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Home My WebLink AboutAPA504...... - r;= NAY 2 9 1984 SUSITNA HYDROELECTRIC PROJECT FEASIBILITY REPORT SUPPLEMENT VOLUME 1 ENGINEERING AND ECONOMIC ASPECTS APRIL1983 ._____ __ ALASKA POWER AUTHORITY __ ----~ - - r""" I I l - TABLE OF CONTENTS VOLUME 1 -ENGINEERING AND ECONOMIC ASPECTS 1 -INTRODUCTION •••••••••••••••••••••••••••••••••••••.••••••••• 1-1 1.1-General ••••••••••.••••••••••••••••••••••••••••••••••• 1-1 1.2-Objectives-Scope ••••••••••••••••••••••••••••••••••• 1-2 2 - 3 - 4 - 1.3 -Organization of Supplemental Report •••••••••••••••••• 1-2 SLIM MARY •••••••••••••••••••••••••••••••••••••••••••••••••••• 2.1 2.2 Scope of Work •••••••••••••••••••••••••••••••••••••••• -Access Plan •••••••••••••••••••••••••••••••••••••••••• 2.3-Refinement of Susitna Development •••••••••••••••••••• 2.4-Transmission Facilities •••••••••.•••••••••••••••••••• 2.5 2.6 - Project Operation •••••••••••••••••••••••••••••••••••• Reservoir and River Temperature Studies •••••••••••••• 2.7 -Estimates of Cost •••••••••••••••••••••••••••••••••••• 2.8-Development Schedule ••••••••••••••••••••••••••••••••• 2.9 -Economic, Marketing, and Financial Evaluation •••••••• SCOPE OF WORK •••••••••••••••••••••••••••••••••••••••••••••• 3.1 -Introduction ......................................... 3.2-Access Plan •••••••••••••••••••••••••••••••••••••••••• 3. 3 -Hydrology Studies .................................... 3.4-Geotechnical Exploration ••••••••••••••••••••••••••••• 3.5-Design Development Update •••••••••••••••••••••••••••• 3. 6 -Environmental Studies •••••••••••••••••••••••••••••••• 3.7 Cost Estimate Update ................................. 3.8-Update Engineering/Construction Schedule ••••••••••••• 3.9-Preparation of FERC License Application •••••••••••••• 3.10-Marketing and Finance •••••••••••••••••••••••••••••••• ACCESS PLAN •••••••••••••••••••••••••••••••••••••••••••••••• 4.1-Introduction ....•....•............................... 4. 2 -Background .•••••••••••••••••••••••••••••••••••••••••• 4.3-Objectives •••••••••••••••••••••••••••••••••••••.••••• 4.4-Existing Access Facilities ••••••••••••••••••••••••••• 4.5-Corridor Identification and Selection •••••••••••••••• 4.6-Development of Plans ••••••••••••••••••••••••••••••••• 4.7-Evaluation of Plans ••••••••••••••.••••••••••••••••••• 4.8-Description of Most Responsive Access Plans •••••••.•• 4.9-Comparison of the Selected Alternative Plans ••••••••• 4.10-Summary of Final Selection of Plans •••••••••••••••••• 4.11-Modifications to Recommended Access Plan ••••••••••••• 4.12-Description of Proposed Access Plan •.•••••••••••••••• i 2-1 2-1 2-1 2-2 2-3 2-4 2-4 2-4 2-5 2-5 3-1 3-1 3-1 3-1 3-2 3-2 3-2 3-4 3-4 3-5 3-5 4-1 4-1 4-1 4-1 4-2 4-2 4-3 4-4 4-6 4-7 4-15 4-18 4-21 TABLE OF CONTENTS (Cont 'd) 5 -REFINEMENT OF SUSITNA DEVELOPMENT •••••••••••••••••••••.•••• 5-1 5.1 -1982 Geotechnical Design Considerations •••••••••••••• 5-1 5.2 -Main Dam Alternatives -Watana •••.••••••••••••••••••• 5-18 5.3-Refinements to General Arrangement ••••••••••••••••••• 5-20 6 -TRANSMISSION FACILITIES •••••••••••••••••••••••••••••••••••• 6-1 6.1-Introduction ••••••••••••••••••••••••••••••••••••••••• 6-1 6.2 Previous Studies ••••••••••••••••••••••••••••••••••••• 6-1 6.3-Electric Systems Studies ••••••••••••••••••••••••••••• 6-2 6.4-Corridor Identification and Selection •••••••••••••••• 6-2 6.5 -Corridor Reassessment: Central Study Area ••••••••••• 6-5 6.6 -Final Corridor Selection ••••••••••••••••••••••••••••• 6-8 6.7-Route Selection •••••••••••••••••••••••••••••••••••••• 6-8 6.8 -Towers, Foundations, and Conductors •••••••••••••••••• 6-9 6.9-Substations •••••••••••••••••••••••••••••••••••••••••• 6-10 6.10-Dispatch Center and Communications •••.••••••••••••••• 6-10 7-PROJECT OPERATION •••.••••••••••••••••••.••••••••••••••••••• 7-1 7.1 -Introduction ......................................... 7-1 7.2-Simulation Model .••••••••••••••••.•••.••••••••••••••• 7-1 7. 3 -Project Reservoirs .................•................. 7-2 7.4-Flow Range ••••.•••.••••••••••••••••••.•••.••••••••••• 7-3 7.5-Energy Production and Net Benefits ••••••••••••••••••• 7-5 8 -RESERVOIR AND RIVER TEMPERATURE STUDIES •••••••••••••••••••• 8-1 9 .- 8.1 8.2 8.3 8.4 8.5 8.6 8.7 -Introduction ••••••••••••••••••••••••••••••••••••••••• 8-1 Early Studies ......•...•............................. 8-1 1982 Studies ••••••••••••••••••••••••••••••••••••••••• 8-2 Eklutna Lake Temperature Modeling ••••••••••••.••••••• 8-4 Watana Reservoir Temperature ••••••••••••••••••••••••• ·8-9 Watana/Devil Canyon Operation ••••••••••••.•••.•••.••• 8-11 Downstream Temperatures •••••••••••••••••••••••••••••• 8-12 ESTIMATES OF COST •••••••••••••••••••••••••••••••••••••••••• 9-1 9-1 9-6 9-7 9-9 9-10 9-10 9-10 9-11 9-11 9-11 9.1 -Construction Costs ................................... 9.2 9.3 9.4 9.5 -Mitigation Costs ••••••••••••••••••••••••••••••••••••• -Engineering and Administration Costs ••••••••••••••••• Operation, Maintenance, and Replacement Costs •••••••• -Allowance for Funds Used During Construction ••••••••• 9.6-Escalation ••••••••••••••••••••••••••••••••••••••••••• 9.7 -Cash Flow and Manpower Loading Requirements •••••••••• 9. 8 -Cant i ngency •••••••••••••••••••••••••••••••••••••••••• 9.9-Previously Constructed Project Facilities •••••••••••• 9.10-Check Estimate by EBASCO ••••••••••••••••••••••••••••• 10-DEVELOPMENT SCHEDULE ••••••••••••••••••••••••••••••••••.••• 10-1 10.1 -Preparation of Schedules •••••••••••••••••••••••••••• 10-1 10.2-Watana Schedule ••••••••••.•••••••••••••••••••••••••• 10-2 10.3-Devil Canyon Schedule ••••••••••••••••••••••••••••••• 10-4 10.4 -History of Existing Project ••••••••••••••••••••••••• 10-6 i i - - - - -I - - r r- 1 r - TABLE OF CONTENTS (Cont•ct) Page 11 -ECONOMIC, MARKETING, AND FINANCIAL EVALUATION ••••••••••••• 11-1 11.1 -Introduction ••••••••••••••••••••••••••••••••••••••• 11-1 11.2 -Cost of Power ••.••••••.••..•••.•.•••.•••••••.•.•••• 11-2 11.3-Financing Plan ••••••••••••••••••••••••••••••••••••• 11-2 11.4 -Change in the Cost Estimate •••••••••••••••••••••••• 11-3 11.5-Comments from 11 Review Report 11 •••••••••••••••••••••• 11-4 11.6 -Generation Planning •••••••••••••••••••••••••••••••• 11-10 VOLUME 2 -PLATES ; i; - - .... - - - r ) I ' - Table 1.1 4.1 4. 2 4.3 5. 1 5.2 5. 3 6.1 6.2 6.3 6.4 7.1 7.2 7. 3 7.4 7.5 7.6 7.7 7.8 7.9 7.10 7.11 7.12 7.13 8.1 8.2 8.3 8.4 8.5 8.6 8.7 LIST OF TABLES Project Parameters and Design Criteria Access Plan Costs Access Plan Costs -Initial Access Within One Year Summary of Wildlife Habitat Issues Associated with Access Alternatives Watana Damsite Joint Characteristics Geologic Time Scale Correlation of Plate Numbers Transmission System Characteristics Technical, Economic, and Environmental Criteria Used in Corridor Selection Technical, Economic, and Environmental Criteria Used in Corridor Screening Summary of Screening Results Watana Pre-Project Monthly Flows (cfs) Modified Hydrology Devil Canyon Pre-Project Monthly Flows (cfs) Modified Hydrology Gold Creek Pre-Project Monthly Flows (cfs) Modified Hydrology Monthly Flow Requirements at Gold Creek (cfs) Monthly Energy Production -Case A, Variable Drawdown Monthly Energy Production -Case A1, 120 Foot Drawdown Monthly Energy Production -Case A2, 120 Foot Drawdown Monthly Energy Production -Case C, Variable Drawdown Monthly Energy Production -Case C1, 120 Foot Drawdown Monthly Energy Production -Case C2, 120 Foot Drawdown Monthly Energy Production -Case D, 120 Foot Drawdown Net Benefit Variation with Downstream Flow Requirement Net Benefit Variation with Watana Drawdown (Case A and C) Stream Water Temperature (°F) for Average Year -Case A Operation Stream Water Temperature ( °F) for Wet Year -Case A Operation Stream Water Temperature (°F) for Dry Year-Case A Operation DYRESM Parameters for Eklutna LakP. Wedderburn Number for Eklutna Lake Simulation Downstream Water Temperature (°C) -Watana Operation Downstream Water Temperature (°C) -Watana/Devil Canyon Operation v Table 9. 1 9.2 9.3 9.4 9.5 9.6 11.1 11.2 11.3 11.4 11.5 11.6 11.7 11.8 11.9 11.10 11.11 11.12 11.13 11.14 11.15 LIST OF TABLES {Cont'd) Summary of Cost Estimate Watana Estimate Summary Devil Canyon Estimate Summary Mitigation Me,asures -Summary of Costs Incorporated in Construction Cost Estimates Summary of Operating and Maintenance Costs Watana and Devil Canyon Cumulative and Annual Cash Flow Financing Requirements -$Million-for $3.0 Billion State Appropriation Summary of Major Forecasts of Oil Price Trends Comparison of Acres Estimate and Actual Cost Reduced to Common (1963) Level Multivariate Sensitivity Analysis, Long-Term Costs and Probability, Non-Susitna Tree Multivariate Sensitivity Analysis, Long-Term Costs and Probability, Susitna Tree Comparison of Base Cases Revised OGP-5 Program Percent Reserve-Medium Load Forecast Annual Energy Dispatch Components of Annual Costs -Non-Susitna Plan Components of Annual Costs -Susitna Plan Susitna Project Delayed Watana Project Alone Alternative Generation Plan Single Hydro Project Developments vi - - - - - - - - Figures 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 5.9 6. 1 6.2 6.3 6.4 7.1 7.2 7.3 7.4 7.5 7.6 8.1 8.2 8.3 8.4 8.5 8.6 8.7 LIST OF FIGURES Location Map Alternative Access Corridors Access Plan 13 (North) Access Plan 16 (South) Access Plan 18 (Proposed) Schedule for Access and Diversion Access Plan Proposed Route Access Plan Details Proposed Route Watana Damsite Top of Bedrock and Surficial Geologic Map Watana Damsite Geologic Map Watana Damsite Upstream Cofferdam and Portal Area Geologic Map Watana Damsite Downstream Cofferdam and Portal Area Geologic Map Watana Damsite Area Geologic Map-Sheet 1 of,2 and Sheet 2 of 2 Watana Relict Channel/Borrow Site D -Top of Bedrock Map Watana Relict Channel/Borrow SiteD-Generalized Stratigraphic Column Watana Relict Channel/Borrow SiteD Geologic Sections Watana Fog Lakes Relict Channel -Top of Bedrock Map Proposed Project Features Gold Creek Switchyard Single Line Diagram and Plan Railbelt 345 kV Transmission System Single Line Diagram Central Study Area Alternative Transmission Routes Watana Reservoir Volume and Surface Area Devil Canyon Reservoir Volume and Surface Area Low-Flow Frequency Analysis of Mean Annual Flow at Gold Creek Minimum Operational Target Flows for Alternative Flow Scenarios Variation in Net Benefit with Downstream Flow Requirement Variation in Net Benefit with Watana Drawdown (Case A and Case C) Map Showing River Cross Sections Eklutna Lake Location Map Eklutna Lake Station Locations Eklutna Lake Temperature Profile-June 18 (E1080) Eklutna Lake Temperature Profile-September 9 (E1091) Eklutna Lake Temperature Profile-September 21 (E1091) Eklutna Lake Temperature Profile-September 9 (E4041, E4061) vii Figures 8.8 8.9 8.10 8.11 8.12 8.13 8.14 8.15 8.16 8.17 8.18 8.19 8.20 8.21 8.22 8.23 8.24 8. 25 8.26 8.27 8.28 8.29 8.30 8.31 8.32 8.33 8.34 8.35 8.36 8.37 8.38 8.39 8.40 8.41 8.42 8.43 8.44 8.45 8.46 8.47 8.48 8.49 8.50 LIST OF FIGURES (Cont'd) Eklutna Lake Temperature Profile-September 21 (E4041, E4061) Eklutna Lake Temperature Profile-June 1 (E5050) Eklutna Lake Temperature Profile-June 18 (E5050) Eklutna Lake Temperature Profile-July 14 (E5050) Eklutna Lake Temperature Profile -July 28 (E5050) Eklutna Lake Temperature Profile-August 11 (E5050) Eklutna Lake Temperature Profile-August 25 (E5050) Eklutna Lake Temperature Profile-September 9 (E5051) Eklutna Lake Temperature Profile-September 21 (E5051) Eklutna Lake Temperature Profile-October 14 (E5051) Eklutna Lake Temperature Profile-November 4 (E5052) Eklutna Lake Temperature Profile-December 31 (E5052) Eklutna Lake Outflow Temperature-June to September Eklutna Lake Outflow Temperature-October to December Eklutna Lake Temperature Isopleths -June 18 Eklutna Lake Temperature Isopleths-July 14 Watana Temperature Profile-June 1 Watana Temperature Profile -July 1 Watana Temperature Profile-August 1 Watana Temperature Profile September 1 Watana Temperature Profile-October 1 Watana Temperature Profile -November 1 Watana Temperature Profile -December 1 Watana Temperature Profile-December 31 Watana Outflow Temperature -June to September Watana Outflow Temperature -October to December Devil Canyon Temperature Profile-June 1 Devil Canyon Temperature Profile-July 1 Devil Canyon Temperature Profile-August 1 Devil Canyon Temperature Profile -September 1 Devil Canyon Temperature Profile-October 1 Devil Canyon Temperature Profile -November 1 Devi 1 Canyon Temperature Profile -December 1 Devil Canyon Temperature Profile-December 31 Devil Canyon Outflow Temperature -June to September Devil Canyon Outflow Temperature -October to December Downstream Temperatures -Watana Operation, DYRESM Downstream Temperatures -Watana Operation, DYRESM Downstream Temperatures -Watana Operation, DYRESM Downstream Temperatures -Watana Operation, 4°C Downstream Temperatures -Watana Operation, 4°C Downstream Temperatures -Watana Operation, 4°C to 2°C Downstream Temperatures -Watana Operation, 4°C to 2°C viii - - -i !""'~ ' - - - r r - - Figures 8.51 8.52 8. 53 8.54 8.55 8.56 9.1 9.2 9.3 10.1 10.2 LIST OF FIGURES (Cont•d) Downstream Temperatures -Watana/Dev il Canyon Operation, DYRESM Downstream Temperatures -Watana/Devi 1 Canyon Operation, DYRESM Downstream Temperatures -Watana/Devi 1 Canyon Operation, 4°C Downstream Temperatures -Watana/Devil Canyon Operation, 4°C Downstream Temperatures -Watana/Devil Canyon Operation, 4°C to 2°C Downstream Temperatures -Watana/Devil Canyon Operation, 4°C to 2°C Watana Development Cumulative and Annual Cash Flow January 1982 Dollars Devil Canyon Development Cumulative and Annual Cash Flow January 1982 Dollars Susitna Hydroelectric Project-Cumulative and Annual Cash Flow Entire Project January 1982 Dollars Watana Construction Schedule Devil Canyon Construction Schedule 11.1 Susitna Multivariate and Sensitivity Analysis Cumulative Probability vs Net Benefits 11.2 Percent Reserve vs Time 11.3 Yearly Annual Costs 11.4 Non-Susitna Plan Medium Load Forecast 11.5 Susitna Plan Medium Load Forecast 11.6 Medium Load Forecast -Long Term Costs ix - - 1 -INTRODUCTION 1.1 -General This supplement to the Feasibility Report has been prepared by Acres American Incorporated (Acres) for the Alaska Power Authority (the Power Authority) under the terms of Revision 4 to the Agreement, dated December 19, 1979, to conduct a feasibility study and preparation of a license application to the Federal Energy Regulatory Commission ( FERC). The original feasibility study was undertaken in accordance with the Plan of Study (POS) for the Susitna Hydroelectric Project, which was first issued to the Power Authority in February 1980 and subsequently revised four times since the original issue to account for scope changes and public, federal, and state agency comments and concerns. A draft of the FERC 1 icense application was filed with FERC on November 15, 1982. Similarly, a draft of Exhibit E -Environmental Studies for the FERC license was submitted to the various state and federal agencies for review and comment. Comments regarding this draft were received during the month of December and January with the final submittal of the FERC license application in February 1983. The Feasibility Report was issued for pub 1 i c review and comment on March 15, 1982 (Acres 1982a). Subsequent to that time, ongoing work continued in the areas of: · -Hydrology -Environmental studies -Survey and site facilities -Geotechnical exploration -Design development -Transmission line -Cost estimates and schedules -FERC 1 icensing -Marketing and financing As a result of this ongoing work, changes, additions, and modifications have been made to the original Feasibility Report. This Supplemental Report is intended to provide an update of information through January 1983. A comprehensive environmental study has been submitted as Exhibit E to the FERC license. Since extensive ongoing studies continue to be done in this area, no supplement to Volume 2 - Environmental Studies of the original Feasibility Report has been prepared for this submittal. Readers interested in the environmental studies to include environmental impacts and recommended mitigation measures are requested to consult Exhibit E to the FERC license. This report is intended as a supplement to the March Feasibility Report and should be used in reference to that document. 1-1 1.2 -Objectives -Scope The objective of the work performed from March 15 through December 1982, was to continue ongoing studies and submit the draft FERC license application. The work has been undertaken in a series of tasks which are: Task 72 -Access Plan Task 73 -Hydrologic Studies Task 75 -Geotechn i ca 1 Studies Task 76 -Design Development Task 77 -Environmental Studies Task 78 -Transmission Task 79 -Construction Cost Estimates and Schedule Task 80 Licensing Task 81 -Marketing & Finance Task 82 -Public Participation Program These ongoing studies have resulted in some modifications to the design and development schemes for the Susitna Hydroelectric Project as set forth in the March Feasibility Report. Project parameters and design criteria are shown in Table 1.1. Details of these changes are pre- sented in the preceding section. The principal changes to the Feasi- bility Report are in the areas of access, environment, and transmis- sion. In addition, changes have also been made in the hydrologic flow regime of the dams to minimize downstream environmental impacts. These modifications have resulted in redesign of the intake structures which are presented in Volume 2 of this submittal. 1.3 -Organization of the Supplemental Report The supplement to the Feasibility Report is presented in 11 sections. Section 1 -Introduction Section 1 is a brief summary of the project background and a general introduction to the report. Section 2 -Summary This section provides a summary of the results of Sections 4 through 11. Section 3 -Scope of Work This section outlines the scope of work undertaken in each of the tasks. Section 4 -Access Roads Section 4 is a detailed discussion of the access road al- ternative studies and the final access recommendation. Section 5 -Refinement of Susitna Development This section presents the refinement to the Susitna Devel- opment based on work carried out from March to December 1982. 1-2 11"'11 - - - - - - - - Section 6 -Transmission Facilities Section 6 addresses the recommended transmission routing for the Susitna Development. Section 7 -Project Operation This section presents the revised flow regime for the Susitna Development. Section 8 -Reservoir and River Temperature Studies This section presents refined reservoir and river temperature studies. Section 9 -Estimates of Costs This section presents the revised project cost estimate which incorporates the changes in the design scheme. Section 10-Development Schedules Section 9 presents the revised project schedule to reflect principally the changes in access routing. Section 11-Economic, Marketing and Financial Evaluation This section presents the revised economic and financial evaluation for the Susitna Development. 1-3 - - - , .... REFERENCES Acres American Incorporated. 1982a. Susitna Hydroelectric Project Feasibility Report. Prepared for the Alaska Power Authority. ,_ TABLE 1.1: PROJECT PARAMETERS AND DESIGN CRITERIA Item River Flows Average flow (over 32 yrs of record) Probable maximum flood inflow Maximum flood inflow with return period of 1:10,000 yrs (unrouted) Maximum flood inflow with return period of 1:25yrs Maximum flood inflow with return period of 1:50 yrs (unrouted) Normal maximum operating 1 evel Average TWL Minimum operating level Area of reservoir at maximum operating level Reservoir live storage Watana 7,990 cfs* 326,000 cfs 156,000 cfs 76,000 cfs 87,000 cfs 2,185 ft MSL 1,455 ft MSL 2,065 ft MSL* 38,000 acres 3.74 X 106* acre ft *Modified from March 1982 Feasibility Report. Devil Can on 9,050 cfs* 346,000 cfs (routed through Watana) 362,000 cfs (unrouted) 161,000 cfs (unrouted) 165,000 cfs (after routing through Watana) (increase attributed to the assumed overlap of Watana peak outflow and peak flow from intermediate catchment) 37,800 cfs 85,000 cfs (unrouted) 39,000 cfs (after routing through Watana) 98,000 cfs (unrouted) 1,455 ft MSL * 850 ft MSL 1,405 ft MSL 7,800 acres 0.35 X 106 acre ft **Area control center for both Watana and Devil Canyon plants. *** Based on a minimum reservoir level in peak demand month (December). TABLE 1.1 (Cont•d) Item Reservoir total storage Dam Type Crest e 1 evat ion Crest length Height Cut-off and foundation treatment Upstream slope Downstream slope Crest width Saddle Dam Type Crest Elevation Crest Length Height Cut-off and Foundation Treatment Upstream Slope Downstream Slope Crest Width Watana 9.47 X 106* .acre ft Rockfi 11 2,210 ft MSL at center 2,207 ft MSL at abutments 4,100 ft 885 ft above foundation at core Core founded on rock, grout curtain and down- stream drains 1V;2.4H 1V:2H 35 ft None Devil Can on 1.09 X 106* acre ft Concrete arch 1,463 ft MSL (+3 ft parapet wa11) 1,650 ft (arch dam including thrust blocks) 646 ft above foundation Founded on rock, grout curtain and downstream drains 20ft Earth/Rock fill 1472 ft MSL 950 ft 245 ft Core founded on rock, grout curtain and downstream drains. 1V:2.4H 1V;2H 35 ft - - -. I - - F" I TABLE 1.1 (Cont 1 d) Item Diversion Cofferdam types Cut-off and foundation Upstream cofferdam crest elevation Downstream cofferdam crest elevation Maximum pool level during construction Water passages Outlet structures Diversion capacity Final closure Releases during impounding Emergency Reservoir Drawdown Maximum capacity Watana Rock fill Founded on allu- vium with slurry trench to rock 1,545 ft MSL 1,472 ft MSL 1,536 ft MSL 2 concrete-lined tunnels, 38 ft dia. Low-level struc- ture with high head slide closure gates 80,500 cfs Mass concrete plugs in line with dam grout curtain 6,000 cfs maxirnurr via regulating gates in diversion plug Devil Canyon Rock fi 11 Founded on alluvium with slurry trench to rock 947 ft MSL 898 ft MSL 944 ft MSL 1 concrete-lined tunnel, 30ft dia. Low-level structure with high head slide closure gates 36,000 cfs Mass concrete plugs in line with dam grout curtain 6,000 cfs maximum via low-level fixed cone valves Low level outlet Fixed cone valves tunnel 30,000 cfs 38,500 cfs TABLE 1.1 {Cont'd) Item Watana Devil Can on Outlet Facilities -capacity 24,000 cfs 38,500 cfs -control struc. Fixed cone valve Fixed cone valves -energy dissip. Six 78" dia. 3-90" dia., four 102" Spillway Design Floods Main Spillway fixed cone valves dia. fixed cone valves Passes pmf pre- serving integrit of dam Passes routed 1:10,000-yr floo ( 15 6' 0 00 c f s) with no damage t structures Passes pmf preserving integrity of dam Passes routed 1:10,000-yr flood {165,000 cfs) with no damage to structures capacity 115,000 cfs 125,000 cfs -control struc. Gated ogee crest Gated ogee crests -energy di ss i p. Flip Bucket -crest e 1 ev. -gate sizes Emergency Spillway -Capacity -type -crest e 1 ev. -chute width 2,148 ft MSL 3 -49 ft H X 36 ft w Pmf minus 1:10,000-yr floo 140,000 cfs Fuse plug 2200/2201.5 310/200 Flip Bucket 1,404 ft MSL 3 -56 ft H X 30 ft W Pmf minus routed 1:10,000-yr flood 160,000 cfs Fuse plug 1464/1465.5 200 - - - - - - - - TABLE 1.1 (Cont•d) Item Power Intake Type Number of intakes Draw-off requirements Drawdown Maximum discharge/unit Penstocks Type Number of penstocks Diameter Powerhouse Cavern size Type Transformer area Control room & administration Access -vehicle -personnel Watana Massive concrete structure embedded in rock 6* Multi-level 120 ft* 3, 870 cfs Concrete-1 ined rock tunnels wit downstream steel 1 iner 6 17 ft conc/15 ft steel 455 ft X 74 ft X 126 ft Underground Separate gallery Surface** Rock tunnel Elevator from surface Devil Can on Massive concrete structure embedded in rock 4* Multi-level 50 ft 3,670 cfs Concrete-lined rock tunnels with down- stream steel liner 4 20 ft conc/15 ft steel 360 ft X 74 ft X 126 ft Underground Separate gallery Underground Rock tunnel Elevator from surface TABLE 1.1 (Cont'd) Item Power Plant Number of units Nominal unit output*** Turbines Rated net head Rated full gate output Rated discharge Station output @ rated hea -best gate -full gate Generator Type Rated output (60°C) Overload (80°C) Power factor Voltage Frequency Speed, rpm Transformers Tailrace Water passages Elevation of water passages Surge Watana Devil Can on 6 4 170 MW at 652ft 150 MW at 542 ft net head net head 680 ft 250,000 hp 3,490 ft3/s* 936 MW* 1,098 MW* Vertical synchronous 190 MVA air- cooled 218 MVA 0.9 15 kV + 5% 60 Hz 225 rpm 9 x 145 MVA 15/345 kV, singl phase Two 34 ft di a. concrete-1 ined tunnels Below minimum tail water Single surge chamber 575 ft 225,000 hp 3,680 ft3js* 560 MW 656 MW Vertical synchronous 180 MVA air-cooled 210 MVA 0.9 15 kV + 5% 60 Hz 225 rpm 12 x 70 MVA 15/345 kV, single phase One 38 ft dia. con- crete-lined tunnel Below minimum tail- water Single surge chamber - ~ ! - - - 2 -SUMMARY This section presents a summary discussion of the work performed on the Susitna Hydroelectric Project since the submission of the Feasibility Report (Acres 1982a) in March 1982. 2.1 -Scope of Work The scope and objective of the work are set forth in Amendment No. 4 to the Acres Plan of Study (POS). Principal areas of work were: -Access Plan; -Hydrologic Studies; -Geotechnical; -Design; -Environmental; - T ran sm i s s i on ; -Construction Costs and Schedules; -Licensing; and -Marketing and Finance. The scope of work performed in these areas are presented in Section 3. The comprehensive environmental studies undertaken during this period are presented in Exhibit E of the FERC license application (Acres 1983). These environmental studies supersede those presented in the Feasibility Report (Acres 1982a). Readers, therefore in these studies, are advised to consult the FERC license application. 2.2-Access Plan The access plan presented in the Feasibility Report (1982a) recom- mended, for reasons of project schedule, that the construction of a pioneer road into the site be completed prior to issuance of the FERC 1 icense. Subsequent to the submittal of the report, this concept was found unacceptable by the various resource agencies and the plan was discarded. Consequently, the original evaluation criteria was refined and addi- tional alternatives were developed. The most responsive plan in each of the three corridors was identified and subjected to a multidisci- pline assessment and comparison. After detailed consideration of these al te rnat i ves, the Power Authority Board of Directors formally adopted the Denali -North Plan (Plan 18), as the Proposed Access Plan in September 1982. This route originates at a railhead in Cantwell and follows the exist- ing Denali Highway to a point 21 miles east of the junction of the George Parks and Denali Highways. A new road would be constructed from that point due south to the Watana damsite. Most of the new road would traverse relatively flat terrain, resulting in a minimum of disturbance 2-1 to areas away from the alignment. This was found to be the most easily constructed route for initial access to the Watana site. Access to the Devil Canyon development would consist primarily of a rail road exten- sion from the existing Alaska Railroad at Gold Creek to a railroad facility adjacent to the Devil Canyon camp area. To provide access to the Watana damsite and the existing highway system, a connecting road would be constructed from the Devil Canyon railhead following a nor- therly loop to the Watana damsite. Access to the north side of the Susitna River would be attained via a high-level suspension bridge con- structed approximately one mile downstream from the Devil Canyon dam. In general, the alignment crosses terrain with gentle-to-moderate slopes which would allow road bed construction without deep cuts. 2.3 -Refinement of Susitna Development (a) Geotechnical Design Considerations (i) Oamsite Work performed in the damsite consisted of geologic mapping and seismic refraction. Results of that work confirmed and refined work performed during 1980-1981. No additional information was found that would aversely affect project arrangement or costs. (ii) Watana Relict Channel Additional drilling and seismic refraction surveys were performed in the Watana Relict Channel to better determine site stratigraphy and material properties. Previous work in this area raised several questions regarding the poten- tial of either breaching of the reservoir and subsurface seepage resulting in potential downstream piping and/or 1 oss of energy. Although the work performed in 1982 did not totally elimi- nate these concerns, it did provide additional information in evaluating these potential problems. Based on this work, the likelihood of such catastrophic events to occur appear small considering (a) the materials within the channel are relatively competent; (b) no widespread perma- frost has been found; and (c) low surface gradients. (iii) Fog Lakes Relict Channel Additional seismic refraction and geologic mapping was performed in the Fog Lakes relict channel to determine the channel's configurations and assess the potential for leakage and breaching of the reservoir rim. Although drilling in the area remains to be done to confirm the seismic data, seepage through the Fog Lakes relict channel is not considered to have any significant economic impact. 2-2 lj i - - - - - - - - !''"" (b) (c) Simi 1 arly, breaching of the reservoir rim was considered impossible due to the more than 100 feet of freeboard above Maximum Pool Elevation. Main Dam Alternatives In addition to the alternative dams addressed in the Feasi- bility Report (Acres 1982a), a concrete-faced rock-filled dam was evaluated. Although the concrete faced rock-fi 11 ed dam appears to offer some advantages over the earth-fi 11 ed dam, it was not considered appropriate for the Sus itna Project because of: -Increase of 70 percent in height over precedent; and -Potential impacts on high seismicity and climate condi- tions. Refinement of General Arrangement Based on design considerations since March 1982, changes were made in the following areas: -Watana project power and outlet facilities intakes; -Devil Canyon project power intake; -Devil Canyon project main spillway gates; nevil Canyon project compensation flow discharge pipe; and Devil Canyon main access road. 2.4-Transmission Facilities The principal work with transmission facilities since March 1982 in- cluded a reassessment of the transmission line corridor within the Central Study Area, and a land acquisition analysis in the northern, southern, and central study areas for the purpose of fine-tuning the alignment and to determine the legal descriptions of the rights-of- way. The routing of the transmission line corridor in the Central Study Area was changed so that it showed the same corridor as the access road between the dams and the rail road extension between Devil Canyon and Gold Creek. The final alignment within this section was chosen to parallel the access road and rail road extension to the maximum extent possible so as to minimize the mileage of new access trail development. The selected alignment represents the optimum alignment of the trans- mission line based on existing data. Land acquisition and environmental studies performed ·j n the transmis- sion corridor resulted in the a 1 i gnment being refined to the extent that most of the problem associated with these two areas would be avoided. 2-3 2.5 -Project Operation Additional studies undertaken since March 1982 included refinements to operating rule curves, downstream flow, and energy demand. Based on these studies, it was determined that the Watana reservoir will be operated at a normal operating level of El 2183 with an annual drawdown to El 2093 with Watana operation and EL 2080 with Watana/Devil Canyon operation. The Devil Canyon reservoir will be operated at a normal operating level of El 1455 with an average annual drawdown of 28 feet. The 1: 30-year according to increased the from 5600 cfs at Gold Creek annual water volume was proportioned on a monthly basis the long-term average monthly distribution. This WY 1969 average annual discharge at Gold Creek 1600 cfs to 7200 cfs, and increased the average annual discharge for the 32 years of record by 0. 5 percent. Project operational flows have been scheduled to satisfy the water requirements in the slough spawning areas during the critical period when the salmon must gain access to the spawning areas in August and early September. 2.6 -Reservoir and River Temperature Studies The dynamic reservoir simulation model DYRESM was used to predict reservoir temperature stratification and outflow temperature for Watana and Devil Canyon reservoirs. The temperature structure for Watana was found to follow the typical pattern for reservoirs and lakes of similar size and climate conditions. In general, stratification occurs during June, July, and August, with maximum surface temperature of 10.9°C occurring in July and August. The model, which includes natural inflow temperature and simulated outflow temperature, shows that, during summer months, the outflow temperature fallows natura 1 temperature trends but is cooler during July and slightly warmer in August. A model of the Devil Canyon reservoir shows that reservoir stratifica- tion is weak in June but builds during July and August. Cooling at Devil Canyon is delayed to late September and early October due partly to the warmer inflows to the Devil Canyon reservoir from Watana. Maximum outflow temperature from Devil Canyon occurs in late July to mid-August and is about 8°C. Temperature from mid-September to December 31 falls from a high of 8°C to a low of 3.5°C. 2.7-Estimates of Cost Changes to the Watana cost estimate made subsequent to the submission of the Feasibility Report {Acres 1982a) included: -Access Plan 18 replacing Plan 5; -Work leading up to diversion was recasted for an accelerated schedule; -Storage facilities were provided at Cantwell; -Material prices were revised to reflect larger transportation route; -Quantities were revised for the intake and spillway; 2-4 - - - - -i - -Al 1 work (other than noted) was estimated on basis of 10-hour shifts; -Construction power was re-estimated based on direct generation at site; and -Contingencies were evaluated for each account. Changes to Devil Canyon cost estimate included: -Access Plan 18 revision; -Intake quantities revised; -10-hour work shifts; and -Cash flow curves revised. In addition, a number of features designed to mitigate potential impacts on the natural environment and on residents and communities in the vicinity of the project were addressed. These mitigation costs have been estimated at $153 million. Costs for full reservoir clearing at both sites have been estimated at $65 million. 2.8 -Development Schedule The project schedules as shown in Section 17 of the Feasibility Report (Acres 1982a), have been updated as a result of on-going studies and span the period from 1983 until 2004. Principal revisions to the Watana schedule include the following: -Replacement of the pioneer road with the Denali Access Plan 18. Work prior to receipt of the FERC license was eliminated. -Activities leading up to diversion were revised for an accelerated schedule; and -The pre-construction of one circuit of the permanent transmission line from Gold Creek was eliminated. Revision to the Devil Canyon schedule included the following: -Incorporation of the Denali Access Plan 18 and the start of access construction was advanced accordingly. 2.9 -Economic, Marketing, and Financial Evaluation Several changes and modifications to the economic, marketing, and financial evaluations have been made subsequent to the Feasibility Report (1982a) based on on-going studies and FERC license requirements. These changes and additions are presented below. (a) Financing The Feasibility Report presented several plans for financing the Susitna project. Since that time, one plan has emerged as the 2-5 most likely. This involves a combination of direct state-of Alaska appropriations and revenue bonds issued by the Power Authority. Watana is expected to be financed by issuance of approximately $0.9 billion (1982 dollars) of revenue bonds. The completion of the Susitna project by the building of Devil Canyon is expected to be financed on the same basis with the issuance of approximately $2.2 billion of revenue bonds over the years 1994 to 2202. (b) Cost Estimate Changes Cost estimates have been changed to reflect adjustments to the project since the Feasibility Report. These changes, however, were relatively minor and made no change in the financial analysis. (c) Comments on the Tussing Report Following submittal of the Feasibility Report, a report entitled "A l a s k a En e r gy P l a n n i n g St u d i e s -S u b s t a n t i at i v e Is sue s a n d t he Effects of Recent Events," a review by A.R. Tussing and G.K. Ericson, was prepared for the Division of Policy Development and Planning, Office of the Governor of the State of Alaska. A detailed response to that report has been provided in Section 10. (d) Generating Planning Studies The generating planning studies which formed the basis of the project economic analysis has been updated since the Feasibility Report, based on comments and review of the March report. 2-6 , - - - - REFERENCES Acres American Incorporated. 1982a. Susitna Hydroelectric Project Feasibility Report. Prepared for the Alaska Power Authority. 1983. Susitna Hydroelectric Project FERC License Application. Prepared for the Alaska Power Authority - - - 3 -OBJECTIVES 3.1-Introduction The scope of work undertaken from the March 15, 1982, submittal of the Susitna Hydroelectric Feasibility Report to present is set forth in Amendment No. 4, dated September 27, 1982. The principal technical tasks undertaken during this period included: -Access Plan; -Hydrologic Studies; -Geotechnical Explorations; -Design Development; -Environmental Studies; -Transmission; -Construction Cost Estimates & Schedules; -Licensing; and -Marketing and Finance. 3.2 -Access Plan The March 1982 Feasibility Report recommended an access plan which, for reasons of project schedule, would necessitate the construction of a pioneer road prior to the FERC 1 icense being issued. Subsequent to the issuance of the Feasibility Report, this concept was found unacceptable by the various reviewing agencies. Consequently, this study involved the development of a new access cri- teria and the development of additional access alternatives within the three potential corridors detailed in 1981 studies. The objective was to delineate the most responsive plan in each corrider and to subject these plans to a multidisciplinary assessment and comparison to ulti- mately arrive at the most acceptab 1 e route. Results of this study are presented in Section 4. 3.3 -Hydrology Studies Work performed under this subtask involved: -The continued collection of baseline climatic, water quality, sedi- ment, discharge, ice, thermal, ground water, stage, and snow creep data; -Preparation of reports on ground water analyses, sedimentation, and post-project esturine effects; -Further refine energy and minimum flow requirements for downstream fisheries; -Prepare ground water report with ground water contours of the study sloughs, ground water sources, and ground water inflow rates; and -Continue reservoir and instream flow studies to enable the project impacts to be assessed and a mitigation plan to be adopted~ 3-l 3.4 -Geotechnical Exploration The following tasks were performed: Additional soil drilling and testing in the Watana relict channel; -Prepare an amendment to the 1980-81 Geotechnical Report; -Develop a scope of a 1982 winter program; and -Prepare necessary contracts to perform the work. 3.5-Design Development Update The scope of this subtask involved the continued updating of various design aspects of the project with particular attention directed to those design changes necessary to meet changing environmental criteria and improve application. Particular areas to be addressed were: -Intake structures; -Construction haul roads; -Transmission line routing; and -Access roads. 3.6 -Environmental Studies (a) Introduction The principal objective of the environmental studies was to con- tinue coordination among environmental study subtasks and subcon- tractors, establish and maintain reporting schedules, continue informal agency contact, and prepare Exhibit E for the FERC license application. (n) Cultural Resource Investigations Work under this program involved: Conducting a reconnaissance Level 1 survey along the proposed transmission corridor from Fairbanks to Healy, Willow to Anchorage, and Watana damsite to the Intertie; -Conducting a Reconnaissance Level 1 survey at the "new" segment of the proposed access route on the north side of the Susitna River, from Devil Canyon to the Parks Highway; -Conducting archaeological evaluations of areas to be impacted by geotechnical testing; 3-2 - i - - - - -. . , - - - - Conducting reconnaissance Level 2 survey on the Tsusena Creek "cat trail" from the Watana Camp area to the mouth of the Tsusena Creek; and -Preparing the cultural resource components of the FERC license. (c) Land Ownership and Acquisition To further define land ownership and acquisition in connection with access road and transmission 1 ine corridor and assist in preparation of Exhibit G for the FERC license application. {d) Land Use Analysis -Mitigation of Aesthetic Impact To further assess aesthetic impacts and develop a draft plan for mitigation of impacts of the Project on the aesthetic resources of the upper Susitna River Basin. (e) Recreation Planning To develop specific proposed sites for recreation facilities to include cost and schedules for development of the facilities. (f) Aquatic Impact Assessment To analyze and interpret available baseline knowledge of the Susitna River aquatic system and examine and present in models and reports the impacts on fishery resources of hyd roel ectri c develorxnent in the upper Susitna Basin. Work undertaken during this period included: -Coordination with the Alaska Department of Fish and Game and the Susitna Hydro Study Group on the fishery and aquatic habitat studies and other groups and agencies involved in assessing impacts on fishery. -Assemble an information management program to collect and compile available knowledge of the Susitna River aquatic system relating specifically to the examination of project impact on fishery resources. -Construction of a dynamic model of the Susitna River Basin which will be used to develop quantitative relationships between aquatic habitats and resources pursuant to various hydro operational scenarios. -Establish a format, schedule, and content of periodic briefings on aquatic study, analysis, and impact assessment efforts to the Alaskan resource agencies. 3-3 (g) Fisheries Mitigation Planning To develop a mitigation plan consisting of quantified mitigation options for each phase of the project as well as to identify defi ci enci es and prioritize studies needed to fulfill the quan- tification requirements of the mitigation plan. (h) Fisheries Mitigation Planning The primary objective of the fisheries mitigation planning effort was to develop a mitigation plan consisting of quantified mitiga- tion options for each phase of the project with the ultimate goal of providing the mitigation documents required by the FERC for license approval. (i) Susitna Hatchery Siting Study To determine if it is appropriate that consideration be given to the feasibility of siting an enhancement hatchery to insure main- tenance of the existing stocks at or above their present popul a- tion levels. (j) Wildlife and Habitat Impact Assessment and Mitigation Planning To continue with ongoing data collection and workshop and field studies; prepare supporting reference documents; assess various project impacts; and develop final comprehensive mitigation plans for inclusion in FERC license application. (I<) Transmission Line Survey To locate the centerline of the transmission lines to include width and location of right-of-way: -Define all points of intersection (P.I.) along the centerline by measuring the station for each P.I. and its bearings; -Provide information regarding the transmission equipment and appurtenance; and -Prepare drawings and documentations as required to meet the FERC requirements for license application. 3.7-Cost Estimate Update To update project cost estimate in connection with the elimination of the pioneer road and the selected access route and to update other planning and design changes for inclusion in the FERC license applica- tion. 3.8 -Update Engineering/Construction Schedule To update construction schedules in connection with the elimination of the pioneer road and the selected access route and other planning and design changes for inclusion in FERC license application. 3-4 IJIIlll I - - - - .... - - - 3.9-Preparation of FERC License Application To prepare and coordinate all engineering and support activities necessary for the preparation of the FERC license application. 3.10-Marketing and Finance Marketing and finance work was directed to: -Further review A. Tussing's draft report 11 Alaska Energy Planning Studies~~; hold meeting to resolve outstanding differences between Tussing's and Acres reports on Susitna project risk analysis; and prepare appropriate responses; and -Resolve issues concerning sources and extent of financing and annual revenues as the basis for preparing applicable portions of Exhibit D. 3-5 - - - 4 -ACCESS PLAN 4.1 -Introduction This section describes the development of alternative access plans from the original Acres POS of February 1980 through to the final selection of the proposed access plan as approved by the Power Authority Board of Directors in September 1982. The main body of this section is con- cerned with the access planning studies which have taken place subse- quent to the issuance of the Susitna Hydroelectric Project Feasibility Report in March 1982 (Acres 1982a). In the latter part of this sec- tion, the modifications and improvements that have been made since the selection of the proposed plan in September 1982 are discussed. In addition, the general guidelines that have been developed for roadway construction and mining of borrow sites are described. 4.2 -Background The original POS proposed that a single access route would be selected by May 1981, to be followed by a detailed environmental investigation. Early in the study, three main access corridors were identified. Plans developed within these three corridors were evaluated on the basis of available information, comments and concerns of various state agencies, and recommendations from the Susitna Hydroelectric Steering Committee {SHSC). After an initial evaluation, the decision was made to assess all three alternative corridors in more detail throughout 1981 and re- commend a selected route later in the year. This assessment included environmental studies, engineering studies, aerial photography, and geologic mapping of all three alternative routes. In March of 1982, the Power Authority presented the results of the Susitna Hydroelectric Feas·fbility Report to the public, resource agen- cies, and organizations. This report recommended an access plan which, for reasons of project schedule, would have necessitated the construc- tion of a pioneer road prior to the FERC license being issued. The construction of a pioneer road, however, was considered unacceptable by the resource agencies and the plan was discarded. Consequently, the evaluation criteria were refined and additional ac- cess alternatives were developed. The most responsive plan in each of the three corridors was identified and subjected to a multidisciplinary assessment and comparison. After consideration of these alternatives, the Power Authority Board of Directors formally adopted the Denali- North Plan, Plan 18, as the Proposed Access Plan in September 1982 {Figure 4.5). 4.3 -Objectives Throughout the development, evaluation, and selection of the access plans, the foremost objective was to provide a transportation system that would support construction activities and allow for the orderly development and maintenance of site facilities. 4-1 Meeting this fundamental objective involved the consideration not only of economics and technical ease of development but also many other di- verse factors. Of prime importance was the potential for impacts to the environment, namely, impacts to the 1 ocal fish and game popul a- t ions. In addition, since the Native villages and the Cook Inlet Region will eventually acquire surface and subsurface rights, their interests were recognized and taken into account as were those of the 1 ocal cornrnuniti es and general public. With so many different factors influencing the choice of an access plan, it was evident that no one plan would satisfy all interests. The aim during the selection process was to consider all factors in their proper perspective and produce a plan that represented the most favor- able solution to both meeting project-related goals and minimizing impacts to the environment and surrounding communities. 4.4-Existing Access Facilities The proposed Devil Canyon and Watana damsites are located approximately 115 miles northeast of Anchorage and 140 miles south of Fairbanks (Figure 4.1). The Alaska Railroad, which links Anchorage and Fairbanks, passes within 12 miles of the Devil Canyon damsite at Gold Creek. The George Parks Highway (Route 3) parallels the Alaska Rail- road for much of its route, although between the communities of Sun- shine and Hurricane the highway is routed to the west of the railroad, to the extent that Gold Creek is situated approximately 16 miles south of the intersection of the railroad and highway. At Cantwell, 51 miles north of Gold Creek, the Denali Highway (Route 8) 1 eads easterly approximately 116 miles to Paxson where it intersects the Richardson Highway. To the south, the Glenn Highway (Route 1) provides the main access to Glenallen and intersects the Richardson Highway which leads south to Valdez. A location map with the proposed access route is shown in Figure 4.1. 4.5 -Corridor Identification and Selection The Acres POS, February 1980, identified three general corridors lead- ing from the existing transportation network to the damsites. This network consists of the George Parks Highway and the Alaska Railroad to the west of the dam sites and the Denali Highway to the north. The three general corridors are identified in Figure 4.2. Corridor 1 From the Parks Highway to the Watana damsite via the north side of the Susitna River. Corridor 2 From the Parks Highway to the Watana damsite via the south side of the Susitna River. Corridor 3-From the Denali Highway to the Watana damsite. The access road studies identified a total of eighteen alternative plans within the three corridors. The alternatives were developed by laying out routes on topographical maps in accordance with accepted road and rail design criteria. Subsequent field investigations resul- ted in minor modifications to reduce environmental impacts and improve alignment. 4-2 - - - - - - """ I - - - The preliminary design criteria adopted for access road and rail alternatives were selected on the basis of similar facilities provided for other remote projects of this nature. Basic roadway parameters were as follows: -Maximum grade of 6 percent; -Maximum curvature of 5 degrees; -Design loading of sok axle and 2ook total during construction; and -Design loading of HS-20 after construction. Railroad design parameters utilized were as follows: -Maximum grade of 2.5 percent; -Maximum curvature of 10 degrees; and -Loading of E-72. Once the basic corridors were defined, alternative routes which met these design parameters were estab 1 i shed and evaluated against technical, economic, and environmental criteria. Next, within each corridor, the most favorable alternative route in terms of length, alignment, and grade was identified. These routes were then combined together and/or with existing roads or rail roads to form the various access plans. The development of alternative routes is discussed in more detail in the R & M Access Planning Study (R&M 1982). 4.6 -Development of Plans At the beginning of the study, a plan formulation and initial selection process was de vel oped. The criteria that most si gni fi cantly affected the selection process were identified as: -Minimizing impacts to the environment; Minimizing total project costs; Providing transportation flexibility to m1n1m1ze construction risks; -Providing ease of operation and maintenance; and -Preconstruction of a pioneer road. This led to the development of eight alternative access plans. During evaluation of these access plans, input from the public, re- source agencies, and Native organizations was sought and their response resulted in an expansion of the original list of eight alternative plans to eleven. Plans 9 and 10 were added as a suggestion by the SHSC as a means of limiting access by having rail-only access as far as the Devi 1 Canyon damsite to reduce adverse environmental impacts in and around the project area. Plan 11 was added as a way of providing access from only one main terminus, Cantwell, and thus alleviate socio- economic impacts to the other communities in the Railbelt (principally Gold Creek, Trapper Creek, Talkeetna, and Hurricane). 4-3 Studies of these eleven access plans culminated in the production of the Acres Access Route Se 1 ecti on Report (Acres 1982b) which recommended Plan 5 as the route which most closely satisfied the selection cri- teria. Plan 5 starts from the George Parks Highway near Hurricane and traverses along the Indian River to Gold Creek. From Gold Creek, the road continues east on the south side of the Susitna River to the Devil Canyon damsite, crosses a low level bridge, and continues east on the north side of the Susitna River to the Watana damsite. For the project to remain on schedule, it would have been necessary to construct a pioneeer road along this route prior to the FERC license being issued. In March of 1982, the Power Authority presented the results of the Susitna Hydroelectric Feasibility Report, of which Access Plan 5 was a part, to the public, agencies, and organizations. During April, com- ment was obtained relative to the feasibility study from these groups. As a result of these comments, the pioneer road concept was eliminated, the evaluation criteria were refined, and six additional access alter- natives were developed. During the evaluation process, the Power Authority staff formulated a further p 1 an, thus increasing the tota 1 number ot p 1 ans under eva 1 ua- tion to eighteen. This subsequently became the plan recommended by Power Authority staff to the Power Authority Board of Directors, and was formally adopted as the Proposed Access Plan in September 1982 (Acres 1982c). A description of each of the eighteen alternative access plans, toget- her with a breakdown of costs, is given in Table 4.1. 4.7 -Evaluation of Plans The refined criteria used to evaluate the eighteen alternative access plans were: -No pre-license construction; -Provide initial access within one year; -Provide access between sites during project operation phase; -Provide access flexibility to ensure project is brought on-line with- in budget and schedule; -Minimize total cost of access; -Minimize initial investment required to provide access to the Watana dams ite; -Minimize risks to project schedule; -Minimize environmental impacts; 4-4 ~' - - - - - - - - '~ - -Accommodate current land uses and plans; -Accommodate agency preferences; -Accommodate preferences of Native organizations; -Accommodate preferences of local communities; and -Accommodate public concerns. All eighteen plans were evaluated using these refined criteria to de- termine the most responsive access plan in each of the three basic corridors. An explanation of the criteria and the plans which were subsequently eliminated is given below. To meet the overall project schedule requirements for the Watana devel- opment, it is necessary to secure initial access to the Watana damsite within one year of the FERC 1 icense being issued. The constraint of no pre-license construction resulted in the elimination of any plan in which initial access could not be completed within one year. This con- straint led to the elimination of the access plan submitted in the Susitna Hydroelectric Project Feasibility Report {Plan 5) and five other plans {2, 8, 9, 10, and 12). Upon completion of both the Watana and Devil Canyon dams, it is planned to operate and maintain both sites from one central location {Watana). To facilitate these operation and maintenance activities, access plans with a road connection between the sites were considered superior to those plans without a road connection. Plans 3 and 4 do not have access between the sites and were discarded. The ability to make full use of both rail and road systems from south- central ports of entry to the railhead facility provides the project management with far greater flexibility to meet contingencies and control costs and schedule. Limited access plans utilizing an all rail or rail link system with no road connection to an existing highway have less flexibility and would impose a restraint on project operation that could result in delays and significant increases in cost. Four plans with limited access {Plans 8, 9, 10, and 15) were eliminated because of this constraint. Residents of the Indian River and Gold Creek communities are generally not in favor of a road access near their communities. Plan 1 was dis- carded because Plans 13 and 14 achieve the same objectives without im- pacting the Indian River and Gold Creek areas. Plan 7 was eliminated because it includes a circuit route connecting to both the George Parks and Denali Highways. This circuit route was considered unacceptable by the resource agencies, since it aggravated the control of public access. 4-5 The seven rema1n1ng plans found to meet the selection criterion were Plans 6, 11, 13, 14, 16, 17, and 18. Of these, Plans 13, 16, and 18 in the North, South, and Denali corridors, respectively, were selected as being the most responsive plan in each corridor. The three plans are described below and the route locations shown in Figures 4.3 through 4. 5. 4.8 -Description of Most Responsive Access Plans Plan 13 "North" (See Figure 4. 