro site to the Nushagak existing power
distribution system at the City of Aleknagik shall be constructed utilizing conventional overhead
(OH) single pole power structures. Both conventional overhead construction and submarine
cable will be needed for the Lake Elva transmission line facilities within the Park. Two
alignment options will be investigated for the Lake Elva transmission line from the Hydro site to
the Grant Lake transmission line just east of the park boundary. The upgrade of the Nushagak
existing overhead single phase distribution line to three phase will be required from the City of
Aleknagik to Waskey Road where a substation will be required to transform the power to the
existing distribution voltage. A new 12.47 kV power line routed along Waskey Road will be
required from this substation to the Nushagak power house substation. A 12.47 kV beaker
addition will be needed at the Nushagak power house substation.
As shown in Exhibit A, the following defines the refined alignments (a larger scale depiction of
the alignments are located in Appendix C):
Transmission Facilities Feasibility Studies, DAHP, Lake Elva and Grant Lake Sites
Page 4
Grant Lake Transmission Line alignment heads dues east from the Grant Lake Hydro Site, taking
the most direct route to the Wood‐Tikchik State Park boundary. Once out of the state park, the
alignment heads southward paralleling the park boundary to the Elva/Grant Junction
(approximately 22.3 mile‐Sub and 20.8 mile‐OH).
Two options for the Lake Elva Transmission Line from Lake Elva to Elva/Grant Junction were
established. The first option is an underwater submarine cable routing through Lake Nerka
which follows an alignment due east toward the park boundary (approximately 20.4 miles).
The alignment exits the eastern most edge of the lake and proceeds overhead (approximately
3.5 miles) to the park boundary at the Elva/Grant Junction (Sub). The second option requires
submarine cable water crossing of Lake Nerka (approximately 2.3 miles), near the mouth of
Amakuk Arm, and then proceeds via overhead construction easterly to the park boundary
(approximately 21.9 miles) at Elva/Grant Junction (OH).
From Elva/Grant Junction, the transmission line alignment continues southward, east of the
state park boundary, to the point where the park boundary turns due west. From this point,
the transmission alignment runs the most direct possible route, allowing deviations for
geographical/water body obstacles, to the existing Nushagak distribution line on the north side
of Wood River at the City of Aleknagik (approximately 21.8 miles‐Sub and 23.4‐OH).
The new transmission line will follow the existing Nushagak distribution line alignment from the
City of Aleknagik along Aleknagik Lake Road to the intersection of Waskey Road (approximately
15.5 miles).
The Substation planned at the intersection of Aleknagik Lake Road and Waskey Road will feed a
new 12.5 kV distribution line routed along Waskey Road to the Nushagak Power House which
will allow power delivery from the Hydro Sites to the Nushagak main powerhouse substation
(approximately 5.6 miles).
5. PRELIMINARY TRANSMISSION DESIGN
Preliminary design determined transmission design parameters including loading criteria,
optimum voltage, conductor size, typical structure type and pole size.
Loading criteria was developed based on climatological data available from the Western Region
Climate Center and Applied Technology Council. A basis of design is included in Appendix D.
Voltage profiles were generated utilizing simple power flow models. The results are shown in
Appendix E. In all cases it was assumed the Nushagak diesel generation was online which is
needed to maintain voltage profiles. The modeling confirmed that a 336.4 ACSR conductor at
an operating voltage of 34.5 kV will perform well for the transmission line power delivery
requirements. The use of 4/0 ACSR will maintain voltage profiles on feeds to the Elva/Grant
junction, with a 336.4 ACSR required from the Junction into Dillingham. For feasibility level
purposes, it was decided to follow a more conservative approach utilizing 336.4 ACSR for all
overhead portions of the project. Power flows indicated that the charging current required for
the Lake Elva submarine cable option running the length of Lake Nerka is a problem. The
Transmission Facilities Feasibility Studies, DAHP, Lake Elva and Grant Lake Sites
Page 5
reactive power requirement for energizing and operation of the cable poses technical
challenges with an extreme high cost.
The upgrade in voltage to 34.5 kV of the single phase line along Aleknagik Lake Road will
require the change out of existing distribution transformers. Conventional single bushing
transformers will be utilized. A neutral will be included on the entire transmission line to help
facilitate protective relaying of the line.
Rural Utility Service (RUS) design parameters are utilized. RUS structures types will be used for
the overhead section of the transmission line and will be single wood pole design. A typical
tangent structure is as shown in Exhibit B. Raptor protection is taken into consideration and
“Suggested Practices for Raptor Protection on Power Lines, The State of the Art in 2006, Avian
Power line Interaction Committee” is used as a guideline.
The typical pole sizes are 40 ft Class 2, and 45 Class 2 and will be direct buried where soils are
acceptable. Pile type foundations are expected in deep peat, or swampy areas.
6. CONSTRUCTION COST ESTIMATE
A construction cost estimate was completed for the alignments shown in Exhibit A. The
following is a list of the assumptions used in the development of the estimate:
Winter construction will be required for all activities north of City of Aleknagik. Use of
snow/ice roads is assumed for the entire length of the alignments north of the City of
Aleknagik.
Transmission Facilities Feasibility Studies, DAHP, Lake Elva and Grant Lake Sites
Page 6
Hydro sites substation transformation and switching is not included in estimate.
Complete replacement of structures, transformers and conductor for the existing
distribution line along Aleknagik Lake Road.
Costs associated with easements, environmental studies and permits are not included in
estimate.
Land cost for the Substation needed at Waskey and Aleknagik Lake Road are not
included in the estimate.
Due to uncertainties associated with man camps, duration of winter (ice road
availability), and material logistics for facilities north of the City of Aleknagik, a bottom
line contingency of 30% were utilized. A 20% contingency was used for all other
facilities.
The cost estimate is based on 2012 dollar value.
The following table presents the estimated costs for the different segments of the project:
Grant Lake to Power House Construction
Grant Lake to City of Aleknagik 35 kV Line $18,655,000
City of Aleknagik to Waskey Road OH 15 kV to 35 kV Conversion $4,236,000
Step Down Substation and PH Sub Addition 15 kV/35 kV 5 MVA, PH Breaker $1,500,000
Waskey Road Power Line New 15 KV Line $1,386,000
Lake Elva 34.5 kV 3 Phase Transmission Line Options
Lake Elva Hydro to Elva/Grant Junction ‐ OH 35 kV Overhead Option $14,847,000
Lake Elva Hydro to Elva/Grant Junction ‐ Sub 35 kV Submarine Option $49,417,000
Mobilization/Demobilization $897,000
APPENDIX A – LAND USE AND
STATUS MAPS
MAP 2-1
REGIONAL LAND STATUS
6
m
i
l
e
s
National Wildlife Refuge
National Wildlife Refuge Wilderness
Bureau of Land Management
Native Corporation
State Owned (TA & Patent)
Other private land
State selected
Native selected
Native allotments within the park
Other private lands within the park
Lake Aleknagik State Rec. Site (SRS)
Wood-Tikchik State Park
Natural features
Private lodge
Research cabin
State Park camp sites
Generalized Land Status
LEGEND
Lands Addressed by this Plan
Miscellaneous
10-4-02
MAP 7-1
PRIVATE LAND WITHIN
WOOD-TIKCHIK STATE PARK
6
m
i
l
e
s
National Wildlife Refuge
National Wildlife Refuge Wilderness
Bureau of Land Management
Native Corporation
State Owned (TA& Patent)
Other private land
State selected
Native selected
LakeAleknagik State Rec. Site (SRS)
Wood-Tikchik State Park
No conservation easement in place - 27
Native allotments - 101 parcels
Other private lands - 9
Generalized Land Status
LEGEND
Lands Addressed by this Plan
Private Land within
Wood-Tikchik State Park
10-4-02
Tier I conservation easement doesn’t
restrict commercial development - 39
Tier II conservation easement allows one
commercial site per parcel - 33
Tier III conservation easement allows no
commercial development on these parcels - 2
Boundary Island
(part of SRS)
MAP 8 - 1
LAND USE DESIGNATION IN
WOOD-TIKCHIK STATE PARK
6
m
i
l
e
s
Native allotments within
the park
Other private lands within
the park
Lake Aleknagik State
Rec. Site (SRS)
Proposed park additions
Wood-Tikchik State Park
Management Unit boundaries
Wilderness
Natural
Recreational Development
Natural features
Private lodge
Research cabin
State Park camp sites
Generalized Land Status
LEGEND
Lands Addressed by this Plan
Land Use Designations in
Wood-Tikchik State Park
Miscellaneous
10-4-02
NO
PATTERN
Boundary Island
(part of SRS)
APPENDIX B –
ENVIRONMENTAL REPORT
NUSHAGAK ELECTRIC AND TELEPHONE
PROPOSED TRANSMISSION LINE ROUTING
ENVIRONMENTAL SUMMARY
Prepared for:
DRYDEN & LaRUE, INC.
3305 Arctic Blvd., Suite 201
Anchorage, Alaska 99503
Prepared by:
TRAVIS/PETERSON
ENVIRONMENTAL CONSULTANTS, INC.
3305 Arctic Blvd., Suite 102
Anchorage, Alaska 99503
329 2nd Street
Fairbanks, Alaska 99701
1088-30
Dryden & LaRue, Inc. 1088-30 August 30, 2012
Nushagak E&T Proposed Transmission Line Routing Environmental Summary Page ii
TABLE OF CONTENTS
1.0 SCOPE OF WORK .............................................................................................................1
2.0 PURPOSE AND NEED .......................................................................................................2
2.1 Purpose of Project ...................................................................................................2
2.2 Need of Project .......................................................................................................2
3.0 POTENTIAL ENVIRONMENTAL ISSUES......................................................................2
3.1 Water Resources .....................................................................................................2
3.2 Ecosystems and Biological Communities ...............................................................3
3.3 Visual Landscape ....................................................................................................4
3.4 Social, Cultural, and Economic Impacts .................................................................4
4.0 POTENTIAL PERMITS AND APPROVALS....................................................................6
4.1 United States Army Corps of Engineers ..................................................................6
4.2 Alaska Department of Natural Resources ................................................................7
4.3 United States Environmental Protection Agency ....................................................8
4.4 Alaska Department of Environmental Conservation ...............................................8
4.5 Federal Energy Regulatory Commission .................................................................9
5.0 CONCLUSION ...................................................................................................................9
6.0 REFERENCES ..................................................................................................................10
FIGURES
Figure 1 – Proposed Transmission Line Routes ..................................................................1
Figure 2 – Private Land within Wood-Tikchik State Park ..................................................5
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1.0 SCOPE OF WORK
Dryden &LaRue Inc. contracted Travis/Peterson Environmental Consulting, Inc. (TPECI)
to investigate possible environmental issues concerning the proposed transmission line
routes for the proposed Elva Lake and Grant Lake Hydroelectric Projects (Figure 1).
TPECI reviewed the proposed transmission line routes, aerial photos, and area maps.
