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HomeMy WebLinkAboutSnettisham Hydroelectric Project First Stage Development Crater Lake Phase Volume 1 of 2 (revised) 1984c{~y o$i3 i Snettisham Hydroelectric Project Army Corps F· t S t D I t ( :g~:~~s Irs age eve opmen CRATER LAKE PHASE DESIGN MEMORANDUM NO. 26 ( REVISED) FEATURE DESIGN FOR LAKE TAP, GATE STRUCTURE, POWER TUNNEL, SURGE TANK, AND PENSTOCK VOLUME 1 of 2 MAIN REPORT REVISED OCTOBER REPLY TO HTENTiON OF NPAEN-PM-C DEPARTMENT OF THE ARMY u.s. AallY BMorMEER DISTRICT, ALASKA POUCH 818 ANCHOIlAG B, ALASKA 99608-0898 SUBJECT: Snettisham Hydroelectric Project, Alaska Second Stage Development, Crater Lake Phase Revised Design Memorandum No. 26, Feature Design for the Lake Tap, Gate Structure, Power Tunnel, Surge Tank, and Penstock Commander, North Pacific Division ATTN: NPDEN-TE ? c JeT "-' ~ 1. Forwarded for your review and approval are 15 copies of the subject report, prepared in accordance with ER 1110-2-1150. 2. Volume 1 contains the main report and feature design level drawings that provide a detailed description of the major components of the re- commended Crater Lake phase development for the Snettisham Hydroelectric project. Also included in Volume 1, as exhibits, are the reports for a number of investigations that were conducted to provide us with the infor- mation necessary to develop a sound design. 3. Volume 2, Technical Appendices, contains the results of our geophysical investigations through 1983, hydraulic design calculations, and the theory used for design of the encased penstoc~ alternatives. 4. This revised document incorporates NPD and aCE review comments on the original November 1983 design memorandum, the approved design in Appendix D of the 1983 DM26 (which served as the authorization to prepare Crater Lake Phase 1 P&S in May 1984), and the Crater Lake Phase 1 plans and specifica- tions. 5. Request your approval at the earliest possible date so that we can maximize our efforts in the development of plans and specifications to support the scheduled award of the Crater Lake Main Contract in late FY85 or early FY86. FOR THE COMMANDER: 1 Incl (15) as Chief, Engineering Division - SNETTISHAM PROJECT ALASKA SECOND STAGE DEVELOPMENT CRATER LAKE PHASE REVISED DESIGN MEMORANDUM NO. 26 VOLUME 1 of 2 MAIN REPORT ABBREVIATIONS The following is a list of definitions for abbreviations used in this report. acre-ft ave Btu C dc ft ft2 ft 3 ft/min ft/s ft3/s ft/s2 ga 1 gal /mi n ga 1 /yr GWh h hp I, 10 in in /s in/yr KVA kW kWh lb 1 b /ft2 1 b/ft 3 lb/hr lb/in 2a 1 b/"i n2g M mi mi /hr mi2 min mo MSL MW MWh pct r/min s V W WY yd 3 yr of Source: acre-foot average British thermal unit degrees Celsius direct current foot square foot cubic foot foot per minute foot per second cubic foot per second foot per second squared ga 11 on gallons per minute gallons per year gigawatt hour hour horsepower modified Mercalli intensity inch inch per second inch per year kilovoltampere kilowatt kilowatt hour pound pound per square foot pound per cubic foot pounds per hour pounds per square inch absolute pounds per square inch gage Richter magnitude mile mil es per hour square mil e minute month mean sea level megawatt megawatt hour percent revolutions per minute second volt watt water year cubic yard year degree Fahrenheit u.S. Government Printing Office Style Manual, January 1973 i SYNOPSIS This design memorandum summarizes the post-authorization studies conducted to date for the Crater Lake phase of the Snettisham Hydroelectric Project, and presents the recommended feature design developed as a result of those studies. The feature design level studies included agency and environmental coordination, geotechnical investigations, computer modelling of the power conduit and its appurtenances, design analyses, a detailed quantity takeoff and cost estimate, and preparation of feature level drawings. The next level of effort will be preparation of plans and specifications. At that time the design of the features will be further refined and detailed. The project recommended herein is the same as authorized by Congress, with only minor departures. The recommended plan is comprised of an open system/wet tunnel lake tap, a wet-well gate structure utilizing a hydraulically-operated slide gate and a bulkhead, an ll-ft diameter modified horseshoe power tunnel 6,020 ft in length, a conventional vented surge tank, a 6-ft diameter steel, saddle-supported penstock 903 ft in length, a 47,000 hp vertical Francis turbine, and a generator with a nameplate rating of 34,500 KVA. Upon completion of construction, this facility will be transferred to the Alaska Power Administration, which is responsible for the operation and maintenance of the combined Long Lake -Crater Lake facility. The total estimated cost of the recommended plan based on September 1984 price levels is $58,495,000. The latest approved estimate of the approved plan presented in OM 23, dated December 1973, is $58,837,000 (Pb-3 dated 7 April 1983 at October 1983 price levels). The recommended plan has annual benefits estimated at $12,165,000 and annual costs of $2,334,000, resulting in a benefit-to-cost ratio of 5.2 at 3-1/8 pct interest rate (based on DRI real fuel cost escalation rates). i i SNETTISHAM HYDROELECTRIC PROJECT, ALASKA Aerial view of the project area showing the approximate alinement of the e,dsting Long Lake phase facilities and the racommended Crater Lake phase facilities in relation to the powerhouse PHOTO TAKEN IN 1968 SNETTISHAM PROJECT, ALASKA Schedule of Design Memoranda No. Subject 1. HYDROLOGY 2. HYDROPOWER CAPACITY 3. SELECTION OF PLAN OF DEVELOPMENT Revised 4. PRELIMINARY MASTER PLAN 5. ACCESS AND CONSTRUCTION FACILITIES Revised SUPPLEMENT NO. 1 6. (DELETED) 7. GENERAL DESIGN MEMORANDUM SUPPLEMENT NO.1, Concrete Aggregate Investigation 8. PRELIMINARY DESIGN REPORT ON POWERHOUSE Revised 9. TRANSMISSION FACILITIES SUPPLEMENT NO.1, Direct Current Transmission SUPPLEMENT NO.2, Direct Current Transmission SUPPLEMENT NO.3, Juneau Substation Auto- transformers SUPPLEMENT NO.4, Taku Inlet Submarine Cable SUPPLEMENT NO.5, Permanent Communications SUPPLEMENT NO.6, Juneau SUbstation SUPPLEMENT NO.7, Suspension Insulator SUPPLEMENT NO.8, Transmission Line Structures SUPPLEMENT NO.8, Transmission Line Construction SUPPLEMENT NO. 10, Relocation of Powerline Facilities for Juneau SUbstation 10. POWER TUNNEL, SURGE TANK & PENSTOCK SUPPLEMENT NO. 1 11. REAL ESTATE 12. (DELETED) 13. DAM, SPILLWAY, & INTAKE STRUCTURE SUPPLEMENT NO. 1 14. PERMANENT OPERATING EQUIPMENT 15. BUILDING, GROUNDS & UTILITIES 16. PLAN OF DIVERSION 17. (DELETED) 18. POWERHOUSE PENSTOCK BIFURCATION 19. POWERHOUSE ARCHITECTURAL DESIGN 20. POWERHOUSE STRUCTURAL DESIGN 21. POWERHOUSE MECHANICAL DESIGN 22. POWERHOUSE ELECTRICAL EQUIPMENT 23. CRATER LAKE PLAN OF DEVELOPMENT 24. POWERHOUSE DESIGN REPORT 25. (DELETED) 26. CRATER LAKE-LAKE TAP, GATE STRUCTURE, POWER TUNNEL, SURGE TANK, AND PENSTOCK, SUPPLEMENT NO.1, Materials Investigation (Revised Design Memorandum 26) iii Date 15 October 1964 31 October 1964 22 January 1965 7 May 1965 22 Apri 1 1965 26 November 1965 29 April 1966 6 March 1967 13 November 1965 14 September 1967 29 August 1966 29 June 1967 23 December 1966 19 January 1968 10 February 1969 20 August 1970 3 September 1970 22 September 1970 24 February 1971 30 December 1970 12 February 1970 17 June 1971 11 August 1971 9 September 1966 27 May 1968 27 March 1967 30 January 1967 24 September 1971 29 March 1972 11 May 1967 22 July 1966 19 September 1967 13 December 1967 29 December 1967 10 January 1968 21 September 1973 28 December 1973 28 December 1973 25 November 1983 25 November 1983 29 October 1984 LOCATION: SNETTISHAM PROJECT, ALASKA CRATER LAKE PHASE PERTINENT DATA Near the mouth of Speel River, 28 mi southeast of Juneau, Alaska. AUTHORIZED: Flood Control Act of 1962, providing for design and construction by the Corps of Engineers and for operation and maintenance by the Department of the Interior. PLAN: Construct an underground power conduit from the existing underground powerhouse to Crater Lake. Install an additional turbine and generator in the powerhouse. PROJECT FEATURES: NOTE: All elevations cited in this report are in feet and refer to Project Datum. MSL is 2.9 ft below Project Datum. Elevations of Tide Planes at Speel River with respect to Mean Lower Low Water and Project Datum are as follows: Highest Tide (Estimate) Mean Higher High Water Mean High Water Half Tide Level (MSL) Mean Low Water Mean Lower Low Water Lowest Tide (Estimate) MLLW 22.5 15.9 14.8 8.2 1.6 0.0 -5.7 PROJECT DATUM 11.4 4.8 3.7 -2.9 -9.5 -11. 1 -16.8 Tidal Datum Planes are based on 7 mo (1/65 to 8/65) of automatic gage operation by USGS. Drainage area, mi2 Annual runoff, minimum, acre-ft Annual runoff, average, acre-ft Annual runoff, maximum, acre-ft Hydrology iv 11.4 113,000 145,500 186,750 Reservoir Maximum observed surface elevation, ft Elevation of natural lake outfall, (full-power pool), ft Elevation of minimum operating pool, ft 1 ,019 1,017 820 81,500 330 145 Initial active storage capacity, acre-ft Area of reservoir at full pool, acres Area of reservoir at minimum pool, acres Type Size, ft Lake Tap Lake bottom elevation at tap, ft Primary Rock Trap Location Bottom area, ft2 Volume of tap material contained, yd 3 Invert elevation, ft Secondary Rock Trap Open system/wet tunnel 1 2 (d i a.) by 10 799 1 ake tap 1 , 152 86 753.5 to 761.5 Location Type Size, ft Invert elevation, ft 400 ft downstream of lake tap Expanded horseshoe section with excavated invert 20 wide by 11 high by 60 long 776 Gate Structure Location Type Service room floor elevation, ft Invert elevation, ft Maximum operating head, ft 200 ft downstream of sec. rock trap Wet-well in rock v 1,040 789 233 Maximum momentary head, ft (during lake tap blast) Service gate, quantity Type Size, ft Bulkhead, quantity Size, ft Type Total length, ft Unlined length, ft 295 Slide 6.B by B.5 B.7 by 9.3 Power Tunnel Modified horseshoe 6,020 4,975 Diameter (modified horseshoe), ft 11 Shotcrete lined length, ft Concrete lined length, ft Diameter (circular), ft Final Rock Trap 920 125 9 Location Type 5,400 ft downstream of gate structure Expanded horseshoe section with excavated invert Size, ft Storage capacity, yd 3 Invert elevation, ft 15 wide by 15 high by 100 long 96 126 to 109 Surge Tank Location 5,160 ft downstream of gate structure Type vented vertical shaft Diameter, ft 10 Top elevation, ft 1,OBO Bottom elevation, ft 145.3 Power tunnel invert elevation, ft 150.0 vi Drift tunnel length, ft 60 Penstock Type Underground, unencased steel Length, ft 903 Steel penstock inner diameter, ft 6 Powerhouse Number of additional units Type of Turbine Vertical Francis Turbine rated capacity, hp 47,000 (based on rated net head, full gate, and generator rated capacity) Generator nameplate rated capacity, KVA Annual firm output, kWh Average annual non-firm output, kWh Tailwater elevation, ft (1) Maximum net head, ft Discharge at maximum net head, ft 3/s Pool elevation at maximum net head, ft (2) Design net head (rated net head), ft Discharge at design net head, ft 3/s Pool elevation at average net head, ft (3) Minimum (critical) net head, ft Discharge at minimum net head, ft3/s Pool elevation at minimum "net head, ft (4) Maximum discharge (hydraulic capacity), ft3/s / (1) Based on generation of 31.05 MW at maximum pool and plant efficiency = 86 pct. (2) Based on generation of 20.70 MW at average pool and plant efficiency = 86 pct. vii 34,500 105,100,000 16,100,000 11.0-12.5 990.5 430 1,019 945.5 300 967 788.0 470 820 518 '(3) Based on generation of 27.3 MW (guaranteed output) at minimum pool and plant efficiency = 86 pct. (4) Maximum discharge is based on the Long Lake turbine model with a prototype throat diameter of 51.5 inches, 100 pct wicket gate opening, and generator blocked output of 34.5 KVA. This occurs at a net turbine head of 912 ft. viii PARAGRAPH 1.01 1.02 1. 03 1.04 1.05 1.06 2.01 2.02 2.03 2.04 3.01 3.02 3.03 4.01 4.02 4.03 4.04 4.05 4.06 5.01 5.02 5.03 SNETTISHAM HYDROELECTRIC PROJECT, ALASKA CRATER LAKE PHASE REVISED DESIGN MEMORANDUM NO. 26 LAKE TAP, GATE STRUCTURE, POWER TUNNEL, SURGE TANK, PENSTOCK TABLE OF CONTENTS LIST OF ABBREVIATIONS SYNOPSIS SCHEDULE OF DESIGN MEMORANDA PERTINENT DATA SECTION 1 -GENERAL Project Authorization Project Location Stage Development Purpose and Scope Prior Investigations Local Cooperation SECTION 2 -REGIONAL DESCRIPTION Environmental Setting Hydrology Regional Geology Tectonic Setting SECTION 3 -RECOMMENDED PLAN General Recommended Plan Changes from Approved Plan SECTION 4 -ALTERNATIVES General Alternative I Alternative II Alternative III Comparison to the Recommended Plan Primary Trashrack/Lake Drawdown SECTION 5 -HYDROLOGY General Water Supply Studies Glacial Mass Balance Study ix PAGE 1-1 1 -1 1-1 1-2 1-2 1-3 2-1 2-1 2-2 2-2 3-1 3-1 3-2 4-1 4-1 4-3 4-3 4-5 4-6 5-1 5-1 5-1 PARAGRAPH 6.01 6.02 6.03 6.04 6.05 _ 6.06 7.01 7.02 7.03 7.04 7.05 7.06 7.07 8.01 8.02 8.03 8.04 8.05 9.01 9.02 9.03 9.04 9.05 9.06 9.07 9.08 10.01 10.02 10.03 10.04 10.05 10.06 TABLE OF CONTENTS (Continued) SECTION 6 -GEOLOGY General Completed Explorations and Investigations Project Site Geology Tectonics and Seismic Risk Studies Engineering Geology Future Investigations SECTION 7 -LAKE TAP General Lake Tap Location Orifice Primary Rock Trap Tapping Operation Primary Trashrack Two-Step Lake Tap SECTION 8 -GATE STRUCTURE General Shaft Operational Facilities Mechanical Design Electrical Design SECTION 9 -POWER TUNNEL General Power Tunnel Power Tunnel Emergency Plugs and Bulkheads Rock Traps Secondary Trashrack Plug and Bulkhead Tunnel Filling and Draining Procedures Rock Cover Criteria for Unlined Tunnel SECTION 10 -SURGE TANK General Description of Recommended Surge Tank Selection of Surge Tank Diameter Maximum and Minimum Surges System Without a Surge Tank Surge Tank Location x PAGE 6-1 6-1 6-1 6-3 6-5 6-6 7 -1 7-1 7 -1 7-1 7-2 7-3 7-4 8-1 8-1 8-3 8-3 8-6 9-1 9-1 9-2 9-3 9-3 9-3 9-3 9-4 10-1 10-1 10-1 10-1 10-2 10-2 PARAGRAPH 11.01 11.02 11.03 11.04 11.05 1.1. 06 11.07 12.01 12.02 12.03 12.04 12.05 13.01 13.02 13.03 13.04 13.05 13.06 13.07 14.01 14.02 15.01 15.02 15.03 15.04 15.05 15.06 15.07 16.01 16.02 TABLE OF CONTENTS (Continued) SECTION 11 -PENSTOCK General Supports and Anchorage Longitudinal Loading Design Criteria Steel Selection Fabrication and Placement Testing SECTION 12 -POWERHOUSE General Changes from Approved Powerhouse Plan Project Feature Operational Controls Machine Shop Tailrace and Tailwater Elevations SECTION 13 -INSTRUMENTATION General Lake Tap Tunnel Lake Surface Elevation Pressure Measuring Devices in Lower Tunnel and Powerhouse Maintenance Signal Transmissions SECTION 14 -MATERIAL SOURCES AND DISPOSAL SITES Sources Disposal Sites SECTION 15 -PERMANENT FACILITIES General Barge Access Airfield Crater Cove Access Road Wastewater Treatment and Disposal Machine Shop Incinerator SECTION 16 -CONSTRUCTION FACILITIES General Recommended Plan xi PAGE 11-1 11-1 11-1 11-1 11-1 11-2 11-2 12-1 12-1 12-2 12-3 12-3 13-1 13-1 13-1 13-3 13-3 13-4 13-4 14-1 14-2 15-1 15-1 15-1 15-1 15-1 15-2 15-2 16-1 16-1 , TABLE OF CONTENTS (Continued) PARAGRAPH PAGE SECTION 17 -OPERATION AND MAINTENANCE 17.01 General 17-1 17.02 Operation, Maintenance, and Replacement Costs 17 -1 SECTION 18 -ENVIRONMENTAL CONSIDERATIONS 18.01 General 18-1 18.02 Impacts of Project Construction 18-1 18.03 Impacts of Project Operation 18-1 18.04 Mitigative Measures 18-1 18.05 Compliance with Environmental Requirements 18-2 SECTION 19 -CONSTRUCTION SCHEDULE 19.01 General 19-1 19.02 Contracts 19-1 SECTION 20 -PROJECT COST COMPARISON 20.01 General 20-1 20.02 Recommended Plan Estimate of Cost 20-1 20.03 Basis for Estimate 20-1 20.04 Comparison of Recommended Plan Estimate and Current Approved Costs 20-1 SECTION 21 -POWER STUDIES AND ECONOMICS 21.01 General 21-1 21.02 Power Market Area 21-1 21.03 Future Power Requirements 21-1 21.04 Thermal Alternative and Power Values 21-7 21.05 Power Studies 21-9 21.06 Project Costs and Benefits 21-12 SECTION 22 -REAL ESTATE '-- 22.01 General 22-1 SECTION 23 -COORDINATION WITH OTHERS 23.01 Alaska Power Administration 23-1 23.02 US Fish' and Wildlife Service 23-1 23.03 US Forest Service 23-1 23.04 National Marine Fisheries Service 23-1 23.05 Federal Energy Regulatory Commission 23-1 23.06 Alaska Department of Fish and Game 23-1 xii 24.01 24.02 24.03 SECTION 24 -SUMMAR~ AND RECOMMENDATION Discussion Conclusion Recommendation- SECTION 25 -DETAILED COST ESTIMATES TABLE LIST oF" TABLES 2-A Great Earthquakes in Southern Alaska 5-A Average Monthly Flows for Crater Creek 6-A Summary of Explorations 10-A Surge Tank Location Transient Characteristics 11-A Penstock Steel Comparative Characteristics 19-A Construction Contracts Schedule 20-A Costs of Recommended Plan and Latest Approved Juneau Area Energy and Peak Demand Juneau Area Power Requirements Costs 21-A 21-B 21-C 21-D 21-E 21-F 21-G 21-H 21-1 25-A 25-B 25-C At-Market Value of Dependable Hydroelectric Power Real Fuel Escalation Rates and Value of Energy 25-0 25-E Juneau Area Energy Use Annual Project Costs Annual Costs of Recommended Plan Annual Demands and Benefits Project Economics Recommended Plan Summary Cost Estimate Recommended Plan Detailed Cost Estimate Alternative Plan I Summary Cost Estimate Alternative Plan I Detailed Cost Estimate Alternative Plan II Summary Cost Estimate xiii 24-1 24-1 24-1 PAGE 2-3 5-2 6-2 10-2 11-2 19-1 20-1 21-3 21-4 21-8 21-9 21-11 21-13 21-13 21-14 21-14 25-2 25-4 25-13 25-14 25-22 n 25-F 25-G 25-H 1 • 2. 1. 2. 3. 4. 5. ,6. 7. 8. 9. 10. 11 • . 12. 13. 14. 15. 16. 17. 18. 19. 20. Alternative Plan II Detailed Cost Estimate Alternative Plan III Summary Cost Estimate Alternative Plan III Detailed Cost Estimate LIST OF FIGURES Upper Hemisphere Stereographic Plot of Discontinuities Juneau Loads and Resources LIST OF PLATES Location and Vicinity Map, Project General Plan Power Tunnel Plan and Profile Penstock Profile Power Tunnel Sections Penstock Tunnel Sections and Details Tunnel Access Adit Plan and Profile Tunnel Plug and Secondary Trashrack Tunnel Plug Bulkhead Details Tunnel A1inement in LakerTap Area Lake Tap Clearing Recommended Plan, Slusher Method Lake Tap and Primary Rock Trap Plan and Profile Lake Tap and Primary Rock Trap Sections and Details Primary Trashrack Power Tunnel Emergency Plug and Bulkhead (Typical) Gate Structure Service Gate Details Gate Position Indicators and Hydraulic Cylinder Bulkhead and Slide Gate Hoist Gate Structure Access Adit and Portal Secondary Rock Trap xiv 25-23 25-31 25-32 6-4 21-6 21. Final Rock Trap and Secondary Trashrack 22. Surge Tank 23. Alternative I Plan and Profile 24. Alternative I Gate Structure Plans and Sections 25. Penstock Profile for Alternatives I and II 26. Alternative II Plan and Profile 27. Alternative II Gate Structure Plans and Sections 28. Alternative III Power-Tunnel Plan and Profile 29. 30. , 31. 32. 33. 34. 35 •. 36. 37. 38. 39. 40'. 41. 42. 43. 44. 45. 46. 47. Alternative III Penstock Profile Alternative III Gate Structure Alternative III Service Gate Details Alternative III Bulkhead and Service Gate Hoist Alternative III Gate Structure Access Adit and Portal Alternative III Final Rock Trap and Secondary Trashrack Alternative III Final Rock Trap Access Adit Plug Plan and Sections Alternative III Air Chamber Surge Tank Lake Tap Clearing Alternate Plan, Clamshell Method Alternative Primary Trashrack Alternative Primary Trashrack Bulkhead Alternative Primary Trashrack Bulkhead Hoist Geology Plan and Profile -Power Tunnel Geology Sections No. 1 -Lake Tap and Gate Structure Geology Sections No.2 -Miscellaneous Geology Profile -Penstock Materials Sources and Disposal Sites Storage -Elevation and Area -Elevation Curves Monthly Inflow Distribution and Elevation Duration Curves xv 48. 49. 50. 51. Reservoir Regu1ation~ Years 1914-1941 Reservoir Regu1ation~ Years 1942-1968 Tunnel and Penstock Optimization/Comparative Costs Sensitivity Analysis of Penstock and Power Tunnel Optimization xvi LIST OF EXHIBITS 1. Snettisham Hydropower Project t Long Lake Power Conduit and Powerhouse Inspection Report; Alaska District t Corps of Engineers; 12 July 1983. 2. Seismic Risk Assessment t Crater Lake Phase t Snettisham, Alaska; DOWL Engineers, Anchorage, Alaska; July 1982. 3. Side-Scan Sonar and Subbottom Profiling Survey, Crater Lake, Alaska; Ocean SurveYt Inc., Old Saybrook, Connecticut; September 1983. 4. Crater Lake -Lake Tap Investigation, Po1arconsu1t, Inc.t Anchorage, Alaska; November 1982. With Indorsements. 5. Lake Tap Clearing Feasibility Study, Crater Lake Phase t Second Stage Development, Snettisham, Alaska; Tryck, Nyman and Hayes, Anchorage, Alaska; June 1984. 6. Snettisham Crater Lake -WES Review of Final Lake Tap Blast; 20 July 1984. 7. Juneau Area Power Market Analysis, U.S. Department of Energy, Alaska Power Administration; September 1980. '8. Addendum to Juneau Area Power Market, U.S. Department of Energy, Alaska Power Administration; October 1980. 9. Juneau Area Power Market Analysis Update of Load Forecast, U.S. Department of Energy, Alaska Power Administration; August 1981. 10. Juneau Area Power Market Analysis Update of Load Forecast, U.S. Department of Energy, Alaska Power Administration; July 1982. 11. Partial Update of July 1982 Juneau Load Forecast, U.S. Department of , Energy, Alaska Power Administration; November 1982. 12. Juneau Area Power Market Analysis Update of Load Forecast; U.S. Department of Energy, Alaska Power Administration; September 1983. 13. Juneau Area Power Market Analysis Update of Load Forecast; U.S. Department of EnergYt Alaska Power Administration; May 1984. 14. Energy Resource Analysis, Federal Energy Regulatory Commission; April 1982. Volume 2 of. 2 -APPENDICES A. GEOTECHNICAL DATA B. HYDRAULIC DESIGN C. PENSTOCK DESIGN xvi i REFERENCES 1. Mattimoc, J. J., Tinney, R. E., Wolcott, W. W., IIRock Trap Experience in Unlined Tunnels,1I Journal of the Power Division, ASCE, October 1964, pp. 29-45. 2. Boillat, J. L., & Graf, W. H., "Settling Velocities of Spherical Particles in Turbulent Media," Journal of Hydraulic Research, Vol. 20, 1982, No.5, pp. 395-413. 3. Boillat, J. L., & Graf, W. H., "Settling Velocities of Spherical Particles in Calm Waters," Journal of the Hydraulics Division, ASCE, Vol. 107, No. HY10, October 1981, pp. 1123-1131. 4. Rouse, H., "Engineering Hydraulics," John Wiley & Sons, 1949, pp. 780-782, 206. 5. Reinus, Erling, IIHead Loss in Unlined Rock Tunnels,1I Water Power, July-August 1970, pp. 457-464. 6. Rahm, Lennart, "Friction Losses in Swedish Rock Tunnels,1I Water Power, December 1958, pp. 457-464. 7. Wright, D. E., Cox, D. E., and Cheffins, O. W., IIPhotogrammetric Measurement of Rock Surfaces in a Power Tunnel," Water Power, June-July 1969, pp. 230-234, 274-279. 8. Munsey, Thomas, IIUnique Features of the Snettisham Hydro Project,1I The Northern Engineer, Fall & Winter 1976, Vol. 8, No.3 & 4, pp. 4-13. 9. Creager, W. P., and Justin, J. D., Hydroelectric Handbook, Second Edition, 1950, John Wiley & Sons, Inc., pp. 100-102, 547, 546. 10. Rathe, L., IIAn Innovation in Surge-Chamber Design,1I Water Power and Dam Construction, June/July 1975. 11. Bergh -Christensen, J., "Surge Chamber Design for Jukla," Water Power and Dam Construction, October 1982. 12. Chaudhry, M. H., IIApplied Hydraulic Transients,1I 1979, litton Educational 'Publishing, Inc. 13. Svee, R., "Surge Chamber with an Enclosed, Compressed Air-Cushion,1I International Conference on Pressure Surges, 6-8 September 1972, Copyright BHRA Fluid Engineering 1972. 14. Rich, G. R., "Hydraulic Transients," Second Revised and Enlarged Edition, Dover Publications, Inc., 1963. 15. Wallis, S., IIMountain Top Tunnels Tap Glacier for Hydropower, II Tunnels and Tunneling, March 1983. 16. U.S. Dept. of Interior, IIDesign of Small Dams," 1974, p. 465. xvi i i 17. Rajaratnam, N., IIErosion by Plane Turbulent Jets,1I Journal of Hydraulic Research, IAHR. Vol. 19, No.1, 1991, pp. 334-358. 18. Simons, D. and Senturk, F., IISediment Transport Technology, II Water Resources Publications, Fort Collins, Colo., p. 705. 19. Maynord, S., IIPractical Riprap Design,1I Misc. paper H -78-7, U.S. Army Engineer Waterways Experiment Station, Vicksburg, Miss., 1978. , 20. IIHydraulic Design of Flood Control Channels,1I Engineering Manual 1110-2-1601, U.S. Army Corps of Engineers, Washington, D.C., 1970. 21. Brater, E., and King, H., IIHandbook of Hydraulics,1I 6th Edition McGraw-Hill Book Co. 1976, p. 4-19. 22. Jaeger, C., IIFluid Transients "in Hydroelectric Engineering Practice,1I Blackie, 1977, pp. 293-333. 23. Binder, R. C., IIFluid Mechanics,1I 2d Edition, Prentice-Hall, Inc., New York, 1949, pp. 204-205. xix .. . . .. SECTION 1 -GENERAL 1.01 PROJECT AUTHORIZATION. The Crater-Long Lake Division of the Snettisham Project was authorized by Section 204(a); Flood Control Act of 1962, Public Law 87-874, in accordance with the plan set forth in House Document No. 40, 87th Congress, First Session, dated 3 January 1961, as modified by the Reappraisal Report of November 1961. This act also authorizes the Secretary of the Army, acting through the Chief of Engineers, to construct, and the Secretary of the Interior to operate and maintain the project. The Bureau of Reclamation was the original operating agency by intent until Department of the Interior Order No. 2900 established the Alaska Power Administration. The Alaska Power Administration will operate the project and market the power generated. This Design Memorandum is prepared and submitted in accordance with EM 1110-2-1150. 1.02 PROJECT LOCATION. The project is located in the Tongass National Forest near the mouth of Speel River at the Speel Arm of Port Snettisham, a glacial fiord in Southeastern Alaska, (Plate 1). The project is 28 mi southeast of Juneau at 58 degrees 08' north latitude and 133 degrees 45' west longitude. 1.03 STAGE DEVELOPMENT. The Reappraisal Report of November 1961 proposed a three-stage development involving the installation of a 20,000 kW generating unit during each stage, for a total of 60,000 kW. The first stage of development would consist of construction of Long Lake waterways; the powerhouse structure, including skeleton bays for all units, and the tailrace facilities; the installation of one turbine, generator and appurtenant facilities; all switchyard and substation structures and improvements, as well as necessary station service equipment to provide for one generating unit's capacity; and, the transmission line and all general property. The second Long Lake generating unit and appurtenant facilities would be installed as the second stage of development. In addition, the electrical equipment would be expanded to correspond with the increased capacity. The third stage would include construction of Crater Lake waterways and the third generating unit, and would also complete the installation of all switchyard and sUbstation equipment. Design Memorandum No.3, "Selection of Plan of Development", dated Jaunary 1965, as revised May 1965 and approved July 1965, recommended the project be constructed in two stages. The first stage would be as proposed in the Reappraisal Report except that the second generating unit would be installed as part of first stage development and a high dam at Long Lake would also be constructed. The second stage of development for this plan would become what was formally authorized as the third stage in the Project Document. The size of the first two generating units was increased from 20,000 kW to 23,350 kW each as recommended in Design Memorandum 10, "Power Tunnel, Surge Tank and Penstock", dated September 1966 and approved March 1967. First stage construction was completed in 1973. During construction the need for the added capacity supplied by the Long Lake dam was reevaluated in comparison with the additional firm energy that could be provided by Crater Lake. In light of the relatively high cost to construct the dam 1 -1 and the need for additional firm energy (because power requirements had increased more rapidly than originally forecast), the decision was made to advance the Crater Lake phase to first stage development and delay the Long Lake dam to second stage development. Based on subsequent yearly power requirement forecasts by the Alaska Power Administration, the need to construct Crater Lake was postponed until 1981 when it became apparent that the additional energy that Crater Lake could provide would be required within an estimated 5 years. The delay from 1973 to the present has shifted Crater Lake construction to second stage development and the Long Lake dam to third stage. Future studies will be performed to assess the economics of diverting Glacier Creek into the Long Lake power conduit as part of third stage development. 1.04 PURPOSE AND SCOPE. This Design Memorandum presents the feature design of the recommended plan of development for the Crater Lake phase, including the pertinent features of the lake tap, gate structure, power tunnel, surge tank, and penstock. This design memorandum outlines the recommended plan of development for the Crater Lake phase, the considerations which resulted in the plan, and detailed cost estimates for each portion of the plan. The alternative plans considered and alternatives to portions of the recommended plan are also outlined. Significant changes in power requirements, results of additional investigations, experiences in the development of the Long Lake phase, and other factors that developed since the issuance of Design Memorandum 23, Crater Lake Plan of Development, were utilized in the studies and investigations necessary for the establishment of criteria for and development of detailed designs of the various components of the plan. 1.05 PRIOR INVESTIGATIONS. The power potential of Crater and Long Lakes were initially investigated by private mining interests in 1913, with subsequent studies made by private corporations between 1920 and 1928. Although applications were filed with the U.S. Forest Service and Federal Power Commission, the applicants failed to make beneficial use of the water and these applications lapsed. Reports by Federal agencies included those by the Federal Power Commission, Forest Service, Corps of Engineers and Geological Survey. The Bureau of Reclamation began more detailed studies in 1958 and completed a feasibility report in 1959. That report, entitled "Crater-Long Lakes Division, Snettisham Project, Alaska," was published in 1961 as House Document No. 40, 87th Congress, First Session. A reanalysis and reappraisal of the report was completed by the Bureau of Reclamation in 1961. The initial House Document No. 40, as modified by the reappraisal report, provided the basis for the project authorization. Beginning in 1967, detailed site investigations, mapping, and data collections were accelerated, primarily concentrating on those items necessary for the development of the Long Lake phase. Limited investigations for the Crater Lake phase were also conducted prior to 1972. Additional mapping, foundation investigations, and other studies for Crater Lake were started in 1972 and culminated in Design Memoradum 23, the general plan of development for the Crater Lake phase. In 1981 detailed investigations were initiated to enable the completion of the feature design report. 1-2 ~. On 21 and 22 June 1983, an inspection tour was conducted of the Long Lake power conduit and the existing powerhouse facilities. This inspection afforded the opportunity to observe the effects of 10 yr of continuous operation of the Corps-designed facility. The results of the inspection are recorded in the inspection report, included in this design memorandum as Exhibit 1. 1.06 LOCAL COOPERATION. The authorizing act does not require local cooperation for this single purpose project. The two local utilities, Alaska Electric Light and Power (AEL&P) and Glacier Highway Electric Association (GHEA), have indicated that they will continue to buy power from the Snettisham source, and have applied for State loans to expand their distribution systems. The State of Alaska has expressed considerable interest in the project and, because this project is viewed as a Federal responsibility, has urged the U.S. Congress to provide a program that would permit the Corps of Engineers to design and construct the remainder of the project in a timely manner. 1-3 SECTION 2 -REGIONAL DESCRIPTION 2.01 ENVIRONMENTAL SETTING. The Snettisham project is located in the Tongass National Forest approximately 28 mi southeast of Juneau, Alaska. The project is at the head of a narrow arm (Speel Arm) of a fiord (Port Snettisham), which is connected to a larger, inland passage (Stephens Passage) that separates the Alaska mainland and the Alexander Archipelago. As with much of coastal Southeastern Alaska, the project area offers a pleasing contrast of steep landscapes, mature forests, icefields, mountain lakes, and ocean waters. The natural landscape is interrupted by the project airfield, jetty, roads, and transmission lines, parts of which are visible from sea level near the project. Crater Lake is 1,019 ft above Project Datum (1022 MSL) in a narrow, steep-walled valley 3,000 to 4,000 ft below the surrounding peaks. The lake is approximately 1 mi long, 0.4 mi wide, a maximum of 400 ft deep, and covers 330 surface acres. The lake drains approximately 11.4 mi 2, of which about 30 pct is covered by snow and icefields. The average annual runoff is approximately 145,500 acre-ft of water. Crater Lake drains into Crater Creek, which flows precipitously for 1 mi to sea level at Crater Cove. The resources of the area have been developed intermittently since 1794 by trappers, miners, fishermen, and loggers. The abandoned mining village of Snettisham is sited on Stephens Passage near Port Snettisham. The abandoned Alaska Pulp and Paper Company mill, the first pulp mill in Alaska, is about 3 mi south of the Snettisham project. Currently, the Port Snettisham area is sparsely settled; there are approximately 14 permanent residents in the immediate project area, all of whom are associated with maintaining the hydroelectric or fish hatchery operations. Access to the project via the airstrip and the small boat basin is open to recreational users. The U.S. Forest Service controls recreational uses of the Tongass National Forest, including the project area. The Forest Service maintains a trail system to the vicinity of Indian Lake and upper Speel River. There is also an unmaintained trail to Crater Lake. Recreational opportunities include fishing in Indian Lake and Speel River, hiking, camping, and tours of the project facilities. 2.02 HYDROLOGY. The project area is in the maritime climatic zone and is in the path of many cyclonic storms that cross the North Pacific. The maritime influence, the Pacific storms, and the orographic lift by the steep coastal mountains produce a local climate characterized by moderate temperatures (at sea level), cloudiness, and heavy precipitation. Average monthly temperatures range from 25°F in January to 55°F in July. Average annual precipitation is about 140 in/yr at sea level and is estimated to be about 230 in/yr in the Crater Lake drainage basin. The large amounts of precipitation produce an abundant water supply. During warm dry periods glacial melt adds significantly to the water supply while cold wet cycles recharge the ice pack and maintain a high volume of runoff at lower elevations. 2-1 2.03 REGIONAL GEOLOGY. Th~ southeastern coast of Alaska is generally a coastline of submergence partially resulting from geologically recent rises in sea level. As such, it has well developed d~owned river valleys, or "fiords," wherever rivers meet the sea. The depth of the fiords is due to deep glacial scouring of the lower reaches of the river valleys. Extensive stream aggradation and alluvial valley clogging has occurred near the mouths of many larger river systems. The high tidal ranges in the area tend to turn the outwash areas to extensive tidal mud flats. As a result, many streams have braided and meandering patterns throughout their lower valley reaches. In sharp contrast to these gentle, coastal stream gradients, many streams emerge and cascade down from steep mountain fronts which parallel the irregular coastline. Most major streams have active glaciers at their headwaters and their courses are usually marked by typical glacial erosional features such as HUH-shaped valleys, cirque lakes, hanging tributary valleys, truncated spurs, and morainal deposits. The country rock of this portion of southeastern Alaska is derived from the Coast Range batholith, which is an extensive complex of igneous and metamorphic rock that trends generally parallel to the Pacific coastline. The entire igneous-metamorphic complex has been modified by agents of erosion. Most prominent has been ice from all four major continental ice sheets of the Pleistocene Epoch and from associated alpine glaciation. Water erosion has played a subsidiary role. The most prominent erosional features have been developed parallel to joints, faults, and lithologic Doundaries along which streams (and later, glaciers) became firmly established. Most valleys and minor tributary draws in the area are therefore topographic expressions of primary and secondary rock structures in the region. Major faulting and much of the jointing reflected by this topographic expression is a result of crustal movements which have taken place since the intrusion of the Coast Range batholith. With the exception of localized weak zones, few pockets of area-wide deep residual weathering exist in the Coast Range mountains. The lack of widespread, deeply weathered zones in bedrock in an area that receives as much as 230 inches of annual rainfall is rare and is probably due to the removal of nearly all weathered materials by glacial scour. This scouring has been recent enough so that significant residual weathering products have not yet covered the bedrock surfaces. 2.04 TECTONIC SETTING. Southern Alaska is one of the most active seismic regions of the world. The regional tectonic setting defines the degree of seismic activity. Table 2-A lists the historical great earthquakes that have occurred in Alaska within a radius of 300 mi of the Snettisham project site. The primary cause of seismic activity in southern Alaska is the stress imposed on the region by the relative motion of the Pacific and the North American lithospheric plates at their common boundary. The Pacific plate is moving northward relative to the North American plate at a rate of about 2.4 in/yr causing the underthrusting of the Pacific plate. This underthrusting results primarily in compressional deformation which causes folds, high-angle reverse faults, and thrust faults to develop in the overlying crust. 2-2 DATE 1899 Sep 04 1899 Sep 10 1900 Oct 09 1949 Aug 22 1958 Jul 10 TABLE 2-A. GREAT EARTHQUAKES IN SOUTHERN ALASKA (Within 300 mi of Project) EPICENTER DEPTH COORDINATES MAGNITUDE (KM) LOCATION 60N 142W 8.5a Near Cape Yakataga 60 140 8.4a Yakutat Bay 60 142 8.1a Near Cape Yakataga, 53 133 8. 1 25 Queen Charlotte Islands 58.6 137. 1 7.9 Lituya Bay a Revised magnitudes are from Thatcher and Plafker (1977). 2-3 SECTION 3 -RECOMMENDED PLAN 3.01 GENERAL. The recommended plan for development of this phase of the project retains the conceptual principles, as approved in OM No. 23, of a lake tap, gate structure, power tunnel, surge tank and penstock leading to a new turbine in the existing powerhouse (see Plate 1). The specific design and alinement of these features has been changed. The following subsections describe the recommended plan and tell how it differs from the approved Plan of Development in Design Memorandum No. 23. 3.02 RECOMMENDED PLAN. A. Lake Tap, Primary Rock Trap and Primary Trashrack. An open system/wet tunnel lake tap is recommended. With this type of tap, the final rock plug will be blasted, causing its fragments to drop into and be permanently stored in the primary rock trap. Following the lake tap, a self-alining, non-secured trashrack is lowered into position from floating equipment on the lake. B. Power Tunnel Emerrenc y Plugs and Bulkheads. There will be two power tunnel emergency bu kheads located upstream of the gate structure. One is located in the power tunnel near the primary rock trap and the other approximately 75 ft upstream of the gate structure. Their purpose is to provide a means of dewatering the power tunnel upstream of the gate structure in the event of a rock fall or tunnel displacement in that reach of tunnel, a slide in the lake tap area or an unsucessful lake tap. C. Secondary Rock Trap. The secondary rock trap, which consists of an expanded tunnel section, is located upstream from the gate structure to prevent rubble from entering the gate slots. This rock trap is designed to intercept any material not retained in the primary rock trap. D. Gate Structure. A partially concrete lined, wet-well shaft houses a service gate and a bulkhead. The service gate is a hydraulically- operated slide type that will close under an unbalanced head to serve as an emergency gate. The bulkhead operates only under balanced head and will be closed when there is need to unwater the gate structure for maintenance. E. Power Tunnel. The recommended design for the power tunnel ;s a generally unlined, ll-ft diameter modified horseshoe tunnel, extending from the primary rock trap to the final rock trap. F. Surge Tank. The surge tank is an unlined, vented, 10-ft diameter shaft located upstream of the final rock trap. G. Final Rock Trap and secondar~ Trashrack. The final rock trap and secondary trashrack are located at t e entrance to the steel penstock to intercept all material which would be harmful to the turbine. H. Penstock. The 6-ft diameter steel penstock is free standing and is supported on concrete saddles inside the penstock tunnel. 3-1 I. Access. Access to the power conduit and its appurtenances is through two access adits. The primary access adit extends from the road near the powerhouse to the final rock trap and is divided into two segments. The lower segment is 645 ft long and intersects the penstock tunnel approxi- mately 303 ft from thepowerhnuse. The second segment is through a combined penstock/access adit tunnel which allows access along the side of the unencased penstock to the final rock trap. The second access is the gate structure access adit which extends from a helicopter pad and staging area through the gate structure service room to the lake shore above the tap. J. Construction Camp. The location of the construction camp is shown on Plate 1. It will be the contractor's responsibility to provide the required structures and utilities, which are discussed in Section 16. 3.03 CHANGES FROM APPROVED PLAN. A. Lake Tap, Rock Trap and Primary Trashrack. .The closed system/dry tunnel lake tap ln DM 23 has been changed to an open system/wet tunnel lake tap. The power tunnel in DM 23 exits from the side of the primary rock trap, while, in the recommended plan, the primary rock trap and power tunnel have the same horizontal alinement. The intake trashrack in OM 23 was a secured structure to be placed after the lake tap and initial lake drawdown had been completed. The primary trashrack in the recommended plan will be a non-secured structure lowered into place from the lake surface. The lake will not be drawn down to facilitate the placement of the trashrack. B. Power Tunnel Emergenc~ Plugs and Bulkheads. Two power tunnel emergency bUlkheads are ;nclu ed in the recommended plan to provide a means of dewatering the power tunnel upstream of the gate structure if damage should occur in the power tunnel between the lake tap and the gate structure. The current approved plan makes no provision for dewatering that reach of tunnel. C. Gate Structure. The gate structure proposed in DM 23 housed two hydraulically-operated slide gates in a dry gate chamber located immediately above the power tunnel. The gates were to be serviced by an overhead hoist. The upstream gate was designed to accept the over-pressure from the lake tap blast. Power was to be provided by an overhead electrical feeder system from the powerhouse switchyard. The recommended gate structure is a deep wet-well with the operating equipment located in the service room and access adits located above the maximum lake elevation. The service gate is a hydraulically-operated slide gate located downstream of the bulkhead. The bulkhead utilizes a tractor-type mechanism. The operating machinery is powered by feeder cables running along the power conduit from the powerhouse. Communications to the gate structure will be through feeder cables that run alongside the power cables. D. Power Tunnel. The power tunnel in the approved plan was designed with a high vertical alinement. It sloped 0.5 pct from the primary rock trap through the final rock trap. The recommended power tunnel has an upward slope of 3.88 pct from the primary rock trap to the gate structure and a downward slope of 12.437 pct from the gate structure through the final rock trap and continuing into the penstock tunnel. 3-2 • E. Surge Tank. The surge tank approved in DM 23 was an 8-ft diameter, 400-ft high, unlined, vented shaft. The recommended surge tank is a 10-ft diameter, 935-ft high unlined, vented shaft. F. Penstock. The penstock approved in DM 23 would be constructed at a 100 pct slope (45 degree angle). It would be encased in concrete, the same as the Long Lake penstock. The recommended penstock has a 12.437 pct slope, which is the same as the power tunnel slope. The penstock is an unstiffened steel pipe supported by steel ring girders and concrete saddles inside the penstock tunnel. During Long Lake phase construction, approximately 200 ft of the Crater Lake penstock shaft was excavated at a 100 pct slope. The recommended penstock tunnel will intersect the existing stub shaft at the powerhouse wall. The stub shaft will be abandoned. G. Access. In OM 23, the existing Long Lake access road would be extended to serve two Crater Lake phase access adits. One adit provided access from the new road to the surge tank, the other provided access from the new road to the gate structure. In the recommended plan there is no new access road construction. The access road was deleted in the recommended plan for the following reasons: an access road would be used very infrequently during the operation of the project; experience with the Long Lake access road has shown that a large amount of maintenance is required to keep an access road passible; and, it provides a significant reduction in adverse environmental impacts. The primary access adit is served by the existing road near the powerhouse. The gate structure access adit will be accessed by helicopter and provides access to the gate structure and the lake shore. H. Construction Came. In OM 23, it was planned that the construction camp facllltles used durlng the Long Lake phase would continue to be used in the Crater Lake phase. The delay in initiating construction of the Crater Lake phase necessitated removal of the camp facilities; therefore, a new camp must be constructed. 3-3 I ! SECTION 4 -ALTERNATIVES 4.01 GENERAL. Presented in this section are three plans which are alternatives to the recommended plan. Since the plan presented in OM 23 was approved, some design criteria have changed and conditions that are pertinent to a sound design for the Crater Lake phase have been more accurately determined. To better compare the recommended plan with the approved plan, two modified versions of the approved plan were developed incorporating the criteria and conditions as known at this time. Another alternative is to maintain the same penstock slope as proposed in the recommended plan except that the penstock would be fully encased in concrete similar to the Long Lake penstock. Also presented is a primary trashrack/1ake drawdown option which is an alternative that can be incorporated into the recommended plan or the three alternative plans. 4.02 ALTERNATIVE I. This plan is the same as the approved plan presented in OM 23 except for the changes described below. The details of this plan are shown on Plates 23 through 25. A. Power Conduit. The power conduit includes the power tunnel, surge tank, and penstock. Several combinations of the power tunnel, vented surge tank, and penstock were studied to determine the most economical. The slope of the power tunnel between the gate structure and surge tank is kept constant at 0.5 pct and the vertical a1inement is kept high to reduce the height of the vented surge tank, which is designed to vent above the maximum lake and surge level (See Appendix B3 for a detailed discussion of the vented surge tank). The studies determined that the most economical plan utilizing this design includes a 12-ft diameter modified horseshoe, unlined power tunnel, 10-ft diameter, unlined, vented surge tank 395 ft high, and a 6-ft diameter steel penstock encased in concrete. The vertical a1inement of the penstock is revised from the approved plan to eliminate the possibility of negative pressures in the penstock (see Plate 25). B. Gate Structure. The gate structure size, configuration and access have been revised from that presented in OM 23. The structure consists of a concrete-lined 18.5-ft by 28-ft by 290-ft high shaft with a 42-ft by 70-ft by 45-ft high concrete-lined room above it. Two hydraulically operated slide gates are provided to close the power tunnel, which is constricted to a 6-ft wide by 8-ft high opening at the gate structure. The gates and related hydraulic hoists are located at the bottom of the dry shaft, immediately over the power tunnel. An elevator provides transportation between the gates and the room at the top of the structure, where a 15-ton overhead hoist is located. The power tunnel air vent extends from a point just downstream of the service gate, up the inside of the dry-well gate shaft, and terminates approximately 12-ft above the service room floor. c. Electrical Design. Power requirements for Alternative I include lighting ln the gate structure and adits, radio link for remote control and monitoring, and service gate hoisting. (1) Power Sources - 4-1 (a) A propane-fired generator is provided for charging of two 12 V batteries. Generator output is approximately 100 W at 12 Vdc. One battery is utilized for starting of a gasoline powered generator and the second is a power supply for the data link and remote control radio system. The battery systems are isolated so that a failure of one system will not downgrade the other. Maximum fuel consumption would be 300 gal of propane yearly for continuous operation. By utilizing demand cycle operation with automatic ignition, it is estimated that consumption will be reduced to 100 gal/yr. (b) A 12.5 kW, air-cooled, 277/480V, 3-phase, gasoline engine-driven generator supplies power for lighting and hoisting. The unit has demand start, so that a light switch located at the access adit portal is turned on signalling to the generator that there is demand. The generator then starts up, supplying power to the lights. The higher voltage is being utilized to minimize voltage drop problems. Both generator sets are exhausted directly outside the access adit. (2) lighting -Incandescent lighting is used in the gate structure and the gate structure access adit. Due to the limited usage of the lighting system and the delay for strike of a discharge lighting system, the incandescent lighting is considered the most practical approach for this project. The lighting load for these two areas is estimated to be 7.5 kW. lighting will not be provided for the final rock trap access adit. (3) Gate Hoisting Control - A hoist control panel and a gate position indicator are provided in the gate structure service room. The control panel provides basic RAISE-lOWER-STOP functions. (4) Remote Control and Monitoring - A low power (less than 10 W) FM radio link is provided between the gate structure and the powerhouse. This link provides for emergency closure of the service gate from the powerhouse and is capable of transmitting data back to the powerhouse such as "service gate open or closed" and low battery voltage (indicating possible failure of the propane-fired generator). An omni-directional antenna (for minimal wind loading) is tower or pole mounted near the gate structure access adit with sufficient height to preclude burial by snow. (5) Service Gate Emergency Closure -As stated above, a radio link provides for emergency closure of the service gate. This is initiated from a key operated three-position switch located at the powerhouse. The switch initiates two signals to close the gate to insure that the closing circuit is not inadvertently activated by a single stray transmission. A similar three-position key operated switch is provided in the gate hoisting control panel in the service room. Capability for emergency closure of the service gate from Juneau is provided by the existing communication system patched into the powerhouse transmitter. D. Access. The main access to the power tunnel is through a 550-ft long, l3-ft diameter vertical sidewall access adit leading to the final rock trap and surge tank. A road is extended from the existing long Lake road system to the final rock trap access adit. Access to the gate structure and lake shore is through a l3-ft diameter vertical sidewall 4-2 r • access adit extending 950 ft from a helicopter pad at elevation 1,035 ft to the gate structure and then continuing 400 ft to the lake shore. The power supply generators and batteries for the gate structure are located in the gate structure access adit near the portal at the helicopter pad. Helicopters are used to provide transportation to the upper portion of the project. 4.03 ALTERNATIVE II. This plan is the same as Alternative I, except for the changes discussed below. The details of this plan are shown on Plates 25 through 27. A. Power Conduit. The power conduit is the same as discussed in section 4.02 A for Alternative I. B. Gate Structure. This gate structure is of the same concept as selected in the approved OM 23 plan, however, additional study has provided a design with more economical dimensions. The proposed design consists of a rectangUlar 26-ft by 16-ft by 47-ft high concrete-lined dry chamber located immediately above the power tunnel. The chamber contains the gate encasements, power and hydraulic units, access hatch to the power tunnel, and a 15-ton overhead hoist. Two hydraulically-operated slide gates are provided to close the power tunnel, which is constricted to a 6-ft wide by 8-ft high opening at the gate structure. The power supply generators and batteries are located in the access adit near the portal. The power tunnel is vented by a 30-inch diameter steel pipe that extends along the crown of the gate structure access until it reaches the point where it rises in the shortest vertical distance in a drilled hole daylighting above the maximum lake pool level. C. Electrical Design. The electrical design, gate controls, and communications are the same as discussed in Alternative I, Section 4.02 C. D. Access. The main access to the power tunnel is as described for Alternative I in Section 4.02 D. Helicopters are used to provide transportation to the upper portion of the project. Access to the gate structure is through a 1,500-ft long, 13-ft diameter vertical sidewall access adit extending from the helicopter pad at elevation 800 ft. A second helicopter pad is located near the lake shore. 4.04 ALTERNATIVE III. This plan is the same as the recommended plan, except for the changes discussed below. The details of this plan are shown on Plates 28 through 36. A. Power Tunnel. Other than a slope of 12.25 percent, the power tunnel is the same as discussed in Section 3.02 for the recommended plan. B. Gate Structure. The gate structure and gate structure access adit house a service gate and bulkhead and all the equipment required to allow their full opertion for power tunnel filling and draining procedure and for emergency situations. The gate shaft is a 10-ft by 12-ft by 251-ft high chamber that houses the gate, bulkhead, stainless steel gate guides, dogging recesses, access ladder, safety and inspection landings, and the power tunnel air vent. The gate structure shaft is shown on Plate 30. 4-3 (1) Service Gate - A tractor gate 6 ft wide by 8 ft high will be utilized as the service gate and will be operated under balanced and unbalanced heads. Normally, the gate will be suspended immediately above the tunnel in the wet portion of the shaft where it will be available for emergency closure. Details of the service gate are shown on Plate 31. (2) Bulkhead -The gate structure bulkhead 6 ft wide by 8 ft high, located 6 ft upstream of the service gate, seals off the power tunnel at the upstream side of the gate structure, thereby allowing the gate structure to be drained for maintenance. The bulkhead can only be operated under balanced head conditions. When not in use, it will be dogged and stored at the top of the shaft. (3) Electrical Design -Power requirements, gate controls and communication are the same as discussed for Alternative I, Section 4.02 c. (4) Mechanical Design - A single l5-ton hoist is used for raising and lowering the service gate and the bulkhead. It consists of a l-hp electric drive motor, worm gear reduction unit, drum gear, cable drum, cable sheaves, and cables as shown on Plate 32. The cable drum rotates at 0.085 r/min and raises or lowers the service gate or bulkhead at a rate of 0.8 ft/min. There are two cable sheaves. One is an overhead motorized sheave; the other is a floor-mounted swivel sheave located near the service gate slot. The overhead sheave is motorized so its position can be adjusted to be directly above either the service gate slot or the bulkhead slot. The hoist utilizes three 1-1/4-inch diameter, 300-ft long cables. The service gate, bulkhead and hoist drum each are equipped with a cable. To operate either the service gate or the bulkhead, their corresponding cables are run through the sheaves and attached to the drum cable. A position indicator shows the position of the gate or bulkhead for their full range of travel. The service gate cable is connected to the hoist cable, which holds the gate in the open position. When operation of the bulkhead is desired, the service gate must first be closed. The remaining 50 ft of gate cable is then disconnected from the hoist cable, unthreaded from the sheaves, and stored on wall brackets in the service room and access adit. The 300-ft long bulkhead cable, which is stored on wall brackets in the adit and service room, is then removed from the wall brakcets. One end of the bulkhead cable is connected to the hoist cable and the other it threaded through the sheaves and connected to the bulkhead. The hoist cable is then wound onto the drum, thereby taking up the slack in the bulkhead cable. The bulkhead can then be lowered. Total time to close the service gate, change the cables, and lower the bulkhead into the closed position is approximately 11-1/2 h. c. Penstock. The penstock profile is shown on Plate 29. The 6-ft diameter steel penstock begins at a point 125 ft downstream of the air chamber drift tunnel centerline and continues at a downward slope of 14.7 pct to the powerhouse. The penstock is approximately 980 ft long and is encased with concrete and grout similar to the encased penstock approved in OM 23. Methods used for the design of the penstock are discussed in Appendix C. 4-4 D. Access. Access to the gate structure is the same as discussed in Section 4.02 D for Alternative I. Primary access to the gate shaft and secondary access to the power tunnel is by ladder from the gate structure service room. The ladder is enclosed in a cage and provided with landings spaced at 30-ft intervals. Suspended beneath the lower observation platform is an extension of the access ladder that can be lowered into the power tunnel to permit access for inspection and maintenance purposes. Access to the power tunnel will be through a 12-ft wide by 13-ft high vertical sidewall adit that intersects the power tunnel in the final rock trap, opposite from and approximately 23 ft upstream of the drift tunnel for the surge tank. The adit begins near the powerhouse, and is approximately 1,500 ft long. The adit crown will be stabilized with rockbolts as determined necessary by Corps of Engineers field personnel. A 30-ft long concrete portal section similar to the existing powerhouse portals will be constructed at the entrance of the access adit to ensure stability of the surface rock and provide protection from falling rock. The adit location is shown on Plate 28. E. Air Chamber Surge Tank. An air chamber surge tank is a chamber offset from the power tunnel, that contains compressed air above a depth of water. It performs the functions of a conventional surge tank but differs by not being open to the atmosphere. The feasibility of constructing an air chamber surge tank was studied with the following results: (1) Size -An air chamber 24 ft wide 129.7 ft long and 22.6 ft high with a total chamber volume of 65,500 ft~ was designed for the nominal tunnel diameter of 11.0 ft. The water volume in the air chamber is 14,500 ft 3 at minimum power pool. (2) Hydraulic Transients -Maximum and minimum water hammer elevations at the unit are 1,329 ft and 549 ft, respectively. The maximum and minimum hydraulic gradient elevations at the air chamber are 1,128.4 ft and 734.4 ft, respectively. The unlined air chamber is excavated from solid rock and is connected to the power tunnel by an 82-ft long, ll-ft diameter modified horseshoe drift tunnel, which slopes upward at 12 pct from the final rock trap to the surge tank. The corners of the drift tunnel are rounded to reduce head losses. Air is provided to the tank by compressors located in the powerhouse. The orifice, which is generally a standard design feature of surge tanks, is omitted from this design to improve water hammer reflection from the surge tank. The air chamber surge tank was found to be less costly to construct than the vented surge tank, but the vented surge tank is the recommended type because it does not rely on extra equipment for its operation. Therefore, the vented tank is simpler, and in the long run, more economical to operate. Hydraulic Appendix 84 covers the air chamber design in more detail. 4.05 COMPARISON TO THE RECOMMENDED PLAN. The conceptual differences between the recommended and approved plans are discussed in Section 3.03. These differences, as modified by the preceeding discussion of the alternative plans, are also the primary distinctions between the recommended and alternative plans. 4-5 4.06 PRIMARY TRASHRACK/LAKE DRAWDOWN. This feature/procedure is an option that can be incorporated in either the recommended plan or the alternative plans. This plan calls for installing a temporary trashrack after the lake tap in the same manner as the recommended plan. Duri ng the fo 11 owi ng winter the lake will be drawn down and maintained at minimum pool by producing power with the Crater Lake generator. During the next construction season a permanent combination trashrack and bulkhead will be installed. An elaborate winch and pulley system is required for operation of the bulkhead. This design does not incorporate a trashrack cleaning device because one was not found that will be compatible with the trashrack and bulkhead as designed. (See Plates 38 through 40.) The time needed to draw the lake down, install the permanent trashrack, and refill the reserv.oir to maximum pool adds approximately 21 mo to the date when firm power-on-line can be achieved, when compared to the schedule for the recommended plan. 4-6 .' " SECTION 5 -HYDROLOGY 5.01 GENERAL. The Snettisham area lies within the maritime climatic zone of Alaska and is greatly affected by the cyclonic storms that cross the Gulf of Alaska. The terrain in the area is mountainous, and orographic lifting and resultant pseudo-adiabatic cooling of moist air masses from the Gulf of Alaska exert a basic influence upon local temperatures and precipitation, creating considerable variation in both temperature and precipitation within short distances. Precipitation data for the 11.4 mi 2 Crater Lake basin is nonexistent. However, if glacial effects are not considered, an estimate of average precipitation based on eXisting average annual runoff data would be approximately 230 inches annually. The Crater Lake basin has very little soil or vegetative cover over the bedrock. The majority of the runoff in the basin is surface flow with some subsurface and base flow. Annual flood peaks predominantly occur in the fall months and are mainly due to intense rainfall. There are 12 yr (WY 1914-20, 1928-32) of streamflow records for Crater Creek at the Crater Lake outlet. Average discharge for the 12 yr of record is 193 ft 3/s. See OM #1 HYDROLOGY for more detailed basin hydrology. 5.02 WATER SUPPLY STUDIES. A. Initial. The initial water supply studies for the Crater Lake basin were presented in OM #1 HYDROLOGY. Linear regression ~nalyses were made to determine the monthly statistical relationships between Crater Creek and Long River flows. Concurrent monthly flows at Crater Creek and Long River were correlated and resultant derived equations used to fill the missing record for Crater Creek for October through December of WY 1921 through 1924, WY 1927, and WY 1933 through 1968. B. Recent. Recent studies attempted to improve the estimates of Crater Creek flows. The "Monthly Streamflow Simulation" (HEC 4) computer program was used to correlate flows at Long River, Dorothy Creek, and Crater Creek. Results did not improve upon those obtained in the initial study; however, HEC 4 was used to fill in the two years (WY 1925 & 26) where flows were not recorded at either station. Monthly flows for 1925-26 were generated by the program based on the statistical flow characteristics of Crater, Long, and Dorothy Creeks. Refer to Table 5-A for Crater Creek monthly flows for WY 1914 through 1968. All recorded and correlated monthly flows were used in the sequential routing for the power studies. 5.03 GLACIAL MASS BALANCE STUDY. There are 11.4 mi2 of drainage area above the Crater Lake outlet. Thirty percent, or 3.4 mi 2, of this area is covered by glaciers. Water supply estimates for Crater Lake have been made solely from streamflow records. These estimates may be high or low, depending on the state of glacial mass balance during the period of streamflow record. If the glaciers were wasting during this period, it is possible that a considerable amount of measured flow was coming out of glacial ice storage; or, if the glaciers were building during the period, measured flow could have been considerably low. The worst case would be one in which the glaciers were wasting during the period streamflow was recorded and then begin building during project operation. The problem of projecting future water supply from glacierized basins, without taking 5-1 account of glacier wasting, is not without precedent. For the 190 MW Grande Dixence project in Switzerland it has been necessary to augment the water supply because glacial wasting was not taken into consideration in estimating design supplies. Glacier studies recently conducted for the Susitna Hydroelectric Project in Alaska have indicated that some of the glaciers covering 4 pct of that basin have been wasting in recent years. Correspondingly, as much as 13 pct of the total flow at one gaging station has been coming out of glacial ice storage. The U.S. Geological Survey is currently studying historical and recent aerial photographs of the Crater and Long Lake basins to see if there is any indication that the glaciers in the basin have been building or wasting. If the study shows that the glaciers have been or are currently active the streamflow data from Long River and Crater Creek will need to be reanalyzed. TABLE 5-A. AVERAGE MONTHLY FLOWS FOR CRATER CREEK (ft~7s ) WY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP AVE 1914 260 108 38 21 45 37 53 144 272 517 409 266 181 1915 313 104 24 36 17 45 74 235 414 497 469 389 218 1916 185 45 33 18 18 19 44 90 370 370 464 470 177 1'917 270 51 33 35 45 23 24 142 305 441 539 361 189 1918 251 250 35 33 17 13 21 129 347 482 591 411 215 1919 202 133 65 68 15 12 47 118 217 417 511 420 185 1920 209 67 45 100 35 16 20 53 177 406 532 262 160 1921 140 92 25 24 31 24 34 138 305 399 360 297 156 1922 290 75 95 34 10 10 35 145 287 437 471 352 187 1923 202 158 41 21 28 38 47 160 297 452 483 502 202 1924 230 198 77 28 17 30 39 229 400 584 566 581 248 1925 388 58 34 72 30 41 47 100 360 399 290 327 179 1926 301 52 48 59 22 49 36 262 501 545 392 353 218 1927 197 124 95 35 27 25 38 161 350 377 357 352 178 1928 135 48 25 89 31 40 42 193 381 528 377 343 186 1929 194 113 82 76 19 49 29 92 382 419 404 347 184 1930 463 222 60 5 9 15 34 104 308 420 484 359 207 1931 225 256 146 68 102 22 45 211 402 417 474 361 227 1932 334 73 28 20 20 15 33 105 284 362 366 429 172 1933 316 42 27 14 13 15 66 211 230 379 367 252 161 1934 219 170 43 7 12 18 31 100 371 420 565 342 191 1935 296 92 67 15 10 20 30 90 251 606 418 276 181 1936 274 66 97 16 13 21 42 194 462 454 371 467 206 1937 762 294 127 26 16 23 35 112 436 379 411 465 257 1938 615 96 62 55 43 46 32 225 309 423 333 535 231 1939 327 84 68 37 26 20 33 124 337 520 608 353 211 1940 373 151 89 28 38 15 43 205 323 485 560 433 229 1941 311 79 43 15 25 24 51 166 372 491 293 202 173 1942 276 166 75 40 33 36 37 158 425 538 536 393 226 1943 361 61 42 45 21 33 56 166 337 585 466 524 225 1944 637 170 125 41 33 37 38 163 488 448 396 291 239 (continued) 5-2 " "', .' " TABLE 5-A. (continued) WY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP AVE 1945 489 151 99 19 15 25 36 209 361 502 357 424 224 1946 644 55 28 13 15 20 30 255 414 403 457 316 221 1947 258 141 36 23 19 53 48 212 409 403 330 525 205 1948 291 100 77 44 20 19 25 243 466 461 372 530 221 1949 208 134 48 35 16 21 37 207 310 410 421 379 185 1950 224 361 76 10 10 15 25 122 323 436 339 413 196 1951 110 38 22 17 15 19 33 160 411 489 291 311 160 1952 114 46 35 12 13 18 42 161 302 511 426 480 180 1953 515 167 45 20 22 17 29 227 428 446 456 376 229 1954 402 51 51 25 89 21 20 108 314 384 271 389 177 1955 184 178 120 33 18 21 24 93 267 506 518 359 193 1956 126 77 22 9 10 15 25 185 226 497 621 278 174 1957 142 163 115 48 15 13 29 177 342 392 354 444 186 1958 241 169 44 84 23 18 42 216 490 474 442 216 205 1959 320 93 52 25 23 21 32 156 404 606 396 240 197 1960 231 101 71 34 18 25 41 177 361 511 434 422 202 1961 355 125 99 52 41 33 52 194 473 691 684 301 258 1962 428 74 23 79 26 31 29 101 340 431 367 480 201 1963 243 152 101 59 70 36 35 138 306 454 330 543 206 1964 321 45 76 50 35 92 43 104 457 600 375 198 200 1'965 292 100 72 102 39 154 34 78 279 412 387 242 183 1966 409 55 42 17 15 86 38 135 340 446 474 485 212 1967 301 83 22 17 18 63 20 137 566 411 495 585 227 1968 153 135 45 20 44 259 34 159 259 431 290 564 199 AVE 301 118 60 37 26 35 37 158 355 464 432 386 201 5-3 SECTION 6 -GEOLOGY 6.01 GENERAL. This section describes the surface and subsurface geological features of the study area that will impact the design and construction of the project. 6.02 COMPLETED EXPLORATIONS AND INVESTIGATIONS. Plate 41 shows the location of all completed core borings in the general vicinty of the power conduit and its features. Subsurface explorations, consisting of eighteen NX core holes totaling 7,140.2 lineal ft, were intended to investigate specific features. All known specific features which were mapped for the earlier design stages have been investigated. Log records of the drill holes and corresponding pressure test results are shown in Appendix A. A summary of the subsurface explorations is presented in Table 6-A. 6.03 PROJECT SITE GEOLOGY. A. General. The regional geology and a major portion of the project s'ite geology have been presented in Design Memoranda 3, 7, 13, and 23. The following information is presented in addition to that which has been presented in previous reports. B. Overburden. There is very little overburden on the steep ~ountain slopes in the area, since most has been removed from the slopes by relatively recent glacial action. The higher reaches of stream valleys have boulder and cobble deposits developed by ice and frost wedging in the bedrock as well as by active erosion from streams and glaciers. In certain areas, snowslides contribute substantial rubble to valley deposits. In the lower stream reaches, where gradients are flatter, deposits of sand, gravel and cobbles occur. C. Bedrock Lithology. The rock in the immediate Snettisham area consists predominately of quartz diorite, quartz diorite gneiss, and biotite-hornblende schist, all in an interwoven and random pattern. The quartz diorite commonly has a gneissic structure with alternating, subparallel, light and dark colored layers containing varying proportions of quartz, feldspar, hornblende, and biotite mica minerals. The light layers consist primarily of equidimensional quartz and feldspar with minor dark minerals. The darker colored layers contain platy biotite mica and tabular to prismatic hornblende as well as the quartz and feldspar minerals. Thin section studies show that the quartz diorite contains approximately 18 pct dark minerals (13 pct biotite mica, 5 pct hornblende); 79 pct light-colored minerals (60 pct plagioclase feldspar, 15 pct quartz, 4 pct orthoclase feldspar); and 3 pct miscellaneous accessory minerals. Granitic and basaltic dikes have intruded along existing joint planes in these rocks. D. Joint Systems. There are two unrelated groups of joints in the area. (1) "Low Angle" Joints -The "low angle" joints are stress relief or "unloading" joints caused by the removal of an overlying rock load by glacial scour and the later removal of the ice load itself. This 6-1 TABLE 6-A. SUMMARY OF EXPLORATIONS LOCATION START FINI"SH SIZE ANGLE ORILLEO HOLE NO. N E OATE OATE CORE FROM VERT. OEPTH REMARKS DH-98 93614 86377 09-30-72 10-08-72 NX 0° 219.2' Rock Trap OH-99 95473 91607 09-27-72 10-09-72 NX 0° 350' Power Tunnel OH-100 93611 86371 10-11-72 10-19-72 NX 35° 310' Lake Tap and Rock Trap OH-l01 94116 88088 10-13-72 10-19-72 NX 0° 232' Power Tunnel OH-l02 93616 86380 10-21-72 10-27-72 NX 45° 334' Crossed Hilltop Fault DH-l03 94271 88228 10-30-73 10-07-73 NX 0° 366.8' Power Tunnel OH-104 95454 91480 09-17-73 10-05-73 NX 0° 454.4' Power Tunnel 0'1 I OH-l05 94135 88085 09-21-73 10-07-73 NX 37.5° 325.9' Power Tunne 1 N OH-l06 95159 91259 10-15-73 10-26-73 NX 35° 415.8' Power Tunnel OH-107 94886 90405 11-12-73 11-22-73 NX 37° 340.2 Power Tunnel OH-108 93451 86209 10-04-74 10-10-74 NX 0° 259.3' Lake Tap OH-l09 93685 86244 10-12-74 10-19-74 NX 0° 277.7' Lake Tap OH-110 93549 86220 10-2G-74 10-25-74 NX 0° 271 • l' Lake Tap OH-ll1 93729.8 86720.3 07-29-82 08-21-82 NQ 0° 747.3' Gate Chamber OH-1l2 93767.6 86703.6 09-10-82 10-02-82 NQ 30° 602.1' Gate Chamber OH-1l3 93731. 0 86699.5 10-06-82 10-14-82 NQ 30° 392.2' Gate Chamber OH-1l4 93731.0 86934.0 10-06-82 10-17-82 NQ 30° 592.1' Power Tunnel OH-1l5 95300.4 91992.3 09-09-82 09-28-82 NQ 45° 650. l' Penstock and Surge r nber " '!! • ., , 1J! " " ~ ~ , ., type of jointing is common in areas of glaciated granitic rocks. These joints are roughly perpendicular to the tensile stress which is usually parallel to the exposed rock surface. In this type of jointing, the rock pulls apart along the lines of least restraint and least tensile strength. Low angle joints commonly die out with depth. S~ch joints were encountered in the Long Lake access adit, the powerhouse access, service, and tailrace tunnels, and in the weir area at Long Lake. (2) "High Angle" Joints -The other major group of joints, the "high angle" joints, are developed by tectonic stresses. ~ese joints exhibit smooth slickensided surfaces, indicating enough movement to shear the interlocking crystalline mineral grains. In general, these joint zones are more nearly planar and more continuous than the low angle unloading joints. In the underground excavation during the Long Lake phase, three major sets of high angle joints, two of which are prominent, were observed. In the powerhouse, one set strikes N25°-35°E and dips 65°SE, and correlates to a set in the Long Lake power tunnel striking N30o-35°E and dipping 75°SE. Another prominent set in the powerhouse strikes N45°-55°E with dips of 55°-80 oSE. This set is the same as the one in the Long Lake power tunnel striking N45°-50oE dipping 75°SE. Another major, but less prominent, set in the powerhouse strikes N65°-80oW with dips of 70o-85°SW. A generally similar set is also visible in the Long Lake power tunnel. Other joints exist but are less pronounced and less persistent. Many joints have chlorite staining and many others have a coating of pyrite. Several highly jointed and fractured basalt dikes are present in the area. These dikes have three major joint sets which usually do not coincide with the joints in the country rock. The joints in the dikes are related to the orientation of the dikes and to chilling and shrinkage. (3) Sterographic Plot -See Figure 6-1 for an upper hemisphere sterographic plot of the attitudes of the discontinuities in the vicinity of Crater lake. 6.04 TECTONICS AND SEISMIC RISK STUDIES. A. General. In order to better understand the impact of the fault zones crossing the tunnel and penstock alinements, the Alaska District contracted DOWL Engineers, Anchorage, Alaska, to perform a seismic risk assessment study for the Crater Lake phase. Their report, dated July 1982, is included as Exhibit 2. In their report, DOWL Engineers estimated the potential slip along local faults. Faults which cross the proposed tunnel alinement and the estimated potential slip for each of these faults are shown in Figure 7 and Table 2, respectively, of the DOWL report. B. Peak Ground Motions. Re-examination of applicable graphs and equations developed in WES report S-73-1, specifying peak motion for design earthquakes, indicates M=2+0.54 10 for strike slip faulting in southeast Alaska. Accepting a magnitude 8.6 event on the Fairweather-Queen Charlotte Fault, gives a local 1=9.3, a maximum site rock acceleration (g)=0.38, a maximum rock velocity of 13.8 in/s and a duration of 10 s plus. All values are far field not time dependant. The duration vs. intensity curve was used instead of the distance/duration curve since it is reasonable to expect some acceleration duration greater than 0.05g, at 105 km, for a magnitude 8.5 event. The District's consultant (DOWL Engineers) has 6-3 t, ,10-~ • L.EGENQs • ROC. PACI A.OWI TA~ • OLD ACCI •• ROAD CINTlftL'Na .. • ~} • TMJICH TU .... IL ~ ~I ... TOC. '" ..> ~ CINTI"L • PAULT ,FIGURE 1. UPPER HEMISPHERE SrEAEOGRAPHIC PLOT OF DISCONnNUITIES' .. ~ .... COliTOUIl. • ~ .. OUT ... CONTOUR. evaluated the Port Snettisham region. Assuming a 100 yr project life, they have arrived at a peak bedrock acceleration of 0.67g for an areal (floating) source and 0.59g for a linear source (Coast Range Megalinement). The linear source is not considered to be an active fault; but the ~istrict feels that an event of magnitude 8.6 and a bedrock acceleration of 0.59g are appropriate for the project design. 6.05 ENGINEERING GEOLOGY. A. Rock Conditions. Eight core holes were drilled to investigate faults crossing the tunnel (see Table 6-A and Appendix A). The power tunnel crosses five prominent and approximately 14 minor shear zones between the primary and final rock traps. These vary from single discontinuities with less than 0.1 ft of gouge or altered rock to an estimated 250 ft of disturbed rock where the tunnel crosses the Tlingit Fault. The Crater Lake tunnel passes through most of the fractures at an acute angle of 20 to 30 degrees, which means that more remedial treatment is required for the zones of altered rock than if the tunnel was perpendicular to the fractures. Geologic maps and profiles of the various features are shown on Plates 41 through 44. Explorations done to date indicate the quartz diorite gneiss bedrock through which the power tunnel will be excavated is generally of good to excellent quality. Localized exceptions will occur at fault zones. The central portions of each of the faults is expected to be closely broken, mylonitized, and altered rock, with definite lenses or stringers of fault gouge. Bordering each central zone are phases of less severly broken or altered rock extending outward to the mass of rock. B. Rock Treatment. Analysis of the rock strength for "average ll fault conditions and "worst case" fault conditions was performed. Results show that minimal support requirements are needed for approximately 250 ft of tunnel constructed through "average" fault conditions. For the Ilworst case" fault condition, which represents the conditions for the five prominent faults that cross the tunnels, support requirements are 6 inches of reinforced shotcrete. For the rock adjacent to the faults, support requirements are tensioned bolts placed 3 ft on center and 2 inches of reinforced shotcrete. Sample calculations of support requirements are shown in Appendix A. Pattern rock bolting will be done in areas where the frequency, dip and strike of fractures requires such reinforcement. Elsewhere, spot bolts will be used to provide safety or to supplement pattern bolts where unfavorable conditions exist. When required, rock bolts will be installed immediately after tunnel excavation to minimize stress relief, overbreakage and rock falls. Approximately 1,400 rock bolts will be required for the tunnels and appurtenant structures. Testing will be restricted to pull tests on rock bolts. The Crater Lake tunnels should not require the usage of set supports; however, the contractor will be required to have ten steel sets on site as a precautionary measure. C. Tunnel Water. Water under relatively high pressures is anticipated to be present in areas of sheared rock. These sheared rock zones should, however, become healed and fairly tight at tunnel depth, confining water inflows to minor drips. Should water become a problem during construction, drain holes will be drilled and shotcrete applied to either seal off or drain the inflow. 6-5 E. Lake Tap. (1) Overburden -The most important area of the project, geologically speaking, is the mass of rock through which the lake bottom will be pierced. The site was originally selected from limited field work and studies of aerial photographs during the Long Lake phase as that area appearing to have the most favorable geology. A seismic refraction survey of the tap area was performed in October 1972 by Shannon and Wilson, Inc., for Taku Constructors. Because of the steep slope of the lake bottom, the records illustrate a bottom derived from diffractions and side reflections rather than true bottom reflections. These factors created water depths in error by as much as 50 ft in the steeper part of the slope, and the reflection pattern would erroneously suggest that up to 40 ft of overburden exists out to the 200-ft water depth. In 1973, a two man submarine was used to investigate the bottom of the lake. Video tapes were made of three traverses of the tap area starting approximately 250 ft deep and moving up contour to the lake surface. An estimate of overburden depth was made by penetrating the overburden with the submarine until the submarine struck solid material. Assuming the attitude of the submarine was level, the very fine grained sediment covering the solid material was estimated to be 3 to 4 ft deep in those few places investigated. Below approximately 145 ft of depth, a horizon of trees was found in all traverses. A geophysical survey of the proposed tap area was performed by Ocean Surveys, Inc. (OSI) during the summer of 1983 to verify the previous findings. The survey consisted of side-scan sonar and bedrock profiling and was intended to define the thickness of overburden, the location of large objects, and the presence and extent of logs in the tap area. The results of the geophysical survey as reported by OSI are included as Exhibit 3. The surveys revealed that there is a probable slide area at the approved tap location. As a result, the tap location for the recommended plan (see Plate 9) has been moved slightly to the north of the original location •. Unfortunately, the survey was unable to distinguish the extent of log debris on the bottom. (2) Bedrock -Three NX core holes were drilled in the tap area in October, 1974. The information received from those holes confirmed earlier surface mapping and air photo interpretations. Open joints are common near the top of the rock and may also exist in the tap area. The logs of the core drillings are shown in Appendix A. 6.06 FUTURE INVESTIGATIONS. A. Power Conduit. To explore for the occurrence of high pressure flows of water or unfavorable ground conditions, an exploratory guide hole will be drilled in advance of the tunnel heading when approaching the prominent fault zones. Drilling of the guide hole will be phased with normal tunneling operations. Evaluation of the integrity of the tunnel surface with respect to the deformation characteristics of the rock is recommended by DOWL Engineers and Polarconsult (Exhibit 4) to assess the overall capacity of the tunnel to deform without damage during earthquakes. This investigation is not needed because the June 1983 inspection of the Long Lake power tunnel indicated that the integrity of the rock surface is excellent with no indication of stress concentrations. 6-6 • ,. B. Lake Tap. (1) Seismic Refraction Survey -In their report titled IILake Tap Investigationsll (see Exhibit 4) Polarconsult, lnc. recommends that a seismic refraction survey be performed in the tap area. In addition, DOWL Engineers and Ocean Survey Inc. also recommend a seismic refraction survey prior to construction. Bedrock surface contours (see Exhibit 3) do show distinct linear features which do not correlate with any known structural features. While these features are most likely deep glacial gouges, the refraction survey will "show any significant rock changes that may represent structural weakness. However, based on the erroneous conclusions of the 1972 Shannon and Wilson report, we do not recommend the conductance of another seismic refraction survey. (2) Geological Explorations -During the summer of 1984 the Alaska District conducted an extensive exploration program in the tap area to better define the quality of rock at the selected site, and the extent and type of overburden that needs to be cleared from the site prior to the tap. The program consisted of three core holes in the vicinity of the tap and 4 to 6 shallow probes within the limits of the area to be cleared. The results of that exploration program were not available for inclusion in this design memorandum, but will be forwarded for review under separate cover. (3) Coring Probes -Before the tap and primary rock trap are excavated, the contractor will be required to conduct coring probes of the lake bottom which will be used to verify the soundness of the selected tap location. These probes will also be used to determine whether grouting is needed to prevent leakage in the tap area. 6-7 SECTION 7 -LAKE TAP 7.01 GENERAL. This section summarizes the design and procedure for connecting the power tunnel to the reservoir. Additional design information is presented in Appendix Bl. The recommended lake tap is referred to in the Polarconsult report (see Exhibit 4) as the open system/wet tunnel type. Prior to the final blast, the tunnel upstream of the gate structure is filled with water that is brought in through the gate structure shaft. The tap configuration is similar to the one used for the Ringedalsvatn lake tap of the OKSLA Hydropower project in Norway. The lake tap consists of an entrance orifice, a large rock trap, and a transition to the ll-ft diameter modified horseshoe tunnel. The open system/wet tunnel tap is preferred because it reduces the impact of the blast forces on the service gate and requires a less complicated rock trap configuration. Details of the recommended tap are shown on Plates 9 through 12. 7.02 LAKE TAP LOCATION. The proposed location of the lake tap is shown on Plates I, 2 and 9. when power tunnel excavation progresses beyond the location of the gate structure, sounding drillings will be repeatedly performed ahead of the tunnel face for a distance of at least twice the length of the next blast round, until the lake tap location is reached. This procedure will aid in determining the best tap location and the presence of rock fractures that could transmit water to the tunnel. The sounding probe will be equipped with a packer for sealing off the hole if water is encountered. 7.03 ORIFICE. The final blast will result in an orifice that is 12 ft in diameter and 10 ft long. Hydraulically, the orifice will act as a short tube with the vena contracta occurring approximately 5 ft from the entrance. Maximum velocity at the vena contracta is 5.7 ft/s. The orifice opens to Crater Lake at elevation 799. 7.04 PRIMARY ROCK TRAP. A. General. The primary rock trap is an integral part of the lake tap. The function of the primary rock trap is to contain the material from the lake-piercing blast and allow flow from the reservoir into the power tunnel with a minimum of resistance and turbulence in keeping with good economics. B. Rock Trap Design. The final blast will produce approximately 86 yd 3 of rubble. The rock trap is sized to contain the final blast material plus an additional 55 yd 3 of material which might occur over the life of the project without restricting the flow into the power tunnel. The rock trap is 64 ft long and 18 ft wide. Because the invert slopes upward at a 12.4 pct slope in the downstream direction, the height of the trap varies from 27 ft near the orifice to 17 ft at the downstream end of the trap. A transition section 38 ft long connects the rock trap to the ll-ft diameter power tunnel. Plates 11 and 12 show the recommended design. 7 -1 7.05 TAPPING OPERATION. A. General. For the tapping operation, the contractor will be required to hire a specialist in construction of lake taps, whose credentials must be reviewed and approved by the Corps of Engineers. This individual will be in complete charge of all technical aspects of the tap construction including drilling pattern, exploratory holes, grouting, shot pattern, powder charges, etc. The Corps will retain the construction management services of a consultant experienced in the design and function of deep water lake taps. The contractor and Corps specialists must be in agreement on procedures prior to beginning work in the tap area, and will confer on a daily basis once work starts. The Corps will act as arbiter should there be a conflict between the recommendations of the experts. This procedure was recommended by Polar Consult and is the same procedure that was followed during the Long Lake tap. B. Tap Site Preparation. Prior to the final blast, all overburden will be removed from the v1cinity of the tap to at least the minimum limits shown on Plate 9. The firm of Tryck, Nyman and Hayes was retained to evaluate several methods of doing the clearing and forward a recommendation. Eight methods to clear the tap site of overburden were evaluated, six of which were ruled out (see Exhibit 5). Portions of the schemes that have been ruled out have possible uses in conjunction with either of the two methods studied in detail. The two methods presented in detail are! (1) excavation by clamshell off of a barge, and (2) excavation by the slusher method. The latter appears to be the least costly of the two alternatives. Under the slusher method, a cable system similar to a high-line would be installed across the lake. A heavy blade/plow/rake would be pulled down-slope, moving the overburden away from the tap site and depositing it in deeper water below the tap elevation (see Plate 10). Details of the two methods that appear to be the most feasible are presented in Exhibit 5. Included in the analysis are equipment li~ts, manpower requirements, equipment layouts, location plans and cost estimate. The exact clearing limits will be determined during the development of plans and specifications. The contractor will be required to verify his clearing progress and final survey by use of either subbottom profiling, side scan sonar, Remote Sediment Profile camera, or divers. The contractor will be allowed his choice of any, or a combination of all, methods available. Exploration drilling, to be completed during the summer of 1984, will be very useful in providing information on the nature of the overburden as well as confirmation of the side scan sonar data concerning depth of overburden. C. Tae Chartes. After the rock trap has been excavated and only the rock plug 1S lef in place between the rock trap and the lake, a precalculated number of holes will be drilled and powder charges set. All charges will be detonated from the helipad/staging area outside the gate structure adit. 7-2 D. Prefilling. Prior to the tap blast, the gate structure bulkhead will be removed to prevent damage and the service gate will be closed. Water will be pumped from Crater Lake to prefill the gate shaft and the power tunnel upstream of the service ga'te. The gate shaft will be filled to an elevation of 24 ft below the elevation of the pool that exists at the time the tap is made (if the lake is at the observed maximum pool of 1,019 ft, the shaft will be filled to elevation 995 ft). The head differential of 24 ft was selected because it is sufficient, along with gravitational forces, to carry rock plug material into the primary rock trap. In addition, a WHAMO run showed that the 24 ft head differential would result in a gate shaft surge up to an elevation of 1040 immediately after the lake tap blast. This surge elevation would preclude any flooding in the gate shaft access adits. The Polarconsult report (Exhibit 4) states that a head differential of 26.2 ft was used for the successful Ringedulsvatn lake tap in Norway. E. Air Cushion. During prefilling, a compressor located at the staging area outside the gate structure access adit will be used to pump air to the lake tap air space in the primary rock trap. The air space acts as a cushion, reducing the effect of the shock wave which is transmitted through the water to the service gate. The water surface elevation in the air space will be maintained at an elevation of 783 ft with the resultant pressure at 90.8 lb/in 2g. A standard 30 hp compressor with a continuous pressure rating of 100 lb/in 2g can pressurize the air space in about 2 hr ff prefilling can proceed as rapidly. F. Blast Reaction. The lake tap blast and consequent surge of water into the rock trap will result in a force of approximately 882,000 lb (a pressure of 295 ft of water) on the gate and a maximum surge of water up the gate shaft to elevation 1,040 ft. The Waterways Experiment Station has confirmed these conclusions, as shown in Exhibit 6. Keeping the gate structure service room (floor elevation 1,040 ft) dry is desirable but not essential since the equipment located there will not be damaged by any short term wetting. All personnel will be out of the gate structure and access adit prior to the blast. G. Time Period. The time between the start of prefilling and the blast will be strictly controlled. In their report, Polarconsult says "The period of time from start of filling the tunnel until triggering the final blast is critical. The work for this period should be planned to the smallest detail aiming at 16 hrs from start of filling until firing (this even if the delay caps should be specially made to resist 300 ft of water pressure for 72 hrs)." H. Instrumentation. A discussion of the instrumentation for the lake tap operation is presented in paragraph 13.02. 7.06 PRIMARY TRASHRACK. A. Design. For design purposes, the bar spacing used for the Long Lake primary trashrack was assumed for the Crater Lake primary trashrack. This spacing is 1/2-inch bars spaced 2-1/2 inches on center. Based on a flow net analysis, the maximum effective gross area for the trashrack is 7-3 approximately 200 ft2. Based on that area and a maximum discharge of 518 ft 3/s, the maximum velocity is 2.58 ft/s. The trashrack will be constructed in two pieces joined by a hinge on its downslope side. The bars of the top piece will fit parallel to and directly over the bars of the bottom piece. There will be a series of guard plates 1 ft by 4 ft by 1 inch thick with a slotted hole that will be bolted around the perimeter of the trashrack. Each plate will have guides welded to the trashrack. Their purpose is to adjust to the lake bottom contour to keep debris from entering into the intake. The recommended design is shown on Plate 13. The trashrack hydraulic design is discussed in greater detail in Hydraulic Appendix Bl. B. Placement. After the lake has been tapped, the trashrack will be lowered into position from the lake surface. The underside of the trashrack will have a tapered guide that will fit into the orifice and serve to aline the trashrack over the orifice and prevent the trashrack from slJding down the rock slope. The trashrack will be held in position by its own weight and 4 concrete cylinder counterweights. The guard plates will be bolted in the raised position during placement of the trashrack. After the trashrack is in place, a hardhat diver will loosen the bolts and slide the plates down until they contact the lake bottom. He will then retighten the bolts. The guard plates will be able to adjust to a maximum of 3 ft below the bottom of the trashrack. The plate guides will be coated with a heavy grease to assist the diver in lowering the plates. C. Cleanin a" Two cables will be permanently attached to the upper rack and secure on the lake shore. When cleaning is to be performed, the cables will be attached to barge-mounted hoists that are powered by 2 hp electric motors. Raising the cables and the upper rack will cause the debris to be deposited on the downslope side of the trashrack. The barge is stored on rails mounted on the rock surface below the gate structure access adit. Utilizing the hoists mounted on the barge, the barge pulls itself up the rails to a point above maximum water surface elevation, where it is dogged off. This protects it from ice that forms on the lake during the winter months. During initial construction of the project, rails will be mounted on the lakeshore from the access adit portal to the reservoir surface at the elevation existing at the time. As the reservoir is drawn down during operation, the barge storage rails will be extended as needed to facilitate barge access. 7.07 TWO-STEP LAKE TAP. A two-step lake tap was proposed for use in OM 23 should the rock conditions at the proposed tap location be judged inadequate to insure a successful tap. A two-step tap is the simultaneous tapping of the lake bottom at two distinct locations. The provision for a two-step lake tap is no longer considered a necessary precautionary measure, because, as stated in Sections 6.06 and 7.02 of this report, investigations will be undertaken during construction to insure that an adequate tap location is found. In addition, Polarconsult, Inc., does not address the need for a two-step lake tap in their lake tap investigation report (Exhibit 4). 7-4 SECTION 8 -GATE STRUCTURE 8.01 GENERAL. The gate structure and gate structure access adit house a service gate and bulkhead and all the equipment required to allow their full operation for power tunnel filling and draining procedures and for emergency situations. Emergency operation of the service gate will become necessary should there be coincidental failure of the wicket gates and spherical valve, failure of the tunnel-filling valve, or in the event of power conduit rupture. The gate structure is completely underground and located approximately 650 ft downstream of the proposed lake tap site. The horizontal location of the gate shaft is based on the most favorable geologic conditions found nearest to the lake tap. The crown elevation of the tunnel at the gate shaft assures a 14-ft seal of water under the worst load demand conditions. 8.02 SHAFT. A. General. The shaft is a lO-ft by 12-ft by 251-ft high chamber that houses the gate, bulkhead, stainless steel gate guides, access ladder, safety and inspection landings, and the power tunnel air vents. The gate structure shaft is shown on Plate 15. B. Service Gate and Bulkhead. (1) General -An economic study to find the optimum gate and bulkhead size compared the cost of head loss through various tunnel openings at the gate structure with the cost of constructing the tunnel opening and its corresponding gate and bulkhead. Over the range of tunnel openings considered, the smallest was the most economical. However, to permit passage of a small tractor during construction, a larger tunnel opening of 6 ft wide by 8 ft high was selected. To seal this size opening, the service gate is 6.83 ft wide by 8.46 ft high. The bulkhead is 8.7 ft wide by 9.3 ft high. A detailed description of this economic study is included in Section 1.02 G of Appendix Bl. (2) Service Gate - A hydraulically-operated slide gate will be utilized as the service gate because this type of gate will permit the use of an open system/wet tunnel lake tap, has been used successfully for similar high head conditions, and is capable of being operated under balanced and unbalanced heads. Details of the service gate are shown on Plate 16. (3) Bulkhead -The gate structure bulkhead, located 6 ft upstream of the service gate, seals off the power tunnel at the upstream side of the gate structure, thereby allowing the gate structure to be drained for maintenance and access into the power tunnel. The bulkhead can only be operated under balanced head conditions. When not in use, it will be dogged and stored at the top of the shaft. The bulkhead includes a flip valve which is operated by a small cable from the service room. The gate shaft is filled through this valve, as described in Section 9.07. 