3) This plan utilizes a roadway from a railhead facility adjacent to the George Parks Highway at Hurricane to the Watana damsite following the north side of the Susitna River. A spur road seven miles in length waul d be constructed at a 1 ater date to service the Devil Canyon development. Traveling southeast from Hurricane, the route passes through Chulitna Pass, avoids the Indian River and Gold Creek areas, then parallels Portage Creek at a high elevation on the north side. After crossing Portage Creek, the road continues at a high elevation to the Watana damsite. Access to the south side of the Susitna River at the Devil Canyon damsite would be attained via a high-level suspension bridge approximately one mile downstream from the Devil Canyon dam. This route crosses mountainous terrain at high elevations and includes extensive sidehill cutting in the region of Portage Creek. Construction of the road, however, would not be as difficult as Plan 16, the South route. Plan 16 "South" (See Figure 4.4) This route generally parallels the Susitna River, traversing west to east from a ra i1 head at Go 1 d Creek to the De vi 1 Canyon dams ite, and continues following a southerly loop to the Watana damsite. To achieve initial access within one year, a temporary, low-level crossing to the north side of the Susitna River is required approximately twelve miles downstream from the Watana damsite. This would be used until comple- tion of a permanent, high-level bridge. In addition, a connecting road from the George Parks Highway to Devil Canyon, with a major high-level bridge across the Susitna River, is necessary to provide full road access to either site. The topography from Devil Canyon to Watana is mountainous, and the route involves the most difficult construction of the three plans, requiring a number of sidehill cuts and the construc- tion of two major bridges. To provide initial access to the Watana damsite, this route presents the most difficult construction problems of the three routes, and has the highest potential for schedule delays and related cost increases. Plan 18 "Denali-North" (See Figure 4.5) This route originates at a railhead in Cantwell, and then follows the existing Denali Highway to a point 21 miles east of the junction of the George Parks and Denali highways. A new road would be constructed from 4-6 - ...... - - - -! this point due south to the Watana damsite. Most of the new road would traverse relatively flat terrain which would allow construction using side-borrow techniques, resulting in a minimum of disturbance to areas away from the alignment. This is the most easily constructed route for initial access to the Watana site. Access to the Devil Canyon develop- ment would consist primarily of a railroad extension from the existing Alaska Railroad at Gold Creek to a railhead facility adjacent to the Devil Canyon camp area. To provide access to the Watana damsite and the existing highway system, a connecting road would be constructed from the Devil Canyon railhead following a northerly loop to the Watana dams it e. Access to the north side of the Sus i tna River waul d be attained via a high-level suspension bridge constructed approximately one mile downstream from the Devil Canyon dam. In general, the align- ment crosses terrain with gentl e-ta-moderate slopes which waul d all ow roadbed construction without deep cuts. 4.9-Comparison of the Selected Alternative Plans To determine which of the three access plans best accommodated both project-related goals and the concerns of the resource agencies, Native organizations, and affected communities, the plans were subjected to a multidisciplinary evaluation and comparison. Among the issues addres- sed in this evaluation and comparison were: -Costs; -Schedule; Environmental issues; Cultural resources; Socioeconomics/Community preferences; Preferences of Native organizations; Relationship to current land stewardships, uses and plans; and Recreation. (a) Costs The relative cost of the three access alternatives is presented in Table 4.2. This table outlines the total costs of the three plans with the schedule constraint that initial access must be completed within one year of receipt of the FERC license. Costs to complete the access requirement for the Watana development only are also shown. The costs of the three alternative plans can be summarized as follows: Estimated Total Cost ($ x 1 o6) Dev i 1 Discounted Plan Watana Canyon Total Total North ( 13) 241 127 368 287 South (16) 312 104 416 335 Denali -North ( 18) 224 213 437 326 4-7 The costs are in terms of 1982 dollars and include all costs asso- ciated with design, construction, maintenance, and logistics. Discounted total costs (present worth as of 1982) have been shown here for comparison purposes to delineate the differences in timing of expenditure. For the development of access to the Watana site, the Denali-North Plan has the least cost and the lowest probability of increased costs resulting from unforeseen conditions. The North Plan is ranked second. The North Plan has the 1 owest overall cost while the Denali-North has the highest. However, a large portion of the cost of the Denali-North Plan would be incurred more than a decade in the future. When converting costs to equivalent present value, the overall costs of the Denali-North and the South plans are similar. (b) Schedule The schedule for providing initial access to the Watana site was given prime consideration, since the cost ramifications of a schedule delay are highly significant. The elimination of pre- license construction of a pioneer access road has resulted in the severe compression of onsite construction activities in the 1985-86 period. With the present overall project scheduling, should diversion not be completed prior to spring runoff in 1987, dam foundation preparation work would be delayed one year and, hence, cause a delay to the overall project of one year. It has been estimated that the resultant increase in cost would likely be in the range of 100-200 mill ion dollars. The access route that assures the quickest completion and, hence, the earliest delivery of equipment and materials to the site has a distinct advantage. The forecasted construction periods for initial access, including mobilization, for the three plans are: Denali-North North South 6 months 9 months 12 months It is evident that, with the Denali-North Plan, site activities can be supported at an earlier date than by either of the other routes. Consequently, the Denali-North Plan offers the highest probability of meeting schedule and the least risk of project delay and increase in cost. The schedule for access in relation to diversion is shown for the three plans in Figure 4.6. (c) Environmental Issues En vi ron mental issues have played a major role in access planning to date. The main issue is that a road wi 11 penni t human entry into an area which is relatively inaccessible at present, causing both direct and indirect impacts. A summary of these key impacts with regard to wildlife, wildlife habitat, and fisheries for each of the three alternative access plans is outlined below. 4-8 - - - - - - - - - (i) Wildlife and Habitat The three selected alternative access routes are made up of five distinct wildlife and habitat segments: 1. Hurricane to Devil Canyon: This segment is composed almost entirely of productive mixed forest, riparian, and wetlands habitats important to moose, furbearers, and birds. It includes three areas where slopes of over 30 percent will require side-hill cuts, all above wetland zones vulnerable to erosion-related impacts. 2. Gold Creek to Devil Canyon: This segment is composed of m1xed forest and wetland habitats, but includes less wetland habitat and fewer wetland habitat types than the Hurricane to Devil Canyon segment. Although this segment contains habitat suitable for moose, black bears, furbearers, and birds, it has the 1 east poten- tial for adverse impacts to wildlife of the five seg- ments considered. 3. Devil Canyon to Watana The following comments app y to ot t e Dena 1-North and North routes. This segment traverses a varied mixture of forest, shrub, and tundra habitat types, generally of medium-to-low productivity as wildlife habitat. It crosses the Devil and Tsusena Creek drainages and passes by Swimming Bear Lake which contains habitat suitable for furbearers. 4. Devil Canyon to Watana (South This segment is high y varied with respect to abitat types, containing complex mixtures of forest, shrub, tundra, wetlands, and riparian vegetation. The western portion is mostly tundra and shrub, with forest and wetlands occurring along the eastern portion in the vicinity of Prairie Creek, Stephan Lake, and Tsusena and Deadman Creeks. Prairie Creek supports a high concentration of brown bears, and the 1 ower Tsusena and Deadman Creek areas support lightly hunted concentrations of moose and black bears. The Stephan Lake area supports high densities of moose and bears. Access development in this segment would probably result in habitat loss or alteration, increased hunting, and human-bear conflicts. 5. Denali Highway to Watana: This segment is primarily composed of shrub and tundra vegetation types, with little productive forest habitat present. Although habitat diversity is relatively low along this segment, the southern portion along Deadman Creek contains an important brown bear concentration and browse for moose. This segment crosses a peripheral portion of 4-9 the range of the Ne 1 china caribou herd; and there is evidence that as herd size increases, caribou are like- ly to migrate across the route and calve in the vicini- ty. Although it is not possible to predict with any certainty how the physical presence of the road itself or traffic will affect caribou movements, population size, or productivity, it is likely that a variety of site-specific mitigation measures will be necessary to protect the herd. These segments combine, as illustrated below, to form the three alternative access plans: North South Denali-North Segments 1 and 3 Segments 1, 2, and 4 Segments 2, 3, and 5 Table 4.3 summarizes the three alternative access plans with respect to potential adverse impacts on wildlife and their supporting habitat. The North route has the least potential for creating ad- verse impacts to wildlife and habitat, for it traverses or approaches the fewest areas of productive habitat and zones of species concentration or movement. The wildlife impacts of the South Plan can be expected to be greater than those of the North Plan because of the proximity of the route to Prairie Creek, Stephan Lake, and the Fog Lakes, which currently support high densities of moose and black and brown bears. In particular, Prairie Creek supports what may be the highest concentration of brown bears in the Susitna Basin. The Denali-North Plan crosses the periphery of the Nelchina caribou range and movement zone between the D~nali Highway and Susitna River. In addition, this route has the potential for disturbances to brown and black bear concentrations and movement zones in the Deadman and Tsusena Creek areas. Overall, however, the potential for adverse impacts with the Denali-North Plan is similar to the South Plan. (ii) Fisheries All three alternative routes would have direct and indirect impacts on fisheries. Direct impacts include the effects on water quality and aquatic habitat, whereas increased angling pressure is an indirect impact. A qualitative com- parison of the fishery impacts related to the alternative plans was undertaken. The parameters used to assess impacts along each route included the number of streams crossed, the number and length of lateral transits (i.e., where the roadway parallels the streams and runoff from the roadway can run directly into the stream), the number of watersheds affected, and the presence of resident and anadromous fish. 4-10 - - -' ' - - - The three access plan alternatives incorporate combinations of seven distinct fishery segments. 1. Hurricane to Devil Canyon: Seven stream crossings will be required along this route, including Indian River, which is an important salmon spawning river. Both the Chulitna River watershed and the Sus i tna River water- shed are affected by this route. The increased access to Indian River will be an important indirect impact to the segment. Approximately 1.8 miles of cuts into banks greater than 30 degrees occur a 1 ong this route requiring erosion control measures to preserve the water quality and aquatic habitat. 2. Gold Creek to Devil Canyon: This segment crosses six streams and is expected to have minimal direct and indirect impacts. Anadromous fish spawning is likely in some streams, but impacts are expected to be minimal. Approximately 2.5 miles of cuts into banks greater than 30 degress occur in this section. In the Denali-North Plan, this segment would be railroad, whereas in the South Plan it would be road. 3. Devil Canyon to Watana {North Side, North Plan): This segment crosses 20 streams and 1 aterally transits 4 rivers for a total distance of approximately 12 miles. Seven miles of this lateral transit parallels Portage Creek, which is an important salmon spawning area. 4. Devil Canyon to Watana (North Side, Denali-North Plan): The difference between this segment and Segment 3 described above is that it avoids Portage Creek by traversing through a pass 4 miles to the east. The number of streams crossed is consequently reduced to 12, and the number of lateral transits is reduced to 2 with a total distance of 4 miles. 5. Devil Canyon to Watana (South Side): The portion between the Susitna River crossing and Devil Canyon requires nine steam crossings, but it is unlikely that these contain s igni fi cant fish populations. The por- tion of this segment from Watana to the Susitna River is not expected to have any major direct impacts; how- ever, increased angling pressure in the vicinity of Stephan Lake may result because of the proximity of the access road. The segment crosses both the Susitna and the Talkeetna watersheds. Seven miles of cut into banks of greater than 30 degrees occur in this seg- ment. 4-11 6. Denali Highway to Watana: The segment from the Denali Highway to the Watana damsite has 22 stream crossings and passes from the Nenana into the Susitna watershed. Much of the route crosses, or is in proximity to seasonal grayling habitat and runs parallel to Deadman Creek for nearly 10 miles. If recruitment and growth rates are low along this segment, it is unlikely that resident populations could sustain heavy fishing pressure. Hence, this segment has a high potential for impacting the local grayling population. 7. Denali Highway: The Denali Highway from Cantwell to the Watana access turnoff wi 11 require upgrading. The upgrading will involve only minor realignment and neg- lig·ible alteration to present stream crossings. The segment crosses 11 streams and laterally transits 2 rivers for a tota 1 distance of 5 mi 1 es. There is no anadromous fish spawning in this segment, and 1 ittl e direct or indirect impact is expected. The three alternative access routes comprised the following segments: North South Denali-North Segments 1 and 3 Segments 1, 2, and 5 Segments 2, 4, 6 and 7 The Denali-North Plan is likely to have a significant direct and indirect impact on grayling fisheries, given the number of stream crossings, 1 ateral transits, and water- sheds affected. Anadromous fisheries impact will be minimal and will only be significant along the railroad spur between Gold Creek and Devil Canyon. The South Plan is likely to create significant direct and indirect impacts at Indian River, which is an important salmon spawning river. Anadromous fisheries impacts will occur in the Gold Creek to Devil Canyon segment the same as for the Denali-North Plan. In addition, indirect impacts may occur in the Stephan Lake area. The North Plan, like the South Plan, may impact salmon spawning activity in Indian River. Significant impacts are likely along Portage Creek because of water quality impacts through increased erosion and because of indirect impacts such as increased angling pressure. With any of the selected plans, direct and indirect effects can be minimized through proper engineering design and pru- dent management. Criteria for the development of borrow sites and the design of bridges and culverts together with mitigation recommendations are discussed in Exhibit E of the FERC License Application. 4-12 - - - - - - (d) Cultural Resources A Level 1 cultural resources survey was conducted over a 1 arge portion of the three access plans. The segment of the Dena 1 i- North Plan between the Watana damsite and the Denali Highway traverses an area of high· potential for cultural resource sites. Treeless areas along this segment 1 ack appreciable soi 1 desposi- tions making cultural resources visible and more vulnerable to secondary impacts. Common to both the Denali-North and the North Plan is the segment on the north side of the Sus itna River from the Watana damsite to where the road parallels Devil Creek. This segment is also largely treelesss making it highly vulnerable to secondary impacts. The South Plan traverses less terrain of a rchaeol ogi cal importance than either of the other two routes. Several sites exist along the southerly Devil Canyon to Watana segment; howevers since much of the route is foresteds these sites are h~ss vulnerable to secondary impacts. The ranking from the least to the highest with regard to cultural resource impacts is Souths Norths Denali-North. Howevers impacts to cultural resources can be fully mitigated by avoidances protec- tion or salvage; consequentlys this issue was not critical to the selection process. (e) Socioeconomics/Community Preferences Socioeconomic impacts on the Mat-Su Borough as a whole would be similar in magnitude for all three plans. Howevers each of the -three plans affects future socioeconomic conditions in differing degrees in certain areas and communities. The important differences affecting specific communities are outlined below. (i) Cantwell The Denali-North Plan would create significant increases in ~ populations local employments business activitys housing, and traffic. These impacts result because a rai 1 head facility would be located at Cantwell and because Cantwell ~ would be the nearest community to the Watana damsite. Both the North and South Plans waul d impact Cantwell to a far lesser extent. (ii) Hurricane The North Plan waul d significantly impact the Hurricane area, since currently there is 1 ittle population, employ- ment, business activity or housing. Changes in socioecono- mic indicators for Hurricane would be less under the South Plan and considerably less under the Denali-North plan. 4-13 (iii) Trapper Creek and Talkeetna Trapper Creek would experience slightly larger changes in economic indicators with the North plan than under the South or Denali -North Plans. The South Plan waul d impact the Talkeetna area slightly more than the other two plans. (iv) Gold Creek With the South Plan, a railhead facility would be developed at Gold Creek creating a significant increase in socio- economic indicators in this area. The Denali-North Plan includes construction of a rail head facility at the Devil Canyon site which would create impacts at Gold Creek, but not to the same extent as the South Plan. Minimal impacts would result in Gold Creek under the North Plan. The responses of people who will be affected by these potential changes are mixed. The people of Cantwell are generally in favor of some economic stimulus and development in their community. Some concern was expressed over the potential effects of access on fish and wildlife resources, but with stringent hunting regula- tions implemented and enforced, it was considered that this pro- blem could be successfully mitigated. The majority of residents in both Talkeetna and Trapper Creek have indicated a strong pre- ference to maintain their general lifestyle patterns and do not desire rapid, uncontrolled change. The Denali-North Plan would impact these areas the least. The majority of landholders in the Indian River subdivision favor retention of the remote status of the area and do not want road access through their lands. This and other feedback to date indicate that the Denali-North Plan will come closest to creating socioeconomic changes that are acceptable to or desired by landholders and residents in the potentially impacted areas and communities. (f) Preferences of Native Organizations Cook Inlet Region Inc. (CIRI) has selected lands surrounding the impoundment areas and south of the Susitna River between the dam- sites. CIRI has officially expressed a preference for a plan pro- viding road access from the George Parks Highway to both damsites along the south side of the Susitna River. The Tyonek Native Cor- poration and the CIRI village residents have indicated a similar preference. The South Plan provides full road access to their lands south of the Sutina River and thus comes closest to meeting these desires. The AHTNA Native Region Corporation presently owns land bordering the Denali Highway and, together with the Cantwell Village Corporation, has expressed a preference for the Denali- North Plan. None of the Native organizations support the North Plan. 4-14 - - - -i - - .., I I - .... ' r r ' (g) Relationship to Current Land Stewardships, Uses and Plans Much of 1 and required for project development has been or may be conveyed to Native organizations. The remaining lands are gene- rally under state and federal control. The South Plan traverses more Native-selected 1 ands than either of the other two routes, and although present land use is low, the Native organizations have expressed an interest in potentially developing their lands for mining, recreation, forestry, or residential use. The other 1 and management plans that have a 1 arge bearing on access development are the Bureau of Land Management 1 S (BLM) recent decision to open the Denali Planning Block to mineral exploration and the Denali Scenic Highway Study being initiated by the Alaska Land Use Council. The Denali Highway to Deadman Mountain segment of the Denali-North Plan would be compatible with BLM 1 S plans. During the construction phase of the project, the Denali-North Plan could create conflicts with the development of a Denali scenic highway; however, after construction, the access road and project facilities could be incorporated into the overall scenic highway planning. By providing public access to a now relatively inaccessible, semi- wilderness a rea, conflict may be imposed with wild 1 ife habitats necessitating an increased level of wildlife and people management by the various resource agencies. In general, however, none of the plans will be in major conflict with any present federal, borough, or Native management plans. (h) Recr«~ati on Following meetings, discussions, and evaluation of various access plans, it became evident that recreation plans are flexible enough to adapt to any of the three selected access routes. No one route was identified which had superior recreational potential associa- ted with it. Therefore, compatibility with recreational aspects was essentially eliminated as an evaluation criterion. 4.10-Summary of F·inal Selection of Plans In reaching the decision as to which of the three alternative access plans was to be recommended, it was necessary to evaluate the highly complex interplay that exists between the many issues involved. Analysis of the key issues described in the preceding pages indicates that no one plan satisfied all the selection criteria nor accommodated all the concerns of the resource agencies, Native organizations, and public. Therefore, it was necesary to make a rational assessment of tradeoffs between the sometimes conflicting environmental concerns of impacts on fisheries, wildlife, socioeconomics, land use, and recrea- tional opportunities on the one hand, with project cost, schedule, construction risk, and management needs on the other. With all 4-15 these factors in mind, it should be emphasized that the primary purpose of access is to provide and maintain an uninterrupted flow of materials and personnel to the damsite throughout the 1 ife of the project. Should this fundamental objective not be achieved, significant schedule and budget overruns will occur. (a) Elimination of "South Plan" The South route, Plan 16, was eliminated primarily because of the construction difficulties associated with building a major low- level crossing 12 miles downstream from the Watana damsite. This crossing would consist of a floating or fixed temporary bridge which would need to be removed prior to spring breakup during the first three years of the project (the time estimated for comple- tion of the permanent bridge). This would result in a serious interruption in the flow of materials to the site. Another draw- back is that floating bridges require continual maintenance and are generally subject to more weight and dimensional 1 imitations than permanent structures. A further limitation of this route is that, for the first three years of the project, all construction work must be supported solely from the railhead facility at Gold Creek. This problem arises because it will take an estimated three years to complete construction of the connecting road across the Susitna River at Devil Canyon to Hurricane on the George Parks Highway. Limited access such as this does not provide the flexibility needed by the project management to meet contingencies and control costs and schedule. Delays in the supply of materials to the damsite, caused by either an interruption of service of the railway system or the Susitna River not being passable during spring breakup, could result in significant cost impacts. These factors, together with the realization that the South Plan offers no specific advantages over the other two plans in any of the areas of environmental or social concern, led to the South Plan being eliminated from further consideration. (b) Schedule Constraints The choice of an access plan thus narrowed down to the North and Denali-North Plans. Of the many issues addressed during the evaluation process, the issue of "schedule" and "schedule risk 11 was determined as being the most important in the final selection of the recommended plan. Schedule plays such an important role in the evaluation process because of the special set of conditions that exist in a subarctic environment. Building roads in these regions involves the consi- deration of many factors not found elsewhere in other environ- ments. Specifically, the chief concern is one of weather and the 4-16 """l I 1 - -1 I - - - - - r- ' - - - consequent short duration of the construction season. The roads for both the North and Denali -North plans wi 11, for the most part, be constructed at elevations in excess of 3,000 feet. At these elevations, the likely time available for uninterrupted construc- tion in a typical year is five months, and at most six months. The forecasted construction period for initial access, including mobilization, is six months for the Denali-North Plan and nine months for the North Plan. At first glance, a difference in schedule of three months does not seem great; however, when con- sidering that only six months of the year are available for con- struction, the additional three months become highly significant, especially when read in the context of the likely schedule for issuance of the FERC license. The date the FERC 1 i cense wi 11 be issued cannot be accurately determined at this time, but is forecast to be within the first nine months of 1985. Hence, the interval between licensing and the scheduled date of diversion can vary significantly, as shown graphically in Figure 4.6. This illustrates that the precise time of year the license is issued is critical to the construction schedule of the access route, for if delays in licens·ing occur, there is a risk of delay to the project schedule to the extent that river diversion in 1987 will be missed. If diversion is not achieved prior to spring runoff in 1987, dam foundation prepara- tion work will be delayed one year, and hence, a delay to the overall project of one year will result. (c) Cost Impacts (d) The increase in costs resulting from a one-year delay has been estimated to be in the range of 100-200 million dollars. This increase includes the financial cost of investment by spring of 1987, the financial costs of rescheduling work for a one-year delay, and replacement power costs. Conclusion The Denali-North Plan has the highest probability of meeting schedule and least risk of increase in project cost for two rea- sons. First, it has the shortest construction schedule (six months). Second, a passable route could be constructed even under winter conditions, since the route traverses relatively flat terrain almost its entire length. In contrast, the North route is mountainous and involves extensive sidehill cutting, especially in the Portage Creek area. Winter construction along sections such as this would present major problems and increase the probability of schedule delay. 4-17 (e) Plan Recommendation It is recommended that the Denali-North route be selected so as to ensure completion of initial access to the Watana damsite by the end of the first quarter of 1986, for it is considered that the risk of significant cost overruns is too high with any other route. 4.11-Modifications to Recommended Access Plan Following approval of the recommended plan by the Power Authority Board of Directors in September 1982, further studies were conducted to optimize the route location in terms of both cost and minimizing impacts to the environment. Each of the specialist subconsultants was asked to review the proposed plan to identify specific problem areas, develop modifications and improvements, and contribute to drawing up a set of general guidelines for access development. The results of this review are capsulized below. (a) An important red fox denning area and a bald eagle nest were identified close to the proposed road alignment, so consequently the road was realigned to create a buffer zone of at least one- half mile between the road and the sites. {b) Portions of the access road between the Denali Highway and the Watana damsite will traverse flat terrain. In these areas, a berm type cross section will be formed with the crown of the road being 11 two to three feet .. above the elevation of adjacent ground. Steep side slopes would present an unnatural barrier to migrating caribou, exaggerate the visual impact of the .road itself, and aggravate the problem of snow removal. To reduce these problems, the side slopes will be flattened using excavated peat material and rehabilitated through scarification and fertilization. (c) The chief fisheries concern was the proximity of the proposed route to Deadman Creek, Deadman Lake, and Big Lake. For a dis- tance of approximately 16 miles, the road parallels Deadman Creek, which contains good to excellent grayling populations. To alleviate the problem of potential increased angling pressure, the road was moved one half to one mile west of Deadman Creek. (d) The preliminary, reconni assance-1 evel, cultural resource survey conducted on the proposed access route 1 ocated and documented sites on or in close proximity to the right-of-way and/or potential borrow sites. The number of these sites that will be directly or indirectly affected will not be known until a more detailed investigation is completed. However, indications are that all sites can be mitigated by avoidance, protection, or salvage. 4-18 - - - - - - - - - r - (e) The community that will undergo the most growth and socioeconomic chang1~ with the proposed access plan is Cantwell. Subsequent to the selection of this access plan, the residents of Cantwell were solicited for their comments and suggestions. Their responses resulted in the following modifications and recommendations: (i) The plan was modified to include paving the road from the railhead facility to four miles east of the junction of the George Parks and Denali Highways. This will eliminate any problem with dust and flying stones in the residential district. (ii) For safety reasons, it is recommended that: -Speed restrictions be imposed along the above segment; - A bike path be provided along the same segment, since the school is adjacent to the access road; and -Improvements be made to the intersection of the George Parks and Denali Highways including pavement markings and traffic signals. (f) The main concern of the Native organizations represented by CIRI is to gain access to their land south of the Susitna River. Under the proposed access plan, these lands will be accessible by both road and rail, the railroad being from Gold Creek to the Devil Canyon damsite on the south side of the Susitna River. After com- pletion of the Watana dam, road access will be provided across the top of the dam to Native lands. Similarly, a road across the top of the Devil Canyon dam will be constructed once the main works at Devil Canyon are completed. In addition, alternative road access will be available via the high-level suspension bridge one mile downstream from the Devil Canyon dam. (g) From an environmental standpoint, it is desirable to limit the number of people in the project area in order to minimize impacts to wildlife habitat and fisheries. In comparison with a paved road, an unpaved road would deter some people from visiting the area and thus create less of an impact to the environment. An un- paved road would also serve to maintain as much as possible the wilderness character of the area. An evaluation of projected traffic volumes and loadings confirmed that an unpaved gravel road with a 24-foot running surface and 5-foot wide shoulder would be adequate. (h) For the efficient, economical, and safe movement of supplies, the following design parameters were chosen: -Maximum grade -Maximum curvature -Design loading: • during construction • after construction 4-19 6 percent 5 degrees sok axle, 2ook total HS-20 Adhering to these grades and curvatures, the entire length of the road would result in excessively deep cuts and extensive fills in some areas, and could create serious technical and environmental problems. From an engineering standpoint, it is advisable to avoid deep cuts because of the potential slope stability problems, especially in permafrost zones. Also, deep cuts and large fills are detrimental to the environment, for they act as a barrier to the migration of big game and disrupt the visual harmony of the wilderness setting. Therefore, in areas where adhering to the aforementioned grades and curvatures involves extensive cutting and filling, the design standards will be reduced to allow steeper grades and shorter radius turns. This flexibility of design standards provides greater latitude to 11 fit 11 the road within the topography and thereby enhance the visual quality of the surrounding 1 andscape. For reasons of driver safety, the design standards will in no instance be less than those applicable to a 40-mph design speed. (i) One of the most important issues associated with the construction of the access road is the development of borrow sites. Potential impacts can be mitigated through selective siting of borrow sites and the use of state-of-the-art gravel-removal techniques. After close consultation with fish and wildlife, recreational, aesthe- tic, and cultural resource specialists, the following guidelines were developed to ensure that any impacts are minimized. -Active floodplain and streambed locations should be avoided; -In locating borrow sites, first priority is to be given to well-drained upland locations, and second priority to first- level terrace sites; -First-level terrace sites should be located on the inactive side of the floodplain and mined by pit excavation rather than by shallow scraping; -If wet processing is required, water withdrawa 1 and discharge locations should be carefully sited to minimize fish and wildlife disturbance. Drawdown in overwintering pools used by fish or aquatic mammals and any disturbances to spawning areas are to be avoided. In addition, water intake structures should be enclosed in screened boxes; -All material sites should be developed in phases by aliquots, and portions of the site which are more sensitive from an environmental standpoint should be left until last; 4-20 - - ., - - -I I I -For rehabilitation purposes, sites should have irregular boundaries, including projections of undisturbed, vegetated terrain into the site. Where ponding will occur, as in first- 1 evel terrace sites, islands of undisturbed vegetated terrain should be left within the perimeter of the operational site; and -Organic overburden, slash, and debris stockpiled during cleaning should be distributed over the excavated area prior to fertili- zation. The rehabilitation of sites is to be completed by the end of the growing season immediately following last use. The modifications and improvements to the proposed access plan, together with the general guidelines that have been developed for roadway construction and mining of borrow sites, have been fully incorporated into the draft FERC License Application. A more detailed description of specific mitigation plans is given in the relevant sections of Exhibit E of the Application. 4.12-Description of Proposed Access Plan (a) Watana Access Access to the Watana damsite will connect with the existing Alaska Railroad at Cantwell where a railhead and storage facility occupying 40 acres will be constructed. This facility will act as a transfer point from rail to road transport and as a storage area for a two-week backup supply of materials and equipment. From the railhead facility, the road will follow an existing route to the junction of the George Parks and Denali Highways (a distance of 2 miles), then proceed in an easterly direction for a distance of 21.3 miles along the Denali Highway. A new road, 41.6 miles in 1 ength, will be constructed from this poi n1: due south to the Watana campsite. On completion of the dam, access to Native lands on the south side of the Susitna River will be provided from the Watana campsite, with the road crossing along the top of the dam. This will involve the construction of an additional 2.6 miles of road, bringing the total length of new road to 44.2 miles. The majority of the new road will traverse relatively flat terrain involving only isolated sections of cut and fill. Where it is not possible to locate the road on sidehill slopes of gentle to moderate steepness, the road will be formed using side borrow techniques; with the crown of the road being two to three feet above the elevation of adjacent ground. By balancing cut and fill and using side borrow techniques, the need for borrow material from pits and consequent disturbance to areas away from the alignment will be minimized. It has been estimated that it will take approximately six months to secure initial access, with an additional year for completion and the upgrading of the Denali Highway section. 4-21 ··--------------------------- {b) Devil Canyon Access Access to the Devil Canyon development will consist primarily of a railroad extension from the existing Alaska Railroad at Gold Creek to a railhead and storage facility adjacent to the Devil Canyon camp area. To provide flexibility of access, the railroad extension will be augmented by a road between the Devil Canyon and Watana dams ites. (i) Rail Extension Except for a 2-mile section where the route traverses steep terrain alongside the Susitna River, the railroad will climb steadily for 12.2 miles from Gold Creek to the railhead facility near the Devil Canyon camp. Nearly all of the route traverses potentially frozen, basal till on side slopes varying from flat to moderately steep. Several streams are crossed, requiring the construction of large culverts. However, where the railroad crosses Jack Long Creek, small bridges will be built to minimize impacts to the aquatic habitat. In view of the construction conditions, it is estimated that it will take eighteen months to two years to complete the extension. (ii) Connecting Road From the railhead facility at Devil Canyon, a connecting road will be built to a high-level suspension bridge approximately one mile downstream from the damsite. The route then proceeds in a northeasterly direction, crosses Devil Creek and swings round past Swimming Bear Lake at an elevation of 3500 feet before continuing in~ south easter- ly direction through a wide pass. After crossing Tsusena Creek, the road continues south to the Watana damsite. The overall length of the road is 37.0 miles •. In general, the a 1 i gnment crosses good soil types with bedrock at or near the surface. Erosion and thaw settle- ment should not be a problem, since the terrain has gentle to moderate slopes which will allow roadbed construction without deep cuts. The connecting road will be bui 1 t to the same standard and in accordance with the design para- meters used for the Watana access road. However, as is the case for the Watana damsite access road, the design standards will be reduced to as 1 ow as 40 mph in areas where it is necessary to minimize the extent of cutting and filling. The affected areas are the approaches to some of the stream crossings, the most significant being those of the high-level bridge crossing the Susitna River downstream from Devil Canyon. 4-22 - - -i - - - - - - r i - - - The 1,790-foot-long, high-level suspension bridge crossing the Susitna River is the controlling item in the construction schedule, requ1r1ng three years for completion. Therefore, it will be necessary to begin construction three years prior to the start of the main works at the Devil Canyon damsite. Figure 4.7 shows the proposed access plan route. Figure 4. 8 shows deta i1 s, for both the Watana and Devil Canyon develoJlllents, of typical road and railroad cross sections, railhead facilities, and the high-level bridge at Devil Canyon. t\,L.ASKA RESOUHC'.:S U.S. DEPT. OF IN.TF::n m;;. 4-23 - - r - - .... REFERENCES Acres American Incorporated. 1982a. Susitna Hydroelectric Project Feasibility Report. Prepared for the Alaska Power Authority. 1982b. Susitna Hydroelectric Project Subtask 2.10-Access Route Selection Report. Prepared for the Alaska Power Authority. 19B2c. Susitna Hydroelectric Project Access Plan Recommenda- tion Report. Prepared for the Alaska Power Authority. R&M Consultants, Inc. 1982. Access Planning Study. Prepared for Acres American Incorporated. Plan Description M i I eage Road Rail Design and Construction Cost ( $ X 1 , QQQ, QQQ) MaIntenance Cost ( $ X 1 , QQQ, QQQ) Logistics Cost ($ X 1 ,OQQ,QQQ) Tota I Cost ($X 1,00Q,QQQ) Construction Schedule for Initial Access (Years> Construction Schedule for Fu II Access (Years) Bridges Major (>1000 ftl Minor (<1000 ftl Roadway: Parks Highway to Devl I Canyon & Watana on South Side of Susltna 62 170 9 214 393 3-4 3 2 1 TABLE 4.1: ACCESS PLAN COSTS 2 Rai 1: Gold Creek To Devil Canyon & Watana on South Side of Sus i tna 58 149 5 214 368 3-4 3-4 2 0 3 Roadway: Dena I I Highway to Watana Parks Highway to Devi I Canyon on South SIde of Susitna. No ConnectIng road. 91* 157 7 228 392 2-3 * Includes upgrading 21 miles of the Denali Highway. 4 Roadway: Dena II Highway to Watana Ra I I: Go I d Creek to Dev I I Canyon on South Side of Susitna. No Connecting road. 65* 16 123 5 228 356 2-3 0 0 5 Roadway: Parks HIghway to Dev I I Canyon on South SIde of Sus I tna Dev i I Canyon to Watana on North Side of Susltna. 81 160 8 216 384 2-3 3-4 2 1 1 Rev Is I on: E Page 1 of 3 6 Roadway: Denali Highway to Watana Rail: Gold Creek to Devil Canyon on South Side of Susitna. Connec- ting road on North Side of Susitna. 107* 16 180 12 228 420 3 0 0 TABLE 4. 1 (Page 2 of 3) Revision: E Plan 7 8 9 10 11 12 Description Roadway: Dena I i Roadway: Gold Rai I: Gold Creek Rat I: Gold Creek Roadway: Dena I i Roadway: Parks Highway to Watana Creek to Dev i I to Dev I I Canyon to Dev i I Canyon Highway to HIghway to Devi I Parks Highway to Canyon on South on South Side of on South Side of Watana. Con-Canyon and Watana Dev i I Canyon on Side of Susitna. Susitna. Roadway: Susitna. Roadway: necti ng Road on North Side of South Side of Devl I Canyon to Dev I I Canyon to Dev i I Canyon to between Watana Susltna. Susitna. Con-Watana on North Watana on North Watana on South and Dev II Canyon nectlng Road on Side of Susltna. Side of Susitna. Side of Susitna. on North Side of North Side of Susitna. Susitna Mileage Road 132* ff.} 56 36 114* 61 * Ra II 16 16 Design and Construction Cost ( $ X 1 1 000, 000) 215 117 126 136 172 127 Maintenance Cost ($ X 1 ,000,000) 9 7 6 6 11 7 Logistics Cost ($x 1,000,000) 228 216 216 214 258 225 Tota I Cost ($ X 1 ,000,000) 452 340 348 356 441 359 Construction Schedule for Initial Access (Years) 2-3 3 2 2 Construction Schedule for Full Access (Years) 3 3 3 3 2-3 3-4 Bridges Major (>1000 ft) 0 0 2 0 1 Minor (<1000 ft) 1 1 1 1 2 *Includes upgrading 21 miles of the Denali Highway. ~J ] '"'J .J c~~ ] ,, .J ] ) -... ] .I ' J _I TABLE 4.1 (Page 3 of 31 Plan Description M i I eage Road Ra i I Design and Construction Qost ($X 1,000,000) Maintenance Oost ($ X 1 ,000,000) Logistics Oost ($ X 1,000,000) Tot a I Oost ( $ X 1 , 000,000) Construction Schedule for Initial Access (Years) Construction Schedule for Ful I Access (Years) Bridges Major (>1000 ft) Minor (<1000 ft) 13 Roadway: Parks Highway to Watana on North Side of Susitna with Branch Road to South Bank at Devil Canyon. 59 115 7 223 345 3 1 2 14 Ra i! /Roadway: Gold Creek Rai 1- road Extension. Roadway: To Devil Canyon and watana on South Side of Susitna. Connecting Road tp Parks Highway. 64 7 174 9 215 398 3-4 2 2 * Includes upgrading 21 miles of the Dena I i Highway. l 15 Ra i I /Roadway: Gold Creek Rail- road Extension. Roadway: To Dev i I Canyon and watana on South Side of Susitna. 49 7 128 6 215 349 3 16 Roadway: Go I d Creek to Watana on South Side of Susitna. Con- necting Road to Devi I Canyon and Parks Highway. 69 156 10 216 382 3 2 2 1 17 Roadway: Dena I i Highway to Watana. Con- necting Road to Dev i I Canyon on South Side of Sus itna. Ra i I: Go I d Creek to Dev i I Canyon on South Side of Susitna. 102* 14 200 12 227 439 3-4 Revision: E 18 Roadway: Dena I i Highway to Watana Connecting Road to Dev i I Canyon on North Side of Susitna. Rai I: Go I d Creek to Dev i I Can yon on South Side of Susitna. 97* 14 188 11 227 426 3 TABLE 4.2: ACCESS PLAN COSTS INITIAL ACCESS WITHIN ONE YEAR Nor:th Plan 13 South PI an 16 Dena I i -North PI an 18 Devi I Devi I Devi I Description Watana Canyon Comb I ned Watana Ca~o_r Comb I ned Watana Canvor Combined Mileage Road 52 7 59 f9 0 f9 61 * 36 97* Ra i I 0 0 0 0 0 0 0 14 14 Construction Cost ($ X 1 ,000,000) 95 20 115 156: 0 156 82 106 188 Logistics Cost ($ X 1 000,000) 118 105 223 115 101 216 127 100 227 Maintenance ($X 1,000,000) 5 2 7 7 3 10 4 7 11 Subtota I ($ X 1,000,000) 218 127 345 278 104 382 213 213 426 Impact of Accelerated Schedule ($ X 1,000 000) 23 0 23 34 0 34 11 0 11 Tota I ($X 1,000,000) 241 127 368 312 104 416 224 213 437 Construction Schedule for Initial Access (Years) 1 1 1 Construction Schedule for Ful I Access (Years> 3 3 3 *Includes upgrading 21 miles of the Dena I i Highway. .I .J .J .J l TABLE 4.3: SUMMARY OF WILDLIFE HABITAT ISSUES ASSOCIATED WITH ACCESS ALTERNATIVES Issue North (13> Waterfowl No waterbodies of high relative importance along route. Raptor Nests Avoids known nest sites. Breeding Birds Least amount of productive forest habitat removed. Aquatic Avoids Fog Lakes-Stephan Lake Furbearers wetlands. Red Fox Den: Concentration Areas Crosses highly productive habitat In Chulitna Pass area. Near productive habitat along Portage Creek. Avoids Jack Long Creek beaver concentration area. Within 1/4 mile of Swimming Bear Lake den sites. Avoids Deadman Creek and Deadman Lake den areas. South ( 1 6) Stephan Lake is of high relative importance to waterfowl. Avoids known nest sites. Greatest amount of productive forest habitat removed. Near Fog Lakes-Stephan Lake wetlands. Crosses highly productive habitat in Chi litna Pass area. Avoids Portage Creek area. Disturbs Jack Long Creek beaver concentration area. Avoids red fox den concentration areas. Dena I i-North ( 18) No waterbodies of high relative importance along route. One-half mile from bald eagle nest on Deadman Creek. Amount of forest removed less than South Route but greater than North Route. Avoids Fog Lakes-Stephan Lake wetlands. Avoids Chulitna Pass area. Avoids Portage Creek area. Disturbs Jack Long Creek beaver concentration area. Within 1/4 mile of Swimming Bear Lake den sites. One-half mile from Deadman Creek and Deadman Lake den concentration areas. . J TABLE 4.3 <Cont 1 d) Issue Brown Bears Black Bears Caribou Moose Secondary Effects: North ( 13) South ( 16) Avoids Prairie Creek concentration Near Prairie Creek concentration area. area; crosses movement corridor between Prairie Creek and Susitna River. Avoids Deadman Creek concentration Avoids Deadman Creek area. area. Avoids den sites. Traverses important south-facing slopes. Least amount of forest is removed. Avoids carIbou range and movement corridor between Dena I I HIghway and Susltna River. Avoids Fog Lakes-Stephan Lake carIbou range. Traverses important south-facing slopes. Least amount of forest is removed. Avoids Fog Lakes-Stephan Lake area. Least potential for secondary effects through public access and recreational development. J I .] Near several den sites west of Tsusena Creek. Fewer south-facing slopes are traversed. Removes greatest amount of forest. Avoids caribou range and movement between Dena I i Highway and Susitna River. Near Fog Lakes-Stephan Lake carl bou ranges. Fewer south-facing slopes are traversed. Removes greatest amount of forest. Near Fog Lakes-Stephan Lake wetlands. Potential for secondary effects through public access less than Dena 11-North Route but greater than North Route. High potential for secondary effects through recreational development of lands south of Susitna River • .! J Dena I !-North ( 18) Avoids Prairie Creek concentration area. Crosses Deadman Creek concentration area. Near several den sites west of Tsusean Creek. Traverses Important south-facing slopes. Removes more forest than North Routh but less than South Route. Crosses caribou range and movement corridor between Dena I i Highway and Sus itna RIver. Avo Ids Fog Lakes-Stephan Lake caribou range. Traverses important south-facing slopes. Removes less forest than South Route but more than North Route. Avoids Fog Lakes-Stephan Lake wetlands. Highest potential for secondary effects through public access and recreational development. - - - - \1 ?FIQPOSEO DAM S;TES SEE INSET LOCATION MAP FIGURE 4.1 I· ' -+~· IICAI..[ 0 4 I MIL£S :Till. ltU[RDI;l[: Mlf: IIIAP fliiCIII UIIS , I: 2:50,000 ;!~d:~ IIIOUO"AINS. ALASKA AL TERN.UIVE ACCESS CORRI>ORS FIGURE 4.2 r I""" ' I - .... I ACCESS PLAN 13 (NORTH) 11 SUSITNA HYDROELECTRIC PROJECT ALTERNATIVE ACCESS PLAN" TitS T2<11 a 1 2 !o • • ~-~m RH IIIK FIGURE 4.3 - - , .... ACCESS PLAN 16 (SOUTH) 11 SUSITNA HYDROELECTRIC PROJECT ALTERNATIVE ACCESS PLAN 11 FIGURE 4. 4 ...... ' I ! I - - - ACCESS PLAN 18 (PROPOSED) 11 SUSITNA HYDROELECTRIC PROJECT AL TERNATlVE ACCESs PLAN II FIGURE 4.5 - - - -' - - SCHEDULE FOR ACCESS AND DIVERSION TIME FRAME FOR EXPECTED ISSUE OF FERC LICENCE DIVERSION CONSTRUCTION INITIAL ACCESS CONSTRUCTION 1985 1986 PL AN IS ( DENALI-NORTH) hiJlliiJIIffi[illill[illJ::.·····).I ACCESS REQUIRED (.1 NO LATER THAN PLAN 13 (NORTH) 111111111111111111 ( I) PLAN 16 (SOUTH) 111111111 ( I ) NOTES: I THIS DATE TO I SUPPORT DIVERSION CONSTRUCTION 1 I I ) RIVER DIVERSION v 111111111111111 ACTIVITY START COULD BE DELAYED AND DIVERSION STILL MET. (I) LATEST START DATE OF CONSTRUCTION ACTIVITY. FIGURE 4.6 0 t 4111L£S SCALE: C I INCH • 2 MILES) FIGURE 4.7 -'""" --1100 ---- -I I ./1} '\. '\ TYPICAL ROAD CROSS sa:TIOII SCALI: • ·-!IIOitod 1 ~ ~ '"'\ ~ \ ,..---- L / _/ /_ HIGH LEY£1. SUSITliA RIVER BRIDGE: ......... 1 __.&..- EXlSTtNCJ IIAIN TWACit lRftlVtfriiG CPS C75 CARSJ OEIIM.TIH CARS CTO CARS! CQI'NT T.&JIURS-f&OCUISJ~UEL. TMIII:DtS ~---~ CMSO C50CAAS) PI8SYMCa AIIID SEALAMUIO CAMt RAIUEAD FACILITY !CAlL. ··- TYPICAL RAILROAD CROSS SECTION sc.w: • ~. I I I I ACCESS PLAN DETAILS PROPOSED ROUTE 0 --our ......, . (IlliCit •ZOD FD:n 0 10 l'l:n ......... UUICII• DIIUT) 0 ... -_,. ......, . liiiCM • IOD nrrJ FIGURE 4.8 I ~ - 5 -REFINEMENT OF SUSITNA DEVELOPMENT 5.1 -1982 Geotechnical Design Considerations The purpose of this section is to update the Feasibility Report (Acres 1982a) based on the results of the geotechnical investigations per- formed during the 1982 summer field season. Details of the geotechnical program are provided in the 1980-81 Geo- technical Report (Acres 1982b) and the 1982 Supplement to the 1980-81 Geotechnical Report (Acres 1982c). The reader should refer to these referenced reports for a comprehensive understanding of the site geo- technical conditions. Information provided in the following sections is a summary of that provided in those reports. (a) 1982 Geotechnical Exploration Program The objective of the geotechnical program was to determine the surface and subsurface geology and geotechnical conditions for the feasibility of constructing the proposed Susitna Hydroelectric Project, including access roads and transmission line corridors. This was accomplished by a comprehensive program of field explora- tion, geotechnical evaluation, and dam studies over more than a three year period, commencing in early 1980. The scope of the geotechnical program was increased in 1982 under Amendments 4 and 5 of the Acres contract to respond to concerns raised by Acres and the Power Authority 1 s External Review Board. The following sub- sections discuss the objectives and results of the 1982 program. (i) Watana Studies performed during the 1980-81 investigations raised a number of unanswered geologic and geotechnical questions regarding the Watana damsite, the Watana relict channel, Borrow Site D, and the Fog Lakes relict channel. The objective of the 1982 geotechnical exploration program was to supplement the results of the previous investigations by performing additional detailed explorations of the particu- lar areas of concern. These explorations consisted of: -Watana Damsite Geologic Mapping to determine: Extent of geologic features identified in previous in- vestigations to include shears, alteration, and frac- ture zones; • Bedrock conditions in the upstream and downstream por- tal areas; and • Geology of 11 The Fi ns 11 and 11 Fi ngerbusterll shear zones. 5-1 -Watana Relict Channel Geologic mapping, seismic refraction surveys, laboratory testing, and subsurface drilling to depths of 250 feet to determine: Channel geometry; • Stratigraphy of the channel sediments; • Continuity of stratigraphic sequence; • Material properties; • Ground water conditions; and • Permafrost conditions. -Borrow Site D Geologic mapping, seismic refraction surveys, laboratory testing, and subsurface drilling to depths of 250 feet to determine: • Material properties; • Stratigraphy; • Material quantities; • Ground water conditions; and • Permafrost conditions. -Fog Lakes Relict Channel Performing geo1ogic mapping and seismic refraction sur- veys to determine: • Channel geometry; • Stratigraphy of the channel sediments; • Ground water conditions; and • Permafrost conditions. (ii) Devil Canyon 1982 Geotechnical explorations for the Devil Canyon site were limited to the completion of the long-term laboratory testing of quarry and concrete aggregate materials begun in 1981 and reading of boreho1e instrumentation installed in 1980-81 for monitoring ground water and permafrost regimes at the damsite. (b) Results of Geotechnical Investigations -Watana The results of the summer of 1982 geotechnical explorations for the Watana damsite, Watana relict channel/Borrow SiteD, and Fog Lakes re1ict channel are summarized below. Detailed descriptions of the geology at the Watana site are given in the 1980-81 Geotechnical Report (Acres 1982b) and the 1982 Supplement to the 1980-81 Geotechnical Report (Acres 1982c). 5-2 -' - - - - - - - - - - - (i) Damsite The Watana damsite refers to the main dam area, as well as the upstream and downstream cofferdam and portal areas. -Overburden The 1982 study found no significant differences in over burden thickness or material types from those previously reported. A map showing the top of bedrock surface con- tours and the type and distribution of surficial sedi- ments is shown in Figure 5.1. This map is based on addi- tional seismic refraction surveys and geologic mapping. -Bedrock Lithology No significant additional information pertaining to bed- rock lithology was found during the 1982 investigation. A geologic map, showing bedrock lithology, is shown in Figure 5.2. -Bedrock Structures • Joints The addition of more than 500 joint measurements to the statistical joint plots has resulted in minor changes to the average orientations and dips of the four joint sets found at the site. Table 5.1 is a summary of joint orientations for the overall damsite area as well as the specific areas of the proposed upstream and downstream portals. Joint plots of the damsite area are in the 1982 Supplement to the 1980-81 Geotechnical Report (Acres 1982c). Plots for the upstream and down- stream portal areas are in Figures 5.3 and 5.4. Sets I and II remain the major sets with Sets III and IV being minor, although locally pronounced. Set I trends northwestward with high angle to vertical dips and is the most prominent set. Set I parallels most discon- tinuities at the site. Set II trends northeastward and is best developed upstream from the dam centerline. Set II is parallel to fracture zones in this area. Set III joints trend northward with moderate to steep dips to east and west. Set III is not present in the up- stream portal area; however, it is well developed in the downstream portal area where it parallels shear and fracture zones. Set IV joints are generally discon- tinuous and appear to be caused by stress relief. Orientations are quite variable, but many trend east- west with shallow to moderate dips to the north and south. These joints are discontinuous and appear to be related to stress relief from glacial unloading. 5-3 The Susitna River is joint controlled in the damsite area. Upstream from the dam centerline, the river parallels Set II joints. Near the dam centerline it is controlled by both Sets I and II; and in the downstream area it is controlled by shear and fracture zones related to Set I joints • • Shears, Fracture Zones, and Alteration Zones These features are defined in the Acres Reports 1982a and 1982c. A geologic map showing the extent of these features is shown in Figure 5.3. Significant geologic features are discussed below. Three structural features, geologic structures pre- viously identified in the damsite as having potential impact on civil design, are "The Fins," "Fingerbuster," and a wide, hydrothennally altered zone. "The Fins" and "Fi ngerbuster" were explored in more deta i 1 during the 1982 field season. The following paragraphs are a summary of the findings. No additional explorations were performed in the area of the left bank alteration zone. "The Fins" is shown in relation to the damsite in Figure 5.2 and in detail in Figure 5.3 This is located on the north bank near the present planned location for the upstream cofferdam and diversion portals. Recon- naissance mapping in this area indicated major shears underlying a series of deep gullies separated by intact rock ribs. Detailed mapping showed that most struc- tural discontinuities crosscut the gullies rather than lie within them. "The Fins" is an area of major shears~ fracture zones, and alteration zones of various orientations. The strongest trend of these discon- tinuities is northwest southeast parallel to Set I joints and northeast-southwest parallel to Set I I joints. Minor shears were a 1 so found trending at various orientations. The northwest trending struc- tures are near-vertical to vertical and consist of shears~ fracture zones, and alteration zones from less than 1 foot up to 10 feet wide. The most significant of these features are found upstream from the proposed portal area. The northeast trending structures consist of fracture zones which are discontinuous and only occur downstream from the proposed portal cuts. These features are up to 6 feet wide and dip moderately southeastward, towards the river~ to vertical. A s e r i e s of 1 ow a n g 1 e ( 1 e s s t han 4 5 a ) s h ea r s d i p pi n g towards the river were mapped primarily above the por- tal area. These shears may cause rock stability pro- blems during excavation. 5-4 - - - - - - - "The Fins" structure trends generally from 300° to 310°. To the southwestt the structure trend across the Susitna River beneath the upstream cofferdam and is exposed to a limited extent on the south bank. To the northwestt "The Fins 11 is inferred to correlate with a hydrothermally altered zone on Tsusena Creek. The "Fingerbuster" is an area of shearst fracture zonest and alteration zones which are best exposed on the north bank of the Susitna River in the area of the proposed downstream diversion and tailrace portals (Figure 5.4). Exposure shows two strong trends of d i scont i nu it i es: northwest-southeast and north-south. The northwest trending discontinuities consist pri- marily of shears and associated alteration zones parallel to Set I joints. These structures are up to 2 feet wide. Related to the northwest trending struc- tures are areas of open joints and loose unstable rock. Large blocks of detached rock are slumping along the intersection of Sets I, lilt and IV joints. The most significant of these areas occurs in the proposed area for the spillway flip-bucket. The north trending discontinuities are primarily frac- ture zones with minor shears which parallel Set I joints. An exception to this is a major shear zone labeled GF70t which corresponds with the andesite porphyry/diorite contact (Figure 5.2). This feature is up to 30 feet wide; however, most of the north trending structures are less than 5 feet wide. The main trend of the "Fingerbuster" is northwest- southeast. To the southeast, the 11 Fi ngerbuster" is projected beneath the river and tentatively correlated with shears on the south bank. The extent of this feature to the northwest is uncertain because of 1 ack of bedrock exposure -Ground Water Conditions Results of the 1982 geotechnical explorations support the findings and conclusions set forth in the Feasibility Report (Acres 1982a) except for the depth of water levels on the right abutment. The previously reported (Acres 1982b) ground water levels of 110 to 280 feet deep were erroneous and should read 110 to 150 feet. In addition, geologic mapping revealed additional springs on slopes at the overburden/bedrock contacts (Figure 5.2)t and persistent 1-2 gpm ground water flows from all boreholes except DH-24 and DH-28 on the south abutment. 