This report summarizes TPECI findings and discusses what environmental issues will
require attention for this project.
Figure 1 - Proposed Transmission Line Routes
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Nushagak E&T Proposed Transmission Line Routing Environment Summary Page 2
2.0 PURPOSE AND NEED
2.1 Purpose of Project
The NETC is proposing to build two hydroelectric generating stations within the
boundaries of the Wood-Tichik State Park. One facility is proposed at Elva Lake and
another sited at Grant Lake. Transmission lines would transport power to Aleknagik
where it would link to an existing line (as shown in Figure 1). The project’s intent is to
provide Nushagak customers with a cost-effective and reliable energy source while
meeting future load demands.
2.2 Need of Project
Nushagak Cooperative serves residents of Dillingham, Aleknagik, and remote villages
throughout the Dillingham census area. Currently, NETC has a diesel engine powered
generating plant in Dillingham which serves its loads. The NETC system currently has a
summer peak load of 3.4 MW and a minimum load of 1.4 MW (at night). Peak demand
occurs in July. The proposed hydroelectric projects would combine to meet nearly
seventy-five (75) percent of the annual load requirements.
The Nushagak Cooperative electric load is met by diesel generators. Therefore, member
rates are highly dependent on fuel costs. Also, the remote nature of the area limits the
electric generation options due to transmission constraints and reliability concerns.
Because of high electricity rates, approximately $0.23/kWh for residential customers, the
State of Alaska pays a portion of customer electric bills via the Power Cost Equalization
Program.
The proposed hydroelectric projects at Elva Lake and Grant Lake would reduce
electricity costs and provide clean, renewable energy to their members.
3.0 POTENTIAL ENVIRONMENTAL ISSUES
3.1 Water Resources
The majority of the proposed transmission line will travel occurs within and directly
adjacent to the boundaries of the Wood-Tikchik State Park and Lake Aleknagik State
Recreation Site. The Wood River-Tikchik Lakes system is a long series of interconnected
lakes and rivers which empty into Bristol Bay.
Lake Nerka, the Grant and Muklung Rivers, Elva Creek, and other unnamed streams are
anadromous bodies of water that may be directly or indirectly impacted by the proposed
project. These waters are important spawning grounds for salmon, predominately
sockeye, but other species are also present. Every possible effort must be made to
minimize any impediments (i.e. dams, spillways, powerline foundations, etc.) that
prevent the movement of salmon to and within these bodies of water.
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With respect to the transmission lines routing, the upper arm of Lake Nerka would be
most directly affected. The transmission line leaving the Elva Lake Powerhouse is
proposed to be a submarine line within Lake Nerka and exiting the eastern reach of the
lake while transitioning to an aerial line. At Lake Nerka and throughout the project area’s
streams and smaller water-bodies, best management practices (BMP) should be utilized
to minimize the disruption of fish habitat and recreational/subsistence activities as a result
of construction.
Wetlands are prevalent throughout the project area. There would be no way to avoid
impacting wetlands during this operation. A Section 404 permit from the United States
Corp of Engineers will be required for this project. This project may fall under COE
Nationwide permits 12 and 17 if it meets the established criteria. Nationwide Permit 12
pertains to utility line activities provided that they do not result in a loss greater than ½
acre of waters for each single and complete project. Considering the scope of the
proposed project, it is unlikely that the project will qualify for a Nationwide Permit 12.
Nationwide Permit 17 is applicable to hydroelectric projects that are less than 5.0 MW of
total generating capacity at the reservoir.
3.2 Ecosystems and Biological Communities
Ecosystems
Vegetation throughout the project site lies within the transitional zone between the
Hudsonian and Eskimoan Biotic Provinces. While dominated by coniferous forest,
vegetation can vary greatly due to topography, geology, and other local environmental
influences.
In general, white spruce and mixed spruce-birch thickets are found up to 900-feet in
elevation. Forest stands growing above 500 to 600 feet typically do not develop to saw-
timber size. Above 900-feet the land is comprised of bare rock, heath tundra, and alpine
meadow. Wet tundra or marsh, are common at the lowest elevations.
Cursory investigation using Alaska Exotic Plant Information Clearinghouse maps have
shown little evidence of invasive, nonnative species within the project area. Hits have
been documented in the Dillingham area causing a potential for invasive, nonnative
species to be transported into the project area on equipment and material.
Biological Communities
The project area is home to a large variety of fauna. Mammal habitat includes: moose,
Brown and Black bear, caribou, wolf, coyote, and wolverine. Small game and furbearers
found in the park include beaver, muskrat, otter, fox, weasel, marten, hare, and lynx.
Ground squirrels and marmots are abundant. The Alaska Department of Fish and Game
has designated the area between the upper and lower arms of Lake Nerka and areas south
of Grant Lake to be important moose habitat (and critical habitat in winter months).
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Due to the large number of waterbodies, wetlands, and the variety of upland habitats, the
list of birds seen in the park is higher and of greater variety than typically found in inland
Alaska. Bird strikes to the transmission lines would be an area of concern for the project.
Five species of Pacific salmon [chinook (king), sockeye (red), coho (silver), pink, and
chum] spawn in the Wood River and Tikchik Lakes systems. Rainbow trout, grayling,
lake trout, Arctic char, and Dolly Varden are also abundant. All play a significant role in
the area’s sport and subsistence fishing. Super saturation of nitrogen as a result of
spillway drainages from dams has been found to have a negative impact on juvenile
salmon potentially resulting in immediate death. Protection of fish populations and
habitat would be a primary environmental concern within the project area.
3.3 Visual Landscape
The Wood-Tikchik State Park and surrounding areas have long been a recreational
destination for people from Alaska, the states, and globally. Photography and general
sightseeing (non-hunting, fishing, or subsistence activities) comprise a large portion of
park visitors. The visual impact of the project is an issue of concern.
There is significant air traffic due to the remote nature of the region. Private and charter
floatplane operations are free to land in the park’s numerous lakes. Floatplanes often fly
‘knap of the earth’ based on landmarks instead of a set fli ght plan and mid-air collisions
with power lines is not uncommon. Power line tower lights and line markers would be a
necessary precaution for the proposed lines creating a significant visual impact.
3.4 Social, Cultural, and Economic Impacts
Social Impacts
The proposed project area lies with a recreational haven used by people from around the
world. World class hunting and fishing, boating and sightseeing tours, wildlife viewing,
photography, and numerous other outdoor activities are enjoyed throughout the park.
Minimizing negative impact and access to these activities due to project construction
would be a high priority.
Temporary impacts during construction include increases in noise and the impact of
construction equipment and crew on tranquil and sensitive areas. Also, the underwater
cable may prevent fisherman (recreational and subsistence) from anchoring their boats
along the corridor and limiting the fishable area of the lake.
There are several parcels of private property within Wood-Tikchik State Park, including a
number of properties that may be affected by the transmission line project (Figure 2).
These properties include parcels at Grant Lake, at the discharge of Elva Creek into Lake
Nerka, and numerous sites along the shores of Lake Nerka.
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Figure 2 - Private Land within Wood-Tikchik State Park
Cultural Impacts
Many of the residents of Aleknagik and Dillingham as well as the surrounding villages
are highly dependent on a subsistence lifestyle. The most important fish and game
subsistence resource in the area is salmon, although moose, caribou, and resident fish are
also important. The area is also used for gathering firewood, picking berries, trapping
and providing other renewable resources for food, clothing, shelter, transportation and
handicrafts. Minimizing the project’s impact on these activities would be a high priority.
As the transmission line route approaches Aleknagik and the surrounding tribal-owned
lands, the possibility of encroaching traditional, historic, or religious properties or other
archeological resources is heightened. An AS 41.35.080 permit may be needed for
historic and archeological investigation on state land.
Economic Impacts
Economic impacts during the transmission line construction and related activities would
rest primarily on its effect on tourism/recreation throughout the area. Construction could
restrict access to large recreational areas (Lake Nerka, Grant Lake, and the Grant River)
as well as sections of Lake Aleknagik, the Wood River, and the Town of Aleknagik itself.
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The proposed transmission line routes lies within the area of important salmon spawning
grounds. The Wood-Tikchik State Park, Lake Aleknagik, and surrounding area’s waters
contribute a significant share of the Bristol Bay commercial sockeye salmon fishery.
Protection and minimization of impact on these waters and habitats are vital to the
population’s economic and subsistence well being.
4.0 POTENTIAL PERMITS AND APPROVALS
When Wood-Tikchik State Park was established, all state-owned lands and waters within
the park were withdrawn from the public domain and designated for special purpose
management. The Legislature made a special finding that two potential hydroelectric
projects, at Lake Elva and Grant Lake, were compatible with park purposes.
Permits and approvals for this project depend on environmental conditions, land
ownership/status, and regulatory jurisdiction. The following section describes federal
and state agency jurisdiction and their permit requirements as they apply specifically to
the project.
4.1 United States Army Corps of Engineers (COE)
Section 404 Permit
The Army Corps of Engineers (COE) regulates impacts to wetlands. The COE enforces
Section 404 of the Clean Water Act (33 U.S.C. 1344) which prohibits the discharge of
dredged or fill material into waters of the United States without a permit from the COE.
Because wetlands exist at several locations along the power line, a Section 404 Permit
will be required. In addition, if a temporary access road is constructed for this project on
wetlands, a Section 404 permit will be required.
This project may fall under COE nationwide permits 12 and 17 if it meets the established
criteria. Nationwide Permit 12 pertains to utility line activities provided that they do not
result in a loss greater than ½ acre of waters for each single and complete project. The
proposed project is not expected to meet these qualifications. Nationwide Permit 17 is
applicable to hydroelectric projects that are less than 5.0 MW of total generating capacity
at the reservoir.
A pre-application consultation with the COE is not required but recommended. This
consultation will prevent delays once the application is submitted for review.
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4.2 Alaska Department of Natural Resources (ADNR)
The State Historic Preservation Office
Section 106 of the National Historic Preservation Act (NHPA) of 1966 requires all
federal and state agencies take into account the effects on historic properties. The State
Historic Preservation Office (SHPO) is a division of Alaska Department of Natural
Resources (ADNR) and regulates impacts to historic, cultural, and archeological
resources. According to the 1966 NHPA, all projects must be submitted to the SHPO for
their analysis and approval.
If investigation, excavation, gathering, or removal from the natural state, of any historic,
prehistoric, or archeological resources of the state (such as Wood-Tikchik State Park) is
required, an Alaska Statute Title 41.35.080 permit may be issued. If the historic,
prehistoric, or archeological resource involved is one which is, sacred, holy, or of
religious significance to a cultural group, the consent of that cultural group must be
obtained before a permit may be issued under this section.