8-1 C. Access. Primary access to the gate shaft and secondary access to the power tunnel is by ladder from the gate structure service room. The ladder is enclosed in a cage and provided with landings spaced at 30 ft intervals. Suspended beneath the lower observation platform is an extension of the access ladder that can be lowered into the power tunnel to permit access for inspection and maintenance purposes. D. Tunnel-Filling Pipe and Valve. (1) Tunnel-Filling Pipe -The tunnel-filling pipe conveys water from between the bulkhead and service gate to the downstream end of the concrete transition. The discharge is directed against a 5-ft by 5-ft steel plate to protect the concrete from the high velocity water jet stream. A 12-inch diameter gipe was selected as the practical size because it allows a constant 9.1 ft 3 /s discharge rate at all pool elevations, which results in a reasonable tunnel filling time (25 h) and unlined tunnel flow velocity (5.2 ft/s). (2) Tunnel-Filling Valve -The valve is a 12 inch diameter globe valve rated at 130 lb/in 2g. The valve can be throttled during filling operations to provide the required flow. Filling should proceed at a slow rate until the penstock is filled to the point where a pool is established in the final rock trap. At that time the filling rate can be increased by opening the valve wider~ (3) Emergency Tunnel-Filling through Service Gate -In the event that the tunnel-filling pipe and valve fail and cannot be repaired in time for a scheduled tunnel-filling, the slide gate can be used to fill the tunnel, similar to the method employed at Long Lake. The slide gate would be cracked open from 0.2 inches to 0.6 inches, depending on lake elevation, in order to provide the required flow for a 25 hour tunnel filling. Gate stops will be provided every 0.2 inches for the first 2 inches of opening in order to prevent an inadvertent rapid opening of the gates which could result in quantities of rock being swept downstream and damaging the secondary trashrack, penstock and turbine. E. Transitions. The lengths of the required transitions from the ll-ft power-tunnel to the 6-ft by 8-ft tunnel opening at the gate structure are 25 ft on the upstream side and 30 ft on the downstream side. These lengths were selected after an economic optimization study compared the cost of construction of various transition lengths to the value of the headloss of each. A detailed description of the economic study is included in Section 1.02 G of Appendix Bl. F. Air Vent. (1) Purpose -The air vent will be required to perform the dual functions of providing adequate airflow into and out of the power tunnel during tunnel filling. It is anticipated that the vent will supply air to the tunnel during the early stages of filling and will allow excess air to be exhausted from the power tunnel during the latter part of the filling process. 8-2 (2) Design -For design purposes, it was assumed that safeguards would fail and the gate operator would inadvertently allow the service gate to move to a 50 percent open position before he could stop it. At 50 pct gate opening and lake elevation at 1,019, the flow through the tunnel is 1,860 ft 3/s, which is also the maximum air flow out of the vents. Air velocities are limited to 296 ft/s which is higher than the 150 ft/s maximum recommended by HOC 050-1 but only slightly higher than recorded air velocities of 280 ft/s that were experienced at Pine Flat Dam (HOC 050-1). Reference 23 indicates that an air velocity of 296 ft/s is a relatively low velocity in terms of compressibility and no problems resulting from compressibility are forseen. Two 24-inch pipes are used resulting in a cross sectional area of 6.28 ft2. The maximum air demand (into the tunnel) that can occur during tunnel filling is 700 ft 3/s and will be easily handled by the recommended vents. A rectangular transition with dimensions 2.0-ft by 6.0-ft will open downstream of the service gate. The vent pipes will extend above the transition, up the gate shaft, and then along the gate shaft access adit to the portal overlooking the lake. 8.03 OPERATIONAL FACILITIES. A. Service Room. The service room is a 24-ft by 30-ft by 25-ft high room located at the top of the gate shaft. The service room floor is at elevation 1040, which is above the maximum lake surface elevation. This room houses a control panel, cable sheaves, hydraulic hoists, and a gate Service area. It also provides access to the gate shaft. B. Access Adits. Primary access to the gate structure is through a ll-ft wide by ll-ft high by 850-ft long vertical sidewall tunnel originating at a helicopter pad and staging area. This pad is constructed from excavated material at approximately elevation 1,035. The adit is unlined except at the portal area. The portal has a concrete canopy and wingwalls to protect it from falling rocks and avalanches. The entrance has a steel gate with lock to keep out intruders. The portals will be equipped with air vents to provide fresh air circulation in the adits (see Plate 19). The bulkhead hoisting equipment is located in an adit enlargement, 75 ft from the service room. From the service room, the adit continues approximately 400 ft to Crater Lake. This section of adit provides access to the lake surface monitoring equipment and primary trashrack cleaning equipment. 8.04 MECHANICAL DESIGN. A. Hydraulic Hoist. (1) Hydraulic System -The hydraulic system consists of an oil reservoir, two electric positive displacement pumps, and related piping, gages, and control valves located as shown on Plate 17. Two 25-hp electric motors will be installed to drive the hydraulic pumps. The motors will drive the pumps at rated speed to provide 1,100 psi to start the slide gate movement, and 40 gpm flow to move the gate at approximately 0.8 ft/min. The gate will take approximately 10 min to move from the fully closed position to the fully up and locked position, and the same time to reclose. The electric motors will be the primary power source with no backup. 8-3 (2) Operation -The gate will be controlled by an electrically operated remote controlled valve. The remote control will be located in the powerhouse and sUbstation and will have four positions: up, hold, down, and off. The hydraulic pump motor will operate when the control i~ placed in the up, hold, or down position. The manual valve will be located next to the gate slot with the hydraulic pump and motor. The manual control valve will be installed in series with the solenoid valve for emergency or power off manual operation of the slide gate. Hydraulic fluid will bypass when the piston has traveled to its full up or full down position, to relieve the pump when the piston has reached the end of its travel. A limit switch activates at either travel extreme to stop piston motion. During gate opening the limit switch stops gate movement every 0.2 inches for the first 2.0 inches. This safety feature is provided to allow the tunnel to be filled by cracking the gate rather than using the tunnel-filling pipe and valve. During gate closure, however, the 0.2 inch limit switch has no effect on gate movement. When the cylinder is to be serviced~ the "8 ft" limit switch can be over-ridden to drive the piston fractionally higher to latch the piston in place in the cylinder head. (3) Design Criteria Hydraulic Hoist -The results of preliminary computations of the starting force to raise the leaf are based on the latest criteria, "Hydraulic Design Criteria" --Vertical Lift Gates -- Hydraulic and Gravity Forces, Sheets 320-2 to 320-2/3, Rev. 10-61, U.S. Army Engineer Waterways Experiment Station, OCE. .(NOTE: The force to tlose the gate is somewhat less than that to open it.) Seal Friction Water Packing Friction Lower Oil Packing Friction Piston and Ring Friction Subtotal, Friction Resistance Weight of Moving Parts Hydraulic Downpull Forces Weight of Oil in Cylinder Subtotal Less Bouyancy Total required Start Force Coefficient 0.70* 0.2 0.2 Varies wicyl Pressure Force (pounds) 490,000 162 2,680 2,560** 495,402 66,000 22,000 4,060 587,462 -6,300 581, 162 1 bf * Coefficient of sliding friction Brass on Brass from "Marks Handbook", Fifth Edition, pp. 218. ** Value at highest pressure. 8-4 ,.- (4) Gate Position Indicator - A gage calibrated in tenths of a foot from 0 to 8 ft will be bolted to the hydraulic cylinder head at the top or fixed end of the gage and bolted to the stem at the bottom or movable end of the gage. When the piston is at the top of its travel with the gate fully opened, the gage pointer shall indicate "8 ft" (as measured from the floor of the gate shaft to the bottom of the gate leaf). When the piston is at the bottom of its travel with the gate fully closed, the pointer shall indicate "0 ft". (5) References -The Cougar Dam Design has been used as a reference and a guide in this design. The gate size and type are similar, as is the head of water. B. Cable Hoist. A 10-ton cable hoist will be used for raising and lowering the bulkhead, and will also be used to remove the hydraulic hoist, slide gate, and other equipment. Stem links will be removed or installed one link at a time, thus the maximum weight to be lifted is that of the slide gate hydraulic cylinder, 15,300 lbs. The hoist size = (15,300 lbs) (1.3fs) = 20,000 lbs load. Thus, a 10-ton base mounted hoist will be installed with an overhead motorized bridge and sheaves as shown on Plate 18. The hoist consists of a l-hp electric drive motor, worm gear reduction unit, drum gear, cable drum, cable sheaves, and cables. The cable drum rotates at 0.085 r/min and raises or lowers the bulkhead at a rate of 0.8 ft/min. The hoist is always operated under power and never allowed to fall freely. There are two cable sheaves. One is a motorized sheave on a motorized bridge, the other is a roof mounted swivel sheave located near the service gate slot. The overhead sheave is motorized so its position can be adjusted to be directly above the bulkhead for operation or the slide gate during maintenance. The hoist is located in the access adit 75 ft from the service room and contains a 3/4-inch diameter, 400-ft long cable. The slide gate, bulkhead and hoist drum share the same cable. A position indicator shows the position of ·the gate or bulkhead for their full range of travel. (1) Hoisting Procedure -The bulkhead is dogged off and stored in the open position. During those times, the hoist cable is slackly connected to the bulkhead and hung on the wall of the adit. When operation is required, the hoist cable must first be removed from the wall of the adit and tightened onto the hoist drum, thereby accepting the full weight of the bulkhead. The bulkhead can then be undogged and lowered. The bulkhead is operational only in a balanced head condition in the tunnel; therefore, the gate shaft must be filled beyond the height of the tunnel before the bulkhead can be totally lowered into the closed position. Time to lower the bulkhead into the closed position is approximately 3.7 hrs. (2) Gate Position Indicator -The bulkhead position indicator for the cable hoist consists of a lIB-inch galvanized steel cable attached to the hoisting cable socket on one end, and to a spring-loaded" positive tension, nonracheted take-up reel mounted on the motorized bridge next to the motorized sheave as shown on Plates 17 and 18. Not shown on the plates are the limit switches that will be activated for the 8-5 bulkhead fully-closed and fully open positions. These will be mounted adjacent to the take up reel. A cable length counter calibrated in tenths of a foot will be installed and be readable from the cable hoist control panel. A counter reading of "0.0" will correspond to bulkhead fuJly closed. Positive readings indicate height of bottom of bulkhead above tunnel floor. The counter will be capable of a readout of up to 300 ft. C. Heating and Ventilation. No heating or ventilation is required. 8.05 ELECTRICAL DESIGN. Power requirements for the gate structure include lighting in the gate structure and adits, slide gate operation, bulkhead 'gate hoist, and remote control and monitoring system. A. Power Supply. Two 15 KV 3-phase power cables are suspended along the roof of the penstock tunnel and then installed in concrete encased conduits in the floor of the power tunnel from the tunnel plug to the gate structure and upper adits. Watertight access handholes are installed at 400-ft intervals along the conduit for installation and repair of the cables. These cables supply power to the project by tapping off of the powerhouse's 13.8 KV bus. The 13.8 kV power is required because the powerhouse's auxilliary system voltage of 480 volts is too low to trasmit power from the powerhouse 7,000 ft to the gate structure service room. One cable supplies normal power while the second table serves as a backup cable. The cables are in seperate conduits because failure of one cable would damage the second cable if they were in the same conduit. At the gate structure, each cable is transformed through a seperate 75 KVA pad mounted 13.8 KV -277/480 volt 3-phase transformer to provide low voltage power to the facility. The 277/480 volt power is used to prevent .large secondary conductor sizes due to excessive voltage drop. A remote controlled automatic transfer switch at the gate structure allows choice of primary feeders from the powerhouse. B. Lighting. Incandescent lighting is used in the gate structure and the gate structure access adit. Due to the limited usage of the lighting system and the delay for strike of a discharge lighting system the incandescent lighting is considered the most practical approach for this project. The lighting load for these two areas is estimated to be 7.5 kW. C. Slide Gate Control. A control panel and a gate position indicator are provlded ln the gate stucture service room. The control panel provides basic RAISE-STOP-LOWER functions. Slide gate raising is incremental. Pressing the RAISE button raises the gate a short distance and automatically shuts off. Lowering of the gate is continuous, with automatic stop at the full closed position. Over travel limit switches prevent over-raising or lowering of the gate. Power requirements for the slide gate are approximately 40 kW. D. Bulkhead Hoist Control. A hoist control panel is provided in the service room for the bulkhead hoist. The panel provides basic RAISE-STOP-LOWER functions. Approximate power requirements are 2 kW. 8-6 E. Remote Control and Monitorin~. A concrete encased conduit installed under the power tunnel wit watertight access points every 400 ft houses control and monitoring cables between the powerhouse and gate structure. Backup cables are provided in a separate conduit in case of primary cable failure. Cables allow remote control from the powerhouse of the slide gate and power sDpply transfer switch, and monitoring of the slide gate position and lake water level. Power requirements are approximately 20 watts. F. Intra-site Communications. The only intra-site communications within the gate structure and adit is between the service room and the hoist room. This is a battery powered intercom with a Ilhardhat" headset jack in the hoist room. The headset is used to overcome the hoisting machinery noise. An alternative would be sound powered headsets. Communication between the powerhouse and gate strucuture is accomplished by interfacing the headset system at the gate structure with the communications system at the powerhouse via a hard wire circuit between the two locations. The hard wire circuit is installed in the floor of the power tunnel in the same trench as the control circuits. Calls are originated from either location and bidirectional conversations are possible. 8-7 SECTION 9 -POWER TUNNEL 9.01 GENERAL. The plan and profile of the ll-ft diameter modified horseshoe tunnel is shown on Plate 2. The power tunnel is approximately 6,020 ft long from the primary rock trap to the penstock. The invert elevation is 761.5 ft at the primary trap and 109 ft at the final rock trap. The tunnel "invert slopes upward at 3.88 pct from the primary rock trap to the gate structure and downward at 12.437 pct from the gate structure to the final rock trap. The tunnel will be excavated in rock and essentially unlined. Components of the power tunnel include the power tunnel emergency bulkheads, the secondary and final rock traps, and the secondary trashrack. The power tunnel is designed according to EM 110-2-2901, "Tunnels and Shafts in Rock". 9.02 POWER TUNNEL. A. Excavat i on. (1) Drill and Blast -The cost estimate is based on conventional drill and blast methods of excavation. A mining equipment company was contacted to confirm that the selected tunnel grade could be negotiated with rubber tired mucking equipment within the tunnel dimensions proposed. Equipment is available to perform the work within safe speeds for tunneling operations. A conveyor system could also be used. (2) Tunnel Boring Machine (TBM) -The contractor will be allowed the option to use a TBM for a round tunnel. A mining company that uses TBM equipment was contacted to confirm that the tunnel could be mined in the hard rock encountered at Snettisham and could be operated on the selected grade. The mining company indicated that this tunnel could be mined by a TBM but a minimum 500 ft radius is required for continuous mining operation. To maintain the recommended tunnel alinement, the contractor may have to over excavate at the intersection of the access adit and the penstock tunnel to allow the TBM to be turned to the power tunnel alinement. The contractor would be allowed to adjust the tunnel curve radius from 100 ft to 500 ft at the curve near the final rock trap. B. Linin~. Only a small percentage of the 6,020 ft of tunnel requires support by pa tern rockbolting. In addition, concrete lining may be required for approximately 125 ft, and shotcrete lining for 920 ft. The transitions in the tunnel for the gate structure will also require a total of approximately 80 ft of lining. Ten steel set supports will be required onsite should they be needed. The steel sets will be cold worked A-36 steel and 11 ft in diameter. Bending moments of the steel sets will be eliminated by complete lagging and back packing. Lagging will be either wood or steel depending on rock conditions. The actual need for rockbolts, steel sets, concrete lining, and shotcrete will be determined by experienced Corps of Engineers field personnel as work progresses. See paragraph 6.05B and Plate 4 for rock support and lining details. Lining material requirements are discussed in Supplement No.1 to this report, "Materials Investigations," dated November 1983. 9-1 9.03 POWER TUNNEL EMERGENCY PLUGS AND BULKHEADS. A. General. Two power tunnel emergency bul kheads wi 11 'be constructed in the power tunnel upstream of the gate structure. One will be located near the lake tap and primary rock trap and the other approximately 75 ft upstream of the gate structure (see Plates 2 and 14). The exact location of the bulkheads will be determined by Corps of Engineers field personnel during construction to insure placement is in sound rock. The purpose of the bulkheads is to provide a means of dewatering the power tunnel upstream of the gate strucure in the event that a rock fall or tunnel displacemnt caused by seismic activity should occur in the upper reaches of the tunnel. They would also be used if the lake tap operation was unsucessful or if a rock slide blocked the entrance to the power tunnel intake. The hinged bulkheads will be designed in accordance with EM 1110-1-2101, "Working Stress for Structural Design" to resist the full hydrostatic design pressures. The bulkheads will be recessed and imbedded in reinforced concrete so as not to restrict flow. The bulkheads will be dogged in the open position to assure against closure during project operation. Hardhat divers will be required to close the bulkheads. The maximum depths that the divers will have to descend to are 230 ft in the gate structure and 262 ft in the primary rock trap area. Because of the short duration that a diving team can work at these depths and the heavy equipment that they will use, the distances they can travel into the tunnel i,s 1 imited, therefore two bulkheads are required. B. Operation. If damage or blockage occurs upstream of the gate structure the following procedures will be followed: (1) Upper Tunnel Bulkhead -If damage to the power tunnel occurs between the two bulkheads, the wicket gate, spherical valve and the hydraulically-operated service gate in the gate structure will be closed. A diving team will attach cables to the primary trashrack and it will be hoisted to the surface. A diving team will enter through the power tunnel intake and close and dog shut the upstream emergency bulkhead. The tunnel will then be drained and repaired. The tunnel upstream of the gate structure will then be filled through the gate structure allowing equal pressure on both sides of the bulkhead. A diving team will then open and dog the bulkhead in the open position. The trashrack will be replaced, the remainder of the power tunnel, surge shaft and penstock refilled. (2) Lower Tunnel Bulkhead -If damage to the conduit occurs upstream of the upper bulkhead, the wicket gate, spherical valve and the hydraulically operated gate in the gate structure will be closed. A diving team will enter through the gate structure and close and dog shut the lower emergency bulkhead. The power conduit will be drained. The section of tunnel upstream of the bulkhead will be abandoned. A new power tunnel will be mined starting between the down~tream emergency bu'lkhead and the gate structure and will reenter the lake at another location with a new rock trap and lake tap using the same procedure as used in the recommended plan. Without the emergency bulkheads a new tunnel and lake tap would have to be started downstream of the gate structure. A new gate structure would have to be constructed and the old gate structure would be abandonded. 9-2 9.04 ROCK TRAPS. A. Secondary Rock Trap. The secondary rock trap is located approximately 130 ft upstream of the gate structure and is designed to prevent rubble from entering the gate slots. The rock trap will intercept any material not retained in the primary rock trap. Details of the secondary rock trap are shown on Plate 20. B. Final Rock Trae. The final rock trap lies on a 12.437 pct slope but in other respects 1S similar in shape to the final rock trap built for the Long Lake tunnel. Maximum velocity through the rock trap is 2.6 ft/s as compared to a maximum velocity of 3.9 ft/s at Long Lake. The lower velocity at Crater Lake results in a conservative design even when the sloping invert is considered. Approximately 96 yd 3 of storage volume is available just upstream from the secondary trashrack. The quantity of materials found in the Long Lake rock trap after 10 yrs of operation indicate that migration of large quantities of materials will not be a major concern (see Exhibit 1). Plate 21 shows details of the final rock trap. 9.05 SECONDARY TRASHRACK. The function of the secondary trashrack is to prevent most particles that are suspended in the water by vortices and turbulence from entering the penstock. A full trashrack is used to provide positive protection for the steel penstock and turbine during the initial stages of operation of the Crater Lake. This trashrack extends across the entire upstream end of the concrete conical section located in the downstream end of the final rock trap. Utilized in the design are 1/4-inch bars spaced 1-7/8 inches on center. The rack is designed to allow removal of the top portion after the system has been operated at or near maximum flow and the tunnel is dewatered for inspection. This should occur approximately one year after power-on-line is achieved. The rack will be cleaned when the power conduit is drained. 9.06 PLUG AND BULKHEAD. The tunnel access plug and bulkhead, shown on Plates 7 and 8, seals the penstock tunnel after the power conduit construction is complete and prior to power tunnel filling and system operation. The 75-ft long plug is located at the downstream end of the final rock trap. To permit future access to the final rock trap, power tunnel, and surge tank, a hinged bulkhead is provided in the plug. The bulkhead is designed in accordance with EM 1110-1-2101, "Working Stresses for Structural Design," to resist the full design pressures that occur at the plug location. The tunnel upstream of the plug is widened and a concrete wall approximately 25 feet long separates the bulkhead forebay from the rock trap to restrict flow near the bulkhead so debris and rock will not be deposited in front of the bulkhead. 9.07 TUNNEL FILLING AND DRAINING PROCEDURES. A. General. This section describes the operation of the service gate and bulkhead for routine filling and draining of the power tunnel. 9-3 B. Filling. Conditions at the start of a normal tunnel filling operation w,ll be: bulkhead closed -water upstream, dry downstream; service gate closed -dry upstream and downstream; tunnel-filling valve closed; flip valve in bulkhead closed; spherical valve closed. The first step is to open the flip valve and fill the gate shaft, permitting the bulkhead to be retracted. Once the bulkhead has cleared the power tunnel as it is being retracted, the tunnel-filling valve can be opened and the tunnel filled with water. Filling should take approximately 25 hr. Once the tunnel and surge tank are full, the tunnel-filling valve will be closed and the service gate will be retracted. The spherical valve is then opened, followed by opening of the wicket gates. C. Draining. To drain the tunnel for inspection or maintainence, the turbine wicket gates will be closed first, followed by closure of the spherical valve. The service gate will then be closed. The spherical valve and wicket gates are then reopened to drain the tunnel. To allow inspection of the service gate, the bulkhead will then be lowered into position and the tunnel-filling valve opened to drain the gate shaft. 9.08 ROCK COVER CRITERIA FOR UNLINED TUNNEL. The criteria for determining where the power tunnel w,11 be 1,ned, when not required because of poor rock conditions, are (as approved in OM 23): a. Minimum rock cover, in feet, vertically above any point in the unlined tunnel shall be equal to eight-tenths of the maximum dynamic pressurehead, in feet, to which the tunnel shall be subjected at the tunnel station; b. The minimum horizontal distance, in feet, to the rock surface at any point in the unlined tunnel shall be equal to 150 percent of the maximum dynamic pressurehead, in feet, to which the tunnel shall be subjected at that tunnel station; c. A point to the side of the unlined tunnel having a horizontal distance from the tunnel equal to the maximum static pressure head shall have a vertical rock cover equal to at least six-tenths of the maximum static pressure head, in feet, to which the tunnel will be subjected at that station. The criteria in paragraph (b.) above is recommended to be modified from 150 pct to 110 pct of the maximum dynamic pressurehead for the minimum horizontal cover. Because of the excellent rock condition, leakage should not be a problem. The recommended plan provides 110 pct of the maximum internal head for the minimum horizontal rock cover. By using the relaxed minimum distance requirement, approximately 400 ft of steel penstock has been eliminated from the recommended plan. 9-4 .' SECTION 10 -SURGE TANK 10.01 GENERAL. The Snettisham project serves an isolated load in Juneau, and at times, during non-peak load periods, the Crater Lake unit may be handling the entire Juneau-Douglas electrical demand. Operation under these conditions requires rapid load pickup, rapid load rejection, and inherent stability under load changes, all of which a surge tank provides. Maximum and minimum water hammer elevation at the turbine without a surge tank are 1,700 ft and 480 ft, respectively, for 3.5 s wicket gate closing and 5 s opening times. With a surge tank in the system, the maximum and minimum water hammer elevations are 1,263 ft and 597 ft, respectively. In addition, a surge tank provides a source of water to enhance rapid load pickup capabilities. 10.02 DESCRIPTION OF RECOMMENDED SURGE TANK. The surge tank is a 10-ft diameter, vented, vertical, unlined surge shaft through rock with a bottom elevation of 145.3 (the drift tunnel invert is at elevation 150.3 ft) and a top (day light) elevation of 1,080 ft (see Plate 22). The surge tank is connected to the power tunnel by an unlined, 60-ft long, ll-ft diameter straight leg horseshoe drift tunnel. The drift tunnel intersects the power tunnel perpendicularly at station 65+59 at an invert elevation of 150 ft. Neither the drift tunnel nor the surge tank contain restricted orifices. The top l5-ft of the surge shaft will incorporate a l6-ft diameter cylindrical concrete cap with a 4 ft diameter steel air vent. 10.03 SELECTION OF SURGE TANK DIAMETER. Surge tank diameter was selected to insure stabl Ilty of the system durlng the most destabilizing hydraulic transient situation, which for this system is a small load increase in the area of decreasing turbine efficiency at a low power pool elevation and minimum hydraulic losses. The Thoma formula was used to calculate a surge tank diameter that would produce borderline stability, and the result was verified by the WHAMO computer program (water hammer and mass ocsillation program). Since the required surge tank diameter will increase with an increase in power tunnel diameter, and since contractors will over excavate the tunnel by using the conventional drilling and blasting technique, a tunnel diameter of 12.4 ft was used in calculations instead of the nominal 11.0 ft tunnel diameter. The Thoma formula predicted a surge tank diameter of 6.0 ft for borderline stability, while the WHAMO program predicted a 7.5 ft diameter. Based on these results, a 10-ft diameter tank was selected yielding a 1.67 to 1.33 safety factor based on tank diameter. 10.04 MAXIMUM AND MINIMUM SURGES. The maximum surge was determined using the WHAMO and MSURGE computer programs simulating a full load rejection from blocked turbine output of 47,000 hp to 0 hp in 3.5 s (closure rate from full gate is 5 s). Maximum reservoir elevation of 1,022 ft, an effective tunnel diameter of 12.4 ft, and minimum hydraulic losses were assumed. The maximum WSEL in the surge tank was calculated to be 1,074 ft by WHAMO and 1,076 ft by MSURGE. The minimum WSEL was determined at 765 ft by using the WHAMO program simulating a wicket gate movement from closed to full open in 5 s with a minimum power pool elevation of 820 ft, maximum hydraulic losses, an effective tunnel diameter of 12.4 ft and tailwater elevation of 11.4 ft. These conditions correspond to a load demand at the turbine ranging from 0 hp to 35,000 hp. 10-1 10.05 SYSTEM WITHOUT A SURGE TANK. Due to significant expense of constructing a surge tank, a hydraulic analysis was performed to determine the feasibility of building the project without a surge tank (see Figures 18 and 19 in Hydraulic Appendix B2). The analysis showed that the polar moment of inertia (WR2) of the turbine/generator would need to be at least 2,106,000 lb-ft 2 to provide adequate governing stability of the system without a surge tank, whereas, the maximum WR2 which a generator manufacturer can provide is only 1,550,000 lb-ft 2 for the Crater Lake system. This concept was then dropped from further consideration. 10.06 SURGE TANK LOCATION. Based on roak cover criteria alone, the surge tank could be connected to the final rock trap at station 67+50 but would need to be inclined about 10 degrees to daylight at the design elevation of . 1,080 ft. Since an inclined shaft would be more difficult and more costly to construct than a vertical shaft, a sensitivity study was conducted using WHAMO to determine the variations in surge tank water surface elevations, water hammer, and stability with the surge tank at various locations in the tunnel. The results are as follows: TABLE 10-A. SURGE TANK LOCATION TRANSIENT CHARACTERISTICS Sta 65+59 Surge Tank Location Sta 67+50 Sta 68+30 Diameter of tank at Incipient Stability 7.5 7.3 8.0 Max. WSEL in Tank 1,074 1,075 1,075 Max. Piez. Elev at Turbine 1,263 1,256 1,253 Min. WSEL in Tank 765 764 764 Min. Piez. Elev at Turbine 597 598 599 Min. Gate Shaft WSEL 810.7 810.8 810.8 The upstream location (station 65+59) results in a slightly lower maximum WSEL in the surge tank (1 ft) with an accompanying increase of 7 ft in water hammer at the unit, which is not significant. Based on surface topo information available at this time, construction of a surge tank at station 67+50 or 68+30 would require an inclined shaft to gain the necessary height to contain the maximum surges expected. Inclined shafts are more costly to construct than vertical shafts. Therefore, station 65+59 was chosen as the location to avoid the increased costs associated with building an inclined surge tank. The location of the surge tank will be finalized during preparation of plans and specifications when more accurate topo information is available for the area. (Note: The major design effort was for the surge tank located at station 67+50 and Plates B3 through B17 in the Hydraulic Appendix reflect this location. ) 10-2 -If' SECTION 11 -PENSTOCK 11.01 GENERAL. The penstock profile is shown o~ Plate 3. The 6-ft diameter steel penstock begins at the tunnel plug and continues at a downward grade of 12.437 pct to near the powerhouse. The penstock ;s 903 ft long and is supported on saddles. 11.02 SUPPORTS AND ANCHORAGE. The penstock is an unstiffened steel pipe supported by steel ring girders and concrete saddles. Ring girders are welded around the penstock at each support to prevent distortion of the penstock and to maintain its ability to act as a beam. The maximum deflection of the penstock between supports is limited to 1/360 of the span. The ring girders are attached to the concrete supports on each side o"f the penstock by direct ·bearing. The concrete for supports has an flc = 6,000 psi. The supports and saddles are designed to resist seismic zone 4 earthquake forces due to the close proximity of the project to seismic zone 4. 11.03 LONGITUDINAL LOADING. There is a sleeve-type expansion joint downstream of the tunnel plug to accommodate movements due to thermal and seismic forces. The penstock will be fabricated in 40-ft long sections and field welded, starting from the powerhouse end and proceeding upgrade. Each section w'ill be allowed to cool to the surrounding tunnel temperature before the next section is welded. With this sequence, internal stresses associated with temperature differential will be kept to a minimum. Because the penstock is located deep in the mountain where temperatures are almost constant, the temperature differential used for design is 20°F. All longitudinal forces, including seismic, are resisted at the concrete thrust block upstream of the powerhouse. Attachments between ring girders and concrete supports have a slotted hole in the longitudi~al direction. Contact surfaces between ring girders and supports are lubricated to reduce frictional resistance using two layers of sheet packing with graphite grease between them. There is 71 ft of penstock from the thrust block to the spherical valve in the powerhouse valve room. This portion of the penstock is supported by two saddle supports. The last 10 ft of the penstock will be a transition from 72 inches to 54 inches, which is the diameter of the valve. There is a sleeve-type expansion joint just downstream of the spherical valve, also. 11.04 DESIGN CRITERIA. With the penstock expansion joint, the only loadings that effect penstock design are the maximum internal dynamic pressure, beam action between supports, and seismic forces. Design stresses for the penstock, under maximum dynamic pressures, are limited to 25 percent of the ultimate strength or 80 percent of the yield strength of the steel, whichever is the lesser. 11.05 STEEL SELECTION. Four types of steel have been studied for the penstock. They are shown in Table ll-A. 11-1 TABLE ll-A. PENSTOCK STEEL COMPARATIVE CHARACTERISTICS T.lEe Steel Design Stresses Price ter Pound Total Weight Total Cost KSI ; n Pace lbs l. ASTM AS16, lS 2.70 1 , 137,000 $3,070,000 Grade 60 2. ASTM.AS37, 17. S 3.07 967,000 2,969,000 Class 1 3. ASTM AS37, 20 3.13 8S6,000 2,679,000 Class 2 4. ASTM AS17 28.7S 3.S7 630,000 2,249,000 ASTM AS17 steel is the most economical steel for the Crater Lake penstock. 11.06 FABRICATION AND PLACEMENT. Fabrication of the penstock will be to ASME BOller and Pressure Vessel Code of 1977, Section VIII Specifications. Plates will be curved by rolling or pressing to a 3-ft radius. The penstock will be shop fabricated into 40-ft lengths. Welding pocedures, qualifications, electrodes, weather protection, etc., will be in accordance with the ASME Boiler and Pressure Vessel Code. Each 6-ft diameter, 40-ft long section will be positioned in place and welded to the adjacent section. Field welds will be made in plates of equal thickness. Longitudinal joints in adjacent sections will be staggered by approximately 30 degrees of cylindrical arc to eliminate a continuous seam. A coal-tar enamel coating may be hot applied by a centrifugal process to the interior surface. The steel will be cleaned by shot or grit blasting, and primed before application of the hot enamel. This process, which is covered by AWWA Standard C203, results in a very smooth glossy surface. The alternate interior coating may be a vinyl system, similar to the existing Long Lake pe·nstock coating. The exterior surface will have a coal tar epoxy coating. 11.07 TESTING. Penstock steel will be supplied with Charpy V-Notch impact values, as specified. Charpy tests will be made in accordance with ASTM A-370 testing standards. Plates will be examined for laminations. Consideration will be given to nil ductility tests. Nondestructive testing will be utilized during steel production, fabrication and testing of the penstock. All welds will be 100 pct radiographically inspected. EM 1110-2-3001 requires hydrostatic testing of the completed penstock to 1.S times the maximum hydrostatic pressure. Because of the extreme difference in maximum dynamic pressures which govern the design of the two ends of the penstock, such a test loading would approach the yield point at the upper end of the penstock, if ASTM A516 steel was selected. If the steel selected ;s ASTM AS17, we recommend conducting the test if the closed spherical valve is not endangered. 11-2 .. SECTION 12 -POWERHOUSE 12.01 GENERAL. A 34,500 KVA nameplate rated generator, turbine, spherical valve, and appurtenances will be installed in the skeleton bay of the existing underground powerhouse. The spherical valve permits isolation of the turbine for maintenance and emergency shutdown in the event of governor failure. For a detailed discussion of the approved powerhouse completion and equipment installation associated with the Crater Lake power unit, see DM 24, Underground Powerhouse -Crater Lake, dated December, 1973. The plans and specifications for the powerhouse completion and supplemental supply contracts have been completed for the Alaska District by the Hydroelectric Design Branch of the North Pacific Division. 12.02 CHANGES FROM APPROVED POWERHOUSE PLAN. A. Turbine. A new turbine selection study, dated April 1984, was performed for the Alaska District by the Hydroelectric Design Branch of NPD and forwarded to higher authority for review. The significant changes in the design are summarized below: Minimum Net Head Guaranteed Output @ Min. Head Rated Net Head Gauranteed Output at Rated Net Head Maximum Net Head Synchronous Speed DM 24 777 ft 37,000 hp 947 ft 47,000 hp 1,012 ft 514 r/min DM 26 788 ft 35,000 hp 945.5 ft 47,000 hp 990.5 ft 600 r/min These changes are a result of the increase in tailwater elevation, improvements in turbine design that have been developed since DM 24 was published, and more accurate hydraulic information. Estimated turbine performance curves are presented in the turbine selection study. The turbine runner will be made of cast stainless steel, ASTM A743, Grade CF-8C. The wearing rings will be made of aluminum bronze, ASTM B148, Grade C. Wicket gate seals will be made of corrosion resisting metal, dissimilar from adjacent materials to prevent galling. Other details of the turbine installation and selection remain as stated in OM 24. B. Governor. The turbine governor will be as described in DM 24, Part II, Section 4.03 except that a three term (Proportional-Integral- Derivative) electro-mechanical governor will be employed. Possible stability problems noted in water hammer studies indicated that the added speed of response and stability of the electro-mechanical governor was warranted. C. Generator. The main power equipment will be as described in DM 24, Part II, Section 5 except as noted here. The generator nameplate will be changed to 34,500 KVA, 75°C stator temperature rise with no overload rating, in accordance with ANSI c50.12-1982. The speed will be 600 r/min to match the revised turbine speed. The minimum specified WR2 of the rotating parts of the generator will be 1,050,000 lb-ft 2 , which is sufficient to limit the turbine overs peed on load rejection to 50 pct with a 5s gate closing time. 12-1 D. Transformer. The power transformer will be rated at 34,500 KVA with a 65°C temperature rise, as current standards no longer allow a 55°C/65°C rating. E. Remote SUBervisory Control. relay design for nit No. 3 wlll be Underground Powerhouse-Crater Lake, as follows: Powerhouse control, metering and identical to that described in OM 24, Section 6, dated December 1973 except (1) "The remote control s~heme described in OM 24, Part I, 6.02b. for Units 1-2, will be replaced with a new microprocessor and CRT-based modern SCADA system. The current system is technologically outdated, and expansion parts necessary to incorporate Unit No. 3 per OM 24, Part II, 6.01b are not available. (2) The annunciation system described in OM 24, Part I, 6.05 will be expanded to provide additional critical alarms on a new local lighted window annunicator as well as to the existing operations recorder and SCADA system. Additional lighted windows and annunciator control switches are necessary to improve the ability of the local plant staff to trouble shoot equipment failures and operate the plant upon operations recorder failure. (3) A load frequency controller with associated time base will be added to replace the aging existing Unit No.1 and 2 controller located at the Juneau substation control room. Operational and maintenance problems with the existing controller dictate relacement with new equipment. 12.03 PROJECT FEATURE OPERATIONAL CONTROLS. In addition to the standard controls required to operate the powerhouse equipment, controls and panels will be installed in the powerhouse for monitoring and controlling some of the remote project features. A. Hydraulic Instrumentation. The powerhouse and substation will include an instrumentation panel that can translate incoming information from differential and standard pressure transducers located at various points of the power tunnel, penstock, and powerhouse. (See Section 13 for a detailed discussion of instrumentation.) The instrument panel has the following readout capabilities: (1) Reservoir surface elevation; (2) Pressure differential between reservoir surface and piezometer ring No.1; (3) Pressure head just upstream of the turbine; (4) Pressure differential between reservoir elevation and a point just upstream of the turbine; (5) Pressure differential between piezometer rings 1 and 2; and 12-2 (6) Other miscellaneous readouts. B. Gate Structure Controls. The following equipment will be installed in the powerhouse and substation to provide remote operation cababilities of the gate structure (see Section 8 for a detailed discussion of the gate structure): (1) Two control panels equipped with up, hold, down and off positions, one each for the hydraulically-operated slide gate and the bulkhead hoisting cable; (2) Two position indicators, one each for the slide gate and bulkhead; (3) Remote control automatic transfer switch for the primary feeders from the powerhouse to the gate structure; and (4) Telephone communication to the gate structure from the powerhouse only. 12.04 "MACHINE SHOP. The existing underground powerhouse facilities will be expanded by providing an underground machine shop adjacent to the existing powerhouse erection bay. See Plate 6 for orientation. The new machine shop (described in detail in Section 15) is equipped with heating, ventilating, lighting, and floor drain facilities that are tied into the existing corresponding facilities servicing the powerhouse. 12.05 TAILRACE AND TAILWATER ELEVATIONS. The tailrace is currently equipped with "Amil Automatic Gates" (a form of Tainter Gate) that maintain tailwater elevations between 11.0 ft and 12.5 ft for operation of an Alaska Department of Fish and Game (ADFG) hatchery. The Alaska Power Administration (APA) has indicated that ADFG will be assessed an annual charge in the future for repayment of lost potential energy due to the high tailwater elevations. ADFG has decided that the hatchery will be able to function with lower tailwater than previously maintained. Ultimate tailwater elevations at this time are uncertain, but regardless of what may happen in the future, the concrete structure that anchors the Amil Gates will remain. This structure will act as a broadcrested weir with a sill elevation of 1.7 ft. Maximum tailwater will remain at "12.5 ft while the minimum tailwater will vary with discharge. Figure 4 in Hydraulic Appendix B shows the expected minimum tailwater elevations for various discharges. The maximum discharge through the tailrace will be approximately 1,640 ft 3/s with the two Long Lake units operating concurrently with the new Crater Lake unit. 12-3 SECTION 13 -HYDRAULIC INSTRUMENTATION 13.01 GENERAL. This section describes the, hydraulic instrumentation required for the lake tap and power conduit. Design of the instrumentation required will be detailed and refined during preparation of plans and specifications with the help of the Waterways Experiment Station. In addition, the temporary lake tap instrumentation will be designed with the assistance of a consultant with expertise in lake taps. Plates 11 and 12 show the location of the lake tap instrumentation, and Figure 27 in Appendix B2 shows a schematic of the permanent conduit instrumentation. 13.02 LAKE TAP. Instrumentation for the lake tap blast will perform the following functions: A. Water Surface Elevation. Water surface elevation in the primary rock trap is important because it determines the size of the air cushion which reduces the blast forces against the service gate. This measurement will help to assure a successful lake tap blast. B. Blast Force Measurement. Pressure cells will be located: (1) Directly under the lake tap at approximately Station 7+70. This pressure cell will probably be destroyed when blast rubble strikes it, but the maximum blast pressure information will have been recorded by that time. Exhibit 4 indicates that the maximum blast pressure occurred 0.25 s after the final blast at the Ringedalsvatn lake tap. (2) Midway between the lake tap and the gate structure at approximately station 10+90. (3) At the service gate at approximately station 14+05. C. Surge in Gate Shaft. The initial flow of water into the lake tap and tunnel will result in a surge at the gate shaft to approximately elevation 1040. Instrumentation will be installed in the gate shaft to record the elevation of the surge and the time at which it occurs. D. Monitoring and Recording. The water surface elevation in the primary rock trap, blast pressures and gate shaft surge height will all be monitored and recorded by a temporary instrument panel outside the gate structure access adit portal. Plates 11 and 12 show the location of the lake tap instrumentation: 13.03 TUNNEL. A. H~draulic Losses in Upper Tunnel. Calculations of hydraulic losses through t e prlmary trashrack, orlflce, and the primary rock trap are important for aiding in determination of major blockages that might occur at the primary trashrack and also for use in any future designs of a similar nature. Instrumentation in this reach of tunnel consists of two independent bubbler gages, the first of which will monitor lake surface elevations and the second which monitors pressures in the power tunnel at approximately station 13+00. 13-1 (1) Bubbler Gage #1 -This gage monitors lake elevations between 820 and 1019. It is located in the lake access adit close to the gate shaft and is connected to the lake by a drilled hole approximately 625 ft long that intersects the lake bottom near the tap at approximately elevation 800. (2) Bubbler Gage #2 -This gage is located in the lake access adit close to bubbler gage #1. It monitors pressure in the power tunnel just upstream of the gate structure transition. The gage is connected to the power tunnel by a vertic~l drilled hole. The point at which the drilled hole intersects the tunnel is fitted with a type of orifice that assures dynamic heads in the tunnel have only minimal effect on the gage readings. The location of the piezometer orifice is not ideal (reference 4 indicates that there should be a straight length of 25 tunnel diameters upstream and 10 tunnel diameters downstream from a piezometer to assure full development of the boundary layer) but because of low velocity heads in the tunnel any resultant errors from the imperfect location are considered to be small. The air for both bubbler gages is supplied by a small compressor located in the lake access adit. The compressor receives its power from the main power supply line. This arrangement will require less maintenance than using bottled nitrogen to supply air to the bubbler gages. (3) Hydraulic Losses - A pressure differential transducer is connected to bubbler gages 1 and 2. The pressure differential transducer registers the pressure difference between the two gages. The difference reflects hydraulic losses occurring in the power conduit as flow moves through the primary trashrack, orifice, primary and secondary rock traps, emergency tunnel plugs, and initial portions of the tunnel. Using standard formulation, losses through the tunnel can be calculated with reasonable accuracy. Losses through the secondary rock trap are small and can be estimated with minimal error. When these losses are subtracted from the total losses as measured by the pressure differential transducer, the remaining losses represent those caused by the trashrack, orifice, and primary rock trap. Signals from the transducer are sent to monitoring panels in the powerhouse and substation. (4) Gate Shaft - A staff gage is located in the gate shaft to measure the complete range of water elevations occurring during operation. This gage will be for general utility and will also be useful as a rough check on the readings being produced by the two bubbler gages. (5) Calibration and Monitoring of System -During normal periods of operation, head differential between the lake surface and gage #2 (at station 13+00) will be established for various discharges. If excessive clogging of the trashrack occurs, the head loss through the trashrack increases. This increase in head loss will be observed at the powerhouse or substation by project personnel and appropriate action will be taken. Monitoring of the upper tunnel hydraulic losses will take place on a continuous basis. 13-2 .' • B. Hydraulic Losses in Lower Tunnel. Consideration was given to installing 1nstruments 1n the lower power tunnel (gate structure to surge tank) to determine hydraulic losses in that reach of tunnel. ~is concept was not pursued when we found that costs for a good system were high when compared to the problematic results that would be obtained. 13.04 LAKE SURFACE ELEVATION. Monitoring of the lake surface elevation is important to assure that the lake elevation does not fall below the minimum pool elevation of 820 and also to help in determining if any excessive head loss is occurring at the primary trashrack and rock trap. The lake surface ~levation is monitored by bubbler gage 1, which is connected to an absolute pressure transducer (in addition to the differential transducer mentioned above). This transducer will send signals to the powerhouse and substation. Absolute pressure transducers are available that can transmit readings to within 0.25 pct of the total range of the transducer (in this case, the range is approximately 0-200 ft). With this arrangement lake elevations are known to an accuracy of approximately 0.75 ft. 13.05 PRESSURE MEASURING DEVICES IN LOWER TUNNEL AND POWERHOUSE A. Surge Tank Water Surface Elevation. A pressure measuring device is located in the surge tank to monitor water surface elevation. This device consists of l-inch diameter pipe that runs from near the bottom of the surge tank to the downstream (dry) side of the access tunnel plug. At that point the pipe is connected to a pressure transducer. The signal from the transducer is sent to the instrument panels in the powerhouse and substation. Monitoring surge tank water surface elevations will allow us to check the stability of the system and the accuracy of computer program WHAMO, which was used to size the tank. B. Tunnel Pressure at the Tunnel Access PlUg. The downstream end of the final rock trap dra1n p1pe 1S f1tted w1th a lind flange with a threaded fitting. This threaded fitting can be utilized for either a pressure gage or an absolute pressure transducer if the need arises at some future time to monitor the pressures in the tunnel at the access plug. C. Powerhouse. A threaded fitting is being made available in the penstock just upstream from the spherical valve to allow connection of an absolute pressure transducer or pressure gage. This pressure data ,can be used to assist in calculating net heads at the turbine and approximate total head losses through the full length of the power conduit. D. Penstock and Spiral Case. Two sets of Gibson test piezometer taps are located in the penstock upstream of the spherical valve and one set of net head piezometer taps are located on the upstream end of the spiral case for determining flows in conjunction with Gibson Efficiency testing. The net head piezometer taps can be used at any time during the life of the project. One set of Winter-Kennedy piezometer taps will be installed on the spiral case some distance downstream of the net head piezometer taps. While the Gibson Efficiency tests are proceeding, pressures will be read on gages connected to the Winter-Kennedy taps so that their readings can be calibrated for determining turbine flow at any future time by the Winter-Kennedy method. 13-3 13.06 MAINTENANCE. The various instruments and appurtenant gear have limited life spans. Therefore, various parts of the above mentioned devices will have to be replaced, and drill holes will have to be blown clear, from time-to-time. The bubbler gages in the lake adit will be accessible for a portion of the year and the various maintenance routines can be undertaken at those times. The required maintenance for the bubbler gages is: A. Replacement of differential and absolute transducers. B. Repair or replacement of the compressor supplying air to the bubble gages. C. Blowing out of the drill holes or tubes extending to the lake and the power tunnel and surge tank. All instrumentation located downstream of the tunnel access plug or in the powerhouse can be replaced at convenience. 13.07 SIGNAL TRANSMISSIONS. Signals from the various transducers will be sent to the powerhouse and substation by a carrier wave system imposed on the power supply line that extends between the powerhouse and gate structure. 13-4 • SECTION 14 -MATERIAL SOURCES & DISPOSAL SITES 14.01 SOURCES. A. General. The Crater Lake phase of the Snettisham Hydroelectric Project Wl I I require approximately 13,500 yd3 of concrete aggregate, 2,700 yd 3 of granular material and 500 yd 3 of unclassified borrow material. The unclassified and granular materials are required primarily for embank- ments and surfacing of the Crater Cove access road~ The concrete aggregate is required during the latter stages of construction for the tunnel lining, gate structure and ancillary features. Locations identified as Crater Cove and Bear Pit were sampled as material sources for the Crater Lake phase of the Snettisham Project (see Plate 45 for locations). The granular material, unclassified material, and concrete aggregate will be obtained from the Crater Cove pit. Blend sand for the concrete will be obtained from Bear Pit. In-depth analysis of the local material sources is provided in Supplement No.1 to Design Memorandum No. 26, Materials Investigations dated November 1983, Supplement No.1 to Design Memorandum No.7 dated August 1967, and "Snettisham Dam Mass Concrete Investigation" dated March 1971. B. Bear Pit (known as Glacier Creek, Borrow Area No.2, Sand Source B, Sand Source D for the Long Lake phase). A substantial deposit of sand exists at this site. The source was used as a blend sand source during construction of the Long Lake phase. It is estimated that 30,000 yd 3 of material are available at this location. Access between the pit and the construction sites will be by the existing road. This source was sampled at 3 locations using hand-dug pits. Laboratory and microscopic (petrographic) examinations of the material show it to be acceptable for concrete aggregate and to be substantially the same as the materials used for previous construction. C. Crater Cove (also known as Borrow Area No.1). The Crater Cove borrow source lS a moderately extensive deposit of sand and gravel from Crater Creek outwash. This was used as the primary source of concrete aggregate during the construction of the Long Lake phase. It is estimated that 110,000 yd 3 of material are available at this location. Access will be via the existing Crater Cove access road. Upgrading is required to the access road before full-scale hauling can begin. This source was sampled at 5 locations using backhoe-dug test pits. Laboratory and microscopic (petrographic) examinations, which are in agreement with the tests made on samples from the same source prior to Long Lake construction, show the material to be acceptable for use as concrete aggregate. D. Other. There is a supplier of Type I cement located in Anchorage, Alaska; however, there is no local source of pozzolan. Portland cement, blended hydraulic cement, and pozzolans, if used by the contractor, will likely be obtained in the continental United States as shipping distances are about equal to that of Anchorage and the established shipping routes to Juneau are from the west coast of the continental United States. Since the materials proposed to be used as concrete aggregates for this phase of the Snettisham Project are from the same sources as used for Long Lake, and are shown by test to be substantially the same material, no further studies of mix design, processing studies, temperature studies or freeze-thaw tests are planned. The same basic mix design will be used for the Crater Lake phase as was used for the Long Lake phase. 14-1 14.02 DISPOSAL SITES. Two disposal sites will be utilized. See Plate 45 for locations. 14-2 '" .. SECTION 15 -PERMANENT FACILITIES 15.01 GENERAL. The existing permanent facilities include an airfield, a boat basin and dock, and living quarters and operational buildings utilized by Alaska Power Administration (APA) personnel. In addition to hydrore1ated facilities, there is a fish hatchery and three single-family units operated and maintained by the Alaska Department of Fish and Game (ADFG). Plate 1 shows the location and configuration of the permanent facilities. 15.02 BARGE ACCESS. A. General. A barge basin and entrance channel were constructed in 1967 for the Long Lake development of the Snettisham project. The lOO-ft wide channel and the 300-ft by 500-ft barge basin were originally dredged to minus 15 ft and minus 25 ft, respectiveiy. All side slopes were set at 1V:6H, except the north end of the basin was 1V:10H. The 76-ft by l56-ft dock was constructed on timber piles to a deck elevation of plus 14 ft. The dock area side slope, which is lV:2H, is protected by a 3-ft thick layer of quarry stone riprap that has slumped somewhat. B. Usability. The most recent survey of the channel and basin conditions was performed in March 1982 and shows that a stretch of channel approximately 3,000 to 4,000 ft south of the dock has silted in to about elevation minus 12 ft. Minimum periodic dredging has been performed by APA personnel to maintain passage through this segment nf the channel. With these minor efforts, the channel remains usable during normal and high tides; therefore, there are no plans to perform major dredging at this time. 15.03 AIRFIELD. The eXisting airfield at Snettisham is a gravel surfaced runway 100 ft wide and 2,500 ft long with a 1,000-ft overrun. This airfield will provide primary commuter access to the project. There are no planned airfield improvements as part of this design. 15.04 CRATER COVE ACCESS ROAD. Borrow material will be obtained from and waste material will be stockpiled in the existing Crater Cove borrow area that was developed during the Long Lake phase of the Snettisham Project. Access to the borrow and waste area will be provided by upgrading the existing access road to the area. The access road will be upgraded along its present alinement utilizing material excavated from the power conduit and granular and unclassified borrow from Crater Cove Pit. Culverts will be placed under the road to maintain discharge of fresh water from Crater Creek to spawning areas identified by the U.S. Fish and Wildlife Service. The access road will be retained as permanent access to the Crater Cove borrow area. 15.05 WASTEWATER TREATMENT AND DISPOSAL. A. Existing Facilities. Presently, the wastewater generated by APA and ADFG personnel recelves primary treatment from a 16,000 gal septic tank. Effluent is disposed of in a leaching field that is located in the Snettisham tidal plain and is subjected to high water conditions. This is a constant source of maintenance and odor problems. 15-1 B. Recommended Facilities. The existing 16,000 gal septic tank will continue to be used to treat the wastewater. A new soil absorption system consisting of four seepage pits will be constructed to replace the existing leaching field. Th~ pits will be located at the north end of the existing permanent facilities compound between an APA garage and ADFG housing where they will be unaffected by groundwater conditions. A lift station is required to pump the septic tank effluent to the recommended disposal site. Because the treatment and disposal system also provides treatment of the wastewater generated by Crater Lake phase construction personnel, the lift station and seepage pits are designed to handle a peak population of 110 construction and inspection personnel and 20 permanent personnel. The existing 16,OOO-gal septic tank will provide adequate treatment at the design level of loading. lS.06 MACHINE SHOP. The machine shop is currently located in the erection bay of the Snettisham powerhouse. As that area will be needed as a construction staging area for the powerhouse completion work, and an assembly area during the turbine and generator installation, relocation of the machine shop is required. The recommended plan is to excavate a chamber of suitable size adjacent to the west end of the powerhouse and connect it to the erection bay with a 20-ft long service tunnel. There will be an 11-ft wide, 80-ft long vertical sidewall horseshoe tunnel that will connect the machine shop with the access adit. A watertight bulkhead will be located at the intersection of the two tunnels to seal off waterflow into the machine shop and powerhouse in the event that the penstock should rupture. The machine shop chamber would have a concrete floor and wire mesh covered ceiling and would be provided with heating, lighting, ventilation, and drainage suitable for a machine shop. There will be doors at both entrances to the machine shop to confine heat within the shop area. lS.07 INCINERATOR. An incinerator will be installed near Bear Pit during the Crater Lake Phase development. The new incinerator is housed in an insulated but unheated, pre-engineered metal building supported on a concrete spread footing foundation system. The building, which has a minimum floor space of lS0 ft2 for storage of materials prior to burning, is designed to withstand a snow load of 2S0 1b/ft2, a wind load of 100 mi/hr, and a seismic zone 3 rated earthquake. The incinerator is to be smokeless and odorless and certified for Federal facilities. The capacity of the incinerator is 200 1b/hr. A SOO-ga1 oil storage tank is located adjacent to the metal building and contains the fuel source for firing the incinerator. The incinerator, which is being constructed for contractor use during construction of the Crater Lake phase, will be turned over to the Alaska Power Administration for permanent use. lS-2 SECTION 16 -CONSTRUCTION FACILITIES 16.01· GENERAL. As stated in OM No. 23, "First Stage Development ~lan, Crater Lake," the resident engineer's office, dormitory, and concrete testing lab provided for the Long Lake phase construction were planned for continued use as Government camp facilities during Crater Lake phase construction. The contractor camp facilities were to be retained to house the construction personnel for the Crater Lake phase as well. Upon completion of the Crater Lake phase construction, the Government camp facilities were to be turned over to the'Alaska Power Administration (APA) as their permanent operating facilities. Due to delay in construction of the Crater Lake phase, the Government camp facilities were relinquished to APA and the contractor camp facilities were removed following the Long Lake phase of construction. All facilities are now fully utilized by the APA. This section will describe the recommended plan for providing construction facilities for Crater Lake phase construction. 16.02 RECOMMENDED PLAN. A. General. The contractor and Government camp facilities are located in the general area indicated on Plate 1. The two camps are estimated to have a combined peak population of 110 persons. The contractor camp housing facilities will be removed upon completion of Crater Lake phase construction, but the Government facilities and utilities provided to service the camp area will be kept intact for future use. B. Resident Engineer Facilities. The contractor will provide the Government with separate office and living quarters. The office quarters are contained in a single unit with a floor area of approximately 1,000 ft2. The living quarters will comfortably house up to 10 Government employees. The office and living quarters will be provided with the necessary utilities to make them self-sufficient. In addition, the contractor will provide the office with a communication link to the Alaska District office. C. Util ities. (1) Wastewater Collection, Treatment, and Disposal - A wastewater collection system will be provided by the contractor installing the camp facilities. The collection system consists of 6-inch diameter services and 8-inch diameter mains which transport the wastewater to a centrally located lift station. The lift station then transmits the wastewater to the upgraded permanent facilities for treatment and disposal. See Section 15.05 for a discussion of the recommended design for upgrading of the permanent wastewater treatment and disposal system. (2) Water Supply -Water is supplied to the construction camp area by connecting a 6-inch diameter main to the existing water distribution system near the APA living quarters. The camp area distribution network will be dependent upon the camp layout chosen by the contractor. The existing water supply system consists of a 30 gal/min well and a 45,000-gal storage tank located on a hillside above the APA facilities. 16-1 (3) Electricity -Electricity is provided to the camp area by either connecting to the existing distribution network, if capacity is available, or by installing a new feeder line from the switchyard. If a new feeder line is installed, a transformer will also be required at the camp site. 16-2 SECTION 17 -OPERATION AND MAINTENANCE 17.01 GENERAL. Responsibility.for this project will be transferred from the Corps of Engineers to the Alaska Power Administration (APA), Department of Energy, for operation and maintenance when construction is complete. The APA will utilize its existing Snettisham facilities and maintenance personnel servicing the Long Lake units to provide maintenance for the Crater Lake unit. No additional operation or maintenance staff requirements are foreseen by APA as a result of the addition of the Crater Lake unit to the hydropower facilities. ' 17.02 OPERATION, MAINTENANCE AND REPLACEMENT COSTS. As a result of this project, the annual operation and maintenance costs for the Snettisham hydroelectric facility may increase by an estimated $235,000, and the annual replacement costs could increase by approximately $15,000. The total annual operation, maintenance and replacement costs for the Snettisham facility are estimated to be $1,000,000 upon completion of the Crater Lake phase of development. 17 -1 SECTION 18 -ENVIRONMENTAL CONSIDERATIONS 18.01 GENERAL. The environmental considerations section nf OM 23 provided an overall review of the Crater Lake environment. More recently, the report titled, "Snettisham Project, Alaska, Environmental Impact Statement, Supplement 1", dated April, 1981, provided a more detail description of the existing ecosystems and environmental resources in the project area. An environmental assessment (September 1983) addressed revisions in project plans. 18.02 IMPACTS OF PROJECT CONSTRUCTION. The recommended plan has the lowest potential for environmental impact of any of the feasible alternative plans evaluated. The impacts that cannot be avoided are those associated with the lessened water flows to the lower reaches of Crater Creek, possible changes to the salinity regime of Crater Cove, the effects of increased human activity on local animal populations during construction, minor impacts associated with the exposure of soil to erosion, and changes in the visual quality of the project site which is in the Tongass National Forest. The potential for damage to intertidal plants is low, particularly with the adopted plan which does not allow intertidal placement of project features or tunnel tailings, with the exception of a maximum of 50,000 yd 3 of fill covering a maximum of 1 acre of intertidal wetlands for repair of the Crater Cove access road. The construction activity will not displace wildlife from any identified critical habitat, but could reduce the numbers of marine mammals (principally seals), ducks, and other waterfowl in and near Crater Cove during construction. Human contact with black bears in the vicinity of the Snettisham powerhouse is likely to increase during construction with a concomitant increase in danger to both bears and humans. Disposal of excavated tunnel material at the upper adit will cover a small area of alpine tundra and may slightly increase sedimentation ~nd erosion onto the slope below. 18.03 IMPACTS OF PROJECT OPERATION. The loss of most of the streamflow to the lower reaches of Crater Creek will increase the probability of freezing or dessication mortality to intragravel salmon fry and to juvenile Dolly Varden overwintering in the stream outlet. The potential area of salmon spawning habitat is comparatively small (estimated at about 500 ft2; U.S. Fish and Wildlife Service, 1982). With the large and rapid changes in salinities and temperature that occur with each tidal cycle in Crater Cove, the existing intertidal plant communities are tolerant to salinity changes likely to occur in the cove as a result of diverting Crater Creek for project operation. Fluctuations of the water surface elevation in Crater Lake will not adversely impact any significant biological resource. 18.04 MITIGATIVE MEASURES. Measures taken to reduce the impacts of this project on the environment include: (1) Use of existing facilities to the maximum extent feasible; (2) Selection of alternatives that allow access to the power conduit through a main access adit utilizing existing roads instead of through multiple adits requiring new road construction; 18-1 (3) Beneficial use of tunnel tailings for construction of the staging area and helicopter pad at the upper adit and for improvements to the Crater Cove haul road; (4) Placement of culverts under the Crater Cove haul road, where shown on Plate 1, to deliver the remaining Crater Creek streamflows to anadromous fish spawning habitat; (5) Minimize Crater Creek streamflow seepage through the road bed of the Crater Cove haul road, thereby maintaining the maximum potential flow over the spawning redds; and, (6) Use of on-land domestic wastewater disposal facilities. (7) Slope protection on the seaward slope of the access road to prevent erosion into the tidelands. In addition, measures to mitigate losses of visual quality, and to revegetate and stabilize soil exposed by construction or deposition of excavated material are being developed jointly by the Alaska District and the U.S. Forest Service in accordance with a Supplemental Memorandum of U~derstanding between the two agencies. The jointly developed plans will be titled "Detailed Action Plans" and will contain detailed information regarding the materials and methods to be used. 18.05 COMPLIANCE WITH ENVIRONMENTAL REQUIREMENTS. The Alaska District has completed an environmental assessment (september 1983) as required by the National Environmental Policy Act and the evaluations required by Section 404(b) of the 1977 Clean Water Act. In addition, a Certificate of Reasonable Assurance will be obtained from the State of Alaska as required by the Clean Water Act. The project is consistant with applicable Coastal Zone Management guidelines. The contractor must obtain a State Title 16 Anadromous Fish permit if required. Detailed Action Plans will be developed with the U.S. Forest Service prior to construction completion, as the need arises. Substantial deviations of the project from the recommended plan presented in this Design Memorandum, particularly if they involve disturbance of or placement of fill in tidelands or subtidal waters, may require additional environmental evaluation and documentation. Deviations also could require modification of the Detailed Action Plans. Contractors will be notified that fill is not to be placed below mean higher high water except for repair of the borrow access road. 18-2 SECTION 19 -CONSTRUCTION SCHEDULE 19.01 GENERAL. The project construction schedule extends over approximately a 42 month period. Power-on-line for the Crater Lake phase of this project can be achieved as early as February 1988. The critical elements of the 9 separate contracts needed for completion of this phase of development are completion of the powerhouse and lower penstock (to permit turbine installation), turbine and generator fabrication and installation, and completion of the gate structure to allow the lake tap to be performed in the August-September time frame. The lake tap period is critical ~s that is the time of year when Crater Lake is normally guaranteed to be ice-free. 19.02 CONTRACTS. The 6 major supply contracts and 3 major construction contracts planned for this phase are listed below. The award dates given are significant if the February 1988 power-on-line date is desired to be met. TABLE 19-A. CONSTRUCTION CONTRACTS SCHEDULE A. Crater Lake Phase 1* Award: September, 1984 B. Turbine Award: February, 1985 C. Lake Tap Site Clearing Award: May, 1985 D. 13.8 kV Switchgear Award: June, 1985 E. Generator Award: July, 1985 F. Governor Award: October, 1985 G. Remote Supervisory Control Award: October, 1985 H. Transformer Award: October, 1985 I. Crater Lake Main Contract** Award: November, 1985 * Includes initial tunneling efforts for the primary access adit and a portion of the penstock tunnel and power tunnel, and camp facility installation. ** Includes powerhouse completion and installation of powerhouse equipment, gate structure, trashracks, penstock, portals, and remaining excavation. 19-1 SECTION 20 -PROJECT COST COMPARISONS 20.01 GENERAL. This section presents a comparison of the cost estimate of the recommended plan to the current approved costs. 20.02 -RECOMMENDED PLAN ESTIMATE OF COST. Recommended plan costs are summarized by feature in Table 25-A. The detailed estimates shown in Table 25-B list construction quantities and unit costs applied to the construction items for each feature of the project. 20.03 BASIS FOR ESTIMATE. The majority of the unit costs used were developed from bid prices of previous projects in Alaska. Adjustments were made to the bid prices after comparison of site accessibility, prevailing wage rates, equipment ownership and operation expense, and transportation costs. For those items for which there was no bid price information available, unit prices were developed using more detailed estimates of production rates, wage rates, and equipment operation costs. Costs for the turbine, generator and other powerplant equipment were furnished by the Hydroelectric Design Branch of the North Pacific Division. 20.04 COMPARISON OF RECOMMENDED PLAN ESTIMATE AND CURRENT APPROVED COSTS. A. General. The latest approved Project Cost Estimate PB-3 is dated 7 April 1983 wlth an effective date of 1 October 1983. These costs are based on the recommended plan in OM 23, dated December 1973. The cost estimate for the recommended plan and the latest approved PB-3 cost estimate are shown in Table 20.A. TABLE 20-A. COSTS OF RECOMMENDED PLAN AND LATEST APPROVED COSTS ($1,000) Cost Recommended Latest Approved Cost Acct Plan Estimate No. Feature Sep 84 Base Oct 83 Base 04. Dam 36,975 35,977 .4 Power Intake Works (36,975) (35,977) 07. Power Plant 7,078 9,771 • 1 Powerhouse (1,475) (703 ) .2 Turbines and Generators (4,411) (6,362) .3 Switchyard Accessory and Misc. Equip. ( 1 , 166) (987) .8 Transmission Plant (26) (1,719) 08. Roads and Bridges 0 3,493 19. Buildings, Grounds, Ut i1 it i es 420 329 20. Permanent Operating Equip. 0 408 30. Engineering and Design 6,232 5,527 31. Supervision and Administration 4,020 3,332 50. Construction Facilities 3,770 0 TOTAL COST, CRATER LAKE DEVELOPMENT 58,495 58,837 20-1 B. Differences. (1) Power Intake Works -The recommended Power Intake Works is $998,000 more than the latest approved cost estimate. The entire Power Intake Works, which includes the lake tap, power tunnel, penstock, gate structure, surge tank and access adits, has been redesigned since Design Memorandum 23 was published. The increased cost is the result of some project features that have been included in the recommended plan but were not present in the OM 23 plan. These include: a secondary rock trap, access adit from the gate structure to the lake, power tunnel emergency plugs and bulkheads upstream of the gate structure, and removal of overburden from the lake bottom. In addition, the recommended plan has a much higher gate structure and surge tank than those presented in OM 23. The project cost increases realized by these additional project features is substantially more than the dollar difference between the recommended plan and approved plan costs for Power Intake Works. The small difference between the two shown in Table 20-A is due to the fact that the rates of inflation used to escalate the latest approved cost were in excess of the actual rates of inflation. (2) Power Plant -Although the recommended plan adds the cost of constructing an underground machine shop adjacent to the existing powerhouse ($899,000), the cost of the power plant feature is less for the recommended plan than the costs reflected in the latest approved estimate. The main factor contributing to the higher costs of the approved estimate is the excessive rates of inflation used to/prepare the estimate, especially in association with the turbine, generator and transmission plant. (3) Roads and Bridges -As a result of the recommended design of the power conduit, the access road to the gate structure and surge tank has been eliminated. The cost of this item is therefore reduced from $3,493,000 in the latest approved cost estimate to zero for the recommended plan. There are some very minor costs associated with upgrading the existing Crater Cove access road for the recommended plan. As this work will be accomplished with tunnel muck, the cost has been incidential to Power Intake Works. (4) Buildings, Grounds, Utilities -The estimated cost of the Buildings, Grounds and Utilities for the recommended plan is $420,000, compared to $329,000 for the latest approved estimate. The increase in cost is due to better detailed information for pricing this work. (5) Permanent Operating Equipment -There will be no permanent operating equipment supplied for the recommended plan, therefore no costs are shown. (6) Engineering and Design -The engineering costs shown for the recommended project reflect the total anticipated expenditures expected to be required to complete the Crater Lake phase of development. Through September 1984 approximately $4.51 million has been expended of the total. The design costs shown for the latest approved estimate reflect a figure of 11 percent of the total construction costs. The reason for the increased 20-2 '" cost is primarily due to the conductance of an unplanned in-lake geological exploration program in the summer of 1984, extensive changes in the surge tank and penstock design as a result of review of the November 1983 draft of this design memorandum, and the subsequent revision and reissuance of this design memorandum. (7) Supervision and Administration -The costs of S&A for the recommended plan is higher than the latest approved plan even though the overall construction costs decreased. The increase in S&A is due to the increase in overhead computed for the increase in E&D. Of the total S&A for the recommended plan, approximately $0.47 million has been expended through September 1984. (8) Construction Facilities -The latest approved estimate shows no cost for construction facilities because at the time OM 23 was prepared (basis for estimate) the plan was to utilize the facilities from Long Lake phase construction. Delay in construction of Crater Lake resulted in loss of use of the old facilities for this phase, therefore, the recommended plan reflects a cost for reconstruction of construction facilities. 20-3 SECTION 21 -POWER STUDIES AND ECONOMICS 21.01 GENERAL. Power studies and an economic analysis of the Crater Lake phase of the Snettisham project were last presented in OM 23 "First Stage Development Plan, Crater Lake" dated December 1973. The following discussions update the power studies and economic analysis presented in OM 23. This section describes the power market area served by the Snettisham Project, its estimated future power requirements, and how existing and planned power sources could meet those power requirements. This section also presents the power capabilities of Crater Lake and a·benefit-cost analysis based on the capabilities, estimated project costs, and the unit costs associated with the most likely thermal alternative to Crater Lake hydro. The Alaska Power Administration (APA) report titled "Juneau Area Power Market Analysis," September 1980, and subsequent updates, was the main source of data for describing the market area, alternative power sources, future demands, and load resource analysis. The APA report and updates referenced above are included as Exhibits 7-13. 21.02 POWER MARKET AREA. The Snettisham Hydroelectric Project is the main power source for Juneau, Alaska's capital. The power market area consists of the City and Borough of Juneau. Juneau is not presently electrically interconnected with any other power market areas. Power in the Juneau area is marketed by two local utilities, Alaska Electric Light and Power (AEL&P) and Glacier Highway Electric Association (GHEA). Government activities constitute the major economic base for the population of 22,880 (1983). Tourism is the major industry, with fishing, transportation, forestry, and mining contributing to the balance of the economy. 21.03 FUTURE POWER REQUIREMENTS. A. General. The Juneau area has had a substantial growth in the use of electrlclty for space and water heating in the past several years. The most noteable growth has been by residentail consumers, but is significant also for commercial, industrial, and Government customers. Historic data shows a 10.9 and 9.3 pct average annual increase in energy sales and peak demands, respectively, from 1970-1984. The number of residential customers has increased approximately 6.0 pct annually and use per customer has increased approximately 2.0 pct annually during this period. The latest load forecasts developed by the APA indicate that power demands will exceed firm hydro energy capabilities until completion of the Crater Lake phase of the Snettisham project. During the 1982-83 heating season local utilities were required to provide over 5 million kWh of diesel generated electricity to supplement energy available from hydro plants. B. Load Forecasts. The Juneau area load forecasts presented in this text were developed by the APA. The Alaska Power Administration studied a number of growth rates to develop the low, medium and high projections presented herein. Forecasts were based on current and historic climatic, economic, population, and power sales data. The wholesale price of energy from the Snettisham Project was recently increased 10 mills/kWh to recover portions of project interest expense which was deferred for the initial 10 yr period of project operation. The local utilities passed on the 10 mills/kWh cost increase to the consumer which amounted to approximately 21 -1 a 10 pct increase in retail power costs. APA does not feel the 10 pct price increase alone would stimulate a significant effort amoung consumers to conserve energy. Each growth rate considered conservation and the trend to electric heating in new construction and conversions. Conservation is reflected in the load forecasts as a decrease in use per customer in the residential sector, reaching 1-2 percent annually by the year 2000. The medium projection was used in the economic analysis presented in this report. Regardless of which load forecast is considered, 60 to 80 pct of the Crater Lake output will be used the first year that power is on-line (1988), and all firm energy will be fully utilized by 1995. Table 21-A show historic energy and peak demands and Table 21-8 shows estimated future power requirements for the Juneau area. A more detailed description of the Juneau area load forecasts are presented in Exhibits 7-13. C. Existing and Planned Generation. (1) The existing and planned generating units supplying power to the Juneau area are shown in Tables 1 & 2 of Exhibit 6. The main power source in the Juneau area was originally hydroelectric generation. Low cost diesel generation became available and the hydro units were abandoned or not maintained. Increases in oil prices have made hydropower economically attractive and the local utilities now plan to rebuild and modernize all their hydro plants. (2) . Alaska Electric Light and Power is a private utility serving primarily the downtown Juneau-Douglas area. AEL&P is currently upgrading its main distribution line from 23 kVA to 69 kVA. Glacier Highway Electric Association is a Rural Electrification Association (REA) cooperative and services mainly the outlying areas along the Glacier Highway. GHEA has one standby diesel generator operated and maintained by AEL&P. D. Alternative Power Sources. Possible alternatives to the Crater Lake Phase of Snettisham considered by APA include other local hydro projects, interconnection with other utilities in Southeast Alaska, tidal power, wind power, geothermal power, and diesel generation. (1) Hydropower -Other potential hydro sites that have been studied in the past by the Corps include Lake Dorothy, Sweetheart Falls, Speel River, and Tease Lake. All sites are within 2 to 6 mi of the existing Snettisham transmission line. All sites require congressional authorization, and environmental assessment and feasibility studies before construction can begin. A summary of the anticipated capabilities of each potential hydrosite is shown on page 40 of Exhibit 6. (2) Intertie -The APA is currently studying the technical and economic feasibility of interconnecting the Snettisham-Juneau area with Petersburg, Wrangell and Ketchikan using a submarine DC transmission system. If the intertie proves to be feasible, the entire Southeast Alaska region would have access to the most economical new power sources. Canada is studying new hydroelectric sites on the Stikine and Yukon Rivers for possible construction during the 1990's. It is possible that a Southeast Alaska system can be interconnected with the Canadian system sometime beyond that time frame. 21-2 TABLE 21-A. JUNEAU AREA ENERGY AND PEAK DEMAND System Net MWh Peak MW Generation % Annual Demand % Annual Fiscal Year MWh 1/ Increase MW Increase 1970 58,266 12.4 9.5 1l.3 1971 63,786 13.8 10. 1 8.0 1972 70,255 14.9 7.8 4.0 1973 75,753 15.5 9.6 4.5 1974 83,059 16.2 13.9 9.9 1975 94,609 17.8 12.4 1l.2 1976 106,296 19.8 5.6 3.0 1977 112,197 20.4 8.9 14.7 1978 122,218 23.4 9.2 -1.3 1979 133,457 23. 1 7.2 13.4 1980 143,128 26.2 16.5 22.9 1981 166,700 32.2 21.7 29.2 1982 202,900 41.6 10.4 -3.6 1983 224,000 40.1 10.4 3.0 1984 247,400 '!:./ 41.3 1/ Includes AEL&P and GHEA sales and losses. 2/ Estimated based on 6 months of data. APA 4/84 21-3 TABLE 21-B. JUNEAU AREA POWER REQUIREMENTS Estimate of Future Demand Fiscal Year Low Medium ~ 1984 GWh 236 237 237 MW 41 41 41 ~\ 1985 GWh 253 254 257 MW 54 55 56 1986 GWh 259 267 273 MW 56 58 59 1987 GWh 267 278 288 f"' MW 58 60.3 62.5 p 1988 GWh 275 289 303 MW 59.7 62.6 65.7 1989 GWh 282 299 317 MW 61.3 64.8 68.9 1990 GWh 288 307 330 MW 62 67 72 1995 GWh 316 353 402 MW 69 77 87 2000 GWh 349 403 485 .. ~ MW 76 88 105 21-4 (3) Alternative Sources -Tidal, geothermal, and wind power are possible future power sources. However, no potential sites within reasonable proximity to the Juneau area have been identified to date, therefore they are not considered to be realistic alternatives at this time. (4) Diesel -Diesel power plants are expected to remain the most likely thermal alternative to hydropower for Juneau, mainly because that is the accepted technology for standby reserves which are anticipated to be actually used about 1 pct of the time. In addition, diesel power is the most practical alternative at this time for firm power supply if hydro and other sources are inadequate. E. Load Resource and System Cost Analyses. A series of load resource and system cost analyses were made by ApA to examine the hydro alternatives that would most likly be utilized in meeting future power requirements in the Juneau area. Three cases were analyzed: (1) No new hydro projects after completion of the Salmon Creek rehabilitation. (2) Construction of Crater Lake addition followed by construction of Long Lake Dam. (3) Construction of Long Lake Dam followed by construction of the Grater Lake addition. Each analysis assumed that no new electric heating applications would be permitted when area demands exceeded the available hydroelectric supply. Results indicate that average system costs for Case 2 (Crater Lake followed by Long Lake Dam) were significantly lower than for Case 1 (no new hydro) throughout the 1980's and 1990's. Comparison of Case 2 and Case 3 indicates lower costs for a plan adding Crater Lake first. The need for additional hydro projects beyond the mid to late 1990's was indicated in the analysis, with Lake Dorothy and Sweetheart projects being the most desirable. Figure 21-A shows estimated future power requirements for the Juneau area and the hydro resources that could meet those requirements. F. Project Repayment Studies. Snettisham Project repayment criteria were initially established in the authorizing document (Section 204 of the Flood Control Act of 1962, Public Law 87-874) and amended by Section 201 of the Water Resources Development Act of 1976; Public Law 94-587. The APA prepared repayment studies to show the impact of Crater Lake and Long Lake Dam on power sales and revenue requirements for the Snettisham Project. All of the repayment studies allow for inflation in operation and maintenance costs through 1984. Actual rates will of course reflect any inflation beyond that date. Study results are as follows: 21-5 FIGURE 2 JUNEAU LOADS AND RESOURCES 550 LAKE DOROTHY 500 -LOW GROWTH (150 GWH) F -----MID-RANGE GROWTH I ---HI GROWTH /' R /' G----e HYDRO RESOURCES /' M 450 /' /' /' E /' N /' /' E 400 /' R LONG LAKE DAM /' G (57 GWrj),' /' Y /' r°,) ",- I-' 350 ",- I O'l CRATER LAKE ",- ",-(99.9 GWH L/,' G 300 ",-, W ",-, , /" .,' , , H EXISTING HYDRO 250 (216 GWH) ffi-----iJ) SALMON CRE K (7. 5 GWH) 200 1984 1986 1988 1990 1992 1994 1996 1998 2000 FISCAL YEAR Average rate, 1986 to end Repayment Assumption 'of repayment period 1. Existing project (without additions of . Crater Lake and Long Lake Dam): (assumptions 26 mills per kWh are identical to official FY 1979 APA power repayment study, except for slightly higher sales figures in the early 1980's). 2. Existing project with addition of Crater 23.5 mills per kWh Lake (1986) and Long Lake Dam (1988) (1980 costs). 3. Same as assumption 2, but with 35 pct inflation of construction costs for Crater Lake and Long 26.5 mills per kWh Lake Dam. 4. Same as assumption 2, but with load growth 24.0 mills per kWh delayed 10 pct. 21.04 THERMAL ALTERNATIVE AND POWER VALUES. A. Thermal Alternative. The most likely thermal alternative to Crater Lake hydro was determined by the San Francisco Regional Office of the Federal Energy Regulatory Commission (FERC) to be a diesel engine generating plant of 7,500 kW total capacity consisting of three 2,500 kW units operating at 40 pct plant factor, over a 35 yr service life, with a heat rate of 10,550 Btu/kWh, capital cost of $530 per kW, and fuel and lubricating costs at $1.0795 and $5.00 per gal, respectively (see Exhibft 12). B. Power Values. (1) FERC Power Values -The power values provided by FERC were used in part for the project benefit-cost analysis and the economic analysis of the power tunnel and penstock. The power values, based on January 1982 price levels for Federal financing at 3-1/3 pct and 7-5/8 pct interest rates, are shown in Table 21-C. Real fuel cost escalation assuming a project-on-line date of 1986 were also provided. (2) Project Capacity Value -Due to the single contingency transmission line from Snettisham, the local utility should install 100 pct backup of needed Crater Lake capacity. Reserve capacity could be provided by installing an oil-fired combustion turbine in Juneau. It would be appropriate to derate the capacity value developed by FERC by the capacity value of the combustion turbine. The resulting capacity value that could be claimed for Crater Lake would be quite small. The impact on total project benefits would be minimal and therefore capacity benefits for Crater Lake were not claimed. 21-7 TABLE 21-C. AT-MARKET VALUE OF DEPENDABLE HYDROELECTRIC POWER (Price Level -January 1982) Without Fuel With Fuel Cost Escalation Cost Escalation Rate of Federal Financing $/kW mills/kWh mi 11 s/kWh 3-1/3% 40.17 95.04 1/ 162.28 7-5/8 % 61. 76 95.04 -141 .53 1/ The breakdown of the at-market energy value without fuel cost escalation Ts as follows: Fuel O&M Step-up Substation costs Hydro-thermal Energy adjustment 82.53 mill s/kWh 8.47 II 0.53 II 3.51 II 95.04 mil ls!kWh (3) Firm Energy Value -The nonescalated energy value provided by FERC was updated to September 1984 cost levels. Fuel costs per kWh were based on a fuel cost of $0.90 per gal, an energy equivilent of 138,700 BTU/gal, and the heat rate provided by FERC of 10,550 BTU/kWh. Variable O&M costs provided by FERC were escalated by 7.2 pct/yr for 1982 and 6.4 pct/yr for the 21 mo in 1983 and 1984 in accordance with the Bureau of Labor and Statistics data related tQ utility salary and wage increases in 1982 and 1983. The step-up substation costs and the hydro-thermal energy adjustment provided by FERC were used. Fuel cost escalation above the general inflation rate was used in the benefit analysis. That portion of the at-market energy value that is a direct result of the fuel cost was escalated for 26 yr from the present and then held constant for the rest of the 100 yr economic life of the project. Real fuel cost escalation rates and the duration of escalation were based on the 1984 Data Resources Incorporated Summer Energy Review Report. Escalation rates and the resulting value of energy are given in Table 21-0. (4) Secondary Energy The marketing agency (APA) and the Alaska District have reservations about the marketability of Crater Lake secondary energy. There are no opportunities for industrial fuel switching in the market area. The majority of the Juneau area power demand is currently met by existing hydroelectric plants that are all subject to the same hydrologic regime, excess water is available to generate secondary energy at all sites at the same time. Power generation at the hydroelectric plants owned by 21-8 "" '" the local utility (AEL&P) is normally maximized while the Snettisham Project floats on the load and generates the remainder of the demand. During the Aug -Oct time frame when excess water is available to generate secondary energy, firm and secondary energy from local hydroplants is in a sense scheduled before even firm energy production from ~nettisham, thus eliminating the majority of the potential demand for seeondary energy from the Snettisham Project. Table 21-0. REAL FUEL ESCALATION RATES AND VALUE OF ENERGY (Source: Data Resources Incorporated) Period 1984-1990 1991-1995 1996-2000 2001-201 0 2011-2088 Escalation Rate (pct) 0.6 Year Energy 1984 1985 1988 (power-on-line) 1995 2000 2010 (end of applied escalation) 2088 (end of project economic life) 3.7 3.4 1.8 o Value (mills/kWh) 1/ 82.94 2/ 83.35 - 84.60 99.64 115.17 134.89 134.89 1/ 10.12 mills/kWh of each energy value is variable O&M. 2/ Drop in energy value attributed to lower fuel costs. There are some instances when secondary energy from Crater Lake could be marketed. Some secondary energy would be marketable during periods of firm hydroenergy short falls before a new hydro resource was brought online. Maintenance of the various hydro and thermal units in the system could be scheduled during the Aug -Oct time frame when secondary energy is available from Crater Lake. Forced outtages in the system would also create a temporary market for Crater Lake secondary energy. APA is currently studying the possibility of interconnecting the Snettisham Project with other southeast Alaskan communities. Construction of such an intertie would provide a market for Crater Lake secondary energy. The assumption was made that on the average there will be a demand for 25 pct of secondary energy potential from Crater Lake. Based on the discussion presented in this section this assumption may be optimistic. 21.05 POWER STUDIES. A. I~odel Assumptions. The Optimum Hydropower Yield Program, developed by the Alaska District, Corps of Engineers, was used to estimate average annual energy, firm annual energy, and secondary energy for Crater Lake. The following assumptions were used in the computer model: 21-9 (1) Storage Capacity Curve, Plate 46. (2) Minimum power pool elevation is 820 ft above project datum. (3) Maximum power pool elevation is 1,017 ft above project datum. (4) Storage available for power regulation is 81,500 acre-ft. (5) Tailwater elevation is fixed at 11.4 ft above project datum. (6) Crater Creek flows observed and estimated from correlation with Long River and Dorothy Creek for WY 1914 -1968 as presented in Table 5-A. (7) Power tunnel equivalent diameter is 11 ft and the penstock diameter is 6 ft. (8) Head -loss coeffi c i ent K is. 0001093 (expected losses) for the relationship HL = K02. (9) Plant capacity is 34,500 KVA at 1.0 power factor. ( 10) ( 11 ) capacity and Plant efficiency is 86 pct. Transmission and station service losses of 5 pct for both energy. (12) Monthly distribution of power demand as shown in Table 2l-E. (13) All available water will be used for power production (no minimum releases required for fisheries in Crater Creek). (14) All observed and correlated monthly streamflows as described in Section 5 of this OM were used in the power routing studies t B. Power Routing Results. (1) Power Capabilities -Results of the power regulations are shown on Plates 47 through 49. Based on 54 yr of routing, Crater Lake has a firm energy capability of 99.9 GWh and a secondary energy capability of 15.3 GWh (includes 5 pct. losses for transmission and station service). (2) Critical Period -The critical period resulting from the assumptions listed above is 31 mo, extending from October 1920 to May 1922 (refer to Plate 48). (3) Dependable Capacity -The dependable capacity of a hydro- electric plant is that capacity that is available when needed. Dependable capacity is needed in Juneau during the peak load season from November through March. The minimum pool elevation reached during the November through March period in the routing studies was 860 ft. Based on a pool elevation of 860 ft, maximum tailwater of 12.5 ft, expected losses through the power conduit, and the assumed turbine characteristics, approximately 29,000 KVA can be considered as dependable capacity. 