5-5 -Permafrost Conditions The interpretation of the permafrost regime at the dam- site remains unchanged from that presented in the Feasi- bility Report, except that the instrumentation in BH-6 indicated permafrost in the "shadow zone" of the north abutment. -Permeability No additional data pertaining to rock permeability was gathered during 1982. The interpretation presented in the Feasibility Report remai~s unchanged. -Reservoir Geology Geologic mapping in the proposed Watana Reservoir area was undertaken as part of the regi anal mapp-ing of the Watana and Fog Lakes Relict investigations. The results of this investigation are discussed in Section 5.1(b),' 5.1(c)(ii), and 5.l(c)(iii) and are shown on the damsite area geologic map (Figure 5.5). (ii) Watana Relict Channel/Borrow SiteD During the course of investigations carried out by the U.S. Army Corps of Engineers (COE) and Acres, subsequent studies in 1980-81 confirmed the existence of a possible buried relict channel running from the Susitna River gorge imme- diately upstream from the proposed damsite to Tsusena Creek, a distance of approximately 1.5 miles. The major potential problems associated with the relict channel are: -Breaching of the reservoir rim resulting in catastrophic failure of the reservoir; and Subsurface seepage resulting in potential downstream piping and/or loss of energy. Breaching of the reservoir rim can be caused by saturation of the unconsolidated sediments within the channel result- ing in surface settlement or by liquefaction during an earthquake. Excessive subsurface seepage can be caused by highly per- meable unit(s) within the channel that would provide a continuous flow path between the reservoir and Tsusean Creek. As a result of these potential problems a supplemental geo- technical investigation was undertaken in the summer of 5-6 - - - - - - - - - - .... - - 1982 to define this .feature in more detail. This investi- gation was to be followed by a more detailed investigation to be performed in the winter 1982-83. Results of that investigation are not expected to be completed until late spring 1983. -Location and Configuration The Watana relict channel is 1 ocated between the present course of the Susitna River and Tsusena Creek and fills an area from the emergency spillway 1 ocation to Deadman Creek. Borrow SiteD is located in the southeast quarter of the channel and overlies the major portion of the in- let area near the Susitna River. The location of the channel is shown on the top of bedrock map (Figure 5.6). The orientation of the relict channel is somewhat irregu- lar, but overall it trends northwest southeast. Maximum overburden thickness is 450 feet. -Geology Twelve stratigraphic units have been delineated in the Watana relict channel/Borrow Site 0 area (Figure 5.7). These units were differentiated by their physical charac- teristics, as identified in the field, and by their mate- rial properties. These characteristics and properties were used to identify the basic modes of deposition which are described on Figure 5.7. The sediments in the relict channel are interpreted to be Quaternary (Table 5.2) in age and are primarily glacial or glacially related in ong1n. The oldest sediment in the relict channel are unconsolidated boulders, cobbles, and gravels (Unit K) found in the deepest part of the thalweg (Figure 5.8). Following deposition of this Unit K, a major glacial advance deposited the basal till (Unit J). It is likely that during this time the Susitna River was blocked from its old channel and forced south to its present day courses. As this glacier retreated, a peroglacial envi- ronment of ponded lakes and braided streams developed and deposited Unit J 1 • Further glacial retreat accompanied by a minor readvance is shown by the deposition of Unit I. Following deposition of Unit I, the area experienced an interglacial stade which resulted in the erosion of t he s u r face of U n it I. St ream c han n e 1 s c u t i n t o t h i s surface and later infilled with Unit H alluvium. At the close of the interglacial stade, a new ice front advanced across the area depositing the dense basal till of Unit G1 • As melting occurred, a proglacial environment de- veloped. Meltwaters appear to have been blocked, result- ing in the formation of glacial lakes at or near the ice margin. The varied clays and silts ot Unit G were de- posited in these 1 akes. As the glacier retreated the lakes drained eroding the upper Unit G, eventually de- positing the outwash silty sands and gravels of Units E and F. 5-7 After retreat of the glacier, the area was again sub- jected to an interglacial period. During this time, erosion took place, resulting in surface streamflows and inception of lakes in lowland areas. Unit D alluvium and Unit D' lacustrine clays and silts were deposited during this time. Also, a minor readvance of the glacier occurred in the southeastern portion of the Borrow Site D area which resulted in the deposition of the Unit M basal till. At the end of the 0/0' interglacial, glaciers again advanced, reworking the upper sediments of Units 0, D', E and F. The glacier became stagnated resulting in the in-place mass wasting of the ice and deposition of the ice disintegration Unit C. Meltwater from this ice mass reworked Unit D. The mass wasting of this last ice mass resulted in the formation of the hummocky knob-and- kettle features which form the present topography. Recent geologic events in the area are confined to post glacial erosion and frost heaving, as represented by Unit A/B. -Ground Water Conditions The ground water regime in the relict channel is complex and poorly understood because of the presence of inter- mittent permafrost, aquicludes, perched water tables, and confined aquifers. Based on limited drilling informa- tion, it appears that possible artesian or confined water tables exist in Units Hand J', while several other units appear to be unsaturated. A perched water table exists locally on top of the impervious Unit G, and possibly on top of Units M, I and J. Limited permeability testing shows an average value of 1o-3 em/sec for most gravelly materials, and 1o-4 to 10-S em/sec for tills and lacustrine deposits. -Permafrost Conditions Oril"lhole samples and ground temperature envelopes from thermistor installations indicate that permafrost in the Watana relict channel/Borrow Site D area is primarily freezing temperature soil rather than solid phase ice. Maximum observed depth of permafrost is about 40 feet. Most of the visible ice is confined in the annual frost zone (averaging 10 to 15 feet deep) in Units C, 0, E, and F; and to Units G, G', and H in permafrost zones. Average ground temperature at depth, with the exception of several frozen shallow holes, range from 0.5°C to about 1. soc. 5-8 -' ' - - - - - - - - - - - - -Engineering Impacts As previously stated, the principal impacts of the relict channel on project design is the potential of breaching the reservoir rim and excessive seepage resulting in either downstream piping or loss of energy. Although the 1982 work has not totally eliminated these concerns, it d i d p ro v i de add i t i on a 1 i n form at i on i n eva 1 u at i n g t he s e potential problems. The results and preliminary con- clusions derived from this program are presented below. -Reservoir Rim Stability Breaching of the reservoir rim may occur by either settlement and/or slumping under static or dynamic condi- tions. Static failure may be either progressive or catastrophic. Several conditions must exist for slides to develop. These are: Widespread, relatively pervious, loose unconsolidated material; • Widespread permafrost in granular material; and/or • Slide surface with gradients sufficient to cause move- ment. A slide occurring in the Watana relict channel is con- sidered unlikely because of the following: A low potential slide gradient exists in the narrow thalweg section near "The Fins" as the result of the rise in the bedrock surface in this area. A slide further upstream near Deadman Creek waul d require an extremely large quantity of material moving on a low gradient to result in a breaching of the reservoir. Similarly, a failure on the Tsusena Creek side of the channel would likewise be on a low gradient and would involve a large volume of material • • The density of the sediments within the relict channel, as determined by the Standard Penetration Tests (SPT) method, are in excess of 60 per foot bel ow unit C, indicating a relatively dense compact material. This is supported by field observations which show that the majority of units exposed on bank cuts are, for the most part, free standing in steep forests • • As previously stated, only localized permafrost exists within the relict channel thereby minimizing the possi- bility of 1 arge-sca 1 e s 1 ides or sett 1 ement resulting from thawing and sediment • • Although only preliminary data is available, the per- meabilit~ of the upper units appear to be relatively low (lo-to Io-5 em/sec). 5-9 • Work performed during 1982 failed to show any contin- uous uniform unconsolidated material in the relict channel. In conclusion, although work performed to date does not fully eliminate the potential for static failure within the relict channel, the likelihood of such a catastrophic event occurring appears to be small considering: (a) the materials within the channel are relatively competent; (b) no widespread permafrost; and (c) 1 ow surface gra- dients. An alternative method for rim failure may be caused by dynamic shaking by an earthquake resulting in 1 ique- faction of the channel sediments. Liquefaction generally occurs in loose, unconsolidated, well-sorted, saturated materials. Earthquake shaking results in the decrease of the shearing resistance of a cohesionless soil and is associated with a sudden, but temporary increase of the pore fluid pressure. The liquefied material is then temporarily transformed into a fluid mass that could settle and/or flow. To initiate a major liquefaction failure within the Watana relict channel requires the existence of a rela- tively continuous liquefiable material throughout the area. Although a few sorted sands and silts occur in the various units such as Units D, o•, E/F, H, and J' (Figure 5.7), these materials occur only as discontinuous lenses. In addition, the high SPT indicates that the material below Unit C is relatively dense compact material. The majority of material in Unit C has blow counts below 20 per foot. This unit, however, is not a critical unit to the reservoir rim stability as it is relatively freely drained on the surface and makes up only a small portion of the rim near ~aximum pool elevation. Results of work performed in 1982 show that there are no large-scale, liquefiable materials in the upper 250 feet of the relict channel. However, additional drilling and testing will be required during FY83 to further characterize the units at depth and provide further evi- dence against potential for liquefaction. -Leakage Potential Tests performed during the 1982 program gave permeabil i-. ties of the units in the upper 200 to 250 feet in the range between 1xlo-3 and 5x1o-4 em/sec. These tests were performed in those portions of the borehole 5-10 - - - - - - - - . - - which appeared to have very coarse gradations, or where drill fluid was lost. Therefore, these results represent the high permeability range within these units • For the purposes of estimating the maximum probable flow which could 1 eak out of the reservoir under full head, the following assumptions were made, all of which repre- sent worst possible cases • • That a continuous flow path exists from inlet to outlet on each unit; • That units are not blocked or occluded at inlet or out- let; • That the average gradient is 9 percent (Elevation 2200 pool to Elevation 1675 at Tsusena Creek, over minimum flow path of about 6000 feet); • That the inlet section can provide all the flow that the critical "weir" section can pass; and • That average permeability over the entire cross-section is 10-3 em/sec. Under these assumptions, for the known channel width of about 14,000 feet and average depth of 200 feet, the loss at full pool would be about 9 cfs. This loss was not considered to have significant effects on project power economics. Therefore, unless one or more of the perme- able units (such as H, tl', and K) are found in subsequent drilling to extend continuously in significant cross- sections and are exposed to the reservoir, the chance of high flows that would impact project economics is consi- dered highly unlikely. -Potential for Failure by Piping Major leakage through the relict channel could result in piping along Tsusena Creek that would cause erosion and progressive failure working back up the channel. Although the geologic model to date does not indicate piping to be a problem, further geotechnical studies planned for the winter of 1983 are intended to determine permeabilities of the lower stratigraphic units in the relict channel. If, subsequent to this program piping is considered a potential problem, then discharge points along Tsusena Creek will likely be controlled by the placement of properly graded materials to form a filter blanket over the zones of emergence. 5-11 (iii) Fog Lakes Relict Channel During the 1980-82 geotechnical investigation, a review of the site and regional geology was undertaken to determine if there were any other places in the Watana reservoir where bedrock dropped below maximum pool elevation. The results of that study indicated that bedrock drops below reservoir level in several areas on the south bank of the Susitna River in the area of Fog Lakes (Figure 5.9). Pre- liminary seismic refraction surveys were undertaken in this area during 1981 with supplemental refraction surveys per- formed in 1982 (Acres 1982c). -Location and Configuration The location of the Fog Lakes Re 1 i ct Channel is shown on Figure 5.9. The relict channel lies between the bedrock high of the proposed Quarry Site A and the hi 11 s of the Mount Watana area approximately seven miles to the east. For discussion purposes, the relict channel can be divided into three sections: west, central, and east. The west section lies between the bedrock high of Quarry A and the bedrock high of the central section. The bed- rock surface in this area appears to be a series of ridges and valleys. Three of these valleys (from 200 to 800 feet wide) fall below reservoir level. The central section extends for approximately 4.5 miles east-west. Bedrock in this area is relatively shallow with the majority of the section having bedrock surface above maximum pool level. The east section of the channel is the largest with a width of from 6000 to 7000 feet wide. This section of the channel consists of a broad area of bedrock above Elevation 2000 flanking a steep sided bedrock gorge trend northeast-southwest. -Geology Based on seismic refraction surveys and limited soil out- crops, three types of sediments were delineated in the Fog Lakes relict channel: • Surficial deposits • Poorly consolidated glacial sediments, and • Well consolidated glacial sediments The surficial deposits generally varies from 0 to 40 feet and overlies bedrock and the glacial units. The glacial sediments range up to a maximum thickness of 580 feet with seismic velocities from 4,300 to 10,000 feet per second. The higher velocity material may be partially to 5-12 - - - - , - ,.... I - - completely frozen. Outcrops of glacial sediments are rare. Only till was observed in outcrop; however, it is likely that other types of glacial and/or glacially- derived sediments, similar to the Watana relict channel, may be present. Bedrock in the relict channel area consists of the Creta- ceous argillite and graywacke on the west side and Triassic metavolcanic rock to the east (Figure 5.5 and Table 5.2). The contact between these two units is the Talkeetna Thrust Fault whose location and trend is nearly coincident with the main thalweg of the Fog Lakes relict channel. -Ground Water Conditions The ground water table in the area appears to be rela- tively shallow, as evidenced by poor surface drainage and numerous ponds, lakes, and bogs. Drainage of the area is toward the Susitna River to the north and Fog Creek to the south. Ground water gradients are expected to be steep in the Sus itna drainage area and very 1 ow toward Fog Creek. Permafrost Conditions Permafrost conditions are likely to be sporadic through- out the area, as evidenced by the existence of typical permafrost features which include black spruce, hummocky tundra, perched ponds on hills, and skin flows. Higher seismic velocities of sediments at depth indicate par- tially to completely frozen material. (iv) Engineering Impacts As with the Watana relict channel, the potential engineer- ing impacts of the Fog Lakes relict channel are seepage and liquefaction potential. Surface flow are not considered a potential problem in that the topographic low in this area is at a minimum of Elevation 2300, one hundred feet above maximum flood level. -Leakage Estimated maximum gradient from maximum pool level to Fog Creek is about three percent over a maximum possible flow area 8000 feet wide, 150 feet deep, and 5 miles long. To a chi eve a flow in excess of 60 c fs, the average perme- ability over this area would have to be approximately 5xlo-1 em/sec. This high an average permeability would require an extremely clean sorted gravel or sand over the entire area. Although no borings have been performed in this area, the geologic history and seismic velocities measured in this area indicate significant 5-13 presence of densely compacted glacial tills which are expected to exhibit permeabilities in the range of 10-3 to 1o-5 em/sec. ~though drilling should be carried out in this area to confirm the seismic data, the Fog Lakes relict channel is not considered to have any significant economic impact on the project as a result of I eakage. -Piping The potential for p1p1ng failure is not considered likely because of the 1 ow gradient and long flow path (about 5 miles). -Liquefaction Liquefaction failure would require that three conditions be present: (a) material of low relative density which is saturated, and could thereby be shaken to a denser state or trend to "flow" under earthquake vibrations; (b) exposure of this unit to or near a free surface so that it can escape confinement; and (c) continuity of the unit from the free surface to the point where the topography is low enough to cause breaching. For the Fog Lakes relict channel, it is highly unlikely that a liquefiable unit exists in adequate continuity, thickness, and susceptibility that a section of reservoir rim could fail to a depth of more than 100 feet. This magnitude of failure, on a ground surface with a slope of not more than 5 percent, would involve probable quanti- ties in excess of 30 million cubic yards. Field verifi- cation by drilling will likely dispel any concerns regarding liquefaction. (v) Construction Material Investigation Investigation of quarry and borrow sites continued during 1982; however, the emphasis on this work was in Borrow Site [). Oetailed discussion of these sites is presented in Acres (1982b). -Rockfill Material Long-term freeze thaw durability testing was completed in 1982. The rock samples from Quarry Site A consisting of andesite showed a maximum lass of just over 2 percent after 150 cycles. It is concluded that Quarry A is a good source of thermal and water-deterioration resistant rock; for construction material, however, reactivity tests on the andesite should be performed to determine its suitability for concrete aggregate. 5-14 - - - - -, I - - - r ! - r - ~ I - - No further direct exploration or testing was conducted in Quarry B. However, mapping in the area related to the Watana relict channel confirmed the previous conclusions regarding the general unsuitability of this site. -Core ~1ateri a 1 Two potential sources (Borrow Site [) and H) of impervi- ous, semipervious core material were previously identi- fied (Acres 1982b). In 1982, exploration of Borrow Site D consisted of geologic mapping, drilling, and laboratory testing. Results of this investigation showed that most stratigraphic units above Unit G are suitable borrow material with Unit E/F exhibiting the most consistent suitable properties. Total volume of borrow material is about 180 million cubic yards over an area of 1130 acres with an excavated depth of 100 feet. The borrow mate- rials consist of nonplastic silty to silty gravelly sands derived from ice disintegration, alluvial outwash deposits (Units C, D, E/F); and local zones of t"il 1 (Unit M) and lacustrine deposits (Unit D' ). Detailed material properties for Borrow Site 0 are included in Acres Reports (1982b, 1982c). The material properties for Borrow Site D as presented in Section 12.6(e)(v) of Acres Report (1982a) remains valid. Although I iquid 1 imits range trom a I ow of 4 to greater than 25 with plasticity indexes as high as 16 percent, the majority of samples lie between the non-plastic and 2 percent plasticity index range. The material water contents were found to range from 5 to 29 percent, with an average of 11.6 percent. Therefore, in selective mining, the average moisture content of 10 percent or less should readily be obtained. Thermometer readings indicate that a significant portion of the borrow materials are below freezing in the natural state; however, no temperature below -0.2°C has been detected. In addition, 1 ittle evidence of ice was observed in the boring. Based on the above, permafrost is not considered to be a problem in borrow site develop- ment. No work, with the exception of continued thermistor read- ; ngs, was performed in Borrow Site H. These readings showed that in all but one hole, the temperatures below the active zone are about +l°C. 5-_15 -Granular Material Granular material for filter, shells, and concrete aggre- gate will come primarily from Borrow Sites E and I. Work in these areas consisted of geologic mapping of surficial deposits and completion of laboratory testing. Mapping did not reveal any conditions which would change the data assumptions or reserve calculations presented in Acres Report (1982c). Freeze-thaw tests perfonned on aggregate from the Borrow Sites E and I showed losses of 2.3 to 7.8 percent after 140 cycles. The results of the absorption, soundness, and abrasion tests show that the aggregate meets the applicable standards for general structural and dam con- struction. Reactivity test results of the aggregate with cement show negligible adverse reactivity. (c) Devil Canyon Site This section summarizes the results of the 1982 geotechnical in- vestigations for the Devil Canyon damsite. The work during this time involved completion of laboratory testing of quarry and con- crete aggregate material begun in 1981 and reading of borehole instrumentation installed in 1980-81 for ground water and tempera- ture monitoring at the damsite. Detailed discussions of the results of this work are in Acres Report (1982c). (i) Geologic Conditions No geologic investigations were performed at the Devil Canyon damsite in 1982. (ii) Ground Water Conditions Ground water readings during 1982 continued to show a seasonal fluctuation in the two north abutment holes (BH-1 and BH-2) with the level in BH-1 fluctuating from about 50 to 150 vertical feet below the surface, and BH-2 showing water levels equal to or slightly exceeding the collar ele- vation of the hole. Until failure of the BH-4 piezometer near the lake on the south bank, the readings indicated water levels varying only a few feet from lake level. (iii) Permafrost Conditions Thermistor readings in BH-1, BH-2, and BH-3 during 1982 confirm the previous data presented in the 1980-81 Geotech- nical Report (Acres 1982b). No permafrost was found in either the bedrock or surficial material at or around the damsi te. The depth of annual frost penetration in bedrock is about 10 to 18 feet, with the deepest frost penetration occurring in May and June. Depth to zero annual amplitude ranges from 40 to 100 feet. 5-16 - -! """" I - - - - , ..... - - .... - - (iv) Permeability ( v) No additional data pertaining to rock permeability were gathered during 1982. The interpretation presented in the Acres Report (1982b) remains unchanged. Devil Canyon Reservoir Geology Geologic mapping was performed in the upper reaches of the proposed Devil Canyon reservoir as part of the Watana dam- site area regional mapping. This area is discussed in Section 5.1(b). (vi) Construction Material Investigation Construction material investigation during 1982 was limited to the completion of laboratory testing begun during 1981 of granular materials for filters, shells, and aggregate. No further investigation for core material for the saddle dam was undertaken. -Gran u 1 a r Ma t e r i a 1 Granular materials will come from Borrow Site G and pos- sibly Quarry Site K (Acres 1982b). Samples from both areas were tested for suitability as a construction material. Borrow Site G This area was identified as the source for all concrete aggregate, grout sand, and filter gravels and sands. The results of general aggregate suitability tests show that the materials are well within the limits for general con- struction use in concrete, and the low absorption and high abrasion resistance indicate probable suitability for general aggregate use in roads, filters, and related uses. The freeze-thaw durability tests show only moder- ate losses up to 150 cycles. Petrographic analysis of the various material types in Borrow Site G show that the material near river level has a more favorable composition and quality than the material in the upper terrace. Chemical reactivity tests to determine the effect of free silicates on concrete were run on this lower level material. Results indicate the aggregate may have an adverse silicate reaction. Based on these test results, Borrow Site G appears suit- able for all uses at the damsite. 5-17 -Quarry Site K Laboratory testing of g ranodi ori te from Quarry Site K consisted of freeze-thaw durability tests. The tests results showed an 8 percent loss after 150 cycles, which is genera1ly considered unacceptable. However, these samples, which were obtained from a surface exposure, were weathered and not believed to be representative of clean, fresh quarry rock. 5.2-Main Dam Alternatives -Watana (a) Introduction Assessment between an embankment type and a concrete arch type dam for Watana was presented in Section 9.8 of Acres Report (1982a). Subsequent to the submittal of the Feasibility Report, questions arose regarding the potential feasibility of a concrete-faced dam at Watana in lieu of an embankment type. A comparison of these two dam types for Watana is presented in the following section. (b) Concrete Face Rockfill Type Dam The selection of a concrete-faced rockfill dam at Watana would initially appear to offer economic and schedule advantages when compared to a conventional impervious-core rockfill dam. For example, one of the primary areas of concern with the earth-core rockfill dam is the control of water content for the core material and the available construction period during each summer. The core material will have to be protected against frost penetration at the end of each season and the area cleared and prepared to receive new material after each winter. On the other hand, rock- fill materials can be worked almost year-round and the quarrying and placing/compacting operations are not affected by rain and only marginally by winter weather. The concrete-faced rockfill dam would also require less foundation preparation, since the critical foundation contact area is much less than that for the impervious-core/rock foundation contact. The side slopes for faced rockfi 11 could probably be on the order of 1.5:H to 1:V or steeper as compared to the 2.5 and 2.0:H to 1:V for the earth-core rockfill. This would allow greater flexibility for layout of the other facilities, particularly the upstream and downstream portals of the diversion tunnels and the tailrace tunnel portals. The diversion tunnels could be shorter, giving further savings in cost and schedule. However, the height of the Wat~na dam as currently proposed is 885 feet, some 70 percent higher than the. highest concrete-faced rockfill dam built to date (the 525-foot high Areia Oam in Brazil completed in 1980). A review of concrete face rockfill dams indicates that increases in height have been typically in the 5-18 - - - - - - - - - .- - - - - range of 20 percent; for example, Paradela -370 feet completed in 1955; Alto A.nchicaya -460 feet completed in 1974; Areia -525 feet completed in 1980. Although recent compacted-rockfill, concrete-faced dams have generally performed well and are inherently stable even with severe leakage through the face, a one-step increase in height of 70 percent over existing structures is well beyond precedent. In addition to the height of the dam, other factors that are beyond precedent include the seismic and climatic conditions at Susitna. It has been stated that concrete-faced rockfill dams are well able to resist earthquake forces, and it is admitted that they are very stable structures in themselves. However, movement of rock leading to failure of the face slabe near the base of the dam could result in excessive leakage through the dams. To correct such an occurrence would require lowering the water level in the reservoir which would take many years and involve severe economic penalties from loss of generating capacity. No concrete-faced rockfill dam has yet been built in an arctic environment. The drawdown at Watana is in excess of 100 feet and the upper section of the face slab will be subjected to severe freeze/thaw cycles. Although the faced rockfi ll dam appears to offer schedule advan- tages, the overall gain in impoundment schedule would not be so significant. With the earth-core rockfill dam, impoundment can be allowed as the dam is constructed. This is not the case for a concr-ete faced rockfill since the concrete face slab is normally not constructed until all rockfill has been placed and construc- tion settlement completed. The slab is then poured in continuous strips from the foundation to the crest. Most recent high-faced rockfill dams also incorporate an impervious earthfill cover over the lower section to minimize the risk of excessive leakage through zones which, because of their depth below normal water level, are difficult to repair. Such a zone at Watana might cover the lower 200 to 300 feet of the slab and require considerable volumes of impervious fill, none of which could be placed until al T other construction work had been completed. This work would be on the critical path with respect to impoundment and, at the same time, be subject to interference by wet weather. The two types of dam were not cos ted in detai 1 because cost was not considered to be a controlling factor. It is of interest to note, however, that similar alternatives were estimated for the LG 2 project in northern Quebec and the concrete face alternative was estimated to be about 5 per cent cheaper. However, the managers, on the recommendation of their consultants, decided against the use of a concrete faced rockfill dam for the required height of 500 feet in that environment. 5-19 In summary, a concrete-faced rockfill dam at Watana is not con- sidered appropriate as a firm recommendation for the feasibility stage of development of the Susitna project because of the follow- ; ng: -Increase of 70 percent in height over precedent; and -Possible impacts of high seismicity and climatic conditions. 5.3 -Refinements to General Arrangement (a) Introduction This sect ion describes refinements made to the general arrange- ments of the Watana and Devil Canyon projects since the presenta- tion of the Susitna Hydroelectric Project Feasibility Report (Acres 1982a). Changes have been made in the following areas: -Watana project power and outlet facilities intakes; -Devil Canyon project power intake; -Devil Canyon project main spillway gates; Devil Canyon project compensation flow discharge pipe; and -Devil Canyon main access road. Table 5.3 is a correlation of the Feasibility Report drawings with those contained in the report. Revisions to the drawings are noted on the table. (b) Watana Project Power and Outlet Facilities Intakes Based upon the change in minimum operating level of the Watana reservoir from Elevation 2045 to Elevation 2065, as described in Section 7, the invert elevation of the approach channel and in- takes has been raised by approximately the same amount to Eleva- tion 2025 minimum (Plate F4). This change saves in rock excava- tion while still maintaining the required degree of submergence. Also, the cross section of each intake was revised to ensure con- stant velocity from the intake gate through the transition to the 17-foot-diameter, concrete-lined penstock. It was thus possible to reduce the power intake gate nominal width by 3 feet 7 inches to 13 feet 5 inches, and the bulkhead gate nominal width by 2 feet to 19 feet. A further change incorporated into the power intake was the pro- vision of a common headpond for all intakes. This additional requirement was deemed necessary to provide better water tempera- ture control and mixing, thus further mitigating the environmental impacts on downstream river temperatures (see Section 8). A low- 1 evel splitter wall between groups of two intakes has been re- tained to facilitate dewatering and maintenance of the lowest shutters. (c) Devil Canyon Project Power Intake A common headpond has been created for each intake penstock simi- lar to the Watana project power intake (Plate F62). In addition, in order to draw from the reservoir surface over a drawdown range 5-20 - - - - ,....,., - (d) (e) of 50 feet, two openings have been introduced in the upstream con- crete wall for each of the four independent power intakes. The upper opening will always be open, but the lower opening can be closed by a sliding steel shutter. Trashracks are located up- stream from the openings, and a heated ice bulkhead will operate in guides upstream from the racks following the water surface, thus keeping the racks free from ice. The approach channel for the power intake has also been raised by 6 feet to Elevation 1361, thereby reducing the required quantity of rock excavation. Devil Canyon Main Sp"illway Gate A minor refinement has been made to the height of the main spill- way fixed wheel gates. An increase in height of 2 feet has been incorporated after further review of the deta i 1 ed arrangement. This results in gates 56 feet high by 30 feet wide. Devil Canyon Compensation Flow Discharge Pipe The compensation flow discharge pipe has been eliminated from the design. Environmental studies performed subsequent to March 1982 show no need to maintain minimum flows in the river bed from the downstream toe of the dam to the tailrace discharge. (f) Dev"il Canyon Main Access Road Realignment (g) The feasibility study previously indicated an access route which followed the crest of the main arch dam, saddle dam, and fuse plug channel bridge. As a result of the introduction of the Susitna river crossing, the alignment of the main access road has been modified from the vicinity of the Devil Canyon switchyard to the rail head. The previously proposed access route has been retained but downgraded to a permanent site road providing access to the dams and an alternative means of access to the railhead. Haul Roads and Disposal Areas Plates F35 and Fll have been added to the drawings showing pro- posed construction roads and disposal areas. This information has been added to assist in a more detailed environmental assessment of the project area. 5-21 ,_. I - - - - - - REFERENCES Acres American Incorporated. 1982a. Susitna Hydroelectric Project Feasibility Report. Prepared for the Alaska Power Authority. 1982b. Susitna Hydroelectric Project 1980-81 Geotechnical Report. Prepared for the Alaska Power Authority. 1982c. Susitna Hydroelectric Project 1982 Supplement to the 1980-81 Geotechnical Report. Prepared for the Alaska Power Authority. l 1 JOIN I SITE S ,KIKI:. SET QUADRAN RANGE AVERAGE,.... I**** All 265"-335. 300° NE 280"-345. 330" 310° SE 270"-350. 320° sw 270"-340. 325" 295" NW 2 65"-335 325" 295" II All 015"-075. 055" NE 0 15"-065" 040° SE 025"-080" 050" sw 040"-oso• 065" NW 050"-070° 065° *Surface data only **Major joint concentration *** Where set Is present Dlt-: RANGE 5 5"NE-65"SW 5 5"NE-70"SW 60"NE-70"SW 60"NE-70"SW 4 5"NE-60"SW 60"NW-60"SE 60"NW-60"SE 65"NW-60"SE 70"NW-70"SE 60"NW-70"SE **** Includes Subsets Ia and lb (see Section 5. 1) l l 1 1 TABLE 5.1: WATANA DAMSITE JOINT CHARACTERISTICS* SPACING"*" SURFACE CC NDITIONS REMARKS AVERAGE" RANGE AVERAGE TEXTURE COATING_ 75"NE 111 -15 1 2' Planar, smooth tc Parallel to major shears, locally rough, fracture zones, and continuous alteration zones. 80"NE 2 11 -10 1 2' Same as above Carbonate and 80"NE alteration, locally. Major carbonate at WJ-6 80"NE 2"-10 1 2' Same as above 90° 111 -15 1 2' Same as above Major carbonate 75"NE at WJ-7 85"SW 111 -15 1 2' Same as above Minor carbonate 75"NE and alteration, locally. Major carbonate at WJ-4 85"NW 1 "-5 1 1-2 1 Para I lei to fracture zones In NE quadrant; no shears or alteration zones. 80"NW 1 11-10' 1-2 1 Planar to Minor carbonate Irregular, smoot to s I I qhtl y rougl 85"NW 111 -10 1 1-2' Same as above Same as above 85"NW 1 "-10 1 1-2 Planar, smooth tc Same as above rouqh 90" 111 -10 1 1-2' Same as above Same as above TABLE 5. 1 (Cont' d) JOIN I SITE STr IKE SET QUADRAN RANGE AVERAGE" Ill All 335°-035° NE 325°-025. SE --- sw 34o·-o2o• NW 335°-035° IV All Variable NE SE sw NW *Surface data only ** Major joint concentration ***Where set is present 350° 350° --- 345° oo5• 075° 090° 310° oooo 090° 090° DIP, RANGE AVERAGE" 45°E-roow 75•E 55•E-ro•w ro•E ------ ro•E-ao•w aooE 45°E-60°W aooE Sha I low to Moderate 15°S 10°N 25°S 40°NE o5•E 25°N 10•N-10°S --- ****Includes Subsets Ia and lb, (see Section 5.1> J SPACING.,..,..,. SURFACE CONDITIONS REMARKS RANGE AVERAGt TEXTURE COATING 0.5"-5' 1-2' Planar to sl ighth Parallel to minor shears, curved, smooth to fracture zones, and slightly rough alteration zones. 211 -10 1 1-2' Same as above Minor carbonatE Weakly developed. and a Iteration locally ------------Not observed. o. 511 -10 1-2' Planar to Minor carbonatE Strongly developed. irregular smooth and alteration to rough locally 0.511 -10 1-2' Same as above. Same as above Same as above. Planar to Probably stress reI i ef, Irregular near surface. 211 -5'+ 1-2' Same as above. ---Same as above. 2"-5'+ 1-2' Same as above. ---Same as above. 6'1-1 0' 2' Same as above. ---Same as above. 611 -10' 2' 211 -5'+ 2-3 1 Same as above. ---Same as above. ... J J .I J ... J J TABLE 5.2: GEOLOGIC TIME SCALE MILLION OF ERA PERIOD EPOCH GLACIATION YEARS AGO Quaternary Holocene Wisconsinan Pleistocene Illinoian Kansan Nebraskan 1.8 Cenozoic Pl i ocene Miocene Tertiary Oligocene Eocene Paleocene 70 Cretaceous Mesozoic Jurassic Triassic 230 Permian -Pennsylvanian Mississippian Pa 1 eozoi c Devonian Silurian Ordovician Cambrian 600 r Precambrian - J Plate Number March Current Feasibility Report Fl F2 F3 F4 F5 F6 F7 F8 F9 FlO Fll Fl2 F13 F14 F15 Fl6 F17 F18 Fl9 F20 F21 F22 F23 F24 F25 F26 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 .J ----] J TABLE 5.3: CORRELATION OF PLATE NUMBERS WATANA Railbelt Area Reservoir Plan Site Layout Title General Arrangement Hydrological Data-Sheet 1 Hydrological Data -Sheet 2 Simulated Reservoir Operation Main Dam-Plan Maim Dam -Section Main Dam-Profile & Detail Main Dam -Grouting & Drainage Diversion -General Arrangement Diversion -Sections Diversion -Intake Structures Main Spillway-General Arrangement Main Spillway -Control Structure Main Spillway-Chute Sections Main Spillway -Flip Bucket Outlet Facilities-General Arrangement Outlet Facilities -Gate Structure Emergency Spillway Emergency Release -Sections Downstream Portals-Plan & Section Power Facilities-General Arrangement Power Facilities -Access Power Facilities -Plan & Sections Power Intake -Sections Powerhouse-Plans Powerhouse -Sections _-• ...C J .J J ... J Revised Item Main access road. Permanent airstrip. Intake approach channel Intake approach channel New drawing Crest elevation profile Power intake Intake structure Intake structure invert elevation Power intakes Intake invert elevation ,J ·~ J , ___ J ] ) TABLE 5.3 (Page 2) Plate Number March Current Feasibility F27 F28 F29 F30 F31 F32 F33 F34 F35 F36 F37 F38 F39 F40 F41 F42 F43 F44 F45 F46 F47 F48 F49 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 Report Title Transformer Gallery-Plan & Section Surge Chamber & Tailrace-Sections Electrical Legend Powerhouse-Single-Line Diagram Switchyard-Single-Line Diagram & Plan Block Schematic Computer-Aided Control System Access Plan-Proposed Route Access Plan-Typical Details General Layout-Site Facilities General Layout -Construction and Haul Roads Main Construction Campsite Village and Town Site Watana and Devil Canyon -Construction Camp Details DEVIL CANYON Reservoir Plan Site Layout General Arrangement Hydrological Data -Sheet 1 Hydrological Data -Sheet 2 Simulated Reservoir Operation Dams -Plan & Profile Main Dam -Geometry Main Dam -Crown Section Main Dam-Sections Main Dam -Thrust Blocks Main Dam-Grouting & Drainage Main Dam-Outlet Facilities Saddle Dam -Section Switchyard Plan Drawing deleted -) Revised Item 1 Access road. Transmission line. New drawing Access road. Permanent airstrip. New drawing Main access road. Transmission lines Main access road ·~J TABLE 5.3 (Page 3) Plate Number March Current Feasibility Report F50 F51 F52 F53 F54 F55 F56 F57 F58 F59 F60 F61 F62 F63 F64 F65 F66 F67 F68 F69 F70 F71 F72 F73 F74 F75 F76 F77 J ~~ 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 J ~ ... J J Title Saddle Dam-Profile & Detail Diversion -General Arrangement Diversion -Cofferdam Sections Diversion-Sections Main Spillway -General Arrangement Main Spillway -Control Structure Main Spillway -Chute Sections Emergency Spillway-General Arrangement Emergency Spi 11 way -Sections Power Facilities-General Arrangement Power Facilities -Access Power Facilities-Plan & Sections Power Intake -Sections Powerhouse -Plans Powerhouse -Sections Transformer Gallery-Plan & Sections Surge Chamber & Tailrace-Sections Tailrace Portal -Plan & Sections Powerhouse -Single-Line Diagram Switchyard-Single-Line Diagram General Layout -Site Facilities General Layout -Construction & Hau 1 Roads Construction Camp-Plan Temporary Village TRANSMISSION Rail belt 345 k V Si ngl e-Li ne Diagram Ester Substation -Single-Line Diagram & Plan Gold Creek -Single~Line Diagram & Plan Willow Substation -Single-Line Diagram & Plan .I .J ~J ' J J Rev i sed It em New drawing New drawing Compensation flow system Power intake. Compensation flow system Compensation flow system Common headpond. Invert elevation. Compensation flow pumps Compensation flow pumps Compensation flow inlet New drawing Access road. Transmission line. New drawing Main access road New drawing New drawing New drawing New drawing ~- j .J J .J J TABLE 5.3 (Page 4) Plate Number March Current Feasibility Report F78 F79 F80 F81 75 76 Title Knick Arm Substation -Single-Line Diagram & Plan University Substation -Single-Line Diagram & Plan Typical Transmission Line Structures 345 kV System Single Diagram & Transmission Corridor CONSTRUCTION SCHEDULES Watana -Construction Schedule Devil Canyon-Construction Schedule New drawing New drawing New drawing New drawing See Figure 9.1 See Figure 9.2 ) Revised Item T IL L AND OUT~ASH / ~ REFE RENCE : BASE N AP FROM COE,I9 78 _1 •• 200, WATA NA TOPOGRAPHY , SHEETS a ANO 13 OF 2& COORDI N ATES IN FUT, ALASKA STATE PLANE I ZOH E 4 ) -~y:_· ___ / ) ---/· .::::::--' ....-----! ~-~-.-/ \ t W/SJANA DAMSITE TOP OF BEDROCK '· AND SURFICIAL GEOLOGIC MAP ---/ _..,.... CO NTOUR LINES --~~C~N~~~~~C ~AiC:~OUR INTERVAL IOO FEE T TOP OF BED ROCK, CONTOUR INTERVAL 20 F EET --TOPOGRA.PHY CO NTOU R I NTERVAL~ FEET OTHER (\> SPAIHGS FI GURE 5.1 N 3225.000 __ /' /. -w'-3""' ' WATANA DAMSITE GEOLOGIC MAP OUTCAOPS SHOWN OH FIGUR£ ~ I 2 GEOlOGIC SfCTIOHS IN ACRES ,tt82c 3 JOI NT PlOTS IN ACRES 1982c SCALE ~~~·00~-;;1400 FEET FIGURE 5 .2 JCJioiT MT UPS TftE.W PORTAL AREA H• 540 \ \ \ \ -:-' 147,500 -~ ALLUVIUM '""' -<::;__: ~~---::---------..-:._----,_ \· ' ' --- ', ~ --~~-~ ---------·---~ ---J .. 7 ·------··---.. ---I l . #"'4; . ">.to\ \~ - ~'l' WATANA DAMSITE · . ...-- UPSTREAM COFFERDAM AND PORTAL AREA GEOLOGIC MAP UP-14l \ \ LEGEND LITHOLOGY: D""'FlCAI.DE>'OSITS• AlLUVIUM TAWS I, AREAS OF THIN VEGETATION, GREATER THAN 50 .. OF TALUS lEX POSED , TALUS 2 , AREA S OF OE"'Sf VEGETATION, LESS THo\N 50 ... Of TALUS EXPOSED . 0 ~~'6'.tTE J:!N~O:Jle ~tORITE IHCLUOU C2l ~ITE PORPHYRY. -K-FaSIC OtKE. CONTACTS : 8EOAOCK . l!lfOROCKISURFictf.l. DEPOSITS , --OASH£0 WHEitE APPRO'ICIWATf . -·-SUftfiCIAL DEPOSITS, APPf!OXIMATE . STRUCTURE : SHEAfi,WlDTM GftfATER THAN S FE£T, N!Atlll • V[RTICAL TO 't"ERTTCAL UI'LDS DIP ~; EXTENT 'tlii'HEA[ Kf'rfOWtt ANO/ 1 1 OR fi"ERRED. r '.,i ~:t.'i:f::1.~Ril~~~ l.:t.~:S p:~~T, . .r SHOWH, EXTENT WHERE KNOW ANOI'Oft I I IN FERRED • ~ ~g~ei~Ne:f~~ng~~~'[f~ Y£"TICAL EX'TENT WHDif: KNOWN AHO/ 1 OR INFERRED. 7~/. _/ FRACTURE ZONf , 'lfi'IOTH FROW I TO f It & l"f!T, INCLINED, VERTICAL.; EXTENT 4 i WHERE KHOWN IMJ/ 0111 INfERIII£0 . 7.9 ,{ .J. JOtiUS : INCL.INEO, OP[H INCLINED f tt,o'!" ANO VERTICAL.. l i ~ SL.Ul!IP IN SIJRFIC:IAL. DEPOSIT$. OTHER : UP-I t..t -SE<TlOf< LOCAnCII . ~ ~~:~~~~~TURE OESCRI8EO IN ~ .... , ... ~ I. L.OCAT'IOH OF EXPLORATIONS IN ACRES, fUZe:. 2 . GEOL.OGIC SECTIONS Otol IN ACRES 1911Zc:. 3 . JOIIriT PLOTTING IIIETHOO IN ACRES , 1982:c:. 4 . TOI"OfiRAPHY ntOM COE ,I911 , t"w200'. 5 . .APPIIIOX IIU.TE EDGE Of IUVEIII, AUGU ST 1112 . 8 . S[ISWIC L.IN€ SECTIONS IN ACRES, lt82a 7. EXTENT Of SHEARS AND FRACTUR£ ZON[S AlliE lfiiFEfU:IEO BASED ON GEOLOGIC MAPANQ AND SUIISUIIIfACE EXPLDRATIONS ANO AlliE SUBJECT TO VERIFICATION THROUGH FUTUM: [)[TAILED INVESTIGATIONS. 40 80 fEET FIGURE 5 .3 N 3,2.~7,000 ., ____ 1 --------f.l .. ,. -,, 1\' --·--- ··---. <-~~;~~--:~~--:__~-;;.;..~-.,, ---- ·· .. ,, ····· ............ --- ·-- --- TALUS 2 DA--t5oo ,.,, --~- ,, ·~. •x:..__:::_ • WATANA DAMSITE . ~--DOWNSTREAM COFFERDAM AND PORTAL AREA GEOLOGIC MAP LEGEND LITHOLOGY ~Sl.RFlCALOEPOSJTES ; D 0 AUJJVIUIII ,INCL..LOfS MINOR AMOUNT$ OF ANGULAR TALUS NATERIAl. TALUS I, AREAS OF THIN VBifTAtlOH, GREATER Tl1AH "'""OF TAWS ' EXPOSW. TALUS 2, AREAS OF DENSE Y£G[TATJON. LLSS THAN ~ 01" TALUS O:POSEO. DIORITE TO QUARTZ DIORITE, INCUIOES MINOR GRANODIORfT£. ANDESITE PORPHRY,INCLUOES MINOR DACITE AND LATITt.. FELSIC OIKE . CONTACTS --8EOROCK, DASHED WHERE APPROXIMATt. ---8EDAOCK /S~f1CIAL DEPOSITS OASH[O WHERE APPROXIMATE . ---SURflCIAL DEPOSITS, APPROXIMATE. STRUC TURE SHEAR; WIOTH GREATER THAN 5 I"EET, NEAR VERTICAL lO VERTICAL lltLESS DIP 9tOWN ~ EX~WiifRE ICNOWN AND/OR IN FI!IflltED. ;~~;,:~ExT~ ~~~:t~Nc~.:,~OR / I"RACTURE ZOH!:, WIOTl1 GRU.TER THAN ~ ~~~J~s;~v~ ~"~···~~~~L~E~?r~~ir:'"~ _... ~ ~ :~~~;RI~~~~::,oQpEH INCLINI!O, VERTICAL. t.....L......!. 8EOROC:k SUJIII P. OTHER DP -1 t ,,"""'"" '"""" LOCAllON . 8 ~~~IC FV.TUM: DCiCAI8ED IN ACRES , ~ SPRING. FIGURE 5.4 .Jl <,... ... ./') ;·c.)/; /1 () FOG ~,. t..-I LAKf.S < 2217 '--:? . .. _.-....... .... · ··:2~!1 0 .... . ----,) ---.A_...~ .... .· .-/' .. •···· .. --·.;/. n .... / 2110 _.--/ .. ... / c __..-'\ ,__. ... / .. ,, __ WATANA DAMSITE AREA GEOLOGIC MAP SHEET I OF 2 .. ") / c.-- c.··.? + LEGEND , LITHOLOGY : CENOZOIC QUATERNARY El ~~OAL OEPOSITS,UNotFnftENTlAT[0,G[NERALL'r ~ ALL..UVIUhl, ALL.UVIAL T!JtRACES ANO FANS. ~ ICE OISIHT£6RAnOH DEPOSITS. ~ OIJl'WASH . ~-.-,-~ TILL. TERTIARY ~ CXWGlOhiERATt:, SANOSTOHE AND Q...AYSTOHE. Q 'WOlCANICUSl'IC S.tHOSTOfr€, SILTS"TOHE AND SHALf . ~ AHDtS ITE PORftHYitY, JiiiiHOR IASALT. IIIIliiiiiii DIORITE TO OUARTl DIORITE , NINOA GR4HOOIOAITE • ~ BIOTITE GRAHOOIOR~. MESOZOIC CRETACEOUS ~ AAGiu.rr£ ANO GRAYWACJ([, TRIASSIC ~ IASAl TlC METAVOLCANIC ROQCS,. METNIAW.T AND S1....UE PALEOZOIC D BASALY'C TO AHDESITIC J£TA'.Q.CANIC R()O(S. CONTACTS : BEDHOOC , DASHED WH(M: !NnMED. ---~~~F'ICIAJ.. OE?OSrTS, ~WHERE -·-SURI"ICIAL OEPOSITS , APPROXIMATE . STRUCTURE , ,A.,., ,A THJtUST r&ULT, T(ETHONUP"Tl4ROWHSIDE:. ~ ~~~~.::=~~~SOIP~ JOINTS,IN CLINED,V£RTICAL.. 8EOOING,INCUNEO, V!"ltTJCAL.. SYNCLINAL AXIS. I. GEOtOOY WOOIFlED rROM CSEJT!Y AND OTHERS, 1979 . 2.0ETAIL MAPS 0, THE WATANA DAMSITE IN A.C:REI, 1982 c: ! ~ o~!~~~~~gL~~~~g&,~~L~,~~I ~A .. S D-3 4 . EXT£HT OF L11ltOLOO'I' AND S"TlHJCT\JRf AJII:f BMW CW AIR PHOTO INTERPRETATlOH AND LIMITW PIEl...O INV£$TlGATIOH AND ARE SUBJECT TO VERIFICATION THROUGH FVTVRE O£TAILED INVESnGATIOHS. 0 zooo 4000 rEEl' SC ALE !!!!!!!!!!!5=-=a-- FIGURE 5 .5 ' ' ' -·, ~ .. il ~ ~ ~ 0 ~ § ~ '" . \ ~ l 5 ~ I •. :.·,---J~~ I ~ "\ ~ t~,_ ~~ . \ "'... . .~ \ ·-_ ---__ , \ ~~ \ ~ \\ \ .)~ ~ e~ '\ -....... J r \.!( t ......... , '• ' ~ 0 ~I ~ ~ l .l33KS 335 iNiiHJJ.111"'< "'l 10 ILl 0:: :::> !,2 lL ', l }~ ~--"', ~ ~ a f ··.,, f ~ & l A~<~ C 13 .·· ;,.,.---·) / / ,/ ~ f WATANA ' . ' . _)! r~-./~· ·~~7 . ··~ -..;_;Y /. ' / RELICT CHANNEL/ . . TOP OF BEDROCK BORROW SITE D MAP { ·-. / LOCATI ON MAP ~ LITHOLOGY CJ a~DRoc~~: 0\JTCRO CONTACT. P, UNDIFFERENTIATED. BED~OCK I SURFICIAL 0 CON TOUR LI NES: EPOSI"TS APPROXI MATE ToP OF BED ROCK' CONTO . : FOOT CONT~S Dti.~.INTERVAL ~O FEET POGRAP HY, CONTOUR IN TERVAL 10 0 FEET OTHER : A A ti GEOLOG IC SECTIO N LOCATION NOTES ' I. EXPLORAnON ACRES,I'l!!2 a i..fGS AND SEIS MIC 2. DETAILED TOP CF NO AC~ES,t'J!!Zt~INE SECTION S SHOWN IN ACRES, l'lEI2 t . BEDROCK IN DAM SITE 3. GEOLOGIC SECTIONS SHOWH 0 AREA SHOWN IN H FIGURE ~.8. UNIT ® TYPE OF DEPOSIT GLACIOLACUSTRINE a WATERLAIN TILL r---- BASAL TILL OUTWASH (TILL ?) GEOLOGIC EVENT LAKES a FLOATING ICE . ICE MASS PARTIALLY DETACHED (FLOATING}. -BASAL MELnNG, ICE THICKENING -...._ MAJOR GLACIAL ADVANCE . " " STRATIGRAPHIC CCl..UMI-1 BORROW SITE 0 RELICT CHANNEL THICKNESS DESCRIPTION 'ci'RAYCi::AYWiTHAN'GULAR 6 - SUBANGULAR GRAVEL 8 COBSLES . UNSORTED , VERY OCNSE . REMARKS LACUSTRINE LAMINATIONS a VARVES PRESENT TOGETHER WITH STRIATED PEBBLES a SAND AS WELL. STRrATioNSON coARsEFRAcTroN -:-u-rrLE OXIDATION, BASAL TILL STRUCTURE INCLUDING POOR SO RTING, HIGH DENSITY 8 IMBRICATION OF ELONGATED FRAGMENTS. ROUNDED PARTICLES, SORTED. ORGANICS FOUND IN UNIT "H". OLDEST UNCONSOLIDATED DEPOSITS FOUND IN WATANA / x x X .. x ... -. .{ ~~~ _R~.NGE BOULDERS, COBBLES, SAND 8 GRAVEL, FOUND ONLY LOCALLY ALONG CHANNEL RELICT CHANNEL AREA. )" K X ><~X x-1 ~G • .:..I.:..F.::T.+R,:O.:.UN:.::D:..:E:=D.:... ----,.,--,.-,-,-,-,-:::::----I-"CO.:..U::_R-cSc=ES.:....;.Illi07 ALWEGSl CUT INTO BEDROCK . f------f---------jf---=:..:.._====='------------./ .A ~ x >< .X X )( J< PRIMARILY DIORITE a GRANODI ORITE ORIU£0 > 10' INTO BEDROCK TO VERIFY. ® ALLUVIUM § BEDROCK .)( X@) )I ,)( )( .k fi WITH OCCASIONAL INCLUSIONS Of X X X _A _A X .X _.x · ;;;~~~T~ ~:~ITE FOUND IN WESTERN NOTE: STRAnGRAPHIC COLUMN DIAGRAMMATIC 8 NOT TO SCALE . WATANA RELICT CHANNEL I BORROW SITE D GENERALIZED STRATIGRAPHIC COWMN FIGURE 5 .7 l ~----------------------------------------------------------------------------------------. I t300 2100 20001 -r 1950 1900 , .. T I BOO "()() mo 2200 21:>0 2100 2050 2000 1050 1900 ~·· 1800 17!50 SECTION A-A 2050 2000 g•950 ~ ~1 900 ~ 1850 1800 1750 WATANA RELICT CHANNEL I BORROW SITE D GEOLOGIC SECTIONS SECTION B-8 ~ SURFICIAL DEPOSIT ~ ICE DtSI NTERGAATION OEPOSin ~ DASAL fLL [];) ALl.UVIIJirlll ~ OUHIIASH 8::::J LACUSTRINE ~ 8 ASA LTILL ~ ALLUVIUN ft:'ITjl OUTWASH ~TILL 8r -SL. ~ ALLUVIUM ,AND LACUSTRINE DePOSITS mE ALLUVIUM C!!:l 8E~OCK ~ L FOR DETAILS OF Snloi.TIGRAPMY SEE FIGURE 5.7 2. fOR LOCAllOH Of' SEtllONS SO: FIG~£ 5 a. 3. EXTENT Of STRATA AHO COHTAC'TS ARE INF't:RR£0 BASED OH INTERPRETATJ>N OF SU85l.ffFACE ElCPl.ORATlO NS AN D A.R£ SU8JECT TO \I ERIFICATlON 8Y FUT URE I,.,.,ESTIGA'nONll . HORIZ . SCALE VERT . SCALE FIGURE 5 .8 ~ i i ~~ ;:~~ I ~~~ ~ 1! ;~g ~ i ~~~ ! 0E O o~:e ~g ! ~~~ ~8w "i o,:> ~~ "' ~ff cc ~ "EE ~~ z ~~~ 01 ~ m ::; .. "' gg~ z 9 u ::> w 0 BJ 1! f! I I <!) J: 8 8 I "' .. I ..J ::; . I .\ ', ,.......,.,. '1~. \-~ • > (\ ~~:.~.-:;,,_.~::_··:.':_.;'_.,~·-_'.) -~~~J .. :?> ' ---- ·--~-: .... -.'), ::\~"'· -~~-. ·: ... -~ ..,:r::-_:~:_\ / t; 'I ·' ·:i •.• I ·' I , .-r-· I . -"" ''·, '.Z.::_ . w - - 6 -TRANSMISSION FACILITIES 6.1-Introduction This section describes the development of transmission facilities from the original Acres American Incorporated POS of February 1980 through to the filing of the FERC License Application in February 1983. The major topics covered in the transmission studies include: -Electrical system studies; -Transmission corridor selection; -Transmission route selection; -Transmission towers, foundations and conductors; -Substations; and -Dispatch center and communications. The main body of this section is concerned with the transmission studies that have taken place subsequent to the issuance of the Susitna Hydroelectric Project Feasibility Report in March 1982 (Acres 1982a). These studies included· a reassessment of the transmission line corridor within the Central Study Area, and a land acquisition analysis in the northern, southern and central study areas; the purpose of which was to fine-tune the alignment and determine the legal descriptions of the rights-of-way. The ways in which these studies have affected each of the six major topics mentioned above are discussed in the following sections. 6.2-Previous Studies The two previously published reports which contain the most information relevant to the transmission line studies are: The Upper Susitna River Basin Interim Feasibility Report, prepared by the COE (1975). -The Economic Feasibility Study for the Anchorage-Fairbanks Intertie, prepared by International Engineering Company, Inc., and Robert Retherford Associates. ( IECO/RWRA 1979). The COE report consisted primarily of an evaluation of alternative corridor locations to aid in the selection of those which maximized reliability and minimized costs. Utilizing aerial photographs and existing maps, general corridors connecting the project site with Anchorage and Fairbanks were selected. This study was general in nature and was intended only to demonstrate project feasibility. The IECO/RWRA report utilized the COE report as background information for both economic feasibility determination and route selection. The corridor selected by IECO/RWRA was very similar to that selected by the COE with further definition. The route selected was based on shortest length, accessibility, and environmental compatibility. The report also presented a detailed economic feasibility study for the Anchorage- Fairbanks transmission intertie. 6-1 These two reports, together with the various subtask reports published by Acres since the POS February 1980, served as the data base for the Susitna Hydroelectric Project Feasibility Report (Acres 1982a), to which this report is a supplement. 6.3-Electric Systems Studies Subsequent to the publication of the Feasibility Report (Acres 1982a) the route of the Intertie between Willow and Healy has been finalized. As a result of this, the transmission system has undergone the follow- ing changes: At the time the Feasibility Report was published, the intertie inter- connected with the Susitna transmission system at Devil Canyon. Since then the i ntert i e has been rerouted to the extent that it now passes approximately eight miles to the west of the Devil Canyon damsite. Studies indicated that the optimum arrangement for connecting to the intertie was to construct a switching station on the south bank terraces of the Susitna River at approximately river mile (RM) 142. The location of this station, referred to as the Gold Creek Switching Station, together with the location of the intertie and other project features, is shown in Figure 6.1. A single-line diagram and plan of the switchyard is presented in Figure 6.2. Following a land acquisition analysis conducted in the latter half of 1982, the transmission line routing was finalized and the lengths of the various line sections recalculated. Thus Table 14.3 of the Acres Feasibility Report (Acres 1982a) summarizing the transmission system characteristics has been revised to include these updated mileages and the additional switching station at Gold Creek. These revisions are presented in Table 6.1. Figure 14.1 of the Feasibility Report, showing the configuration of the recommended system. was also changed accordingly and is presented as Figure 6.3. 6.4-Corridor Identification and Selection Developnent of the proposed Susitna project requires a transmission system to deliver electric power to the Railbelt area. The pre- construction of the intertie system will result in a corridor and route for the Susitna transmission lines between Willow and Healy. Therefore three areas were identified as needing further study: -Northern study area, to connect Healy with Fairbanks; -Central study area. to connect the Watana and Devil Canyon damsites with the intertie; -Southern study area, to connect Willow with Anchorage. The identification of candidate corridors was based on the considera- tion of previous studies, existing data, aerial reconnaissance, and limited field studies. Corridors 3 to 5 miles wide, which met the criteria discussed in paragraph (a) below, were then selected in each of the three study areas. 6-2 - ' ~ i . ~ - l l l - -I I~ - (a) (b) Selection Criteria The objective of the corridor selection conducted by Acres was to select feasible transmission line corridors in each of the three study areas, i.e., northern, central, and southern. Technical, economic, and environmental criteria were developed to select potential corridors within each of the three areas. These cri- teria are listed in Table 6.2. Environmental inventory tables were then compiled for each cor- ridor selected, listing length, number of road crossings, number of river and creek crossings, topography, soils, land ownership/ status, existing and proposed development, existing rights-of-way, scenic quality/recreation, cultural resources, vegetation, fish, birds, furbearers, and big game. These tables and a more thorough discussion of the technical, economic, and environmental criteria in Table 6.2 above, are included in the Transmission Line Corridor Screening Closeout Report of September 1981 (Acres 1981). Based on this analysis, 22 corridors were selected: 3 in the southern study area, 15 in the central area, and 4 in the northern study area. Three of the corridors in the southern study area run in a north-south direction, while one runs northeast to Palmer, then northwest to Willow. Corridors in the central area are in two general categories: those running from the Watana damsite west to the intertie, and those running north to the Denali High- way and the Chulitna River. Co rri do rs in the northern study area run either west or east to bypass the Alaskan Range, then proceed north to Fairbanks. The location of these corridors is shown in the Feasibility Report (Acres 1982a). Screening Criteria The selected corridors were then subjected to a further evaluation to determine which ones met the more specific technical, economic, and environmental criteria described in Table 6.3. The rationale for the selection of these criteria is explained in the Closeout Report of September 1981 (Acres 1981). In addition to these criteria, each corridor was screened for re- liability. Six basic factors were considered: -Elevation: Lines located at elevations below 4000 feet will be less exposed to severe wind and ice conditions which can inter- rupt service. -Aircraft: Avoidance of areas near aircraft 1 anding and take- off operations will minimize the risk of power failures. Stability: Avoidance of areas susceptible to land, ice, and snow slides will reduce the chance of power failures. 