Alaska Statute Title 16 Fish Habitat Permit
The Alaska Department of Fish and Game regulates specific rivers, lakes, and streams or
parts of them that are important for the spawning, rearing, or migration of anadromous
fish. The Anadromous Fish Act (AS 16.05.871) and the Fishway Act (AS 16.05.840)
require that activities within or across specified anadromous fish streams that could
represent an impediment to the efficient passage of fish or construction activities that
would disturb the natural flow of a specified anadromous stream, river, or lake, will
require a Title 16 Fish Habitat permit. Because work will be performed in or around
numerous anadromous habitats (Lake Nerka, the Grant and Muklung Rivers, Elva Creek,
and other unnamed streams), a Title 16 Fish Habitat Permit will be required for this
project.
State Land Use Permit
An ADNR land use permit is required for construction projects on state-owned lands or
crossing state-owned lands for access. This includes temporary access roads. In addition,
a land use permit may be required for certain activities on state-owned land that occur
below the ordinary high water line of navigable streams and lakes. This permit is
required for most activities that occur in streams and lakes. In addition, any hydro-
electric project must receive approval of an ADNP dam engineer for dam designs and
maintenance and operations plans.
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Temporary Water Use Permit (at Dam Sites)
ADNR regulates temporary withdrawals from water from state owned sources and issue a
water use permit. A Temporary Water Use Permit is required if freshwater from any
subsurface or surface source, on a temporary basis, on all lands regardless of ownership,
is used. This permit may be required when taking freshwater for uses for dust abatement,
material compaction during construction, domestic uses at construction camps, and
hydro-seeding after construction.
Special Use Permit
Special Use Permits are issued by ADNR State Parks for a variety of activities and uses
occurring within a state recreation area or state park. Special Use Permits under 11 AAC
18.010 is required of all commercial activities in the park.
4.3 United States Environmental Protection Agency (EPA)
To prevent the discharge of oil into waters of the United States or adjoining shorelines,
the Environmental Protection Agency (EPA) has established the Pollution Prevention
Rule published under the Clean Water Act. This rule mandates that all facilities and/or
projects implement a Spill Prevention, Control, and Countermeasure (SPCC) Plan if the
project is non-transportation-related, above ground storage capacity greater than 1,320
gallons, and has a reasonable expectation of a discharge into or upon navigable waters of
the United States or adjoining shorelines. If the Nushagak Hydroelectric Transmission
Line Project meets these three criteria, an SPCC plan will be required.
4.4 Alaska Department of Environmental Conservation (ADEC)
Section 401
Section 401 of the Clean Water Act grants States and eligible Tribes the authority to
review, approve or deny federal permits that result in discharge into State and Tribal
waters including wetlands.
The Alaska Department of Environmental Conservation (ADEC), in conjunction with the
COE 404 permitting, will analyze projects for impacts to water quality and recommend
mitigation measures to prevent water pollution. ADEC will issue a Certificate of
Assurance in accordance with Section 401 of the Clean Water Act. Furthermore, under
Section 401 of the Clean Water Act, ADEC has the authority to review and comment on
the SPCC Plan required by EPA for storage of large quantities of oil.
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Storm Water Pollution Prevention Plan
The goal of ADEC’s Storm Water Program is to reduce or eliminate pollutants in storm
waters so that pollutants do not reach land or waters of the state. Storm water discharges
often contain pollutants in quantities that could adversely affect water quality. Storm
water discharges are regulated under the NPDES program, and certain storm water
discharges require an NPDES permit from EPA.
The State of Alaska requires that any construction project that disturbs one or more acres
must be covered by a Construction General Permit (CGP) before any soil is disturbed at
the site. The permit coverage must be continued until all building is completed and the
ground is completely stabilized with a permanent, perennial, vegetative cover.
Development and implementation of a construction storm water pollution prevention plan
(SWPPP) is the key condition of the CGP.
4.5 Federal Energy Regulatory Commission (FERC)
The Federal Energy Regulatory Commission (FERC) is an independent agency that
regulates the interstate transmission of natural gas, oil, and electricity. FERC also
regulates natural gas and hydropower projects. As part of that responsibility, FERC
regulates the transmission and wholesale sales of electricity in interstate commerce and
licenses and inspects private, municipal, and state hydroelectric projects. Furthermore,
FERC oversees environmental matters related to natural gas and hydroelectricity projects
and major electricity policy initiatives.
FERC safeguards the environment by ensuring that planned projects will minimize
damage to the environment. As a result, the National Environmental Policy Act (NEPA)
process will be initiated. NEPA is required to analyze environmental impacts of the
proposed project as a whole. Both the dam and transmission portions of the project will
be considered as one. A key component of this is that FERC requires an Environmental
Impact Statement (EIS) or Environmental Assessment (EA) for the project. NEPA
documents typically require at least three years to complete and has an extensive public
involvement program.
5.0 CONCLUSION
The rising cost of shipping fuel to the Dillingham and Aleknagik requires NETC to
investigate other sources of energy. The proposed hydroelectric projects at Elva Lake and
Grant Lake are a viable alternative to diesel fuels. The ability to reduce energy cost,
lower the dependency on diesel fuel, increase reliability and opportunities for future
growth, and provide a clean, renewable energy source are all benefits the proposed
project can provide.
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TPECI has reviewed available pertinent information regarding the Nushagak
Transmission Line Project including the proposed transmission line routes, aerial photos,
and area maps. TPECI anticipates the following environmental permits are required for
this project:
U.S. Army Corps of Engineers
o Section 404 Wetland Fill Permit.
Alaska Department of Natural Resources
o State Historic Preservation Office Clearance;
o Alaska Statute Title 16 Fish Habitat Permit;
o State Land Use Permit;
o Temporary Water Use Permit; and
o State Parks Special Use Permit.
U.S. Environmental Protection Agency
o Spill Prevention, Control, and Countermeasure Plan; and
o Review of Wetland Impacts.
Alaska Department of Environmental Conservation
o Section 401 Certification; and
o Storm Water Pollution Prevention Plan
Federal Energy Regulatory Commission
o FERC Licensing; and
o NEPA - Environmental Assessment or Environmental Impact Statement.
TPECI recommends the following actions for the transmission line route:
Avoid spanning areas where float planes access the lake system;
Avoid laying underwater cable in areas where fisherman congregate;
Span all creeks and rivers wherever possible;
Utilize existing trails as much as possible;
Avoid construction during hunting season;
Limit construction on wetlands areas to winter months; and
Start the FERC NEPA process as soon as possible.
6.0 REFERENCES
ACHP,2012. Section 106 Regulations Summary. Advisory Council on Historic
Preservation, Website Database, August, 2012.
ADNR, 2012. Coastal Management Program. Alaska Department of Natural Resources,
Website Database, August, 2012.
Dryden & LaRue, Inc. 1088-30 Sept. 10, 2012
Nushagak E&T Proposed Transmission Line Routing Environment Summary Page 11
ADNR, 2012. Permits and Leases. Alaska Department of Natural Resources, Website
Database, August, 2012.
ALRC, 2012. Alaska Statutes. Alaska Legal Resource Center, Website Database,
August, 2012.
EPA, 2012. Section 401 Certification. U.S. Environmental Protection Agency, Website
Database, August, 2012.
EPA, 2010. Spill Prevention, Control and Countermeasure (SPCC) Regulation. U.S.
Environmental Protection Agency. pp.1-8.
J. Wall, 1985. United States Army Corps of Engineers Regulatory Program Application
Information. Army Corps of Engineers, Anchorage, Alaska. pp.1-20.
ADNR, 2002. Wood-Tikchik State Park Management Plan. Alaska Department of
Natural Resources, Division of Parks and Outdoor Recreation, pp. 1-139
.
APPENDIX C – TRANSMISSION
LINE ALIGNMENTS
APPENDIX D – BASIS OF
DESIGN
10/30/2012 1
Dillingham Area Hydro Project
Basis of Design Memorandum
34.5kV Transmission Line
1. STANDARDS
The line will comply with the requirements of the following standards:
a. 2012 edition, National Electrical Safety Code (NESC), Grade B construction
b. American National Standards Institute (ANSI)
c. National Electrical Manufacturers Association (NEMA)
d. American Society for Testing and Materials (ASTM)
e. American Wood Preservers Institute (AWPI)
f. Rural Utility Service (RUS)
2. DETAILED DESIGN REQUIREMENTS
a. Loading Criteria
The line will be designed for the following loading criteria:
(1) NESC Heavy Loading:
4 psf wind (40 mph), ½-inch radial ice, 0°F with NESC Grade B load/strength
factors as summarized below:
Item Wind
Loads
Wire Tension
Loads
Vertical
Loads
Steel Structures, Anchors &
Foundations 2.50/1.00 1.65/1.00 1.50/1.00
Guys 2.50/0.90 1.65/0.90 N/A
Wood Structures 2.50/0.65
1.65/0.65
1.50/0.65
(2) Extreme Wind Loading
While NESC Rule 250C does not apply to structures under 60 ft in height the
importance and remoteness of the line dictates some attention to high wind
exposure. 100 mph will be used on structure and wire with no ice, 20°F with
load/strength factors = 1.33/1.00 for wood structures and 1.1/1.00 for steel
structures, guys, anchors and foundations.
10/30/2012 2
(3) Extreme Ice Loading:
One (1.0) inch radial ice at a density of 57 lbs/cubic ft., 0°F, no wind, with
load/strength factors = 1.30/1.00 for wood structures and 1.1/1.00 for steel
structures.
b. Structure Type
34.5 kV deadend structures will be single wood pole with Hughes type arms configured
to RUS assembly ZC8X, a double deadend on crossarm modified for raptor protection.
34.5 kV tangent structures will be single wood poles configured to RUS assembly
ZC1X, modified for raptor protection
15 kV deadend structures will be single wood pole with Hughes type arms configured
to RUS assembly C8X, a double deadend on crossarm modified for raptor protection.
15 kV tangent structures will be single wood poles configured to RUS assembly C1X,
modified for raptor protection
c. Line Conductor
Future conductor for the 35kV and 15 kV circuits will be:
336.4 kcmil, 26/7 ACSR
Code name: “Linnet”
Weight: 0.463 lbs/ft.
Diameter: 0.720 inches
Rated Tensile Strength: 14,100 lbs Rated Ampacity: 510 Amps
New conductor tension in percent of the conductor’s rated tensile strength will not
exceed the following:
NESC Loading (½-inch ice, 4 psf wind, 0°F, plus k = 0.30) ....................................50%
Extreme Ice Loading (1.0 inch ice, no wind, 0°F)……………….............................70%
Initial Unloaded Tension, 0°F ...................................................................................20%
Final Unloaded Tension, 0°F …................................................................................15%
Typical sag and tension tables for Linnet conductors are included at the end of the
design memorandum.
g. Clearances
Minimum vertical design clearance above ground will be 23.5 ft. Ground clearances
will be based on the conductor sag at 1.0 inch radial ice (57 pcf), at 0°F, or at the
maximum design operating temperature, whichever is greater. The maximum design
operating temperatures for the 35 kV circuit is 120º F.