21-10 However, because of the single contingency transmission line which serves the project, this capacity is not dependable at the load center and therefore has no economic value. Table 21-E. JUNEAU AREA ENERGY USE (1000 kwh) FY % of FY79 FY % of FY80 FY % of FY81 1979-81 Month 1979 Total 1980 Total 1981 Total Average% OCT 10,711 8.0 11 ,750 8.4 12,932 8.5 8.3 NOV 11 ,669 8.7 11 ,663 8.3 13,458 8.8 8.6 DEC 12,065 9.0 12,858 9.2 16,466 10.8 9.7 JAN 12,697 9.5 13,667 9.8 13,636 9.0 9.5 FEB 11 ,963 9.0 11,904 8.5 12,906 8.5 8.7 MAR 11,737 8.8 12,392 8.8 13,600 8.9 8.8 APR 10,549 7.9 11 ,243 8.0 12,228 8.0 8.0 MAY 10,603 7.9 11,066 7.9 11 ,313 7.4 7.7 JUN 9,933 7.4 10,315 7.4 11 , 136 7.3 7.4 JUL 10,397 7.8 10,795 7.7 11,132 7.3 7.6 AUG 10,529 7.9 10,993 7.8 11 ,427 7.5 7.7 SEP 10,604 7.9 11 ,482 8.2 11 ,836 7.8 8.0 133,457 140,128 152,070 C. Value of One Foot of Head. Average annual project benefits were divided by the average project net head of 950 ft to obtain the value of one foot of head. The average project net head is equal to. the gross head defined below minus the losses in the power conduit at average flow conditions. Benefits were based on energy values and fuel cost escalation rates that were current at the time the power conduit was optimized. The .nonescalated energy value provided by FERC, real fuel cost escalation rates developed in 1984 by Data Resources Institute (DRI) and a discount rate of 3-1/8 pct were used to determine the average annual project benefit of $12,165,000. The average annual value of one foot of head based on the above figures is $12,805. D. Power Conduit Size Optimization. A number of power tunnel and penstock sizes were analyzed to determlne the most cost effective combination. The effect of head-loss characteristics on project benefits for each conduit size, combined with their associated construction costs, was used as the basis for the optimization. The expected average headloss for each size penstock and power tunnel with the plant operating under expected average conditions was determined utilizing the following conditions: gross head of 960.6 ft (based on average pool elevations of 972 ft and normal tailwater elevation of 11.4 ft); average plant output of 23,300 kW (based on an expected generation duration curve provided by APA); and plant efficiency of 86 pct. The resulting average headlosses were multiplied by the average annual value of one foot of head determined in Section 21.05 C. This value was added to the average annual construction cost of each conduit. Construction costs 21-11 were based on equipment and techniques currently used in this type of construction. Cost levels for the optimization studies were September 1984. The size having the lowest combination of construction and headloss costs was selected as the most cost effective. Based on the above approach, the 11.0-ft diameter power tunnel and 6.0-ft diameter penstock were chosen. Results are shown on Plate 50. E. Sensitivity Analysis. Project benefits and the value of one foot of head are based solely on energy benefits. Energy benefits are sensitive to estimates of real fuel cost escalation rates. Because of the many uncertainties in the world oil market today, a wide range of real fuel cost escalation rate estimates have been made by various organizations. The 1982 estimate by Canadals energy, mines and resources department predicts a 1.7 pct real fuel cost escalation rate. One projection used by the ~tate of Alaska in 1982 to project future oil prices is based on the assumption that oil prices will stay level with inflation. The ORIls 1984 estimate and the real fuel cost escalation rates referenced above were used in the sensitivity analysis. The analysis shows that a lower estimate of real fuel cost escalation results in a lower value of head10ss costs. The lower head10ss values do not offset the increased construction costs of the larger size conduits. Therefore, the economic optimization tends toward the smaller size tunnels and penstocks. A graphical representation of the sensitivity analysis is shown on Plate 51. 21.06. PROJECT COSTS AND BENEFITS. A. General. Only costs and benefits attributed to Crater Lake are presented in this report. An analysis was done in which Crater Lake was treated as an ongoing phase of the Snettisham project. The present worth of Crater Lake costs and benefits were based on the Long Lake 1973 power-on-1ine date and combined with those costs and benefits attributed to Long Lake. The analysis resulted in a positive benefit to cost ratio. This section presents construction costs and power benefits associated with Crater Lake on an average annual basis. All costs and power values are based on September 1984 price levels. Annual costs and benefits were developed using ~-1/8 and 8-3/8 pct discount rates for Federal financing. The basic analysis and the power conduit optimization were done using the 3-1/8 pct discount rate because the Snettisham project was originally authorized at the 3-1/8 pct discount rate for Federal financing. The 3-1/8 pct discount rate falls in the range of estimates for inflation free discount rates; therefore, the economic analysis using the 3-1/8 pct rate can be considered an inflation free analysis. All costs are considered to be inflation free. B. Project Investment Costs. Total project costs include construction costs, Englneerlng and Deslgn (E&O) costs, and Supervision and Administration (S&A) costs. E&O costs are estimated at $6.23 million, $4.51 million of which has been expended through fiscal year 1984. S&A costs are estimated to be ~4.02 million, $0.47 million of which has been expended through fiscal year 1984. Total project investment costs include total project costs plus interest during construction. Interest during construction was calculated 2-12 using 3-1/8 and 8-3/8 pct interest rates compounded annually. The actual (1974-1984) and estimated (1985-1988) annual project costs are shown in Table 21-F. TABLE 21-Fu ANNUAL PROJECT COSTS Fiscal Year Project Cost ($1,000) 1974 1975 1982 1983 1984 1985 1986 1987 1988 600 620 2,000 570 1, 193 10,000 20,000 20,000 3,513 58,495 Construction Start Power-on-line C. Annual Costs. Annual costs include the amortized investment costs, operation and maintenance costs, and the costs of interim replacements. Investment costs were amortized over 100 years at 3-1/8 and 8-3/8 percent to obtain annual investment costs. The annual operation and maintenance costs associated with the Crater Lake phase are estimated to be $235,000. Interim replacement costs are estimated as $15,000 annually. Table 21-G summarizes the annual costs for the recommended plan. TABLE 21-G. ANNUAL COSTS OF RECOMMENDED PLAN Cost Item ($1,000) Construction Cost 1/ Engr & Design Cost-2/ Supervsn & Admin Cost 3/ Total Project Cost Interest During Canst. Total Investment Cost Interest & Amortization i/ Operation & Maint. Cost Replacement Costs Total Annual Cost l/ Includes 20 pct contingency. 48,243 6,232 4,020 58,495 5,118 63,613 2,084 235 15 2,334 ~/ E&D is 13.0 pct of construction cost, of which $4.51 million was expended prior to FY 85. 1/ S&A is 6.5 pct of construction cost plus 24 percent of E&D for overhead, of which $0.47 million was expended prior to FY 85. 4/ 100 years at 3-1/8 pct. 21-13 D. Project Benefits. Only firm and secondary energy benefits were claimed for the Crater Lake project. Juneau is not an area of high and persistent unemployment, therefore employment benefits were not claimed. The energy value provided by FERC and updated by Alaska District was used to determine project energy-benefits. Fuel costs were escalated by the real fuel cost escalation rates developed by DRI. The energy values were applied to the year-to-year demand for Crater Lake energy, and present worth was calculated for each based on the 1988 power on-line date. Energy benefits were totaled for the 100 yr economic life of the project and amoritized over 100 years to arrive at an average annual benefit. Table 21-H shows yearly Crater Lake energy utilization, the energy values and energy benefits claimed thru 1992, the year energy from Crater Lake is fully utilized. Table 21-1 shows project economics for the Crater Lake project at 3-1/8 and 8-3/8 pct discount rates and DRI real fuel cost escalation rates. Project economics were also tested with a zero real fuel cost escalation rate. TABLE 21-H. ANNUAL DEMANDS AND BENEFITS Energy Energy 2/ Supplied by Suppliea CRATER L. Energy by Exist Firm Sec Firm Energy Fiscal Demand 1/ Hydro Energy Energy Value Year (GWh) (GWh) (GWh) (GWh) mi 11 s/kWh 1988 POL 289 216 47 3/ 0 84.60 1989 299 216 82.9 0 85.02 1990 307 216 90.9 0 85.45 1991 316.2 216 99.9 0 88.08 1992 325.4 216 99.9 3.8 90.82 1/ Mid-range growth r-ate. 2/ EXisting and planned by 1985 (firm energy). J/ Based on 1 May 1988 POL (May-Sept firm monthly energy) 4/ 3-1/8 pct discount rate. TABLE 21-1. PROJECT ECONOMICS Present Worth 4/ Energy Benefits ($1,000) 3,856 6,611 7,082 7,782 8,075 With DRI Fuel Cost Escalation No Fue 1 Cost Escalation Discount Rate (pct) Total Annual Benefits ($1,000) Total Annual Costs ($1,000) Annual Net Benefits ($1,000) B/C Ratio 3-1/8 1 2, 1 65 2,334 ~,831 5.2 21 -14 8-3/8 10,477 6,418 4,059 1.6 3-1/8 8,099 2,334 5,765 3.5 8-3/8 7,504 6,418 1,086 1.2 SECTION 22 -REAL ESTATE 22.01 GENERAL. The main project area consists of approximately 14,022 acres located within the publically-owned lands of Tongass National Forest. This area includes Crater Lake and Long Lake and a portion of the Speel Arm flats suitable for a power generating station and support facilities. The real estate was withdrawn from the public domain and from appropriation under the United States mining laws, but not from leasing under the mineral leasing laws, by Public Land Order No. 4108, dated 26 October 1966, for protection of the facilities constructed in conjunction with this project. Other documents discussing the project areas are the Supplemental Memorand~m of Understanding between the U.S. Forest Service and the Corps of Engineers, dated 18 September 1967, and Design Memorandum No. 11, Real Estate, for the Snettisham Project, dated March 1967. 22-1 SECTION 23 -COORDINATION WITH OTHERS ·23.01 ALASKA POWER ADMINISTRATION. As the Federal Agency that will be responsible for operating and maintaining the project after completion, the Alaska Power Administration (APA) has been consulted during the advance engineering and design phase of this project. In addition, the APA prepared the Power Market Analysis and its subsequent updates which are included as Exhibits 7-13. 23.02 U.S. FISH AND WILDLIFE SERVICE. The U.S. Fish and Wildlife Service (USFWS) has been coordlnated wlth throughout the development of this memorandum. Studies by that agency were funded to determine the nature of existing ecosystems in the Crater Cove and Crater Creek area and to identify the potential impacts of the project. The Fish and Wildlife Coordination Act Report supplement for the Crater Lake phase, as prepared by the USFWS, is on file at the Alaska District~ Corps of Engineers. Several protection and mitigative measures are recommended in that document and are discussed in detail in the project environmental assessment (September 1983) and in Section 18 of this report. Coordination with the USFWS will continue both during and after construction. 23.03 U.S. FOREST SERVICE. The U.S. Forest Service (USFS) has been coordinated closely with throughout the development of the project. As the agency responsible for ensuring the protection of the lands on which the project is being constructed, the USFS has agreed to develop joint Detailed Action Plans with the Corps of Engineers, in accordance with an existing Snettisham agreement. 23.04 NATIONAL MARINE FISHERIES SERVICE. The National Marine Fisheries Service has been coordinated with in preparation of the Coordination Act Report and the environmental assessment. 23.05 FEDERAL ENERGY REGULATORY COMMISSION (FERC). The energy values used in the project economics analyses were prepared by FERC. Their information is presented as Exhibit 14. 23.06 ALASKA DEPARTMENT OF FISH AND GAME ~ADF&G). The ADF&G has provided input to the Coordlnatlon Act Report and t e proJect Environmental Impact Statement. 23-1 SECTION 24 -SUMMARY RECOMMENDATION· 24.01 DISCUSSION. The recommended plan as described in this design memorandum is the composite result of studies and analyses of the several features of the project. Wet and dry lake tap alternatives were evaluated, with the wet tap methodology selected for the recommended plan. Various power tunnel alinements and surge tank schemes were considered. Economic evaluation resulted in an optimum plan utilizing a constant-sloped deep tunnel, a conventional vented surge tank, and an unencased steel penstock located in a combined penstock and access adit tunnel. Power needs analyses were performed in cooperation with the Alaska Power Administration to determine the required generator size, resulting in the recommendation of a 34,500 KVA generator. 24.02 CONCLUSION. In conclusion, the recommended project plan as described in this design memorandum represents the most favorable of the alternative plans examined for developmerit of the Crater Lake Phase of the Snettisham Hydroelectric Project. The plan will provide optimum reliable hydropower and attractive economic benefits. 24.03 RECOMMENDATION. The District Engineer recommends that the Crater Lake Phase of the Snettisham Hydroelectric Project be approved for construction in accordance with the design as put forth in this Feature Design Memorandum. The construction is to be performed by the Corps of Engineers and financed through Federal channels. 24-1 SECTION 25 -DETAILED COST ESTIMATES 25.01 General. This section provides a summary and detailed cost estimate for the recommended plan and each of the three alternative plans. Costs are provided by programming subfeature for the recommended plan only. Brief descriptions of the recommended and alternative plans are presented in Sections 3 and 4, respectively. 25-1 SNETTISHAM PROJECT, ALASKA RECOMMENDED PLAN TABLE 25-A. SUMMARY COST ESTIMATE Prlce Level -september, 1984 SECOND STAGE DEVELOPMENT, CRATER LAKE PHASE Feature or Item 04 DAM 04.4 Power Intake Works Gate Structure Secondary Rock Trap Primary Rock Trap and Lake Tap Gate Structure Access Adit Access Adit to Lake Power Tunnel Power Tunnel Emergency Plugs and Bulkheads Primary Trashrack Surge Tank (Vented) Penstock and Penstock Tunnel Fi na 1 Rock Trap Penstock Tunnel Plug and Bulkhead Primary Access Adit Total Cost, 04.4 Power Intake Works TOTAL COST, 04 DAM 07 POWER PLANT Powerhouse Completion Tail race Machine Shop 07.11 07.12 07.13 07.2 07.31 07.32 07.33 07.8 Turbines and Generators Accessory Electrical Equipment Switchyard Miscellaneous Equipment Transmission Plant TOTAL COST, 07 POWER PLANT 19 BUILDINGS, GROUNDS AND UTILITIES Utilities TOTAL COST, 19 BUILDINGS, GROUNDS, AND UTILITIES 25-2 Amount $4,244,000 173,000 1,460,000 1,805,000 1,367,000 8,986,000 985,000 4,627,000 3,067,000 5,663,000 416,000 2,935,000 1,247,000 $36,975,000 $574,000 2,000 899,000 4,411,000 739,000 401,000 26,000 26,000 $7,078,000 $ 420,000 ~ 420,000 Total $36,975,000 $ 7,078,000 $ 420,000 TABLE 25-A Sheet 1 of 2 ~ / I SECOND STAGE DEVELOPMENT, CRATER LAKE PHASE· (Conti nued) Feature or Item 30 ENGINEERING AND DESIGN TOTAL COST, 30 ENGINEERING AND DESIGN 31 SUPERVISION AND ADMINISTRATION Amount TOTAL COST, 31 SUPERVISION AND ADMINISTRATION ,50 CONSTRUCTION FACILITIES Construction Camp Facilities TOTAL COST, 50 CONSTRUCTION FACILITIES TOTAL COST TABLE 25-A ,::; " <' .... ,' '. '. " ; 25-3 $3,770,000 $3,770,000 Total $6,232,000 ~4,020,OOO $3,770,000 $58,495,000 TABLE 25-A Sheet 2 of 2 ~ ~~ lOt • .. t. SNETTISHAM PROJECT, ALASKA RECOMMENDED PLAN TABLE 25-B. DETAILED COST ESTIMATE Prlce Level -SeRtember, 1984 SECOND STAGE DEVELOPMENT, CRATER LAKE PHASE Feature or Item 04 DAM 04.4 Power Intake Works Gate Structure Rock Excavation, Service Room Rock Excavation, Shaft Rock Bolts Concrete· Reinforcement Steel Ladder/Cage & 8 Platforms Vent Pipe, 24" dia. Tunnel Filling Pipe Globe V~lve, 12" Bulkhead Hoist System Slide Gate & Machinery Steel Floor Grating Guardrail Bulkhead : . Gate Guide <Stainless .... Gate Dogging Assembly Lighting., . , ~\ .~ Power Transmi'ss i on System Communication System Instrumentation System Subtotal C()ntingency 20% "'r ". '. Total Cost, Gate Structure ,SecQndary Roc~ Trap Rock Excavation Contingency 20% Total Cost, Secondary Rock Trap Primary Rock Trap and Lake Tap Rock Excavation Lake Tap Unit Quantity CY 1,254 CY 1,130 LF 5,180 CY 654 LBS 32,500 LF 250 LF 1,320 LF 80 EA 1 LS 1 LS 1 SF 70 LF 70 LBS 15,000 LBS 61,000 LS 1 LS 1 LS 1 LS 1 LS , CY 462 CY 1,207 Job 1 Unit Price $320.00 78,0.00 46.00, 890.00 1.80 .' 45.00 165.00 66.00 11,700.00 25,000.00 360,000.00 95.00 20.00 5.30,: .8.75., . . 2,000~ 00 20,000.00 . 40,000.00 20,000.00' 40,000.00 " $ 312.00 $ 312.00 LS 'Amount $401,000 881,000 239,000 582,000 59,000 11 ,000 218,000 5,000 12,000 25,000 360,000 7,000 1,000 80,000 534,000 2,000 20,000 40,000 20,000 40,000 ~3,537,OOO 707,000 $4,244,000 $144,000 29,000 $173,000 $377 ,000 840,000 TABLE 25-8 Sheet 1 of 9 25-4 SECOND STAGE DEVELOPMENT, CRATER LAKE PHASE (Co~tinued) 04 DAM (Continued) Feature or Item Urlit Quantity' 04.4 Power Intake Works (Continued) , Primary Rock Trap and Lake Tap (Continued) Subtotal Contingency 20% Total Cost, Primary Rock Trap and Lake Tap Gate Structure Access Adit 'Rock Excavation CY 4,250 Common Excavation CY ~ 2,150 Fill (Rock from Excavation) CY 2,150 Concrete, Structural CY 12 Reinforcement LBS 1,200 Steel Gate LBS 1,060 Helicopter Pad (Excavation Material Leveled) LS 1- Electrical Lighting EA 40 Subtotal Contingency 20% Total Cost, Gate Structure Acces~Adit , Access Adit to Lake Rock Excavation ,"'CY 3,150"' Common Excavation 'CY 1,670 Rock Bolts, 1 in dia. x 10 ft EA 90 " in di a. x 14 ft :EA ~!< 50" Concrete' CY 12 Reinforcement LBS 1,200- Steel Gate LBS 1,060 Electrical Lighting EA 20 Subtotal Contingency 20% Total Cost, Access Adi~ to Lake Power Tunnel (11 ft dia.) Rock Excavation CY 22,110 Concrete CY 190 Reinforcement LBS 57,760 Rock Bolts, Grouted LF 19,020 Steel Sets EA 10 Shotcrete SY 3,530 Subtotal Contingency 20% $ " $ Unit Price $320.00 20.00 30.00." 890.00 1.80 3.75 3,000.00 400.00 " 320~OO " 20.00 460.00 640.00 890.00 1.80 3.75 40Q.00 I, : '. Or> ;.;. ~. "';, 255.00 890.00 1.80 46.00 4,500.00 186.00 Amount $1,217,000 243,000 $1,460,000 $1,360,000 43,000 65,000 11 ,000 2,000 4,000 3,000 16,000 -$ ,1 , 504, 000 301,000 $1,805,000 '$1,008,000 , 33,000 ,", , ,. 41,000 )32~000 11 ,000 ' ,~, , 2,000 ' 4,000 8,000 .. ~j ~. : ., "$l~'367 ,000 ; ... ~ $5,638;000 169,000 104,000 875,000 45,000 657,000 $7,488,000 1,498,000 TABLE 25-B "', .,' ./ SECOND STAGE DEVELOPMENT~ CRATER LAKE PHASE (Continued) 04 DAM (Continued) Feature or Item Unit Quantity 04.4 Power Intake Works (Continued) Power Tunnel (11 ft dia.) (Continued) Total Cost, Power Tunnel Power Tunnel Emergency Plugs and Rock Excavation Steel Bulkhead Concrete Reinforcement Grout Holes Subtotal Contingency 20% Bulkheads CY 608 LBS 36,000 CY 422 LBS 10,000 LF 1,320 Unit. Price ;-: $312.00 5.30 890.00 1.80 35.00 ;~ Amount , .. $8,986,000 $ . 190,000 . 191,000 376,000 18,000 46,000 .',," $ 821,000 ".164,000 Total Cost, Power Tunnel Emergency Plugs and Bulkheads $ 985,000 Primary Trashrack Steel Concrete Weights Reinforcement Operating Cable Installation Cables Barge and Hoist Remove Overburden Above Lake Tap (Under Water Excavation) Subtotal Contingency 20% Total Cost, Primary Trashrack Surqe Tank Rock Excavation, Shaft Rock Excavation, Drift Concrete Reinforcement Wire Mesh Rock Bolts Vent Pipe Level and Pressure Monitoring System Subtotal Contingency 20% Total Cost, Surge Tank LBS CY LBS LF LF LS LS CY CY CY LBS SY LF LBS LS 25-6 42,600 $ 4.10 $ 175,000 2 1,500.00 3,000 100 1.80 ., ;-~ '0 400 20.00 8,000 ··800 20.00 16,000 1 11 0,000.00 11 0,000 :)\ ; .', ,'.-(, :7 1: t'~·:1·.'~ 3,545,000. QO <) ;;.:.3,545,000 "''':..,'): '-'1~1-:) . ;~;.: ,'11$3,856,000 ~. (~'''' . i r" : . 771,000 . - . i ',. -"' ;:' $4,627,000 .... ; i·" .... r~ 2,960 $ 635.00 .' $1:,.880,000 240 214.00:,.·, ,.\ .... ,·::·51,000 58 890.00 52,000 2,900:,. " ;·1-.80: ,\'7) r f5,000 3,700 7,600 1,924 1 30.00 46.00,\ 3.75~ .. .. ' 100,000.00 111,000 'f .350, OOO~- 7,000 100,000 . $2,576,000 511 ,000 $3,067,000 TABLE 25-B Sheet 3 of 9 SECOND STAGE DEVELOPMENT, CRATER LAKE PHASE (Continued) 04 DAM (Continued) Feature or Item . Unit Quantity 04.4 Power Intake Works (Continued) Penstock and Penstock Tunnel Rock Excavation Cy 6,500 Shotcrete SY 182 Penstock Steel, A 517 LBS 630,000 Concrete, Penstock Supports CY 348 Reinforcement LBS 14,000 Lighting EA 40 Rock Bolts LF 970 Subtotal Contingency 20% Total Cost, Penstock and Penstock Tunnel Final Rock Trap Rock Excavation CY 1,579 Steel Trashrack LBS 2,163 Subtotal Contingency 20% Total Cost, Final Rock Trap Penstock Tunnel Plug and Bulkhead .. Rock Excavation CY 2~300 Concrete Cy 2,030 Reinforcement LBS 21 ,000 1 2 in d i a. Pipe LF 65 12 in Valve EA 1 Steel Bulkhead LBS 10,000 Grout Holes (34 @ 30 ft) LF 1,050 Subtotal Contingency 20% Total Cost, Penstock Tunnel Plug and Bulkhead Primary Access Adit Rock Excavation, Tunnel CY 2,580 Common Excavation, Portal CY 1,050 Fi 11, Common CY 55 Rock Bolts, Grouted LF 650 Rock Excavation, Portal CY 1,225 Conc ret e, Port a 1 Cy 27 Reinforcement LBS 3,700 25-7 Unit Price $ 214.00 186.00 4.60 890.00 1.BO 400.00 46.00 $214.00 4.10 $214.00 890.00 1.80 150.00 8,500.00 5.30 35.00 $214.00 20.00 30.00 46.00 250.00 890.00 1.80 Amount· \ $1,391,000 34,000 2,898,000 310,000 25,000 16,000 45,000 $4,719,000 944,000 $5,663,000 $ 338,000 9,000 $ 347,000 69,000 $ 416,000 $ 492,000 1,807,000 38,000. 10,000 9,000 53,000 37,000 .. $2,446,000 489,000 $2,935,000 $ 552,000 21,000 2,000 30,000 306,000 24,000 7,000 TABLE 25-B Sheet 4 of 9 ." .~ SECOND STAGE DEVELOPMENT, CRATER LAKE PHASE (Continued) 04 DAM (Continued) Feature or Item 04.4 Power Intake Works (Continued) Primary Access Adit (Continued) Personnel Gate Pre-Split Clearing Lighting Subtotal Contingency 20% Total Cost, Primary Access Adit Total Cost, 04.4 Power Intake Works TOTAL COST, 04 DAM 07 POWER PLANT 07. 11~Powerhouse Completion Substructure Concrete Superstructure Concrete Penstock Branch Concrete Cement Reinforcement Demolition Misce11~neo~s Metal Painting Features Painting Equipment Dust Protection and Barracading Generator, Cooling, Gland and Wear Ring Piping ' .. 'Electrical Conduit System c\ Lighting Subtotal Contingency 20% Unit Quantity LBS SF ACRE EA 1,060 2,500 2 20 CY 204 CY 73 CY 66 CWT 1,615 LBS 40,000 LS 1 LBS 6,333 LS 1 LS 1 LS 1 LS 1 LS 1 LS 1 Total Cost, 07.11 Powerhouse Completion 07.12 Tailrace Bulkhead Guide, Series 300 Stainless Steel LBS 420 25-8 Unit Price 3.75 30.00 5,000.00 400.00 $ 785.00 1,160.00 215.00 9.20 1.80 5,000.00 5.60 17,000.00 24,000.00 12,000.00 31,000.00 5,000.00 3,000.00 $ 3.90 Amount 4,000 75,000 10,000 8,000 $1,039,000 208,000 $1,247,000 $36,975,000 $36,975,000 $ 160,000 85,000 14,000 15,000 72,000 5,000 35,000- 17 ,000 24,000 12,000 31,000 5,000 3,000 $478,000 96,000 $574,000 $2,000 TABLE 25-B Sheet 5 of 9 SECOND STAGE DEVELOPMENT, CRATER LAKE PHASE (Continued) 07 POWER PLANT (Continued) Feature or ·Item Unit Quantity Price 07.12 Tailrace (Continued) Contingency 20% Total Cost, 07.12 Tailrace 07.13 Machine Shop Rock Excavation Rock Bolts Concrete Reinforcement Heating and Ventilation Lighting and Elect. Power Chain Link Fabric Watertight Bulkhead Subtotal Contingency 20% Total Cost, 07.13 Machine Shop . CY LF CY LBS LS LS SY LBS 07.2 Turbine, Generator and Governor Turbine . EA Insta ll .. Turbi ne EA Spheric~l Valve' EA Install: Spherical Valve . EA Branch Pipe and Installation (A 51.6 Steel) . LS Generator and Installation EA Governor and Installation EA Subtotal .. Cont i ngen~y .20% ~-~-'.) , ...... 1,200 $ 4,850 350.00 46.00 890.00 1.80 15,000.00 20,000.00 30.00 5.30 15 750 1 1 136 10,000 1 1 . 1 1 1 1 1 $ 872,000.00 300,000.00 355,000.00 89,000.00 56,000.00 1,800,000.00 204,000.00 Total Cost; 07.2 Turbine, Generator and Governor ;"f-,)"· ... ".--' ;,. : ,:'O~ . .3l Accessory Electrical Equipment Main Generator Cable . Tray System Insulated Power Cable (Over 1,000 Volts) 13.8 KV Metal Enclosed Bus Grounding System 480-Volt Power Outlets LS LS LS LS LS 1 $14,010.00 1 43,260.00 1 54, 180.00 1 3,300.00 1 1,000.00 $ Amount o 2,000 $420,000 223,000 13,000 1,QOO 15,000 20,000 4,000 53,000 $749,000 150,000 $899,000 $ 872,000 300,000 355,000 89,000 56,000 1,800,000 204,000 $3,676,000 735,000 $4,411,000 $14,000 43,000 54,000 3,000 1,000 TABLE 25-B Sheet 6 of 9 25-9 .. SECOND STAGE DEVELOPMENT, CRATER LAKE" PHASE (Continu~d) 07 POWER PLANT (Continued) Feature or· Item Unit Quantity Price . Amount 07.31 Accessory Electrical Equipment (Continued) Misce11anous Electrical Equipment & Accessories LS 13.8 KV Metal Clad Switchgear LS Control Cable Tray System LS Insulated Wire and Cable (below 1,000 Volts) LS Subtotal Contingency 20% 1 375,250.00 ,. 85,700.00 l' 18,330.00 1 21,630.00 375,000 86,000 18,000 22,000 $616,000 123,000 Total Cost, 07.31 Accessory Electrical Equipment $739,000 07.32 Switchyard Excavation and Backfill Concrete Foundation Cement Reinforcement . Bus Support Insulators High Voltage Busses Power Transformer Lighting Arrestors High Voltage Disconnects Subtotal Contingency 20% Tota 1 Cost,. 07.32 Switchyard 07~33 Miscellaneous Equipment ',(, ~ ,', ,~, Heating and Ventilation Unwatering and Drainage Piezometer Piping C02 pi pin'g . , Governor Air Station and Brake Air Piping Lub and Gove"rnor Oi 1 Piping Subtotal Contingency 20% CY CY CWT LBS LS LS EA EA LS LS LS LS LS LS LS 285 10 47 1,500 1 1 1 3 1 $16.50 : 650.00 9.20 1.80 6,000.00 13,000.00 253,000.00. 11,910.00 11 ,000.00 $ 5,000 7,000 o 3,000 6,000 13,000 253,000 36,000 11 ,000 $ "334,000 , . 67,000 . $:,,401,000 $ 3,000.00 $ 3,000 . /,~ l' ."," 1 0,000.00 "<:' 10,000 ...... ,,.-"--"3,000~OO"'-" .. "."-3,000 y'l ' "1,000.00 " .. ",\" 1 ,000 G$j ,::--:, ."", ,"'f') :: .. '-; :J. '! ;; J. !:' 2,000. om 2,000 l' 3,000.00 3,000 $ 22,000 4,000 Total Cost, 07.33 Miscellaneous Equipment $ 26,000 25-10 TABLE 25-B Sheet 7 of 9 SECOND STAGE DEVELOPMENT, CRATER LAKE PHASE '(Continued) , 07 POWER PLANT (Continued) Feature or Item Unit Quantity Price ",' Amount 07.8 Transmission Plant . ,H. , ' Status Switchboard LS '·1 $22,000.00 $22,000 Contingency 20% Total Cost, 07.8 Transmission Plant TOTAL COST, 07 POWER PLANT 19 BUILDINGS, GROUNDS, UTILITIES Util ities Waterline, Sewer1ine, Forced Main, Lift Stations and Seepage Pits LS Electrical Service for Lift Stations LS Subtotal Contingency 20% Total Cost, Utilities TOTAL COST, 19 BUILDINGS, GROUNDS, UTILITIES 30 ENGINEERING AND DESIGN Through September 1984 Anticipated to Complete TOTAL COST, 30 ENGINEERING AND DESIGN 31 SUPERVISION AND ADMINISTRATION Overhead on E&D Through FY 84 Overhead on Remaining E&D 6.5% of Construction Cost TOTAL COST, 31 SUPERVISION AND ADMINISTRATION 25-11 1 1 'I . -' 1..;-I ... $336,000.00 14;000.00 -', , . $ 4,000 $26,000 $7,078,000 $ 336,000 14,000 $ 350,000 70,000 $ 420,000 $420,000 4,512,000 '1,720,000, ,:"" ';',"" ~ $6,232,000 "".,.,-,. j .... "$0,232,000 " , 1: ;',; r :" :: : :j ~~ . ~:\ ~r-~ ->'~J :-." $471,000 ,.,,' 413~ 000; «',Jr" c,,: , 3, 136', 000/ ~>;:,:. $4,020,000,(;,nr, ,. i $4,020,000 TABLE 25-B Sheet 8 of 9 .,; SECOND STAGE DEVELOPMENT, CRATER LAKE PHASE (Continued) Feature or Item Unit Quantity Price Amount 50 CONSTRUCTION FACILITIES Transformers and Electrical Connections for Contractors Camp LS $34,000.00 $ 34,000 Lodging, Food and Camp Services MAN DAYS 44,400 70.00 $3,108,000 $3,142,000 628,000 Subtotal Contingency 20% Total Cost, Construction Facilities TOTAL COST, 50 CONSTRUCTION FACILITIES TOTAL COST, CRATER LAKE STAGE DEVELOPMENT 25-12 $3,770,000 3,770,000 $58,495,000 TABLE 25-B Sheet 9 of 9 TABLE 25-C. ALTERNATIVE PLAN I -SUMMARY COST ESTIMATE (PRICE LEVEL -SEPTEMBER 30, 1984) FEATURE Primary Rock Trap and Lake Tap Primary Trashrack Secondary Rock Trap Gate Structure Gate Structure Access Adit Access Adit to Lake Power Tunnel Surge Tank Final Rock Trap Final Rock Trap Access Adit Road to Final Rock Trap Access Adit Penstock Penstock Construction Adit Powerhouse Completion Turbine and Generator Accessory Electrical Equipment Miscellaneous Power Plant Equipment Tailrace Switchyard Transmission Plant Permanent Buildings Ut i 1 ities Construction Camp Facilities Subtotal Supervision & Administration Engineering & Design Total Cost, Alternative Plan I 25-13 TOTAL COST $ 1,369,000 4,627,000 148,000 10,844,000 2,802,000 1,546,000 10,493,000 1,594,000 413,000 1,547,000 481,000 11,537,000 930,000 574,000 4,411,000 739,000 26,000 2,000 401,000 26,000 292,000 420,000 5,611,000 $ 60,833,000 4,838,000 6,232,000 $ 71,903,000 TABLE 25-0. ALTERNATIVE PLAN I -DETAILED COST ESTIMATE (PRICE LEVEL -SEPTEMBER 30, 1984) UNIT FEATURE OR ITEM UNIT QUANTITY PRICE AMOUNT PRIMARY ROCK TRAP AND LAKE TAP Rock Trap Excavation CY 940 $ 312.00 $ 293,000 • Lake Tap LS 1 840,000.00 840,000 Concrete CY 8 890.00 7,000 Reinforcement LB 400 1.80 1,000 I" Subtota 1 $ 1, 141 ,000 Contingencies -20% 228,000 ~ Total Cost, Primary Rock Trap and Lake Tap $ 1,369,000 PRIMARY TRASHRACK ... Steel LB 42,600 $ 4.10 $ 175,000 Concrete Weights CY 2 890.00 2,000 Reinforcement LB 100 1.80 0 .., Operating Cable (Wire Rope) LF 400 20.00 8,000 Installation Cables LF 800 20.00 16,000 Barge and Hoists LS 1 11 0,000.00 11 0,000 .', Remove Overburden Above Lake ~IB 1 LS 3,545,000 Tap (Underwater Excavation) ., Subtotal $ 3,856,000 Contingencies -20% 771,000 Total Cost, Primary Trashrack $ 4,627,000 "', SECONDARY ROCK TRAP .. Rock Excavation CY 268 $ 312.00 $ 84,000 Steel LB 9,628 4.00 39,000 '" Subtota 1 $ 123,000 Contingencies -20% 25,000 Total Cost, Secondary Rock Trap $ 148,000 .' '" 25-14 TABLE 25-0 (Continued) UNIT FEATURE OR ITEM UNIT QUANTITY PRICE AMOUNT GATE STRUCTURE Rock Excavation, Service Room CY 4,440 $ 320.00 $ 1,421,000 Rock Excavation, Shaft CY 5,260 780.00 4,103,000 Concrete CY 1,880 890.00 1,673,000 Reinforcement LB 94,000 1.80 169,000 Slide Gate #1 LB 82,400 5.30 437,000 Slide Gate #2 LB 60,000 5.30 318,000 Air Vent LF 730 200.00 146,000 Rock Bolts LF 5,180 46.00 238,000 Hoist, 15-ton EA 1 25,000.00 25,000 Steel Grating SF 620 95.00 59,000 Steel Hatch' EA 1 3,000.00 3,000 Ladder with Cage LF 276 75.00 21,000 Elevator with Motor, 1,000#CAP LS 1 325,000.00 325,000 Hydraulic Pump/Tank EA 1 32,500.00 33,000 Structural Support for Vent & LF 276 10.00 3,000 Ladder Lighting, Generators, Control 'Panel w/Monitoring & Communication LS 62,600.00 63,000 Subtota 1 $ 9,037,000 Contingencies -20% 1,807,000 Total Cost, Gate Structure $ 10,844,000 GATE STRUCTURE ACCESS AOIT Rock Excavation CY 5,940 $ 320.00 $ 1,901,000 Common Excavation CY 2,150 20.00 43,000 Fi 11 CY 2,150 30.00 65,000 Rock Bolts: 1110 x 10 1 LF 2,700 46.00 124,000 1110 x 141 LF 700 46.00 32,000 Concrete, Mass CY 137 890.00 122,000 Concrete, Structural CY 12 890.00 11 ,000 Reinforcement LB 7,500 1.80 14,000 Steel Gate, Personnel LB 1,060 3.75 4,000 Helicopter Pad (Excavation LS 1 3,000.00 3,000 Material Leveled) Electrical Lighting EA 40 400.00 16,000 Subtota 1 $ 2,335,000 Contingencies -20% 467,000 Total Cost, Gate Structure Access Adit $ 2,802,000 25-15 TABLE 25-0 (Continued) . UNIT FEATURE OR ITEM UNIT QUANTITY PRICE AMOUNT ACCESS ADIT TO LAKE Rock Excavation CY 3,620 $ 320.00 $ 1,158,000 Common Excavation CY 1,670 20.00 33,000 Rock Bolts: 1110 x 10 1 EA 90 460.00 41,000 110 x 141 EA 50 640.00 32,000 Concrete CY 12 890.00 11 ,000 Reinforcement LB 600 1.80 1,000 ," Steel. Gate, Personnel LB 1,060 3.75 4,000 Electrical Lighting EA 20 400.00 8,000 " Subtotal ~ 1,288,000 t-Gontingencies -20% 258,000 ... Total Cost, Access Adit to Lake $ 1,546,000 POWER TUNNEL ~;l Rock Excavation CY 25,500 $ 255.00 $ 6,503,000 Concrete Tunnel Lining CY 1,134 890.00 1,009,000 Reinforcement LB 345,100 1.80 621,000 ".. Stee 1 Sets EA 10 4,500.00 45,000 Shotcrete SY 387 186.00 72 ,000 Rock Bolts, Grouted LF 10,745 46.00 494,000 ". Subtotal $ 8,744,000 Contingencies -20% 1,749,000 It Total Cost, Power Tunnel $ 10,493,000 SURGE TANK Rock Excavati on, Shaft CY 1,283 $ 780.00 $ 1,001,000 Rock Excavation, Drift CY 190 214.00 41,000 ~. Concrete, Surge Tank Enclosure CY 45 890.00 40,000 Reinforcement LB '4,186 1.80 8,000 Steel Orifice, 111 Plate LB 3,026 4.50 14,000 Rock Bolts LF 2,200 46.00 101,000 Wire Mesh SY 1,222 30.00 37,000 Concrete, Drift Lining CY 58 890.00 52,000 Reinforcement LB 19,140 1.80 34,000 Subtota 1 $ 1,328,000 Contingencies -20% 266,000 , Total Cost, Surge Tank $ 1,594,00r 25-16 TABLE 25-0 (Continued) UNIT FEATURE OR ITEM UNIT QUANTITY PRICE AMOUNT FINAL ROCK TRAP Rock Excavation CY 1,328 $ 214.00 $ 284,000 Steel Trashrack LB 2,100 4.10 9,000 Concrete CY 35 890.00 31,000 Reinforcement LB 11 ,000 1.80 20,000 Subtota 1 $ 344,000 Contingencies -20% 69,000 Total Cost, Final Rock Trap $ 413,000 FINAL ROCK TRAP ACCESS ADIT Rock Excavation, Tunnel CY 2,610 $ 214.00 $ 559,000 Excavation, Common CY 1,100 20.00 22,000 Rock Bolts LF 400 46.00 18,000 Rock Excavation, Portal CY 1,300 250.00 325,000 Concrete, Portal CY 27 890.00 24,000 Reinforcement LB 3,700 1.80 7,000 Personnel Gate LB 1,060 3.75 4,000 Pre-Sp 1 itt i ng SF 2,600 0.30 78,000 Clearing ACRE 2 5,000.00 10,000 Concrete, Plug CY 165 890.00 147,000 Bulkhead LB 10,000 5.30 53,000 Lighting EA 16 400.00 6,000 Fill, Common CY 1,200 30.00 36,000 Subtotal $ 1,289,000 . Contingencies -20% 258,000 Total Cos~, Final Rock Trap Access Adit $ 1,547,000 ROAD TO FINAL ROCK TRAP ACCESS ADIT Excavation CY 13,420 $ 20.00 $ 268,000 Clearing ACRE 1.4 13,500.00 19,000 Gravel Surface CY 1,800 30.00 54,000 Guardrail LF 2,000 30.00 60,000 Subtota 1 $ 401,000 Contingencies -20% 80,000 Total Cost, Road to Final Rock Trap Access Adit $ 481,000 25-17 TABLE 25-0 (Continued) UNIT FEATURE OR ITEM UNIT QUANTITY PRICE AMOUNT PENSTOCK Rock Excavation CY 6,535 $ 214.00 $ 1,398,000 Concrete Liner CY 4,900 890.00 4,361,000 .. Steel Liner, A537 CL2 LB 1,097,285 3.40 3,731,000 Rock Bolts LF 2,700 46.00 124,000 Subtotal ~ 9,614,000 "" Contingencies -20% 1,923,000 Total Cost, Penstock $ 11,537,000 lit, PENSTOCK CONSTRUCTION ADIT ,.. Rock Excavation CY 2,610 $ 214.00 $ 559,000 Concrete Plug CY 214 890.00 190,000 Wire Mesh SY 17 30.00 1 ,000 I' Rock Bo lts LF 400 46.00 18,000 Reinforcement LB 3,890 1.80 7,000 .. ;. Subtotal $ 775,000 Contingencies -20% 155,000 Total Cost, Penstock $ .1' Construction Adit 930,000 POWER PLANT Powerhouse Completion Structural Concrete Substructure Concrete CY 204 $ 785.00 $ 160,000 .. Superstructure Concrete CY 73 1,160.00 85,000 Penstock Branch Concrete CY 66 215.00 14,000 Cement CWT 1,615 9.20 15,000 Reinforcing LB 40,000 1.80 72 ,000 Demolition LS 1 5,000.00 5,000 Miscellaneous Metals LB 6,333 5.60 35,000 Painting, Architectural Features LS 1 16,650.00 17,000 Equipment LS 1 23,850.00 24,000 Miscellaneous Dust Protection & Barricading LS 11,930.00 12,000 Mechanical Items Generator Cooling, Gland & Wear Ring Piping L5 31,400.00 31,000 Electrical Items Conduit System LS 5,360.00 5,00u Li ght i ng System LS 3,300.00 3,000 " 25-18 TABLE 25-0 (Continued) UNIT FEATURE OR ITEM UNIT QUANTITY PRICE AMOUNT POWER PLANT (continued) Powerhouse Completion (continued) Subtota 1 $ 478,000 Contingencies -20% 96,000 Total Cost, Powerhouse Completion $ 574,000 Turbine, Generator and Governor Turbine EA 1 $872,200.00 $ 872,000 Insta 11 Turbi ne EA 1 300,000.00 300,000 Spherical Valve EA 1 355,000.00 355,000 Install Spherical Valve EA 1 88,750.00 89,000 Branch Pipe (A5l6 Steel & LS 1 55,580.00 56,000 Installation) Generator EA 1,800,000.00 1,800,000 Governor EA 204,000.00 204,000 Subtotal $ 3,676,000 Contingencies -20% 735,000 Total Cost, Turbine, Generator and Governor $ 4,411,000 Power Plant, Accessory Electrical Equipment Main Generator Cable LS $14,010.00 14,000 Tray System Insulated Power Cable LS 43,260.00 43,000 (Over 1,000 volts) 13.8 KV Metal Enclosed Bus LS 1 54,180.00 54,000 Grounding System LS 1 3,300.00 3,000 480-Volt Power Outlets LS 1 1,000.00 1,000 Misc. Electrical Equipment & LS 1 375,250.00 375,000 Accessories 13.8 KV Metal Clad Switchgear LS 85,700.00 86,000 Control Cable Tray System LS 18,330.00 18,000 Insulated Wire & Cable LS 21,630.00 22,000 (1000 Volts & Below) Subtotal $ 616,000 Contingencies -20% 123,000 Total Cost, Accessory Electrical Equipment $ 739,000 Miscellaneous Power Plant Equipment Heating and Ventilation LS 1 $ 2,800.00 $ 3,000 Unwatering & Drainage Piping LS 1 9,610.00 10,000 Piezometer Piping LS 1 2,590.00 3,000 C02 Piping LS 1 770.00 1,000 Governor Air, Station & LS 1 1,800.00 2,000 Brake Air Piping Lube & Governor Oil Piping LS 3,020.00 3,000 TABLE 25-0 (Continued) UNIT ~' " FEATURE OR ITEM UNIT QUANTITY PRICE AMOUNT POWER PLANT (continued) Miscellaneous Power Plant Equipment (Continued) 11" Subtota 1 $ 22,000 Contingencies -20% 4,000 Total Cost, Miscellaneous Power Pl ant Equipment $ 2,6,000 1ft Tailrace Bulkhead Guide 300 Series LS 420 $3.90 2,000 It' Stainless Steel Contingencies -20% 0 .. Total Cost, Tailrace $ 2,000 Switchyard Switchyard Structures & Equipment ." Excavation & Backfill CY 285 $ 16.50 $ 5,000 ~, Concrete Foundation CY 10 650.00 7,000 Cement CWT 47 9.20 0 ". Reinforcement LB 1,500 1.80 3,000 .' Bus Support Insulators LS 1 5,850.00 6,000 High Voltage Busses, LS 1 12,980.00 13,000 " Pittings & Accessories Power Transformers EA 1 253,000.00 253,000 .. Lighting Arrestors EA 3 11,910.00 36,000 High Voltage Disconnects LS 1 10,820.00 11 ,000 .. Subtota 1 $ 334,000 Contingencies -20% 67,000 w Total Cost, Switchyard $ 401,000 j/j TOTAL COST, POWER PLANT $ 6,153,000 TRANSMISSION PLANT t'-: Status Switchboard LS $22,000.00 $ 22,000 Contingencies -20% 4,000 ~' Total Cost, Transmission Plant $ 26,000 PERMANENT BUILDINGS ~' Transmission Maintenance LS $92,500.00 $ 93,00r Bldg (Remodel Extg Bldg) f' Machine Shop (Metal Bldg SF 1,200 125.00 150,000 w/Slab on Grade, Complete) 25-20 TABLE 25-0 (Continued) UNIT FEATURE OR ITEM UNIT QUANTITY PRICE AMOUNT PERMANENT BUILDINGS (Continued) Subtotal $ 243,000 Contingencies -20% 49,000 Total Cost, Permanent Buildings ~ 292,000 UTILITIES Waterline, Sewer1ine, Forced LS $336,000.00 $ 336,000 Main & Seepage Pit Electrical Service For Lift Stations LS $14,000.00 14,000 Subtotal $350,000 Contingencies 20% 70,000 Total Cost, Utilities $ 420,000 CONSTRUCTION CAMP FACILITIES Provide Lodging, Food & MD 66,316 $ 70.00 4,642,000 Camp Services Transformer & Electrical LS 34,000.00 34,000 Service Subtotal $ 4,676,000 Contingencies -20% 935,000 Total Cost, Construction Camp Facilities ~ 5,611,000 TOTAL COST, CONSTRUCTION ALTERNATIVE PLAN I $60,833,000 25-21 TABLE 25-E. ALTERNATIVE PLAN II -SUMMARY COST ESTIMATE (PRICE lEVEL -sEPTE8MER 30, 1984) FEATURE Prlmary Rock Trap and Lake Tap Primary Trashrack Secondary Rock Trap Gate Structure Gate Structure Access Adit Power Tunnel Surge Tank Final Rock Trap Final Rock Trap Access Adit Road to Final Rock Trap Access Adit Penstock Penstock Construction Adit Powerhouse Completion Turbine and Generator Accessory Electrical Equipment Miscellaneous Power Plant Equipment Tailrace Switchyard Transmission Plant Permanent Buildings Ut i1 it i es Construction Camp Facilities Subtotal Supervision & Administration Engineering & Design Total Cost, Alternative Plan II 25-22 TOTAL COST $ 1,576,000 4,627,000 148,000 2,942,000 3,463,000 10,493,000 2,240,000 413,000 1 ,547,000 481,000 11,537,000 930,000 574,000 4,411 ,000 739,000 26,000 2,000 401,000 26,000 292,000 420,000 3,980,000 $ 51,268,000 4,216,000 6,232,000 $ 61,716,000 TABLE 25-F. ALTERNATIVE PLAN II -DETAILED COST ESTIMATE (PRICE LEVEL -SEPrEMBER 30, 1984) UNIT FEATURE OR ITEM UNIT QUANTITY PRICE PRIMARY ROCK TRAP AND LAKE TAP .Rock Trap Excavation CY 1,490 $ 312.00 Lake Tap LS 1 840,000.00 Concrete CY 8 " 890.00 Reinforcement LB 400 1.80 Subtotal $ Contingencies -20% Total Cost, Primary Rock Trap and Lake Tap $ PRIMARY TRASHRACK Steel LB 42,600 $ 4.10 ~ Concrete Weights CY 2 1,000.00 Reinforcement LB 100 1.80 Operating Cable (Wire Rope) LF 400 20.00 Installation Cables LF 800 20.00 Barge and Hoists LS 1 11 0,000.00 Remove Overburden Above Lake JB 1 L5 Tap (Underwater Excavation) Subtotal $ Contingencies -20% Total Cost, Primary Trashrack $ SECONDARY ROCK TRAP Rock Excavation CY 268 $ 312.00 $ Steel LB 9,628 4.00 Subtotal $ Contingencies -20% Total Cost, Secondary Rock Trap 25-23 AMOUNT 465,000 II> 840,000 7,000 1,000 '" 1,313,000 263,000 .. ' 1,576,000 .. 175,000 2,000 0 II' 8,000 16,000 11 0,000 " 3,545,000 .. 3,856,000 771,000 4,627,000 IF ., 84,000 39,000 '" 123,000 25,000 $ 148,000 M' ~,' TABLE 25-F (Continued) UNIT FEATURE OR ITEM UNIT QUANTITY PRICE AMOUNT GATE STRUCTURE Rock Excavation CY 1 ,619 $ 320.00 $ 518,000 Concrete CY 620 890.00 552,000 Reinforcement LB 31,000 1.80 56,000 Slide Gate #1 LB 82,400 5.30 437,000 Slide Gate #2 LB 60,000 5.30 318,000 Air Vent LF 1,275 188.00 240,000 Hoist, 15-Ton EA 1 25,000.00 25,000 Rockbo lts LF 220 46.00 10,000 Hydraulic Pump/Tank LS 1 32,500.00 33,000 Lighting, Generators, Control LS 1 63,000.00 63,000 Panel w/Monitoring & Communication Clearing AC 0.5 16,000.00 8,000 Excavation, Common CY 3,200 60.00 192,000 Subtota 1 $ 2,452,000 Contingencies -20% 490,000 Total Cost, Gate Structure $ 2,942,000 GATE STRUCTURE ACCESS ADIT Rock Excavation CY 7,311 $ 320.00 $ 2,340,000 Common Excavation CY 2,150 20.00 43,000 Fi 11 CY 2,150 30.00 65,000 Rock Bolts: 1 "0 x 10' LF 4,760 46.00 219,000 1 "0 x 14' LF 700 46.00 32,000 Concrete CY 150 890.00 134,000 Reinforcement LB 7,500 1.80 14,000 Steel Gate, Personnel LB 1,060 3.75 4,000 Helicopter Pad (Excavation LS Material Leveled) 1 3,000.00 3,000 Electrical Lighting EA 80 400.00 32 2 000 Subtota 1 $ 2,886,000 Contingencies -20% 577 ,000 Total Cost, Gate Structure Access Adit $ 3,463,000 POWER TUNNEL Rock Excavation CY 25,500 $ 255.00 $ 6,503,000 Concrete Tunnel Lining CY 1,134 890.00 1,009,000 Reinforcement LB 345,100 1.80 621,000 Rock Bolts, Grouted LF 10,745 46.00 494,000 Stee 1 Sets EA 10 4,500.00 45,000 Shotcrete SY 387 186.00 72,000 25-24 TABLE 25-F (Continued) UNIT FEATURE OR ITEM UNIT QUANTITY PRICE AMOUNT POWER TUNNEL (Continued) Subtota 1 $ 8,744,000 Contingencies -20% 1,749,000 .' Total Cost, Power Tunnel $ 10,493,000 ., SURGE TANK 11" Rock Excavation, Shaft CY 1,283 $1,200.00 $ 1,540,000 Rock Excavation, Drift CY 190 214.00 41,000 " Concrete, Surge Tank Enclosure CY 45 890.00 40,000 Reinforcement LB 4,186 1.80 8,000 Steel Orifice, 111 Plate LB 3,026 4.50 14,000 " Rock Bolts LF 2,200 46.00 101,000 Wire Mesh SY 1,222 . 30.00 37,000 Concrete, Drift Li n i ng CY 58 890.00 52,000 Reinforcement LB 19,140 1.80 34,000 '" Subtotal $ 1,867,000 Contingencies -20% 373,000 ,." Total Cost, Surge Tank $ 2,240,000 ,. FINAL ROCK TRAP Rock Excavation CY 1,328 $ 214.00 $ 284,000 Steel Trashrack LB 2,100 4.10 9,000 • Concrete CY 35 890.00 31,000 ~, Reinforcement LB 11 ,000 1.80 20,000 ,. Subtotal $ 344,000 Contingencies -20% 69,000 .. Total Cost, Final Rock Trap 413,000 FINAL ROCK TRAP ACCESS ADIT Rock Excavation, Tunnel CY 2,610 $ 214.00 $ 559,000 Common Excavation CY 1,100 20.00 22,000 Rock Bolts LF 400 46.00 18,000 • Rock Excavation, Portal CY 1,300 250.00 325,000 Concrete, Portal CY 27 890.00 24,000 Reinforcement LB 3,700 1.80 7,000 " Personnel Gate LB 1,060 3.75 4,000 Pre-Splitting SF 2,600 30.00 78,00r Clearing ACRE 2 5,000.00 10,000 Concrete, Plug CY 165 890.00 147,000 25-25 TABLE 25-F (Continued) UNIT FEATURE OR ITEM UNIT QUANTITY PRICE AMOUNT FINAL ROCK TRAP ACCESS ADIT (Continued) Bu"1 khead LB 10,000 5.30 53,000 Adit Lighting EA 16 400.00 6,000 Fill, Common CY 1,200 30.00 36,000 Subtota 1 $ 1,289,000 Contingencies -20% 258,000 Total Cost, Final Rock Trap Access Adit $ 1,547,000 ROAD TO FINAL ROCK TRAP ACCESS ADIT Excavation CY 13,420 $ 20.00 $ 268,000 Clearing ACRE 1.4 13,500.00 19,000 Gravel Surface CY 1,800 30.00 54,000 Guardrail LF 2,000 30.00 60,000 Subtotal $ 401,000 Contingencies -20% 80,000 Total Cost, Road to Final Rock Trap Access Adit $ 481,000 PENSTOCK Rock Excavation CY 6,535 $ 214.00 $ 1,398,000 Concrete Liner CY 4,900 890.00 4,361,000 Steel Liner, A537 CL2 LB 1,097,285 3.40 3,731,000 Rock Bolts LF 2,700 46.00 124,000 Subtotal $ 9,614,000 Contingencies -20% 1,923,000 Total Cost, Penstock $ 11,537,000 PENSTOCK CONSTRUCTION ADIT Rock Excavation CY 2,610 $ 214.00 $ 559,000 Concrete Plug CY 214 890.00 190,000 Wire Mesh SY 1 7 30.00 1,000 Rock Bolts LF 400 46.00 18,000 Reinforcement LB 3,890 1.80 7,000 Subtota 1 $ 775,000 Contingencies -20% 155,000 Total Cost, Penstock Construction Adit $ 930,000 25-26 TABLE 25-F (Continued) UNIT FEATURE OR ITEM UNIT QUANTITY PRICE AMOUNT POWER PLANT Powerhouse Completion Structural Concrete Substructure Concrete CY 204 $ 785.00 $ 160,000 Superstructure Concrete CY 73 1,160.00 85,000 Penstock Branch Concrete CY 66 215.00 14,000 Cement CWT 1,615 9.20 15,000 • Reinforcing LB 40,000 1.80 72 ,000 Demolition LS 1 5,000.00 5,000 Miscellaneous Metals LB 6,333 5.60 35,000 ." Painting, Architectural Features LS 1 16,650.00 17,000 Equipment LS 1 23,850.00 24,000 flf' Miscellaneous Dust Protection & Barricading LS 11 ,930.00 12,000 Mechanical Items Generator Cooling, Gland " & Wear Ring Piping LS 31,400.00 31,000 Electrical Items Conduit System LS 5,360.00 5,000 1'" Lighting System LS 3,300.00 3,000 Subtotal $ 478,000 ." Contingencies -20% 96,000 Total Cost, Powerhouse Completion $ 574,000 ,., Turbine, Generator and Governor Turbine EA 1 $872,200.00 $ 872,000 Install Turbine EA 1 300,000.00 300,000 Ii' Spherical Valve EA 1 355,000.00 355,000 Install Spherical Valve EA 1 88,750.00 89,000 Branch Pipe (A5l6 Steel & LS 1 55,580.00 56,000 l> Installation) Generator EA 1 1,800,000.00 1,800,000 Governor EA 1 204,000.00 204,000 Subtota 1 $ 3,676,000 Contingencies -20% 735,000 Total Cost, Turbine, Generator and Governor $ 4,411,000 Accessory Electrical Equipment Main Generator Cable LS $14,010.00 14,000 Tray System Insulated Power Cable LS 43,260.00 43,00tJ (Over 1,000 volts) 13.8 KV Metal Enclosed Bus LS 1 54,180.00 54,000 Grounding System LS 1 3,300.00 3,000 25-27 TABLE 25-F (Continued) FEATURE OR ITEM UNIT POWER PLANT (continued) Accessory Electrical Equipment (continued) 480-Vo1t Power Outlets Misc. Electrical Equipment & Accessories 13.8 KV Metal Clad Switchgear Control Cable Tray System Insulated Wire & Cable (1000 Volts & Below) Subtotal Contingencies -20% LS LS LS LS LS Total Cost, Accessory Electrical Equipment Miscellaneous Power Plant Equipment Heating and Ventilation LS Unwatering & Drainage Piping LS Piezometer Piping LS C02 Piping LS Governor Air, Station & LS Brake Air Piping Lube & Governor Oil Piping LS Subtotal Contingencies -20% QUANTITY 1 1 1 1 1 1 1 1 Total Cost, Miscellaneous Power Plant Equipment Tailrace Bulkhead Guide 300 Series Stainless Steel Contingencies -20% LS Total Cost, Tailrace Switchyard Switchyard Structures Equipment Excavation & Backfill CY Concrete Foundation CY Cement CWT Reinforcement LB Bus Support Insulations LS High Voltage Busses, LS Pittings & Accessories Power Transformers EA Lighting Arrestors EA 25-28 420 285 10 47 1,500 1 1 1 3 UNIT PRICE 1,000.00 375,250.00 85,700.00 18,330.00 21,630.00 $2,800.00 9,610.00 2,590.00 770.00 1,800.00 3,020.00 $3.90 $ 16.50 650.00 9.20 1.80 5,850.00 12,980.00 253,000.00 11,910.00 $ $ $ $ $ $ $ AMOUNT 1,000 375,000 86,000 18,000 22,000 616,000 123,000 739,000 3,000 10,000 3,000 1,000 2,000 3,000 22,000 4,000 26,000 2,000 o 2,000 5,000 7,000 o 3,000 6,000 13,000 253,000 36,000 TABLE 25-F (Continued) UNIT FEATUR E OR ITEM UNIT QUANTITY PRICE AMOUNT Switchyard (Continued) High Voltage Disconnects LS 10,820.00 $ 11 ,000 Subtotal $ 334;000 Contingencies -20% 67 2 000 Total Cost, Switchyard $ 401,000 ., TOTAL COST, POWER PLANT $6,153,000 ". TRANSMISSION PLANT Status Switchboard LS $22,000.00 $ 22,000 .. Contingencies -20% 4,000 Total Cost, Transmission Plant 26,000 1ft PERMANENT BUILDINGS Transmission Maintenance LS $92,500.00 $ 93,000 .. Bldg (Remodel Extg Bldg) Machine Shop (Metal Bldg SF 1,200 125.00 150,000 w/Slab on Grade, Complete) fI!' Subtotal $ 243,000 Contingencies -20% 49,000 III Total Cost, Permanent Buildings $ 292,000 UTILITIES II, Waterline, Sewerline, Forced LS $336,000.00 $ 336,000 Main & Seepage Pit II" Electrical Service for Lift Stat ions LS 14,000.00 14,000 .. Subtotal 350,000 Contingencies -20% 70,000 Total Cost, Utilities $ 420,000 CONSTRUCTION CAMP FACILITIES Provide Lodging, Food & MD 46,900 $70.00 3,283,000 Camp Services Transformer & Electrical LS 34,000.00 34,000 .. Service 25-29 !>' TABLE 25-F (Continued) FEATURE OR ITEM UNIT CONSTRUCTION CAMP FACILITIES (Continued) Subtotal Contingenci~s -20% Total Cost, Construction Camp Facilities TOTAL COST, CONSTRUCTION ALTERNATIVE PLAN II 25-30 QUANTITY UNIT PRICE AMOUNT $ 3,317,000 663,000 $ 3.,980,000 $51,268,000 TABLE 25-G. ALTERNATIVE PLAN III -SUMMARY COST ESTIMATE (PRICE LEVEL -SEPTEMBER 30, 1984) FEATURE Primary Rock Trap and Lake Tap Primary Trashrack Secondary Rock Trap Gate Structure Gate Structure Access Adit Access Adit to Lake Power Tunnel Surge Chamber Final Rock Trap Final Rock Trap Access Adit Penstock Powerhouse Completion Turbine and Generator Accessory Electrical Equipment Miscellaneous Power Plant Equipment Tailrace Switchyard Transmission Plant Permanent Buildings Ut il it i es Construction Camp Facilities Subtotal Supervision & Administration Engineering & Design Total Cost, Alternative Plan III 25-31 TOTAL COST $ 1,566,000 4,627,000 148,000 4,268,000 2,539,000 1,546,000 8,986,000 3,190,000 383,000 3,106,000 7,952,000 574,000 4,411 ,000 739,000 26,000 2,000 401,000 26,000 292,000 420,000 3,841,000 $ 49,043,000 4,072,000 6,232,000 $ 59,347,000 1 TABLE 25-H. ALTERNATIVE PLAN III -DETAILED COST ESTIMATE (PRICE LEVEL -sEPTEMBER 30, 1984) UNIT FEATURE OR ITEM UNIT QUANTITY PRICE AMOUNT PRIMARY ROCK TRAP AND LAKE TAP Rock Trap Excavation CY 1,490 $ 312.00 $ 456,000 Lake Tap LS 1 840,000.00 840,000 Subtotal $ 1,305,000 Contingencies -20% 261,000 ~H- Total Cost, Primary Rock Trap and Lake Tap $ 1,566,000 ~~ PRIMARY TRASHRACK Steel LB 42,600 $ 4.10 $ 175,000 ", Concrete Weights CY 2 890.00 2,000 Reinforcement LB 100 1.80 0 Operating Cable (Wire Rope) LF 400 20.00 8,000 Installation Cables LF 800 20.00 16,000 ~ Barge & Hoists LS 1 11 0,000.00 11 0,000 Remove Overburden Above Lake LS 3,545,000.00 $ 32 545 2 000 Tap (Underwater Excavation) " Subtotal $ 3,856,000 Contingencies -20% 771,000 '" Total Cost, Trashrack $ 4,627,000 f!' SECONDARY ROCK TRAP Rock Excavation CY 268 $ 312.00 84,000 Steel LB 9,628 4.00 39,000 .. ' Subtotal $ 123,000 Contingencies -20% 25,000 .. ' Total Cost, Secondary Rock Trap $ 148,000 GATE STRUCTURE , Rock Excavation, Service Room CY 1,094 $ 320.00 $ 350,000 Drift Rock Excavation, Shaft CY 1,130 780.00 881,000 Rock Bolts LF 5,180 46.00 238,000 Concrete CY 654 890.00 582,000 . Reinforcement LB 32,500 1.80 59,000 Steel Ladder/8 Platforms LF 250 45.00 11,00 Vent poi pe (2 -2211) LF 520 150.00 78,000 25-32 Table 25-H (Continued) UNIT FEATURE OR ITEM UNIT QUANTITY PRICE AMOUNT- GATE STRUCTURE (continued) Tunnel -Filling Pipe, 8 11 dia. LF 80 36.00 3,000 Globe 'Jalve, 8 11 EA 1 5,600.00 6,000 Hoi st, 15-ton EA 1 25,000.00 • 25,000 Steel Floor Grating SF 96 95.00 " 9,000 Guardrail LF 70 20.00 1,000 Tractor Gate LB 19,000 5.30 101,000 Bulkhead LB 15,000 5.30 80,000 Gate Guides, Stainless Steel LB 122,000 8.75 1,068,000 Gate Dogging Assemblies LOT 1 2,000.00 2,000 Lighting, Generators, Control LS 1 62,600.00 63,000 Panel w/Monitoring & Communication Subtotal $ 3,557,000 Contingencies -20% 711,000 Total Cost, Gate Structure $ 4,268,000 GATE STRUCTURE ACCESSADIT Rock Excavation CY 5,260 $ 320.00 $ 1,683,000 Common Excavation CY 2,150 20.00 43,000 Fi 11 (Rock from Excavation) CY 2,150 30.00 65,000 Rock Bolts: 1110 x 10' LF 2,700 46.00 124,000 1110 x 14' LF 700 46.00 32,000 Concrete: Mass CY 137 890.00 122,000 Structural CY 12 890.00 11 ,000 Reinforcement LB 7,450 1.80 13,000 Steel Gate, Personnel LB 1,060 3.75 4,000 Helicopter Pad (Excavation LS 1 3,000.00 3,000 Material Leveled) Electrical Lighting EA 40 400.00 16 2 000 Subtota 1 $ 2,116,000 Contingencies -20% 423,000 Total Cost, Gate Structure Access Adit $ 2,539,000 ACCESS ADIT TO LAKE Rock Excavation CY 3,620 $ 320.00 $ 1,158,000 Common Excavation CY 1,670 20.00 33,000 Rock Bo It: 1110 x 10' EA 90 460.00 41,000 1110 x 14' EA 50 640.00 32,000 Concrete CY 12 890.00 11,000 25-33 Table 25-H (Continued) . UNLT FEATURE OR ITEM UNIT QUANTITY PRICE AMOUNT ACCESS ADIT TO LAKE (continued) Reinforcement LB 600 1.80 1,000 Steel Gate, Personnel LB 1,060 3.75 4,000 I!' Electrical Lighting EA 20 400.00 8,000 Subtotal $ 1,288,000 l!>' Contingencies -20% 258,000 Total Cost, Access Adit to Lake $ 1,546,000 '" POWER TUNNEL Rock Excavation CY 22,110 $ 255.00 $ 5,638,000 III Concrete CY 190 890.00 169,000 ,. Reinforcement LB 57,760 1.80 104,000 Rock Bolts, Grouted LF 19,020 46.00 875,000 ,.. Steel sets EA 10 4,500.00 45,000 Shotcrete SY 3,530 186.00 657,000 , Subtota 1 $ 7,488,000 Be Contingencies -20% 1,498,000 Total Cost, Power Tunnel $ 8,986,000 ,.. SURGE CHAMBER 11'. Rock Excavation CY 3,255 $ 780.00 $ 2,539,000 Rock Bolts, Grouted LF 410 46.00 19,000 .. Level & Pressure Monitoring LS 1 100,000.00 $ 100,000 System fI' Subtotal $ 2,658,000 Contingencies -20% 532,000 '*' Total Cost, Surge Chamber $ 3,190,000 FINAL ROCK TRAP Rock Excavation CY 1,210 $ 214.00 $ 259,000 Stee 1 Trashrack LB 2,163 4.10 9,000 " Concrete CY 35 890.00 31,000 Reinforcement LB 11 ,000 1.80 20,000 Subtota 1 $ 319,000 Contingencies -20% 64,00( Total Cost, Final Rock Trap $ 383,000 25-34 Table 25-H (Continued) UNIT FEATURE OR ITEM UNIT QUANTITY PRICE AMOUNT FINAL ROCK TRAP ACCESS ADIT Rock Excavation, Tunnel CY 6,890 $214.00 $ 1,474,000 Common Excavation CY 1,050 20.00 21,000 Fill CY 55 30.00 2,000 Rock Bolts LF 1,740 46.00 80,000 Concrete CY 27 890.00 24,000 Reinforcement LB 3,700 1.80 7,000 Steel Bulkhead LB 10,000 5.30 53,000 Steel Gate, Personnel LB 1,060 3.75 4,000 Rock Excavation, Portal CY 1,225 250.00 306,000 Pre-Splitting SF 2,500 30.00 75,000 Clearing ACRE 2 5,000.00 10,000 Concrete, Plug CY 580 890.00 516,000 Adit Lighting EA 40 400.00 16,000 Subtotal $ 2,588,000 Contingencies -20% 518,000 Tota 1 Cost, Final Rock Trap Access Adit $ 3,106,000 PENSTOCK Excavation CY 4,140 $ 286.00 $ 1,184,000 Concrete CY 3,100 890.00 2,759,000 Rock Bolts LF 750 46.00 35,000 Steel Penstock LB 575,786 4.60 2,649,000 Subtotal $ 6,627,000 Contingencies -20% 1,325,000 Total Cost, Penstock $ 7,952,000 POWER PLANT Powerhouse Completion Structural Concrete Substructure Concrete CY 204 $ 785.00 $ 160,000 Superstructure Concrete CY 73 1,160.00 85,000 Penstock Branch Concrete CY 66 215.00 14,000 Cement CWT 1,615 9.20 15,000 Reinforcing LB 40,000 1.80 72,000 Demo 1 it i on LS 1 5,000.00 5,000 Miscellaneous Metals LB 6,333 5.60 35,000 Painting, Architectural Features LS 16,650.00 17,000 Equipment LS 23,850.00 24,000 Miscellaneous Dust Protection & Barricading LS 11,930.00 12,000 25-35 Table 25-H (Continued) UNIT FEATURE OR ITEM UNIT . QUANTITY PRICE AMOUNT POWER PLANT (continued) Powerhouse Completion (continued) Mechanical Items Generator Cooling, Gland and Wear Ring Piping LS 31,400.00 31,000 Electrical Items Conduit <\ystem L<\ 5,360.00 5,000 Lighting System LS 3,300.00 3,000 Subtotal $ 478,000 '" Contingencies -20% 96,000 Total Cost, Powerhouse Completion $ 574,000 1" Turbine, Generator and Governor Turbine EA $ 872,200.00 $ 872,000 , .. Install Turbine EA 300,000.00 300,000 Spherical Valve EA 355,000.00 355,000 Install Spherical Valve EA 88,750.00 89,000 .. Branch Pipe (A516 Steel & LS 55,580.00 56,000 Installation) Generator EA 1,800,000.00 1,800,000 Governor EA 204,000.00 204,000 II" Subtotal $ 3,676,000 Contingencies -20% 735,000 It Total Cost, Turbine, Generator and Governor $ 4,411,000 Accessory Electrical Equipment Main Generator Cable LS $ 14,010.00 14,000 Tray System Insulated Power Cable LS 43,260.00 43,000 , (Over 1,000 volts) 13.8 KV Metal Enclosed Bus LS 1 54,180.00 54,000 Grounding System LS 1 3,300.00 3,000 iI!!<' 480-Volt Power Outlets LS 1 1,000.00 1,000 Misc. Electrical Equipment & LS 1 375,250.00 375,000 Accessories 13.8 KV Metal Clad Switchgear LS 85,700.00 86,000 Control Cable Tray System LS 18,330.00 18,000 Insulated Wire & Cable LS 21,630.00 22,000 (1000 Volts & Below) Subtotal $ 6l6,00l Contingencies -20% 123,000 Total Cost, Accessory Electrical Equipment $ 739,000 25-36 Table 25-H (Continued) UNIT FEATURE OR ITEM UNIT QUANTITY PRICE AMOUNT POWER PLANT (continued) Miscellaneous Power Plant Equipment Heating and Ventilation LS 1 $2,800.00 $ 3,000 Unwatering & Drainage Piping LS 1 9~610.00 10,000 Piezometer Piping LS 1 2,590.00 3,000 C02 Piping LS 1 770.00 1,000 Governor Air, Station & LS 1 1,800.00 2,000 Brake Air Piping Lube & Governor Oil Piping LS 3,020.00 3,000 Subtotal $ 22,000 Contingencies -20% 4,000 Total Cost, Miscellaneous Power Pl ant Equ i pment $ 26,000 Tail race Bulkhead Guide 300 Series LB 420 $3.90 $ 2,000 Stainless Steel Contingencies -20% 0 Total Cost, Tailrace $ 2,000 Switchyard Switchyard Structures & Equipment Excavation & Backfill CY 285 $ 16.50 $ 5,000 Concrete Foundation CY 10 650.00 7,000 Cement CWT 47 9.20 0 Reinforcement LB 1,500 1.80 3,000 Bus Support Insulators LS 1 5,850.00 6,000 High Voltage Busses, LS 1 12,980.00 13,000 Pittings & Accessories Power Transformers EA 1 253,000.00 253,000 Lighting Arrestors EA 3 11,910.00 36,000 High Voltage Disconnects LS 1 10,820.00 11 ,000 Subtotal $ 334,000 Contingencies -20% 67,000 Total Cost, Switchyard $ 401,000 TOTAL COST, POWER PLANT $6,153,000 TRANSMISSION PLANT Status Switchboard LS $22,000.00 $ 22,000 Contingencies -20% 4,000 Total Cost, Transmission Plant $ 26,000 25-37 Table 25-H (Continued) UNIT FEATURE OR ITEM UNIT QUANTITY PRICE AMOUNT PERMANENT BUILDINGS Transmission Maintenance LS $92,500.00 $ 93,000 Bldg (Remodel Extg Bldg) Machine Shop (Metal Bldg SF 1,200 125.00 150,000 w/S1ab· on Grade, Complete) Subtota 1 $ 243,000, Contingencies -20% 49,000 Total Cost, Permanent Buildings $ 292,000 I' UTILITIES Waterline, Sewer1ine, Forced LS $336,000.00 $ 336,000 .' Main & Seepage Pit Electrical Service for Lift Station LS 14,000.00 14,000 Subtotal $350,000 ,- Contingencies -20% 70,000 Total Cost, Utilities $ 420,000·' CONSTRUCTION CAMP FACILITIES r' Provide Lodging, Food & MD 45,247 ~ 70.00 $ 3,167,000. Camp Services Transformer & Electrical LS 1 34,000.00 34,000., Service Subtotal $ 3,201,000 Contingencies -20% 640,000 .' Total Cost, Construction Camp Facilities $ 3,841,000 TOTAL COST, CONSTRUCTION ALTERNATIVE PLAN I I I $49,043,000 25-38 D CRATER COVE X DISPOSAL AREA 5 4 DOCK ; L-CONSTRUCTION CAMP FACILITIES t x 2 +.51 'A(I'le OCIAN LOCATION MAP VICINITY MAP SCALE IN MILES o • 10 ELEVATIONS OF TIDE PLANES LOWER LOW WATER AND PR(),JE~Tr DS~TEUEML RiVER REFERRED TO MEAN HIGHEST TIDE (ESTIMATE) MEAN HIGHER HIGH WATER MEAN HIGH WATER HALF TIDE LEVEL (MSLl MEAN LOW WATER MEAN LOWER LOW WATER ~~~~l~T T~~~u~ESTIMATE) ARE AS FOL LOWS: MLLW PROJECT DATUM 22.5 11.4 15.9 4.8 14.8 3.7 8.2 -2.9 1.6 -9.5 0,0 -11.1 -5.7 -16.8 11.1 0.0 NOTE: ALL ELEVATIONS SHO WITH RESPECT TO PR~~Eg~ DT~TESE PLANS ARE ........ _ ... PLATES 9 a 10. UM, EXCEPT -- U.S. AMlY DIOMER DlSTNCT c.-sOO'EJIGINEEIIS AIIOtORAGE. ALASKA Ja. m SNETTISHAM PROJECT. ALASKA t-::"_--, ... ------J .. ___ SECOND STAGE DEVELOPMENT .. _ CRATER LAKE G~K D C B A ~oeo LOCATION AND VICINITY MAP __ ~o ~~~~~j-~PITR~O~JE~C=T~G~E~N~E~R~A~L~P~L~A~N~~ ~... ...... SCALE: ~ =-r..~A..::S::....::SH=O:.::W:.:.N=----1 .~~~iiii'!ru~ru z~Av9 84 _-.L-.. PLATE o C B A LAKE SURFACE EL.1019 5 SECONDARY----~~\ ROCK TRAP -I-CJ- PRIMARY ROCK TRAP 8 LAKE TAP 1400 IZOO 1000 SLOPE 0.006 1019' (MAX. POOL) EL.IOZ7 MAX. HYDRAULIC GRADIENT PLAN 2 ~AXIMUM HYDRAULIC GR:~ =======--==-=== MIN. HYDRAULIC GRADIENT AT z 0 EL.BII 820' (MIN. POOL) SURGE TANK '.765' ~~~~--~~----~~~;;~;;;;;;~~~~;;;;;;~~::::::::~-=-=-:-:-~------__________ . ____________________________________________ ~M~IN~I~M~U~M~H~Y~D~R~A~U~L~I:C~G~R~A~D~I~E~N~T~ _______________________ -=_=_=_=_=_=_=_==_=_=~~----__1BOO ~ ;:: BOO ... > '" ...J '" 600 400 ZOO 0-00 PRIMARY ROCK TRAP INV. EL. 761.5 5~OO 10-00 15:.00 20~OO --====== ;:: -VENTED SURGE TANK ~~ .. I 30!OO 35~00 40-00 45+00 PROFILE 200' 0 200' I I SCALE' ,'. 200' SLOPE. 0,'2437. J 400 50-00 55-00 ......... _ ... JeL ~~--~Or.-.------~ GEK "'I + "' '" :000 FINAL ROCK TRAP 60-00 65!00 68+00 ........... _ ..... _ """'- m SNETTISHAM PROJECT, ALASKA SECOND STAGE DEVELOPMENT ':t::-"? CRATER LAKE -. POWER TUNNEL PLAN & PRORLE o c B A 1"= 200' -~:!i!~~L==~-;;;;;;---------1 ::=-1-------------1 DIwwIng 1-8NE-88-0e- Code; 18-03/1 ___ 0. __ __ 5 4 3 DESIGN. MEMORANDUM NO, 26 PLATE 2 t D ,- C f... '" ~ ~ ~ f:: ~ '" ~ ... - B A 1200 1100 ~ 1075 ~?" roo 600 500 400 300 cOO /00 o 66+00 5 I 4 EL. 1080 EL. 759 I 67+00 68+00 69foo rofOO ~~ I ; I I 59+00 70+00 5 I 4 Maximum 7/-1-00 I · Gradienf H droU /lc I TZfOO Min'/num H. 731'00 PENSTOCK TUNNEL PROFILE Scale: 1"= 50'-0· I 1 I I 7/-1-00 TZ+OO 7.3"00 3 I ctroulic Groc(/enl Ground surrace 74-1-00 751'00 76+00 .... ,Il! I ! I I 74+00 75+00 76+00 PENSTOCK PLATE THICKNESS PROFILE 1 ASTM A517 St<!'el Horizontal Scale: 1"= 50'-0· 3 t I 2 ~II ~ o~'! -: I I I 77-t-OO T8+00 SCALE IN FEET 50 0 50 EL 126S EL. 597 100 I 1 D ,...... C - B .,..... ....... ~ __ -+ __________________________ ~ __ ~ ____ ~r-- I u.s. ARIIY ENGINEER DISTRICT CORPS OF ENGINEERS ANCHORAG<. ...... SKA _lor-"" SNETTISHAM PROJECT; ALASKA 1-__ t.4_T ______ ...-..l1ii&iiI SECOND ST AGE-OEVELOPMENT ......... r-:t::--CRATER LAKE EEL PENSTOCK PROFILE -of .. A DESIGN MEMORANDUM NO. 26 PLATE 3 +- D c B A 5 HARDWOOD OR STEEL LAGGING AS REQ~ NEAT I ~r=KING AS iEQUIREO TYPICAL UNUNED SECTlON SCAlE: I/~·I'-O· TYPICAL SET SUPPOR1B> SECllOfI SCALE: 1/21 .1'-0. 5 4 ELECTRICAL a cc:wt.I\JIICATION LINES (TYP.) 4 3 ~PATTERN AN~ SPOT ROCI< BOLTS AS REQUIREO~I,) SEE NOTE ~ ~..(I r-- "--=--=-J _-=_ TYPICAL SHOTCRETE SECTION NEAT UNE CONCRETE LINED SECT10N SCALE, liz:' • I' -cf 3 t 8LOCKING AND WEOO .... G .. 2' 0' 2' -GRAPt4C SCALE 1/2~. I'_ON .' 2 3 TAPE EXTENSOMETER ANCHOR POINTS AT 120', TYPICAL 1 3 MP8X'. AT 120· TYPICAL SEE NOTES D INSTlUIENTA TlON SECTION SCAJ..E: 1/2·· "-0" t I 2 INSTRUMENTATlON NOTES 1. MPax STA11ONS. 'LENGTH AND ANCHOR POSITIONS TO BE DETERMINED IN THE FELD. ANCHOR POsITIONS WU NOT EXCEED 3 PER t.4PBX. LENGTH WU NC:)FNAll. Y BE LESS lltAN 50 FEET. 2-_x COYER Pl.A TE SHAll. BE MOOFIED TO SERVE AS A TAPE EXTENSOMEl'ER ANCHOR POINT, 3 ... AREAS lHAT ~ SHOTCRETED OR MAY RECEIVE $HOTCRETE AT A LATER DATE HEAD FRAME SHALL. SET SUCH THAT COVER PLATE IS FLUSH OR is EXTENDABLE SUCH THAT rT WILL BE FLUSH W[TH SHOTCRETE. 4. TAPE'EXTENSOMETER ANCHOR POINT SHALL BE DIRECTLY OPPOSITE (,.oo) FROM _x, -. 0.,. Approved u.s. ARMY ENGMEEA Dt$llnCT CORPS OF ENGINEERS ANCHORAGE, ALASKA c B r.III't SNETTlSHAM PROJECT.ALASKA Ii;;;iI SECOND STAGE DEVELOPMENT A t-:_=--Wft--:.-.. -------I '1Jt::"""'" CRATER LAKE POWER TUNNEL SECTIONS ...... N'_ 1--""-'=='---.., number: t--------.... __ '_0'_- DESIGN MEMORANDUM NO. 26 PLATE 4 o c B A 5 6' ¢J A 517 .steel Penstock 4 Stiffener rin3 T r T Anchor RcdS----~L,~r=~J::r----------~~~~ I I I ACCESS ADIT/PENSTOCI( TUNNEL LONGITUDINAL SE.CT/ON Scale: i" ::=-/'-O'~ ca'-o" 10'-0" 10'-0' Tunnel 6'-.3" .------_+_~ Tunnel eKcol/Ufion Electrical t Communication {i{}t!5 stiffener rin9 Penstock /' Tvnn.!!1 £i<:ctrical .$ CommunicatIOn lines ~SuPPOrf ring Anchor Rods 3 \ Anchor R5Jd.s rrom A?f>ra.: 5t<r 74 +130 11> stq 77+ 7 SECTION ® From A?t"r<>><S=;Cr/ONfb ~ 74+&:/ Scale: J" = 1'-0" Slotted holes in steel /£ Scale:,f" = /-0" . £ lectr,cal';CommunicaTlon -\ lines '\ Penslock STiffener ring STIFFENER RING PLAN Scale: j-" = 1'--0" SECTION ® Scale: ,": I~O" 5 4 --Plug excavation ---Design line Drain 3 t 0 n ql l0C4tlon fb k ckf"'rmin.td IfI tile F~/c/ 2 Exisfin9 £x.cq,vq+,on (To be abandoned) ~~~ PENSTOCK TH12UST8LOCK ELEVATION Conr1~:t t'o ~X/~ft"5 drqtn oyoT"'m- 4-- Sea/e:fll = /'-0" SCALe IN FeET o 4-.9 Ii'. . .......... Description. U.S. ARMY £NQIfiEER DISTRICT CORPS OF ENGINEERS ANCHORAGE., ALASKA I!IIP.I SNETTISHAM PROJECT. ALASKA I;i:;;I SECOND STAGE DEVELOPMENT t-::o..-_----c.-r ,------1 ':t::..""'!' CRATER LAKE E€L r:::-~~---j PENSTOCK TUNNEL SECTIONS & DETAILS I-SNE-96-06-19- 03/27 ___ 0'_- DESIGN MEMORANDUM NO. 26 APPENDIX-o-PLATE 5 o c B A 5 D c A 5 ACCESS/PENSTOCK TVNNEL /7+00 4 /6+00 4 3 / ACCESS ADIT PLAN SCALe: /'=30'-0" 15rOO 14~OO STATION ACCESS ADIT PROFILE SCALE: '":30'-0" 3 t MACHINE SHOP ADIT SLOPES UP liT .IIPPROx. 6 % GRIIDE TO MAIN ACCESS .II0lT '3~OO \~b WATERTIGHT '-;:;, BULKHEAD ~ wrrH VeHICLe. ~ ACCE5:I COOR /z~oo SCALE /N ~EeT o 30 60 2 8::.AL-E I'. 3O~O· 1/+00 .... bot 1-::-"'-... -,-0,,-. -----1 EEL-- (NOT sHOW;f) FOWEII:.HOUSe ........... 0... Approyed u.s. ARIIV ENGINEER DI$l1DCT CORPS OF ENGItEERS ANCHORAGE. ALASA m SNETTISHAM PROJECT, ALASKA SECOND STAGE DEVELOPMENT ':t::;.:;::' CRATER LAKE TUNNEL ACCESS ADIT PLAN & PROFILE - D c 8 A .. ,- number. 1--------1 ~"'1!-b'/J( VfJlJ2-Drawlnrgl-SNE _ 96 _ 06-19-~~. Code: 03128 --_ .. _- DESIGN MEMpRANDUM NO,26 APPENDIX "0" PLATE 6 D c B A 5 R .. rwvqbl .. F<"r;ng _II 0' high, Ireqf,<I fimbo!'r) 5 4 3 EXPCH1'5.IOn Joint- IC:" l' Drain ... ":." ~ .... ....... 75'-0" PLAN AT l Scale: 1° = 10'-O~ SECTION (2) Scale: 1"=10'-0" SECTION 0 Scale: I~=IO'-O" 4 3 t 2 Bar .3 -J Hartz. IiiJ Ii" o. c. F¢ Rod Veri. (i) 4" o·c. Temporar!l parfion of frashraclr " Permanent p?rtion or frashrack SCALES IN FfTT 5 0 5 10 L--I ' 5C4f14' /' .. 5':..O~ 10 ·0 10 eo ••••• I :';icq/4' /r:.IO~O' Not"" \ I '\ / ./ E~fric.q/ qnd co':'",J.JncqfJon line'5, nat ~hownJ rl.¥} throJ./gh Q vfllidor eXGC/'v'f:lt~c/ In tlJt!-f(jnl1~1 I/)verf. The exqct /OCQfIOI1 fo ~ d~f~r""Mtd. -..., ... Date Ap .... OVN U.S. ARMY ENGINEER DI$TRlC:T CORPS OF ENGINEERS ANCHORAGE, ALASKA o..fvnedbW: SNETTISHAM PROJECT, ALASKA SECOND STAGE DEVELOPMENT ~t:.:::::' CRATER LAKE JBL c:J 1--------===----1 Dr .. nbv: EEL TUNNEl.iPLUG & SECONDARY :TRASHRACK DnlwlnV'-5NE.96-06-19- Code: 03129 ___ 0' __ DESIGN MEMORANDUM NO.26 PLATE 7 D c B A D r- C -+- B r- A 5 I 4 1 7' -10' C.C. END It: S. ! VB' ~ 1'-3' 1'_3' :1 4 SPACES @.-1'_ 4'· 5' -4' ':J'SEAL • .-.- 0 ~3 0 0 io • q .... v --' ., on til ' 81-' O-:'!'...J z @ « ~ ::l\!ll u O· ~~\ f'o-v ":, :: :::: :: t--6-....o.L.---I :: -'i. 0 ~ IT :: :: :: :: :1 O· ,~, 'I II 11 II C r'T' _ II II II II II f-'--:--f---I II I, II " " t--....,,--'-I .... =;R"J==Flfi======fll=~== ... == :?-======f~F===== ::= =='=;~='F " " II II :: ',' II CONT. III II: II I II VERT. I II II BAR__ :: II II :: II -... II :: :: t-'------t ,I " II I' t-----I " t----.L-II 1=-===== l1oJ=:::'===fIl=F==::',\= If/===== .. t=lf~===== ~/== ... =.&, " II Il[~ II " II II "CONT. II SKIN It. " II ., ". 1\ \" II 'I II HOR. II II " " I' II II " " " II II II 1-'-----1 00 " II " I, f----'-I 1===.===== :?1="=====F\l= ::.==:!=~~t======Fll'F===== -lFF===-==: t-r-----t " II II II " II " II II II " " II II " " " II II II II II II II II " 1\ II II II f-L----I " II " " 1------1 " t---...L...j F'" = = = =F~ ~=== ... = ~ 1=====::. if i="== === I"~ f"===== ~ )====::.-:: kTi5• • 11 ~ ('--!.i' SEAL 1'-" "II "11 II" II II II " 2' TYP. II I. ['J "" II /I r 0 "II II 1\ 0 1-'-"7""---1 "" "" t---:::-....L.-J , 1 "---'t _ ol~=...,r'-=;~.)-------;T=== =. Fr=== == F(,::::::~ '':;T:F: r:"=='"-= '"('~ 'J ""1 ,., II"",· 1\ \I " II II ,,\I "'t o f--u---I--:: :: :: 1\ :: l. :: f--..."r.-,._; 0 ~ ~~~o~A±'::o~~~~o~~~~o~~~~~~~~"~~~:~:::~~o~~:~~~o~~~o~-(~~~BB~~o~~c--~~·-- J , ·J·SEAL....) ':".,.. ' ~END~~L.~7~·~.~I. ____________ ~5~S~P_~_C~E~@~I~~=4·_.~6='-~B~·~T~Y~P.~A~L~L~S~ID~E=S~ ___ ------.~i_.-7-·_.~tENO It. ELEVATION SCALE:I·J.:'·,'_O" 2 ~iENDIt. j ;.... , , -- ..... ~ qy 5 B'-O' I CONT. HOR. ) 4 rt..ENDIl.~ ...---; io rt"'-~----,----- ~.t" 1\"2" I 3' 3 3 t ENDIl.\ ~ \ ~ Tl i: Ii I. II II Ii:! II ii II II a "" ~ '! Ii [ ~ BA~\ STIFF TYI:' + ii II " II " Ii ""'----:i " II " II 11 2 1 - ~' STEEL ROD r STAINLESS -B"'~ j2t ~"--""~ri~~~~ld'~-4:::!....4 ----jL J I I rh ~ ~_ ~~ :: J ~ l"-.i"1.:..::t j \.~ ---, 1t---'--T'i"I~ l' Ofrl ~I '----------.------STAINLESS UPSTREAM 1 GATE FRAME../ I I I ' I I' \jL~t SECTION ~ fo' SCALE:6"=I'·0· ~ RUBBER 'J' SEAL SOLID BUL8 Symbol I .... c' ....... I" ....... SCALE IN FEET 0 I SC.4LE: IN 1/"cIfES 0 c' 4' 6' , , , SCALE IN INCHES o ,-c?" 03" I I I I Dat. Approved D c B f-- 2 u.s. A_V ENGINEER DISnUCT CORPS OF ENGINEERS ANCHORAGE. AUSl'tA 00 ........ , ~ SNETTISHAM PROJECT, ALASKA t-;::=J-;:-:B:-L ____ --j IiiIOI SECOND STAGE DEVELOPMENT Dno ..... , ~::.::.:::::-CRATER LAKE WOODARDS ~~~' L TUNNEL PLUG t'~;:H'=~STI="",;,,-.::"'.E=c.,,--r-t:=:--_B=-=U-,=L:::..:K:.:..H'iE~A=D~D'lE,~T~A~IL~S~ __ ~ ... lEa· ~. -'"'AS SHOWN .. ~ , D£S.~~·I--::-:::::-'-=-';=:":':"':''----< nu";':;;-r------.... r.=~~---j D"~'7 II-v A B A c~"1'-~£· ·.··~·M r.IHh~dtJ~~~~~~~~~~ ~ Code:I-SNE-96-OS-I9-<l5114 · ____ 0. __ DESIGN MEMORANDUM NO. 26 PLATE 8 ------------~~~~~~~~~~~------~~~ A i- 5 4 3 ~ A K £ ~ ~z L T £ R R A C ,,0 -----'<0 ,,~ D '2S ------'30 ~"'" '3. /':00 "0 + ~': A .OOH-ICK) POWER "DDO:~~az TUNNEl.; I f 5 4 3 t 2 Srnwbol 1 ,,, __ ---&\0 'II'" tF' .;)., 0'" as. 0"" 0 •• ISo os. --~-O.O _---00. __ --010 ----". 910 ~ _--,-910 ~~~~~~ ____ ~ry~~~.~o ____ ~~~~~~ SCALE I N FEET ....,I.ton. ~ption. 0... Approv.d D c B 1. [UVAnCNS ~ IN I"UT JH) 1tE":REJ«:E) TO ~ SEA ~ QoIS't). COoml.Jt ~Ti~~.d.:s5SH~';~~~:~PRO.n;CT DATUM) t---_--'---_______ ---,,--______ ---.J __ ...L __ --I to 0XlRD1NAT'f SYS~ IS IN FEET 1HJ IS THE OCM..I,.. SY'ST&I (USACE 196'1). ]. SK:ItELIt«: IS N'PflOXI""'TE, AT N-I l!':LEVATlCN (7 1020 FEET N!JOIf MSl JH) IiMS PU>TlED f.:JoI SIOf Sc.tfoI SCHAR [)I,TA. ... THE Itfl:R"ATlCN PIlfSEN1'eD (I'll 'OilS own REPRESENTS M 1lE5I.A...TS OF Sl.RVF.YS PER- F<JtIoIfD In' OCEJN SlR'o'£YS. TNC-. (:tI 16-17 .J\A.Y 198] ArK> CAN CN...Y ~ c:.tHSIDEJIfO AS Itt::lJCATI"" THE CCKlIT1~ EXISTlr-G AT THlt.T 11P'E. . 2 o-Igned b,.: """ U.S. ,vwy ENGINEER DISTlaCT CORPS OF ENGINEERS ANCHORAGe, ALASKA JBL ~ l-~~_=.~.~.,----~~ SNETTISHAM PROJECT, ALASKA SECOND STAGE DEVELOPMENT CRATER LAKE t.t.L- TUNNEL ALIGNMENT IN LAKE TAP AREA --I-= 20' I~~~~~::::~o;,~~~_:~~-~~-------~ • O···'~7Av9M Dr.wlng Code: I-SNE-96-06-19-031 Sheet __ .' __ DESIGN MEMORANDUM NO. 26 PLATE 9 A D - c B A 5 I 4 I 3 I 2 " rAPPROX. LOC::"* OF HOIST --?e ~ -( -- ANCHOR IN ROCK ~~\ .ACK""Ul !.INe 1 ,\ £A_8IROCk Vl~~ --------~~ ---·""K!IA... .... -----__ _ _ _ e - IS<:RAPER-........ ~~A~~~~X.~2~~~' ________________________________________ ~~~~\ + • , , 5 I 4 PlAN LAKE SURFACE LOAO UtE ---, (WEIGIIT F NECESSARY) ELEv: 1020· DI8PO~~A~ ~.!..fIO~ _ _ _ ," :~~:::':"~.l" ·m PROFILE i· I SCRAPER .:-:"!: .. : '.":~'.: + . .. . ,.:~> m" .<: ~.~': . 3 t EA8T_~~ III .~ . •••• III ..... ...... . • -II .. :~'.:'" ,". "': ..•. :;:.;.~~' . I i o 1 .. ' ..... o' e' 2 , .. 7 ~ ........ APPROX. LOCATION OF HOIST LAKE TAP,\ '-GATE STRUCTURE SITE PLAN ".T .•. ........... _ . I u.s. ARMY EJIIG*EER DISTRICT CORPS OF ENGINEERS ANCItORAGE, ALASKA. Iw.I SNETTlSHAM PROJECT, ALASKA IiiIiiI SECOf«) STAGE DEYB.OPMENT 1-_--.-.'----1 :=-"-CRATBI LAKE I-::-W_. +1._' _Q_-_.~----jLAKE TAP CLEARING ctooc....... RECOMMENDED PLAN IsLUSHER METHOD I DESIGN MEMORANDUM 26 PLATE D - C B - A 10 5 o c B 5 4 ~ . '" g 1--_____ -'p~R!'.IM'!A~R'!:Y~RO'!:C'e!K'___'T.'!R"_A'::P.:. ~6:!.4' _______ +_---T~R~A~N-"-S'..!IT~IO!CN!.:.:..;3"B'--· ___ ...,., __ -,PO"W .. "-,,ER~ NOTE' BAR SPACING NOT TO SCALE FOR TRASHRACI( DETAILS SEE PLATE 8. 4 PLAN 10 '" SCALE IN FEET I~" JO'.O" .., I 3 2 3 t 2 MOreS; 1. AOOmONAl PRESSI..R: ~ TO EE LOCAlED AT STATK)N 10 .. 70 Net AT 8EAYICE GATE (.AP'FIRO)(. STA.. 1'" "00). FOR MOtITOANG LAKE T~' IElLAST 2. FWW. ~11ONOF 1>£ LAKE TN' LOCATION IS DEPENlEN'T ON THE It-STU ROO< CONDITIONS t-KJ -.L BE MADE If( 1>£ FELD. 3. TlWlHlAO< TO BE PUT If( PlACE AnBl LAKE T lIP BLAST AHO BEFORE POWER OPERAllONS _ ........... Dncriptlons U.S. ARMY ENGINEER OtSTlUCT CORPS OF ENGINEERS ANCHORAGE, ALASI(A r.IIP.II SNETTISHA'" PROJECT, ALASKA Ii;IiiI SECOND STAGE DEVELOP"ENT J---~.Jl>~-----l ::~ CRATER LAKE t-------,.-~..., LAKE TAP AND PRIMARY ROCK TRAP PLAN AND PROFIlE AS SHOWN ____ 0' __ DnwIng 1-SHE -96 -06 Cod_: ~ -0 4 o c B A DESIGN MEMORANDUM 26 PLATE 11 D 8 ----'s TRASH RACK LAKE TAO\..:oLUG TO BE REM DESIGN LINE DESIGN LINE AIR CUSHION 5 19' -0" SECTION D II 12 SeE PLATE 4 ~iECTION NOTE: POWER TUNN DETAILS 4 SECTION. ~I-.,""', 8 ...... ,2 :-1 SCALE, ,"·,0' ~~~ZlRC~I~~ COVER FOR AlA ROCK £L.~ 780 FILLER PIPE \ R PIPE .. IGNITION 1------" AIR FILLE -7 It-----WIRES ~ II TEA SURFACE II WIRES l~:~EVICE II MONI'Tt) DETAIL" A SCALE: 1-· 5 \ II 12 4 3 2 PRESSURE CE:LL *3 TRASH RACK .' s' o· .. !w ~~ SCALE: I".S-O 10' 3 2 t Ao~D AT SER-IIlIm.:. LDCATEn AT STATIIJj 10+70 SSURE CElLS 1P BE 1. AIII\TI~\~~R!JX. STA. 1Q+{X)). IS DEPENDENT 00 THE VICE GA OF THE I.AI:£ TAP LOCAT:~ THE FIELD. 2. FIIW. ~~I~~~~I!JIS AIID WILL BE I'IAOC CIN(; BLAST AHD BEFORE IN-SITU AFTER I.AI:£ PIER TO BE PUT IN PLACE 3. TMSIl~f1ATI!JIS BEGIN, PlIlER vnc 8 5 4 T5 6>< 3 ~T-F'i2AM"E j..--'l'Xn;:HSIOI-1 Fi::>f2. ° COU~wr: l;U PA::>RI 1£-FT. PIA. a O / ___ IHTAKf-Ol'Z1f1 li!11 II11I1 i ( ..---LI D 1:1 ! i!llt/Ii 'I ...... , I I I I' t-"-iii ,1 '1 I' " "-II Q, " !: '0- I'i, " \ II' , \ ~10 I I I) I' I' I : Ii 'i II I )1 \ I ' i I\f:~=-=-----= -= ~ ~ =-= ==-=:c 'l~ I11I % (, i J II ~ I) j II I I., ,I'\!I I, ':: / Ul' I \ ~ : II! ' I ;' iii ~: A :: \\2' "-" I 1/ il 0 "'-I' ilill ............. =------.-~~ , ll)! ..-1 , ii' i ~ I I I i !: 'i I i~ I --I ii Iii! 111 -T /< _ ill --() -~ r--~2'PIA.5-n... PIPE- / , -I r \ 't .. COUI4'WT. CrLlIDE,1Yf'. \ I '-/ ----- c .-10 B A 5 4 3 GUIDE' CABW:: L.\fTII-Hi-HOQ\( s '" i _ LIFTING: EYE f'1-V;Z" A 3 t 2 /STEEL PL V.2· ~ f,AJ(S :5 "x Yz.'@z'tl-o.c. T5 3" 3." S-/'<P '0 -' ;:~~~I,~~O" ® I-\OTcS: • CONC~E:re COUNT!:': F<'We: 161"1,1'( WI LL 'Be: lNSi-Al.-'l-e:D A'P1"Cl(. ~'l1RA!.-t::: \~ It-! PI.A£.E _ • GrUlDe CA1!>L.IO~ vJ\L..l-~e:. 5~UfZ,e1/ "-HP $1"Vf2.e:V ""bOVE. M"""-L."""'£ t:L.e:V- STEEL ANGLEGUlD£ t I2E:TAIN£R COUNTEffWEIGHT PARTIAL ELEVATION SC4LE: /"=2'-0' 1"~4'-O'STEEL te,SLOTTEO TYP. AL L AROUND TRASHRACK (0 z' a' ~' .. , =-:::J GRAPHIC SCALE: ,-. 2' -O· " Q " tt i1--=:::J .. ..t==~. __ ' GRAPHIC SCALE: ,-. "-0· 2 D s ....... Dat. Approved u.s. ARMY ENGINEER DlSTYl:ICT CORPS OF ENGIIEERS ANCHORAGE, AlASKA 00 ....... ., ftft SNETTISHAM PROJECT, ALASKA CAM E RO 1;;;;1 SECOND STAGE DEVELOPMENT 1-,-"",-... -•• -, ---=-=--'tlt:;;::.'" CRATER LAKE PDC PRIMARY TRASHRAC.",,",K~ __ --I "~~~2~w~~N~~~~'==·::1o~~·~A~S~SH~O~W~N-l~nu~·~ _____ ~ 1-....e:~~.~8R. 0. •• : _i ~"'" ' ___ 0'_- DESIGN MEMORANDUM NO. 26 PLATE 13 c B A o - c B r- A 5 I @; I I I I 8ulkhead~ I I I 4 Contact grouted SECTIONAL PLAN AT SPRINGLINE Scale: I": s'-o" cv- ~-----~~------------,~-~ ~::::r~~ ____ ~ f . () " ~ . C) " " " 5 -0 ~ I I I I 8ulkhead~ I I I I I I I I I I I . ,~ J ::: 4 I 3 . 10 " ~ I 3 t G '0\ II II Ji ( I ~ ,,~. ,,10 Co II , '0 , ~ 10'-0" i 'r SECTION Scale: 1"= ,J'-ON 21'-0" II II .ll SECTION '" :': . ~ ~ / 0 2 I Y Grouted rockbolfs 4s required E)(cGvcr/ed fO~'\. \ open bulkhead \ V ~:~. ~~ -' J ~ . '0 , -<0 "" D I. I 2 '/ 10'-0" ! i'.. J I 14'-0" SECTION Scale: 1"=,3'-0' ~ , ~ / o I .1 u.s. AlWY ENGIPEER DlSTRtCT CORPS OF ENG~RS ANCHORAGE. ALASKA _by' f.'IIP.I SNETTlSHAM PROJECT. ALASKA I--__ ...::.J-=B-=L~ Iii:;;I SECOND STAGE DEVELOPMENT Drawn Or. -:::::;::::-CRATER LAKE EEL ~~.L_ POWER TUNNEL EMERGENCY ;;;;;: ~-;;:'r PLUG & BULKHEAD (TYPICALJ s_ ., DESIGN MEMORANDUM NO. 26 PLATE 14 o - c B A D c B A 5 Access 4dif 2-2'-0' ¢ Air venls Run to loire access add podol Removable sl<¥!1 graling covers 4 Brtdge crane Non-swivel sheave Hydraulic hoid 3 Removable COYer fOr hn"k)""iOrl-~ Sleel ladder 2 10' Z-ZCO "pl Air venls r .~ t ~==C~~~~~~~ ELI040 ... ,,,:"'-" 5 Dogging recess Gale slots -~----:;"" Sfem support Rtmovable Ladder sakly landing (ij) .30' ~~~-~~ ~~~~ EL.1019 MOJ(. AJol Ma,,_ spacing--_. "~~ PLAN AT EL. 1040 Scale: I'~ 4'-0" 15' STeelladder ___ -- 3' ~-)?e'no,va,tJ~ sled grating Caver ror service gam Bulkhead I I I Gale guide anchor assembljl, TYP. Gale seal plale assembly, Trp. +-''!--4-----Gafe gUide, TYP. --t--i-f'2c...---Ladder Wfthca~c 1rT----Gale slot 5u:m Support 2' SECTION Scale: I" = Z '-0" -"""F"fcT---bJ:t1=;]~-steel ladder (Cage nol Shown) with cage Inspection terrace wilh post and railing ----------........ - "----Transition of AJwer Tunnel IU----c~--:t'_t--Exlension ladder Bulkhead guides --~ (stainless dee!) EL.8IS Concrele lining Terrace----~J y;, EL.806 Ext"nSlon ladder _.---.: __ -""i=-'+fjl\-l.... 6.7'xSl.3' Bulkhead EL.8Z':: Z-ZeO" ¢ Air 1/en15 Fbwe Tunnel -...::: ---2'-0·){ 6 I Air ~~ -v:nl Iral7sitlon £: ¢ steel by-poss pipe (Opposite wall) Concren. bhck-ou~ TYp. Flow ~ A--4-~"---z-c'-o"¢ Air venls L IZ' ,3' 4' .1 -------I-Z--"~B~~~-p~a~~~s--p~¢-e--~----~===:===~------~/O~'------------~ 8T;:G7:'~""': :'"".". ~.::,:.~ ... ~.:, .• '(II;:, SECTION © 10' 4' c' 25' .30' ShafT ct. STa 14+00 GATE STRUCTURE AT POWER TUNNEL ~ SECT/ON 0 Scale: 1'= 5'-0· 4 Scale; 1"= 2'-0" 5A-5' Sleel ;e lunn.!'1 prolection NOTE: SCALE IN FrET C 0 C 4 ~ I GRAPHIC SCAL e:: I'. z. co'· SCALE IN FEET 'L q 4 t( GRAPHIC SCAL.E; I". 4-~ 0" SCALE IN FEeT 5 P 5 f GRAPHIC SCAle; f -. 5 1_0" Ducts containing power, communication and inslromentalion lines (not shown) run From fhe gate sfructl/re downslream 10 lhe powerhOuse. Similar dvcfs run upslream to the primary rock trap which conlain instrumentation and ignition cables ror Ihe tap blasf. 3 2 5,... ... Gale sial RJwer Tunnel Iny. EL.789 Loo/(ING UPSTREAM GATE STRUCTURE SECTION Scale: /" '" 5'-0" A. ...... . _ .... . 0. .. u.s. ARlilY ENGINEER otSTRICT CORPS OF ENGtHEERS AHCtfORAGE, ALASKA .,..."... '" ftIP.I SNETTISHAM PROJECT, ALASKA CAMERO 1;;;;;1 SECOND STAGE DEVELOPMENT 1-'_=.'--•• -:.'-"'=-------1 ~t::::.::::" CRATER LAKE EEL GATE STRUCTURE ~~: -~ AS SHOWN ... ..-f----------J ..... , 2..7 AV9 (34 ...... r. ...... __ .. _- __ CoM: I· SHE -96~19-0317 DESIGN MEMORANDUM NO. 26 PLATE 15_ D c B A D c B A 5 6'-10" If J '.3" ¢ --1r-",",- IF=ji;\, -#K- I 1000 PLAN scale: In; 1'-0' Ifl SECTION 0 Scale: I"" 1'-0" o _JL-____ ,Lr=-=-~-~_ti_1Q __ ll_ -,,-----,'-11' -rr=!F-" ----n- I1 II [[ II :: II II II II II :: II II II II II II "" II II =»====~=~~~=~=~====~~-,~ II II II II II II II II II II I[ " 1/ II II II II II II Ii \: II II II =»====-=M==I:=~=~=~====~~=,1= :: £.!L-:::::: ---D.i" :: :: =~====~=~~~~~=~====~~-4~ II II II II II II II II II II Ii II II II II _ ~ ____ ~ __ ~~~~_~ ____ ~L_ L -rr -----n----=--=:;;=---=--=::!1----,,-r II II II II II II II II II II II II II II II II II II _~ ____ ~ ___ ~ ___ ~ ____ ~L_ L -rr----~---~---~----"-r II II Iii" II~" II Ii /I ~ II II =~====~===~===~= ==~~=J~ /I II II II II II II II II II II II II II II II II II h _____ ~ ___ ~ ___ ~ _____ ~L L IT rr-~---"T1---_n---__n---_n--\, , Ii 1/ II /I II II II \\ II I II II II II II \ i~ __ Jj ___ Jj ___ " ___ JJ ___ ~ ___ ~ 5 UPSTREAM ELEVATION Scale: 1"-1'-0" 4 ~/"-lljNPT "deep Drill and reum i' fiJr FN-Z fit ond provide // bronze lock pin (TYP. all cap screws) Yerf. /eM seal SECTION Scale: ,y': 1'-0" \) tel .1 ~ • ~~ (!;) .' ~ ~ " lEI tl ~ ~ END ELEVATION Scale: 1"= 1'-0' 3 Sial ead IE ror rib TO pass Throt/flo @ Ifl : \)1 , ~ ~ ,C? I ..... '" ~~ BarlJ<6 1-6~ s" - ee Del<ll10 SECTIP': 0 Scale: I ; 1-0 GATE LEAF 4 3 t .f S' ! ! -1 -1 ~lLLi 0 ~ I 0 f9 0 1 01 F:> 0 1 I 0..1. Fi 01 01 I 0 1 0 1 01 I 0 =9 °1 0 1 10 1 01 I 0 0 2 stem ~# fs '" SECTION 0 Scale: 6": 1'-0' seal Ring leaf SECTION Scale: 6"= 1'-0" ® " Ring 2" a e" 4" 6" ~---=~--~===---~ '0" Ring ~~~ 6' 10" - IISpoces fij) 6'~5'-6" D (0) [1 o lL~ _O--=-~ -~LL 0 0 II II II II " ~II ¥I,,"I Gale seal Ttnish ~ stainless sleel weld Mlh E 310 dec/rode _______ (ASTM 4298-62T) DETAIL 0 Scole: ,y': 1'-0" NOTES: STEM ASSEMBL Y Scale: Ii": 1'-0' f 0 - I S '({ ' I 1 J I I. Use i' buckin9 bars for all groove ""'Ids thai ure made from one sid!!' onlfJ. o -+[l+: I 0 I 0 "~:: 10 0--h II II I II J: Jl 0 II " II " --11 II ;; ~I II '! I.e --_ll_ ---Jl ~J JlIT II II II '---!I!i II II U I.L _ IT-' 1i :....::n II II :i II II II II II II 11 II II II II II II II :: II II II :: !! II :; II II II II II II " " II " " " .JJ -'L -'L -''-- DOWNSTREAM ELEVATION Scale: I': I'-ON 10 I 0 1'= 10 10 ;= 111 0 I 0 I" ,0 I 0 ' = 1° 10 I 10 ~ s"....., U.S. ARMV ENGINEER DISn.:T CORPS OF (MGINEERS AHCttORAGE, ALASKA SNETTISHAM PROJECT, ALASKA SECOND STAGE DEVELOPMENT t-::""'-:-:--_--:-.,-, ----j ':~ CRATER LAKE £EL SERVICE GA TE DETAILS ~~" Scale: AS SHOWN =..c. CIMIef. _1A. 1--:-.-------1 number. 1-------"1 t-==~=c;;__-____, DO'"'Z.7 A" B4 -"''''''.:?.~ f~"( Drawl"91-SNE-a6-06 CHI!!F, ..... DIY. Code: -19-03/ ___ 0' __ D c B A 2 DESIGN MEMORANDUM NO, 26 PLATE 16 1.-.- o c B A 5 POINTER SLOT W/BEVEL ED6E SL IOIN6 INDICATOR ROD GUIDE TUBE- REAR VIEW SCALE: 12 "=-!'-0" L ''''IT SWITCH AT /0,0' [§g----~-:---:' , I ... ~ , I .J ________ ::'-!J 4 MILE. : INDICATOR SCALE PLAN SCALE: 6": I~O" SCALE PLAN DETAIL SCALE: 6": /'-0" THE LETTERS, FIGURES, 'AND GRADUATIONS HAVE BEEN CIIT IN THE PLATE, FILLED wi TH BLACK ENAMEL ON WHITE BACKGRoUliD AND BAKED. BLACK -....;...i _~-_~ __ .L ~_ : I~/ ~l POINTER SCALE; 12"~(-0" LIMIT SWITCH ATMI67'(OR 0.2") 0GUIDE SUPPORT SCALE: I ": I~O' HYDRAULIC PISTON POSITION INDICATOR SCALE: I"=: (-0" 5 4 3 2 ILLER AND BREATHER CAP OIL SUPPLY TANK PISTON STEM CYLINDER~ THERMAL RELIE F ..-/ VALVE HYDRAULIC PIPING SCHEMATIC NTS OPEN SOCKET r---' CA 8LE F! TTiNG __ LIFTING LUGS ~L-_____ G_A_T_E_L_E_~F ~ HorST CABL E POSITION INDICATOR DETAIL NTS 3 t 2 25 HP ELECTRIC PRESSURE SWITCH U.S. APMY ENGWEER OIST'RCT CORPS Of' ENGItEERS ANCHORAGE. ALASKA GATE POSITION lNrJrCATORS a HYDRAULIC CYLINDER ~'!r-p.~, -'~;;ro~C"~ 1--------1-::::.-i--------1 ___ 01 __ DESIGN MEMORANDUM NO. 2.6 PLATE 17 o c B A D c B A 5 \ \ \ \ \ 4 p r n LIST OF MATERIAI_S ITEM DESCRIPTION OTY STOCK SIZE 1 SINGLE HELICAL GEAR REDUCERS, OVERALL RATIO 20670:1 Z RATIO 15911, 130:1 2 REVERSIBLE MOTOR, 1750 RPM I IHP 20816013 3 GATE POSITION INOICATOR TAKE-UP REEL AND LIMIT SWITCH I 4 OVE RHEAD MOTORIZED SHEAVE ON BRIDGE CRANE I 10 TON CAPACITY 5 ELECTRIC ALLY RELEASED BRAKE I 6 FLEXIBLE COUPLING 2 7 DRUM SHAFT, UNS 610350 CD I 6':.:L X 72" L 8 DRUM I 3'<fX 4'L 9 PILLOW BLOCK, SELF AL IGNIN6 2 10 ROLLER, HORIZONTAL I I'p X 1-112' L 1 1 ROLLER, HORIZONTAL I 1'<1 X 2-1/2'L 12 ROLLER, VERTICAL 2 1'¢X3'L 13 SHEAVE, CLOSED, ROOF-MOUNTED SWIVEL I 3'#- 14 WIRE ROPE, J/4"~-6XJ7 I 400' 15 KEY, DRUMSHAFT, UNS6 10350 CD I 1-1/2"X 1-1/2"X 20" 16 HYDRAULIC CYLINDER, 1100 PSI DESIGN I 30 "+ W/9 -1/4"j> STEM 1 7 HYDRAULIC PUMP AND CONTROLS SEE PLATE 17 NOTES /) BULKHEAD AND SLIDE GATE ARE SERVICED BY SAME HOIST CABLE. 2) BULKHEAD'S NOMINAL POSITION IS DOGGED AND DISCONNECTED FROM THE HOIST CABLE. 3) SLIDE GATE'S, NOMINAL POSITION IS APPROXIMATELY Z FEET ABOVE POWER TUNNEL ROOF AND CONNECTED TO THE HYDRAULIC CYLINDER STEM. 5 4 3 SLIDE GATE AND BULKHEAD HOIST PLAN SCALE: 1/4" ~ 1 '-0" BRIDGE CRANE W/ NON-SWIVEL SHEAVE MOUNTED ON A BEAM THAT's MOTORIZED IN 2 HORIZONTAL IMENSIONS AND LOCKS IN PLACE FOR HOISTING. GA TE POSITION I NDICA TOR CABLE FINISHED FLOOR BULKHEAD 6ATE~ SLOT 3 t 2 ITEM 0 IS MOUNTED ON SAME MOTORIZED TRUCK AS IS THE NON-SWIVEL SHEAVE. SWIVEL SHEAVE WIRE ROPE TO DRUM SLOT 4 0' ~' ......... 2 Ro ........ ........ D... Approved U.S. ARMY ENGINEER DtsTRICT CORPS OF ENGINEERS ANCHORAGE, ALASKA --S"R" M ~ SNETTI S~AM PROJECT, ALASKA t-::--.,..=.c...;.c...'----tl;;;;;l SECOND STAGE DEVELOPMENT --" ':'t;:--CRATER LAKE SRM ~c\f...~ ~MECH.S£C. BULKHEAD AND SLIDE GATE HOIST ""-__ D' __ DESIGN MEMORANDUM NO. 26 PLATE 18 D c B A • 5 I 4 I 3 ~ ~Berm D T \ ~ '\J " ::t ..... EL.1035 c PORTAL ELEVATION £L. 1035 Scale :if"= 1'-0" (J o (J 16 24 .. 8 - 1/ '-0" TYPICAL ADIT SECTION 0 Scale: 1'= ;'-OM I! 0 C 4 6 A 5 I 4 I 3 t I 2 / ApproKimale eXlsimq~ / grade v/ ////Iz Berm / J- ?'O' /~ [:. J ;,1 ~/ I 1'0 canoP!J~~./ -Z--"" / • I'~ x 14' Rock bolls \0 :t(') e (jj) 5' c -...f?\ '''''~/\IV--o .. ~~ D -r- / c _ S'ope-O.g?5 I c'-o" ~v Fill rrom cufs (Ta be '" graded and compacfed) I 2 SECTION scale:i-~ 1'-0" 8 ......... _ ...... Date Appro_" ~-~-----------~-+--~~ u.s. ARMY ENGINEER DISTRICT CORPS OF ENGINEERS AMCttORAGE, ALASKA _ .. ' r.IIr.'I SNETTISHAM PROJECT. ALASKA I-:---__ J_B_L--j IIiiIOI SECOND STAGE DEVELOPMENT A -_Or. ~:::;:.:::::o CRATER LAKE EEL GATE STRUCTURE ACCESS ADIT & PORTAL ~.~ ac.a.: A8 SHOWN ~ -_... -z7A"5~ -. f--------I -"'''7!1::t):,:'}1(ntL-DrawIne 1-aNE-,.-oe- ~.""DlY. Code: 1'-01/10 ...... of DESIGN MEMORANDUM NO. 26 PLATE 19 D - C B - A 5 5 B S·0.03-88 ------ J 4 PLAN li? OF POWER TUNNEL SCALE: 1--10' C I APPROXIMATELY 1M FEET TO BEGINNING OF GATE STRUCTURE TRANSITION FLOW;::, POWER TUNNEL SECTION A SCALE' I'· 10' II' /-r-~~OESIGN LINE I I/~ -= -t~1 -+ ... c!' SPAINGLINE 1 1' /'" "'\\ 10 \ ' in --i -- 1 I 4 I 3 I 2 D£SIQII LINE. --/, fr\,--'-I"'I- 44<,cYA~E~ ~(,. "'. 1 ~~ . 1111 1>'..tzbj: U ~ ... , 11/ / / -j -__ I----,l .. t- I. .20··,(W .1 ~~l!SN 0 3 I 2 t 1 D - C -+- B 10' 0 10' 20' !w.... I GRAPHIC SCAlE: 1-·0'·0· !S' O' !S' 10' --. GRAPHIC SCALE: ,-. !S' -o· _ ....... --~---t---------------------------+---+----i,-- a.......,.. II" r.IIP.I :rNJ"' IIiiIiiI 1-=---.,--------1 ....... "- -bY' CAl( "-' I U.s. ARMY ENGINEER DISTRICT CORPS Of ENGINEERS ANCHORAGE. ALASKA SNETTISHAM PROJECT, ALASKA SECOND STAGE DEVELOPMENT CRATER LAKE SECONDARY ROCK TRAP a: ~r. -ac. .. : AS SHOWN =..oe .~ . IlL Date: number. \------------1 ~ k~ Dl'awlng1-sNE-.e-oe-11 u...t 0' __ ~. ____ . Cocfe: 03/11 I DESIGN MEMORANDUM 26 PLATE 20 A 5 D , . C ~ g ~ ~ ~ ~~ __________ ~rn~A"~SrrITI~~L-____________ ~ ~ .. B DESIGN LlNE---~,y' I ",.b 1 ,..' I ---+--- 1- A SECTION SCALE: I··~·-O· 5 4 REMOVABLE FAIRING WALL I3'HIGH) PLAN AT <t POWER TUNNEL 4 3 " '4' FAIRING ALL Tl'!ASHRACK WITH n.MPCRARY UM,R SECTION '--'-'-'-=--'--------;::\~~\ ~ + .. .. .. t; ROCK TRAP : zzzzzJ AREA AVAILA81.E fOR SEJlMEHT STORAGE 3 ELEV. 1I~.4' TUNNEL PLUG TUNNEL PLUG ,'t<l . <1'., '----~-. BEGIN PENSlOCK AT STA.68-+7~ t ELEV. -116.17 DESIGN LINE-------# SECTION 2 D 2 1 NOTE: REMOVABLE FAIRING WALL WILL ALLOW ACCESS TO ROCK TRAP AND POWER TUNNEL. - 10 0 10 .WHWe! ," -'0'-0· .... --. Date Approved U.S. ARMY ENGMEER DlSTNCT CORPS Of ENGINEERS ANCHORAGE. ALASKA r.IIr.'II SNETTlSHAM PROJECT, ALASKA = SECOND STAGE DEVELOPMENT I---"L.l/O"---__ -< ....... "-CRATER LAKE Drewnbf'l JKf--~ ~~~~i FINAL ROCK TRAP AND I' SECONDARY TRASHRACK D C B A '1~~~;;;~=::=t<-;;;:--. A~S:...:::SHO.:.:.:W~N:.:.....__j =-r---------------I ....., ~'Ar. DrewInt I-SNE-96-OS-Sheet __ ., __ Code: -19 -03/12 DESIGN MEMORANDUM 26 PLATE 21 5 I 4 T U)'-O· DIA. SURGE TANK D r---DRIFT TUNNEL +, ~ "'-0·1 1 ~ B I -r--<V , C TAPERED JUNCTlON----'\--+--!!I--+~-_--'~, \POWER TUNNEL . r b ~ -7TO POWERHOUSE --t't---~ ---ll~-------'/ · ~~~\"~--i>l--A ----=o~~ PLAN SCALE: '·0 '0'-0· .... f-- DRIFT TUNNEL B {j"V4 /~W" PROFILE SCALE: '·0 '0'-0· A I 4 I 3 I 2 STEEL PIPE ~ t ~:-- ELEV.-1080·t± --..... "" ~ . o , ;., I ~~~r--:~-~ , "-0.-"'- .J!.;)' 17'/ ELEV. '074' , \ tf MAX. WSEL (LOAD REJECTION) r POWER TUNNEL' \ I 70';t I' J TAPERED JUNC-riON \ 'n:'. --=-'O=-'-,-O=-·o'D""I""A·,--<.,1 ~\rrtGN UNE7 g\'j ! ~ J ( ~, ~lf b DESIG)LlNE-V,io"~11 ~ I \\~ I. SURGE TANK ELEV.o'1!ICY! --.I~ I:~ .m '"'~ V ~-~...I.~_'_l_II;:==-'il--' ===l~ DRIFT TUNNEL~ ~ If ~ -++--- DESIGN UNE ----, , " o , ~ ~f- SECTION jlCALE: '"0 11'-0· 3 t I SECTION SCALE: ,.= 5'-0· 'a' 0' 'A' 20' 1M •••• , GRAPHIC SCALE: ,". id-O" " 0' " 10' .. -... GRAPHIC SCAL.£. 1-·5'-0· 2 MIN. WSEL 785' (LOAD DEMAND) NOTE: FINAL SURGE lANK LOCATION TO BE DETERMINED AFTER C.O.E. SURVEY OF AREA NEAR TOP OF SURGE TANK • RevlakMt. . ....., ~rtptl_ • I U.S. ARMY ENGINEER OI$TRIICT CORPS OF ENGINEERS ANCHORAGE, ALASKA _Or-r.IIr.I SJIIETTISHAM PROJECT, ALASKA ;JtJ;r Iii&iiII SECOND STAGE DEVELOPMENT 1-::-_--,0-"----1 ':t:.:--CRATER LAKE )I~ ~~&kQ~d.:;:;;:'1 .... .....,:;:,'" SURGE TANK $ ..... __ 0, __ DESIGN MEMORANDUM 26 PLATE 22 D C B A o C B A GATE STRUCTURE SECONDARY PlOCK TRAP 1400 /350 1.300 IZ50 IZOO 1150 /100 f.-1050 ~ 1000 ~ 950 ~ ;:: 900 ~ 850 '" ~ 800 750 700 5 Gafe Structure EL 1038 Slope Slope -~ ~~Q~. 00~5====d,~==::'§O~' 0§O§'6~====~~E. 035 Crot", Loke EL 1019 '---I-~- Troshrack 5 foo St'condar!l Rock Trap Rock Trap 101-00 UNLINED POWER TUNNEL MINIMUM ROCK COVER EL.I040 15foo ZOfOO Z5foo PLAN PROFILE loo' 0' lOa' zoo' ••••• I GRAfWlC SCALE: 1"-100'-0" VERTICAL zoo' 0' zoo' 400' ...... ! , I GRAPHIC SCALE: I', ZaJcO" HORIZONTAL Slope 0.005 2 45foo 50+00 SSfoo - 1-::-_---, ... -----1 GEK 1 l 1150 -1 /100 1050 Sur~ Tank 1000 950 J 900 850 ~ Ir) I 800 750 Final fibck Trap 700 6OfOO 65"00 _ ...... -. .... u.s. AIIIIY ENQIIIEER DISTRICT CONI'S OIF ENGItEERS ANCtIORAGE" ALASKA f.- ~ IJ; ~ ~ i:: ~ '" ~ -... m SNETTISHAM PROJECT, ALASKA SECOND STAGE DEVELOPMENT 0::::;"'-CRATER LAKE ALTERNATIVE I PLAN & PROFILE --~~~~~:::'~h_;;;;~A;!S....!S!.!H:!.!O,!JW!!!!N---j =-1--______ -1 :1iQ"1{Jt'-~~031~ ___ af __ 5 4 3 2 DESIGN MEMORANDUM NO.26 ~------~--------~------~----------~---------~t----------~--------------~~· PLATE 23 o c B A D C B A 5 ~=:!'!::=::::::!!==~=±::w±=::::::!l==l···· [LEv. 750.0 5 " I'MIN. CONCRETE LlNING-----i SECTION : .• ' ELEVATOR GATES A 4 [LEV. 1040.0 LADDER 4 3 ...... : ... .t.," ~ .. ........ ELEVATOR ACCESS 1000· CAP HAT-=-H_~j ___ " 'Q (~" LAaDER _--.111:+-____ _ \ -; -VENT --~ ~~"'~:;;;::"':;-L -+-----iIT -+--+--+---+--+--+-1- ...... ,-: , ---- '" ".> 1:. ••• :': •• ' .....• AT ELEIJ. 766.0 GATE ROOM FLOOR PLAN 70'-0· .. : ~'--.,.~.~. • i! .... '":'" .' -: ...... , ,-., '%I _"", • ,.."\ •• ELEVATOR ---------- 'i. "aNORAIL ______ _ 'i' -.. -+-+-- HATCH \ ~~i\'~~8~~~,t'.~'~"'~~~~~~~f=I'_=0·~~~~,~"c~'~ .. _~r~''/~";~'~"~"~~ "'0 PLAN AT ELEVATION 1040.0' SCALE; 1/8-.1'40· 3 t 2 24'-0· 1 ? .. .. 13 VERTICAL SIDEWALL ACCESS ADiT STEEL GRATING FLOOR '--=<1-~ A ~ENT B.EV. I04() [LEV. 766.0 I' .. 1.1 .1 ,,: i ,I. 'U I ,1,1 I ·11 'I' ,II' I 'I':: 1 :.-I, I 6', I I I ·ir·W~I1T ELEV, 750,0 i' 1 -""'''-''--'='---'r-'-, L'~_:"""~ .': .... :....:...J .. e'" ,r?' 10' lP' GRAPHIC SCALE: 3/32':1-0" " lO' I ~' •••• 0' 10' GRAPHIC SCALE: 1/8"I~O' '-. .: .' 10' SECTION SCALE: 1/4-·1'-0- ......... B ........... -- U.s. ARMY EJtG8rEER DCSTRICT CORPS OF EJIGINEERS ANCHORAGE. ALASKA ............ ,. r.IIr.II -SNETTISHAM PROJECT, ALASKA CAME:.eo Iii:iII SECOND STAGE DEVELOPMENT 1---=----10:' ..... --CRATER LAKE ALTERNATIVE 1. GATE STRUCTURE PLANS AND SECTIONS D C B A GRAPHIC SCALE: 114"I~O' I -.AS SHOWN -, ~~~~~~~t.-;;;;;;----=-I ::::=-1--------1 DNwIIItII-SNE·K-oB-19-eo..: OSIIT ...... __ .. _- 2 DESIGN MEMORANDUM NO. 26 PLATE 24 -+ D c ,..: ... Z Q F ~ W ...J W B 800- 700- 600- 500- 5 POWER TUNNEL ROCK TRAP CONCRETE ----~ 400-STEEL PENSTOCK---~ 300- zOO- 0- ., ., w z " ~ .... w ~ ...J ... I 6~OO I· 11l~ If- 12f- I 66+00 A STA. 65+65 --L- 66+00 5 I 67+00 67+00 I 68+00 68+00 4 I 69+00 69+00 4 PENSTOCK, 6' DIA. I 70+00 70+00 71+00 71+00 I 12+00 PROFILE SCALE,.'. 50'-0' 3 I 73+00 I 74+00 75 +00 I 76+00 PLATE THICKNESS SHOWN ARE FOR ASTM A537, CLASS :II STEEL 73+00 74+00 75+00 76+00 PLATE THICKNESS PROFILE 3 t 2 77+00 77+00 2 ...J ...J ; 8 a: w ~ .. w .. en + 5 CD", "'0: ~~ en ... --800 --700 --600 -500 ,..: ... z o --400 ;: --300 --200 --100 ~ ...J W 1 I 78+00 I 79+00 --0 SCALE IN FEET ~~~~-=_~O~==~50~ __ ~/qv 78+00 1-:-_-... --,-•• -, ----I JKL ~~·~.L;' ~~~~J -. -- u.s. ARMY ENGIfrEER DlSTllCT CORPS OF ENGIfrEERS ANCHORAGE. ALASKA III SNETTISHAM PROJECT, ALASKA SECOND STAGE DEVELOPMENT :::;:--CRATER LAKE PENSTOCK PROFILE FOR ALTERNATIVES I & n D c B A ~~~~::::~D~;;:_A_S_SH_O_W_N--j~~ _____ --i ___ 0' __ DESIGN MEMORANDUM 26 PLATE 25 D A CRATER LAKE -+- GATE STRUCTURE SECONDARY ROCK TRAP CRATER LAKE ELEV. 1019 ~ TRASHRACK 5 GATE STRUCTUR'E 5-00 10+00 15->00 I X STATIC HEAD 1.5 X DYNAMIC HEAD lfNUNED PC1NER TUNNEL MINIMUM ROCK COVER 4 20+00 25+00 PLAN o· 200' 400' , POWER TUIINEL. 12' DlA, 35+00 PROFilE 100' 0' 100' 200' 10 •••• • . I GRAPHIC SCALE: I·~IOO'-O" VERTtcAL 200' 0' 200' 400' 10 •••• • . I GRAPHK: SCALE: r-200-rf HORIZONTAL 3 t SLOPE 0.00& , 40-00 45~00 50<00 2 PROFILE AT SURGE TANK 1150 " 1100, I " 1050 " 15 SURGE TANK~t: 1000 ~ " ~ '" '" " ., ... " Z " '" 950 " " .. ': ... 900 z " 0 Q " .~ ~ " ~ 850 « " > '" '" ., -' :: 800 '" " " 750 FINAL ROCK TRAP 700 55+00 60+00 65+00 -a.----- _... ftII'I L-E£AI:: IiiIiiI SNETTISHAM PROJECT. ALASKA SECOND STAGE DEVELOPMENT ::::--CRATER LAKE 1--------1 -.. ' ROC ALTERNATIVE n PLAN & PROFilE -AS SHOWN -~~~~~:::=-r ...... ;;;;;;;-----':"~---1 =-1--------1 DNwIng I-SNE-96-06-19- Ce*: 03/19 DESIGN MEMORANDUM NO. 26 ___ of __ PLATE 26 D c B A 5 l 4 26' -O· o . v . r: "r "L ,'-~'M'N ", '" , -II c . , PLAN AT GATE ROOM FLOOR SCALE: 1/4-• ,'-o· -+- ,', 8 ,Jf.-., D' 1 ~ ~ ,I ~,~ : I :I~YO' ~ M I ,UN'T II i • ~~r~~~~ __ ~E~L,~1~"~ , "II ""I • II ,~, ~ ,. 'II. " I 0 II 0 ',I '"I" .11' ~. ,.,' :lj'll '''., oil'> ," II' • '~' I,> 'I' '," -II , '. ' I. ' I • .1 ,I • , I ' , I ' C 'I ~--.' • 0' SLIDE GATE OP£N'NG .1 --"V I < "'. ~11: Ll ' ". t) 0.. ~ O. , ta. ". .' " ' A ~~7i'i"" SEC TI ON 1"':'\ SCALE' 114', ,'-o,-\.....8 J 5 1 4 I 3 AIR VENT WILL CONTINUE DOWN APPROXIMATELY 500 fEET ANO THEN RISE IN A DRILLED HOLE FROM THE AOIT TO ABOVE MAXIMUM LAKE ELEVATION 1 3 t I 2 " }. rc 1: yl-----15 TON HO'ST ~==~=====~~~==~ -."; " -0' "'N-I--- SECTION A SCALE: 1/4"· 1'-0· s' o· s' '0' _.- GRAPHIC SCALE: 1/4"1',0" ':',' .. ~ ", HATCH fl. 766 """,,ptIon. I u.s. ANlY ENOIIEER DISTRICT CORPS OF EMGDEERS ANCItORAGE,AlASKA _Or-ftIP.II SNETTISHAM PROJECT, ALASKA JBL IiiIiiI SECOND STAGE DEVELOPMENT 1-::-_--,-..,-, ----I ~::::"'":" CRATER LAKE RDC f1r'mr:_L :.. ALTERNATIVE][ GATE ~~~ STRUCTURE PLANS & SECTIONS o c 8 A ~~'If' ,_-, -.. ~. 1'4-="-0· Nt~ DES. HR. a.te: nvmtMr: 1--------1 ~bN4o-;=-=~:;:, '::-SNE-~----I -.. .f I 2 DEStGN MEMORANDUM NO, 26 PLATE 21 D A LAKE SURFACE EL.1019 GATE STRUCTURE 5 SECONoARY--...--..\ ROCK TRAP a LAKE TAP 0+00 5 \ [.~/" ! ' /; ,. , I /'~ .. ( PLAN 2 MAX. HYDRAULIC GRADIENT AT AIR CHAMBER = 1128.4' 1 D c .sLl~~ ______ ~~~~~~~r-~G~A:T~E~S~T~R~U~CT~U~R~E~~~~~::~~~==~=-~~~~~::::========::==:===~~-======-~~~~ ______ =M~A_X __ IM~U=M~H=Y==D=R=A=U~L~IC~G_R_A_D~I~E~N:T~==::::====:::::::===~====~~==~===-~~~tl 1', 2 0 0 0 0 0 (FLOOR ELEV.1040.o1 SLOPE 0.006 ___ £L.IOll4.6 MAX. HYORAIJUC GRADIENT MIN. HYDRAULIC GRADIENT AT ~+oo 10+00 UNLINED POWER TUNNEL MINIMUM ROCK COVER SECONDARY ROCK TRAP I~+OO 20+00 25+00 4 MINIMUM HYDRAULIC GRADIENT 30+00 3~+OO 40+00 4~+OO 50+00 PROFILE 200' o 200' . I I SCALE· I·· 200' 3 2 t AIR CHAMBER '_7:...:3:..4:..:.~4~' ____ _ z o ;::: 600 ~ AIR CHAMBER~ SURGE TANK I 400 200 '" ..... '" FINAL ROCK TRAP ~5+00 60+00 65·00 -a_ - _ ... ED 1--:,----:-----------1 .. __ SNETTISHAM PROJECT, ALASKA CRATER LAKE DrawN'" G£K ., ......... FIRST STAGE DEVELQPMENT t---------j ALTERNATIVE m ~&.;"';'~d'-POWER TUNNEL PLAN 8 PROFILE ~.~~~~~.~~~:~,~~~~_r_. _,_,~_.~,~~ _____ 1·_' __ 2_0_0_'~~~ ____________ ~ ....... _N ___ t_ CeM: OVJ3 - _ __ of __ DESIGN MEMORANDUM NO. 26 PLATE 28 B A 0 c B A 1300 IG 1150 700 6 400 300 200 o 66+00 5 QS ~ t--. I() <::i -..; EL. 1128. 4 "J EL.734._4 __ Steel Pensfock 67"00 5 SECTION Scale: 1"'.3 '-0" Rock Trap FinGl Rodf Trap Access Add 58+00 69~00 69+00 4 COncrete TO +-00 71+00 71'+00 PROFILE Scole: I'~ 50'·0' 70+00 T!+OO 4 3 2 GROUND SURFACE It. Pensfock EL T.S 74100 75+00 76+00 78100 78+00 74+00 PLATE THICKNESS PROFILE 75+00 76+00 77/00 78+00 3 2 t ELI 1.329.4 EL.548.7 SCALE IN FEET ~~~~-= __ ~O====~50~! ______ I00 I-------l Drawn br: EEL ~e"~_J .. CHEF~ /"=50'-0" ---- U.S. ARMY ENGitEER DlSTIl1CT CORPS OF EMGItEERS AJICItfJRAGE, ALASKA m SNETTISHAM PROJECT, ALASKA SECOND STAGE DEVELOPMENT ~t::"? CRATER LAKE ALTERNATIVE m PENSTOCK PROFILE ___ 0'_- DESIGN MEMORANDUM NO. 26 PLATE 29 0 c B A o c B A 5 L'-- -.-----~--~ -. '" 7' 1 -I .30' <l •. '~ .. ! ;.. Z-I'IO'fj Air venls __ 5 "- §,. ~ -- Ladder Safely landing (jV 30' Max, spacing --, ~ - ~ sre"'lladder----~ with cage Bulkhead and Gale gUIdes ----=:c - (Slainless sled) .::: EL815_/ " Concrete lin/n9--'''" 4 l 3 I Removable sfl. grating ~oy.er fOr bulkhead "\ 3C' ! \ ~' \. J, / /1 }...[ \;;J', Z -I ~ 10"¢-Air venls wi rocK sc:e€'rJ cover.,s /'S!cel ladder ,.,"".,',-."" IS-Ton sheove £L.1019 Max, Pool PLAN AT EL. 1040 Scale: 1'= 4'-0' 4 I 3 I t I <l Power Tunnel 2 2 ------/~O·' O!..6" Blockouls TYP. Scale: I" ~ 2 '-0" -c:-r --t;'l,-(~~e;: !1~~~wn) , J f-' --IF" I<'~ ~1: _ ,I 1[==1' I '1! EL 806 L' --I'---:-- ~~. ' : "',' I ' 1---" Extensk:1I7 ladder -I ! , I ;' .----f--E -r.c:c:--;-,... Gate slol I ~,i < j ~,_l<,J L': <~ Power Tunnel -"f-"'--..----""}fT;t:-_-,'-'~__._,c_;--'-., 11171< EL 789 '\)1' ___ ~' I " / """~1)W , ,I LOOKING 8"'" Bf/-pass P'p9/.3 6 1 3--1 UPSTREAM GATE STRUCTURE SECTION Scale: rz 5'-0· ........... I u.s.. ARMY ENGIIEER DISTRICT CORPS OF EHGIlEERS ANCHORAGE. ALASKA DHIpoHI b,.l "" CAMERO L:,;;I SNETTISHAM PROJECT, ALASKA SECOND STAGE DEVELOPMENT ':t:::::" CRATER LAKE ~:.:..:::.::.:...::::-~ EEL 5."i"'k.r'A", _ I, _ ~~ ALTERNATIVE m GATE STRUCTURE 1'~~·f:""~t:L·~~·~· ~dZ~'J-;;-;;;;-'::::A.::cS-=S,-,H.::cO.:.:W",N'-1 =~ '---------t f-CHIE DEs. BR. I Date: I -.. ., DESIGN MEMORANDUM NO. 26 PLATE 30 o c B A Defad~ 01 I D GUIde shoe Detall--o c . Cl " ~il( ~ lrj '" B +------ A 5 F= - - __ 4_'-4i" C d ¥:5 ./~It: i ~Draln " Skin ;E .3 '-.3! " HALF SECTION 8) 4 ~~ 0 Scale: Ij'= 1'-0' JiiDJ s'-lIP Do99in9 beam HALF PLAN =============~========= =================== :1: r-----iii F=====================l================== I!: il! =============~=======~================= = J :1: It: i x 5-------1 III =====================~================= II: !I! =====================i================= 1 II F================ !~ II II iii o o Dra;n~ HALF UPSTREAM £LEV. HALF DOWNSTREAM ELEJ/. Scale: Ij' = 1'-0' 5 4 3 i"¢>HU. sockelnead lJdt WI/h nut and wmmpt"-- r¢> Pin--~~~ if' Side Oat-__ ~'- ,;>1"¢ Rn//PI--~ Rollers DETAIL 0 Ou f to out of' rollers Scale: 6'= I~O" -GUIde shoe Roller-_ It!!. DefOJI (0 SIDE ELEVA TlON Scale: Ii": 1'-0" 3 t 2 Seal 1'-4" 'Skin IE seal i "¢ IIt''( socket head screw SECTION ® Scale: li'~ 1'-0' 2 2}'¢ Rol""r ddS/de bar r ¢ P/i'-_~'''''''f- ;" Roller frack _~~~~~~~~~ DETAIL ® Scale: 6"= 1'-0" I" Skin ~---~:n Ii II Seal bar- -i 'Seal rdainer #"¢ lIex sockel head Screw Symbol DETAIL @ Scale: 3'~ 1'-0" J" '- SCALE IN FEET I 0 ~=-~~~'--='I'~-O~'~----- SCALE IN INCHES o .3" 6" 9' Ic' ,3"<l c O' SCALE IN INCHES c~~ __ ==~q __ ~~C~'~~~4_' __ ~6' 6" = 1'-0" RevlsJons DeacrlpUons If/xS o.t. Approved U.S. AAMY ENGINEER DISTRICT CORPS OF ENGINEERS AHCtt0R4GE. ALASKA ~~.' I'Jft SNETTISHAM PROJECT, ALASKA 1--____ --11;;;;;1 SECOND STAGE DEVELOPMENT 0::::::::-CRATER LAKE ALTERNATIVE m SERVICE GATE DETAILS -. ~i£~~==JoD .. ;;:.;;-,=-""-==---j :.':='-r-------i IJrawtn9 1-SNE-cus-oe Cod.: -, 9-031 DESIGN MEMORANDUM NO. 26 ___ of __ PLATE 31 D c B A D c B A 5 4 LIST OF MATERIALS r-!-TEM NO. ITEM QUANTITY STOCK SIZE Sill ,L~ "CIe"'-Go ...... REDv<",,-~ ~ 1-RAirO 1$1\":\ 130: 2 R,E'"vE"~~ 1e:1..~ "IoTOR,112L&'M 1 ~. ~O81.013 .3 AT:-p~:; IriON IN" C~To,. j LlmJT .sw " 4 O"~R.~E:Ab MO r~ ...... ,1.€OD SH(;AVE ON ,."'1\(. ... I ,5 "'f"ON. '-A PAC rV ') eL.EC~RIc...I'1("I...Y RC C.t:~S€V 2~A~E Q ~LE'" Ie € ~OJPLl'" G. ... 7 PRv SH"F T """ G. 0',,"0 en I 0"'" 7Z 'l.- S 'Dl2.vM I "'~ ~.~. '9 f?II-L[\~ 5LO<,1( SEL..-f-AL-1GoNl"i.fL 1- ROLLER H-OR, >CONT, L , I'</>, It' 1 1 RI-'It. Ft< ".,. ,lonNTA I I'd> , 2~'L 1 2 fl...O~LE, lIE .... , A Z I'dJ ~ 3' (.... 13 <;~EAvE' c.I-O~€O R ,T!'C' ,., I 3'''' 14 WIRE fZ.aPE 1'-<-"-6.37 3 .300 ' 15 I<.EY ~"V"'''''M'' V '''' 035"0 <-D 1 jl.tJ.."'I.. 1 "z."'1(20·/ NOT£S : n BULKHEAD ~ SE'YI"" IM,-E" E'II"H HIIYE THE'I"-OW>-l DE'DI""iED ;:r.BCE' ,-Hlli ""'f..J "'i'-""'~ -ro ,HE DRVIr1-D€/.)/C4rfil:J ;'+O,S'" CAIlLi.:. ~ B ULKHEAl)'S >-lOHINIIL R?5ITIO'-' 15 DO",bED , DISU'>-l>-lE",-E"D FfWf-1 ,-He HO..,,-""''3LE', 3) 5ERVfC.k ('fArE! "'0Il1IH4L Paslno", 15 fvSr IH!.OvE "rHE P(wV£R. rUNHEf-~ C.ON"JCC rf;.D rD fH-€ HOtS.,-CA-B( .. £. 5 4 3 SERVICE GATE AND BULKHEAD HOIST PLAN SCALE: '/4""",-0" OVI<RHEAP TRACK (BOL TeD INTo CEIL/tiE,) 2 .r OVERHEAD MOTORIZI<D '---------,-~-----._,__--' fs~~1.~~ 'f~cll~· ,AJSLA(G FOfZ 1-4015 TIN~) 4 .. ~ __ ,O_'~ ___ ~~' ...... e' P"W-MiI 1'-0" 3 2 t Symbol Raylalona Oesc .. lpbons Date Appl"'lJ'Y'ed U.S. ARMY ENGINEER DISTRICT CORPS OF ENGINEERS ANCHORAGE. ALASKA o. • ...,nedb,.: r.IIr.'I S RM IIi;UJ SNETTISHAM PROJECT, ALASKA SECOND STAGE DEVELOPMENT ':E~ CRATER LAKE t-::-... -.w-n-:-'.y'--', ----1 SRM ALTERNATIVE m BULKHEAD I-t.""im:",;"-·"",.-€,,,~t"'"'. ",s~"'-~.~"'---1f-:--;.A...:N:..:.::D:....::SERVICE GATE HOIST D c B A ""!"'""'~'L..<Z' Sc ... , I". 4'-0· .h ••• ~~~H'~~~'~OE~S<~.~B~.~. ---i-D.-•• -'----------~~~!~~·~------------~ Drewing 1-SNE-98-06 Code: -18-03/37 DESIGN MEMORANDUM NO. 26 ' ___ 0' __ PLATE 32 5 D c B l A 5 I C\J :> -cp BERM > C\J :I: 12' a" PORTAL ELEVATION SCALE:I/S""I'-O· 4 (-0" l 14'_0" 12'-0· ~~ UNLINED CONCRETE LINED TYPICAL ~DIT SECTIONS SCALE: 3/S .IJ'-O· 4 J b , -<.0 C\J 7'··0" .. 3 3 t 2 VARIES ~ 70'(MIN) 10' O' 10' 20' ••••• i 6RAPHIC SCALE: 1/8'.1'-0' " _ .:' .s· ti' GRAPHIC SCALE: 114"1'-0" '-_ .' :=J' 8RAPHIC SCALE: $/8'01'-0' 2 NOTE: =0 -' <.0 C\J 1 -0 , b r<') L FINAL ROCK TRAP ACCESS ADIT SECTIONS WILL BE THE SAME fjS THAT FOR THE GATE STRUCTURE ADIT. 2. FI NAL ROCK TRAP ACCESS ADIT PORTAL WILL BE THE SAME AS THE EXISTING POWERHOUSE PORTALS. -....... Descriptions Date Approv" u.s. A"" ENGDEER DtSTRICT CORPS OF ENGINEERS ANCHORAGE. ALASKA --." r.Ift SNETTISHAM PROJECT, ALASKA CMA£= IiiIiiI SECOND STAGE DEVELOPMENT l-_--.,,-.----1 ":t:::--CRATER LAKE W~::. ALTERNATIVEm t------j GATE STRUCTURE ACCESS ADIT AND PORTAL ~W~l'~~ ..... , AS SHOWN :s.::-..!-~~~ SA. o.t.: numblwl f-------I ~b~ _. ~1-SNE-g6-06 ~r~ Code; -18-03 DESIGN MEMORANDUM NO, 26 __ vl_ PLATE 33 D C B A 5 COMBINED DUCT 5 3/4-PIEZOMETER DUCT ~:i~I~ZOMETER RING ~~r:TA. 6S+00. AIR CHTA~::L DRIFT --4 30' TRANS I TID" • FLOW I ASHRA()( WILL IJ'PER 1 OF J:rER INrTlAL BE REMOVED OPERATION. PER tOO OF He" ENTRANCE .lOfT J f' • R'tINFORcm CONCRETE 4 3 OtAM8ER DftIl;TOR ~~~tsl 1~~~ ___ ~~_EP_LA_TE~3'~~~. __ _ PLAN SCALE: .--10'-0· ~ UMENTATIOfIf, CT CARRYING N'~ AIR CIi.MeER. WIRES a PlPELI II'MOOIAED / • -~ HORSESHOE ---::6 \ ---1 , \ \ ELEVATION SCALE: '-·10'-0" 3 t EL.-140.00 DUCT DESIGN LINE SECTIO~ SCALE: ,-. 5"-0 10 . I--10'-0· 20 I '0 . 2 :il ~I t;j TRANSITlON·20· 4.0' 2 TRANSITION-25' s' DIAMETER S~ItIiE ·PENSTOCK TO ENCASEMENT :!S' CONCRETE ........... ",,,::: WITH TEMPORARY TRASHRACK ~~iR PORTION. • DISTRICT =:=::l=====----li-lUI.,.S. ";::s~=.= -~HORAGE, JECT ALASKA -SNETTISH\~~~~EVELOPMENT 1m SECOND CAKE m --:-:::--I ':t::::" Clff~RNATI~~p AND FINAL RO;KT1ASHRACK SECONDA~ .... t Scaie:AS SHOWN ::!~ D c B A 5 _ ~ -~ 1I'-O"_~Fi 4 -rr :V' fi' ¢ Grout holes " , " 'I .... '--. 'J ' >-- Excavation lOr ~ __ i. , \0 open add bulkhead : i==T~~ 9 ~, \ ~ ~ , --(A) [APPCOX' access T add elfcavotiCY1 -----.~~ 3 2 1 f'tlfwater PIPe.S From~'=IOII " 9'"0"'<1 '00k hoy AIf' Chamber Surge 7O.nk upstream From bulkhead rrame :4pprox. access 1~ add excavation ):: 1 ~. Pluq desI9n "' ............. \. \. Excavation lOr /:::: ~-:::--.~ Ime ~ open adil D bul/rtJeod ~ '(Q Ad it Bul khead~ , ~ , f-t-.--+-f- " Downstream bulkMad frame eft Add ~------~--~--~ \ ~~.-~~~~-Spring line . <::J ~ 1 Excavate far ~\ :::i V - - -::7ral =-P/~ --T ''''\"\''//A_~ Approx. aCCess J ~'-O' .. \ adt! excavation f.:l--=.--",-~.,\\ 75-0' Contact grout SECTIONAL PLAN AT SPRlNGLINE 'o.! , , '0;) <::J tJ. I /1'-0" ~ 5 NTS. <::J -.!.. , ';t , .' ';t " , ID Slope 0.01 SECTION N.TS. 4 Approx. accl!'ss add ercavation ---Excovatl!' fOr 9<1fe valve 1= ===. 3 t II , II II 1/ II ,lL ,l1 7 J-4" SECTION N.TS. 17'-0' , "I-, -" 5'-0' TYP. SECT/ON 0 N.TS. !l.: t ~ .' " 2 ~ ~ ~ , t.... ........ Excamte lOr drain pipe SECTION NT S. o ........... u.s. A_Y ENGINEER DIS11UCT CORPS OF ENGltEERS ANCHORAGE, Al..ASKA _Or. r.IIP.II SNETTISHAM PROJECT, ALASKA JBL IiiIiiI SECOND STAGE DEVELOPMENT I--::-_-.::: ... .:::.==----Io:=..--CRATER LAKE ALTERNATIVE m FINAL ROCK TRAP ACCESS ADIT PLUG PLANS AND SECTIONS DrwwInw 1-SNE-88-oe c..: -18-03/40 DESIGN MEMORANDUM NO. 26 ___ 0' __ PLATE 35 D c B A .... f-- EL 155.0'---~-i iif= El.140.0' B A 5 4 8.' DRIFT TUNNEL ~ ~ w C '-METAL COtiDUIT I 2 CISTERNS I r"-LAOOER ~PLATFORM ~4 WATER PlPE9 ~ 514-DIA. V -~ PRESSURE 01 FERENTIAL GAGES ~SONK; EDtO DEVICE PLAN SCALE~ '-·'0' r--SMALL CONDtJIT CARRYING 3 I 2 129.7'. 13.4' WIRES TO METAL CONDUIT ~ EL te6"'_,.--_L 1--4~~'//~'~--------'Y'~B _____________________ ~~.#.M'~~~~" _______ EL. I .... ' -n--SONIC EOf) OEVX:E I EL. I.I."~I--:-=:;:;-________________ + _________________________ ----j _______ EL.I.I..' 1"11'- PLATFOR"'----fl ~LADDER ~ El...113.1' RANGE OF WATER SURFACE' E1 " EL 166,9' EL. 163.8'_ ". ~ ~~ ~'j,~[j~;L--------------:_------------===:;;;;~~;::=~I-::_:~---' _______ EL. 183.8' V/A'," I 13.4' .1 ~ ~ SECTION A SCALE' ,--,0' f-SON It B:tI) DEVICE EL.I ••.• • /~A EL. 181..' __ / [ ~ SMALL CONDUIT ___ CARRYING WIRES ____ --- CISTERN AIR CHAMBER CONDITIONS WITH ZERO FLOW THROUGH POWER CONDUIT GAGE PRESSURE IN AIR OiAMBER (FEET OF WATER) 600 .