6-3 Topography: Lines located in areas with gentle relief will be easier to construct, repair, and maintain in operation. -Access: Lines located in reasonable proximity to transportation corridors will be more quickly accessible and,· therefore, more quickly repaired if any failures occur. The screening criteria and reliability factors for each corridor were evaluated utilizing topographic maps, aerial photos, aerial overflights, and published materials. Each corridor was then assigned four ratings (one each for technical, economic, and environmental considerations, and one overall summary rating). Ratings were defined as follows: A -recommended C -acceptable but not preferred F -unacceptable From th~ technical point of view, reliability was the main objec- tive. An environmentally and economically sound corridor was rejected if it would be unreliable. Thus, any line which received an F technical rating was assigned a summary rating of F and eliminated from further consideration. Similarly. because of the critical importance of environmental considerations, any corridor which received an F rating for environmental impacts was assigned a summary rating of F, and eliminated from consideration. (c) Selected Corridors In the Feasibility Report (Acres 1982a) the selected transmission corridor consisted of the following segments: -Southern Study Area Central Study Area -Northern Study Area Corridor (2) Corridor (1) Cor ri do r ( 1) ADFC ABCD ABC Descriptions of these corridors and reasons for the rejection of the other corridors are presented in Section 2 of Exhibit B, FERC License Application (Acres 1983a). More detail on the screening process and the specific technical, economic, and environmental ratings of each alternative is included in Chapter 10, Exhibit E of the FERC License Application (Acres 1983). However, at the time the Feasibility Report was published, the routing of the proposed access road between the dams i tes was undecided. The location of the access road is of major importance in relation to the transmission line within the central study area. both in terms of economics and environmental impact. There- fore. following the selection of the Denali-North Plan as the pro- posed access route in September 1982, the transmission line corri- dor alternatives in the central study area were reassessed. 6-4 _, I - - - - ..... - - - ,... r - Of the 15 corridors originally considered in the central study area, 11 were found to be unacceptable, since they had an overall rating of "F." The 4 remaining corridors were then subjected to a more detailed evaluation and comparison to determine which corri- dor most closely satisfied the screening criteria. 6.5-Corridor Reassessment: Central Study Area The four corridors i dent ifi ed as being acceptab 1 e in terms of the technical, economic, and environmental criteria described in the Feas- i bi 1 ity Report (Acres 1982a) are corridors 1, 3, 13, and 14. The 4 corridors comprise the following segments: Corridor One ABCD AJCF ABCF AJCD -Corridor Three -Corridor Thirteen -Corridor Fourteen Segments ABC and AJC link Watana with Devil Canyon and, similarly, Seg- ments CD and CF link Devil Canyon with the intertie. In order to compare the four corridors more directly, a preliminary route was selected in each of the segments. These routes are shown in Figure 6.4. On closer examination of the two routes between Devil Canyon and the i ntert i e, the route in Segment CD was found to be superior to the route in Segment CF for the following reasons: (a) (b) Economic A four-wheel-drive trail is already in existence on the south side of the Susitna River between Gold Creek and the proposed location of the rail head facility at Devil Canyon. Therefore the need for new roads along Segment CD, both for construction and operation and maintenance, is significantly less than for Segment CF, which requires the construction of a pioneer road. In additio-n, the proposed Gold Creek to Devil Canyon rail road extension will also run parallel to Segment CD. Another primary economic aspect con- sidered was. the length of the corridors. However, since the lengths of Segments CD and CF are 8. 8 miles and 8. 7 miles, respectively, this was not a significant factor. Amongst the secondary economic considerations is that of topography. Segment CF crosses more rugged terrain at a higher elevation than Segment CD and would, therefore, prove more difficult and costly to con- struct and maintain. Hence, Segment CD was considered to have a higher overall economic rating. Technical Although both segments are routed below 3000 feet in elevation, Segment CF crosses more rugged, exposed terrain with a maximum elevation of 2600 feet. Segment CD, on the other hand, traverses 6-5 flatter terrain and has a maximum elevation of 1800 feet. The disadvantages of Segment CF are somewhat offset, however, by the Susitna River crossing that will be needed at RM 150 for Segment CD. Overall, the technical difficulties associated with the two segments may be regarded as being similar. (d) Environmental One of the main concerns of the various environmental groups and agencies is to keep any form of access away from sensitive ecolo- gical areas previously inaccessible other than by foot. Creating a pioneer road to construct and maintain a transmission line along Segment CF would open that area to all terrain vehicle and public use, and thereby increase the potential for adverse impacts to the environment. The potential for environmental impacts along Seg- ment CD would be present regardless of where the transmission line was built, since there is an existing four-wheel-drive trail, together with the proposed railroad extension, in that area. It is clearly desirable to restrict environmental impacts to a single common corridor; for that reason, Segment CD is preferable to Segment CF. Because of potential environmental impacts and economic ratings, Segment CF was dropped in favor of Segment CD. Consequently, Corridors 3 (AJCF) and 13 (ABCF) were el im·inated from further con- sideration. The two corridors rema1n1ng are, therefore, Corridors 1 (ABCD) and 14 (AJCD). This reduces to a comparison of alternative routes in Segment ABC on the south side of the Susitna River and Segment AJC on the north side. These routes were then screened in accordance with the criteria set out in the Transmission Line Corridor Screening Closeout Report of September 1981 (Acres 1981). The key points of this evaluation are outlined below: (d) Economic For the Watana development, two 345-kv transmission 1 ines will be canst ructed from Watana through to the i ntert ie. When comparing the relative lengths of transmission line, it was found that the southern route utilizing segment ABC was 33.6 miles in total length compared to 36.4 miles for the northern route using Segment AJC. Although a difference in length of 2.8 miles (equivalent to 12 towers at a spacing of 1200 feet) seems significant, other fac- tors were taken into account. Segment ABC contains mostly wood- land black spruce in Segment AB. Segment BC contains open and woodland spruce forests, low shrub, and open and closed mixed forest in about equal amounts. Segment AJC, on the other hand, contains significantly less vegetation and is composed predomi- nantly of low shrub, and tundra in Segment AJ and tall shrub, low shrub and open mixed forest in Segment JC. Consequently, the amount of clearing associated with Segment AJC is considerably less than with Segment ABC, resulting in savings not only during 6-6 - - - - - -· - - - - - .... r I construction but also during periodic recutting. Additional costs would also be incurred with Segment ABC because of the increased spans needed to cross the Susitna River (at RM 165.3) and two other major creek crossings. In summary, the cost differential between the two segments would probably be marginal. (e) Technical (f) The route along Segment AJC traverses generally moderately sloping terrain ranging in height from 2000 feet to 3500 feet, with 9 miles of the route being at an elevation in excess of 3000 feet. Route ABC traverses more rugged terrain, crossing several deep ravines, and ran~es in elevation from 1800 feet to 2800 feet. In general, there are advantages of reliability and cost associated with transmission lines routed under 3000 feet. The nine miles of Route AJC at elevations in excess of 3000 feet will be subject to more severe wind and ice loadings than Route ABC, and the towers will have to be designed accordingly. However, these additional costs will be offset by the construction and maintenance problems with the more rugged topography and major river and creek cross- ings of Route ABC. The technical difficulties associated with the two segments are therefore considered similar. E nv i ronmenta 1 From the previous analysis, it is evident that there are no signi- ficant differences between the two routes in terms of technical difficulty and economics. The deciding factor, therefore, reduces to the environmental impacts. The access road routing between Watana and Devil Canyon was selected because it has the 1 east potential for creating adverse impacts to wildlife, wildlife habi- tat, and fisheries. Similarly, Segment AJC, within which the access road is located, is environmentally less sensitive than Segment ABC, for it traverses or approaches fewer areas of produc- tive habitat and zones of species concentration or movement. The most important consideration, however, is that for ground access during operation and maintenance, it will be necessary to have some form of trail along the transmission line route. This trail would permit human entry into an area which is relatively inacces- sible at present, causing both direct and indirect impacts. By placing the transmission and access road within the same general corridor as in Segment AJC, impacts will be confined to that one corridor. If access route and transmission line are placed in separate corridors, as in Segment ABC, environmental impacts would be far greater. Segment AJC is thus considered superior to segment ABC. Conse- quently, corridor 1 (ABCD) was eliminated and Corridor 14 (AJCD) selected as the proposed route. 6-7 6.6 -Final Corridor Selection Table 14.6 of the Feasibility Report (Acres 1982a), which gives the summary of ratings for each of the three corridors, was revised following the change to the proposed transmission line corridor in the central study area. The revised table is presented as Table 6.4. The transmission line corridor presented in the FERC License Applica- tion thus changed to: -Southern Study Area -Central Study Area -Northern Study Area Corridor 2 ADFC Corridor 14 AJCD Corridor 1 ABC A more detailed explanation of the screening and final selection pro- cess, with particular reference to environmental constraints, is given in Chapter 10 of Exhibit E, of the FERC License Application (Acres 1983). 6.7-Route Selection (a) Studies Prior to Publication of Feasibility Re~ort The route selection methodology followed in Section 14.3 of the Feasibility Report (Acres 1982a) resulted in the development of recommended routes for each of the three study areas. The data base used in this analysis was obtained from: -An up-to-date land status study; -Existing aerial photographs; -New aerial photographs produced for selected sections of the previously recommended transmission line corridors; -Environmental studies including aesthetic considerations; -Climatological studies; -Geotechnical exploration; -Additional field studies; and -Public opinions. Many specific routing constraints were identified during the pre- liminary screening, and others were determined during the 1981 field investigations. These constraints were collated, placed on a base map, and a route of least impact selected. (b) Studies Subsequent to Publication of Feasibility Report The ori gina 1 corridors which were three to five miles in width were narrowed to a half mi 1 e and, after final adjustment, to a finalized route with a defined right-of-way. As discussed earlier, the routing of the transmission line corri- dor in the central study area was changed so that it shares the same general corridor as the access road between the dams and the railroad extension between Devil Canyon and Gold Creek. The final 6-8 - - - - - - - - ~ I .... - - - (c) alignment within this section was chosen to parallel the access road and railroad extension to the maximum extent possible so as to minimize the mileage of new access trail development. It is also desirable to minimize the number of bends in the corridor to keep the number of special structures and, therefore, the cost to a minimum. With both these objectives in mind, the selected alignment, as shown in Figure 6.1, represents the optimum align- ment of the transmission line based on existing data. In the latter half of 1982, a land acquisition analysis was con- ducted along the length of the transmission line corridor, the purpose of which was to identify areas where land acquisition would present a problem. Additional environmental studies identi- fying environmentally sensitive areas were also undertaken. These studies have resulted in the alignment being refined along the northern and southern corridor stubs to the extent that most of the land acquisition problems and environmentally sensitive zones have been avoided. The selected transmission line route for the three study areas is presented in Exhibit G of the FERC License Application (Acres 1983b). This route will be subject to some minor revision during the final design phase once the detailed soils investigations and engineering design are completed. Right-of-way Preliminary studies have indicated that for a hinged-guyed x-con- figuration tower the following right-of-way widths should be sufficient. 1 tower 2 towers 3 towers 4 towers 190 feet 300 feet 400 feet 510 feet These right-of-way widths were developed assuming the following parameters: -Height from tower cross arm to ground 85 feet; -Horizontal phase spacing, 33 feet; and -Level terrain (less than 10° slope). During final design, these right-of-way widths may vary slightly where difficult terrain is encountered or the need for special tower structures dictates. b.8 -Towers, Foundations, and Conductors The types of towers, foundations, and conductors to be utilized in the transmission system have not changed since the publication of the Feasibility Report. In general, hinged-guyed, x-configuration towers, of the type selected for the intertie, will be used. Guyed pole-type structures will be used on larger angle and dead end structures; and a 6-9 similar arrangement used in especially heavy loading zones. A span of 1200 to 1300 feet is expected with final spans varying to greater and lesser values in specific cases depending upon span ratio and loading zone. Typical tower and foundation details are given in Figures 14.6 and 14.7 of the Feasibility Report. (Acres 1982a). 6.9-Substations As discussed earlier, the intertie has been re-routed since the Feasi- bility Report was issued; and the Gold Creek switching station added to the transmission system. The switching station will be located in a wooded area on the south bank terraces of the river at approximately RM 142. The location of the switching station is shown in Figure 6.1. A single-line diagram and plan of the switchyard is presented in Figure 6.2. 6.10-Dispatch Center and Communications The operation of the transmission facility and the dispatch of power to the load centers will be controlled from a central dispatch and Energy Management System (EMS) center. It is recommended that the center be located at Willow since a suitable site could be developed at the Willow Switching Station site. The center will operate in conjunction with northern and southern area control systems in Fairbanks and Anchorage. The generation at the Susitna Hydroelectric sites would be controlled at the Watana power facility. The Energy Management Center would orchestrate the avera 11 operation of the system by request to the three local generation-control centers for action and direct operation of the Gold Creek Switching Station and the four 345-kv switching and substations along the transmission system. As recommended in the Feasibility Report (Acres 1982a), the system communications requirements will be provided by means of a microwave system. The system will be an enlargement of the facility being pro- vided for the operation of the intertie between Willow and Healy. Communications into the hydroelectric plants will be via a microwave extension from the Gold Creek Switching Station. 6-10 - - - - - - - - - REFERENCES Acres American Incorporated. 1981. Susitna Hydroelectric Project Transmission Line Corridor Screening Closeout Report. Prepared for the Alaska Power Authority. 1982a. Susitna Hydroelectric Project Feasibility Report. Prepared for the Alaska Power Authority. 1983. Susitna Hydroelectric Project FERC License Application- Exhibit E. Prepared for the Alaska Power Authority. 1983a. Susitna Hydroelectric Project FERC License Applica- tion-Exhibit B. Prepared for the Alaska Power Authority. 1983b. Susitna Hydroelectric Project FERC License Applica- tion-Exhibit G. Prepared for the Alaska Power Authority. International Engineering Company, Inc./Robert W. Retherford Associates. 1979. Economic Feasibility Study. Prepared for the Alaska Power Authority. TABLE 6.1: TRANSMISSION SYSTEM CHARACTERISTICS Length Number of Voltage Line Section (mi ) Circuits (kV) Watana to Gold Creek 37 2 345 Devil Canyon to Gold Creek 8 2 345 Gold Creek to Willow 79 3 345 Willow to Knik Arm 44 3 345 -Knik Arm Crossing* 3 3 345 Knik Arm to University 19 2 345 Substation (Anchorage) Gold Creek to Ester 185 2 345 ,-Substation (Fairbanks) - - - - TABLE 6.2: TECHNICAL, ECONOMIC, AND ENVIRONMENTAL CRITERIA USED IN CORRIDOR SELECTION Type 1. Technical -Primary -Secondary 2. Economical -Primary -Secondary 3. Environmental -Primary -Secondary Criteria General Location Elevation Relief Access River Crossings Elevation Access River Crossings Timbered Areas Wetlands Devel O(lllent Selection Connect with Intertie near Gold Creek, Willow, and Healy. Connect Healy to Fairbanks. Connect Willow to Anchorage. Avoid mountainous areas. Select gentle relief. Locate in proximity to existing transportation corridors to facilitate maintenance and repairs. Minimize wide crossings. Avoid mountainous areas. Locate in proximity to existing transportation corridors to reduce construction costs. Minimize wide crossings. Minimize such areas to reduce clearing costs. Minimize crossings which require special designs. Avoid existing or proposed developed areas. Existing Transmission Parallel. Right-of-Way Land Status Avoid private lands, wildlife refuges, parks. Topography Select gentle relief. Vegetation Avoid heavily timbered areas. - - -l - ~· - TECHNICAL Primary Secondary ECONOMIC Primary - Secondary - ENVIRONMENTAL .... Primary Secondary - TABLE 6.3: TECHNICAL, ECONOMIC, AND ENVIRONMENTAL CRITERIA USED IN CORRIDOR SCREENING Topography Climate and Elevation Soils Length Vegetation and Clearing Highway and River Crossings Length Presence of Right-of-Way Presence of Access Roads Topography Stream Crossings Highway Railroad Crossings Aesthetic and Visual Land Use Presence of Existing Right-of-Way Existing and Proposed Development Length Topography Soils Cultural Resources Vegetation Fishery Resources Wildlife Resources -TABLE 6.4: SUMMARY OF SCREENING RESULTS - - ..... ' I I I I I I ~) HIGH LEVEL BRIDGE ·\.__.~-0· ..f --...... \ ~~ \ ) ( ) '"\..f)'v. I v _ _,..-· / -/ PROPOSED PROJECT ----FEATURES ~-- LEGEND ' -RAIL ROAD E~TENSION -~~iQOSED ACCESS ---PROPOSE Ll N E D TRANSMIS --INTERTI SION fo//;;iY'iJ IM~ . -····· NT AREA IFUTUIItE I WIL LOW LW> I I I I I I ~-... :--o--1 <--~--~, WILLOW LWZ ---,----------- 1 l4S I('J IUS I IT ----;r,------------- 1 I ,;l i 'l : ~ "'' It ' EIIIIMG L J; "' I ' srr ~----+~HI-.._ I I I I I I I I I I MET I I I -~ ... .., @- [fiiiN&- ~ e -~ e-~ - I~ [ ~~ I ~ I ~ e ap F --j I ~ : ~ 1 11i 1 -r 1 · I ' ___ ...j_J. __ _ -~ 3M~ KV BUS 2 --------- L ----------- '---> Ll WATANA ~ WILLOW E5T£R ESTER LWI : LF2 LFI ::l ~J ::1 --l t --l<;-1 f I -----1 _______ ._, __ -I. I ' I / Q 1.1. I '' ll I f ..L ..L ..L.L , , L r UJ W .H LJ ~,I_.H H~ ... .;..1...,+-'m \ '1!-..J :-...!.~:---t :·-f- I I' J< J lt~ .L ..L J, J, J,j, eL -L ~ ~ "[lifO¥[ Iff FUTUIIIE ~:t~~ •IH~H ~ ~ 3 3 ,..,.., \ t-!~H+f I < -1 .-....L-t :-~:-+;--, L -3 I I (-I -3 l '---> LZ WATAMA rl 0 i I -1 I I I I I I I : : ~ : l] I I ~ 1 : I I I.,. I I 1 I 1 t I •' I --,------~-·--,--+-----J I I , __ J -f <--«-•., I I I I I I L> D<v1l. CAN'I"ON IFUTUftE) I I ·------f •H:-• ~i I I I I I L4 D£1/IL CAlli 'I" ON (FUTU .. E) SINGLE LINE DIAGRAM GOLD CREEK SWITCHYARD SINGLE LINE DIAGRAM AND PLAN TO W1UOW eoo·-o• RELA•'I" BUILDING I o I --t fu?L".~~ ~ :=::=" ~:=:~j J··- SWITCHYARD PLAN SCALE A SCALE A"O~~IOQ!iiiiiiiii200 ~flitCH • 100 FEET I Fl GURE 6.2 ~----------------~------~l 44 MILES ------( I r -- 1 I I I LKI 19 MILES LUZ CHUGACH ELECTRIC ASSOCIATION 78 MILES ---,-----l 1815 MILES I ~~~---t=-'-1-----r--F"'-----,-t- 1 ' I ' I .:, I'' ! ~:- I I --~ ' -, ;J ~ : '1 ~ I I I SHUNT REACTa.. r'1 lTJ .. ~. t--FUT1JM: GOLD CREEK : : I r--------- I ESTER {fAIAIAHI(S) ....... ""-'-EY fL!Clli'IC . ...,~ --... --+,...._ _ _,'-:-1---_._-+--... -r l2 ~L:S I L.4 8 MILES L-----~~~~~~~~~~~~~~~~~~~~~-------~ UNIVERSITY IANCHORAR ) ---------, ANCHORAGE WUNICIPAL LIGHT a POWER 2.50 MVA 3<t!!/II!!-IS.81tV 6 X 170 MW UNITS ~ -1993 ---2002 I I I I I t --~-!002 ,,.sr:::n:-· i I _J-~----l-·------·---1 I I I 1 l , ~, ~ . ! . I l ~ r : I ! r! · r · DEVIL L -~;; L~, .tl CANYON I ~ l I l ~i! : ;-+ 1:!. ~~-I I ~ : ; I ; • ; 1 ! , ! I I I I. I I I : -~-1----~-!----~-L~- L ---.i_X ~ ~ ~IT_L --_j RAILBELT 345 KV TRANSMISSION SYSTEM SINGLE LINE DIAGRAM FIGURE 6 .3 1 . .. I l 1 CENTRAL STUDY AREA ALTERNATIVE TRANSMISSION ROUTES FIGURE 6.4 - r - 7 -PROJECT OPERATION 7.1 -Introduction The energy potential of the Sus i tna Hydroelectric Project was assessed using a monthly energy simulation model developed specifically for the project. Studies made to determine optimum height, drawdown, and impact of downstream flow requirements are reported in Appendix A, Hydrological Studies of the Susitna Hydroelectric Project, Feasibility Report (Acres 1982a). Extension of these studies was made in 1982 to include refinements to operating rule curves, downstream flow, and energy demand. Downstream flow requirements were refined during the fishery mitigation plan development and particularly affected flow timing to ensure coincidence with critical spawning periods. Further details of the mitigation plan are given in the Susitna Hydroelectric Project, License Application, Exhibit E (Acres 1983). Complete output for the selected operations is given in Attachment A of this report for Watana operation and Watana/Devil Canyon operation. 7.2 -Simulation Model A multi-reservoir energy simulation model was used to evaluate the optimum method of operating the Susitna Hydroelectric Project for a range of post-project flows at the Gold Creek gaging station 15 miles downstream from the Devil Canyon damsite. The simulation model incorporates sever'al features which are satisfied according to the following hierarchy: -Minimum downstream flow requirement; -Minimum energy demand; -Reservoir operation rule; and -Maximum usable energy (demand). Input to the model includes the reservoir storage-elevation relation- ships, powerhouse characteristics, streamflow at the damsites and at the reference downstream location, system demand for a given year, system demand pattern, and reservoir operating rules, plus other minor operating and program specific values. Weekly and monthly energy simulation programs were developed. Ho\t'Jever, their only difference is in the basic time step. Both programs have the following solution path: -Meet minimum energy demand; -Check reservoir levels against rule curve; -Check energy production against energy demand; and -Meet downstream flow requirement. 7-1 The m1n1rnum energy demand was determined as a fraction of the monthly energy demand. This fraction was iteratively derived so that the mini- mum energy is produced at all times and all available reservoir storage is used. The monthly energy is based on the energy pattern developed by ISER/Woodward Clyde (ISER/~Iood~t~ard Clyde 1980). During periods of above average runoff, the reservoir levels remain substantially higher than average. This results, during periods of back-to-back wet years, in spillage during summer months. To reduce this spillage and waste of energy, it is worthwhile to draw the reser- voir down during the winter months of wetter periods. This is achieved by the rule curve. The rule curve check wi 11 compare reservoir 1 evel s after minimum energy production with the rule curve. If reservoir levels are above the rule curve level, more water is released through the powerhouse. The amount of the release is the quantity of water in storage over the rule curve level times a fraction. This fraction is usually equal to one and is wsed to maintain additional storage in the reservoirs, particularly in early summer months. To ensure that the above release does not result in energy production in excess of system needs, a check is made against system energy demand. This demand is for a given year and is equal to the forecast for that year (Battelle 1982). The period demand pattern is based on studies by Acres American (Acres 1983a). If overproduction occurs, powerhouse flows are reduced and the water is saved in storage. Energy requirements are met within a given percentage (generally one percent) whenever the minimum or maximum energy routines are evoked. This, however, can be negated by downstream flow requirements which could cause excessive powerhouse flows. In this situation, flows are shifted to the spillways in a specified manner so that Watana power- house flow is reduced first, or the majority of the spillage is at Watana. Since the dmvnstream flow requirement is applied last, it takes precedent over the energy production requirements. Downstream flow requirements are met by releasing as much flow from Devil Canyon as possible, given drawdown limits. Releases from viatana to meet down- stream flow requirements occur only when Devil Canyon is at its lowest permissible water level. 7.3 -Project Reservoirs (a) Watana Reservoir Characteristics The Watana reservoir will be operated at a normal maximum opera- ting level of El 2183 above mean sea level but will be allowed to surcharge to El 2190 in 1 ate August during wet years. Average annual drawdown will be to El 2093 with Watana operation and El 2080 with Watana/Devil Canyon operation. The maximum drawdown for either operation scenario will be to El 2065. During extreme flood events, the reservoir will rise to El 2193.3 for the 1:10,000 year flood and El 2200.5 for the probable maximum flood. 7-2 - - - - - - -! - - - - - - (b) At El 2185, the reservoir will have a surface area of 38,000 acres and a total volume of 9.47 million acre-feet as indicated in the area-capacity curves in Figure 7.1. Maximum depth will be 735 feet, the mean depth wi 11 be 250 feet, and the shoreline 1 ength will be 183 miles. The reservoir will have a retention time of 1. 65 years. Within the Watana reservoir area, the substrate classification varies greatly. It consists predominantly of glacial, colluvial, and fluvial unconsolidated sediments and several bedrock litholo- gies. Many of these deposits are frozen. Devil Canyon Reservoir Characteristics Devil Canyon reservoir will be operated at a normal maximum opera- ting level of El 1455 above mean sea level. Average annual draw- down will be 28 feet,with the maximum drawdown equaling 50 feet. At El 1455, the reservoir will have a surface area of 7800 acres and a volume of 1.09 million acre-feet. Figure 7.2 illustrates the area capacity curve of the reservoir. The maximum depth wi 11 be 565 feet, the mean depth will be 140 feet, and the shoreline length will total 76 miles. The reservoir will have a retention time of two months. Materials forming the walls and floors of the reservoir area are composed predominantly of bedrock and glacial, colluvial, and fluvial materials. 7.4-Flow Range (a) Pre-Project Flows The 32-year discharge record at Gal d Creek was combined with regional analysis of streamflow records to develop a 32-year record for the Cantwell gage near Vee Canyon at the upper end of the proposed Watana reservoir. The flow at Watana and Devil Canyon was then calculated using the Cantwell flow as the base and adding an incremental flow proportional to the additional drainage area between the Cantwell gage and the damsites (Acres 1982a). The avai 1 ab 1 e 32-year record was considered adequate for deter- mining a statistical distr·ibution of annual energies for each annual demand scenario considered; thus, it was not considered necessary to synthesize additional years of record. The 32 years of record contained a low flow event (water year [WY] 1969) with a recurrence interval of approximately 1000 years, as illustrated in Figure 7.3. This WY was adjusted to reflect a low flow frequency of 1:30 years, since a 1:30-year event repre- sents a more reasonable return period for firm energy used in system reliability tests. 7-3 Although the frequency of the adjusted or modified year is a 1:30- year occurrence, the two-year, low-flow frequency of the modified WY 1969 and the succeeding lo1<1 flow, WY 1970, is approximately 1:100 years. The unmodified two-year, low-flow frequency is approximately 1:250 years. This two-year, low-flo1<1 event is important in that, if the reservoir is drawn down to its minimum level after the first dry year. the volume of water in storage in the reservoir at the start of the winter season of the second year of the two-year sequence will be insufficient to satisfy the mini- mum energy requirements. Hence, the modified record was adopted for use in the energy simulation studies. The 1:30-year annual water volume was proportioned on a monthly basis according to the long-term, average monthly distribution. This increased the WY 1969 average annual discharge at Gold Creek 1600 cfs. from 5600 cfs to 7200 cfs, and the average annua 1 dis- charge at Gold Creek for the 32 years of record by 0.5 percent. The resulting monthly flows at Watana, Devil Canyon, and Gold Creek ar~ presented in Tables 7.1, 7.2, and 7.3, respectively. Weekly flows at the damsites were determined from daily records at Gold Creek prorated in proportion to drainage basin area at the damsites and Gold Creek. (b) Project Flows A range of project operational target flows from 6000 to 19,000 cfs at Gold Creek was analyzed. The flow at Go 1 d Creek was selected because it was judged to be representative of the Devil Canyon-to-Talkeetna reach where downstream impacts will be the greatest. Additionally, the flows can be directly compared ~tJith the 32 years of discharge records at Gold Creek. The range of project flows analyzed included the operational flow that would produce the maximum amount of usable energy from the project neglecting downstream flow considerations {referred to as Case A) and the operational flow which would result in essentially no impact on the downstream fishery during the anadromous fish spawning period {referred to as Case D). Between these two end points, five additional flow scenarios were analyzed. In Case A, the minimum target flow at Gold Creek for the month of August and the first half of September was established at 6000 cfs. Flow was increased in increments of 2000 cfs for the August- September time period, thereby establishing the target flow for Cases A1, A2, C, C1, and C2. The August-September flow for Case D was established at 19,000 cfs. The resulting seven flow scenarios were adequate to define the change in project economics resulting from a change in project flow requirements. The monthly minimum target flows for all seven flow scenarios are presented in Table 7.4 and Figure 7.4. 7-4 - - - - - - - - In the reach of the Susitna River between Talkeetna and Devil Canyon, an important aspect of maintaining natural sockeye and chum salmon reproduction is the provision of access to the slough spawning areas hydraulically connected to the mainstem of the river. Access to these slough spawning areas is primarily a function of flow (water level) in the main channel of the river during the period when the salmon must gain access to the spawning areas. Field studies during 1981 and 1982 have shown that the most critical period for access is August and early September. Thus, the project operational flow has been scheduled to satisfy this requirement; i.e., the flow will be increased the last week of July, held constant during August and the first two weeks of September, and then decreased to a level specified by energy demand in mid-September. 7.5-Energy Production and Net Benefits (a) (b) Energy Production The reservoir simulation model was run assuming 120 feet of draw- down at Watana and 50 feet at Devil Canyon for the seven flow cases given in Section 7.4(a). Additional runs were made for Watana drawdowns of 80, 100, and 140 feet for Cases A and C. Monthly average and firm energies for the seven flow cases for Watana and Watana/Devil Canyon operation are given in Tables 7.5 through 7.11. Case A and Case C energies for 80, 100, and 140 feet drawdown are given in Tables 7.5 and 7.8, respectively. These tables show the variation in average and firm monthly energies. Net Benefits The energies given in Tables 7.5 to 7.11 were used as input to the generation planning model which determines the long-tenn, present- worth cost of producing energy for the Rail belt. · The present- worth cost is determined by using the Optimized Generation Planning Model, Version 5, (OGP5) (General Electric 1979). This model determines, in 1982 dollars, the present-worth cost of supplying the Railbelt energy needs by various means of generation (thermal or thermal and hydroelectric). The best all-thermal option has a present-worth cost of $8,238 million (1982 dollars), and this value is used to measure the net benefit of the Susitna Hydroelectric Project. The present-worth cost of each of the seven flow cases is given in Table 7.12 and the net benefit in Figure 7. 5. Variation in present-worth cost with Watana down- stream is given in Tables 7.13 and the net benefit variation in Figure 7.6. In the OGP analysis, no change in construction costs has been assumed for the various drawdown scenarios. This provides, there- fore, a comparison of net benefit from energy production only and does not reflect the actual net benefit from the scheme. The project cost is based on the scheme given in the Feasibility 7-5 Report (Acres 1982) which had an intake structure providing facil- ity to draw to 140 feet. Consequently~ for drawdowns 1 ess than 140 feet, an additional benefit would result due to savings in intake construction. It has been estimated that intake cost difference between 80-and 160-foot intakes is about $0.5 million per foot of intake. Above 160 feet drawdown, substantial costs are incurred due to excessive excavation and rock support. Another adjustment to net benefit results from the analysis made in OGP with respect to loss-of-load probability (LOLP). This quantity determines the reliability of the system and, consequent- ly~ the need for additional capacity. In the OGP analysis for the 140-foot drawdown (Case C), the LOLP for the year 2010 is 0. 0954 days/year. In the 120-foot drawdown case, the LOLP is 0.0527 days/year in 2010. This large difference is due to the addition of a gas turbine in February 2010 in the 120-foot drawdown case. Since OGP assumes system costs are con- stant from year 2010 to 2040, the difference in cost (due to number of gas turbine units) is significant. Therefore, assuming a gas turbine is added in January 2011, this would result in an additional cost in the 140-foot drawdown case of about $41 million or a reduction of the net benefit to $1,227 million. Adjusted drawdownjnet benefit relation is given in Figure 7.6. Present- worth cost and net benefit for the two flow cases with drawdowns assumed are given in Table 7.13. The incremental difference between Watana drawdowns of 120 and 140 feet is approximately $60 mill ion. This value represents about 5 percent of the net benefit and about one percent of the present worth cost. The uncertainties associated with rock support costs and the increase in environmental impact with increased drawdown result in the selection of 120-foot drawdown at Watana. Further analyses into environmental impacts, primarily with respect to outflow temperatures, power studies, and geotechnical investigations~ may result in modification to this drawdown. The OGP analysis for the seven flow cases (Table 7.12 and Figure 7.5) shows an impact on the net benefit between Case A and Case C. This is due to August powerhouse flows being generally below the usable energy limit for that month. Between Case A and D, how- ever, the net benefit is reduced by about $550 million, or 45 per- cent. This is mainly due to the loss in average annual energy as a result of spillage in August to meet downstream flow require- ments. The spillage associated with the higher flow cases pre- vents storage of water in August-September for release during winter months. Also, flows are generally in exceedance of power requirements. 7-6 - - - - - - -J !-i .I ~- ..., 1. ,_ I I""" - The impacts of the various flow scenarios on fisheries, tributary, downstream water rights, and other downsteam use are discussed in detail in Exhibit E of the Susitna License Application (Acres 1983). Based on the environmental impacts (Acres 1983) and the economic analysis discussed above, it was judged that while Cases A, Al, and A2 flows produced essentially the same net benefit, the loss in net benefits for Case Cis of acceptable magnitude. The loss associated with Case Cl is on the borderline between accept- able and unacceptable. However, as fishery and instream flow impacts (and hence mitigation costs associated with the various flow scenarios) are refined (Acres 1983), the potential decrease in mitigation costs associated with higher flows will not offset the loss in net benefits. Thus, selecting a higher flow case such as Cl cannot be justified by savings in mitigation costs. The loss in net benefits associated with Cases C2 and D is considered unacceptable, since the mitigation cost reduction associated with these higher flows will not bring them into the acceptable range. Therefore, the Case C flow scenario has been selected. 7-7 - - - REFERENCES Acres American Incorporated. 1982. Susitna Hydroelectric Project Feasibility Report. Prepared for the Alaska Power Authority. 1982a. Appendix A. 1983. Ex hi bit E. Susitna Hydroelectric Project Feasibility Report- Prepared for the Alaska Power Authority. Susitna Hydroelectric Project FERC License Application- Prepared for the Alaska Power Authority. 1983a. Susitna Hydroelectric Project FERC License Application-Exhibit B. Prepared for the Alaska Power Authority. Battelle Pacific Northwest Laboratories. 1982. The Railbelt Electri- city Demand (RED) Model Specifications Report. Prepared for the Office of the Governor, State of Alaska. General Electric Company. 1979. Optimized Generation Planning Program (OGP). Electric Utility Systems Engineering Department. Schenectady, New York. ISER/Woodward Clyde Consultants. 1980. Demand for the Alaska's Railbelt. Authority. Forecasting Peak Electric Prepared for the Alaska Power l YEAR 1 2 3 4 ~:c .J 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 MAX MIN MEAN OCT 4720. 3299. 4593. 6286. 4219. 3859. 4102. 4208. 6035. 3668. 5166. 6049. 4638. 5560. 5187. 4759. 5221. 3270. 4019. 3447. 2403, 3768. 4979. 4301. 3057. 3089. 5679. 2974. 5794. 3774. 6150. 6458. 6458. 2403. 4523. NOV 2084. 1107. 2170. 2757. 1600. 2051. 1588. 2277. 2936. 1730, 2214. 2328. 2263, 2509. 1789. 2368. 1565. 1202. 1934. 1567. 1021. 2496. 2587. 1978. 1355. 1474. 1601 • 1927. 2645. 1945. 3525. 3297. 3525. 1021. 2059. ItEC 1169 t 906. 1501. 1281. 1184. 1550. 1039. 1707. 2259. 1115. 1672. 1973. 1760. 1709. 1195. 1070. 1204. 1122. 1704. 1073. 709. 1687. 1957. 1247. 932. 1277. 876. 1688. 1980. 1313. 2032. 1385. 2259, 709. 1415. --1 1 TABLE 7.1: WATANA PRE-PROJECT MJNTHLY FLOW (CFS) MJDIFIED HYDROLOGY JAN 815. BOB, 1275. 819. 1088. 1388. 817. 1373. 1481. 1081. 1400, 1780. 1609. 1309. 852. 863. 1060. 1102. 1618. 884. 636, 1097. 1671. 1032. 786. 1216. 758, 1349. 1578. 1137. 1470. 1147. 1780. 636. 1166. FEB 642. 673. 841. 612. 803 • 1051. 755. 1189. 1042. 949. 1139. 1305. 1257. 11B5. 782. 773. 985. 1031. 1560. 748. 602. 777. 1491. 1000. 690. 1110. 743. 1203. 1268, 1055. 1233. 971. 1560. 602. 9B3. MAR 569. 620. 735 t 671. 638. 886. 694. 935. 974. 694. 961. 1331. 1177. 884. 575. 807. 985. 890. 1560. 686. 624. 717. 1366. 874. 627. 1041. 691. 1111. 1257. 1101. 1177. 889. 1560. 569. 898. APR 680, 1302. 804. 1382. 943. 941. 718. 945. 1265. 886. 1070. 1965. 1457. 777. 609. 1232. 1338. 850. 1577. 850. 986. 814. 1305. 914. 872. 1211. 1060. 1203. 1408. 1318. 1404. 1103. 1965. 609. 1100. MAY 8656. 11650. 4217. 15037. 11697. 6718. 12953. 10176. 9958. 10141. 13044. 13638. 11334. 15299. 3579. 10966. 7094. 12556. 12827. 7942. 9536. 285/'. 15973. 7287. 12889, 11672. 8939. 8569. 11232. 12369. 10140. 10406. 15973. 2857. 10355. JUN 16432. 18518. 25773. 21470. 19477. 24881. 27172. 25275. 22098. 18330. 13233. 22784. 36017. 20663. 42842. 21213. 25940. 24712. 25704. 17509. 14399. 27613. 27429. 23859. 14781. 26689. 19994. 31353. 17277. 22905. 23400. 17017. 42842. 13233. 23024. JUL 19193. 19787. 22111. 17355. 16984. 23788. 25831. 19949. 19753. 20493. 19506, 19840. 23444. 28767. 20083. 23236. 16154. 21987. 22083. 15871. 18410. 21126. 19820. 16351. 15972. 23430. 17015. 19707. 18385. 24912. 26740. 27840. 28767. 15871. 20810. AUG 16914. 16478. 17356. 16682. 20421. 23537. 19153. 17318. 18843. 23940. 19323. 19480. 19887. 21011. 14048. 17394. 17391. 26105. 14148. 14078. 16264. 27447. 17510. 18017. 13524. 15127. 18394. 16807. 13412. 16671. 18000. 31435. 31435. 13412. 18629. l SEF' 7320. 17206. 11571. 11514. 9166. 13448. 13194. 14841. 5979. 12467. 16086. 10146. 12746. 10800. 7524. 16226. 9214. 13673. 7164. 8150. 7224. 12189. 10956. 8100. 9786. 13075. 5712. 10613. 7133. 9097. 11000. 12026. 17206. 5712. 10792. ANNUAL 6648.1 7733.7 7776.7 8035.2 7400.4 8719.3 9051.0 8381.0 7769.4 8011 • 0 7954.0 8602.9 9832.9 9277 t 7 8262.7 8451.5 7374.4 9095.7 8032.2 6100.4 6114.6 8588.5 8963.4 7112.0 6313.7 8402.7 6834.8 8232.6 6992.2 8183.7 8907.9 9580.4 9832.9 6100.4 8023.0 .I YEAR 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 MAX HIN MEAN OCT 5758. 3652. 5222. 7518. 5109. 4830. 4648. 5235. 74351 44031 6061. 71711 54591 6308. 5998. 5744. 64971 38441 4585. 39761 2867. 4745. 5537. 4639. 3491. 35071 70031 35521 69361 45021 69001 7246. 7518. 28671 5324, NOV 2405. 12311 2539. 3233. 1921. 2507, 1789. 27741 3590. 2000. 2623. 2760. 2544. 2696. 20851 26451 19081 14581 2204. 1783. 1146. 3082. 29121 21551 14631 1619. 1853. 2392. 3211. 2324. 39551 36991 3955. 11461 2391 t TABLE 7. 2: DEVIL CANYON PRE-PROJECT 1-llNTHLY FLOW (CFS) 1-llDIFIED HYDROLOGY [I[C 1343. 1031. 1758. 1550. 1387. 1868 t 1207 I 19871 2905. 1371. 2012. 2437. 1979. 18961 1387. 1161 I 14781 1365. 1930. 1237. 8101 2075. 23131 1387. 997. 14871 1008, 2148. 2371. 15491 2279. 15541 2905. 8101 1664. JAN 951. 906. 1484. 1000. 1224. 16491 922. 15831 17921 13171 1686. 2212. 1796. 1496. 9781 9251 12791 13581 18511 1012. 757. 1319 t 2036. 1140. 843. 1409. 897. 16571 18681 13041 1649. 1287. 2212. 7571 1362. FEB 736. 768. 943. 7461 930. 12751 8931 1389. 1212. 1179. 1340. 15941 14131 13871 900. 829. 11137. 12681 1779. 8591 709. 944. 1836. 1129. 746. 13421 876. 14701 1525. 1204. 1383. 1089. 1836. 709. 1152. MAR 670. 697. 828. 767. 729. 1024. 852. 1105, 1086. 8781 1113 t 16391 1320. 958. 664. 8671 1187 t 1089. 1779. 7801 722. 8671 1660. 955. 690. 12721 8251 13611 1481. 1165. 1321. 997. 1779. 664. 1042. .J APR 802. 1505. 879. 1532. 1131 t 1107. 867. 1109. 1437. 1120 t 1218. 2405. 1613. 811. 697. 1314. 1619. 10541 17911 9591 1047. 986. 15661 9871 949. 14571 1261 • 15101 15971 1403. 1575. 1238. 2405. 697. 12671 MAY 10491. 13219. 4990. 17758 t 15286. 8390. 15979. 12474. 11849. 139011 14803. 16031. 12141. 17699. 4047. 12267. 8734. 14436. 14982. 9154. 10722. 3428. 19777. 7896. 15005. 14037. 11305. 112121 11693 t 133341 11377. 11676. 19777. 3428. 12190. JUN 18469. 19979. 30014. 25231. 23188. 28082. 31137. 28415. 24414. 21538. 14710. 27069. 40680, 24094. 47816. 24110. 30446. 27796. 29462. 19421. 17119. 31031. 31930. 26393. 16767. 30303. 22814. 356071 18417. 24052. 26255. 17741. 47816. 14710. 26078. J JUL 21383. 21576. 24862. 19184. 19154. 26~13. 29212. 22110. 21763. 23390. 21739. 228811 24991. 32388, 21926. 26196. 18536, 25081. 24871. 17291. 21142, 22942. 21717. 17572. 17790. 26188. 18253. 21741. 20079. 27463. 30002. 31236. 32388, 17.291. 23152. AUG 18921. 18530. 19647. 19207. 24072. 24960 t 22610. 19389. 21220. 28594. 22066. 21164. 222.42 t 22721. 15586. 19789. 20245. 30293. 16091. 15500. 18653. 30316. 18654. 19478. 15257. 17032. 19298. 18371. 15327. 19107. 20196. 35270. 35270. 15257. 20928. SEP 795(. 19799. 13441. 13928. 11579. 13989. 16496. 18029. 6989. 15330. 18930. 12219. 14767. 11777. 8840. 18234. 10844. 15728 t 8226. 9188. 8444. 13636. 11884. 8726. 11370. 15155. 6463. 11916. 8080. 10172. 12342. 12762. 19799. 6463. 12414. .I . _ l ANNUAL 7537.8 8615.9 8918.0 9356.4 8866.9 9707.4 10608.2 9668.7 8866.8 9649.6 9084.4 10021.3 10946.5 10431.8 9250.7 9555.5 8697.0 10460.4 9175.4 6800.1 7063.9 9657.2 10199.0 7738.3 7160.5 9606.6 7705.5 9438.8 7765.1 9023.0 9994.5 10577.9 10946.5 6800.1 9129.7 .. J ....... ] YEAR 1 'l L 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 MAX MIN MEAN OCT 6335. 3848. 5571. 8202. 5604. 5370. 4951. 5806. 8212. 4011. 6558. 7794. 5916. 6723. 6449. 6291. 7205. 4163. 4900. 4272. 3124. 5288. 5847. 4826. 3733. 3739. 7739. 3874. 7571. 4907. 7311. 7725. 8212. 3124. 5771. NOV 2583. 1300. 2744. 3497. 2100. 2760. 1900. 3050. 3954. 2150. 2850, 3000. 2700. 2800. 2250. 2799. 2098. 1600. 2353, 1906. 1215. 3407. 3093. 2253. 1523. 1700. 1993. 2650. 3525. 2535. 4192. 3986. 4192. 1215. 2577. DEC 1439. 1100. 1900. 1700. 1500. 2045. 1300. 2142. 3264. 1513. 2200. 2694. 2100, 2000. 1494. 1211. 1631. 1500. 2055. 1330. 866. 2290. 2510. 1465. 1034. 1603. 1081. 2403. 2589. 1681. 2416. 1773. 3264. 866. 1807. TABLE 7. 3: GOLD CREEK PRE-PROJECT 11JNTHL Y FLOW (CFS) 11JDIFI£D IWDROLOGY JAN 1027. 960. 1600. 1100. 1300. 1794. 980, 1700. 1965. 1448. 1845. 2452. 1900. 1600, 1048. 960. 1400. 1500. 1981. 1086. 824. 1442. 2239. 1200. 874. 1516. 974. 1829. 2029. 1397. 1748. 1454. 2452. 824. 1474. FED 788. 820. 1000. 820. 1000. 1400. 970. 1500. 1307. 1307. 1452. 1754. 1500. 1500. 966. 860. 1300. 1400. 1900. 922. 768. 1036. 2028. 1200. 777. 1471. 950. 1618. 1668. 1286. 1466. 1236. 2028. 768. 1249. MAR 726. 740. sao. 820. 780. 1100. 940. 1200. 1148. 980, 1197. 1810. 1400. 1000. 713. 900. 1300. 1200. 1900. 833. 776, 950. 1823. 1000. 724. 1400. 900. 1500. 1605. 1200. 1400. 1114. 1900. 713. 1124. APR 870. 1617. 920. 1615. 1235, 1200. 950. 1200, 1533. 1250, 1300. 2650. 1700. 830. 745. 1360, 1775. 1167. 1910. 1022. 1080. 1082. 1710. 1027. 992. 1593. 1373, 1680. 1702. 1450. 1670, 1368, 2650. 745. 1362. MAY 11510. 14090. 5419. 19270. 17280. 9319. 17660. 13750. 12900. 15990. 15780. 17360. 12590. 19030. 4307. 12990. 9645. 15480. 16180. 9852. 11380, 3745. 21890. 8235, 16180. 15350. 12620. 12680. 11950. 13870. 12060. 13317. 21890. 3745. 13240. JUN 19600. 20790. 32370. 27320. 25250. 29860. 33340. 30160. 25700. 23320. 15530. 29450. 43270. 26000. 50580. 25720. 32950. 29510. 31550, 20523. 18630. 32930. 34430. 27800. 17870. 32310. 24380. 37970. 19050. 24690. 29080. 18143. 50580, 15530. 27815. JUL 22600. 22570. 26390. 20200. 20360. 27560. 31090. 23310. 22880. 25000. 22980. 24570. 25850, 34400. 22950. 27840. 19860. 26800. 26420. 18093. 22660. 23950. 22770. 18250. 18800. 27720. 18940. 22870. 21020. 28880. 32660. 32000. 34400. 18093. 24445. AUG 19880. 19670. 20920. 20610. 26100. 25750. 24530. 20540. 22540. 31180. 23590, 22100. 23550. 23670. 16440. 21120. 21830. 32620. 17170. 16322. 19980. 31910. 19290. 20290. 16220. 18090. 19800. 19240. 16390. 20460. 20960. 38538. 38538. 16220. 22228. s£F· 8301. 21240. 14480. 15270. 12920. 14290. 18330. 19800. 7550, 16920. 20510. 13370. 15890, 12320. 9571. 19350. 11750. 16870. 8816. 9776. 9121. 14440. 12400. 9074, 12250. 16310. 6881. 12640. 8607. 10770. 13280. 13171. 21240. 6881, 13321. ANNUAL 8032.1 9106.0 9552.1 10090.4 9681.6 10256.4 11473.3 10384.1 9476.4 10559.9 9712.3 10809.3 11565.2 11072.9 9799.6 10168.8 9431.8 11218.5 9810.6 7200.1 7591.2 10251.0 10885.5 8086.2 7631.0 10275.4 8189.3 10109.0 8194.5 9489.3 10747.7 11255.3 11565.2 7200. 1 9753.3 DATE CASE - Jul Se_p A A1 A2 c C2 C2 D 25 7 4000 5000 5000 6000 6000 6000 6000 26 6 4000 5000 5000 6000 7000 7000 7500 27 5 4000 5000 5000 7000 8000 8500 9000 28 4 4000 5000 6000 8000 9000 10000 10500 -29 3 4000 5000 7000 9000 10000 11500 12000 30 2 4000 6000 8000 10000 11000 13000 14000 31 1 5000 7000 9000 11000 12500 14500 16000 J .~-l ~ ~----] l '} 1 1 ·~ ~} . "C") J 1 TABLE 7.5: MONTHLY ENERGY PRODUCTION: CASE A, VARIABLE DRAWDOWN ENERGY (( WHl 8C DRAWDOWN 100 1 DRAWDOWN 120 1 DRAWDOWN 140 1 DRAWDOWN MONTH watana Alone WatanatDev11 Canyor WaTana Alone Wa tana/Dev i I Canyor watana Alone Watana/Devi I Canyor watana Alone watana/Devl I Canyon Firm Average Firm Average Firm Average Firm Average Firm AveragE Firm Average Firm Average Firm Average Oct 215 279 459 557 238 290 459 551 244 296 482 548 259 294 505 553 Nov 234 291 503 568 263 334 503 683 269 340 528 678 285 332 553 672 Dec 277 383 588 710 307 379 587 809 315 407 617 801 334 378 647 797 Jan 287 357 537 657 281 357 537 746 288 356 564 742 305 355 591 744 Feb 295 307 417 575 218 279 417 640 224 291 438 637 237 278 459 631 Mar 238 248 467 480 244 279 467 619 250 290 490 627 265 279 514 623 Apr 184 186 392 391 204 260 392 396 209 253 409 515 222 257 430 511 May 233 276 499 499 196 248 451 451 200 266 423 484 212 250 417 480 Jun 161 277 345 509 179 245 345 475 183 236 363 440 194 249 381 447 Jul 164 311 353 470 182 216 353 434 187 216 371 424 198 224 390 430 Aug 173 365 370 520 192 317 371 469 196 286 390 454 208 305 408 441 Sep 175 250 375 520 195 307 375 485 200 239 394 461 212 298 413 473 Annual 2636 3530 5305 6456 2699 3511 5257 6758 2765 3476 5469 6811 2931 3499 5708 6802 - - - TABLE 7.7: MONTHLY ENERGY PRODUCTION: CASE A2, 120• DRAWDOWN ENERGY (GWH) Month Watana Alone Watana/Devil Canyon Firm Average Firm Average .... Oct 223 252 592 592 !'-' Nov 246 338 507 674 Dec 288 431 593 787 Jan 264 379 542 738 Feb 205 324 421 625 Mar 229 303 471 624 '~ Apr 191 248 396 451 May 184 218 399 479 r Jun 168 239 349 446 Jul 171 191 357 421 Aug 229 288 435 491 r Sep 210 229 400 469 Annual 2608 3440 5462 6797 f TABLE 7.8: MONTHLY ENERGY PRODUCTION: CASE C, VARIABLE DRAWDOWN ENERGY (_( WH) 8C 1 DRAWDOWN 100 1 DRAWDOWN 120 1 DRAWDOWN 140 1 DRAWDOWN MONTH watana Alone WatanatDev II Canyor watana Alone Watana/Devi I Canyor watana Alone Watana/Dev i I Canyor Watana Alone Watana/Devil Canyon Firm Averag_e Firm Average Firm Average Firm Average Firm AveragE Firm Average Firm Average Firm Avera_g_e Oct 218 266 594 594 215 258 593 593 221 263 610 610 233 263 640 640 Nov 238 335 441 685 237 328 431 612 243 322 472 635 256 320 497 650 Dec 281 332 516 718 277 375 504 761 285 388 551 769 300 387 581 791 Jan 257 310 471 627 253 337 461 708 260 346 504 716 274 345 531 732 Feb 199 216 367 477 197 257 358 589 202 283 392 615 213 283 413 599 Mar 223 232 410 507 220 273 400 615 226 286 438 613 238 285 462 569 Apr 186 189 344 413 184 256 336 447 189 250 366 507 199 248 386 497 May 179 200 382 382 177 250 479 479 182 258 401 445 192 256 376 425 Jun 163 357 303 458 161 240 296 480 165 227 324 429 174 229 339 471 Jul 167 324 310 477 164 246 303 434 169 205 332 406 185 209 347 416 Aug 316 482 468 538 309 397 462 513 303 373 479 520 333 370 502 512 Sep 276 308 492 545 270 283 489 523 266 274 469 508 197 273 396 489 Annual 2703 3551 5099 6421 2664 3500 5112 6754 2711 3475 5338 6773 2794 3468 5470 6791 ) .) .J .J _) J .J - -J .J ii!OiB'; TABLE 7.9: MONTHLY ENERGY PRODUCTION: CASE C1, 120 1 DRAWDOWN - ENERGY (GWH) Month Watana Alone Watana/Devil Canyon Firm Average Firm Ave rage ,-. Oct 209 237 603 603 Nov 230 303 447 572 Dec 270 377 522 753 Jan 246 337 477 699 Feb 191 279 370 610 -Mar 214 283 415 598 Apr 179 249 346 499 - May 17 2 255 334 460 ~ Jun 157 223 340 418 Jul 160 201 316 396 ,f!IJ"~ Aug 377 434 543 542 Sep 304 295 569 553 Annual 2709 3473 5282 6703 - TABLE 7.10: MONTHLY ENERGY PRODUCTION: CASE C2, 120 1 DRAWOOWN ·""" ENERGY \GWH) Month Watana Alone Watana/Devil Canyon Firm Average Firm Average -. Oct 200 218 590 590 Nov 221 272 421 518 - Dec 258 361 492 719 Jan 236 330 450 683 - Feb 183 274 350 600 Mar 205 279 391 584 Apr 171 248 327 487 ~ May 165 253 318 453 Jun 150 220 322 413 Jul 153 198 311 389 Alllll Aug 448 496 543 543 Sep 323 321 567 567 Annual 2713 3470 5082 6546 - - TABLE 7.11: MONTHLY ENERGY PRODUCTION: CASE 0, 120' DRAWDOWN ,_. ENERGY {GWH) - Month Watana Alone Watana/Devil Canyon Firm Average Firm Ave rage -Oct 188 193 587 587 Nov 208 236 410 473 Dec 243 321 480 645 Jan 222 314 439 646 Feb 172 265 341 513 Mar 193 274 381 527 Apr 161 245 319 483 - May 156 250 338 425 -Jun 141 214 282 441 Jul 144 197 288 398 -Aug 556 597 543 543 Sep 321 359 569 569 Annual 2705 3465 4977 6250 - - CASE The rma 1 A Al A2 c Cl C2 D TABLE 7.12: NET BENEFIT VARIATION WITH DOWNSTREAM FLOW REQUIREMENT $1982 X 10tl PWC 8238 7023 6998 7012 7097 7189 7357 7569 Note: Assuming 120' drawdown at Watana. ""'!~\ -' NET BENEFIT -, 1215 1240 - 1226 1141 1048 - 881 669 ~ - -,, - IF' CASE A .... c - f""". NOTE: 1. OGP Analysis r TABLE 7.13: NET BENEFIT VARIATION WITH WATANA DRAWDOWN (CASE A AND CASE C) $1982 X 106 1 DRAWDOWN PWC NET BENEFIT 80 7197 1041 120 7023 1215 140 6944 1294 80 7380 858 100 7148 1040 120 7097 1141 140 6970 1268 160 7035 1203 assumes no change in project costs. - ,.,., I- LlJ LlJ LL z 0 ~ > ·-LlJ ...J LlJ - - 2600 2500 2400 2300 2200 2100 2000 1900 1800 1700 1600 1500 1400 0 SURFACE AREA (ACRES x 104 ) 6 5 4 3 2 0 ~ ~ ....... > / / "" VOLUME / '\ SURFACE AREA / \ I \ I I \ I \ 2 4 6 8 10 VOLUME (ACRE-FEET x 106) WATANA RESERVOIR VOLUME AND SURFACE AREA \ 12 14 FIGURE 7.1 ,.... I ...... 1- UJ UJ .... IL. z 0 ~ > UJ ...J UJ 1500 1400 1300 1200 1100 1000 900 0 SURFACE AREA (ACRES x 103 ) 12 10 8 6 4 2 0 ~ / v ~ / v v / ~ VOLUME / ~SURFACE AREA I v ~ v \ I I I I I 2 4 6 8 10 VOLUME {ACRE-FEET x 105) DEVIL CANYON RESERVOIR VOLUME AND SURFACE AREA ~ 12 \ 14 FIGURE 7.2 ') -(/) 1.1-(,) 0 0 0 !50 40 30 20 1-----10 LIJ (!) 9 0::: ~ a (,) • • • • • ] ) l 1 l j l -~·· ·--+----··!· ·~-----+-----+-----+-+ -----------0 !Q 7 -5 4 1----3 2 1.01 ·wv 1969 1.25 2 5 10 20 RECURRENCE INTERVAL (YEARS) LOW-FLOW FREQUENCY ANALYSIS OF MEAN ANNUAL FLOW AT GOLD CREEK 50 100 rt----=-500 1,000 10,000 ) J ) FIGURE 7.3 20 18 16 14 ~ 12 "-0 0 ~ ~ 10 4J "' 0: ~ <f) c 8 6 4 2 0 - OCT NOV DEC NOTES' I) LETTERS DESIGNATE THE VARIOUS SCENARIOS CONSIDERED ( ie. A= CASE A). 2) FLOW REPRESENTS GOLD CREEK FLOWS. i ' c,c,c,o -- ALL CASES JAN FEB MAR APR MAY MINIMUM OPERATIONAL TARGET FLOWS FOR ALTERNATIVE FLOW SCENARIOS AI A2 A D C2 ' Cl c ! A2 ' : AI ) ' I A L ~ ' JUN JUL AUG SEP FIGURE 7.4 - - - - I- LL. w z w 1300 1200 1100 m 900 1-w z BOO 700 60 rb. ~ ~ .... -----1----·---- I A AI 6 B -~ ~ """' 1"1 ~ ·----· --" ---- 1\ \ -·--\ -- I 1\ b A2 c Cl C2 10 12 14 16 MINIMUM AUGUST FLOW (CFS) NOTE! I. NET BENEFIT BASED ON THERMAL OPTION COST OF $ 8238 x 106. 2. MI.NIMUM FLOW AT GOLD CREEK. VARIATION IN NET BENEFIT WITH DOWNSTREAM FLOW REQUIREMENT --- 1\ ~ \~ D IB FIGURE 7.5 -I I - - ID Q N ro !!! ~ 1400 1300 1200 ;: 1100 u:: ILl z ILl III I- ILI z 1000 900 800 60 .....----~ ~ ( b,....... // ~/ .....-J ...... -m ..I j:J / v / v// . / / v / ~v ) D LEGEND: f:s--~ CASE A 0 CASE C Er--[) CASE C -• (ADJUSTED) - (~ (~ 80 100 120 140 160 WATANA DRAWDOWN (FEET) VARIATION IN NET BENEFIT WITH WITH WATANA DRAWDOWN (CASE A AND CASE C) FIGURE 76 ATTACHMENT A DETAILED OUTPUT WATANA OPERATION WATANA/DEVIL CANYON OPERATION ,_ 'I -I ..... :i. '7"00 ~ 0 l9SO.O ~~ooo ~o 2050 .. 0 MINIMUM STORAGE= MAXIHUM F',H,.Q = SUSITNI::; HEF' k!ATI'YA ?1.8!':1 CASE C 120,~ tmh!~~4! 2:i5:JOOO? 0 3330000 .. 0 4250000,0 :131 (;()iJO. 0 6650000.0 8l89'i99.~.) 10020000 .. 0 12210C00.0 5733000.0 MAXIMUM STORAGE 19391.0 STtRT WSEL-=2185.0 TWEL=1455,0 PMAX=.10200Ei07 MONTH! Y BASELOAD DEMAND 0+297968£+06 Ot337748E+06 0~382500£+06 Oi349605C+06 0.3006~5~+06 0.304088£+06 0.26239S~t06 0.?1~418Et0f 0,??9~00EtOA 0,226R21EIOA 0.23R298Ef06 0.250537£+06 MOMTHLY DISCHARGE REQUIREMENT 2000.0 1000.0 1000.0 1000.0 1000.0 1000,0 1000.0 6000.0 AOOO,O 6484.0 12000.0 9300.0 MONTHLY WAT~R LEVEL 2184.0 2171.0 2154.0 2137.0 2122.0 2107.0 ?093.0 2100.0 2135.0 2165.0 2180.0 2]90.0 MONT: :LY FLOW n \STR! BUTTON 1 ~ () .-~ 0 \/ ~ ._, 1.0 1.0 i ,-., .::. + • ._. 1.0 0.8 0.7 ,_ MONTHLY L.F,..:. 0.375 NO. YEARS Of SIMULATION = - - .- PDS"' 0 NStC" 118 NDF.F"' LL NDFF1.= 0 NDSFL= ~··. l,jo\.J '-' YEAR TOTE TOT SEC TOTDF 1 o.317l7F+lO 1),87162E·l09 o.74103Erot.. ... '} 0,27670E+10 o. 2c.989E+09 0.31644E+07 .l .. '1 0. 341321=:+1 0 o,.9129·~E+0'1 0+227971=.:-:·05 >I 4 o.36156E+1o o.11153E+to o.ooooor+oo 0::: o.3t810F.tlo 0 :· 6831. 1. f.+ 0? o.37742r+ot. ., 6 0,36494Et10 o.11~HE+!O 0 .19~;79E +07 7 o.39~.,(:F.tlO 0, 144:'i7Et10 O.OOOOC'E-100 B 0, 36~573E+10 0,11570Et10 o.ooooo::too 7' 0.3.~.947!=:+10 0' 119·1·~E+10 0, OOOOOE ·l 00 10 0.31765Et10 0.67861Et09 0.24329Ft07 i1 0. 35h·18F. + l 0 0, lO.q5E+10 o.oooooE:oo :l2 0.37044E+10 0 .120,HE+10 O.OOOOOE+OO p: o. 11.9571=:+10 O, lt.95·~E+10 o.oooooE+oo 14 0,41354Et10 0.16351E+10 o.oonoor-+oo 15 0 i 3:,732F. + 10 I)' 117'2'1E+ 10 0. 2,~8891:·: 05 :!6 (),32976£+10 0.79900[+09 0 .1724t.E +07 17 o •. 1-18,~7F+lO 0 ,. 9877RF.: +09 0.13M2E{0? :l8 0.36868£+10 0.11893E+l0 0.278/5[:+07 19 o.38596F+10 o.nsnE+lO O.OOOOOE+OO :20 0, 30244E +1 0 0.52784E+09 o.37512E+07 21 o.?711.1F.+10 0,21258E+09 0.143331=:~·07 ')"') 0. 27529£ +1 0 0.25585[+09 0.31947£+07 .:.:..-"" n o •. ~o7o1J:::+lo 0 ,.1.5700Ft10 O.OOOOOE+OO 24 0 .33210E+10 0.82235E+09 0 .1M·.06f+07 r)t::-' o.30t57F+10 0,.5181~E~09 0.3028·1E~07 """ .... ' 26 0.29076E+10 0.40827E+09 0.98166£+06 ,.,.., .,:.. .~ 0.1478SF+10 0, ';;?8'20E +09 O.OOOOOHOO 28 0.31772£+10 0.6799:l:Et09 0,30018E+07 29 0.3"i385f:t10 0.10382E+10 O.OOOOOF+OO 30 0 ,297B1E+10 0.48066£+09 0.2R0~·W+07 31 o.37.'';69J:::+10 0 .12·!.,.L .. ~E +1 0 O.OOOOOF+OO ., ..... 0.41730E+10 0 • 16 778F. +l 0 O,OOOOOE'+OO ~)k .. J J .I ... J J ,I J .. J .. ..I ) J ·-] .J J 1 AVFRAGF MONTHLY FNFRGY ~ND POWER MONTH TOTAl Pi'JWEP MW OCT 35'2.793 NOIJ 447.625 DE!: sn,o0~ JAN 465.451 FEB 120.705 MAP 383.747 APR 3~16t805 I~ A'( 346.974 JUN 31.5 :· '-:;~ JUL 276.054 AUG !':,01 .• 70:-:: SEF' 380.197 AIJH:t;GE MONT::LY 110NTH INFLOW OCT 45n.8t NO I) 2059.05 DEC 1414.81 JAN 1165.55 FEB 983.27 1'\AF: 8l7'8 + 33 APR 1099.71 MAY 10354.69 JUN 23023.7? .JUL 20810.12 AIJi1 18628.5? SEF' 10791.97 DELMASS = STOF:FND = ~3TORST ART = I NFLCIJ t.f1SS OUTFL, MASS = PEAK PflWEF: MW 352,.793 447.625 1n.0n 465.451 ,1?0, 705 383.747 3-~6. 805 346.974 3,5,1.5:.:~ 2it,.054 ';"01.701 380 + 197 DISCHI'"iRGES f',H,FLmJ 676.':!.07 8667.67 1.0300.94 9399 .lB 8~~85 ~· 3~ 8098.33 7478.08 7519 • .:.1 M28,34 5549.63 9778.77 7310t72 OFFF'EAK POWER MU 15? ,. 793 447.625 1'2'2,002 465.451 4"::!0.70:-J 383.7•17 T~6. so::; 316~974 11.5,.15~ 276.054 !'501 ,. 