Following is a table detailing the derivation of the ground clearance criteria:
10/30/2012 3
Clearance Over Roads and
lands traversed by vehicles
Snow 7.0
Height of object under line (reference height) 10.0
Mechanical and Electrical clearance component 4.5
Extra clearance for survey and construction variations,
and possible sag increase due to unusual snow/ice
2.0
TOTAL DESIGN CLEARANCE 23.5 feet
Attachments:
Sag – Tension Tables
10/30/2012 4
ALUMINUM COMPANY OF AMERICA SAG AND TENSION DATA
DAHP - 336.4 ACSR
Conductor LINNET 336.4 Kcmil 26/ 7 Stranding ACSR
Area= .3070 Sq. In Dia= .720 In Wt= .463 Lb/F RTS= 14100 Lb
Data from Chart No. 1-782
English Units
Span= 300.0 Feet NESC Heavy Load Zone
Creep is NOT a Factor Rolled Rod
Design Points Final Initial
Temp Ice Wind K Weight Sag Tension Sag Tension
F In Psf Lb/F Lb/F Ft Lb Ft Lb
0. 1.00 .00 .00 2.603 5.92 4958. 5.92 4958.
0. .50 4.00 .30 1.650 4.85 3831. 4.61 4032.
32. .50 .00 .00 1.222 4.93 2794. 4.39 3136.
-50. .00 .00 .00 .463 1.50 3474. 1.37 3807.
-20. .00 .00 .00 .463 2.00 2605. 1.64 3173.
0. .00 .00 .00 .463 2.46 2115.* 1.89 2751.
30. .00 .00 .00 .463 3.33 1566. 2.42 2156.
60. .00 .00 .00 .463 4.26 1223. 3.13 1665.
90. .00 .00 .00 .463 5.01 1042. 3.97 1315.
120. .00 .00 .00 .463 5.42 963. 4.82 1083.
167. .00 .00 .00 .463 6.06 861. 6.02 868.
212. .00 .00 .00 .463 6.66 785. 6.62 789.
* Design Condition
APPENDIX E – VOLTAGE
PROFILES
The following Power Flow results are based on 1.5 MW from Lake Elva and 3.0 MW from
Grant Lake delivered to the Nushagak Power Plant with a system peak load of 4 MW and a
minimum load of 1.4 MW with Nushagak diesel generation on line. The values displayed are
the bus voltages (%) and the line flows (MW/MVAr). . All loads were set to 95% power factor.
The transformer taps were adjusted by a maximum value of 2.5% to improve the voltage profile
(varies from case to case).
The results confirm two facts. First, the Nushagak plant needs to be online under most, if not all,
loading conditions (minimum loading results look okay). Second, the charging produced by the
Lake Elva cable is a problem. At 1.0 per unit voltage, it produces about 2.65 MVAr. Overall,
Grant Lake looks acceptable and Lake Elva have reactive issues that need to be overcome which
may be possible installation of reactors and operational procedures.
Grant_Lake
34.5 kV 1 0 2 .8 2 %
Grant_Lake_Gen
4.16 kV 1 0 0 %
Junction
34.5 kV 1 0 1 .8 4 %Junction2
34.5 kV
Lake_Elva
34.5 kV
Lake_Elva_Gen
4.16 kV
Dillingham
34.5 kV 9 9 .8 2 %
Dillingham_Gen
12.47 kV 1 0 0 %
Max
4.211 MVA
4
j1.3
Gen2
5 MW
1.2
j1.7
Min
1.474 MVA
T1
5 MVA
2.9
-j0.3
Gen3
1.5 MW
T3
3 MVA
Cable1
Gen1
3 MW
3
-j0.4
3
-j0.4
T2
5 MVA
-2.5% TapP
Open
Max
4.211 MVA
Min
1.474 MVA
Gen2
5 MW
Gen3
1.5 MW
Cable1
T3
3 MVA
Junction
34.5 kV
Dillingham
34.5 kV
Dillingham_Gen
12.47 kV
Junction2
34.5 kV
Lake_Elva
34.5 kV
Grant_Lake_Gen
4.16 kV
Lake_Elva_Gen
4.16 kV
3
-j0.5
2.9
-j0.4
T1
5 MVA
T2
5 MVA
-2.5% TapP
Grant_Lake
34.5 kV
Gen1
3 MW
1 0 2 .8 2 %
1 0 1 .8 4 %
9 9 .8 2 %
3
-j0.5
2.9
-j0.4
1 0 0 %
2.9
-j0.3
4
j1.3
1.2
j1.7
1 0 0 %
3
-j0.4
3
-j0.4
Open
Grant_Lake
34.5 kV 1 0 2 .3 %
Grant_Lake_Gen
4.16 kV 1 0 0 %
Junction
34.5 kV 1 0 1 .3 5 %Junction2
34.5 kV
Lake_Elva
34.5 kV
Lake_Elva_Gen
4.16 kV
Dillingham
34.5 kV 9 9 .0 5 %
Dillingham_Gen
12.47 kV 1 0 0 .7 8 %
Max
4.211 MVA
Gen2
5 MW
Min
1.474 MVA
1.4
j0.5
T1
5 MVA
-2.5% TapP
1.4
j0.5
Gen3
1.5 MW
T3
3 MVA
Cable1
Gen1
3 MW
1.4
j0.09
1.4
j0.09
T2
5 MVA
-2.5% TapP
Open
Max
4.211 MVA
Min
1.474 MVA
Gen1
3 MW
Gen2
5 MW
Gen3
1.5 MW
Cable1
T3
3 MVA
Junction
34.5 kV
Dillingham
34.5 kV
Dillingham_Gen
12.47 kV
Junction2
34.5 kV
Lake_Elva
34.5 kV
Grant_Lake_Gen
4.16 kV
Lake_Elva_Gen
4.16 kV
1.4
j0.07
1.4
j0.2
T2
5 MVA
-2.5% TapP
Grant_Lake
34.5 kV 1 0 2 .3 %
1 0 1 .3 5 %
9 9 .0 5 %
1.4
j0.07
1.4
j0.2
1 0 0 .7 8 %
1.4
j0.5
1 0 0 %
1.4
j0.09
1.4
j0.09
1.4
j0.5
Open
T1
5 MVA
-2.5% TapP
Grant_Lake
34.5 kV 1 0 0 .7 9 %
Grant_Lake_Gen
4.16 kV 1 0 0 %
Junction
34.5 kV 9 7 .8 5 %Junction2
34.5 kV
Lake_Elva
34.5 kV
Lake_Elva_Gen
4.16 kV
Dillingham
34.5 kV 9 2 .0 9 %
Dillingham_Gen
12.47 kV 9 2 .6 3 %
Max
2.948 MVA
2.8
j0.9
Gen2
5 MW
Min
1.474 MVA
T1
5 MVA
-2.5% TapP
2.8
j1.1
Gen3
1.5 MW
T3
3 MVA
-2.5% TapP
Cable1
Gen1
3 MW
3
j1.1
3
j1.1
T2
5 MVA
-2.5% TapP
Min
1.474 MVA
Open
Max
2.948 MVA
Gen2
5 MW
Gen3
1.5 MW
Cable1
T3
3 MVA
-2.5% TapP
Grant_Lake
34.5 kV
Junction2
34.5 kV
Lake_Elva
34.5 kV
Grant_Lake_Gen
4.16 kV
Lake_Elva_Gen
4.16 kV
3
j1
2.9
j1
T1
5 MVA
-2.5% TapP
T2
5 MVA
-2.5% TapP
Junction
34.5 kV
Dillingham
34.5 kV
Dillingham_Gen
12.47 kV
Gen1
3 MW
1 0 0 .7 9 %
9 7 .8 5 %
9 2 .0 9 %
3
j1
2.9
j1
9 2 .6 3 %
2.8
j1.1
2.8
j0.9
1 0 0 %
3
j1.1
3
j1.1
Open
Grant_Lake
34.5 kV 1 0 2 .3 %
Grant_Lake_Gen
4.16 kV 1 0 0 %
Junction
34.5 kV 1 0 1 .3 5 %Junction2
34.5 kV
Lake_Elva
34.5 kV
Lake_Elva_Gen
4.16 kV
Dillingham
34.5 kV 9 9 .0 5 %
Dillingham_Gen
12.47 kV 1 0 0 .7 8 %
Max
2.948 MVA
Gen2
5 MW
Min
1.474 MVA
1.4
j0.5
T1
5 MVA
-2.5% TapP
1.4
j0.5
Gen3
1.5 MW
T3
3 MVA
-2.5% TapP
Cable1
Gen1
3 MW
1.4
j0.09
1.4
j0.09
T2
5 MVA
-2.5% TapP
Open
Max
2.948 MVA
Gen1
3 MW
Gen2
5 MW
Gen3
1.5 MW
Cable1
T3
3 MVA
-2.5% TapP
Junction
34.5 kV
Dillingham
34.5 kV
Dillingham_Gen
12.47 kV
Junction2
34.5 kV
Lake_Elva
34.5 kV
Grant_Lake_Gen
4.16 kV
Lake_Elva_Gen
4.16 kV
1.4
j0.07
1.4
j0.2
T1
5 MVA
-2.5% TapP
T2
5 MVA
-2.5% TapP
Grant_Lake
34.5 kV 1 0 2 .3 %
1 0 1 .3 5 %
9 9 .0 5 %
1.4
j0.07
1.4
j0.2
1 0 0 .7 8 %
1.4
j0.5
1 0 0 %
1.4
j0.09
1.4
j0.09
1.4
j0.5
Open
Min
1.474 MVA
Grant_Lake
34.5 kV
Grant_Lake_Gen
4.16 kV
Junction
34.5 kV 1 1 1 .1 3 %Junction2
34.5 kV 1 1 1 .9 1 %Lake_Elva
34.5 kV
1 1 3 .2 3 %
Lake_Elva_Gen
4.16 kV
1 1 0 .6 4 %
Dillingham
34.5 kV 1 0 2 .0 4 %
Dillingham_Gen
12.47 kV 1 0 0 %
Max
4.211 MVA
4
j1.3
Gen2
5 MW
2.7
-j1.9
Min
1.474 MVA
T1
5 MVA
-2.5% TapP
1.3
j3.4
Gen3
1.5 MW
1.5
j0
1.5
j0
T3
3 MVA
-2.5% TapP
Cable1
Open
Gen1
3 MW
T2
5 MVA
-2.5% TapP
Max
4.211 MVA
Min
1.474 MVA
Gen1
3 MW
Cable1
T2
5 MVA
-2.5% TapP
Grant_Lake
34.5 kV