~ TOO 7!5Q 800 8~ 900 1025 ,-------,'----.,--,-----,----c----,-:----, r~~AL CONDUIT tw- ro """ -" ~ ~~= U, EL "6.0' _I ~~,('W.s;w 1 EL.IU.· 1 ~ SECTION c VITAL STATISTICS MINIMUM AIR PRESSURE tOEM.\ND1 • '567 FT (GAGE) MAXIMUM AIR PRESSURE (REJECTIONl • 955 FT (GAGE) L~~UY~~:EEL orOE T '::' AT MIN. POa..l • r:s~FTFT' MAXIMUM WSEL (REJECTION AT MAX. POO..)o 173.1 FT MINIMUM WSEL (STEAm STATE) 168.0 FT MAXIMUM WSEL (STEADY STATE) • 17Z..2: FT AIR YOLUME FOR STABILITY ANALYSIS • 51,000 FT' ::~ ~~~ ~g:: ~~gc:o~""~~':~'S ~:~ ~! NOTE' .THE SURGE TANK DRAWING AND OTHER INFORMATION ON THIS PLATE ARE BASED ON AN 11FT. NOMINAL DJAMETER POWER TUNNEL. -. _. Dot. I u.s. ARlilY ENGINEER DISTRICT CORPS OF ENGIEERS ~GE,'ALASI<A Appro"eeI _Or-I'!IIr.I SNETTISHAM PROJECT. ALASKA D r- c 8 SECTION B SCALE: '-.10' J).J;J I;;;i;I SECOND STAGE OEVELOPMENT 1-::----:-..,-. "'::"'--=--/-1 ::::""'"' CRATER LAKE JKL A ALTERNATIVE m 0 10 20 30 I , , AIR CHAMBER SURGE TANK ,-• 10' 1--..... _'..:.A.::S'--"S_H)c:.:.W..:.N'--~ =-1--______ --1 ..... , -.. I 4 I 3 I DESIGN MEMORANDUM 26 PLATE 36 t o C B A 5 ANCHOit UNE8-4 REO,D. (2 ... T BOW, 2 AT STERN) 5 4 SECTlOtIAL BARGE SIDE VIEW 4 LAKE SURF"'CE '" 3 3 t 2 SECTIONAL .... RQE FRONT VIEW 2 -- 1 HOPPER BARQE --Descrtption. u.s. ARMY ENGIfIEER OIS'TRCT CORPS OF ENGINEERS ANCHORAGE, ALASKA SNETTISItAM PfIO.JECT, ALASK ... SECOND ST ... GE oevB.OPIIENT ~:::--CR ... TER LAKE KE TAP CLEARING-AL TERNAT PLAN LAMSMELL METHOD -~!!i,j~Li!,~!!!l~o;;;;'-----1 ::.:::.-1--------1 ~,-,&_04 ... ___ of __ DESGIN MEMORANDUM 26 PLATE 37 o C B A o c B A 5 4 .3 '3 Guide support, TYP. steel pipe (Seh. 40) shrae k guide 3 'i @J 3"0. c. P---Sf_) frusses /; Do99in9 Ie ( (TYP. 4 corners) PLAN NO SCALe Ie corners) ~~'z~1i'~c------TS 6 '4 Framing (Sell. 40) .~~~:Si'(" TS.3'.3 Guide support, TYP. SECTION NO SCALE o TEMPORARY TR.f'·,sHR.!\CK ( Note'TraShra.ck To Be Pla.ced From Barge) Immediatel8 Mter Ta.ppinca Opera.fion 5 3"¢ Steel pipe {sen. 40) Trashra:ck gUide 4 3 2 st"",,/ frUSS~ fROCk balfs 20' /IZ'Dia,lntak.e TS3 (Seh. ~ .... \;J '\i 0- ~ .... x.3-~ 80) COt/crefe Fad~ \ " + + 'I + ;/ A \ \ + t±i 1 V 2' / I + -t + / /~-~</- \ I. \ I ! I I '" "-----~~ + +i 16~ ~ . .!. PLAN Scale: I'~ 3 '-0" I 2' ' i ~ t----I- kb~ ------------ ~ -Bar,J-j 6J .3" o. c. '- t 20' /Bar 3 • j 6J .3'0. c. , I 12 ' I 13 ' .I SECTION 0 Scale: 1'= .3'-0' PERMANENT TRASHRACK (Note:Tra.shra.ckTo Be Pla.ced After\ l La.ke Dra .. Do .. n I 3 t \ VROClrbOlf I \ GRAPHC SCALIE: r· S'-o· 2 _ ....... ........ u.s. ANn ENGINEER DISTRICT CORPS ~ E"G~RS ANCHORAGE., ALASKA _107> r.III'I SNETTISHAM PROJECT. ALASKA C.AME.I(O IiiIiiI SECOND STAGE DEVELOPMENT 1-----107>-. ----'----.< ~:::--CRATER LAKE EEL ALTERNATIVE PRIMARY TRASHRACK """""" Code:I-5f£-96-0&f9-03I21 DESIGN MEMORANDUM NO.26 ___ 01_- PLATE 38 o c B A o c B A 5 4 I INTAKE BULKHEAD DETAIL SCALE: I·· 4'-0· SHEAVE SUPPORT 2'(1 WIRE ROPE (MARINE TYPE) 4.5' QI SHEAVE / / / ...- ./ / CLOSE INTAKE BULKHEAD _ ~12'QlINTAKE "-" " " \ \ \ \ ~~~~~~~========~======~~PEN : \ I 5 OPEN \ I SOCKET \ I I ' \ I , / "-"- ........... ----- 25 ..;.;SE;:,;:C:;-:,T:=-;IO::-=N..,.,.......,.,:-® SCALE· I". 4'-0· ,I 4 41 °/. \.O'?~· ~S ~~ , ""0(''1-, 'f'" , , \ ' , , , , \ \ ~~S BULKHEAD OPEN CABLE it> N PLAN@,-EL.1038' 3 EL.IOI' V LAKE TAP EL.BOO 16' BULKjiEAD CLOSE CABLE CONTROL STATION 45' GEAR AND MOTOR CONTROL STATION 12' GEAR AND MOTOR CONTROL STATION 1038' PRIMARY ROCK TRAP 2 ACCESSADIT _TO POWER SOURCE INTAKE BULKHEAD PROFILE AT LAKE TAP SCALE: 1".50'-0· ~I ~! f-ol,~--t 22 SPA6\lI'-O· "22' L 1lz==ll=jrii==zJ.'=="9 TRANSVERSE SECTION 1 L ~ 12'-6" I 12'-6" t--------j ICSUtU~. 8 LONGITUDINAL SECTION SCALE:I"·2'-0· ~ 0' 2' 4' --j GRAPHIC SCALE: I". 2'-0' ~ o' ~ I' -. j GRAPHIC SCALE' I" '4'-(/' DI 0' D' 10' "III.I::.-I::..t::::=~_~· GRAPHIC SCALE:lo,.,'-O· .' O· " IZ' \000 __ I GRAPHIC SCALE"',.'-O' --- u.s. ARMY BGNE£R DISTRICT CORPS OF EHGItEERS ANCHORAGE, ALASKA _... r.III'I SNETTISHAM PROJECT. ALASKA SCALE' I" .60'-0· ---'-----'/r---'--- I-::-G_"'_M:-£_~ __ --lliiliil SECOND STAGE DEVELOPMENT -.... -:c.:..""?' CRATER LAKE ~ 3 2 t ALTERNATIVE PRIMARY TRASHRACK BULKHEAD -~~~~:::JD~~~-~~~r------~ _--_0'--- DESIGN MEMORANDUM NO. 26 PLATE 39 o c B A 5 I 4 I 3 I 2 1 LIST OF MATERIALS D G.ATE-OPEN -GA"TE-C.LOS"P ITEM NO. ITEM QUANTITY STOCK SIZE D <:..A8Le -C.A~LE R<:"Llc.<:" (,,, ~, <;;\ j~£L.\( A.L ,'" 2-fl...ATI.:l .38.S": 1 --'" MO'Oi !'.EvE :'B~E "SO p"", 5'1011' Z03V/4. ~ ;~ "'-10 " l=LEltJEt..E" (.O>JPI.~I('" ,,>TO T< C_'''' " C.Ai~ PO~'''\ON, l...",O\<-A"O~~ E /M.II SWlrc"" I ...r Po-1M ", 3' '- ~ fi DR. M ·HAFl UNS ~I01-';' Z. 10"4 1 1 1 1 1 ~ 1 1 __ 7 ... v .< O!~O ( -z. z.. y~ "11: z.'z. '~}II<. -z<CI " 8 P'c Ow 6<.0(1 G-o 9 fZ..€VE R!i€~ "'E-ARS,I T RA-, 1:1 , ~ I v, .. " ",0"'" "2."-x 17 Z. ,,~o ' -'-~~ ~y /D p, "" ("_~ ... K......... "-.r. 7: I -12 ELE(''-'''(.Al-LY 1'-E.>'£ASEi) c."-A .. .eo - tt--" -4 ~~ NOTE: SEE PLATE 39 cv=----=: BULKH"'-"O I?E'TAIL<;, ~ I--Q CONTROL STATION « C C @ t:.L. 1040 V) V) w U u I « r----- PRII'-1ARY TRASHRUK BUL-KHEAD HOIST PLAN 5CAL..e.~ 3/,,,11_1'-0" B B _ ....... -Descriptions ..... Appro .. " -- I U.s. AMlY ENGINEE:R DISTRICT CORPS Of ENGINEERS AIICHORAGE, ALASKA ~br. m SNETTISHAM PROJECT, ALASKA A SRM SECOND STAGE DEVELOPMENT A o......b,.: ::",="""'cRATER LAKE SRM et1 b't 1/:." .~ •. : AL TERNA nVE PRIMARY ,.: 0 , • , ,. cHiE. NECH. 'EC . TRASHRACK BULKHEAD HOIST ~.----.. -.. -.. S?!~ Scale: 3""6'-0' -..-..... 3" ::: 1<::./-0" CHI F. DE~. 8R. D ••• : -, ~»'ffv:C -...... Ih_ 0' Code:I_SHE-K-O~t9-00n 5 I 4 I 3 I 2 DESIGN MEMORANDUM NO. 26 PLATE 40 t D C 1400 ~ i: 1200 « 0 .... t) "' 3 1000 0: Q. Z g 800 « > "' ...l "' 600 400 B 200 A 5 PRIMARY ROCK TRAP I '+00 NOTE: .,-/ HILLTOP FAULT K)+OO 1. TUNNEUFAULT INTERCEPTS ARE STRAIGHT LINE PROJECTIONS OF APPARENT DIPS. DIPS NORMALLY VARY. PROJECTIONS ILLUSTRf'TE THE LlKEU HOOD OF AN INTERSECTION AT TUNNEL ELEVATIONS. EXACT LOCATION' OF INTERSECTIONS CAJINOT BE GUARANTEED. 5 DH-III SECONDARY ROCK TRAP 15+00 4 \ " \ \ 2~+OO \ " PLAN ,I \ 30+00 200' I PROFILE 9 290 ' SCALE' 1·.200' 3 t 3e+OO GROUND SURFACE QUARTZ DIORITE GNEISS, GRAY, LIGHTLY WEATHERED, HARD GENERALLY MASSIVE _Ba. ~Qtz. -It.,Fr. Occ. SI. Mod. HI. Ct. AI. Gr.AI. S'r. s..-. POWER TUNNEL 4to+oo Cuortz diorlt. Qneill Granodiorite/Granite Balolt Quartz Joint. FrClctur. Shear OccCllionol Slightly Moderately Highly Crushed Altered Granodiorite, Ahered Strin9l' Serlcl •• 4e+OO LEGEND Hi. 4 0"". F, Sfn. FeS Co. Ch. CI. Woo. 2 TLiNGIT FAULT \ \ \ \ \ \ \ \ \ \ 50<00 High Angle Open Iron stolnl Pyrite \ \ \ \ \ \ \ \ \ Corbonat.' (Colcit.) Chlorit. Sllckenllde. Drill Hole Clay Wea'tMred 2 \ " " \ \ \ \ \ " \ ".00 , , s_ " " " , 1 , \ "~ , \ \" \' \ '" \ Bo. " \ "~ \, \ \ { ., \\ \ " \ " \ " 60+00 \ '\ \ Bo. \ F •. ~, A. ~" \ " \ \ \ \ 65+00 68.75 .......... DHcriptiona - u.s ....... V ENGINEER DISTNCT CORPS OF EHGIfiEERS AIICIIORAGE, AU"" z o ;:: _0.. ..,...,. SNETTISHAM PROJECT, ALASKA I-::-_P_AT ___ ----l loliil SECOND STAGE DEVELOPMENT -by, GEK -:::;e.. CRATER LAKE GE'OLOGY PL.AN AND PROFILE POWER TUNNEL --_ .. _- DESIGN MEMORANDUM NO. 26 PLATE 41 D c B A 1400- 13!50 - D 1300- 12~0- 1200- 1150- 1100- 1050-... ... C :i 0 >:1000- "" > W ..J w 950- 900~ 750- B A 5 LAKE SJRFACE \l P,.MARY ROCK TRAP ElEV.IOI9! 4 CLIFFSIDE AWLT DH-I02 I \ { I f J If ( f{~ { II .. ~ ... </-. ~. 0."" ~ d-t..- <J' (F' • 0" \ \ \ \ \ \ \ \ \ \ GATE STRUCTt..AE GATE SHAFT . ", . ./' ~, -. -~ ~(. \ ;' ~"A' >-4--\--"""" . ,10. i:~: ==============~~===;;=f.~ t TUNNEL STATION POWER TUNNEL !, " - l SECONOARt ROCK TRAP ;; ~~ Co. L---7~~~~-~B~+~00~---~9~'0~0~---~~~+~00=----~I~I+~00~----1~2~+OO~---~13~+oo~--~-.:r~~1~4=+OO~---~~~·OO 7~0 _ ; LAKE TAP AND GATE STRUCTURE SECTION SCALE: I' • 50' 5 4 3 3 t ott o· !wow .... 2 SECTION A SCALE: 1"-50' 4142 "" 00' . d ,-. sct'-o· 2 1 -1400 ) \ -1350 ) \ ) ) ) -1300 \ -1250 \ ) -1200 ) -1150 I -1100 j 1 -1050 ... ... :i -1000 ~ ... "" > W ..J -950 w -900 -B50 -BOO -750 -700 -650 SEE PLATE 41 FOR LEGEND ......... r.:-_-_-----:.-.,----1 <.AI<.. ........... Description • Oat. A.pproved U.S. AMIIIY ENGINEER DISTRICT CORPS Of ENGINEERS ANCHORAGE, ALASKA m SNETTISHAM PROJECT, ALASKA SECOND STAGE DEVELOPMENT ':.~ CRATER LAKE GEOLOGY SECTIONS NO. 1- LAKE TAP & GATE STRUCTURE f-Sc_a'_"'---,1_'_=,..:5::..:0::..:'_--1 ~~= f-------~ r.~~~='--__1 Date: Ap!'1'."'Jl"~ ~_Dr.',.,..t... Dnlwtng 1-SNE-96-01 CodtI: - _ ...... __ 0' __ DESIGN MEMORANDUM NO. 26 PLATE 42 D c B A 5 4 DH-IOS D c o-POWER TUNNEL. SECTION B SCALE! 1-.50' 41 B A I POWER TUNNEL • IN'I. EL. 327 SECTION SCALE: I '!IO' 5 4 IOSO 1000 950 900 850 z o 800 5 .. ~ 750 700 650 600 1200 1150 1100 1050 950 z o j: 900 ~ 850 750 700 650 -' W 3 ) \ 3 t 2 TL.INIlIT \ FAULT SEE SECTION @ 1&)0 ~ \ \ \ \ \ \ \ ) \ \ \ ) \ \ \ \ \ ) \ ) \ ) 1250 IZOO TSIMSHIAN FAUL.T 1150 1100 DH-I06 1000 950 900 \ \ \ \ \ \ \ \ \ \ 850 SECTION 0 SCAL.E'! -so IIOTE: l. FAUlT 11!TaC£l'T$ AlE. STMIGIfl LINE PROJECTIONS OF API'AAEJIT DIPS. DIPS.lIOIIIW.lY VARY. PROJECTIONS IllUSTMTE lIE L1w.I1Ql!l OF AI! IITEItS€CTIOII ~l TlJNIIIl ElEV~TIONS. EXACT lOCATlOII OF lllEIISECHOIIS CNmOT 11£ GUARNlTEED. td fI low wi "" . ~. l~:': \ ' +'...- • ,POWER TUNNEL. . I IN'I. EL 301 800 750 SEE PLATE 41 FOR LEGEND ........ --_ . u.s. ARMy ENGINEER Dt$TRlCT CORPS OF ENGINEERS ANCHOPtAGE. ALASf(A -"', r.III'tI SNETTISHAM PROJECT, ALASKA l-_PA_._T ___ --I1iiIiiI SECOND STAGE DEVELOPMENT -Or. '/It:;:::'.'::" CRATER LAKE JKL GEOLOGY. SECI.I.ONS .NO. 2 F===~~-+~ ___ M==IS~C=Er=LLANEOUS ..... , 1"'50' ....... ~~~~~~o;,;;;----'----'-'--I ~ J-------I F ~: I-S.-96-01" Code: 01-0-". ___ 0'_- D c B A 2 DESfGN MEMORANDUM NO.26 PLATE 43 D c B A 1100 1000 900 80 \ 700 \ \ ~ ~ 600 \ M ) ~ \ z o ii ,. ... .J III 400 200 100 \ ) ) ~ ~ ~ 5 4 3 GROUND SURFACE ;----,--8ASAl.T DIKES LARTZ DIORITE GNEISS E"STOCK TUNNEL PLUG 72>00 73<00 74+00 PROFILE SCAlE: ,-• 50' 2 PENSTOCK FAULT 75+00 76<00 77<00 1 NOTE' 1, TOOEVFAULT INTERCEPTS ARE STRAIGHT LINE PROJECTIONS OF APPARENT DIPS. DIPS NORMAllY VARY. PRDJECTlOHS ILLUSTRATE THE LlKELli100D OF All INTERSECTION AT TUNNEL ELEVATIONS. EXACT LOCATIO!! Of INTERSECTIO~S CAtlHOT BE GUARANTEED. SEE SHEE;T II FOR LEGEND !K>' o· _.0001 "",' 1 '\ SEE PLATE 41 FOR LEGEND -........ ......... Oate Ap~ U.S. AAMV ENGINEER D4STRtCT CORPS OF EMGINEERS AHCHOft.AGE. AUSI(A D c "";'.:';"-" m SNETTISHAM PROJECT, ALASKA A r-:=;::-:----j us...., ..... SECOND STAGE DEVELOPMENT --y: .. -CRATER LAKE )~ GEOLOGY PROFILE PENSTOCK ___ 0' __ 4 3 2 t 5 __ ._._ .... ~ ______ -L ____ -=-_______ ...l-_____ -=:-______ -L. __________ --=--=-::..:..~=:.:.;:.,;::..:;~=-=-'-"-'-'-"-'-=-'-_____ -" PLATE 44 o 5 ,:~.<~ -". °0 ~ CRATER .- LAKE :; EL.IOI9 LAKE TAP 5 2 t 1 o c B ------_ .. ...... __ 0' PLATE 45 5 I 4 I 3 I 2 1 ~ ~ c AREA IN 100 ACRES Q ~ DRAINAGE AREA IN PERCENT OF TOTAL, 11.25 SQUARE MILES 4 3 I U 100 90 80 70 60 50 40 30 20 10 0 1300 I I I I I I I IliDO • 0 -. 0 1£ L -----I-/ -~6 0 01 .. .... r HIGHEST ELEVATI N IN W~ ITERSHEI ""7 IZOO 1200 ... I-~ V ... ... ~ v ... 0 -:I ., j:! 04 '----------~ ~ z r-c c ~ - S'f°" Q ., I--~ :> ----U 0 r--.. 1100 .......... V 1100 a :z: .n7l" ~ > .... MEAN E P< f ~ ~ z ~ I-~, -... ~2 > ~ t ~ 0 .... ELEVATION 1017 01 .. ~ MAXIMUM POWER PO< / .. > ~ ;-..... ... .... .... :I 1000 1000 11.1 ... -::> 0 \ ... .... T\A\L LAKE S RFACE E L. 101 • .... 0 ... c / 0 C Q g ~ c .... U I--z w 5 10 -. ~ 0 DRAINAGE AREA IN SQUARE MILES ABOVE A GIVEN ELEVATION a: .... 11. .. ~AINAGE AREA VS. ELEVATION ABOVE CRATER LAKE OUTLET > .ao'" ... 900 V \ .... > ... 0 01 .. .... l-I -... ... I ... -~ -800 100 z '/ ~ .... .. > -... .... ... 700 700 V B -B 600 I I I I I I 100 0 5<> 100 15<> 200 250 300 350 STORAGE IN 1,000 ACRE -FE ET SURFACE AREA -STORAGE VS. ELEVATION CUIWa --............... D ... _ .. -- I u.s. ARMY ENGItEER DISTRICT CORPS OF ENGINEERS ANCHORAGE, ALASKA A ;~~"", ~. m SNETTISHAM PROJECT, ALASKA A SECOND STAGE DEVELOPMENT -..., ~::::.:::-CRATER LAKE ~w "" l1.=-.~":: SrQRAGE~ELEV. .AND ~EA ELEV. CURVES ~.". -AS SHOWN -. .L. ... --. .. ---u~ ~'~-o~J~1 -af 5 I 4 I 3 I 2 'DE~ MEMORANDUM 26 PLATE 46, t 5 4 I 3 I 2 I 1 RESERVOIR ELEVATION -DURATION CURVE RESERVOIR INFLOWS -MONTHLY DISTRIBUTION 1914-1968 1050 1914-1968 1000 i MAXIMUM 1025 AVERAGE D D 900 MINIMUM E 1000 ~ L ~ 800 E ~ I r--V 975 A -------- N 700 T F r--.--- I 950 ........... L 0 ......... ~ 0 600 .---N W r-- 925 I ~ I 500 ,-----N N f--900 \ 400 F C - E F .--- E 875 \ S 300 T ,---r--850 1 200 825 I gQD 100 800 tm:J ~ C C 0 I'll 20 30 40 50 60 70 80 90 100 I I I I I I OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP AVER PERCENT OF TIME EXCEEDED MONTH f--I-- HEAD DURATION CURVE RESERVOIR INFLOW -DURATION CURVE 1914-1968 1914-1968 1040 800 1020 8 I---700 8 1000 ---I-----1\ 980 I 600 H ......... '-...... N \ E 960 F A -------- L D 0 500 " 940 ~ W ~ I I'-... N 920 I 400 -. -.......... ~ N ~ ....... --..... -... -F 900 f--E "" C 300 E F ~ T 880 '\ S 860 200 i'-. '\ "" 840 I ~ 100 ~ u.s. ~y ENGINEER DlSlWCT ......... CORPS OF ENGINEERS 820 I'--AIICIIOIIAGE, AlASKA 0 _ ... \. m SNETTISHAM PROJECT, ALASKA A 800 \) .. , SECOND STAGE DEVELOPMENT A 0 10 20 30 40 50 60 70 80 90 100 0 10 20 30 40 50 60 70 80 90 100 -... r::;:--CRATER LAKE I) \IV~ ¥ONTHLY INFLOW PERCENT OF TIME EXCEEDED PERCENT OF TIME EXCEEDED l:r ...... J;lISTRIBUTIO.N& . ~. ELEVATION DURATION CURVES ~ ... -,uSHOWN -~."':;'6L ---.-~~. ~ I-!M;-M-CN--_ .. -Code; 01-0112 5 I 4 I 3 I 2 :lit! f~28 PLATE-47 t 5 4 .,00 ,.. .. 0 700 e .. o D eoo .... 0 ~ .. 00 ~ 4S0 ~ 400 I N 360 ~ 300 2S0 200 lS0 100 60 0 31 MONTH CRITICAL PEROID 1040 C 1020 1000 .. eo ~ .. eo i "40 920 N I .. 00 N ~ .. eo ~ 1\ \ \ \ \ \ \ 1\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 1\ \ \j \ \ \ " \ \ Ii \ ~ V .. eo ~ "40 ~ .. 20 "00 B 1& 17 18 , .. , ... 13 ~ 12 11 I 10 N co ~ & t:l 7 H 8 os ... 3 A '" 0 5 4 3 \ r 1\ ~ '\ \ II \ \ \ \ \ \ \ I 1\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ V \ ~ \ V V V V \ V V V \I , WATER YEAR (OCT 1 TO SEPT 30) 3 t 2 "\ \ {I\ ~ \ \ 1\ \ \ \ \ \ \ \ \ \ \ \ ~ V \ V V V 2 II 1\ I \ \ U V 1II7lE: M.L aIMS III TltIS PlATE lIE. IASfI III TIE FilIAl f'OIjER 1I£6IIUf\1Il STIIlIES _ITIt A IW(IIUI PQIER POOL EL£VATIIIl OF 1017 JUT ~ "1.llUI f'OIjER POOl EL£VATIIIl OF 820 FEET. M.L EL£VATJOIIS ME lASED III I'IIIlJ£CT MM. -. -ptiona De'e Approved u.s. .... , ENGINEER DISTRICT CORPS OF ENGINEERS _GE,ALASKA _0 .. SNETTISHAM PROJECT, ALASKA seCOND STAGE DEVELOPMENT :l::-"""" CRA TEA LAKE - D. -"'" \)w.M. RESERVOIR REGULATION YEARS 1914-1941 ___ 0'_- PLATE 48 D c B A 5 4 "'00 750 700 660 D .. 00 660 ~ 600 H 460 (l ~ 400 r!. 360 ~ S 300 260 200 150 100 50 0 1040 C 1020 1000 .. eo ~ .... 0 ; .... 0 i .. 20 N r!. .. 00 ~ .. eo 1\ ~ ~ 1\ r II 1\ ~ ~ J 1\ \ \ 1 \ \ ~ 1 1 1\ / \ 1\ I~ \ \ \ \ \ \ \ \ \ \ \ I \ \ \ \ \ 1 \ 1 \ \ u \ V ~ \ \/ \ \ ~ , \j ~ \ , \ \ .... 0 .... 0 l 620 "00 B '''' 17 16 115 14 13 I 12 1 1 r!. 10 § .. '" tJ 7 H 6 .. 3 A 2 WATER YEAR (OCT 1 5 4 3 ~ {~ r 1\ 1\ 1\ ~ \ \ 1\ 1\ \ 1 \ \ \ \ \ \ 1 \ \ \ \ \ \ \ \ V \ \ V \ ~ u ~ V 310) 3 t 2 1\ 1\ 1\ 1 \ 1\ II \ \ \ \ \ ~ \ \ \ \ \ ~ j 2 1\ r U ~ 'V ........ .-rE: MJ.. t1IMS 1* 11I1S tiuTE lIE. lASED 1* TIE FIlIAL I'0IO _TlI* STlIIIES WITH A 'WUM POIIEIt POOl ELEVATlI* (If 11111 fEET AA) "IRllUI POIO.POOl EllVATlI* OF 820 fEET. MJ.. ELEVATlI*S fCE lASED 1* PIIOJECT DATIII. -o.t. Appro,," u.s. AAIiIY EJ«:i8IEER DtSTWlCT CORPS OF ENGINEERS ANCHOIWlE. ..... SkA D c B SNETTISHAM PROJECT, ALASKA A SECOND STAGE DEVELOPMENT '::;--CRATER LAKE RESERVOIR REGULATION YEARS 1942';;1968 ___ of_·_ PLATE 49 5 I 4 I 3 I 2 1 PENSTOCK DIMETER N FEET EClUVAlENT DIMETER-uu£D POWER 'fI..N.El.... 45 5.0 55 ~ 65 7D 9 10 11 12 13 14 I I I I I I I I I I I I ,.qres, I 1. CXJNSTR.CllON COSlS _ BASED 00 SEPlEMlER 1984 ~ 350 r-I 1100 r-2. ALI. COST""'<1O BEEN AtHW..lZED USN:l 3 1/8 PeJUNT I D1SCOlHT RA 1£ D D I 3. TOTAL COSlS Ea.JAl. AVERAGE NHJAl. VALl£ c:F TOTAL COST' IEAOl.OSS PLUS A\/8lAGE NHJAl. COSTS. I • 325 ~ -J;.1oST ECONoMICAL DIAMETER 100> r- rOTAlCOST -3JO r-CONSTRUC"OON COST-900 -- 27~ r-Em - -MOST ECONOMICAl DIAMETER .,.,.... '---.:RUB8ER TRE EXCAVATON ECllFMENT C C 250 r-700 -CONSTRUCTON COST rJ) U) a: a: ~ :5 22S r-8 Em - -z z - 8 ~ S:! x x rJ) ~ I- rJ) 125 r-8 500 -8 ...J :;J. « :::> ~ z z z « « B UJ I~ B c:J « 100 r--a: ~ « 75 -150 r---s ....... ..... -Dot. Approved -VAllE OF I-EADlOSS - VAllE OF l-EADLOSS 50 -100 r- I u.s. ANI' EMGftrEEA DlSTfUCT CORPS OF EMGDEERS ANCHORAGE, ALASkA 25 -STEEL PENSTOCK V S. COST 50 r-l.N.N:D POWER TlN£l... Dn6rgMcI br-ED sr£TllSHAM PRo.ECT, ALASKA A EClUVAlENT DIMETER v.s. COST O.~ CRATER LAKE A Dnwn by; us_eaoo . FAST STAGE DEVELOPMENT .. -V.H.S. TUNNEL AND PENSTOCK ~i1'~1-OPTIMIZATION I COMPARATIVE -COSTS 0 I I I I I I 0 I I I I I I ~~ ...... ASSHOWN -4.5 5.0 55 60 65 7D' 9 10 11 12 .13 14 ... ..- 1'1'-Dote, ---PENSTOCK DIMETER N FEET EOUVALENT DIM£fER-U'.I..I POWER TlN£l... r. '.L, .,1;. ~ --...... .1 Code: -SM: ....... l ... 'l4 5 I 4 I 3 I 2 . DESIGtI MEMORANDUM 26 PLATE 50 t 5 4 3 2 EQUIVALENT DIAMETER -UNLINED POWER TUNNEL 375 o o MOST ECONOMICAL CONSTRUCTION COST :m MOST ECONOMICAL 800 DlAMETER-- ---DIAMET/;/L ___ CONSTRUC~ COST ICIES: C MOSTECONOMICAL DiAMETER 1. CXlNS1IU:lION = _ &.SED ON SEPIB&R 1984 P!EES-C 2. AU. COST HAVE BEe< A>N.JAUZm 1S(l3 1/8 P13'I::eIT 700 Z75 01SC0l.NT RATE. 3. TOTAl. = EQ..W. AV£IW3E. """-.I.\l. VAlLE OF I£ADLOSS PLUS AV£IW3E. """-.I.\l. COSTS. C/) (/) ~ II: « 600 2SO --' --' .... 0 ~ 0 0 ;;;; § 0 a X ~ f!? X (J) (J) 500 0 225 L.E<EN) I-0 (/) 0 --' 0 0 '" "" RE. COST ESCAlA T10N 0 « --' i • • ... 1."" RE. COST ESC«.AlION « ::> z ~ -9-i?--.:r 2. '" RE. COST ESCAlA lION ID.R.'.J B Z B « UJ 200 ffi 100 CJ « > II: « UJ > « 150 75 --V ALI..E OF t-EAn.OSS s ...... --..... Appro¥ecI 100 V ALI.£ OF HEADLOSS 50 u.s. A_Y EMlM;EA DISTRICT CORPS Of ENOIlEERS MCItORAGE, ALASKA 50 25 -.." m SNETTlSHAM PRo..ECT, AlASKA A UNLNED POWER T\.N'olEL Sn:a.. PENSTOCK V S. CQST'-\)~ CRATER LAKE A EQUIVALENT DIAMETER V.S. COST 0....... II" us....,,,,",,, FRST STAGE DEVELOPMENT .. -V.H.S. SENSITIVITY ANALYSIS PENSTOCKtJo POWER ruNNEL OPTIMZA N 0 0 _10,· AS SHOWN -10 11 12 13 14 ... ..-- ~......., Dotr. EOUV ALENT DWv£TER-I..N..N POWER TaN:!... PENSTOCK DIMETER N FEET ---_ .. -eo.: ........... ...oans 5 4 3 2 PLATE 51 t (- EXHIBIT 1 INSPECTION REPORT EXISTING SNETTISHAM FACILITIES JULY 1983 ALASKA DISTRICT CORPS OF~ENGINEERS NPAEN-PM-C MEMORANDUM FOR RECORD 12 July 83 SUBJECT: Snettisham Hydropower Project, Long Lake Power Conduit and Powerhouse Inspection 1. On 21-22 June, an inspection was made of the Long Lake portion of the subject project. The inspection afforded the unique opportunity of witnessing the effects of ~O years of continuous operation of a Corps- designed hydropower facility, at a time when design is being prepared for the second phase of the project. The attendees were as follows: Hod Moore Joe Gianotti Pete Williamson Pat Gal braith Joe Leeak Roy Camaro Dave Mierzejewski NPAEN NPAEN-DB NPAEN-FM-G NPAEN-FM-G NPAEN-DB-ST NPAEN-DB-ST NPAEN-H-HY Joe Wexler Jeff Johns Wayne Rowe Bruce Munholand Lew Gustafson Ron Mead NPAEN-H-HD NPAEN-H-HD NPAEN-PM-C NPAEN-PM-C NPDEN-GS WES Messrs. Gordon Hallum, Tom Spicher, and Ralph Alps of the APA were principally responsible for coordinating and conducting the inspection tour. The log of a follow-up phone conversation with Tom Spicher is attached as inclosure 4. 2. Long Lake. The lake was down approximately 70 feet from the spillway crest. Tom Spicher indicated in subsequent conversations that the lake is filling rapidly. 3. Dam and Weir. Other than the presence of small pieces of wooden form still embedded in the structure, the concrete for the weir is in good condition. There is a calix hole located approximately halfway along the weir and 20 feet downstream that is still open for a depth of approximately 30 feet. 4. Diversion Tunnel. The diversion tunnel slide gate is still jammed in the gate slot in an open position. The tunnel could not be inspected because a rock dam in the diversion tunnel outlet channel has caused the accumulation of water to a considerable depth. The reason for the rock dam is unknown. From a distance, there does not appear to be any structural failure. 5. Tunnel Dewatering. a. The bulkhead gate is not usable because the rubber seals are badly deteriorated. The deterioration was likely caused by the diesel fuel used to prevent ice from forming in the bulkhead slot during the winter. NPAEN-P~l-C SUBJECT: Snettisham Hydropower Project, Long Lake Power Conduit and Powerhouse Inspection b. The slide gate was closed and there was some leakage around it. There was a constant flow of water approximately 5 inches in depth out of the 12-inch diameter pipe used for draining the access adit drift tunnel. The source of water was primarily the leakage around the slide gate, as there was no appreciable leakage in the tunnel itself. c. The 8-inch bypass in the powerhouse system was used to drain the final portion of the power tunnel and the penstock. Draining through the turbine was stopped when governor hunting began and turbine speed dropped below 450 RPM, which is approximately the minimum speed necessary for lubrication. d. Dewatering of the power conduit spanned the time period from 0800 hours on 18 June to 1400 hours on 21 June. 6. Inta ke Structure. a. The intake structure was inspected down to the level of the slide gate bonnet cover. No damage or irregularities were observed. However, Gordon Hallum said that when power was lost to operate the sump pump, the intake structure dry well filled with water to the lake level. The level of water in the dry well seemed to remain in equilibrium with the fluctuating lake levels. b. The intake channel and trashrack were inspected by three scuba divers. The concrete was in good shape, and the trashrack and intake channel were found to be free of debris. c. The powerline to the gate structure is disrupted every winter and needed to be repaired to provide lighting to the gate structure for the inspection. 7. Power Tunnel. a. There is very little dripping or leakage in the power tunnel and no evidence of distress whatsoever. The concrete and the rock are in excellent shape. b. The entire power tunnel is free of rockfalls. In a few spots there are some gravel and silt deposits. c. The walls and ceiling of the power tunnel have a thin coating of fine glacial flour silt adhering to them. .' .' NPAEN-PM-C SUBJECT: Snettisham Hydropower Project, Long Lake Power Conduit and Powerhouse Inspection 8. Shotcrete. a. In a few places (approximately station 81+00), the experimental shotcrete lining is peeling off in large chunks. b. At the time of placement, the shotcrete, which utilized approxi- mately 3/8 inch aggregate, was sprayed over rock bolt plates without any reinforcing mesh. 9. Rock Trap. a. The rock trap is virtually clear of any gravel, sand, and rock. b. Sediment samples were taken at stations 78+50, 81+00, and 82+78. The results are shown on inclosures 1 through 3. c. Rocks up to approximately 1/2 inch in diameter (may be larger) were found deposited on ledges and outcroppings near the penstock entrance approximately 4 feet above the floor of the rock trap. 10. Surge Tank. a. The surge tank was viewed from the drift tunnel because there was 6 feet of water in the bottom of the tank. b. We were told there is no problem with rock fall in the tank. c. The surge tank appears to have been overexcavated at its base as rock bolts extend about 4 feet horizontally from the rock surface in this area. d. The steel plate for the surge tank orifice is covered with a buildup of barnacle-like deposits that can be easily removed by hand (not tightly bonded). They do not seem to have a detrimental effect on the steel plate. The deposits appear to be a result of chemical action between the steel and the water. 11. Penstock Trashrack. Approximately 15 percent of the trashrack was clogged with grass, with the bulk of the clogging toward the top of the rack. Structurally, the trashrack is in sound condition. 12. Bifurcation. a. There is considerable peeling of the vinyl paint upstream and downstream of each spherical valve. Tom Spicher attributes this to poor application technique, probably because the steel was near 40 degree F when application was made. NPAEN-PM-C SUBJECT: Snettisham Hydropower Project, Long Lake Power and Powerhouse Inspection b. No other penstock sections experienced peeling. c. A 0.1 cubic foot deposit of silt was observed on the penstock invert just upstream of the bifurcation. 13. Draft Tubes. Slight cavitation was noted at the pipe openings into the draft tubes and in the draft tubes where there is an irregular surface from welding. None of the cavitation is serious enough to warrant repair. Ralph Alps believes most of this cavitation took place in the early days of operation when there was low demand and low flow. 14. Scroll Cases. The leading edge of the first stay vane showed considerable cavitation, with the remainder of the stay vanes showing only slight pitting (up to .1 inch deep). No other damage was observed on the scroll cases. No damage was observed on the exterior faces of the guide vanes. 15. Turbines. According to Ralph Alps, the turbine runner blades are checked yearly and there has been a slight "frosting" on the blades but no cavitation damage observed. 16. Instrumentation. a. There is very limited space in the powerhouse for an acoustic flow meter. This will have to be taken into consideration when designing the Crater Lake instrumentation. b. Tom Spicher indicated that all the piezometers behind the slide gate in the intake structure are plugged. c. There are piezometer rings in the penstock at station 94+25 and 93+25 to be used in conjunction with Gibson tests. These piezometer 1ines~ which enter the powerhouse near the spherical valves, should be used ;n any future hydraulic loss tests. d. In light of the condition of the upstream piezometer rings, Tom Spicher is concerned about the adequacy of the study and report made by Waterways Experiment Station on the head losses in the tunnel. The studies were also made while there was a low power demand. Apparently, the people making the study were unaware of the piezometer taps in the bifurcation and penstock (referenced above) that were available and the conditions of the piezometers at the intake structure. 17. Valve Room. The valve room has water dripping from the ceiling at the location for the third spherical valve and the maintenance area at the same end of the valve room. .. .. NPAEN-PM-C SUBJECT: Snettisham Hydropower Project, Long Lake Power Conduit and Powerhouse Inspection 18. Powerhouse. a. Generally, the powerhouse is in good contition and housekeeping appears adequate. b. According to Joe Gianotti, there appears to be less leakage into the powerhouse now than 10 years ago, indicating that the rock seams have tightened up a little over the years. c. The powerhouse crane is not connected to the standby power supply, requiring a jury rig mechanism to operate the crane when the generators are shut down. 19. Machine Shop/Erection Bay. a. Located in the erection bay are two lathes, two drill presses, one power hacksaw, a grinding wheel, several work benches, and tool bins. APA says they need this equipment and a machine shop space adjacent to the erection bay to fa~ilitate routine maintenance of the powerhouse equipment. b. APA proposes that a machine shop be built by enlarging the 'Crater Lake power tunnel access adit with a drift tunnel that connects to the existing erection bay. The drift tunnel should be of sufficient size to allow a pickup truck to pass through. The adit would be used as the machine shop area. In addition, an exterior adit door, lighting, heating and ventilation would be required. 20. Tailrace. The Alaska Department of Fish and Game (ADFG) has put in self-regulating, irrigation-type gates in the tailrace to maintain an essentially level tailrace pool and to keep out salt water that would otherwise enter with high tides. They did this to provide a constant source of fresh water for their adjacent fish hatchery. This essentially holds the water level of the tailrace above Elevation 11. 21. Transmission Line. a. Gordon Hallum mentioned that the tower that went down a little over a year ago on the ridge above the east cable terminal building was caused by the failure of a guy. The guy has been replaced and the tower repa-ired and reerected. Apparently, the damage to the tower was minor. b. Gordon Hallum also stated that APA spent approximately onehalf million dollars about 2 years ago to remove the tower at the location where ~ previous tower was downed by an avalanche years ago, and moved the adjacent tower toward the location of the removed tower; essentially replacing two towers with one tower and increasing the two spans so that they now have no tower in the avalanche path. This has given them no trouble since. NPAEN-PM-C SUBJECT: Snettisham Hydropower Project, Long Lake Power Conduit and Powerhouse Inspection c. The APA line crew was checking the transmission line for loose guys, wear on insulators and hardware, and the general condition while we were at the site. d. Gordon Hallum stated that APA has waited years for Bonneville Power to receive fun~ing to run experimental tests on the abandoned transmission line on Salisbury Ridge. APA intends to remove that line next summer. They lost one of the towers on that line last winter. Much of the line still has the conductor on it. e. The new steel towers in the relocated portion of the transmission line are almost impossible to see because they blend so well against the background, whereas the old green colored aluminum towers are more visible. 22. Permanent Facilities. The transmission maintenance building, formerly the resident engineer office, is partially used for project office, storage of lumber, and other incidental items. Some rooms are unused. The warehouse building is being used for warehousing and main- tenance of vehicles. The double quonset hut, erected by the contractor during construction of Long Lake phase, is leased to the ADFG. The other warehouse on the lower level of the camp is being used to store transmission line parts and hardware, with the partially assembled towers lying outside the building. The old concrete lab is leased by APA to ADFG, who use it as a temporary dormitory, housing up to a dozen people during the summer. The ADFG has three family homes erected near the dormitory. The APA dormitory building accommodates four twobedroom apartments for permanent operating personnel, plus a one bedroom apartment for Ralph Alps when he is at the project site. The other rooms are used for temporary personnel, sleeping as many as four per room in double bunks. 23. Access. a. Intake Structure Access Road -In reasonably good shape; was easily traversed by a two-wheel drive vehicle after APA had performed some maintenance and restoration work prior to our visit. b. Access Adit Road -The road and culverts are totally washed out at the Glacier Creek crossing. After some roadwork prior to the inspection tour, the road was traversable with a four-wheel drive vehicle; otherwise, in good shape. c. Crater Cove Haul Road -The Crater Cove haul road has been cut in two places: at Crater Creek, for fish passage to spawning areas, and between Crater Creek and the borrow area. To use the borrow area or achieve access to it, the road must be restored with culverts in ~ccord­ ance with criteria from ADFG that NPAEN-DB-C has on file~ furnished by NPAEN-PL-EN. Other minimal work is required to restore this road to a permanent haul road. NPAEN~P~-C SUBJECT: Snettisham Hydropower Project, Long Lake Power Conduit and Powerhouse Inspection d. Messrs. Alps and Hallum advised that APA found it necessary to push material out of the boat basin channel at low tide with a dozer in order to maintain navigation to the dock. This was prior to the 1982 Corps hydrographic survey, resulting in the survey showing a deeper channel than previously existed. The portion of the channel excavated is located across from and between the dock and outflow channel from Crater Cove. Apparently, Crater Cove outflow keeps the outer entrance channel scoured out adequately. Barge traffic is possible at high tide. 24. Maintenance/Repair. The sump pump in the intake structure had been removed and APA advised us that they planned to install a submersible sump pump in its place. 25. Power Demand And Sales. a. Ralph Alps stated that APA operated through December, January, and February with two generators supplying power for the city of Juneau, essentially drawing Long Lake down in accordance with the rule curve. In late March, the weather turned cooler than normal; increasing the seasonal power demand, resulting in the need for two generators in March, also. There was insufficient water supply to operate two generators, so diesel generation was used. The lake was drafted to approximately elevation 723, 19 feet above minimum pool. b. Ralph Alps also mentioned that APA is currently charging 16 mills per kilowatthour. When the 10year rate freeze moratorium expires, the rate will probably go up to 28 mills because APA has to pay annual operating costs plus pay back 1 percent per year of the original investment costs for construction of the project. The Alaska Electric Light and Power Company (AEL&P) is currently charging its residential customers approximately 6 cents per kilowatthour. AEL&P's costs for generating electricity with their diesel units is presently running 11 to 12 cents per kilowatthour, which results in a loss to the company. Included in the 6 cents charge mentioned is the cost of payment for the diesel fuel. Attempts are being made to apply a moratorium to the installation of electric heat in Juneau, thereby, reducing the increase in electrical demand. 26. General. a. The rate of growth of alderbrush and other vegetation on the spoil pile at the access adit is such that the spoil pile should not be visible from the main camp and Snettisham Arm within another 8 to 10 years. b. The project as a whole looks good, the maintenance and house- keeping is good, and the power tunnel, penstock, underground powerhouse concept is an excellent one that should continue in use for many years. NPAEN:=-Prv'I-C SUBJECT: Snettisham Hydropower Project, Long Lake Power Conduit and Powerhouse Inspection c. Except for some minor points, the power conduit and accessories appeared to be in good condition. d. Crater Lake was icefree at least 2 weeks prior to the subject inspection. This is unusual in that ice does not normally leave Crater Lake until late July or early August. 27. Conclusions. a. As applied in the Long Lake tunnel, the usage of shotcrete for tunne 1 support appea rs to be a fa i1 ure. The" pop out" may be caused by a lack of drain holes. By changing the Long Lake tunnel shotcrete designs to incorporate precautions to prevent breakup, it is possible that shotcrete could be used as a tunnel support device for the Crater Lake tunnel. b. Additional grass-matting of the penstock trashrack is not anticipated, as it appears that the majority of the flow passes over the trashrack. c. The recent increase in power demand and limited ability of the Long Lake units to meet that demand clearly demonstrate the need for POL from the Crater Lake Phase as soon as possible. It also indicates that the heavier than historically recorded construction activities in the Juneau area are causing the power demands to increase rapidly. 28. Recommendations. a. A solution should be found to permanently repair the powerline to the intake structure to provide a constant reliable power source. b. Piezometer lines should be cleared before further hydraulic loss tests are carried out for the Long Lake tunnel. Pressure readings at the powerhouse should be taken from the Gibson test piezometer lines located in the lower penstock. The existing pressure gages in the powerhouse are connected to the 8-inch raw water bypass and should be used only when limited accuracy is required. c. The suspended ceiling in the valve room should be extended the full length of the valve room when the Crater Lake unit is installed. d. The powerhouse crane should be wired so that it can be operated from the standby emergency power supply. NPAEN-PM-C SUBJECT: Snettisham Hydropower Project, Long Lake Power Conduit and Powerhouse Inspection e. Consideration given to the APA request for expanding the power- house facility by including a drift tunnel between the Crater Lake access adit and the erection bay and expanding a portion of the access adit to house a machine shop. f. To meet the rising power demand in the Juneau area, the dam on Long Lake should be constructed as soon as Crater Lake is on line, and feasibility studies should be started in the near future for developing one of the many other stages of the Snettisham project. 29. On 22 June, Messrs. Wayne Rowe and Bruce Munholand visited Vivian Kee and Guy Pence of the US Forest Service (USFS) in Juneau. The following topics were discussed: a. Side Scan Sonar Permit -Ground work was laid with Vivian Kee for obtaining a USFS permit for Ocean Survey to be onsite to conduct a side scan sonar of Crater Lake. Bruce Munholand stated that he would have Phil Fontana of Ocean Survey contact Vivi an Kee di rectly to work put the remaining details. b. Detailed Action Plans (DAP)-Guy Pence was concerned about the need to begin processing DAP to cover the Crater Lake Phase construction. Mr. Rowe explained to Mr. Pence what the existing schedule was and that work on DAP was not really necessary, or appropriate, until P&S are near completion. Mr. Pence concurred after being briefed on what the likely project schedule is. c. Environmental Assessment (or Considerations)-Mr. Pence also questioned the status of the environmental investigations or discussions for the Crater Lake Phase. Mr. Munholand stated that he felt Mr. Pence had received all material that is available to date for reviewal, but would coordinate with Mr. Guy McConnell, NPAEN-PL-EN, and have him give Mr. Pence a call to confirm. 4 Incl as CF: NPAEN-DB NPAEN-DB-ST NPAEN-FM NPAEN-H-HY NPAEN-H-HD NPAEN-PL-EN NPAEN-PM-C (Munholand) NPDEN-TE (Bickley) (dupe) APA (Spicher) >-:r '-' ~ ~ >-CD cr ..... z L:: >- Z LoJ U cr ..... ... 0 U. S. STANDARD SIEVE NUMOERS HYDROMETER lVJ U. S. srANDAHD SIL~(I Of'£NING Itj 'NCIlES r--:"---r-.--.:;6-_~;., A 2 11" Itt + I I~ I 11 3 • 6 8 10 14 16 20 30 40 50 70 100 ]40 200;:.....---.---r--,------,,___---,.-.,,-r-r-,--,---.--.-------, 1 II I I 'I I I II I I I 0 -'\r------ -.-----------. - -.---11---;------------.--------'-_.-.• ----_.- :lO 10 t-I-+--+----j-X ~ I~_' -\---HrH-i-t-t---j--I---I--H--J-t-t--/--I--H++-+-+-i-+--i---I' - --+--1--1--+----1 80 \ 20 ~-+_-+---H1~~+-~+-~\.4----1rH~~_t___lr-+_-----r- 70 60 50 1-1--/----1----+' -.--1----·· -.------.~ --.-.---1.'1----!.--+------J+1--H---l .. +1.-------1--. -1--1-~ H-iH--H_+-1--+_--I-- I ~--~-+--_rl~~+-~+--+-~,H~~~~i-_+--_+-H_I_r~~-~~,___-_+~t_r+_+_+_~I--_+~+r+-+-~-+--j---~ -1- \ 1 ---------.( ~i\" -... -I' -.--.---T~--t---I-H-H-I--I---I--I---j-H-I-+-t-+-;---l---I I H-~-+----rt-H-/-+-_.J -... -+-----1 . -1---------.-- --I-~------\ ~ --1---: i---+-I-~--i 1 -'---}++-+----l 1'''---.---" -.(~ ... -~ ------... -.... _ .. -'-1---'" -. '--c------.---+-.-/-+-- 30 40 50 60 70 (.0 I : - \ rri--1-1 ++-+--+--+--+--+---1 T1--lI-I-·H-H--I---t--I--I-•. -\. . .• ~ --1------f --,-1--·-H----1- 20 1 ! I .. -t_-t----t.-!+.t-t-l-+-+-l-=r-· D."", ___ . --__ ++----I+-t-f-l--l-+--+---+----H -H-+--i-i----l 90 100 10 I~ i " ---t_-r~--+H-+-+-r+_+_-r---+~~H_~_+--+____j 01--+---'-1--+----++++-+-/·---t-.-+---Hr-t-t-t-+....,I--I---j----. f" .~-,:r, )-ffi-'I-t-f-t--I-----/---H 500 100 50 10 5 I 0.5 0.1 '-' 0.05 0.01 0.005 0.001 GRAIN SIZE IN MILLIMETERS !r L' W j: >- OJ 0: uJ Of> rr. .( 0 u ~ ... u cr w Q. COBeLES I GRAVEL I SAND I I I ~E I FINE I COolRSE M(DIUJ,C I FINE I SILT OR CLJ.Y I S~rr.p:e Nu. Elev or Depth Cla~ifi:.ltion Nat w ~ LL PL I PI ! I ~ LS 4092 ___ ._ -G~-=-Z-~~*f~~}Y.1;l--_--. ____ . ____ ~_ --.~1---.~lli __ 1 .-~: t~.~~~~k~-ll.1J.a.j-.Lq:t.~e.-.ll!'.a~/+- ----------.-.... -.-_______ ._f3~.,O'% .. _Gr~y.eJ .. ___ ~ ~-== ~-=--=-jT--Area -~::t--tl' S-h·a~-·--·---·-·-~·----- 36.0% Sand -........ -!.I ..... -..... -------------- ---+------~ -1 tr.i.ll I 8oring~~.~~,------------------------__+ GRADATION CURVES Dale 6-29-83 ENG FORM I MAY CJ 2087 U. S. STAHOARD $1(\'[ OPENING IN INeliES U. S. STANDAIlD !>ILV£ NUMllEflS 6 4 3 2 I -t -~ -~ . 3 4 6 8 10 14 16 20 30 40 50 70 100 140 200 I II .... l--Tir---i-I I I I ----rl II I I I I IIYDflOIA En II . ICXl o '\. ~-I-----I++-++-j'-'---f-.----H-- ~~-~~-----+~+-~-r~--+~\.+-----rHrr~-+--I---I-----H-1-+~-4-~-~----14-1~·f4~--~-1-----~-I~-t-+~-~-~---~--~lO ~--r-~----+r++14-~-+-V-----j-riH-·~-+-4---j--------·~~+4-~-+--+-----j -·I-!--1--+--+---+-----j .70f---1r--+--4-----++++-+~-1---+--+--\1,---t+-1f-+-+--t--+--I---+----~ 1 30 ~ 6Qf-t--i---+---t-+++-i-t--I--+---+--\-\-\-i-~ -I-I--t---+----I t1-r-j---.+++1 +-+-+--I--+---I++++-~-+--l---l---I40 1---4--1___+----~~r+-~-J--II~~I)---_+t-J-t-+-_J_+_-t---t_-----f-----/--j-·-----.,..-+-II-1-1-+-+--I,--I---I----1 ; .-\ ---t--I--t--------1--j-'.--'----I__---I-H-I-+-f-!---+---t--I--+-l-+-+-+-----t---i ~ " ~--+~------+-----.--1-'-1--f-----------.-.--------I-+--:::=:=.=:~-=--=-:~ ~ 40~--r-_+----_r~r+~~~--+---~lrH~r+-+-4---+-----~+-~-j-+_!~-+---l----_++++4-r-+--4---~----.~t~~~--r-_+----~60 Q,. t--------------.. -. -. --.. -------.~. ---------------.. ----.. . .. --I···· ---------r-.--.---. I---i--f------ ~r_t--~_+----_r~~·~~~--+---~ .. '~I---~+~_+~--_i-----~~~-+-+_+_~---I__--_4++-~_;--t-~--+_----t70 t--i--r---t----4+·-I-f--+--!--------.. ~D. ----._-... -.----. --~ -.-----.--_.-..... -1----I----~ 2o~~--r_--_H++~-+-r--~--~rrr+'~~'-+_--_h~~r+I_+--r_--_H++~~_r~r_--1+t1_t_4_~~_+--~~ f----l---<I>----t--++++-+-i --t---1---++-·t-+-t-I---~k .. -. 1--++--,--f-f-t--·t--t--/---t 10f---1--L-~----_+~~~4-~~+-----HH~~-+-4--~----+\·~tl~-~~--~-+-----H~~4-+-4---~---444~~_+~---r--~~ -r--4__l---t-----~ ~-r-: --+---_i-l-+-+-j-_.----·t---t-----t+-t-i-I---t--t---I---·.,.. ft===E~ -,~=-----t----t goo I 100 50 10 5 I 0.5 0.1 -O.O:-:-5-'-....L..--.L..----~O.O::-':I...J...,.J.---'="0.-;!:;00:-:-5.J--...J...--'-----;:;-;:!0.~·F -t--/--_1___+-+-----1 GRAIN SIZE IN MILUM ETERS I SILT OR CLAY I GRAVEL SAND COBBLES I I I COARSE I I COARSE FINE MEDIUM FINE Sam~le No. Elev or [)cpth ClassifiColtion Nat w "LL PL PI I--'L-:::S,.;...-..4-=09-=-3=-+------'---+----=G-.:::"p-_ -S'--a-n-d":""y-G-r a-v-e-'----+--=---+-----=-=----+-----==---+-----=--I Project era te r La k e --------~------------+--~---7~~~-~~~~---------I------- ----t---------------'I---_-'---""-G r'-"(wit~.L __ . __ . _____________ 1 _____ S ta. 81+00 ~ LO W > )0- CJ c: '" VI '" C; I U >- Z w U a: w Q.. 74.0% Grave' S . ----·--I--------~---------~25·~O~San~d·~------·---------t------+------'~~pett~sham ---------------------1 LO% 200· ~No. #2 GRADATION CURVES Dale 6-29-83 ENG FORM I MAY 63 2087 ) U. S. STANDARD SIEVE OPENING IN INCH£S U. S. STANDARD SIEVE NUMBERS HYDRDMETER 6 (3 2 ' I t 1-·l 3 4 6 8 10 14 16 20 30 40 50 10 100 140 200 o -I--+--+---i·---IOJf----+_+_-I __ I_I_ -H~"'r8.;'1 I f I :~_~ r--'---~~ :l+~-I ~ +r ---t-----1 %,--l---il--l'--_ ___ __ ___ I~> _, ___ -... "1_1_ 1 _,_, ___ t~ ___ ._ -l-l-. -I-_+-r---I-I_-+~~_~'~~===:IO ~~t~~~---~~'~~r-r--+---h~~~~-~-r---~++4-~--~-+--~+4~~~~-+-----H-~~~j--+--+---~20. 1\ t--i-j--\----l-f-l-I--1-+-c--f---1---l-H-+"J --.-,--. -r---I--+---1+·I-+-~I-I----'---1--1-I--l---1--+--If----1 tj j) -----.---~-1-_+_--+I-++_1_I-+__If-_1-~-_+_I__l_1--1-I-I--f_~--__130 " , I --r-----h~·· rr--11----+t.-i--t--i-f-----1 ~ 60 ;JJH·--+-+I--+---+----++++-H-+--1--+----l+++-l-1I-1----ir--+----i40 ~ ; :o:::I==:~~:+_1-++'~-l-~-l--_+I--~:I-~---+-_-_-_---1:-~ ~_ ~_~_:~-Illl-l*fj== r!II~,~ -~= __ ___ _ ~ __ -I----l--.--I~ i _~ i 60§ ~ 3Cf-,+-I, -+ ,:----I----+-+-1--I-n l __ + __ --_ ~:=,=,:::::=:: -----. ---I-r-1":---= -~HI. -i1_ -+--'\---,_-=,. --f-i-I--T---/Q ~ 1Oltf-t-. ~~-----f-.------·····-------!-I---"-\:1------·----·-:· --'~f------eo I--l--"---ii +-. --t----.. --------. f----·t~-I--·-l1j----~ -l--i1'_--1 10 90 f--4--l-i; --+-._. --------. ----' -1--t-------. -'~----f----'-.. -r-,.--------H-I--1--1--i,---·+--I--I-·_- O~-~~---.~l~~~-L-L-~----~LL~~--L--L--~J~~~~~I--~: __ L-__ ~~~~~-L __ ~ __ ~~J~~~-L_~_~IOO 5C<l 100 50 10 5 I 0.5 0.1 0.05 DOl 0.005 0.001 70H-+--l----f .. -_1---1-_1-_1 ___ 1_ t--i-t---+-----~-. -~ --\---1---- GRAIN SIZE IN MILLIMETERS GRAVEL SAND COBBLES SILT OR CLAY COAA$[ , fiNE I MEOI'JM I FINE SJmpl. No Elev or Deplh CIJ~lfication Nal w" LL PL PI ( , _ LS-4094 SM -SillYJ~.r~..Y.~l'y_Sand. ____ ~-_--ProlC£_1 _cx..aJ:er_l~.~~---LL.u.Llj~J:~7J7t ____ t-____ --If--_~(=G.!...:ra~.!J.njJe L __ ... __ .. _. __ . __ ....... _ .. ____ ._. __ . _____ .. __ .. _ .. ~~~ ... ~~:J8 ______ . _____ ... __ . ___ .. _. ____ J ...,. ...... ..... ... ~~: ~~ ~~~ ~el. ...--"'-' ---.--~!~~ .. ?0.~ tt_!s_ha!!l... . ... _ .. _",_,,_, __ .... ____ . __ ._/ 14.0%-200----··-------"--------. -1 Boring!,!o. #3._. __ ... 1 GRADATION CURVES Date 6-29-83 ENG FOAM I MAY 03 2087 OATE 8 July 83 TELEPHONE OR VERBAL CONVERSATION RECORD For use of this form, see AR 340·15; the proponent Clgency is The AdjutClnt General's Office. SUS.JS:CT OF CONVERSATION Snettisham -Long Lake Facilities Inspection, 21-22 June 83 INCOMING CALL PERSON CAL.L.ING AOORESS PHONE NUMBER ANO EXTENSION Tom Spicher Alaska Power Administration 586-7405 PERSON CAL.L.EO OFFICE PHONE NUMBER ANO EXTENSION Bruce MlJnholand NPAEN-PM-C 2-3925 OUTGOING CALL PERSON CAL.L.ING OFFICE PHONE NUMBER ANO EXTENSION PERSON CAL.LED AOORESS PHONE NUMBER ANO EXTENSION SUMMARY OF CONVERSATION Mr. Spicher called to provide some preliminary information from observation~ during subject inspection. The following information was supplied at this time because he felt that it may be applicable to Crater Lake design at some future date. Details will be supplied to us in seven independent reports to be published and distributed in the near future. 1. Gibson Taps a. Not installed as specified. Spec location 92+45 for upstream tap. Actual location is 92+06.5 b. Installed plugs are 1/8 inch too short. c. Drawing 117 4 l-SNE~ 6-06-19-01/20 /A'':i.-,'''I,-J;:,,-c. r£ -'tC' ;.:;.;.:.lr~/L, ::1.fC .. ·..;,'~c.-· C~El~/i!-'-_c' LE~/~~~T// ~.f-/");.:=:{. '~it-'~:-~': 2. Winter-Kennedy Taps. Taps are 1/8 inch too long; never filed when installed. 3. Penstock a. Very uniform cylindrical shape. b. Paint is in lIexceptional" condition. c. Mr. Spicher estimates that it could be operated another 30 years before repainting need be considered. 4. Gi bson Test a. APA would like to conduct Gibson Test on Long Lake units at this time; however, the utility (AEL&P) has indicated that at the present time, they can't handle the load surge created by wicket gate opening time of as short as 5 seconds. • ( !H31-71 REPLACES EDITION OF I FEB sa WHICH WILL BE USED. ,." .. .. b. Would like to plan on testing Long Lake-at the time when we are ready to test the Crater Lake unit. By then AEL&P should have adequate capacity. c. Will require very tight time schedule (correlation) for -radio signals from powerhouse to gate structure to get an accurate determination of time. Suggest we consider a hardwire system of communications between the powerhouse and gate structure for this test. 5. Discharge Tunnel. The discharge tunnel for unit 3 (Crater Lake) has a bed of very light fines that is greater than 2 feet in thickness. 6. Intake Taps. The bottom taps at the intake are totally plugged and the upper taps are partially plugged. Attempts to unplug them have failed. 7. Maintenance. In August APA will replace the governor air compressor and a station service receiver. The existing compressor will be replaced with a larger and higher pressure unit, as the existing compressor takes too long to get back on line after the unit is down. The existing compressor will be cJeaned up and retained as a backup unit. CF: NPAEN-A NPAEN-DB NPAEN-H-HD ;~,'rt,~ ,;,,\ -c:-' (,l.IV:/"','k';':q..,.)~ J ., /' ;:/) --/~,// / /, /~ ~ , .. / ,'.. ," . '" -I . BRUCE A. MUNHOLAND Project Manager EXHIBIT 2 SEISMIC RISK ASSESSMENT CRATER LAKE PHASE SI'~ETTISHAM PROJECT J ALASKA JULY 1982 DOWL ENGINEERS " I I.._J ! i Seismic Risk Assessment Crater Lake Phase Snettisham Project, Alaska July 1982 ------------ ........ ..' . 0°' ...... ot£~O .... ' .. o . ow ._ . ~ '.-. • M~ '. '. ".~ •• ';.p.~~~ "'"~ 0 .... . ' ·8~.~" .... '. .,..O.O'o..~ U ... . . . . . ..... . . . . I J Prepared for [P~~I:U U. S. Army Corps of Engineers Alaska District .... D ...... O ..... W ...... L~E~ngineers u.s. Army Corps of Engineers P • O. Box 7 0 0 2 Anchorage, Alaska 99510 Attention: ~r. Pete Williamson 4040 "8" Street Anchorage, Alaska 99503 Phone (907) 278-1551 (Telecopier (907) 272-5742 ) July 26, 1982 W.O. #013777 Subject: Seismic Risk Assessment -Crater Lake Gentlemen: Transmitted herein is the Seismic Risk Assessment Study for the Crater Lake Phase of the Snettisham project which DOWL Engineers performed at your request. Our report describes the seismic risk at this site in the broader context of the regional tectonic setting of Alaska. We address both geologic and seismologic elements of the seismic evaluation process and thereby provide information on earthquake sources, recurrence rates, ground acceleration, and guidance in selecting "design" earthquakes. This study is intended to provide those persons charged with selecting project design criteria and acceptable risk levels a rational basis on which to make decisions. If you have any questions regarding our report please feel free to contact us. Approved by: lQ e-.~lf Melvin R. Nichols, P.E. Partner DC: jb2k Very truly yours, D~~NGINEERS dcu::tt!~{!L Geotechnical Engineer Robert L. Burk, Ph.D. Geologist SEISMIC RISK ASSESSMENT SNETTISHAM HYDROELECTRIC PROJECT CRATER LAKE PHASE Prepared by: DOWL Engineers Anchorage, Alaska July 1982 prepared for: u.s. Army Corps of Engineers Alaska District ,." TABLE OF CONTENTS INTRODUCTION · . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . METHODOLOGY/SCOPE OF WORK . . . . . . . . . . . . . . . . . . . . . . . . . . . . REGIONAL SETTING AND PLATE TECTONIC HISTORY . . . . . . . . . . MAJOR FAULT SYSTEMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 1 2 6 13 Fairweather/Queen Charlotte Fault System •••••••• 13 Chugach/St. Elias Fault System •••••••••••••• 17 Denali Fault System Aleutian Megathrust Lesser Local Faults · . . . . . . . . . . . . . . . . . . . . . . . . . . · . . . . . . . . . . . . . . . . . . . . . . . . . . . . · . . . . . . . . . . . . . . . . . . . . . . . . . . . . SEISMIC GAPS · . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SEISMIC RISK · . . . . . . . . . . . . . . . . .................... 19 21 24 27 30 Statistical Procedure ••••••••••••••••••••••••••• 31 spatial Distribution of Ground Shaking •••••••••• 36 Cumulative Seismic Risk ••••••••••••••••••••••••• 36 FAULT SLIP ACROSS THE TUNNEL ALIGNMENT . . . . . . . . . . . . . . . 43 CONCLUSIONS AND RECOMMENDATIONS ...................... 46 REFERENCES CITED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 i ~ ENGINEERS Figure 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Table I. II. LIST OF FIGURES Earthquake Epicenter Map -Alaska 1899-1981 •• Geologic Time Scale . . . . . . . . . . . . . . . . . . . . . . . . . Generalized Geologic Section •••••••••••••••• Major Faults in Alaska •••••••••••••••••••••• Major Faults and Lineaments -Southeast Alaska Fault and Lineament Map (USGS) •••••••••••••• Fault/Lineament Map (COE) ••••••••••••••••••• Seismic Gaps in Alaska •••••••••••••••••••••• Earthquake Epicenters Map ••••••••••••••••••• Cumulative Magnitude/Frequency Relationship Average Attenuation Relationships for Rock · .... Idealized Distribution of Ground Shaking Cumulative Seismic Risk (Areal Source) . . . . . . Cumulative Seismic Risk (Linear Sources) · . . . Comparative Seismic Risk . . . . . . . . . . . . . . . . . . . . LIST OF TABLES "Maximum Earthquakes" Associated with the Major Faults in the Port Snettisham Area Potential Slip Along Local Faults Which Cross the Crater Lake Tunnel Alignment ii · . . . Page 7 8 10 12 14 25 26 28 33 34 35 37 39 40 43 23 45 ~ ENGINEERS SEISMIC RISK ASSESSMENT -CRATER LAKE INTRODUCTION Development of Crater Lake as a hydroelectric power source is the final portion of a three-phase plan for the diversion of Crater Lake and Long Lake outflows through separate waterways to a common powerplant at tidewater. These lakes are in the Port Snettisham area, approximately 25 miles southeast of Juneau, Alaska. The proposal involves tapping Crater lake with a pressure tunnel similar to the one now in existence at Long Lake. Due to geologic constraints dam construction has not been proposed for Crater Lake. Power generated by this project would be conducted by overhead transmission lines and submarine cable to the Juneau substation. The Crater Lake project borders one of the most seismically active zones in the world. In order to incorporate appro- priate design measures to mitigate seismic hazards the U.S. Army Corps of Engineers, Alaska District contracted DOWL Engineers to conduct a seismic risk assessment study for this project. - 1 - ~ ENGINEERS METHODOLOGY/SCOPE OF WORK The complete assessment of seismic risk for a development entails the combination of three related, yet independent disciplines: Geology/Seismology (Seismicity) Soil/Rock Mechanics (Geotechnical Engineering) Structural Engineering (Dynamic Analysis) The physical factors and the mathematical modeling discussed herein are by their nature general to the entire Port Snettisham area, and are not restricted to the Crater Lake area. The geological and seismological information gathered 'during this study and the evaluation of seismic risk pre- sented herein should be useful in establishing design criteria for development of a power project at Crater Lake. This report addresses the geologic and seismologic elements of the seismic evaluation process in order to provide infor- mation on earthquake sources, recurrence rates, ground acceleration, and guidance in selecting "design" earth- quakes. The sources of earthquakes which may affect a proposed structure(s), and the character of the shaking produced by an earthquake as it travels to a study si te are evaluated wi thin the framework of geology/seismology. The way in which local soil or rock condi tions below the study si te respond to and alter that motion is addressed through ground response analyses (geotechnical engineering). And finally the dynamic behavior or response of a structure founded on that site to the ground shaking transferred through the soil - 2 - ~ENGINHRS .. deposit is analyzed through dynamic structural analyses. Therefore, a complete earthquake analysis examines the source of earthquakes, the effects of travel path on the shaking produced at the source, and the response of struc- tures to that modified shaking. Ground respon~e analyses and dynamic structural analyses were not within the scope of this study, since the structure under consideration is a tunnel carved through bedrock. A "structure" of this configuration generally is unaffected by site specific ground response peculiarities associated with above ground structures. Its behavior is more accurately tied to the local bedrock deformation and shaking induced by local and regional earthquakes. The assessment of the seismic exposure or seismic risk of a si te begins wi th an investigation of the regional tectonic and geologic setting, and the seismicity of the area around the site. The size of the study area must be large enough to include the largest event that may minimally affect the si tee A typical seismic study area is usually 75, 000 to 100,000 square miles, although regional geologic features (faults) may dictate different areal limits. Once the study area has been defined, all known or inferred faults within the area are investigated regarding their past, present, and potential activity. This procedure describes the seismicity within the study area. The average rate of occurrence of various size earthquakes wi thin the area can be inferred from statistical analyses of historical earthquake records, and in some cases from well documented field investigations of known faul ts. The computed recurrence intervals for earthquakes large enough to affect - 3 - ~ ENGINEERS the structures or systems within the subject development are then used to assess the seismic risk or seismic exposure of the site. This portion of a seismic study defines the character and limits of the "input" to the second phase of the general procedure involved wi th earthquake engineering analysis --site response or ground response. Ground response is that portion of the analysis (geotechni- cal engineering) which assesses how the soil at the develop- ment site will respond to regional shaking that might reasonably be expected to occur in the bedrock below the site during a particular des ign period. Since the soil deposit below any surface si te is a mechanical system or "structure" in the same sense as a building or bridge might be considered, it will respond uniquely to vibratory motions just as a structure of more classic description will. Although human-made structures such as buildings and bridges are usually assemblages of discrete elements (beams, columns, walls, floors, etc.), and soil deposits are more clearly described as continuous media, the classic laws of motion appear to describe the response of both systems equally well. Therefore, the second element of the earth- quake engineering schema describes how a specific soil deposi t will respond to probable earthquake motions, and thereby describes the "input" motion, which might be expected at the base of a structure founded at the subject site. This second element of the total process then leads to the final consideration -dynamic structural analysis. The general text of this report describes in some detail the regional tectonics and geology of the study area, the - 4 - ~ ENGINEERS .' .' seismici ty of the study area, and finally the seismic risk associated with the site in terms of peak bedrock motions. The reader should recognize that the geologic and seismic data, the methods of analysis, as well as the conclusions presented herein, can be expected to change somewhat and become more refined as new data· become available to the profession, and as the physical mechanisms which describe earthquake phenomena (source models, attenuation relation- ships, etc.) become better defined. One should view this report as being "state-of-the-art" within the engineering profession in Alaska in 1982, based on accepted design practice and probabilistic methods of inference, and not as an absolute definitive prediction of earthquake exposure within the Port Snettisham area. - 5 - ~ ENGINEERS REGIONAL SETTING AND PLATE TECTONIC HISTORY The northwestern margin of the North American continent is one of the most active mountain building, seismic and volcanic regions of the world (see Figure 1). Most of this activity is related to movement along the boundary between two major, adjacent, blocks (plates) of the earth's crust termed the Pacific and North American tectonic plates. Plate tectonic theory forms the basis for understanding the geology of continental margins and plate boundaries, and provides a framework for discussing the seismicity and bedrock geology of Southeastern Alaska. According to theories of plate tectonics the crust of the earth is divided into a number of lithospheric plates which move relative to one another. Ocean trenches such as the Aleutian Trench, are viewed as sites of large-scale under- thrusting of plates of oceanic crustal materials. Sediments that fill these trenches may be subsequently scraped from the down-going plate and accreted to the overlying plate as this underthrusting continues. Due to various tectonic forces these accreted materials also become amalgamated. Ten tectonostratigraphic terranes bounded by known and inferred faults have been identified in southeast Alaska. The differences in the rock units and the implied structural and depositional histories are so great that large-scale tectonic juxtaposition is required (Berg, et el, 1978). This mosaic of discrete tectonic elements is indicative of a long, complex history of both amalgamation and accretion. Amalgamation apparently began in Permian time (see Figure 2) and major accretion took place in Late Cretaceous time. Subsequent tectonic activity has modified these terranes by - 6 - ~ ENGINEERS EXPLANATION 0 B·j- 0 7.0 TO 7.9 0 6.0 TO 6.9 MAGNITUDE ~ .... Engineers LOCATION OF MAJOR EARTHQUAKES -ALASKA 1899 -1981 FIGURE GEOLOGIC TIME SCALE SubdivisIons of Geologic Time Radiometric Ages (millions of years Er~s Periods Epochs before the present) (Recent) Quaternary Pleistocene 1.8 u Pliocene -6 0 N Miocene 0 z 22 w u Tertiary 01 I gocene 36 Eocene 58 Paleocene 63 u Cretaceous -145 0 N Jurassic 0 U) 210 w ~ Triassic 255 Permian 280 Pennsylvanian 320 u Mississippian -0 360 N Devonian 0 w 415 oJ < Silurian a.. 465 Ordovician 520 Cambrian 580 " PRECAMBRIAN (No worldwide subdivIsions) Birth of Planet Earth 4,650 FIGURE 2--Geologic Time Scale I ''-- displacement along the major fault zones such as the Chatham Strai t fault and by Cenozoic intrus ions and thermal meta- morphism (see Figure 3). Terranes which have been documented for Southeastern Alaska are part of a larger sequence of discrete terranes along the west coast of North America. Remanents of at least six 1 i thospheric plates are present wi th in th is area. During Precambrian and Paleozoic time multiple microcontinental plates and volcanic arcs moved away from and toward North America to accommodate the marginal ocean basins that opened and closed behind the migrating arcs (Churkin and Eberlein, 1977). This succession of microplate movements was followed by large-scale northwestward drift in Mesozoic and Cenozoic time and development of an arc-trench system. An arc-trench system is normally thought of as having a three part system composed of a trench, and arc-trench gap and a magmatic arc (volcanic and plutonic). This triparti te system was originally thought to be represented by the Chugach, Matanuska-Wrangell, and Gravina-Nutzotin terranes. These terranes form concentric arcs across Southcentral and South- eastern Alaska. The Chugach terrane which consists of late Mesozoic formations, such as the Valdez Group, was thought to represent trench deposits similar to those forming in the present-day Aleutian trench (Berg, et aI, 1972). More recent evidence suggests that Chugach terrane is allocthon- ous and has been displaced northward at least 1000 km since the early Tertiary (Cowan, 1982, Plafker, et aI, 1977). - 9 -~ ENGINEERS sw QUEEN CHARLOTTE fAULT CHATHAM STRAIT- PERIL STRAIT FAULTS BARANOF ISLAND KUIU ISLAND KUPREANOF ISL AN 0 CHUGACH CRAIG ADM IRALITY FleUltE 3--Generalized Geologic Section across Southeast Alaska-- 'ot) W~·b see Figure 5 for location--Sb,Bay of Pillars fm.; CSu, undivided Silurian to Carboniferous formations;Dc,Cannery fm.;Dg,Gambier Bay fm.;Pzs,"Stikine" "Asitka";Ph,Halleck fm.;Pp,Pybus fm.;Trv,Hyd Group;Trw,Whitestripe Marble; Trg,Goondip Greenstone;Trt,"Takla"iJtrg,Jurassic or Triassic granitic rocks;Kt,foliated tonalite sill;Tg,Tertiary granitic rocks;amph,amphibolite;m,marble;ops,orthogneiss, paragneiss and schist;um,ultramafic rocks. Upper Cretaceous and Tertiary plutons west of Tracy Arm terrane are not shown. Hodified from Berg ~~, 1978. ~' ... ......... Er. ineers ~ '. "! '" 1 GENERALIZED GEOLOGI C PROJECT TAKU SECTION NE AL AS K A I CANADA AREA\ COAST RANGE BATHOLITHIC COMPLEx gn,i .. dome Tg TRACY ARM o 2~ 1)0 Km L __________ ~' __________ ~' HORIZONTAL SCALE FIG! E 3 Today the Pacific plate is being subducted at the Aleutian trench at a rate of 6-8 cm/year. Movement along the eastern border of the Pacific plate is represented by dextral (right lateral) slip along major fault systems such as the Queen Charlotte fault. The apparent trend in motion through time in Southeastern and Southcentral Alaska is a shift from an oblique transform-arc juncture to a simple right-angle juncture. This implies that motion is being shifted to the Fairweather-Chugach-St. Elias system so that eventually approximately a right angle will exist between the Aleutian trench and this fault system. Whatever the long-term trends work out to be it is clear that motion along the eastern border of the Pacific Plate occurs along discrete faults and major earthquakes are associated wi th those faults. Major fault systems in Alaska are shown in Figure 4. -11 -~ ENGINEERS , , I FAUL T SYSTEMS , I. DENALI I I IA FAIRWELL SEGMENT , IB HINES CREEK STRAND , IC MeK IN LEY STRAND I 10 SHAKWAK VALLEY STRAND IE CHATH AM STRAI T 2 CASTLE MOUNTAIN 3 KNIK 4 CHUGACH -ST. ELIAS ,5 FAIRWEATHER 6 JACK BAY a WHALEN BAY 7 ALEUTIAN MEGATHRUST ~; ** B CONTINENTAL MARGIN * .-.;.. * TRANSITION -------* '9 CLARENCE STRAIT LINEAMENT ~ "~ "\ .. ". < , " '\ MAJOR FAULTS IN ALASKA FI( ~E 4 ~ ~ • 'I 1 , MAJOR FAULT SYSTEMS At least since early Paleozoic time southeastern Alaska has experienced significant tectonic deformation, plutonic in- trusion and widespread metamorphism. The most recent major events occurred in Tertiary time and activi ty in varying degrees has continued into the Quaternary. Major structural features have a northwesterly trend and prominent among these features are several faul ts for which major Recent movement has been suggested (Yehle, 1977). various names have been applied to the faults in South- eastern Alaska, and various interpretations can be found for the connections between faults. We use the following nomen- clature for the faults shown in Figure 5 after work by Yehle (1977): (lA) Queen Charlotte Fault, (lB) probably adjoined segments, (2) Transition Fault, (3) Chichagof-Baranof, (4) Fairweather, (5) Chugach-St. Elias faults, (6) Chatham Strait fault, (7) Lynn Canal, (8) Chilkat River, (9) Dalton, (10) Duke River, (11) Totschunda, (12) Shakwak Valley, (13) Denali System, (14) Sandspi t Faul t, (15) Clarence Strai t lineament, (16) Coast Range lineament. This section refers to these faults and lineaments and discusses fault history as it applies to earthquake potential. Fairweather/Queen Charlotte Fault System The Fairweather fault is the most significant active fault exposed along the eastern coast of Alaska. This fault has had a long and complex history; however, Late Quaternary movement has been predominantly right-lateral strike slip. The surface trace of the Fairweather fault is topographi- cally expressed as a north~est-trending depression that -13 - ~ ENGINEERS 1 s' ~ \ "-\'2. ' 13-4' ~\ I' ~ \9 \ "- ,'\ YUKON ___ T_ERRI ORY _____ _ t-"T--~\ \ __ _ \-j-0 :6 ~ r ~ _----,60· BRITISH COLUMBIA .. -' '- ~ ~ ~ ~. ~ ~"( ~ ~ N \ , \ ... \ \ \U .. AREA OF GENERALlZE~ ~ .. , ., GEOLOGIC SECTION --'"., .. -. -. ~ I .. ) ~, \ \ It ",. SEE TEXT FOR EXPLANATION. MODIFIED FRON' YEHLE, 1979. IQ 0 1'0 .ao 60 eo 100 "I\.U 8 H 8 F3 F3 F3 E+3 F"3 E="3 seAL!:: ~EnglneerS FIGURE 5 MAJOR FAULTS AND LINEAMENTS SOUTHEASTERN ALASKA extends for approximately 280 km from Icy Point to the upper Seward Glacier area where it probably merges with the east trending Chugach-Saint Elias faul t system (Plafker et aI, 1978). This topographic depression is approximately 1 kilo- meter wide at Lituya Bay, the site of a major landslide and water wave triggered by the 7.9 event on this fault on July 10, 1958 (Miller, 1960). No other historic earthquakes have been related to known slip on the Fairweather Fault. Where the fault can be seen at the surface the bedrock is intensely sheared; however, much of the depression along the fault is covered by ice or water. The closest approach of this fault to Port Snettisham is about 160 kilometers to the northwest. Several major and great earthquakes have been associated with the Fairweather/Queen Charlotte Fault System. The maximum event attributed to the fault is the 1899 Yakutat Bay earthquake, which had an estimated magnitude of 8.6. A magnitude' 8.1 earthquake just north of Queen Charlotte Island was recorded in 1949. -Several major events wi th magnitudes greater than 7.0 have also been attibuted to this fault during the past 70 years. The entire fault system has a length of approximately 725 kilometers. Because of the historic seismicity associated with this fault, and because of its potential rupture length, a magni- tude 8~5 event should be the "credible maximum" associated wi th this fault. During the July 10, 1958 event movement probably occurred over a 280 km segment of the faul t wi th a maximum of 6.5 -15 - ~ ENGINEERS meters of dextral slip and 1 meter of dip slip observed at Crillon Lake (Tocher, 1960). Over the last 1,000 years the slip rate of the Fairweather fault has been at least 4.8 em/year and probably closer to 5.8 em/year. This rate is roughly equal to the 5.4 em/year rate of relative slip calculated for the motion of the Pacific and North American plates. This suggests that the Fairweather transform fault that takes up all or nearly fault is a all of the Pacific/North American plate motion. Major valleys crossing the fault are probably older than Sangamon interglacial stage and are dextrally offset an average of 5.5 km. These data suggest that the present displacement rate could not have begun more than 100,000 years ago (Plafker, et aI, 1978) • An analysis of the length of subducted ocean crust beneath the Aleutian are, and offsets on the San Andreas system, among other evidence, suggest hundreds of kilometers of total slip between the two plates during the past 10 million years (Isacks et aI, 1968). The Denali fault system which consists of Chatham Strait, Dalton, Duke River, Totschunda and Denali faults has had a Holocene slip rate of at least 2 em/year (page, 1972). Total slip since Miocene time is probably no more than 4-5 km (Plafker, et aI, 1978) and not greater than 40 km (Lanphere, 1978). To take up the large amount of slip indicated by other evidence Plafker et al (1978) infer that the Transition fault, which is part of the Fairweather system, bridges the gap between the eastern end of the Aleutian trench and the northwestern end of the Queen Charlotte fault zone. They further suggest that this zone along which major Cenozoic movement occurred may still be weakly active seismically. This activity was indicated by a -16 - ~ ENGINEERS ,. series of earthquakes of up to Ms 6.7 that occurred south- west of Cross Sound during July, 1973. Chugach-St. Elias Fault System The Chugach-St. Elias Fault System is thought generally to be the continental expression of the impingement of the North American and Pacific tectonic plates immediately north of the Gulf of Alaska. The area is believed to be one of the zones of transition between dextral tectonic slip along the plate margins southeast of Yakutat Bay and underthrusting along the Aleutian megathrust. The Transition fault repre- sents another transition zone. Continuity of relative I motion between the two plates implies both dextral and 'thrust components along the continental margin south of the Chugach-St. Elias Front; however, 'only thrust slip is expressed within this fault system (Bruns and Plafker, 1975). The Chugach-St. Elias Fault System is expressed by late Tertiary or early Pleistocene uplift along the southern front of the Chugach and St. Elias Mountains. The faults of this system are high angle north-dipping reverse faults accompanied by intense folding. The relative displacement along the faul ts, and the intensi ty of folding increase northward from the continental margin in the Gulf of Alaska toward the mountain front. The main fault of this system, the Chugach-St. Elias Fault, extends a distance of 270 kilometers from the delta of the Copper River eastward to its juncture with the Fairweather Fault at Yakutat Bay. -17 - ~ ENGINEERS This fault, which dips northward at an angle of 30 0 to 60 0 , is estimated to have a stratigraphic throw of at least 3,000 meters (Miller, et al, 1959). -- Three great earthquakes associated with the Chugach- St. Elias Fault System occurred approximately 80 years ago. A magnitude 8.3 event occurred in September 1899 followed a week later by a magnitude 7.8 event. Almost one year to the day after the September 8.3 event, the area was again rocked by a magnitude 8.3 earthquake. Although the time frame in which these events occurred is generally accepted as that in which lesser earthquakes would be classified as aftershocks of the main 1899 8.3 event, the magnitude of the subsequent events is such that one is forced to view them as independ- 'ent major earthquakes in their own right (Richter, 1956; Sykes, 1971). Although these earthquakes are "officially· cataloged (NOAA) as having occurred in the same location (60 o N. 142°W.), the lack of an extensive array of seis- mological instrumentation at that time made precise location of the earthquakes impossible. It is probable, however, that release and redistribution of stresses within this very complex "corner" of the regional tectonic environment may have initiated a sudden redistribution of accumulated strain along other adjacent or nearby structural elements of the fault system. Only minor surface expression of fault rupture was reported for these events because of the remoteness of the epicentral area from population centers, inaccessibility of the affect- ed area, and the masking of rupture zones by glaciers and snow fields. -18 - ~ ENGINEERS Because of the h istor ical se i smici ty assoc ia ted wi th this fault system, and its potential rupture length, a magnitude 8.3 event should be considered the "credible. maximum" associated with the Chugach-St. Elias Fault System. However, due to its distance from the study site (over 200 miles), it was not cons idered to be capable of appreciably affecting the site. Denali Fault System The Denali Fault System is a major arcuate tectonic feature which extends for more than 2,000 km across south-central Alaska, Northwestern Canada and Southeastern Alaska. This fault system includes a number a different segments which have had separate histories of activity. Movement on this system has been dominantly dextral although vertical separa- tion has been suggested for portions of the system. The Dalton segment of the Denali system extends into South- east Alaska where it is sometimes called the Chilkat River fault. This fault then joins the Chatham Strait fault which in turn intersects the Queen Charlotte fault to the south. Although the Chatham Strait Fault is usually considered part of the Denali system, Lanphere (1978) raises the possibility that the Denali continues along what Brew and Ford (1977) have considered the Coast Range megalineament or some other unrecognized structure. Brew and Ford (1977) do not con- sider this megalineament to represent a major structural discontinuity at least in near surface rocks. The Chatham Strait fault has had several kilometers of ver- tical separation since Eocene time wi th the west side up -19 - ~ ENGINEERS (Loney et aI, 1967). Ovenshine and Brew (1972) suggest as much as 205 km dextral separation and cite what they term weak evidence for dextral separation of 50-100 km since early or mid-Tertiary time and other evidence for 100 km of separation in pre-Late Triassic time. Detailed fieldwork along the Chatham Strait fault is difficult since it is con- cealed by a series of linear fjords. Deformation, including faulting of sediments has been interpreted from seismic pro- files may indicate Holocene movement along the south end of the fault west of Coronation Island. The Shakwak Valley segment of the Denali Fault is the northwest striking lineament which joins the McKinley and Hines Creek Strands in the central portion of the state, and 'strikes southeast more than 580 kilometers into the Yukon Territory, Canada. This remarkably linear topographic feature separates Paleozoic or Precambrian schists to the northeast from Paleozoic and Mesozoic slightly metamorphosed sedimentary rocks to the southwest. The closest approach of the Shakwak Valley segment of the Denali Fault to Port Snettisham is 160 kilometers. In spite of the geologic evidence of major prehistoric dis- placements along the Denali Fault System, the currently measured slip rates along the fault (less than 3mm/yr) (Page and Lahr, 1971), and the historic record of past earthquake acti vi ty indicate that this fault system has historically had a low level-of seismicity. Only two historical events wi th magnitudes larger than 7.0 are believed to be associ- ated with this fault sys tern. A magni tude 7.4 earthquake along the McKinley Strand in 1912, and a magnitude 8.3 event in 1904 are associated with the Farewell segment of the -20 - ~ ENGINEERS fault system. These segments are in central Alaska and are out of the area of major concern for this study. Eleven earthquakes of magnitude 6.0 or greater have occurred throughout the central and eastern segments of the system since 1900. Al though the historical evidence suggests a moderate magnitude earthquake for design considerations, geologic evidence forces the adoption of a magnitude 8.5 event as the "credible maximum" for the Shakwak Valley and the Chatham Strait segment of the Denali Fault System. Aleutian Megathrust The subduction zone between the North American and Pacific Ocean tectonic plates is topographically expressed in the 'North Pacific by the arcuate Aleutian Island chain, the mountains that form the Alaska Peninsula and the deep Aleu- tian oceanic trench. The subduction zone in this area of the Pacific is thought to be shallow north dipping thrust zone termed a "megathrust" (Coats, 1962). The unusually shallow angle of thrust is inferred from hypocentral locations and fault plane solutions of the earthquakes that continually express the tectonic realignment along the northern limits of the Pacific plate. Although a simplistic interpretation of earthquake epicenters and topographic expression implies the Aleutian megathrust is a smooth cir- cular arc wi th a radius of approximately 800 miles, it is now believed that the arc is composed of relatively short straight line segments joined together at slight angles. It is further thought that these segments are tectonically independent, and may be separated by transverse tectonic features somewhat like the transform faults associated with areas of sea-floor spreading. There has been a tendency for -21 -~ ENGINEERS the hypocenters of large earthquakes to occur near one end of these blocks, and the accompanying aftershocks to spread over the remaining portion so that during large events strain is released over an entire segment of the megathrust zone, but stops abruptly at the discontinuity between individual segments (Sykes, 1971). Nearly the entire Aleutian Arc between 145°W and 1700E has ruptured in a series of great earthquakes since the late 1930s (Kelleher, 1970 r. The last great event was the 1964 Prince William Sound earthquake, which was the largest ever recorded on the North American continent (8.4-8.6). The epicenter of the event was 40 miles west of Valdez. Strain release accompanying this earthquake resulted in gross tec- 'tonic warpage of an area of approximately 108,000 square miles. Because of the high historical seismicity, and the potential area of rupture along the megathrust, a magnitude 8.6 earth- quake should be the ncredible maximum" associated with this feature. However, because of its distance from the study site (over 300 miles) it was not considered to be capable of appreciably affecting the project area. Table I lists the major fault systems that can affect the study site and describes some of the ground motion parameters expected at the site that are associated with "maximum earthquakes" along those faults. -22 -~ ENGINEERS 1. N w 2. 3. *4. *5. TABLE I "MAXIMUM EARTHQUAKES II ASSOCIATED WITH THE MAJOR FAULTS IN THE PORT SNETTISHAM AREA Approx. Distance IIMaximum Length to Site Earthquake" Fault System (Mi) (Mi) (M L ) Denali 1,050 (Chatham Strait Segment) (250) (40) (8.1) (Shakwak Valley Segment) (360) (100) (8.3) Fairweather/Queen Charlotte 725 100 8.6 Transi tic;m 400 120 8.3 Coast Range Megalineament 300+ 10 8.2 Clarence strait Lineament 400+ 70 8.4 ~ • Not considered to be an active fault. ", z ~ z ", ", ~ '" Peak Predominant Acceleration Period (%g) (Sec) 20 0.5 0.7 5 0.7 5 0.8 49 0.4 10 0.6 Lesser Local Faults Small faults and lineaments have been identif ied in the Crater Lake area, however, it is important to emphasize that lineaments are not necessarily faults. Linear features at the earth I s surface can be produced by: glacial features, flow foliation in plutonic rocks, dikes, erosion along bedding or geologic contacts, erosion along foliation planes in metamorphic rocks, and erosion along predominate joint . sets. Figure 6 shows a fault and lineament map of the Crater Lake area. Faults and lineaments are undiffertiated on this map, however, fault gouge and breccia have been noted in field 'observations (Miller, 1962). The mapped length of these faul ts and lineaments is less than six miles, however, it should be pointed out that even active faults are typically difficult to trace in granitic rocks, and this difficulty is compounded when forest and muskeg· cover exists. Major faults and lineaments trend either northeast or east-west. A more detailed map of faults and lineaments at the project site is given as Figure 7 after work by the U.S. Army Corps of Engineers. All of these faults have a mapped length of less than 3,000 feet. No offsets of Quaternary deposits was noted by the Corps and these faults are probably inactive; however, activity of faults in the Crater Lake area has not been fully established. -24 -~ ENGINEERS .' " •• .. • ,/ /'" MODifiED fROM' t.t ILLER, 1~62. 1000 0 H E3 / / ./ -- 2000 4000 6000 1000 I ICALl / / / / ,L.~­ . / / : ,'J ___ ---,/7--// ;1/ II ~o~ . ....... Engineers EXPLANATION' -----_ ..... . LINE AMENT/fAULT DASHED WHERE APPROXIMATELY LOCATED, DOTTED WHERE CONCEALED FAULT AND LINEAMENT MAP tRATER LAKE AREA F.lGURE 6 EXPLANATION JOINTS a FAULTS /UNDIFFERENT IA TED) JOINTS a FAULTS I INfERRED) QUARTZ OIORITE /PREDOMINANT ROCK THROUGHOUT PROJECT) .00' o zoo' 400' SCAlf €~l¥v:# ". Engineers FAUL T I LINEAMENT MAP -CRATER LAKE AREA if- MODIF lED FROM' DESIGN MEMORANDUM 23, U. S. ARMY CORPS OF ENGINEERS, ALASKA DISTRICT. FIGURE 7 , , - ' .... .... ' .... SEISMIC GAPS (1970), Sykes and temporal (1971) and others have studied the distribution of great earthquakes Kelleher spatial (M>7.7) along the Aleutian megathrust zone and the major system of Southcentral and Southeastern Alaska. Although the historical records are somewhat meager for thi~ region, apparent trends suggest the space-time distribution of great earthquakes approaches lineari ty, . and progresses from east to west. Moreover, the aftershock zones of great earthquakes (rupture surfaces) tend to abut one another with very little overlap. Great and large earthquakes do not appear to rerupture the same area within a span of several tens of years. The exception to this "rule" is the sequence 'of great events that occurred at the turn of the century along the Chugach-St. Elias Fault System. Areas of seismic quiescence ("seismic gaps") between rupture zones have been observed along the Alaska-Aleutian tectonic boundary as well as other tectonic margins in the Pacific. Observation of the historic space-time sequence of earth- quake occurrence has shown that gaps between two rupture zones tend to "fill in" with large or great earthquakes within a few tens of years in the Alaska region (Figure 8). A gap of 120 to 180 miles is evident between the aftershock zones of the 1958 Lituya Bay earthquake (M=7.9) and the 1964 Prince William Sound earthquake (M=8.5). The Chugach- St. Elias Fault System lies within this gap. Kelleher (1970) postulated that region to be the likely location of a major earthquake wi thin the next 20 years. -27 - ~ ENGINEERS / SOURCE: LAHR, !.! £! (1979) a PAGE (1975). ~ ~Enb .leers ' .. j,"~' ~" SEISMIC GAPS IN 1964 8.5 ALASKA 'J 1 FIGl E 8 -~ His hypothesis was borne out on Feburary 28, 1979 when a magnitude 7.7 occurred north of Icy Bay (60.62°N. 141.5l o W. ). This event, and attendant aftershocks, are believed to have released the accumulated strain in the eastern portion of the gap (Lahr, 1979) (Figure 8). Esti~ mates of the seismic moment and accompanying fault slip (approximately 4.5 m) associated wi th the main shock can account for the strain accumulated in the area since the 1899-1900 series of events, if an average relative motion of 5 to 6 cm/yr between the Pacific and North American plates is assumed. However, the entire gap was not filled in this tectonically complex "corner" during the rupture sequence (Lahr, et aI, 1979); therefore, the probability of a major earthquake occurring within the gap in the near future 'should still be considered high. Until the 1972 Sitka earthquake the offshore area of central southeastern Alaska was considered to be in a seismic gap. Although advances have been made in the field of earthquake prediction in recent years, the necessary precursory para- meters are not yet well defined, nor is the requisite in- strumentation deployed regionally to measure and record such data. Therefore, the seismic exposure or seismic risk associated with the Snettisham area should be a:;;sessed by the more classic probabilistic approaches, but should be tempered with the less rigorous observations of regional seismic history. -29 - ~ ENGINEERS SEISMIC RISK The term "risk" as it applies to earthquake engineering can be defined as the probability that a specific site will experience a given level of ground shaking during a spec- ified design period. The design period is usually con- sidered as the socioeconomic life of the structure or system under consideration. Several methods of assessing seismic risk are currently used within the industry. Each is based on statistical interpre- tation of the historical earthquake record of the region under consideration. If the seismological history and the geological setting of a study area is well known, the more refined methods of risk assessment can be used with a good level of confidence. However, if the earthquake record is short and incomplete and the seismotectonic framework is not fully defined, a more general and conservative approach may be appropriate. We have considered two source models in this study. The source in the first model was considered to be an areal source encompassing the entire study region. That is, earthquakes were considered equally likely to be generated anywhere within the study region. For the second source model we considered only the mapped faults (and lineaments) within the study region to be earthquake sources. The earthquake history of the region is rather meager for the period before 1964, and the seismograph network is still too sparse to delineate the local and regional activity with sufficient detail to assess individual faults with confi- dence. Therefore, we made assumptions regarding the seis- -30 - ~ ENGINEERS micity of individual faults within the study region relative to the gross seismicity of the region. statistically based seismic risk analyses generally assume that earthquakes occur randomly in space and time wi thin a given source area or along a given 1 inear source ( faul t) , but with the same average rate of occurrence as that estab- lished in the past. A Poisson distribution model, which estimates the probability occurrence of rare events, is used to assess the probability of various levels of ground shak- ing at a specific site within a source area. The model as- sumes that future events will occur randomly, and indepen- dently of past events, but with the same mean frequency dis- tribution of the historical events within the region. This procedure is based solely on statistical interpretation of the historical seismic activity of the subject region. Little account is given to regional geologic setting, or the geophysical processes that actually produce earthquakes. The recent theories of global plate tectonics, and the con- tinuing expansion of the Worldwide Network of Standard Seis- mographic Stations have begun to allow significant advance- ments to be made in the field of regional seismology. However, until more complete seismic source models are de- veloped and the actual earthquake data base is greatly ex- panded, long-range earthquake prediction techniques will con- tinue to rely heavily on statistically based stochastic probability analyses. Statistical Procedure The historical . distribution of earthquakes (seismicity) , according to magni tude, location, and time of occurrence -31 -~ ENGINEERS within the Southeastern Alaska region was researched through our data files obtained from the National Oceanic and-Atmos- pheric Administration (NOAA) Environmental Data Service (Figure 9). These files are updated periodically to include the most recent worldwide events. Our data spans the period from 1899 to 1981. The historical seismicity of this region was analytically described according to the relationship proposed by Richter (1958). A graph of this relationship is shown in Figure 10. This graph shows the historical frequency distribution, or the mean annual distribution of earthquakes within the Port Snettisham study region. The size of the region was deter- mined in the following manner. A lower limit of bedrock motion that might affect the project site was selected--in this case a bedrock acceleration of 0.05g. The maximum dis- tance from the site that an upper bound magnitude earthquake (M=8.6) would produce this level of rock acceleration was determined by using one of several published attenuation relationships (Schnabal and Seed;" 1972) (Figure 11). The computed distance was used as the-"search radius" for this study. All earthquakes known to have occurred within the area circumscribed by that radius were used as the data base. Figure 10 shows two interpretations of the historical earth- quake data. The solid line is a plot of the actual data normalized to" an annual basis for the 80 year historical record without regard to the change in monitoring instrumen- tation throughout that period. The dashed line represents the data extrapolated to account for those lesser events which were not recorded prior to the deployment of the -32 -~ ENGINEERS .. II! '..,0 ' .. , .... \jl ... ~ • -, " ~ . 134" 1 o· ., ........ YUKON TER RI ORY Wj~;;-~i\_-g.. ____ IiJ.-__ -I-__________ --___ ~60" , ~ ~ f N , 0 0 0 EXPLANATION 0 0 0 0 o D -- 8+ 7.0 TO 7.9 6.0 TO 6.9 5.0 TO 5.9 4.0 TO 4.9 LESS THAN 4.0 OR UNASSIGNED -EARTHQUAKE SEARCH AREA 10 0 10 10 100 IIf\.O iHA I E3 I SCALI· MODIFIED FROM: YEHLE, 1979. BRITISH 14 \ \ \ \ \ \ \ COLUMBIA 58" ~ , , ~EngineerS EARTHQUAKE EPICENTERS MAP (1899-1981) SHOWING MAJOR FAULTS 8 LINEAMENTS FIGURE 9 10.0 c: II 0:: 1.0 ex ILl >-...... en ILl :!oI: ex ;:) o :r I- 0:: ex w IL o 0:: ILl 0.10 CD :::IE ;:) z B \ B \ \ ~ o \ E1 \ . lOG n = 3.67 -0.72 M o lOG n = 2.23 -0.52 M H ISTOR leAL DATA ~EXTRAPOlATED DATA \ \ \G o \ \ \ \ \ E\ . \ \ \ O.OIL---~---L--~----L---~--~--~--~--~ o 2 3 4 5 6 7 8 9 ~EngineerS MAGNITUDE, M CUMULATIVE MAGNITUDE/ FREQUENCY RELATION'SHI P FIGURE 10 I , i ~ .. 1'" 100 b ~ .. .... .. .. IE tI ..... ~ 0 -.... oq Q: '0 ~ ..J ~ <.J (.) oq ~ ::> ~ )( oq ~ o 10 20 ", .... b ~ '- .30 DISTANCE > .. ~; ~ , 80 70 60 ~O 40 40 '0 FROM CAUSATIVE 60 FAULT R (MILES) 70 (R), MILES 80 90 100 AVERAGE VALUES'" OF MAXIMUM ACCELERATION IN ROC/< (SCHNABEL a SEED, 1972) ~ Engineers AVERAGE ATTENUATiON RELATIONSHIPS FOR ROCK FIGURE II Worldwide Network of Seismograph Stations, and prior to the - installation of the local seismograph networks. The method of extrapolating the recent data used for this study m"ainly affects the number of occurrences of smaller earthquakes. The increase in the frequency of earthquakes with magnitudes less than about 6.0 is evident in Figure 10. The conse- quences of the increase in the number of lesser magnitude earthquakes within the study region will be addressed in the section of this report dealing with seismic exposure and its engineering significance to the project. Spatial Distribution of Ground Shaking ~he spatial distribution of various levels of ground shaking (earthquake "intensity") for a given magnitude earthquake have been found to be reasonably described by elliptically shaped contours spreading concentrically away from the plane of fault rupture (Housner, 1969; Marachi, 1972) (Figure 12). This spatial shape was combined with an appropriate rock acceleration attentuation relationship (Figure 11) to esti- mate the areal extent associated with specific levels of bedrock motion for various magnitude earthquakes. Cumulative Seismic Risk The temporal distribution of earthquakes by magnitude, and the spatial distribution of bedrock acceleration for a given magni tude earthquake, were combined to compute the mean annual frequency of occurrence of a given level of bedrock acceleration within the" study region. The spatial and temporal distribution combinations were then used with the Poisson probability distribution to compute -36 - ~ ENGINEERS "" '" '" til, lOOO~--~--~----.---~---r--~r-~ 500~--~---+--~r---+----r---;-'~ . 100 en &1.1. = ~ . l&.I a:: 10 :l l- ll. ~ :l a:: I- ..J :l ~ 0.5 O./~--~ __ ~ __ ~~ __ ~ __ ~ __ ~~~ 234567 B 9 MAGNITUDE FAULT 1-4----L,J IDE AlIZED CONTOUR LINES OF INTENSITY OF GROUND SHAKING I~ '6rrw Engineers IDEALIZED DISTRiBUTiON OF GROUND SHAKING FIGURE 12 the probability of the site experiencing various levels of bedrock acceleration at least once for several "design periods·. The graphical representation of those probabili- ties for an areal source is shown in Figure 13. A similar procedure was used to develop risk curves for the site by assuming the mapped faults and lineaments in the study region to be limiting linear sources. The risk. curves associated with the Chatham Strait Fault and the Coast Range Megalineament for a 100 year design period are shown in Figure 14. The difference in the seismic exposure at the site associated with the two.linear sources is due to their different 2roximities to the site (40 miles and 10 miles respectively) • The difference in seismic exposure between linear sources and an areal source is due to the assumptions that earthquakes on linear sources are constrained to occur no nearer than the closest approach of the fault to the site, whereas earthquakes associated with an areal source are not constrained and can· affect the site from any dis- tance. The risk curves shown in Figure 13 can be very powerful planning and design tool. They allow the owner/agency/ design team to quantify the risks involved with their selec- tion of seismic loading criteria in terms of the present and future economic ramifications of their selected criteria. Simply stated, seismic damage to structures can be lessened by "buyingW added strength in the original design. Or, the ·costs· can be deferred until after an event, and spent in repairs. Generally, retrofit repairs are more costly than precautionary design extras.- -38 - ~ ENGINEERS .' 1J{i:.' .' 100r-~~~--__ ~-------------------------------------------------------' ~ 0 w u z w 0 w w u x w 50 u.. 0 ~ .... DESIGN P~RIOD (YR.) - ...J -m ct III 0 0:: Q.. 10 20 30 40 50 60 70 PEAK BEDROCK ACCELERATION, 0mox (%g) @Y~ Engin~erS CUMULATIVE ,SEISMIC RISK (AREAL SOURCE) FIGURE 13 , ~ 0 w u z w 0 w w u x w LL. 0 >- I-- -J -III ex III 0 IX: (l. 100~------------------------------------------------~--------------, 50 COAST RANGE MEGALINEAMENT CHATHAM STRAIT FAULT 10 20 30 DESIGN PERIOD 100 YEARS 40 50 60 PEAK BEDROCK ACCELERATION, 0mox (% g) CUMULATiVE SEiSMIC RiSK (LINEAR SOURCE) , , ... '~11! ..,,.,, "! "Il" 70 L...-_____________________________________________ ~_ --~ -lL-__________ _ " Aseismic design practice usually includes the 'selection of - two levels of acceptable risk and their associated expected ground motions for an established design period. One is an. extreme event ftcollapse threshold earthquake ft , and the other is a more probable ftdamage threshold ft or ftoperating basis ft event. Above ground structures such as buildings or trans- mission lines are usually designed to elastically accommo- date the ground motion associated with the ftdamage thres- hold ft event. Elastic design fo~ that level of excitation should keep architectural damage. to a minimum or insure the uninterrupted operation of life lines during those events likely to occur during the design life of the structure or system. The more severe (ftcollapse threshold ft ) ground J1lotion with low risk exposure is then used as the extreme event survivability loading condition. More refined ductile analyses can be employed to insure the survivability of above ground structures, and to mitigate loss of life of the occupants during the extreme events that may occur during the design period. For example, if the useful life or de- sign life of a structure is assumed to be 100 years, and it is decided that the structure should suffer little or no damage during those events likely to occur during that period, then one might choose to design the structure to elastically withstand ground motions with a probabil i ty of exceedence of, say, 40 to 50 percent. However, more impor- tantly, one might account for extreme event survivability by designing for ground motions associated with exceedence probabilities of 10 percent or less during the design period, and employ design procedures which account for duc- tile behavior of the structure. Although architectural and minor structural damage may occur during an extreme event, the survivability of the structure should not be compro- mised. -41 -~ ENGINEERS In assessing the ground motion parameters associated with the two levels of risk considered for this study, we exam- ined the effects of the lack of complete instrumental data for the very short period of record available. The risk curve for a 100 year design period is reproduced in Figure 15 (solid line) along with a similar curve, which represents a somewhat lesser seismic exposure. The curves developed for Figures 12 and 13 were based on the extrapolated magni- tude/frequency relationship as shown in Figure 9. The. dashed curve in Figure 14 was based on the magni tude/ fre- quency relationship for the historical data only. It is evident that as the number of lesser magnitude earthquakes increases relative to the number of large magnitude events, the exposure to low levels of .ground shaking at the site increases, whi.le that for significant ground shaking remains about the same. Therefore" the level of ground shaking that should be accounted for during the ·operating basis earth- quake-increases, while that for the ·collapse threshold earthquake· remains essentially the same. We recommend . using the more conservative approach by incorporating the extrapolated magnitude/frequency relationship into the risk analysis. -42 - ~ ENGINEERS t·· " ~ 0 UJ (,) Z UJ 0 UJ UJ (,) X UJ LL.. 0 ~ I- ...J -a:J c( a:J 0 a:: a.. 100~~~~--------------------------------------------------------~ 50 '\. , \ \ \ \ \ , " -----------~-I I'\. I : ~ I I "'- I I ......... I , ........... I I ~~ I ~ ______________ J. ______________ _ I I o ~--------------~----~----------------------~------------~--~ o 10 20 30 40 50 60 70 PEAK BEDROCK ACCELERATION, 0mox (%) ~ Engineers' COMPARATIVE SEiSMIC RISK FIGURE 15 FAULT SLIP ACROSS THE TUNNEL ALIGNMENT Six faults which cross the proposed tunnel alignment were mapped by the U.S. Army Corps of Engineers, Alaska District during their geologic site investigation of the site (Figure 7) • Al though shear zones were identified during their reconnaissance, no offsets in recent glacial or alluvial de- posits were discovered (U.S. Army, 1973). These faults are consid"ered" to be inactive by the Corps with regard to the present geologic evidence at the site. However, one of the most destructive effects of earthquakes on buried linear structures such as pipelines or tunnels is fault displace- ment which crosses their alignment. In some instances that possibility can be accounted for in design and construction. Therefore, we have included an estimate of the potential amount of slip produced by earthquakes generated along each of the six mapped faults (Table II). These estimates are based on an empirical relationship between fault rupture length and surface slip established by Bonilla (1970). Since the data available to establish thi's relationship are quite sparse, the amounts of slip shown in Table II should be viewed as orders of magnitude only, and not with the pre- cision that the significant digits indicate. -44 -~ ENGINEERS 1. 2. 3. 4. 5. 