701 380.197 r~ND HEAD F'EA~: 6761;.07 8667,67 1.0100.91 9399.18 8681.35 8098.33 7478.08 7519~61 66?8.34 15549 ~63 9?7R, 77 7310.72 TOTAL F.t·!FF:i'W GWH ·~6~~478 322.290 :-::=:8.369 3·16.296 ·~82t.71~ 285.507 ~49.700 258.149 nf..,91.r) 2Q5 t 38 11 173.2t.7 273.742 OFFPFr.1:< .~7.~6~ 07 p.f,67.b7 103C0.94 9;:i99.18 ~j,~85 + 4~ 8098.33 7478t.08 ?519.t.1 6,6 :<8. :!,1 5549.63 9778~77 7310.72 0.347480E+10 KWH 0 .18298725[ +06 0. %5~(~000F:·: 0? 0, 9t.540000E +07 0.1.8591853F+09 0.18573549E+09 OFFPEAK PEAK FNFRGY ENERGY DFFICIT GWH GWH MW 262~478 ;:i2?.290 388.369 3<l6.296 282.713 285t507 249.700 258.149 226~910 205.384 373.267 ?73. 742 HEAfl 722.36 71~S.O~ 701.89 f/?.6. ?R 67L 40 657.18 643.20 639,7A 659.07 t-.89' 4l 711.24 721 +58 o.ooo o.ooo o.ooo o.ooo o.ooo o.ooo o.ooo o.ooo o.ooo o.ooo o.ooo o.ooo SF' ILL o.oo 0 ,•:)0 o.oo o.oo o.oo o.oo o.oo o.oo o.oo o.oo o,.oo o.oo 0.360 o.so~ 0,.017 0.015 0,009 0. 0~)9 0.007 0.232 o.oco o.ooo o.ooo o.ooo HLOSS o.oo o.oo o.oo o(ooo O~OO o.oo o.oo n f\(; !._1 + l,_~iJ 0.00 o.oo o.oo o.oo SEC MW 55 t 186 110 •. :58.1 139.519 115.8&.1 120, Ot·8 79. t·f.-.8 84.417 102.788 85.652 49.232 263. ·106 129.660 l NFLD41 CF~-3 \'P 1 11 :!.2 13 14 iC:: J.._' 16 17 :1.8 19 20 21 ')·") ... ·~-'- 23 24 25 ... 3!. .,:.,;,_l :27 OCT ~71. 9: 'i 3:~99} 1 459? ,, 9 628:; + 7 4?1.8 >1 3859~2 1 ~. 0? I :r, 4208.0 601·1' 9 36t~8 t 0 ::;],.~:)~3 t.049t3 ·1·~~:7 •. ~ 5560.1 :-)187' 1, 4?:i9 .4 5?21. :· ~~ 32b9t8 ·1 ~') 1. 'i {• {j 3447t0 ?·101,.1. 3768 ·~ 0 4979:1 4301.2 1036r5 3088.8 ~!1?'i ·~ j, 2973,5 5791?9 3773~9 .~t~O+O 6458.0 ' J ':?081 ,.6 1107~:!. ?1/(l,1 2756.8 1.":.99 ,t. 2051.1 1 ~';88, '1. 22?t:. '; 6 :~·?33 :· 9 17?9~5 ?:? t! ·:· ~:i 2327~S ??6:-t.,.·~ 2:;os p s:~ 17f:l9, 1 23.68.2 1. ::..s;:;' :t,: 1202.2 11'1·1~1 1567.0 1. o:-~f) :· -t .2496 t .\; ?~87t0 1977.9 t ~3·~ ~· 7 1474.4 1JO'I ,. 1 1926.7 26~~t3 19·~4 '9 :3:)2'),.0 3297.0 DEC 1. t .L..;.J: 9 1115,1 1,.~72t3 1973.2 1.760,.t 1708~9 11'::1:1:.? 1070~3 1'~01~.~ 11')1 .t. 170·1 ';· 1073~0 7~')9 ~ 3 1687.4 1.957 ;.·1 1246.5 s.131 ~ 6 127b.7 87.~ ~-? 1587 ':; i, 979' 7 131?.6 :~012 .o 1385 .o 81:'id 8')P.. t 0 127·1· .. ~; 818+9 1()87 <·:~ 1388 .. 3 816,.9 137::1.0 1.18":! ·:··~· 1081.0 1.·'100.j 4 1779 •) 9 t60::i,9 1308.9 8:1 '? ~-(i 863.0 1. ().~/i , . .;1 1102i2 1617 , .. ..s 8B4,0 63.4{-2 1097,j 1.!:~7~).)9 1031.5 78·~ t ·~· 1215~8 757~8 134S+7 1.577,9 113(-.,8 1.47{),0 1147.0 FEB 641.7 673.0 H4l~O t.11, 7 ~?03' t. 1050.5 754.8 J 189.0 :to 41 ,. "? 949,0 1138 i• 9 1.304 t 8 1257,1 1181\,7 ..,r'"\of I ! O.i. + ,:J 772~7 984 ,. 7 1031.~ :!.560.~ 748.0 .~02 .. i. 777+4 1491.1 1000.2 1110.3 7~1 .. ::: j 202 '7' 1.267.7 1055.4 1233.0 971.lJ J MAF' 569 i·1 619.8 ?35.() f:,?rJr'.? 638.2 8B6~1 .594~4 9":::'. 0 973t5 6'?4 ~ 0 9.61 .• 1 1331 .o 1176.8 883 ~t. 5?5~2 8i)7 t 3 984t7 R89;.5 1560,4 t.86 .o ·~·24 .1 717.1 1:!.~~·6t0 87:::.9 .527~3 1041+4 690.7 :1110 .s 1256.7 1101.2 1177.0 889,0 .I .~PO ,l 1302.2 :j:J3 t 'i 1382t0 'i~2t·~ 9~~~0,)8 718.3 945.1 12·~5 :·1 885.7 10·~9.9 1965.0 14"!7.4 7'? f, t f., 609.2 1232.e-4 1. :rz.s, .~ =---· ;) MAY JIJN JU!... AUG SEP 86~5.9 16432.1 19193.4 16913+6 7320+4 116~9.8 18517.9 19786~6 16478~0 17205.5 4216.5 ::;~1773(.4 2211()•'? 1735.5+3 11571t'..J 15037.2 21469.8 17355.3 1~~81 .6 11513.5 11696.8 19476.7 1.6983.6 20420.6 9165.5 671R.1 24881.4 23787.9 23537.0 13147.8 12953.3 27171.8 25831.3 19153.4 13194.4 10176.2 25275.0 19948.9 17317.7 14841.1 9957.8 22097t8 19752.7 18843.4 5978+7 10140.6 18329.6 20493.1 23940.4 12466.9 \3044.2 13233.4 19506.1 19323.1 16085.6 13637,9 2278~.1 19R39.R 19480.2 10146,2 11333.5 36017.1 23443.7 19887.1 12746.2 15299,2 20663.4 28767.4 2l011.4 10800.0 ~578.8 42841.9 20082.8 1~0~8.2 75?4.2 10966.0 21213.0 23235.9 17394.1 16225.6 7094f1 25939~6 16153~5 17390.9 9214+1 12555.5 24711.9 21987.3 26101+5 13672.9 12826t7 25704.0 22082r8 14147.5 7163~6 7942.0 17509.0 15871.0 14078.0 8153.0 9536.4 14399r0 18410~1 16263+8 7224.1 2857.2 27612.8 21126.4 27446.6 12188.9 t5973~1 ?7429+3 19820~3 17509t5 10955t7 7287.0 23859.3 16351.1 18016.7 8099.7 12889+0 14780+6 15971.9 13523~7 9786.2 1167?~2 26689.2 23130.4 15126.6 13075r3 8918.8 19994.0 17015.3 18393.5 5711.5 8569,4 31352.8 19707,3 16807.3 10613.1 11211.5 17277.2 18385.2 13412.1 7132.6 1?369.3 22904.8 24911.7 16670.7 9096.7 101~0.0 23400.0 26740.0 18000.0 11000.0 10406,0 j7017.o 27B40.o 31435.0 12o26.o j .J J J J J 1 ..... 1 . 1 ··--1 POWEFi'f~OUSE F!.OW cr'"' ·!-,;:;. VI;• ,,, OCT tWI.' DEC JAN FEB MAP AF'F~ MAY JUN JUL AUG SEF' 1 ~;.~.~··1 ,. /-, 971.6,3 11.28!=)~3 9703~·~· 89'58.::2 8080.8 7383!-7 5.;j32. 5 4853.9 ·1617 +4 9033.6 8301.0 ~ ,.., 5840.9 6640.7 7?16.0 7189,9 6/90.0 6468.3 5674.3 7874.1 4835.5 4778.1 8808.0 ~1"\,!C' C" .. _ .JL~·W. L • ..l 3 7082,9 1016-1,1 1.1..-s 17 '·t J.i)l-':1 ,(l 91.57.!1 82·16, 7 7~07.~ 1:" "T"'j I '""' ·J.j-~0+0 5002~3 4797.2 8436.3 6391.0 4 8269.3 1075·) t 7 11397.6 9709.4 8928.2 818/,4 808:=i.6 11375,6 47'59 .6 45t/.J. 9 8071 .6 55·13. 5 C" ,.! 5691 :. :J .~!19:1. i''" 1. 1.1(H) + 2 997:1.:3 ~'119 •. -s 8149.9 76--,6.2 8369.3 4962.2 4590.8 6320.6 5545.5 6 5684.0 724t .• 1 11665.9 10278.8 9367.0 8397.8 76:~4. 4 5258.9 5174.6 6849.6 14063.1 8457.8 7 7/;20 ·)!) 'i58?' 1 1.115~.0 9707,4 9071.3 8206.1 7421.9 95C0,1 9088 • .5 8818.7 10055.4 8275.0 " 0 7778.5 10270~5 11823.4 102t.3+5 fie" .f":.l:: r.::: 1·.1-..J._!. 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"" .. .. ........ ..,. ... .... ... .... ... ... .... .. ... ... .. .. ... .. .. .. .. ... .. ... ... ... .. ... u oooooooooooooooooooooooooooooooo 0 -N~~n~~m~o-N~~~~~ro~o-NM•~~~oo~o-N ~ ----------NNNNNNNNNN~MM >·~ - - - - - - - .fllll!llit. - - l PRE -P~:OJF:CT F!..OIJ ~ D/S LOCATION YF: OCT NOlJ DEC .JAN 613:-:i.O ~58~.0 1.4:39.0 1.0~7,0 38,l8. 0 1300.0 1100 .o '960.0 51?1.0 27-1·"+· 0 1.900.0 1.600.0 8202.0 3497t0 1700.0 1100.0 5.~04. f) 21.00.0 1.S00.0 1100. i) 5370.0 2760.0 2045.0 1794.0 4911..0 1.900.0 1. 300.0 980Ji :s8oe .• o 3050 .. 0 2142.0 1700.0 8~12.0 39)-1, I) 32~?·1· 0 1. 96~)'!) 4811.0 2150.0 1513.0 1448.0 6";:~;8. () ?8~1). t) 2201'). •') 1845 •. 0 779r~ tO 3000.0 2694.0 2452.0 591A.O ~~7CO, 0 :~1.00.0 1.900,() 6723.0 2800.0 2000.0 lt.oo. o 6.1),19 Ji ?2~::o. (1 1.4'7'4. 0 1.0~8.0 62'7'1.0 27'7'9 .o 1211.0 960.0 7201 ,.() ~098 ,. {) 1.631. ,() 1. J~ co+ f) 41t.3 .o 1600.0 1500.() 1500.0 49U.l,O 23:11t0 ~os:). o J. 981 ) I) 4272.0 1906.0 1330.0 1086.0 31::-:~.o 1?.11+0 8.£.~ .• () 824.0 !5288. 0 3407.0 229(),0 1~42.0 58-17 Jj 3093.0 :;.~510. 0 ~2:3'i. 0 4826.0 2253~0 1465.0 120~).() 3733.() l5n, 1) 1.031Jj 874,.0 3739.0 1700.0 1603.0 1516.0 771'1.() 1991,1) 1.081.. 'J 974.0 3874.0 26.50.0 2403,0 l8:29.0 7571..0 35?;)+() 2589,1) 2029.0 4907.0 2535.0 1681.0 1397.0 TH 1 .• ~) ·11'12.0 ?41.l,,l) 1718.{) /'725.0 3986.0 1773.1 j453.6 ) FEB r!AF: 788.•') 726.0 820.0 7,(10 + (• 1000t0 880.0 8/0.0 8?0.0 1000.0 780.0 1400.0 1100 .o 970,0 9-~0. 0 1500.0 1200.0 1.107.0 11·18 .o 1307.0 980.0 14;')2.0 1197.0 175'1· t (l 18H•.o 1500.0 HGO, 0 1500.0 1000.0 %6.0 71.3 + 0 860.0 900.0 13GO. 0 1300.0 1~00.0 1200.0 1. '100 ,I) 19CO.O 922.0 833.0 788.0 7'76.0 1 03t.. 0 9~10 rO ·~o~s ~ o 1.8~3t0 1200.0 1000.0 777. i) 724.0 1471.0 1400.0 9~0t0 900.0 1618.0 1500.0 1.£.~8. 0 1.605.0 1286.0 1?0(). 0 1-1-~6.0 11!00.0 1'l-C' • ..... .,:_ j.....,:. t 0 1114.3 . 1 l Af'F: MAY JUN JUL AUG SEF' 870.0 11510.0 196CO,O 22600.0 19880.0 8301.0 16J7.0 14090.0 20790.0 22570.0 19670.0 21240.0 920.0 5419.0 32370.1 26390.0 20920.0 14~80.0 1615.0 19270.0 27320.1 20200.0 20610.0 15270.0 1235.0 17280.0 25250.0 20360.0 26100.0 12920.0 1200.0 9319.0 29860.0 27560.0 25750.0 14290.0 950.0 17660.0 33340.0 31090.1 24530.0 18330.0 1200.0 13750.0 30160,0 23310.0 20540.0 19800.0 1533.0 12900.0 25700.0 22880.0 22510.0 7550.0 1250.0 15990.0 23320.0 25000.0 31180.0 16920.0 13CO.O t5780o0 15530.0 22980.0 23590.0 20510.0 2650.0 17360,0 29450.0 24570.0 2?100.0 13370.0 1700.0 12590.0 43270.0 25850.0 23550.0 15890.0 830.0 19030.0 26000.0 3~400.0 23670.0 12320.0 745.0 4107.0 50580.0 22950.0 16410.0 9571.0 1360.0 12990.0 25720.0 27840.0 21120.0 19350.0 1775.0 9645.0 32950.0 19860.0 21830.0 11750.0 1167.0 15480.0 29510.0 2ASOO.O 32620.0 16870,0 1910.0 16180.0 31550.0 26420.0 17170.0 8816.0 1072.0 9852.0 20523.0 18093.0 16322.0 9776.0 1080.0 11380.0 18630.0 22660.0 19980.0 9121.0 1082.0 3745.0 32930.0 2~950.0 31910.0 14440.0 1710,0 21890.0 34430.0 22770.0 19290.0 124CO.O 1027.0 8235.0 27800.0 18250.0 20290.0 9074.0 992.0 1.6180.0 17870.0 18800.0 16220.0 122~0.0 1593.0 15350.0 32310.0 27720.0 18090.0 16310.0 1373.0 12620.0 24380.0 18940.0 19800.0 6881.0 1680.0 12680.0 37970.0 22870.0 19240.0 12640.0 1702.0 11950.0 19050.0 21020.0 16390.0 8607.0 1450.0 13870.0 24690.0 28880.1 20460.0 10770.0 1670.0 \2060.0 29080.0 32660.0 20960.0 13280,0 1367.5 13316.7 18143.0 32000.0 38538.0 13171.1 _] ,) POST-PROJECT FLGW @ D/S LCCATION CFS Y~: 1 c:-w 6 7 0 \,J 9 u 12 13 :!.4 15 1.6 17 :ts 19 21 22 23 24 :?8 30 31 .. , .~..:. OCT NDtJ DEC FEB MAF~ AF'F-: !1AY JUN JUL AUG SEF' 7279~7 1021~)7 1155~:·1 991.7:~ 9104~S 8237.7 7573.6 8186.6 8021~8 8024.0 12000.0 9281.6 6389*8 6833,4 7909.8 73~1.9 6437.0 6588.5 5989~1 10314.3 7107t6 7561.5 12000~0 9300,0 8()61t0 107~8~0 t201A~4 10190~1 9~16~3 8391.7 7623.6 6529~3 11599.0 9076.3 12000.0 9300.0 l0185~6 11490+9 11816t4 9990~5 9~3At5 81!1.7 8~18+6 15608t4 10809t9 7405~6 1?000t0 9300~0 7076.~ 709?.0 11At6.1 10190)~ 9316.~ 8291.7 7938~6 13952.5 1.0735.5 7967.2 12000.0 9300.0 7194,8 7955,0 12161.4 10684~5 9716.5 8611~7 7903.6 7859,8 10153~2 10621.7 16276.1 9300.0 8~68.7 9891,0 11416,4 9870~~ 9286.~ 8451.7 7653.6 14206.8 15256.8 11077.5 15432t0 13410.6 9376.5 11044.0 12258.4 10590.5 9816,5 8711.7 7903.6 10574.5 12008,4 8109.5 12000,0 12213.0 1t78~.5 11948i0 13380,~ 10855~5 9623.~ 8659.7 8236.6 97~6.4 8565.8 7883.0 12000.0 9121.3 6874,9 6933.2 8170~4 10338.5 9623~5 8~91 o7 795~.6 12818.1 9828+6 9287.8 16208.8 11843*4 10128)5 10843}9 t?316.4 10735)5 9768.~ 8708.7 8003.6 12317t7 7167~0 8286.8 12000.0 9300.0 8227.4 10993,9 12810.4 11312t~ l0070~5 9321.7 9353.6 13838.4 11869.2 9477.6 12000+0 9300t0 7128.7 10691.0 t22t~.4 10790.5 9816.~ 8911.7 8403.6 9298.8 24151.8 9985.7 11666.9 10429.8 10293.5 10794.0 12116.4 10490.5 9816.5 851] .7 7533.6 15342.2 10296.0 15148.5 15146.6 9300,0 7777,9 102~4.0 11610.4 9938.~ 9282.5 8224.7 74~8.6 6061.3 26091.6 7887.3 12000.0 93CO.O 7290,9 6966.6 7678.9 9657.5 9176.5 8411.7 8063.6 9735.6 9469,8 9771.5 12000.0 13506.1 1077~.3 10092.0 11747.4 10290.5 9616.~ R811,7 8478.6 7809,8 13486.7 8261.6 12000.0 9300.0 6~51~.;+:_; 6'7~(:2.t. 7S'8A.7 10390~5 9716t5 8711?7 7870,.6 1206t .• t. 11t..35.B 10362t9 2270· .. ~+4 119:i0.6 8470t:j 10346~9 t217t.4 1.0871~5 10216.~ 9411.7 8613.6 12739.5 13601.8 10042.6 12000.0 9300t() 6581~8 6882~1 7830t0 7838~5 9238t5 8344.7 7725.6 7168t9 7865~7 6851t7 12000~0 9300.0 6628.8 700~.5 8012.9 7518.? 6386.1 6770,9 5919.8 7271.7 9213.6 8997.1 12000.0 9300.0 7491*4 7700.8 8481+6 7681,2 6677.7 6847,.7 6091.4 6389.6 10181.0 7762~3 13l49.0 9300.0 8728,t 110P6.9 1?6?6,1 11129,5 10344,5 9334,7 8413.6 18134.9 16601.7 7692,0 12000,0 9300,0 6221.8 6864.6 11581.4 10090.5 9516.5 8511.7 7730.6 6206.9 8914.3 6484.0 12000.0 9300.0 6457~0 6741~5 7724,6 7179~3 6725.3 8235.7 7695~6 12733~3 79~8.9 7482t9 12000.0 9300t0 6551~3 7008.3 8137~7 7~74~4 A719,3 6895.6 6120tR 9024.5 13190.5 11080.7 12000.0 9300~0 9816.0 9987,0 11197.1 986t.~ 9?66.~ 8411.7 8076.6 9568.3 9350.3 6512.6 12000.0 8050.5 6728.2 7351i4 8392,5 7616~2 66~6~5 7982.3 8383.6 9665.2 19061.3 7908.1 120)0.0 9300t0 7~69,2 10067,7 1270~.4 10919.5 9984,5 9116.7 8~05.~ 8669.0 6616.9 7243.2 120CO.O 9300.0 7014,9 7274,0 8119.1 7475,8 6537.4 6576.7 5R11.1 9810.6 6908,0 11710.4 12000,0 9300.0 684?.2 11972.1 1253~.4 10638.5 9782.5 8911.7 8373.6 8888.2 11112.6 15151.9 12030.3 9300.0 10320.3 11979.9 11889.5 103~4.1 9~52,1 B~2A.o 8071.1 10118.3 60oo.o 979?.0 26194.0 10461.1 .I .J ] J J , .... 21 J ' C .•.•. J J .cl .J J .• J .I ) l l l 1 AVE~:r,GE HFAD FT YF: OCT tWlJ DEC JAN f:">="?• '~t· MAF: AF'F: -~ i-. v· r!f-1, JUN JUL AUG SEF' 1 "';1•""\j""\ ..., 7:~~)? ........ -J ~ 69f)i.5 A74~5 659.~ 645.0 641 1:' 656.3 681 •. 9 702 • 0 708+B i ··.:-r {-,-: / '.} / .. ,,.( ,..; J :? ?O~l.8 .:.9 11.2 687 .8 674f7 c.b3 .2 t.52 .3 6'11 + •'::.• 6~1 ~. tL. 6:i8.8 ~:-.st. to -4 707t3 i-"1' 1:' ... ""~ + ._1 ·:r 711. • J. ., ..... , ..., I:" 7~17 \•~ 690 ~ ;j .F4,.3 659.5 645.0 636.7 .556.2 692.9 716.4 7-28. 1. ,, / . ...: .·: ~ ~' 4 730L7 722t5 ?tY?, 5 690.5 674t5 .:):,9 + 5 6~~Jt0 642.2 1.. .L~ -, '-''-'~ + ._. t/10 + 3 709.6 ...,.., _, ... , i.:..lt.! c:· ,J 72:1.~1 no,.1 7(i7,:-) 69fj ~· :--J .674 ·i !3 J.L:"'Q c:-~-·J .. td 645.0 641.8 tc:'n C•-• .l! + 7 685.8 709.8 7?4. ,~i f:.. 726.0 720.2 707,5 6~'0 t 5 t,?4 .. :~ 659.5 6,~5. 0 t.39;; .. l 660.7 .t.nr:: c:-._,, ._1 io ._1 718.8 730~9 7 73~,0 7?~t5 707.'5 6'J>() + 5 67-4.~ 659.5 645.0 642.0 663.4 ·!!9.~ "t 71'1 .4 731 .o ~;..J 8 ?32.0 722.5 ?07,5 690.5 674~5 t.~i9' 5 64:5. i) 641 t i C.t-2.9 .::,94t4 71:;.5 728.8 9 .,~.., .. •Ji. ' 1) 7'2?~. ~ 707.5 690t5 .~74 + ~ 659.5 645.0 641 .7 661 .9 692.4 715. 1 -"J'r"\""1 •• , /.::..i.t/ 10 719, 7 i'14 1 70:: .6 6';'0 .5 I-, .-, C:' 659.5 61~5.0 6·~ 1 . ., 658.4 686 + :i 714.2 730.9 .. \ C•l "'t !-._1 . I 11 TP,O 77:~ t ~; 707t~ 69t),_~ .~74 + ~ 1.. I::".-. t:-b45~0 I A,.., {': .554~0 676t8 701 <:; -,. ..... .-.. I I...•J'T + •.) O'"t.::t;..i t ~· / .·.: 1,_1 ... ~.1 12 ?29.4 ....,.-,.:_ c:- /;;;:..4 ..... ' 707.5 690.5 674.5 f.;-i9 + :_; 645t0 M2.0 00..5+ 1 693~9 716.3 728. 1 13 710 ~-~ 7?"~ ~5 707,.'5 690.5 04.!1 65 1?,5 645.0 641 n 664l· 1 696.9 718. ., 730.6 tO I 14 ...,......... il l .;.i.. + 'rJ 7'1') c::: ,r:.:..~t....J 707,5 690.5 674 <: lo ,) 659 ~-5" f.:.'15,0 l. ., .... , "') ..... .,~to.i... 6c·1 .6 694.4 719.2 728.8 1"' 730. :r. :7~2~1 707~5 690~5 674.5 659.5 ,qs.o 635.9 658.4 69tlt <:; 713.8 71.7 ,., ~· .., t t:) J.t. 717t2 712.9 704 .1 67'0,3 674. ~i 659 ~s 6f~5.0 6·~1 .8 f.61 .2 ~n-w ( b7j +C< 717.8 730.2 17 71? {>f) 7?~t~ 707.'5 ,£,9i) ~!5 674.') 659~~ 645.0 6·~0 ~ 2 661 .3 691 . ., 710.4 no.b .:::. J.S 7:20 ~c. !'14.2 _, .... I' " 1S90,. 5 C-74.:~ f.~;·+ 5 6 '15. 0 641 9 4'-1 695.4 !'18.7 731 .o l \}.~of+ ~t ' ';.•t·~· • n ?3~ ~ 1~) ""'"-'""' 1:' 707+5 ,!,9f) o:: ·574 + 5 [.t:"r\ ~ 645.0 642.0 663~3 .~.95 + 5 714.7 718. ? J7 i ~:: .. ~: + . ! =· ·~\ \ri1 \oi'1(·d ~" ,;:'J 71b.4 710.4 700.9 6B8 ~ :; 674 c· ~ .... ! ~ _.:;-r-: rR· ~~,_!.., + ._1 6 -~ 5 t 0 641. 1 <~ r:: I "' t•~O + 0 680. 1 695.2 t.-99,5 21 .~9.~. 9 6t\8 ~· 3 67~t5 .. , .. ..., 649.8 637.4 624.9 b24.2 639.3 6t.3. 3 .~.84 'i 6"r2.? t-\..•.1. + / . 22 690.3 .:S83 + '"' 673.6 6t·1 .:')·)9, 9 ,1-.'37 + 8 b2:i .2 61t .• 4 637.4 6??1'6 709.6 729.7 7 + ~ ""' .;:.,:) nL·'l 7~?~5 707,7; lr'\"' e' 0 7 1) (> ..J 674t5 .~.59 t 5 645.0 642.3 t,t.3t8 694.8 714.7 723 ~ :5 :::.~4 724.7 719.7 """,..-, c· /U/ + ... r '0 ..... r;:;• 0 ·'J ·~· 674 .5 t-~9.5 ~ /tC' ,._ t•"i'd 'I,) 6·~0. 4 t·61 ~. . ...:.: 690.7 708.8 715.6 '")<:' 71.3, ·! 70·:·~-~ 6'?6t3 t-84.,0 t~72 + 4 £. J:'n r-645,0 6A2.0 rt:"e-1:' \~7t .• 4 691 0 LOO "! .L....·.J ' 1-'-..1 7 + . .,.; 0\ooll.l.;.,_{ t\.1 ..... I" • ... • t ~ .. ~ ?t. 1 C'O ~ 691 .o t-79 '4 666.9 65\~' t < 645.4 ,:)34 + 4 63,:;. 7 J.lr"l , 695t7 '716.Q 726.8 f~· / ..... I)~ l ";....1QL~1 27 7~c~~-:·' 72;:.:.5 707~~ 6'?0~5 ~ 7.A -. l c:-,-, C." 645~0 641 t t, 659.? -686.3 704.9 7l0.~) C\1"-tt·.i lJ.,,.J,.. t :3 28 , .. 07 ,2 701 t •.) 69:l ·' ,.o; C,79+8 c. c.~· t 5 ~~~53T5 t.·~5 +0 641 ·15 663.3 695~2 715.0 723~8 29 ?2\-51-t' 7•11 ...• :.J. ·) :~ 707~5 .!.';i(i ~ 5 674.:3 659.5 645~0 641.8 6:;7 •. 5 683.2 700.5 703+6 30 701~3 695+3 68tl 0 672~3 661 1:' c·51 T4 6·~ 1 i 6,~ 1 ·' t.t.2,9 .•· QC' :' 718.4 ...,1"\ ~ -· "'' + .... .1 • ~ ,.,. •,) C• l ,) + 0 /.::Vt/ ~· 7?8.1 ""71"\-'""' a/ /()7 ~ 3 ·~91)) ~:; 674+3 6~9t5 645t0 6.41 .., t.62,.:? 696.0 719.4 n:o. 1 .j .L /.·: .• ·:oil._., . / ... -.,,.., /'31 t2 "722~5 707 .5 690.5 674f5 f..59.5 f.r~S,O M1 ., 6!:i7 ~2 689&t. 720 .::i ?32.8 ,:•.t. . l J TOTAL FNFRGY GWH 1 ,, ,t,', 3 4 .. - \o,i 6 7 C\ 0 9 10 11. 12 13 14 15 16 17 18 19 20 21 22 o"\"7 ~~ 24 25 26 27 28 29 30 31 32 .. J OCT :'2). :· .~f 221~0 '"J.77J-, 323.9 121..1 221.2 ~99.0 305.3 37,~ ·~ y 221~2 14?,.8 253.5 ~.16 .~~ 358.3 255.0 221.4 :qCj 'I) 221.1 ·~97 .B 221.1 220,/ 221.0 108 t· '2 221.3 221. f) 2~:0 ~ 9 103:.8 220.9 ~~21 '7 221~1 't21.:~ 354. 7' J NO!J ;:,q, 1. 240.9 ::::=n, o 403.0 :~4·~· f 2 270t8 1:19,2 385.0 ~09' i' 241.3 ~8~ .~~ 386.9 38·1 ,.:; 393.7 ~66~7 241. /' :-;:-:;8.1 241.0 177 :·2 241.1 ?l1, 1 240.9 39·'> • .s 246.1 ~4 t, I) 243~2 :'!;)9 '7 241.0 3·1:1.8 241.1 ·1:?.3~ 7 423.2 J DEC 4::?8.0 284.5 ·1.o1(l ~ .~. 432+3 JAN 359:3 260.1 37,6 (•3 359.4 369,4 380.5 "TI:'n oor ..:·'k..i7} ,J; 379.9 381,.9 369.1 181),9 39~5. 0 388,7 377~6 360 .t. 353,8 3,~.8,4 369.9 389!.0 282.0 260,0 260.1 391.0 367.3 260,.1 2t.o .1 357,;:> 2t.o. 1 387.5 260.1 383.:i 371.6 .. J FEB '292 .,~, 202~0 299 <· t 291.6 2S:'7 + 9 305.'1 296,3 310.5 105,6 '302.6 308.:3 314.2 312.7 310.3 297.2 296.9 303.8 305.3 .322.6 296.1 202.0 202.0 320.3 304.3 216,1. 202,0 295.9 202.0 313.0 202.0 311.9 303.3 285.7 226.2 :-::91.6 ?8~'.3 288.1. 296.9 290.1. 798 tl~ :3~Jo f ~~~ 290.1 299.6 312v6 307.2 296.8 285.9 294.1 3C0.4 297,0 3?.0.8 289.8 226.2 226.2 313.9 29tl+ 5 287.8 776.2 2'?0.0 2t,8. 0 310.0 226.2 307.2 297.0 .. ~ ... J 247.1 188.9 ~!'!1.2 270.t. 2:J5t9 255.8 2~~~s i) 4 2~i6.0 266 •. 7 25t.1.0 260.1. 290,1 273,1 250.3 244.7 2t,5.6 2·~9 .1 252.8 277' i. 252.8 188.9 188.9 2l8.0 25~1 + 9 2!53.5 188.9 2~i9 fo :3 26 .. ~ t 6 271.5 188.9 271.3 261.2 193v7 2?0.7 181.8 391,,~. 288.0 180.4 327.0 240.8 234.1 239.7 329.8 348.2 276.7 399.8 181~8 265.3 180.5 314.6 323.0 180.8 181.7 181.8 420.7 180.5 325.0 182.5 202.5 191.0 273.6 285.5 239.7 248.0 JUN. 165.3 165,3 170~3 170.4 16'7',.8 177.4 312.8 245.0 170.4 165.3 165.3 179.0 C"no"""i .. 1 ..._to,;;,+.,:.., 170.2 .:.26. 9 170.3 ")")•'1 ") .a:...a:...a:..tA.. 235.2 266.9 165.3 165.3 170.9 330.6 1?0.6 165.3 270.4 169.9 428.3 165.3 176.2 186,8 1C.t .. 2 .JUL 168.8 175.8 178.2 168.8 168.8 255.4 :.329.2 176.8 176.5 176.0 174.6 l?t .• t. 283.2 354.2 187.4 19?.1 168.8 206.9 212t7 168.8 168.8 179.4 176.6 169.8 168.8 253.3 168.8 176.9 168.8 288.7 344.5 208.2 AUG 340.4 334.0 324.0 307.1 240.5 542.0 387.8 33t...!' 318.3 343.4 2';>0.8 360~2 424.0 481.5 367.7 318.4 288.0 623.7 344.0 SEF' 305.2 197.6 241.4 207 .t. 208 t ~.) 320.7 3l3~B ?74.3 283.1 280.2 182.3 1")"11"1 r.:· .&:...::7tJ 276.2 294.2 270,. 1 393.3 252. s) 332.0 2:15.2 27s.::; 266.0 266.8 294.S 309.1 247.? 228.7 253.7 ?73.1 285.7 287~5 265. s~ 35r1, 2 ,I l 1 . -1 -l l WSEL (MONTH l=:NDl FT YF: OCT rWlJ DEC JAN FEB MAR APF.: MAY JUN JUL AUG SEF' 1 218~L·~ 217.1 .• o 21.14.0 ~117,0 21~~2:-0 2107.0 2093.0 2100,.1 "11'i'f t:: .,;. ~ ,;.,.;.. t ...... 2151.3 2164.6 2163.0 ") 2158.7 2149.6 2136.0 2123.3 211:..2 21.01.5 2091 " 2100 + c:. 2127.0 2155.9 2168.8 2188.2 .<.. ·-=· .j .2184,0 ·~171.,0 ::?1 ;';4. 1) /t:'i7,.0 21:'2~0 2107.0 ""'"""''"' / .... ::: •}., ,j. ~ · .. } 2090.4 2132~0 2163.9 2178.9 2187 •. ] 4 2184.0 2171.0 2154,0 2137.0 2122t0 2107.0 2093,0 2101.4 2133.3 215?.4 2171t9 2181.6 .,. 21.79' l 2171..0 ?1.:"!4.1) ?117Ji .::?1?2+0 21J)7 .o 2i)93.0 21COt7 2128.7 2152.9 2176.6 2182.5 .J 6 :un.4 2171 .o 2154.0 2137.0 2122.0 2107.0 2093.0 207'6, 4 2135.0 2165.9 2181 .8 2189,9 .., 2184,0 :~171.0 :':?t:)4,i) ;~1.17.0 21.22{-0 2 jJ)7 '(i 2093.0 21.00 •. 9 2135,9 2166.7 2182t0 2190.0 i 8 2184.0 2171.0 2154.0 2137.0 "of .-, ... \ ..... ,t' .L.i.L t \} 210?,0 2093.0 2100.4 2t3:..s 2163~3 2177~7 2190.0 9 ?18·LO ?1.7:1..J) ?1.:i4 f-i) 2137 :-n 21.22 ,. 0 2107:.0 2093.0 ?.1.00.3 2133t5 2161.3 2179.0 2176.4 10 2173.0 21t.5~2 215·1.0 2137t0 :2122.0 2107.0 2093.0 2100.4 212·:·~ 5 21 ~:;.~ .• 6 2181.7 2190.0 11 :~18-LO ;:17:1..0 21.14t0 ?.1:!,7>":1 2122 :· 0 2107.0 .2093 t 0 2101.0 21l7 .1 2116.5 21.66.5 2184.? 12 2184.0 2171.0 215•1. 0 2137.0 2122.() 2107.0 2093.0 2101 .1 2135.1 2162~8 2179.8 2186.4 13 21.8·1. () :?1. ?~ .• 0 ?.1:)1Jl ?1:P,.0 21??t0 21.()7,() 20'13.0 2100.6 2137.6 2166.2 2181.1 2190.0 •I ' 2184.0 217~ ~o 215·'\ .o '"'""'1 ....... .., f'i 2122.0 21.07.0 2093.0 2101.4 2131 .s 2167~0 2181 2186.2 J. "! .,;;. ,J. ~I ~ .• J . ~· 15 2184,0 2171..0 21~4.1) ?.117 ,I) 21.22 ,. 0 2107.0 2093.0 2088,. 9 2137 +1 21t.:: •• 1 2172.6 2173.0 16 2171~3 2164.5 2153.? 2137~0 2122t0 2107.0 2093.0 2100.5 2131 " • 7 2165t2 2180.5 2190.0 17 ?.t81. 0 ?.1.71.,1) ? l :l4. 1) ?t:l;7' i) ?122t0 2107.0 2093.0 2097t3 21:;5.3 2157. 1 2173.7 2177.6 l8 2173.~; 2164.9 2154.0 :2137 ,tl 2122.0 2107~0 2093.0 2100.9 213~;.4 216!5. 3 2182.0 2190.0 19 ?1.84,0 21?1,,.1) 2l:"i4JI ?137. l) 21.~?,,:) 2"1.07.0 ?1)'13 ~ 0 2100+ s· 21:35. (s 21h5.4 2174.1 2173.3 20 216'7'.4 2161.3 21:'5;),4 ?137 .o 2122.0 210!'.0 :2093.0 2099.3 ..., 1 ....... 7. ,.., ..:...J. • .:-w;. 7 214t~t3 2154.2 "1 .,. .• 0 ""'-• ._1.&..; t r 21 2~.·18{.9 ?1.37. 7 ~)P3,·~ ?1.1 0 ;(i 209S',!=j 2085.4 2074t4 2084.0 2104.6 2131+1 2147.8 2147.5 .. .,.., .>:....!-2143.1 213·1.8 2122\4 2110.0 2099,8 208~~9 ?074 t :; 2068+3 2116.4 2148.8 2180 t :i 2188.8 23 2184,0 2171. ,I) 2134.0 ~117r0 21.22,0 21.07,0 2i)93 (· 0 2101..5 2E6,.0 2163.6 2175.8 2180.8 24 217B~5 2171.0 215·1.0 2137.0 2122.0 2107.0 2093.0 2097.8 213/~ .t\ 2156.8 2170.7 21?0.4 25 21h5.8 ::?1:57t::; 21·15, l ?.1:~2t-7 2122~0 2107~0 2093 ~J) 21.00.9 2120.1 2142.7 2150+1 2155.? ')' .... 0 21~;1.0 2141 • r> 2127t9 2115.8 21(•6., 3 20.,:4.b '"'""I·~M A -. k'JO"i+~ 2099.1 213~j.t. 21.£5 ''7' 2176.1 2187~5 '17 21.84 ,l) ·zPL i) 21:"!4JJ .?117 J) ?.122,0 21.07~0 2093f0 2100. 1 2129,.2 2153.4 2166.5 2164 • .::. ... , 28 2t59.8 2152.1 2140.6 2129.0 2119.9 210·?.0 2093+0 2100.1 2135,6 2163v9 21/'t .• o 2181.5 29 2181. ,6 2171..0 ";.T'!4,0 ?117 ,I) 2122.0 2Fi7,0 20'13.0 2100.6 2124,.S 2151t8 2159.2 2158.0 30 2154.5 2146.2 2133.3 2121.2 2111.7 2101.0 2091.3 2100.7 21.35~0 2166.3 2180.5 2182+9 31 2183,7 2L71..0 ?n-L0 ?137+0 2122~0 21.07.0 2093 •. 0 2100.4 2135.1 2166.9 2181.9 2188,A 32 2184.0 2171.0 2151.() 2137+0 2122.0 2107.0 2093.0 2100.4 2123.9 2165.4 2185.6 2190.0 ·<;·.o..=o J ·~ ..•..... ) EL MA::<, STOW\GE = rHN. STOF:AGE = SUSITNA HEF' WATANA 2190 DC 1455 (;ASE.C 120;!mh:R2!apr·t: STfJRAGE 2~550~1')0. 0 3l3C"COO+G 42:iO:JOO t 0 53/~.oeoo to 66;:;oooo +o 8l.89999.5 10020001).0 12?1.CC;co.o -1 ooo·:)~)o to -1. c-o coco+ tJ -·:!. 00(;000 t 0 9,~5 .. ~(:(:-0+0 ~5733\')~)0 "i) El. STOF:AGE o~o 75CO}O 2~5():JQ ~ 0 8~0•i0' 0 132000t0 195000t0 292000~0 4 5,!,(!(;-0 + () 707000~0. 101:3(>j0, 0 1484000.0 1 0';'201)0 ~ 0 741000.0 MAXIMUM P,H,Q ~ 19391.0 START W~EL=2185,0 TWEL=1455,0 PMAX=.10200E+07 MAXIMUM P,H.O = 13763.2 STA~T WSEL=l455.0 TWEL= 850.0 PMAX=.600~0E+06 MONTHLY WATER LEVEL 2185.0 2170.0 2150.0 2130.0 2112.0 2095.0 2080.0 2092.0 2125.0 2160.0 2180.0 2190.0 145~.0 145~.0 145~.0 14~5.0 1155.0 14~5.0 1455.0 1455.0 1455,0 1455.0 1455.0 1455.0 MONTHLY ~LOW DISTRIBUTION 1 n l 1 • 1 ,!) 1. " tU ·~ I,} ~u .! "'i,.) } f.) ' 0 q o. 9 .s-~ '"' 0 ? J ~j ' 1.) I,..J t t;t ' 1 0 i. .o l ~ 1 tO i 0 1 tO I t ',,; J. • 1 "'l,j 1 (•0 1 .o I' t-0 0 (\ OtO .... l 'J MONTHLY FLOW REQD 2000.0 1000.0 1000.0 1000.0 1000.0 1000.0 1000,0 6000.0 6000.0 6~84.0 12000.0 9300.0 t YE~RS OF SIMULATION = 32 TFR = O.OtOO DEMAND FACTOR 0.460 MONTHLY PDWFR DEMnND 0.580511E+06 0.658012E+06 0,745200E+06 0.681113Et06 0,585727E+06 0.592434[+06 Of~t1207F~·06 0t476181~~-0~ 0~447120~~·06 0.441901£+06 0.164260£+06 Ot·188106E+06 .J J ··-•-'"-J .J J ..... J ~,.~. _,) .] .) J . .. ) l 1 LOWEP F:F.SFF:'.'OIP MTH P, H, F!..m.J CFS OCT NOV DEC .JAN FEB Mr: APR rl,;Y .!UN JUL AUG SEF ANN 97.64 'l) 9112.,:. 1.0881.,2 10287' ~; 9924~~~ 9059~2 7793 :· 9 5826 t ,:1 1123t~6 4736.1 5947 + ~~ ?838.4 HFAn FT ..,,..,.. C"" f ._·~ ,') ~· ·,I 713.2 .t-,99' 1. 681.9 6..'J4, 8 t.48 ~ 2 63~ :-1 629·+ 8 f-2~. ~ t·86 .4 7:1.? ~ !"j 72~~ + 7 ·~-SO:· 9 PC~·.'~P ~NFRGY fiLl GWH 50},8 469.8 519~7 50·:~· .6 476.3 423~6 35:5{-3 2t·4 -~ 6 241.5 234*1' 30·~· ~-6 410.6 3?7'" :~ 338,2 ·109 :-0 376.9 320~1 315.1 255,.8 1%.9 173 ,.9 174.8 228:1. 295+/ 288t5 P,H,!="LOW CFS 7318+"4 9444~5 '1.1.128(-2 10484.6 100'14,3 920'1 .o BOt)~~ 7 ?.~56' 6 SH.~, 1 7094.4 11.12R,1 9421.~ '8 '1094 ., 2 ENEF:GY ( GWH) OCT ··AF'R MAY-SEP ANNUAL AVEF:AGE FIRM (YEAR 22 \ OCT (<\)EF.: 610.1 FIF:M ~~1-9 t " 7 yp 22 4465.8 3375t0 NOV ., ~., 4 ~ ·=··.:'.i-t-!-t_\ Ia~·-· ·~ 'i / -:: ; .-:; 2306.9 DEC .JAN ~ .. "n .... /tY7 t.! ?ltq 4 !"'51 ,H :=:04 :· .,j 67!'2t7 5527 ~-6 FEB 615+3 ..,,., . ("", ., ,. .1 ' 7 PRESFNT WORTH COST BASED ON REGRESSION ANALYSIS 1.3274.9 PRESENT WORTH COST <S*10*16) = INFI.CW MASS ~C-FT t21156 720E+09 OUTFLOW MASS AC-FT .21137 31~E+09 DELTA STOR, (AC-1 0,\8 OOOOOOE+06 DELTA STOR, CAC-T 0.40 OOOOOOF+03 HFAD FT 590 ':~ 605r0 605t.O t\05i'O .:.os. () 605~0 604.8 604.7 604.9 t.(F~ t 9 591.5 577.4 MAP 613~2 ·E8,4 F'OWF.~: ENERGY MW GlJH ',12.2 411.7 ~85 ,.1 457.1 440.1 401.3 348+9 ...,....,. ...... -· .,:. ,_:~..:. ~ / 355.1 309+2 474.5 393.9 ENEF:GY FtPP 507 .o 3t;6 ~ 4 ~87~2 (GWHI MAY 445.0 ~t:"'r"l lf ;;;._;,;:,.,. "! -, 1 TOTAL ENERGY (OWH) F'F:OD \!SED 610.1 634.7 769.9 ?17 .o t-15~8 613.7 507+0 445.1 4"Jqt5 404.8 581.1 579~3 6908.1 JUN 6J.O,l 634 ~ .~. 769+3 ?l·S ~ 4 61.5~3 t-13+2 ::o7+o 445+0 4"~9.4 404.!' 519.9 ~;os +o JUL AUG 429.4 404t7 519.9 358,.'? ~--.n ~ ..:·~'=' t-0 543+ 1 SEP 508.0 c-1 r-, n .JC~•:. t 0 l ! ..., _, ,.~ .., Ol.!L+l C"t:'· .... .., ! .J ... J .·:I r 0 l RESFRVOXR l INFLOW <CFS) OCT @\} DEC JAN FEB MA~: r'"~P~~ MY JUN JUL AUG SEF' 1 471'1,9 ~081 :··~~ J.1. .~:=): 9 81.") ,.1 641.. 7 569~1 .580 :· 1. n F t:"'t::"' '""' 16432.1 l91'13 + 4 1691.3.6 7320.4 C•O:l.,_l._,l ;:. ! " 3299 •\ 1 11.07.3 9%.2 80~.(1 673.0 c:.1'7'.8 1302.2 11649,8 18~i17.9 19786. t. 16478.0 1.7205~5 . ..::. ., 4~9~~ ~ 7~ 21. 7r), J. 1. :.::o 1. • f) 1.274,:; 841.0 735f0 803 ~· 9 4216.") 25773.4 22110.9 17356.3 11571.0 " 4 t.285. 7 2756.8 1281.2 818.9 611.7 670.7 J;\82.0 15037.2 21469.8 17355.3 16681.6 11513.5 "' 421.8,9 1.~99 :q~l 1UrL8 1087.8 803 :· ~ 618 •. ~, 942 ··' 11696.8 19476t7 l6983.6 20420.6 91.~5.~) ...! ' ;\859.2 2051.1 1549.5 1388.3 10~i0, 5 886.1 940.8 6718.1 24881.4 23787,9 2~537~0 13447.8 (:) 7 41.0?,.-, 1.58:-1 ~ J. 't 1)18 ~ .-s P,J..6 ,. '1 7~4.8 694.4 718 .. :1, 12953.3 ':'.71. 71.8 ?5831y3 1.9153.4 131.94.4 B ·~208 '0 2276~6 1707.() 1373~0 1189 .o 935.0 945.1. 1017,6.2 25275t0 19948,9 1731?. 7 148·~1.1 9 .S011 ,. 9 ~931>9 ."\_ ... ,C".., t:"' t ·1:=!0 .. -s 1041.7 97~3. 5 1265.4 9957+8 22097.8 19752.7 18843.4 t:"n""'ln .• , .::..:.:.. ._: . ., t ·..' • ..1 '!/\':I:. / 10 3668.0 1729~5 1115.1 1081.0 7'49.0 694.0 885.7 10140.6 18329.6 20493.1 23940.4 12466.9 11 31·~~i. "! 2~~11:.~ 1..-1??.~ l ~1)0. ·1 1.1.1:8.9 %1. ,1. 1069,9 13044.~ 13233,.4 19506.1 19323.1 16085.6 3.2 6049.3 2327~8 1973.2 1779,9 130·~.8 1331 • 0 196~i.O 136:57.9 22784,1 19839.8 19480.2 1(1146.2 n J~~17 ~· ,~. n.,1 ,J\ 1. 760. ·1 1.1!08.9 P"!7.4 117t .. 8 1457,4 U.333.5 36017.1 23443.7 1.9887.1 127·16.2 14 5560.1 2~i08. 9 1708.9 1308 '9 1184.7 883 •. :. 776.6 15299.2 2066~.4 287t.7 t4 21011.4 10800.0 10:: :"!18.7,1. 1. 789'!. 1.1.94,'/ R:-i?~O 781 .•. ~ 57~i'2 609.? :,578~8 42841 <· 9 20082.8 140'\8.2 75?.4t2 ... 3.6 4759.4 2368.2 10/'0.3 8t.3.(i -.1'"'";1• ..... ""'! 807.,3 ~23?~·4 10966.0 21213.0 23235.9 17394~1 162?~;. 6 / / .,;,:, + l 17 5?"~"1. :·? :1. ~.~;; i·1 '!. '201.-'i l%0,.'1 984.7 9:34 '7 1. :r3s ~ 4 7094 t 1 :25919.6 16153.5 1.7390.9 9214.1 18 3269.8 1202.2 1121.6 u 02 ':? to:q .3 889.5 849.7 12!555 ~ 5 24711.9 21987.3 26104.5 13672.9 19 l\01.9,1'} 1.914,:7, 1.70 L? 1..-q7 •. ~ 1.5.·9). 4 1560.4 1576~7 1.2826i· 7 25704.0 22082.8 14147.5 7163 •. ~ 20 3447.0 1567.0 1071.0 884.0 748.0 C.RA.O 850.0 7942.0 17509.0 15871.0 14078.0 8150.0 21, 210iL l 1.010 '9 709.~ ·~16.? i)()?, 1. 6:?4.1. 9P.6 :· 4 9516.4 14399.0 1.8410.1 16263.8 n~4.1 .·-~.., 3?68.0 2496.4 1687.4 1097,1 !·'!'"? t 4 717.1 813,7 "JOC""l "' 27612.8 21126.4 27446.6 12188.9 .. :.""' ·''-'·-ll +L. n 4979,1. :~~87 + t; 1.9!'!7,4 1.1;70.9 1..191.4 1 :::.• .. '). {) 1305:4 1~973' l 27429.3 19820 •. 3 17:.09.5 10955t7 ~~4 ,~301.2 19:?7.9 1246.5 1031.5 1000,2 87~~9 914.1 7287.0 ·"1-..0c'Q -t 163~1.1 1801f..7 8099.!' ..:.,. ,j;.,J._I .. t ;;'J ")o:' 10!').'),~ 1.3~.!} :·? 911 .•. ~ 7!,6 t .. ~ t.R9+9 6:~7.~ 871 ,9 12889.0 14780.t.. 15971.9 13523.7 '""'7nt.. .~i ~~J 7 l 0\..• t ::;.:, 'l' 3088.8 1474.4 1276.7 1215.8 1110.3 1041.4 1211.2 11672.2 26689.2 23430.4 15126.6 13075i3 .... o 27 ::5679' 1. 1.6()1.,l 87,~ ~? 7:)7t8 743.? 690.7 10")9,8 8938t8 199'74.0 1701.5.3 18393.5 5711.5 28 ?973.5 1926.7 168?.5 1348.7 12f•2 t 9 l1H),8 1203.4 8569.4 31352.8 19707.3 16807.3 10613.1 29 :)79.L 9 ;?..S4:'5 ,1 1.979 '7 1.":.77.9 1.?.')7.7 1.256.7 1408,4 1.1231.5 17'277.2 18385.2 13412.1 7132,.6 30 3773~9 1944.9 1312 •. £ 1.136.8 1055.4 1101.2 1317.9 1?369.3 22904.8 24911.7 16670t7 909[;.. 7 ..,. ·'i 1 ::)i), r) ::)5271 ,. () ~03·~ ~o 1·~70t·1~' 1 :::~::; t f) 1.177 t 0 1.404.0 10140,.0 ?3100.0 2f,7·!10t0 18000.0 11000.0 ,J .L ... ,,,.\ 6~58.0 3297+0 1385.0 1147.0 971 ,o 8BS\ ~ 0 1103.0 10406.0 1i'017.0 278·10. 0 31435.0 12026.0 ~:L:: AVE: 4~!2~~ > 8 ':20!19' 1. 1·11.4.:-l 1.1..~!).;; 983.3 898 •. 3 1099.7 101~4t7 23023,7 20810.1 18628.5 10792.0 ,I ] l.cll J .] .J J .J .. J c.l . .J J J l l l l 1 l F'OWEF:HOUSE FLOW <CFS! on NOt,' DEC JAN FEB MAR M'F: MAY JUN JUL AUG SEF' 1 ::;s.~ 1, 1. 1JH~::;, 0 1n1.4 "~ 114~8,.'1 t () 78~:-j t :=; 8708.4 7282}'1 4470.>2 ·101.1.() 3799t5 4080.9 75-~6 t? 2 11900.0 ~ ...... " ""' 1\ ,:;y...,,=· +"7 79~1.1 _,"l',..C" ( .! ·-·"'t~' + C' 6377~0 C.5U .7 682~.P. C,;:\44.3 4283.0 3925.0 T7'94, 0 6939.1 '1 9061.,9 '1830 ':'j 1.~~7.~.:.~ 11. 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WATER SURFACE AT START OF MONTH (FTl OCT NOV DEC JAN 1 218~,0 ?t8J,A 2170,0 ?t~t.J 2 2167.9 2153.5 2142.8 2128.8 3 2190,0 218?.~ 2170.0 21~1.9 4 2190.0 ?185.0 2171.7 2153.3 5 2188~0 217~tR ?t~7~~i 2t~0.&) 6 2188.2 2177.5 2170.0 2152.0 7 2190,0 118~,0 2t70~0 2t~lti) 8 2190.0 2185.0 2171.0 2153.3 9 2190.0 ?185.1 ?17?.~ ~155.9 10 2180.4 2167.0 2158,7 2147,1 11 2190.0 2t85.0 2170.8 ?15J.t 12 2189.8 2182.6 2170.0 2152.9 13 2190.0 2182.0 2170.0 2t52.2 14 2190.0 2185,0 2171.1 2153.3 15 2190.0 218~.0 2170.0 21~1.1 16 2190.0 2180.4 2170.0 2151.0 17 219~~v 2tA5t0 ?17n~n ?t~1.4 18 ?181.5 2167.3 iis§.i 2146.4 19 ?.1.90.•.i 218"!.•? 2'1.7>'),? ?1.7!?.~ 20 2180,0 216f,O ?157.~ 214~.4 21 2157.9 21~0.1 ~1?.8.8 2114.? 22 ?153.4 2138.2 2129.8 2117.4 23 2190,0 218i,O ?171.1 21~4.1 24 2190.0 2184.3 2170.0 2151.4 25 217))0 21~7)2 ?147.8 2113t8 26 ?162.1 2146.7 2136.1 2122.8 27 ?190,0 21S~.0 2170,0 21~0.7 28 2167.9 2153.0 2144.2 2132.0 29 2190.0 218?..6 2170.0 21~2.8 30 ?163.2 2149,8 2140.3 2127.1 31 2187,? ~178,0 2t70,0 ?132.8 32 2190.0 2185.0 2172.6 2154.2 .1 .1 FEB MAR APR 21~0.3 2112.0 2095.0 2115t7 210~~4 ?09?~5 2132.0 21t~.7 ~095~0 2132.8 2114.0 2095.0 2130.0 2112.0 2095.0 2132,5 2114,6 ?09~+0 2110,0 21t2.0 2095,0 2133.9 2116.2 2097,3 2117.4 21t9.5 2101.1 2130.0 2112.0 709~.0 2111.8 2116.0 2097.2 2J31.2 2116.7 2099.0 21.T'L 1 211."i,.!"i 2097 ,O 2133.8 ?11A,2 2097,0 2110.4 2112.0 2095.0 2130.0 2112.0 209~.0 ?111.0 2113.0 2095,0 2130.0 ?11?.0 209~.0 21~3~~ 2116.~ 2098.9 2130.0 2112.0 209~.0 21C0,6 208R,4 2074,3 2j01.9 209~.9 2080.2 2137!.7 ?118,7 2101.3 2130.8 211/,8 ?09~.0 21?0.7 21t0.5 2095.0 21l0.6 ?101 .2 2088.6 2\10.0 2112.0 2095.0 2120.3 2111.2 ?09~.0 211~.8 2116.4 2098.3 21]4.8 2105.2 2093.4 213~.5 2115.9 2097.4 2134.4 2116.4 7097.3 ) MAY JUN 2080 (· 0 20B9. 8 7080~0 2092~5 2020 ;. G 2078 t 1 2080.0 2098,8 2080.0 2092.7 2080~0 2085tl 20HO ,. 0 2094. -~· ?080,0 2092.2 2C·:~3, 3 20'?2, 4 2080.0 2092.4 2080.0 2093.0 208?.9 ?098.1 2080\'0 2092+3 2080 .. () 2099t0 2080t0 2076.3 '/080 t 0 ?092. ~ 2080~0 2085t9 2080.0 2092.7 2081.6 2094.6 2080.0 2087.4 20.~,5 .. () 2072t 7 2069.1 2065.0 2083 •. ~ 2105.1 ?080+0 2085~2 2o:=w, o 2093 .1. 2078.7 2092.4 2080 ,. 0 2091. 1 2080, 0 2090, t. 2080.6 2092.3 2080.0 2092.6 2080.0 2092.1 ?080t0 2092t1 .JUL 2115.3 2121.1 2125t1 2128.4 21·:~5t0 2125.4 2135~8 2129.6 21?5' 4 '11 '")") '1 ..::.. ·~ .;:.....:., .. ,_1 2111.4 2130.8 2151t6 2126.8 2151.4 2125~3 212·6+8 2128t9 2133.0 2115.3 2097.0 211::..0 21%.8 2125.1 2U4.9 213:?~9 21?4.1 2141.0 2118.3 2125.4 21?5,7 2117.2 AUG SEP 2180.6 2176.1 2180.0 2188,4 2190,0 2180.5 2180.2 2180:: .• 2 2170.2 2181.5 2190.0 2190.0 2l86t2 2180.7 2174.6 2190.0 2179 '~; 2156t8 2151.4 2184.8 2187.2 217?.4 2156.3 2180.? 2171.8 218].2 2163.1 2180.:; 2183.6 2190.0 J ENERGY FROM RESERVOIR 1 CGWHl 1 "' .< 3 4 .,. J 6 7 8 9 10 11. 12 13 14 15 1~~ 17 .,, .. , .1 .. 0 19 '){1 .• :.J 21 31 ''/.'") ~~\ "- OCT ;~1.7::-i 450.2 363.7 44/ ,.3 398.4 ?.77 .. 9 282.1 34~i :· 9 449.8 31.9 ~ 7 405t2 :!,.~';', -~ 335t2 320v~ 41() .1 3:JL9 452t? ~74,7 452.9 14?,9 433.1 31.2' ,, 302~B -~~() ~·~· 44C .• 2 339 ,.9 44t .• 3 399~1. 442.2 4:54' 1. -~··..... "' ,jJ ',.J r "'1 ...,7_, 0 •1/ / ;. I} NOV 3'7'0 !· 8 249.9 :< .• ~.8 '6 409.7 ~~() :.~4 249.2 10:-}~1 409,1 10.1.8 250.1 t) i. i)',!; :376.8 3:)9 ':i 4i.4,5 11.?,8 "'1"""'!""1 •• ...:•"--' t . ..::. -~(i 4 :-/~ 250;2 H?,.8 25·) ~8 ?47~:; 240.0 4\? .. ? 402.7 ~~1. .:) 248.4 1 C>:'i , B 244.4 189 .. 7 245t2 31.:'1' ·1 411.2 DEC ~.~-::1 i 9 289~8 1.t)L.s 464.6 136,.9 463,7 ·~·~5 :· •;.\ 464.3 -~.~ 1. ':1. 291~2 ,:) 6 .7, ~ '7"~ 461.0 -~6 7; ., 466.0 !.).~::; '::i 467.2 ~}.~4 ~ i. 291 • .:> .. :.~9 ~f) 292+5 ~~:~7 tl ~ 2B3~1 ·1.~3 ~? ,, f ' r= ;oo ...... : ?91. :· 9 28? .. 2 ·~i~6~4 284.8 ·16~~'~.~ 287.6 ·1M,7 4~-s6 7 7 JAN P'L5 2·~2 + 8 41.9.9 420.8 ·~07.8 41.9,1 4~~1. ;\ 0 420 .t: 41.9,:) 3~"52 ~ 7 ·H 'f •. 1 41!)-',8 4?0~6 421.11 4?0.8 422~~ •1 )c 9\, 4 340+6 4t9:.9 313.9 219 .. 5 25B ,t;. ,t1_7,.9 4?1~2 ?/,~~-1 2t·O, 2 41, ~ T? 260.0 .-11.9~2 261.4 4?1..() 423.3 FEE: 2:·"17. 9 202.4 T:.~ .• 4 356t1 ::547.7 3~-'1 + 8 1·1·~~? 3:i;-;~8 :~;:;.~. ~· 9 352.)4 3~:)~7 :357.3 :rc:;.'i •?. :\~i5.8 ~~)4. 8 ;\·~6t8 1~,4 + 6 35~..i t 1 ~~:)t~ 346~0 1.99i· 7 199.6 ~3:~ t8 ~;;~.6 201.:~ 199.7 11:'!.8 200t7 ~~~1.:.0 201.6 1:::.~ ~· :-; 357 -~2 MAf~ ----, AFP 239,0 ?23 .~ 243.1 262~0 ?47.>6 24775 ?·~0 ,.?. 281.8 304 :· 1 245+7 283,3 299;\4 294.0 271.9 :~:3t.) 7 257.1 260t-6 244~6 ~0~ :· 7 244.6 16?,"'1 18?,7 :.302 .. 7 '1111. '7 ..:.."'1• ... •• .r 245~1 l82~9 251 '4 -] MAY 1!51 .. i,.) 214.7 167.0 239.1 212.8 153.1 ~33.~ 168.6 205~6 165 .l 254 ~~ 0 244 + ~i 206,3 24~f5 171.8 194.3 1~3~7 241.8 247 ~· 7 JUN :1.34 ~8 144.8 107.3 212 .. 5 11.2' 4 174,8 209.4 222.4 1'10.8 116.2 143t5 204,2 1.99.0 217+7 195,.1. 160,7 19'r .2 JUL 137 .e. 143.4 i33.8 144.7 138.4 189.2 21.8.4 D9.4 14L7 126.2 136t·~1 152.0 252t5 213.9 2·16 t 6 H-9.2 134.7 186.0 174.8 AUG 228,. 1 SEF' 279t2 261.6 218+2 158.1 15.£. t 0 474.8 503.1 340.? 220~3 386.1 150.8 185.6 486.0 411.8 196.4 397.4 185t1 521~4 258t? ~7'1 " ·" 1 ·''· , ,_. 218+1 342~0 350t7 309.8 •''F"!'1 0 "-~! i' w 278.0 301t5 196.? 258!.9 188,0 267t1 458 ?t' 1 ANN 3-469Tt.. 2894 ti 27'80 ~ 4 3447.:2 3049.1 3603+4 2%2.6 3804 (· 0 4191.3 INFLOW (CFSI OCT 1 .~ .. ~ tj :;~ > ~ ::2 1 .. ,...,!;".-, / ,·.J.::. ' 9 3 i"\fi"'ll\ 7C• '!'l ' 7 .. 1 04,'3 0 l't J. • 0:: 1.23.~:~ ._, :· ? r:-l 1 < 79 8 .i . 7 ..., ! .-.;.-~ i Q -·~--:· 0 821G .., ,_, • / Co i..02G:J ,. :) 10 1 240B. \::· 1 1. o"\l\'11 7'-)·.••.! ' 1 ., ... ) ··-~ j 1458 , 7 ~· 13 1. 0::?4'7 ' '1 .•, 1 4 92B3 1 ,. '" lc:: .. ~ 8973 ' 7 J.6 1 1 • •' ,., .;;c.~ . 0 1 .., 9-1?~ ,.., / ' 7 :1.8 j 1")'7 1 ... :. ...;..-. .J . .l..i... > .~ 19 75.~{) > / 20 ~ ?294 • 1 21 l2~.~ '\ , 1 >'!; ..... ., ~"L~: -,n ,-, .. ·:...::. J. .i..\..' £ . • 0 .-,·z S!11? :~ .:..-J ' :::_~4 01\~'·") '· '!.'·-'.::;.. • 8 2~ 1.:277'9 ,. 1 .. ~ 1 12318 1 .. ;., .... • • J. ...,..., 99?8 -1 ..::.l ,. .. ~,:~s )/380 • ~ 29 t 1 :r21. • {\ .. " ]0 J.:486 • 4 7 ' 1 ., ..,,-,.., .-, ~· '· . ...:,.._;-.-r.·. ' ~r r\ J 0221 4 ·.'!.;. . ) •c••~ 1J)}5.~ : 1. 7072 ~ • ,J. i r):~r9 ... ,. -·1 . 1 392 c. . 706/. .;. ;; 7139 • 0 " 1./J 1_ 7: -~ '· ' 1 1404 ·-· 1. 1. 18:.~; ., ? 707'7 . 9 1. 1 :;:~:;< . ·'··' :· -~ 1 0500 .::· J. ' !~\ 99(~0 t 3 1 1 ""':: '"T 1:' 0:: .t.4C::•,J ' ·..J 1.:1,09 .., '· .... 9034 1'\ ' 7 1. 1 1-11 :· .~. ?070 • .s ~-1. "'""ll.'\ ··:·'11.J ' ? 7055 t6 714~ . i) 7399 ' t:' '-' J. l 310 -, -:· ( 1 ... {"\'"'tf!" -~) \/ "!.:: '-' • .:. 704~<. 8 71 19 c: ' '•' 1. 1,1)/.~ 1'\ , n ~,o~t:·-· -· / .t..!.! • .;) tt)97H :· .4 ., ?228 ' ' ..., ·:>-oar:- l,,ll : I I~ ,f ' 1 135:2 • <:!' ~~1 J DEC MAF: t?1P8~~ 11~71.~ 10879+8 8809~3 8065~7 7443~3 6171 +5 6589 0 t2~3?~A l1~10.6 111?1+8 9801.~1 12518.4 11589.2 11137t2 99?3.? lt7R1_.~ t12l9.8 10909.~ P8A8,7 12568,9 11637.5 ~118~.7 10153+1 12~8~~? t11h0l1 10872 9 8991~6 12527.7 11605.1 11167~2 ~036~.0 1277~~~) 116?4f~ ~1111r~ 103?0t1 8039.7 9862t0 11138,9 9017.2 12~ht,~ 11A~6,1 1tt~A~1 1.03~~+1 12635+8 11805~8 11292t4 10~33tl 12~~6)t 11~97~1 11147~A t03~~t0 12476~8 11592.~ 111A8 9 10314,7 12198~3 1t~f8:9 t1118.3 8801.1 12443;5 11559.9 10808.6 9006.2 12~4?~~ 116!7.A 111R0.8 98?8+6 8036+4 9~55~7 11248~1 9228t4 12~1t.8 tt~~t.R ttt/9+~ 10388.7 7998.0 8703+6 108~8tR R919~3 81~10~1 7~-~0.0 A5~4.~ 6689.? 8?85.0 7~73.9 6563.5 6686+' t2~h4~7 tffA~~~~ 11~~14.~ 10417.7 12470.4 11559~3 1114?.7 9477.8 8~01~9 7:~9?~A 64?6~~ ROh7 •. , 8152.2 7527~7 6568~9 6690~3 121~~)~ 1.11~A)~ 108~A,O 89A4~~ 8235.9 7536a0 6~~R.8 907~t6 12397~1 ttf19~1 11197.4 10391~1 8140.7 7489.2 6504t2 6582~8 1~319)0 t1190.6 i111?i6 103~1.8 12458t0 11592.9 11121t6 10331t1 .J J .J .J 7026 ·)2 ..., 1:,-.-4 '7 ,• ; •:J l ~ .;. 8)3·~~\: ..,..,......... ... :' / :..1:..:0 :. -1· 7?10+2 7470:J. 873;' .• I,) 9lt~'7' ~ 8 -.. ..., ......... , .. , l!~..::..,.,..- 8767 2 9~1~.8 9101,'7 e3ot. ~ s· 7:~99 ·~ 3 7917~2 :32?1.~9 7.~.~56 ~ ~ 93'?9 ·~ 6 J';-i6J .8 ~1-t'O+·~ 58541-6 'i4l4~~~; 7589 + ~:; 7551~9 58~i~. 2 7s,q.o 8112.6 93B8 /:.. ;;qs.~ '?2~~5 ~ 8 8E:58~2 ,J 6305;-t.J 6047+:j 7913.0 5743~6 5765 t· 5 741'? .. 4 97'5·~J .1 9~?80. 3 9876(.4 7(t'?3r5 t·222 ~ 3 8?.82 ~ 9 '1'107t0 1(:·079~3 ?279+6 ~;·~~~77+4 ?'1~0;. ·:;· ?'? ·1(L. 7 8/3875 t!~.·~074 9?.~,0~3 5749+6 9~;70~9 10254.5 6904.? 1041.4.4 9:;85. 2 9R08, 2 5610~.~~ 10~.81 ~·::;· 7043~1 7634~2 t.206.o 10402.5 '1024~1 9f,·1·?,2 ·14~4 ~ ~ 99:=:s ;.1 5.988 + 5 5991 + 7 7426 i· 7 6448 + q 5194,9 7881.1 10266,8 10319 •. ~. ~;c:.82' ~ 6871. ,~. 9442 •. L, 601.1.0 R' ?~. 1' ~'7~21 t 7 .~.57~.;;. 2 6444 + 8 t-715.4 10235.4 .:.?23 + 3 5579 + 5 798t.t2 'J,5(i5~9 62:1:8' 7 9·~81, 9 6509.5 5366~9 .J , ..... J .JUL I Oc0 .J AUG 5'i87i9 t.·~! ··1 t.,. 0 7·~1\.~1.0 t-211 3 t 2 6'114t4 8438~2 ut:n ,. 7 7193,3 .:)794. 4 10:204&2 6443.2 B582.9 16223.3 J SEP 8177.1 Qt:''"Y""' ... _. .' ·.J.:.•k 1,! 7630.4 t.:.o7"4 6~;37 f ~5 J .J --~' J ---, POWERHOUSE FLOW <CFS) OCT ND'J DEC .JAN FEB MAF 1 ,L. .. ·~.0?:,·11.r)?::=.~:1 12·181:-'7 1_1.:j74i·\~; 1J):~:~7.i') 8809+-: ~ 6552.5 7072t3 8065t7 7443~3 6471.5 6589t0 3 6189,8 t022Aft 121~~,3 ~t~10t6 111~1.8 9807.8 4 bA23,0 11385.9 12518.4 11589.2 11137,2 9929.7 5 .~7:'i7 Ji 70A9 ,r) 1 t7P1, ·1 t 1. :~:w ,. s 1.")909, ::i P.:3A.8. 7 6 6746,9 7139.0 12562.4 11637.5 11186.2 10159.6 7 7A?9,8 1101?.~ 12478,/ \t~AA.9 10872,9 R99t,A a s211~2 11397~6 12527t7 11605.1 111~7.2 103A~.o 9 10?05,5 11185.? 1?775.0 1\6?4.3 11~1},1 103?0.~ 10 6708.1 ,7079.9 8039.7 9862.0 11158,9 9017.2 11 9042·A 11149.7 t?~A1,2 11A.1A.l ttlf8.1 103~5,1 12 A580.S 10507.2 12629.3 1j805.8 11?92.4 10433~1 13 661!:? 9907)0 t2~~9.A 11~97.1 t\147.A 10351~0 14 9289.6 11228.8 12476.8 11592.5 11168.9 10314.7 15 8980,? 11309.? t?19t.R 115~8.9 1t125.~ 880~.1 16 6758.8 9041.7 12437~0 11566~4 10808.6 9006~2 17 9178.~ 111~1.6 12~~~.1 tt6~7.6 ttt80.A 981~.1 18 6612~1 7070.6 8036~4 9555~7 11248~1 922R.4 19 75A7~2 t1.?71.~ 1~61t+H t1A21t8 1't79,h t0388t7 20 6593~6 7055~6 7998~0 R703~A 10838.8 8919~3 21 66f3~6 71~~}0 8110~1 7~10,t) h5~4.6 66R9+? 22 6972t? 7399+5 8285.0 7573.9 65A3.~ AA8~t7 23 8~18.9 11304.0 12564.7 tt66~.0 11?\4.~ 10417,7 ;)..; 6265.8 1093j,9 1'2463.9 11:'i59.~ 11142 .... 9484.3 25 6578)8 7041,8 A~01~Y 719?,6 A1?6J? 80A7+1 26 6617~7 7119.5 8152.2 7527.7 6568t9 6690.3 27 7791 9 tt076~8 1J4~9tt 113~?,8 108~~,n 89A4+~ 28 6679.8 7257.3 8235.9 7536.0 6538.8 907~.6 29 6722.0 t0985.t 12590.6 11649.5 11197,4 1039t.t 30 6785.9 722St4 8140.7 7489.2 65n1~? ~5R?&8 31 668~~? R89t.8 t23t2.~j tt~90th 1~142t6 t035,.8 32 7855.0 1134~.7 12458.0 11~92.9 11121.6 10331~1 ) 7405.:-0 7026.2 7181 d 8134 •t· 7713,4 7i10~? 7470:.1 8742.8 ?:~~~·? + 8 .,...,.-~--~ ..., .t/£..L~/ 8774~0 9514.8 '1'1\)8 .,4 8?:1~ +t• 729'? ~ 3 7917~2 n,.,.;" ,-, •-:o.:.:.c:..J. :· 7 7f,5t .. 5 93'1'7'(·1~' 75t_\1 T8 ,L,~;44 ,.4 ;-:;85 .. 1 t t. 9414.3 7~i89. 5 7~~1 :· 9 5853~2 7864r0 R112.o 93:18,6 7318.3 '?262 •. 5 8Rt. ·1 + 9 o'"'\.t\f\C" .. '1 .;.v .. .J.J r ...- l MAY ,.:;3{)5 ~· 0 7913.0 5765~5 9743.6 '78761'4 6222.,:3 '?90Ctt-~ 7279.6 -,nc-~ ll /'J'._f/t-f 8638~5 '?213~8 9~570 ~ 9 6904,7 nt::-,r"' .., 7 .. 1 i \.•;. / 1:""""1~1"'1: 1'"\ ·.J / .,;, • ., t ., 7043.1 ~~206 (• 0 9024.1 9454 ~· 5 5988,:=; .6087' 6 6244,8 10266.8 9436,1. JUN t.047 f 5 5!'43. t· 7439.4 9980.3 7023.5 8382.9 tC079~1 7910,7 bt-40.4 !57~6.3 102~·~.5 1.0~07{.7 9808,2 10541 •. :, 7634t2 l03'?5.8 9640.5 9'1R8,1 5991t7 1.~·4 ·18 ~ 9 6796.2 10319.6 6871.3 tJ)17~8 991:':.i,O ·5444' 8 ) 1 .. 1 JUL AUG SEP 5989i5 109·10.6 8949.8 5714.3 10860.0 7859.1 6373.2 10727.2 8261.1 5760,1 10597~0 7958~4 5950.5 9971t6 79~9.1 7547.1 11209,6 10143.6 9210.5 11699.7 13763.2 5931.7 10849.2 8401.8 5865t2 10679t8 8738t8 6339.8 10197.7 13012.6 6024.0 10476.1 7719,9 7147.3 11064.4 8148.6 8172t5 13763+2 13763.2 9378.0 11050,5 1j008.1 8342.2 11145.8 8569.0 7540.4 10669.3 9528.7 6056.7 10414.6 8394.3 8122t5 12864t8 13763~2 8922.8 10920.5 8709~9 5682.0 11178.0 8712.0 6324.6 10672.8 8622~5 5742~0 1010~.9 9248.8 8408.5 11364.1 8784.2 5805.8 11188~1 8952.0 5796.9 11037.0 8420.1 8905.6 1094l ,6 8144.7 5796.6 11497t7 8882.3 8499.0 11131,2 8576.1 5721t3 10936.5 8773t4 8585t9 10A~6.7 8702.4 9188.2 11236.0 8362.0 8176.9 13763.2 12762.0 7094.4 11128.1 9424.B ) U,., w lfJ (!:1 =::. •:I: ...J =::. -, z =::. -J >- <'.!: ::c: CL u_ <'.!: Ct:: <( ~"E: ~ w LL z •:I: -:! 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('·J ,::-· .. ; ('·J t1 ':'! t"'J : ::! :>- <J: ~.J ) •c,f_CJ WATER SURFACE AT START OF MONTH CFTl UCT 1.1~~ '~) 1455#0 ·: 1:!:) ; :) 145:it0 1. -1~~~ =· 0 1455~0 1. 1:-57-i) i) 1455.,0 1. ;j <:;:; : r;. 1455-~tj 11~:,;:-(i 145~i~O l43~i}0 1455+0 1 4")5' () .1455+G •f. ·1!1:; ~ {j 14554o0 115"! J; 1455t0 t 4::)~:; ~ i) 14~55~0 11~::J.r) 1455+0 1. 4~;:-) t0 14~5~5.0 1 4;';5 'J) 145:1.0 J.{1~!)ti) 1•155 .o ~.·1~~~0 145:'1.0 DEC 1. ~1S5 + t) 14::~~5:.0 t ·1:·?~ ,. 0 14~~~;~o t :1 ~;;_j t, ij 14:i5 ~ 0 1 . .:1~~ ·=· i) 1455~\.J 1 ... ~ ~; :-.t ~-() 145:;,() 1, 4 !~!=) :· >) 1455.0 1. ·15?":· " f) 1455.() 1. 4~:-'i 'i) 14:;5 .. 0 lA"i"!,•) 1455~0 l·~"'i!'i. {j 1455Ji 1. ,~!=_i~j ,. 0 14:;5 + 0 1."1·~;;~:-0 14:;5 .() 1 ·1 ";:-) ., i) 1455+() 1_ .. 1~!1 "r:~ 1455.0 J -lC::"i :· (i 1455~0 H5t:;,i) 14:;s.o FE:S 1 ·~ ?) !::i {· 0 1455+0 l~"!t:;,() 1455.0 1. -~::;~ (· {) 1455.0 1.4~1(.0 14~~~ .. (! 1.4r.~1 '"() 1455}0 1. ·~::~ ~J) 1455~~:1 1 '~5~i ~ () 14~'55.0 14:)!1.0 ·~ "' C' '=" ..... , .:.. .z...r •.. '·-',. ,, ... t-15:-J~O 145:lt-(! 1_4~~t0 1455.0 14~~:.o 1455.0 1. 4!S!=.i ~ 0 1455~0 1455.0 1455,0 1_4~:-;.o 1455.0 1.-·1::;:.;+() 14~~i.O 'i.-157:i ~o 1455~0 AP~.: MAY .JUN JUL SEF' 14tl.7 1413 ,(! 1.4:27f0 1417 .t. 1428~<3 1431~~5 1455.0 14:23 .~: 1-421.4 145:'i,O 1420,() 1434.1 1455.0 1449.7 1432,:!; 1430,.~ 1420+~;:· 1455 d) 1411,7 1406,7 1417.0 1446.0 l428 .::; 1405+0 1410.2 142::<.6 1405.0 1433.2 14!.1.8 1428.2 1434.9 1455.0 AVE 1426,7 1455.0 14~5.0 14~5.0 1\~~.0 14~5.0 1455.0 1454,7 1454.7 1455.0 1454.9 1428.2 --•cc•~ -• ] ) J l ) ' J .J ] J -) 1 .. J ENFRGY FROM RESERVOIR 2 <GWH) 1 .. ·: 4 C" ,.! 6 7 8 9 10 11 .,., .1.~ 13 14 15 :16 p :!.8 19 ~)() ~1 29 30 31 -.r ... ~ ,,}..:.., AVF. OCT ?1.4,1. 203,7 ~?0~:( ~ 7 208.9 ~1.0:1 211.9 ?47,:') 266.5 ::rn, 0 208t6 291·.1 205~9 ?09 ,.1, 301 ,,::. ~91. ~ 1 21LB 307:4 ?O~,c, ?4:·,; :· ~ 205~0 ~!)7) ·~ 21t.+8 2?f. }3 200t8 ~04 ~·~· 205~B ~ .. 18 ~ 9 207~7 ?1.0,8 211.0 ?07,9 137,(-, 222~0 321.:0 357~4 ?21 ;. 9 r;_, ... ·"' .( .O::.~.&.ft.L ~45~7 ..,C"-J ~·'\ .,j., • .'.! rO :-;.~!) ,. :; 222~2 '!'-". L "l' •}•.,11,1foo; 329.8 ~1.1, :-0 352~5 3~:) ~ (j ~c·-: o ~\..·--· + ,_,. 34'i' ·1 221v'1 3:i3~9 221t5 ~~4>"? 232.)3 3:-'i4:8 343.1 ??1. ;· 1, 223.5 347,7 22?t8 1-i··~ t 8 226+9 ?7'1; 1 35-~. ~ 1 DEC ~{)4 :· '7 261.t· ~0.', ,.3 406.1 :-;s2 .. ·2 407.5 -~1)4 :-8 406.4 41.4,4 260~8 ·~07~·~. 409.6 1')7,:1 404.7 ,10~ :·? 403 ~ ·4 ·1(\~J 260,? ~09,1 259.4 ?.',4,.() 268v7 -~07 ~·~· 404 ,.3 ~~~9 ~ .~. 264.4 ·~04, !. 2t·7' 1 ~NL~ 264t0 W'!,R 404.1 ~61., 0 .JAN :;7~~4 2-41.4 17 1~!-~~ 375.9 ~,q,l; 377~~ 17!1~2 376.4 177 (· .1. 319.9 ..,...., . ., ,-: ·1 / / \' u 3S2,9 17,~ ~ ~:~ 376+0 1:75 ~ ,; 37~+? 17·~ ~ B 309 ~ 7' ~i7 t 1) 282.3 ~~14 .,~ ~At:" """! /~~I+ i 178~1 374.9 ·n?.i-1 244+2 :;,~.8 + 1~1 244.4 177}9 ·:~ ... ., Q ... .i.l}~ +I' 17.~ t (J ::76.0 :"~: :1 ;') \· J. FEB 31.9,0 189.6 :-r:::; ,. 9 32t .• 3 11.9,.~. l?7~7 ~ 1_ 8 t :; ~?7 t :? 1~~1 { .. ., .......... ,, l"\ .j / b • 'I 1)7~? 330~8 12l~ (• .4 32i,2 :~:?:) f 9 ?:J6,t.. 1"/7 t .~ 3?9.5 3?7 (•:-:; 317 .. 5 1:n, 0 192.3 3~8.6 326+5 t~:P..1 J 92.4 .~ULO 191.6 3~8 ~ 1. 190.5 ::r~'"(-~ 325.8 .-.,.,r:-~ -·: 'J.J f / ] 217 .o 290(.8 294.4 337.1 2j~.;-; 31!5.8 335+1 AFR 232.4 220.~ 2:34,8 ol""'\w;'t:" ..., £.~.t~'·t-. 242~7 242.0 214.5 274.4 <94,1. .., /1_,.., .-1 .i. l.L.. !· -r 275.4 298.7 •"''l"\t:" n .·:IJ·-'~ r 26~ tV 22'?~1 248.5 ~58~1. 240 •' ·-· ?95,1 ?3?~4 203 "c. 18:::.8 295f5 238.2 237,0 183.7 ~., • ., f 8 254.6 ?94,/ 72~~. 7 290.7 278+3 2!'!1. 2 MAY '204 .5 256.7 187.0 3lt. ,o 320.1 201.8 121 ' 1, 236.1 2~8t1 2BQt2 300,2 310.4 223.9 310.7 186.0 228.4 ?01 t :~ 292i/ 306.7 194.2 195~7 201.2 TB.O 1B4.3 306.1 2t.5 .1 21.3.3 217.8 21.8.:; 259.0 ?02.3 211.1 248,2 JUN 189.8 180t3 233.5 313.3 220.5 263.1 316.4 303.6 ?49r2 208.4 180.7 321.9 126~7 ::107.9 3.'30 + 6 239. t. 326.3 302~t.· 313.!1 188.1 202~4 211.9 323.9 ?15t7 188.9 311.2 202.3 321.1 175.1 238.7 ?:?7 .+ !J 175.5 JUL 1.94.3 185.3 206.7 186.8 193.0 244.8 29_8.8 192,4 190.2 205t6 195.4 231.8 265.1 304.2 270(.6 244.6 19.~ t 5 263.5 289.4 184~2 205.1 186.2 272~7 18i.9 188.0 288.9 t87.6 275t7 185,6 278.5 298t0 264.9 230.1 AUG 342.2 3,~0. 0 339.9 333.1 316.4 356.5 379f5 3·~2' 7 316.8 ;:IJ-:'!. 8 330.0 352.7 ·'1'16. 4 356.9 3~4~7 339.1 328.3 417.3 341.5 317.9 335.3 335.0 3,~0 r5 347.1 344.7 346.3 3%.8 35,1. 5 342.0 337.7 3~8.4 446.4 353.0 SEP 244.7 432.0 344.0 254.8 2~'3 .1 245t2 432.0 252~3 251t2 251.0 288.2 266.3 25i;8 243.6 245,6 255.8 255.4 254~2 255.8 253~8 400.6 283.6 ANN 3359.2 2747.4 T101.? 3633.1 3315.5 3508.3 3%5.5 367t~~ 5 3727.1 3306.7 3606.2 3757.9 39·~6. l 3980.9 36M.1. 3476.2 3642 ,::,; 3575~4 38,~8 + 4 297?~9 2742.1 2778.8 3935.6 3388.2 2883.3 2988.0 34·10 + 6 3112.1 3476.9 2948.3 3631.9 3824.6 l TOTAL ENERGY PRODUCED <GWH) on NtJ!) DEC JAN FEB MAR AF'R' MAY JUN JUL AUG SEF' ANN 1 A~.t .., n8.,~ 870,7 79.;. {) J ~ r , .... 588 .. 5 471:4 ..... 1:"1:" c:-324.6 331.9 495.8 0::"10 "" 6599.7 ·T·11. :· / •':':•":• -i-7 j._t._I f. .:.J \J\ool•J t .,_1 ') 653.9 471.9 551~4 :i04 ~ 2 392.0 438+5 444.0 471.3 325~1 328.8 49~ .t. 494.1 55t.t..9 .-:. ~ 5., 1. { ~~ 689}\.:; 870 tt? '"?ril r; .~H;~, 3 t.56 ~-1 -477~9 354.0 340.8 340.5 538.2 464.4 6772.1 I 7lJ. + •.,: 4 572t5 767~1 870.7 79A. 7 682 .. 4 1.1. !j ""'t 517.4 555 .. j ~25~8 331.5 476.6 390.1 7150.2 t..'\..'~ ~ .j 5 6::)7 ~ .~ .-1'7•") r.; Sl 9 ,.1. 77~t~ ·~67 ,.3 592,.8 490,3 533 ,.1 332~8 331.4 4~0.7 392.4 6502.5 . 1 ! •·• -:• ~,I ' 610.2 473i3 871.1 796.f:, t.82 t 6 t88. t• 489.6 354.9 438.0 43,LO 627,1 787.0 7263.0 0 7 1:"·'").1':' " T=;o,9 870 ... /·1 79·~.? l:.~i1 {· 7 598.8 474~7 ~54t-~ 5'25.8 517.1 700.3 ..,..,.c;-"""' 7914.0 .._1.• .• • ,I : ~ 1 1-:J;J+..::. (0 ~48ot• 76C.t9 8?0.7 ... Jrt ... , .1 683,0 697.4 cc.-1 .-, 404,7 526.0 3:!,1.9 539~1 59i.5 7314.0 \) l :" l 1J...,IO t ~ 'i ,~7~~; 9 "7·~·?t~ •l/1:" r: 796.3 ~~8? ,.4 \~193 ·~ 4 598, ·;~ 4.b3,. 7 440,1 331.9 505.7 475.6 7307.3 •')/ .J :· d lO 658.4 472.3 1:'1:""'""1 .... , .... -"') I' 679,4 599.6 488.! ·""t:" "') ..,.., :1 1 331.8 £;::;',.,"! .... 794.5 6562.3 ,_1.,).:.: t \.1 C::/ . .:.. ~ 0 ,~._1 ~...:... ~.i."'itW •• .t~·j,_l. / 11. 61.1,1') 7.~6 ~ 8 870,A. 79/ {•i) LO-. 1'1. 6'?2 t 3 558}7 554,1 324 '·~ 332.0 469.1 377.6 7038.4 '·'' ,t."::t :-'·} :i.2 611.1 7/)t\ t 6 870.6 P.02.8 688.1 692.8 598.1 555.0 526.1 383.9 617.4 430,.3 7482.9 n 57:=i, 1 .~70.8 874,8 7'7.~ t :1 ~~~!~t-8 69::!.1 579,9 430.2 ~·"'\~ .., 517.6 98'1.1 918.1 82~6t4 .J..::.\J t / 14 ~ 7 ~ l:t 76t.,~ 9 870.7 797.0 t·83 .o 692+3 532.9 555+2 ~1"\C' I !"i18.1 690.8 755.9 8024.7 0-...•0 t .J t.~L,' t t, •c-,qt,8 ...,,...., I'\ 870:7 7'?.~. ~ 0 .~:~1).8 588.;) ~16!1) 8 157.8 c---.c-..., 517.2 624.0 451.2 n~7.4 .L-.1 l •'J. i C· l') ,J.t:.,_r + ; . ' ,J:.22+0 611.1 870+6 ...,,.,..., .... f:.f·,?. • 4 6()~' 2 !SO:i .6 422~7 400.3 413.7 5~16. 3 690.4 7147,0 .l.t:• i 7/ ' I 17 629 :·1 T;!;,R S70,7 7'1~~ ;, ?. l.M.I"'\ . 6:.:~ <· 9 5t8~7 3~5~0 525+6 311.2 ·1.~5.8 430.3 701.2. 7 •.; I}.·: : . 1.8 'C"O ..., j, ~, "' "" 552.0 650 .t. bB4,6 , ... .,.. -'"\ 484.9 534.5 525.9 449.4 752.4 953.4 7331.3 Q._I~J + .:_, '. / .t.. .. ..:. 0 .I~'"!~·~ 19 s·~o ,. i. 7.1~ ;. 7 878t1. 791-,,.9 ,;s:-,,o 6'1'2.8 597,8 554,.4 1:'..-\ I I:" 517.3 Anc-1.. 511.0 75-10.0 ,.J.:.O + ._t 6f., ._i + 0 '")('; 657.9 472+2 551.'7' :.t96 '2 t.t.3 t 5 59 f.' 1. 48, ,., 355.? 324.9 334.3 508ti 523.9 6066.9 .;..'J + ' 2l ,-j~() :· 1. 47L7 l:"l:"of ,:; ~{).~ + 1, 19l.7 418.:3 ""1 I I "'!' 401.1 324.3 331.7 478.8 469.1 53i3.3 . :.J '· ·JOO' ,_, ,.;--., 649.9 472.3 551.8 ""All -391.9 438.4 36t. + 4 352.9 358.9 328.8 578.7 630.1 5624.4 ,: .. .L_ ,_JIJ I fo ,"\ 23 58~~~ 7 7.~7,1) 870,8 7%.3 ~8?,4 691.4 598,3 5~4.6 1=::'-"'l J ~ 518.3 636.6 617.0 78,19.8 J.:.O +·.' 24 503 .{:. 745~8 870.7 796.1 682.1 634.5 484.9 35:t+O 362.0 3f12 .~ 512.9 567.5 6857.9 25 6~/) l J. 17?, 1. ~~11 ~~; ~i) ~ + ~ .F'" f'l 539 •. , ·~8?: 3 ~54,1 324 .. 4 331.3 5C0.1 471.4 5778.2 •.! 7 .. ·: {· , 26 f.52.0 471.8 551.6 504.3 JQ"1 ,., 438. ,t, 366 .t. 461.5 52tq5 517.5 562.2 523 .::i 5968.4 : 1 .. ,,_ f .:,'. .,~ ~8lL8 75:-,+ 1 870' ::; 780~7 f.,q,s 597,.7 498.1 "TI:"I:' 1:' 325,0 342.1 554.5 557.3 6887.8 &...I ·i·..'.W t ·I :,!8 654.0 472.2 551 ~ S' 504.5 3l7'2.2 601.0 510.8 355~4 526.1 517.6 673.4 452.1 6161.2 2'1 6()9,'1 711,:') 870.,.~ 797 ,I) e::;1.o 692.6 5"17 ~ 5 430.3 324.9 331.9 495.0 513.1 7080.3 ~~0 653~2 472.1 551..6 504.3 392.1 438.7 466.8 496.7 457.9 501.4 532.3 443.8 5910.9 .,.. f,S~ ,O !19 ~ ~ ;_; 870 •• ~ 79l) ·i 9 .~8?' 9 692.4 589.4 371.6 522.4 517.5 614.8 520.9 7436.0 .J I. 32 621.0 767.3 870.8 799.;\ f.83.0 692.4 565.0 388.4 ;"1:32.0 448.6 988.8 859.2 8015.8 A!JF .s:~.o, 1 ~1·1. 7 7.~9' 9 7P,'I .~15.8 611.7 507,0 445.1 429.!"; 404.8 581.1 579.3 6908.1 J I '~"· ,I ~ ... J .I .I -~-• .. J _cl .I J .. 1 ) l TOTAl USABLE ENEF:GY (GWH) 0\.T NOIJ DEC JAN FEB MA~: AF'F: MAY Jl!N JUL AUG SEF' ANN 1 1'31.,7 n8,,1 870. ~i 7% ,l) .~//: .• 9 5R8t5 471,4 3!15.5 124.6 331.9 495.8 538.5 6599.5 ... ,, .·: 653i9 471.9 551.4 50:~ t 2 392.0 438.5 444.0 471 t ;:\ 325.1 328.8 491.6 494.1 5566.9 .., 5.11,,0 689,.~ 870~:1 796,.1. 1:82,1. 65.'1.1. 477,9 3!'!4.0 340.8 3110.5 5~8.2 464.4 6771.0 .,;) 4 572.5 ?61.: .. 8 870.5 796.1 682.1 664.3 517.4 554.3 525.6 331.5 476.6 390.1 7147.7 5 /,.1'!""7 l 47::>.~ 819 '~-77?. t 1 6/·,7. 3 592.8 490.3 533.1 332.8 331.4 ·H0.7 392.4 6502.5 I.J• .l! ) t1 6 610.2 473.3 870.5 796.1 t.f:2 t 1 691.9 489.6 354.9 438.0 434.0 5,n,1 568.8 6952.4 7 5~~5' 'l T':;0,9 :-:170, ~:; 796,). 61, ·1. 7 598.8 474,7 554.3 ~"i~ .. 517 t 1 543.1 568.8 7390.0 I ,.•..:..'-1 t C· 8 548,6 ?6t .• s 870.5 796.1 -:.82.1 691.9 556.2 404.7 525.6 331.9 539.1 568.8 7282.3 9 .F.),9 7/:t;.,\1 870,3 79.'·., J. .,82.1. 691.9 597.6 4.,3. 7 440.1 331.9 505.7 475.6 7298.8 10 658.4 472.3 552"0 t.72 + 6 679.4 599.t. 488.1 445.2 324.6 331.8 51)3.1 ~;68 .8 6335.9 11 61.3 ,f) 7f. .. '1 'B 870.:"! 796. 1. t.8~.1 691.,9 5!18.7 554.1 324.2 332.0 469.1 377.6 7036.0 12 t-11.1 706.6 870.5 79f:.., 1 682.1 691 • 9 ~9/'.r. 554.3 ~25.6 383.9 543.1 430.3 7393.1 13 :'ii'B ,. 3 /:.70,8 870) :=j 79,1:,,). 682.1 691..9 579,9 430,? 525.6 517.1 543.1 568.8 7454.4 :!.4 (:.36.5 766.8 870 .:; 796.1 6R2 ,1 691.9 ~i32. 9 ~i54. 3 525.6 517.1 543.1 568.8 7685.6 15 61.1.,8 7.~ .. ~. 8 H70, ~; j'J6, I) 680.8 588.5 ;~65,8 357.8 525.6 517.1 543.1 451.2 7175.() :!.6 f,22 .o 611.1 870.5 796.1 6A3.4 603.2 505.6 422t7 400.3 413.7 5·~3 .1 :;68. 8 7020.4 17 .~29:.1 7:;~;; '8 870 ;. 3 796,) 68?..1. 6!13.9 518.7 355,.0 .,..,.,. J. ..J..:..~tu 331 .• 2 46:i .8 430.3 701.2.:~ 18 658,3 ~72.2 5·52. 0 650.6 682.1 61::'\.2 48~.9 ~34.~ c·..,~ 1 ,_1.,:.""' + \:• 449.4 5'13. 1 568.8 6734.6 19 520' 1, 7'~"~~7 870.;;) 796, ). t~8~ ~ 1 .~91. ,. 9 5'?7 t6 5'54.3 525~6 517.1 4'i!5.6 511.0 7528.5 :~o 657+9 472.2 551.9 596.2 I. " 7 1:" W-0-..J + •·-' 596.1 481.9 _,.C"C' .-._ .. , ... h.} • £. 324.9 334.3 508.9 C'')"'1' ,., ·-•.:...:a f 7 6066.9 21 .~5() ~ 1, 471., 7 3!11..3 51)4,:1. 39:1..7 43:1.3 366)3 401,1 324.3 331.7 478.8 469.1 5378.3 ... ~ ..... .,:.:4 649.9 472.3 551.8 504.3 391.9 ~38.4 ~65.4 352t9 3~i8,9 328.8 543.1 568.8 5527.6 23 ~8r~, 7 7M,8 870.:! n.:), t 682 ,.1 691.9 ~1"\"'"1 I -.17 i fo l1 !154.3 525.6 51?.1 543.1 568.8 7702 + ~.i ..,,'\ '!::"'(' • ..,. .t. 745.8 870.5 796.1 682.1 63-'1 t 5 484 .. t:,' 355.0 362.0 312.6 512.9 567.5 6857.5 .;.·~..,. ;h),~ ...... 25 g):)' 1. -1n, .1. ~?51.~;; 504,? 392,0 519 t•~· ·~82 ,3 554.:1. 324.4 331.3 500.1 471.4 5778t2 '")' t.O .:\52 tO 471.8 551.6 504.3 392t2 438.f.. :~66. 6 461.5 525.t.. 51? .1 51J.3.1 523.5 5948.0 .,, i-l 5R;i,.8 T"i1.··1 871)) ::; 780r? .~1~.1. 8 597.7 4'18.3 3!15 f ~i 325.0 342.1 543.1 557.3 687C..3 28 654.0 472.2 551.9 ~;04.5 392.2 601.0 510.8 35~i.4 525+6 517.1 543.1 452.1 60?9.9 '"'" .',()9,9 71:1.;:; 871),:') ?%, :t ,~8?., 1, 691.9 597,:) 430.3 324f9 33l..9 495.0 513.1 70?7.6 .:.7 30 ~53.2 472.1 551.6 504.3 392t1 43P..7 46f .• p. 496.7 457.9 501.4 532.3 443.8 5910.9 31. 6,1?,1) ~91 ,:') 871)~:1 7'7' .s ' 1. 68'~ ·:. 1. 69L9 589,.4 371.6 522.4 51? .1 543.1 520.'1 73A1. t. "i.'-\ ~·.a::. 621 .o 766.8 870.5 796.1 682.1 691.9 !"i6!"i,O 388.4 332~0 448.6 543.1 568t8 ?2?4;.3 AVF: 6 J.f)' 1. ~::-;.1, /; 769,.:·~ 7J.6 • .r) .::. 1. !') •. ~ 613.2 '507,0 445.0 429~4 404.7 51'i' 9 508.0 ~_..,..., ... \ ...., 0//.:.:. t/ FORFCAST DEMAND ENEF:GY <GWH) OCT NOV DEC JAN FEB MAF: APR MAY ..JUN JUL AUG SEF' 677,0 7.~.~., B 870 ':) 79.s. J. .~8?. l 691.9 597,.6 554.3 525t6 517.1 543.1 568.8 7790.9 PRF.-F'ROJECT FLOW AT GOLD CF:EEI': <CFS) OCT NOV DEC JAN FEB MAf\ APf\ MAY JUN JUL P;UG SEF' 1 .111:') '0 ~~81,1) 1..119' () 10::.!7.0 788.0 ?"~i: .• 0 S?OtO 11. ~)1_ 0 '() 1'1t.OO.O 22600.0 l98RO,O 8301.0 .. , 3848.0 1300.0 1100.0 9f:..l) .o 8?0.0 740,0 J617.0 14090.0 20790,1) 225?0.0 19670.0 21240.0 ... "" :-J571,,0 ~744 ,f) 1.900:.0 1, 600' I) 1.001) t 0 880,0 ·no,o ~)419,0 3:2370.1 '?61'10t() 20920.0 1·1·180.0 4 8202.0 3497.0 1700.0 1100.0 8?0.0 820j0 1f.15. 0 19270.0 273:?0.1 20200.0 20610.0 15270.0 5 ~6J).1 ,{) :~100) 0 1, :=!(:0. 0 1.1~')0. 1) 1.()i') I) , 0 780,1) 12~5~0 1n:1o,.o :!5·~~:o to 20360.0 261()0.0 12920.0 6 53?0.0 2760.0 2045.0 1794.0 1400.0 1100.0 1?00.0 9~1 ~r\ ~ o 29860.0 27~;6o.o 257~50 t 0 1·~290.0 'i 49:'5J. ,f) 1.91)1),1) 1.~0(),1) 980.1) 97() .(l 9~0.0 9~10 ~ 0 1. ? . .;.!-,() '0 3T340, 0 1109(1,1 24510.0 18330.() / (J 5806.0 3050.0 2142.0 1700.0 1:;oo.o 1200.0 1200.0 13750.0 30160.0 23310.0 20540,0 1980(),0 w 9 8~11 ,1) :w=:;.~,o :!,~.·')4 ,I) 1%5 ,f) 1.307 .o lHH,O 1533,0 12900.0 257(~(1. 0 228[~0 "0 :22540~0 7!:i~;o'" o 10 4811.0 2150.0 1513.0 1448.0 130?.0 980,0 1250 .. 0 15990.0 23320.0 25000.0 311BO,O 1,)920,. (i 1' !. ~558 ~ r; ~~8':0 ,. !) ~~01) :· () 1.81"),1) 1. ,rP ,o 1197.0 1.3CO,O 15780+0 1~i5~0.0 '22980 .o 2359(1~0 ·~o~;1.o.o 12 7794.0 3000.0 2694.0 2452.0 1754.0 1810.0 2b~i~ .o 1 T~60 .0 29-4~.i·) + 0 245'.70.0 22100.0 13370.0 13 591.6 ,I) ?.700 ·~I) ::!11)0,1) 1900 •. 1) 1500,(< 1400.0 1700.0 1. 25'?)0 t 0 43270.0 2ss~:o. o 235:10 t 0 1. 58S'\). 0 14 L -,.-, ..... ""' p.J..:...j.+V 2800.0 2000.0 1t.OO, 0 1~iOO.O 1.0()(!,0 830.0 19030,() 2.'·.000. (! 34400.0 23670.0 12320.0 15 6119 ,fj 2250 t l) 1.194 ,() 10~8. () 91-..l·~ + {) :tn.o 745 ,.o 4307+0 505HO.O 22950.0 16440 •. () 91:'-J 1 .o , ._r / J. p 6291.0 2799.0 1211 .o %0.0 Q:! A f'.. 900.0 1360.0 12990.0 25720.0 27840.0 21120.() 1.93~5CI • 0 ,\,..1 ,_:,t·•1dtU 17 7~0~:; ~f) 2098,1) LS1t.t) 1. 4l)l), i) 1, 3!)!) !· 0 1300.0 1 ·-··~!:' ,c, '7'f:.45 '0 '329~0 ~· 0 19:i60.0 21830t0 1.1750.0 . // :-' ;.l,..J :1.8 41,63 .o 1600.0 1500.0 1500.0 1400.0 1200.0 11tl7.() 15480~0 2'7'510. 0 26BOO,O 326'20.0 t,:.8?0. f) 19 1'100) I) 1151,0 ~()~5.0 1981.0 1.900.0 1.900.0 11'1.(), 0 J.t.180.0 315~~0 t 0 26420.0 171?0,.0 881·:i .o ''n ·1272 .. 0 1906.0 1330.0 1086.0 9?2,0 s;:~:~. o 1022.0 9852~0 1"\ ..... 1::"""''""' 1\ 1809"3.0 16322.0 977b.O .l.J ..;:,~} ... i..::.~~) -)• .. ) 21 11.14,1) ~. ~J.~L 0 P..L,~.!) 82 1.0 7.~8. f) 77a:S t 0 1080 ,\) 11380' 0 186:z.o.o 22660t0 19980.0 9U1.0 "';I"") 5288.0 3407.0 2290.0 1442.0 103f..O 9~0.0 108?.0 3'?45t0 3?930.0 J""!""~C:•t::•r-. ,1\ 31910,0 14440.0 .\~.""' ..::,j,'J._Ijt\} '1"1 .:..·J ~847,0 1on. o 2:11 () '1) ~~19. 1) 202:=) <· () 18?3.0 17lO,.O ?V390 ,. 0 7.4130.0 227?0.0 192fJ0 t 0 12-<100.0 ~~4 4826.0 2253.0 1465.0 1200,0 1200.0 1000.0 1027.0 8235.0 1"\ .,\:'I ..... ,., .-'1 .::. i \)\Jtl • '·-' 18250.0 202~1(:; + 0 90'?4.0 "lC:: :u:n, o 1.521' I) 1.014.0 874.0 777.0 7?4.0 '?~)2 C• 0 1t.180. 0 17870.0 18800.0 16220.0 1.22~()~0 .:a:..·-· 26 3739.0 1700.0 H~03.0 1516.0 1471.0 1400.0 1~9:;{po 1535:) .. 0 32310.0 2??20t0 18(1 1y<:"i '() 1t:.::no.o "l'i 7Th', 0 1. 993 ,i) 1,1)~i1,,() 971.0 951) ,.I) 900,0 1.373 :· 0 l2C..'~(): 0 '?43:~0' 0 1.8940~0 19:300.0 o:~!Sl +o ,;_/ 28 3874.0 2650,0 2403.0 1829.0 1618.0 1500.0 1f,80. 0 P680.0 379?0t0 22S70t0 19240 ·> 0 12640.0 29 7:171..0 3:1'~:-) ,I) ?:')89.0 20~9.1) l·S168 ~O 1605.0 1?02' 0 1.1950.0 l '10~!0 ,. () 21020.0 16390.0 :::~607~0 30 •1907. 0 2535.0 1681.0 1397.0 1286.0 1200.() H:;o,o 1.1.870. 0 24t80. 0 28880t1 20460t0 10?70.0 31. 711.1.,1) Hn,11 2Hf;,O 1. 7-"l8 fo i) H·~6.1) 14('0 ,.() 1.670:-0 1'2().L,0. 0 '?9080.0 326·~0 t 0 20960.0 13280y0 32 7725t0 3986.0 1773.1 14:'53.6 1235.6 1114.3 1~Z.t.7t~ 1.::~q6,7 18143.0 32000 l 0 2·85~5B l' 0 131'.!'1 .1 AIJI=: !1770):i ?577, 1. lR07,~ 1471 • .1. 1.:::49.1 11'?1.7 136L :7 n?4o.o 2?814 .. '? 24445 ~-1 2222B ~-1 i ·7·..,.,_,1 n J.· .. ~\~~\)f<7 .. I .] .] -~ .] I .. 1 J J J .. J ~ --~ POST-PROJECT FLOWS AT GOLD CREEK !CFSl OCT NOll DEC JAN FEB 1 7179,~ 109~4~4 1~5zs.: t16~o~~ 1o9~9.~ 88A~.1 2 6748.5 7141.1 81~4.~ 7497.6 6524.0 6631.9 3 6819,1 10411.l 1~f6R.R 117~6.9 1\lRO,A 98~9.6 4 7~07.4 11650,3 12668.v 11689.6 11211.6 9983.0 5 72~t.7 7247+7 11896)~ 11~1~tA 10979.8 891.9.1 6 7?86,5 7392.2 12739.4 11782.4 11311.0 1053A,O 7 791?,9 11123.8 12~72,1 116~5,? 10~19.8 QQ79.3 8 8787.9 11673.8 12683.1 11721.9 11278.3 10458.6 9 109RJ,0 tt84~.R 11114.1 11797,3 1l?07.9 10382.6 10 7116.3 7230.1 8181.8 9993.1 11286.8 911~.3 1\ 9519,9 1\577.0 1~749.7 11804.9 1t?R0,1 104~9.1 12 7203.6 10747.3 12886.7 12045.8 114~2.8 10604.2 13 7073)8 100~}+9 12680~9 ~1701r4 1t)34~? 10432.7 14 9704.9 11332.8 12580.8 11696.5 11281.5 10356.3 15 9~10.9 11473.8 1?~98,7 116~8.9 11191.~ 88~2.~ 16 7305,8 9195.c 12487.2 11601.1 10839,8 9039,3 17 10186.9 11321.8 12~88.7 117!8.9 11?9~.4 9947.7 18 A931.1 7212,; 8171.5 9697.8 11379.8 9339.~ 19 7881.9 114?3,0 12737.1 11751,6 1t3C0,9 105tO,O 20 A889.6 7178.6 8091.0 8777.6 10901.8 897?,3 21 ~921.1 721~.3 819~.1 7607.1 66\3.9 67,~.4 22 7~15.1 7724~t 8500.2 7697~1 6655.9 A7A9.9 23 88~8.9 11~84~7 1~7A~)t tt867t9 t1106o1 10580.9 24 6153.2 11030.1 12541.9 11619.5 11214.1 9529.~ 25 A8?0~4 7t01}9 8010~~ 74?1~9 A4~7.:~ 8101.8 26 6849~9 7200,1 8268.7 7634t9 6697.7 6SlR.4 27 8~?7.~ 11?1A)8 1?31?~2 114~0.0 109~~9.8 9019t.J 28 7001.4 7515.6 8491.4 7707~6 6687.1 9?14.o 29 73~6.7 11299.3 12808.2 11810.6 113~0.4 10515.~ 30 7190~6 7439~1 8272t3 7582.1 6~86.6 A618.1 31 7096~~ 9128,8 1~649i:i 11t89o6 1.1??3.6 10410~8 32 8334.0 11632.7 12677.1 11759~5 11268.2 10448.4 ?472~.s ?138.6 ?522f.8 8217~8 78:37 ~· :~ 7HO~~. 8 ?5~i;~ '8 E:F:33. 8 94.4~ ~-~ '?~~52" 8 88~16 :-:< 97e;~·. 4 9lq5.0 fi?:3?.? ?34?~.:=3 7962!-8 ::::377 f 8 7769t8 9518~-6 7C:,2~~8 6~)77 '8 5S'5~) + 4 r'\C"'I:'II ,-~ "}" J.,IQ ~· 1;-t. 7\~29 ~ 8 7~;94 y :3 c:·, .... ,""\0 C" ,J! C• ,~ '!' ~..i 711'"7~ ,"'\ .' ..,. l .. 1.:. ,, 8:('8/ t 8 9493~:-:f 7~6~; + 5 9357 ·~ 5 f!994. 4 hAY JUN JUL '13(:115 + 2 (;,'184. '? 7:3~~0 + ~; 98·~1+3 10471.8 6484+0 '?84~2+4 t,7:i0.4 AU13 12000.0 12000t0 12000.0 15191 .8 12000.0 12000.0 12000 •. 0 12000.0 SEF' 93CO .. G 1 c~.