Dillingham_Gen
12.47 kV
Grant_Lake_Gen
4.16 kV
1.5
-j0.04
1.5
j3.3
1.5
j3.3
T1
5 MVA
-2.5% TapP
T3
3 MVA
-2.5% TapP
Junction
34.5 kV
Dillingham
34.5 kV
Junction2
34.5 kV
Lake_Elva
34.5 kV
Lake_Elva_Gen
4.16 kV
Gen2
5 MW
Gen3
1.5 MW
1 1 1 .1 3 %
1 0 2 .0 4 %
1.5
j3.3
1 0 0 %
1.3
j3.4
4
j1.3
2.7
-j1.9
1 1 1 .9 1 %
1.5
j3.3
1 1 3 .2 3 %
1 1 0 .6 4 %
1.5
j0
1.5
j0
1.5
-j0.04
Open
Grant_Lake
34.5 kV
Grant_Lake_Gen
4.16 kV
Junction
34.5 kV 1 1 1 .1 3 %Junction2
34.5 kV 1 1 1 .9 1 %Lake_Elva
34.5 kV
1 1 3 .2 3 %
Lake_Elva_Gen
4.16 kV
1 1 0 .6 4 %
Dillingham
34.5 kV 1 0 2 .0 4 %
Dillingham_Gen
12.47 kV 1 0 0 %
Max
4.211 MVA
Gen2
5 MW
0.06
-j2.8
Min
1.474 MVA
1.4
j0.5
T1
5 MVA
-2.5% TapP
1.3
j3.4
Gen3
1.5 MW
1.5
j0
1.5
j0
T3
3 MVA
-2.5% TapP
Cable1
Open
Gen1
3 MW
T2
5 MVA
-2.5% TapP
Max
4.211 MVA
Min
1.474 MVA
Gen1
3 MW
Cable1
T2
5 MVA
-2.5% TapP
Grant_Lake
34.5 kV
Dillingham_Gen
12.47 kV
Grant_Lake_Gen
4.16 kV
1.5
-j0.04
1.5
j3.3
1.5
j3.3
T1
5 MVA
-2.5% TapP
T3
3 MVA
-2.5% TapP
Junction
34.5 kV
Dillingham
34.5 kV
Junction2
34.5 kV
Lake_Elva
34.5 kV
Lake_Elva_Gen
4.16 kV
Gen2
5 MW
Gen3
1.5 MW
1 1 1 .1 3 %
1 0 2 .0 4 %
1.5
j3.3
1 0 0 %
1.3
j3.4
0.06
-j2.8
1 1 1 .9 1 %
1.5
j3.3
1 1 3 .2 3 %
1 1 0 .6 4 %
1.5
j0
1.5
j0
1.5
-j0.04
1.4
j0.5
Open
Grant_Lake
34.5 kV 1 1 5 .1 1 %
Grant_Lake_Gen
4.16 kV 1 1 2 .4 6 %
Junction
34.5 kV 1 1 3 .7 9 %Junction2
34.5 kV 1 1 4 .5 8 %Lake_Elva
34.5 kV
1 1 5 .9 %
Lake_Elva_Gen
4.16 kV
1 1 3 .2 4 %
Dillingham
34.5 kV 1 0 2 .0 9 %
Dillingham_Gen
12.47 kV 1 0 0 %
Max
4.211 MVA
4
j1.3
Gen2
5 MW
0
-j1.6
Min
1.474 MVA
T1
5 MVA
-2.5% TapP
4
j3.3
Gen3
1.5 MW
1.5
j0
1.5
j0
T3
3 MVA
-2.5% TapP
Cable1
Gen1
3 MW
2.9
j0
2.9
j0
T2
5 MVA
-2.5% TapP
Max
4.211 MVA
Min
1.474 MVA
Cable1
Dillingham_Gen
12.47 kV
1.5
-j0.04
2.8
-j0.09
4.3
j3.5
1.5
j3.5
T2
5 MVA
-2.5% TapP
T3
3 MVA
-2.5% TapP
Grant_Lake
34.5 kV
Junction
34.5 kV
Dillingham
34.5 kV
Junction2
34.5 kV
Lake_Elva
34.5 kV
Grant_Lake_Gen
4.16 kV
Lake_Elva_Gen
4.16 kV
T1
5 MVA
-2.5% TapP
Gen1
3 MW
Gen2
5 MW
Gen3
1.5 MW
1 1 5 .1 1 %
1 1 3 .7 9 %
1 0 2 .0 9 %
2.8
-j0.09
4.3
j3.5
1 0 0 %
4
j3.3
4
j1.3
0
-j1.6
1 1 4 .5 8 %
1.5
j3.5
1 1 5 .9 %
1 1 2 .4 6 %
2.9
j0
2.9
j0
1 1 3 .2 4 %
1.5
j0
1.5
j0
1.5
-j0.04
Lake_Elva
34.5 kV
1 0 3 .0 5 %
Junction234.5 kV
1 0 2 .2 9 %
Grant_Lake
34.5 kV 1 0 3 .5 %
Grant_Lake_Gen
4.16 kV 1 0 1 .1 5 %
Junction
34.5 kV 1 0 2 .1 3 %Lake_Elva_Gen
4.16 kV
1 0 0 .7 3 %
Dillingham
34.5 kV 9 7 .8 3 %
Dillingham_Gen
12.47 kV 1 0 0 %
Max
4.211 MVA
4
j1.3
Gen2
5 MW
Min
1.474 MVA
T1
5 MVA
-2.5% TapP
4
j0.02
Gen3
1.5 MW
1.5
j0
1.5
j0
T3
3 MVA
-2.5% TapP
Gen1
3 MW
2.8
j0
2.8
j0
T2
5 MVA
-2.5% TapP
Cable1
Max
4.211 MVA
Min
1.474 MVA
OpenOpen
0
j1.5
Gen2
5 MW
Cable1
Dillingham_Gen
12.47 kV
Grant_Lake_Gen
4.16 kV
Lake_Elva_Gen
4.16 kV
2.7
-j0.1
4.2
j0.1
1.5
j0.1
1.5
-j0.05
T1
5 MVA
-2.5% TapP
T2
5 MVA
-2.5% TapP
T3
3 MVA
-2.5% TapP
Grant_Lake
34.5 kV
Junction
34.5 kV
Dillingham
34.5 kV
Junction234.5 kV
Lake_Elva
34.5 kV
Gen1
3 MW
Gen3
1.5 MW
1 0 3 .5 %
1 0 2 .1 3 %
9 7 .8 3 %
2.7
-j0.1
4.2
j0.1
1 0 0 %
4
j0.02
4
j1.3
0
j1.5
1 0 2 .2 9 %
1.5
j0.1
1 0 3 .0 5 %
1 0 1 .1 5 %
2.8
j0
2.8
j0
1 0 0 .7 3 %
1.5
j0
1.5
j0
OpenOpen
1.5
-j0.05
Lake_Elva
34.5 kV
9 8 .6 1 %
Junction234.5 kV
9 7 .2 1 %
Grant_Lake
34.5 kV 1 0 0 .3 1 %
Grant_Lake_Gen
4.16 kV 1 0 0 %
Junction
34.5 kV 9 6 .9 4 %
Lake_Elva_Gen
4.16 kV
9 7 .5 4 %
Dillingham
34.5 kV 8 7 .5 8 %
Dillingham_Gen
12.47 kV 8 6 .9 7 %
Max
4.211 MVA
4
j1.3
Gen2
5 MW
Min
1.474 MVA
T1
5 MVA
-2.5% TapP
4
j1.6
Gen3
1.5 MW
1.5
j0.5
1.5
j0.5
T3
3 MVA
-2.5% TapP
Gen1
3 MW
2.9
j1.5
2.9
j1.5
T2
5 MVA
-2.5% TapP
Cable1
Max
4.211 MVA
Min
1.474 MVA
OpenOpen
Gen2
5 MW
Cable1
Grant_Lake
34.5 kV
Lake_Elva
34.5 kV
Grant_Lake_Gen
4.16 kV
2.8
j1.3
4.3
j2
1.5
j0.6
1.5
j0.4
T1
5 MVA
-2.5% TapP
T2
5 MVA
-2.5% TapP
T3
3 MVA
-2.5% TapP
Junction
34.5 kV
Dillingham
34.5 kV
Dillingham_Gen
12.47 kV
Junction234.5 kVLake_Elva_Gen
4.16 kV
Gen1
3 MW
Gen3
1.5 MW
1 0 0 .3 1 %
9 6 .9 4 %
8 7 .5 8 %
2.8
j1.3
4.3
j2
8 6 .9 7 %
4
j1.6
4
j1.3
9 7 .2 1 %
1.5
j0.6
9 8 .6 1 %
1 0 0 %
2.9
j1.5
2.9
j1.5
9 7 .5 4 %
1.5
j0.5
1.5
j0.5
OpenOpen
1.5
j0.4
Appendix III‐1 DRAFT DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
APPENDIX III
HYDROLOGICAL SYNTHESIS, RESERVOIR ROUTING & ENERGY
GENERATION FORMULAE
Appendix III‐2 DRAFT DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
APPENDIX III
HYDROLOGICAL SYNTHESIS, RESERVOIR ROUTING &
ENERGY GENERATION FORMULAE
Table AIII-1. Slope & Intercept Values with Correlation Coefficients for Synthetic
Monthly Correlation Equations for Grant Lake Outlet discharge as a function of Nuyakuk
River discharge.
Month m b r2
January 1.2544 -0.3346 0.977
February 1.6095 -0.6807 0.977
March 0.8376 -0.0188 0.996
April 0.8495 0.0226 0.953
May 2.5315 -2.2183 0.959
June 0.201 3.8373 0.978
July 0.2473 0.8845 0.972
August 0.5103 -0.3408 0.993
September 1.0803 -2.2224 0.959
October 1.0278 -1.168 0.574
November 1.0319 -0.8747 0.914
December 0.4435 0.6022 0.966
QGrant = m QNuyakuk + b
m and b are the monthly slope and intercept values respectively as above and;
QGrant = Unit runoff from Grant Lake Gage watershed, cfs per square mile (csm)
QNuyakuk = Unit runoff from Nuyakuk River gage watershed, csm
Appendix III‐3 DRAFT DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
Table AIII-2. Slope & Intercept Values with Correlation Coefficients for Synthetic
Seasonal Correlation Equations for Lake Elva Outlet discharge as a function of Nuyakuk
River discharge.
Winter: (J, F, M & A) Summer: (M, J, J, A
& S) Fall: (O, N & D)
m 0.326193 1.0957 2.411593
b 1.027267 1.1505 -4.036737
R2 0.565 0.784 0.885
QElva = m QNuyakuk + b
Where; m and b are the seasonal slope and intercept respectively as above and;
QElva = Unit runoff from Lake Elva gage watershed, csm
& QNuyakuk = Unit runoff from Nuyakuk River gage watershed, csm
RESERVOIR STORAGE FORMULAE
Reservoir Storage-Inflow/Outflow Relationship
ΔSi = Ii – Oi
where;
i = An integer in value from 1 to 12 corresponding the month of the year.