6. TABLE II POTENTIAL SLIP ALONG LOCAL FAULTS walCH CROSS THE CRATER LAKE TUNNEL ALIGNMENT MaEEed Len2th Potential SliE** Fault* (Ft) (Mi) (Ft) (In) Junction 2,975 0.56 0.21 2.5 Cliffside 1,715 0.33 0.13 1.6 Tsimpsian 1,485 0.28 0.12 1.4 Hilltop 1,315 0.25 0.10 1.3 'rlingi.t 1,115 0.21 0.09 1.1 Penstock 345 0.07 0.03 0.4 * From USGS Map, Miller 1962. **' Based on a empirical relationship between mapped fault rupture length and known average surface slip (Bonilla, 1970). -45-~ ENGINEERS CONCLUSIONS AND RECOMMENDATIONS The seismic considerations for tunnels are somewhat differ- ent from those normally associated with above ground struc- tures. Lined or unlined tunnels through competent rock basically respond to the passage of seismic waves as the rock responds. That is, the tunnel and the rock deform together. There is usually no separation between the tunnel liner and the rock. Similar behavior has been observed for the exposed rock within unlined tunnels where the rock is competent and fracturing along the tunnel face is minimal. However, where the surrounding rock is highly fractured and/or the bond between the liner and the rock is poor, local spalling has been observed after strong earthquake shaking. Therefore, we recommend that the quality of the rock through which the tunnel is to be constructed be examined closely. Some areas of the tunnel may require lining to overcome deficiencies in rock quality that may be encountered. The gouge zones of the faults crossing the tunnel alignment would be prime areas of concern in this regard. If the economic consequences of impairment to th~ tunnel due to offset along the mapped faults warrants mitigation mea- sures be taken in the design and construction of the system, then further field studies would be warranted to ascertain the probable amount and direction of slip. We also recommend that the mechanical properties of the rock, especially the deformation characteristics, be thor- oughly established, so that the integrity of the tunnel surface can be evaluated regarding the probable deformations -46-~ ENGINEERS .' .' across the alignment axis due to the passage of seismic shear waves. Unlike buildings, transmission lines can be longer than the wave length of the seismic waves which may impact them. Therefore, long linear structures such as the proposed tunnel at Crater Lake should be assessed with re- gard to their overall capacity to deform without damage. Finally, we recommend that the dynamic stability of the slopes at the intake of the tunnel be evaluated with regard to the seismic risk criteria selected to be appropriate for this project by your agency.. Past experience has shown that most of the distress to underground pipelines during major earthquakes occurs where the line daylights or has shallow cover. Generally, the effects of earthquakes in those situ- ations was related to slope instability of the soil or rock above or below the structure. -47-~ ENGINEERS REFERENCES CITED Berg, H. C., D. L. Jones, and o. H. Richter, 1972, Gravina Nutzotin belt tectonic significance of an upper Mesozoic sedimentary and volcanic sequence in southern and southeastern Alaska: U.S. Geological Survey Pro- fessional Paper 800-0, p. 01-024. Berg,. H. C., O. L. Jones, P. J. Coney,' 1978, Pre-Cenozoic tectonostratigraphic' terranes of southeastern Alaska and adjacent areas: U.S. Geological Survey Open File Report 78-1085. Bonilla, M.G., 1970, Surface faulting and related effects: in Weigel, R.L. (Editor), Earthguake Engineering: Englewood Cliffs Prentice-Hall, Inc., 317p. Brew, D. A. and A. B. Ford, 1977, Coast Range megalineament and Clarence Strait lineament on west edge of Coast Range batholithic complex, southeastern Alaska: U.S. Geological Survey Circular 751-B, p. B-79. _ Bruns" or. R. and G. Plafker, 1975-, Preliminary structural map of the offshore Gulf of Alaska Territory province: U.S. Geological Survey OF 75-504. Churkin, M. Jr., G. o. Eberlein, 1977, Ancient borderland terranes of the North American Cordillera: correlation and microplate tectonics: Geo. Soc. Amer. Bulletin v.98, p. 769-786. Coats, R. R., 1962, Magma type and crustal structure in the Aleutian arc in the Crust of the Pacific Basin, AGU Geophysics Monograph 6. Cowan, O. 5., 1992, Geological evidence for post -40 m.y. B. P. large-scale northwestward displacement of part of southeastern Alaska: Geology v.10, p. 309-313. Housner, G.W., 1969, Engineering estimates of ground shaking and maximum earthquake magnitude: Proceedings of the 4th World Conference of Earthquake Engineering, Santiago. Isacks, B., J. Oliver, L. new global tectonics: 119, p. 5855-5999. Sykes, 1968, Seismology and the Jour.·· Geophys. Research v. 73, -48 - ~ ENGINEERS .. Kelleher, J. A., 1970, Space-time seismicity of the Alaska- Aleutian seismic zone. Jour. Geophys. Research v.75, #29, p. 5745-5756. Lanphere, M. A., 1978, Displacement history of the Denali fault system, Alaska and Canada: Can. Jour. Earth Science v.15, p. 817-822. Lahr, J. C., 1979, Personal Communications. Lahr, J. C., G. Plafker, et al., 1979, Interim report on the st. Elias earthquakeof""""28 February 1979: u.s. Geolog- ical Survey OF 79-670~ . Loney, R. A., D. A. Brew, M. A. Lanphere, 1967, Post-Paleo- zoic radiometric ages and their relevance to fault movements -northern southeastern Alaska: Geo. Soc. Amer. Bulletin, v.78, p. 511-526. Marachi, N.D., Dixon, S.J., 1972, A method for evaluation of seismicity: proceedings of the International Confer- ence on Microzonation, v.1. -Miller, D. J., 1960, Giant waves; in Lituya Bay, Alaska: . U.S. Geological Survey, Professional Paper 354C, p. 51-86. Miller, D. J., T. G. Payne, G. Grye, 1959, Geology of pos- sible petroleum provinces in Alaska: u. S. Geological Survey Bulletin 1094. Miller, J. e., 1962, Geology of waterpower sites on Crater Lake, Long Lake and Speel River near Juneau, Alaska:. U.s. Geological Survey Bulletin 1031-0, 101p. OVenshine, A. T. and D. A. Brew, 1972, Separation and his- tory of the Chatham Strait fault, southeast Alaska, North America: 24th Proe. of the Int. Geo. Congress Section 3, p. 245-254. Page, R., 1972, Crustal deformation on the Denali Fault, Alaska, 1042-1070, Jour. Geophys. Research, v. 77, i8, p. 1528-1533. Plafker, G., J. Hudson, T. Bruns, M. Rubin, 1978, Quaternary offsets along the Fairweather fault crustal plate interactions in southern Alaska: Jour. Earth Sciences v.15, p. 805-816. -49 - Late and Can. ~ ENGINEERS Plafker, G., D. L. Jones, E. A. Passagno, Jr., 1977, A Cretaceous accretionary flysch and melange terrane along the Gulf of Alaska margin: u.s. Geological Sur- vey Circular 751-B, p. B41-B43. Richter, C. F., 1958, Elementary Seismology: Freeman and Co., San Francisco. Sc.hnabel, P.B., and H.B. Seed, 1972, Accelerations in rock for earthquakes in the western United States: Report No. EERC 72-2, University of California, Berkeley, July. Sykes, L. R., 1971, Aftershock zones of great earthquakes, seismicity gaps, and earthquake predicition for Alaska and the Aleutians: Jour. Geophys. Research. v.76, 132, p. 8021-8041. Tocher, D., 1960, The Alaska earthquake of July 10, 1958 - movement on the Fairweather fault and field investiga- tion of southern epicentral region: Seismol. Soc. AIDer. Bulletin, v.50, 12, p. 267-292. U.s. Army Corps of Engineers, 1973, Snettisham, Alaska, Design Memorandum 23, First Stage Development Plan, Crater Lake. Yehle, L. A., 1977, Reconnaissance engineering geology of the Metlakatla area, Annette Island, Alaska, with emphasis on evaluation of earthquakes and other geo- logic hazards: U.s. Geological Survey OF 77-272. -50 - ~ ENGINEERS " ( EXHIBIT 3 SIDE SCAN SONAR AND SUBBOTTOM PROFILING SURVEY CRATER LAKEJ ALASKA SEPTEMBER 1983 . OCEAN SURVEY J INC. FINAL REPORT SIDE SCAN SONAR AND SUBBOTTOM PROFILING SURVEY CRATER LAKE, ALASKA Prepared For: Departmen~ of the Army Alaska Dis.trict U. S. Army Corps of Engineers P. O. Box 7002 Anchorage~ Alaska 99510 Prepared By: Ocean Surveys, Inc. 91 Sheffield Street Old Saybrook, Connecticut 06475 TABLE OF CONTENTS 1.0 INTRODUCTION 2.0 DATA ACQUISITION -EQUIPMENT AND PROCEDURES 2.1 Horizontal Control and Vessel Positioning 2.2 Trackline Coverage and Control 2.3 Vertical Control 2.4 Soundings 2.5 Subbottom Profiling f'f 2.6 Side Scan Sonar 3.0 DATA PROCESSING AND PRESENTATION f' 3.1 Trackline Reconstruction 3.2 Soundings 3.3 Subbottom Profiles 3.4 Side Scan Sonar Images 4.0 INTERPRETATIONS .> 5.0 CONCLUSIONS AND R E CO Mr., END A T ION S APPENDIX A -Equipment Specifications FINAL REPORT SIDE SCAN SONAR AND SUBBOTTOM PROFILING SURVEY CRATER LAKE, ALASKA 1.0 INTRODUCTION During the period of July 15 to July 17, 1983 Ocean Surveys, Inc. (OS'l) conducted a multi-sensor geophysical survey at a si te at Crater Lake in southeastern Al aska. Thi s work was performed-for the Alaska District of the U.S. Army Corps of En~ineers (Contract No. DACW85-82-C-0019) to aid in the design of the lake tap for the Crater Lake phase of the Snettisham Hydroelectric Project. The primary objectives of the survey were to: a. Map the elevation of the bedrock below the lake surface b. Map the thickness of unconsolidated materials overlying the bedrock c. Determine the location of submerged debris (boulders and trees) greater than 5 feet in anyone dimension To meet these objectives, OSI acquired sounding, subbottom profi1ing, and side scan sonar data in an area 400 feet north and 200 feet south of a shore point along the tunnel route to the proposed tap position. The survey area extends west from the shoreline to the 250 foot depth contour. In addition to the acquisition of the geophysical data, OSI also conducted an onshore horizontal control survey to verify the existing land control and to tie an additional control poi nt establ i shed for thi s offshore survey to the exi sti ng control. Final Report-Crater Lake, Alaska Page 2 2.0 DATA ACQUISITION -EQUIPMENT AND PROCEDURES The study area at Crater Lake is characterized by very steep bottom slopes (25 to 90 degrees) and water depths ranging from approximately 5 feet near the shoreline to 250 feet at the outer limit of the survey area. Because of these slopes, it was critical that survey vessel position .data and water depth .measurements acquired during the survey were especially accurate to allow proper interpretation of the seismic and side scan sonar data. To meet the above requirements, O'SI employed the following equipment and procedures. 2.1 Horizontal Control and Vessel Positioning On July 15, 1983, existing horizontal control stations ~ "Creek", "USGS 20-G" and "USGS 21-G" were recovered. An attempt to recover station "DeCopperwald" failed as it appears that the station had been buried beneath the debris of a recent landsl ide. EDM and transit measurements made from the recovered stations verified that the relative postions of the three stations with respect to one another are correct as calculated from the local grid coordinates determi~ed for the stations during previous land surveys. Employing stations "20-G" and "Creek" as a baseline, an additional control station, "OSI-1" was established to optimize the g~ometry for accurately determining the postion of the survey vessel. To insure the 'a~quisition of the most accurate vessel position data, OS1 employed a Cubic DM-40A "Autotape" dual range dynamic electronic positioning system to simultaneously determine the ranges between the survey vessel and control stations "Creek" and "OSI-1". The "Autotape" system is comprised of three components: two "", Final Report-Crater Lake, Alaska Page 3 responder units which are deployed on shore at hori,zontal control stations and an interrogator which is installed aboard the survey vessel. Range measurements are acquired by phase comparisons of microwave reference signals which are received and retransmitted by the two responders to the interrogator. The measured ranges~ which are automatically ,updated at a one second rate ha~e an accuracy of + 0.5 meters .:!:. 1: 1 000 ~ 000 0 f the mea s ur e d d i, st a n c e, and are dis P 1 aye don the interrogator console. During this survey, each one second update was logged on paper tape employing a Hewlett- Packard S150-A thermal printer. 2.2 Trackline Coverage and Control Survey data were acquired along 36 tracklines oriented east/west and 11 trackl ines oriented north/south. For the east/west tracklines, the survey vessel was conned along transit "boresight ll lines originating from control station IICreek II. Empl oyi ng stati on 1120-G II as a backsi ght, the transit angles for the IIboresights" were calculated to produce a series of near-parallel tracklines running nominally perpendicular to the bottom contours and spaced 25 feet'apart at the eastern 1 imit of the survey area (i .e. at the shoreline). The course of the vessel during survey operations was controlled by the transit operator who relayed course corrections to the boat driver via VFH radio insuring that the survey vessel would be kept precisely on the desired trackline. The 11 north/south tracklines were run parallel to the shoreline employing visual ranges to keep the vessel on the desired course. During all survey operations, sequentially numbered navigation lIeventsli were marked on all data records every 15 to 20 seconds to allow correlation of the geophysical and Final Report-Crate~ Lake, Alaska Page 4 positioning data. 2.3 Vertical Control An elevation of 1020.00 feet (referenced to the Mean Sea Level Datum [MSL]) was employed as the zero depth datum for all vertical measurements. This elevation corresponds to the mean elevation of the lake surface during the period of data acquisition and was determined by running a level traverse from station "20-G" (elevation 1036.77 MSL) to the lake surface and back to "20-G". Along the traverse a temporary bench mark was established near the lake edge from which the water surface elevation was measured periodically throughout the two day period of survey operations. Measurements over the two day period showed a variation in lake level of no more than 0.3 feet from the initially measured elevation of 1020.01 feet. 2.4 Soundings Sounding data wer~ acquired along survey tracklines employing a Raytheon DE-7I9 survey grade echo sounder equipped with a speci al narrow beam (3 degrees) transducer. Because of the signal path geometry produced by the steep slopes and deep water within the survey area, use of a narrow beam transducer was essential to obtain a more nearly vertical measurement of water depth than could be acquired with the standard (8 degrees) transducers. When properly calibrated the DE-719B has a stated accuracy of + O. Os ~ + 1 inc h 0 f the i n d i cat e d de p t h • P rio r tot h e mobilization of the field equipment, the echo osounder was electronically calibrated to provide depth measurements for a water mass sound speed of 4800 feet per second. In order to correct the field measurements for the actual speed of sound in the water of Crater Lake, a series of depth/temperature .. .' Final Report-Crater Lake, Alaska Page 5 profiles was obtained to a depth of 300 feet and the actual speed of sound calculated for zero salin-ity water according to the formulas presented in U.S. Naval Oceanographic Office publication SPHS8 IITables of Sound Speed In Sea Waterll. In addition to the measured depth/temperature profiles, a IIbar chetk" was performed at a depth of 30 feet to provide a second means of determining the sound speed existing in the upper portion of the water column. 2.S Subbottom Profiling Subbottom profil ing data were acquired along ten east/west t r a c k 1 i n e ssp ace d 1 0 0 fee tap art and a 1 0 n g two nor t h / sou t h tielines employing two separate systems; a 300 joule IIBoomer ll and a 7 kHz "pinger". Both profiling systems were run s i m u 1 tan eo u sly wi t h t he res u 1 tin g data p resented ina s p 1 i t trace format on an EPC 3200 graphic recorder with each trace displaying 1/4 second of two way travel time. The "Boomer" is a relatively high power, broad band system that provides shallow seismic reflection information through a variety of overburden materials (silts, sands, gravel s, etc.). The system employed consi sted of an OSI 300 joul e power supply~ an OS! high resolution "Boomer" transdu.cer mounted on a surface towed sled, an OS! 10 element hydrophone array and a Krohn-Hite electronic passband filter. Source signals were transmitted at 1/4 second intervals with the received Signals filtered through a 400 Hz to lS00 Hz passband and amplified by 20 decibels prior to being printed on a graphic record. The U pin g e r u, in con t r a s t, i salow power, r e 1 a t i vel y h i g h frequency system which provides high resolution seismic reflection information through soft sediments (muds, silts, soft clays, etc.). The system employed at Crater Lake con s i sted of a Raytheon Model PTR-I06 two k i 1 owatt Final Report-Crater Lake, Alaska Page 6 transceiver and a Raytheon wi th the IIBoomer", IIPi nger" at a 1/4 second rate. r~odel TC-7 kHz transducer. As source signdls were transmitted 2.6 Side Scan Sonar Side scan sonar images of the lake floor showing an area 300 feet on either side of the survey vessel were acquired along seven north/south tracklines employing a Klein Model SA-350A dual channel side scan sonar transceiver~ a Klein Model 402A-00IA towfish, and an EPC 3200 graphic recorder for record presentation. Side scan sonar images of objects projecting above the lake floor are best defined when the sonar beam strikes a target at an oblique angle. This condition was achieved at Crater Lake by rotating the towfish (where the sonar beams ol"'i gi nate) to angl es of 0 ~ 15, 30 and 45 degrees from the horizontal to compensate for the varying slopes of the lake floor throughout the survey area. 3.0 DATA PROCESSING AND PRESENTATION The field data acquired at Crater Lake were interpreted and processed to produce 5 plan drawings: Drawing No. 72242A -Survey Trackline Map Drawing No. 72242B -Lake Floor Elevation Map Drawing No. 72242C -Bedrock Elevation Map Drawing No. 722420 -Unconsolidated Material Isopach Map Drawing No. 72242E -Submerged Object Location Plan , .. Fi nal Report-Crater Lake, Al aska Page 7 3.1 Trackline Reconstruction Survey trackl ines were reconstructed from the "Autotape" ranges recorded every second during data acquisition. These values together with the local grid coordinates of the appropriate control stations were input into OS1 I s DEC PDP 11/34A computer which calculated the grid coordinates for each recorded position. During calculation of vessel positions, geometric considerations for control station elevation, antenna heights and range calibration data were also input to yield the most precise computations. The computed XY positions were plotted on a base map at a horizontal scale of 1:240 (1 inch = 20 feet) to produce the survey tracklines presented on Drawing 72242A. Also shown on the drawing are the run number for each trackl ine, the position of each· navigation "event" and the types of data acquired along each trackline. 3.2 Soundings All sounding data were automatically input into the computer by digitizing the echo sounder records on a Summagraphics tablet digitizer. These data were then corrected for the water mass speed of sound computed from the temperature/depth profiles and correlated with the survey vessel position data vi a the numbered "events" marked on each data set. The corrected depth measurements were, in turn, referenced to MSL and plotted at 2.5 foot intervals along each trackline on a basemap at a horizontal scale of 1:240. The plotted values were hand contoured at 5 foot intervals to produce a topographic map of the lake floor (see Drawing 72242A). This map provided the true water depth and bottom slope information required for the analysis of the subbottom profiling and side scan sonar data. Final Report-Crater Lake, Alaska Page 8 3.3 Subbottom Profiles A 1 tho ugh s e i s mi c d a t a we I" e a c qui red f rom bot h t he " Boorne I" " and IIpingerll systems, only the IIBoomer" consistently penetrated through the overburden within the survey area to allow discrimination of the bedrock surface. Since the main objectives for acquiring the subbottom profiling data were to map the top 0 f the bed I" 0 c k sur f ace an d the 0 vel" bur den thicknesses, only the "Boomer" data were rigorously analyzed. Analysis of these data proceeded in two phases: deter- mination of the position of the bottom reflection points and determination of overburden thicknesses. Since the "Boomer" transmits a signal with an essentially hemispherical beam pattern into the water column, the first received reflections are not necessarily returns from directly beneath the source-receiver system but instead from that portion of the bottom with the shortest slant range path. In areas with deep water and steep bottom slopes such as those encountered at the Crater Lake site, the first reflections received may be returned from a considerable horizontal distance in front of, to the side of, or eve~ from behind the source-receiver pair. For this reason, it is necessary to first determine the positions of the apparent reflection points in order to accurately map the subbottom data. For the "Boomer" data acquired at Crater Lake, the slant range to the lake floor reflection point was determined at each· navigation lIevent ll from the recorded travel times and the water mass sound speed. Employing these ranges, the true water depths below the "event" positions, and the local bottom slopes measured from the lake floor elevation map, the horizontal distances to and the water depths at the apparent lake floor reflection points were calculated. Plotting the positions of these points with respect to the lIevents ll produced a trace of the first or IInormal incidence ll Final Report-Crater Lake, Alaska Page 9 reflection path along each trackline. Following the determination of the positions of the first reflection points, the graphic records were visually analyzed for the presence of a subbottom reflector representing the top of the bedrock surface. A top of bedrock-reflector was interpreted on the "Boomer" records and traced onto a mylar overlay along with the trace of the lake floor reflector; the vertical separation between these two reflector traces . bei ng the one way si gnal travel time through the overburden material. In order to map the thickness of the overburden and the top of the bedrock, a conversion from travel time to thickness has to be performed. This conversion requires that the measured travel time between the two reflectors is multiplied by the propagational velocity of a compressional seismic wave through the materials composing the overburden.. Since the compressional wave velocities for the overburden materials at the site were not physically measured, an average value was obtained by comparing the travel times to the apparent bedrock reflector with the thicknesses of the overburden measured in 3 drill holes (DDH-108, DDH-109, DDH-110). Comparison of these two data sets resulted in a value of 4850 feet per second for the overburden velocity. It should be noted that typical velocities for the types of overburden materials reported in the drill hole logs average 10% to 15% greater than 4850 feet per second (Hamilton 1969). However, since no other data were available, the 4850 feet per second value computed based upon the available borings has been employed. Given the apparent discrepancy in the computed velocity versus characteristic velocities, computed thicknesses should be considered as minimum values with actual thicknesses possibly being up to 15% greater. The computed overburden thicknesses were plotted on the base Final Report-Crater Lake, Alaska Page 10 . map at the appropriate positions determined from the first arrivals and hand contoured to produce an isopach map of unconsol idated material s overlying the bedrock (Drawing No. 722420). Bedrock elevations were determined along each trackline by overlayinQ the isopach map onto a plot of measured water depths and adding the thicknesses to the water depths. The resulting depth to bedrock values were then referenced to MSL and hand contoured at 5 foot intervals to produce the bedrock elevation map (Drawing No. 72242C). 3.4 Side Scan Sonar Images The side scan sonar records were inspected and all di screte targets larger than 5 feet in anyone dimension were traced t' on mylar overlays attached to the side scan records. P Additionally~ locations which displayed a grouping or cluster of individual targets overlapping each other preventing discrete identification and/or presentation have been del ineated on the overlays. Unfortunately, the exposed bedrock and coarse sediments present on the lake floor caused a high density of background backscatter 'on the records preventing the determination of the nature of each individual target (i.e. boulder, tree, etc.). There was one exception, however, where a target, interpreted as a tree remnant, appeared to be partially within the sediments and partially within the water column. As was the case with the subbottom profiles, determination of the true position of the side scan sonar's first arriving signals had to be made before the exact positions of the son art a r get s c o·u 1 d be a s c e r t a i ned. I nan arE! a w her e the bottom is essentially horizontal, the first returns printed on each channel of a side scan record come from directly below the towfi sh. Si nce the towfi sh i s to'~ed at some Final Report-Crater Lake, Alaska Page 11 altitude above the bottom, reflections received from objects on either side of the towfish are returned along a slant range path. These reflected signals are presented at distances proportional to their slant range travel times on a dual channel graphic recorder and the horizontal distance to the object is e~sily calculated. At a site like Crater Lake, however, where the images were acquired along tracklines parallel to steep bottom slopes, the first bottom returns can be from points at some distance upslope of the towfish position. For each target marked on the overlays, the travel path geometry had to be resolved by employing the measured water depth below the towfish, the depth of the towfish below the lake surface, the local bottom slope and the travel time for the first bottom return. Accordingly, measurements and calculations were made for each ta~get and the true positions plotted on the base map tQ produce the Submerged Object Location Plan (Drawing No. 72242E). The center of each object has been plotted and a measure of its apparent length indicated on this drawing. 4.0 INTERPRETATIONS Review of the acquired data and visual observations made at the site revealed that the study area is markedly different north of the tunnel alignments than it is to the south. On the north side of the alignment, the shoreline is typified by a steeply dipping rock surface that continues offshore for a short distance before becoming covered with increasing amounts of sediment. From the shoreline down to an elevation of approximately 800 feet, the rock appears to maintain the same general gradient as observed on shore. Below the 800 foot contour and out to the offshore limit of the survey area, the slope of the rock surface lessens with increasing amounts of sediment cover which reaches a maximum thickness of 30 feet near the outer edge of the defined project site. Final Report-Crater Lake, Alaska Page 12 In contrast, on the south side of the alignment, the structure of the rock is more complex. The rock along the shoreline forms a "shelf" which appears to be covered by 10 to 15 feet of sediment and rubble. Between elevation 1000 and 900, the rock is exposed on the lake floor and the rock slope is nearly vertical. There are indications on the sounding, seismic and sonar records that rock overhangs may exist along the trend of the vertical face (see Drawing 72242B). At the foot of the steep slope, the rock contours show a high degree of irregularity down to an elevation of 870 feet where the general slope becomes more uniform and the overburden gradually thickens. Approximately 70 feet south of the shoreline point above the tunnel alignment, debris from an apparent landslide was observed both on shore and immediately offshore. The location of this debris correlated almost exactly with an area delineated on the side scan sonar records displaying a high density of-objects on the lake floor. The outlined area is believed to define the offshore extension of the slide and appears to terminate very close to the proposed tap location at an elevation of 800 feet. The longitudinal axis of the slide is also roughly coincident with a zone through which the rock contours change trend from generally northwest/southeast to north/south. As large scale joint patterns were observed in the exposed bedrock on shore, the change in the orientation of the rock contours offshore may al so be associ ated wi th the i ntersecti on of two 1 arge joint planes. If so, it is possible that the rock in the transition may would be fractured and relatively weak. As the proposed tunnel alignment crosses through this transition zone approximately 135 feet offshore at elevation 870, it appears this feature may warrant further investigation as a potential problem to tunnel construction. .'< Fi nal Report-Crater Lake, Al aska Page 13 In contrast with the apparent variations observed in the bed roc k, the com po sit ion 0 f the 0 v e r bur den t h r 0 ugh 0 u t the survey site appears to be fairly uniform with the exception of the area outl ined on the side scan sonar presentation where 1 and s 1 i de deb r i sis bel ie v e d to be present • Information acquired from the drill hole logs and the appearance of the seismic returns from the overburden suggest that the unconsolidated material is a poorly sorted glacial moraine or till composed of constituents ranging in size from clay to cobbles with occasional boulders. In addition to the above unconsolidated material, there is a1 so a third "layer" immediately overlying the lake floor. This layer exists asa thin, discontinuous zone of low density material which was evident on the echo sounder records as a a weak, discontinuous reflection approximately 2 to 4 feet above the hard lake floor. As this zone caused a reflection of the high frequency echo sounder signals (200 kHz) but not the lower frequency "Boomer" or the "pinger" signals, material overburden it was interpreted to be extremely low density (fluff) and was not considered as part of the during overburden thickness calculations. The large amount of rock flour observed to be entering the lake in runoff from the nearby ice fields suggests that the "fluff" is composed of concentrated rock flour that lacks the required specific gravity to compact under the influence of gravity and which may exist as a viscous layer at the lake fl 00 r • 5.0 CONCLUSIONS AND RECOMMENDATIONS Fi g ure 1 presents a cross secti on of the 1 ake along the proposed tunnel alignment showing approximately 15 to 17 feet of unconsolidated material overlying the bedrock at the proposed tap location. The upper portion of the overburden, DISTANCE ALONG TUNNEL ALIGNMENT 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 1020 0 1000 I 20 980 I 40 Iw 960 a:l z 60 ~o ON t--zl z 80 ....J 940 00 CJ) u-t-:::E :.::I(/) uz 100 r 920 oct r a: a: lJJ lJJ It-lJJ W lL.. lL.. 900 120 z z I :I: 880 140 r z a... 0 w 0 r 860 160 c::{ > W ....J 840 180 w 820 200 800 ----TUNNEL ROUTU 220 PROPOSED TAP 790 240 DAT7E. SEPT· 83 OCEAN SURVEYB,INC. ~~--~~~~--+---~~~~~--4 FIGURE NO. VAK OLD SAYBROOK, CONNECTICUT SCALE I = 50 BY VERTICAL S IiORIZONTA . .: ~. , Final Report-Crater Lake, Alaska Page 14 near the tap, may be comprised of landslide debris containing large boulders and tree remnants. Analysis of the side scan sonar data indicates that the possibility of encountering sizable objects on the lake floor at the tap location would be greatly reduced by moving the proposed tap position farther offshore (see Drawing 72242E). Attention is also directed to the possible existence of a weak zone in the rock along the proposed tunnel alignment as this feature may represent a potential problem to the tunnel design. The possibility of a weak zone has been inferred based upon the change in structural trends observed in the contour map of the bedrock surface and not upon physical evidence from within the rock column. If such a zone would have an adverse impact on project construction and/or operation, additional drill holes are suggested to determine the actual condition of the rock in the area in questions. As an alternate and more cost effective method to determine the consistency and competency of the bedrock within the above zone, overlapping seismic refraction data could be acqui red empl oyi ng ei ther di screte 1 ake floor and/or continuous marine refraction techniques. These data can be analyzed to determine the compressional wave velocity values of the rock which is, in turn, indicative of the competancy of the rock through this zone. REFERENCES 1. Hamilton, E.L. 1969 Sound Velocity, Elasticity and Related Properties of Marine Sediments, North Pacific Naval Undersea Research and Oevelopment Center Technical Publications 143 2. Tables of Sound Speed In Sea Water U. S. Naval Oceanographic Office Special Publication 58 APPENDIX A Equipment Specifications -.CUBIC WESTERN OATA "'~ - - OCEAN SUR\IEYSoINC •. (a,j OLD SAYBROOK. CONNECTICUT -- ""'" Automatic positioning system for ships, dredges and helicopterSt - ,,\IUII 'I'(·t.,~ • .. o oJ ~ I .~.} ... J i Specifications, Autotape DM-40A Operating Range: 150 kilometers (300 Km by line crossing) Range Accuracy: 50 cm + 1:100.000 X range. Maximum Range Rate: 160 knots -higher rate possible with reduced resolution. Operating Frequency: 2900 to 3100 mHz Transmitted P:)wer: 1.0 watt maximum. Frequency Stability: 1 part per million. Antenna 8eam Width: (1/2 Power) Directional: Variable beam from 1200 10 300 in Horizontal. 100 Vertical 0lT!ni: 3600 Horizontal 100 Vertical Display Rate: Automatic: 1 per second Fine: 4 per second Intermediate/Coarse: 2 per second External: on manual or electronic command: 1 per second maximum. -·at • ,;l~) .• , r'} .~, ~.) Dispiay: 5-digit numerical 10 9999.9 melers for both ranges based on index of refraction ot 320 N. Data Outputs: 20 line binary-coded decimal 1-2-4-8 for each range. Communications: Integral t'No-way communications from Interrogator to all Resoonders. Range Resolution: 10 centimeters Physical Characteristics: RF Assembly: 30/.", 6IY,", 7V,", 6 Ibs. Interrogator: 11", 20Y,", 21", 55 Ibs, Responder: 8", 14", 11", 22 Ibs. Variable Beam: 12" X 15" X 23 H at 120°, 12 Ibs. Omni: 15" long, tV •. " diameter, 1 lb. Temperature: Operating: _100 to +50o C. Storage: _650 to +65°C, Power Requirements: Interrogator: 95 watts. 12 vdc. Responder. 70 watts, 12 vdc. Either unit available for 24 vdc. operation. .' ,. .. .... OEseR IPTION The Raytheon Model DE-719B Fathometer® Depth Sounder has been designed for use as a portable survey instrument to provide accurate, detailed permanent recordings of underwater topography. Its low power con- sumption, portability, ease of set-up and rugged construction make it ideal for use on small boats. The complete system consists of a trans- ducer and recorder. The transducer mount and rigging are stowed in the recorder case when not i,l use. I n operation, the trans- ducer is mounted on the sectional tube supplied and the tube is then secured to the side of the boat. When the battery cable has been connected, the equipment is ready to operate~ The DE-719B is advance design equipment utilizing completely solid state circuitry, magnetic keying and electronically controlled stylus speed. The equipment is housed in a splash-proof aluminum cabinet required for operation in unprotected locations. FATHOMETER@ DEPTH SOUNDERS Model DE-71gB DE-719B Interior Controls Model DE~719B Fathometer® Depth Sounder PRODUCT DATA PAGE 1 High resolution chart recordings result from a combina- tion of very narrow transducer beamwidth, high sound- ing rate, fast stylus speed and fast chart paper speed. The DE-719B's flexibility is increased by a front panel tide and draft adjustment, speed of sound control and four paper speeds_ Calibration markers that indicate phase in use, tide/draft and sound speed compensa- tion are permanently recorded on the chart for future reference. Equipment can be adjusted to either foot or metric scale recording with use of chart paper of appropriate scale. • Portable, compact, lightweight • Calibration marker • TIde and draft adjustment • Four selectable chart speeds • Hinged chart window for running chart notations • Fix Marker switch • Phase Marker • Remote fix-mark receptacle • Chart paper speed adjustable by external control FEATURES • May be used with up to 1500 feet of transducer cable • Standby switch • Foot or metric scale calibration • Available for 12V DC, 115/230V AC operation, 50-60Hz • Plug-in printed circuits • Magnetic keying • Belt driven stylus • New stylus design -long life, quick replacement • Completely solid state OCEAN SURVEYS, INC. o ~ CSI [RAYTHEOEJ FATHOMETER® DEPTH SOUNDER PRODUCT DATA' DE-71gB SPECIFICATIONS Depth Range .... Sounding Rate ................................ . Voltage Input ...................... . ...... . Current Input ............... ~ . . . . . . . ...... . Accuracy ......................... . ......... . Operating Frequency .................. . ........ . Transducer ...•.•.....•.•........... . ........ . Transducer Beamwidth .......................... . Chart Paper Speed ............................. . Chart Paper ...•............................... Recorder Dimensions Net Weight ......................... . 0-55, 50· lOS, 100-155, 150·205 Feet 0-16.S. lS·31.5. 30-41.5, 45·61.S Meter!> (Note 11 534 Soundings per minute 12 Volts DC (Note 2) 2.S Amperes ±O.S%± 1" of indicated depth 208 KHz Barium titanate -model 200T5HAD Optional model 724SA aO at the half power points 1, 2, 3, 4 inches per minute 7 inches x 60 feet Height (including handle) -18" Width 15-3/8" Depth 9· 1 /16" Recorder w/transducer and rigging 47 Ibs. Recorder only -38 Ibs. Tide and Draft Adjustment: A .minus 5 to plus 30 foot adjustment may be set in by means of a control knob. This varies the position on the chart of the transmitter signal, but allows a sharp fixed referp.nce zero-line to remain at the chart zero calibration line. Sound Speed Compensation: A control is provided to compensate for water temperature and salinity can· tent. Adjustment of the control permits the recording accuracy to be calibrated to a "check·bar" reading. A calibration marker, that indicates the degree of compensation, is permanently recorded on the chart. Fix Mark: A front panel switch is provided to inscribe a solid, vertical reference line on the chart. This line is used as an event marker or time reference. A receptacle is included to rermit connection 0f iln external fix·mark switch, available as In accessory. Standby Switc:b: This switch eliminates warm-up drift during survey operations. Transducer: The DE·719B is supplied with the 200T5HAD transducer which may be fitted to the six foot section tube for outboard mounting or permanently installed through the hull. In situations where extreme bottom definition is required, the optional model 7245A narrow beam (2V,o at -3dB) transducer is recommended. 1 J 1~/;/ -- . ------_ .. __ .----..... - 2OOT5HAD Transducer 7245A Narrow·Beam Transducer (Note 11 All of the above basic depth ranges may be multiplied by two by means 01 the range doubling switch. (Note 21 The system will operate within specifications between 11.5 and 14.8V DC 1I1PU:' On ordrr. the €louipmenl can he furnished with a built·in power converter. The converter will permit operation on 115/230V AC. 50 1060Hz. :I' addition to 12V DC. RAYTHEON MARr:E COMPAr~Y 676 ISLAND POND ROAD • MANCHESTER. N.H. 03103 i .. ." Il1p()n I--.It:! [JI 'i <).III~s & Service Ff1c:illlle~i. Seilttrt~. """imIlHJII: l (los Anfleles): Housron: ~Iew iJ, Ip.;)n~ RnVlheon S",v'cc Co .. 6·8. Siljanqade. 2300 Cooenh"n"n •. Denmark. Teleph~"~ ~M 3311 • OT' r p l',.. ", • 603 ·668·1IiOO 1001. '\lor!olk. B!'!(I~ '-/" !'.1 .. n/:helile' • IN EUHOPE -'gLO I\REJ\S. R.i'ylhp.Gn f"':,rnpitI1Y. Inlefr~d"(ln,d OCEAN SURVEYS, INC. Q-Yj) . os. OLD SAYBROOK, CONNECTICUT . . ... '" HYDROSCAN KLEIN SIDE SCAN SONAR . . -_. ------j ~~~ .. ~ ~ ".' ~: .r:: .. -.' -. DUALCHANNELRcCORDER SPECI FICATIONS: SONAR FREQUENCY: RANG:: SCALES: PAPER SPEEDS: SIZE: ':VEiGhT: INPUT VCLTAG~: D.C. INP'JT CURREJ\!T: PAPER'/v'IDTH: WRITING \VIDTH: SCALE UNES: RECORDI'~G COLOR: i'APER CAPACiTY: ·J\'JODEl_ 401 10JKHz istandardl. 50 KHz or 200 KHz (oi=!ional). Qtl':crs ilvailable for bo~tom profilirg or other applications. 75, 150 and 300 meters (standard I. The recorder may easily be calibrated for any three rang~ scales from 37 to 600 meters, 100, 150 and 200 lines per inch (40, 60 and 80 lines per centimeter) (standard). The recorder may be easily recalibrated for alternative paper speeds. Height . Width Oep~h 25.4Cm (10") 84.4Cm (33 ~/:. "I 59.7Cm (23 :/2") 45.4Kg ! leO LCs.l w;thout A.~. Supply 53 Kg (117Lbs) wirh A.C. Supply D. C. 23-30 VOl ts (In;J ut p~')tecred from reverc:e \/el ~~;if) or o'Jervoltage) A.C. iWith Opti.)l1al Model 401 ·010 A.C. Suprlyl 105-125 Volts Or 210-230 Volts. 47·63H.:. 23 Cm \ 11 inche3! 12.7 Cm (Each Channell Ever)' 15 meters {Adjustable from 210 25 meters; S~pia (standard) cr black (opti.,.", 91.4 Mer,,:,::> ;300 F-~etl. .: '. OCEAN SU~VEVSJ INC. Varied types of Sound Source transducers have been developed by EG&G for a wide range of Seismic Profiling applications. The basic Sound Sources are inter-changeable and modular in design to be used with the standard EG&G Energy Source Components, Hydrophones. and Seismic Recorder. UNIBOOM TM The Model 230 UNIBOOM Unit Pulse Boomer is a moderate penetration, high resolution Sound Source transducer utilized for widely varied seismic profiling applications. The electromechanical sound transducer is mounted on a catamaran and is designed to operate 'JlIith the EG~G capacitance Energy Sources, Seismic R~oide~a~d matching H-ydrophone streamer_ The unique electromechanical assembly consists of an insulated metal plate and rubber diaphragm adjacent to a flat-wound electrical coil. A short duration. high power electrical pulse discharges from the separate Energy Sources into the coil and the resultant magnetic field explosively repels the metal plate. The plate motion in the water generates a single broad band acoustic pressure pulse. The elimination of the strong cavitation or ringing pulse associated with standard Boomers and Spark arrays -combined with the broad band frequency spectrum. (1) permits the- bottom echo to appear as a fine line; (2) provides a clear cross·sectional record of the sub·bottom interfaces; and . .~) penetrates most types of marine materials, including hard· ~ A:kedsand. up to 75 meters. The UNIBOOM op.erates equally well in salt water or fresh water. Applications for the Model 230 Unit Pulse Boomer include reconnaissance geological survey. mineral exploration. foundation studies for offshore platforms. harbor development and cable/pipeline crossing surveys. OLD SAYBROOK, CONNECTICUT TEL: (20J)J88-46JI TLX: 966429 SPECIFICATION BULLETIN SP-13 SEIS~;1IC PROFILING SOUND SOURCES UN I BOOM ™ (continued) SPECIFICATIONS Pulse Character Energy Level: Duration: Sou rce Level: Spectrum: Repetition Rate: @100watt·seconds 0_2 milliseconds 95 db ref. T microbar at T meter 700 Hz to 14 kHz 6 pulses/second SUMNER AND CALLAHAN TUNNELS, BOSTON HARBOR UNIBOOM SYSTEM ENERGY SOURCE 234 I 230 SOUND SOURCE SEISMIC RECORDER 254 '1 265 HYDROPHONE UNIBOOM SYSTEM & 1000 WATT·SECOND SPARKER TRIGGER BANK POWER SUPPLY 231A 232A SEISMIC RECORDER 254 I I I I 230 267A 265 SOUND SOURCE SPARKARRAY HYDROPHONE @200 watt-seconds @300 watt-seconds 0.2 milliseconds. 0.2 milliseconds 104 db ref. 1 microbar 107 db ref. 1 microbar at 1 meter at 1 meter 500 Hz to 10 kHz 400 Hz to 8 kHz 4 pulses/second 2 pulses/second Dimensions: Weight: 84 em (WI to 59cm{HI x 158cm (Ll (33" x 23" x 62") 90 kg (200 Ibs.) Cable Length: 25 meters (80ft.) Towing Speed: 2 to 8 knots 1" 'fI,' \ -- UCt:AN :::;URVEY5. INC.l::!~ as .. I OLD SAYBROOK, CONNECTICUT The RTI-lOOO Survey System is a dual purpose, portable system designed for shallow-water, sub- bottom profiling and high resolution bathymetry. Sub-bottom penetratian is achieved with a pawerful transceiver and a law frequency transducer mounted aver the side af a small boat. Resu Its are displayed an a campact, dry paper recarder capable of ane foot resolutian. The recorder's high frequency transmitter and transducer enables precise depth sounding to be Portable Survey System Model RTT-l000 AnS\\ ers the n~' for a portable sub-bottom profiling system that gi\es consistently good results under difficult shallow-water conditions. • Law cost • Simple to set up. operate, maintain • Simu Itaneous operation at two frequencies -One foot layer resolution • Highly accurate hydrographic records (0.5%) conducted Simultaneously with sub-bottom profiling. Advanced system features such as automatic initicl and battom-triggered time variable gain, law-ring trc::s- ducer, and a receiver tailored ta high resolution prafiling requirements assure optimal perfarmar.ce under the difficult conditians posed by shallow wc!'er. All items are packaged in rugged carrying cases ;::nd con ce set up and operating in minutes. The system is ideolly suited to the survey of lakes, rivers, and coastal reg ions. 5 · 1'-• o e~]-rJ cCltlons Features J Raytheon Transducer Model TC-7 Material: Lead Zirconate Titanate Input power capability: 2000 watts mcximum Frequency: 7 kHz Bcndwidth: 2.7 kHz Beamwidth: 36 degrees Dimensions: 17" dia.x 7' high Weight: 35 pounds Cable length: 50 feet Accepts extremely short pulses. Wide bandwidth minimizes ringing. light weight/portable. Easy to mount. Heavy duty mounting hardware. Rugged carrying case. Rcytheon Precision Transceiver Model PTR-l06 Power Output: 2COO watts maximum Manual gain, initial time variable gain, and Frequency: 7 kHz (others available in tv\oCel automatic bottom triggeredlVG for PTR 105A) optimal performance in shallow water. Voltage input: 115 AC or 12 volts DC with High powerfor maximum penetration. optional inverter Variable pulse lengths. Pulse width:.1 ms.-tO ms Coherent keying for sharp pulses. Electronics: All solid state Dimensions: 19" x 17' x 51,4" Weight: 55 pounds Rcytheon Survey Fathometer ~ Mocel DE-719 RTT AcaJracy: 0.5% + 1" of depth Eight selectable depth scales. Voltage input: 12 volts DC Four chart speeds. Electronics: All solid state Tide, draft, and speed of sound adjustments. Chcrtpaper: 7' x 60' Center or edge keying. Calibration: Feet or meters Integral transmitter/transducer for high Operating frequency: 7 kHz and/or resolution survey. 200kHz Dimensions: 18" x 153/a"x 91f16" Weight: 47 pounds .. : For spedfic information on price and delivery, or for applications assistance, contact: Raytheon Company, Ocean Systems Center, West Main Road, Portsmouth, R.J. 02871. Telephone: (401) 847-8000. TWX: 710-382-6923. ~AYTHEO~ Outside U.SA and Canada, contact: Raytheon Company, International Affairs, 141 Spring Street, Lexington, Mass. 02173. Telephone (617) 862-6600. TWX: 710-324-6568. Cable: RA YTH EON EX. .. .. II' " CORPS OF ENGINEERS l,l ~I-----/-­ I .I .I .I ~--i ~: -- !~ .. '. ~ ..... ' ..... : ". E .RUN NUMBER EVENT MARK WITH £VDfT NUM':R INDICATES TIUOtLlH£ v:TENOS BEYC»CD 5U'V£Y LIMITS SOUJlfOINGS TRACKLINE 5aJNOINGS AND SEISMIC TRACKLIHIE SIDE SCAN Sl:*AR TRACKLINE 1. ~'ft: snT8'll IS IN JUi /IHJ IS ~ DI:M..'''' S1"51!M (lISofC£ l~). 2. ~IN! 1$ ......... UOAlt. AT If4 EU'IAn('~ or 1020 P'EET I«Nf. I'!il. ItKJ .-s I"\..OTln) """" srot SCJIrr4 SOtIIl Mr .... ,. 111E II'N"tJIItotAT1CJo1 PItfSBfTE) BoI THIS OWI.T ~ n1E II£SIA.T'S Q~ SI..RVEY'S II"£R- P"CII'EDB'I'~SI.aYE"I'5,Jr«:.,"16-.17 ...I.A..Y 14!)~ SCALE I N FEET CHECK GRAPHIC SCALE eEFORE USING U. S. ARMY -I @ .@ -;;/ . ~ . I _I® _-r ! OCEAN SURVEYS, INC. ALASKA DISTRICT OLD SAY8ROOK. CONNECTICUT @ COR PS OF ENG! NEERS ANCHORAGE. ALASKA """ V.A.KASK SNETTISHAM PROJECT ALASKA I ST STAGE DEVELOPEMENT CRATER LAKE PHASE TRACKLI NE PLOT DATI:: 15·AUG-1983 051 ORAWING NO. TZ242-A SHEET I Of 5 INV. NO. DACW85-1 SNE 92-07-04 CORPS OF ENGINEERS L A R c ,01' ~ / ~~~ ~-----------." _ ~k -~ ~ ~ ::; ." .", ." E 86 400 -.:. 1. ELfVATICt6 AAE IN FEEl ,IH) I\EFElIDCm ro P'£AN S[A lE'tEl (I'ISL). ~ INTERVAl '5 5 !'fiT. 2. CCQttII~n:S AA£ IN FfEl N<l IN THE COo'lIN:> S'I"S'TE'I (I../S.IIrO:E 1')(,,+). J. StOEUr:.: rs Jrf>f'R(lXl,...,n;. _T NIl ELEVATlC»II CF 1020 !"EfT HSl I<KJ WAS PI..'JTTUl fRCI'I SIOC SCNI SCtWI: ClATA. '. Tt£ IfflJ!tfo'ATlON PRESENTED CN THIS OWI.T REPRfS~ THE RESlA.. TS OF SlRVEYS PER- f'ClApofi) 8'( OC£AN SlRVEYS, Ur.. ON 16-17 .M...Y l"J83 ,IH) ~ ot4..Y 8f C(J6IDEREO AS 1rc>ICATINi THE CCKlITIQo6 EI(I5-TI"':; AT T11AT THE. E V.A.I(ASK ...... IQJIrIIRAD. u.s. ARMY e'" e\' § e'19 .. ' ~., efP eff> eTO $6 .. - '0 40 SCALE IN FEET t, z E 86200 00 00 CHECK GRAPHIC SCALE BEFORE USIHG ALASKA DISTRICT COR PS Of ENGI NEERS ANCHORAGE, ALASKA SNETTISHAM PROJECT ALASKA I ST STAGE DEVELOPEMENT CRATER LAKE PHASE LAKE FLOOR ELEVATIONS INV. NO. DACW85-SNE 92-07-04 CORPS OF ENGINEERS c .to ... no ... .. 0 ••• "0 '" "0 88B Jj~-Ug ~ R R A T L A __ IXIH-.. ... DOH-IQZ K E 010 OT' I. ElEVATtCHS AAE IN I"UT fIH) IIfI"'ERDClD TO I'£AH SEA t..f'fa. (~). ecNI"tUI. tN"I'UVAl Is S I'1':ET~ t. CClClRD%IW\.'T1:: SYSfUoI ts f:"l F'fH NCJ IS Tl£ COo'LIr-G S1'SfUoI (USACf 1<;16'+). 3. StOtfLlhE IS Ai'PROX1MfE, A.T AM O.£VATTCJoj 01' 1020 fEET I«NE MSL NCJ WAS PlOTTEtI f1l(JI( Sloe SCAN saiIAfl ClATA, II. THE Irfl'JAHATICf'II PRESfHfEO ()I'll 1111 S ow,T REPR£SO<rS n£ RfSlA...TS OF SLR'Y'EYS PER- FmED BY OCEAN S~.i. It«<:. QI'II 16-1] JlA..T 1983 /JKJ CAN ot..T ee CCJl6I0EJtE0 AS H£lICATlI'G 1l£ CCH;l1T1~ o:.ISTI~ AT .1ltII.TTlI'E.· . VA..KASK M,J. KCWIlAD P •. F A A 8 o <t '" _----&10 &,'J e,'L0 z 0" CHECK GRAPHIC SCALE BEFORE USING U. S. ARMY 875 000 0'" 090 0" 900 .0' 9,0 9" .,0 .., .,0 ." .,0 ., . •• 0 ¢' •• 0 9" 9TO E 86200 m 80 ALASKA DISTR leT COR PS OF ENG! NEERS ANCHORAGE. ALASKA SNETTISHAM PROJECT ALASKA I ST STAGE DEVELOPEMENT CRATER LAKE PHASE BEDROCK ELEVATIONS DA~ 15 AUG· 1963 OS\ DRAWING NO. 1ZZ42-C SI-&T l 01 5 INV. NO. DACW85-.1 SNE 92-07-04 CORPS OF ENGINEERS s=? ~ -'0 " '0 + ro-----------, ,,--------- '0--__ _ E 86 200 ........ : .". c R A t E ~z R ",DOH-II .. DOH-IQZ L A K E 1. TliIOlJ'ESSes NIE. IN I'!n IHl WERE DfRIVEt> AIO'I SlISHIC MTA eftD'I'l" ~ CCM'RfS- SICHIIIl VELOCITY (I" !tIS) Fl/SEC. CCNTCJ...R. IKfERVAL'5 5 FffT.{SEE RI:J'OAT DISCUSSION) :l. COOROIMlU'fS M£. IN fEET flKJ rN Tt£ OOMlft.G SYSTD'I (USACE 1961+) • . . ,. StDRELIi£. IS N'P'IIOXI""TE, AT />N Elf'VATlCf.! OF 1020 fEET /'t5L .IK) ""'-S P\.OTTED FRC)IoI SlOE SCNoI SOWt: MT .... ~. ~~~=~~~:T ~ In' 0CEJrf0j s~s, 1....:. ON 16-17 ..u..y 198) I/H) CN4 CN..Y 8E (ONSIDERfi> AS 1N)ICATlt-G Tt£ CCKlIYIONS EXISTlt-C ... " 1'l1'TtJI'E ••. DelIAH .uIII V.A.I(ASI( U. S. ARMY z 10 + E 862 20 40 00 00 SCALE IN FEET CHECK GRAPHIC SCALE 1[f'0Rf USIN6 ALASKA OISTR leT CORPS ~ ENG I NEER5 ANCHORAGE. ALASKA SNETTISHAM PROJECT AlASKA I ST STAGE DEVELOPEMENT CRATER LAKE PHASE ! ~ ISOPACH MAP-UNCONSOLIDATED MATERIALS INV. NO. DACW85-.1 SNE 92-07-04 CORPS OF ENGINEERS c R A T £ R L A K £ + + • t· . .. • t· ·12' ... •.. • t· . ,,' ... . ,.' ... .... ' .. "A"a CENTDI Of SUJIII[RGED oe.I£CT • _!lOt lNOICAns APPARENT L.£NGTH . •. + -'I' .12' ' .. -II' ' •. . "' • 20' a . .. ... .IQ' ..~ I. -..ffS u-..urn"" SIll!: 5C.ItI ... -. 2. ~ST11D'IrSIM"E!T,tH)ISTH! DCIWlI"'" S'TS'TS't (U5,lra. ."'), ,: ~I~ 's ......, ... ft. AT". ElrIIAT!tJt rl1020P"fnIWl1tf.HSt.f!H).al1"'l.D11'!I) .... stOl:S(JIIMSOIIIItDl'TA. t. 'M1~nCII~CIIIMlotm ~ n«.·.eu.n rI ~ f'D- It'CIIfBI' lIT .IXVIM ~. lfiC. ON 1,""17 .u. T 191' J«) ColIN CN..T • CDlS10B1!D AS IJiOICA11IC 11« (I(IC).nCN DISTI", JoT ~T !t" ' .. • 10· ... ... ....A.ItASIt IU_ U. S. ARMY • 10' • roo T'., .14' -'0' -'0' . .. .14' . .. + 10 , 00 SCALE I N FEET CHECK GRAPHIC IlCALE lUOIt£ USI ... ALASKA DISTR ICT CORPS 0' [NGIN[!:'" ANCHORAGE. ALASKA SNETTISHAM PROJECT ALASKA I ST STAGE DEVELOPEMENT 00 CRATER LAKE PHASE SUBMERGED OBJECT LOCATION PLAN .... 15· AUG· 1983 I NY. NO. DACW85-SNE 92-07-04 EXHIBIT It LAKE TAP -INVESTIGATIONS- CRATER LAKE SNETTISHAM PROJECT, ALASKA NOVEMBER!, 1982- POL~RCONSULT, INC. polarconsult ENGINEERS. ARCHITECTS· ECONOMISTS· PLANNING CONSULTANTS 4 November 1982 U. S. Army Corps of Engineers Dave Hendrickson Contract Offlcers Representative P. O. Box 7002 Anchorage, Alaska 99510 Reference: Contract No. DACW85-82-C-0017, Appendix A, Scope of Work and Modification P0002. Dear Mr. Hendrickson: In accordance with the referenced contract, enclosed is our final report, dated November 1982. This report addresses contract concerns dealing with 1) Additional Explorations and/or Surveys; 2) Recommended Lake Tap Design Configuration wi th Supporting Text and Recommendations as to Whether a i-1odel Study is Required; 3) Recommendations on Viability of Pressure Shaft and Surge Chamber Versus Concept Shown in the Design Memorandum; and 4) Completion of two oral presentations to the Corps, one on July 28th and the other on October 21st. It has indeed, again, been our pleasure to work wi th the Corps of Engineers on the Snettisham Project. Very truly yours, rris J. Turner, P.E. roject Manager MJT/tsb enclosures: Report Billing 2735EASTTUOORROAO • SUITE201 • ANCHORAGE. ALASKA 99507 • PHONE (907)276·3888 • TELEX:26708PCAAHG SNETTISHAM PROJECT ALASKA SECOND STAGE DEVELOPMENT CRATER LAKE FUTURE POWER TUNNEL a CRATER LAKE LAKE TAP -INVESTIGATIONS REPORT NOVEMBER, 1982 PLAN polarconsult, inc. ENGINEERS ARCHITECTS ECONOMISTS PLANNING CONSULTANTS ANCHORAGE,ALASKA SNETTISHAM PROJECT ALASKA SECOND STAGE DEVELOPMENT CRATER LAKE LAKE TAP STUDY -INVESTIGATIONS FINAL REPORT Prepared by: Polarconsult 2735 E. Tudor Road, Suite 201 Anchorage, Alaska 99507 November 1982 1.0 1.1 1.2 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 3~0 3.1 3.2 3.3 3.4 3.5 4.0 4.1 4.2 4.3 4.4 5.0 5.1 5.2 5.3 5.4 5.5 6.0 6. 1 6.2 REFERENCES. General. Summary. TABLE OF CONTENTS 1. 2.1 1. 2.2 Additional Explorations ... Alternative Lake Taps, Model Studies Design Contigencies ................. . 1. 2. 3 Viability of Increasing Unlined Part of Headrace ......................... . GEOLOGY. General .. Rock Description. Weakness Zones. Rock Stress ... Water Leakage. Air Leakage ..... Seismic Risks. .. .-. ADDITIONAL INVESTIGATIONS. General ............... . The Lake Tap Area. Sonar Surveying Under Water .. The The Gate Chamber/Shaft Area .. Surge Chamber/Unlined Pressure LAKE TAP-ALTERNATIVES/MODEL TESTS. General ..... Alternative 1 : 4.2.1 Notes ... Closed System/Dry Shaft Tunnel. Alternative 2: Open System/Wet Tunnel .. Conclusion .. LAKE TAP ALTERNATIVES ET.AL./DISCUSSION .. General •..... The Lake Tap. Trash Rack ... Intake Structures. Conclusion ..• Area .. and . 1 · •••• 2 · • 3 • . 3 . ...••. 3 . . . . . . . . . . . 5 · . . . . . . . 8 • •• 8 • ••••• 8 .8 10 · . . . . . .11 ... 12 · ... 13 · ... 15 · . 15 .15 . ..... 16 • •• 1 7 · 19 · .... 21 .21 .21 .24 · .25 .30 • •••••• 32 · .32 33 • •••••• 35 • ••• 36 38 HEADRACE ALTERNATIVES ....... . ............................ 39 Tentative Layouts/Discussion General .............. . · . 39 The Penstock Solution .. . . -, . , .. · .... 40 6.3 Alternative 1: Tunnel at High Level and Unlined Pressure Shaft ........................... 41 6.4 Alternative 2: Sloping Headrace Tunnel With Air Cushion Surge Chamber .................... 46 6.5 Conclusion ............................................... 51 7.0 SU~mARY OF ADDITIONAL INVESTIGATIONS/INFORMATION REQUIRED DURING THIS STUDY ............................... 54 8.0 ATTACHMENTS ..................................... ;; ........ 57 ( 1.0 REFERENCES The Report is based, in part, on the following studies,drawings, and information: U. S. Army Corps of Engineers. 23, 1973. Design Memorandum Ingenior Chr. F. Groner. January 1973. Recommended arrangement. Report to U.S. Army Corps of Engineers Contract No. DAC\'J85-7 4-C-0004. Alaska Geological Consultants, 1974 Foundation Report Geologic Map -Penstock. Lake and Crater Lake, U.S. Army COE. Seismic Risk Assessment. DOWL Engineers, 1982 Air Photos from Crater Lake to the Station, U.S. Army COE. Long Power Video Tapes of proposed lake tap area, U. S. Army COE. 1 1.1 GENERAL Under Contract DACW85-82-C-0017, Polarconsult Alaska, Inc. has undertaken the review of the Snettisham Design Memorandum 23, First Stage Development plan, Crater Lake. Specifically our areas of contract concern have been: o Additional exploration and surveys required, if any. o Lake Tap Design Configuration and Model Studies; o Discussion of Viability of Unlined Pressure Shaft o Two oral presentations to the Corps of Engineers on these subjects. The report which follows discusses these points in some detail with the exception of the oral presentations (only briefly mentioned), which were presented to the Corps on July 28 and October 21, 1982. : 2 11' .. 1.2 1. 2.1 SUHMARY Additional Explorations Our analysis of the available geological data (elsewhere referenced) and drill logs, and the site visit of July 28 to Snettisham have lead us to conclude that: 1) A seismic refraction survey of the tap may be appropriate, especially if the side scan sonar, which currently has not been done, cannot provide the necessary delineation of the overburden, rocks, boulders, trees, etc. in the vicinity of the tap area; and 2) that there is a need for additional explorations and tests, which are covered in some detail in Section 3.5, dealing with the surge chamber and pressure shaft. These tests to establish the location of the air chamber et. al.should be possible during the construction phase of the work. : 3 1. 2.2 Al ternative Lake Taps, Model Studies and Design Contingencies Based on the study of the existing data, the site visi t, and discussions with Corps personnel, a completely definitive recorrunendation on the lake tap cannot be made at this point in time but must await the receipt of additional information on the tap area and an overall economic comparison between the various schemes. However, our impressions of the lake tap design configurations and model studies are are outline below: 1) We do not believe the model study is necessary for the Crater Lake lake tap. Section 4.0 and 8.0 of this report discuss our reasons for this opinion. 2) The recommended lake tap design configuration would (subject to evaluation of the additional data as noted above) be a) either a tap similar to what is shown in the Design Memorandum #23 except for two changes, i. e.: 1) tunnel invert and tap invert at the same elevation and 2) a slightly different configuration from the tunnel crown to the tap crown at the point of piercing, or b) our current preference of a wet well intake chamber with an air 4 ,. " .. co.' "'" 1. 2.3 cushion which we find easier to construct, possibly cheaper, and with excellent tapping results. We are not sure at this time whether a dry intake chamber or a wet well intake would be the economically preferable solution. Because of tha t, we cannot categorically recommend which of the two lake tap configurations should in fact be utilized on the Snettisham proj ect. All things being equal, our preference would be for a wet well with a dampened lake tap, utilizing water column differential between the lake level and the intake structure with an air cushion at the point of piercing. It is also important that experienced crews be used in the construction phase. Viability of Increasing Unlined Part of Headrace The concept is technically viable. Additionally, information is needed as to how the Corps views underground tunnel size economics, since the parameters really dictate the overall economics of a penstock versus unlined pressure shaft, and surge tank versus surge chamber, etc. Our preference is for an unlined pressure shaft and surge chamber. 5 We cannot now, without revised estimates and discussions with the contractors, say which is cheaper. However, it is felt to be important to find out more about the Corps I views on size of drilling equipment and the utilization of rubber tired equipment. For example, in Norway today larger tunnels are used both with standard drilling and blasting Much of operations or this is done with boreing machines. for ease of construction rather than as a requirement for the hydraulic waterways. In other words, if the Crater Lake project was being done in Norway today it is quite certain that a pressure shaft rather than the penstock would be utilized. However, the size of the pressure shaft and the unlined power tunnel would dictate whether or not an intake structure versus a surge chamber would be used. If the tunne 1 sizes stay in the vicinity of the si zes that are now shown, most likely a surge tank would be utilized. Addi tionally, there is a clear feeling that an access adit should be provided so that the 6 .. penstock construction work, to the extent possible, is separated from the existing valve chamber and power house including the /maintenance area and access tunnel. 7 2.0 GEOLOGY 2.1 GENERAL Based on review of available reports, core logs, and visit to the site, which also included an inspection of some of the cores, the following summaries can be made. 2.2 ROCK DESCRIPTION The most suitable term for the rocks at the site seems to be gneissic quartz diorite. The rocks vary in mineral composition and color from dark hornblende and mica gneisses to light granodiorite. The quartz content varies also for all types of rocks. Basalt dykes have been found by core drillings and one is to be seen at the entrance of the access to the power tunnel of the Long Lake project. Except for weakness zones (shear or fault zones) the rocks are sound and of a good quality for tunneling. The jointing is generally moderate to' low except for weakness zones and core drillings give mostly 100% core recovery. 2.3 WEAKNESS ZONES ... : The term "weakness zones is, in this report, used as a general term for fault or shear zones to point out the 8 1 importance of the rock quality in such zones. It is a relative term, and the rock quality in a weakness zone might vary from just a few parallel joints causing no tunneling problems to crushed and decomposed rock including swelling clay, which can cause heavy stability problems. According to core drillings, two rather large weakness zones (15 25 foot width) with very poor rock quality are found. One of these zones is found in borehole (Oct. 1972) drilled at an inclination from the shore of Crater Lake against the gate chamber (see Plate 1). This zone is probably also found in the new drill hole DHl12 (1982) . The other zone if found in drill hole DH105 (1972) , and borehole DH101 shows (probably) part of the same zone as shown in borehole DHI05. The rock in these two zones is of very poor quality and concrete lining at the tunnel face will be required. (The term "at the face" means that the lining should be done before drilling for the next round is started.) The other mapped weakness zones seem to be of minor importance for the tunnel stability even if some of them will require reinforcement (rock bolting, shotcrete) and/or grouting. The numbering refers drillholes (July 1982). to the 9 last renumbering of the 2.4 Plate 1 shows a cross section through drillholes DH111, DH112, and DHl13 where the weakness zones observed are marked. As can be seen, the gate chamber/shaft is well sited. The power tunnel between the intake gate and the tap point will probably intersect the bad weakness zone logged in hole DHI02. The exact location of the point of intersection should be found by sounding drillings ahead of the tunnel face as the tunnel excavation is carried out. Special attention should be paid to two weakness zones shown on drawings of the penstock/bifurcation for the Long Lake project. These two zones (650 and 1000 feet from the bottom of the shaft) might cross the Crater Lake penstock or surge chamber area. They have 2" - 6" gouge material, are heavily jointed and gave water seepage into the shaft during construction. ROCK STRESS To our knowledge, there have not been any rock stress measurements done, but according to topography (mountain heights up to 1500 2500 feet) rock stresses high enough to give spalling in tunnels at low levels are possible. However, experience from 10 2.5 the Long Lake project (power station and penstock) give no indications that high rock stresses should cause spalling or any other major problems for the tunneling. On the other hand, the rock stresses should be high enough to give possibilities for unlined pressure tunnels provided proper overburden criteria are used for the design. In order to better evaluate the rock stress conditions, stress measurements should be performed at the bottom of the shaft excavated in 1970 (for the Crater Lake phase) and as far as possible from the power station. ~"lATER LEAKAGE Very often water leakage into a tunnel is a problem. During the presentation meeting at the u.S. Army COE office on October 21, 1982, we were informed that permeability tests as well as measuring of the artesian head in drill hole DH11S (1982) had been performed. As the results are not available at present, however, only general evaluations can be done here. 11 2.6 From the Long Lake project, no water leakages causing prob lems are reported except for the tap area. The core logs for the Crater Lake project describe generally good and sound rock that should give practically no water leakage, but there is some information of calcareous veins and circulating water loss during core drillings, indicating that water leakage can occur in some places. An area of concern is the lake tap at Crater Lake where precautions have to be taken (such as grouting of the tap area) to prevent/reduce water leakage as the tunnel proceeds towards the point of tap. .' .' ... Water leakage from a high pressure tunnel should not f occur as long as the ground water pressure is higher than the head in the tunnel. Even if the water head in the tunnel exceeds the ground water level, the water leakage from the tunnel should not be more than the water inflow and, as such, be of minor importance. AIR LEAKAGE If an air cushion surge chamber is chosen for the Crater Lake project, the permeability around the chamber is of great importance. In this respect the permeability tests and artesian water head measurements carried out in drill hole DHllS (1982) 12 g,' 2.7 might provide a valuable basis for judgement at this stage of planning. As the results are not available so far, only general comments can be given. The artesian head could give information about the elevation at which the water enters into the rock. Besides, the head might say something about the dip of the two weakness zones detected in drill hole DHl15. If the head is higher than what corresponds to elevation 1125', an air leakage air chamber should most likely from the compressed not occur. Judging from the observed rock quality and experience from similar construction in Norway, it seems to be quite realistic to find a site for the chamber in the proper area giving low or practically no air leakage. The chamber could-either be located on the downstream side of the sheer zone (Tsimpsian) or between this zone and the next zone moving upstream (Tlingit). SEISMIC RISK The report from DOWL Engineers, dated July 1982, provides an assessment of the seismic risk at the Snettisham Proj ect. The conclusion to be drawn from this report for the Crater Lake project seems to be that the generally good geologic conditions (Le. no active fault zone within 40 miles of the station) 13 requires no special precautions except for possible surface structures and the lining of major weakness zones. Such construction has to be designed according to the general seismicity in the area (zone III). 14 'fHo f' 3.0 ADDITIONAL INVESTIGATIONS 3. 1 GENERAL There seems to be two areas where further investigations are necessary before the construction phase: 1) the lake tap 2) the air surge chamber 3.2 THE LAKE TAP AREA In the lake tap area, leadline logging and surveying from submarine have been performed showing the sloping of the bottom of the lake and surface conditions. Also, core drillings have been done to confirm rock quality and investigate the location of the weakness zones in the area. Depending on the sonar logging results there might still be uncertainties concerning the intake ground conditions at the tap point. If the sonar loggings show overburden, which can be rock blocks, slabs or boulders, highly consolidated moraine, logs, or uncertain depth to bedrock, then seismic refraction measurements should be performed at 30' on center as shown on Plate 1 to give supplementary information concerning depth to bedrock 15 and rock quality near the rock surface. Five profiles should be measured as shown on Plate 1, thus providing opportunities for choosing the best place for the tap. 'The profiles should cover the elevation range 780' 1020'. 3.3 SONAR SURVEYING UNDER WATER This surveying is a very important point for a successful tapping operation. ~ Design Memorandum 23, Plate no. 3, Dec 1973 shows one underwater map. Drawing I-SNE-95-08-08-02 shows a partly changed underwater map (Nov. 1974). Drawing I-SNE-95-08-08-03 has some changes from the above mentioned drawing between D850-125. ". It is important that the underwater area is mapped as accurately as possible. vle suppose that the underwater surface map should be controlled by the planned side scanning sonar investigations and mapped at a scale 1" = 25'. The direction at the tap and the last part of the tunnel from the gate shaft out into the lake, will depend largely on this underwater mapping and with the overburden situation, the rock fault location, and the 16 3.4 resul ts from the sounding dri llings which should be done as the tunnel excavation advances towards the weakness zones and the tap point. THE GATE CHAMBER/SHAFT AREA Borehole DH102 (1972) the core at tunnel shows an 8 -10 meter length of level near the gate area where there are core losses of up to 30% and the rest of the cores are highly broken and altered. On Plate 1 a sketch is provided of the outcrop of weakness zones which can be seen in the terrain and also from aerial photos. The new borehole DH111 (1982) drilled vertically through the gate chamber shows 5-6 weakness zones at elevations 1330' and 1180' approximately. Since these zones are located at high level, they are of minor interest in the chamber area. This drill hole does not give information about the direction (strike and dip) of the weakness zones indicated on Plate 1. The new angle hole DHl12 shows weakness zones approximately 225' and 440' from the top of the hole. The first of these might coincide with the zone trace visible on the surface. 17 The new angle holes DHl13 (1982) and DHl14 (1982) have been drilled, but the proper summary logs are not available in Anchorage at present. However, from very preliminary logs, received over the phone from the site, it has been learned that DHl13 shows weakness zones at depths of approximately 110' and 380'. The latter might be connected to the zone trace on the surface indicating that the zone's dip might be close to vertical. Drill hole DHl14 intersects a bad zone dipping northerly. According to the phone-reported log, a 100% loss of circulating water occurred at 151' depth. Further down the hole, clay gouge, soft gouge, chlori te and calcium carbonate are found. This zone will probably give water leakage into the tunnel and might demand a concrete lining. The gate chamber/shaft area and the tap area are looked upon as a whole and appear to be pretty well covered by core drillings. Based on the findings from these drillings, it should be possible to draw the traces of the weakness zones at tunnel level to a reasonable accuracy, thus finding the best tunnel alignment up to the tap point. It is found that further investigations should not be needed for the final design phase. It is, however, stressed that sounding drillings should be carried out ahead of the tunnel face (length at least two times 18 .. the length of each round) during excavation to control plans and avoid surprises. The soundings should go in as a part of the specifications and be started some 30' before the intersection tunnel -weakness zones are expected. 3.5 THE SURGE CHAMBER/UNLINED PRESSURE SHAFT AREA The new angle drill hole DHl15 (1982) starting at elevation 775' (which is a better starting point than the originally proposed elevation 600') gives valuable information about the rock conditions in the air surge chamber/unlined pressure shaft area. However, as the hole length is kept to 650' after moving the start point 175' higher up the hillside, the bottom of hole is located at elevation 315', whereas the pressure headrace tunnel and the alternate unlined pressure shaft will be situated at a lower level. The length of the drill hole DHl15 should preferably have been increased to bring the bottom of the hole down to elevation 100'. If a pressure tunnel with an air surge chamber or an unlined pressure shaft is chosen for the project, the access adit to the gravel trap at the upstream end of the steel-lined part of the headrace will enable exploration ahead of the excavation of the adit to be done so that the weakness zone(s) found in DHI06 and 19 DHl15 could be located at tunnel level, thus giving a base for making the final decision concerning the location of the upstream end 6f the steel lining. It is of importance that the headrace tunnel should be excavated beyond the air chamber area before the chamber's location is finally decided. Also, core drillings with water pressure tests should be performed from the pressure tunnel before the final location of the air chamber is chosen. Registration of water inflow (leakage) to the pressure tunnel during excavation is an important means of evaluating possible surge chamber and air leakage from the air cushion of deciding whether or not precautions such as grouting should be necessary. At this stage of the construction work, rock stress measurements should also be performed to ensure that rock stresses are of an acceptable level for the air surge chamber. 20 4.0 LAKE TAP -ALTERNATIVES/MODEL TEST 4. 1 GENERAL Two different systems or alternative taps could be applicable for the Crater Lake piercing, neither of which by our judgement should require a model study. The reasons for this, as well as descriptions of the systems, are hereunder outlined. 4.2 ALTERNATIVE 1, which could be called the CLOSED SYSTEH/DRY TUNNEL alternative, is equal to the recommended solution shown in Design Memorandum No. 23, Plate 17, except for two minor modifications. This alternative is covered fairly well by a model study run at the Water and River Laboratory of the Technical University of Norway in 1968. The study was done for a Norwegian lake tap, the Askara Lake tap, blasted some 10 years ago. This tap had dimensions and water depth not too different from what is proposed for the Crater Lake scheme, except that the tunnel dimensions and depth were somewhat larger at Askara than those proposed for Crater Lake. The series of model tests were run for 14 different configurations for the tap and rock trap area. Nine of these configurations are illustrated on five 21 attached sheets, marked 111.1 through 111.5, extracted from the laboratory's report of 30 January, 1969. It is believed that the figures speak for themselves, even if the text is in Norwegian, and thus that there should be no need for a description in words of the various configurations tested. Most of the configurations were tested both with the dead end rock trap drained and filled with water up to the invert of the power tunnel. From the model tests it was concluded that the configuration shown on sheet 111.4, bottom of page, with an lS-meter long dead end tunnel 2-meters wider than the power tunnel over a length of 14-meters from the dead end, and the trap invert l.S-meters lower than the power tunnel invert was the best of the tested configurations. The model tests ilso showed that it is essential that the dead end trap is drained when the final blast is executed. This is clearly seen from figures extracted from the test report as given below. 22 Distribution of rock from the final plug in percent of total amount (figures in ( ) valid when the rock trap is filled with water) : In dead end rock trap In additional rock trap approx. halfway between dead end trap and gate shaft On invert of power tunnel between dead end trap and gate shaft At intake gate 87(29)% 7(34)% 1(10)% 5(27)% The model studies carried out for the Askara Lake tap, as briefly above, described were useful as they lead to important adjustments of the preliminary plans for this tap. As the conditions for the planned lake tap at Crater Lake are only slightly different from those for the Askara tap, there should be little doubt that model studies on ~he Crater Lake tap would not provide more knowledge of significant importance for the design of the Crater Lake lake tap. The conclusion reached is that no model study on the lake tap for the Crater Lake scheme is required, if the closed system/dry tunnel alternative is chosen for the lake tap. 23 4.2.1 Notes: 1. The configuration for the lake tap at Askara as shown on sheet III. 4 of this report (same principle as on plate 17 of Crater Lake Design Memorandum No. 23) was modified during the final design, such that the power tunnel invert and the dead end tunnel invert had the same level. To retain the rock from the final plug in the trap, a concrete sill was established at the inlet to the power tunnel from the rock trap. The sill had drainage holes at the bottom large enough to make the rock trap self drained. The reasons for these ... modifications were of practical/economical nature, as draining the trap by pumping was avoided and the dead end tunnel could be excavated cheaper than would be the" case with the shown configurations. 2. As a consequence of the configuration of the tap and rock trap area as shown on plate 17, Design Memorandum No. 23, as well as on Exhibit 1, Groner drawing no. 1515-103 (see also plate 12 of Design Memorandum No. 23), a substantial amount of air will be trapped underneath the power tunnel roof between the tunnel inlet and the intake gate. The only way this air, which will be compressed following the final blast, can escape the tunnel is through the vent pipe downstream of the intake gate. As the air will be fairly highly 24 4.3 compressed, rather violent outbursts of. air must be expected as the intake gate is fully drawn the first time. To reduce these outbursts, slight modifications of the tunnel roof near the final plug should be considered during detail design in such a way that most of the air could escape through the tap inlet following the final blast. ALTERNATIVE 2, which could be referred to as the OPEN SYSTE~1/WET TUNNEL alternative, is illustrated by sketches shown on the attached figures 1 through 4. This sytem has been applied for several lake taps carried out in Norway the last years, and is now often preferred over other methods both for technical and economic reasons. The sketches are taken from the Oksla hydro power plant owned by NVE-Statskraftverken (Norwegian State Electricity Board) completed 26 January, 1980 by fireing the final plug of the Ringedalsvatn lake tap. The power tunnel for this plant is considerably larger than the Crater Lake tunnel (with a cross section qrea of or 375 2 ft. ). The water depth at the tap point is also higher for the Ringedalsvatn tap (85 meter or 280 ft.) than for the Crater Lake tap. : 25 As the open system/wet tunnel may not be w.ell known, a short description of the Oksla hydro power plant and its lake tap follows. Figure 1 provides an overview showing an underground power plant with an inclined power tunnel (called a pressure tunnel in Norway) avoiding a pressure shaft or penstock. The figure also shows that a compressed air cushion surge chamber was chosen for this plant instead of a conventional surge shaft, usually with an upper and a lower chamber. Figure 2 shows the upper part of the power tunnel between the intake gate shaft and the lake tap point. The elevations in meters 456.0 and 448.0 indicates the water levels in the lake and gate shaft, respectively, at the moment when the final plug was blasted. On the section drawing the location of pressure cells installed (as a part of an ongoing research program) to measure the pressure rise during the final blast are indicated. Near the upstream end of the tunnel the 19 last rounds towards the plug are indicated by lines normal to the axis of the tunnel. Soundings carried out ahead of the tunnel face over this portion of the tunnel are also indicated. (The change of the tunnel direction was done to reach the most favorable tap point. ) 26 Figure 3 show.s in some detail the intake gate shaft with the location of the main gate and bulkhead gate. The gate positions are shown as of when the plug was blasted. Location of equipment to control the water filling of the tunnel between the gate shaft and the tap point, and to assure that the air cushion ·underneath the final plug is maintained until the plug is executed, is also indicated. Figure 4 shows the result of the pressure fluctuations during the final blast and a short time afterwards. Also, used delay capsule numbers and amount of dynamite ignited by each delay cap are shown. From the figure it can be seen that in the case of an open piercing, the main intake gate is closed, the bulkhead gate and the gate shaft are open, and both gate shaft and the tunnel between the gate and the plug, are filled with water -in this case pumped in from the lake through the gate shaft. The quantity of water pumped in is so determined that the waterhead (lake to gate shaft) will meet two principal requirements: 1) the surge in the gate shaft after the final blast should be kept below the top of the shaft, and 2) sufficient water inflow to the tunnel should be provided such that the debris from the final plug and 27 the possible overburden could be suitably distributed and deposited in the tunnel (which for this purpose has an enlarged cross sectional area in the vicinity of the plug) . From the figures it can also be seen that the tunnel towards the plug is designed such that, when filling it with water, an air cushion is created below the final plug. For the Ringedalsva tn lake tap this cushion enclosed approximately 150 (150m 3 under atmospheric pressure). normal-m 3 of air It is of vital importance that such an air cushion is created and maintained until the final blast occurs to avoid that the pressure shocks from the break-through blast are transmitted through water against the main gate, which might thus be damaged. The volume of the air cushion depends upon the quantity of dynamite needed to blast the final plug (especially the load igni ted by the first caps), the distance between the plug and the gate structures, and the dampening of the shock aimed at. It is obvious that the shock dampening will be larger, the larger the air cushion. From the results of the measurements done during the Ringedalsvatn lake tap the following is extracted: 28 Pressure in air cushion before blasting approx. 9 bar Max. pressure measured near the plug 12.5 bar Max. pressure measured at the gate 9.1 bar Max. surge in the gate shaft above the water level in the lake 5.8 meter The water level rise ln the g~te shaft took 26 seconds which corresponds well with the calculated value of 29 seconds. The 5. 8 meter surge above the reservoir level which occured in the gate shaft after the final blast counted 72.5% of the chosen 8-meter water level difference between shaft and reservoir before the blast. This corresponds well to experience with this type of piercing from other lake taps, and the computations. Based on the experience from the Ringedalsvatn lake tap and other taps carried out according to the same open shaft/wet tunnel method, one can with reasonable certainty assume that the water in the gate shaft will oscillate to a level amounting to 70 -90% of the level difference (reservoir to shaft) before the final blast, depending on head losses due to friction and turbulence. Based on experience from the Ringedalsvatn lake tap and , .. other lake taps of the same type, our conclusion is that there is no need for a model study on the lake tap 29 at Crater Lake if the open system/wet tunnel alternative is used as long as the distance between the tap point and the gate structures is sufficient. 4.4 Conclusion: Referring to contract No. DACW-82-C-0019, Lake Tap Crater Lake, Description Item c; our conclusion is that there should be no need for a model study on the lake tap at Crater Lake, whether or not the closed system/dry tunnel method or the open system/wet tunnel method is chosen for the tap. If the closed system/dry tunnel alternative is chosen, the lake tap configuration could be as shown on plate 17 of Design Memorandum 23, First Stage Development Plan, Crater Lake with the smaller modifications indicated in this report. Should, however, the planned investigations regarding overburden (loose material, boulders, debris, etc.) show unfavorable conditions, a ~ double-plug lake tap as shown on plate 18 of the Design .' Memorandum might be chosen to minimize the chance of having the inlet blocked by overburden material. In this case, there shouldn't be any need for a model study as long as the configuration is kept as shown on plate 18. The modifications mentioned above for the single-plug tap should also be considered for a possible double-plug lake tap. 30 If the open system/wet tunnel method is chosen the configuration briefly shown above for the Ringedalsvatn lake tap could be adapted to suit the Crater Lake lake tap, and no model study should be required as long as the distance between the final plug and the gate structures is sufficient. Based on the knowledge at present about the conditions in the tap and gate chamber/shaft area the distance between the tap plug and gate will most likely be approximately 600'; which is considered a sufficient distance. Should there, for some unforeseen reason, be a need for reducing this distance, this would be possible if the air cushion underneath the plug is made large enough to reduce the shock effect from the blast against the gate structures (possibly, in combination with strengthening of the structure s) .. From an overall standpoint (design and construction), it is owner important that the contractor as should have experienced personnel well as the at the site, especially during the excavation phase, from the intake gate towards the final plug blast. 31 5.0 LAKE TAP ALTERNATIVES ET.AL. DISCUSSION 5. 1 GENERAL There are at least two different alternative systems feasible for the Crater Lake lake tap: 1. The closed system/dry tunnel alternative. 2. The open system/wet tunnel alternative. (Other alternatives -such as the closed system/partly filled tunnel -are considered of minor interest for the Crater Lake project, and will not be dealt with in this report.) Alternative 1 can be chosen whether a gate chamber at low level or the shaft solution with the gate chamber above the lakes Hm'lL is selected. Alternative 2 demands the shaft solution. Each of the mentioned two alternatives has its pros and cons, which will be discussed in this part of the report. It is found that none of the alternatives clearly stands out as to be preferred from a technical point of view. This is probably also valid when questioning 32 5.2 economy covering both construction cost and operation/ maintenance. The latter should be proved by cost estimating for comparison. Items for comparing estimates are, besides the tap itself, gate structures with gate chamber/shaft/access and access to the lakeside for trash rack cleaning. THE LAKE TAP Compared to alternative 2, Alternative 1 requires,a more complicated configuration, resulting in more costly rock excavation for alternative 1 than for alternative 2. Alternative 1 exposes the largest portion of rock close to the rock surface towards the lake and is thus the most sensitive alternative concerning weakness zones and rock reinforcement works. Both alternatives will have pipes through the concrete plug around the intake gates for ignition wires. Al ternative 2 will, in addition, have pipes both for cables to the water level gauge needed in the air cushion underneath the final rock plug and for filling compressed air into the cushion during the filling of the tunnel. The end of this pipe for compressed air should have a diffuser cap to avoid damage to the igni tion wires and water level gauge. Alternative 2 calls for pumps and pipes to be able to fill the 33 tunnel and gate shaft rather quickly before the final blast. The pipe (s) down the gate shaft, for water filling, should preferably be flexible, for example, 8~ or 10" ARMTEX pipe (to reduce and "smoothen" the water velocity down the gate shaft). Alternative 2 could also have a pipe (depending on tap configuration) for deairing. Alternative 1 is more demanding than al ternative 2 concerning drainage as close up to the final blast as possible. For alternative 2, the periods of time from start of filling the tunnel until triggering the final blast is critical. The work for this period should be planned to the smallest detail aiming at 16 hours from start of filling until firing (this even if the delay caps should be specially made to resist 300' of water pressure for 72 hours). Talking about installation needed and complexity, alternative 1 is preferable over alternative 2. Alternative 1 leads to uncontrolled inflow of water to the tunnel following the final blast, whereas the inflow is controlled if alternative 2 is chosen. In this respect, alternative 2 has a clear preference. Whilst alternative the intake gate 1 gives the largest impact against caused by the water' s inflow, al ternative 2 could perhaps be considered as somewhat 34 ... .. 5.3 more risky when talking about maintaining the air cushion which is essential to avoid an undampened shock transmission from the detonations to the gate. However, as the pressure in the air cushion is less than the water head in the lake, the quantity of air that eventually must be pumped into the 9ushion should probably not exceed the quantity of water leaking in. The water leakage into the tunnel should not be so great as to prevent drilling and loading of the final plug, and hence the question is considered of little practical interest. Considering the lake tap itself only, it can be said that there is no important difference between the two alternatives. According to current Norwegian practice, alternative 2, the open system/wet tunnel method is, as a rule, preferred both for technical and economical reasons. As, however, the choice between alternatives can be influenced by conditions outside the tap/intake area, the closed system/dry tunnel method sometimes is chosen for economical reasons. TRASH RACK As learned from the submarine inspection, considerable quantities of trees, logs and branches are found on the lake bottom in the tap area. It is evident that 35 5.4 these trees et.al., should be removed prior to the lake piercing. It is further clear that the lake carries trees, etc.~ and therefore that the tap opening should have a trash rack preferably even a rough, intermediate rack installed before the first draw-down of the lake. It is recommended that the permanent rack should have cleaning equipment, and that there, for cleaning purposes, should be an access to the hillside above HWL in the lake. This might well, for reasons of cost, influence the choice for tap alternatives towards the open system/wet tunnel alternative. INTAKE STRUCTURES As stated above, the lake tap alternative 2 demands a gate shaft up to a gate hoist chamber with invert some 10-20' above Crater Lake's HWL, whereas alternative 1 could either have the same shaft or a gate hoist chamber some 30' above the invert of the headrace tunnel at the gate (recommended plan according to DM !II' 23). In this respect, alternative 1 could thus be said to be the most flexible one. Alternative 2 gives the opportunity to excavate a "'. tunnel from the gate chamber to the lake side as an '" acce ss to the trash rack cleaner. This adit would be 36 only 380'-400' long. Close to the lake side this tunnel could be enlarged to form an underground housing for the trash rack cleaning equipment. It is judged that alternative 1 should also have an access to the lakeside to be able to serve the trash rack cleaner. As the hillside along the lake is quite steep, this access should probably also be through a tunnel. It is assumed that a tunnel is found to be the most economic access solution in this case, one will have the following total lengths of access adi ts and gate shaft: Alternative 1: Adit to gate chamber Adit to trash rack clean~r Gate shaft Alternative 2: Adit to gate chamber Adit to trash rack cleaner Gate shaft Approximately 1270' Approximately 1270' Approximately 12-15' Approximately 820' Approximately 390' Approximately 240' Ai ternative 2 will need a 225-230' higher gate shaft than alternative 1, also a 225-230' longer gate operating rod. The rod will need side supports {side 37 5.5 bearings) anchored to the shaft wall by mean~· of concrete brackets to avoid buckling of the rod when setting the gate. Even if the gate shaft with operating rod and ladder is expensive (could the hoist be omitted and the shafts' be dimensions reduced?) , it is felt that the construction cost for the longer access adi ts, which alternative 1 needs, will be close to balancing the cost for the higher gate shaft with equipIllent which alternative 2 calls for. Thus, difference in construction cost between the two tap alternatives is thought to be of no particular iIllportance with respect to choice between the alternatives. CONCLUSION Based on the above discussion of some of the pros and cons attached to the two alternatives for performing the lake tap at Crater Lake, the conclusion is that no important arguments are found which could lead to a clear recommendation that one alternative should be preferred before the other. This is valid when talking about technical differences, probably also when comparing costs (operation and maintenance included). The last statement should be proved by cost estimating for comparison. 38 6.0 HEAD RACE ALTERNATIVES Tentative Layouts/discussion 6.1 GENERAL The following two alternatives to the solution shown ln Design Memorandum 23 are seen for headrace features to take the power water from Crater Lake to the power house: Alternative 1: Unlined headrace tunnel at high level with unlined 45° pressure shaft and a flat, steel-lined pressure tunnel at elevation 100'-140' to meet the inclined dead end shaft excavated in 1970. Alternative 2: Unlined pressure tunnel sloping approximately 12% from the intake gate down to a flat steel-lined pressure tunnel at elevation 100 '-140' to meet the inclined dead end shaft excavated in 1970. This alternative implies an air cushion surge chamber. The final alignment and configuration for the alternatives will probably be inf 1 uenced by the location of the two mapped weakness zones in the area (Tsimpsian and Tlingit faults), and the plans should 39 6.2 probably be modified to some extent as the excavation works detailed knowledge about the rock conditions. (As an example, possible modification af the location of the air surge chamber is indicated on Plates 7 and 8.) Based on tentative layouts (plan and profile) roughly illustrated by Plates 3 through 8, the headrace alternatives 1 and 2 are briefly discussed in this part of the Report. Some remarks are given on the basic solution, reference Design Memorandum No. 23. THE PENSTOCK SOLUTION The basic. solution as shown in Design Memorandum 23 implies that the muck from the shaft excavation must be loaded in the valve chamber and from there transported to the deposit through the existing power house and access tunnel. Besides space for the loading operations, the valve chamber and adj acent tunnels/ caverns should also give room for the shaft hoist with working platform, drill jumbo and other equipment needed for the shaft excavation. The excavation works will result in polluted air and water which have to be pressed/pumped from the valve chamber. To reduce the possibility that dust air should enter the power house I possibly being harmful for the electrical equipment, the power house and .,. 6.3 workshop area should be shut off from the construction area and subjected to some over-pressure. Both the scarce working space available and the dust/water questions make somewhat problematic, time expensive. It is therefore the solution indicated consuming, and, suggested that an thus, access adit to the shaft be considered to separate the construction from the existing power house. ALTERNATIVE I: TUNNEL AT ·HIGH LEVEL, UNLINED PRESSURE SHAFT. (Plates 3 and 4) The configuration shown on Plate 3 is probably the one that brings the tunnel and pressure shaft as near to the hillside as possible for reasons of needed rock cover, thus providing the shortest waterway from Crater Lake to the power house. It might be necessary to bring the upstream end of the steel-lined tunnel further into the rock masses depending on rock quality which will be revealed during excavation of the access adit. Plate 4 indicates two al ternative elevations to the steel lined tunnel. The alternative indicated by dashed lines is found to be the preferable one. The reasons for this could be given as follows: 41 The full-lined alternative gives the best rock cover at the downstream end of the gravel trap and also possibly the shortest steel lining (90' -lOa' shorter) together with the simplest steel lining configuration. The alternative means that the inclined shaft, excavated in 1970, should be omitted and that blasting is necessary very close to the existing valve chamber and the Long Lake bifurcation. It also means that the access adit invert at the portal should be at a low level to land at the proper level at the gravel trap so as to avoid a contra-sloping adit and pumping. The dash-lined alternative brings the blasting away from the Long Lake penstock, allows the access adi t portal at a favorable elevation, self-drained and well-sloping. thus making the adit Judging the pros and cons, it is found that the alternative indicated with dashed lines should be preferred and it is suggested that the fur~her planning for comparing alternatives be based on this solution. The following description is based on the assumption that this suggestion is agreed upon. Description: An access adit with a length of some 1150' leads into a gravel trap with invert at elevation in the range of 100'-140'. The invert of the adit at the portal could 42 be chosen so that the adit's slope will be appropriate for rail-carried equipment (i. e. maximum 1:100, preferably flatter). By this, the cross sectional area of the adit could be kept to a minimum for excavation purposes (in Norway a cross section area in the range of06-9 m2 (65 100 ft2) would have been chosen for practical/ economical reasons). The upstream end of the access adi t should have a concrete plug not less than 75' long (depending on rock quality). The plug should have a steel door, approximately 6'5" by 6'5" to allow the entrance of a small tractor for digging out gravel from the gravel trap. Cement grouting around the plug should be carried out. The dimensions of the gravel trap will depend on how small grains one wants to have settled in the trap. As a first approach, the length of the trap could be assumed to be in the range of 100'-150' (30-45 m) and the volume probably some 1200-1300 yd 3 (900-1000 3 m ). A shot-crete or concrete lining on the trap's roof adjacent to the steel lining should be considered to avoid that falling rocks are sucked into the steel lining. The gravel trap should provide reasonably good space for loading out the muck and for the shaft hoist with platform, drill joints, etc. 43 From part the of excavated. gravel trap the waterway both and the the horizontal 45 0 pressure steel shaft lined are The steel lined part is assumed to be excavated using rail- carried equipment. The cross section could be as indicated by the sketch. The length of the tunnel from the gravel trap to the shaft, STEEL RAIL 44 excavated in 1970, would probably be some 750'- 800' and the length of the steel· lining down to the spheric valve, some 900'-950'. The 45°-pressure shaft will probably have a length of 950'-1000'. ... The cross sectional area should be decided by economic calculations (which likely will show more than 40 which again 1S minimum for construction equipment available in Norway). Plate 4 outlines an alternative surge shaft solution often chosen in Norway for reasons of cost: Instead of choosing the vertical shaft (or tank) solution, the inclined pressure shaft is continued up to the cross sectional leve I needed to serve as a surge tank. If the area of the pressure shaft is sufficient to give a stable power plant (which often is the case), this surge tank solution tends to be the cheapest one. There are two main reasons for this: 1) the surge shaft can be excavated in the same working rhythm learned during the pressure shaft excavation without a new rigging, and 2) the surge tank excavation can be performed without disturbing impact on the headrace tunnel excavation. Plate 3 indicates an alternative location for the access adit to the headrace tunnel, namely that the adit could be moved upstream. Making up the construction schedule, this might prove to be advantageous as one will arrive at the intake and tap area sooner, obtaining better time for the works in 45 6.4 this area such as gate erection, grouting, and other rock reinforcing works which should be reckoned with and taken into account. ALTERNATIVE 2: SLOPING UNLINED PRESSURE TUNNEL WITH AIR CUSHION SURGE CHAMBER. (Plates 5 through 8) Two tentative layouts are shown for this alternative. Plates 5 and 6 show a configuration where both the access adit to the pressure tunnel and the steel lined part of the waterway are taken up beyond the assumed location of the Tsimpsian Shear Zone at tunnel level. This layout proposes the access adi t to be excavated through the shear zone before the excavation for the steel lined part is started. character revealed and at conditions at the earliest Thus, the shear zone tunnel level will be stage of work. The configuration indicated could be said to be the safe one. However, as the shear zone is judged to represent no serious problem for the tunneling, it is suggested that one should go for the more "venturesome" solution indicated by Plates 7 and 8 to take advantage of the possibilities for saving costs that this configuration .. yields. The two layouts are, in principle very much ~, alike, and what is said in the following will, to a large degree, apply also to the more safe {and less 46 flexible) layout. It could be remarked that the configuration shown on Plates 5 and 6 takes a steel lining some 1400' long at low level, and that for this reason the solution indicated might not compete with the recommended configuration shown in Design Memorandum 23. Plates 7 and 8 show a configuration that could be looked upon as a first approach to the sloping tunnel/ air cushion surge chamber solution. It is proposed that this approach should be subject to more detailed considerations to arrive at a choice between alternatives. The configurations could be described/discussed as follows: An access adit some 1300' long leads into a gravel trap with invert at elevation approximately 100'. The adit's invert at the portal could be at elevation approximately 20', giving a slope of approximately 1:16 for the adi t. As the sloping headrace tunnel for practical/economical reasons should be excavated using rubber tired equipment (this is true in Norway, probably also in Alaska), the cross sectional area of the adit should not be less than around 190 ft2 (1 7-18 2 m ). The upstream end of the access adit 47 should have a concrete plug with a steel door as described for alternative I' (see page 43). In this case, the steel door might have increased dimensions to allow the entrance to the gravel trap and tunnel of a small truck; for example, a circular door with a diameter of 11'-12' (3.5 meters). NOTE: It is proposed that (before turning towards the gravel trap) the adit be excavated through the weakness zones found in drill hole DR11S (1982) in order to be able to judge the true character of these zones and thus to be able to identify the final location of the gravel trap. What is said on page 43 about the gravel trap for alternative 1 also applies to alternative 2 and is not repeated. The steel-lined part of the waterway should be excavated using rail-carried equipment to keep the dimensions down to what is needed for concreting around the steel liner. This means that the muck from this excavation should be reloaded in the gravel trap and transported out the adit on trucks; otherwise the dimensions for this part of the waterway will be as stated on page 43 for Alternative 1. 