~~~4. :_; nco.o 1 ,~.t~70 ~ 0 ·;:·;::co, o 9300.0 nco.o 10~52~B 9300t0 '1'300 .o ,- - - - 8 -RESERVOIR AND RIVER TEMPERATURE STUDIES 8.1 -Introduction The objective of the reservoir temperature studies was to determine the impact of project operation on water temperatures immediately down- stream from the damsites. Companion studies were made to extend these outflow temperatures to critical locations between the damsites and Ta 1 keetna. The results of these studies are used to determine the best out 1 et works and power intake configuration to achieve downstream water tem- peratures consistent with the fishery mitigation plan and, when possible, to maintain acceptable ice cover growth and stability. Two models were used in the reservoir temperature study. Early studies had used the Reservoir Temperature Stratification Program developed by the U.S. Army Corps of Engineers (1972). Results from this study are given in Acres (1982). Review of these findings resulted ·in the recom- mendation to the Alaska Power Authority to continue reservoir tempera- ture modeling with a more detailed model and to verify this model with collection of temperature profiles and other data at an existing Alaskan lake or reservoir. Several models were reviewed for availability and suitability for Alaskan conditions. Of importance was the requirement to model reser- voir temperatures under ice-covered conditions and the ability to model selective withdrawal intakes. The program Dynamic Reservoir Simulation Model (DYRESM), by Imberger and Patterson (1978, 1980), was selected as a suitable model due to its general acceptance in the field of tempera- ture modeling and its application to lakes and reservoirs in Canada. An ice-cover subroutine was developed by Dr. J.C. Patterson and Acres to model winter conditions. Two programs developed in-house were used to predict water temperatures in the downstream reach between the damsites and Talkeetna and to establish ice cover formation and growth. Reservoir temperature model- ing, in conjunction with the project operation model, provided the necessary upstream boundary condition of temperature and discharge required for the downstream temperature model (HEATSM). This in turn provided the upstream boundary condition (ice generation section) for the ice model ( ICESM). Together, the three programs provide a complete model of the reservoir and river reach thermal condition. 8.2 -Early Studies The conclusion drawn from temperature studies f·inalized in 1981 (Acres 1982) was that single power intakes capable of drawing water to the lowest operating level would not be able to provide the downstream tem- peratures required for fisheries. Consequently, intake structures with the capability of withdrawing at variable levels were found to provide acceptable temperatures during the summer months. However, winter temperatures were not as acceptable because of delay of ice-cover formation and subsequent uncertainties of ice-cover stability. 8-1 The operational philosophy of the power intake was to draw off water as close to the surface as possible, given the intake layout and hydraulic submergence criteria. This operation was assumed for three weather conditions of wet, average, and dry, and for two downstream flow condi- tions. Downstream conditions assumed were Case A (best power opera- tion, August minimum flow of 6000 cfs) and Case D (least environmental impact, August minimum flow of 19,000 cfs). Results of the temperature modeling for Case A for the reach from Devil Canyon dam to Talkeetna with Watana/Devil Canyon operation are sum- marized in Tables S.1 to S.3 for average, wet, and dry weather condi- tions. Cross-section locations are given in Figure S.l. Generally, summer (July and August) water temperatures at Go 1 d Creek are about 10°C for all weather conditions assumed. June and September tempera- tures at Gold Creek are about S°C. Winter (October to IVlay) tempera- tures at Gold Creek never fall belovl 3°C for the three weather condi- tions assumed. Similarly, at Talkeetna summer water temperatures are about 12°C, June temperatures are about 10°c, and September tempera- tures are about soc. Winter temperatures are such as to prevent the establishment of a significant ice cover above the Susitna/Chulitna confluence at Talkeetna. Further details of the models and the results can be found in Appendix A4 of Acres. (19S2). S.3 -19S2 Studies (a) Introduction During 19S2, studies of reservoir temperatures were extended to include recorded meteorological data at Watana and elaboration of modeling techniques. Previous studies based on a monthly time step were unable to provide the necessary details on possible daily temperature fluctuations to the fishery mitigation plan. The extended studies required the selection of a reservoir tem- perature model which could provide daily temperature results and be able to accurately model meteoroiogical forcing, wind mixing, inflow dynamics, and outflow dynamics on the same daily time step. After review of several models with the above qualifications, the program DYRESM was selected. The selection of DYRESM was based on a general review of the model's analogues of the physical system, the availability of the model and of one of the authors (Dr. J.c~ Patterson) for consulta- tion, and the verification or use of the model on deep, glacial- fed lakes in British Columbia, notably Kootenay Lake. A brief general description of the model is given below in Section S.3(b). De t a i1 e d d i s c us s i on o f t h e mode 1 an d it s an a 1 o g u e s i s g i v en i n Imberger and Patterson (19SO). Modifications to the basic program are discussed in subsequent sections of this section. S-2 - - - - - - - (b) - - - Verification of DYRESM was accomplished by modeling the dynamics of Ekl utna Lake, Alaska, and by comparison of the results with measured data. Details of this verification and of modifications made to DYRESM to better model the temperature regime are given in Section 8. 4. Reservoir temperature results for Watana and for Watana/Devil Canyon are given in Sections 8.5 and 8.6, respec- tively. DYRESM ~~odel Predictions of reservoir temperatures stratification and outflow temperatures have been made using a one-dimensional numerical model developed by Imberger et al. (1980). The DYRESM model has been modified to include ice-cover formation and outflow hydrau- 1 ics associated with multiple intake structures. DYRESM approaches the problem of reservoir temperature (and salinity) modeling by parameterization of the physical process rather than numerical solution of the appropriate differential equations. The reservoir is modeled by a system of horizontal layers with uniform properties ~Jhich move up and down, in accor- dance with the volume-depth relationship, as inflow and withdrawal increase and decrease the reservoir volume. Each model layer has dimensions suited to the function or condition it is required to represent. For example, the reservoirs mixed layer may be modeled by a combination of several layers starting with a reasonably coarse layer structure in the epilimnion and graduating down to a very narrow fine layer in the transition zone. The construction of the model DYRESM consists of a main program with subroutines which separately model each of the physical pro- cesses of inflow, withdrawal, mixed layer dynamics, and vertical transport in the hypolimnion. Other subroutines provide support for handling frequently required data such as volumes, density, etc. The physical processes involved in the modeling require definition of the time step over which they act. Inflow and outflow dynamics generally change relatively slowly from day to day, whereas the mixed layer dynamics require a much finer time step. In DYRESM, the base time step is set at one day for calls to subroutines which deal with inflow and outflow. Calls to other subroutines are based on the dynamics of the situation and range from fifteen minutes to twelve hours. Meteorological data are generally assumed to be input as daily averages, except for wind speed which is also given as six-hour resultant wind speeds. Allowance is built into the program for short wave radiation absorption between day and night. DYRESM requires comprehensive data on wind speed, short-and long-wave radiation, temperature, vapor pressure, . and precipitation in addition to physical characteristics of the reservoir and inflow and outflow quantities. 8-3 Detailed discussion of DYRESM is provided in Imberger et al. {1978), Imberger and Patterson (1980) and Fischer (1979). 8.4-Eklutna Lake Temperature Modeling The program DYRESM has been extensively used in Canada and Australia to predict thermal and salinity profiles within lakes and reservoirs. To aid in assessing the acceptability of DYRESM for Alaskan conditions, a data collection program was established in 1982 to obtain information on the thermal structure of Eklutna Lake and to collect meteorological data. Eklutna Lake is located approximately 30 miles north of Anchorage (Figure 8.2). It is a natural glacial lake formed by blockage of the valley by moraine. In 1965, a hydroelectric project was developed at the lake to utilize the flow and storage capacity. Powerhouse faci 1 it ies are connected to the 1 ake vi a a single tunnel with an intake located in the northern end of the lake (Figures 8.2 and 8.3). Elevation-area storage curves were developed by R&M Consultants from the hydroelectric project construction drawings and topographical maps (R&M 1982). (a) Data Collection Program The reservoir temperature model DYRESM requires detai 1 ed daily meteorological data. These data include on a daily basis: -Mean temperature {°C); -111ean wind speed (m/s); -Air vapor pressure (mb); -Total short-wave radiation (kj/m2); -Precipitation (mm); and -Long-wave radiation (kj(m2) or, as an alternative, cloud cover as percent of sky. In addition, the version of DYRESM used requires resultant wind speed for six-hour increments. These variables were collected at a weather stat ion 1 ocated near the southern end of the 1 ake (Figure 8.2). A "Weather Wizard" similar to those used in the Susitna Basin was established. In addition to climate data, information on the quantity and temperature of inflow to the lake as well as powerhouse and over- flow quantities are required. The inflow data requirement was met by establishing two gaging stations on the major tributaries which measured temperature and stage; station locations are shown on Figure 8.3. Periodic measurements were made at these stations to determine the stage-discharge relationship so that daily flows caul d be estimated. Temperatures were measured on a cant inuous basis at the two locations. Powerhouse and overflow quantities were obtained from records kept at the Eklutna powerhouse. 8-4 - - - - - - - - - - Appro xi mat ely at two-week intervals, measurements of 1 ake tempera- ture profiles were made at up to seven stations. In addition, measurements of turbidity and conductivity were made at selected locations. The above information was collected by R&M Consultants and was reduced to the form required by OYRESI\1. Their report (R&M 1982) contains a summary of this information. On those occasions when either weather data or streamflow informa- tion was missing or not reliable, estimates were made based on other sources. The periods covered by estimation are given in R&M ( 1982). (b) Eklutna Lake Modeling Results Before modeling commenced for Eklutna Lake, a review of DYRESM was made to ensure that any site-specific parameters were accurately represented. This review resulted mainly in adjustments to mete- orological variables, particularly wind speed. In DYRESM, the wind speed is assumed to be measured at a height of 6 m and is adjusted within the program to provide an estimate of the wind speed at the water surface. This adjustment is required to correct for the velocity distribution within the turbulent boundary 1 ayer usually existing at an air/water interface. The Weather Wizard instrument, however, measures wind speed at about 2 m above surrounding scrub vegetation, so an underestimation of wind speeds would occur if no correction was applied. Based on boundary 1 ayer theory, the wind speeds measured were adjusted by the ratio given below. wsd = (~) 1/7 • wsg hg Where: WSd wind speed used in DYRESM; ws 9 measured wind speed; hg = gage height above ground and vegetation (2 m); and; hd = OYRESM assumed height (6 m). This produces an increase of 17 percent in measured wind speeds. Other key site-specific parameters used in OYRESM are given in Table 8.4. These are based on measurements at the site and recommended values (Patterson 1982 Personal communication; Imberger and Patterson 1980). The initial run of DYRESM for Eklutna Lake was made for the periods June 1 to June 18 and August 25 to October 13. These periods were selected for calibration of the model because of the uncertainties associated with July and August meteorological data (R&M 1982). The comparisons of measured and estimated profiles 8-5 with·i n Ek 1 utna Lake are given in Figures 8. 4 to 8. 6 for June 18, September 9, and September 21. These results show acceptable agreement between estimated and measured profiles for June 18 and September 9. However, on September 21 the measured profile shows substantial mixing to depth indicated by the warmer hypolimnion, whereas the estimated profile remains substantially stratified. Review of the meteorological data indicates that two periods of high winds occurred between September 9 and September 21. These events would explain the mixing to depth of warmer surface water with cooler hypolimnion water and could produce the profile measured. In DYRESM, however, these wind events have only caused deepening to about 50 feet. Consequently, the base version of DYRESM would appear to be not strictly applicable during high wind shear events. Fortunately adjustments can be made to the model to provide adequate representation of the mixing process during high wind shear. This is discussed below. DYRESM has three condit·ions under which the assumption of one- dimensionality is valid (lmberger 1980). The most important condition for Eklutna is given by the ~Jedderburn number: w ;::: .9.J!. • h U*2 I Where: w ;::: Wedderburn number; gl ;::: effective reduced gravity across the thermocline; h ;::: depth of the mixed layer; L basin scale; and U* ;::: surface shear velocity. Spigel and Imberger (1980) have shown that for W>1, the departure from one-dimensionality can be assumed minimal. For O<W<l, the departure is severe but can be parameterized, and for W<O, the 1 ake overturns. To determine whether these criteria for one- dimensionality were violated, the Wedderburn number for Eklutna Lake was determined for selected days from meteorological data and the simulated temperature profile; these values are given in Table 8.5. This shows that for September 15 and 21 (periods of high winds), the Wedderburn number is less than or close to one. Con- sequently, the one-dimensionality of DYRESM is not strictly valid during these periods. Fortunately, the problem can be resolved by modification of the vertical diffusion coefficient, which is a scale of the efficiency of transport of mass and momentum. The global vertical diffusion coefficient Ez is a measure of the mixing caused by wind and inflows for a given stratification and forcing history. Ez is computed as follows: 8-6 - - """'· - - r I ! E z Where: Ez K1 H Pw Ps E s = = = global vertical diffusion coefficient; a function depending upon the basin shape, the stratification, and the forcing history; reservoir depth; po~1er introduced by wind at the surface; power introduced by the inflowing streams; potential energy of the stratification in the whole 1 ake; and stability parameter. Imberger and Patterson (1980) recommend a value of K1 of 0.048. However, Patterson (Personal communication 1982) proposed values of K1 of 0.096, 0.24, and 0.48 during periods when the Wedderburn number is less than one. Analyses were made with these values, and it was found that K1 equal to 0.096 provided the best fit of simulated profiles measured. Comparisons with measured profiles for September 9 and September 21 are given in Figures 8.7 and 8.8, respectively. The parameterization affects only those periods of weak stratifi- cation or high winds. Periods with moderate-to-strong stratifica- tion or moderate wind speeds would result in DYRESM using the recommended value of K1 0.048. Obviously, this method requires much more refinement and justification, but it is believed the present method is adequate. With the above parameterization of the m1x1ng process during periods of low Wedderburn numbers, a simulation was made of Ekl utna Lake temperature for the period June 1 to December 31. This was broken into two periods of June 1 to August 25 and August 25 to December 31 to model the system accurately. This breakdovm isolated the estimated Eklutna meteorological data of July and August and permitted better analysis of the August 25 to December 31 period. In addition, a reevaluation of meteorological and other input was made to ensure accuracy. This review resulted in changes in some meteoro 1 ogi cal variables in September through December. Simulated and measured profiles at the station in the approximate center of the lake are given in Figures 8.9 to 8.19. In general, most profiles are modeled to within 0.5°C. This is generally within the observed variations of temperatures between measuring stations {R&M 1982). 8-7 Deviations in measured and simulated profiles can be explained through an assessment of the meteorological variables used, the reliability of the measurement of these variables, and the general modeling techniques used in DYRESM. Reduction of the magnitude of deviations could be achieved by a very fine tuning of the model to meet specific conditions and adjustments to input data to produce better results. In most cases, however, the temperature profi 1 es are reasonably estimated; consequently. there appears to be no justification to undertake a major reevaluation of estimated meteorological data or modeling technique. Outflow temperatures from Eklutna Lake are given in Figures 8.20 and 8. 21. In general. the simulated outflm'l temperature is 1 oc below the measured temperature during July to mid-September. From mid-September to December. simulated and measured temperatures match well. In late June and early July, severe deviations between measured and simulated temperatures occur (Figure 8. 20). This deviation is believed to be a result of a combination of DYRESM inadequacy in modeling a three-dimensional system and possible underestimation of air temperature and solar radiation and overestimation of wind speed. variables for which data were not available during much of this period. The configuration of Eklutna is such that the portion of the lake near the intake structure is shallower than the rest of the lake (Figure 8.3). This would result in a greater mixing influence from the intake structure than is modeled by DYRESM. The major portion of the temperature deviation is, however, believed to be caused by uncertainties associated \'lith data collected during this period. The model results for June 18 (Figure 8.10) show a very reasonable match to measured profiles as does that of July 14 (Figure 8.11) •. This indicates that average meteorological condi- tions over the entire period. June 18 to July 14. are suitably measured. However, estimates of conditions on a-daily basis may be in error. Errors in estimates of ~'lind speed, in particular, can have a major influence. since overestimation would result in too much epil imnion mixing and subsequent deepening. which in turn. would result in cooler outflm1 temperatures. Errors in out- flow temperature measurements may a 1 so be present. Temperature i s,opl eths for June 18 and July 14 for the 1 ake are given in Figures 8.22 and 8.23, respectively. These demonstrate the tem- perature pattern throughout the lake and provide further documen- tation that DYRESM is modeling the system adequately. The deviation in temperatures from July to mid-September is believed to be caused by the model approach of assuming an average lake temperature profile. Field measurements indicate that Ek 1 utna Lake is generally warmer in the intake aea than in the mid-lake area. This would explain the higher measured tempera- tures. 8-8 - - - - - F"· ! Ice-cover formation on Ekl utna Lake began during the 1 atter part of November 1982 with a full ice cover believed to have been formed in mid-December. DYRESM, as the result of a slight daily overestimation of cooling rates during late October and November, estimated ice-cover formation to begin November 17 with a full ice cover on November 29. Measurements made on January 14, 1983, indicated an ice-cover thickness of around 18 inches. This com- pares favorably with an ice thickness of 21 inches predicted by DYRESM. The above discussion establishes the adequacy of DYRESM to predict the winter and summer thermal stratification of a glacial lake under Alaskan meteorological conditions. It is, therefore, believed that the program DYRESM can predict an average reservoir temperature profile to within 0.5°C and outflow temperature to within 1°C. It is likely that ice cover formation and ice thickness is predictable to within five days and five inches, respectively. 8.5 -Watana Reservoir Temperature Detailed daily simulations were made of the temperature structure of Watana reservoir operating under Case C power operation conditions (12,000 cfs minimum August flow). Meteorological data collected at Watana camp for June to December 1981 were used as input to DYRESM. (a) Reservoir Temperature Profiles Temperature profiles for the first day of each month of June through December are given in Figures 8.24 to 8.30, respectively. A profile for December 31, 1981 is given in Figure 8.31. The temperature structure at Watana follows the typical pattern for reservoirs and lakes of similar size and climatic conditions. In general, stratification occurs during June, July, and August. Maximum surface temperatures occur in July and August. The maxi- mum surface temperature simulated was 10.9°C on July 3 and August 28. Depths to the thermocline are variable with strong dependence upon weather conditions, particularly wind speed. In June, typical mixed layer depths are small, about 5 to 15 feet. During July and August, the heat balance is positive into the reservoir and moderate-to-strong stratification occurs. Mixed layer depths dur- ing this period can be about 130 feet, with a sharp temperature gradient of approximately 5°C in about 50 feet. Multiple-mixed layers are estimated in Watana because of periods of warm, calm weather that provide surface warming with little mixing interspersed with windy periods which cause deepening by mixing warm surface waters with cooler water below. The duration and magnitude of the wind dictate the amount or depth of mixing occurring; hence, the step-like appearance of some summer profiles ( Figure 8. 27) • 8-9 Cooling in September results in the gradual destruction of summer stratification and the deepening of the epil imnion to depths in excess of 150 feet. This process continues until isothermal con- ditions occur which are simulated to occur in mid-October. Iso- thermal conditions continue until water reaches its maximum densi- ty, after which reverse stratification takes place. For the Watana reservoir simulation with 1981 data, a weak reverse stratification (Figures 8.30 and 8.31) occurs in late November and remains relatively stable throughout December. Under other meteorological conditions, the simulated depth to the hypolimnion of about 180 feet could be much less due to less surface mixing or earlier ice cover formation. Ice-cover formation on Watana reservoir was estimated to occur on November 20 with a full ice cover on November 22. Ice thickness on December 31 was estimated at 31 inches. (b) Outflow Temperatures The multiple-level intake at Watana allows the utility to provide variable water temperatures within a range dictated by the thermal structure within the reservoir. The ph"ilosophy of operating this structure is to provide water temperatures as close to ambient river temperatures as possible. In general, this results in the intake closest to the surface being used, provided hydraulic sub- mergence criteria are met. However. on a few days, deeper intakes are used to provide water temperatures which are closer to those required. The outflow temperature immediately downstream from Watana dam is given in Figures 8.32 and 8.33. This temperature series repre- sents the temperature used as input to downstream temperature modeling discussed later. Effects of spillage, when it occurs, have been included in the estimate of outflow temperature. The comparison of natural (inflow) temperature and simulated out- flow temperature shows that during summer months, the outflow temperature follows natural temperature trends but is cooler dur- ing July and slightly warmer in August. On most days, however, outflow temperatures in July and August are within 0.5°C of natural temperature. In June, outflow temperatures lag signifi- cantly behind natural temperatures because of reservoir filling and the heat required to warm the sizable Watana reservoir. The reverse is true in September, when cooling is insufficient to provide close to ooc outflow temperature (Figure 8.33). During September to mid-November, the simulation shows a gradual reduction of outflow temperature from 9.5°C to rc (Figures 8.32 and 8.33). Stable outflow temperatures of around 2°C start in mid-November and continue throughout December. Temperatures are expected to remain close to 2°C unti 1 spring breakup, which is generally in May. 8-10 - """' ~. - - - - - - - 8.6 -Watana/Devil Canyon Operation (a) Reservoir Temperature Profiles The DYRESM program was used to predict reservoir temperature pro- fi 1 es and outflow temperatures at the Watana and Devil Canyon reservoirs. Case C power operation was assumed in both cases. Watana i nfl m~ and meteoro 1 ogy were assumed to be the same as for Watana operation. However, Watana outflow is changed as the result of different power operation when Devil Canyon powerhouse is on 1 i ne. Watana outflow quantity and temperature plus flow and heat contri- bution from the area between the dams ites is used as input to Devil Canyon reservoir. This provides a much more stable tempera- ture input to Devil Canyon than for Watana, with a delay in warm- ing of water in June and cooling of water in September. However, De vi 1 Canyon wi 11 exhibit the genera 1 pattern of early summer warming, summer stratification, and fall-to-winter cooling through an isothermal condition to reverse stratification. Stratification and outflow temperatures at Watana under the assumed Watana/Devil Canyon operation scenario are essentially the same as for Watana operation. Typical reservoir temperature profiles at Devil Canyon are given in Figures 8.34 through 8.40 for the first of each month from June to December. Figure 8.41 shows the profi 1 e for December 31. Devil Canyon reservoir, because it is smaller than Watana reser- voir, exhibits responses to meteorological conditions in a manner more similar to Eklutna Lake. This is particularly true for strong wind storms which result in stepped temperature profiles, as shown in Figures 8.35 and 8.36. Generally, reservoir stratifi- cation is weak in June but builds during July and August. Typical mixed 1 ayer depths are about 50 to 70 feet during the summer months. For 1981 weather data, cooling at Devil Canyon is delayed to late September and early October. This is partly because of the warmer inflows to the Devil Canyon reservoir from Watana. Isothermal conditions occur in late November with cooling until maximum density water is present throughout the reservoir depth. Reverse stratification begins in mid-December and the reservoir is very weakly stratified on December 31. Mixed 1 ayer depth in Decernber is about 30 feet; ho~~ever, it would be greatly influenced by severe cold weather, mixing events, and the outflow and temperature of Watana. The maximum Devil Canyon reservoir surface temperature of 8. soc occurred on August 28. The minimum surface temperature of 2.4°C occurred at the end of the simulation period (December 31, 1981). No ice formation was observed for the simulation of Devil Canyon. 8-11 (b) Outflow Temperature Devil Canyon outflow temperatures, 1 ike Watana, are assumed to follow the inflow temperature as close as possible. The two-level intake structure at Devil Canyon provides some flexibility but not as much as at Watana. This problem, however, is not acute, since Devil Canyon operation provides a more stable water surface level. Maximum outflow temperatures occur in late July to mid-August and are about soc. Temperatures in June fluctuate because of the tendency for mixing and deepening of the thermocline during this weak stratification period. Outflow temperatures for June to September are given in Figure S.42 and for October to December in Figure S.43. For this simulation period, large summer runoff resulted in power operation under full reservoirs, and spillage occurred at both reservoirs. This is reflected by the depression of temperatures to about soc during the maximum spillage period around August 19 (Figure S.42). This coldest temperature occurs for only one day, with temperatures rising to about 6°C after three days. As spill- age reduces, outflow temperatures increase and eventually return to about 7°C by early September. De vi 1 Canyon outflow temperatures from mid-September to December 31 exhibit a much more gradual fluctuation in temperatures than those observed at ~Jatana. Temperatures during this period fall from a high of soc on September 14 to a low of 3.5°C on December 31 (Figures S.42 and S.43). S.7-Downstream Temperatures (a) Watana Operation The outflow temperatures estimated by DYRESM with 19S1 meteorolo- gical data and Watana operation have been used to determine the water temperatures in the reach between Watana and Talkeetna. The discharge and outflow temperatures from Watana are input to the HEATSM program to make this estimate. Case C (12,000 cfs minimum flow in August) has been assumed. Results of the HEATSM analysis are presented in Figures S.44, S.45, and S.46 for the period June to December. During June and July, warming of the Watana discharge occurs between the damsite and Talkeetna. For the two days in August, shown in Figure S.44, the heat balance between the water and atmosphere results in no heating or cooling, and temperatures at Talkeetna are equal to the Watana outflow temperatures. In September, the heat balance in the reach becomes negative, resulting in cooling, and Talkeetna temperatures are below those of the outflows at Watana. This cooling continues throughout the winter months. Because of the gradual reduction in outflow S-12 - - (b) temperature in September and October. the downstream temperatures exhibit a similar trend, which is clearly demonstrated by the upstream movement of the ooc front with time (Figure 8.46). Coincident with stable outflow temperatures is the establishment of a stable ooc water temperature at river mile (RM) 150 (Portage Creek). Hence, this would be the probable upstream limit of ice generation. Table 8.6 summarizes the temperature variation for locations at Watana dam. Sherman. and Talkeetna for June through December. Because of the sensitivity of ice-cover formation and growth to the mitigation plan selected and to uncertainties associated with climatic conditions. sensitivity analyses have been performed to determine downstream temperature conditions under two other out- flow temperature conditions. The first assumes a warm period with selective withdrawal giving 4°C water continuously from October through April. This scenario would result in water temperatures being greater than 0°C above RM 131 (near Sherman) at all times under the assumed average weather conditions. Results are shown in Figures 8.47 and 8.48. The second scenario assumes a linear reduction from 4°C to 2°C between November 1 and mid-January. This case also shows a trend of upstream movement of the ooc front. The maximum movement is to Rl'1 150 (Portage Creek). Results are shown in Figures 8.49 and 8. 50. Watana/Devil Canyon Operation The temperature regime downstream from Devil Canyon dam is different from existing conditions or conditions under the Watana- only operation. Similar studies. therefore. were made to estimate the temperatures in the reach between Devil Canyon damsite and Talkeetna. Three cases of outflow temperatures were assumed in addition to two meteorological conditions. The first scenario uses the temperature regime for 1981 meteorolo- gical records at Watana and Devil Canyon outflow temperatures given by the reservoir temperature model for Watana/Devi 1 Canyon operation. Results of the HEATSM program are given in Figures 8. 51 and 8. 52 for June to September and October to December. respectively. Generally. outflow temperatures are warmed with distance downstream during June and July; this warming is about 2°C by Talkeetna. In August. climate and water temperatures are in balance with no significant warming or cooling occurring. Cooling begins slowly in September with a gradual l°C reduction between Devil Canyon damsite and Talkeetna on September 15. This accelerates as winter progresses. reaching a maximum cooling in January. On December 31, outflow temperatures of 3.5°C are cooled to about 0.5°C at Talkeetna. 8-13 During the spill period in August and early September of 1981, the minimum outflow temperature of 4.6°C observed on August 21 has warmed to 4. 7°C at Sherman and to 4. 9°C at Talkeetna. Tempera- tures at Devil Canyon, Sherman, and Talkeetna for the days shown in Figures 8.51 and 8.5Z are given in Table 8.7. To assess the i~pact of other winter outflow temperatures on down- stream temperatures, two scenarios were assumed. The first assumes a constant outflow temperature of 4°C throughout the w-inter (Figures 8.53 and 8.54) and a linear reduction in outflow temperature from 4°C on November 1 to zoe on January 15 (Figures 8. 55 and 8. 56). The first case produces temperatures above ooc for t~e entire reach between Devil Canyon dam and Talkeetna until January 15. On January 15, 0°C water is estimated to occur at RM 99, just upstream from Ta"lkeetna. During the latter part of January, less cooling occurs and water temperatures for the reach remain above 0°C. With reduction in outflow temperatures to zoe on January 15 and the maintenance of this temperature to April 30, 0°C water is estimated to occur at about RM 119 on January 19 (Figure 8.55). This is the most upstream location for this water temperature and, hence, the probable upstream 1 imit of ice production. The 0°C water front moves downstream to about RM 104 in February and below Talkeetna in March. 8-14 - - - r - - - - REFERENCES Acres American Incorporated. 1982. Susitna Hydroelectric Project Feasibility' Report-Appendix A. Prepared for Alaska Power Authority. Fischer, H.B., et al. 1979. Mixing in Inland and Coastal Waters. Academic Press. New York. Imberger, J. et al. 1978. Dynamics of Reservoir of Medium Size. Jour Hydraulic Division, Proc. American Society of Civil Engineers-.- 104, No. HY5, 725-743. Imberger J. and J.C. Patterson. 1980. A Dynamic Reservoir Simulation Model -DYRESM:5. Proc. Symposium on Predictive Ability of Surface Water Flow and Transport l~odels. Berkeley, California. Michel, B. 1971. Winter Regime of Rivers and Lakes. Cold Regions Science and Engineering Monograph 111-B1a. Prepared for the U.S. Army Corps of Engineers. Patterson, J.C. November 1982. Personal communication. R&M Consultants. 1982. Glacial Lake Studies. Prepared for Acres American Incorporated. Raphael, J.M. 1962. Prediction of Temperature in Rivers and Reservoirs. Journal Power Division, Proc. American Society of Civil Engineers. 88 (P02), 157-181. Spigel and Imberger. 1980. The Classification of Mixed Layer Dynamics in Lakes of Small to Medium Size. Jour. Phys. Oceanage. U.S. Army Corps of Engineers. 1972. Reservoir Temperature Stratifica- tion. Hydrologic Engineering Center. .. J .....• l ...... l .... ) TABLE 8.1: STREAM WATER TEMPERATURE FOR AVERAGE YEAR (°F)-11 CASE A11 OPERATION Cross Section January February March April May June July August September October November December LRX 68 39.0 39.0 39.0 39.0 42.3 44.8 49.6 49.3 45.7 39.7 39.0 39.0 LRX 61 38.8 38.8 39.0 39.0 42.4 44.8 49.6 49.5 45.7 39.7 39.0 38.8 LRX 54 37.9 38.3 38.7 39.2 43.0 45.5 50.2 50.2 45.9 39.6 38.3 38.3 LRX 47 37.4 37.8 38.5 39.4 43.2 46.0 50.4 50.5 46.0 39.6 38.1 37.9 LRX 41 37.2 3 7.8 38.5 39.4 43.3 46.2 50.5 50.7 46.0 39.6 37.9 3 7.8 LRX 34 36.7 37.2 38.1 39.6 43.7 46.8 50.9 51.3 46.2 39.4 37.4 37.2 LRX 27 35.8 36.5 37.9 39.7 44.2 4 7.5 51.3 51.8 46.4 39.4 36.9 36.5 LRX 21 35.1 36.1 37.8 39.9 44.6 48.0 51.6 52.3 46.6 39.2 36.5 36.0 LRX 15 34.0 35.2 37.4 40.1 45.1 48.9 52.2 53.2 46.8 39.0 35.8 35.1 LRX 9 32.9 34.5 37.0 40.5 45.9 49.8 52.7 54.0 46.9 38.8 35.1 34.3 LRX 3 32.2 34.0 36.7 40.6 46.2 50.5 53.1 54.7 47.1 38.8 34.5 33.6 Discharge Bel ow Devi 1 Canyon { cfs) 10514.0 8883.0 8072.0 7903.0 9344.0 10288.0 9070.0 8665.0 6972.0 7403.0 9425.0 11864.0 TABLE 8. 2: STREAM WATER TEMPERATURE FOR WET YEAR ( 0 F} -"CASE A" OPERATION Cross Section January February March Ap ri 1 May June July August September October November December LRX 68 39.0 39.0 39.0 39.0 42.3 44.8 50.2 49.5 45.1 39.6 39.6 39.0 LRX 61 38.8 38.8 39.0 39.0 42.4 45.0 50.2 49.6 45.1 39.6 39.0 38.8 LRX 54 37.9 38.3 38.7 39.2 42.8 45.5 50.5 50.0 45.3 39.4 38.3 38.3 LRX 4 7 37.4 37.9 38.5 39.4 43.2 46.0 50.7 50.4 45.5 39.4 37.9 37.9 LRX 41 37.2 37.8 38.5 39.4 43.2 46.2 50.9 50.4 45.5 39.4 37.9 37.8 LRX 34 36. 7 37.2 38.1 39.6 43.5 46.6 51.1 50.7 45.5 39.2 37.6 37.2 LRX 27 35.8 36.7 37.9 39.7 44.1 47.3 51.4 51.3 45.7 39.0 36.9 36.7 LRX 21 35.2 36.1 37.8 39.9 44.4 47.8 51.6 51.6 45.9 39.0 36.5 36.1 LRX 15 34.0 35.4 37.4 40.1 45.0 48.7 52.0 52.2 46.0 38.8 35.8 35.2 LRX 9 33.1 34.7 37.0 40.5 45.5 49.6 52.3 52.9 46.2 38.7 35.1 34.5 LRX 3 32.2 34.2 36.7 40.6 46.0 50.4 52.7 53.2 46.2 38.5 34.7 33.8 Discharge Below Oevi 1 Canyon ( c fs) 10708.0 9066.0 8004.0 7889.0 10606.0 11052.0 13763.0 14085.0 12783.0 6540.0 9680.0 12436.0 ) .I .I J j J J 1 . --1 1 TABLE 8.3: STREAM WATER TH1PERATURE FOR DRY YEAR (°F) -"CASE A" OPERATION Cross Section January February March April May June July August Sept ember October November December LRX 68 39.0 39.0 39.0 39.0 42.3 44.4 48.9 48.6 45.3 39.7 39.0 39.0 LRX 61 38.8 38.8 39.0 39.0 42.4 44.4 48.9 48.7 45.3 39.7 38.8 38.8 LRX 54 37.8 37.9 38.7 39.4 43.2 45.3 49.5 50.0 45.7 39.6 38.3 38.1 LRX 47 37.0 37.6 38.3 39.6 43.7 45.7 49.8 50.7 45.9 39.4 37.8 37.6 LRX 41 36.9 37.4 38.3 39.6 43.9 45.9 50.0 50.9 45.9 39.4 37.6 37.4 LRX 34 36.1 36.7 38.1 39.7 44.2 46.4 50.4 51.8 46.0 39.4 37.2 36.9 LRX 27 35.1 36.0 37.8 39.9 45.0 47.3 50.9 52.9 46.4 39.2 36.5 36.0 LRX 21 34.3 35.4 37.6 40.1 45.5 47.7 51.3 53.6 46.6 39.0 36.1 35.4 LRX 15 33.1 34.5 37.0 40.5 46.4 48.7 51.8 54.9 46.9 38.8 35.2 34.3 LRX 9 32.0 33.6 36.7 40.6 47.1 49.6 52.3 55.9 47.1 38.7 34.5 33.4 LRX 3 32.0 33.1 36.5 41.0 47.7 50.4 52.9 56.7 47.3 38.7 34.0 32.7 Discharge Below Devi 1 Canyon (cfs) 8353.0 6742.0 6914.0 5842.0 6079.0 10041.0 7988.0 4707.0 4474.0 6914.0 7934.0 9463.0 - - - DAY Aug 25 Sept 1 Sept 9 Sept 15 Sept 21 Oct 1 Oct 7 Oct 14 TABLE 8.5: WEDDERBURN NUMBER FOR EKLUTNA LAKE SIMULATION (RUN 1070) DENSITY (kg/m3) CNS co (M) U* M/S X 10-3 999.348 999.958 2.64 0.635 999.955 999.955 4.51 0.954 999.645 999.953 5.99 2.098 999.785 999.952 12.84 8.932 999.856 999.951 16.40 4.699 999.909 999.951 22.95 0.992 999.937 999.952 30.24 1.383 999.955 999.951 50.01 1.675 Note: 1. Lake overturns. w 10.6 10.2 2.5 0.3 1.2 22.5 7.2 -3.51 .~ DATE June 15 30 July 15 31 Aug 15 31 Sept 15 30 Oct 15 31 _J';~ Nov 15 30 Dec 15 31 - TABLE 8.7: DOWNSTREAM WATER TEMPERATURES (°C) WATANA/OEVIL CANYON OPERATION LOCATION Devi 1 Canyon Dam Sherman 5.0 5.6 5.1 5.7 7.3 8.0 7.7 8.0 7.8 7.8 6. 5 6.5 8.1 8.0 6.9 6.5 6.8 6.2 6. 2 5.3 5.3 4.4 4. 5 3.4 3.9 2.8 3.4 2. 5 Talkeetna 6.8 6.6 9.1 8. 7 7.8 6.7 7.7 5.7 5.2 3.7 2.5 1.4 0.8 0.6 SUNSHINE '""--- \ ( 1 · ... 1 MAP SHOWING R NOTE JVER CROSS SECTIONS 21-REFER 112-REFER~ fO LRX 21 0 URX 112 FIGURE 8.1 -' - - .... - H1 ,-,1 Raggedt~P <·~ f q,\;- t1/a('ter Mountain .,~1, ...... 1.-~ R1rrl PP:>~k , I EKLUTNA LAKE LOCATION MAP SOURCE: RSMCONSULTANTS INC. FIGURE 8.2 - ,:;:· ,'. i c::~---1 ~--.. l d ·~ k ~ I /1 ' :,_"( I ! ) ) f0 -i + ! --\ . '--<,\\ i! r I \ 20 . SOURCE: R8 M CONSULTANTS INC. \ ·,I ! ·./ .5 ___J ,· -.22 -/ EKLUTNA LAKE STATION LOCATIONS . 29 ·~ FIGURE 8.3 -) J ~-1 ··--) J l 6 50 J~ 8 J 8 [!] / r ~ -Hf !40 :1 1::1 ~ 5 8 en I&J E; ID 8_ Cl30 " 1::1 1- J: I G (!' iij J: El ~ 171 ...... 8 ~ [D [D 10 rh G LEGEND G c:J MEASURED JUNE 18 EJ -SIMULATED (EI080) I 04 5 6 7 8 9 10 II 12 13 14 TEMPERATURE (°C) NOTE·. EI080 REFERSTO EKLUTNA LAKE TEMPERATURE PROFILES FIGURE 8.4 RUN CODE l 6'"' 50 -::E --40 30 r E1 ... ,.. EI J 10 I E1 0 4 5 6 l E:J ) ~ ~8 ~ D ~ ~ m l.!.J J G E1 7 8 8 9 TEMPERATURE (°C) 10 FR f1 EKLUTNA LAKE TEMPERATURE PROFILES l LEGEND G MEASURED SEPTEMBER 9 -SIMULATED (EI091) I II 12 13 14 FIGURE 8.5 6 (' 5 0 0 0 2 I j I 10 5 6 v El 8 [!] 7 l [!] [!] [~ ~ ;J E: ....... L.:.J 8 J ~ .. l ... .. J 9 TEMPERATURE {°C) 10 EKLUTNA LAKE TEMPERATURE PROFILES l LEGEND c:J MEASURED SEPTEMBER 21 -SIMULATED (EI091) I II 12 1:3 14 FIGURE 8.6 -1 ) r- I ,_:. 6 ~ ~ I C!J J 8 -~ ~ L:.J 50 ...,.J [p ~ EJ /f 8 -:IE . --40 b' ::E 0 1- b CD I 1&.1 > 0 ID cs:30 I 1- ::t: (.!) iii :I: 2C rll I I I 9 10 I I LEGEND I EJ MEASURED SEPTEMBER 9 Elf -SIMULATED WITHa 1: 0.48 ( E4041) I ---SIMULATED WITH a1= 0.096 (E4061) 04 5 6 7 8 9 TEMPERATURE (°C) 10 II 12 13 14 EKLUTNA LAKE TEMPERATURE PROFILES FIGURE 8.7 J -l J l [!] G 6 [b ~ 50 8 -~40 2: ~ G b al LLI f) al h ct:30 f-:.J 1- :X: !!J ijj :X: [!] 2::: I I J / [!)-'- rr-" ~ 10 r: LEGEND MEASURED G E1 SEPTEMBER 21 --SIMULATED WITH a I; 0.48 (E4041) G ___ SIMULATED WITHal; 0.096 ( E4061) 04 5 6 7 8 9 10 II 12 13 14 TEMPERATURE (°C) EKLUTNA LAKE TEMPERATURE PROFILES FIGURE 8.8 ] l l 6L 50 I / ~ -:E -40 f :E 0 ..... ..... 0 In w > 0 Ill ct 30 ..... ::r (!) w ::r 2C 10 LEGEND INITIAL PROFILE -JUNE I (E5050) 03 I 4 5 6 7 8 9 10 II 12 13 TEMPERATURE (°C) EKLUTNA LAKE TEMPERATURE PROFILES FIGURE 8.9 l 6 5 0 c:¢ p 0 [!] t::J G EJ 0 ~ ~ E r.J 0 [!] 2 :0 IEJ G IV 10 l:j EJ EJ 0 4 5 6 [!] ~ I aEJ ..J .r rt:l [!] l!J L.J -~ G.__ 7 8 9 TEMPERATURE {°C) 10 EKLUTNA LAKE TEMPERATURE PROFILES l II ] }' LEGEND EJ MEASURED JUNE 18 -SIMULATED (E5050) I 12 13 14 FIGURE 8.10 ] -----~ --1 ~---l ~--. -I l' 6C _dHf 50 r:1 ~ [] L.:J [] [!] ~ [!] [] ~ 8 !40 :I v~ ~ [] b y 1'0 ILl . > 0 ID C( 30 [ / .... :I: (!) ijj r ::&: [ 2~.; EJ G 10 EJ LEGEND 0 MEASURED JULY 14 -SIMULATED (E5050) 0 _1 5 6 7 8 9 10 II 12 13 14 15 TEMPERATURE (OC) EKLUTNA LAKE TEMPERATURE PROFILES FIGURE 8.11 1 l 1 l 6 ... r+P [p ./ ro 50 / ....-c: 8 8 ..... ~40 :IE 8 ~ b EJ a! w e; EJ a! <(30 ~ .... ::J: (!I iLi ::J: 0/ 2 ... 0 10 LEGEND D 0 MEASURED JULY 28 SIMULATED {E5050) 0 1 5 6 7 8 9 10 II 12 13 14 15 TEMPERATURE (OC) EKLUTNA LAKE TEMPERATURE PROFILES FIGURE 8.12 sn 50 40 30 [:J [!] a 8 [!] 10 [!] 0 5 6 i 1 . ~ r:-1 r.l/ v ! 7 8 9 -l - --<).---- r ."'':J -- 10 TEMPERATURE (°C) ......... II EKLUTNA LAKE TEMPERATURE PROFILES ·········] _j; ~: LEGEND [J MEASUREC AUGUST II _SIMULATED (E5050) I 12 13 14 15 FIGURE 8.13 ) J l 61"' EJ . r.: ~ ~ 8 8 r.l 50 T • .,--.- ~ r-t!T / 8 ~ :E -40 v :::E ~ ..... 0 ID w / > 0 ID 430 ~I ..... J: (,!) w J: 20 -co 10 r:::J LEGEND 0 MEASURED AUGUST 25 -SIMULATED (E5050) I 05 6 7 8 9 10 II 12 13 14 15 TEMPERATURE (°C) EKLUTNA LAKE TEMPERATURE PROFILES FIGURE 8.14 6 50 40 30 . _,.. .. " v G 10 J 8 0 4 5 6 . -] _J -~ ~ G ~ 8 k( ....... I . 7 8 9 TEMPERATURE (0C) r- ,_! I+ '":"1 '-' 8 8 L:IJ 10 EKLUTNA LAKE TEMPERATURE PROFILES LEGEND E1 MEASURED SEPTEMBER 9 SIMULATED -(E5051) l II 12 13 14 FIGURE 8.15 ~) . --] l -J 6 u 5 0 0 2 10 0 4 5 6 _I:; [ ,....., ~ [!] / G 7 J ::::1 ..., ~ ~ 8 ] _] 9 TEMPERAnJRE (°C} 10 EKLUTNA LAKE TEMPERATURE PROFILES LEGEND [] MEASURED SEPTEMBER 21 SIMULATED -(E5051} I II 12 13 14 FIGURE 8.16 ] 6~ fR [!] 8 50 8 -:::t -40 :E g [!] b ID 11.1 ~ CD I,....., <3:30 CJ 1- :I: C) w :J: 2C I EJ 10 LEGEND 8 MEASURED EJ OCTOBER 14 _SIMULATED ( E5051) i 04 5 6 7 8 9 10 II 12 13 14 TEMPERATURE (°C) EKLUTNA LAKE TEMPERATURE PROFILES FIGURE 8.17 l ) __ ] c:J sr El EJ 50 c::J -:::E ~4o ::E ~ El 5 ID LLI > 0 Ill <(30 L..:J 1- J: (.!) iij J: c::J 21.. c::J 10 LEGEND 8 MEASURED c::J NOVEMBER 4 -SIMULATED (E5051) j_ 03 4 5 6 7 8 9 10 II 12 13 TEMPERATURE {°C) EKLUTNA LAKE TEMPERATURE PROFILES FIGURE 8.18 _) :_-_ _) ~~ --_ _J --~l --_J l 6~ cp ----~ G I'--El El 50 , L.:..J G 8 8 -8 !40 L.:J ~ ~ 8 b r: CD 1&1 I: > 0 0 CD <t30 1- :I: (!) iii :I: 2"' 10 LEGEND El MEASURED JANUARY 13 SIMULATED DECEMBER 31 (E5051) r.-t I 00 I 2 3 4 5 6 7 8 9 10 TEMPERATURE (°C) EKLUTNA LAKE TEMPERATURE PROFILES FIGURE 8.19 14 12 I 10 I II <.> !!.. I! 8 I 6 I ' I 4 I I 2 I I I I ' I 0 I I I I • I I I I I I I I I I I I I -- rV 1\ RECORDED OUTFLOW\ A A TEMPERATURE A A A I \[VW VV~JV V\ A~ ~ llfJ ~vv\ v ~~ "'"'{' ... ___ L_~-~/\ ___ I 1["\.J ... ~ I ~~ ,.1 ,. / • I ~ ./\/J ..:~ .,.. ,.. ',..// .... II 21 JUNE NOTES: I} TIME SCALE IS IN INCREMENTS OF 10 DAYS. 2} BASED ON 198.2 DATA. " ,.. -, ~ ------... .,. ... '\ '-----t-J L~"-.... - I \ -J -.... -...._._, 1-... _ SIMULATED OUTFLOW I--SIMULATION RESTARTED TEMPERATURE -M i ' I I I II 21 31 9 19 29 a IB SEPTEMBER 28 JULY AUGUST MONTH EKLUTNA LAKE RESERVOIR TEMPERATURE SIMULATION JUNTO SEP I \..... ......... B FIGURE 8.20 14 12 10 u ~ B "' cr :::l !;< cr "' ll. :I! "' 1-6 4 0 /RECORDED OUTFI...OW TEMPERATURE tS-~ 8 ...... 18 OCTOBER -~ K,\_ ' .... -, 0'~ ', A .... r----v_ y_~ .... .... _ SIMULATED7 OUTFLOW TEMPERATURE I I 28 7 17 NOVEMBER 27 NOTES: MONTH I) TIME SCALE IS IN INCREMENTS OF 10 D•\YS_ 2) BASED ON 1982 DATA. EKLUTNA LAKE RESERVOIR TEMPERATURE SIMULATION OCT TO DEC i -- ' r ' i K:.A rAf 7 17 DECEMBER 27 -- I FIGURE 8.21 '"""'~ 50 40 ... II: .., ... "' ::r :30 ~ "' .... .. "' 0 20 10 0 2 4 6 8 SOURCE R 8 M CONSULTANTS INC. 10 :r ? 12 14 OI~ECTION 0~ now @--w--sTA.USED IN I THIS PLOT (TYP.) 16 18 THOUSANDS OF FEET 20 I 22 24 I H I EKLUTNA LAKE PROFILE TEMPERATURE ISOPLETHS FOR JUNE 17 a 18 28 I :30 I :32 I /// :34 I SPILLWAY [L[V • 871 :36 I ... "' "' ... ~ ,.: ... ... "' 800 750 700 FIGURE 8.22 50 40 ... 0: "' ... "' 2 30 ! 20 10 0 " ... ... "' 0 0 2 4 SOURCE RBM CONSULTANTS INC. 6 DIRECTION 0~ FLOW ~STA.USED IN I THI5 PLOT (TY P.l ---------------~= ---#/ -(// -----6.0 ....... TENPEIIATUII[ °CELSIUS ----------------5~------ 8 10 12 14 16 18 20 22 24 26 THOUSANDS OF FEET EKLUTNA LAKE PROFILE TEMPERATURE ISOPLETHS FOR JULY 14 28 30 34 SPILLWAY tLtV.• 871 36 ... "' "' .. z > 800 ~ 750 "' 700 FIGURE 8.23 l - - i= w w LL. 2200 2150 2100 2050 5 2000 ~ > w ..J w 1950 1900 1850 1800 1750 I I 2 1( v-- I I v I I I 4 5 6 7 8 WATER TEMPERATURE (°C) SIMULATED PROFILE IN WATANA JUNE I, 1981 I I 9 10 II 12 FIGURE a24 r I I ·- ~ 1- LIJ ILl !!:: 2200 2150 2100 2050 ~ 2000 ~ :> LIJ .J ILl 1950 1900 1850 1.800 1750 2 I ~ v / ~ I 3 4 5 6 7 8 WATER TEMPERATURE (°C) SIMULATED PROFILE IN WATANA JULY I, 1981 9 .-.J_ 10 II 12 FIGURE 8.25 - - 2200 2150 2100 2050 t5 2000 ~ ::> ~ _J ~ 1950 1900 1850 1800 1750 2 I v v ~ / ~ I 3 4 5 6 7 8 WATER TEMPERATURE C°C) SIMULATED PROFILE IN WATANA AUGUST I, 1981 9 10 ) II 12 FIGURE 8.26 - 2200 2150 2100 I F""' 2050 .. -f=' IJJ IJJ LL. ~ 2000 ~ > w ...J IJJ -1950 1900 1850 I -1800 1750 2 1 I v v ~ I v I / v / I I I I I 3 4 5 6 7 8 WATER TEMPERATURE (°C) SIMULATED PROFILE IN WATANA SEPTEMBER I, 1981 I 9 (J I 10 II 12 FIGURE 8.27 2200 2150 2100 2050 -~ w w ~ ~ 2000 ~ > w ...J w ''""'" I 1950 !"""" 1900 r ,_., 1850 1800 1750 -2 ~ I v~ I 3 4 5 6 7 8 WATER TEMPERATURE (°C) SIMULATED PROFILE IN WATANA OCTOBER I, 1981 I I I 9 10 II 12 FIGURE 8.28 - !"'"" - 2200 r---~----~--~----~--~---4----4---~~--~---4----~--~ 2150 1-----+-----+----+-----H----+--------+-----+-----f--------+-------l-----+-----t 2100 r----+-----+----+-----~---+--------+-----+-----f--------+-------1-----+---_, 2050 i= w w IL. -~ 2000 ~ > w ...J w 1950 1900 r----+-----+----+-----~---+-------1-----+-----f--------+---~~---+---~ 1850 ~--~----+---~----~--~--~----~----~--~-------\~--~--~ 1800 1-----+-----+----+-----~---+---~-----+-----~---+---~f--------+----; 1750 ~--~----~--~----~--~--~~--~----~--~--~~--~---...J 2 3 4 5 6 7 8 WATER TEMPERATURE (°C) SIMULATED PROFILE IN WATANA NOVEMBER I, 1981 9 10 II 12 FIGURE 8.29 - -;:: w w LL 2200 2150 2100 2050 ~ 2000 ~ > w ..J w 1950 1900 1850 1800 1750 \ ' "' ' 1\ 2 \ ~ 4 5 6 7 8 WATER TEMPERATURE (°C) SIMULATED PROFILE IN WATANA DECEMBER I, 1981 9 10 II 12 FIGURE 8.30 - - 2200 2150 2100 2050 ~ 2000 i;i >' LLJ ...J w 1950 1900 1850 1800 1750 ' I"\ ~ I 2 I I \ I n I 3 4 5 6 7 8 WATER TEMPERATURE (°C) SIMULATED PROFILE IN WATANA DECEMBER 31, 1981 9 10 II 12 FIGURE 8.31 14 12 10 lJ ~ w B 0:: ::::> f- "' 0:: w a.. ::E w f- 6 4 2 0 i I /\(\ ... A ~ 1/ ~ '-/ \ '"'"·[ ' i (A i I \ ! r-· ,_ .... I v /-, ~/-~ ..... (' ____ , \\ N Vt I "---._, I r'~-"' I I I rf ..................... , I I I I .... , I I t" .) I I I I I ,-"" I II I I h> I \ I I . I ~, I I v I ~I t' \'! J1 ~~ I I \ /1 \_OUTFLOW _ _) ' " II i ' ~ \ .... , ~ i L.._j ',, ~ r ~r /'"I I I [\ " ..... I I .J I If 1 I I I \1 v \ If I I I 1 d ' \ ' L I -,~ 10 20 30 9 19 29 8 18 28 7 17 SEPTEMBER 27 7 JUNE NOTES: I) TIME SCALE IS IN INCREMENTS OF 10 DAYS. 2) BASED ON 1981 DATA, WATANA OPERATION 3) RUN W402D; WITH OUTFLOW TEMPERATURE FOLLOWING INFLOW TEMPERATURE. 4) JULY INFLOW TEMPERATURES ESTIMATED JULY AUGUST MONTH WATANA RESERVOIR INFLOW AND OUTFLOW TEMPERATURES JUNTO SEP FIGURE 8.32 J I I I I I I I I I 1 I 14r-------r--------,---------.--------~--~-----.---------.--------~--------------~--r-------~ 12r-------r-------~L-------~---------t---------r---------r--------4---------+-----~--~------~ 10~----~r-------~---------+---f- u 8~---r----~------+-----~------+----~------+-----~----'-+----~ ~ w a:: ~ ' ~ ' a. ', ~ 6~--~~~------~---------+ ,_ ....... 4~-----~~-------4---------+--~'~ ... ~~ ... -+ ... --------~--------4---------+---------+-----~,--~------~ 2 ----..... 0 I ......... ... , \olo""',, \ F ------------- \ INFL7 '\. 7 17 27 OCTOBER 6 16 26 NOVEMBER I 6 16 DECEMBER NOTES: MONTH I) TIME SCALE IS IN INCREMENTS OF 10 !lAYS. 2) BASED ON 1981 DATA, WATANA OPERATION 3) RUN W4020; WITH OUTFLOW TEMPERATURE FOLLOWING INFLOW TEMPERATURE. WATANA RESERVOIR INFLOW AND OUTFLOW TEMPERATURES OCT TO DEC 26 I FIGURE 8.33 1500 1450 I 1400 1350 f- LLI LLI LL z 1300 0 ti > LLI _J LLI - 1250 1200 -1150 1100 0 ~ I / I I I I 2 3 4 5 6 7 8 9 WATER TEMPERATURE (°C) SIMULATED PROFILE IN DEVIL CANYON JUNE I, 1981 I ' 10 II FIGURE 8.34 1500 1450 1400 -1350 -1- LLJ LLJ I.J... -z 0 1300 ~ > LLI ...J LLI - 1250 1200 1150 - 1100 0 - I } (_~ ,.,.... ) ) 2 4 5 6 7 8 9 WATER TEMPERATURE (°C) SlMULATED PROFlLE IN DEVIL CANYON JULY I, 1983 10 II FIG ORE 8.35 - ,.., .. - - r I - - - 1-w w IJ.. z 0 ~ > w ..J w 1500 1450 1400 1350 1300 1250 1200 1150 1100 0 I J I ~ ~ ~ I ) I ) I J 2 3 4 5 6 7 8 9 WATER TEMPERATURE (°C) SIMULATED PROFILE IN DEVIL CANYON AUGUST I, 1981 10 II FIGURE 8.36 1500 1450 1400 1350 ~ I-w w LL. -z 0 1300 ~ > w ...J w 1250 1200 1150 -1100 0 I I I I ry I ~ LJ I I I I 2 3 4 5 6 7 8 9 WATER TEMPERATURE (°C) SIMULATED PROFILE IN DEVIL CANYON SEPTEMBER 1,1981 I 10 II FIGURE 8.37 -1500 1450 - 1400 1350 i= w w LL. z -Q 1300 .... ct > w _j -w 1250 - 1200 1150 1100 0 ! - ~ v ( ( I I ' 2 3 4 5 6 1 8 9 WATER TEMPERATURE (°C) SIMULATED PROFILE IN DEVIL CANYON OCTOBER 11 1981 10 11 FIGURE 8.38 I""" I- ILI ILl LL. 1500 1450 1400 1350 ~ 1300 !;i > ILl ...J ILl 1250 1200 1150 1100 0 c!~ ) 2 3 4 5 6 7 8 9 WATER TEMPERATURE (°C) SIMULATED PROFILE IN DEVIL CANYON NOVEMBER I, 1981 10 II FIGURE 8.39 1500 1450 1400 1350 I-w w LL. z 1300 0 ~ w _J w 1250 1200 1150 1100 0 I I I I I I 2 3 4 5 6 7 8 9 WATER TEMPERATURE (°C) SIMULATED PROFILE IN DEVIL CANYON DECEMBER I, 1981 I 10 II FIGURE 8.40 1500 1450 1400 1350 -1-w w u. z 0 1300 i= <( > w ...J lJJ 1250 - 1200 1150 - -1100 0 l ~ ~ 2 4 5 6 7 8 9 WATER TEMPERATURE (°C) SIMULATED PROFILE IN DEVIL CANYON DECEMBER 31, 1981 10 II FIGURE 8.41 14 12 10 4 2 0 ,...__ ~ ~I 1\ INFLOW ~ 1 r-1\h r-- ~ l! '\ 1 '-"'\/~ It' ....... (',/ '{ v ·, ...,,,..\ \ ,--, """"' I \I ( '.! \ I OUTFLOW ~ I /\ f\ ~ lJ I \ r, 1 " I 1\ ,.,.--\ f, I I r/ I I I V I I \ I\ I I ...... , I .I I I I \/I I \i \ : \1 "'" 7 I \./~) .,J L' ~ l• ~ L \.J , r ,, ~ I 10 20 30 9 19 29 8 18 28 JUNE NOTES: I. TIME SCALE IS IN INCREMENTS OF 10 OAYS. 2. BASEO ON 1981 OATA. 3. WATANA ASSUMED UPSTREAM. l DYRESM RUN W4010) 4. OUTFLOW TEMPERATURES ARE BASED ON DYRESM RUNS DC 1020, DC 1021 AND DC 1022. JULY AUGUST MONTH DEVIL CANYON RESERVOIR INFLOW AND OUTFLOW TEMPERATURES JUNE TO SEPTEMBER I I , ... ~--/. ! 7 =-,"' ---, I -~ ~- ---- - 17 SEPTEMBER 27 I 7 FIGURE 8.42 14 I 12 10 K- 4 2 0 I I I I I I I I I i \ I I I I I ! ! r-----, 1-----.. .... : ~ ' OUTFLOW] '. " , ........... __ : .. ~ -... ... ---I ~ ---! -----I ........... ~ ---...... ___ ! __ 7 17 OCTOBER 27 I 6 1'-- 16 NOVEMBER I 6 16 DECEMBER NOTES: MONTH l) TIME SCALE IS IN INCREMENTS OF 10 !lAYS. 2) BASED ON 1981 DATA. 3) WATANA ASSUMED UPSTREAM. (DYRESM RUN W4010) 4) OUTFLOW TEMPERATURES ARE BASED ON DYRES M RUN DCI022 DEVIL CANYON RESERVOIR INFLOW AND OUTFLOW TEMPERATURES OCTOBER lO DECEMBER . I I······ .• -... I 26 FIGURE 8.43 u 0 "" 0:: ::J ~ 0:: "" a. ::; "" .... 12.5 12.0 11.5 11.0 -~ ----JUL31 --------- 10.5 10.0 9.5 AUG 31 9.0 8.5 8.0 AUG15 7.5 95.00 101.00 107.00 113.00 119.00 125.00 NOTE: I. MODEL ASSUMES 1981 METEOROLOGICAL DATA RECORDED AT WATANA. 2. WATANA TEMPERATURE AND DISCHARGE FROM DYRESM MODEL. ( RUN WA4020) 131.00 137.00 143.00 149.00 155.00 161.00 167.00 RIVER MILE WATANA OPERATION: DOWNSTREAM TEMPERATURES -JUN TO AUG 173.00 179.00 185.00 V/ATANA DISCHARGE (CFS), JUN 15 4410 JUN 30 4210 JUL 15 4130 · · JUL 31 3970 AUG 15 6250 AUG 31 21000 (RELEASE) FIGURE 8.44 9.0 8.5 8.0 7.5 7.0 0 0 111 6.5 0: :::l \< 0: w 0. :;; w 6.0 ... 5.5 5.0 4.5 4.0 95.00 101.00 107.00 113.00 NOTE: I. MODEL ASSUMES 1981 METEOROLOGICAL DATA RECORDED AT WATANA. 2. WATANA TEMPERATURES AND DISCHARGE FROM OYRESM MODEL. {RUN WA4020) 119.00 125.00 131.00 137.00 143.00 149.00 155.00 161.00 RIVER MILE WATANA OPERATION DOWNSTREAM TEMPERATURES -SEP 167.00 173.00 179.00 185.00 WATANA DISCHARGE {CFS); SEP !5 !2200 (RELEASE) SEP 30 9460 FIGURE 8.45 I I ! I I I I I I I I I I I I ! l u !!.- "' "' " !c "' "' ... :::1! "' .... 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 95.00 NOTES, I. MODEL ASSUMES 1!0181 METEOROLOGICAL DATA RECORDED AT WATANA. 2. WATANA TEMPERATURES AND DISCHARGE FROM DYRESM MODEL. (RUN WA4020) RIVER MILE WATANA OPERATION: DOWNSTREAM TEMPERATURES -OCT TO DEC WATANA DISCHARGE (CFSh OCT IS 6110 ' OCT 31 5820 NOV IS 6S80 NOV 31 10070 DEC 15 IOS40 DEC 31 12500 FIGURE S.46 4.0 3.5 3.0 -2.5 '-' 0 "' "' ::0 ~ 2.0 "' a. ::; "' 1- 1.5 1.0 o.o APR 30 ---_-----~;,;.;...;;.~---------------------~ --APR 15 .-.-~ _____ .....,., --__ ......... --- 95.00 101.00 107.00 113.00 119.00 125.00 131.00 137.00 143.00 149.00 155.00 161.00 167.00 RIVER MILE NOTE: MODEL ASSUMES DAILY BASED LONG TERM AVERAGE METEOROLOGICAL DATA AND MEAN MONTHLY FLOWS AT WATANA. WATANA OPERATION: DOWNSTREAM TEMPERATURES -JAN TO APR OUTFLOW TEMPERATURE 4°C 173.00 185.00 WATANA DISCHARGE ;(CFS): JAN 9400 FEB 8690 MAR 8100 APR 7480 FIGURE 8.47 4.0 3.5 3.0 2.5 0 ~ w a: ::> !i 2.0 a: w a. ::E w 1- 1.5 1.0 05 0.0 95.00 101.00 107.00 113.00 NOTE: MODEL ASSUMES DAILY BASED LONG TERM AVERAGE METEOROLOGICAL DATA AND MEAN MONTHLY FLOWS AT WATANA. 119.00 125.00 131.00 137.00 143.00 149.00 155.00 161.00 167.00 RIVER MILE WATANA OPERATION: DOWNSTREAM TEMPERATURES -OCT TO JAN OUTFLOW TEMPERATURE 4°C 173.00 185.00 WATANA DISCHARGE (CFSl: OCT. 6770 NOV. 8670 DEC. 10300 JAN. 9400 FIGURE 8.48 0 Z.5 D UJ 0: ::J ~ 2.0 w Q. ::;; w 1- 1.5 95.00 101.00 107.00 113.00 NOTE: MODEL ASSUMES DAILY BASED LONG TERM AVERAGE METEOROLOGICAL DATA AND MEAN MONTHLY FLOWS AT WATANA. 119.00 125.00 131.00 137.00 143.00 149.00 155.00 161.00 167.00 173.00 RIVER MILE WATANA OPERATION: DOWNSTREAM TEMPERATURES -OCT TO JAN OUTFLOW TEMPERATURE 4 TO 2°C 179.00 185.00 WATANA DISCHARGE (CFS}: OCT 6770 NOV 867D DEC 10301 JAN 9400 FIGURE 6.49 I I l I ! l I I l ! l 1 I I I I l I I I I I j ! I I l I I I I (.) ~ .... "' ::> ~ ~r· .... Q. :::E w ,_ 00 95.00 101.()0 107.00 113.00 119.00 NOTE: I. MODEL ASSUMES DAILY BASED LONG TERM AVERAGE METEOROLOGICAL DATA AND MEAN MONTHLY FLOWS AT WATANA. 12!5.00 131.00 137.00 143.00 149.00 155.00 1&1.00 167.00 173.00 RIVER MILE WATANA OPERATION: DOWNSTREAM TEMPERATURES -JAN TO APR OUTFLOW TEMPERATURE 4 TO 2°C 179.00 185.00 WATANA DISCHARGE (CFSh JAN 9400 FEB 8690 MAR 8100 APR 7480 FIGURE 8.50 ---~L31 ---- AUGI5 ---------- 5.0 9500 NOTE: I. MODEL ASSUMES 1981 METEOROLOGICAL DATA RECORDED AT WATANA. 101.00 2. DEVIL CANYON TEMPERATURE AND DISCHARGE FROM DYRESM MODEL. (RUNS DCI020 AND DCI021) 107.00 --- 113.00 11900 125.00 131.00 137.00 143.00 RIVER MILE WATANA I DEVIL CANYON OPERATION DOWNSTREAM TEMPERATURES -JUN 1D OCT 149.00 DEVIL icANYON DISCHARGE (CFS): JUN 15 7920 JUN 30'~'74-Q· · JUL 15 6830 JUL 31 6480 AUG 15 9940 AUG 31 24100 (RELEASE) SEP 15 13750 SEP 30 10600 OCT 15 7450 FIGURE 8.51 6.0 0.5 L---~--~--L---L---L---~--~--~--~--~--~--~---L---L---L __ _L __ _L __ -L--~--~--~ NO TEe 95.00 101.00 I. MODEL ASSUMES 1981 METEOROLOGICAL DATA RECORDED AT WATANA. 2. DEVIL CANYON TEMPERATURE AND DISCHARGE FROM DYRESM MODEL. (RUN DCI022) 107.00 113.00 119.00 125.00 131.00 137.00 143.00 149.00 RIVER MILE WATANA I DEVIL CANYON OPERATION DOWNSTREAM TEMPERATURES -OCT TO DEC 155.00 DEVIL CANYON DISCHARGE (CFS): OCT 31 8690 NOV IS 10300 NOV 30 10500 DEC IS 10900 DEC 31 II 100 FIGURE 8.52 0 0 w a: :::> ~ a: w a. ::E w ~ 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0 95.00 101.00 10700 113.00 119.00 125.00 131.00 137.00 143.00 RIVER MILE 149.00 DEVIL GANYDN DISCHARGE (CFS), OCT 7~20 NOV 9440 DEC 11,130 JAN 10;480 NOTEo MODEL ASSUMES DAILY BASED LONG TERM AVERAGE METEOROLOGICAL DATA AND MEAN MONTHLY FLOWS AT DEVIL CANYON. WATANA/ DEVIL CANYON OPERATION DOWNSTREAM TEMPERATURES -OCT TO JAN OUTFLOW TEMPERATURE 4° FIGURE 8.53 2.5 0 0 "' "' ::l ~ 2.0 "' "' ll. :::!! "' ,_ 1.5 0.0 APR 30 -----------~---.:.;:;..:~;...._-----------~R.J!-__ _.---- 95.00 101.00 107.00 113.00 119.00 125.00 131.00 RIVER MILE - 137.00 143.00 149.00 r~o··· .. DEVIL CANYON DISCHARGE lCFSl: JAN 10_480 FEB 10,~90 MAR 921)0 APR 8010 NOTE, MODEL ASSUMES DAILY BASED LONG TERM AVERAGE METEOROLOGICAL DATA AND MEAN MONTHLY FLOWS AT OEVI L CANYON WATANA/DEVIL CANYON OPERATION DOWNSTREAM TEMPERATURES -JAN TO APR OUTFLOW TEMPERATURE 4°C FIGURE 8.54 4.0 3.5 3.0 u 2.5 0 "' "' ::0 ~ "' 2.0 "' a. 2 "' ... 1.5 1.0 0.5 QO 9500 101.00 107.00 113.00 119.00 125.00 131.00 RIVER MILE 137.00 143.00 149.00 i i-"""~---- 1' I DEVI~ CANYON DISCHARGE (CFS): OCT 7320. _ .. NOV 9440 DEC l,l,130 JAN !0,480 i I NOTE: MODEL ASSUMES DAILY BASED LONG TERM AVERAGE METEOROLOGICAL DATA AND MEAN MONTHLY FLOWS AT DEVIL CANYON. WATANA/DEVIL CANYON OPERATION DOWNSTREAM TEMPERATURES -OCT TO JAN OUTFLOW TEMPERATURES 4 TO 2°C FIGURE 8.55 4.0 3-5 30 0 2.5 ~ "' a: ::> !< ffi 2.0 .. "' "' .... 1.5 1.0 0.5 0.0 95.00 101.00 107.00 113.00 119.00 125.00 131.00 RIVER MILE 137.00 143.00 149.00 DEVIL CANYON DISCHARGE (CFS): JAN 10,480_ FEB 10,090 MAR S200 APR SOlO NOTE: MODEL ASSUMES DAILY BASED LONG TERM AVERAGE METEOROLOGICAL DATA AND MEAN MONTHLY FLOWS AT DEVIL CANYON. WATANA/DEVIL CANYON OPERATION DOWNSTREAM TEMPERATURES -JAN TO APR OUTFLOW TEMPERATURE 4 TO 2° C FIGURE 8.56 '""' -~ 9 -ESTIMATES OF COST This section, originally included as Section 16 in the March 1982 Feasibility Report {Acres 1982a), presents estimates of capital and operating costs for the Susitna Hydroelectric Project, comprising the Watana and Devil Canyon developments and associated transmission and access facilities, which have been updated as a result of on-going studies. The costs of design features and facilities incorporated into the project to mitigate environmental impacts during construction and operation are identified. Cash flow schedules, outlining capital requirements during planning, construction, and startup, are presented. The approach to the derivation of the capital and operating cost esti- mates is described. Changes which have been made in the Watana cost estimate include: -Access Plan 18 replaced Plan 5 (see Section 4); -Work leading up to diversion was recasted for an accelerated schedule; -Storage facilities were provided at Cantwell, and an item for opera- tion and maintenance of these facilities was added to the estimate; -Material prices were revised to reflect the longer transportation route; -Quantities were revised for the intake and spillway; -All work, other than noted above, was estimated on a basis of 10-hour shifts; -Construction power was reestimated based on direct generation at site; and Contingencies were evaluated for each account. Changes which have been made in the Devil Canyon cost estimate include: -Access Plan 18 replaced Plan 5 (see Section 4); -Intake quantities were revised; -All work was reestimated on the basis of 10-hour shifts; -The discussion of operation and maintenance costs was rewritten and Table 9.5 was added to show the breakdown of costs; and -The cash flow curves were revised and Table 9.6 was added. The total cost of the Watana and Devil Canyon projects is summarized in Table 9.1. A more detailed breakdown of cost for each development is presented in Tables 9.2 and 9.3. 