ΔSi = Change in active storage volume in reservoir for month i, Acre feet
Ii = Reservoir inflow volume for month i, Acre feet
Oi = Reservoir outflow volume for month i, Acre feet
With Oi = 1.98 (Qi pwr + Qi fish + Qi Spill)
Appendix III‐4 DRAFT DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
Where: Qi pwr = Project Power Production Flow for Month i, cfs
Qi fish = Instream Flow Release for Month i, cfs
Qi Spill = Reservoir Spill, cfs
Reservoir Stage-Storage Relationships
Grant Lake G-1: S = [(WSE/193.85)12.08 – 69,576] / 1000
Grant Lake G-2: S = [(WSE/188.13)11.81 – 77,149] / 1000
Lake Elva E-1: S = (WSE/196.87)6.13 - 19.6
Lake Elva E-2: S = (WSE/48.29)5.19- 20.7
where;
S = Reservoir Storage Volume, 1000 Acre Feet
WSE = Reservoir Water Surface Elevation, feet NAVD 88
ENERGY GENERATION FORMULAE
Monthly energy output from Project
I. Ei = 24 Ni Pi
where;
Ei = Net monthly energy output at bus after losses for month i, kWh
i = An integer in value from 1 to 12 corresponding the month of the year.
Ni = Total number of days in month i, i.e., Jan. = 31, Feb. = 28.25. . . Dec. = 31.
Pi = Average monthly electrical power at bus, as determined by equation (eq.) II,
below.
Appendix III‐5 DRAFT DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
II. ܲ ൌߟ௧
Q γH୬ୣ୲
737
where;
Pi = Net average electrical power output from Project for month i, kW
ܳ ൌ Power flow for month ݅, cfs
H௧ ൌ Net head for month ݅,݂݁݁ݐ; as determined by eq. III, below, and;
ߛ ൌ Unit weight of water ൌ 62.4 pounds/cubic foot
ߟ௧ ൌ Generation transmission
⁄system efficiency,%; with;
ߟ௧ ൌ ߟ௬ௗ ߟ ߟ௧௦ ୀ ଼ଷ.ହ%
where;
ߟ௬ௗ ൌ Turbine efficiency,% = 92.5%
ߟ ൌ Generator Efficiency,% = 94.5%
ߟ௧௦ ൌ Transmission system effiency,% ൌ 95.5%
H௧ = Hi – h + Σh୫୧୬୭୰ , where;
Hi = Static Head for month i, feet
H௧ = Net head for month i, feet
h = Head loss in penstock due to friction for month i, feet
∑h୫୧୬୭୰ = Sum of minor hydraulic energy losses in intake, penstock, fittings,
bends, etc. for month i, feet
where; h ൌ݂ ቀ
ቁ ௩మ
ଶ
Appendix III‐6 DRAFT DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
and; h ൌ ∑k ሺ ௩ మ
ଶ ሻ
with; f = Darcy-Weisbach friction factor
L = Penstock length, feet
vi, = Velocity in water in penstock for month i, feet/sec
g = 32.2 feet/sec2
kminor = minor loss coefficient, varies with fitting
Appendix IV‐1 DRAFT DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
APPENDIX IV
ECONOMIC FORMULAE
Appendix IV‐2 DRAFT DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
APPENDIX IV
ECONOMIC FORMULAE
Present lump-sum-value of a future lump-sum value
PV = FV/(1 + i)n
Present lump-sum value of a uniform series of benefits (or payments)
PV = A ቀሺଵାሻ ି ଵ
ሺଵ ା ሻ ቁ
Where;
i = Annual Discount or Finance Rate, %
n = Number of periods, years
A = Annual payment or benefit, $2013
PV = Present-value lump sum, $2013
FV = Future-value lump sum, $(Year F)
F = 2013 + n
Appendix V‐1 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
APPENDIX V
GEOTECHNICAL REPORT
American Geotechnics 2300 N Yellowstone Hwy, Suite 203 • Idaho Falls, ID 83401 • (208) 523-8710
5260 Chinden Blvd. • Boise, ID 83714 • (208) 658-8700
DRAFT
August 31, 2012
File No. 12B-G2303
Civil Science
3160 W. Clubhouse Drive
Lehi, UT 84043
Attention: Brian Craven, PE
SUBJECT: Elva Lake Hydroelectric Project
Geotechnical Reconnaissance
Dear Brian,
This letter constitutes our geotechnical report of observations and recommendations for the proposed
Elva Lake Hydropower Facility located in the Wood-Tikchick State Park, Alaska. On July 6th 2012, our
geotechnical engineer, Mr. Stan Crawforth, performed a reconnaissance level review of site conditions
via helicopter with Mr. Mark Storm, Hydrological Engineer, of Civil Science. Our general objectives
were to evaluate the situation and layout of possible water retention structures, types and locations of
earthen borrow for dam construction, reservoir overflow locations, conditions along penstock corridors,
and conditions at potential powerhouse locations. Additionally, my field reconnaissance was an
opportunity to understand the logistics for planning possible future subsurface explorations leading to
the detailed engineering design of the aforementioned facilities.
Two alternative concepts are considered here in, namely,
• Run of the River Dam and Penstock
• Lake Tap and Tunnel
Run of the River Dam and Penstock
Lake Elva is a deep lake situated within a high mountain lake setting with an outflow creek that empties
into Lake Nerka, as shown on Figure 1.
For a run of the river, it appears feasible to locate a retention dam about 200 yards below the southeast
end of the lake at the outflow creek. An overflow spillway may be located over the top of the dam with
Elva Lake Hydroelectric Project - DRAFT
Geotechnical Reconnaissance
File No. 12B-G2303
August 31, 2012
American Geotechnics Page 2
an armored downstream face or possibly cut onto the adjacent abutment rock (preferred). The location
of a proposed dam site is shown on Figure 1.
We have discussed the special site conditions and the project objectives with the Dam Safety and
Construction Unit of the Alaska Department of Natural Resources. Borrow constraints include the lack
of low permeability soil such as silt or clay. Limited quantities of sand and gravel are assumed to be
available based on surface observations. The possible lack of easily accessible sand and gravel may
preclude the feasibility of roller compacted concrete dams, unless lake dredging is possible.
There is an abundance of rock. Graded blast rock could be utilized for random fill and erosion
countermeasures. It is desirable to use minimal quantities of man-made materials. Such materials must
ultimately be airlifted to the project site. Two typical dam sections are presented as Figures 2 and 3.
Rock-fill dam with Concrete Facing: A rock-fill dam with concrete facing is illustrated for
concept. This alternate provides for a large zone of random rock fill (blast rock). A 1V:1.5H
steepened downstream slope is not uncommon for rock fill dams. A continuously reinforced
layer of concrete facing may be placed on the upstream face as the primary liner inhibiting water
infiltration and to resist erosion by water and ice. An upstream slope no steeper than 2.5H:1V is
required for construction of the concrete facing.
Rock-fill Dam with Composite Liner: A second alternate consisting of a rock-fill dam with
composite liner is illustrated. Random rock fill is the dominant earth material placed in
downstream and upstream zones. The downstream slope is steepened to 1V:1.5H. Within the
interior of the dam is a composite liner surrounded by a cushion and filter layers. The filters are
necessary to control migration of soil particles under hydraulic pressure.
The composite liner could consist of a textured 60-mil HDPE liner placed immediate on top of a
pre-fabricated geosynthetic clay liner (GCL). The GCL comes in rolls and consists of a thin layer
of expansive bentonite clay sandwiched between two synthetic fabrics. If a hole in the HDPE
liner exists, water will penetrate causing the clay to swell and effectively seal small holes in the
HDPE liner. Together, the HDPE membrane with the GCL create a very low-permeability
composite liner. This type of infiltration barrier is not common with dams where there is an
abundance of clayey material to create a massive low-permeability zone.
Elva Lake Hydroelectric Project - DRAFT
Geotechnical Reconnaissance
File No. 12B-G2303
August 31, 2012
American Geotechnics Page 3
This concept is presented herein due to the unique borrow constraints at the project site. Based
on a telephone conversation, the Dam Safety and Construction Unit appears willing to consider
this type of liner system as feasible. At the upstream slope, a large rock (riprap) layer is
proposed to resist erosion by water and ice.
Borrow
The region has been glacially scoured leaving little soil for conventional dam construction. However,
we suspect that sand and gravel deposits may exist as small alluvial fans in the immediate vicinity of the
proposed power house.
Blast rock will be plentiful.
Lake Tap and Tunnel
Lake Elva is situated about 260 feet above Lake Nerka as shown on Figures 1 and 4. It appears feasible
that a tunnel (10-foot diameter horseshoe shape) could be excavated, using drill and blast methods from
Lake Nerka upward towards Lake Elva. Figure 4 shows a lake tap concept; wherein, a rock plug is
removed to release lake water into a tunnel. The tunnel could be partially fitted with an HDPE penstock
between the power house and a concrete tunnel plug fitted with a butterfly control valve. This concept
allows for winter tunnel construction.
Tunneling with a lake tap is not regulated by the Dam Safety and Construction Unit of the Alaska
Department of Natural Resources.
There are several natural shoreline protrusions along the shoreline of Lake Nerka that appear protected
from snow slides that could accommodate a power house facility and boat dock.
Rock from tunnel excavations would be used to build the terrain around the power house. Most likely,
the powerhouse can be founded on rock. Steel penstock pipe from the tunnel portal to the powerhouse
could be covered with blast rock.
Data Deficiencies
Topographic survey information is needed to determine crest elevations for dams and the associated
storage-capacity curve for the lake. An aerial survey should be commissioned to advance the
engineering.
Elva Lake Hydroelectric Project - DRAFT
Geotechnical Reconnaissance
File No. 12B-G2303
August 31, 2012
American Geotechnics Page 4
Geotechnical drilling and soundings should be performed at structure locations and potential borrow
sources to prove-out quantities for potential concrete and filter aggregates and other earthen materials.
A value analysis should compare the concepts of a Run of the River Dam and Penstock verses a Lake
Tap and Tunnel.
Closure
Please contact our office if we can provide an additional briefing on the aforementioned reconnaissance
level observations and opinions.