48 The pressure tunnel sloping from the upstream end of the gravel trap is proposed to continue in the same direction as the steel lined part to cross the first of the main shear zones Tsimnsian) at a favorable angle before turning towards Crater Lake. The tunnel will have a length in the range of 5500'-5800' and a slope of 1:8 to 1:9 to land at the proper elevation a little downstream from the gate structures. As already mentioned, the tunnel will, for technical/economical reasons have a cross sectional area of some 190 ft2 2 (17-18 m ), and the reduction in head loss will, of course, be taken into account when doing economic calculations to compare alternatives. As this alternative does not need an access adit in the intake/tap area, it should be noted that the larger tunnel probably should proceed beyond the gate shaft towards the lake tap. Even if this procedure will take more concrete for the gate structures, it is thought to be cheaper than changing over to rail-carried equipment at the top of the sloping tunnel with reloading onto trucks at this point. The last part of the tunnel towards the tap point should probably not have an enlarged cross sectional area, but the mucking-out should be carried out according to the load-and-carry method, using a small (wheel) loader. 49 Depending on the rock conditions In the air chamber area revealed by the excavation of the downstream'part of the pressure tunnel and the investigation/ me~surements during construction proposed elsewhere in this report, the air cushion chamber could either be located on the downstream side of the Tsimpsian shear zone or on its upstream side (i.e. between the Tsimpsian and the Tlingit zones). The air chamber should have an adit of 150'long (45-50 meters) -cross sectional area and slope as for the pressure tunnel -to bring the chamber itself up to the appropriate level. The chamber should, again for practical/economical reasons, have the form of a short tunnel. According to simplified calculations the following chamber dimensions should probably provide a stable power plant and meet the upper and lower surge limits: Width 35' -40' (11-12 meters) Length 110' -120' (34-37 meters) Height 25' -30' (8-9 meters) This should result in the excavation of some 3200 yd 3 (2400 m3 ) of rock or a little more, and an air volume of some 2600 yd 3 (2000 m3 ) or a: little more. This would be in addition to the access adit. 50 6.5 To obtain easier water flow out of the chamber due to load increase, or starting up the unit, the invert of the chamber should preferably be given a gentle slope (for example 1: 40) towards the pressure tunnel. It should also be noted that the upstream part of the adit probably should have a conical shape (roof to be lifted towards the chamber) so that a substantial part of the adit could go in as a part of the surge chamber. A restricted inlet (orifice) to the air chamber is not used in Norway and should probably not be considered for the Crater Lake project. The surge chamber should have a water level gauge to moni tor the air cushion. There should also be a pipe in to the cushion so that air lost through adsorption, and possibly also through some leakage of air out of the chamber, can be replaced. The compressor (for air feeding into the chamber) could be placed in a small cave located in the upstream part of the access adit. CONCLUSION 1. Having reviewed the penstock alignment and adjacent features as shown in Design Memorandum 23, there is a clear feeling that an access adit should be provided so that the penstock construction work,to the extent 51 possible, is separated from the existing valve chamber and power house/maintenance area/access tunnel. By doing this, the features otherwise needed to avoid dusting down are omitted, and the shaft excavation, especially the loading and transportation of the muck, could be carried out in the simplest and most economical way. In spite of the cost of the adi t itself and the somewhat more complicated penstock alignment, it is thought that the adit solution al together represents the best and cheapest penstock solution. 2. Subsequent to reviewing the geologic information made available, tentative layouts for two alternative headrace solutions have been worked out: 1. Headrace tunnel at high level with unlined pressure shaft. 2. Sloping headrace tunnel with air cushion surge chamber. The alternatives are illustrated on Plates 3-4 and 7-8. The conclusion arrived at is that there should be no doubt that both alternatives are feasible. Consequently, reduction of the length of the steel- lined part of the waterway is viable. 52 3. Comparing the basic headrace solution (OM 23) and the two alternatives indicated from a technical (operational) point of Vlew, it is judged that the three solutions could be considered equal. Comparing the basic solution to the alternatives from an economic point of view, it can, judged on the basis of Norwegian experience and prices, be stated that the basic solution would most likely be overruled by either of the alternatives. 4. Comparing the two alternatives from an economic point of view it is not possible to judge which is the preferable one. The choice could be done following comparative cost estimating. When doing this, the lesser headloss 60nnected to the sloping pressure tunnel-air cushion surge chamber solution should be taken into account. 53 7.0 SUMMARY OF ADDITIONAL INVESTIGATIONS/INFORMATION PROPOSED OR REQUIRED DURING THIS STUDY This section summarizes our views on required investigations et.al. Most of these have now been done as a part of our previous recommendation and are included herewith, just to note our overall concerns in these areas. Proposed by Corps of Engineers: A. Sonar survey of intake area, and mapped at a scale of 1" = 25'. B. Drillhole No. 111, No. 114, and No. 115*. Proposed by Consultant A. Seismic refraction measurements in 5 profiles at the intake. B. Drillhole No. 112 and No. 113. C. Rock stress measurements in the shaft behind the power station. 54 D. Detailed measurement of the blasted Crater Lake shaft behind the power station. Exact measures of length, angles, and cross section are required for preparation of the plan and specifications. SECTION PLAN E. Measurement of the rock pressure in the end of inclined shaft behind the power station. 55 F. All new core drilling should include: 1) Permeability test (Lugeon tests with test lengths of 5 meters) 2) Photographs of the cores. 3) Core logging inlcuding RQD~values 4) Drillhole No. Length 111 90° 750' 112 60° 400' 113 60° 600' 114 60° 600' 115 45° 750' (or the bottom ele- vation of 215 feet. ) : 56 'cc ,,:, 8.0 ATTACHMENTS o Askara Model Tests (Pages 59 to 63) o Ringedalsvatn Lake Tap (Pages 65 to 68) 0 Plates -Plate 1 -Drill Hole Location -Plate 2 -Drill Hole Location -Plate 3 -Headrace Alternative 1 -Plan -Plate 4 -Headrace Alternative 1 -Profile -Plate 5 -Headrace Alternative 2 -Layout #1 -Plan -Plate 6 -Headrace Alternative 2 -Layout #1 -Profile -Plate 7 -Headrace Alternative 2 -Layout #2 -Plan -Plate 8 -Headrace Alternative 2 -Layout #2 -Profile 57 ASKARA MODEL TEST SCHEMATICS Sheets 111.1 through 111.5 58 INNLEDENDE FORS0K + FORS0KSSERIE A,S,C ( J FR. I N G. C HR. F. G R 0 N E R S T E G N . N R. 43 2 -037 ) .,. ....... 1a m ,. . -. .. ) .... >,. FORS0KSSERIE D,E ASKARA KR.~FTVERK TUNNELUTSLAG UNDER VANN 1----...:::.....--. VASSDRAGS· OG HAVNELA80RATORIET VEO NTH I 600423 .... - \JAN. 1969 I IIL1 I . ., ALT I i I ALT l-l I J LJ 'r , ~~( ~-~~I ~~,~~.~~~~. ~-~--~ \~:;;:=::::;-:;:--=' ·~·I ~~~.~ ~.. Ir _. ___ .~\ ~,..-.... · --.--,... ... .. --~ 1 FORS0KSSE:J .. 10 rr. "lo,... I - ) .,-----;, 6m~' I 12m '-------'------' .1 I I I - >~r FORSGKSSER1E G. H. (IFR. JNG. CHR .F. GR8NERS SKISSE 432-SK-23) '. I ASKARA KRAFTVERK . TUNNElUTSLAG UNDER VANN 111.2 VASSORAGS-OG HAVNEl.ABORATOR:ET VEO NTH I 600423 I JAN. 1969 FORS8KSSERIE I ( IFR.JNG. CHR.F. GRO~JERS SKISSE 432-SK-23) I ___ oJ ),...-...... """), )/ I " .. ....... ./c , . I ~~'====>~~====Y~,....====~),====.v/==~.~~=-=~~,====~~~==~.'~==~l'====~==~"==~ __ - FORS0KSSERIE J , .. ASKARA KRAFTVER~\ TUNNELUTSLAG Ur~Dt.:R YANN VASSORAGS-OG HA'INELABORATORIET VEO NTH I 600423 I 1--13 I JAN. 196~j iL. ,. FCRS8KSSERIE: Y. Ie ----18m ------..1 . ., -. " FORSGKSSERIE L, N ASKARA KRAFTVERK .,...-------- ..... . I ~ "' I j. TUNNELUT5LAG UNDER "ANN . IIi L1 VASSDRAG5-OG HAVNELABORATC~IET VED NTH I 500423 l JAN. 1S69J ----; , II ,,. .Ie , -- '''' >, '" FORSGKSSERIE M .' ASKARA KRAFTVERK TUNNELUTSLAG UNDER VA~N T1-- VASSDRAG5-OG HAVNELABORATORIET VEO NTH I 600423 I JAN. 1969 . 1.8 RINGEDALSVATN LAKE TAP Figures 1 through 4 64 ~<O...-_______ ~~_-I_________ ------.- -1--------- LDNGITUOINAL SECTlON. Fig. 1. ~70 ~70 (1542 ttl r (1470 ft.lit1&~ . --- ~bO ~ -... ==-~v~4~56~,O~(~14~96~f~tJ~ __ !.--______________ ~so .1.)0 : . 1.20 ) ~ . ~ 1 0 J 1.00 J' J . m .380 • )70 ~.l6O I I I ... _- ...... _---- 1 SOUNDINGS -------.... IL-----------------======:EEftR:tlrbrfrd ------/ / 3')0 1114e ttl .' PRESSURE CELU· -I-HO-rt~~~ PRESSURE CELL 2. SECTION ,-----=====--. __ 2~8.Q~m~. ---------.rt~2) r- 1 I B 79 ttl c::--0.l'tl-rlL-..:. -0----=-1'"' PJ~ ________ ~~ -"-.I~ P31 PLAN P33 . Fig. 2 ~~oj ~ 10 I ~OO )qO • }80 • 370, )bO, 3'>0 J JE FO~R __ .BLES (MEASURE) PIPE EQR: AIR-FILLING. CABLES DE-AIRING WATER LEVEL . .f;--t GAGE , A A I', 1AIN GATE. 204. ft.)~ , ~--5 3 __ ~~~~~~~~~~"~~~1 2 SECTlON OF GATE SHAEL PIPES. FOR -------.=C-,---,--"A B~~. S - M E A SUR E . 1. AIR-FILLING' .2. '----"'C~A6.1ES ~ IGNITION 3. ,---,QEJ~Jj~JILG_ . . . 4. I " WATER LEVEL ' 'I.----- SECTION. A .. A. GAGE {PERMANENT) ,5. {120B ftl .~ -'" P 33' FINAL· PLUG' AND ADJACENT TUNNEL SECTION Fig. ( . 500 (1640ft E z o I- ~ 490 480 470 ~ 460 -I w 450 J 4f. ~1444 f 0 t.) 1 I, " . " , . , 0 SEC. : , ----~ / PRESSURE CE~~ ~. : . - : PRESSURE CELL 2. -~~ I ' -.-,.. f , CELL 1. 1 .~., >:. PRESSRE f ~. \.~ . . " ~ .i_ --------.".. -.", , '-.~. --~ .. .; __ '"f W . ,-.. "'-'" -....... ...... .... ~-.--.-' ~ . " I'-. ..::.:a-:.::::-,..:. ? -- 681012141618 i "10""" ,',' DELAY NO. 3 5 '/ 9 1113 i511 I 0,5 -2 1,5 1 2,5 '! DELAY. DYNAMIT~ NO~ KG. ibs, 0 7,8 17 3 15,6 34 1n 5 15,6 341/2 6 11,7 26 7 ' 15,6 34 1/z B 23,4 51 1/z 9 ' 39,0 . 86 10 23,4 51 1/2 1 1 621+ . 138 12 31,2 69 13' 64,1 141 . 1/. 90,9 200 ~5 117,6 259 16 96,2 212 17 21,4 47 . 18 801 177 SUM:: 716 1578 Fig. 4. (0.'$ Ot INGINIlU ---------;, ....... " _ I / i 11 . I .,..-/ j', \ \ \"'I:Z: ~ . . " " \ ~..f'. .~/\ • c. .. ",., ""'''''','' LA . . \. \ \ UlllllllOllS Oli mil (;ItA"'lIUt AI.., . Ott 112.0" III !." .. IIc,... .... _ SECTION A-A ... _ " '1lfJ-o" _1 -... c ... o ...... ~-...:... 'j'" u •• ~.~ ••••• " .og .' O,..,." ... ,·,tI, .... '1 'Mal O ... ,)O,o'U .... ", .. '''.',. UO ,:. lOol~) U. II'''W. , .. ~ ",ltl" 11:" o LI .... ~ UI I· .. ~ •• , Lk3 ''';''l.· ",. U. $ . .aIMl' PLATE 3 80{) j'O() 30() 100 '. SNETTISHAM -CRATER LAKE HEADRACE ALTERNATIVE 1 TUNNEL AT HIGH LEVEL'WITH 45% UNLINED PRESSURE SHAFT PROFILE ·1 ~ PLATE 4 ) , .:./- LEGEND L ___ ~=:J • .u.JO~ w~.I,"'l'il~S lONE ..../ '"' L~-=:J ~~~~:::;, .. !~~tl,~,;~'r~~T""~AAI ~()(.. ---------JD'N1S It '''!Jll~ l""U,Illl1{to" .. l[Ol _.~ __ -.---~.-lJlHt CIION Ot 1I0lE NUll ~ "0 f1 jga' NO' ....... ~-:.---=.:--:.=j r..~~ .. ,' " .. ,' ,". I()O·· O· o j'UlWu:.lD 11()llS -11131 o Cllr;lIl""l,f.j IIO\.e5 ~ 11113 ol> (.ullI·~ 01 lli(,'" lll~ Mdll5 ~ III'~ -~---, U.S. AHMY lNGINl't..:H OI~IHICT. ALASKA ""~'~HEADRACE-ALTEFiNATPJE2~-' - ,,, .. ---LAYOUT .. 1 ' ,-" ... --SLOPING PRESSURE TUNNEL ..... ". WITH AIR CUSIlION SUnGE CHAM[JER: 1o.'1r>.!JC----~---. -.. ,. ... ,., •• ~~------~ ••. ' .... I' .. If; PLATE 5 "Joe) 6a~ '9~ .5 ()tJ .i;O() ~I '3 atJ .. • \\~ J.\ SNETTISHAM -CRATER LAKE HEADRACE ALTERNATIVE 2 LAYOUT -#1 SLOPING PRESSURE TUNNEL WITH AIR CUSHION SURGE CHAMBER PROFILE PtA I F ij PLATE 7 '-..:: \~\ \~ -.... '"" -l> ? "'" £1. () ______ .-"V 5.5 OD I "0 ,;.;/t!. I ,r -", -to ~ ...... I-/U/£' Cl'ahl' /t:?ke .~------~-~Q_-- SNETTISHAM -CRATER LAKE HEAD RACE ALTERNATIVE 2 LAYOUT #2 SLOPING PRESSURE TUNNEL WITH AIR CUSHION SURGE CHAMBER PROFILE PL. E 8 ADDITIONAL CLARIFICATIONS IN RESPONSE TO THE CORPS OF ENGINEERS REQUEST January 1983 ~- o "Page 3, Section 1.2.1, paragraph 2: "No additional explorations are deemed necessary prior to construction, however, as is discussed in Section 3-.5, explorations in advance of construction will be necessary in the surge chamber area." Since DH1lS did not penetrate the potential surge chamber area and since the exact location and extent of the faults are unknown, it is·only prudent to explore the area, by visual inspection, as part of the construction activities before a final decision should be made as to the exact location of the chamber. If questionable conditions are encountered a possible pressure test may be necessary to determine its air holdin~ capabilities." o Page 6 -2nd paragraph, 14th line, last two words: "Delete the words intake structure and add vented surge tank in lieu thereof". o Page 13, first parac:tfaph: "The air surge chamber solution does not demand that the pore pressure _ in the Iock corresponds to elevation 1125 feet (or higher). If this is the case, however, ~ne can be almost sure that there will be no need to tighten the rock by expensive -works such as grouting, steel-lining, etc. to prevent air leakages." o Page 21, Section 4.2, and sheet III 4: "Data-from the Askara Lake tap: Hater head at tap point approximately 280 ft. (85 !>1)- Cross section area of tunnel approximately 105 sq. ft. ( 9 • 8 sq. H) Cross section of plug approximately 70 sq. ft. (6.5 sq. M)II. o Page 27, last paragraph: "The surge in the gate shaft following the final blast can be calculated. According to experience, the measured surge corresponds fairly well to the calculated surge. Neglecting the effect of the blast itself, the calculations are in principle simple. Deciding headloss parameters is a problem and the reason why calculated and measured values do not exactly correspond. Depending on the loss conditions, our experience tells that the surge in the shaft will amount to 70-90 per cent of the difference between the water levels in the lake and in the shaft. Water inflow between the plug and the gate is determined to be sufficient once suitable air cushion in the trap area has been obtained, such a configuration of water, air and trap size should ensure proper distribution and intrapment of the final blast at the point of tap." 1 o "Page 36 "Since access to the area near th"e tap is alrnos1 assured with an open system/wet tunnel, little if any ey 'a costs will be involved in obtaining access to clean '-11~ trash racks. In contrast, the closed system/dry tunne: aiternative m~y not have access and in order to 'clean thL trash rack, such would have to be provided." o Page 35-36, trash rack: "In correlation with our comment! on debris and overburden removal , a trash rack is most certainally a requirement at" Crater Lake. He recommend C' temporary trash rack of a size to keep trees out of the: tal: point and tunnel. Once this twap has been successfully accomplished, a permanent trash rack, which can be cleanedI" should be installed. As we also noted to the Corps on OUI Bradley Lake evaluation, the trash rack should be, so designed as to allow easy access to cleaning of the rack., Trees have been determined to be ~n the' tap area, consequently, we have every reason to expect debris collection facilIties to be of paramount importance to successful operations from Crater Lake. . ~ o Page 51, 1st paragraph: "We are suggesting that th~ cross sectional areas of 2the "surge chamber n (1, 000 . ft) and" access adit (190 ft) be transitioned. at their Doint of intersection. By doing this, the adit cross secti;nal area will provide even greater volume for the surge chambe::: ". while yet allowing a smooth (rather then an abrupt) transi tion between the two structures therebv allowinc the air to also flow easier through an orifice tr~nsition. JThi~ can best be accomplished through a conical sloped roof froIT the adit.to the valve chamber." o Debris and overburden in the lake tap area: "Three i terns· are of critical importance in the tap area, they are rock slabs over the tap point; tightness of rock at the point of piercing and debris and overburden. The first two concern~ will be further evaluated during probing operations as one approaches the point of tapping. As to the last concern, this question should be addressed as soon as possible,~ certainally the evaluation of the yet to be accomplished,. side scan sonor is of paramount importance. Since without the bene fit of the sonar scan of the tap area, all we have", been able to evaluate are the existing sounding and subnarine video tapes which 'were marginal at best. Yet, we did notice what appeared to be large trees and debr~s in and~ among the overburden in the tap area. Hi thout question, this must be removed to an area sufficiently below the point' of tapping and area wise, such that the overburden material ".]ill no longer present a probable tap blockage. There is' just not enough information available so that we could g~ ~ a more preci~e definition af the extent at this time." ( o Report Recommendations pertaining to additional surveys and explorations (summarized here is one section for the Corps): (a) Surveys: 1. 2. ,..,f"AL.+lol'\ Tap area - A seismic ~QfFatuee survey of the tap (see also plate I) may be ap~fPpriate, especially if the side ~ sonar cannot provide necessary delineation of the debris and overburden in the vicinity of the tap area (paragraph 1, page 3 and paragraph 3.2 page 15). Powerhouse "area -In order to better evaluate the rock stress conditions, stress measurements should be performed at the bottom of the shaft excavated in 1970 (for the Crater Lake phase) and as far as possible from the power station (paragraph 3, page 11) . 3. Registration of water inflow (leakage) to -the pressure tunnel during excavation. is an important ~eans of evaluating possible air leakage from the air cushion surge chamber and of deciding whether or not precautions such as grouting should be necessary. At this stage of the construction work, rock stress measurements should also be performed to ensure that rock stresses are of an acceptable level for the air" surge chamber (last paragraph, page 20). 4. Detailed measurement of the blasted Crater Lake shaft behind the power station. Exact measures of length, angles, and cross section are required for preparation of the plan and specifications (paragraph E, page 55). 5. Heasurement of the rock pressure in the end of inclined shaft behind the power station (paragraph F, page 55). (b) Explorations: 1. Sounding drillings should be carried out ahead of the tunnel face (length at least two time the length of each round) during excavation to control plans and avoid surprise (last paragraph, page 18 and first paragraph, page 19) . ( 1 ) Side scan sonar ~s considered very important to better evaluate the tap area and overburden conditions, suggest unden·,7ater surface mapping should be done at scale of 1 "=25' . 3" " 2. If a pressure tunnel with an air surge chamber c:': an unlined pressure shaft is chosen for +-1! project, the access adit to the gravel trap at le upstream end of the steel-lined part of t~~ headrace will enable . explora tion ahead of tl ~ excavation of the adit to be done so that the weakness zone (s) found in DH106 and DHl15 could ~,R located at tunnel level, thus giving a base ft ~ making the final decision concerning the 10caticJll of the upstream end of the steel lining. It is of importance that the headrace tunn~_ should be excavated beyono the air chamber area before the chamber's location is f inally decide~' Also, core drillings with water pressure test.; should be performed' from the pressure tunn~l before the final location of the air chamber .Y' chosen (last paragraph, page 13, and first t\· I paragra?hs, page 20). 3. Any new core drilling should i.nclude: 1) Permeability test (Lugeon tests with te~~ lengths of 5 meters) . 2) Photographs of the cores. 3) Core logging including RQD-values. 4) Drillhole No. 111 112 113 114 115 Dip. 90 0 60 0 60t) 60° 45° (Paragraph F, page 56.) Length 750' 400' 600' 600' 750' (or the bottom elevation of 11\ 215 feet.) · " " ' EXHIBIT 5 LAKE TAP CLEARING FEASIBILITY STUDY CRATER LAKE PHASE SECOND STAGE DEVELOPMENT SNETTISHAM J ALASKA JUNE 1984 TRYCK J NYMAN AND HAYES LAKE TAP CLEARING FEASIBILITY STUDY CRATER LAKE PHASE SECOND STAGE DEVELOPMENT SNETTISHAM ~ ALASKA Prepared for: THE DEPARTMENT OF THE ARMY ALASKA DISTRICT~ CORPS OF ENGINEERS ANCHORAGE, ALASKA Contract No. DACW85-84-D-0003 Delivery Order No. 3 Prepared by: TRYCK~ NYMAN & HAYES 740 "I" Street Anchorage~ Alaska 99501 With Assistance From: Mr. Al Mathews Consulting Engineer Tacoma, Washington LAKE TAP CLEARING FEASIBILITY STUDY CRATER. LAKE PHASE SECOND STAGE DEVELOPMENT SNEl'TISHAM, ALASKA TABLE 0 F CONTENTS 1.0 Introduction 2.0 Site Description 3.0 Climatology 3.1 General 3.2 Precipitation 3.3 Temperature 3.4 Sunshine 3.5 Snow 3.6 Lake Ice 3.7 Avalanches 4~0 Existing Lake Bottom Conditions 5.0 Proposed Methods of Clearing 6-.0 5.1 Clamshell Method 5.1.1 Plant and Equipment 5.1.2 Production Schedule 5.1.3 Mobilization Schedule 5.2 Slusher Method Pros 6.1 6.2 6.3 6.4 5.2.1 Plant & Equipment 5.2.2 Production Schedule 5.2.3 Mobilization Schedule and Cons Slusher Method -Pros Slusher Method -Cons Clamshell Method -Pros Clamshell Method -Cons 7.0 Bench Above Tap 8.0 Construction Difficulties and Costs 9.0 Mobilization Through the Tunnel 9.1 Pros -Lake Access Through the Tunnel 9.2 Cons -Lake Access Through the Tunnel Page No. 1 2 2 2 2 3 3 3 3 3 3 4 5 6 8 8 9 10 12 - 12 13 13 14 14 14 14 15 16 17 17 TABLE OF CONTENTS(Continued) 10.0 Crew Sizes for Slusher Method 10.1 Clearing Crew, Each Shift (2 shifts) 10.2 Clearing Crew, Day Shift (1 shift) 10.3 Mobilization Crew at Lake (1 month 10.4 Mobilization Crew at Snettisham (1 month) 10.5 Unload and Pre-assemble Crew (1 month) 10.6 Administration and Supervision (6 months) 10.7 Demobilize 10.8 Diving for Inspection and Emergencies 11.0 Crew Sizes for Clamshell Method 11.1 Clearing Crew, Each Shift (3 shifts) 11.2 Clearing Crew, Day Shift Support (1 shift) 11.3 Mobilization Crew.at Lake (Same as 10.3) 11.4 Mobilization Crew at Snettisham (Same as 10.4) 11.5 Unload and Pre-assemble Crew 11.6 Administration and Supervision 11. 7 Demobilize 11.8 Diving for Inspection and Emergencies 12.0 Additional Studi~s 13.0 Contractor Comments 13.1 Underwater Construction Inc., Anchorage, AX 13.2 S. J. Groves & Sons Company, Bellevue, WA 13.3 Parsons-Brinkerhoff, Sacramento, CA 13.4 J. A. Jones, Charlotte, North Carolina 14.0 Conclusions Plates 1, 2, 3 and 4 APPENDIX Cost Estimating Sheets (6) Mesotech Sonar Systems Literature Page No. 17 17 17 18 18 18 19 19 19 19 19 19 20 20 20 20 20 20 20 21 21 21 21" 21 21 1.0 INTRODUCTION LAKE TAP SITE CLEARING FEASIBILITY STUDY CRATER LAKE PHASE SECOND STAGE DEVELOPMENT SNEITISHAM HYDROELECTRIC PROJECT, ALASKA The purpose of this report is to make recommendations regarding feasible methods of clearing the overburden from the proposed lake tap site at Crater Lake, Snettisham Hydroelectric Project. This work was prepared for the Alaska District of the U.S. Army Corps of Engineers (Contract No. DACW 85-84-D-0003) to assist in the preparation of contract documents and solicitation of bids for the clearing of the proposed lake tap. Government furnished materials provided to assist in the preparation of this document included: ~, • "Final Report Side 'Scan Sonar and Subbottom Pro'filing Survey, Crater Lake, Alaska"; Ocean Surveys, Inc., 1983 • Video Tapes of the bottom of Crater Lake at the Lake Tap Site, taken in 1973 • Exhibit Drawing, Project Location and Vicinity Map • Photographs of Crater Lake and surrounding area • Drill hole logs for in-lake dtill holes No.' s DDH-l08, DDH-l09, and DDH-llO; drilled October 1974 and logs prepared November 1974 • Exhibit Drawing, Proposed tunnel alignment in Lake Tap tunnel, tap, bedrock contours, drill-hole locations limits) area (showing and cleating • U.S. Geological Survey Quadrangle, Taku River (A-6) • "Snettisham Project Alaska, Crater Lake First Stage Development; Design Memorandum #26, Plate 2, Power Tunnel Plan and Profile," U. S. Army Engineer Disttict, Alaska • "Snettisham Project Alaska, Crater Lake First Stage Development; Design Memorandum #26, Plate 6, Lake Tap and Primary Rock Trap Plan and Profile," U. S. Army Engineer District, Alaska • "Snettisham Project Alaska, Crater Lake First Design Memorandum #26, Plate 9, Gate Structure;'~ District, Alaska Stage Development; U, S. Army Engineer • Snettisham-Crater Lake Phase Critical Path Schedule (Design Memorandum #26 through power-on-line) • "Snettisham Project Alaska, First Stage Development; Design Memorandum #1, Hydrology," U. S. Army Engineer District, Alaska, 1964 . o "Snettisham Project Alaska, First Stage Development; Design Memorandum 117, Ge~eral Design Memorandum Vol. 1 of 2, Main Report, t. U. S. Army Engineer Distri~t, Alaska, 1964 o t'Snettisham Project Alaska, First Stage Development; Design Memorandum 112, Hydropower Capacity," U. S. Engineer District, Alaska, 1964 o "Snettisham Project Alaska, First Stage Development; Design Memorandum HI, Hydrology," ·U. S. Army Engineer District, Alaska, 1964 2.0 SITE DESCRIPTION The Snettisham Hydroelectric Project is located near the northern end of Speel Arm of Stephens Passage. approximately 28 miles southeast of Juneau, Alaska. EXisting facilities include an underground powerhouse at approximately sea level~ a power tunnel to Long Lake, a 2500 ft., long gravel runway, and associa- ted maintenance facilities. The proposed expansion of the Snettisham Project is known as the Crater Lake Phase to be constructed in two or more stages. The Lake Tap Clearing, as presently scheduled, will be performed prior to the start of Stage II excavation work. Stage I excavation includes the primary adit, the power tunnel from Station 75+00 to approximately 45+00, camp facilities and a haul road. Stage II excavation includes the power tunnel from approximately Station 45+00 to 8+50, gate structure, adit, surge tank, pen stock tunnel, machine shop and drift. Crater Lake is 1019 feet above project datum (1022 MSL) in a narrow, steep-wa:.1led valley 3-4000 feet below the surrounding peaks. The lake is ap- proximately 1 mile long, 0.4 miles wide, a maximum of 400 feet deep with a sur- face area of about 330 acres. The proposed Lake Tap Site is located in 220 feet of water at a point about 230 feet from the closest shoreline. The area to be cleared ranges in depth from 250 feet just below the tap to 0 feet at the shore line above the tap site. A steep rock face rises 1,400 feet above the shoreline (See Plat 1). 3.0 CLIMATOLOGY 3.1 General The climate of the Crater Lake area is characteristic of southeastern Alaska consisting of high precipitation, lack of sunshine and frequent winter storms. Weather patterns are a result of the rugged terrain and the areas position in the path of sto~s which track across the Gulf of Alaska. The mountainous terrain has a strong influence on temperatures and results in significant vari- ations in precipitation and temperature within relatively short distances. 3.2 Precipitation Although no records exist at the Crater Lake site, estimates made in 1964 for the general area have proven to be accurate. It is estimated that the average annual precipitation over the Long Lake and Crater Lake basins is approximately 200 inches. Precipitation for Crater Lake is estimated to be 230 inches. The heaviest precipitation occurs in southeastern coastal areas during the fall and winter. 3.3 Temperature Based on records at the Juneau Airport, which are considered representative of those encountered at lower elevations, monthly normal temperature for January is 26° F and for July is 55° F. Extreme temperatures range from a high of 84° in July to a low of -21° in December. It is to be n9ted that variations in 10-• cal radiation and air drainage produce significant differences in temperatures particularly between upland or sloping areas and flat, low terrain. Because Crater Lake is deeply incised in the steep mountainous terrain, air drainage may result in the build-up of a cold layer of air on the lakes surface. 3.4 Sunshine There-is very little difference in the amount of sunshine received at various locations throughout southeastern Alaska; in general, the amount of sunshine is relatively low. The length of day varies from about 6.3 hours in late December to about 18.3 hours in late June. 3.5 Snow Normally the first snowfalls begin toward the end of October, however, snowfalls have been recorded in the early part of September at Juneau. At lower elevations, there is very little snow accumulation until the latter part of October with accumulation beginning at higher levels in the early part of October. Peak accumula~ion is reached in the middle of March with the snowfall at Crater Lake reaching 7-15 feet. 3.6 Lake Ice During three visits to Crater Lake during the winter months the accumulation of snow, sleet and slush measured at the lake surface has been on the order of 7-15 feet. The consistency of the material at the lake surface has been that of a soft ice or slush, not hard ice nomally associated with a frozen lake. 3.7 Avalanches Because of the depth of snowfall and the steepness of the terrain, avalanches in this area are common, as evidenced by debris in the lake and from aerial photographs taken during the winter months. 4.0 EXISTING LAKE BOTTOM CONDITIONS A geophysical survey at the Crater Lake site was conducted July 15-17, 1983 by Ocean Surveys, Inc. to aid in the design of the lake tap. This work was accom- plished under contract No. DACW85-82-C-oOl9. The purpose of the survey was to map the subbottom bedrock profile, determine the thi~kness of unconsolidated materials overlying the bedrock, identify the location of any submerged debris .greater than 5 feet in anyone dimension. This was accomplished using soundings, subbottom profiles and side scan sonar. " .' A detailed description of the equipment procedures and findings of the geophysical work conducted by Ocean Surveys, Inc. is contained in their final report "Side Scan Sonar and Subbottom Profiling Survey, Crater Lake, Alaska". It is to be noted that as a result of the report findings, the lake tap loca- tion has been moved to the north. As currently located, the depth of unconsolidated deposits at the tap is in excess of 20 feet. Moving upslope from the tap, the deposits thin out to ° feet at about 20 feet from shore. The material to be cleared consists of soil and rock ranging from rock flour and silt up to fragments and boulders several feet in diameter. Other debris con- sists of tree remnants ranging from small twigs and branches up to large trunks and stumps several feet in length. The amount of this material is variable ,. from occasional trees and limbs to piles of intertwined trees and stumps. Video tapes of the bottom conditions were-made in September of 1973 using a minisubmarine. Several traverses of the bottom were made at that time covering the general area of the proposed tap from the shoreline (elevation 1,0],9) to approximately the 770-foot elevation or about 2S0-foot of depth. The location of the traverses are shown on the drawing "Snettisham Project Alaska Hydrographic Survey of Crater Lake -Hydrographic Map lA" by Alaska Geological Consultants, Anchorage, Alaska; part of contract No. DACW8S-C-0004. The geophysical work conducted in 1983 1s consistent with the information contained in the submarine reconnaissance of the lake bottom. In addition to the trees, boulders and rock flour, an old metal building was located along line "B" at a depth of approximately ISO feet (south of the proposed tap). Other information consists of three borings made in October of 1974~ The borings encountered 2-7 feet of overburden consisting of boulders, cobbles, gravel and mud with some wood recovered. The borings were primarily concerned with the nature of the bedrock and, therefore, provide limited information with regard to the unconsolidated deposits. The holes were drilled from a float at Crater Lake, and at the time of drilling, lake fluctuations up to 3-foot daily, made it difficult to determine the exact elevation of the top of bedrock. S. ° PROPOSED METHODS OF CLEARING Underwater excavation can normally be accomplished by hydraulic dredging, dragline, clamshell, slackline cableway and slusher. Due to the nature of the material, which includes large rocks and boulders, and because of the depth of water, hydraulic dredging has been ruled out for this project. Conventional dragli~e excavation with a barge-mounted machine is not considered to be feasi- ble because of the steep angle of the drag cable due to the depth of water. Additional methods considered included mechanical vibration, underwater jetting, and airlift pumping. It is doubtful that any of these three methods alone would be capable of accomplishing the lake bottom clearing. More infor- mation regarding size and distribution of rock and soil particles would be needed to evaluate the effectiveness of these methods. The airlift pump method would be capable of removing particles up to 3 or 4 inches in diameter, however, it would not be able to remove the larger material or much of the vegetative debris. A very ,large compressor would be required (3500 CFM at 200 psi) to airlift material at these depths. Mechanical vibration or water jetting might be used in conjunction with other mechanical means of clearing in an effort to increase productivity. It is questionable whether contractors would be willing to mobilize the equipment necessary to try these methods unless they could be assured of their successful use. Therefore, the three methods considered technically feasible for the Crater Lake project are: 1) excavation by clamshell; 2) slackline cableway; and 3) slusher. The slackline cableway and the slusher method are basically similar in that they are both operated by a cable system and would require almost identical equipment including cables, winches, sheaves. In terms of equipment, the basic difference between the two systems is that the slackline cableway utilizes a bucket-type excavation device, whereas the slusher uses a blade or hoe-type excavation implement. Operationally, the slackline cableway would re- quire hauling and discharging into a receiving hopper for disposal. The slusher method would drag the material downslope to the west and leave it on the bottom of the lake. It has been decided to consider slusher and clamshell excavation in order to compare the costs and risks associated with the two methods. The steep bottom slope combined with the tapered fill--the thicker deposit at the bottom of the slope--may result in the fill sliding downhill if excavation begins near the bottom. In this scenario, excavation would create an unstable upslope condition thus causing the material to slide into the area already cleared. This would allow excavation to proceed from a single point thereby increasing the efficiency by reducing the amount of time required for moving. However, the success of this approach is difficult to predict, particularly without additional information on the nature of the material on the lake bottom. 5.1 Clamshell Method It is contemplated that the clamshell method would employ a stiffleg derrick mounted on a sectional barge and operated by a double drum hoist with a swinger attachment. The barge would be moored to 2 anchors offshore and 2 rock anchorages in the cliff above the east shoreline and positioned by means of winches. The clamshell would dump into a hopper barge for transportation and discharge in deeper water. Trees and logs would be loaded onto a separate cargo barge and taken to the west shore for disposal (See plate 4). 5.1.1 Plant and Equipment (Clamshell Method) (a) Excavation Equipment 1 24' x: 42' sectional barge -75-ton capacity 1 -stiff-leg derrick, 40 ft. boom, l5-ton capacity (@40') 1 -200 H.P. diesel-driven, double drum hoist. Each drum to have capacity for 300 ft. of .. l-inch wire rope. 200 fpm line speed. Also, power takeoff to operate swinger. 1 -50 kw diesel-electric set 1 -power-driven (elec.) mooring winches 3 -500 lb. anchors 2 -4 cu. yd. clamshell buckets 1 -15 ft. jib boom, 5-ton -elec. hoist 2 -20 cu. yd. hopper barges, each consisting of two sets of sectional floats, 25-ton capacity each, and one 20 cu. yd. bottom dump hopper 1 -18" x: 36' sectional barge, 27-ton capac- ity (for hauling trees) 1 -grapple (for lifting trees from bottom) 1 -D-4 tractor with dozer and boom (for disposing of trees) (b) Marine Equipment 4 -24-ft. motor launches 1 -lot: anchors, lines, fenders, etc. (c) Installation Equipment 1 -300 cfm air compressor 2 -jackhammers 1 -skilsaw 2 -air wrenches 2 -welding machines 2 -sets: oxy-acetylene equipment (d) Support and Maintenance Equipment 1 ~ 18 x 36 sectional barge, 27-ton capacity 1 shop trailer 1 -office/first aid trailer 1 -lot: tools, jacks, etc. 4 -two-",ay radio outfits 1 -25 kw diesel generator set ( eJ Materials 5,000 lb. misc. structural steel and plate 5 MBM misc. lumber and timber 1,000 lb. misc. bolts and hardware 20 -I-inch x 10 ft. rockbolts (f) Diving Eguiment 2 -complete sets for two divers ($) Port Snettisham Equipment -I -10-ton truck crane with 40 ft. boom 1 -5-ton flatbet truck 1 -office trailer 1 -warehouse trailer '" .' 5.1.2 P~oduction Schedule (Clamshell Method) 4 cu. yd. bucket holds 2.5 bank cu. yd. Fill facto~ 0.5 Difficulty factor 0.5 Average load per cycle -0.625 cu. yd •. Average depth -160 ft. Cycle time: Swing 5 sec. Lower 160 ft. 40 sec. Close 8 sec. Hoist @ 200 fpm 48 sec. Swing 5 sec. Dump 3 sec. Total 109 sec. -27.5 cycles per 50-min. hr. -17 cu. yd. per hr. Wo~k two 12-hr. shifts per day with 10-1/2 hrs. productive work per shift. Produce 357 cu. yd. per day. Require 56 days, allow 2-1/2 months. Haulage -Travel to deep water and dump. Travel time ~ 10 min. Use two sets of 25-ton capacity floats to carry hopper. 5.1.3 Mobilization Schedule (Clamshell Method) Crew to unload and pre-ass~ble at Port Snettisham -allow one month (larger crew than for slusher method). Fly in equipment -70 trips @ 1 hr., work 4 hr. per day. Allow 18 days (c~urrent with work at lake) • . ", Mobilize and assemble at lake: Assemble 3 barges Assemble 2 hopper barges Install anchors and anchorages Set-up hoists and equipment Set +.ines, buoys, etc. Miscellaneous Total Demo bilize : Disassemble and fly to Snettisham Load out Total Allow 1-1/2 months. Overall Schedule: 1. Plan, design and purchase 2. Deliver, off load, and preassemble 3. Mobilize at lake 4. Perform work 5. Demobilize 5.2 Slusher Method 6 days 6 days 2 days 4 days 2 days 2 days 20 dais a 1 month 18 days 24 daIs 42 days April 1985 May 1985 June 1985 1 July to 15 Sept. 1985 15 Sept. to 1 Nov. 1985 As noted above, the slusher method involves pulling the overburden downslope by use of a hoe-type rake attached to a cable system. The material would be moved to a point below the lake tap which would prevent the debris from interfering with future operations. The disposal area would be below elevation 790 feet. The excavating equipment associated with the slusher, includes a 72-inch hoe-type scraper, 2 double drum winches, a 72-inch hoe-type rake, wire rope and various sheaves. A complete plant and equipment list is included in Section 5.2.1. ,,' ,F f!' .. The scraper is attached to a loadline and backhaul line both of which are attached to a winc'h located on the west shore. The, loadline would be attached to a sheave located directly opposite the tap. The backhaul anchorage would be to the rock cliff above the lake tap on the east shore. Lateral coverage of the clearing area would be provided by a bridle arrangement at the backhaul anchorage. The bridle ropes would be attached to the second double drum winch also to be located on the east shore (See plate 3). It has been assumed that there is not a site near the backhaul anchorage that would be safely accessible by helicopter. Therefore, the load hoist would be located in the valley just north of the outhaul anchorage. Crew members would travel from that area to the bridle winch by skiff. 5.2.1 Plant and Equipment (Slusher Method) (a) Excavating Equipment 2 -72-inch scrappers @ 7,000 lb. (includes one spare) 1 -125 H.P. diesel-driven, double drum hoist. Each drum to have capacityu for 800 ft. of I-inch wire rope. 200 fpm line speed. 1 -25 H.P. diesel-driven, double drum hoist. Each drum to have capacity for 500 ft. of l/2-inch wire rope. 100 fpm line speed. 6-swivel-mounted sheaves for 1" wire rope -36" dia. 6 -swivel-mounted sheaves for 1/2" wire 6 -double sheave blocks for 1/2" wire rope -18" dia. 10,000 ft. -I-inch wire rope 2,000 ft. -l/2-inch wire rope 1 -72-inch hoe-type rake, 6,000 lb. (b) Marine Equi pmen t 1 -12' X 24' sectional barge, 12-ton capacity 1 -24 ft. motor launches 2 -l5-ft. jib booms for barge- S-ton capacity, elec. hoist 1 -25-kw diesel generator set 1 -lot: anchors, lines, etc. (c) Installation Equipment 1 Caterpillar D-4 tractor-bulldozer 1 -600 cfm air compressor 1 -air track drill 2 -jackhammers 2 -sk1lsaws 2 -. air wrenches 2 -welding machines 4 sets -oxy-acetylene equipment (d) Support and Maintenance Equipment 1 -shop trailer 1 -office/first aid trailer 1 -lot: tools, jacks, etc. 6 -two-way radio outfits 2 - 6 x 12 ft. pontoons (for dock) 1 -30 ft. Bailey Bridge (for dock) 1 -25 kw diesel generator set (e) Materials 20,000 lb. misc. structural steel and plate 20 MBM misc. lumber and timber 2,000 lb. misc. bolts and hardware 50 -I-inch x 20 ft. rockbolts (f) Diving Equipment 2 -complete sets for 2 divers ". '" (g) Port Snettisham Equipment 1 -10-ton truck crane with 40 ft. boom 1 -5-ton flatbed truck 1 -office trailer 1 -warehouse trailer 5.2.2 Production Schedule (Slusher Method) Estimated quantity -20,000 cu. yd. Assumed average haul -300 ft. Basic production (200 ft. haul) -66 cu. yd. per hr. (50-min. hr.) Slope factor (30 0 slope) -1.9 Extra haul factor -0.70 Difficulty factor -0.75 Average production -66 x 1.9 x 0.7 x 0.75 -65 cu. yd. per hr. Work two 12-hr. shifts with 10-1/2 hr. productive work per shift Produce 910 cu. yd~ per day Require 22 days -1 month Allow, for checking, diving, and contingency -1/2 month Total time for pe~ormance -1-1/2 months 5.2.3 Mobilization Schedule (Slusher Method) Crew to unload and pre-assemble at Port Snettisham -allow one month. Fly in equipment 32 trips @ 1 hr., work 4 hrs. per day -allow 8 days· (concurrent with mobilize and assemble at lake). Mobilize and assemble at lake: Grading site (including helipa4) 5 days Set-up trailers 2 days Build dock 2 days Assemble barge 1 day Drill & set anchorages 6 days Set-up hoists & tie down 2 days 'Thread cable 2 days Miscellaneous 2 days TOTAL 23 days ,. 1 month Demo bilize: Disassemble and fly to Snettisham Load out Allow one month 8 days 16 days 24 days Overall Schedule: 6.0 6.1 1-Plan, design, and purchase May 1985 2. Deliver to Port Snettisham, off load, and pre-assemble June 1985 3. Mobilize at lake July 1985 4. Perform work 1 Aug. to 15 Sept. 1985 5. Contingency 15 Sept. to 1 Oct. 1985 6. Demobilize October 1985 PROS AND CONS Slusher Method -Pros (a) Scraping bottom downslope, should clean better. (b) . Any boulders which cannot be dragged down slope probably safe from sliding onto intake. (c) Requires less plant and equipment and is therefore a relatively simple operation. (d) Requires less energy since material won't have to be raised to the lake surface. (e) Requires less time. .' II .' 6.2 Slusher Method -Cons (a) Scraper might have difficulty cleaning behind prominent rock outcrop or behind large boulder. (b) Some trees may not get satisfactority buried. (c) Requires more development onshore. ~d) Requires more site communication. 6.3 Clamshell Method -Pros (a) Can excavate around any object. (b) Requires less onshore development. (c) Requires less site communication. (d) Does not leave any excavated trees in the lake. 6.4 Clamshell Method -Cons (a) Cannot excavate large boulders. (b) Lesa positive cleaning of the slope. (c) May have trouble puJ.llng out trees. (d) Requires more plant and equipment. (e) Requires more energy. (f) Requires more time. (g) Requires separate disposal of trees. (h) May be a problem with operation of the clam bucket on steep slope. 7. 0 BENCH ABOVE TAP Some consideration should be given to constructing a bench in the rock above the tap to trap debris from future slides. The nature of the debris in the existing slide, to the north of suggests that the origin of the material was from above the lake. have been the result of a landslide or an avalanche. Judging by the of the surrounding slopes, no area of the lake looks to be free from slides of either source. the tap, This may steepness potential The bench would most economically be constructed above the shoreline and could serve as a storage area and 'launch site for the maintenance barge if left at the lake. It could also act as a staging area and helicopter pad for future 'maintenance or construction activity. The bench might eliminate the need for the adit east of the gate shaft. 8.0 CONSTRUCTION DIFFICULTIES AND COSTS This project presents particularly difficult conditions to perspective bidders. The combination of a remote location, inaccessibility, a short con- struction window and the nature of the work involved results in a unique high risk situation. Contractors which are qualified to perform this work ,will accordingly provide a significant contingency if they are required to bid the work on a lump sum basis. Our estimate to complete this work based on a fixed amount is $3.5 million for the slusher method and $5.9 million for the clamshell method. We estimate that a savings of 10-15% or more could be realized if the work were bid on the basis of reimbursable costs rather than a fixed amount. The .' contractors would be asked to bid on hourly rates for a given method of con-~' struction with a target amount to complete the work. We have made several assumptions with regard to the equipment and manpower that would be required to perform this work. We feel that because of site conditions, time restrictions and remoteness of the project that a well equipped and manned operation is essential and is reflecte~ in our cost estimates. We recommend that minimum requirements for manpower and equipment be included in whatever type of construction contract is, ultimately used. For example, we have assumed that the movement of material from base camp at Snettisham to Crater Lake will be accomplished with a Sikorski Sky-crane. We have also assumed that a fully equipped diving station would be set up at the start of the construction that would be available for immediate use upon need. The station would also be used for required inspections. A detailed breakdown of our construction cost estimates are included in the appendix. One question which needs to be resolved as part of the contract preparation for lake bottom clearing is the definition of what '"clean'" is considered in terms of the clearing effort. For the purposes of this report, we have assumed that a '"clean condition'" will be achieved when all material has been removed to within approximately 2 feet of bedrock. We assume material contained in a 2-foot layer would ~ot pose a problem if it were to enter the power tunnel dur- ing the lake tap construction or during future operation of the project. However, for the purpose of computing the quantity of material which would be handled, we have included all material down to bedrock assuming that a certain amount of debris will be picked up and redeposited through slumping at the sides of the clearing limit or from settlement of rock flour which is put into suspension during clearing operations. In preparation of cost estimates for this work--both methods--an allowance has been made for land disposal Disposal would consist of stock piling on shore at either lake or near the far shore, directly across the lake from slusher and clamshell of vegetative debris. the west end of the the tap location. I' Such disposal may not be necessary; a determination concerning this requirement will have to be made. The incremental cost included in the estimates is minor ($50-75,000). 9.0 MOBILIZATION THROUGH THE TUNNEL It is understood that the Corps believes that its fiscal 1984 and 1985 funding precludes driving the tunnel past Sta. 35+00 in fiscal 1985. Nevertheless, it plans to perform the lake tap site clearing in fiscal 1985. It is felt that if the funding necessary to perform the clearing were instead allocated to the tunnel, it could be driven to Sta. 14+00 in 1985, and the gate shaft and adit to the lake could be completed as well. This would permit the mobilization of the clearing plant to be handled through the tunnel, thus saving the expensive helicopter cost for mobilization and also for access during performance of the work. In addition, it would appear that the hoist operating station and the dock could be installed at the end of the adit to the lake, thus simplifying the operation. It is also noted that the Corps will need such a dock and also a barge for servicing the intake trash-rack cleaning mechanism. We foresee no problem in utilizing the gate shaft for mobilizing construction equipment for either the slusher or clamshell methods. The sectional barges would consist of segments 8'-10' wide by 15'-20' in length by 4'-6' in depth where the motor launches would be approximately 24' long by 6'-8' wide by ap- proximately 3' in depth. Plate 9 of Design Memorandum No. 26 indicates that the rock excavation for the gate structure will be approximately 12' by 15' at the point where the shaft intersects the power tunnel, narrowing to 10' by 12' at a point approximately 18' above the tunnel soffit. These dimensions are adequate to accommodate the equipment even considering that ventilation equip- ment will occupy part of the tunnel space. Upon installation of the concrete lining, air ducts, access ladder and gate structures, the clear shaft area will be reduced. It would, however, still provide a means of demobilizing much of the equipment. If it were assumed that one of the sectional barges was to remain at Crater Lake for future use as a work platform, the largest materials which would have to be demobilized for the slusher method would include the air-track drill, D-4 cat, motor launch, two winches and the scrapers. The air-track dri~ would be utilized during the early stage of construction and-could be demobilized as soon as its work was completed. The winches could be disassembled and a major portion of the parts moved through the finished gate structure; the scrapers could be torch cut to sizes which would pass through the shaft. It is our contention that if the project equipment were carefully selected, most if not all of it could be demobilized through the gate structure thus eliminating or greatly reducing the cost of very expensive helicopter assistance. If the same contractor doing the tunnelling was also responsible for clearing, he would be motivated to plan and schedule around such an approach if it were cost effective. The use of the tunnel for personnel access during the clearing operation does not seem to be cost effective for several reasons including (1) the requirement for full-time helicopter service at the site for emergency use, (2) the addi- tional time (and cost) required to move personnel to and from the lake, and (3) possible conflicts with other operations (in the tunnel and gate structure) being performed concurrently with the clearing. A more detailed review of per- sonnel access, may be warranted once schedules are established for the tunnel, gate shaft and clearing operation. Plate 2 depicts-the changes which would be made in the Corps schedule to accommodate this change. 9.1 Pros -Lake Access Through Tunnel (a) Saves considerable helicopter expense (b) Saves set-up expense on west shore of lake (c) Simplifies winch and hoisting arrangement by ~ocating all power equip- ment near ther adit. (d) Should show a significant saving on tunnel costs because it eliminates demobilizing and remobilizing for 2,100 ft. of tunnel. (e) Provides time to drill exploratory holes ahead and plan for grouting defective rock zones between Sta. 14+00 and lake tap inlet prior to awarding a construction contract. 9.2 Cons -Lake Access Through Tunnel (a) Requires change in program for performing the work. (b) Requires change in contract packaging. (c) Requires helipad to be constructed from other materials. However, this cost is offset by saving in driving helipad adit from inside, thus avoiding an expensive helicopter based operation. 10.0 CREW SIZES FOR SLUSHER METHOD 10.1 Clearing Crew, Each Shift (2 Shifts) 1 -Shift foreman 1 -Hoist operator 1 -Bridle winch operator 2 Oilers 1· -Launch operator 1 -Shift mechanic 1 -Signalman 10.2 Clearing Crew, Day Shift Support (1 Shift) 1 -Foreman ,. ( 1 -Launch operator 2 -Deck hands 2 -Mechanics 2 -Mechanic helpers 1 -Timekeeper/Clerk 10.3 Mobilization Crew at Lake ( 1 month) 1 -Foreman 2 -Launch operators 1 -Bulldozer operator 3 -Mechanics 1 -Driller 2 -De<;k hands 1 -Driller helper 2 -Millwrlghts 6 -Laborers 10.4 Mobilization Crew at Snettisham (1 month) 1 -Truck crane operator 1 -Oiler 1 -Truck driver 2 -Riggers 10.5 Unload and Pre-assemble Crew (1 month) 1 -Foreman 1 -Truck crane operator 1 -Oiler 1 -Truck driver 2 -Riggers 3 -Mechanics 2 -Millwright s 4 -Laborers 10.6 Administration and Supervision (6 months) 1 -Supe~ntendent 1 -Engineer 1 -Office man 1 -Secretary 10.7 Demobilize Same as Mobilization Crews. 10.8 Diving for Inspection and Emergencies Provide diving crew for two separate weeks. 11.0 CREW SIZES FOR CLAMSHELL METHOD 11.1 Clearing Crew, Each Shif~ (3 Shifts) 1 -Shif~ foreman 1 -Clamshell operator 1 -Oiler 3 -Launch operators 4 -Deck hand 1 -Shift mechanic *1 -Spot~er * (Added) 11.2 Clearing Crew, Day Shift Support (1 Shift) 1 -Foreman " p. 1 -Launch operator 2 -Deck hands 1 -Tractor operator 3 -Mechanics 3 -Mechanic. helpers 1 -Timekeeper/Clerk 11.3 Mobilization Crew at Lake -Same as 10.3 11.4 Mobilization Crew at Snettisham -Same as 10.4 11.5 Unload and Pre-assemble Crew Same as 10.5? but add: 1 -Rigger 1 -Mechanic 1 -Millwright 2 -Laborers 11.6 Administration and Supervision Same as 10.6, but for 7 months 11.7 Demobilize Same as Mobilization Crews. 11.8 Diving for Inspection and Emergencies Provide diving crew for four separate weeks. 12.0 ADDITIONAL STUDIES Prior to advertising for construction~ we recommend that additional borings be taken within the clearing limits in order to better define the nature of the unconsolidated material. Submarine borings taken to date in Crater Lake have been for the purpose of determining the nature of the bedrock and have provided only cursory information with regard to the unconsolidated deposits. Drilling time and difficulty in drilling through the unconsolidated layer would be helpful as well as the retrieval of samples if possible. Additionally, a detailed inspection dive of the site should be conducted and video tapes made of the bottom conditions. During the dive, high resolution side scan sonar (as manufactured by Mesotech, see Appendix) mapping of the site would be accomplished which would also be utilized to direct the diver to spe- cific·objects. It is estimated that the cost of the diving inspection and side scan sonar survey would be $55-60,000, not including helicopter transportation or subsistence costs. Alternatively, a remote controlled, self-propelled video camera reconnaissance should be considered. 13.0 CONTRACTOR COMMENTS 13.1 Underwater Construction, Inc., Anchorage, Alaska We had extensive conversations with Mr. Richard Livingston of Underwater con- struction regarding the construction aspects of this project, as well as during support for inspection and construction activities. Mr. Livingston was in gen- eral agreement with regard to the technical feasibility of both the clamshell and slusher methods. He did feel that airlift pumping at these water depths was practical. Mr. Livingston also concurred with our estimates for labor, plant and support facilities to accomplish this work. He consider this to be a "high risk" project. 13.2 S. J. Groves & Sons Company, Bellevue. Washington We spoke with Mr. Fred Walter of S. J. Groves & Sons Co. regarding the proposed mehtods of clearing for the lake tap. He reviewed our estimated production rates, equipment requirements and costs. He felt that the time. required to perform the clearing by these two methods would be approximately the same, that is our production rate for the slusher was high. Based on that assumption, the /' cost for performing this work would be greater than $3.5 million. He did not ~ .. feel hopper barges would be required, but that the material could be dumped on flat barges with some kind of low sid~boards. Mr. Walter did not think divers would be needed. He suggested that competitive bidding would result in the lowest cost and that bidding the clearing work with the tunneling would be preferable. 13.3 Parsons -Brinkerhoff t Sacramento, California We talked to Mr. Koenig of Parsons-Brinkerhoff. He was under the impression that their firm was going to be awarded a contract to prepare a report regard- ing the clearing operation and did not provide any additional comment. 13.4. J. A. Jones, Charlotte, North Carolina Mr. Woods of J. A. Jones was contacted. He was familiar with the project as a result of previous discussions with the Corps of Engineers, but due to pressing "'-business matters was unable to provide additional input at this time. 14.0 CONCLUSIONS We estimate that the least cost method of removing approximately 20,000 cubic yards of unconsolidated soil, rock and vegetative debris at the proposed lake tap is by using a slusher to rake the material down slope into deeper water. .- The slusher is a blade-type device that is attached to cables which in turn are activated by winches, similar to a slackline drag. This is an older method of excavation but suited for this project, because of smaller plant requirements and associated mobilization and operation costs. There may not be many contractors experienced with this method. The estimated cost of performing the clearing is $3.5 million, not including contingencies. A P PEN D I X LAKE TAP CLEARING . CRATER LAKE, SNETTISHAM EQUIPMENT COSTS -CLAMSHELL METHOD Equipment Equipment Purchase . Rental per Equipment F .O~B. Sea. Month Wt. Lb. 1 200 HP Diesel Winch $ 5,000 25,000 1 50 KW Diesel Elec. 1,000 3,000 1 Power Mooring Winch 1,700 3,000 3 500# Anchors $ 1,500 2 4 cu.yd. Clam Buck 3,000 16,000 1 5 T. Elec. Hoist & Jib 7,500 1 24 x 51 Sect. Barge 90,000 2 20 cu. yd. Hopper Barge 150,000 1 16' x 34' Sect. Barge 40,000 1 Grapple 3,000 1 300 CFM Compress 2,500 1 Stiff Leg @ 15 Ton 5,000 30,000 1 D4 Cat 3,900 4 24' Launches 48,000 2 Jack Hammers 150 1 Skil Saw 200 2 Air Wrenches 1,000 2 Welding Machines 900 1 16 x 34 Sect. Barge 27 T. 4,000 1 Shop Trailer 400 1 Off. Trailer 200 ' 4 2-Way Radios 11,480 1 25 KW Generator 1,300 1 10 T. Truck Crane 9,500 1 5 T. Flatbed 2,200 1 Off. Trailer' 400 1 Warehouse Trailer 300 3 Chain Saws 1,000 $390,680 $13,700 LAX! TAP CLEARING CRATER LAKE, SNE'IT ISHAM EQUIPMENT COSTS -SLUSHER METHOD Equipment Equipment Purchase· Rental per Equipment F.O.B. Sea. Month Wt. Lb. 2 72-Inch Scrapers $ 15,000 14,000 1 125 HP Diesel Winch $ 4,200 10,000 1 25 HP Diesel Winch 1,700 3,000 1 72-Inch Rake 6,000 6,000 1 16' x 34' Sect. Barge 40,000 26,800 1 24 Ft. Motor Launch 12,000 2 15 Ft. Jib Booms for BA 4,500 2 25 KW Diesel Gen. 1,300 2,000 ih', 1 D-4 Cat 3,900 1 600 CFM Compress 3,250 1 Air Track Drill 6,250 2 Jackhammers 150 111'.> 2 Air Wrenches 1,000 2 Skilsaws 400 2 Welding.Machines 900 1 Shop Trailer Sm 400 1 Office Trailer Sm 200 2 8' x 17' Pontoons for Dock 40,000 13,400 1 30 Ft. Bailey Bridge 24,000 24,000 1 10 T. Truck Crane 4,500 1 5 T. Flatbed 2,200 1 Office Trailer 200 1 Warehouse Trailer 300 6 36" Sheaves for 1" 3,500 6 18" Sheaves for 1/2" 1,000 6 Double Sheave Blocks 2,000 10,000 Ft. 1" WR 21,000 16,000 2,000 Ft. 1/2" WR 1,500 800 Barge Anchors & Lines 3,000 3 Chain Saws 1,000 6 Two-way Radios 17,220 .. t193,120 $29,450 /~ I , General Forman Launch Operator Deck Hands Mechanics Mech. Helper Hoist Operator Bridle Winch Opere Oiler Sigyia1man Laborer Truck Driver Crane Operator Cook Cook Helper Housekeeper Housekeeper Help Riggers Millwrights Dozer Operator Driller Driller Helper Project Manager Superintendent Clerk Off. Engr. LAKE TAP CLEARING CRATER LAKE, SNETTISHAM LABOR RATES Standard Time Including Labor Overhead 47.25 37.00 19.30 37.00 33.00 39.50 39.50 33.00 30.50 30.50 32.50 33.75 31.50 30.00 27.50 27.00 35.00 37.00 39.50 37.00 30.50 Overtime Including Labor Overhead Per Week 63.00 49.50 26.00 49.50 44.00 52.50 52.50 44.00 40.75 40.75 43.50 45.00 42.50 40.00 36.75 36.00 46.50 49.25 52.50 49.50 40.75 2,000.00 1,500.00 675.00 800.00 LAKE TAP CLEARING CRATER LAKE. SNETTISHAM COST SUMMARY -CLAMSHELL METHOD COST COST COST· PER PER PER LUMP NUMBER NUMBER NUMBER DAY SHIFT MONTH SUM DAYS SHIFTS MONTHS TOTAL Unload & Preassemble $9128 24 $ 219,072 Mob & Assemble at Lake 7849 24 188,376 Mob Crew at Snettisham 2240 24 53,760 Clearing 5019 120 602,280 Dayshift Support 4919 60 295,140 Demob 7849 18 141,282 2240 18 40,320 Load Out 7849 24 188,376 2240 24 53,760 Administration $19,900 7 139,300 Diving $144,732 144,732 Equipment Rental 40.450 5 202,250 Small Tools 49,248 49,248 Supplies and Equipment 390,680 390,680 Salvage Value (175,340) (175,340) Fuel, Lube, Parts Etc. 1000 90 90,000 Materials 500011 Steel 1,250 1,250 5 MBM Timber 2,500 2,500 10001/ Bolts Hardware 2,000 2,000 20 I" x 10' Rock Bolts 1,200 1,200 Camp Costs 35 5,700 199,500 Logistics Beaver Aircraft 18,000 18,000 Hughes 500D 147,150 147,150 Skycrane 912,000 912,000 Barge/Tug from Seattle 275,'000 275,000 I I SUBTOTAL 4.,532,516 Contractor Gen OH & Profit 30% .L.l5f) 735 5,8 . • 271 'l '" " ~ " .. ~ ., LAKE TAP CLEARING CRATER LAKE, SNETTISHAM COST SUMMARY -SLU·SHER METHOD COST COST COST PER . PER PER LUMP NUMBER NUMBER NUMBER DAY SHIFT MONTH SUM DAYS SHIFTS MONTHS TOTAL Mobilization Unload & Preassemble $6860 24 $ 164,640 Mob & Assemble at Lake· 7849 24 188,376 Mob Crew at Snettisham 2240 24 53,760 Clearing Crew/Day 4950 33 163,350 Clearing Crew/Night 5357 33 176,781 Demobilization Disassemble at Lake 7849 8 62,792 2240 8 17,920 Load at Snettisham 7849 16 125,584 2240 16 35,840 Admin. & Supervision $19,900 6 119,400 Diving Cost 140,232 140,232 Equipment Rental 29,450 4 1~7,800 Small Tools 22,000 22,000 Supplies & Equipment 193,120 193,120 Salvage Supplies & Equip. ( 76,560) 06,560) Fuel, Lube, Parts, Etc. 500 60 30,000 Materials 20,00011 Steel 5,000 5,000 20 MBM Timber 10,000 10,000 2000# Bolts/Hardware 4,000 4,000 50-1" x 20· Rock Bolts 3,000 3,000 Camp Costs 35 3,325 116,375 Logistics Beaver--Aircraft 15,000 15,000 Hughes 500D 114,450 114,450 Skycrane 450,000 472,000 Barge/Tug from Seattle 275,000 275,000 SUBTOTAL 2,702,980 Contractor Gen. OH & Profit 30% 810.894 LAKE TAP CLEARING CRATER LAKE, SNETTISHAM TRANSPORTATION AND SUPPORT COSTS C = CLAMSHELL METHOD S = SLUSHER METHOD COST COST COST TOTAL TOTA PER PER PER LUMP NUMBER NUMBER NUMBER LUMP CLAMSHELL SLUSH MONTH DAY HOUR SUM MONTHS DAYS HOURS SUM METHOD METHO. I S Beaver Aircraft $300 50 $ 15,01 C 300 60 $18,000 S Hughes 500D $21,000 3.5 73,51 S Helicopter 195 210 ·40,9 C 21,000 4.5 94,5,00· C 195 270 52,650 S Sykorski 5,500 64 352,01 Sky crane S (Mob-Demob) $60,000 2 120,01 C 5,500 144 792,000 C 60,000 2 120,000 S Barge Service 11,000 25 275,01 S From Seattle 11,000 25 275,000 (2 R.T. Plus Loading Time) Divins Sueeort S&C Mob & Set Up 31,116 31·,116 31,1: S Equip. Standby Charge 150 120 18,01 C 150 150 22,500 S&C Inspection Dives 15,000 4 60,000 60,01 S&C Demob 31,116 31,116 31,1: OF LANDSLlDE--~ TUNNEL '-----BOTTOM CONTOURS o 20 40 60 80 i SCALE IN FEET Deale ....... w. G.C.F. m I---------l.,. __ D,...,'I'\ Dey; of~ Checked b., PLATE 1 U.S. ARMY ENGINEER OISTRICT CORPS OF ENGINEERS ANOHORAGl,AlASKA SNETTISHAM PROJECT, ALASKA CRATER LAKE LAKE TAP CLEARING SITE PLAN -~--------------i~J~~·~-~---------~ SNETTISHAM-CRA TER LAKE PHASE FY 84 ~I. FY 85 ~I. FY 86 ~I. FY 87 ~I""" FY 88 CY 84 CY 85 ~I. CY 86 CY 87 ~I· CY 88-----:. JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOY DEC JAN FEB MAR APR MAY JUN JUL AUG BEP OCT NOY DEC JAN FEB MAR APR M" Y JUN JUL AUG SEP OCT NOY DEC JAN FEB MAR APR lolA Y JUN JUL AUG 8EP OCT NOY DEC JAN FEB MAR APR NPO/OCE CONT" rED ;:: DM 26 REVIlEW REV -"E ...... IOEO ... ~""'!!'! T£ PRELIM. -'"\ "E"AIIE IIPO/O E l~ -I":'" CWT8. P£"IXq _REVE' > J I ..-DE_ I--,"XC.V.T •• iE '" MIE"! jwr "" T( "A'8E. T£ IMAI" 1 "~_IT' fiE 1 EXCA. ATION NPO COO f"""''''' r:,-=r-TUNI LTD L ADIT T LAKe STAGE 1 EXCAVATION I_~ f.-'" fa. REVE!" ~AD' ~:'~f .. . -. TU~ L TO aTA l'tOO ITA • .-.... I-T -~ "..1 OEM .,LlrE l'Aun IIIIIAleEGA E SHAFT .NDN VICE. ...~ oaiLi E ........ POUlT> _coo .I'URC ,. ... MOO. ~AT LAIC!, '1000-jEtocv f..D MOKp LAKE TAP SITE CLEARIN( ~-:!"'-".-1lHAU0W .~ ~...!!-' ~~. ~~ ~.!!. ~ flOIA&.,. teE AND AWAItO AN DELIY RTO ~TT A" OULD DOC'. ETC ~-fLO. ---f-........ l-) -TIWE ..... pRM C E ..... "-1"'-' ~..': ::..~ STAGE 2 EXCAVATION EX ""V.'-' f---~ a.e.ECT ~~ r"' -'--; -- I I ~ ~= TIVE~ E8II"!...I.. EJCCA .TE PENSTOCK DESIGN .n~~ ---...-. lOA ~ ... -"ACH !!.E.H P CON TRue MAC IHE • OP -- - t--t-----.-- ........ .,in" ~ / EXCA ATE NaT CK TU ) porr ..... _ .... I'-Tor .. ~-. ~ T~L .... "Co' ~FO ~U'Q' TANK IEC. NO F L. EXC 'tATE P"'" III LAKE TAP DESIGN -""'\ME .. DE .... ... ~. r-IIPUT IIEVEW COAR. LA. ,",DC' RA". ~...I ROC TR. LI KE 1 ~P ! 1\ - - r--if •• 0 REP HE ~ 'i""LUD IT" '\ FOR LAKE •• ~ Oft EX ORIN. t..~ AND i "C ""ORAT POWER ouaE c ~pL!TIO I NpAIN O/OCE II .. CO. MENTI A DOE." 'OR. TE iii \ 0' PO EIitHOUI ST" CTUIitE ONTROl .INITRI ~EHTATI N. III ••• ICAT .EN DC. GATE • G. Hora ING INaT LL Qj ... o QA E ~ STAL QATE nR IN. ALL POWERHOUSE N •• "EpA"E COWl'. "E' ouT A MACHI E aHOp "IYI •• CO" ... a "I!VIEW CO ".,. ~ E"TlSE E~ ~MEH CON ,",OL. PORT L .11< HEAD .ETC. HOII INO OUI~ NT ~WER IUPPL PRI ARV EST U IT *3 D~ ~8ILIZ -COMPLETION "C AGE FO REVIEW Z V -~-, NTR L8. T rNEL 'NIH( R41H ACK., .ND LEAN P iii 1\ / [) / IN. .LL< HERA 0 .. A 0 / POWER CONDUIT oaTAIN IE aERY CEO " ELiaUMAI y DE.,. REYIE '1 AL DEli N "EVII!W' CO~ PO ERHO .E C .. "LE ION 'N TAll URa'N ''''E • IN TALL URB'ft NON IwaE R~ IN IN EQUI WENT / --t--ANCILLARY -J f V / V V V I !!"UM!! ATIOH .... J ELiV " TUR IHE I 8EO. I /' ~ HIJ " TUR INE ON-Nil EoO f IWJV • I •• ITCH EA" I / ~ IsEE~ 0 IGINA SCHE IULE lofJ..,y, GE RAT" Hl.'V TR. "0 ER J ELiV " GO E"NO ;1 DELIV " IU~ "V,. RYC NTRO L ~ u.s. ARMY ENGINEER DISTRICT CORPS OF ENG~RS ANCHORAGE, ALASKA - De .......... ~1 1m SNETTISHAM PROJECT. ALASKA G.C.F. CRATER LAKE Ot-..... " b,1 W H . us_"-.. -LAKE TAP CLEARING PROPOSED ALTERNATE C ........... ~l CLEARING SCHEDULE PLATE 2 EXCAVATION & LAKE TAP ... w ........ " Be ... , _heel ~~ ref.rMiCe O •• el. 6/B4 number. nlt~ /-g:..~NE-96-0HB-02 Sheel 2 ef 4 " rAPPROX. LOCATION OF HOIST --". /( ANCHOR IN ROCK · ................ LOAD LINE ~\ ANCHOR IN ROCK WEST SHORE LINE PLAN LAKE SURFACE EA ELEY. 7110' ~ DISPOSAL AR ___ _ ::;,'" =11T iTI.= PROFILE I I SCRAPER I 140'-300' I LEARED APPROX. AREA TO BE C u ________________ _ APPROX. 2500' EAST SHORE LINE ELEY.l020' APPROX. LOCATION OF HOIST LAKETAP\ • SITE PLAN " .. T .. 8. ~ -'-'-'- 0. ........... , m G.C.F ....,~ --------, ::I'_ D!" •• " b.2 W.H. Check.db.: PlATE 3 Se.I.: AS NOTED -01-18-03 '--GATE STRUCTURE AL TERNA T/VE ANCHOR LlNES-4 REQ,D. (2 AT BOW, 2 AT STERN) SECTIONAL BARGE SIDE VIEW LAKE SURFACE 'V SECTIONAL BARGE FRONT VIEW HOPPER BARGE " 0' 6' 12' :--<l .GRAPHIC SCALE 3116"·1'-0" • -''''-'- O' ...... nedlt'l G.C.F. m U,S. ARMY ENOIHUR 0 STRICT CORPS OF ENGINEERS ANC~AGE,AlASKA SIE1TISHAM PROJECT, ALASKA CRATER LAKE I-O-,.-wn--b'-:-W-,-H-.----i ':t::'-"-:' LAKE TOP SITE CLEARING METHOD Checkedb,: PLATE 4 CLAMSHB..L ALTERNATIVE Scol.: 3/16·.1'-0· Sh •• t ret.rence I-----~---_I numberl F'---"---·----1 1-18-0 S __ 4_ef_4_ EXHIBIT 6 SNETTISHAM CRATER LAKE WES REVIEW OF FINAL LAKE TAP BLAST JULY 1984 DISPOSITION FORM For use of this form, see AR 340-15; the proponent agency is TAGO. REFERENCE OR OFFICE SYMBOL SUBJECT I: I NPAEN-H-HD Snettisham Crater Lake-WES Review of Final Lake Tap Blast I I TO NPAEN-DB FROM NPAEN-H-HD DATE 2 Aug 84 .~exler/hb/2-2329 CMT 1 1. Inclosed is the WES review of NPA's analysis of the final lake tap blast. The review was made by Dr. Frank Neilson. 2. - A phone call was made to Dr. Nei 1 son to cl arify some of the corrunents. I ncl osure 2 is the log of that conversation. ~~~ 2 Incl ENDRICKSON as Chief, Hydraulics/Hydrology Branch CF: NPAEN-FM NPAEN-PM-C !...NPAEN~H-I1Q. NPAEN-DB-ST DAEN-CW~-D (Munsey) DEPARTMENT OF THE ARMY ALASKA DISTRICT CORPS OF ENGINEERS IIItKPI.,.YTO ATTKNTION OPt POUCH 898 ANCHORAGE, ALASKA 99506 NPAEN-H-HD SUBJECT: 30 May 1984 Snettisham Project, Crater Lake Phase, Lake Tap Blast COl11l1ander Water Experiment Station P.O. Box 631 Vicksburg, Mississippi 39180 1. The final lake tap blast at Crater Lake will be a critical undertaking and, therefore, it is requested that WES review the analysis of the final blast that has been developed by the Alaska District (NPA). The NPA investigation includes: a. Total force acting on the closed service gate at station 14+00. This force includes blast pressure and the combined static and dynamic water pressures resulting during the surge immediately after the blast. b. Surge height of the water column in the gate shaft. c. Dispersal of the final blast rubble in the primary rock trap and the section of tunnel between the primary rock trap and the gate structure. 2. A package of calculations and drawings was sent to Dr. Frank Neilson of the Hydraulics lab under separate cover. 3. If any further information is required, please contact Joe Wexler or Jeff Johns at 907-552-2329. FOR THE COMMANDER: ,. . ' ." " " ,- .' "', WESHI (30 May 84) 1st Ind SUBJECT: Snettisham Project, Crater Lake Phase, Lake Tap Blast DA, Waterways Experiment Station, Corps of Engineers, PO Box 631, Vicksburg, MS 39180 2 0 JUL '84 TO: Commander, US Army Engineer District, Alaska, ATTN: NPAEN-H-HD, Anchorage, Alaska 99506 1. The following review comments, Crater Lake lake tap, as requested in the basic letter, are of hydraulic calculations for the flow passage upstream of the service valve. The boundary conditions are: a. The service valve remains closed during the event. b. The lake bottom in the vicinity of the lake tap is cleared of debris. c. Initial lake water-surface elevation is 1019 ft; initial gate shaft water-surface elevation is 995 ft; valve elevation is 789 ft. d. A pressurized air mass is contained in the short riser between rock trap and tap face. e. Dimensions are as shown in DM26, Plates 6 and 7 (received separately; notations dated 25 May 1984). f. The dri11ing-and-detonation plan is as shown in drawing (Snettisham Project No. DACW-68-C-0026; J.D.C. 32; 7/11/68; Rev. February 69). g. The blast sequence is, first, to shatter the core of the tap plug (cavities for initial material expansion are provided) and second, to peel successive layers from the periphery of the core until the trap is fully formed. h. The debris shape will be angular and range in size from small (sand size) to a maximum dimension of about 1.5 ft. L The volume of material (granite, S.G. = 2.65) will be about 1131 ft 3 ; i.e., a 12-ft-diameter by 10-ft-1ong cylinder. Review comments, referenced by topics listed in paragraph 1 of the basic letter, are as follows. 2. Hydraulic Conditions Due to Blast (Topic a., Blast, 30 May 1984). The blast is within the rock mass (bore holes) and, additionally, separated from the water column by air trapped in the riser. The detonation plan (para. 1f.) and sequence (para. 19.) are such that the initial unshattered displacement of the rock face towards the flow passage is small. Buffering from the water column is provided by the trapped air and pressure relief is provided by the free surface in the well. Consequently, although blast energy may be transmitted to the gate structure through the rock mass, essentially no energy from the initial blast will be transmitted through the water column. The first large 2 2 a JUL '84 WESHI SUBJECT: Snettisham Project, Crater Lake Phase, Lake Tap Blast hydraulic pressure pulse will be the hydrostatic lake pressure and will arrive at the gate approximately 1/7 second following detonation. The gate will be subject to a vertical rapidly-applied hydraulic loading (1019-995 = 26 ft) that decreases as the valve-well water surface increases. The gate structure will be subject to a horizontal rapidly-increasing applied loading (995-789 = 206 ft to 1019-739 = 230 ft) that varies with surge elevation. The design of the gate hoist mechanism and structure must accommodate these dynamic loads in order to hold the gate closed (para. la.). 3. Surge (Topic a., Surge and Topic b., 30 May 1984). The calculation of hydraulic surge elevation (WHAMO program or by calculator) is straight-forward and reliable. Uncertainties, due to loss coefficient and area determinations, are small because of the low maximum velocity head (l-ft during the initial surge between lake and valve well). The surge height (relative to lake level; 1039-1019 = 20 ft) calculation should be correct within ±l ft; the addition of blast loading extrapolated from the Ringedalsvatn data is, because of time of occurrence, a conservative consideration. 4. Blast Rubble (Topic c., 30 May 1984). The rubble will be deposited within the rock trap with fine materials moving with the flow to a distance less than 44· ft, the maximum surge movement, beyond the static-pool trajectory. The rubble mound (as shown in DM 26, Plate 6) immediately following the first surge will be concentrated between stations 7+48 and 8+12; i.e., to the toe of the trap. No additional net transport is anticipated although some restructuring of the rubble may occur during subsequent oscillations. 5. Studies. The definitions of boundary conditions (para. la.-li. above) are subject to question for highly dynamic construction procedures. The nonhydraulic factors (hydrologic, foundations and materials, structures, and mechanical) appear to require a high degree of construction expertise and intense in- spection procedures. Changing any of these factors obviously will cause some change in hydraulic effects. If such factors are changed, new hydraulic effects can be evaluated; however, the new boundary conditions must be clearly identified. FOR THE COMMANDER AND DIRECTOR: 2 {f/t,~ F. R. BROWN Engineer Technical Director 3 DATE TELEPHONE OR VERBAL CONVERSATION RECORD 2 August 1984 Fa. use of this fo.m, see AR 340·15; the p.oponent agency is The Adjutant Gene.'!I'. Office. SUBJECT OF CONVERSATION WES Review of Lake Tap Blast INCOMING CALL PERSON CALLING ADDRESS PHONE NUMBER AND ExTENSION Frank Neilson WES 601-634-2615 PERSON C:ALLED OFFIC:E PHONE NUMBER AND EXTENSION Joe Wexler NPAEN-H-HD 907-552-2329 OUTGOING CALL PERSON CALLING OFFIC:E PHONE NUMBER ANO EXTENSION PERSON C:ALLED ADDRESS PHONE NUMBER AND EXTENSION SUMMARY OF' C:ONVERSATION 1. I (JW) had several points to clear up with Frank about his review of the lake tap blast calculations: a. Paragraph 2 -What is the vertical applied hydraulic loading? Frank was referring to the fact that a pressure would be applied in all directions including vertically. This could result in additional vertical forces if there are any horizontal flanges on the gate. b. Paragraph 2 -liThe gate structure will be subject to a horizontal rapidly- increasing applied loading of 206 to 230 feet that varies with slJrge elevation." This change in load refers to a rapidly occurring transient. The gradual increase to the final surge height occurs over a longer period of time. c. Paragraph 3 - I asked Frank if the surge height calculations were acceptable. Frank responded that the step method used was a dependable one (he had not done any calculations himself) and our answer should be correct within +1 ft. d. Subparagraph l(i) indicates a total volume of 1,131 ft 3 in the orifice plug. This calculation considers only the material in the plug with no considera- tion given to overbreak or bulking that will take place after the plug is blasted out. e. Paragraph 4 refers to a limiting distance of 44 ft. This distance is the vertical height that the surge will move in the gate shaft. The horizontal distance moved by small particles in the primary rock trap area will be considerably less than 44 ft because the cross sectional area of the trap is larger than the cross sectional area of the gate shaft. 'Iy~ /lL tJ~ JOSEPH WEXLER NPAI='N_I-l_l-ln REPLACES EDITION OF I FEB 58 WHICH WILL BE USED. IMJl-71 EXHIBIT 7 JUNEAU AREA POHER ~1ARKET ANALYS IS SEPTEMBER 1980 ALASKA POHER AD~1HJISTRATION ( .Juneau Area Power ~1arket Analysis .sa pt amber. 1980 'r '. ·U·S. Depart ment of Energy .' A:I ask a Po w erA d min i st rat ion Juneau, Alaska 99802 • ~- . -~ Department Of Energy Alaska Power Administration P.O. Box 50 Juneau, Alaska 99802 Colonel Lee Nunn, District Engineer U.S. Department of the Army Corps of Engineers P.O. Box 7002 Anchorage, AK 99510 Dear Colonel Nunn: September 12, 1980 This is Alaska Power Administration's final report for the Juneau Area Power Market Analysis. The power market analysis includes a new set of load projections for the Juneau area through year 2000 and a review of alternative sources of power. Load/resource and system cost analyses were prepared for different cases and various growth rates to determine effects on power rates. Based on the results of this study, APA believes the following course of action with respect to the Snettisham Project is appropriate: 1. 2. The Corps of Engineers should proceed with actions to construct the Crater Lake unit so that power from the unit will be available in the 1986-1987 time frame. The decision on construction of the Long Lake Dam should be deferred at the present time, and then reconsidered in future years as conditions may warrant. A draft of this report was circulated to area utilities, State offices, and the general public for informal review and comment. In addition, a public meeting was held on August 28, 1980, for public review and comment. All comments have been incorporated and letters of comments are appended. Sincerely, -. Robert J. Cross Administrator ':_-,,_.- .,. ... CONTENTS TITLE PAGE PART I INTRODUCTION --------------------------------1 AUTHORIZATION --------------------------1 DESCRIPTION ----------------------------1 SCOPE ----------------;..--------2 P ART I I SUMMARY -----------------------------------3 PART III POWER MARKET AREA --------------------------7 POPULATION ---------------------------7 ECONOMIC BASE ---------------------- ECONOMIC OUTLOOK ----------------------7 PART IV EXISTING AND PLANNED POWER SYSTEMS ---------11 PART V POWER REQUIREMENTS -------------------14 POWER USE IN THE 1970' s ---:------------14 FACTORS AFFECTING FUTURE DEMANDS --------21 ESTrnATES OF FUTURE DEMANDS ------------22 PART VI ALTERNATIVE POWER SOURCES --------------38 EXPANSION OF EXISTING HYDRO ------------38 OTHER POTENTIAL HYDRO ----------------38 INTERCONNECTION -------------------40 STEAMPLANTS -----------------------41 DIESEL -----------------------------41 MISCELLANEOUS ALTERNATIVES --------------41 PART VII LOAD/RESOURCE AND SYSTEM COST ANALYSIS ------43 INTRODUCTION ---------------------43 ASSUMPTIONS --------~-----------------43 METHODOLOGY ---------------------------44 LOAD MANAGEMENT --------------------------46 RESULTS -------------------------------46 PART VIII FINANCIAL ANALYSIS -----------------------57 REPAYMENT CRITERIA -------------------57 REPAYMENT STUDIES ---------------------58 RESULTS ------------------------------59 APPENDIX A. SYSTEM COST ANALYSES OUTPUT ------------------ B. COST COMPARISON PLOTS OF ALTERNATIVES --------- C. CRATER LAKE CONSTRUCTION COSTS --------------- D. COMMENTS ----------------------------------- BIBLIOGRAPHY NUMBER 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. TABLES Juneau Area Power Sources----------------------- Juneau Area Hydro Units --------------------- Juneau Area Energy and Peak Demand Trends in Data Juneau Area Energy Sales and Percent of Sales by Sector - Analysis of AEL&P Data Use per Customer by Class . Percent of Total Energy Consumption. by Sector. in the Juneau-Douglas Area Forecast Assumptions Juneau Area Power Requirements Summary Juneau Area Load Forecast -Medium Case -Normal Use -- 11. Juneau Area Load Forecast -High Case -Normal Use - 12. 13. 14. 15. 16. 17. 18. 19. 20. Juneau Area Load Forecast -Capital Move Case - Juneau Area Load Forecast -Electric Heat Loads Comparison of Load Estimates Market for Crater/Long Energy Snettisham Project Data -----------_.'----------- Annual Energy Production Without Crater/Long Additions ----,--- Annual Energy Production With Crater/Long Additions --------------------- System Energy Costs, 0 Percent Inflation ------ System Energy Costs, 5 Percent Inflation ------ PAGE 12 13 15 16 17 19 .. 20 23 25 26 27 28 29 36 37 39 49 50 51 52 21. 22. 23. 24. System Energy Costs, Alternate On-Line Dates -- Crater/Long Additions -Displacement of Diese1- Electric Generation Electric Heat Conversion, Displacement of Fuel Oil Consumption ----------------------------- Investment Cost Summary, Crater/Long Lake Additions 54 55 56 60 FIGURES NUMBER PAGE 1. Snettisham Project and Juneau Power Market Area Location Maps -------------------8 2. Juneau Area Population ----------------9 3. Residential kWh Use Per Customer -----------18 4. Estimated Peak Demands ------------33 5. Estimated Energy Requirements -------------34 6. Comparison of APA and Utility Estimated Peak Demands -------------------------35 .. 7. Growth Rate Modifications (Load) ------------47 8. Growth Rate Modifications (Energy) ------------48 9. Juneau Loads and Hydro Resources -------------50a ." 4!i"- PART I. INTRODUCTION The Snettisham Project was authorized and designed as a staged project to meet the long-term loads of the Juneau area. The Corps of Engineers is responsible for design and construction, and the Alaska Power Admin- istration is responsible for operation and maintenance of Federal proj- ect facilities. The first or Long Lake stage was completed and has been in commercial operation since October 1975. It is the intent of Alaska Power Admjnistration to complete the remainder of the authorized project (Crater Lake and increased reservoir storage at Long and Crater) when needed to meet area power demands. To insure a timely and appropriate completion of the authorized project, APA makes periodic evaluation of future markets for project power, appropriate analyses to demonstrate that the additions are feasible, and alternative cost projections. Estimates of future power demands, prepared by APA and local utilities in early 1980, provided an indication that construction start on one or more of the additions may be desirable as early as 1982. The detailed studies recorded in this report were undertaken to develop specific recommendations. Authorization The Snettisham Project was authorized by the Flood Control Act of 1962, Public Law 87-874, in accordance with the plan set forth in House Docu- ment No. 40, 87th Congress, First Session, dated January 3, 1961, as modified by the reappraisal report dated November 1961. Description Snettisham is the largest hydroelectric project in Alaska and the main power source for Juneau, Alaska's capital city. The Snettisham Power- plant is 28 air miles southeast of Juneau. The Long Lake stage, now on-line, includes a low dam at the outlet of Long Lake, power tunnel and penstock totaling 10,000 feet in length, and an underground powerplant with two generators, each with a rated capac- ity of 23,580 kilowatts. Power is transmitted to Juneau over a 44-mile- long, 138,000-volt transmission line, which includes a 3-mile underwater section. The Juneau Substation, located 4 miles south of Juneau, is the point of delivery to the local utility system. Supervisory control equipment provides for operating the Snettisham Powerplant from the Juneau Substation. The powerplant site is remote, accessible only by air or water. Onsite facilities include an air strip, barge dock and boat harbor, a local road system, living quarters, warehouses, and water and sewer systems, all maintained by the APA maintenance staff stationed at the Project. The staff also has capability to operate the project onsite in case of problems with the supervisory control system. Crater Lake stage-is an authorized future addition which would add 27,000 kilowatts of capacity and 106 million kWh per year annuai firm energy. New facilities to develop Crater Lake include a tunnel and penstock to tap the lake and installation of a new turbine-generator unit in the existing powerplant. Long Lake dam would add 57 million kWh of firm annual energy to the project. New facilities would include a dam raising the water surface elevation of Long Lake from the present maximum of 818 feet MSL to a new elevation of 885 feet MSL. Scope The scope of the present work consists of projections of future load growth in the Juneau area, load/resource and system cost analyses of various alternative system configurations, and a repayment analyses to test project financial feasibility. Environmental considerations are not covered in this report. The existing Environmental Impact Statement (EIS) was prepared in 1971 by the Corps of Engineers and they will be responsible for necessary further environmental studies and statements prior to construction. APA will be responsible for compliance to National Environmental Protection Act (NEPA) with respect to project operations. 2 ... • PART II. SUMMARY Juneau presently obtains hydro generation from the Snettisham Project, Long Lake Stage. Several small hydro units, owned and operated by Alaska Electric Light and Power, contribute to the hydro capability in the area. Area power demands are experiencing significant growth due to expansion of the local economy and a shift in the pattern of electric energy use. This shift to electric space heating and water heating has been caused primarily by the high cost of fuel oil. Estimates by Alaska Power Administration and the local utilities of future power demands indicate the present surplus of power will be utilized in just a few years. Significant va.riables affecting future growth include: (1) the extent of change in the local economy; (2) effectiveness of local conservation of energy; and (3) the changing patterns of electric energy use which may include some form of electric transportation. Juneau has an excellent opportunity to displace a large amount of oil and to become less dependent on this unpredictable commodity through the development of the· potential hydro in the area. The development of these "renewable resource" projects would also allow the continued trend in electric heating in the Juneau area. The continued conversion to electric heating is desirable only to the extent that power supplies can be made available from hydro or other renewable sources at reasonable cost. The ideal situation would be the utilization of the renewable resources available in conjunction with careful conservation with any electric conversions (e.g., heat pumps, energy efficient homes) to ensure most efficient use of the available energy supplies. Current studies have utilized the most recent data and economic outlook for the Juneau area in forecasting future load growth. Three growth rates were studied--medium, high, and capital move. Each of these growth rates considered conservation and the trend to electric heating, both in new construction and conversions, in the Juneau area. The medium growth rate is considered the most likely, and received the most detailed study. The range in potential demands is shown below; details are provided in part V. High (hydro case) Medium (hydro case) High (diesel case) Medium (diesel case) Juneau Area Energy Forecasts (1,000 kWh) 1980 157,000 157,000 144,000 144,000 3 1990 468,000 351,000 258,000 183,000 2000 703,000 538,000 339,000 228,000 The upper level, or "hydro case" forecasts assume gradual expansion of electric heat application be~een now and the year 2000 with electricity accounting for about two-thirds of the area space heating requirements in that year. The lower or "diesel case" assumes no additional electric heating applications. A review of possible power supply alternatives included local liydro projects, interconnection with other towns in Southeast Alaska, steam- plants, tidal power, geothermal power, and diesel generation. The most likely options available for meeting future demands would include: (1) 'construction of the Crater Lake addition to the Snettisham Project; (2) construction of the Long Lake Dam Addition to the Snett- isham Project; (3) adding diesel generation units to the existing system as needed, and (4) rehabilitation of the Salmon Creek plants of the AEL&P system. This analysis assumed the Salmon Creek rehabilitation will be completed by 1984. Other attractive hydroelectric projects in the area such as Lake Dorothy, Sweetheart, Tease Creek, and Speel River would be available to meet longer term needs. A summary of the capabiiities of the existing Snettisham Project and the Crater/Long Additions is shown in the following table: Project Existing Crater Lake Long Lake Dam Total Project Capacity (kW) 47,160 27,000 74,160 Firm Annual Energy (1,000 kWh) 168,000 106,000 57,000 331,000 Estimated investment costs for the new units based on 1980 price levels are as follows: Crater Lake Unit Long Lake Dam $44,633,000 $35,089,000 Incremental operation, maintenance, and replacement costs are estimated at $62,000 per year, or roughly 10 per~ent of current OM&R for the Project. Load/resource and system cost analyses were performed to examine alter- native strategies for meeting the future requirements for power in Juneau. Three cases were analyzed: Case 1. No new hydro projects after completion of the Salmon Creek rehabilitation. Case 2. Construction of Crater Lake addition followed by construction of Long Lake Dam.' 4 . -~" ". .... .. .. Case 3. Construction of Long Lake Dam followed by construction of Crater Lake addition. Each study assumed that no new electric heating applications would be permitted when area demands exceeded the available hydroelectric supply. That limit would be reached in about 1983 for Case 1, and about 1992 for Cases 2 and 3, under the medium load assumptions. Indicated average system costs for Case 2 (Crater Lake followed by Long Lake Dam) were significantly lower than for Case 1 (no new hydro) throughout the 1980's and 1990's. Comparison of Case 2 and case 3 results indicated lower costs for a plan adding Crater Lake first, with slightly higher costs if Long Lake Dam is added first. Significant oil savings would be achieved as a result of (1) use of electricity in lieu of oil for space heating, and (2) avoiding use of fuel oil for power generation. Case 2 results, with medium load growth, indicated total oil savings of 42 million gallons for the years 1986 to 1999, with an estimated value in excess of $50 million. The need for additional hydro projects beyond the 1990's was indicated in the analysis with Lake Dorothy and Sweetheart projects being the most desirable. Since Crater Lake is the most favorable project for con- struction at this time, future planning efforts for any additional projects should be deferred until load growth beyond the Crater Lake project indicates a need. Future power costs, following full utiliza- tion of Snettisham production, will increase regardless of the new hydro units brought on-line. However, the costs of power fram the Crater/Long Additions will be lower than any future hydro project. Projects beyond Crater/Long will require full Congressional authorization for any work to proceed toward construction. In the e~ent no new hydro projects are added to the existing system, it is assumed that future growth would have to be held down through meas- ures of increased conservation and load management. The continued conversion to electric heating would be discouraged due to the economics of producing electricity with diesel units. In essence the future growth is directly related to the availability of renewable resource hydro energy. Snettisham Project repayment criteria are governed by language in the initial project authorization (Flood Control Act of 1962) as amended by the Water Resources Development Act of 1976. The present wholesale rate of 15.6 mills per kilowatt-hour reflects deferral of portions of the interest expense for an initial 10-year period pursuant to the 1976 Act. All costs, including the deferred interest, are to be repaid in a subse- quent SO-year period which begins in 1986. APA power repayment studies at the end of FY 1979 indicate the rate will need to be increased to about 25.6 mills at the end of the 10-year initial period. These compu- tations include allowance for inflation in operation and maintenance costs through 1984. 5 - Additional power repayment studies were prepared for this report to illustrate impact of Crater Lake and Long Lake Dam on sales and revenue requirements for the Snettisham Project. Study results are as follows: Repayment Assumptions 1. Existing project (without additions of Crater Lake and Long Lake Dam): (Assumptions are identical to official FY 1979 APA power repayment study, except for slightly higher sales figures in the early 1980's.) 2. Existing project with addition of Crater Lake (1986) and Long Lake Dam (1988) (1980 costs). 3. Same as item 2, but with 35 percent inflation of construction costs for Crater Lake and Long Lake Dam. 4. Same as item 2, but with load growth delayed 10 percent. Indicates average rate, 1986 to end of repayment period 26 mills per kWh 23.5 mills per kWh 26.5 mills 24.0 mills All of the repayment studies allow for inflation in operation and main- tenance costs through 1984, only. Actual rates will of course reflect any inflation beyond that date. Based on results of the study APA believes the following course of action with respect to the Snettisham Project is appropriate: 1. The Corps of Engineers should proceed with actions to con- struct the Crater Lake unit so that power from the unit will be available in the 1986-1987 time frame. 2. Decision on construction of the Long Lake Dam should be deferred at present time, and then re-considered in future years as conditions may warrant. The studies indicate the importance of establishing improved con- servation practices in all electric uses and maintaining a close watch on impacts of new electric heating loads. 6 ..' PART III. POWER MARKET AREA The power market area is generally the City and Borough of Juneau. Power is delivered to area customers through two local utilities, Alaska Electric Light and Power (AEL&P) and Glacier Highway Electric Associa- tion (GHEA). The Snettisham Project location and service areas of the two utilities are shown on figure 1. The Juneau area is isolated in that it is not electrically intercon- nected to any other power syst em. The rugged terrain in the area has prevented any feasib le interconnections with other areas up to the present time. Population The Juneau area population is shown on figure 2. The trend was steady with an average increase of 743 persons per year or 3.8 percent annual growth based on the 1978 population. Economic Outlook Juneau has had a generally strong economy throughout the 1970' s, evi- denced by substantia~ growth in employment, population, construction programs, and large increases in personal income and property valua- tions. The capital move issue remains a serious threat to the local economy, but most agree it is expected that growth will continue throughout the 1980' s • The growth in government emp loytnent is not expected to be quite as large as in recent years--consequently, it seems reasonable to assume overall growth in the 1980's somewhat less than the 1970's. A fairly strong construction program in 1980 and 1981 is evidenced by building permits and normal development projects. The Alaska economy will be stimulated by a $500 million capital budget appropriated by the 1980 Legislature. This will tend to insure a strong economy Statewide. The Juneau area received a sizable portion of this appropriation to develop a convention center, the University of Alaska Juneau, and money for home loans. Residential and commercial construction is expected to be approximately the same for 1979, 1980, and 1981 according to City and Borough Public Works officials based on past, existing, and anticipated building per- mits. Although there was a slowdown in the first half of 1980, plans are emerging for a block of 20 and SO low income and elderly housing units to add to the 1980 construction season. Forty-eight units of a ·90-unit all-electric condominium complex are proceeding rapidly with occupancy planned for the first 48 units by December 1980. 7 -,' FIGURE 1 lOCATION MAP Snettisham Proj ect and Juneau Power Market Area •• ..... 1''' If' LOCATION MAP .. 8 ~, •• " J UIII ac JUNEAU AREA POPULATION 40,000 HISTORIC POPULATION 1910 13.556 35,000 1911 14.478 1912 14.979 1913 16.593 30.000 1914 17 ,195 1915 17 ,714 1916 18,760 25,000 1971 19,174 1918 19,500 20,000 15,000 10,000 5,000 0 1970 71 12 13 74 15 16 71 78 19 80 81 82 83 84 85 86 87 88 SOURCE: ALASKA DEPARTMENT OF LABOR STATISTICAL.QUARTERLIES 1970-78 N t " 'j. ,1,\ There are several other major construction projects planned for comple- tion before 1985· that will tend to stabilize population and electrical growth at the past growth trends. They include: two or three. hotels in the planning and financing stage. the convention center funded during 1980. a Southeast Alaska resource center library. rebuilding of one school. and a new school to be located in the Lemn Creek or Valley area. 10 PART IV. EXISTING AND PLANNED POWER SYSTEMS The existing and planned power generating units in the Juneau area are shown on table 1. These units include those owned by the two local utilities and the present Snettisham Project. The capacities and energy available from the hydroelectric units, existing and planned, are shown in table 2. The Juneau area originally depended on hydroelectric power, but with the advent of low cost diesel generation many of the original hydro units were abandoned or allowed to deteriorate mechanically. The recent increases in oil prices has reversed this situation with hydro units now being added or upgraded in the local system. The Snettish~ Project, located 28 miles south of Juneau, has'been in operation since 1973. The project is operated by Alaska Power Admin- istration and with a capacity of 47,160 kW is the source of power for Juneau. The project is presently capable of producing 168 million kWh of firm annual energy and in 1979 furnished about 60 percent of Juneau's electric energy. Alaska Electric Light and Power (AEL&P) is a private utility with a heritage dating back to the gold mining days. Their transmission and distribution system serves primarily the Juneau-Douglas downtown areas and the Mendenhall Valley. Full standby generation is provided to handle any Snettisham interruption by use of diesel generation, local hydropower, and a scheduled combustion turbine. Hydro units provide energy on a year-round basis as well as reserves. AEL&P is in the process of rebuilding and modernizing all their hydro plants. The Upper Salmon Creek powerplant is scheduled for rewinding the generators to increase the capacity from the present 2,800 kW to 4,500 kW. The Lower Salmon Creek unit is proposed for reconstruction by the mid-1980's and could provide 1,200 kW of peaking capacity. The combustion turbine scheduled for installation in 1980 would be oil-fired and have a capac- ity of 20,000 kW. The main distribution line of of AEL&P is being upgraded from 23 KV to 69 KV. By 1983 or earlier, the upgrade will be completed and will supply power from the Thane Substation at the south end of the system to the Mendenhall River at the north end. Glacier Highway Electric Association (GHEA) is a REA cooperative and services the area from roughly mile 10 on the Glacier Highway to mile 21. GHEA has one standby diesel generator, operated and maintained by ~L&P. 11 Table 1 Juneau Area Power Sources UTILITY Year Installed Peak Average Original Capacity Capacity Annual Construction kW kW kWh Existins Generation Diesels, Gold Creek * Enterprise 1952 1,250 1,250 Enterprise 1954 1,200 1,250 Enterprise 1961 3,750 3,750 Fairbanks Morse 1963 1,136 1,136 Fairbanks Morse 1966 1,136 1,136 Diesel, Lemon Creek * GM 1969 2,500 2,750 GM 1969 2,500 2,750 GM 1974 2,500 2,750 GM** 1975 2,500 2,750 Hydro, Gold Creek 1904 1,600 1,600 *** Hydro, Annex Creek 1915 3,700 3,700 *** Hydro, Salmon Creek No. 1 Lower 1914 (proposed reconstruction) No. 2 Upper 1914 2,800 2,800 *** Subtotal 26,572 27,622 ProEosed bI 1985 Hydro, Salmon Creek No. 1 (upgrading) 2,800 3,000 **** No. 2 (rebuilding) 1,200 1,200 **** Combustion Turbine 20,000 20,000 * Subtotal 24,000 24,200 Utility Total by 1985 50,572 51,822 ALASKA POWER. ADMINISTRATION Hydro, Snettisham - Long Lake 1973 47,160 211 million * Used only for standby reserve. ** Owned by GREA, operated and maintained by AEL&P. *** Average total utility hydro annual generation estimated at 40 million kWh. **** Upgrading and rebuilding estimated to add 10 million k~fu to total utility hydro generation. 12 .. ~,~ <II ,.. +~ , .,. f"'" .. Name Gold Creek Annex Creek Upper Salmon Creek Lower Salmon Creek Snettisham Table 2 Juneau Area Hydro Units Existing and Planned Installed Firm Capacity Energy kW 1,000 kWh 1~600 4 3~700 * 2,800 * 2~800 8,300 47,160 168~000 Totals 58,060 213,300 Average Energy 1,000 k\olh ** ** ** 10,000 211,000 261,000 • Total firm energy from existing utility hydro approximately 37 million kilowatt-hours. •• Total average energy from existing utility hydro approximately 40 million kilowatt-hours. 