9.1 -Construction Costs This section describes the process used for derivation of construction costs and discusses the Code of Accounts established, the basis for the estimates, and the various assumptions made in arriving at the esti- mates. For general consistency with planning studies, all costs developed for the project are in January 1982 dollars. 9-1 (a) Code of Accounts Estimates of construction costs were developed using the FERC for- mat as outlined in the Federal Code of Regulations, Title 18 (Government Printing Office 1982). The estimates have been subdivided into the following main cost groupings: Group Production Plant Transmission Plant General Plant Indirect Costs Overhead Construction Costs Description Costs for structures, equip- ment, and facilities necessary to produce power. Costs for structures, equip- ment, and faci 1 i ties necessary to transmit power from the sites to load centers. Costs for equipment and facili- ties required for the operation and maintenance of the rroduc- tion and transmission plant. Costs that are common to a number of construction activi- ties. For this estimate, only camps and electric power costs have been included in this group. Other indirect costs have been included in the costs under production, trans- mission, and general plant costs. Costs for engineering administration. and Further subdivision within these groupings was made on the basis of the various types of work involved, as typically shown in the following example: -Group: -Account 332: -Main Structure 332.3: -Element 332.31: -Work Item 332.311: -Type of Work: Production Plant Reservoir, Dam, and Waterways Main Dam Main Dam Structure Excavation Rock The detailed schedule of account i terns is presented in Acres (1983). 9-2 - - - - - - - - - (b) Approach to Cost Estimating (c) The estimating process used generally included the following steps: -Collection and assembly of detailed cost data for labor, mater- ial, and equipment as well as information on productivity, cli- matic conditions, and other related items; -Review of engineering drawings and technical information with regard to construction methodology and feasibility; Production of detailed quantity takeoffs from drawings in accor- dance with the previously developed Code of Accounts and i tern listing; -Determination of direct unit costs for each major type of work by development of labor, material, and equipment requirements; development of other costs by use of estimating guides, quota- tions from vendors, and other information as appropriate; -Developnent of construction indirect costs by review of labor, material equipment, supporting facilities, and overheads; and -Development of construction camp size and support requirements from the labor demand generated by the direct and indirect con- struction costs. The above steps are discussed in detail in the fo 11 owing: Cost Data Cost information was obtai ned from standard estimating sources, from sources in Alaska, from quotes by major equipment suppliers and vendors, and from recent representative hyd roel ectri c pro- jects. Labor and equipment costs for 1982 were developed from a number of sources (State of Alaska 1982; Caterpillar 1981) and from an analysis of costs for recent projects performed in the Alaska environment. It has been assumed that most contractors will work an average of two 10-hour shifts per day, 6 days per week. Because of the severe compression of construction activities in 1985-86, it has been assumed that most work in this period will be on two 12-hour shifts, 7 days per week. The 10-hour work shift assumption provides for high utilization of construction equipment and reasonable levels of overtime earnings to attract workers. The two-shift basis generally achieves the most economical balance between labor and camp costs. 9-3 Construction equipment costs were obtained from vendors on an FOB Anchorage basis with an appropriate allowance included for trans- portation to site. A representative list of construction equip- ment required for the project was assembled as a basis for the estimate. It has been assumed that most equipment would be fully depreciated over the life of the project. For some activities such as construction of the Watana main dam, an allowance for major overhaul was included rather than fleet replacement. Equip- ment operating costs were estimated from industry source data, with appropriate modifications for the remote nature and extreme climatic environment of the site; Alaskan labor rates were used for equipment maintenance and repair. ·Fuel and oil prices have been based upon FOB site prices. Information for permanent mechanical and electrical equipment was obtained from vendors and manufacturers who provided guideline costs on major power plant equipment. The costs of materials required for site construction were esti- mated on the basis of suppliers' quotations, with allowances for shipping to site. (d) Seasonal Influences on Productivity A review of climatic conditions, together with an analysis of experience in Alaska and in northern Canada on large construction projects, was undertaken to determine the average duration for various key activities. It has been projected that most above- ground activities will either stop or be curtailed during the period of December and January because of the extreme cold weather and the associated lower productivity. For the main dam construc- tion activities, the following assumptions have been used: -Watana dam fill -6-month season; and -Devil Canyon arch dam -8-month season. Other aboveground activities are assumed to extend up to 11 months depending on the type of work and the criticality of the schedule. Underground activities are generally not affected by climate and should continue throughout the year. Studies by others (Roberts 1976) have indicated a 60 percent or greater decrease in efficiency in construction operations under adverse winter conditions. Therefore, it is expected that most contractors would attempt to schedule outside work over a period of 6 to 10 months. Studies perfonned as part of this work program indicate that the general construction activity at the Susitna damsite during the months of April through September would be comparable with that in the northern sections of the western United States. Rainfall in the general region of the site is moderate between mid-April and 9-4 - """': I - - - - - - - - - mid-October, ranging from a low of 0.75-inch precipitation in April to a high of 5.33 inches in August. Temperatures in this period range from 33°F to 66°F for a twenty-year average. In the five-month period from November through March, the temperature ranges from 9.4°F to 20.3°F with snowfall of 10 inches per month. (e) Construction Methods The construction methods assumed for development of the estimate and construction schedule are generally considered as normal and in 1 ine with the available level of technical information. A conservative approach has been taken in those areas where more detailed information will be developed during subsequent investi- gation and engineering programs. For example, normal dri 11 i ng, blasting, and mucking methods have been assumed for all under- ground excavation. Also, conventional equipment has been con- sidered for major fill and concrete work. Various construction methods were considered for several of the major work items to determine the most economically practical method. For example, a comprehensive evaluation was made of the means of excavating material from Borrow Site E and the downstream river for the W at an a dam s h e 11 s • A com p a r i son of ex c a vat i on by d rag 1 i n e , dredge, backhoe, and scraper bucket methods was made, with consideration given to the quantity of material available, distance from the dam, and location in the river or adjacent terraces. (f) Quantity Takeoffs (g) Deta i 1 ed quantity takeoffs were produced from the engineering drawings using methods normal to the industry. The quantities developed are those listed in the detailed summary estimates in Appendix C of the Feasibility Report (Acres 1982b). Indirect Construction Costs Indirect construction costs were estimated in detail for the civil construction activities. A more general evaluation was used for the mechanical and electrical work. Indirect costs included the following: -Mobilization; Technical and supervisory personnel above the 1 evel of trades foremen; -All vehicle costs for supervisory personnel; -Fixed offices, mobile offices, workshops, storage facilities, and laydown areas, including all services; -General transportation for workmen onsite and offsite; -Yard cranes and fioats; Utilities including electrical power, heat, water, and com- pressed air; 9-5 -Small tools; -Safety program and equipment; Financing; -Bonds and securities; -Insurance; -Taxes; -Permits; -Head office overhead; -Contingency allowance; and -Profit. In developing contractor 1 s indirect costs, the following assump- tions have been made: -Mobilization costs have generally been spread over construction items; -No escalation allowances have been made, and therefore any risks associated with escalation are not included; -Financing of progress payments has been estimated for 45 days, the average time between expenditure and reimbursement; -Holdback would be limited to a nominal amount; -Project all-risk insurance has been estimated as a contractor 1 S indirect cost for this estimate, but it is expected that this insurance would be carried by the owner; and Contract packaging would provide for the supply of major mater- ials to contractors at site at cost. These include fuel, elec- tric power, cement, and reinforcing steel. 9.2 -Mitigation Costs As discussed in previous sections, the project arrangement includes a number of features designed to mitigate potential impacts on the natur- al environment and on residents and communities in the vicinity of the project. In addition, a number of measures are planned during con- struction of the project to mitigate similar impacts caused by con- struction activities. The measures and facilities represent more costs to the project than would normally be required for safe and efficient operation of a hydroelectric development. These mitigation costs have been estimated at $153 million and have been summarized in Table 9.4. In addition, the costs of full reservoir clearing at both sites have been estimated at $85 million. Although full clearing is considered good engineering practice, it is not essential to the operation of the power facilities. Both above cost items include direct and indirect costs, engineering, administration, and contingencies, and have been included in the accounts of construction costs in the estimate. 9-6 - - - ~i - - I~ A number of mitigation costs are associated with facilities, improve- ments, or other programs not directly related to the project or located outside the project boundaries. These would include the following items: -Caribou barriers; -Raptor nesting platforms; -Fish channels; -Fish hatcheries; Stream improvements; -Sa 1 t 1 i ck s ; -Habitat management for moose; and -Fish stocking program in reservoirs. The costs of these programs, including contingencies, have been estima- ted as follows and listed under project indirects in the capital cost estimate. Watana •••••••••••••••••••••••••••••••••• $32.0 million (approx.) Devil Canyon •••••••••••••••••••••••••••• 5.0 million (approx.) Total Project ••••••••••••••••••••••••••• $37.0 million (approx.) Finally, a number of studies and programs will be required to monitor the impacts of the project on the environment and to develop and record various data during project construction and operation. These include the fallowing: -Archaeological studies; -Fisheries and wildlife studies; -Right-of-way studies; and -Socioeconomic planning studies. The costs for the above work have been included under project over- heads and have been estimated at a~proximately $20 million. 9.3 -Engineering and Administration Costs Engineering has been subdivided into the following accounts for the purposes of the cost estimates: . -Account 71 • Engineering and Project Management • Construction Management • Procurement -Account 76 • Owner • s Costs The total cost of engineering and administrative activities has been estimated at 12.5 percent of the total construction costs, including 9-7 contingencies. This is in general agreement with experience on projects similar in scope and complexity. A detailed breakdown of these costs is dependent on the organizational structure established to undertake design and mana9ement of the project, as well as more defini- tive data relating to the scope and nature of the various project components. However, the main elements of cost included are as fo 11 ows: (a) Engineering and Project Management Costs These costs include allowances for: -Feasibility studies, including site surveys and investigations and logistics support; -Preparation of a license application to the FERC; -Technical and administrative input for other federal, state, and local permit and license applications; -Overall coordination and administration of engineering, con- struction management, and procurement activities; -Overall planning, coordination, and monitoring activities ~elated to cost and schedule of the project; -Coordination with and reporting to the Power Authority regarding all aspects of the project; -Preliminary and detailed design; Technical input to procurement of construction services, support services, and equipment; -Monitoring of construction to ensure confonnance to design requirements; -Preparation of startup and acceptance test procedures; and -Preparation of project operating and maintenance manuals. (b) Canst ruction Management Costs Construction management costs have been assumed to include: -Initial planning and scheduling and establishment of project procedures and organization; -Coordination of onsite contractors and construction management activities; -Administration of onsite contractors to ensure harmony of trades, compliance with applicable regulations, and maintenance of adequate site security and safety requirements; -Development, coordination, and monitoring of construction schedules; -Construction cost control; -Material, equipment, and drawing control; -Inspection of construction and survey control; -Measurement for payment; -Startup and acceptance test for equipment and systems; -Compilation of as-constructed records; and -Final acceptance. 9-8 f~W'-, ...... - - - - - - - - ...., I - - - - - - (c) Procurement Costs Procurement costs have been assumed to include: -Establishment of project procurement procedures; -Preparation of nontechnical procurement documents; -Solicitation and review of bids for construction services~ sup- port services~ permanent equipment, and other items required to complete the project; Cost administratton and control for procurement contracts; and -Quality a~surance services during fabrication or manufacture of equipment and other purchased items. (d) Owner•s Costs Owner•s costs have been assumed to include the following: -Admtnistration and coordination of project management and engineering organizations; Coordination with other state~ 1 ocal, and federal agencies and grOups having jurisdictton over or interest in the project; -Coordination with interested public groups and individuals; -Reporting to legislature and the public on the progress of the project; and -Legal costs (Account 72). 9.4 -Operation, Maintenance~ and Replacement Costs The facilities and procedures for operation and maintenance of the project are described in Section 15 of the Feasibility Report (Acres 1982a). Assumptions for the size and extent of these facilities have been made on the basis of experience at large hydroelectric develop- ments in northern climates. The annual costs for operation and mainte- nance for the Watana development have been estimated at $10.4 million. When Devil Canyon is brought on-1 ine, these costs increase to $15.2 mill ion per annum. Interim replacement costs have been estimated at 0. 3 percent per annum of the capital cost. The breakdown in Table 9.5 is provided in support of the allowance used in the finance/economic analysis of Susitna Hydroelectric Power Development. It is based on an operating plan involving full staffing of power plant and permanent town site support with a total of 105 personnel at Watana and another 25 when Devil Canyon comes on-1 i ne. This provides manned supervisory staff on a 24-hour, 3-shift basis and maintenance cr~ws to handle all but major overhauls. Overhauls would involve contracted 1 abor for which a nominal allowance has been made. It recognized that major overhauls are normally unlikely in the first 10 years or more of plant life. In earlier years, this allowance was a prudent provision for unexpected startup costs over and above those covered by warranty. 9-9 The allowance for contracted services also covers helicopter operations and access road snow clearing/maintenance. Allowances have also been made for environmental mitigation as well as for a contingency for unforeseen costs. Estimates for Susitna have been based both on original estimate and actual experience at Churchill Falls. It should be realized that alternative operating plans are possible which eliminate the need for permanent townsite facilities and rely on more remote supervisory sys- tems and/or operations/maintenance crews transported to the plant on a rotating shift basis. Cost implications of these alternatives have not yet been examined. 9.5-Allowance for Funds Used During Construction At current high levels of interest rates in the financial marketplace, AFDC will amount to a significant element of financing cost for the lengthy periods required for construction of the Watana and Devil Canyon projects. However, in economic evaluations of the Susitna pro- ject, the low real rates of interest assumed would have a much reduced impact on assumed project development costs. Furthermore, direct state involvement in financing of the Susitna project will also have a signi- ficant impact on the amount, if any, of AFDC. For purposes of the feasibility study, therefore, the conventional practice of calculating AFDC as a separate line item for inclusion as part of project construc- tion cost has not been fall owed. Pro visions for AFDC at appropriate rates of interest are made in the economic and financial analyses described in Section 18 of the Feasibility Report (Acres 1982a). 9.6 -Escalation All costs presented in this section are at January 1982 levels, and consequently include no allowance for future cost escalation. Thus, these costs would not be truly representative of construction and procurement bid prices because provision must be made in such bids for continuing escalation of costs and the extent and variation of escala- tion that might take place over the lengthy construction periods involved. Economic and financial evaluations discussed in Section 18 of the Feasibility Report take full account of such escalation at appropriately assumed rates. 9.7-Cash Flow and Manpower Loading Requirements The cash flow requirements for construction of Watana and Devil Canyon are an essential input to economic and financial planning studies. The basis for the cash flow are the construction cost estimates in January 1982 dollars and the construction schedules presented in Section 10, with no provision being made as such for escalation. The cash flow estimates were computed on an annua 1 basis and do not include adjust- ments for advanced payments for mobilization or for holdbacks on construction contracts. The results are presented in Table 9.6. The manpower loading requirements were developed from cash flow projec- tions. These curves were used as the basis for camp 1 oading and associated socioeconomic impact studies, and are presented in Figures 9.1 through_ 9. 3. 9-10 - - - - - - ... .., -' - "'"' 9.8 -Contingency Contingencies on construction costs have been assessed for each account within the 10 to 20 percent range and included in the cost estimates. Contingency averages approximately 15 percent over the total construc- tion cost. The contingency includes cost increases which may occur in the detailed engineering phase of the project after more comprehensive site investigations and final designs have been completed and after the requirements of various concerned agencies have been considered. The contingency estimate also includes allowances for inherent uncertain- ties in cost of labor, equipment, and materials, and for unforeseen conditions which may be encountered during construction. Escalation in costs as the result of inflation is not included. No allowance has been included for costs associated with significant delays in project implementation. 9.9-Previously Constructed Project Facilities An electrical intertie between the major load centers of Fairbanks and Anchorage is currently under construction. The line wi 11 connect existing transmission systems at Willow in the south and Healy in the north. The intertie is being built to the same standards as those pro- posed for the Susitna project transmission 1 ines and will become part of the licensed project. The line will be energized initially at 138 kV in 1984 and will operate at 345 kV after the Watana phase of the Susitna project is complete. The current estimate for the completed intertie is $130.8 million. This cost is not included in the estimates of this section. 9.10-Check Estimate by EBASCO An independent check estimate was undertaken by EBASCO Services Incor- porated. The estimate was based on engineering drawings, technical information, and quantities prepared by Acres. Major quantity items were checked. The EBASCO check estimated capital cost was approxi- mately 7 percent above the Acres estimate. A meeting was held with the Power Authority, EBASCO, and lkres to review differences in the estimates. It was generally possible to reconcile the differences and it was concluded that no major changes were required in the Feasibility Report Estimate. 9-11 - ·- - - REFERENCES Acres American Incorporated. 1982a. Susitna Hydroelectric Project Feasibility Report. Prepared for the Alaska Power Authority. 1982b. Appendix C. Susitna Hydroelectric Project Feasibility Report- Prepared for the Alaska Power Authority. 1983. Susitna Hydroelectric Project Feasibility Report - Appendix C (Revised). Prepared for the Alaska Power Authority. Caterpillar Tractor Co. 1981. Caterpillar Performance Handbook. Government Printing Office. Resources, Part 1 and 2. Washington, O.C. 1982. Conservation of Power and Water Code of Federal Regulations. Title 18: Roberts, WilliamS. July 1976. Regionalized Feasibility Study of Cold Weather Earthwork. Special Report 76-2. Cold Regions Research and Engineering Laboratory. State of Alaska. 1982. Agreements of Wages and Benefits for Construction Trades. ..,.,,, -I - Category Production Plant Transmission Plant General Plant Indirect Total Construction Overhead Construction TOTAL PROJECT TABLE 9.1: SUMMARY OF COST ESTIMATE January 1982 Dollars $ X 10 6 Watana Oev I I Canyon Tota I $2,293 $1,064 $3,357 456 105 561 5 5 10 442 207 649 3,196 1,381 4,577 400 173 573 $3,596 $1,554 $5,150 No. 330 331 332 333 334 335 336 ESTIMATE SUMMARY TABLE 9.2 WATANA ESTIMATE SUMMARY CLIENT ALASKA POWER AUTHORITY TYPE OF ESTIMATE Feasibility PROJECT ___:.S_:_US.:....:I:....:.T~NA~H~Y.:....:DR_:O:..-=E.:_L E_C:._T_R_I C_P_RO_J_E_CT ___ _ APPROVED BY __ ~J~D~L~--- DESCRIPTION AMOUNT TOTALS PRODUCTION PLANT Land & Land Rights •••••••••••••••••••••••••••••••••••••••••••••••••• $ 51 Powerplant Structures & Improvements ••••••••••••••••••••••••••••••••• 74 Reservoir, Dams & Waterways •••••••••••••••••••••••••••••••••••••••••• 1,547 Waterwheels, Turbines & Generators ••••••••••••••••••••••••••••••••••• 66 Accessory Electrical Equlpment ••••••••••••••••••••••••••••••••••••••• 21 Mlscel laneous Powerplant Equipment (Mechanical) •••••••••••••••••••••• 14 Roads & Railroads •••••••••••••••••••••••••••••••••••••••••••••••••••• 214 Subtotal ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 1,987 Contingency •••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 306 TOTAL PRODUCTION PLANT ••••••••••••••••••••••••••••••••••••••••••••••• $ 2,293 J JOB NUMBER FILE NUMBER P5700.00 P5700.14.09 OF 5 S HEET _ ___;_l __ BY ____ _ DATE __ _ CHKD JRP DATE 2/82 REMARKS -.I No. --] ESTIMATE SUMMARY CLIENT ALASKA POWER AUTHORITY PROJECT SUSITNA HYDROELECTRIC PROJECT DESCRIPTION TABLE 9.2 WATANA TOTAL BROUGHT FORWARD TRANSMISSION PLANT .................................................. 350 Land & Land Rights •••••••••••••••••••••••••••••••••••••••••••••••••••• 352 Substation & Switching Station Structures & Improvements •••••••••••••• 353 Substation & Switching Station Equipment •••••••••••••••••••••••••••••• 354 Stee I Towers & Fixtures ••••••••••••••••••••••••••••••••••••••••••••••• 356 Overhead Conductors &.Devices ••••••••••••••••••••••••••••••••••••••••• 359 Roads & Trai l.s •••. •••••••••••••••••• ••••• •• ••••••••• ••••• •• ••••••. •••. Subtota I ••••••••••••••••••••••••••••••••••••••••••••••••••••••••• •-• ••• Contingency •••••••••••••••••••••••••••••••••••••••••••.•••••••••••••••• TOTAL TRANSMISSION PLANT ••••••••••••••••••••••• •-• ••••• ,. •·• ••• , •••••••• TYPE OF ESTIMATE Feas ibi 1 ity APPROVED BY JDL AMOUNT TOTALS < x 1 o6 > (x 106) $ 2,293 $ 8 12 131 131 100 13 395 61 $ 456 $ 2,749 .... ] JOB NUMBER P5700.00 P5700. 14.09 FILE NUMBER SHEET __ 2 __ 5 OF ___ _ BY _____ _ DATE __ _ CHKD ,JRP DATE 2/82 REMARKS -1·· . No. 389 390 391 392 393 394 395 396 397 398 399 ESTIMATE SUMMARY CLIENT ALASKA POWER AUTHORITY PROJECT SUSITNA HYDROELECTRIC PROJECT DESCRIPTION TABLE 9.2 WATANA TOTAL BROUGHT FORWARD ................................................. GENERAL PLANT Land & Land Rights ••••••••••••••••••••••••••••••••••••••••••••·•••••••• Structures & Improvements ••••••••••••••••••••••••••••••••••••••••••••• Office Furniture/Equipment •••••••••••••••••••••••••••••••••••••••••••• Transportation Equipment •••••••••••••••••••••••••••••••••••••••••••••• Stores EQuipment •••••••••• , ~ •••••••••••••••••••••••••••••••••••••••••• Tools Shop & Garage Equipment ••••••••••••••••••••••••••••••••••••••••• Laboratory Equipment •••••••••••••••••••••••••••••••••••••••••••••••••• Power-Operated Equipment •••••••••••••••••••••••••••••••••••••••••••••• Communi cations Eq u i pment •••••••••••••••••••••••••••••••••••••••••••••• Miscellaneous Equipment ••••••••••••••••••••••••••••••••••••••••••••••• Other Tangible Property ••••••••••••••••••••••••••••••••••••••••••••••• TOTAL GENERAL PLANT ••••••••••••••••••••••••••••••••••••••••••••••••••• J J TYPE OF ESTIMATE Feasibility APPROVED BY ___ J_O_L ___ _ AMOUNT TOTALS $ 2, 749 $ 5 $ 5 $ 2, 754 .J J J JOB NUMBER P5700,00 P5700.14.09 FILE NUMBER SHEET __ 3 __ 5 OF ___ _ BY _____ _ DATE __ _ CHKD JRP DATE 2/82 REMARKS Inc I uded under 330 Inc I uded under 331 Inc I uded under 399 " II " II " II " II II II " " II II No. I 61 62 63 64 65 66 68 69 ) l ESTIMATE SUMMARY TABLE 9.2 WATANA CLIENT ALASKA POWER AUTHORITY TYPE OF ESTIMATE Feasibility PROJEcT ---=s u=s~I_,_T=NA...:..._:_:H--'-'Y D=R=O=E L=E=-=C:....:...T.:...:;R I~C::........:_P R=O=J=E-=-CT=---------APPROVED BY ___ J_DL ____ ~ DESCRIPTION TOTAL BROUGHT FORWARD ••••••••••••••••••••••••••••••••••••••••••••••••• INDIRECT COSTS Temporary Construction Faci I ltles •••••••••••••••••••••••••••••••••••••• Construction Equipment ••••••••••••••••••••••••••••••••••••••••••••••••• Camp & Contm i ssary •••••••••••••••••••••••••••••••••••••••••••••••••••••• Labor Expense •••••••••••••••••••••••••••••••••••••••••••••••••••••••••• Super1ntendence ••••••••••••••••••••••••••••••••••••••••••••••••••••••• Insurance •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• Mitigation •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• Fees ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• Note: Qosts under accounts 61, 62, 64, 65, 66, and 69 are included in the appropriate direct costs I i sted above. Subtotal •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• Contingency ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• TOTAL INDIRECT COSTS •••••••••••••••••••••••••••••••••••••••••••••••••• TOTAL CONSTRUCTION OOSTS AMOUNT TOTALS $ 2,754 $ 373 29 402 40 $ 442 $ 3,196 JOB NUMBER P5700.00 Fl LE NUMBER ------:.P__;:5....:...7-=-0-=--0 ':.....:l'--"4o-'-.-=-0-=--9 _ SHEET __ 4___ OF __ 5 __ BY _____ _ DATE __ _ CHKD .JRP DATE 2,/82 REMARKS See Note See Note See Note See Note See Note No. 71 72 75 76 77 80 ESTIMATE SUMMARY CLIENT ALASKA POWER AUTHORITY PROJECT SUS !INA HYDROEI ECIRI C PRD.JECT DESCRIPTION TABLE 9.2 WATANA TOTAL CONSTRUCT I ON COSTS BROUGHT FORWAf{) •••••••••••• • • • • • •••••••••• ~ •• OVERHEAD CONSTRUCTION COSTS <PROJECT INDIRECTS> TYPE OF ESTIMATE FeasibiJ ity A'PPROVED BY __ ....... JLLDLJ..I ____ _ AMOUNT TOTALS $ 3,196 Engineering/ Administration ••••••••••••••••••••••••••••••••••••••••••• $ 386 Legal Expenses •••••••••••••••••••••••••••••••••••••••••••••••••••••••• 14 Taxes ................................................................. Administrative & General Expenses ••••••••••••••••••••••••••••••••••••• Interest •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• Earnings/Expenses During Construction ••••••••••••••••••••••••••••••••• Tot a I Overhead •••• , ••• , ••••••• , •• , , , , , , , , , ••••••• , , , , •••• , •••••••••••• 400 TOTAL PROJECT COST •••••••••••••••••••••••••••••••••••••••••••••••••••• $ 3,596 J j JOB NUMBER P5700. 00 Fl LE NUMBER _P_5_7_0_0..:_. 1"--4"--._0_9_ SHEET_~5...__ __ OF 5 BY ______ DATE __ _ CHKD JRP DATE 2/82 REMARKS Inc I uded In 71 Not ap p I I cab I e Inc I uded in 7 1 Not inc I uded Not inc I uded .I J J ) ____ ] j • ESTIMATE SUMMARY TABLE 9.3 JOB NUMBER P5700.00 DEVIL CANYON ESTIMATE SUMMARY FILE NUMBER P5700. 14.09 CLIENT ALASKA POWER AUTHORITY TYPE OF ESTIMATE Feasibility SHEET 1 OF 5 SUSITNA HYDROELECTRIC PROJECT JDL BY DATE PROJECT APPROVED BY CHKD JRP DATE 2L82 No. DESCRIPTION AMOUNT TOTALS REMARKS (X 1 06 } (X 106 } PRODUCTION PLANT 330 Land & Land Rights •••••••••••••••••••••••••••••••••••••••••••••••••••• $ 22 331 Powerplant Structures & Improvements •••••••••••••••••••••••••••••••••• 69 332 Reservoir, Dams & Waterways ••••••••••••••••••••••••••••••••••••••••••• 646 333 Waterwheels, Turbines & Generators •••••••••••••••••••••••••••••••••••• 42 334 Accessory Electrical Equipment •••••••••••••••••••••••••••••••••••••••• 13 335 Miscellaneous Powerplant Equipment (Mechanical} ••••••••••••••••••••••• 11 336 Roads & Ra. i I roads ••••••••••••••••••••••••••• • ••••••••••••••••••••••••• 119 Subtotal •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 922 Contingency ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• 142 TOTAL PRODUCT,ON PLANT •••••••••••••••••••••••••••••••••••••••••••••••• $ 1,064 350 352 353 354 356 359 No. ESTIMATE SUMMARY TABLE 9.3 DEVIL CANYON CLIENT ALASKA POWER AUTHORITY TYPE OF ESTIMATE Feasibility PROJEcT _s_us_I_T_NA_H_Y_DR_O_E_L_EC_T_R_I _c _P_R_OJ_E_C_T ___ _ DESCRIPTION TOTAL BROUGHT FORWARD ••••••••••••••••••••••••••••••••••••••••••••••••• TRANSMISSION PLANT Land & Land Rights •••••••••••••••••••••••••••••••••••••••••••••••••••• Substation & Switching Station Structures & Improvements •••••••••••••• Substation & Switching Station Equipment •••••••••••••••••••••••••••••• Steel Towers & Fixtures ••••••••••••••••••••••••••••••••••••••••••••••• Overhead Conductors & Devices ••••••••••••••••••••••••••••••••••••••••• Roads & Trai Is •••••••••••••••••••••••••••••••••••••••••••••••••••••••• Subtotal •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• Contingency ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• TOTAL TRANSMISSION PLANT •••••••••••••••••••••••••••••••••••••••••••••• APPROVED BY _____ J_D_L ______ _ $ AMOUNT 7 21 29 34 91 14 TOTALS $ 1,064 $ 105 $ 1,169 J JOB NUMBER P5700.00 FILE NUMBER _P_5_7_0_0_. 1 .. 4~._0_9_ SHEET __ 2___ OF ___ 5 __ BY _____ _ DATE __ _ CHKD ,JRP DATE 2/82 REMARKS Included In Watana Estimate Included in Watana Estimate ) TABLE 9.3 ESTIMATE SUMMARY DEVIL CANYON CLIENT ALASKA POWER AUTHORITY PROJECT ____:::_S=US=-=Ic...:...T.:...:.:NA....:........:.H~Y.::..:DR..:..:O:..::E.=.:L E=-..:C:....:.T..:....:R~I C::.._:_P.:....:._RO::....::J~E~CT.:..__ ___ _ No. DESCRIPTION TOTAL BROUGHT FORWARD ••••••••••••••••••••••••••••••••••••••••••••••••• GENERAL PLANT 389 Land & Land Rights •••••••••••••••••••••••••••••••••••••••••••••••••••• 390 Structures & Improvements ••••••••••••••••••••••••••••••••••••••••••••• 391 Office Furniture/Equipment •••••••••••••••••••••••••••••••••••••••••••• 392 Transportation Equipment •••••••••••••••••••••••••••••••••••••••••••••• 393 Stores Equipment •••••••••••••••••••••••••••••••••••••••••••••••••••••• 394 395 396 397 398 399 Tools Shop & Garage Equipment ••••••••••••••••••••••••••••••••••••••••• Laboratory Equipment •••••••••••••••••••••••••••••••••••••••••••••••••• Power-Operated Equipment .............................................. Communications Equipment .............................................. Miscellaneous Equipment ............................................... Other Tangible Property ............................................... TOTAL GENERAL PLANT ••••••••••••••••••••••••••••••••••••••••••••••••••• TYPE OF ESTIMATE Feasibility APPROVED BY _____ J_D_L ______ __ AMOUNT TOTALS $ 1,169 $ 5 $ 5 $ 1,174 ) JOB NUMBER P5700. 00 Fl LE NUMBER __ P_S-_7_0_0_. 1_4_._0_9_ SHEET __ 3'----OF 5 BY______ DATE ___ __ CHKD JRP DATE 2/82 REMARKS Inc I uded under 330 Inc I uded under 331 Included under 399 " " " " " " " " II II II II II II No. 61 62 63 64 65 66 68 69 ESTIMATE SUMMARY TABLE 9. 3 DEVIL CANYON CLIENT ALASKA POWER AUTHORITY TYPE OF ESTIMATE Feasibility PROJECT SUSITNA HYDROELECTRIC PROJECT APPROVED BY ____ ~J=D~L ______ __ DESCRIPTION TOTAL BROUGHT FORWARD ••••••••••••••••••••••••••••••••••••••••••••••••• INDIRECT COSTS Temporary Construction Faci I I ties ••••••••••••••••••••••••••••••••••••• Construction Equipment ••••••••••••••••••••••••••••••••••••••••••••••• camp & CommIssary •••••••••••••••••••••••••••••••••••••••••••••••••••• • Labor Expense ••••••••••••••••••••••••••••••••••••••••••••••••••••••••• Superintendence ••••••••••••••••••••••••••••••••••••••••••••••••••••••• Insurance ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• Mitigation •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• Fees •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• Note: costs under accounts 61, 62, 64, 65, 66, and 69 are included in the appropriate direct costs I i sted above. Subtotal •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• Contingency ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• TOTAL INDIRECT COSTS ••••••••••••••••••••••••••••••••••••••••••••••••• TOTAL CONSTRUCTION COSTS ) AMOUNT $ TOTALS $ 1.174 - - 184 - - - 4 - 188 19 $ 207 $ 1,381 _j JOB NUMBER FILE NUMBER P5700.00 P5700.14.09 S HEET ___ 4 __ __ OF 5 BY _____ _ DATE ____ __ CHKD JRP DATE 2/82 REMARKS See Note See Note See Note See Note See Note See Note .J 71 72 75 76 77 80 No. --} ESTIMATE SUMMARY l TABLE 9.3 DEVIL CANYON CLIENT ALASKA POWER AUTHORITY TYPE OF ESTIMATE Feasibility PROJEcT ---=sc..=.u=s I"-'T--'-'N'--'-A-'-H.:....;.Y_;:_D.;_:_RO:....::E=L=-E c.::....T'-R_I .::....c _P_R_OJ_E_C_T ___ _ APPROVED BY JDL DESCRIPTION AMOUNT TOTALS (X 1 06) (X 106) TOTAL CONSTRUCTION COSTS BROUGHT FORWARD •••••••••••••••••••••••••••••• $ 1,381 OVERHEAD CONSTRUCTION COSTS (PROJECT INDIRECT$) Engineering/ Administration •••••••••••••••••••••••••••••••••••••••••• $ 167 Environmental Monitoring ••••••••••••••••••••••••••••••••••••••••••••• 6 Legal Expenses ••••••••••••••••••••••••••••••••••••••••••••••••••••••• - -Taxes ................................................................ Administrative & General Expenses •••••••••••••••••••••••••••••••••••• - Interest ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• - Earnings/Expenses During Construction •••••••••••••••••••••••••••••••• - Total Overhead Costs ••••••••••••••••••••••••••••••••••••••••••••••••• 173 TOTAL PROJECT COST ••••••••••••••••••••••••••••••••••••••••••••••••••• $ 1,554 JOB NUMBER P5700.00 FILE NUMBER P5700.14.09 SHEET __ 5 __ _ 5 OF ___ _ BY _____ _ DATE __ _ CHKD .JRP DATE 2/82 REMARKS Inc I uded In 71 Not Applicable Inc I uded in 7 1 Not Inc I uded Not Inc I uded TABLE 9.4: MITIGATION MEASURES -SUMMARY OF COSTS INCORPORATED IN CONSTRUCTION COST ESTIMATES COSTS INCORPORATED IN CONSTRUCTION ESTIMATES Outlet Facilities Main Dam at Devil Canyon Tunnel Spillway at Watana Restoration ot Borrow SiteD Restoration ot Borrow Site F Restoration ot Camp and Village Restoration of Construction Sites Fencing around Camp Fencing around Garbage Disposal Area Multi level Intake Structure Camp Facilities Associated with Trying to Keep Workers out of Local Communities Restoration of Haul Roads SUBTOTAL Contingency 20% TOTAL CONSTRUCTION Engineering 12.5% TOTAL PROJECT WATAN~ $ X 10 47' 100 1,600 600 2,300 4,100 400 100 18,400 10,200 BOO 85,600 17' 100 102,700 12,800 115,500 DEVIL C~NYON $ X 10 14,600 NA NA 1,000 2,000 NA 200 100 9,000 500 27,400 5,500 32,900 4,100 37,000 - ~' 152,500 - - - - - j ._J ] l J J ) _] J -.. J J ) ] TABLE 9.5 SUMMARY OF OPERATING AND MAINTENANCE COSTS WATANA DEV I L CANYON ($ 000 1 s Omitted) ($ 000 1 s Omitted) Expense Expense Labor Items Subtotal Labor Items Subtotal Power and Transmission Operation/ Maintenance 5,330 990 6,320 1,920 500 2,420 Contracted Services 900 900 480 480 Permanent Townsite Operations 540 340 880 120 80 200 A II owance for Environmental Mitigation 1,000 1,000 Contingency 900 500 $10,000 $ 4,600 Additional Allowance from 2002 to Rep I ace Commu n J-i·y Fac i I it i es 400 200 Total Operating and Maintenance Expenditure Estimate Power Development and Transmission Faci I ities WATANA $10,400 DEVIL CANYON $ 4z800 TABLE 9.6 WATANA AND DEVIL CANYON CUMULATIVE AND ANNUAL CASH FLOW JANUARY 1982 DOLLARS-IN MILLIONS ANNUAL CASH FLOW CUMULATIVE CASH FLOW <TO END OF YEAR) YEAR WATANA DEVIL CANYON COMBINED WATANA DEVIL CANYON COMBINED 1981 27.6 27.6 27.6 27.6 82 12.9 12.9 40.4 40.4 83 28.7 28.7 69.2 69.2 84 48.5 48.5 117.7 117.7 85 199.5 199.5 317.2 317.2 86 283.9 283.9 601.1 601.1 87 295.4 295.4 896.5 896.5 88 369.0 369.0 1265.5 1265.5 89 438.4 438.4 1703.9 1703.9 90 627.6 627.6 2331.5 2331.5 91 608.8 4.9 613.7 2940.3 4.9 2945.2 92 429.0 47.9 476.9 3369.3 52.8 3422.1 93 153.2 68.6 221.8 3522.5 121.4 3643.9 94 73.7 64.3 138.0 3596.2 185.7 3781.9 95 64.9 64.9 250.6 3846.8 96 115.3 115.3 365.9 3962.1 97 201.3 201.3 567.2 4163.4 98 291.8 291.8 854.0 4455.2 99 279.7 279.7 1138.7 4734.9 2000 241.7 241.7 1380.4 4976.6 2001 156.0 156.0 1536.4 5132.6 2002 17.6 17.6 1554.0 5150.2 TOTAL 3596.2 1554.0 5150.2 11/08/82, REVISED DEVIL CANYON CASH FLOW _j J .J ., 0: .. ...J ...J 0 0 u. 0 ., z ~ ...J ...J :I ~ 0 ...J u. :I: "' .. u "' > i= .. ...J "' 2 "' u 4000 r-----------~ ------.------.-------.-------,------.-------r------.-------,------,------.------~1' .------.-------,------, I 3500 3000 2500 2000 1500 1000 500 0 ~----+----+-------+----+---~·----+-----+----4---CU--M--UL~~~IVE-C~ASI--FLO __ W~~~~~ IV i 1982 1983 1984 1985 1986 ,, 1987 1988 1989 1990 1991 1992 YEARS WATANA DEVELOPMENT CUMULATIVE AND ANNUAL CASH FLOW JANUARY, 1982 DOLLARS --i 1993 1994 i I I ·- 1995 1996 1997 BOO 700 600 ., 0: .. ...J ...J 500 0 0 u. 0 ., z 0 :::; ...J 400 ! ~ 0 ...J u. :r "' .. u 300 ...J .. "' z z .. 200 100 0 FIGURE 9.1 I "' "' "' ...J I ...J 0 0 2000 I ... 0 I "' "' 1500 I 0 :::; ..J i ~ ...J 1000 I ... % I "' I <I " l 500 I l 0 1992 19 93 1994 ! I I I I I I J I I l I I I CUMULHIVE CASH I FLOW\ /v 1995 1996 1997 1998 1999 2000 YEARS DEVIL CANYON DEVELOPMENT CUMULATIVE AND ANNUAL CASH FLOW JANUARY, 1982 DOLLARS 2001 2002 i ! 400 "' a:: i ' "' ...J ...J 300 0 0 ..... 0 "' "' 0 ...J 200 ...J 'i ,., 0 ...J ... ' :z: 100 "' c <> ...J "' ::;, z "' "' 0 2003 FIGURE 9.2 6500 ~ 6000 5500 5000 - 4500 "' "' <t ..J -' 4000 0 0 lL 0 "' 3500 z 0 :i -' :i 3000 "' 3 lL :r 2500 "' C( u '"' > ~ 2000 ..J ::> 2< ::> u 1500 1000 500 0 1982 1983 1984 1985 1986 1987 1-- ,~ LV -··-r --------------- 1 I ! t ' I I I I I I I /v i ' ·I· ....,.,.,... _/ v~ I\ -t'l Ulll ATI~E CAl~ 1iLd~ 1-- : 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 YEARS SUSITNA HYDROELECTRIC PROJECT CUMULATIVE a ANNUAL CASH FLOW ENTIRE PROJECT JANUARY, 1982 DOLLARS ;. '· 1999 iooo 2001 650 600 550 500 rn "' 450 C( -' ..J 0 0 lL 400 0 ., z 0 :::; 350 ..J :i "' 0 300 ..J lL :r rn C( 250 u ..J C( ::> z z 200 C( 150 - 100 50 0 2002 2003 FIGURE 9.3 ~ ' ' - 10 -DEVELOPMENT SCHEDULES This section, originally included as Section 17 in the March 1982 issue of the Feasibility Report (Acres 1982a), describes the development schedules prepared for both Watana and Devil Canyon to meet the on-line power requirements of 1993 and 2002, respectively. These schedules have been updated as a result of on-going studies and span the period from 1983 until 2004. Schedules for the development of both Watana and Devil Canyon are shown in Figures 10.1 and 10.2. The main elements of the project have been shown on these schedules, as we 11 as some key interrelationships. For purposes of planning, it has been assumed that a license will be awarded by December 31, 1984. Revisions to the Watana schedule include the following: The pioneer road was replaced by Denali Access Plan 18 (Section 4). Work prior to receipt of the FERC license was eliminated; -Activities leading up to diversion were revised for an accelerated schedule; and -The preconstruction of one circuit of the permanent transmission line from Gold Creek was eliminated. Revisions to the Devil Canyon schedule include the following: -Denali Access Plan 18 was incorporated, and the start of access construction was advanced accordingly. 10.1 -Preparation of Schedules Preliminary schedules were first developed by estimating the durations of the main construction activities and arranging these in logical se- quence. Some activity adjustments were then made to reduce excessive demands on resources, such as underground excavation or concrete plac- ing. The preliminary schedules were then used as a basis for the prep- aration of cost estimates. The schedules were also reviewed for over- all compatibility with major constraints such as licensing, on-line power requirements, and reservoir filling. At both sites the period for construction of the main dam is critical; other activities are fitted to the main dam work. A study of the front end requirements of Watana concluded that initial access work should commence immediately after receipt of license and be completed in the shortest possible time to permit a sufficiently rapid buildup of man- power and equipment to meet construction requirements. During devel O(lllent of the final project arrangement and preparation of the cost estimates (Section 9), the preliminary schedules were modified and refined. As estimating data were developed, the production rates and construction durations were calculated. Networks were deve 1 oped for the main construction activities and the durations and sequences of activities determined. The overall schedules were modified to suit. l 0-1 10.2 -Watana Schedule Commencement of construction: Initial access road Site facilities Diversion -April 1985 -Apri 1 1985 -July 1985 Completion of construction: Four of six units ready -January 1994 Six units ready -July 1994 Commencement of commercial operations: Four of six units Six units -January 1994 -July 1994 The Watana schedules were developed to meet two overall project con- straints: -FERC license would be issued by December 31, 1984; and -Four units would be on-line by the end of 1993. The critical path of activities to meet the overall constraints was determined to be through site access, site facilities, diversion, and main dam construction. In general, construction activities leading up to diversion in 1987 are on an accelerated schedule whereas the remain- ; ng activities are a normal schedule. These are highlighted as follows: (a) Access Initial road access to the site is required by October 1, 1985. Certain equipnent will. be transported overland during the preced- ing winter months so that an airfield can be constructed by July 1985. This effort to complete initial access is required to mobi- lize labor, equipment, and materials in 1985 for the construction of site facilities and diversion works. {b) Site Facilities Site facilities must be developed in a very short time to support the main construction activities. A camp to house approximately 1000 men must be constructed during the first 18 months. Site construction roads and contractors' work areas have to be started. An aggregate processing plant and concrete batching plant must be operational to start diversion tunnel concrete work by April 1986. At site, power generating equipment must be installed in 1985 to supply power for camp and construction activities. 10-2 - ll'!l'iill - - - - (c) (d) - - r I (e) i I Diversion Construction of diversion and dewatering facilities, the first major activity, should start by mid-1985. Excavation of the portals and tunnels requires a concentrated effort to allow completion of the lower tunnel for river diversion by October 1986. The upper tunnel is needed to handle the spring runoff by May 1987. The upstream cofferdam must be placed to divert riverflows in October 1986 and raised sufficiently to avoid overtopping by the following spring. Main Dam The progress of work in the main dam is critical throughout the period 1986 through 1992. Mobilization of equipment and start of site work must begin in 1986. Excavation on the right abutment, as well as river alluvium under the dam core, begins in 1986. During 1987 and 1988, dewatering, excavation, and foundation treatment must be completed in the riverbed area and a substantial start made on placing fill. The construction schedule is based on the following program: Quantity Year ~yd 3 x 10 6 ) 1987 3 1988 6 1989 12 1990 13 1991 13 1992 12 1993 3 Accumulated Quantity (yd\ 10 6) 9 21 34 47 59 62 Fill Elevation October 15 (feet) 1660 1810 1950 2130 2210 Reservoir Elevation (feet) 1460 1865 2050 2185 The program for fill placing has been based on an average six months season. It has been developed to provide high utilization of construction equipment required to handle and process fill materials. Spillways and Intakes These structures have been scheduled for completion one season in advance of the requirement to handle flows. In general, excavation for these structures does not have to begin until most of the excavation work has been completed for the main dam. 10-3 (f) Powerhouse and Other Underground Works The first four units are scheduled to be on line by late 1993 and the remaining two units in early 1994. Excavation of the access tunnel into the powerhouse complex has been scheduled to start in late 1987. Stage I concrete begins in 1989 with start of instal- lation of major mechanical and electrical work in 1991. In general, the underground works have been scheduled to level resource demands as much as possible. (g) Transmission Lines/Switchyards Construction of the transmission lines and switchyards have been scheduled to begin in 1989 and be completed before commissioning of the first unit. (h) General The Watana schedule requires that extensive planning, bid selec- tion, and commitments are made before the end of 1984 to permit work to progress on schedule during 1985 and 1986. The rapid development of site activities requires commitments, particularly in the areas of access and site facilities, in order that con- struction operations have the needed support. The schedule has also been developed to take advantage of possible early reservoir filling to the minimum operating level by October 1992. Should this occur, power could possibly be generated by the end of 1992. 10.3 -Devil Canyon Schedule Commencement of construction: Main access -April 1992 Site facilities -June 1994 Diversion -June 1995 Completion of construction: Four units -October 2002 Commencement of commercial operations: Four units -October 2002 The Devil Canyon schedule was developed to meet the on-line power re- quirement of all four units in 2002. The critical path of activities was determined to follow through site facilities, diversion, and main dam construction. 10-4 - - - - - - (a) Access It has been assumed that site access facilities built to Watana will exist at the start of construction. A road will be construc- ted connecting the Devil Canyon site to the Watana access road including a high-level bridge over the Susitna River downstream from the Devil Canyon dam. At the same time, a ra i 1 road spur will be constructed to permit railroad access to the south bank of the Susitna near Devil Canyon. These activities will be completed by mid-1994. (b) Site Facilities Camp facilities should be started in 1994. that buildings can be salvaged from Watana. could also be started at this time. It has been assumed Site roads and power (c) Diversion (d) (e) Excavation and concreting of the single diversion tunnel should begin in 1995. River closure and cofferdam construction will take place to permit start of dam construction in 1997. Arch Dam The construction of the arch dam will be the most critical con- struction activity from start of excavation in 1996 until topping out in 2001. The concrete program has been based on an average 8-month placing season . for 4-1/2 years. The work has been scheduled so that a fairly constant effort may be maintained during this period to make best use of equipment and manpower. Spillways and Intake The spillway and intake are scheduled for completion by the end of 2000 to permit reservoir filling the next year. (f) Powerhouse ahd Other Underground Works (g) Excavation of access into the powerhouse cavern is scheduled to begin in 1996. Stage I concrete begins in 1998 with start of installation of major mechanical and electrical work in 2000. Transmission L i nes/Switchyards The additional transmission facilities needed for Devil Canyon have been scheduled for completion by the time the final unit is ready for commissioning in late 2001. 10-5 (h) General The development of site facilities at Dev·il Canyon begins slowly in 1994 with a rapid acceleration in 1995 through 1997. Within a short period of time, construction begins on most major civil structures. This rapid development is dependent on the provision of ~upport site facilities which should be completed in advance of the main construction work. 10.4 -History of Existing Project An intertie is planned to permit the economic interchange of up to 70 megawatts of power between major 1 oad centers at Anchorage and Fair- banks. Connecting to existing transmission systems at Willow in the south and Healy in the north, the intertie will be built to the same standards as those proposed for the Susitna project transmission sys- tem. It will be energized initially at 138 kv. Subsequent to con- struction of the Watana project, the intertie will be incorporated into the Susitna transmission system and will operate at 345 kV. Construction of the intertie is scheduled to begin in March 1983. Com- pletion and initial operation is planned for September 1984, well in advance of the anticipated date for receipt of a FERC 1 icense on December 31, 1984. 10-6 - - - - - - - 1!101! I r .i REFERENCES Acres American Incorporated. 1982a. Susitna Hydroelectric Project Feasibility Report. Prepared for the Alaska Power Authority. i I I ! I l ! I I l I I ~ ~ DESCRIPTION 1983 1984 1985 1986 1987 1988 1989 1990 nliii 1992 1993 1994 01 PIRCL.._ 02 INITIAL ACCESS -- 0> 04 MAIN ACCESS 05 06 SITE FACIUTIES 06 01 08 DIVERSION TUNIIIELS ~~~~~~~==~==========~============t=====~~~c~a~~~~~~-~;-~1 ;Jm~-~=======t============t========J~~~~~~~;;;;;t~;:-==-~~~~~-P~UM~======~========================~~~ ~ MttiiHIHIII t•r•r•l•l •••• -o8 -----+------f-----11-llhi-!.HIHM~II~HIII; i ~= 09 10 COffERDAMS II 12 MAIN DAM 13 14 RELICT CHANNEL 15 16 MAIN SPILLWAY 11 18 EMERGENCY SPILLWAY 19 ao OUTLET FACILITIES 21 f- 22 POWER INTAKE •• 24 PENSTOCKS 25 26 POWERHOUSE 21 28 TRANSFORMER GALLERY I CABLE SHAFTS .. 30 TAILRACE/SURGE CHAMBER 31 32 TIJRBINE /GENERATORS .. - 34 MECH./ ELECT. SYSTEMS 36 SWITCHYARD I CONTROL BLDG. 31 58 TRANSMISSION UNES 39 f--- '40 IMPOUNDMENT 42 TEST AND COMMISSION 43 .. - -~~---+~-.-=u~MW=---+-----~~~--,+.----------~-,+a-----T----~~~----------~-,+.---------~-~-.+a-----------+~ HUHittT..IIHIIIIItllfllfllltll~~ ...... HHHIII~)I "'-'-'-''-'-''-'\~ ''-'-'-'-'-'-'-'-"" •'-'-''''-'''-' ''''-'-'-'-'-''-' IHIIIIIIIIIIIIIHIItfUIIIH ,,,, .. ,.,, .. ,,. IIIUIIIHIHIIIIIII •tiiiiiiiiiiiiUIIIIIIIIIIutUHIIIIIIH - IIIIIIIIIIIIHIIIIIIMIIIIIIIII IHIIIIIIIHUitlttUIUltlM ......... II lllftH HIIIIHIIHifUIIIIIIHHeRIIIIIIIHIII lllflllliMIIUIIIIIQII ..,,,,,,,,,,..,_ ---~,,,,,,,,, ""''"' .•.•...•.... FUSE PLUG llllhUI.IHIIIIIIII ...........•.•. 'I 11'''1'1""·••• ••••••••••••••• _[_ .. ··· P.·················~··············~··· ............... .. .... , ........ I ........ ~ ..•...... ··············~··· ··················!-··~ 13 14 15 16 11 18 19 21 23 •• 33 34 .. CA .. ~ ~' WATANA CONSTRUCTION SCHEDULE lllltllllltHMIHU IHIIIIItr''-"-'-'-'-'-'-'-'-'\. )'I'll ············~ I :: "'-........,..... ~~···1·1·1•111, I 31 38 ~-:,.....,... ~.. 39 .......... ACCftS/FACfU11ES : atHIHIIIIIIIII EXCAVATIOIIJFOIJtiDMloN TREATMEIIT ... ,'\."'\.'\.'\.'\.'FILL -COMCitET£ I a1a1a1• -CHANICALIELECTIIICAL --IIIPOUIIDMEtfT ---·---40 J..1-~1 W2 WS 4 ~5 Vtl 011..._.... o4l l. ••••••• ..~ •••• t •••• ..~l.l .......... 42 43 .. FIGURE 10.1 DESCRIPTION 1992 1993 ,. 1994 1995 1996 1997 1998 1999 200(f" 2001 2002 2003 01 ; 01 02 MAIN ACCESS J 02 "' 00 04 SITE FACILITIES ..... ~ ... .. -.,. : 04 00 -.l.. 011 06 DIVERSION TUNNELS IIIIIIHIIIII 06 07 *·~· .. T ; 07 08 COFFERDAMS ~''i'''''' "'-'''" I I 'oo 09 ' i : ' 08 t-10 MAIN DAM 111111111~11 IIIIIIIIUIHIUIIIIIIMiflllllllllf 10 II I II 12 SADDLE DAM IIIIIIIIIIIIIIIIIIIIIIHIIIIRII ·'''''''''' '''''''''" I 12 13 : .. 14 OUTLET FACILITIES ., •.•.....•.. ..•.......• ~ I 14 .. ! • • 16 MAIN SPILLWAY HllllllltHIIIIIIIIIIIIIIIIII. ""1111111111.1111111111111 111111111 ... , ........... .. 17 ......... 17 18 EMERGENCY SPIL.l..WAY lllltiiHHIIMHIIIHIHIIHI ltttltltMMHtlflMMIHHIIIIII _..,.\.,,, 18 19 ' I 19 20 POWER INTAKE 111111111111111111111111111111 " .... •••••••i••••••• I "' 21 ' I 21 22 PENSTOClCS IIIIIIIIIUIIIIIIIIIIIHI I .. 23 ·~ .... •TA-1 i .. _ I 23 c-24 POWERHOUSE IIIUHIIIN ..... HIIIIIIIIIII 11111111111111111111 2 20 .,.-I -·-· .. .. 26 TRANSFORMER GALLERY I CABLE SHAFTS ...iumifiilftiimntnnnHIHIIUUI ' •.•...... .. 27 I 27 28 TAILRACE/SURGE CHAMBER 11111111 IIIIIIIIIIIIIIIIHIIIHIIHIHUifflftUf ~IINIHtttHNJHN 128 29 .. 30 TURBINES/ GENERATORS , ........•........ ············~···· ••••••••• 1 I"' 31 PH CaANI!:S ' I 31 32 MECH./ ELECT. SYSTEMS .•.•.•.•.. ......•.•. ···········--+ .... ·········; 32 33 PCAYA11GtUA..L • .._..i.-I " 34 SW!TCHYARD I CONTROL BLDG. IIIIIIIIIIIIIIIC\.'-'-'-'-'-'-' ···········.~ I "' 30 -.in... TOWEII8/--I ,. .. TRANSMISSION I..INES 1111111.11111111 liiiiiiiliiiiiil, ...... 1 ••••• , I .. 37 . ~ I 31 38 IMPOUNDMENT --..,.-· "'_ .. __ .. 39 .,.__., 1 .,. •· .,. p....... 139 40 TEST 8 COMMISSION ••••• ····l·········l 140 41 41 ~ 42 ' 42 43 43 44 .. LEGEND ~ ................ _. aCCU81FACIUIEI 11111111111111111 EXCAYATIONIFCII.fiiDA1JON11EATIEJIT "-'-"-"-"-"-"-' RLL -"""""""' •1•1•1•1 ~TRICAL --.nociUNDIENT DEVIL CANYON CONSTRUCTION SCHEDULE FIGURE 10.2 -11 -ECONOMIC, MARKETING, AND FINANCIAL EVALUATION 11.1 -Introduction The purpose of this section is to document the changes and further studies which have taken place since the publication of the Feasibility Report (Acres 1982a). There have been few changes in the financial studies presented. For the FERC 1 icense application, a calculation for the cost of power was made and a financing plan was selected as the most probable. In August, a report reviewing the Feasibility Study from a financial purview was published by Arlon Tussing and Associates. The findings of this report prompted a reassessment and update of several underlying factors in the financial and risk analyses. The results of those con- siderations are presented in Subsection 11.5. The third area of update is in the generation planning studies which formed the basis of the project economic analysis. One critical factor of change is in the cost of the projects. The impact of the cost change on the economic and financial analyses has been addressed. Similar to project costs, a change in the proposed project operation has been made s ·j nee the Fe as i bil i ty Report. The change resulted from mitigation studies involving the maintenance of downstream flows for fishery spawning. As a result of the operation change, the energy produced by the plant and the monthly distribution has changed. The impacts of this shift on project economics have been reviewed. The primary tool used for generation planning studies is the General Electric Optimized Generation Planning (OGP) simulation model. Version 5 of the model was used for the feasibility report analysis. In May 1982, GE released Version 6 of the program. The changes in the program and its impacts on study results have been checked and documented in Subsection 11.6. Finally, there were several issues raised in reviews of the Feasibility Report. These issues included the assessment of Watana, Devil Canyon, and Chakachamna as single projects and an alternative staging from the recommended plan. They are: The impact of changing probabilities in the multivariate sensitivity analysis; A discussion of percent reserve margins; -Annual system cost components; and -Delay of the project. The following subsections address each of the areas mentioned i n d i v i du a 11 y • 11-1 11.2 -Cost of Power One requirement of Exhibit D of the FERC 1 icense application was for an annual cost to be presented. As a two-stage (Watana and Devil Canyon) development with varying levels of energy output and the assumption of ongoing inflation (at 7 percent per annum), the real cost of Susitna power will be continually varying. As a consequence, no si~ple, single-value real cost of power can be used. For the purposes of the application, the following cost was adopted. Table 0.9 in Exhibit D (Acres 1983) gives the year-by-year projected energy levels on the first line; and on the second, the year-by-year unit cost of power in 1982 dollars. Costs are based on power sales at cost assuming 100 percent debt-finance at 10 percent interest. This is seen to resu)t in a real cost of power of 122 mills in 1994 (first "normal" year of Watana), falling to 73.95 mills in 2003 (the first "normal" year of Watana and Devi 1 Canyon). The real cost of power would then fall progressively for the whole remaining life. The cost of power given in Table 0.10 in Exhibit D (Acres 1983) is designed to reflect as fully as possible the economic cost of power for purposes of broad comparison with alternative power options. It is, therefore, based on the capacity cost which would arise if the project were 100 percent debt-financed at market rates of interest. It does not reflect the price at which power will be charged into the system. 