Respectfully Submitted
American Geotechnics
DRAFT
Stanley G. Crawforth, PE
Alaska Geotechnical Engineer
G. Alexander Rush, PE
Idaho Geotechnical Engineer
Appendix VI‐1 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
APPENDIX VI
CAPITAL COST ESTIMATES
TABLE AVI-1. GRANT LAKE PROJECT ALTERNATIVE G-1 ESTIMATED CAPITAL COSTS.GRANT LAKE PROJECT ALTERNATIVE G‐1ITEMUNITS QUANTITY unit cost DESCRIPTION SUB TOTALPROJECT DEVELOPMENT Planning & Design HRS. 150$ PAID W DEVELOPMENT GRANTS‐$ LEGAL COUNCIL AND REGULATORY SUPPORTHRS. 500$ Other NETC Funding‐$ ACQUISITIONSACRES 250,000$ Other NETC Funding‐$ PRE PROJECT DRILLINGFEET 1 50,000$ OPTION PAYMENT 50,000$ PERMITTING HRS. 200$ PAID W DEVELOPMENT GRANTS‐$ LICENSINGHRS. 200$ PAID W DEVELOPMENT GRANTS‐$ CONSTRUCTION MANAGEMENT & MANAGEMENT EXPENSES LUMP 1 3,500,000$ PAID W DEVELOPMENT GRANTS 3,500,000$ MOBILIZATIONSTANDARD MOBILIZATIONLUMP 1 500,000$ 500,000$ STAGING YARDLUMP 10% 400,000$ LEASE $, & SET UP 40,000$ MACHINERY AT 20 UNITS 20 TONS EACHTONS 600 82$ CAT‐JOHN DEER‐CASE‐OTHER 49,200$ BARGE FREIGHT SEATTLE WASHINGTON DILLINGHAM AK TONS 5,732 270$ 1,547,640$ PIPE FREIGHTTONS 1,471 164$ 241,244$ CEMENT FREIGHTTONS 290 164$ 47,560$ TURBINES & transformer FREIGHTTONS 120 197$ 23,616$ INFRASTRUCTURE COMPONENTS CONSTRUCTION MACHINERY @ 44,000 # eachPIECES 22 150,000$ NET LESS SALVAGE 3,300,000$ COMMUNICATIONS TOWERLUMP 1 120,000$ TURN KEY 120,000$ cut raw costCU YD. 270,000 7$ ON SITE PIT 1,890,000$ PROJECT ROADSFEET 19,660 20$ ON SITE PIT 393,200$ Foundation groutingEa 800 600$ Press. Grouting 480,000$ DAMCU YD. 20,260 35$ ON SITE PIT 709,100$ DAM LINER CONCRETE SIX BAG CU YD. 800 600$ TBD 480,000$ DAM WORKS incl. SpillwayLINER 1 1,000,000$ TBD 1,000,000$ PIPELINE & IntakeFEET 16,100 480$ 1/4 WALL STEEL 7,728,000$ PENSTOCK APPURTENANT ITEMS; THRUST RESTRAINT, CORROSION SYSTEM, VACUUM/AIR RELEASE, DRAINS SUB ASSEMBLY'S 5 170,000$ MISC. 850,000$ TAIL RACECU YD. 120 800$ 6 BAG CONCRETE 96,000$ POWER HOUSE TURBINE DECKCU YD. 450 800$ 6 BAG CONCRETE 360,000$ POWER HOUSE STRUCTUREBUILDING 1 350,000$ STEEL 350,000$ POWER SWITCHING & WATER CONTROLPIECES 14 80,000$ STANDARD TYPE 1,120,000$ Turbine/GeneratorKW 2,400 650$ Francis Type 1,560,000$ POWER LINE ROAD & REVEG.MILES 51 75,000$ BUILT W TRANSMISSION 3,825,000$ MAN CAMPUNITS 35 20,000$ 700,000$ MATERIAL SUPPLIES & CONSUMABLE S FREIGHTTONS 3,220 164$ GROUND TRANSPORT 528,080$ Generation Alternative G‐1 Subtotal 31,488,640$ Contingency (25%) 7,872,160$ Generation Alternative G‐1 Total 39,360,800$ Grant ‐Aleknagik T‐Line (Glacial Moraine ‐Adjusted to Route and w/o ice road)MILES 41.5 224,661$ T‐line: Glacial Moraine Alternative 9,323,416$ T‐line: Park boundary Transmission AlternatiVe 14,656,700$ ALEKNAGIK TO DILLINGHAM 35kV UpgradeLS 1 6,682,500$ ALK > DLG 6,682,500$ ALK > DLG 6,682,500$ Subtotal Glacial Moraine Alternative 16,005,916$ Subtotal Park Boundary Alternative 21,339,200$ Contingency (25%) 4,001,479$ Contingency (25%) 5,334,800$ Glacial Moraine Transmission Alternative Total20,007,395$ Park Boundary Transmission Alternative Total26,674,000$ Construction Total (Generation+Transmission+Contingency) 59,368,195$ Construction Total (Generation+Transmission+Contingency) 66,034,800$ Const. Finance 10.3% 6,124,200$ Const. Finance 6,811,902.34$ TOTAL PROJECT COST: G‐1 with Glacial Moraine Alternative 65,492,396$ G‐1 with Park Boundary Transmission Alternative 72,846,702$ Appendix VI‐2DAHP CONCEPTUAL FEASIBILITY STUDYGRANT LAKE AND LAKE ELVA PROJECTS
TABLE AVI -2. GRANT LAKE PROJECT ALTERNATIVE G-2 ESTIMATED CAPITAL COSTS.GRANT LAKE PROJECT ALTERNATIVE G‐2ITEMUNITS QUANTITY UNIT COST DESCRIPTION SUB TOTALPROJECT DEVELOPMENT Planning & DesignHRS. 150$ PAID W DEVELOPMENT GRANTS‐$ LEGAL COUNCIL AND REGULATORY SUPPORT HRS. 500$ Other NETC Funding‐$ ACQUISITIONSACRES 25,000$ Other NETC Funding‐$ PRE PROJECT DRILLINGFEET 1 50,000$ PAID W DEVELOPMENT GRANTS 50,000$ PERMITTINGHRS. 200$ PAID W DEVELOPMENT GRANTS‐$ LICENSINGHRS. 200$ PAID W DEVELOPMENT GRANTS‐$ FINANCINGHRS. 150$ Other NETC Funding‐$ CONSTRUCTION MANAGEMENT & MANAGEMENT EXPENSES LUMP 1 3,500,000$ PAID W DEVELOPMENT GRANTS 3,500,000$ MOBILIZATIONSTANDARD MOBILIZATIONLUMP 1 500,000$ 500,000$ STAGING YARDLUMP 0 400,000$ LEASE $, & SET UP 40,000$ MACHINERY AT 20 UNITS 20 TONS EACHTONS 600 82$ CAT‐JOHN DEER‐CASE‐OTHER 49,200$ BARGE FREIGHT SEATTLE WASHINGTON DILLINGHAM AK TONS 5,732 270$ 1,547,640$ PIPE FREIGHTTONS 1,471 164$ 241,244$ CEMENT FREIGHTTONS 290 164$ 47,560$ TURBINES FREIGHTTONS 120 196$ 23,520$ INFRASTRUCTURE COMPONENTS CONSTRUCTION MACHINERY @ 44,000 # each PIECES 22 150,000$ NET LESS SALVAGE 3,300,000$ COMMUNICATIONS TOWERLUMP 1 120,000$ TURN KEY 120,000$ cut raw costCU YD. 270,000 7$ ON SITE PIT 1,890,000$ PROJECT ROADSFEET 19,660 20$ ON SITE PIT 393,200$ Foundation Prep/Grouting (35' deep hole)Ea 1,100 600$ 660,000$ Gravity Dam w/ Ogee CrestCU YD. 10,000 350$ Sand from Roadway or Penstock alignments 3,500,000$ DAM FDN prep/diversionLS 1 500,000$ TBD 500,000$ DAM WORKSLS 1 320,000$ TBD 320,000$ PIPELINEFEET 16,100 480$ 1/4 WALL STEEL 7,728,000$ PENSTOCK APPURTENANT ITEMS; THRUST RESTRAINT, CORROSION SYSTEM, VACUUM/AIR RELEASE, DRAINS SUB ASSEMBLY'S 5 170,000$ MISC. 850,000$ TAIL RACECU YD. 120 800$ 6 BAG CONCRETE 96,000$ POWER HOUSE TURBINE DECKCU YD. 450 800$ 6 BAG CONCRETE 360,000$ POWER HOUSE STRUCTUREBUILDING 1 350,000$ STEEL 350,000$ POWER SWITCHING & WATER CONTROLPIECES 14 80,000$ STANDARD TYPE 1,120,000$ TURBINEKW 2,400 650$ Francis Type 1,560,000$ POWER LINE ROAD MILES 51 75,000$ BUILT W TRANSMISSION 3,825,000$ MAN CAMPUNITS 36 20,000$ 720,000$ MATERIAL SUPPLIES & CONSUMABLE S FREIGHT TONS 3,120 164$ GROUND TRANSPORT 511,680$ Generation Alternative G‐2 Subtotal 33,803,044$ Contingency (25%) 8,450,761$ Generation Alternative G‐2 Total42,253,805$ Grant ‐Aleknagik T‐Line (Glacial Moraine ‐Adjusted to Route and w/o ice road) MILES 41.5 224,661$ T‐line: Glacial Moraine Alternative 9,323,416$ T‐line: Park boundary Transmission Alternative14,656,700$ ALEKNAGIK TO DILLINGHAM 35kV UpgradeLS 1 6,682,500$ ALK > DLG 6,682,500$ ALK > DLG 6,682,500$ Subtotal Glacial Moraine Alternative16,005,916$ Subtotal Park Boundary Alternative21,339,200$ Contingency (25%) 4,001,479$ Contingency (25%) 5,334,800$ Glacial Moraine Transmission Alternative Total20,007,395$ Park Boundary Transmission Alternative Total26,674,000$ Construction Total (Generation+Transmission+Contingency) 62,261,200$ Construction Total (Generation+Transmission+Contingency) 68,927,805$ Const. Finance 10.3% 6,422,632$ Const. Finance 7,110,333.88$ TOTAL PROJECT COST: G‐2 with Glacial Moraine Alternative 68,683,832$ G‐2 with Park Boundary Transmission Alternative 76,038,139$ Appendix VI‐3DAHP CONCEPTUAL FEASIBILITY STUDYGRANT LAKE AND LAKE ELVA PROJECTS