13 P ART V. POWER REQUIREMENTS This part summarizes the studies of power requirements, including analy- ses of historic data and estimates of future demand. The studies are presented in more detail in appendix D. Power Use in the 1970's Juneau area power requirements increased at an average rate of 10 per- cent per year-(system net generation) in the years 1970 to 1979, and a similar increase will be recorded in 1980. Increases in peak demand for the same period averaged 9.3 percent. The increases are attributed primarily to economic growth in the area--substantial increases in employment, earnings, and population. Table 3 has statistics on system net generation and peak demand in the 1970's, and table 4 summarizes changes in th~ period. As of 1979, utility sales to consumers totaled 119.6 million kilowatt- hours, with 43 percent in residential sales, 31 percent commercial and industrial, and 26 percent to 'government customers. Table 5 summarizes the sales data' from 1970 to 1979. The sales increased by 110 percent in the period, but there waS little change in distribution between the three main customer classes. Further analysis of residential sales indicated numbers of customers increased at an average of 6.0 percent per year while per-customer use increased at 2 percent. The data further indicates that per-customer use increased quite rapidly up through 1975, declined slightly in 1976 and 1977, and then showed significant increases in 1978 and 1979 (see Figure 3). The trends since 1975 probably reflect significant conserva- tion practices as well as a more recent increase in use of electricity for water and space heating. Table 6 provides a fur~her analysis of residen~ial use in 1979 for the AEL&P sys~em. At ~he end of the year, 75 percent of the AEL&P reSiden- tial. customers were in the "general" class; 24 percent had electric hot water systems, and slightly less than 1 percent were all-electric. Table 6 also shows per-customer use under the three residential rate schedules-5,887 kWh per year for "general", 11,140 kWh per year for general with hot water, and 21,315 kWh per year for all-electric., These numbers are based on the customers for the first half of the year and the actual figure will probably be higher. The "general with hot water" customers are for the most part single-family dwellings, while the "gen- eral" class includes almost all apartments in the AEL&P service area. Table 7 summarizes the estimated Juneau area energy balance for 1977. Electricity accounted for 11.1 percent of to'tal use, with fuel oil estimated at 45.9 percent of total use. Largest categories of use are fuel oil for residential use (33.4 percent) and gasoline in surface transportation (24 percent). ' 14 , Table 3 Juneau Area Energy and Peak Demand System MWh Peak Generation Percent Demand Fiscal Year MWh Increase MW 1970 58,266 12.4 1971 63,786 13.8 1972 70,255 14.9 1973 75,753 15.5 1974 83,059 10.0% 16.2 1975 94,609 17.8 1976 106,296 19.8 1977 112,197 20.4 1978 122,218 23.4 1979 137,522 27.5 -.- • 15 , , oil • Population Peak Demand, MW Energy, Net Generation, Million kWh** Energy, Sales, Million kWh Residential Sales, Million kWh (44% total) kWh per Customer No. Customers Commercial Sales, Million kWh (30% of total) Government Sales, Million kWh (26% of total) * Compounded annually Table 4 Juneau Area Load Study Trends in Da ta 1970 1979 13,556 12.4 58.3 57.0 25.3 5,888 4,305 17.0 14.7 2,968 19,500 (1978) 27.5 137.6 119.6 51.2 7,035 7,273 37.1 31.3 ** Net generation includes system losses and company use Percent Change Annual 1970-1979 Change 44 743 122 9.3%* 136 10.0%* 110 8.6%* 102 8.1%* 19 2%* 69 6.0%*** 329/year 83 6.9%* 113 8.8%* *** 1975-1979 residential customers increased from 5,495 to 7,273 or 7.2% per year compounded %00' "' 6l6'-Ol6t' 1tI;>:>.1"d ,,11".1"11, ~'lO~'6'I l'[O('~O' O"Z09'ZOI %9Z ~I6l61-0l6' lU9:>.1"d "lIu.1nllV 9l 9Z lZ .1:10("L .I'lH'll .!.:.."JlUL 9"H9 l'Ol9'Or: 9'ltti ~'H,,'9Z zot II, 6l61-0l6' 1119:1.1",1 '( I( Z'ltl'l[ t'9?t'U II'ZlI'1'Z ('090'Z "'''~9'''t ,'90""( Z,," II, 6l6'-Ol6, lu":>.111d (" (., U~ 1:6l O;l'1 I'H{~ ("9{6" 6""'"'~" ,,'('I"Z" lI'llll O"ZfZ'lZ 9RUl'l\, I( 6'[Os'lt "'!!;6" ~'Z!;~'6l 9Ru ;III V l., !.:ll!'U l"6Z l " 9'lOl'lI( l'~I" '96 liZ .l'l(O'lZ "'611l It'tH'H Ot cn",l ~ 'lilli" l'lIIO'll lit D2~~ ~'9l1 " lI'ltll'9( 9l 2'til~'tl fi'''ti6 ti '~III II '''OO'Zl l( t'9u'Lz ('ll9' I ""'9'!;" H L:J.!.(!! ti""Ol til 5'Z55'~Z l'nl 'I II' 99( , I" 9" t'ou'U l'c;o,~' t ,,'c;LII'1( "Z 6'til9'U 11''169 1i'~9'; l""i('91 I( "(llt'tz Fmrr- It' filO'ZZ !ilt UP.J1 , '!illl t I '''liZ'Of 1'011'1 'If) .;Z Z ''1'!!i '91 ~"fH 9"r.g" I'll('';1 til 6'6till'61 9"T9PI ('11';'111 9" 9.:~ 1I'9lO t r.' 600 'II l O"Hr.'09 I 'n'1 I'lZIi'ti , ,. '''t, • I" '''.I, qZ 'U~~.'"J L!!L','d. I" '''.1, t; " 7.11 l ",IIlln R;:t't~f; lU;'tI"UJ~"f'~_, It rOIl"I ('!lII( " I'Zlt'li c;o, 2'0' 'l~ ti"6g'l l"Z9';''1l Ol ('''96'91 ~mr,- li"lll't;I ~ I"IJU"!'!"~II ''':1:1J:1(, ... l'ql!,I.-' V::III:' ,,,'!::tv 111,,:1·):'01 " .. n.1. V:!I!:I ,,,'!::IV FIGURE 3 RESIDENTIAL KWH USE PER. CUSTOMER 8,000 CI:: t:J ::;:: 0 E-4 til ::::l tJ ..J. 7,000 < 1-4 E-4 :z: t:J Q 1-4 til t:J f), CI:: CI:: 6~000 t:J ~ ~ ,. 5,000 1970 1975 1980 ". YEAR. • T 'fable 6 Analysis of AEL&P Data Use Per Custumer by Class Customer Class Number CustoliJers % kWh Sales % kWh/Customer General (11 ) Dec 79 4,849 15 Dec 18 4,151 Average 4,803 28,216,103 62 5,881 General with Hot Dec 79 1,540 24 l-later (12) Dec 78 1,440 Average 1,490 16,599,325 36 11,140 All Electric (13) Dec 79 56* 1 Dec 78 29 Average 42 895,243 2 21,315 Total Residential Dec 79 6,445 ...... 11+12+13 Dec 78 6,226 \0 (excluding Outside Average 6,335 45,111,211 1,225 Light ing--46R) Total Residential Dec 79 6~483 100 11 + 12 + 12 + 46R Dec 78 6,265 Average 6,374 45,814,861 100 1,188 Significant Changes in 1919: 100 new hot water customers--46 pe rcent of all new ellS tome rs . 21 newall-electric heat customers--~3 ~erc\nt i~crease over 1918. * June 1980 figures indicate about 13 a 1-e ectr c customers Summarl Glass Use/Customer 1919 General 5.887 1I0t Water 11,140 All-Electric 21.315 Total Residences 7,225 (excludes outside lighting) Table 7· Percent 9f Total Energy Consumption, by Sector, in the Juneau-Douglas Area (1977, percent) Aviation Sector Electric1 ty Gasoline Diesel Fuel Oil Fuel Jet Fuel Propa~e Total (1) (2) (3) (4 ) (5) (6) (7) (8) (9) Residential 4.34 33.42 .80 . 38.56 Conunercial and Indus trial 3.18 .65 5.16 .27 9.26 Goverrunent 2.84 7.35 10.19 Transportation N Surface 23.95 4.13 28.08 0 Harine 1. 37 1. 30 2.67 Air 2.83 7.65 10.49 Other* .75 .75 TOTAL 11.11 25.32 6.08 45.93 2.83 7.66 1.07 10.00 * Represents line losses. Percentage totals may not add to 100 percent due to rounding. See footnotes in table 13. SOURCE: Applied Economics Associates, Inc. , . ~ , Factors Affecting Future Demands Future area power requirements will reflect changes in the area economy, continuing pressures to increase efficiency of energy use for all pur- poses, and any changes in patterns of energy use. Area Economy The capital move issue is of course a major uncertainty for the future of the Juneau area economy. There are several recent studies estimating impacts of the move including those completed by Homan-McDowell Asso- ciates and Rivkin Associates. It was felt that the report prepared by Rivkin Associates best represented the effects of a capital move, there- fore that report provides the basis for the long range estimates of future power demands presented in this report. The issue is not a new one--having been around in one for,m or another for at least 50 years. For utility plans, the move needs to be considered as a contingency case. In other respects, the outlook for the Juneau area economy is for continued modest growth. Strong areas in the economy include construction (public works, commer- cial, residential), tourism, and expansion of retail trade. Renewed interest in gold mining is also expected to affect the local community. However, for this analysis no new major industrial loads are expected. Conservation There are certainly many evidences that Alaskans are placing a high priority on actions to increase efficiency of energy use and reduce oil use where possible. Definitive statistics on the potential aren't available and probably won't be for a long time to come. Visible items in the Juneau area include a substantial upgrade of build- ing practices with respect to energy efficiency, conservation invest- ments by many homeowners (including some very interesting experiments in passive solar design), a proliferation of small, fuel-efficient vehi~ cles, and a large, but as yet unquantified, move towards use of wood in space heating. . Major new conservation incentives will be available in both State and Federal programs. Of particular interest are the State's new programs using energy audits and grants and loans for conservation and renewable resources (1980 legislative action, the impacts of which won't be fully evident for a while). New Federal conservation initiatives (1978-1980 legislation) will also provide substantial resources for improving energy efficiency--but these programs are for the most part not yet reflected in local energy use statistics. Substitution of Electricity for Petroleum Products Oil prices are now at levels which make electric water and space heating attractive to many people in Juneau. With a general outlook that oil prices will continue to rise more rapidly than other energy costs, the 21 incentive to consider electric heat is very strong. The actual eco- nomics are of course a function of the individual application. Obvi- ously, a shift to electric heat in the Juneau area, makes sense only if the electricity comes from renewable resources. APA would be opposed to any shift to electric heating when the source of electricity is oil or gas generation. Statistics at the end of 1979 showed 24 percent of residential customers using electricity for water heat and another 1 percent in the all-elec- tric class (AEL&P system only). The number of oil-electric homes in the entire system increased from a total of 59 in December 1979 to a . total of about 165 in June 1980. Sales of electric water heaters have been strong, and a large share of new residential construction in 1980 incorporates electric heat. Studies by APA and others have indicated that electric heat pumps hold great promise. for the Juneau area. AEL&P, GHEA, and APA initiated further investigations of heat pumps in late 1979--the program includes eight air-to-air heat pumps in individual residences and monitoring of performance over a two-year period. Initial results are quite satisfac- tory. The heat pumps are of interest since their efficiency should be at least twice as high as alternative electric heat applic~tion (elec- tric boilers or direct resistance heating). APA estimates that approximately 30 heat pumps are now in operation in the Juneau area. There is also likelihood that electricity will eventually satisfy a significant portion of surface transportation requirements for the Juneau area. The current generation of electric vehicles is very effi- cient (most passenger and light truck EV's have "fuel" economy on the order of 0.3 to 0.5 kWh per mile). However, operation characteristics-- particularly for winter driving conditions----leave much to be desired. Electric bus or light-rail transportation may also be of interest in the future. Estimate of Future Demands . A detailed estimate of the Juneau area power needs was based on the most recent data and the economic outlook for the Juneau area. Various assumptions concerning the main factors affecting power demands were made in this study. Assumptions The economic outlook for the Juneau area is a continuation of the past trends of the 1970's through 1985 with a possible slow-down for the 1979-1980 period. The population increase during the 1970's averaged 5 percent and most current studies and planners are looking for a 3-per- cent to 6-percent population increase through 1985. Population growth assumptions for the years beyond 1985 are shown on table 8 for the medium, high, and capital move cases. Additional assumptions on elec- tric use and sales are also included in this table. Conservation is expected to play a large role in the future power demands of Juneau. This trend is evident in all parts of the country and even more pronounced in Alaska where hi~h fuel costs have always encouraged conservation measures. It is assumed that conservation 22 Population Increa58 (i.lyr) . People per Residential Customer kWh per Customer Increase (i.lyr) Population Increase (i.lyr) N w People per Residential Customer kWh per Customer Increase (i.lyr) Population Increase (i.lyr) People per Residential Customer kWh per Customer Increase (i.lyr) Residential Sales (i.) Commercial Hales (i.) Government Sales (X) Losses and Utility Use (i.) System Load Factor (X) .' ,. Table FOR E CAS T 1 9 7 Q 1 9 7 9 8 A.S SUM P T ION S 1 9 8 o 1 9 8 ~ MEDIUM LOAD GRpWTH . . . . . . . . . . . . . . 1 9 9 o 1 9 9 !2 2 o o o "'< ---------5 -----)''''< -------------2 --------------------.:....)'" 3.2 "'<------2.8 ------)"'<-2.7 -)"'<-2. 6-)A<-2.5-)'" "'<------------2 ------------)"'<-----2 ---------)"'<--0 --)'" HIGH LOAD GROWTH A(__________ 5 ______________ )A<__ 3 __ )A<______ 2 --------)'" 3.2 A< _____ 2.8 _______ )A<_ 2.7 _)A<_ 2.6 _)A<_ 2.5 _)A A<__________________ 2 ________________ )A< ____ ~__ 0 _______ )A CAPITAL MOVE CASE . . . . . . . . . . . . . . . . . . . . A<_______ 5 _______ )A<2)A< 1 )"'<O)A<-30)"'<------2 ________ )A 3.2 A< _____ 2.9 ----.:....--)"'<-2.7 -)"'<-2.6 _)A<_ 2.5 _)A A<______________ 21. _____________ )A<______ -2 __ )A<___ 0 __ )A ALL CASE§ A< __________________________ 44 ___________________________ )A A< __________________________ 30 ___________________________ )A A(__________________________ 26 ___________________________ )A A< ______ 15 ___________ )A< ____________ lO------------------)A -<------~7 --------~~<------~--------60------------------>~ •• ;., I measures such as smaller, energy efficient homes, as well as new and innovative methods for home heating Will continue in future'yearsr These methods include, but are not limited to, passive solar, wood stoves, multi-fuel boiler systems, and heat pumps. Previous studies by APA concerning the role of electric power in Southeast Alaska and the feasibility of heat pumps for space heating point out the tremendous potential for conservation. The amount of energy use for electric heating is based on criteria outlined in the Potential for Residential Heating Energy Conservation, and Renewable Resource Utilization in Southeast Alaska, APA, January 1980. The percentage of existing homes using electric heat was expected to increase gradually to the year 2000 at which time 66 percent would be electrically heated. New home construction would have electric heating in 50 percent of the new units in 1980. This would increase to 66 percent by 1985 and continue at that level to the year 2000. -Each elec- trically heated residence represents 23,800 kWh of energy annually which results in a total energy consumption of 200 million kWh in the year - 2000. This figure is greater than the firm energy available from the existing Snettisham Project which can produce 168 million kWh of firm annual energy. Adding the expected commercial and government electric heat growth, the energy sales for electric heating in 2000 will be 282 million kWh. The remaining homes not heated electrically in the year 2000 were assumed to continue on oil heat or use other forms of heat such as propane or wood for fuel. The distribution of electric heat was assumed to be divided equally between heat pumps, electric boilers, and resistance baseboard heating. Demands A summary of the Juneau area power requirements is shown on table 9 for the three cases examined. This summary indicates the future demands due to electric heating as well as normal growth. Additional detailed data on future sales and generation can be found in tables 10 through 13. Figures 4 and 5 show plots of the energy requirements and peak demands for the three cases studied. Comparison with Other Forecasts Figure 6 compares APA's estimate of peak demand with an independently estimated combined peak of GHEA and AEL&P. GHEA estimates were prepared using REA methods while the AEL&P estimates were prepar~d using a con- sultant and in-house engineers. The results show similar results with less than 2 percent variation in the 1980 to 1985 period and less than 5 percent variation in the 1985 to 1990 period. Additional comparisons of forecasted energy requirements are shown on table 14. Market for Additional Hydropower A summary of the estimated market for hydro energy is shown in table 15 for the period 1986 through 1999. Additional comparisons of total area energy requirements are also shown on this table for the same period. 24 • Jummu AI"e8 Load Study T8blq 9 Junuau A~"ii rowel" RC'Iu'l"c,,,,,nts Su,o""'I"Y Hed" ... Case IlIlIh Csse Cae'ta) tlova Casts HUrlAa) U8ct~lc lIuat ~ lIo(1llal Klectl"lc IIeat Tutal NorlAal 'UOlcU Lc lie II t ~ 1919 (:I .... 111.~ 111.5 till 27.5 Zl.5 198U IOlIh 144 11 151 144 11 151 144 11 151 II~ 21.4 5 II 28 5 11 21.4 ~ 11 N 1'1115 (;111, 168 8l 251 194 109 )0) 169 11 242 lJI 11\1 12 12 64 11 41 18 12.2 21.11 60 1990 1:1111 18) 168 151 258 210 468 122 11 1')5 1-11/ ]') 64 99 49 80 129 21.2 21.8 51 1995 (:III, 201 241 450 )01 290 591 142 104 246 till ')') ')2 III 58 110 168 26.9 19.8 66.1 :.wuo (;11" 228 )10 518 119 )64 10) 161 116 297 till 41 118 161 65 119 204 )0.6 51.8 82.4 Tab Ie 10 JUIlUItU Ar~a Load forecaat HedlulA Caao -Normal lIae ill! 1919 1980 ill1 1990 199~ 2000 1'01''' lilt I Ull" 19,~00 20,41~ 21,~OO 21, 7~0 26,210 28,940 11, 9~0' P~ople per CuatollMlr 2.8 2.8 2.8 2.8 2.7 2.~ 2.~ Ru.lldtllltl a I Cust 0II1II ra 6,868 1,271 7,680 8,480 9,710 ll,~80 12,180 "Wh/I!ualomer"" 6,8~~ 1,01S 7,180 7,920 l,S10 1,110 1,110 Reuldenlla& Sales (441) kllh X 10 41,080 51,168 55. I 67.2 11.1 82.6 91.1 e,lIuulCrc I a 16Sa lea (101) kWh X 10 11.$ 11.111 17.6 45.8 49.8 ~6.1 62.1 CUVUtlllQUllt 6 Sa lea (261) .... 21.8 11,1 12.6 19.1 41.2 48.9 ~1.8 a-kllh It 10 l'ollli Salca, kllh X 106 (l001) I2S.1 1~2.1 166. I 181.8 201 Nct Gellurat I.)n, kllh I an 6 ..... 111.5 144.0 168.0 182.7 206.6 221.1 till I'eak •• ..,. 27. ~ 27.4 12.0 14.1 19.1 41. ) rUI'"latlnn aa61luwd to Increalle ~I tbrollah 1980, thlln 21 throuSh 2000 •• kllh/cu"lUllM!r BaIiUlAc.1 tn Increase 21 through 1985, thcn decreaao to 901 of that Icvel b~ 199~ • ••• Nul gCllurat 1011 rllt 10 tu allies was IISI 111 1919 IIlId lIallll ..... !!1 the sallie 'Ill" 1980, bllt .ltUJUDlc<l to decruadu to llOI by 198~ . .. u 611% II.Ulllill cllPIICity factur aaallulud 1980 all.1 IIher. .. '1: 'f. T .. ble 11 Juneau Arca Load forecilat 111811 Caae -No rlla 1 Ua8 ill! !ill 1980 ~ ~ ~ 2000 I'0l,ulat 1un" 19,5OIl 20,41S 2l,SOO 27,440 '11,810 H,120 18,780 People per Cuat .... er 2.8 2.1 2.8 2.1 2.7 2.S 2.S Rlltlldllllt lui CustOlll8rs 6,868 l,27l 7,680 9,800 11,780 14,OSO IS, SIO "Uh lells tome r .... 6,85S l,OH 7,180 7,920 8,740 8,140 8,740 Rcs'dllllttal Sales (441) kllh X 10 41.080 SI.168 SS. I 71.6 101.0 122.8 IlS.6 G.,IIIIUllrcllll Sale» (101) kllh X 106 Sale» 11.2 11.6 S2.9 70.2 81.1 92.S GUlier 0100 lit Sa Ill» (261) ." ... X 11)6 Sa les kUh ]1. 1 12.6 4S.9 60.9 72.6 80. I 'I'utlll SalllK, kWh X 106 (1001) 119.6 12S.] 176.4 214.1 279.1 108.2 Het Generat10u ...... 111. S 144.1 194 258 107.0 ]]9.0 t1W I' .. ",k· ••• 21.S 28 ]7 49 Sit 6S • I'ul'ulat lOll assullM!.1 to tncrease 5% throullh 1980, tlliln 2% through 2000 •• 1tl-ll,fCllstollwr assulDed til tucrll8sc 21 annulIlly throush 1990, thlln relua1n cOllstant. Het gen.:rattoll rutlo tn s'1ll:s waa liS! tn 1979, lIssulQe.1 the alliac for 1980, alld thcn assualc.1 til decrll811.e to 110% by 1985. uu bOX auuual clIl,aclty factor assUI.od. 1980 IIlId after. Table 12 Juneau Arell Load forecaet -Capltul Hove Cllee .!.!!! .ill!! ill! .!ill. ill.! .!!!!! :lOOO. 1'''11111 at 1011 20,4U 21,500 22,110 2],040 2],040 16,000 19,500 Peop 11$ pur Custo188r 2.8 2.8 2.8 2.8 2.1 2.1 2.5 Res Ide lit hi CUlltll/lI8rll 1,2l] 7,680 1,990 8,5]0 8,510 5,925 1,800 kWh/Cllstomer 1.015 1.180 7.470 1,920 8.240 8.240 8.240 RUlllduntlal Sale. (441) kllh X III 51.2 55.1 59.1 61.6 70.] 48.8 64.] COhllllCrclll1 6 Sa les (l01) kUb X 10 11.1 1l.6 40.6 46.0 41.8 ll. ] 4].8 I:ovu r nlllent 6Sa les (261) kWh I 10 11.] 12.6 12. ] ]9.9 41.5 28.8 ]8.0 N Total Salea. kllb I 10 6 125.] 1l2.6 15].5 159.6 llO.9 146.1 go kllh I 106 Ne t Generation. 1l1.5 144 152 169 116 122 161 till I'u Ilk 21.5 21.4 28.9 ]2.2 ll.5 2].2 ' ]0.6 'j , oil ' .,;", Juneau Area Load Forecast Table 13 Electric Heat Loads -Mediwn Case 1979 1980 1985 1990 1995 2000. Population 20.475 21.500 23.750 26.210 28.940 31.950 Peop Ie /Cus tomer 2.8 2.8 2.8 2.7 2.5 2.5 Residential Customers 7.273 7.680 8.480 9.710 11.580 12.780 Res ide nt ia I Electric Heat Sales Existin~ Customers 7.273 % Using Electric Heat 1 2 15 33 50 66 No. of Customers 70 145 1.090 2.400 3.640 4.800 Use/Customer -23.800 kWh. Million ~\fu 3 26 57 82 114 New Customers 407 1.207 2.437 4.307 5.507 % Using Electric Heat 50 66 66 66 66 No. of Customers 200 800 1.610 2.840 3.630 N Use/Customer -23.800 kWh. \0 Million kWh 5 19 38 68 85 Subtotal Residential Total Electric Customers 70 345 1.890 4.010 6.480 8.430 % of Total Customers 1 4 22 41 56 66 Total Million k\fu 9 45 95 150 200 Commercial Electric Heat Sales Million k\fu •• 1 7 14 23 30 Government Electric Heat Sales Million kWh ••• 2 23 44 48 52 Total Electric Heat Sales. Million kWh 12 75 153 221 282 Total Net Generation. Hillion kWh 13 83 168 243 310 Peak Demand. MW**** 5 32 64 92 118 dO, Juneau Area Load Forecast Table 13 (cant. ) Electric Heat Loads -High Case 1979 1980 1985 1990 1995 2000 Population 20,475 21,500 27,440 31,810 35,120 38,780 People/Customer 2.8 2.8 2.8 2.7 2.5 2.5 Residential Customers 7,273 7,680 9,800 11,780 14,050 15,510 Residential Electric Heat Sales Existing Customers 7,273 % Using Electric Heat 1 2 15 33 50 66 No. of Customers 70 145 1,090 2,400 3,640 4,800 Use /Cus tome r -23,800 kWh* Uillion kWh 3 26 57 82 114 New Cus tome rs 407 2,527 4,507 6,777 8,237 % Using Electric Heat 50 66 66 66 66 No. of Customers 200 1,670 2,970 4,470 5,440 w Use/Customer -23,800 kWh * 0 Million kWh 5 40 71 106 129 Subtotal Residential Total Electric Customers 70 345 2,760 5,370 8,110 10,240 % of Total Customers 1 4 28 "46 58 66 Total Million kWh 9 66 128 188 243 Commercial Electric Heat Sales Million k\fu** 1 "10 19 28 36 Government Electric Heat Sales Million k\fu*** 2 23 44 48 52 Total Electric Heat Sales, M illi on kUh 12 99 191 264 331 Total Net Generation, Hillion kWh 13 109 210 290 364 Peak Demand, MW**** 5 41 80 110 139 . . .. . ,.; " Table 13 (cont) Juneau Area Load Forecast The use per customer is based on an average of 1,415 gallons of fuel oU used per customer in 1971. Assuming 20% energy conservation and 60% furnace efficiency, the equivalent electric use is: 1,415 gal X 80% X 60% X 138,000 BTU/gal ~ 3,412 BTU/kWh -28,635 kWh The electric heat customers were assumed to have the following distribution: Resistance Boilers lIeat Pwnps Average electric 33.3 X 28,635 - 33.3 X 28,635 - 33.3 X 14,311 - heat use/customer - 9,535 9,535 4,161 23,811 Round to 23,800 'Ii * Commercial customers used 15% as ouch fuel oil aa total residential customers in 1911. Assume same rate in the future, 20% conservation, and similar rate of conversion to electric heat • •• * Energy used by governments is based on conserving 20% and converting major facilities to electric heat by 1990. **** Peak demand based on 30% plant factor. ., ~ ·1. 'l'ul>111 11 (cullt) J::lllclrlc lI"u l IAlad .. -Cllpltal tluvu Call II ill2. ~ .!2.!! .!!.!.! 1987 ~ 2000 I::I"ctric lIullt UI>" E~lstln8 CuStONIiCS 7,273 I U~lllg "1~ctrJc IIlIut I 2 5 U U 14 )0 Nil. ot Custollleu 70 145 240 1,090 1,090 1,050 2,110 Ulle pur ~ulltu"'lIr -2),800 kUh II 10 ) 5 26 26· 25 ~O Ne" Cust ullle rs 407 717 1,2~7 0 0 0 I Usl1l8 EluctrJc IIl1l1t 50 66 66 Nu. uf Cuutulllt!rll 200 473 810 Uiil! p"r ~ulltUIIIUC -21,800 kllb II 10 5 11 20 SuLtullil lCulild~ntlll1 Nu. uf Eluct ric CIIS tOIiIiU. 70 345 711 1,920 1,090 I,O~O 2,110 I uf Tot81 CustolQars 4 kUIi X 10 9 16 46 26 25 ~O COWQ" cct U 16 .. JIICt ric 1I~lIl Ii 111 II. kllh X 10 2 7 4 4 8 Goverllllll!IIt 6 ElectrJc lIalil SIIIII. klill X 10 2 7 11 19 12 16 'I'ol u I UecAric Ileal 5111e. kllil X 10 U 41 66 n 66 124 'I'otul lI"t (i"llucutlun , 1-1/11 X 10 II 41 73 81 73 1)6 Pellk 1)"111<1 lid , .. II 5 17.9 27.& 1l.6 27.& ~l.& ~!l of Horillal Ulld ElectrJc lIelll toadli COIIII>Jn.,,1 Hct (;ullucutlull I-I/h X 10 151 199 242 259 12) 202 I'cak I) "IQ<I lid , .. II 12.4 46.8 60 65.1 17.1 64.4 1 " ,. ... 200 100 50 a 1970 JUNEAU AREA LOAD STUDY ... :ESTUtATED·PEAK'· DEMAND .. 1915.> . 1980 -...,.., .---... 1985 " " ./ "--~ . ..... ...... ..... • ,-- 1990 --- -... ------....... -. 1995 2000, 400· 300 200 100 ---.-- o 1970 , '" '" ' JUN£AU AREA LOAD STUDY ESTIMATED ENERGY REQUIREMENTS / / / / " ., • ./ ,..'" / " , ./ / /'" ..... . " . ...- ./ / ./ " .......... ,...-..... ~\_--. - . ,.'" • ..-• - - -.• &c-"""" , ,.."-~---, , , ."... ..... _. -, ,~:;.--\ .~ \ .~ \ .~ \ \ \ \ . --: . ...--. .,..."... \ .-.--" \\ \ . .-- 1975 1980 1985 . 1990 .' ..... • '" " /' CAPITAL MOVE CAS~ -- • _. - ---------_. 1995 »j H C) 2000 ~ Yl r~ 100 99 80 70 -$ 60 -'~ ;\ 50 :) 40 ~ t:J ..., 0 a:: ~ 30 20 10 o 1979 FIGURE 6 / / " COMPARISON OF APA & UTILITY / ESTnfATED JUNEAU PEAK DEMANDS / ? / / AEL&P ONLY (MAY 1980 ESTIMATE) TOTAL AEL&P AND GHEA SYSTEM -----------~ NOTE: A2A ESTIMATES INCLUDE GLACIER HIGIDolAY ELECTRIC ASSOCIATION LOADS --ROUGHLY 10% of AEL&P. • " ~ - 0 . .. Table 14 Comparison of Load Estimates Percent Annual Growth Utility Estimates AEL&P (CH2M Study 5/20/80) 12. 7% GIIEA (Study for REA 12/31/79 15.0% APA Estimate (5/1/80) 1980-1985 1985-1990 1990-1995 Hedium Case Normal Use 3 2 2.5 Normal plus Electric Heat 10 7 5 High Case Normal Use 6 6 4 Normal plus Electric Heat 14 9 7 Estimated Net Generation -Including Electric Heat Utility Estimates 1980 1985 1989 APA EstiJnate 1980 1985 1989 MW 27.7 63.3 93.3 AEL&P Million kWh 120.7 265.9- 349.8 (Medium) 32 64 92 GHEA MW Million 2.9* 12.5 6.2* 27.3 9.8* 43.0 157 33 251 78 331 119 * System load factor assumed 50 percent by APA for this summary. kWh (High) 157 303 435 1995-200_0 2 3.6 2 3 MW 30.6 . 64.6 97.4 Total Million kWh 133.2 280.8 399.4 Table 15 MARKET FOR CRATER/LONG ENERGY Estimated ,Juneau Ene,.glj Demand Yea,. 1000 kWh 1986 271,000 1987 291,000 1988 311,000 1989 331,000 1990 351,000 1991 370,800 1992 390,600 1993 410,400 1994 430,~00 199'450,000 1996 467,600 1997 485,200 1999 502,900 1999 520,400 JUNEAU AREA Ma'rket rO" Ne.., H~d,.oelect"ic Ene,.g~ 1000 kWh 65,000 (24) 85,000 (29) 105,000 (34) 125,000 (38) 145,000 (41 ) 164,800 (44) 184,600 (47) 204,400 (50) 224,200 (52) 244,000 (54) 261,600 (56) 279,200 (58) 296,800 (59) 314,400 (60) ( ) indicates pe,.cent or total a,.ea ,.e~ui,.ements Medium Q,.o..,th Rate APA 6/80 37 Ene,.glj Supplied blj C,.ate,./Long 1000kWh 65,000 85,000 105,000 125,000 145,000 163,000 .. .. II .. II .. .. .. PART VI. ALTERNATIVE POWER SOURCES This part examines alternative power sources in the Juneau area. Analy- ses and costs are presented for the most likely alternatives, (1) the authorized Crater Lake and Long Lake dam portions of the Snettisham Project and (2) diesel electric generation. Alternatives considered include local hydro projects, interconnection wi th other towns in Southeast Alaska, s'teamp lants, tidal power, wind power, geothermal power, and diesel generation. Expansion of Existing Hydro Salmon Creek The proposed rebuild of the Lower Salm:m Creek Unit would add about 2,500 kW to the capacity and about 10 million kWh of average energy to area supplies. While these are significant additions they are a small part of the expected area needs (1980 demands expected to be about 27,200 kW and 144 million kWh). This study assumes that the Salroon Creek rehabilitation will be completed by 1984. Snettisham The Snettisham Project was authorized by Congress in 1962. The Corps of Engineers constructed the Long Lake stage of the project with initial operation occuring in December 1973. Two stages remain to complete the project. The Crater Lake stage involves completing the tunnel to Crater Lake and adding a third unit in the existing powerhouse. The Long Lake Dam stage involves a laO-foot concrete gravity dam at the outlet of Long Lake to increase the storage capacity. The transmission line, power- house, and substations were initially constructed to handle the full development. Initial design and drilling of both sites has been com- pleted. The rock at the Long Lake damsite has been scaled to receive the dam. Table 16 gives the energy, capacity, and costs for the various stages of the Snettisham Project. The earliest on-line date for the Crater Lake stage is May 1986 while the earliest on-line date for the Long Lake dam stage is October 19~5. The Crater Lake stage is the most economical increment and the logical next addition. The advantage of the Long Lake dam addition is that it would firm up a larger block of energy for winter use. Other Potential Hydro Hydropower proj ects in the Juneau area have been studied extensively since 1900. The best undeveloped sites that have emerged through the years of study include Lake Dorothy, Sweetheart, Speel River, and Tease Lake. All sites are within 2 to 6 miles of the existing Snenisham 38 .. , Table 16 Snettisham Project Data Installed Capacity Stage kW Long Lake 47,160 Crater Lake 27,000 Long Lake with Dam 47,160 Total Long and Crater with Dam 74,160 Incremental Energy Construction Million kWh Cost Firm Average $ Million 168 211 106 118 39.5* 225 236 33.6* 331 354 73.1* Annual O&M Cost $ Thousand 600 50 650 * January 1980 prices. Inflation could increase these costs 35 per- cent between 1980 and the mid construction period. Interest during construction will be added to determine final investment cost. 39 transmission line and considered among the more economical sites in Alaska, roughly in the order listed above. A summary of project fea- tures is shown below. Lake Dorothy Sweetheart Lake Speel River Tease Creek Installed Capacity kW 34,000 29,000 63,000 16,000 Firm Energy Million k\fu 150 125 275 70 Lake Dorothy is 3 miles north of the Snettisham transmission line under- water cable terminal on Taku Inlet, 15 miles southeast of Juneau. Project studies between 1949 and 1955 included initial design, costs, geology, and a status report. The project would need to have Congressional authorization, an environ- mental assessment, and final feasibility studies before construction could begin. The Sweetheart Fall site is 36 miles southeast of Juneau at the south end of Gilbert Bay in Port Snettisham. Development would involve a powerplant at tidewater, a 9,OaO-foot tunnel, and a 200-foot-high con- crete dam. Preliminary studies have been done by several companies proposing Feder~l li~ensing and several Federal agencies. The project would need Congressional authorization, environmental assessment, drill- ing at the damsite, and preliminary and final feasibilities before construction could begin. Speel River powerplant would be roughly 6 miles north of the existing Snettisham Project. A concrete dam 220 feet high and 3,200 feeot of tunnel would be required. Studies similar to those made for the Sweet- heart project have been made and similar future studies would also be required. Tease Creek is a mile across Pore Sneeeisham from the existing Snett- isham Powerplant and was originally developed in 1913 with a small hydro unit supplying power to a pulp mill. The unit operated until 1923. The site has since been abandoned. Development would require a 140-foot- high dam and 6,000 feet of tunnel and penstock. The full group of authorizations and studies would be required. Interconnection A detailed study is being done by APA to determine the technical and economic feasibility of interconnecting the Snettisham-Juneau area with Petersburg~frangell and Ketchikan. The interconnection idea is attrac- tive because the entire region would then have access to the most eco- nomical new power sources, and the ability to shift surplus from one part of the region to another. Underwater d.c. transmission technology appears to offer the best chance for such interconnections. Studies to date indicate possible need and justification for the interconnection in the late 1980's, following completion of Ketchikan's Swan Lake Project and the Tyee Project for service to Petersburg and Wrangell. 40 Such interconnection would enhance feasibility of, the Snettisham ex- pansiori to the extent that power surplus to Juneau area needs could be u i'i1ized in the other communi ties. APA has examined the possibility of interconnection with Hoonah to make Snettisham pm.er available to that city. Because of the rela- tively small power demands at Hoonah, we have not yet found a feasible interconnection plan. Also, because of the small loads, service to Hoonah 'would not affect materially the feasibility of the Snettisham expansion. Interconnection with neighboring areas of Canada is considered as a long-term possibility. The Canadians are investigating new power production facilities on the Stikine River and Yukon River for possible construction during the 1990's, and it is quite possible that Juneau and Southeast Alaska will be interconnected with the Canadian systems in the long-term. Steamp1ants Wood wastes at the major mill sites are essentially fully utilized. Wastes at logging operation sites are not utilized now due to the costs of collecting and preparing the wastes for use as fuel. Utilization of large areas of Southeast commercial units are restricted by wilderness and monument set asides, thus limiting the potential for expanding the Southeast timber industry. The best area for utilization of wood as fuel would be those smaller communities lacking good access to hydro. Wood is not considered a reasonable alternative for Juneau at this time. Solid waste, or garbage fuel, for steamp1ants could supply only a small fraction of the areas's needs and is not considered a major power source. Solid wastes as fuel would probably be best suited for direct heating systems, rather than production of electric power. Steamp1ants are not considered to be competetive with Snettisham incremental costs. Miscellaneous Alternatives Several other alternatives, such as tidal power, geothermal power, and wind power, were considered. However, due to state-of-the-art tech- nology, cost. and proximity to the Juneau area, they are not realistic planning alternatives at this time. Diesel Diese1-e1ectric powerp1ants are expected 'to remain the main alternative to hydropower for most Southeast Alaska communities. It is of interest to Juneau for two primary reasons: (1) it is the best accepted tech- nology for standby reserves in which anticipated actual use is in the order of 1 percent of the time and (2) it is the most practical alter- native for firm power supply if hydro and other alternatives don't prove out. 41 -.- .. There are two basic ~ypes of diesel generation considered to this study. Internal combustion diesel units, being more efficient, would be utilized for firm power while conbustion turbine units, being cheaper to install, would be considered for standby to handle peak load. A summary of unit characteristics is shown below. Fuel Capital O&M Efficiency Cost* Cost Internal Combustion 13 kWh/gal $955/kW l¢/kW Combustion Turbines 9 kWh/gal $200/kW $5/kW/yr. * January 1980 c-osts The following tabulation presents the estimated cost of diesel genera- tion for an internal combustion unit. Since combust±on turbines would not be utilized for firm energy~ costs were not prepared for that type unit. Fixed Annual Costs Operation ~nd Maintenance Fuel Cost-8l¢/gal at 13 kl-lh/gal Diesel Generation Cost 17.5% of $995 * Assuming 60 percent plant capacity factor. = = = = = = $167.13/year 3.2¢/kWh* $52.56/kW/year l¢/kWh 6.23¢/kWh 10. 43¢/kWh The fixed annual cost of 17.5 percent is based on 10 percent financing assumed for the private utility which markets 90 percent of the area's energy. The capital cost is based on APA estimates for heavy duty base load generation plants. The cost of diesel fuel and its availability is called into question by several recent events. They include the Administration's policy mini- mizing the use of fuel oil, emphasis on increased use of renewable resources, the 1973 oil embargo, the recent shortages, and increasing costs. Costs for this analysis were assumed at 8l¢ per gallon beginning in 1980. The following tabulat~on shows the effect of escalating fuel prices at 3 percent and 5 percent annually and the resulting cost of energy from the fuel alone. 1980 1985 1990 2000 3 Percent Fuel Cost ¢/gallon 81 94 109 146 Escalation 5 Percent Energy Cost Fuel Cost ¢/kWh** ¢/gallon 6.23 81 7.23 103 8.38 168 11.23 215 ** Assumed efficiency of 13 kWh per gallon of fuel. Escalation Energy Cost ¢/kWh** 6.23 7.92 12.92 16.54 The above costs with the modest rates of annual increase serve to show the high effect fuel costs have on the energy cost for the diesel gener- ation alternative. 42 ... ' ~'" ~ ft'! .. ... PART VII. LOAD/RESOURCE AND SYSTEM COST ANALYSES Introduction A series of load/resource and system cost analyses was made to examine the probable timing of major hydro generation investments and the con- sequences of utilizing diesel generation instead of new hydro to meet future demands in Juneau. The impact of these hydro inves tments on power system costs versus the impact of diesel generation was the end result of these analyses. The analyses were completed for the folloWing basic power supp ly strategies : 1. No new major hydro projects. All future demand to be met with diesel generation. 2. Meet future 4emand with Crater Lake Addition followed by Long Lake Addition. 3., Meet future demand with Long Lake Addition followed by Crater Lake Addition. The system cost analyses processed output data from the load/resource analyses computer runs. System costs were determined by year to amor- tize investments and pay all annual costs (fuel, O&M, etc.). Inflation rates of 0 and 5 percent and a fuel escalation rate of 3 percent were utilized in the studies. The system cost analyses include generation costs and c,osts of trans- mitting power to Juneau--basically the costs to the system for its power supply, reserve generation capacity, and main transmission system. The analysis does not include costs for the distribution system, customer service, billing, and utility administration. This section summarizes assumptions, methodology, and results. Assumptions Basic assumptions used in the load/resource and system cost analyses include: 1. Analyses Will be on a mnthly basis for Fiscal Years 1980 through 1999. 2. Cost base is January 1980. 3. Inflation rates of 0 and 5 percent, with construction costs increasing at inflation rate and fuel costs increasing at 3 percent above inflation rate. 43 4. Two growth rates were analyzed: medium 7 and high. 5. Local capacity of 100 percent of demand is required in event of tranmission line failure between Juneau and Snettisham. 6. Transmission losses of 1.5 percent for energy and 5 percent for capacity. 7. Max~um plant factor for fossil-fuel generation units is 50 percent. 8. Fossil-fuel generation will be minimized as much as possible. 9. Hydro plants designed for 115 percent o~'nameplate capacity for limited reserve requirements. 10.· Lower Salmon Creek hydro will come on-line in 1984. 11. Earliest on-line dates and capacities of potential hydro sites are: Capacity Firm Energy Project Date (kW) (kW) Crater Lake 1986 27,000 106 million Long Lake 1986 --57 million Lake Dorothy 1992 34,000 150 million Sweetheart 1992 29,000 125 million 12. New hydro projects must be utilized 25 percent of rated output before allowed to come on-line. 13. Repayment criteria for the Snettisham addition would be as specified in the authorizing legislation (50 years and 3 percent interest). 14. The cases involving the development of additional hydro will allow for additional growth from electric heating conversions until the projects are fully utilized. 15. The case with no new hydro projects will limit electric heat conversion upon full utilization of the present Snettisham Project. 16. Internal combustion diesel units would be utilized to meet firm energy demands while combustion turbine units would be added to meet increases in res~rve requirements. 17. Load/resource analyses are based on ~ritical year energy while the financial analyses is based on average year energy. Methodology As stated in the introduction, three cases were analyzed to determine timing of new generation investments and their impact on total power system costs. In addition to the analyses of the effects of adding Crater and Long Lake projects to the system, the need for and timing for adding Dorothy and Sweetheart projects was also examined. 44 Jt!' .. .... .. The first step was to perform a series of load/resource analyses. These analyses determined the schedule of major investments based on assump- tions of load growth. and cons traints as to when the facilities could come on-line. The load/resource analyses a1so determined the annual energy production of the individual hydro plants and by type for fossil-- fuel plants. Once the annual energy production from each type of generating plant is known. the annual cost of energy production for each facility is calcu- lated. Summing the annual cost for each of the facilities gives a total cost for the system being analyzed. Since total cost and total energy are then known. the average annual energy cost for the entire system can be found. By comparing the average energy costs over the period of analyses. the alternative configurations can be ranked based on the cost of energy. All other things being equal. the system configuration producing energy at the lowest cost should be selected as the most desirable. The load/resource model attempts to match forecasted electric energy requirements with appropriate generating capability additions. The model schedules new plant additions. keeps track of older plant retire- ments. and computes the loading of installed capacity on a month-by- month basis over the period of study. New additions are scheduled to assure that both peak loads and energy requiremen~s. including reserves. are met with the least amount of installed capacity. Generating plants are loaded in the order of lowest to highest marginal energy cost. The general approach for the load/resource analyses is to summarize existing and planned gross resources for each month. adj ust them down- ward for a reliability margin and for system transmission losses to arrive at net resources. If the case being analyzed allows new hydro projects and the net resources include non-hydro generation equal to 25 percent of any available hydro project which can be brought on-line. the new hydro is added to the system thereby minimizing diesel genera- tion. At some point the net resources will not meet the forecasted peak loads or energy demands and additional generation must be added. If no new hydro projects can be brought on-line then new diesel combustion turbine generation is forced on-line to meet shortages. The system cost analyses were computed utilizing output data from the load/resource analyses in conjunction with cost· data for present and future generation facilities. Load/resource output data included on- line and retirement dates for planned and existing facilities. output from each type generation plant and individual hydro plants. plant factors for all plants. and shortages of capacity and energy. All costs are based on January 1980 price levels and are escalated at a rate equal to the rate of general inflation (0 and 5 percent in this study). Fuel prices are inflated at the general inflation rate plus 3. 3-percent escalat10n rate. 45 - ~ .- Load Management The load/resources studies incorporate a further assumption that new electric heating applications would be curtailed or prohibited if demands exceed the available hydro supply. Such action can be accomplished through inverted rate structures which penalize users of electric heat, and through strict building standards relating to electric heat installa- tions. The purpose is to avoid use of oil to produce power for electric space heating and is a relatively common "form of load management. A second form of load management is through the use of interruptive sales. Both local'utilities are considering this type of load management, mainly for larger government installations. This could be extended to the residential sector at the time appropriate technology is available to enable this sector to utilize interruptible sales. Interrruptible sales decrease the reserve requirements of a system and will limit the use of diesel generation when the Snettisham Project is fully utilized. This aspect of load management is not reflected in the present studies, thus the future cost of reserves is expected to be somewhat less than shown in the studies. Results Case 1 (no new hydro projects after completion of the Salmon Creek rehabilitation). After full utilization of available Snettisham capacity, increases in demands would have to be met by adding diesel generation. Under either the medium or high load assumptions, curtailment of new electric heat applications would be needed by about 1983. Table 17 indicates source of energy production under this case. The study indicated small portions of requirements would be met by diesel generation starting in about 1982 and increasing to about 14 percent of the total by 1990. (note that the study assumes hydro capability limited to critical year firm energy. In most years, significant additional usable hydro supply would be available, so actual production from the diesel generation would be somewhat smaller). Case 2 (assumes addition of Crater Lake followed by Long Lake Dam). Table 18 indicates the source of energy production in this case while. figure 9 compares the load and hydro resources in the Juneau area. Full utilization of the two Snettisham additions would occur in the early 1990's. Curtailment of new electric heating applications would be needed by 1992, unless additional hydro projects such as Lake .Dorothy or Sweet- heart Lake were developed. Table 19 shows a comparison of average system generation and transmission costs for Cases 1 and 2 assuming 1980 price levels; table 20 presents a similar comparison with a 5 percent inflation assumption. Case 2 appears significantly more attractive in both comparisons. Case 2 also is supplying a substantially higher portion of total area energy requirements. (Case 1 assumes no new electric heating applica- tion after 1982; Case 2 meets requirements for new electric heating through 1992.) 46 r ....................................... " ... " ...................................................... . 160- 120- thousand 80 - kw 40 - Il 0 1 1 1 1 1 1 0 -I 1 80 G ROW T H RAT E M 0 Q I E I C A T I a N 8 MEDIUM GROWTH RATE WITH: o -Unrestrained Electric Heat Growth * -Growth with ProJ8ct5 + -Growth with Diesels 0 0 0 0 0 0 0 + + + + + 0 + + 0 I I 85 90 YEAR 0 + o o o o o o 0 0 ... ... ... ... ... it '* + + + + + + + + I I 95 00 ALASKA POWER ADMINISTRATION JUNEAU AREA POWER MARKET ANALYSIS JUNE-1980 • : .' • .' . i l .... ' • • • • • • • • • • • • .. • • • • • • • • • • • • • • • • • • • • • • • • • • • • .. • • .. • • • • • • • • .. • • • • • .. • • • • • • • • • • • • • • • • • • '. " • , , • , • • • I • • • • • • • • • • ',.. .. ' .. ; . : ..... .......................................................................................................................... million kWh 520-1 I I I I I I I 1 390- 260- o 130- o - 80 0 G B g ~ T l:I B ~ I Ii . t1 0 MEDIUM GROWTIi RATE WITH: o -Unrestrained Electric Heat Growth * -Growth with ProJects + -Growth with Diesel 0 + 0 0 0 + I 85 0 0 + + 0 0 + + o + I 90 YEAR D 0 + I E I c 6 I I 0 0 0 it it-it- + + i- . I g ~ S 0 * + I 95 0 * + 0 0 0 * + + + ALASKA POWER ADMINISTRATION JUNEAU AREA POWER MAR~ET ANALYSIS JUNE-1980 I 00 . .. ~ . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , .. . .. .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . , . .. . . .. .. . . . .. .. .. . . .. . . . t " . ... ' Table 17 CASE 1 -ANNUAL ENERGY PRODUCTION WITHOUT CRATER/LONG LAKE ADDITIONS ******~************************************************* * * UTILITV UTILITY : * * YEAR * HYDRO DIESEL :SNETT!SHAM TOTALS * ******************************************************** * * * 1980 * * * * 1981 * * * * 1982 * * * * 1983 * * * * 37.000 37.000 37.000 37.000 122,200 141.300 3,300 157. 100 11,900 167.400 * 159.000 * * 178,300 * * 197.400 * * 216,300 * * * * * 1984 * No ~urther electric heat growth * 42,400 11.900 166,900 221.200 * * * * 1985 * * * * 1986 * * * * 1987 * * * * 1988 * * * * 1989 * * * * 1990* * * * 1991 * * * * 1992 * * .* * 1993 * * * * 1994 * * * * 1995 * * * * 1996 * * * * 1997 * * * * 1998 * * * * 1999 * * * 45,300 .. .. .. .. .. II II .. .. .. II " " " 13.500 167.300 16,000 167.900 18,700 168,200 21. 500 168,400 24,500 168,500 27,600 II 32,400 II 37,300 .. 42,200 II 47,000 II 51,900 .. 56,200 " 60,400 II 64,700 " 68,900 " * 226, 100 * * 229.200lt * 232,200 * 235.200 * * 238,300 * * 241,400 * * 246,200 * * 251, 100 * * 256,000 * * 260.800 * * 265.700 * 270.000 * * 274.200 * * 278,500 * * 282,700 * ******************************************************** Medium Growth Rate 49 All numbers rounded Table 18 CASE 2 -ANNUAL ENERGY PRODUCTION WITH CRATER/LONG LAKE ADDITIONS (1000 kWh) ********************************************************************* * * UTILITY : UTILITY : * * YEAR * HYDRO : DIESEL :SNETTISHAM: CRATER LONG: TOTALS * ********************************************************************* * * * * 1980 * 37,000 122,200 159,200 * * * * * 1981 * 37,000 141,300 178,300 * * * * * 198~ * 37,000 3,300 157, 100 197,400 • * * * * 1983 * 37,000 11,900 167,400 216,300 * * * .. * * 1984 * 42,400 ~4, 500 168, 500 235.400 * * * * * 1985 * 43,300 40,700 II 254, 500 * * * *. * 1986 * .. II 61,000 274,800 * * * * * 1987 * ... 1, 100 .. 80,200 295, 100 * * * * * 1988 * .. II 93,300 6,300 315,400 * * * * 1989 II II 104,700 17,200 335,700 .,. * * * * .. * * 1990 * .. .. 2,700 II 106,300 33, 100 355,900 * * * * * 1991 * II 8,300 II II 47,300 375.900 * * * * * 1992 * .. 10,500 II " 50,300 380,900 * I"~ * * * * *AA,...,.,.AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"""".,'''''',...." •. ,'''''""""'~"""'''·'.'''''A'''6''''''''''''''''''''* * * No further electric heat growth * .,. * * * * 1993 * " 13, 100 " " 52,200 385,400 * * * * * 1994 * II 16,300 II II 54,200 390,600 * ,.. * * * * 1995 * '1 20,200 .. .. 55,200 395,500 * * * * ". * 1996 * II 2.3,900 .. .. 55,700 399.700 * * * * * 1997 * II 27,800 II II 56.000 403,900 * '" * * * * 1998 * II 31,700 II .. 56,400 408,200 * ,. -.'" * * * * 1999 * " 35,600 " " 56,800 412, 500 * ,.. * * * ********************************************************************* Medium Growth Rate ~ All numbers rounded SO .. APA 6/80 •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • it • • • • • • • • • • • • • .. • • • • • • • • • • • MILUON kWh . . JUNEAU LOA D 6 • 600-11---MEDIUM GROWTH RATE LOAD -HYDRO RE60URCEa 4~0- {,LONG UKE IIAM (+57) /'" ./'" ./'" 300-CRATER LAKE-- (H06) / ./'" ./' ,/ ./'" II::Xlti'l'lNG ~ I (206) " I" SALMON CREEK -I ".-I (+7.5) I / I 1~0-w" o - I I 80 85 90 Y E A R H Y D B 0 ......... / ~ .- H E 6 0 U H C E 6 ......... ----ADDITlONAL FUTURE IIYIlRO /'" PROJECTS COULD MEET TIIIS PORTlON OF LOAD GROW'f1l I I 95 00 ALASKA POWER ADMINISTRATION .JUNEAU AREA POl·IER HARI(ET ANAL va I a JUNE-19BD • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • •••• * ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• . . " ; ~ Table 19 ... SYSTEM ENERGY COSTS (c/kWh) -.- 0 WITH AND WITHOUT CRATER/LONG LAKE ADDITIONS 01-INFLATION **************************************** * * MEDIUM GROWTH RATE * * * (CASE 2) (CASE 1) * * * WITH WITHOUT * * YEAR * PRO~ECTS PRO~ECTS * **************************************** * * (1983) * * * :AAAAAAAAAAAAAAA* * 198:5 * 3. 5 2. 7 * * * * * 1986 * 3. 3 3. 5 * Ii> * * * * 1987 * 3.2 3. 6 * * * * * 1988 * 3. 4 3. 7 * * * * * 1989 * 3. 4 3.8 * • * * * * 1990 * 3.3 3. 9 * * * * * 1991 * 3. 4 4. 1 * ."'A."' A.", ....... "'."' ...... ,,~ .' * * * No -Purthe,. * 1992 * 3_4 4_3 * elect,.ic heat * *AAAAAAAAAAAAAAA: * growth .. * 1993 * 3. :; 4. :; * * * * * 1994 * 3. 5 4.6 * * * * .. * 1995 * 3.6 4. 8 * * * * * 1996 * 3. 7 5. 0 * It" * * * * 1997 * 3. 8 5. 2 * * * * * 1998 * 3.9 5.4 * * * * * 1999 * 4. 0 5. 7 * * * * ... **************************************** $}' CRATER LAKE ON-LINE --1986 LONG LAKE ON-LINE --1988 3 pe1"cent annual -Pl.el cost escalation· '" APA 6/80 .. 51 Table 20 SYSTEM ENERGY COSTS (c/kWh) WITH AND WITHOUT CRATER/LONG LA~E ADDITIONS 57. INFLATION **************************************** * * MEDIUM GROWTH RATE * * * (CASE 2) (CASE 1) * * * WITH WITHOUT * * YEAR * PRO~ECTS PRO~ECTS * **************************************** * * (1983) * * * :~AAAAAAAAAAAAAA* * 1985 * 4. 0 2.9 * * * * * 1986 * 3.7 3.9 * * * * * 1987 * 3. 7 4.0 * * * * * 1988 * 4.0 4.3 * * * * * 1989 * 4. 1 4. 0 * * * * * 1990 * 4. 1 4.9 * * * * * 1991 * 4.4 5. 3 * * * * * 1992 * 4.4 5. 8 * * *AAAAAAAAAAAAAAA: * * 1993 * 4. 6 6. 3 * * * * * 1994 * 4.8 6. 9 * * * * * 1995 * 5. 1 7. 0 * * * * * 1996 * 5.4 8.3 * * * * * 1997 * 5. 8 9. 0 * * "* * * 1998 * o. 2 9.9 * * * * * 1999 "* o. 6 10. 9 * **************************************** CRATER LAKE ON-LINE --1986 LONG LAKE ON-LINE --1988 3 pel'cent annual ~uel cost escalation APA 6/80 52 "A " ,""_",, .. ,.",r .. ·, " No rUl'thel' electl'ic heat gl'owth Case 3 (assume adcling Long Lake Dam first followed by Crater Lake Unit). This case tests the question whether Crater Lake or Long Lake Dam should be constructed first. -As inclicated. on table 21, average system genera- tion and transmi~sion costs are lo~r if Crater Lake is constructed first, and somewhat higher if Long Lake Dam is constructed first. Effects of High Growth Rate Assumption In Case 1 (no new hydro) the high growth rate load assumption would result in increased use of oil for power and a further increase in system costs. For case 2 and 3, (Crater and Long Lake Addition) the full capability of Snettisham Project would be utilized by about 1988 under the high load assumption. Effects of Capital Move Assumption Specific option cost analyses were not made for this load assumption. Oil Savings Significant amounts of fuel oil would be saved through (1) avoidance of oil consumption in cliese1-e1ectric generators, and (2) displacement of • fuel oil through the electric heat app lication. Table 22 summarizes .. estimated oil savings for the period 1986 to 1999--a total of 42 million gallons in 14 years due to the clisplacement of cliese1 generation by the projects while table 23 inclicates the oil savings attributable to con- version to electric heating. S3 .- Table 21 SYSTEM ENERGY COSTS (c/kWh) ALTERNATE ON-LINE DATES CRATER/LONG LAKE ADDITIONS **************************************** * * MEDIUM GROWTH RATE .. * * (CASE 2) (CASE 3) .. * * CRATER-/86 LONG-/86 * * YEAR * LONG-'88 CRATER-'88 * **************************************** * * * * 1985 * 3. 5 3. 5 * * * * * 1986 * 3.3 3.4 * * * * * 1987 * 3.2 3.8 .. * ... * * 1988 * 3. 4 3. 5 *. * * * * 1989 * 3.4 3. 4 * * * * * 1990 * 3. 3 3.3 .. * * * * 1991 * 3.4 3.4 * * * .. * 1992 * 3.4 3.4 * * *""""""AAAAAAAA ....... AAAA: AAAAA .. 'AAA ....... AAAA,'* * 1993 * 3. 5 3. 5 * * * .. * 1994 * 3. 5 3. 5 * * * * * 1995 * 3.6 3.6 * * * * * 1996 * 3. 7 3. 7 * * * * * 1997 * 3.8 3. 8 * * * * * 1998 * 3. 9 3.9 * * * * * 1999 * 4. 0 4. 0 * **************************************** o peT'cent geneT'al inflation 3 peT'cent annual fuel cost escalation APA 6/80 54 """AAA.-'AA.-' ....... No fUT'the'l" elect'l"ic heat gT'owth Table 22 CRATER/LONG LAKE ADDITIONS ." .. ~ DISPLACEMENT OF DIESEL-ELECTRIC GENERATION *************************************** * * MEDIUM GROWTH RATE '* * * ENERGY OIL COST '* * * (1000) (1000) (1000) * * YEAR * kWh gallons $ * *************************************** * * * * 1986 * 15,977 1,775 1,717 * * * * * 1987 '* 17,669 1,963 1,955 * * * * * 1988 * 21,515 2.391 2.453 * * * * * 1989 * 24,518 2.724 2.879 * * * '* * 1990 * 24,872 2,764 3,008 * * * * * 1991 * 23,881 2.653 2,975 * * * * * 1992 * 26,842 2.982 3,444 * * * * * 1993 * 29,088 3,232 3,844 * * * * * 1994 * 30,705 3,412 4, 180 * * * * * 199~ * 31,712 3,524 4,446 * * * '* * 19q6 * 32,230 3.581 4.655 * * * '* * 1997 * 32.588 3.621 4,848 * ,fI" * * * * 1998 * 32,946 3,661 5,048 * * * * t" .. * 1999 * 33,304 3,700 5,256 * * * * *************************************** * * * ~, *TOTALS* 377,847 : 41.983 : 50.710 * * * * *************************************** CRATER LAKE ON-LINE --1986 LONG LAKE ON-LINE --1988 o pe~cent gene~al inflation 3 pe~cent annual fuel cost escalation All numbe~s a~e rounded APA 6/80 ~' ... 55 Table ~3 ELECTRIC HEAT CONVERSION DISPLACEMENT OF FUEL-OIL CONSUMPTION *************************************** * * MEDIUM GROW~ RATE * * * ENERGV OIL COST * -* * (1000) (1000) (1000) * * * kWh gallons .. * ***********************.*************** * 1986 * 45,000 2,231 2, 158 * * * * * 1987 * 62,000 3,074 3,074 * * * * * 1988 * 79,000 3,917 -. 4,019 * * * * * 1990 * 96,000 4,760 5,031 * * * * * 1991 * 11:3,000 5,602 6,098 * * * * * 1992 * 128,000 6,:346 7, 11:5 * * * * * 1993 * 128,000 6,:346 7,:329 * * * * * 1994 * 128.000 6,346 7,:548 * * * * * 199' * 128.000 6,:346 7,775 * * * * * 1996 * 128.000 6,:346 8,008 * * * * * 1997 * 128.000 6,:346 8,249 * * * * * 1998 * 128,000 6,:346 8,7'1 * * * * * 1999 * 128,000 6,:346 9,013 * * * * *************************************** * * * *TOTALS*1,4:36,000 : 70,:352 : 84, 168 * * * * *************************************** ° pe~c.nt gene~al in~lation :3 p.~c.nt annual Tuel cost escalation All numbe~s a~e ~ounded APA 6/90 56 , -- 0 PART VIII. FINANCIAL ANALYSES This section presents data on revenue requirements and wholesale power costs, for the Snettisham Project, with and without Crater Lake stage and Long Lake Dam. The method used is a standard power repayment study (computerized) developed by the Water and Power Resources Service. The power repayment study shows expected revenues and costs for each year of the project repayment period. The study is used to estimate average rates suffi- cient to repay reimbursable costs. This analyses uses average sales in the computation of repayment costs which differ from the critical year generation figures in the load/re- source analyses. Critical year energy was utilized in the previous section to insure that adequate generation is available during critical water years. Average energy sales are utilized in this section as these more closely approximate the actual conditions. Repayment Criteria Repayment criteria for Snettisham were initially established in the project authorization (Section 204 of the Flood Control Act of 1962, Public Law 87-874): SEC. 204. (1) For the purpose of developing hydroelectric power and to encourage and promote the economic development of and to foster the establishment of essential industries in the State of Alaska, and for other purposes, the Secretary of the Army, acting through the Chief of Engineers, is authorized to construct and the Secrtary of the Interior is authoirzed to operate and maintain the Crater-Long Lakes division of the Snettisham project near Juneau, Alaska. The works of the division shall consist of pressure tunnels, surge tanks, penstocks, a powerplant, transmission facilities, and related facilities, all at an estimated cost of $41,634,000. (b) Electric power and energy generated at the division except that portion required in the operation of the diviSion, shall be disposed of by the Secretary of the Interior in stich a manner as to encourage the most widespread use thereof at the lowest possible rates to consumers consistent with sound business principles. Rate schedules shall be drawn having regard to the recovery of the costs of producing and transmitting the power and energy, including the amortization of the capital investment over a reasonable period of years, with interest at the average rate (which rate shall be certified by the Secretary of the Treasury) paid by the United States on its ',arketable long-term securities outstanding on the date of this Act and adjusted to the nearest one-eighth of 1 per- centum. In the sale of such power and energy, preference shall be given to Federal agencies, public bodies, and cooperatives. It shall be a condition of every contract made under this Act for the sale of power and energy that the purchaser, if it be a purchaser for resale, will deliver power and energy to Federal agencies or facilities thereof within its transmission area at a reasonable charge for the use of its transmission facilities. All receipts from the transmission and sale of electric power and energy gener- ated at said division shall be covered into the Treasury of the United States to the credit of miscellaneous receipts. t·· .. .' The Secretary of Treasury certified 3 percent as the project interest rate pursuant to the formula in Section 204(b) of PL 87-874. Project repayment criteris were amended by ~ection 201 of the Water Resources Development Act of 1976; Public Law 94-587: Section 201. (a) Section 204(b) of the Act of October 23, 1962 (76 Stat. 1173, 1174), is amended by striking the period at the end of the second sentence and insert the following: ": Provided, 'That the Secretary of the Interior, in determining reimbursable costs, shall not include the cost of replacing and relocating the original Salisbury Ridge section of the 138-kilovolt transmission line: Provided further, that the Secretary of the Army, acting through the Chief of Engineers, shall relocate such transmission lines, at an estimated cost of $5,641,000.". (b) 'The Crater-Long Lakes division of the Snettisham Project near Juneau, Alaska, as authorized by Section 204 of the Flood Control Act of 1962, is modified with respect to the reimbursement payments to the United States on such proj ect in order to provide (1) that the repayment period shall be sixty years, (2) that the first annual payment shall be 0.1 per centum of the total principal amount to be repaid, (3) thereafter annual payments shall be in- creased by 0.1 percentum of such total each year until the tenth year at which time the payment shall be 1 percentum of such total, and (4) subsequent annual payments for the remaining fifty years of the sixty-year-repayment period shall be one-fiftieth of the bal- ance remaining after the tenth annual payment (including interest over such sixty-year period). The Interior Department Responsibilities for the Snettisham Project were assigned ·to the Secretary of Energy in the DOE Enabling Act, Public Law 95-91. In accordance with the 1976 Act, portions of the project interest rate are being deferred during' an initial 10-year period which ends on Oc~ober 1, 1985. All projec~ cos~s, including the deferral 1n~erest, are to be repaid in a subsequent 50-year period ending in 2035. The present wholesale power rate of 15.6 mills per kilowatt-hour reflects the interest deferral. 'The rates will need. to be increased at the end of the 10-year period, with or without the Crater and Long Lake Dam additions • Repayment Studies A set of repayment studies was prepared to illustrate the following cases: 1. Existing project, 1980 costs; 2. Existing project plus the Crater Lake and Long Lake additions, 1980 costs; 58 , 3. Case 2 modified to reflect an inflation assumption of the Corps that costs would be inflated 35 percent at the midpoint of construction; 4. Case 2 modified to reflect a lower total growth assumption of 10 percent lower .load growth until project are fully utilized. Each of the cases assumes the present rate of 15.6 mills per kilowatt- hour would be maintained throughout the initial 10-year period, and estimates an average rate to meet repayment requirements over the bal- ance of the repayment period. Table 24 is a summary of investment costs for the Crater and Long Lake Additions. Additional assumptions used in the repayment studies include the follow- ;ing: 1. Repayment period -50 years. 2. Interest rate - 3 percent. 3. Medium growth rate. 4. Crater Lake a. Investment cost -$44,633,000 b. Annual O&M cost -$50,000 c. Annual replacement cost -$12,000 . d. On-line date -1986 5. Long Lake Dam a~ Investment cost -$35,089,000 b. On-line date -1988 6. All costs associated with existing project are an extension of repayment studies camp leted by APA in March 1980. Results The results of the repayment analysis are summarized in the following table. The figures indicate the wholesale power rate which would be required in 1986 to repay all project costs. 1. Existing Project (1980 Costs) 2. Existing project plus Crater and Long Additions (1980 Costs) 59 Mills 26.0 23.5 • f"- .. ., .. f-* Table 24 INVESTMENT COST SUMMARY ($/million) CRATER/LONG LAKE ADDITIONS CRATER LONG LAIo<.E LA 10<. E TOTAL Const"uction 39,:;500 33, 578 73,078 Inte,.est du,.ing Const,.uction 3,555 1, 511 3,881 P-rio-r Investment Costs 1.1 1, 578 1,578 Investment 44,633 35,089 78,537 1/ Costs incu",.ed ~o,. p,.evious design investigations by Co,.ps and APA APA 1/80 60 3. Exis~ing Project plus Cra~er and Long Addi~ions (35% Cost Increase) 4. Existing Project plus Crater and Long Addi~ions (10% Reduction in Growth) 61 Mills 26.5 24.0 . • APPENDIX A System Cost Analyses Output System Cost Analyses Output An example of the output from the system cost analyses is shown on the following pages. As indicated, this output is from a case utilizing a medium plus electric heat growth rate, 0 percent general inflation, and 3 percent fuel escalation. All numbers in this output were rounded during computer processing. A-l ~ I 'v GROWTH RATE: MEDIUM + ELECTRIC HEAT FUEL ESCALATION RATE: 3X GENERAL INFLATION RATE: OX ALASKA POWER ADMINISTRATION JUNEAU AREA LOAD STUDY JUNE-1980 ***************************************************************************** .Ia-!~§'Q * 1 981 * * INST. ANNUAL ANNUAL ENERGY * INST. ANNUAL ANNUAL ENERGY * * CAP. COST ENERGY COST * CAP. COST ENERGY COST * * (kW) (!Ii) <t1Wh) ($/kWh)* OW) ($) (MWh) ($/kWh)* **.~**~**~*~**********************~********************************************************* HELlnURCES * * * a**~********~**~ * * * * * HVnRn .~ * .~ * * * UTIL.ITIES * 8,450 630,000 37,000 .017 * 8,450 630,000 37,000 .017 * * * .~ SNETTISHAM * 47, 160 1,906,000 122,200 .016 * 47, 160 2,204,000 141. 300 .016 i!- .~ * * Cr<ATEI~ LAKE -I~ 0 0 0 .000 * 0 0 0 .000 *. * * i!- I_DI",jG L.A~~E * 0 0 0 .000 -It 0 0 0 .000 * iI· * i!- DUROTHY * 0 0 0 .000 i~ 0 0 0 .000 * iI * * S~·IEETHEART * 0 0 () .000 * 0 0 0 .000 *. * * * com). nmo INE * 17,900 390,000 0 .000 * 17,900 390,000 0 .000 i!- * * •• DIESEL * 18,222 17 L 000 0 .000 * 18,222 171. 000 0 .000 * -I~ * * II· *. Ia- fNEHGY LOSS It -( 2, 400~)-* -2,600:> ~ .z. 'I~ * ~ 1~ * I< k~~II~***II******~*~************************************************************************** * * * rOTAL * 91,732 3,097,000 156,800 .020 * 91,732 3,395,000 175,700 .019 * ·11 * *************i~**************************************************************************.*** :s-- I w GROWTH RATE: MEDIUM + ELECTRIC HEAT FUEL ESCALATION RATE: 3'l. ALASKA POWER ADMINISTRATION JUNEAU AREA LOAD STUDY JUNE-1980 GENERAL INFLATION RATE: O'l. *********************************************~,******************************* * L~82 * 1.983 'II- * INST. ANNUAL ANNUAL ENERGY * INST. ANNUAL ANNUAL ENERGY * * CAP. COST ENERGY COST * CAP. COST ENERGY COST II- * ( kW) ($) (MWh) ($/kWh)* ( kW) ($ ) (MWh) ($/kWh)* ******************************************************************************************** RESOURCES * * II- **************** * * * * * HYDRO * * II- * * ,II- UTILITIES * 8,450 630,000 37,000 .017 * 8,450 630,000 37,000 .017 * * * * SNETTISHAM * 47, 160 2,450,000 157, 100 .016 * 47, 160 2,612,000 167,400 .016 * * * ,~, CRATER LAKE * 0 0 0 .000 * 0 0 0 .000 * * * * LONG LAKE * 0 0 0 .000 * ° 0 0 .000 * * * * DOROTHY * 0 ° 0 .000 * 0 0 0 .000 * * * * mJEETHEART * 0 0 0 .000 * 0 0 0 .000 * * * II- COMB. TURBINE * 20,400 490,000 0 .000 * 27,900 790,000 0 .000 * ii' * * DIESEL * 18,222 430,000 3,300 . 130 * 18,222 1,144,000 11. 900 .096 * * * * * * II- ENEHGY LOSS * < 2,900)-* ,-3,200:'-* '- iI' * II- * * K ******************************************************************************************** * * II- TOTAL * 94,232 4,000,000 194,500 .021 * 101,732 5,176,000 213, 100 .024 It * * It ******************************************************************************************** !I-- I .t-- GRm.JTH RATE: I"IELHUI"I ... ELECTRIC HEAT FUEL. ESCALATION RATE: ::n GENERAL INFLATIUN RATE: 0% ALASKA POWER ADMINISTRATION JUNEAU AREA LOAD STUDY JUNE-1980 ••••••••••• *.***.***.******************************************************** -II-l_«tfl.i * 12.§.2 * * INST. ANNUAL ANNUAL ENERGY * INST. ANNUAL ANNUAL ENERGY • * CAP. COST ENERGY COST * CAP. COST ENERGY COST • * <Ie W) ($ ) (MWh) ($/kWh)* ( leW) ($ ) (MWh> (to/kWh>* ••• ** •• **.*.*.*** ••••••• **.* ••••• ****.**.******.*.********* •• ***.**** •• ********************. HES()Uf~CES • * * *-11-*.**** .... *.* •• * * * * • II- t lynRIJ * • !t- it • II- UTILITIES * 10, :350 968,000 42,400 .023 * 10,350 1,210,000 45,300 .027 !t- • * .. SNETTISHAM • 47, 160 2,628.000 168,500 .016 • 47. 160 2, 62B.000 168,500 .016 II- • * II- CRATB'l LAI(E * 0 0 0 .000 • 0 0 0 .000 .. * * * LONG L.AKE * 0 0 0 .000 * 0 0 0 .000 II- -I. * * OOROTHY * 0 a 0 .000 * 0 0 0 . 000 * * -It • Sl-JEETHEAHT ... 0 0 0 .000 * 0 0 0 .000 * ~. * • cOI-m. TUR B I NE n 32.'J00 990,000 0 .000 * 37.900 L 198.000 100 11. 980 * it * II- DIESEL * 18,222 2,222,000 24,500 .091 * 18,222 3,659,000 40,700 .090 * * * II- 'j} * II- ENERGY LOSS ·It .'" -" 3,500> * < 3,800) * * * * -It * * ********* •• ******.********.***************.******************************************n****** * * .. rUrAL. * lOB, 632 6.808,000 2:31.900 . 029 * 113.632 8. 695.000 250,800 .035 * k* •• ~~~U**~ •• U~ •• *************************************************************************_* ~ I VI GROWTH RATE: MEDIUM + ELECTRIC HEAT FUEL ESCALATION RATE: 3X GENERAL INFLATION RATE: OX ALASKA POWER ADMINISTRATION JUNEAU AREA LOAD STUDY JUNE-1980 ***************************************************************************** * 1986 * 1.987 * * INST. ANNUAL ANNUAL ENERGY * INST. ANNUAL ANNUAL ENERGY * * CAP. COST ENERGY COST * CAP. COST ENERGY COST * * (kW) ($) (MWh) ($/kWh)* (kW) ($) (MWh) ($/kWh)* ******************************************************************************************** f~ES[)URCES * * * **************** * HYDRO * * UTILITIES * 10,350 1, 210, 000 45,300 * SNETTISHAM * 47, 160 4,380,000 168,500 * CRATER LAKE * 27,000 1, 673, 000 61.000 * LONG LAKE * 0 0 0 .j(- DDROTHY * 0 0 0 * SWEETHEART * 0 0 0 * COMB. TURBINE * 45,400 1, 491, 000 0 * DIESEL * 18,222 171,000 0 * * ENERGY LOSS * .~ 4, 100> '" * i~ * * * * .027 * 10,350 1,210,000 * .026 * 47,160 4,380,000 * .027 * 27,000 1,673,000 * .000 * * .000 * * .000 * * .000 * * .000 * * * * * * o o o o o o 52,900 1, 791,000 18,222 267,000 * * Il- * 45,300 .027 * * 168,500 .026 .Il- Il- 80,200 .021 * * 0 .000 * * 0 .000 * * 0 .000 * * 0 .000 * * 1, 100 .243 * * * 4,400)-* "' Il- *k****************************************************************************************** * * * TOTAL. * 148,132 8,925,000 270,700 .033 * 155,632 9,321,000 290,700 .032 * * * ******************************************************************************************** :>.-I 1)\ GROWTH RATE: MEDIUM + ELECTRIC HEAT FUEL ESCALATION RATE: 3% ALASKA POWER ADMINISTRATION JUNEAU AREA LOAD STUDY JUNE-1980 GENERAL INFLATION RATE: 0% ***************************************************************************** * l'l§!:1 * 1989 * it INST. ANNUAL ANNUAL ENERGY * INST. ANNUAL ANNUAL ENERGY * * CAP. COST ENERGY COST * CAP. COST ENERGY COST * * ( kW) ( $ ) (MWh) ($/kWh)* ( kW) ( $) (MWh) ($/kWh)* U"~~***.***~*******************************it************************************************ HESnURCES * * )I- ****k**k******** * * * * )I- HYDRU * * * * * * UTILITIES * 10,350 1,210,000 45,300 .027 * 10,350 1,210,000 45,300 .027 * * * * SNETTISHAM * 47, 160 4,380,000 168,500 .026 * 47, 160 4,380,000 168,500 .026 * ·It * )I- CRATER LAKE * 27,000 1,673,000 95.300 .018 * 27,000 1,673,000 104,700 .016 * * * * LONG LAKE * ° 991,000 6,300 . 157 * 0 1,322,000 17,200 .077 * it * * DOt1[)THY * 0 0 ° .000 * 0 0 0 .000 * .* * * SHEETHEART * 0 0 0 .000 * 0 0 0 .000 * ·It * * COMU. TURUINE * 60,400 2,091. 000 ° .000 * 67,900 2,392,000 0 .000 * it· * )I- DIESEL * 18,222 171. 000 0 .000 * 18,222 171,000 0 .000 .11- .* * * It· * * ENEflGY LOSS it <: 4,700)-* -( 5,000> * II· * * it * )I- ***********************************************************************Hitll-****************** * * * TOTAL * 163,132 10,516.000 310,700 .034 * 170,632 11, J48,000 330,700 .034 * * * * **~****.************************************************************************************ ~ I -l GROWTH RATE: MEDIUM + ELECTRIC HEAT FUEL ESCALATION RATE: 3X GENERAL INFLATION RATE: OX ALASKA POWER ADMINISTRATION JUNEAU AREA LOAD STUDY JUNE-1980 ***************************************************************************** * 1990 * l~ * * INST. ANNUAL ANNUAL ENERGY * INST. ANNUAL ANNUAL ENERGY * * CAP. COST ENERGY COST * CAP. COST ENERGY COST * * (kW) ($ ) (MWh) ($1 kWh) * <leW) ($ ) (MWh) ($/kWh)* ******************************************************************************************** RESOURCES * * * ***-11-***-11-******** * * * * * HYDfHJ * * * * * * UTILITIES * 10.350 1. 210. 000 45.300 .027 * 10.350 1.210.000 45.300 .027 * * * -Ii- SNETTISHAI"1 * 47. 160 4.380.000 168.500 .026 * 47. 160 4.380.000 168.500 .026 * * * * CRATER LAKE * 27.000 1.673.000 106.300 .016 * 27.000 1.673.000 106.300 .016 * * * * LONG LAKE * 0 1.322.000 33. 100 .040 * 0 1.322.000 47.300 .028 * * * * DOROTHY * 0 0 0 .000 * 0 0 0 .000 * * * * SL.JEETHEAR T * 0 0 0 .000 * 0 0 0 .000 II- * * * CDI'm. TURD INE * 75.400 2.692.000 0 .000 * 82.900 2.992.000 0 .000 * * * * DIESEL II-18.222 434.000 2.700 . 161 * 18.222 1.030.000 8.500 1 ~~ 1 II· * * II- * * * ENERGY LOSS * < 5.300> * ,-5.600> -It-'- * * * * * II- ******************************************************************************************** * * * TOTAL * 178.132 11.711.000 350.600 .033 * 185.632 12.607.000 370.300 .034 * * * ******************************************************************************************** ~ I co GHOWTH RATE: MEDIUM + ELECTRIC HEAT FUEL ESCALATION RATE: 3% OENEHAL INFLATION RATE: 01. ALASKA POl-JER ADMINISTRATION JUNEAU AREA LO,AD STUDY JUNE-1980 ***************************************************************************** * 1.'2'/2 * 1.993 ,It * INST. ANNUAL ANNUAL ENERGY * INST. ANNUAL ANNUAL ENERGY * * CAP. COST ENERGY COST * CAP. COST· ENERGY COST * * ( kW) ($) (I'1Wh ) ($/kWh)* ( kW) ($) (HWh) ($/kWh)* It.****************************************************************************************** HESOURCES ,* * * .~************** * • * * * HYDRO it * * II * • UTILITIES -It 10.3tiO 1.210.000 45.300 .027 * 10,350 1. 210. 000 45.300 .027 * ·It * • SNETTISHAH * 47. 160 4.380.000 168.500 .026 * 47. 160 4,380.000 168.500 .026 * * * * CRATER LAKE * 27.000 1. 673. 000 106.300 .016 * 27.000 1.673.000 106.300 .016 It * * ·It LONG LAKE * 0 1. 322,000 50.300 .026 * 0 1,322.000 52.500 .025 * * * * DOROTHY * 0 0 0 .000 * 0 0 0 . 000 * * * * Sl-JEE.THEART i .. ° 0 0 .000 * 0 0 0 .000 * It * * CON \J, T umn NE * EK!. 900 2.992.000 0 ,000 * 82.900 2. 9'J2. 000 0 ,000 * it * It DIESEL * 18. ;;~22 1.249.000 10.500 . 119 * 18.222 1.556.000 13. 100 .119 * * * * * * * ENEfWY LOSS * ~ 5.600)-* " 5.700)-• <" ,~ 'Ii' * * * * * ****.*************************************************************************************** * * * IOTAL * 18~), 632 12.826.000 375. ~]OO .034 * 185.632 13.133.000 380.000 .035 * "' * * P> I \0 GROWTH RATE: NEDHJM + ~LECTRIC HEAT FUEL ESCALATION RATE: 3% AL.ASKA POWER ADMINISTRATION JUNEAU AREA LOAD STUDY JUNE-1980 GENERAL INFLATION RATE: OX ***************************************************************************** * 1994 * 1.995 * * INST. ANNUAL ANNUAL ENERGY * INST. ANNUAL ANNUAL ENERGY * * CAP. COST ENERGY COST * CAP. COST ENERGY COST * * (kW) ($) (MWh) ($/kWh)* (kW) ($) (ML-Jh) ($/kWh)* *~****************************************************************************************** RESOURCES * * * **************** * .~ * * * HYDRO * * * * * * UTILITIES * 10,350 1,210,000 45,300 .027 * 10,350 1. 210, 000 45,300 .027 * * * It SNETTISHAM * 47, 160 4,380,000 168,500 .026 * 47, 160 4,380,000 168, 500 .026 * * * * CRATER LAKE * 27,000 1,673,000 106,300 .016 * 27,000 1,673,000 106,300 .016 * * * * LONG LAKE * 0 1,322,000 54,200 .024 * 0 1,322,000 55,200 .024 * .11-* II- DOROTHY * 0 0 0 .000 * 0 0 0 .000 * * * II- SWEETHEART * 0 0 0 .000 * 0 0 0 .000 * * * * COMB. TURBINE * 85,400 3,092,000 0 .000 * 85,400 3,092,000 0 .000 * * * II- DIESEL * 18,222 1. 948, 000 16,300 .120 * 18,222 2,428,000 20,200 .120 * .. * * * * * ENEHGY LOSS * < 5,800)-* .( 5,800> * * * It * * It ******************************************************************************************** II * II- fOTAL .. 188,132 13,625,000 384,800 .035 * 188,132 14,105,000 389,700 .036 * * * * II*II*~.************************************************************************************** ~ I ...... 0 GROWTH RATE: I'IEDIUM + ELECTRIC HEAT FUEL ESCALATION RATE: 3% ALASli.A POWER ADMINISTRATION JUNEAU AREA LOAD STUDY .. JUNE-1980 GENERAL INFLATION RATE: OX ***************************************************************************** * !.~.'t~ * 1~27 * * INST. ANNUAL ANNUAL ENERGY * INST. ANNUAL ANNUAL ENERGY * * CAP. COST ENERGY COST * CAP. COST ENERGY COST * * (HI) ($) (11Wh) ($/kWh)* (kW) ($) (/"IWh) ($/I(Wh)* **.*~.***k*~~kll-.******k~"******************************************************************* f<E!::iDl.mCES ·R * * R***R*»********* * * ·It * * HYDfHl * * .11- I~ * .11- UTILITIES * 10,350 1,210,000 fJ5,800 .027 * 10,350 1,210,000 45,300 .027 * i/. * * SNETTISHAI1 * 47, 160 4,380,000 168,500 .026 * 47, 160 4,380,000 168,500 .026 '11- it * A CRATER LAl,E * 27,000 1,673,000 106,300 .016 * 27,000 1,673,000 106,300 .016 A * * * 1.01'10 LAli.E A 0 1,322,000 55,700 .024 * 0 1. 322, 000 56,000 .024 * * * * nDROTHY II 0 0 0 .000 * 0 0 0 .000 * il· A * SWEETHEAHT * 0 0 0 .000 * 0 0 0 .000 * il * ·It tlll'lu. nmu HIE * 8~,1J00 3,092,000 0 .000 * 87,900 3, 192,000 0 .000 * -It * * DIESEL. i~ 18,222 2.919,000 23,900 .122 * 18,222 3,455,000 27,800 . 124 A i~ * * .\1. * * FNEHGY L lJ~·~;.1 " <: 5,900:;-* ,.. 6,000:'-* "- ·11· *. R U *. * " I :: ~. J~ iHI ~ II II * 1t II-*11--I~ II-il il-R R II Rilli -II * 11 -Ii 1I-IIIIiI -II il1I it*II·*U *·RIHI·* i:i-il·***·U-*iI·****1dil< It i~****** * ** ·,*"**************-II--IHI·** II * * Tfn,;L. .. ~. "t) 1 ~i;:-! H, ~)96, 000 393.800 . 037 * 190.632 15.232.000 397.900 . 038 I/- .u..x ,e ... " ~ I ..... ..... GROWTH RATE: I'IED I UI'1 + ELECTR I r, I-IEA T FUEL ESCALATION RATE: 3% GENEHAL INFLATION RATE: OX ALASKA POWER ADMINISTRATION JUNEAU AREA LOAD STUDY JUNE-1980 *_*_ •• ********************************************************M**~*********** * ~ * 1,999 * * INST. ANNUAL ANNUAL ENERGY * INST. ANNUAL ANNUAL ENERGY * * CAP. COST ENERGY COST * CAP. COST ENERGY COST * * (kW) ($) (MWh) ($/kWh)* (kW) ($) (MWh) ($/kWh>* *********n~Uk**********************************************************************~******** ~ESOU~CES * * * ft~~~*.********** * * * I} * HYDRO * * 'I} 'Ii" * Ii" ,IT ILl T I E:tl * 10,350 1,210,000 45,300 .027 * 10,350 1,210,000 45,300 .027 * 'Ii" * II- SNETTISHAM * 47, 160 4.380.000 168. 500 .026 * 47, 160 4,380,000 168, 500 .026 * * * ,It- CRATER LAKE * 27,000 1,673.000 106.300 .016 * 27,000 1,673,000 106,300 .016 * * * * LDNG LAI.t..E * 0 1. 322, 000 56,400 .023 * 0 1. 322, 000 56,800 .023 * * * * DDfWTHY * 0 0 0 .000 * 0 0 0 .000 * * * * Bl.JEETI-lEART * 0 0 0 .000 ii, 0 0 0 .000 * it * * cm·lB. TURB INE * 87,900 3.196,000 0 .000 * 87.900 3,264.000 400 8. 160 * * * * DIESEL * 18.222 4.015,000 31.700 . 12-' * 18.222 4.556,000 35,200 .129 It- * * * * * * ENEHGY LOSS * .( 6,000> * <: 6, 100:> * * * * * * * *-******************************** •• ******************************************************** * * * T01'Al_ * 190,632 15.796.000 402,200 .039 * 190,632 16,405.000 406,400 ,040 * * * ****~U*********************************R**************************************************** APPENDIX B Cost Comparison Plots of Alternatives ENERGY C[)tiT 0:1 cent5 I t-' pe ..... kWh ~L.L_tLJ_E _.tL __ LH_ E-B G Y C 0 c.' ~ I c· ~ 6 -0 -NO NEW FEDEHAL HYDRO (Case 1 ) * -WITH NEW F'EDEHAL HYDfW (Cas~ 2) '86 -Crater Lake CI '88 -Lung Lake u 0 4, -- 0 a 0 a 0 3 -. 0 a ~. a II' a * a * 'I~ a * ·It il' * * ~. * .~ ,II 1. -- I< U 0 () () --; . --------.----------------.-.-----.----------------------------.-,---._-------.--------------r----------.--.-------.... -,- I • I I I 80 0:5 90 95 00 IviED I UI"I GIWLHH HATE 0% General Inflation 3% Fuel Escalation YEAR ALASKA POWER ADMINISTRATION JUNEAU AREA POWER MARKET ANALYSIS JUNE-19BO tJ;j I N · . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ~ . . . . . . . . . ENERGY COST cents HIH' kWh li __ Y Ei _T E .t1 __ ~_~ G Y __ G-.!l S _L-B. 12-1 0 -N() NEJJ FEOEfML HYDRO (Cust: 1) '1 - 6 -- ;j _. 0 0 I I I 1 0 -I 1 80 * -WITH NEW FEDERAL HYDRO (Case 2) 186 -Crater Lake o 188 -Long Lake i!- 0 0 ii· 0 I 85 el it- 0 D * 0 * ·It 0 i!- I 90 YEAR MEDIUM GROWTH RATE 5% Gener~l Inflation 3% Fuel Escalation 0 i!- 0 D i!-* 0 i!- 0 i!- I 95 D 0 0 0 it iI' iI' i!- ALASKA POWER ADMINISTRATION JUNEAU AREA POWER MARKET ANALYSIS JUNE-19BO I 00 ENERGY COST o;l cents I w per kWh ENE R G Y COS T S 6 -a -LONG LAKE('B6); CRATER LAKE( 'B6) (Case 3) * -CRATER LAKE('B6); LONG LAKE('BB) (Case 2) 4. - 3 - L- o - (, a i~ a a a a .11-£) a .,~ 0 a a a 0 a a a o -,---------------------,,0--------------------, I ---,- I 80 MEDIUM GROWTH RATE 0% General Inflation 3% Fuel Escalation I I 85 90 YEAR 95 ALASKA POWER ADMINISTRATION JUNEAU AREA POWER HARKET ANALYSIS JUNE-1980 00 APPENDIX C Crater Lake Construction Costs COST ACCT. NO. 04. .4 07. . 1 .2 .3 .8 08. 19. 30. 31. CONSTRUCTION COSTS CRATER LAKE PROJECT FEATURE DAM Power Intake Works POWERPLANT Powerhouse Turbines & Generators Accessory Electrical Equipment Transmission Plant ROADS BUILDINGS, GROUNDS, UTILITIES ~NGINEERING & DESIGN SUPERVISION & ADMINISTRATION Source: Corps Or Engineers ,January, 1980 C-l COST ($1000) (26,789) 26,789 (4,783) 445 3,916 493 19 990 922 2,686 3, 240 39, SeQ APPENDIX D Comments ALASKA ELECTRIC LIGHT AND POWER CO. 13. N. FRANKLIN STREET t:· JUNEAU. ALASKA ••• 01 Mr. Robert J. Cross Administrator (907) !588·2222 Alaska Power Administration p.o. Box 50 Juneau, Alaska 99802 Dear Bob: August 29, 1980- Reference is made to the Alaska Power Administration's draft "Juneau Area Power Market Analysis" dated July, 1980. The Alaska Electric Light and Power Company (AELP) concludes from the Analysis (and its own studies) that immediate steps should be taken to initiate the construction of the Crater Lake addition to the Snettisham Hydroelectric Project. As was pointed out in the Load/Resource and System Cost Analysis Section (Part VII), it will be necessary to rely on diesels to a minor extent in 1982 and a much greater extent starting in 1983. Thus, if Snettisham is not expanded the Juneau area may find itself with diesel electric energy requirement which it has successfully eliminated for the last several years. The Analysis indicates for the earlie.st Crater Lake will be on line by 1986. There are many factors which could cause delay in completion of any Snettisham addition including the lack of Federal funds as a result of government fiscal constraints or the nuances of the appropriation process as well as construction or environmental problems. Thus, AELP urges that steps be taken now to proceed with the Crater Lake addition. Please telephone me if I can answer further questions. WAC/ak Very truly yours, tJA~.·L.,.y a . ~ William A. Corbus Hanager Glacier Highway Electric Association Inc.< P.O. Box 115 • Auke Bay, Alaska 99821 • Phone (907) 789-7344 September 3, 1980 Mr. Robert J. Cross, Administrator Alaska Power Administration P.o. Box 50 Juneau, Alaska 99802 Dear Bob: We have reviewed the Juneau Area Power Market Analysis and the forecast of the Juneau area loads. This work reflects our appraisal of Juneau's energy future. We concur with your findings and support your recommendation that work should proceed to construct the Crater Lake unit so that the unit will be available in the 1986-87 time frame. S;;;;;',/d!t ~~wallS' Manager Glacier Highway Electric Association CYW:jsm .. .' "," ( Bibliography Bib liography 1. Juneau Area Load Estimate, H:ay 1980, Alaska Power Administration. 2. State and Federal Employment in Juneau, Sixth Annual Report, December 1979, Homan-McDowe11 Associates. 3. Socio-Economic Impact Analysis for Juneau and the Matanuska-Susitna Borough, March 1978, Rivkin Associates. 4. Role of Electric Power in the Southeast Alaska Economy, March 1979, Alaska Power Administration. Other Data Sources Alaska Electric Light and Power Load Estimate. Glacier Highway Electric Association Load Estimate Prepared for REA. EXHIBIT 8 JUNEAU AREA POWER MARKET ANALYSIS ADDENDur~ OCTOBER 1980 ALASKA POWER ADMINISTRATION @. . .,,; . r~# , :' • Department Of Energy Alaska Power Administration P.O. Box 50 Juneau. Alaska 99802 October 3, 1980 Colonel Lee R. Nunn, District Engineer U.S. Department of the Army Corps of Engineers P.O. Box 7002 Anchorage, AK 99510 Dear Colonel Nunn: We received additional comments on our draft Juneau Area Power Market report from the Alaska Power Authority and the State's Division of Energy and Power Development after we had finalized the report. The comments and our responses are enclosed as an addendum to our report, and we'll distribute the addendum along with this report. We're pleased to note the Alaska Power Authority and the Division of Energy and Power Development concur in our recommendations with respect to the Crater Lake unit of the Snettisham Project. Enclosures Sincerely, ., . / I .,.,~.~ . /--::1 -/ /. t-~ c... !" . C· /t'-" /_ ''''{..,.! ",''V,. ., V' . .;. , ~ r~obert J. Cross Y Administrator 1 ADDENDUM Juneau Area Power Market Report October 1, 1980 . , ( JAY 5 HAMMOND GOVI!:RNO" \\ rTF I~\ II r r~ \i0f11 u ll ?' mi\ rL 1M (~rr. ;/~j~.\::: i :'.'.~.:£ .. v / iI I . ., \ I I :!......., U ,,\ I In \ "--') ,(\. \ I f7i.\ I" t, " ~ u U \...! .J '--' J u L:J L! ..J '-=-: .. Ir' ?:\lJ ; ":1 .. j 'J i. DEPART~IENT OF CO~IMfERC~'·~&.. /, ECO:\"OMIC DEVELOp~alENT'\' ~ -;:,',; ,I :,".~ DIVISION OF ENERGY & POYVER DEVELOPMENT September 16, 1980 Mr. Robert J. Cross Administrator Department of Energy Alaska Power Administration P. O. Box 50 Juneau, Alaska 99802 Dear Mr. Cross: , 7TH FLOOR MACKA Y BLDG. 338 DENALI STREET ANCHORAGE, ALASKA 99501 PHONE: (90l! 27S'{)SOR The draft "Juneau Area Power Market Analysis" was forwarded to the Division of Energy and Power Development 'for review. This letter summarize~ the gist of the comments telephoned by them to your Mr. Floyd Sumners on September 8, 1980. In general we are in agreement with the conclusions reached by the study. It would seem prudent to proceed with the acquisit;on of funding for the already authorized Crater Lake project is so that the additional capacity can be brought on line in an orderly as needed manner. Although you have probably already caught them, the follo\>Jing typo's were noted duri.ng the revi ew of the study: Page 11, line 2, first paragraph -Table! should be Table 1. ~age 14, second paragraph -Table # should be Table 3. . -Table $ should be Table 4. third paragraph -Table % should be Table 5. Page 22, fifth paragraph -The word 'particula~' should be . 'particularly'. Page 36 -The decimal point is misplaced under theTotalM~~ column 13.60' should be '30.6'. Page 46 in thelnext to Page 46 in the next to the last paragraph -There is a transposition in the wor'd 'compa ri son' .. Mr. R. Cross Sept" 16, 1980 Page Two 1. On page 22 the first paragraph contains the sentence "Obviously, a shift to electric heat makes sense only if the electricity comes from renewable resources. II While this is true within the context of this nalysis'we think the statement too general. Under some scenarios coal, wood or even petroleum produced electricity might make electric heat practical. 2. We think the derivation of the 30% load factor for electrical heat merits further explanation. In our opinion it seems low. This would 3. imply a load whose demand would normally be covered with peaking generation; a function not normally supplied by hydroelectric generation. l~e fel t that the estimated peak demand curves on page 33 mi ght be 1 abel ed a little more clearly. On page 41 the fuel efficiency assumption of 9 ki110watt hours per gallon of fuel turbines is applic~ble only to a simple cycle gas combustion turbine. The overall efficiency of combined cycle or regenative cycle combustion turbines rivals that of a diesel engine. While these options are generally only practical on a larger sizes it is not beyond the realm of possibility that even firm energy could be produced by a combustion turbine. Although we don't disagree with your assumptions, clarification might be helpful. 4. On page 42 we think it might be helpful of the lifetime of the diesel engine was established. According to our interest tables 17.5% at 10% compound interest corresponds to a lifetime of approximately 9 years. This seems short for the large, slow-speed, properly maintained unit that would probably be used for this type operation. 5. On page 46 the first paragraph asserts that state regulatory action could pr~hibit electric heating applications. We question whether this is fact under existing statutes including PURPA. We further question if it were fact if it could be practically enforced. We f"rther question in view of Juneau's limited industrial development how significant interruptable loads really are. Oa page 59 at the bottom of the page under IIResults ll the final units are not identified. We presume you meant mills but it would be helpful to add that. We hope these cOl11T1ents will be helpful and feel that none will alter the conclusions reached in the study. As stated previously we agree with those conclusions. If we can be of further help or if you would like more clarification please let us know. cc: John Farnan S"incere1y, Clarissa Quinlan Di rector Response to Division of Energy and Pm-1er Development 1. We agree in part. A \-1ood or coal-based generating system could make electric heating practical from both an energy conservation and economic vie\-1point. Hm-1ever, APA remains opposed to any electric heating using petroleum produced electricity. 2. The 30 percent figure is an estimated annual load factor for the electric heat portion of the load. On a daily or weekly basis, heating loads create a very high load factor during colder periods of the year, in effect, increasing the base load in the winter months. Actually, hydro generation is very \-1ell suited to serving this kind of load if reservoir storage is adequate to produce the energy in the winter months when needed. 3. We agree on the fuel consumption figure. For this study simple cycle combustion turbines were utilized to satisfy reserve require- ments only with the internal combustion diesel being used for firm energy production. We agree that combined cycle combustion turbines could have been used, but.we did not do so for this study. 4. We used an estimated life of 35 years for the diesel engines. Our fixed costs of 17.5 percent include interest costs of 10 per- cent with the additional 7.5 percent composed of costs for insur- ance, replacements, taxes. and depreciation. 5. We deleted the statement that regulatory action could be used to prohibit ne\v electric heating applications. The largest im- mediate area for interruptible sales is for larger government and commercial buildings. Both Juneau area utilities have tariff filings for interruptible rates before the Alaska Public Utilities Commission for this purpose. The Juneau Federal Building will soon be using this rate, and there appears to be significant potential for increased utilization of this type rate. . / Phone: (907) 277: )l (907) 276-_" Mr. Robert Cross Alaska Power Administration Post Office Box SO Juneau, Alaska 99802 Dear Bob: " ... ::;. :.'. _ Ii. : " " ~'. _.' . . , ,;' -:r, ; ~ '" >; "', S~ptember 11, 1980 We have reviewed your draft Juneau Area Power Market Analysis and can offer just comments. . . .. . . . . 1.' On p,age 40 in the section titled lIinterconnection", you state that "expansion of Snettisham is the most economical regional source of new power" •. While this may be true, we note on page '37 that there is very little firm energy from Snettisham additions available after 1991 for transmission to any major load centers outside of Juneau. Perhaps that clarification should be added on page 40 •. . 2~' In, our attempts toi denti fy reaso~ab 1 ecost'powera lternati ves for the ';community of Hoonah,. we find there is a, great deal of local interest in an· interconnection to. Snettisham'.· This alternative begins to look very .. attractive in lightof-th~ anticipated loads;both at ~oonah and Hawk . Inlet, much of 'which would result from planned. timber and mining activity •. A letter from SealaskaCorporation on thesubjec.t ;'S attached . . ' , Mr. Bob-Martin of THREA, Mr. Bob. Loescher of Sealaska Corporation, and officials from Noranda' Mining Company can all provide ins.ights into likely future power requirements. .. " ...... . .. ~-. ': " , In sum~ary~ it seems to u~that a Hawk Irilet/Hoonah interco~nection, because of distances involved and load requirements, may make at ,. least as much sense in the near term as an interconnection to Petersburg! Wrangell and Ketchikan~You may want to address the possibility in your report and consider this load centerasapossible,marketforSnettisham • . .."i ..•.• : power~, ,<" ., .;.; ·>.-~'~~~~k~~~ . . ·.3~'Wesuggest that'you may want: to . give:'lhe co~tof powera~ai'ysis'results '. (your Appendix B) a more prominent position in the report, perhaps ' .. '. f~cluding the findings ~n>the summary section· of the report. ' •. . "., 4: .. ·-·'v~~ present the possibility. of a caPit~l.·inove:· ~cenari 0, but dO: not " analyze the impact on power costs that'.would result. Although an" '. unlikely scenario, perhaps. it would seem appropriate to follow-through with a discussion of what the possibl~ risks are in proceeding wit~- Snetti sham additions. ;!'!;:~t;~;~~J,~~~~~~~{~!~~'~t~ Mr. Robert Cross September 11, 1980 Page Two On the basis of the information presented in your report, \,ie concur in your recommendation to construct the Crater Lake unit. We recommend your consid- eration of an interconnection to Hawk Inlet and Hoonah in light of much larger loads than anticipated when you addressed the concepts' viability at the request of Hoonah's mayor last year. Attachment: as noted Sincerely, 'L. y ""\ v-V- Eric P. Yould Executive Director September 2, 1980 Eric Yould Alaska Power Authority 333 W. 4th Avenue, Suite 31 Anchorage, Alaska 9~SOl Re: Hoonah Energy Study Dear Mr. Yould: RECEIYEQ Thank you very much for your letter of August 7, 1980 and also for the meeting that was held here at Sealaska Corporation to review a draft report of the Hoonah Wood Generation Feasibility Study. After a thorough discussion and review by our staff and with other corporations affected by this report, we have drawn the conclusion that document is incomplete and does not represent the probable impact that Native corporations will have due to their activity in the timber industry in the Hoonah area. With regard to the future of the wood generation feasibility study, I would like to draw your attention to previous correspondence that I have previously submitted to you with regard to the initiation of this study. ." Of primary concern to Sealaska Corporation, in consultation with " Hoonah Totem Corporation and the Tlingit-Haida Regional Electrica~ Authority, is the focus by the Alaska Power Authority and governmeni agencies on the types of alternate energy sources possible for the Hoonah area. We continue to be of the opinion that a small hydroelectric facility on Gartina Creek would provide a good source of energy production which could be relied upon to replace, existing diesel fuel requirements at the existing generation plants. Additionally, recent discussions with Noranda Mining Company, who has holdings on northern Admiralty Island which is located between Outer Point, North Douglas Island, and Hoonah, Alaska, may provide the best long term solution to energy supply for the community of Hoonah. The Noranda Mining Company attended our meeting the other day and indicated a constant requirement for 5.5 megawatts of energy to operate its mill site and camp ~ facilities at Hawk Inlet, Alaska on line on or about 1983 or 1984. Eric Yould September 2, 1980 Page 2 Coupled with a potential need of 2 to 3 megawatts of industrial power requirements at Hoonah by the Native corporations, a possibility exists that the economics for an underwater transmissio line utilizing excess Snettisham hydroelectric dam power might become feasible. It is our opinion that if any work is to be done to analyze energy supply alternatives for the Hoonah area, that both hydroelectric potential at Gartina Creek and the underwater transmission feasibility study should be priority among those agencies, potentia industrial, and residential users and the municipality concerned with energy for Hoonah. We urge your consideration of these views and are available for further discussion. Thanking you for this consideration. cc: Frank Roppel, STC Robert Martin, Jr. THREA Sincerely, t SEALASKA) CORPORATION !j. \) L. l· / Robert W( 'loescher, Natural Resources City of Hoonah Mayor Miles Murphy John Hinchman, Huna Totem Corporation Frank See Director Response to Alaska Power Authority Comments 1. We agree with this comment and wording in the final report is consistent with that vietV'. 2. He agree that development of a netV' m~n~ng load at HatV'k Inlet could improve the feasibility for delivery of Snettisham power to Hoonah and we are making arrangements to evaluate this option. Our report does not recognize the possibility of this mining load. If.service to Hoonah and Hawk Inlet proves feasible, the total demands on Snettisham pmV'er in 1990 would be approximately 8 percent larger than indicated in our reports. 3. We agree that the system·costs could have been more prominently displayed. These costs are fully detailed in Chapter VII, "Load Resource and System Cost Analyses." 4. An additional analyses was completed which examined wholesale energy costs for the Snettisham Project in the event of a capital move in conjunction \V'ith the construction of the Crater Lake addition. This analyses indicates that a wholesale energy cost of about 53 mills would be required to repay all project costs. This is six mills higher than the projected rate in 1986 with no netV' project additions. We have not estimated total impacts on power system costs. Increases would be relatively small since system reserve requirements would be made smaller and the surplus hydro energy would minimize requirements for diesel generation. Overall, this would be a relatively small risk when compared to the con- sequences of energy shortage and high cost diesel generation in the event the project is delayed and no capital move occurs. EXHIBIT 9 JUNEAU AREA POWER r'lARKET ANALYSIS UPDATE OF LOAD FORECAST AUGUST 1981 ALAS KA POWER Am~ I N I STRAT ION JUNEAU AREA feWER MARKEl' ANALYSIS UPDATE OF LOAD FOREX:AST AUGUST 1981 INTRODucrION In September 1980 Alaska Power Administration (APA) completed a J\IDeau· Area Paver Market Analysis which supported a recarmendation to the Corps of Engineers to proceed with actions to construct the Crater Lake unit of Snettisham. Power fran the Crater Lake addition was detennined to be needed in the 1986-1987 tine frane. The purpose of this update of the load forecast portion of the 1980 FOWer market report is to detennine if the previous estimates of power needs are still reasonable and conditions still support seeking fundS' for Crater Lake. BASIC DATA Electric use and other data is collected annually to detect changes in historic trends that rcay affect future energy use. Data examples include: electric use data fran the utilities, State and local governmant building plans, building permits and hare construction trends, contractors workload, Borough capitalIIOVe impact studies, and in"tel:views with State officials. These trends are then carpared" to past trends and used in part in estimating future uses. Energy, Net Generation, M'm Fiscal Year Peak Demand, M'l 1979 1980 133,457 143,128 23.1 26.2 Detailed historic data is shown on Table 1. Nl.lIIber of Residential CUstarers 1979-1980 % Change 7.2 13.4 Calendar Year Average 7 ,197 7,490 +4.1% * Use Per Residential CUstarrer, kWh. 7 ,110 7,770 +9.3% *Primari1y due to increased electric heat and hot water use. o Ristoric data shows 1970-1979 Energy Sales increases of: Peak Demand Number of Residential CUstarers Use Per Residential Custarer 1 +8.6% +7.1% +6.0% +2% 1981 (9 rronths) 121,000 32.2 o There is a strong trend toward increased electric hot water heating and all electric hOItes due to the increase in oil prices. * Number of AEL&P CUSTI:MERS Class of Residential -CUSi:OIrEr Dec. 31, 1979 4,849 1,540 Dec. 31, 1980 4,829 1,753 June 30, 1981 4,680 General General with hot water All electric 56 358 1,834 559 * Total 6,445 6,940 7,073 AEL&P serves 90% of the area custarrers. o In early 1:979 there were roughly 2 residential heat purrp systems. By December 1980 there were 45 to SO, and by mid 1981 there were 120 • Several net{ ccrmercial establishrrents also use heat pumps, and a f€!N older businesses are insta J 1 ing them. o The Federal Building was converted to electric heat in 1980, but not used. New State and local governm:nt building plans are currently for using electric heat. Partial conversion to electric heat by all levels of governm:nt i13 likely. o The number of State fQsitions increased 205 (5.5%) in.l980 which is near the past six year average. The outlook for 1981 is similar. o Federal Govenment fQsitions remained stable and the outlook is the sane. o Local gOVeJ:J'lIIeI1t increased rrore than average in 1980, and the outlook is for nearer the nonn. o The payroll and economic indicators are increasing scrrewhat faster than the previous years. OUtlook is for a continuation past the mid 1980's. o The :t:Otential Juneau to Hoonah intertie could increase the 1986 energy use by 15%. o The start up of the Noranda mine in 1985 or 1986 could add roughly 300 errp10yees at Hawk Inlet, 200 of which w"'Ould live in Jtmeau. o Heating oil costs increased 20% annually between 1978 and mid 1981. 