11.3 -Financing Plan In the Feasibility Report, several plans were presented for financing the Susitna project. At this time, one plan has emerged as the most likely. This plan is presented in the FERC license application (Acres 1983). The financing of the Susitna project is expected to be accomplished by a combination of direct state-of-Alaska appropriations and revenue bonds issued by the Power Authority but carrying the "moral obligation" of the State. On this basis, it is expected that project costs for Watana through the end of 1989 will be financed by $1.8 billion (1982 dollars) of state appropriations. Thereafter completion of Watana is expected to be accornpl ished by issuance of approximately $2.4 bill ion (1982 dollars) of revenue bonds. The year-by-year expenditures in constant and then current dollars are detailed in Table 11. I. These annual borrowing amounts do not exceed the Authority•s estimated annual debt capacity for the period. The revenue bonds are expected to be secured by project power sales contracts, other available revenues. and by a Capital Reserve Fund (funded by a State appropriation equal to a maximum annual debt service) and backed by the "moral obligation" of the state of Alaska. 11-2 - - - - - - , ... _, I The completion of the Susitna project by the building of Devil Canyon is expected to be financed on the same basis requiring (as detailed in Table 11.1) the issuance of approximately $2.1 billion of revenue bonds {in 1982 dollars) over the years 1994 to 2202. Summary financial statements based on the assumption of 7 percent inflation and bond financing at a 10 percent interest rate and other estimates in accordance with the above economic analysis are given in Table 11. 2. The actual interest rates at which the project will be financed in the 1990s and the related rate of inflation evidently cannot be determined with any certainty at the present time. A material factor will be securing tax-exempt status for the revenue bonds. This issue has been extensively reviewed by the Power Author- ity•s financial advisors, and it has been concluded that it would be reasonable to assume that by the operative date the relevant require- ments of Section 103 of the IRS code ~·10uld be met. On this assumption, the 7 percent inflation and 10 percent interest rates used in the analysis are consistent with authoritative estimates (Data Resources Inc. July 1982)' forecasting a Consumer Price Index (CPI) rate of inflation 1982-1991 of approximately 7 percent and interest rates of AA Utility Bonds (nonexempt) of 11.43 percent in 1991 dropping to 10.02 percent in 1995. 11.4 -Change in the Cost Estimate ·As discussed in Section 9, the cost estimate has been revised to reflect adjustments to the project made since the Feasibility Report. The following summarizes those estimated changes. January 1982 $ x106 License Feasibility Application Percent Studx Estimate Estimate Change Change Watana 3647 3596 (51) ( 1. 4) Devil Canyon 1480 1554 74 5.0 Total 5127 5150 23 0.44 Because of the relatively minor changes in the cost estimate, no changes have been made in the financial analysis. Since the Watana project cost has decreased and it is the more critical project to finance, and, since it is the first to be constructed, the change would in theory make financing easier. However, because of the minimal change in numbers, the impact on the financial projections is insigni- ficant. 11-3 11.5 -Comments from "Review Report" After publication of the Feasibility Report, a report entitled 11 Alaska Energy Planning Studies-Substantiative Issues and the Effects of Recent Events,11 a review by A. R. Tussing and G. K. Ericson, was pre- pared for the Division of Policy Development and Planning, Office of the Governor of the State of Alaska. This dociiJlent, 11 Alaska Energy Planning Studies-Substantiative Issues and Effects of Recent Events 11 (the review), covered four reports sub- mitted to Alaska state agencies including the draft Susitna Hydro- electric Project Feasibility Report. After publication of the review, a commentary responding to comments was prepared. This subsection is a summary of the key comments and responses. This summary confines itself to the review only of the feasibility report study and related data. It does not respond to the comments made in the review on data developed by Battelle and the Institute of Social and Economic Research, University of Alaska. The review commentary deals with: World Oil Prices: long-term future of world oil prices. -Alaskan Fossil Fuel Prices: market prices versus opportunity values, linkage between coal and oil prices, and linkage between gas and oil prices. -Reliability of Susitna Construction Cost Estimate: construction cost estimates, and risk analysis. -Financing Issues: real discount and interest rates. These issues are identified as those requiring further treatment to deal with apparent misunderstandings and need for further comment aris- ing from the review. The summary here presents the issue and commen- tary in support of the feasibility report relative to the issues. (a) World Oil Prices, Long Term The review asserts that oil price forecasts are too high and suggests that real (inflation-adjusted) prices wi 11 continue to be be1ow 1982 levels for the remainder of the century. Price forecasts used in the feas·ibil ity report were adopted from the Battelle Alternatives Study. Nonetheless, an updated check of forecasting was done to confirm or indicate the necessity for changes in the oil price base used in the feasibility report. The results of the survey of forecasts is presented in Table 11.3. 11-4 - - - ~I - - - - - (b) The forecasts used in the report are in close agreement with those of all the major forecasting organizations shown in Table 11.3. The forecasts are all of recent date and take into account all recent trends. Thus, one piece of evidence cited in the review is that Data Resources, Inc. (DRI) now forecasts a decline in Europe•s oil con- sumption during the rest of this century, while today there is an excess oil-producing capacity in the world. Such partial analysis cannot lead to the conclusion that oil prices will decl·ine over the next 20 years. This requires consideration of the future levels of oil demand outside Europe: worldwide supply/demand con- ditions, etc. DRI, taking all such factors into account, supports the position taken in the report with a forecast of 2.8 percent growth in real terms. A second factor cited by the review is the sealing down of oil price projections by the Alaska Department of Revenues in its Petroleum Production Revenue Forecast. The state•s forecasts made in the spring of 1982 point to declining real oil prices through 1998. Of the numerous eminent authorities engaged in long-term energy forecasting, this alone is cited by the review. Table 11.3 summarizes all the major forecasts for comparison with the report •s base case scenario of 2 percent real escalation, bounded by low and high scenarios of 0 percent and 4 percent, respectively. Of the 16 authorities surveyed, only one presented a case with long-term declining real oil prices. Although a wide range of oil prices is reflected in these projec- tions, it is clear that with the single qualification already noted, they are all calling for positive real growth in world oil prices over the long-term horizon required for power planning studies. The report did not, however, exclude the possibility of zero real growth in oil prices; it merely assigned it a lower possibility of 25 percent compared with the 50 percent probability assigned to the 2 percent growth case. It is Acres assessment that the review does not present a case for rejecting this assessment (and the similar forecasts shown in Table 11.3) and effectively assigning 100 percent probability to the zero growth scenario. A 1 ask an Foss i 1 Fue 1 Prices (i) Market Prices Versus Opportunity Values An issue raised by the review was the assessment of prob- able future costs of fossil fuels for generation in the Railbelt from local coal or gas supply conditions. Both the Feasi bi 1 ity Study and the Battelle study reviewed the prior studies made of Beluga coal costs and worldwide coal production cost estimates. The use of production 11-5 costs for natural gas and coal would be wholly appropriate and desirable for the financial analysis of a power project from the narrow perspective of private investors or owners. As a public project, however, Susitna should be, and was, appraised from the point of view of the state as a whole and valued the fossil fuels at its opportunity cost in terms of potential exports. It is for this reason that Acres supported the net-back approach in which the value of coal and natural gas in Alaska was determined as the c.i.f. (landed) price in the most likely (East Asian) market less the cost of transpor- tation from Alaska to that market. {ii) Linkage Between Coal and Oil Prices The review is critical of the approach whereby 11 both con- tractors have deduced their price assumptions for Railbelt coal and gas wholly from forecasts of oil prices in Japan.11 The statement may be misleading as, in fact, it is the real growth rates in coal and gas export prices that are esti- mated, in the most 1 ikely case, to equal real rates of world oil price escalation. Base period (1982) opportunity values of coal and gas were determined (as shown above) independently of oil prices. In the most likely (base) case, it forecasts that there waul d be no change in rel a- tive prices; that is, the 1982 price ratios among oil, gas, and coal would be maintained during the planning period. This estimation is supported by forecasts of coal and natural gas prices provided in the report. A moving average of coal/oil price ratios exhibits relatively little fluctuation over the 8-year period. (There is an estimated probability of over 65 percent that the ratio is 0.42 .:!.:_0.04.) (iii) Linkage Between Gas and Oil Prices The emphasis of the criticism of Feasibility Report assump- tions relating to natural gas is centered on the fact that the current price of Cook Inlet natural gas is signifi- cantly below the 11 0pportunity value 11 suggested in the report, and that this price is not expected to increase to levels in line with the opportunity value. It is main- tained that 11 Cook In 1 et gas prices will be established largely on the basis of factors local to the region,11 and thus, these prices wi 11 be insula ted from the effects of world price movements. Regardless of whether Cook Inlet gas prices do or do not equal opportunity values, the results of the Susitna public cost/benefit analysis would not be altered. In fact, it is 11-6 - """" I - - - - (c) - 1 I only the opportunity values which are of relevance, and the Cook Inlet domestic gas prices at any point in time should not be an issue of any concern in, an analysis of net economic benefits. This results solely from the fact that, if export markets exist for LNG at the prices which have been determined in the Report, then it must be assumed that the rational gas producer in Alaska would select the opportunity to receive the highest price that is offered for the gas. Reliability of Susitna Construction Cost Estimates (i) Construction Cost Estimates A third area of concern expressed in the review was the reli- abi 1 ity of the project capital cost estimate. The concern appears to be based on generalizations stemming from the "mega project" experience of the last decade. This questioning does not appear to be founded on any detailed data or experience of hydroelectric power develop- ment engineering and construction. The only specific mega projects cited to justify allegations of "misplaced specif- icity, subjectivity, and over-optimism, institutional blind spots, and underallowance for noncompletion" in the Acres construction cost estimate are the Trans Alaska oil pipeline and the Washington Public Power Supply System nuclear reactor program. It is Acres view that neither of these projects has any practical bearing on a site-specific, basically conven- tional engineering hydroelectric power development such as Susitna where the project estimate has been as extensive, evaluated and assigned as high a confidence level as in the Susitna case. Cost-estimate review on a risk basis was conducted in the Feasibility Report by relating to a list of projects compiled by an external source. It is recognized that this approach did not include major hydroelectric projects in northern areas, nor did it reflect the Acres experience in project cost-estimating. To provide further support for the project cost estimate, Acres experience on a project simi 1 ar to Susitna was reviewed. Table 11.4 provides in detail a review of Acres Church"l"fl Falls Hydroelectric Power Project estimate versus outcome. Two estimates of costs ar~given. The first, for 1963, is in the nature of an early stage feasibility estimate~ while the second, for 1968, is a final, pre-contract estimate broadly comparable in confidenc~ level to that produced in the Susitna Feasibility Report. It is seen that, reduced to 11-7 comparable purchasing power (1963 dollars), the 1963 estimate is at variance from the final cost by 4.2 percent. This favorable (negative) variance has to be viewed, furthermore, in light of the fact that between 1963 and 1968 there was an increase from 10 to 11 in the number of hydroelectric units and an increase in the rating of all generators from 450 MW to 475 MW. The Churchill Falls Power Development in Labrador, Newfound- land, is a 5225 MW development in a remote area. It is comparable to Susitna as a giant hydroelectric project. It will be noted that in place of the single large dam which creates the operating head and storage reservoir for Watana, a large number of fill structures were constructed at Churchill Falls with an aggregate length of over 42 miles and volume of more than 40 million cubic yards. Construction work spread out over 2500 square miles of reservoir area was inherently more difficult to control than a concentrated development area such as Watana. Other examples of estimate/final cost comparisons uphold Acres record of performance on major hydroelectric power projects in northern latitudes and at remote sites. (d) . Real Discount and Interest Rates The review took issue with the standard methodology by which Acres derived the 3 percent real discount rate used in the cost/benefit analysis in the feasibility report (Section 18.3 to 18.21) and argues for 4.5 percent as the appropriate rate. The 3 percent discount rate was derived from two sources. First, it was given as a guideline for economic evaluation by the Depart- ment of Commerce of the State of Alaska. The second source was the generally accepted studies summarized on page 18.4 of the Feasibility Report. It is clearly possible to question the standard methodology giving rise to this parameter. Here, as in other parts of the study, however, it was study pol icy to avoid unnecessary controversy by not questioning accepted methodology or guidelines unless the alternative approaches materially affected Acres conclusions. A more precise approach is that of determining the Project Speci- fic Rate (PSR). This is done by first estimating the weighted average interest cost of project borrowing and the opportunity interest cost of any funds provided by the state of Alaska, with the weightings being the proportions of these two types of capi- tal •. This weighted average is then converted into a real discount rate (approximately) by deducting the relevant rate of inflation. The interest rates used would be those obtained at the time that the capital is to be raised; and the rate of inflation, the long- term rate expected over the life of the borrowing. 11-8 ...... - - - """'~\ I - - -On the basis of the DRI forecasts and on the assumption that the opportunity cost of state-provided funds is the interest rate forecast for federal government securities while the project borrowing is in the form of tax-exempt bonds (see Table 18.22 in the Feasibility Report), the weighted averaged interest rate with the state appropriation of $2.3 bill ion can be determined. The DR I forecast interest rate on federal funds and on tax-exempt bonds, both over the relevant capital raising periods and un- weighted, are 10.4 percent and 8.1 percent, respectively. This gives a weighted average PSR of 9.1 percent in money terms. The long-term forecast rate of CPI inflation from 1985 to 1995 (again as given by DRI) varies between 7.1 (1985-90) and 6.5 per- cent (1990-95). No forecast is given for the post-1995 period. The implied real rate of interest relevant to the cost/benefit at a long-term inflation rate of 6.5 percent is, therefore, approxi- mately 9.1 -6.5 = 2.6 percent. At these rates of inflation, therefore, this alternative methodology, using DRI data, does not support a higher discount rate than the 3 percent discount rate used in cost/benefit analysis carried out for the feasibility study and dealt with in the report. The position taken in the review is that the discount rate should be that at which the project is financed. This is the PSR approach just described. As such, it produces a lower (not higher) rate than that used in the Acres analysis. The review suggests, however, that the appropriate rate is 4.5 percent on the grounds that this is the DRI forecast of real interest rates on corporate bonds* in 1992. Since the project is not being financed by corporate bonds but by tax-exempt bonds and by the state of Alaska, it cannot be argued that this 4.5 percent has any relevance. The relevant tax-exempt and federal bond rates consistent with the 4.5 percent corporate bond rate give the result outlined above. It would also be noted that the DRI 4.5 percent real interest rate on corporate bonds is very much higher than the Wharton or Chase forecasts or indeed any of the other main forecasting agencies. These are generally in the range of 3-2.4 percent. If these fore- casts, rather than the DRI forecast used above, are accepted, then, taking into account the advantages of tax exemption, the 3 percent discount rate used for the Sus itna cost/benefit analysis is conservative in that the appropriate PSR should be significant- ly lower. This became apparent in the course of the Acres analysis but was not pursued, since it merely had the effect of reinforcing rather than controverting the conclusions reached. In summary, it appears to Acres that the review is mistaken as to the outcome of the methodology which it proposes and that, cor- rectly stated, this methodology (which Acres stresses is only an approximation) gives a result which would argue that the discount rate promulgated by the Alaska Department of Commerce and used by Acres is too high, not too low. * Using the CPI and not IPD, the rate is 4.0 percent. ll-9 11.6 -Generation Planning After circulation of the feasibility report, several items of work were accomplished in response to questions and comments. These involved the following areas of analysis: -Multivariate analysis-sensitivity of load probability; -Changes to the generation planning model; -Impacts of project changes; and Other issues. Each of these areas is explored individually in the following text. (a) Multivariate Analysis -Sensitivity of Load Probability To account for variance in forecasting, the economic analysis was approached on a probabilistic basis. Several key variables were chosen; a range of low, medium, and high variable values were estimated; and probabilities were assigned to each value. A pro- bability tree was constructed with each combination of variables assigned a resultant probability. The original analysis is discussed in more detail in Section 18 of the feasibility report. The multivariate sensitivity analysis analyzed the four variables: load forecast, alternatives capital cost, fuel cost escalation and Susitna capital cost; and assigned a range of probabilities to each. Some concern has been expressed regarding the likelihood of the probability distribution being different from the assumed "base case" of 0.20, 0.60, and 0.20 for the low, medium, and high load forecast scenarios. A recalculation of the probabilities was made using the distribution 0.60, 0.30, and 0.10. Tables 11.5 and 11.6 summarize the calculation for the non-Susitna and Susitna trees. The results of the analysis show that the expected value of net benefits is $971 million. This is a result of the difference in the non""Susitna and Susitna plans ($7 ,624 -$6,653 = $971). Compared to the base case multivariate analysis, the $971 million expected value is approximately 33 percent less than the base case value of $1,450 million. Figure 11.1 plots the net benefit curves. (b) Changes to the Generation Planning Model In May 1982, General Electric released Version 6 of the OGP Pro- gram. Version 5 of the program was used as the primary tool for the generation planning studies for the feasibility report. Several changes were made to the program in Version 6 in response to user comments. These include a possible 30-year study period (replacing 20), more options for maintenance scheduling, and increased program flexibility. Two changes particularly relevant 11-10 - - - - - - - - (c) - - ~I (d) to the Susitna analysis are the possibility of economic overbuild- ing (adding units on an accelerated schedule) and carryover of excess hydropower from wet months to dry months. The latter gives a more favorable (and accurate) value to the potential hydro energy produced by the project. In order to test the impact of these terms on the results of the generation planning, the base c~se, with and without Susitna, was reanalyzed with OGP-6. Table 11.7 summarizes the results. The results were reduced to a long-term cost in a manner identical to the feasibility report. The revisions in the program had no impact on the non-Susitna case. For the with-Susitna case, the increased value of the hydro energy increased net benefits by about 5 percent. Impact of Project Changes Two changes in the project affecting economic analysis have taken place since completion of the Feasibility Report; a change in cost estimate, and a change in operation schedule. The change in the cost estimate is small. The most current esti- mate for the total project in 1982 dollars is $5,150 million, 0.44 percent higher than the feasibility estimate. The cost of the Watana project went down $51 million, while the Devil Canyon cost went up $74 million. These minor changes would have a negligible impact on the results of economic studies. Therefore, no revision in analysis or sensitivity to cost-change data tests were done. After completion of the Feasibility Study, a major focus of in- stream flow study was the selection of a project operation scheme with mitigation of downstream filling impacts as an objective, along with optional power production. A series of cases were tested with flows varying from optimal energy production to 11 no- impact11 case. A case which fell into the middle of these extreme was selected. The net benefit of this case are $114 mill ion as compared to $1176 million. This 3 percent difference in net bene- fit did not warrant a full revision of the economic study. Other Issues After completion of the Feasibility Report, several comments were raised which required additional study or explanation. Those issues are presented in the following paragraphs. (i) Discussion of Percent Reserve Margin In planning system electrical need, there are a number of methods that can be used to measure a system•s reliability and determine the need for the addition of capacity. It is common utility practice to plan to a statistical measure of 11-11 reliability: loss of load probability (LOLP) in conjunction with some minimum percent reserve margin. Computation of LOLP involves probabi 1 i sti c forced outage rates, planned maintenance, peak load, and reliable energy considerations. LOLP is commonly expressed as a loss in days per year or, in some systems, hours per year depending on the size of individual units in the operating system. Percent reserve margin can also be calculated in a variety of ways relating capacity, load, contracts for power exchange, and the largest units on the system to a single measure of avail- able capacity. In modeling the Alaskan Rai"lbelt System for generation planning studies, the LOLP criteria of 0.1 day per year was used as the 11 trigger point" for capacity additions. In other words, in every year, the OGP model calculates the system reliability LOLP without any additions. If the system as it exists violates the LOLP criterion of 0.1 dayjyear, the model then examines combinations of available alternative unit capacity additions that would meet this reliability criterion. From these alternative system mixes, the least cost (or production cost optimal choice) is selected and the system is operated for the following year. At this time, the percent reserve margin is calcula- ted for that year using the equation: percent reserve = capacity -load 1 oad in the peak month (December in the Rail belt System) Therefore, the calculation of percent reserve in this con- text is independent of the "need" for capacity which is determined by the LOLP criterion. Alternatively, the OGP model can plan to a percent reserve margin and calculate LOLP after expansion has been made. However, this option was not exercised because of the variety of methods for computing percent reserve and the difficulty in arriving at a consensus on a reliable percent reserve resulting from the system size. An alternative method of calculating reserve margins involves subtracting the largest unit of capacity out of the total available system capacity. Other methods sub- tract the largest "string" of intertied units from the total capacity to arrive at a reserve margin. In any case, the percent reserve is merely a simple statistic of avail- able capacity to meet load regardless of "acts of God" and forced outages. 11-12 - - - ( i i ) 1"'1 Table 11.8 summarizes the two sets of statistics for the medium-load, forecast-base non-Susitna and Susitna plans. The planning criteria were LOLP less than 0.1 day per year, and percent reserve was calculated using the noted equation. Figure 11.2 plots percent reserve versus time for the two plans. The following paragraphs discuss the variations among plans. As previously mentioned, the system model examines the available units for addition in a year when reliability is not met. In the first year of the study, 1993, the units available for the non-Susitna plan are 200-MW coal, 200-MW combined cycle, 70-MW gas turbine, and 10-MW diesel units. Of these, a single 200-MW unit meets the LOLP criterion in the most cost-effective manner. In the Susitna plan, the Watana project added in a single stage is 680-MW, which is considerable for that particular year; however, as load grows and existing units retire, percent reserve decreases. No other units are needed in the system. In year 2002, additional capacity is needed. The Susitna plan adds the 600-MW Devil Canyon project which again raises the percent reserve. The non-Susitna plan has the capability to add only small increments of capacity relative to the Susitna project. The addition of 200-MW or smaller units meets reliability criteria with a smaller reserve margin. As Susitna is added in 600+ MW increments to take advantage of its full energy potential, the reserve margin becomes very 1 arge. Much of the reserve margin capacity rests idle from 1993 on. In year 2010, the non-Susitna plan has a calculated LOLP of 0.099 indicating that criterion is nearly violated in that year. This LOLP corresponds to a percent reserve of 32.5 percent, which indicates the level of capacity installation over LOLP needs. In both plans, the percent reserve is always above this level, varying as the various size units are installed. Annual System Costs Each year the OGP model dispatches available energy genera- tion to meet load. Table 11.9 shows the annual energy dispatch in GWh by generating unit type for the two plans. Figure 11.3 shows the annual system costs plotted for the two plans. This figure represents the initial cost of the Watana project having higher system cost during the first few years, remaining about the same during the years 1996 to 2001, and showing significant savings in the years 2003 to 2010. 11-13 (iii) Annual System Cost Components The annual system costs consist of a number of components: Investment Costs: O&M: Fuel Costs: Non-Susitna Co a 1 NGGT Coal Combined Cycle NGGT Other Hydro Di ese 1 s Coal GT Natural Gas CC Natural Gas Oi 1 Sus itna Susitna NGGT Sus i tna Combined Cycle NGGT Other Hydro Diesels GT Natura 1 Gas CC Natural Gas Tables 11.10 and 11.11 list the annual yearly costs by com- ponents for the non-Susitna plan and the Susitna plan. Figures 11.4 and 11.5 depict the components graphically. The most dramatic comparison is the portion of Susitna investment cost versus the coal investment and fuel cost components in the non-Susitna plan. Figure 11.6 plots the annual system long-term costs for both plans during the 1993 to 2010 system modeled period and the 2011 to 2051 economic extension period. (iv) Discussion of Delay of Project The Railbelt system technically needs capacity installation in December 1992 to meet the LOLP reliability criteria. However, Acres has scheduled the study to start in 1993, suggesting that the December 1992 peak would be met by extending one or two retiring units until major new units are on line in January of 1993. Delaying vJatana Stage One to 1994, therefore, poses a problem, since it is necessary to have some type of capacity in 1993. Two impacts occur when a Susitna project stage is delayed. First, there is an increase in fuel costs during the year of delay to make up generation not provided by Susitna. For ex amp 1 e, with Watana, in 1993, fuel costs are $25 million. Without Watana and using two.new natural gas tur- bines, fuel costs are $128 million in 1993. Second, there is a decrease in Sus itna investment cost present worth. For example, $100 invested in 1993 is $76 in 1982 dollars. One hundred dollars invested in 1994 is $74 in 1982 dollars at a 3 percent discount rate. 11-14 - - - - - ( v) The lowest production cost alternative in 1993 is a 200-MW coal unit. However, this unit, followed by the large Watana project in 1994, is only used one year, hardly a justification for building a large plant. Alternatively, two 70-MW gas turbines can be installed in 1993, run to meet peak until Watana comes on line, then used as standby until the later years. This system plan (C3) is shown in Table 11.12. This plan reduces net benefits approximately 4 percent to $1,133 million. Delaying both stages of the Susitna plan one year results in essentially the same net benefit as the previous case. This plan (C4) has a long-term (LTC) cost of $7,165 million. However, it must be compared to a without-Susitna plan which has been extended to year 2053 rather than 2052, since the Susitna project life is 50 years from the year Devil Canyon is installed. This modification makes the non-Susitna plan LTC $8,299 million; therefore, net bene- fits are $1,134 million. Delaying both stages of the project two years (plan C5) increases fuel costs in years 1993, 1994, 2002, and 2003 as the result of dispatching of thermal units to meet load. Again, the net impact is partially offset by the decrease in present worth of Susitna costs; and the net benefits are $1,130 million, 4 percent less than the base case. Watana Project Alone Only the Watana projections were examined in the medium- and low-load forecast cases. Table 11.13 summarizes these plans. Under the medium-load forecast, the Watana only project was tested at two installed capacities: 680 MW and 1020 MW. Although the larger capacity plan displaced some additional capacity and since no additional average or firm energy is associated with these units, the net effect is a negative benefit of $102 mill ion. The second stage of Watana was capital cost of the $58.8 million. The low-load forecast plan shows a negative net benefit of $96 million for the Watana-only scheme. Two notes on the calculation of net benefits and long-term cost are: (1) When comparing Watana-only project plans with the base case alternative plan, it is necessary to compute the LTC cost to year 2043, when Watana is installed in 1993 (medi urn-1 oad case), and 2045, when Watana is installed in 1995 (low-load case). 11-15 (2) When a Susitna plan installs a 200-MW coal plan in the planning horizon, it is necessary to add in the cost of a Beluga transmission tie in the year it is added, calculated in 1982 dollars. This cost was estimated as $53.5 million (from the upper limit capital cost report, July 1981), and is added to the long-term cost. (vi) Alternative Railbelt Hydro Assessment Previously, the Development Selection Report (DSR) examined various alternative developments of the Susitna Basin. The Watana/Devil Canyon selection was chosen as the least-cost, long-term generation plan. This assessment reviews some of the possible alternatives, using the same criteria as the Susitna feasibility study and updated data on the hydro- power alternatives. Generation plans were developed for the following scenarios and long-term costs compared to the base case without-Susitna plan. -Devil Canyon -Watana -Chakachamna -De vi 1 Canyon -Chakachamna -Watana -Watana only -Devil Canyon only -Chakachamna only -Devil Canyon -Watana Reverse staging of the Susitna project has some unique cost implications. First, the possibility exists that the Devi 1 Canyon project could be on 1 i ne sooner than 1993, perhaps as early as late 1991. This situation was not modeled; however, in the without-Bradley Lake case, it may reduce the 1 ong-term cost and increase net bene- fits over the value presented here. Second, the interim years between Devil Canyon (1993) and Watana (2002) require additional capacity to be added. Five 70-MW gas turbines are needed to supply energy to the system. Capital Cost (i ncl udi ng IDC) impacts of Devil first followed by Watana are summarized below: Canyon Watana Devil Canyon Total 1982$ X 106 $4,094 1,631 $5,725 Devil Canyon $2,203 Watana 3,558 $5,761 Building Devil Canyon first increases the cost compared to a later staging because of additional adjustments of transmission, intakes, diversions, cofferdams, access roads, and site facilities. 11-16 - - - - - 1 I I Total energy impacts of Devil Canyon first compared to Watana/Devil Canyon are as follows: Watana Devil Canyon Total Available Energy, GWh 3,459 2,631 3,334 2,763 6,793 5,394 Devil Canyon Watana 2,585 2,264 4,208 3,130 6,793 5,394 Note that this is a tally of available energy which is slightly greater than usable energy by year 2010. The results of the generation plans for the base case - Watana/Devil Canyon and the reverse staging Devil Canyon/ Watana are summarized in Table 11.14. Long-term costs in the latter case increase by 4 percent over the Watana first case reducing net benefits to $896 million. -Chakachamna -Susitna The 330-MW Chakachamna hydroelectric project was also examined in the DSR. Two updated generation plans--one with the Chakachamna project in 1993 followed by Devil Canyon, the other Chakachamna followed by Watana--were analyzed under the same parameters as the feasibility study base case. Capital costs and energies were provi- ded by Bechtel, Alternative "B" with average annual ener- gy of 1,492 GWh, firm energy of 1,374 GWh, and a capital cost of $1,450 million including IDC and transmission costs. With the addition of Chakachamna in 1993, Devil Canyon can most effectively be staged in 1997 with further expansion of Beluga coal units in 2003 and 2010. Six 70-MW gas turbines are added in the post-2000 period. The total LTC (1993-2051) of this plan is $8,186 million as shown in Table 11.15. The Chakachamna-Watana generation plan was staged as 1993-2000, respectively, since Watana alone is a larger energy project than Devil Canyon. Addition a 1 capacity added are three 70-MW gas turbines and a 200-MW combined cycle unit. This plan has a 1993-2051 LTC of $8,241 million, with negative net benefits of $4 million when compared to the base case non-Susitna plan. The possibility of a Chakachamna-Devil Canyon-Watana or Chakachamna-Watana-Devi l Canyon plan was examined; how- ever, the excess capacity and energy provided in these scenarios, given the medium load forecast, are over 1,000 GWh and were, therefore, not modeled as such. 11-17 ------------~------------------ -Single Hydro Project Developments Three single development cases were examined under this topic: Watana, Devil Canyon, or Chakachamna alone. Table 11.15 summarizes energies, capital costs, and long- term costs for each of these scenarios. LTCs are com- puted for 50 years of the project. 11-18 - - -' -' - - - - REFERENCES Acres American Incorporated. 1982a. Susitna Hydroelectric Project Feasibility Report. Prepared for the Alaska Power Authority. 1983. Exhibit D. Susitna Hydroelectric Project FERC License Application- Prepared for the Alaska Power Authority. Data Resources Inc. July 1982. U.S. Long-Term Review. Lexington, Massachusetts. .-. TABLE 11.1: FINANCING REQUIREMENTS -$MILLION FOR $1.8 BILLION STATE APPROPRIATION 1994 Revenue Bonds 230 95 386 96 364 97 325 98 1085 99 1346 2000 1513 01 1377 02 269 Total Devil Canyon Bonds 6895 TOTAL SUSITNA BONDS 11402 99 155 136 114 355 412 433 368 67 2139 4517 TABLE 11.2: $1.8 BILLION (1982 DOLLARS) STATE APPROPRIATION SCENARIO P~ge 1 of 3 7% INFLATION AND 10% INTEREST 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 CASH FLOW SUMMARY ($Million) 5n Energy GWH 0 0 0 0 0 0 0 0 3387 3387 Real Price-Mills o.oo o.oo 0.00 o.oo o.oo o.oo 0.00 0.00 50.85 62.99 466 Inflation Index 126.72 135.59 145.08 155.24 166.10 177.73 190.17 203.48 217. 73 232.97 520 Pr 1 ce-Mill s o.oo o.oo o.oo o.oo 0.00 0.00 o.oo o.oo 110.73 146.75 INCOME 516 Revenue o.o o.o o.o o.o 0.0 o.o o.o o.o 375.0 497.0 170 Less Operating Costs 0.0 o.o o.o 0.0 0.0 o.o 0.0 o.o 26.9 29.3 517 Operating Income 0.0 0.0 o.o o.o o.o 0.0 o.o o.o 348.1 467.7 214 Add Interest Earned on Funds o.o 0.0 o.o 0.0 o.o o.o o.o 0.0 o.o 5. 6 550 Le~s Interest on Short-Term Debt 0.0 o.o o.o o.o o.o o.o 0.0 o.o 0.0 16.1 391 Less Interest on Long-Term Debt o.o o.o o.o o.o 0.0 o.o o.o o.o 411.1 444.4 548 Net Earnings From Opers o.o o.o o.o D.O o. 0 o.o o.o o.o -63.0 12.8 CASH SOURCE AND USE 548 Cash Income From Opers o.o o.o o.o D.O o. 0 0.0 o.o o.o -63.0 12.8 446 State Contribution 403.7 472.7 479.7 499.5 797.9 o.o 0.0 0.0 o.o 0.0 143 Long-Term Debt Dravldowns o.o o.o o.o 0.0 140.4 1564.4 1417.6 988.6 396.1 229.7 248 llorcap Debt Drawdowns o.o o.o o.o o.o o.o 0.0 o.o o.o 98.0 17.7 549 Total Sources of Funds 403.7 472.7 479.7 499.5 938.3 1564.4 1417.6 988.6 431.1 260.2 320 Less Capital Expenditure 403.7 472.7 479.7 499.5 938.3 1564.4 1417.6 988.6 333.1 259.2 448 Less Worca~ and Funds o.o o.o 0.0 o.o o.o o.o 0.0 o.o 98.0 17. 7 260 Less Debt epayments o.o o.o o.o o.o 0.0 o.o o.o o.o 0.0 16.4 141 Cash Surplus (Deficit) o.o o.o o.o o.o o.o o.o o.o o.o o.o -33.1 249 Short-Term Debt o.o o.o o.o o.o 0.0 o.o 0.0 0.0 o.o 33.1 444 Cash Recovered o.o o.o o.o o.o o.o 0.0 0.0 o.o 0.0 o.o BALANCE SHE£ T 225 Reserve and Cont. Fund o.o o.o o.o 0.0 o.o o.o o.o o.o 56,5 61.6 371 Other Working Capital o.o o.o o.o o.o o.o o.o 0.0 o.o 41.5 54.1 454 Cash Surplus Retained o.o o.o o.o o.o o.o o. 0 o.o o.o o.o o.o 370 Cum. Capital Expenditure 403.7 876.4 1356.1 1855.6 2794.0 4358.4 5775.9 6764.6 7097. 7 7356.9 465 Capital Employed 403.7 876.4 1356.1 1855,6 2794.0 4358.4 5775.9 6764.6 7195.7 7472.6 461 State Contribution 403.7 876.4 1356.1 1855.6 2653.5 2653.5 2653.5 2653.5 2653.5 2653.5 g62 Retained Earnings o.o o.o 0.0 o.o o.o o.o o.o 0.0 -63.0 -50.2 555 Oebt Outstanding -Short Term o.o o.o o.o 0.0 o.o o.o 0.0 o.o 161.0 211.8 554 Debt Outstanding -Long Term o.o o. 0 o.o o.o 140.4 1704: 8 3122.4 4111.0 4444.1 4657.4 542 Annual Debt Drawdown $ 1982 o.o o.o o.o o.o 84.5 880.2 745.4 485.8 181.9 98.6 543 Cum. Debt Drawdown $ 1982 o.o o.o o.o o. 0 84.5 964.7 1710.1 2196.0 2377.9 24 76.5 519 Debt Service Cover 0.00 o.oo 0.00 o.oo o.oo o.oo o.oo o.oo 0.85 0.99 ] _ _) .J j J ) TABLE II.2 (Cont'd) Page 2 of 3 I995 I996 I997 I998 I999 2000 200I 2002 2003 2004 CASH FLOW SUMMARY ($Mill ion) 73 Energy G~IH 3387 3387 3387 3387 3387 3387 3387 5223 54I4 5605 52 I Real Price-Mills 61.36 69.57 65.59 6I.68 58.03 54.6I 5I.40 63.57 59.90 62.52 466 Inflation Index 249.28 266.73 285.40 305.38 326.75 249.62 374.IO 400.29 428.3I 458.29 520 Price-Mills I52.95 I85.56 I87 .I8 I88.34 I89. 6I I90.92 I92.30 254.4 7 256.58 286.53 INCOME 5I6 Revenue 5I8.0 628.4 633.9 637.9 642.2 646.6 65I. 3 I329.0 I389.0 I605. 9 I70 Less Operating Costs 32.0 35.0 38.I 4I.6 45.4 49.6 54.I 9I.I 99.4 I08.5 5I7 Operating Income 486.0 593.5 595.8 596.2 596.7 597.0 597.2 I237.9 I289.6 I/197.4 2I4 Add Interest Earned on Funds 6.2 6.7 7.3 8.0 8.7 9.5 I0.4 II.4 I9.I 20.9 550 Less Interest on Short-Term Debt 2I.2 24.2 27 .I 28.2 29.5 30.5 3I.6 32.8 45,6 48.4 39I Less Interest on Long-Term Debt 442.8 44I.O 439.0 436.8 434.4 43I.8 428.9 I088.3 111. 8I 1105.3 548 Net Earnings From Opers 28.2 I35. 0 I37.0 I39.2 I4I. 6 I44.3 I47.2 I28.I I5I.4 364.5 CASH SOURCE AND USE 548 Cash In come From Opers 28.2 I35.0 137.0 I39.2 I4I.6 I44.3 I47.2 I28.I I5I.4 364.5 446 State Contribution 0.0 o.o o.o 0.0 o.o o.o o.o o.o o.o o.o I43 Long-Term Debt Drawdowns 386.I 363.6 324.8 I085. 4 I346.9 I513.I I377.3 269.3 o.o o.o 248 Horcap Debt Drawdowns 8.I 29.3 11.2 I2.2 I0.6 I0.4 I2.3 I28.0 24.7 42.8 549 Total Sources of Funds 422.4 527.9 473.0 I236. 8 I499.I I667.8 I536.7 525.4 176.I 407.3 320 Less Capital Expenditure 4I8.2 478.8 440.0 I200.6 I462.I I628.3 I492.5 362.3 90.9 99.2 448 Less Worca~ and Funds B. I 29.3 11.2 I2.2 I0.6 I0.4 12.3 I28.0 24.7 42.8 260 Less Debt epayments I8.0 I9.8 2I.8 24.0 26.4 29.0 32.0 35.I 64.I 70.5 --- I4I Cash Surplus (Deficit) -22.0 0.0 o.o o.o o.o o.o 0.0 o.o -3.6 I94.8 249 Short-Term Debt 22.0 o. 0 o. 0 o. 0 o. 0 o. 0 o.o o. 0 3. 6 -58.7 444 Cash Recovered o.o 0.0 o.o 0.0 o.o o.o o.o o.o o.o I36.I BALANCE SIIEET 225 Reserve and Cont. Fund 67.2 73.4 BO.I 87.4 95.4 I04.I II3.7 I9I.3 208.8 227.8 37I Other Working Capital 56.6 79.7 84.2 89.I 9I.7 93.4 96.2 I46.6 I53.8 I77.6 454 Cash Surplus Retained o.o 0.0 0.0 0.0 0.0 0.0 o.o 0.0 o.o 0.0 370 Cum. Ca'pita 1 Expenditure 7775.I 8253.9 8693.9 9894.5 11356.6 I2984.9 I4477.4 I4839 0 7 I4930;5 I5029.7 465 Capital Employed 7898.9 8407.0 8858.3 1007l.I 11543. 7 I3I82.5 I4687.2 I5I77.5 I5293.I I5435.I 46I State Contribution 2653.5 2653.5 2653.5 2653.5 2653.5 2653.5 2653.5 2653.5 2653~5 2653.5 462 Retained Earnings -22.0 113 .• 0 250.I 389.3 530.9 675.I 822.3 950.4 110I. 8 I330.2 555 Debt Outstanding -Short Term 24I.9 27I.2 282;4 294.7 305.2 3I5. 7 328.0 455.9 484.3 468.4 554 Debt Outstanding -Long Term 5025.5 5369.2 5672.2 6733.6 8054.I 9538.I I0883.4 11117.6 11053.5 I0983.0 542 Annual Debt Drawdown $ I982 I54.9 I36.3 113.8 355.4 4I2.2 432.8 368.I 67.3 o.o o.o 543 Cum. Debt Drawdown $ I982 263I.3 2767.7 288I. 5 3236.9 3649.I 4081.8 4450.0 45I7 0 3 45I7.3 45I7 0 3 5I9 Debt Service Cover I.02 I.25 I.25 I.25 I.25 1.25 I.25 I.OB 1.07 1.25 TABLE 11.2 (Cant' d) Page 3 of 3 2005 2006 2007 2008 2009 2010 2011 20I2 20I3 TOTAL CASH FLOW SUMMARY ($Million) 73 Ener~ GWH 6092 6147 6250 6472 6544 6616 6638 6660 6682 104826 52 I Real rice-Mills 53.98 50.38 46.72 42.59 39.74 37 .II 34.95 32~ 91 31.02 0.00 465 Inflation Index 390.27 524.69 56I.42 600.72 642.77 687.77 735.91 78 7.42 842.54 o.oo 520 Pr 1 ce-Mi 11 s 264.68 264.32 262.31 255.84 255.46 255.2 5 257.23 259.I6 26I. 34 o.oo INCOME 516 Revenue 1612.3 1624.7 1639.3 !655. 7 I671. 6 1688.6 1707.3 I725.9 I746.1 24625.8 I70 Less Operating Costs 118.4 129.2 I4I.O 153.9 I68.0 I83.4 200.I 2I8.4 238.4 2202.0 5I7 Operating Income 1493.9 1495. 5 1498.3 1501.8 I503.6 I505.3 I507 .2 I507. 5 I507.8 22423.8 2I4 1\dd Interest Earned on Funds 22.8 24.9 27.1 29.6 32.3 35.3 38.5 42.0 45.9 4I2.4 550 Less Interest on Short-Term Debt 46.8 so. 5 55.6 6I.5 66.1 70.7 75.9 79.7 83.8 925.8 39I Less Interest on Long-Term Debt 1093.3 1090.5 1082.0 1072.6 1062.3 1050.9 I038.4 I024.7 1009.6 16744.9 548 Net Earnings From Opers 371.5 379.3 387.8 397.2 407.5 418.9 43I.4 445.I 460.3 5I65.4 CASH SOURCE liND USE 548 Cash Income From Opers 371.5 379.3 387.8 397.2 407.5 4I8.9 431.4 445.I 460.3 5165.4 446 State Contribution o.o 0.0 o.o o.o 0.0 o.o 0.0 o.o o.o 2653.5 143 Long-Term Debt Drawdowns 0.0 0.0 o.o o.o o.o 0.0 0.0 o. 0 o.o 11403.2 248 Worcap Debt Drawdowns 36.4 51.3 59.3 45.8 45.9 52.0 37.7 41.2 44.9 8I9.7 549 Total Sources of Funds 408.0 430.5 447.I 443.0 453.4 470.8 469.1 486.3 505.2 20041.9 320 Less Capital Expenditure I08.2 118.1 128.9 I40.7 153.6 I67. 6 I82. 9 199.7 217.9 I6447.4 448 Less Worca~ and Funds 36.4 51.3 59.3 45.8 45.9 52.0 37.7 41.2 44.9 819.7 260 Less Debt epayments 77.6 85.3 93.9 103.2 113.6 124.9 137.4 151.2 I66.3 1410.7 14I Cash Surplus (Def1c1t) 185.7 175.8 165.0 I53.3 140.4 126.4 11I.O 94.3 76.1 1364.1 249 Short-Term Debt 0.0 o. 0 0.0 o.o 0.0 o.o o.o 0.0 o. 0 o.o 444 Cash Recovered 185.7 175.8 165.0 I53.3 140.4 126.4 111.0 94.3 76.1 I364.1 BALANCE SHEET 225 Reserve and Cont. Fund 248.7 271.4 296.2 323.3 352.8 385.1 420.3 458.7 500.6 500.6 37I Other Working Capital 193.2 . 221.7 256.2 274.9 291.2 310.9 313.4 316.2 319.2 319.2 454 Cash Surplus Retained o.o 0.0 o.o 0.0 0.0 0.0 o.o 0.0 o.o o.o 370 Cum. Capital Expenditure 15138.0 15256.1 15385.0 15525.7 15679.3 15846.9 16029.9 16229.5 16447.4 1644 7. 4 465 Capital Employed 15579.8 15749.2 15937.4 16123.9 16323.3 16542.9 16763.5 17004.3 I7267. 2 17267.2 46I State Contribution 2653.5 2653.5 265 3. 5 2653.5 2653.5 265 3. 5 2653.5 2653.5 2653.5 2653.5 462 Retained Earnings 1516.0 1719. 5 1942.3 2186.3 2453.4 2745.9 3066.3 3417.1 3801.3 380I.3 555 Debt Outstanding -Short Term 504.8 556.1 615.3 661.1 707 .o 759.0 796~7 837.8 882.7 882.7 554 Debt Outstanding -Long Term 10905.4 lOR20.1 10726.2 10622.9 10509.4 10384.4 10247.0 10095.8 9929.6 9929.6 542 Annual Debt Drawdown J 1982 o.o 0.0 o.o o.o o.o 0.0 o.o 0.0 o.o 4517.3 543 Cum. Debt Drawdown 1982 4517.3 4517.3 4517.3 4517.3 4517.3 4517.3 4517.3 4517.3 45I7.3 4517.3 519 Debt Service Cover 1.25 1.25 1.25 1.25 1.25 1.25 1.25 1.25 1.25 o.oo .J ) .. _) - TABLE 11.3: SUMMARY OF MAJOR FORECASTS OF OIL PRICE TRENDS Source Date Resources Inc. International Energy Agency -Low -High tJS Energy Information Administration Energy Mines and Resources Canada Ontario Hydro Energy Modeling Forum, World Oil Report* -averag~ of 10 models -range of 10 models Dr. F. Fesharaki, Reseurce Systems Institute East-West Centre, Honolulu Date of Forecast Summer 1982 Spring 1982 Spring 1982 Summer 1982 Spring 1982 February 1982 Spring 1982 Forecast Trend (percent) +2.8 -0.5 +2.0 above +3 +1. 7 +1.8 +3.4 +1.9 +5.3 +1.7 *The 10models are: Gately-Kyle-Fischer (New York Univ.), lEES-OMS (U.S. Dept. of Energy), IPE (M.I.T.), Salant-lCF (U.S. Federal Trade Commission and ICF, Inc.), ETA-MARCO (Stamford Univ.), WOIL (U.S. Dept. of Energy and Environmental Analysis, Inc), Kennedy-Nehring (Univ. of Texas and the Rand Corp.), OlLTANK (Chr. Michelsen Institute), Opeconomics (BP Co. Ltd.), OILMAR (Energy and Power Subcommittee, U.S. House of Representatives). TABLE 11.4: COMPARISON OF ACRES ESTIMATE AND ACTUAL COST REDUCED TO COMMON (1963) LEVEL $ Mi 11 ions Percent Current 1963 of 1963 Dollars Dollars Estimate 1963 Estimate (inc 1. contingency) (1) 488.2 488.2 100.0 1966 Estimate (incl. contingency) (2) 563.3 489.5 100.3 Completion Cost 665.6 467.8 95.8 NOTE: (1) 1963 Estimate was for 10 x 450 MW Units; 1966-68 Estimate and Actual was for 11 x 475 MW Units. (2) The project budget provided for a contingency allowance of $41 million, i.e., approximately 8 percent of the base construction cost estimate and a provision for escalation of $102 mill ion based on a rate of 4.5 percent per annum, constant over the construction period. ~ ~" - - TABLE 11.5: MULTIVARIATE SENSITIVITY ANALYSIS, LONG-TERM COSTS AND PROBABILITY, NON-SUSITNA TREE (1982~) $ X 10 Rank (Low-Long-Term High~ ID Cost Probability 1 T27 4412 .03 2 T24 4590 .09 3 T21 4856 • 03 4 T18 5489 .015 5 T15 5661 .045 6 T12 5991 .015 7 T26 6101 .06 8 T23 6878 .18 9 T09 7184 • 005 10 T06 7313 .015 11 T20 7460 • 06 12 T03 7624 .005 13 T17 7915 .03 14 T14 8238 .09 15 T25 8492 .03 16 T22 8746 .09 17 T11 8858 .03 18 T19 9253 .03 19 Tl6 10321 .015 20 T08 10503 .01 21 T13 10637 .045 22 T05 10859 .03 23 no 11272 .015 24 T02 11569 .01 25 T07 13742 .005 26 T04 14194 .015 27 TOl 15058 .005 1.000 1J LTC -long-term costs Using probability distributions: Low Load Forecast 0.60 Medium Load Forecast 0.30 High Load Forecast 0.10 1.00 1/ Cumulative Incremental P robabi 1 i ty l TC • 03 132.36 .12 413.10 .15 145.68 .165 82.34 • 21 254.75 .225 89.87 .285 366.06 .465 1,238.04 .47 35 .. 92 .485 109.70 .545 44 7.60 .55 38.12 .58 237.45 .67 74L42 .70 254.76 .79 78 7.14 • 82 265.74 .85 277.59 .865 154.82 .875 105.03 .92 478.67 .95 325.77 .965 169.08 .975 115.69 .980 68.71 .995 212.91 1.000 7 5. 29 Cumulative LTC 132 545 691 773 1,028 1,118 1,484 2,722 2,758 2,868 3,315 3,354 3,591 4,332 4,587 5,374 5,640 5,918 6,072 6,177 6,656 6,982 7,151 7,267 7,335 7,548 7,624 1'11'!!1 TABLE 11.6: MULTIVARIATE SENSITIVITY ANALYSIS LONG-TERM COSTS AND PROBABILITY, SUSITNA TREE - (1982~) 1/ $ X 10 -Rank (Low-Long-Tenn Cumulative IncrementaT Cumulative High) ID Cost Probability Probability LTC LTC ~ 1 S45 5543 .09 .09 498.87 499 2 S42 5757 .18 .27 1, 036.26 1,535 3 S36 5827 .045 .315 262.22 1,797 4 S39 6097 .09 .405 548.73 2,346 -5 S33 6151 .09 .495 553.59 2,900 6 S44 6437 .0375 .5325 241.39 3,141 7 S30 6477 .045 • 5775 291,47 3,432 -8 S41 6650 .075 .6525 498.75 3,931 9 S35 6738 .01875 .67125 126.34 4,058 10 S38 6991 .0375 .70875 262.16 4,320 11 S32 7062 .0375 .74625 264.83 4,585 ~ 12 S27 7087 .003 • 7 4925 21.26 4,606 13 S18 7108 .009 .75825 63.97 4,670 14 S09 7151 .003 .76125 21.45 4,691 -15 S43 7331 .0225 .78375 164.95 4,856 16 S29 7388 .01875 .8025 138.53 4,995 17 S40 7543 .045 .8475 339.44 5,334 -18 S34 7650 .01125 .85875 86.06 5,420 19 S37 7884 .0225 .88125 177.39 5,598 20 S31 7974 • 0225 .90375 179.42 5, 777 21 S26 7986 .00125 .905 9.98 5,787 -22 S17 8008 .00375 .90875 30.03 5,817 23 S08 8050 .00125 .91 10.06 5,827 24 S24 8326 .006 .916 49.96 5,877 ~ 25 S15 8347 .018 .934 150.25 6,027 26 S28 8371 .01125 • 94525 94.17 6,121 27 S06 8390 .006 .95125 50.34 6,172 28 S25 8886 .00075 .952 6.66 6,178 29 S16 8908 .00225 .95425 20.04 6,199 30 SOl 8951 .00075 .955 6. 71 6,205 31 S23 9225 .0025 .9575 23.06 6,228 32 S14 9247 .0075 .9650 69.35 6,297 33 S05 9290 .0025 .9675 23.23 6,321 34 S21 9614 .003 .9705 28.84 6,350 -35 Sl2 9758 .009 .9795 87.82 6,437 36 S03 9784 .003 .9825 29.35 6,467 37 S22 10126 .0015 .9840 15.19 6,482 38 Sl3 10147 .0045 .9885 45.66 6,528 39 S04 10190 .0015 • 99 15.29 6,543 40 S20 10514 .00125 .99125 13.14 6,556 41 Sll 10658 .00375 .995 39.97 6,596 -42 S02 10683 .00125 .99675 13.35 6, 609 43 S19 11414 .00075 • 997 8.56 6,618 44 SlO 11558 .00225 .99925 26.01 6,644 -45 SOl 11584 .00075 1. 00000 8.69 6,653 1.00000 11 Using probability distributions: ~I Low Load Forecast 0.60 Medium Load Forecast 0.30 High Load Forecast 0.10 1.00 - - OGP-5 Non-Susitna Susitna OGP-6 Non-Susitna Susi tna TABLE 11.7: COMPARISON OF BASE CASES REVISED OGP-5 PROGRAM Cumulative Costs 1993-2010 3,213 3' 197 3,213 3,066 1/ 2010- Annual 491 385 491 384 1982 Present Worth of System Costs $ X 10 6 Long-Term Estimated Cost 2011-2051 1993-2001 5,025 8,238 3,943 7,062 5,025 8,238 3,929 6,995 Net Benefit 1,176 1,243 ll 2010 annual cost is projected 41 years at 3% and present worth 26 years to 1982 at 3% to arrive at the 2011-2051 estimated present worth. TABLE 11.8: PERCENT RESERVE -MEDIUM LOAD FORECAST.lf Non-Susitna Susitna Peak Total Total Load Capability LOLP Capability Year (MW) (MW) % Reserve days/years (MW) % Reserve 1993 947 1373 45.0 0.063 1853 95.7 1994 965 1542 59.8 0.027 1822 88.8 1995 983 1495 52.0 0.077 1774 80.5 1996 1003 1624 61.9 0.059 1704 69.9 1997 1023 1620 58.4 0.084 1630 59.4 1998 1044 1635 56.6 0.092 1575 50.8 1999 1064 1635 53.6 0.055 1575 48.0 2000 1084 1591 46.8 0.059 1531 41.2 2001 1121 1661 48.2 0.038 1531 36.6 2002 1158 1608 38.9 0.062 2079 79.5 2003 1196 1625 35.9 0.087 2026 69.4 2004 1233 1695 37.5 0.057 2027 64.4 2006 1323 1794 35.6 0.049 1939 52.7 2006 1323 1794 35.6 0.052 1917 44.9 2007 1377 1994 44.8 0.023 1987 44.3 2008 1430 1968 37.6 0.066 2032 42.1 2009 1484 2037 37.3 0.051 2031 36.9 2010 1537 2037 32. 5 0.099 2102 36.8 capacity -1 oad l/ As calculated in peak month: % reserve = load LOLP daysjyear 0.000 0.000 0.000 0.000 0.000 0.001 0.002 0. 015 0.032 0.000 0.001 0.001 0.017 0.068 0.025 0.029 0.050 0.025 - - -' ..... ~ - - - - -! TABLE 11.9: ANNUAL ENERGY DISPATCH 1/ NON-SUSITNA PLAN (GWh) NG NG Year Coal GT cc OIL HYDRO TOTAL - 1993 1758 610 1733 4.0 631 4736 1995 2887 226 1177 0.6 631 4922 2000 3983 68 787 0 631 5469 2002 4236 95 891 0 631 5853 2005 4283 300 1214 0 631 6428 2010 5486 434 1240 0 631 7791 SUSITNA PLAN (GWh) NG NG OTHER Year COAL GT cc OIL HYDRO SUSITNA TOTAL 1993 140 0 578 0 631 3387 4736 1995 183 2 719 0 631 3387 4922 2000 239 83 1129 0 631 3387 5469 2002 0 0 0 0 631 5222 5853 2005 3 0 0 0 631 5539 6428 2010 53 6 616 0 631 6485 7791 ll Medium Load Forecast. -----·-·---· TABLE 11.10: COMPONENTS OF ANNUAL COSTS -NON-SUSITNA PLAN 1/ (Millions $) Coal Coal Coal NGGT NGGT NGGT NGCC NGCC OIL Year INV 0/M Fuel INV 0/M Fuel 0/M Fuel 0/M&Fuel TOTAL 1993 44.2 6.6 36.7 0 5.1 26.2 6.4 47.0 3.9 176.1 Cum. 44.2 50.8 87.5 87.5 92.6 118.8 125.2 172.2 176.1 1995 73.9 12.1 61.6 0 2.7 10.4 5.5 37.3 3.4 206.9 Cum. 73.9 86.0 147.6 174.6 150.3 160.7 166.2 203.5 206.9 2000 114.2 18.4 100.5 6.4 2.2 4.6 5.1 40.4 3.2 295.0 Cum. 114.2 132.6 233.1 239.5 241.7 246.3 251.4 291.8 295.0 2002 114.2 19.3 109.0 9.8 2.6 6.7 5.6 45.8 3.3 316.4 Cum. 114.2 133.5 242.5 252.3 254.9 261.6 267.2 313.0 316.3 2005 114.2 20.0 111.4 24.3 5.0 25.2 6.8 62.0 3.5 372.4 Cum. 114.2 134.2 254.6 269.9 274.9 300.1 306.9 368.9 3 72.4 2010 152.8 29.1 150.8 32.0 7.1 38.3 7. 5 69.5 3.9 491.0 Cum. 152.8 181.9 332.7 364.7 3 71.8 410.1 417.6 487.1 491.0 l/ Medium Load Forecast .I J J J TABLE 11.11: COMPONENTS OF ANNUAL COSTS -SUSITNA PLAN l/ (Million$) Other Susitna Susitna Hydro NGGT Thermal Coal NG Year Investment 0/M 0/M Inv 0/M Fuel Fuel Total 1993 199.1 12.2 2.8 0 7.3 4.7 20.4 246.5 1995 199.1 12.7 2.9 0 7.7 6.4 26.9 255.9 Cum. 199.1 211.8 214.7 214.7 222.4 228.8 255.9 2000 199.1 14.1 3.2 0 8.8 7.8 59.6 292.6 Cum. 199.1 213.2 216.4 216.4 225.2 233.0 292.6 2002 294.0 22.4 3.3 0 5.3 0 0 325.0 Cum. 294.0 316.4 319.7 319.7 325.0 325.0 325.0 2005 294.0 23.8 3.5 0 5.2 0.7 16.0 343.2 Cum. 294.0 317.8 321.3 321.3 326.5 327.2 343.2 2010 294.0 26.2 3. 9 11.9 7.7 1.9 39.7 385.3 Cum. 294.0 320.2 324.1 336.0 343.7 345.6 385.3 1 Medium Load Forecast """ I TABLE 11.12: SUSITNA PROJECT DELAYED Base Case Base Case Non-Susitna Sus itna Susitna Delayed A c C3 OGP ID L9J9 L9K3 LOW9 1) DATES: WATANA/DC 93/2002 94/2002 ADDITIONS 4 Coal 3 GT 's 3 GT' s 9 GT's 2007 1993* 2008 1993* 2010 2010 $ x 10° (198 2 PW) 1993 -2010 $3,212.8 $3,199.4 $3,140.1 2010 Cost 491.0 385.3 387.4 ]j 2010 to 20XX Cost 5,024.7 3,943.0 3,964.5 Long-Term Cost 8,238 7,062 7,105 8,299 C4 8,360 C5 Net Benefit $1,176 $1,133 ll Dates modeled are from 1993 through 2010 in all cases. '{I Factors: 2010-2051 = 10.2336 (A, C, C3) 2010-2052 = 10.3598 (C4) 2010-2053 = 10.4824 (C5) C4 L2W5 94/2003 3 GT's 1993* 1993* 2010 $3,137.9 388.7 4,026.9 7,165 $1,134 C5 -' L2W7 '""'I 95/2004 3 GT's ~ 1993* 1993* 2010 $3,099.2 394.1 - 4,131.1 7,230 $1 '130 .. ·. _] -] -l 1 TABLE 11. 13: WATANA PROJECT ALONE Medium Load Forecast 1280 MW Non-Susitna Susitna OGP ID L919 L9K3 System 600 MW B 680 MW 93 200 MW N 600 MW 02 630 MW GT 210 MW GT $ Mi 11 ions 1/ 2010 yearly-491.0 385.3 1993-2010 3,212.8 3,119.4 LTC $82 8,238 7,062 y Transmission Totals 8,238(A) 7,062 7,589(B) Net Benefit 1,176(A) ll Economic Factors: Medium Load: to 2051 10.2336 to 2043 8.9119 2/ $53.5 in 2005 = $27 1982 PW 2010 = $23 1982 PW 680 MW Watana L189 680 MW 93 400 MW B 420 MW GT 479.8 3,295.3 7,571 27 8,232 7,598 (9) (B) 1020 MW Watana L671 680 MW 93 340 MW 02 400 MW B 350 MW GT 485.5 3,344.4 8,313 27 8,340 (102)(A) Low Load Forecast Non-Susitna L195 400 MW B 200 MW N 560 MW GT 404.3 2,639.9 6,878 6,878(C) 6,374 (D) Low Load: to 2054 to 2045 1280 MW Susitna L9K7 680 MW 95 600 MW 04 359.5 2,881.9 6,650 6,650 228(C) 10.4824 9.2367 680 MW Watana L4R7 680 MW 95 200 MW B 280 MW GT 394.2 2,805.9 6,447 23 6,470 (96)(0) TABLE 11. 14: ALTERNATIVE GENERATION PLANS Non-Susitna Watana Devil Canyon Chakachamna Chakachamna Case Plan Devi 1 Canyon Watana DC Watana ID L9J9 L9K3 L5XZ9 L2Z3 L309 System Mix 800 Coal W/93 DC/93 C/93 C/93 (Added capacity 560 GT DC/02 W/02 DC/97 W/00 only) 210 GT 350 GT 400 Coal 200 cc 420 GT 210 GT $ X 106 ( 198 2) 1993-2010 $3,121.8 $3,119.4 $3,168.3 $3,206.6 $3,259.9 2010 491.0 385.3 407.8 486.6 486.7 2011-2051 5,024.7 3,943.0 4,173.3 4,979.7 4,980.7 Long-term cost (1993-2051) $8,237 $7,062 $7,341 $8,186 $8,241 Net Benefit $1,176 $ 986 $ 51 ($4) . I J TABLE 11.15: SINGLE HYDRO PROJECT DEVELOPMENTS Case Watana Devi 1 Canyon Chakachamna ID Ll89 L6I 1 L9E1 _. Capacity 680 MW 600 MW 330 MW Available 1993 1993 1993 ,-. Aver age Energy 3459 GWh 258Y GWh 1492 GWh Firm Energy 2631 GWh 2264 GWh 1374 GWh $ X 106 ( 1982) Capital Cost $4,094 $2' 203 $1, 450 ( inc 1 ud i ng I DC and transmission) Long-term costs $7,598 $7' 656 $7' 271 (1993-2042) ,_ Net Benefits ( 9) ($67) ($317) compared to non-Susitna plan LTC ( 1993-2042) of $7, 589 million - 1.0 .9 .8 >-• 7 1- ...J ~ .6 ID 0 0::: a.. .5 LL.I > i= .4 Cl: ...J ::::l :::!: .3 ::J (.) .2 .I (4500) (3500) -1 l 1 .... ~ / v v , / LOW LOAD FORECAST BIAS / v / 't' / v v / L' BASE CASE v v / / / ~ v ~ v / ~ v ~ (2500) (1500) (500) 0 500 1500 2500 3500 NET BENEFIT $ X 10 6 ( 1982 $ ) SUSITNA MULTIVARIATE SENSITIVITY ANALYSIS CUMULATIVE PROBABILITY VS. NET BENEFITS -J ........, 1--- f/" I I i I 4500 5500 FIGURE 11.1 ~ 90 - 80 - 70 - ~""" 60 z - (!) It: <I :::!: LLI > It: LLJ C/) LLJ 50 It: - ~ 0 40 - - 30 - 20 - ..... 10 1990 L...__ - - n l.t ~ }i :: j~ ·=· I ., l.: ' I ' ., : . . NON SUSI' 1995 MEDIUM - - .J PLAN I 2000 YEAR LOAD FORECAST L...__v SUSITNA - 1....-...., t : -: ••••• ] ,...,.,. I 2005 PERCENT RESERVE VS. TIME PLAN •••I 2010 FIGURE 11.2 1-500 - - 450 - - 400 - ,_ -iA- z 350 - 0 ...J ...J ~ 1- (/) 0 (.) -~ 300 ~ - ex 1.1.1 >- - 250 -~ 200 -r 150 - "'"" ' 100 1990 _f; ? ! 1995 MEDIUM LOAD NON SUSITNA PLAN ' .~ - ., SUS I TNA PLAN ., 2000 YEAR YEARLY ANNUAL COSTS FORECAST F H Jl' .. ( ) J .· ' '"' ··.} { "' 2005 2010 FIGURE 11.3 en z 0 ....J ....J ::E * l-en 0 u ....J <t :::::> z z <[ 500~----~--------------------------------- 300~--------------- 200~---------------~ 176.1 1993 2000 2005 YEAR 491.0 -------------------------1 5z:~~--OTHERS: (OIL/HYDRO) '1-4--GT 0 a M t-4-----NATURAL GAS GT INVESTMENT COSTS 2010 NON-SUSITNA PLAN MEDIUM LOAD FORECAST FIGURE 11.4 - 500~--------------------------------------------------------------_, - F" 400 385.3 NG FUEL COST (/) z THERMAL 0 aM 0 ...J ...J GT INVESTMENT COST ::iE ~ 292.6 OTHER HYDRO 0 a M 300 ~ 1111 11111 11111!1 SUSITNA 0 aM (/) 0 1111 11111 l l SUSITNA u 11111 1111111 INVESTMENT COST r ...J Ill ! c:r 111 IIIII I I IIIli ' :::::1 II II 11111 1 z Ill z II II 1111111 <[ Ill Ill II II 1111111 Ill II Ll I ~II II 200 Ill I IIIII 1111111 ,, 1111 Ill II I I 1111 r111111 II ,,,, Ill II I I 1111 r 1 t 1111 II 1111 Ill II I l 1111 IIIII II II Ill Ill ,r, ' I 1111 I 1111 II rl Ill Ill I 111 1 I Ill ~ 1111 'I II I rl Ill I 11 r 1 I I 1111 II I I I I Ill r I 1111 1111 II 11 l I I I 1111 Ill I I 1111 100 1111 11 ,, Ill I I I 11 I II Ill 111111 I I 11 I 1111 11 t 111111 Ill II ,,,1 II II Ill 111111 I 11 I 1111 II II Ill II IIIII IIIII I r 11 1 1111 11 'I Ill 1111111 111 r11 II IIIII r<-II Ill 111111 1111111 1111 II 1111111 111111 1111 II II Ill I I I 1111111 II Ill 1111111 111111 ~ 1111111 ,r,l II I t I 1111111 111111 I I I -0 1993 2000 2002 2005 2010 YEAR SUSITNA PLAN MEDIUM LOAD FORECAST FIGURE 11.5 (f) 1- (f) 0 u -:E ILl 1- (f) >-(f) LL.. 0 3t a. r""" ! ILl > ;::::: <t _J ;j :::E :::E I ;j u 9000 8000 7000 6000 5000 4000 3000 2000 1000 0 1990 I / / 7 / NON-SUSITNA PLAN // I 7 / / / / 7 / I L/ SUSITNA PLAN / / / ll/ I I I MODELED PLAN /;/ ;; I ~ ECONOMIC EXTENSION 17 /J ~ 2000 2010 2020 2030 2040 YEAR MEDIUM LOAD FORECAST -LONG TERM COSTS / / / 2050 FIGURE 11.6