TABLE AVI-3. LAKE ELVA PROJECT ALTERNATIVE E-1 ESTIMATED CAPITAL COSTS.LAKE ELVA PROJECT ALTERNATIVE E‐1ITEMUNITS QUANTITYUNIT COSTDESCRIPTION SUB TOTALPROJECT DEVELOPMENT Planning & DesignHRS. 150$ PAID W DEVELOPMENT GRANTS‐$ LEGAL COUNCIL AND REGULATORY SUPPORT HRS. 500$ Other NETC Funding‐$ ACQUISITIONSACRES 25,000$ Other NETC Funding‐$ PRE PROJECT DRILLINGFEET 1 50,000$ PAID W DEVELOPMENT GRANTS 50,000$ PERMITTINGHRS. 200$ PAID W DEVELOPMENT GRANTS‐$ LICENSINGHRS. 200$ PAID W DEVELOPMENT GRANTS‐$ FINANCINGHRS. 150$ Other NETC Funding‐$ CONSTRUCTION MANAGEMENT & MANAGEMENT EXPENSES LUMP 1 3,000,000$ PAID W DEVELOPMENT GRANTS 3,000,000$ STANDARD MOBILIZATIONLUMP 2 500,000$ 750,000$ STAGING YARDLUMP 20% 400,000$ LEASE $, & SET UP 80,000$ MACHINERY AT 20 UNITS 20 TONS EACHTONS 600 395$ CAT‐JOHN DEER‐CASE‐OTHER 237,000$ FERRY TIME FOR AIR LIFT EQUIPMENT MOVE IN HRS. 22 10,000$ 220,000$ BARGE FREIGHT SEATTLE WASHINGTON DILLINGHAM AK TONS 3,216 270$ 868,320$ PIPE FREIGHTTONS 944 300$ 283,200$ CEMENT FREIGHTTONS 346 300$ 103,800$ TURBINES FREIGHTTONS 80 300$ 24,000$ INFRASTRUCTURE COMPONENTS CONSTRUCTION MACHINERY PIECES 17 225,000$ NET LESS SALVAGE 3,825,000$ COMMUNICATIONS TOWERLUMP 1 120,000$ TURN KEY 120,000$ PROJECT ROADSFEET 16,838 20$ ON SITE PIT 336,752$ DAMCU YD. 225,000 37$ ON SITE PIT 8,325,000$ DAM LINER CONCRETE SIX BAGCU YD. 650 600$ TBD 390,000$ GROUTED HOLESEA 2,550 600$ high fracture in rock 1,530,000$ PIPELINEFEET 7,757 450$ 1/4 WALL STEEL 3,490,650$ PENSTOCK APPURTENANT ITEMS; THRUST RESTRAINT, CORROSION SYSTEM, VACUUM/AIR RELEASE, DRAINS SUB ASSEMBLY'S 5 170,000$ MISC. 850,000$ TAIL RACECU YD. 120 800$ 6 BAG CONCRETE 96,000$ POWER HOUSE TURBINE DECKCU YD. 450 800$ 6 BAG CONCRETE 360,000$ POWER HOUSE STRUCTUREBUILDING 1 350,000$ STEEL 350,000$ POWER SWITCHING & WATER CONTROLPIECES 12 80,000$ STANDARD TYPE 960,000$ TURBINEKW 1,500 650$ Francis Type 975,000$ POWER LINE ROAD MILES 2 75,000$ 150,000$ Docks ‐ 2 East Nerka & Elva mouthlump 1 1,300,000$ 1,300,000$ MAN CAMPUNITS 36 20,000$ 720,000$ MATERIAL SUPPLIES & CONSUMABLE S FREIGHT TONS 1,608 420$ GROUND TRANSPORT 675,360$ Transmission (To Grant Lake Junction ‐includes submarine cable 2.3 miles) 11,877,600 Subtotal41,947,682$ contingency 25% 10,486,920.50$ Subtotal Construction52,434,603$ Const. Finance 10.3% 5,408,957$ TOTAL PROJECT COST57,843,559$ Appendix VI‐4DAHP CONCEPTUAL FESIBILITY STUDYGRANT LAKE AND LAKE ELVA PROJECTS
TABLE AVI-4. LAKE ELVA PROJECT ALTERNATIVE E-2 ESTIMATED CAPITAL COSTS.LAKE ELVA PROJECT ALTERNATIVE E‐2ITEMUNITS QUANTITY UNIT COSTDESCRIPTION SUB TOTALPROJECT DEVELOPMENT Planning & DesignHRS. 150$ PAID W DEVELOPMENT GRANTS‐$ LEGAL COUNCIL AND REGULATORY SUPPORT HRS. 500$ Other NETC Funding‐$ ACQUISITIONSACRES 25,000$ Other NETC Funding‐$ PRE PROJECT DRILLINGFEET 1 50,000$ PAID W DEVELOPMENT GRANTS 50,000$ PERMITTINGHRS. 200$ PAID W DEVELOPMENT GRANTS‐$ LICENSINGHRS. 200$ PAID W DEVELOPMENT GRANTS‐$ FINANCINGHRS. 150$ Other NETC Funding‐$ CONSTRUCTION MANAGEMENT & MANAGEMENT EXPENSES LUMP 1 3,000,000$ Construction Phase 2,800,000$ STANDARD MOBILIZATIONLUMP 2 500,000$ 750,000$ STAGING YARDLUMP 10% 400,000$ LEASE $, & SET UP 40,000$ MACHINERY AT 20 UNITS 20 TONS EACHTONS 600 395$ CAT‐JOHN DEER‐CASE‐OTHER 235,000$ FERRY TIME FOR AIR LIFT EQUIPMENT MOVE IN HRS. 22 10,000$ 220,000$ BARGE FREIGHT SEATTLE WASHINGTON DILLINGHAM AK TONS 4,112 270$ 1,110,240$ PIPE FREIGHTTONS 944 300$ 283,200$ CEMENT FREIGHTTONS 346 300$ 103,800$ TURBINES FREIGHTTONS 80 350$ 28,000$ INFRASTRUCTURE COMPONENTS CONSTRUCTION MACHINERY @ 44,000 # each PIECES 17 225,000$ NET LESS SALVAGE 3,825,000$ COMMUNICATIONS TOWERLUMP 1 120,000$ TURN KEY 120,000$ PROJECT ROADSFEET 17,018 20$ ON SITE PIT 340,358$ DAMCU YD. 25,900 37$ ON SITE PIT 958,300$ DAM LINER CONCRETE SIX BAGCU YD. 650 600$ TBD 390,000$ GROUTED HOLESEa 1,700 600$ TBD 1,020,000$ PIPELINEFEET 15,200 450$ 1/4 WALL STEEL 6,840,000$ PENSTOCK APPURTENANT ITEMS; THRUST RESTRAINT, CORROSION SYSTEM, VACUUM/AIR RELEASE, DRAINS SUB ASSEMBLY'S 5 170,000$ MISC. 850,000$ TAIL RACECU YD. 120 800$ 6 BAG CONCRETE 96,000$ POWER HOUSE TURBINE DECKCU YD. 450 800$ 6 BAG CONCRETE 360,000$ POWER HOUSE STRUCTUREBUILDING 1 350,000$ STEEL 350,000$ POWER SWITCHING & WATER CONTROLPIECES 12 80,000$ STANDARD TYPE 960,000$ TURBINEKW 1,250 650$ Francis Type 812,500$ POWER LINE ROADMILES 2 75,000$ BUILT W TRANSMISSION 150,000$ DOCKS, 1 @ Nerka south 1 @ Elva Creeklump 1 1,300,000$ 1,300,000$ MAN CAMP UNITS 36 20,000$ 720,000$ MATERIAL SUPPLIES & CONSUMABLE S FREIGHT TONS 2,056 300$ GROUND TRANSPORT 616,300$ Transmission (To Grant Lake Junction ‐includes submarine cable 2.3 miles) 11,877,600 Subtotal37,206,298$ Contingency 25% 9,301,575$ Subtotal Construction46,507,873$ Const. Finance 10.3% 4,797,578$ TOTAL PROJECT COST 51,305,450$ Appendix VI‐5DAHP CONCEPTUAL FEASIBILITY STUDYGRANT LAKE AND LAKE ELVA PROJECTS
TABLE AVI-5. DAM VOLUME ESTIMATES
Elevation (ft) Contour area (sq ft) Depth (ft)Incremental
Volume (cu ft)
Cummulative
Volume (cu ft)
Estimated Dam
Volume (cu yd)
Dam Volume (cu
yds) from CAD
Percent
Difference (%)
490 15,718 0 ‐ ‐
495 18,097 5 84,538 84,538
500 29,359 5 118,641 203,179
505 27,546 5 142,264 345,443
510 18,902 5 116,122 461,564
514 9,491 4 56,787 518,352 19,198 20,259 5.2%
Elevation (ft) Contour area (sq ft) Depth (ft)Incremental
Volume (cu ft)
Cummulative
Volume (cu ft)
Estimated Dam
Volume (cu yd)
Dam Volume (cu
yds) from CAD
Percent
Difference (%)
450 2,698 0 ‐ ‐
460 2,961 10 28,294 28,294
470 2,943 10 29,519 57,814
480 2,763 10 28,529 86,343
490 2,373 10 25,678 112,021
500 1,902 10 21,372 133,393
508 1,527 8 13,714 147,107 5,448 5,383 ‐1.2%
Elevation (ft) Contour area (sq ft) Depth (ft)Incremental
Volume (cu ft)
Cummulative
Volume (cu ft)
Estimated Dam
Volume (cu yd)
Dam Volume (cu
yds) from CAD
Percent
Difference (%)
280 54,919 0 ‐ ‐
300 75,462 20 1,303,805 1,303,805
320 75,098 20 1,505,598 2,809,403
340 65,551 20 1,406,491 4,215,895
360 53,874 20 1,194,246 5,410,140
380 12,269 20 661,426 6,071,567 224,873 224,712 ‐0.07%
Elevation (ft) Contour area (sq ft) Depth (ft)Incremental
Volume (cu ft)
Cummulative
Volume (cu ft)
Estimated Dam
Volume (cu yd)
Dam Volume (cu
yds) from CAD
Percent
Difference (%)
325 9,884 0 ‐ ‐
330 24,941 5 87,060 87,060
335 25,554 5 126,237 213,297
340 23,436 5 122,474 335,771
345 20,440 5 109,688 445,460
350 16,372 5 92,030 537,489
355 11,696 5 70,170 607,659
360 8,062 5 49,396 657,055
362 5,103 2 13,166 670,221 24,823 25,821 3.9%
Alternative G‐1 Dam Volume
Alternative G‐2 Dam Volume
Alternative E‐1 Dam Volume
Alternative E‐2 Dam Volume
Appendix AVI‐6
DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
Appendix VII‐1 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
APPENDIX VII
MAJOR PERMITS REQUIRED FOR DAHP CONSTRUCTION
Appendix VII‐2 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
APPENDIX VII
MAJOR PERMITS REQUIRED FOR DAHP CONSTRUCTION
Table AVI-1. Major Permits Required for DAHP Construction.
Agency / Entity Permit / Finding / Action Comments
Federal Energy
Regulatory
Commission
License to Construct Preliminary Permit No. 14356 Issued
U.S. Army Corps
of Engineers Wetlands Permit, NWP 17 -
U.S. EPA Storm Water Pollution
Prevention Plan -
ADNR DPOR Special Use Permits Also required for studies.
ADNR Property
Rights
Transfer / Lease /
Easement Authorizations -
ADNR Materials Sale Agreement -
ADNR Water
Rights
Water Use Permit / Water
Rights
Requires ‘possessory interest’ in
property before issuance. Subject to
MOA with ADF&G.
ADF&G Fish Habitat Permit
*Required for Construction. Other
T16 Permits may be required for
study activities.
ADF&G Instream Flow *Memorandum of Agreement for
Instream Flow Reservation
ADOT&PF Right-of-Way Use Permit *Aleknagik-Dillingham Distribution
Line Upgrade
ADOT&PF Load Permits* *Varies depending on construction
mobilization method.
Appendix VIII‐1 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
APPENDIX VIII
MAPS OF AFFECTED INHOLDINGS
Appendix VIII‐2 DAHP CONCEPTUAL FEASIBILITY STUDY
GRANT LAKE AND LAKE ELVA PROJECTS
Appendix VIII‐3 DAHP CONCEPTUAL FEASIBILITY STUDY GRANT LAKE AND LAKE ELVA PROJECTS
Appendix VIII‐4 DAHP CONCEPTUAL FEASIBILITY STUDY GRANT LAKE AND LAKE ELVA PROJECTS