2 o Energy sales for AEL&P (90% of area load) were near the past average trend for 1980, and for the first six rronths of CY 1981 the overall trend is higher with a 10.6 percent increase over last year. Historic sales data is" shown on attached Table 2. Residential Cormercial Government Total CY 1979 45.8 35.5 30.5 111.1 Million KWH -Sales CY 1980 51.8 37.4 29.8 119.7 % of 1979 113 105 102 107.7 6 rronths 1981 30.9 18.6 16.1 65:"5 % of 1st 6 rro. 1980 124 102 100 110.6 o Energy sales for GHEA (10% of area load) during the first six rronths of CY 1981 are up 22 percent for residential, 9 percent for all other uses, and an overall increase of 18%. EVALUATION OF BASIC DATA The Juneau area has shown very strong econanic conditions in 1980 and 1981, with a similar outlook through at least the mid 1980 1 5. The prime factors appear to be State expenditures and State arid local governrrent increases in personnel and budgets. Residential construction" has increased and is IPaintaining a" steady pace primarily due to the availability of State financing. Ca:mercial building has lagged, but shopping centers and office buildings are under construction now. The University of Alaska has an aggressive construction plan with buildings becan:ing operational in 1981, 1982, and one per year planned over the next decade. The proposed Noranda mine and Sealaska Corporation plans will add to the local economy. rvnst new-construction plans include electric heat with several using the rrore efficient heat purrps. Except for the capital nove situation, the ronstruction plan and economic situation of the State support an outlook for the next several years of rontinued strength and growth as strong as has been experienced since 1975. ESTIMATE OF EUl'URE DEMANDS Assumptions Two cases were re-analyzed; the medium load growth case and a capital IIDVe case. Both cases reflect significant uses of electric heat. The high growth case was not re-analyzed after it was detennined that there were no significant changes fran previous studies. 3 M::diurn Load G.rcwt.h case o Population will grow at two percent annually. People per residential cust.cner will rerrain at 2.6 until 1985 then decline to 2.5. Kilowatt hours per residential custc:::mer will increase 2% per year until 1985, decline 2% per year until 1995, then remain stable. - o The ratio of sales l::etween residential, ccrmercial, and gove.nlIIEIlt will continue the past 10 year trend of 44%, 30%, and 26% re~vely. o The existing residential custarers will convert to electric heat for a total of 15% by 1985, 33% by 1~90, 50% by 1995, and 66% by the year 2000. . o Ninety percent of new residences will be all electric instead of 66 percent as asS1..1IIEd in last year I s study. This is a significant increase. Other assumptions on use of heat pumps and continued conservation are the sarre. o t-lost planned govemrcent buildings ~NOuld l::e electrically heated. Half of the City and Borough schooLS would convert to electric heat over the next decade. Part of the ma.jor. State office buildings would ·routinely convert to electric heat in the late 1980 I s. This conversion was previously estinlated to occur in -the early 1980 I S as part of the State-wide conservation plan. However, the State has postponed these plans. For the purt:Oses of this study, it is now as~ that conversions will occur in the late 1980 I S as part of routine building upgrading. o The Federal Building, which converted to an interruptible electric heat system in 1980, will start using electric heat in the fall of 1981. o Distribution system losses will rem:U.n at about 10%. Capital MJve case o The population would continue increasing 2% annually through 1982, and after the vote increase only 1% per year through 1985, remain stable through 1987, and then decrease 30% by 1990. From the low level in 1990 it would increase 2% annually through w.e year 2000. o Assurrptions on electric heat are at the sarre pace, except half gove.nlIIEIlt use was asSl.lIIEd after tbe rrove. 4 RESULTS Data for the first half of 1981 indicates continuation of strong past trends. (Utility sales are up 12% overall, and Snettisharn sales are up 19%.) Utility data shews electric heat is increasing rapidly and has compensated for the lag in COItll'ercial use and strong conservation in governrrent use. The updated estimate based on 1980 data is shewn in the attached Table 3 and graph. Lower census figures for 1980 resulted in a 10 p:rcent reduction in the estirtE.ted nurrber of custarers for the year 2000, and required revision of the estirnate rrade last. year. Hewever, the revised census figures affected only a 2 percent change in 1985 which is the critical near tenn period of this study. The est.irnated peak use for the 1980-1981 winter was lower than the forecasted value due pr.irnarily to the unusually wann winter and the Federal Building using oil heat instead of electric heat rrDst of the winter. The results of the updated est.irnate of energy use, and the first nine rronths data for Fiscal Year 1981, indicate less than 2 p:rcent change fran the previous load estimates. We, therefore, conclude that recamendations for the need for Crater Lake in the 1986-1987 tine frarre are still valid. APA will continue to make· annual assessments of energy uses and changed conditions in the Juneau area to verify the decision to proceed with Snettisham additions. Detailed supp:>rting data and analysis are available in APA' s office. 5 .. Table 1. Juneau Area Energy and Peak Derrand System Mvll % Peak HI'l % Generation Annual Dem3nd Annual Fiscal Year wm: * Increase m Increase 1970 58,266 12.4 1971 63,786 13.8 1972 70,255 10.2 14.9 1973 75,753 15.5 1974 83,059 16.2 7.1 1975 94,609 17.8 1976 106,296 19.8 0" 1977 112,197 7.7 20.4 1978 U2,218 23.4 ~ 1979 133,457 (R) 23.1 (R) 13 .4 1980 °143,128 26.2 U.8** 22.1 1981 (161,000) ** 32.2 (Dec. 80) ... * Includes AEL&P and GHEA sales and losses. ** Estimate based on nine rronths data. (R) Revised fran previously published data. 6 rabl •. 2 Jun.au An. Enerl' 5al .. and PorCODt of 5Alo. b, Socto~ (1000. KllII) Juneau Area Load Study Table 3. Juneau Area Power Requiranents Summary l/ Fiscal Year Medium case capi tal Move Case 1979 mIl 1980 Study 1981 Study 1980 Study 1981 Study M-J 133.5 133.5 23.1 23.1 1980 GVH 157 143.1 143.1 . -~--' M-J 33 26.2 26.2 1981 GlH 1/ 161 1/ M-J 32.2 32.2 1985 Glli 251 244 242 229 ttW 64 62 60 57 1990 GlII 351 347 195 192 00 MW 99 98 51 48 7'~_,.~_r 1995 mIl -150·--442 246 218 M-J 131 132.0 67 56 2000 GlII 538 529 297 244 MW 161 161 84 65 \./ 1/ Based on data up through June 1981. z a H 600 500 400 ~~ 300 :J~ 200 JUNEAU AREA LOAD STUDY ESTIMATED ENERGY REQUIREMENTS 1981 Update .--. . /' .--- ./' 100 -.,/ .-" _f~ ~. --0 I o 1970 1975 1980 • • )( e Case t eal Mo"" Cap 1985 1990 1995 200 EXHIBIT 10 JUNEAU AREA POWER r~ARKET .l\NALYS I S UPDATE OF LOAD FORECAST JULY 1982 ALASKA POWER ADrHN ISTRATION JUNEAU AREA POWER fl\ARKET ANALYSIS UPDATE OF LOAD FORECAST July 1982 Alaska Power Administration U.S. Department of Energy CONTENTS INTRODUCTION 1 BASIC DATA .•............•••...... ~....................... 1 EVALUATION OF BAS IC DATA ..............•..........•....... 8 Residential Sector .................................. 8 Commercial and Government Sector .••..•...••......... 9 Residential Energy Use per Customer •••..•••.•••..... 9 Weather Influence on Energy and Capacity .••.•....... 10 ESTIMATES OF FUTURE DEMANDS ...........•.....•.•.•••.....• 13 ~lethods ••••••••••••.••••••••••••.••••••••••••••••••• 13 Assumptions ••..••••.....••.••.••.•••.••••••••.•...•. 13 Basic Load Growth Case ......•••••••••• ~ ••....•. 14 Capital Move Case .............................. 15 RESULTS AND CONCLUSIONS .............•.•••...•.•.......... 17 TABLES 1 Juneau Area Energy and Peak Demand .••••.•..•...... 2 2 Juneau cArea Energy Sales and Percent of Sales by Sector ....................................... 3 3 Juneau Airport Heating Degree Days •••••••••••••••• 5 4 Basic Case Estimate of Future Demands •••••••..•••. 16 5 Juneau Area Power Requirements Net Generation •.... 18 6 Comparison of Juneau Area Hydro Resources and Estimated Loads ••••....•••••••.••.••••••••••.•.• 20 FIGURES 1 October-April Net Generation Adjusted for Weather. 12 2 Estimated Energy Requirements •••••••••••••.••••••• 19 JUNEAU AREA POHER r·1ARKET ANALYSIS UPDATE OF LOAD FORECAST r~AY 1982 INTRODUCTION Alaska Power Administration (APA) estimated Juneau area power requirements through the year 2000 for this study, which updates similar studies dated September 1980 and August 1981. The area has experienced a significant increase in peak demand and energy IJse since 1980. These increases, especially those for the winters of 1981 and 1982, were examined in detail. Both the 1980 and 1981 studies indicated area power use would exceed critical year firm energy from existing hydroelectric plant during FY 1983. This new study indicates this \'1i11 indeed happen. BASIC DATA In order to better define conditions that contributed to the large increase in energy use this past year, data was gathered on energy use, economic, and climatic conditions. Energy and capacity use data came from monthly and annual reports prepared by APA and the two local utilities, climatic data from the National' Oceanic and Atmospheric Administration (NOAA), and economic data from State and local sources. o Table 1 presents annual system net generation and peak demand for fiscal years 1970 through April 1982 along with annual percent increases. Table 1 indicates: --1981 net generation was 16.5 percent above 1980 --1982 October though April net generation was 26.7 percent above similar period for 1981 --1981 peak demand of 32.2 MW was 22.9 percent over 1980 --1982 peak demand (Jan 82) of 42 MW was 30.4 percent above 1981 o Table 2 presents sales by residential, commercial, and government sector for the 1970-1981 period. Tabulated below is sales by sector and percent changes for 1980,1981, and 1982. Residential customer use increased the most dramatically. Part of the commercial buildings were out of service for remodeling in 1981. Sales GWh. Change Sales GWH Change % of Oct-Apr Oct-Apr Oct-Apr CY 1980 CY 1981 % of 1980 FY 1981* FY 1982 1981* Residential 52.2 72.3 139 42.2 60.2 143 Commercial 37.9 40.4 107 22.8 27.5 121 Government 33.3 35.5 107 21.3 22.4 105 129.4 148.2 114.5 86.3 110.1 128 * AEL&P sales increased proportionately to account for GHEA sales. 1 2 TABLE l. Juneau Area Energy and Peak Demand System Net MWH % Peak M\~ % . Generati an Annual Demand Annual Fiscal Year r~WH* Increase MW Increase 1970 58,266 12.4 1971 63,786 13.8 1972 70,255 14.9 1973 75,753 15.5 10.1 7.4 1974 83,059 16.2 1975 94,609 17.8 1976 106,296 19.8 1977 112,197 20.4 8.9 14.7 1978 122,218 23.4 9.2 -1.3 1979 133,457 (R) 23.1 (R) 7.2 1980 ::".·143,128 26.2 16.5 22.9 1981 166,700 32.2 30.4 1982 (Oct-May)(144,200) 42.0 (actual) 23.0 1982** 205,000** 42.0 * Includes AEL&P and GHEA sales and losses. ** Estimate based on 7 months data. (R) Revised fram previously published data. APA 6/82 ....., -CO N .!!LQ. .!ll!. Res ident lnl Sale. AF.L&P 23,034.1 24,562.7 GIIE ... 2.315.3 2.579.9 TotAL 25.349.4 27,142.6 Percent 44 45 Commercial SIlle8 At:L&P 15.712.9 17,322.1 GIIE ... 1.251.4 1,388.3 Tot,,1 16.964.3 18,710.1 Percent 30 31 Government Solie. AEL&P 13,541.9_ 13,927.1 GHEA 395.3 417.1 Outdoor Light. 782.5 741.0 Total 14,719.7 15,085.2 Percent 26 25 Total .57,033.4 60,937.0 * Lighting Included • Table Z. .!21! 2S,009.2 3.026.8 31.036.0 46 18,511.3 1. 388. 6 19,89Y.9 29 15,327.1 483.6 733.5 16,544.2 25 67,480.1 Juneau Are. Eneray Saleo and Percent of Sale. by Sector Calendar Year !ill. 1974 .!ill. !ill 30,298.1 31,875.2 33,865.8 36,174.8 3,185. r 3,545.2 3,794.1 4.126.5 33,483.2 35,420.4 37,659.9 40,301.3 45 46 43 42 22,039.4 21,366.8 25,614.1 27,018.2 1,339.4 1,185.7 1,622.3 1,828.5 23,378.8 22,552.5 27,236.4 28,846.7 31 29 31 30 16,398.7 17,545.5 22,008.8 25,253.4 565.9 621.4 815.9 789.4 694.8 704.9 994.9 17,679.9 18,861. 7 ·23,529.6 27,037.7* 24 25 26 28 74,541.9 76,834.6 88,425.9 96,185.7 (1000 IMI) ill! .ill! .!21.! .!lli .!ill 38,701.6 42,143.4 45,814.9 51,939.3 64,387.0 4.291.7 4.936.3 5,353.1 6,375.6 2 ~O' 0 47,079.7 , 42,993.3 51,168.0 58,214.9 72,289.0 42 43 43 45 48.8 Average Percent 1970-1981 18 44% 29,552.5 31,406.1 34,654.4 36,548.5 38,H8.0 1.951. 4 2,060.3 2,482.8 1,319.0 I S13 3 31,503.9 33,466.4 37,137.2 37,867.5 40,371.3 31 31 31 27.2 Average Percent 1970-1981 18 30% 27,232.0 26,825.5 30,670.7 31,328.6 32,531.0 872.8 931.6 631.6 1,988.5 1,364.5 0.7 I 010.1 28,104.8* 27,757.1* 31,302.3* 33,317.8 35,566.2'" 27 26 26 26 24.0 Averege Percent 1970-1981 18 26% 102,602.0 108,303.2 119,607.5 129,400.2 148,226.5 o Residential sales continued increasing into 1982 with most of the growth in the all-electric customer class as' shown by AEL&P data. AEL&P October though April Sales GWH Class of Residential Customer Genera 1 General w/Hot water All electric Total AEL&P Residential 1980 18.6 11.0 1.3 30.9 1981 . 18.1 12.9 6.5 37.5 1982 18.5 15.7 19.1 '5"3:3 o The strong trend toward all e 1 ectri c homes is further illustrated by the shift in number of AEL&P customers from the general class to the hot water and all electric classes. Class of Residential Customer Genera 1 . General w/ hot water All electric Number of AEL&P CUSTOMERS* 12/31/79 4,849 1,540 Total AEL&P Residential 56 6,445 12/31/80 4,829 1,753 348 6,940 12/31/81 4,237 1,886 872 7,085 04/30/82 4,434 1,944 1,021 7,399 * AEL&P serves 90% of the area customers, and is considered representative of GHEA customers. GHEA does not report data in exactly this form. The above data also indicates a strong steady increase in the number of total customers. o This was the energy use per residential customer including both AEL&P and GHEA for previous calendar years: Energy Use and Residential Customers CY 1979 CY 1980 CY 1981 Number of Residential Customers Use per Residential Customer, KWH 7,197 7,110 7,490 7,770* 7,801 9,270* * Increase due primarily to new electric heat and hot water use. o Heat pump installations are continuing for both residences and commercial applications .. Heat Pump Installations 1979 - 2 1980 -45 to 50 1981 -150 o Table 3 presents heating degree days for July 1958 though April 1982. 4 5 TABLE 3. JUNEAU AIRPORT HEATING DEGREE DAYS " ( I, Season July Aug Sept Oct Nov Dec Jan Feb Mar Apr May June Total 1958-59 230 316 521 736 928 1076 1449 1022 959 781 582 285 8885 1959-60 328 378 498 757 911 926 1146 911 1019 713 470 409 8466 1960-61 321 355 466 660 915 956 1062 932 938 746 538 371 8260 1961-62 262 339 511 760 1027 1246 1182 1097 1095 756 627 447 9349 1962-63 250 305 486 645 810 1132 1147 885 1023 B46 500 431 8460 1963-64 288 244 375 625 1093 993 1098 835 1118 785 610 336 8400 1964-65 324 347 453 614 980 1496 1291 1154 923 813 693 487 9575 1965-66 292 297 435 654 1045 1182 1746 1090 1071 805 667 355 9639 1966-67 ,265 382 466 812 ' 1191 1188 1291 963 1261 824 592 300 9535 1967-68 340 303 444 671 973 1162 1432 1043 984 808 508 374 9042 1968-69 248 . 281 516 802 920 1405 1801 1219 1054 727 464 218 9655 1969-70 343 448 521 724 975 921 1329 830 876 770 601 422 8760 1970-71 387 405 553 783 1110 1343 1607 1029 1112 784 658 346 10117 1971-72 227 290 504 811 1001 1360 1519 1315 1186 906 618 432 10169 1972-73 207 293 535 810 907 1275 1423 1126 986 752 585 404 9302 1973-74 343 404 505 732 1253 1143 1550 1006 1242 765 556 437 9936 1974-75 349 315 437 690 851 957 1296 1129 1063 791 541 402 8821 1975-76 281 337 402 712 1088 1244 1132 1131 1006 706 597 384 9020 1976-77 280 275 427 679 717 938 918 690 893 673 531 320 7341 1977-78 243 196 428 695 1062 1423 1233 922 954 683 525 317 8681 1978-79 298 262 427 612 1037 1134 1370 1505 904 712 528 378 9167 1979-80 251 205 415 609 ,830 1187 1404 895 949 678 477 278 8178 1980-81 283 308 472 628 783 1333 843 899 786 772 392 316 7815 Avg 23 yrs = 8981 1981-82 257 275 ' 469 682 841 1175 1584 1213 1017 816 Source: Climatalogical. Data, National Oceanic and Atmospheric Administration APA 7/82 The policy of conservation and conversion to electric heat by the State and Borough has changed significantly, and these subjects are receiving less emphasis or have been completely eliminated from the planning process in some cases. Last year the University of Alaska had plans for constructing a large new building each year for the next 10 years, but now plans are for about half or less of tRat activity due to budget constraints. Although, University buildings under construction and planned for the next year or two will have electric heat. The data indicates a lessening of large building electric heat new demands starting about the mid 1980's. State government comprising two-thirds of the area economy added over 200 jobs to the area in 1981 for an increase 0.6 percent above the 5.7 percent average growth over the past seven years. This growth has maintained'demand for new homes and more State office space. Commercial loads which lagged in 1980 and early 1981 started increasing the latter half of 1981 and now a six to seven million KWh load is foreseen for FY 1983. This amounts to a 16 percent increase in commercial sales for FY 1983 and is based on data concerning buildings under construction or scheduled for completion by mid 1982. Economic and construction information was obtained from contractors, utilities, and interviews with Borough and State officials. ,a a a Residential Sector Plans: Essentially all new housing was all electric in 1981 with similar plans for 1982, according to the contractors with firm starts in 1982. Roughly 800 housing units were identified for electric he~t durin[ 1982 and 1983 calendar years. They include new construction, conversion to electric heat, or sale of condominiums with electric heat. Commercial Sector Plans: Commercial developments under construction and planned for FY 1983 will use electric heat for 80 to 90 percent of the total floor space. Buildings include private offices rentals for the State offices, condominium offices, and shopping center additions. Over 6 million KWh of new requirement ~'Jere identified for FY 1983--rough1y three times the increase of CY 1981. Government Sector Plans: City and Borough near term construction in FY 1982-83 will use electric heat except for the High School. Several Borough buildings are planned for conversion from oil heat to heat pumps, but plans were not specific enough for inclusion in this study. Two new buildings developed commercially and rented to the State will be in operation in FY 1982 and two more for FY 83. The Federal Building was to start using electric heat June 1982. a The University of Alaska buildings unde~ construction and planned for the near future, are scheduled to be all electric heat. a Over the long term, City and Borough and State no longer are considering converting most of their existing facilities to electric heat. This is a sharp contrast to 1980 plans and proposed bonding for conversion and increased conservation through remodeling. 6 ... ...' o State goyernment increased above the seven year average rate during 1981. Funding appears adequate for FY 1983 at last years level with similar growth in numbers of employees forecast for the next two years, according to State officials. o Federal government employment declined three percent in 1981 with a similar outlook for 1982. o Total government employment, including local government, was up 4.9 percent December 21, 1981, over a year earlier. o With a favorable vote on the capital move t outlook is good for private hotels, and shopping centers, and Native Corporation land development, according to several sources with firm plans. o The potential Juneau to Hoonah intertie could increase 1986 energy use by 13 percent. o Noranda Mining Corporation indicates operation will begin in 1985 with the first full year of production in 1986. Present plans call for 300 employees with approximately 150 imported to Juneau with the other 150 hired and trained locally--almost all would live in Juneau and commute to the mine. 7 EVALUATION OF BASIC DATA This section evaluates the basic historic data with a view toward explaining recent high growth and looks for trends that could affect future growth. All data shO\'/s very large growth in terms of percentage increase and amount of use in FY 1982. Changes are substantially greater than previous years, and two factors were identified. First, and most notable, was residential electric heat increase. Second was steady economic growth in both State government and commercial areas. Residential Sector A brief examination of October though April AEL&P residential energy sales and number of customers for the past three seasons data presented in the previous section illustrates part of these trends. Residential Sales increase by Class of customer Oct-Apr Oct-Apr Class of Customer 1981/1980 1982/1981 1981 as 1982 as GWH % of 1980 GWH % of 1981 General -0.5 -97.3 --0:4 102.2 General w/hot water 1.2 117.3 2.8 121.7 All· e 1 ectri c 5.2 400.0 12.6 293.4 Total 0:6 121.4 15.8 142.9 Genera 1 Cl ass 7" --Sales remained fairly stable the past three years. --Number of customers declined nine percent between December 1979 and April 1982, primarily by converting to other classes of service. --Use per customer has increased. General with Hot Water Class --December 1979 through April 1982, 404 customers (26 percent increase) were added to AEL&P system. --Hot water customers use about twice as much energy as general customers. --Forty percent of AEL&P customers are in the hot water and all electric classes. All Electric Class --Almost all new homes built since 1979 are in the all electric or water class with an estimated 90 percent or more being all electric. --For FY 1981 and 1982, eighty percent of the increase in October to April AEL&P residential energy use occurred in the all electric c1ass--12.6 GWh of 15.8 GWh. --October-April winter energy use during the past three years increased from 1.3 GWh (four percent of the residential use) to 19.1 GWh (36 percent of the residential use). 8 ,", --Number of AEL&P all electric customers used more energy than the 4,334 general class customers October 1981 through April 1982--19.1 GWh compared to 18.5 GWh. --Roughly 150 or 15 percent of all electric customers use heat pumps. Commercial and Government Sectors --Commercial and Government sales increased slower than residential sales (Table 2) until January 1982. --January through April 1982 commercial sales were up 3.5 GHh--more than any annual increase in the past decade (Table 2). Only 10 percent of the increase was due to all electric customers. --Remodeling older commercial buildings during 1980-81 and more intense energy use in these completed buildings during January through April 1982 accounts for part of the increase. --Government customers in AEL&P area used 1.4 GWh more in January through April 1982 period than for a similar period in 1980 or 1981. This is 60 percent of the amount used in the full calendar year 1980. GHEA data, although only 10 percent of the size of AEL&P, also shows similar trends of large increases for fiscal year 1982 and the early months of calendar year 1982. Residential Energy Use per Customer Residential c~stomer use increased 2,160 KWh per customer between 1979 and 1981, fora total of 30 percent, due primarily to the trend of shifting away from oil and toward electric hot water and all electric heat. The following tabulation gives a more detailed breakdown of K~~h per customer by c1 ass of customer for 1980, 1981, and a K~vh use adjusted for weather. Class of Customer General General w/hot water All electric KWH per Customer CY 1980 CY 1981 5,980 11 ,520 23 2 900 6,080 12,120 23,780 May 1981 thru April 1982 6,500 12,900 27,500 The 1980 and 1981 data was calendar year data and include warmer than normal winters. The May 1981 to April 1982 twelve months of data was the most recent data reflecting the highest electric heat use. This was also a period containing the normal number of degree days and could be cons i dered an average year for weather. The May 1981 through April 1982 data was assumed reasonable for estimating future demands. Use per customer for each class \Alas calculated from AEL&P data and totaled for 12 months. By calculating the use per customer each month, influence of the varying number of customers was eliminated. Difference between 1980-81 and 1982 data was significant, and quite ~vident from examination of degree days shown on Table 3. 9 Fiscal 1978 1979 1980 1981 1982 Avg l~eather Infl uence on Energy and Capacity Juneau area power demands have always been sensitive to weather--highest peaks and energy use during the coldest times. We expect addition of space heating to increase this sensitivity since energy requirements for heating are almost directly proportional to outside temperatures. Heating Degree Days October-A~ri 1 October-April Net Generation Annual Increase Fiscal Year degree days % of avg GWH GWH % 1978 6,970 100 77.5 +9.1 +11 1979 7,279 105 86.6 +2.7 +3 1980 6,552 94 89.3 +12.7 +17.2 1981 6,044 87 102.0 +27.3 +26.8 1982 7,328 105 129.3 Average 6,955 On a monthly basis weather variations are much more pronounced. Heating degree days/months Net Generation, GWH 10 ... Year Dec Jan Feb Dec-Feb Total Dec Jan Feb Dec-Feb Total'" 1,423 1,233 922 3,578 12.217 12.238 10.398 1,134 1,370 1,505 4,009 12.178 15.244 14.643 1,187 1,404 895 3,486 13.332 14.279 12.469 1,333 843 899 3,075 17.072 15.681 14.228 1,175 1,584 1,213 3,972 19.745 23.952 18.758 1,167 1,334 1,040 3,624 On an annual basis, growth is high when a cold year follows a warm year, while growth is lower when a warm year follows a cold one. Similar relationships are apparent on a monthly and ~easonal basis. For example, February 1979 was an unusually cold month with net generation 36 percent higher than February 1978 which was much warmer. The next two Februari es--1980 and 1981--\'Iere also quite warm and had power demands below the 1979 amount. On a seasonal basis, FY 1980 and 1981 loads reflected warmer than average weather, particularly in the winter seasons. The winter of 1981-1982 was much colder than the prior year (20 percent colder measured by degree days). Power use for October 1981 to April 1982 was 26.7 percent above the prior year. This was by far the largest seasonal growth of record. 34.853 42.065 " 40.080 46.981 62.455 .' There are similar relationship in area peak demands. The January 1982 peak of 42 MW was 30 percent above the prior winter (December 198D peak of 32.2 r~W). Measured in degree days, January 1982 was 19 percent colder· than December 1980. This relationship would probably be more clear on the basis of daily records. Figure 1 presents an estimate of the impa~t of weather on seasonal loads. The data represents October to April periods for the fiscal years 1978 to 1982. A "weather adjustment" was added to actual load when the season was warmer than normal, or subtracted if the season was cooler. The results were estimated loads which would have occurred if average temperatures prevailed in each of the five years. These data suggest that the 1980 and 1981 loads would have been 3.2 percent and 6.6 percent higher, respectively, if "normal" weather had occurred -in those years. They also suggest that growth rates in the 16 to 18 percent range would have occurred in 1981 and 1982 if normal weather had occurred--up from growth rates of around nine percent for the previous two years. 11 FIGURE 1. October-April Net Generation Adjusted for Weather 130 1-0 120 1" ~ ~ 110 -~ t::l 100 -c o ..-I ~ 90 1-0 QJ C QJ t::l 80 ~ .u Z o Actua1 ~ With Temperature Adjustment 70 ~------------------~--------~--------~--1978 1979 1980 1981 . 1982 Fiscal Year Calculations Net generation adjusted based on degree days. Adjustment = i (Average degree-da~s minus Average actua 1 ) Oct-Apr Degree Da~s Net Generation-GWH Annual FY Act Avg Avg-Act Adj Act Adj Adj load GWH 1978 6,970 6,955 -15 -.001 77.5 77.5 +7.1 1979 7,279 -324 -.0233 86.6 -2.0 84.6 +7.5 1980 6,552 +443 +.0319 89.3 +2.8 92.1 +16.6 1981 6,044 +911 +.0656 102.0 +6.7 108.7 +17.1 1982 7,328 -373 -.0267 129.3 -3.5 125.8 Increase % +9.2 +8.8 +18.0 +15.8 These evaluation of data become the basis for verifying the forecast in the next section. 12 ESTIMATE OF FUTURE DEMANDS Estimates of future demands were made for a basic case and a capital move case. T ... ,o variations of the basic case were examined. First, the loads of the Juneau to Hoonah transmission intertie were added to show the effect of this increased load. Second, electric heat loads were restricted after FY 1983 to reduce the anticipated deficit from hydropower. Emphasis was placed on near future trends. All cases assume continued use of significant electric heat for residential consumers (except for the restricted electric heat analysis), conservation, and a decrease in longer term conversion of government buildings te electric heat. The same methods of calculation and assumptions on use per customer were used in all cases. The data for this 1982 Juneau area load forecast update has two significant items affecting the forecast. 1. A dramatic incr~ase in residential electric heat for a-normal FY 1982 winter which followed two warmer winters, and a general increase in the area economy. 2. A de-emphasis by the Borough and State on converting existing buildings to electric heat. Method Method of estimating future use was changed this year. Previous estimates for-residential use were based on number of customers and the average use per customer. Commercial and government loads were estimated as a percent of residential use, which historically was consistent. With the higher proportion of residential customers using electric heat in 1981 and 1982, the previous method needed refining. This year estimates were separated by class of residential service into general, general with hot water, and all electric. The total use was calculated by multiplying the average use per customer for each class by the number of estimated customers in each class. A check indicates the results were satisfactory. For commercial and government loads, electric heat was estimated separately. This may become a tool to refine the estimate of the overall system plant factor for determining near-term peak demand more accurately. Commercial and government increases could not be estimated as a percent of residential due to the increased disproportionately high residential electric heat use in 1981. Continuation of trends based on past percentages was used with additions of specific large projects and specific electric heat loads. Table 2 shows the percent change in the residential sector. Assumptions The FY 1982 estimated loads for the basic case were based on sales and net generation data for seven months extended to 12 months, assuming that October-April constitutes 61.6 percent of 12 months use based on the three-year average distribution of energy use for 1979-81. 13 For 1983 and after 7 estimates were based on these assumption outlined in the following paragraphs. Basic Load Growth Case Population and Customers Growth: 1982-1986 1986-2000 Population per residential Annua 1 Growth continue at 4% 2% customer' 2.6 System Load Factor This is lower than electric heat. 55% previous years due to increase in Residential Sector General Class: Number of customers decrease at two percent per year through 1995, then remain constant. Use per clJstomer increases at two percent per year through 1986 7 then decreases two percent per year to 1995, remaining constant after 1995. 'The compensating increase in use and decrease in customers would show no significant change in the 1982 level of use through 1986. General 'with Hot Water Class: Continued increased amounts to 10 percent of new homes and two-thirds of the general class customers converting. Use per customer to remain at 12,900 KWh annually based on AEL&Pdata adjusted for 1982 experience and the weather. All Electric Class: Ninety percent of all new customers and one-third of general customers converting would use the all electric class would be all electric. Use per customer would be 27,500 KWh based on AEL&P data adjusted for 1982 experience and \'leather. Commercial Sector FY 1983 loads would increase 16 percent over FY 1982 based on identified loads of 6.7 million KWh. For 1984 and beyond, 1 million KWh for lights and 2 million KWh for heat was estimated based on long term trends. This annual increase is similar to the increase estimated in previous years when commercial use was a consistent percent of residential use. Government Sector Past· estimated increases of 1.9 million KWh per year would continue' the same as when use was based on a percent of residential use. Specific additional electric heat use is noted where it is identifiable. Specific Borough, school, University and State electric heat conversion plans not actively being considered in 1982 were eliminated from estimates of future years loads. The Federal building is scheduled to being use of electric heat the latter part of FY 1982. 14 ,> t, ~' .. Calculations and results of the basic case future demand estimate are presented in Table 4. Basic Load Growth Case with Restricted Electric Heat o Electric heat would be restricted by eliminating any new hookups after September 30, 1983. This includes all-electric and electric hot-water hookups. o All new residential customers would be placed in the general class after September 30, 1983. o Other assumptions on number of new residential customers, commercial use, government use and continued conservation were the same as for the basic case. Basic Load Growth Case with Juneau-Hoonah Intertie o The Juneau-Hoonah intertie would be completed in 1986 adding 9.8 MW and about 36 million KWh additional load. Capital Move Case The projected move was estimated in this study to start in 1988 instead of 1985, as set out in the previous 1980 and 1981 Juneau area electric load estimates. Information is based on background study of socia-economic impacts on the Juneau area prepared by Rivkin Associates, Ma rch 1978. ;~' o Population would increase only one percent per year through 1985, remain stable through 1988, and then decrease 30 percent by 1990. From the low level in 1990 it would increase two percent annually through the year 2000. (These assumptions are similar to the 1980 and 1981 study based on the Rivkin capital move study). a Assumptions on electric heat use was at the same pace as the basic case, except half of the use by government was assumed after the move. 15 Table 4. Basic Case Estimate of future Demands Fiscal Year ~ 1982 -12!!L ~ ~ 1986 ~ 1988 1989 1990 ~ 2000 7 010 12 010 Popu 1 a t ion 20,085 21,125 22,170 23,060 24,000 24,930 25,430 25,950 26,470 26,990 29,800 32 ,890 People per Customer 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 Residential Customers 7,725(fY) +400(e) 8,125 8,525 8,870 9,230 9,590 9,780 9,980 10,180 10,380 11 ,460 12,650 (Average) Residential Sales 4,900(~) General Class, No. Customers 5,165 4,800 4,700 ;;4,600 4,500 4,410 4,320 4,230 4,140 3,750 3,750 KWH/Customer 6,074 6,920 ~ 34.0 ~ 34.0 jJ 34.0 jJ 34.0 ~ 6,890 6,750 6,620 6,480 5,870 5,870 KIm, .1 11li on 31.4 20.9 33.9 30.4 29.2 28.0 26.8 22.0 22.0 Hot Water Class, No. Customers 2,040 2,125 ~ 2,235 2,340 2,445 2,550 2,630 2,710 2,790 ~,870 3,020 3,140 KWH/Customer 12,000 13,600 / . 30.3 §j 31.7 Y 33.1 §j 34.5 §.J 12,900 12,900 12,900 12,900 12,900 12,900 KWH, Nfll i on 24.5 17 .8 28.9 -33.9 35.0 36.0 37.0 39.0 . 40.5 All Electric Class, No. Customers 520 1,100 1,490 1,830 2,185 2,540 2,740 2,750 3,160 3,370 4,690 5,760 KWH/Customer 23,800 27,800 Y 27,500 27.500 27,500 27,590 27,500 27,500 27,500 27,500 ' 27,500 27,500 KWH, Hillion 12.4 21.5 30.5 4 •• 0 50.3 60.0 69.9 75.4 75.6 86.9 92.7 129.0 158.4 Subtotal Residential, 93.3 y K~IH, MOli on 68.4 60.2 105.3 !Hi.O 127.1 138.4 139.7 139.8 150.9 156.5 190.0 220.9 Commercial Sales (historic 30%) Subtotal CommerCial, 44.6 y KWH, Million 39.7 27.5 51.6 56.6 62.0 65.0 68.0 71.0 74.0 77.0 92.0. 107.0 Government Sales (historic 26%) 36.4 Y Subtotal Government, GWH 34.9 22.4 44.6 47.0 48.9 58.9 60.8 62.7 64.6 72.9 82.4 102.0 Street Lighting, Residential & Goverment, GWH 1.1 1.2 1.2 1.2 1.2 1.3 1.3 1.3 1.4 1.5 Total Sales, GWH 142.5 110.4 174.31/ 202.6 220.8 239.2 263.5 269.7 274.8 290.8 307.7 365.8 431.4 Net Generation, GWH 205.0 11 (115% of Sales) 166.7 128.8 233.0 254.0 275.0 303.0 310.0 316.0 334.0 354.0 420.0 496.0 System Capacity Factor % 59.0 55.7 55.0 55.0 55.0 55.0 55.0 55.0 55.0 55.0 55.0 55.0 Peak Demand, ~n~ 32.2 42.0 42.0 48.0 53.0 57.0 63.0 64.0 66.0 69.0 73.0 87.0 103.0 I:. 11 Based on October to April sales being 61.6 % of annual. Electric Heat reduced 4.4 GWH for other 5 month summer sales. y Based on 7 month AEl&P sales plus 80% of spring use for 5 months(2.05 GWH) plus times 10 percent for GHEA. G~IH=21.5+(5x2.05) 80Xx1.1=30.5. 11 Based on 7 month generation being 61.6% of annual generation less 4.4 GWH for decreased summer electric heat use. 1/ General class customers total use assumed to remain the same through 1986 by increase in usc per customer and decreased customers. 5/ Hot ~/ater customers estimated to increase 105 customers and 1.4 GWH per year through 1986. :[/ Approximate use per customer. I-' 0\ A 7/B2 '¥ :, ~ 1 • , , ~ ., 't " ~ , ~ /-, RESULTS AND CONCLUSIONS \ The Juneau area experienced very rapid increases in electric power use in the past 2 years (since 1980). The January 1982 peak demand of 42 t·1W \'/as 30.4 percent above the previous winter. Estimated FY 1982 net generation of 205 million kWh would be 23 percent over FY 1981 amounts. Increases for the FY 1981 over FY 1980 amounts were 22.9 percent for peak capacity and 16.5 percent for net generation. The power use data reflect continued strong area economic growth as well as significant shifts towards use of electricity for water and space heating. Part of the increases in 1982 were due to normal weather conditions. Power demands during the previous two winters were relatively low due to milder than normal weather conditions. A base case forecast ;s presented in Table 5 and Figure 2. It is estimated that growth rates in energy demand will be 13.7 percent in 1983, nine percent in 1984, and 8.3 percent in 1985. The period 1986 to 2000 will average 3.6 percent. If electric heat was restricted for all new construction in FY 1984, the loads would be 15 percent less than the basic case by 1986 and 23 percent by 1990. If the loads associated with a Juneau/Hoonah intertie are added, an overall increase in energy demand of 13 percent would result in 1986. A separate forecast was made for the capital move case, based on parameters similar to the 1980 and 1981 .estimates except that the move date was revised from 1985 to 1988. Results are that Juneau loads would increase:;, to a higher level before they drop .. (See Figure 2.) A comparison of Juneau area hydropower resources and forecasted demands shows that under critical year water supply conditions a hydropower generation deficit could occu~ as early as FY 1983 (Table 6). Under average conditions the deficit may not occur until FY 1984. Weather conditions could aggravate or modify the timing of the deficit possibly one year, however, FY 1985 load estimates appear more certain to be short of hydropower. The firm energy deficit rises to 93 GWh in 1986, or about 30 percent of the area load. In 1987 100 GWh of the Crater Lake 105 GWh firm energy would be used the first year of full operation. If the Juneau to Hoonah transmission intertie were constructed in 1986, hydropower deficits would increase by roughly 31 GWh. For the basic case with restricted electric heat, critical year water supply conditions would still produce a deficit in 1983. Under. average conditions the deficit would be delayed until 1986. The conc·lusions that the Crater Lake addition will be needed by or before mid-1986, are still valid. Analysis of trends in Juneau load growths for 1981 and 1982 as presented previously, would indicate 16 to 18 percent annual growth. If this trend 17 TABLE 5. Juneau Area Power Requirements Basic Case Basic w/Restricted Fiscal Year Case Electric Heat 1981 GWH 166.7 MW 32.2 1982 GWH 11 205 205 MW 42 42 1983 GWH 233 233 MW 48 48 1984 GWH 254 244 ~lW 53 51 1985 GWH 275 249 MW 57 52 1986 G~m 303 259 r~w 63 54 1990 GWH ". 354 274 MW 73 57 1995 GWH 420 294 MW 87 61 2000 GWH 496 318 MW 103 66 1/ Based on 7 months data. 2/ Intertie assumed in 1986. Basic Case w/ Juneau/Hoonah 2/ Capital Intertie -Move Case i05 42 233 48 235 49 242 50 343 244 70 51 390 177 80 37 452 194 94 40 528 212 110 44 APA 7/82 18 Jli~' II' "'" f· .. 600 500 400 200 .".. 10 . ,.".. .--.-. ...-.----- ·FIGURE 2. Juneau Area Lond Study Estimated Energy Requirements 1982 Update I, I ~ ~ ~ , .. Growth at 17% per year~~' ~Medium Case 1981 Estimate ••.• • • • I ... . .. . . ~ / / . . . . .••••• • •• '~Basic Case 1982. Restricted ... . . Base Case 1982 . '-:')(-><-x Electric Heat "'-x, ,~apital Move Case _________ " ~x ______ x . . ..-- .--./ . ~ O+-~ __ ~~ __ ~~ __ ~~~~ __ ~-L __ ~~ __ ~~~-L __ ~~ __ ~~ __ L--L--J. I .J.._--I-_.l.--_.I...--J 1995 2000 1970 1975 1980 1985 1990 Year APA 7/82 FY 1983 1984 1985 1986 1987 TABLE 6. Comparison of Junea Area Hydro Resources and Estimated Loads Resource Snettisham Long Lake AEL&P Hydro Annual Firm 168 42 2IIT Energy GWH Average 211 48 259 Estimated Loads & Deficit Basic Estimated Loads-GWH 233 254 275 303 310 Case Deficit-GWH Firm Average -23 +26 -44 + 5 -65 -16 -93 -44 -100 -51 Basic Case with Restricted Estimated Loads-GWH 233 244 249 259 263 Electric Heat Oeficit-GWH Firm Average -23 +26 -34 +15 -39 +10 -49 O' -53 - 4 APA 7/82 20 .' .' were to continue at 17 percent rather than the conservative component method of analysis presented in the above cases, system generation needs for the next few years could be: ~h MW 1982 205 42 1983 240 49 . 1984 280 57 1985 320 66 These figures may be compared to those in Table 5. 1986 370 76 APA will continue assessing energy use and changing economic and heating conditions in support of the decision to proceed with Crater Lake Construction. Reservoir operation and load management studies in cooperation with local utilities appear essential to minimize costs to the consumer in the interim before Crater Lake comes on line. Detailed supporting data and analysis are available in APA'soffice. 21 EXHIBIT 11 JUNEAU AREA POviER r'1ARKET ANAL YS I S PARTIAL UPDATE OF LOAD FORECAST NOVEMBER 1982 ALASKA pm~ER ADMINISTRATION Alaska Power Administration Partial Update of July_1982 Juneau Load Forecast November 1982 Introduction Alaska Power Administration (APA) has compared the actual Juneau area power requirements through the end of fiscal year 1982 (September 30, 1982) with projections made in July 1982. The earlier projections were based on data through April 1982 and this comparison reflects any changes due to a differing growth pattern than originally forecast for the remainder of the fiscal year. Basic Data The basic data and assumptions used previously were essentia1ly the same for this study with minor changes in the distribution among user c1asses made to reflect actual conditions. The projections for the base case and the case with electric heat-restric- tions at the end of FY 1983 were updated and new projections were also made for a case involving electric heat restrictions at the end of calendar year 1982. Results and Conclusions Table 1 presents annual system net generation and peak demand for fiscal years 1970 through 1982 along with annual percent increases. The only elements differing from the July 1982 study are the net generation and percent increase for 1982. The actual net generation for 1982 was 202,900 MWh for an increase of 21.7 percent. The earlier study had forecast only slightly higher figures--205,000 MWh and a 23 percent increase. Table 2 presents the estimates of future demand for the base case. Compared to the earlier projections the actual totals for FY82 were: o higher for total residential customers (2%) o higher for general class (8%) o lower for hot water class (9%) o lower for all electric class (5%) o total residential use slightly lower (3%) o commercial use slightly higher (5%) The residential sector was expected to have fewer general class customers than the previous year due to customers switching from general class to hot water class. This apparently did not happen as there were actually more general class customers than the previous year. Slight adjustments were thus made to reflect this in future years. The total sales and net generation were also adjusted for future years to reflect slightly lower figures for FY82 than expected. This resulted in somewhat lower total loads in the forecast. Ill" Table 1. ~uneau Area Energy and Peak Demand I" System Net MWH i. Peak MW :~ '" Generation Annual Demand Annual Fiscal Year MWH* IncT'ease Mw IncT'ease ------------------------------------------------'", 1970 58,266 12.4 9. 5 11. 3 , 1971 63,786 13.8 10. 1 8. 0 1972 70,255 14.9 7. 8 4. 0 '", 1973 75,753 15.5 9.6 4. 5 1974 83,059 16.2 I!" 13.9 9.9 .' 1975 94,609 17.8 12.4 11. 2 fII" 1976 106,296 19.8 5. 6 3. 0 1977 112,197 20.4 ... 13.0 14. 7 1978 126,800 23.4 9. 5 -1. 3 1979 138,900 23. 1 (R) '" 4. 5 13. 4 ~, 1980 145,200 26.2 14.8 22.9 .. 1981 166,700 32.2 21. 7 30. 4 1982 202,900 42.0 f' * Includes AEL8cP and GHEA sales and losses. !ft. (R) Revised -From previously published data. APA 11/82 .. Table 2. Estimate of Futu~e Demands Base Calie Fiscal Veal' 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1995 2000 C::;=8c:_=c:;:;=n:=_ _;:c:= ... c:c===a U'c:a==G. #:ICIIUI;C:===-C .. ::II::;:. ==u;;a;;:; •• cz=_= •• r:t=ls;;: •• *;U:&:1:1" =_ ... _==== a:====a ===;a;c:_ Population 20.085 21. 49~ 22.35' 23.250 24.180 25.146 25.650 26.160 26.685 27.220 30.050 33. 180 People per Customer 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 Residential Customers 7.725 8.267 8.600 8.940 : ~ 9.300 9.670 9.865 10.060 10.260 10.470 11.560 12.160 (Average) Residential Sale. General Class. Customers 5.165 5.289 5.160 4.980 4.880 4.860 4.730 4.790 4.545 4.505 4.055 4.065 KWH/Customer 6.074 7.052 7.083 6.890 6.890 6.890 6.890 6.750 6.620 6.480 5:870 5.870 KWH. Mill ion 31. 4 37.3 36.6 34.3 33.6 33. 5 32.6 32.3 30. 1 29.2 23.8 23.9 Hot Water Clasli. Customers 2.040 1.935 1.980 2.085 2, 190 2.295 2.375 2.455 2.535 2.615 2.765 2.885 KWH/Customer 12.000 13.100 12,900 12.900 12,900 12.900 12.900 12.900 12.900 12.900 12,900 12.900 KWH. Mil lion 24.5 25.3 25.5 26.9 28.3 29.6 30.6 31. 7 32.7 33.7 35. 7 37.2 All Electric Class. Customers 520 1.043 1.460 1.875 2.230 2.515 2.760 2.815 3, 180 3.350 4,740 5.810 KWH/Culitomer 23.800 26.700 27.500 27, 500 27,500 27.500 27.500 27.500 27.500 27.500 27.500 27. 500 KWH, Million 12.4 27.8 40.2 51'.6 61. 3 69.2 75.9 77.4 87.5 92. 1 130.4 159.8 Subtotal Residential. KWH. Mi 11 ion 68.4 90.5 102.2 112.8 123.2 132.3 139. 1 141. 4 150.2 155. 1 189.8 220.9 , Commercial Sale. Chhtoric (307.) Subtotal C ommerc ia I. KWH. Million 39.7 46. 7 53. 7 59.0 64.0 69.0 71. 0 74.0 77.0 80.0 95.0 110.0 Government Sales (hhto~ic (267.) Subtotal Govt .• GWH 34.9 37. 1 44.6 47.0 48.9 58.9 60.8 62.7 64.6 72.9 82.4 102.0 Street Lighting.Residential 8c GoveT'nment. GWH 1.1 1.2 1.2 1.2 1.2 1.3 1.'3 1.3 1.4 1.5 Total Sal eSt GWH 142. 5 174.2 201. 6 220.0 237.3 261. 4 272. 1 279.4 293. 1 309.3 368.6 434.4 Ne t Genera ti on. GWH (1157. of Saleli) 166. 7 202.9 231. 9 253.0 272.9 300.6 312.9 321. 3 337. 1 355.6 423.-9 499.5 SI/stem Cap. Factor 7. 59.0 55.0 55.0 55.0 55.0 55.0 55.0 55.0 55.0 55.0 55.0 55.0 Peak Demand. MW 32.2 42.0 48. 1 52.5 56.6 62.4 65.0 66.7 70.0 73.8 88.0 103. 7 (Revised) APA 11/82 Table 3 and 4 present the estimates of future demand if electric heat-- including hot water--is restricted at the start of calendar year 1983 and fiscal year 1984 respectively. Restricting'electric heat at the earlier date would result in about 8 percent lower net generation in 1985 and 16 percent lower in 1990. Restrictions at the later-date would result in 5 percent lower in 1985 and 14 percent lower in 1990 compared to the base case. Table 5 summarizes the net generation and peak demand for the three cases. Table 6 compares the hydro resources and estimated loads for the Juneau area under the three cases. The firm energy figure for Snettisham is higher than used in previous studies. Original power studies by the Corps had indicated 168 GWh of firm energy while the latest studies associated with the design of Crater Lake show 179 GWh of firm energy_ Both these figures are theoretical and actual firm energy will have to be proven through operation of the project. All cases indicate an energy def·icit of firm energy while only the base case experiences deficits of average energy in a few years. Restricting electric space and hot water heating in January versus October of 1983 would result in slightly lower deficits of firm energy. • Table 4. estimate of Future Demands Elec tric Heat Rutricted 10/83 Fiscal Veal' 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1995 2000 ===-==_=a=::;:;a=_ ':===1;= a:a==aul' a===== ===:a;aa a:; &;:n:::;;;c:= ~=;;::u:;r;;;c J;;Qa:::::;iiu:::a a:==:=== _c:;;:;;u.:o:ag A=C=_= =====curol a==;:;;:;:.;n::lI Population 20.085 21.495 22.355 23.250 24. 180 25. 146 25.650 26.160 26.685 27.220 30.050 33,180 People per Customer 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2. 6 2.6 Residential Customers 7,725 8,267 8,600 8.940 '. 9,300 9.670 9,865 10,060 10,260 10.470 11,560 12.760 (Aver.age) Residential Salell General Class.Culltomers 5.165 5.289 5, 160 5, 185 5,545 5.915 6.110 6,305 6.505 6.715 7.805 9.005 KWH/Cu5tomer 6.074 7.052 7.083 6.760 6.900 7.040 6.900 6,760 6,630 6.500 5,890 5.890 KWH. Million 31.4 37.3 36.6 35.1 38.3 41. 6 42.2 42.6 43. 1 43.6 46.0 53. 0 Hot Water Class. 11 Customers 2.040 1.935 1.980 2.055 2,055 2.055 2.055 2,055 2.055 2.055 2.055 2.055 Kl-lH/Customer 12.000 13. 100 12,900 12.900 12.900 12.900 12.900 12.900 12.900 12.900 12,900 12.900 Kl-lH. Mi 11 ion 24.5 25.3 25.5 26.5 26.5 26. 5 26.5 26.5 26.5 26.5 26.5 26. 5 All Electric Class. Customers 520 1.043 1.460 1.700 1.700 1.700 1.700 1,700 1,700 1,700 1,700 1.700 KWH/Customer 23.800 26.700 27,500 27.:;00 27,500 27,500 27.500 27,500 27,500 27.500 27.500 27,500 KWH. Million 12.4 27.8 40.2 46:8 46.8 46.8 46.8 46.8 46.8 46.8 46.8 46.8 Subtotal Residential. Kl-lH,Million 68.4 90.5 102.2 108.3 111.5 114.9 115.4 115.9 116.4 116.9 119.2 126.3 Commerc hI Saleli (historic (301.) Subtotal Commercial. KWH,Million 39.7 46.7 51. 6 53.6 56.2 57.0 58.0 59.0 60.0 61. 0 66.0 71.0 Government Sales (h htoric (261.) Subtotal Govt. , GWH 34.9 37. 1 44.6 46. 5 46.4 51. 1 53.0 54.9 55.8 57.8 67.3 76.8 . ,', . ..... ' Street Lighting.Residentlal It Government. GWH 1.1 1.2 1.2 1.2 1.2 1.3 1.3 1.3 1.4 1.5 Total Sale5, GWH 142.5 174.2 199.5 209.6 215.3 224.2 227.6 231. 1 233.5 237.0 253.9 275.6 Net Generation. GWH (1151. of Sales) 166.7 202.9 229.5 241. 1 247.6 257.8 261.8 265.7 268. 5 272.6 292.0 316.9 SI/stem Cap. Factor X 59.0 55.0 55.0 55.0 55.0 55.0 55.0 55.0 55.0 55.0 55.0 55.0 Peak Demand. MW 32.2 42.0 47.6 50.0 51. 4 53.5 54.3 55.2 55. 7 56.6 60.6 65.8 1/ Hot Water Cla51i included in restriction. APA 11/82 Table 3. Estimate 0' Future Demands Electric Heat Restricted 1/83 Fiscal Veal' 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1995 2000 _==._=:r:==:::::a =::: • .:::;: •• ua:::u:=uiiI c=====--=====!=8 =sa:c:n::UII c:c:r===z; a:;=;&Aa:a:a =&:::.a:r •• ==ccrag =_U::I:=:_ ====== =====a Population 20,085 21. 495 22,355 23,250 24,180 25, 146 25,650 26, 160 26,685 27,220 30,050 33, 180 People per Customer 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 Residential Customers 7,725 8,267 8.600 8.940 9.300 9.670 9.865 10.060 10.260 10.470 11.560 12,760 (Average) Residential Sales General Clas'i.Customers 5,165 5,289 5.220 5,560 5.920 6.290 6,485 6,680 6,880 7.090 8. 180 9,380 KWH/Customer 6,074 7.052 7,083 6,760 6.900 7,040 6,900 6.760 6.630 6.500 5.890 5.890 KWH. Mi 11 ion 31. 4 37.3 37.0 37.6 40.8 44.3 44.7 45.2 45.6 46. 1 48.2 55.2 Hot Water Class, 1/ Customers 2,040 1,935 1,980 1.980 1,980 1,980 1.980 1.980 1.980 1.980 1.980 1.980 KWH/Customer 12.000 13.100 12.900 12.900 12.900 12.900 12.900 12,900 12,900 12.900 12,900 12.900 KWH. Million 24.5 20.3 25.5 25.5 25.5 25.5 25.5 25.5 25. 5 25.5 25. 5 25.5 All Ehc tric Class. Customers 520 1.043 1.400 21 1,400 1.400 1. 400 1.400 1,400 1,400 1.400 1,400 1.400 KWH/Customer 23.800 26.700 27.500 27.500 27,500 27.500 27.500 27,500 27,500 27,500 27,500 27,500 KWH. Million 12.4 27.8 38.5 • 38. 5 38.5 38.5 38.5 38.5 38.5 38. 5 38.5 38.5 Subtotal Residential. KWH,Million 68.4 90.5 101. 0 101. 6 104.9 108.3 108.8 109.2 109. 7 110. 1 112.2 119.3 Commercial Salel (historic (307.) Subtotal Commercial. KWH, MUH on 39.7 46.7 51.6 53.6 56.2 57.0 58.0 59.0 60.0 61. 0 66.0 71. 0 Government Sales (hhtoric (267.) Subtotal Govt .• GWH 34.9 37. 1 44.6 46.5 46.4 51. 1 53.0 54.9 55.8 57.8 67.3 76.8 .\" ..... Street Lighting.Residential " Government. GWH 1.1 1.2 1.2 1.2 1.2 1.3 1.3 1.3 1.4 1.5 Total Sales. GWH 142. 5 174.2 198.3 202.9 208. 7 217.6 221. 0 224.4 226.8 230.2 246.9 268.6 Net Generation. GWH (1157. of Sales) 166.7 202.9 228. 1 233.4 240.0 250.3 254. 1 258. 1 260.8 264.8 284.0 308.9 System Cap. Factor 7. 59.0 55.0 55.0 55.0 55.0 55.0 55.0 55.0 55.0 55.0 55.0 55.0 Peak Demand. MW 32.2 42.0 47.3 48.4 '49.8 51. 9 52. 7 53.6 54. 1 55.0 58.9 64. 1 1/ Hot Water Clas. included in restriction. 2/ Total all electric customers on 9/30/82 ",as 1.303. APA 11/82 " Table 5. ~uneau Area Power Requirements Electric Heat Electric Heat Basic Restricted Restricted Fiscal Year Case 1/83 10/83 ---------------------------------------------- 1981 GWH 166. 7 MW 32.2 1982 GWH 202.9 202.9 202. 9 MW 42.0 42.0 42.0 1983 GWH 232 228 230 MW 48 47 48 1984 GWH 253 233 241 MW 52 48 50 1985 GWH 273 240 248 MW 57 50 51 1986 GWH 301 250 258 MW 62 52 54 '1990 GWH 356 265 273 . MW 74 55 57 1995 GWH 424 284 292 MW 88 59 61 2000 GWH 500 309 317 MW 104 64 66 (Revised) APA 11/82 Table 6. Resource Snettisham Long Lake AEL8<P Hydro Base Case Estimated Deficit-GWH FY Loads-GWH Firm Average 1983 1984 1985 1986 1987 232 253 273 301 313 -11 -32 -52 -80 -92 +32 +11 -9 -37 -49 Comparison of Juneau Area Hydro Resources and Estimated Loads Annual Energy GWH Firm Average 179 (R) 42 ==== 221 216 (R) 48 ==== 264 Estimated Loads and Deficits Electric Heat" Restricted 1/83* Electric Heat Restricted 10/83* Estimated Deficit-GWH Estimated Deficit-GWH Loads-GWH Firm Average Loads-GWH Firm Average -------------------------------- ---------------- 228 -7 +36 230 -9 +34 233 -12 +31 241 -20 +23 240 -19 +24 248 -27 +15 250 -29 +14 259 -38 +5 254 -33 +10 262 -41 +2 (R) Revised from previously published data. * Includes electric hot water heating. (Revised) APA 11/82 EXHIBIT 12 JUNEAU AREA POWER MARKET ANALYSIS UPDATE OF LOAD FORECAST SEPTEMBER 1983 -ALASKA POWER ADMINISTRATION .. ,~-" ;... .~"\ :~~.;}( September 16, 1983 Colonel Neil Saling Alaska District Engineer Corps of Engineers P.O. Box 7002 Anchorage, Alaska 99510 Dear Colonel Saling: We are enclosing our latest update of load forecasts for the Juneau area. This study incorporates actual power use data through June 1983 and projects requirements through the year 2000. We are estimating FY 1983 net generation of 228 million kwh, or 12.4% above the previous year. A relatively mild winter plus cur- tailment of interruptable customers both helped to hold down the size of the increase. We estimate the 1983 growth would have been approximately 15 percent if "normal" weather had occurred. Our future estimates include both "low" and "high" ranges, plus a "moratorium" case which assumes no new users of electricity for space and water heating after January 1, 1984. The results show projected requirements of from 274 to 395 million kilowatt hours per year by 1990 and 317 to 492 million kwh/year by 2000. The estimates of future demands incorporate much smaller rates of increase than the area has experienced in recent years. For example, our high case shows a 1984 increase of 10.5% followed by 7.9% in 1985 and 6.4% in 1986. For the 1983-2000 period, the "high" case has average growths of 4.6%, the low case 3.2%, and the "moratorium" case 2%. Given the current and projected strength of the area economy, our estimates of future requirements may be too low. The area experienced a hydro deficit in the 1982-1983 winter, as had been predicted in previous studies, requiring use of the oil-fired generators to supplement the hydro supply. The deficit is expected to increase each year until the Crater Lake unit of Snettisham Project is completed. If Crater Lake is available in early 1987, we estimate an immediate market of from 40 to 75 percent of the Crater Lake firm energy. We believe the new studies reaffirm the need to proceed as quickly as possible with completion of the Crater Lake Unit. Enclosure Sincerely, Q ,/J/~ /~s/C0/~~ Robert J. Cross Administrator 2 JUNEAU AREA POWER MARKET ANALYSIS UPDATE OF LOAD FORECAST SEPTEMBER 1983 Alaska Power Administration U.S. Department of Energy CONTENTS Page INTRODUCTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 BASIC DATA....................................................... 1 EVALUATION OF BASIC DATA....... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Residential Sector................................... . . . . . . . . 7 Commercial and Gov~rnment Sector......... ........ .... .... .... 7 Residential Energy Use pel" Customer.... ... ..... ...... ........ 8 Weather Influence on Energy Use...................... . . . . . . . . 8 ESTIMATE OF FUTURE DEMANDS ....................................... 13 RESULTS AND CONCLUSIONS .......................................... 18 TABLES 1. Juneau Area Net Gene~ation and Peak Demand........ ... ........ 2 2. Juneau Area Energy Sales and Percent Or Sales by Sector.. .... 3 3. ,Juneau Airport Heating' Degree Days................... . . . . . . . . 5 4. Juneau Area Recent Electric Trends .. _. . . . . . . .. . . . . . . . . . . . . . . . . 9 5. Juneau Net Generation AdJusted ror .We;'ather ............ '" . . . .11 6. Estimat~ of Future Demands, Electric Heat Moratorium 1/84 .... 15 7. Estimate Or Future Demands,_ No Moratorium -Low Growth..... . . 16 8. Estimate of Future Demands, No 'Moratorium -High Growth ...... 17 9. Comparison of Juneau Area Power Requirements ................. 19 10. Comparison of Juneau Area Hydro Resources and Estimated Loads........................................ 21 FIGURES 1. Weather AdJusted Net Generation.... . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2. Estimated Energy Requirements ................................ 20 INTRODUCTION Alaska Power Administration (APA) estimated Juneau area power requirements through the year 2000 for this study, which updates similar studies completed annually for the past several years. The area has experienced a significant increase in peak demand and energy use since 1980 and the previous studies indicated area power use would exceed critical year firm energy from existing hydroelectric plants during fiscal year 1983. This past spring local utilities were required to furnish over 5 million kwh of diesel generated electricity to supplement that available from the hydro plants. The need for this diesel generation will generally increase each spring as area reservoirs are drawn down until additional hydro energy is available from Crater Lake. BASIC DATA The basic data and assumptions used previously were essentially the same for this study and included data on energy use, economic, and climatic conditions. Energy and capacity use data came from monthly and annual reports prepared by APA and the two local utilities, climatic data from the National Oceanic and Atmosphere Administration (NOAA), and economic data from State and local sources. Table 1 presents annual system net generation and peak demand for fiscal year 1970 through June 1983 along with annual percent increase. A few significant points can be made about this table. (1) The dramatic increase in 1982 is partially attributable to the cold weather during that winter; (2) the lower annual increase in 1983 is due to a combination of the cold winter in 1982 and the mild \'/irrter in 1983; (3) the lower peak in 1983 occurred for the same re~sons; (4) the 1983 energy use would have been about 3 million kwh higher if the interruptible class customers had not been shut off in the spring. Table 2 presents sales by residential, commercial, and government sector for the 1970-1982 calendar year period. Residential customer use continues to increase the most with 1982 sales accounting for 52 percent of the total sales compared with the 13-year av~rage of 45 percent for that sector. Commercial and government sectors have both decreased in the percent of overall sales since 1979. Part of the reason for this strong growth in the residential sector is the trend to all-electric homes in the area. An examination of recent residential sales in the AEL&P service area is shown below. AEL&P October through Aeril Sales (million K\'/h) Class Residential Customer 1980 1981 1982 1983 General 18.6 18.1 18.5 17.8 General w/hot water 11. 0 12.9 15.7 15.7 All Electric 1.3 6.5 19.1 24.0 TOTAL 30.9 37.5 53.3 57.5 This trend towards all-electric homes is further shown by the shift in the number of AEL&P customers from the general class to the hot water and all-electric classes. 1 Table 1. ~UNEAU AREA NET GENERATION AND PEAK DEMAND Stjstem Net MWH i. Peak MW i. Generation Annual Demand Annual Fiscal Year MWH* Increase MW Increase =========== ========== ========== ========= ========== 1970 58,266 9.5 1971 63,786 10. 1 1972 70,255 7.8 1973 75,753 9.6 1974 83,059 13.9 1975 94,609 12.4 1976 106,296 5.6 1977 112,197 8.9 1978 122,218 9.2--e: 1979 eo_ 133,457 7.2 1980 143,128 16.5 1981 166,700 21. 7 1982 202,900 10.3 ** 1993 (Oct-June) 174,754 12~4 1993 228,000 *** * Includes AEL&P and GHEA sales and losses. *'* Increase over same period in 1982. *** Estimate based on 9 months data. 2 12.4 13.8 14.9 15.5 16.2 17.8 19.8 20.4 23.4 23. 1 26.2 32.2 41. 6 40. 1 40. 1 11. 3 8.0 4.0 4. 5 9.9 11. 2 3.0 14.7 -1. 3 13.4 22.9 29.2 -3.6 APA 8/83 Junldl '" ... .. "e lI"e ,,> Tabh 2. ~UNEAU AREA ENERGY SALES AND PERCENT-OF 8ALE8 BY 8ECTOR (1,000 KWH) CALENDAR VEAR 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 aa.a._ • .. _----.... ---._=8."' • •• ca:cc. _=Cn=aaaa -=._.-=-.. m._.=-_.a_=_. •••• R ... aClc=a._ •••• ==-.&1I:la=_=- Residential Sale. ~~ AELS.P 23.034 24,563 28.009 30,298 31,875 33,866 36, 175 38,702 42,143 45.815 51,939 64.387 83.813 GHEA 2,315 2,580 3,027 3.18:5 3.545 3.794 4, 126 4.292 4.936 5,353 6.376 7.902 10.477 ""''''--~~'''''-"V""~"""""" .... -."""''''''''''-..'V f\r"",,..,,,,,,,,,,,,,,,, .... "''''''''''''''''' "'fIV""fIV""~ "''''''V''''''''''''' "" ... "' ... ...,""..,. ""'''''''''''''''''''.,. """'''''''''''''I\t ",,,,"'''''''fiV''' "''''''''#V~'''4V ....... "'...,"'''W'''''''"' Total 25.349 27.143 31.036 33.483 35.420 37,660 ·40.301 42.994 47.079 !S1, 168 58.315 72.289 94,290 Percent 44 45 46 45 46 42 42 42 43 43 45 49 52 Average Percent 1970-82: 45 X Commercial Sales AEL&'P 15.713 17.322 18, 511 22.039 21,367 25,614 27,018' 29.552 :]1,406 34,654 36,548 38.798 46,925 GHEA 1.251 1.388 1,389 1,339 1.186 1,622 1.828 1,951 2.060 2,483 1,319 1,573 1.840 "'''''''''''''''''''' ","'''''''''WI\;"", ""4\1"''''''''''''' "'v"\J"'''''''''''''' "'''''''~'''''' """'''''''''''''''' "''''''''''''''''''V 4IV"''W'''''''''''' "'''''''f\t...,,,,,,, "'''''''''''''''''''' "'''''''''''''''''''''' "'''''''''''''''''4\1 "'''''''-.,''''''''' Total 16.964 18,710 19,900 -23.378 22.553 27,236 28.846 31,503 33,466 37, 137 37,867 40,371 48.76~ w Percent 30 31 :i!9 31 29 31 30 31 3i 31 29 27 27 Average Pet-cent 1970-82: 30 X Qovernment 8ale. AELS.P 13.542 13,927 1:5,327 16,399 17,546 22,009 ,2~, 253 27,232 26,826 30,671 31,329 32,531 36,884 GHEA 395 . 417 484 566 621 816 ' .. '789 873 932 632 1,988 1,964 2,161 Outdoor •... Lights 782 741 734 695 705 995 1 1,071 965 "'''''''''''',..,''' ... "''''lIV'''''''''''' "''''''''''''''''''''' """'''''''IiV''''''' "'''''''~'''''' "'''''''''' .... '''''''' "''''''''''''''''''' 'V"'~"'''''''' "'4IV""""~"''''' """'''''''''''''''''' "''''''''''4\t''''''4\t "'W4\t"''''''''''''''' .... "WIIIWfIWfIWfIWfIW Total 14.719 1~,085 16,545 17,660 18.872 23.820 26,042 28,105 27,758 31,303 33,318 35,566 40,010 Percent 26 25 25 24 25 27 27 27 26 26 26 24 22 Average Percent 1970-82: 25 X ======.::1 c:=c:c=== ;:;::;::a:asza ...... am. a=_=::::;:tl;l _'-:_.;&:1. _ _ 'EI:'I==:xa ••• ==== _:a:====_ -====== _==:::==a _.===== .. a:::n:t:&:1:l1II TOTAL 57,032 60,938 67,481 74.521 76,845 88,716 95, 189 102,602 108,303 119.608 129,500 148,226 183.065 APA 8/83 Junld2 Number of AEL&P Customers Class of Residential Customer Dec'79 Dec'80 Dec'81 Dec'82 ~1ay 183 General 4,849 4,829 4,327 4,470 4,207 General w/hot water 1,540 1,753 1,886 2,008 1,954 All El ectri c 56 348 872 1,344 1,573 TOTAL 6,445 6,940 7,085 7,822 7,734 AEL&P data was presented above since GHEA does not report residential classes in this form. AEL&P serves 90% of the area customers and is considered representative of GHEA customers. The shift in the residential sector to the hot water and all-electric classes caused the use per customer in the sector to increase. Tracking this energy use for both AEL&P and GHEA for the last several calendar years shows: Residential Customer Energ~ Use CYl979 CY1980 CY1981 CY1982 Average No. of Cust. 7,197 7,490 7,801 8,493 Residential Energy Sales 51.2 58.2 72.3 94.3 (l11ill i on kwh) Use per Customer 7,11.0 7,770 9,270 11,100 .... .:;.. The increases in use per customer can bt; attt{buted primarily to new electric heat and hot water use, however, part of the 1982 increase is due to the cold weather encountered during that year's season. A summary of heating degree days for the past 25 years is shown on Table 3. Economic and construction information was obtained from contractors, utilities, and Borough officials. A summary of the major points revealed: o Residential Sector Plans: Essentially all new housing in 1982 was all-electric, however, the 1983 building shows a trend to installation of fuel oil heating systems.. About 10 percent of new construction appears to be installing the fuel-oil units. o Commercial Sector Plans: The favorable vote to retain the capital in Juneau has resulted in a period of catch up following eight years of doubt about the capitals location. Major expansion of the area's two largest shopping malls, construction of a new Fred t4eyer store, new valley motels and new shopping malls are examples of some of the activities occurring in this sector. The Gold Creek Development should contribute significantly to growth in the downtown area. o Government Sector Plans: The vote to retain the capital in Juneau should result in a moderate growth to meet new programs and maintaining of most state positions currently in Juneau. Federal employment should continue at its present level. Retaining the capital will result in construction of additional needed office space and a second addition to the State Office Building is being planned. Nearly 300,000 square feet of additional space requirements at a minimum have been identified by 1991 and an additional 300 000 square feet of optional office space. ' 4 ., .. '" Table 3. 0UNEAU AIRPORT HEATING DEGREE DAYS FY Oct Nov Dec 0an Feb Ma-r Ap-r May 0un 0ul Aug Sep Total ==== ================================================================= 1959 736 928 1076 1449 1022 959 781 582 285 328 378 498 9022 . 1960 757 911 926 1146 911 1019 713 470 409 321 355 466 8404 1961 660 915 956 1062 932 938 746 538 371 262 339 511 823(). 1962 760 1027 1246 1182 1097 1095 756 627 447 250 305 486 9278 1963 645 810 1132 1147 885 1023 846 500 431 288 244 375 8326 1964 625 1093 993 1098 835 1118 785 610 336 324 347 453 8617 1965 614 980 1496 1291 1154 923 813 693 487 292 297 435 9475 1966 654 1045 1182 1746 1090 1071 805 667 355 265 382 466 9728 1967 812 1191 1188 1291 963 1261 824 592 300 340 303 444 9509 1968 671 973 1162 1432 1043 984 808 508 374 248 281 516 9000 1969· 802 920 1405 1801 1219 1054 727 464 218 343 448 521 9922 1970 724 975 921 1329 830 876 770 601 422 387 405 553 8793 1971 783 1110 1343 1607 1029 1112 784 658 346 227 290 504 9793 1972 811 1001 1360 1519 1315 1186 906 618 432 207 293 535 10183 1973 810 907 1275 1423 1126 986 752 584 404 343 404 505 9519 1974 732 1253 1143 1550 ~006 1242 765 556 437 349 315 437 9785 1975 690 851 957 1296 1129 1063 791 541 402 281 337 402 8740 1976 712 1088 1244 1132 1131 1006 706-·:· 597 384 280 275 427 8982 1977 679 717 938 918 690 893-673 531 320 243 196 428 7226 1978 695 1062 1423· 1233 922 954 683 525 317 298 262 427 8801 1979 612 1037 1134 1370 1505 904 712 528 378 251 205 415 9051 1980 609 830 1187 1404 895 949 678 477 278 283 308 472 8370 1981 628 783 1333 843 899 786 772 392 316 257 275 469 7753 1982 682 841 1175 1584 1213 1017 816 627 257 220 310 435 9177 1983 699 1027 1029 1073 924 931 663 470 272 287 315 466 8156 25-Vea ... Ave-rage 704 971 1169 1317 1031 1014 763 558 359 287 315 466 8954 Source: Climatological Data, National Oceanic and Atmospheric Admin. Note -Last 3 months of 1983 assumed as ave ... age. 5 APA 8/83 heatdays o State government positions increased 5.5 percent during 1982 which is about the same as the eight-year average of 5.7 percent per year. o Federal government employment remained essentially stable with less than a one percent increase to 1,219. o Local government employment increased 2.4 percent during 1982. o Private sector employment increased 6.8 percent in 1982. o Noranda Mining Corporation is continuing plans for operation of its site on Admiralty Island by about 1986. Approximately 300 employees would be involved with most living in Juneau. 6 EVALUATION OF BASIC DATA This section evaluates the basic historic data and explains the recent growth and looks for trends that could affect furture growth. Residential Sector A summary of October through April AEL&P residential energy sales and number of customers for the past four seasons was presented in the previous section. Examination of this data shows the following trends: Residential Sales by Class of Customer Oct-Apr Oct-Apr Oct-Apr FY1981 FY1982 FY1983 ncrease Increase Increase Class Gwh % Gwh % Gwh % General -0.5 -2.7 0.4 2.2 -0.7 -3.8 General with hot water 1.9 17.3 2.8 21. 7 0.0 0 All Electric 5.2 400.0 12.6 193.8 4.9 25.6 TOTAL 6.6 21~4 15.8 42.1 4.2 7.9 General Class ..... . Sales decreased slightly the past three years. Number of customers declined 13 percent between December 1979 and May 1983. Use per customer has increased. All Electric Class ,. Almost all homes built since 1979 are in the all-electric or hot water class. For FY 1981, 1982, and 1983, 85 percent of the increase in October to April AEL&P residential energy use occurred in the all-electric class. October to April energy use during the past four years increased from 1.3Gwh (4 percent of the residential use) to 24.0Gwh (42 percent of the residential use). Commercial and Government Sectors . Commercial and Government sales increased at less than half the annual rate of residential sales since 1979 (9 percent versus 22 percent). 7 Comnlercial customers increased only 2 percent from 1979 to 1982 while sales increased by 31 percent during this same period. Part of this increase is due to all-electric costomers and part to weather. Government sales increased by 25 percent during the 1979 to 1982 period. The reasons given for the commercial sector would apply here also. Residential Energy Use Per Customer Residential customer use increased 3~990 kwh per customer (56 percent) between 1979 and 1982 primarily because of the trend to electric hot water and all-electric heat and secondarily because of colder weather in 1982. A breakdown of energy use in the various classes for the past four years shows: General General w/Hot Water All Electric CY1979 5,850 11,070 23~560 Kwh per Customer Class CY1980 5,970 11~520 24~530 CY1981 6,070 12~120 23~760 CY1982 6~460 13~060 26,590 The 1980 and 1981 calendar years include warmer than normal winters (based on a '25-year average) while 1982.weatner was colder than normal. The 1983 heating season is again warmer than average. A summary of recent trends in electrical use in the Juneau area is shown on Table 4. Weather Influence on Energy and Capacity Juneau power demands have always been sensitive to weather and this is clearly shown by Table 1 where the 1981~ 1982, and 1983~ generation and peak figures are shown. The cold 1982 season resulted in increases in energy and peak of 21.7 percent and 29.2 percent respectively while the warm 1983 season following the cold 1982 season resulted in an energy increase of only 12.4 percent and a decrease in the peak of 3.6 percent. 8 Table 4. Change FY79 <--x--> ======= ======= Population 19, 174 2 Residential Customers 7, 197 4 All-Electric Customers 69 110 Residential Sales (MWH) 51, 168 14 1..0 Commercial Sales (MWH) 37, 137 2 Government Sales (MWH) 31,303 6 Residential Sales 43 5 Y. aT Total Commercial Sales 31 -6 'l. OT Total Government Sales 26 0 'Y. of Total it -Estimated ,",UNEAU AREA RECENT ELECTRIC TRENDS Change Change FY80 (--Y.--> FY81 (--Y.--> FY82 ======= ======= =.:===== ======= ======= 19,500 3 20,085 7 21,495 7,490 3 7,725 7 8,267 145 259 520 101 1,043 58,315 24 72,289 30 94,290 37,867 7 40,371 21 48,765 33,318 7 35,566 12 40,010 45 9 49 52 29 -7 27 ° 27 26 -8 24 -13 21 Change (--'Y.--:> ======= 6 6 55 2 13 -7 -6 4 10 FY83 * ======= 22,720 8,738 1,618 96,600 54,900 37, 100 49 28 23 APA 8/83 Junld6 The increase in the use of electric space heating should increase this sensitivity to weather since energy requirements are directly proportional to outside temperatures. Analysis of recent weather data and net generation figures shows the following: Heat Degree Da,ls October-Apri 1 October-Apri 1 Net Generation Annual Increase Fiscal Year Degree Days % of Avg. Gwh Gwh % 1978 6,970 103 77.5 1979 7,279 108 86.6 +9.1 +11'.7 1980 6,552 97 89.3 +2.7 +3.1 1981 6,044 90 102.0 +12.7 +14.2 1982 7,328 109 129.3 +27.3 +26.8 1983 6,346 94 143.0 +13.7 +10.6 Average 6,753 Examination of weather on a monthly basis shows variations to be more pronounced. Heating Degree Da,ls Net Generation, Gwh Fiscal .... " ,Year Dec Jan Feb Dec-Feb Total Dec Jan Feb Dec-Feb Total 1978 1,423 1,233 922 3,578 12.2 12.2 10.4 34.8 1979 1,134 1,370 1,505 4,009 12.2 15.2 14.6 42.0 1980 1,187 1,404 899 3,486 13.3 14.3 12.5 40.18 1981 1,333 843 1,213 3,075 17.1 15.7 14.2 47.0 1982 1,175 1,584 1,040 3,972 19.7 24.0 18.8 62.5 1983 1,029 1.073 924 3,026 22.4 23.7 4.5 65.6 Avg. 1,213 1,251 1,084 3,524 Since growth is high when a cold year follows a warm year and low when a warm year follows a cold year, the large increase in fiscal year 1982 energy use and peak should be adjusted down to reflect the cold weather occurring then wh-ile 1983 should be adjusted upward. By adjusting the loads by adding a II wea ther adjustment ll to the actual load when the season was warmer than normal and subtracting if the season was colde~ loads which would have occurred if average temperatures had prevailed were estimated. ' Tabl e 5 presents a surrmary of adjusted net generation figures for the past six years and F~gure 1. graphically shows a comparison of actual and adjusted figures show the annual growth to be in the 15 to 18 percent range if Ilnormalll weather had occurred the past three years. There is also a slight decrease in annual growth since the peak in 1981 as shown on Table 5. 10 ~.' I-' I-' Table 5. JUNEAU NET GENERATION ADJUSTED FOR WEATHER FV Actual ======= -------------- 1978 8,801 1979 9,051 1980 8,370 1981 7,753 1982 9,177 1983 8,156 25-Vear Average 8,954 Degree Days Val'iation Tram Average Degrees (X) ======== -153 97 -584 -1,2P1 223 -798 ======== -1. 7 1. 1 -7.0 -15.5 2.4 -9.8 1 Net Generation GWH ======= 122.2 133.5 143. 1 166.7 202:9 228.0 " * -Degree Days pel'cent variation times 0.2 Temperature Adjusted AdJustment Net ~~~~~~~~~~~~~~~~~~ Generation X * GWH GWH ======= ;::s====== =====;::;= 0.3 0.4 122.6 , -0.2 -0.3 133.2 ~ 1.4 2.0 145.1 3. 1 5.2 171. 9 -0.5 -1. 0 201.9 ~ 2.0 4. 5 232.5 Annual Increase ~~~~~~~~~~~~~~~~~~ GWH ======= 10.6 11. 9 26.8 30.0 30. 5 'Y. ======= 8.6 8.9 18.4 17.5 15. 1 APA 8/83 adJtemp .EGEND .. FiQure ~. WEATHER ADJUSTED -. NET GENERATION "" 250.0+--.. -----------------------------------------------------------------------i I I I I I ~ I I I I I I ':<':<50+ 4 .... •• I I I I I I , I I 200.0+ I I I I I I I I I ~75.0+ I I I I I I I I I ~5o.°i I I I I I I I I ~25.0+ Ix .......... I ':. I I I I I I I x .-'. I I Ir I ~ I J I" I I .' I I ~ I t ~Oo.O+ i<, ++------------+--------------+------------+------------+------------+" ~978 ~979 ~980 ~98~ ~982 ~~ (0) Actual Net Generation (~) Adjusted Net Generation YEAR APA -AUG ~'383 "" ESTIMATE ON FUTURE DEMANDS (r-Estimates for future demands were made for three cases. These include 1) \, With electric hear moratorium on January 1, 1984; 2) No electric heat moratorium with low growth; and 3) No electric heat moratorium with high growth. The case with a moratorium assumes that an area-wide moratorium would occur and all cases use the same methods of calculations and assumptions on use per residential customer. Assumptions The FY 1983 estimated loads were based on net generation data for the first nine months of the year and extended to a 12 month period by assuming that October-May generation accounts for 76.8 percent of the annual generatiQn. This is based on the six year distribution of energy use for fiscal years 1977-82. For 1984 and after, estimates were based on the assumptions below: All Cases Population Growth (based on estimates in the April 1983 "Juneau Economic Study" by Homan-McDowe 11 and forecasts for AEL&P prepared by CH2r·1 Hi 1 n . 1983 -1990 1990 -2000 '" Population per residential customer _ , "," ~ Resi~ential Use per Customer: 1983 -1986 1986 -1995 1995 -2000 System Load Factor Electric Heat Moratorium Residential Sector .. 3% annually 2% 2.6 2% annual increase 2% annual decrease constant 55% General Class: The number of customers would increase each year as all new customers would fall in this class following the moratorium. Genera 1 wi th Hot t~a ter Cl ass: The number of customers woul d remain constant after fiscal year 1984. All Electric Class: The number of customers would remain constant after fiscal year 1984. Commercial Sector Loads in this sector were assumed to increase at a rate of 3 percent annua lly. Government Sector: This sector will grow at a rate of 2 percent annually. No Electric Moratorium with Low Growth Residential Sector General Class: Approximately 10 percent 'of new customers in the residential sector in 1983 are going into this class. This percentage was assumed to increase to 60 percent of the new residential customers by 1990. General with Hot Water Class: About 15 percent of new customers in the residential sector in 1983 are going into this class. This percentage was assumed to increase to 30 percent of new resi dentia 1 custol<lers by 1990. All Electric Class: About 75 percent of new residential sector customers in 1983 are going into this class. This percentage was assumed to decrease to 10 percent by 1990. Commercial Sector Loads in this sector were assumed to increase at a rate of 4 percent annually. Government Sector Loads in this sector were assumed to increase at a rate of 3 percent annually'." . No El ectri c ~10ratori urn with Hi gh Growth Residential Sector General Class: The 10 percent figure for new residential customers in 1983 going into this class was assumed to continue. General Class with Hot Water: The 15 percent figure for new residentials customers in 1983 gOing into this class was assumed to continue. All Electric Class: About 75.percent of new residential customers in 1983 went into this class. This percentage was assumed to continue. Commercial Sector Loads in this sector were assumed to increase at a rate of 6 percent annually. Government Sector Loads in this sector were assumed to increase at a rate of 5 percent annually. Tables 6 through 8 present the load forecasts for the three cases through the year 2000. 14 ". ~- Table 6. ESTIMATE OF FUTURE DEMANDS ELECTRIC HEAT MORATORIUM 1/84 Actual FV FV FV FV FV FV FV FV FV FV FV 1982 1983 1984 1985 1986 1987 1988 1989 1990 1995 2000 a=_z:;=:a a:n:==;:::1 lD:aa:::a.a.a • =QICI_. a=;:za;u:::u: • :a __ eag _.=a;::,;;r .... =:c:r.,;=-a:;ll:Q:===-a = c::u==_ &:a:=:_ Population 21,495 22,720 23.910 24,980', 25,710 26.230 27.090 27.560 2B.050 30.970 34.190 People per Customer 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 Residential Customers S.267 S.738 9. 196 9. 60S 9.SS8 10,088 10,419 10,600 10,788 11.912 13.150 (Average) Residential Sales (Historic: 45X) General Class CUlOtomerlO 5,289 5,176 5,311 5,723 6,00.3 6,203 6.534 6.715 6,903 8.027 9,265 KWH/CulOtomer 7.052 6.500 6.760 6.895 7.033 6.895 6.760 . 6.627 6.498 5.885 5.885 Hi 11 i on KWH 37.3 33.6 35.9 39. 5 42.2 42.8 44.2 44.5 44.9 47.2 54. 5 Hot Water .Class 11 CUlOtomerlO 1.935 1.944 1,965 1.965 1.965 1,965 1,965 1.965 1.965 1,965 1,965 KWHICustomer 13.100 12,000 12.700 12.954 IG.213 12.954 12.700 12.451 12.207 11.056 11. 056 Million KWH 25.3 23.3 25.0 25. 5 26.0 25. 5 25.0 24. 5 24.0 21. 7 21. 7 ..... All Electric: Clasli Ul, CUlOtomers 1.043 'J, 618 1.920 1.920 1.920 1.920 1.920 1.920 1,920 1.920 1.920 KWH/CulOtomer 26.700 24.500 26.000 26,520 27.050 26.520 26,000 25,490 24,990 22.635 22,635 Mi 11 ion KWH 27.8 39.6 49.9 50.9 51. 9 50.9 49.9 4B.9 4B.O 43. 5 43. 5 Subtotal Residential. MiBion KWH 90.5 96.6 110. B 115.8 ';120. 1 119. 1 119.0 117.9 116.8 112.4 119.7 .' Commercial Sales (Historic: 30X) SUbtotal Commer!! 1al. Million KWH 46. 7 54.9 56.5 58.2 60.0 61. 8 63.6 65.6 67.5 78.3 90. 7 Government Sales (Historic: 25X) Subtotal Government. Hi 11 i on KWH 37. 1 45.7 46.6 47. 5 48. 5 49. 5 50. 5 51.5 52. 5 58.0 64.0 Street Lighting.Residential & Government. Mi 11 ion KWH 1. 1 1.2 1.2 1.2 1.2 1.3 1.3 1.3 1.4 1.5 . Total Sales. Million KWH 174.2 198.3 215. 1 222.8 229.8 .231. 6 234.4 236.2 238. 1 250. 1 275.9 Net Generation. Million KWH (liS,. of Sales) 202.9 228.0 247.4 256.2 264.3 266.3 269.6 271. 7 273.9 287.6 317.3 System Cap, Factor X 21 55. 0 65.0 55.0 55.0 55.0 55.0 55.0 55.0 55.0 55.0 55.0 Peak Demand. HW 42.0 40. 1 51,,4 53.2 54,9 55.3 56.0 56.4 56.8 59.7 65.9 . 11 Hot Water ClaSIi inc:luded in restriction. 21 Mild winter cause~ 1983 to d Hofer. APA 8/83 Junldfl Tab le 7. ESTIMATE OF FUTURE DEMAND NO ELECTRIC HEAT MORATORIUM -LOW GROWTH Actual FY FY FY FY FY FY FY FY FY FY FY 1982 1983 1984 1985 1986 1987 1988 1989 1990 1995 2000 :a=:a::;a:s::.a _::::I=a-=a =====::a a==-==_ DJ:::U:::a==:a a=a:: .. ==-•• ::a==iII .. CIIIZ.==_ ======-==_===-_==11=:;:1:1 Population 21. 495 22,720 23,910 24,980 :25,710 26,230 27,090 ';27,560 28,050 30,970 34, 190 People per Customer 2.6 2.6 2.6 2.6 2.0 2.0 2.6 2.6 2.6 2.6 2.6 Residential CU5tomers 8,267 8,738 9, 196 9,608 9,888 10,088 10,419 10,600 10,788 11,912 13, 150 (Average) Residential Sales (Historic 45'1.) General Class, I Customers 5,289 5,176 5,222 5,284 5,354 5,424 5,573 5,672 5,786 6,459 7,202 KWH/Customer 7,052 6,500 6,760 6,895 7,033 6,895 6,760 6,627 .6,498 5,885 5,885 Mi llion KWH 37.3 33.6 35.3 36.4 37. 7 37.4 37.7 37.6 37.6 38.0 42.4 Hot Water Class, Customers 1,935 1; 944 2,013 2,095 2, 151 2, 191 2,257 ';2,302 2,359 2,696 3,067 KWH/Customer 13, 100 12,000 12,700 12,954 13,213 12;954 12,700 12,451 12,207 11,056 11,056 Million KWH 25. 3 23.3 25.6 ' 27.1 28.4 28.4 28.7 28. 7 2B.8 29.8 33.9 -All Electric Class, en, Customers 1,043 1,618 1,961 2,229 2,383 2,473 2,589 2,625 2,644 2,756 2,880 KWH/Customer 26,700 24,500 26,000 26,520 27.,050 26, 520 26,000 25,490 24,990 27,500 27,500 Mi llion KWH 27.8 39.6 51.0 59. 1 64.5 65.6 67.3 66.9 66. 1 75.8 79. 2 I Subtotal Residential, Million KWH 90.5 96.0 111.9 122. 7 ~30.5 131. 4 133.7 133.';2 132. 5 143.6 155. 5 .' Commercial Sales (Historic 307.) Subtotal Commercial. Mi 11 ion KWH 46.7 54.9 57. 1 59.4 61.8 64.2 66.8 69.5 72.2 87.9 106.9 Government Sales (Historic 257.) SUbtotal Governme,nt, Million KWH 37. 1 45.7 47. 1 48.5 49.9 51.4 53.0 54.0 56.2 65.2 75. 5 Street Lighting,Residential 8< Government, Million KWH , 1. 1 1. ';2 1.2 1.2 1. ';2 1.3 1.3 1.3 1.4 1.5 " Total Sales, Million KWH 174.2 198.3 217.2 231. 7 243.4 248.2 254. 7 258. 5 262.2 298. 1 339. 5 Net Generation, Million KWH <i157. of Sales) 202.9 228.0 249.8 266.5 280.0 285. 5 292.9 297.3 301. 5 342.8 390. 4 System Cap. Factor '1. 1/ 55.0 65.0 55.0 55.0 55.0 55.0 55.0 55.0 55. 0 55. 0 55, 0 Peak Demand, MW 42.0 40. 1 51. 8 55.3 58. 1 59.3 60. 8 61. 7 62.6 71. 1 81. 0 1/ Mil d winter cau5ed 1983 to d if'fer. APA 8/83 Junldf3 Table 8. ESTIMATE OF FUTURE DEMANDS NO ELECTRIC MORATORIUM -HIGH GROWTH Ac:tual FY FY FY FY FY FY FY FY FY FY FY 1982 1983 1984 1985 1986 1987 1988 1989 1990 1995 2000 a::===== ====;;;:.a ==:a:-=:_8 =J;:a;;I===_ _a==-=_ .101.== .. •• ===--_====cz a;;===== 11:====::1 .1::==== Population 21.495 22.720 23.910 24.980 25.710 26.230 27.090 27,560 28.050 30.970 34. 190 People per Customer 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 ·2.6 2.6 2.6 Residential Customers 8.267 8.736 9. 196 9.608 9.8BB 10.0B8 10.419 10,600 10,7BB 11,912 13, l~O (Average) Residential Sales (Hhtoric: 45%) General Clas •• Customers ',289 5, 176 5,222 5,263 5,291 5,311 5,345 5.363 5,381 5.494 5.618 "WH/Customer 7.052 6. 500 6.760 6,895 7,033 6,895 6,760 6,627 6.498 5,885 5.885 Mi Ilion "WH 37.3 33.6 35.3 36.3 37.2 36.6 36. 1 35. 5 35.0 32.3 33. 1 Hot Water Clas~. Customers 1,935 1.944 2,013 2.074 2, 117 2. 147 2.196 2.223 2.252 2,420' 2.606 "WH/Customer 13. 100 12.000 12.700 12.954 13.213 12.954 12.700 12.451 12.207 11.056 11.056 Million "WH 25. 3 23.3 25.6 26.9 ·28.0 27.8 27.9 27.7 27.5 26.8 28.8 -...J. All Electric Clas •• Customer!> 1.043 '1.618 1.961 2.270 2,491 2,631 2.979 3.014 3. 136 3.998 4.927 "WH/Customer 26.700 24.500 26.000 26,520 • 27.050 26.520 26,000 25.490 24.990 22.635 22.635 Million "WH 27.8 39.6 51. 0 60.2 67. 1 69.8 74.8 76.8 78.9 90.5 111. 5 Subtotal Residential. Mill ion "WH 90.5 96.6 111.9 123.4 :132.3 134.2 138.9 140. 1 141. 3 149.6 173.4 .'; Commercial Sales (Historic: 30%) Subtotal Commercial. Mi 11 ion "WH 46.7 54.9 58.2 61. 7 65. 4 69.3 73.5 77.9 82.5 110.5 147.8 , Government Sales (Historic: 25%) Subtotal Government. Million KWH 37.1 45.7 48.0 50.4 52.9 55. 5 58.3 61.2 64.3 82. 1 104.7 Street Lighting.Residential & Government. Million KWH 1 .. 1 1.2 1.2 1.2 1.2 1.3 1.3 1.3 1.4 1.5 Totai Sales, Million KWH 174.2 198.3 219.2 236.6 251. 8 260.2 272.0 280. 5 289.5 343. 5 427.5 Net Generation. Million KWH (liS,. of Sales) 202.9 228.0 252. 1 272. 1 289. 5 299.3 312.8 322.5 332.9 395.0 491.6 System Cap. Factor ,. II 55.0 65.0 55.0 55.0 55.0 55.0 55.0 55.0 55.0 55.0 55.0 Peak Demand. MW 42.0 40. 1 52.,3 56. 5 60.1 62. 1 64.9 66.9 69. 1 82.0 102.0 II Mild winter caused 1983 to d iffl!r. APA 8/83 Junld,f2 , RESULTS AND CONCLUSIONS Considerable increases in electric power use have been experienced in Juneau in the past few years. These increases reflect substantial growth in the area's economy and the shift from oil to electricity for a significant part of space heating. Weather related factors have also played a role in creating large increases during certain years. This is shown by the incre{ises in energy use in 1981, 1982, and 1983 (estimated) of 16 percent, 22 percent, and 12 percent, respectively. These three years consisted of a warm weather year followed by a colder year, followed by a warm year again. Adjusting those years for weather would result in increases of about: 1981-18 percent; 1982-17 percent; and 1983-15 percent (if the interruptible customers were not shut off, 1983 would have been about 1.7 percent a 1 so. ) The three forecasts prepared for this study included on involving an electric heat moratorium at the beginning of the calendar year 1984 and two forecasts--a low and a high--which do not have the moratorium going into effect .. Table 9 summarizes the forecasts made at this time and also compares them with forecasts previously completed by APA and the local utilities. The following general statements relating to annual electric growth under the latest estimates can be made: El ectric Heat t·'oratorium -future annual growth decrease from the 5.9 percent projected for 1984 to about 1 percent by 1990. Annual growth from 1983 to 1990 is about 2.7 percent and about 1.5 percent from 1990 to 2000. Ann~al growth from 1983 to 2000 is about 2 percent . . ,' No t10ratorium/Low Growth -future annual "growth:. decreases from 8 percent projected for, 1984 to about 1. 7 percent by 1990. Annual growth from 1983 to 1990 is about 4.1 percent and about 2.6 percent from 1990 to 2000. Annual growth from 1983 to 2000 is about 3.2 percent. No Moratorium/High Growth -future annual growth decreases from 10.5 percent projected for 1984 to about 3.4 percent by 1990. Annual growth from 1983 to 1990 is about 7 percent and about 4 percent from 1990 to 2000. A"nnua 1 growth from 1983 to 2000 is about 4.6 percent. " Figure 2 graphically compares this year's forecast and those completed previously. A comparison of Juneau area hydro power resources and forecasted demands is shown on Table 10. The firm energy deficit beginning in 1983 increases each year and by 1987 amounts to a shortage of 45 million kwh in the case with an electric moratorium, 65 million kwh for the no moratorium/low growth case and 78 million kwh for the no moratorium/high growth case. Deficits would also occur under average conditions since the Juneau area load is not large enough to utilize the large portion of this average energy occurring in the fall. The rapid growth in area power requirements will probably persist next year due to the strong increases in the commercial sector and the extensive construction activity which hasn't shown up as electric use yet. It is possible that next year's actual increase will be higher than projected due to this activity, however, the 15 to 18 percent annual growth rate should decrease as Juneau would be facing a deficit of firm hydro energy of 200 million kwh by 1987. 18 Table 9. COMPARISON OF JUNEAU AREA POWER REQUIREMENTS I I APA 1982 Forecasts I I I I ~~~~~~~~~~~~~~~~~~~~~~~~~~~~II Electric Heat No No I I Electric Heat I I Moratorium Moratorium Moratorium I I Basic Restricted I I Fiscal Year 1/84 LOlli Growth High Gl'olilth I I Casa 10/83 I I :;:;:;:-==;;;===::::;== ====:::s:.:====c= c:====c====;==~ ~=:a:======_= __ I I a:l;.=~a=::::=_===. •• ;I1\::===a==.::=== I I I I I I 1983 GWH 11 22B 228 228 I I 232 230 I I MW 40 40 40 I I 4B 48 I I I I I I 1984 GWH 247 250 252 I I 253 241 I I MW 51 52 52 I I 52 50 I I I I I I 1985 GWH 256 266 272 I I 273 248 I I HW 53 55 56 I I 57 51 I I I I I I 1986 GWH 264 280 ·289 I I 301 258 I I MW 55 58 60 I I 62 54 I I f-O I.D I I I I 1987 GWH 266 286 299 I I 313 262 I I Ht-I ,55 59 62 I I' 65 54 I I I I I I 198B GWH ,270 293 313 I I 321 266 I I HW 56 61 65 I I 67 55 I I I I " I I , 1989 GWH 272 297 322 I I 337 " 268 I I MW 56 62 67 I ,-70 56 I I I , I I 1990 GWH 274 302 333 ' I 356 273 ' I HW 57 63 69 I I 74 57 I I I I I I 1995 GWH 288 343 395 I I 424 292 I I MW 60 71 82 I I 88 61 I I I , I I 2000 GWH 317 390 492 I I 500 317 I , Ht-I 66 81 ,102 I I 104 66 ' I 11 Based on 9 months records. Latest Utility Forecasts ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Electric Heat No Moratorium Moratorium 1184 LOlli Gl'olilth c::a._a:_aa •• === 1j;:=:;_=~==:5C:==== 223 223 48 48 234 243 51 54 246 263 54 59 256, 277 56 62 264 287 59 65 275 302 61 68 284 312 63 70 293 321 65 72 No Moratorium High Growth aca:;;;:::==o=:=== 223 48 246 55 270 61 291 66 307 70 330 76' 348 80 367 85 APA 8/83 Jlt5 EGEND 500;---------------------------------------------------------------------------------------il I @I I I I I I I I I I I I J I I I I 400+ I' I x I I " I I' I I I I :f. f I /' x I I +/ @ I I .~./ I I +./@./ :), I 300+ +./ / x ~"I I / @ x-x/ _~<) I I /.-&::::::::x/·lE' I I @;1 ~-*-I$I--I I I ~/~~:;:::-$-<:)-O........ I w: ~ __ .... I . I .;#_,r <:,.....-I I i I I I 200+ i I /-I I I I I I /= I I " I I I I _./' I I _./'-I I _./'"-I 1.00+ -/-I I _/-I I ./'=~-I I =-= I 1=/ I I I I I I I I f 0+ I ++--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+-~+--+--+. ~97~ 75 80 85 90 95 2000 (=) (* ) (x) (@ ) ( ." \ ( .) l Hi 5 tor i.: Load Electric Heat Moratorium ~/84 No Moratorium / Low Growth No Moratorium / Hiqh Growth Base Case ~982 APA Forecast ~estricted Electric Heat ~982 YEAR Table 10. COMPARISON OF ~UNEAU AREA HYDRO RESOURCES AND ESTIMATED LOADS Resources ========= FiT"m Annual EneT"gy GWH Snettisham Long Lake 179 AEL&P Hydro 42 ===== 221 Estimated Loads and DeTicits (GWH) ============================ Electric Heat No MOT"atoT"ium MOT"atoT"ium ., Low Growth ~~~~~~~~~~~~~~~~~~ ~",.,..,..,..,._.,..,..,."It.~"'~~~~ . -. Estimated Estimated FY Loads DeTicit Loads DeTicit ------------------------------ 1983 228 -7 228 -7 1984 247 -26 250 -29 1985 256 -35 266 -45 1986 264 -43 280 -59 1987 266 -45 286 -65 " * Includes electT"ic hot wateT" heating. 21 No MOT"atoT"ium High GT"owth ~.,.~.,..,..,.~.,.~.,..,.~~.,.~~~~ Estimated Loads -------- 228 252 272 290 299 Deficit -------- -7 -31 -51 -69 -78 APA 8/83 Jlt6a The overall conclusion of this study is that the Crater lake addition to Snettisham is needed regardless of which forecast is chosen as from 40 to 70 percent of the project's output could be utlized the first year on-line in 1987. APA will continue to monitor and assess energy use and changing economic conditions in order to determine the appropriate generation facilities beyond Crater lake and the optimum timing for these facilities as firm energy from Crater lake would be fully utilized by 1990 under the higher growth case and by 1993 under the low growth case. Potential hydro sites beyond Crater lake would include long lake Dam, lake Dorothy, Sweetheart Creek, and Speel River. AEl&P has proposed a cooperative study to look into future development of generation facilities in the Juneau area to ensure the best utilization of the area's hydro resources. • .-'l. ", 22 EXHIBIT 13 J U,iEAU AREA POWER MARKET ANAL YS IS UPDATE OF LOAD FORECAST MAY 1984 ALASKA POWER ADMINISTRATION JUNEAU AREA POWER MARKET ANALYSIS UPDATE OF LOAD FORECAST MAY 1994 ALASKA POWER ADMINISTRAfIQN U.S. DEPARTMENT OF ENERGY • Department Of Energy Alaska Power Administration P.O. Box 50 Juneau, Alaska 99802 Colonel Neil Saling Alaska District Engineer -Corps of Engineers P.O. Box 7002 Anchorage, AK 99510 Dear Colonel Saling: May 8, 1984 We are enclosing our latest update of load forecasts for the Juneau area. This study incorporates actual power use data through March 1984 and projected re- quirements through the year 2000. We are estimating FY 1984 net generation of 247 million kWh --10.3 percent above the previous year. A very mild winter plus curtailment of interruptible customers have helped to hold down the size of the increase. Our future estimates include low, medium, and high projections. The results show projected requirements of from 300 to 345 million kWh per year by 1990 and 364 to 507 million kWh per year by 2000. The estimate indicates full marketability of Crater Lake power by 1990, or shortly thereafter. The estimate of future demands incorporate much smaller rates of increase than the area experienced in recent years. Given the current strength of the area economy, our estimates may be too conservative. The area has experienced a hydro deficit the past two winters, as had been predicted in previous studies, requiring use of oil-fired generation to supple- ment the hydro supply. The deficit will increase each year until the Crater Lake unit of Snettisham Project is completed. We believe the new studies reaffirm the need to proceed as quickly as possible with completion of the Crater Lake Unit. Enclosure Sincerely, /~4a~+- Robert J. Cross Administrator CONTENTS Page ·INTRODUCTION ••••••••••••.••••..••••.•.••••..•••••.••..•.••••...•.•. ~ . 1 BASIC DATA............................................................. 1 EVALUATION OF BASIC DATA............................................. 8 Residential Sector ................................................................... ~.. 8 Corrmercial and Government Sector................................. 9 Weather Infl uence on Energy Use ..•...... " . . • . . . . . . . . . . . . . . . . . . . . . 9 ESTIMATE OF FUTURE DEMANDS............................................ 12 RESULTS AND CONCLUSIONS.................................. .•..•...•... 18 TABLES 1. Juneau Area Net Generation and Peak Demand ................... .. 2. Juneau Area Energy Sales and Percent of Sales by Sector ....... . 2a. End of Calendar Year Statistics •...... ~ .•...................... 3. Juneau Airport Heating Degree Days •...........•................ 4. Juneau Area Recent E1 ectric Trends ........................... .. 5. Juneau Net Generation Adjusted for Weather ...•......•.......... 6. Estimate of Future Demands, Low Projection ••..•....•........... 7. Estimate of Future Demands, Medium Projection ...............•.• 8. Estimate of Future Demands, High Projection ••......•........... 9. Comparison of Juneau Area Hydro Resources and Estimated Loads .............................................................. .. FIGURES 2 3 4 6 10 11 15 16 17 21 1. Estimated Energy Requirements.................................. 20 INTRODUCTION Alaska Power Administration (APA) estimated Juneau area power requirements through the year 2000 for this study. This estimate updates similar studies completed annually for the past several years. The area has experienced a significant increase in peak demand and energy use since 1980 and the previous studies indicated area power use would exceed critical year firm energy from existing hydroelectric plants during fiscal year 1983. This actually occurred during the spring of 1983 as local utilities were required to furnish over 5 million kWh of diesel-generated electricity to supplement that available from the hydro plants. The hydro shortage during the past wi nter woul d have been .. much hi gher than the 13.0 mi 11 i on kWh actua 11 y gener- ated by diesel if the weather had not been so mild. The need fo.r diesel gener- ation will generally increase each spring as area reservoirs are drawn down until additional hydro energy is available from Crater Lake. BASIC DATA The basic data and assumptions used for this study are essentially the same as those used in previous studies and includes data on energy use, economic, and climatic conditions. Energy and capacity use data came from monthly -and annual reports by APA and the two local utilities, weather data from the National Oceanic and Atmospheric Administration (NOAA), and economic data from State and local sources. Table 1. presents annual system net generation and peak demand for fiscal years 1970 through 1984 along with annual percent increases. The dramatic increase in 1982 is partially attributable to the cold weather during. that winter while the lower annual increase in 1983 is due to a combination of the cold winter in 1982 and the mild w·inter in 1983. The winter in 1984 was also mild which kept the energy growth rate and system peaks down. Energy use in 1983 and 1984 would19ave been about 3 million kWh higher if the interruptible class customers-had not been shut off in the winter. Table 2. presents sales by residential, commercial, and government sectors for the 1970-83 calendar year period while Table 2a. examines the 1982 and 1983 years in more detail. Residential customer use continues to be the largest sector with 1983 sales accounting for 51 percent of the total sales compared with a 13-year average of 45 percent for that sector. Com- mercial and government sectors have both decreased in the percent of over- all sales since 1979. Part of the reason for this strong growth in the residential sector had been the trend to all-electric homes in the area. An examination of recent residential sales in the AEL&P service area ;s shown below. Jj Building Federal Bldg. Bill Ray Center Harborv;ew School Gold Belt Bldg. Peak Demand 2,000 KW 300 KW 1,000 KW 500 KW T.ble.1. ~NEAU AREA ENERQV AND PEAK DEMAND a"stem Net MWH X Peak Qeneration Annu.l Demand Fiscal Year MWH 11 Incr •• se MW ____ C== ____ --------------_._---=:======---=- 1970 58.266 12. 4 9. 5 1971 63.786 13. 8 10.1 1972 70,255 14. 9 7.8 1973 75,753 15. 5 9.6 1974 83,059 16.2 13.9 1975 94,609 17.8 12.4 1976 106,296 19.8 5.6 1977 112, 197 20.4 8.9 1978 122,218 23. 4 9.2 1979 133,457 23. 1 7.2 1980 143, 128 26.2 16. 5 1981 166,700 32.2 21.7 1982 202,900 41.6 10.4 1983 224,000 40. 1 10.4 1984 247,400 12 41. 3 11 Includ.s AELLP .nd QHEA sales .nd losses. 12 Estim.t. based on 6 months data. 2 MW % Annual Increase -----=---- 11. 3 8.0 4.0 4. 5 9.9 11.2 3.0 14. 7 -1. 3 13.4 22.9 29.2 -3.6 3.0 APA 4/84 Jlt1 ,,, • " ,. T.Ue 2. .JUNEAU AREA ENERGY BALES AND PERCENT OF CALENDAR YEAR 1970 1971 1972 1973 1974 197' 1976 ••••••• • •••••• ••••••• ••••••• .. _----••••••• -_._ .. - R •• ad.n".l B.l •• AELIoP 23.034 24.'63 28.00'9 30.2'98 31.87:S 33,866 36. 17' OHEA 2.3Ut 2.'80 3.027 3. 18:S 3.:54:S 3.7'4 4.126 ... ~ ... "" .. .., ... "" .................. ... .. "' ... /IIw"" ..... ... ............... "' ... ""~ ... f\t ... ... "" ...... "" ...... "" ........ Tohl 2'.349 27.143 31.036 33.483 3:S.420 37,660 40.301 P.rcen' 44 4' 46 4' 46 42 42 CO_Irchl B .... AEL .... 1'.713 17.322 18. :Sll 22.03' 21.367 2'.614 27.019 OHEA 1.2'1 1.398 1.389 1.33'9 1.196 1.622 1. B29 ........ ""' .......... ........... "' .. .. .. <I\tt"" ......... ""' .. """ ...... ""'''''' ....... ~ ........ ... ............. , ... "" .......................... Tot.l 16.964 18.710 ., •• 00 23.378 22.:S'3 27.236 29.946 Percent 30 31 29 31 29 31 30 Govern.en' B,l •• AELIoP 13.'42 13.927 1',327 16.399 17.:546 22.009 2'.2'3 OHEA 395 417 484 '66 621 916 799 Out'oor LI.llh 782 741 734 ", 70' 99' "\it ............... "" ........... "" .... .. ""-..""..,"" .. -....,..,"""~ .. "'~"" ............. ..., .. """'..,"'--~ ~""~~~"'oIItt. Tot.l 14.719 .,.OB' 16. '4' 17.660 19.872 23.BaO 26.042 Pe .. c.nt 26 2' 2' 24 2' 27 27 -.-.... ..... -. .-.. -_. _ .. _-------~---------------TOTAL 157.032 60.938 67.481 74.'21 76.94:S BB.716 <;I,. 199 8ALES BY BECTOR (1.000 t(WH) 1'77 1978 197'9 1990 . -_ .... ••••••• . .. -... .-._--- 38.702 42. 143 4:s.81' :S1,939 4.292 4,936 ,.3:S3 6.376 """'''' .. ''' .... "" ............ "' .. .. ... "'''' ...... ........ ~-""' ... "" 42.'94 47.07' '1.168 :S9.31' 42 43 43 4:S Av.r •• e Percent 1970-83: 4' 29.':S2 31.406 34.6'4 36.:S49 1.9'1 2.060 2.493 t. 319 .......................... ...... "" .......... "" .................... ... ..................... 31.'03 33.466 37. 137 37.867 31 31 31 29 Aver •• e P.rc.nt 1970-93: 30 27.232 26.926 30.671 31.329 873 932 632 .IL99&. ~"''''' ........ ~~ ....... ""~"'..,"" .... ~~"' ...... ~ ~ ...... ...,..., ....... 29. 10' 27.7'B 31.303 33.319 27 26 26 26 1.'1 ...... Pe .. cent 1970-83: 2:S -------------. .------.------102.602 109.303 119.60B 12<;1.:S00 19 •• ••••••• 64.387 7.902 "" .... """"' ..... 72.289 49 Yo 39.798 I. '73 .. ...... , ........ 40.371 27 Yo 32,'31 1.964 1.071 ..,""~"" ........ .., 3',:S66 24 Yo -------149.226 .982 1983 ... -... ••••••• B3.B13 93.8'8 10.477 12,316 ............ 41\10"" .. tIiIrIr ...... "'''' .. 94.290 106. 174 '2 " 46.92' '4.037 1.840 1.900 .................. """ .. ......... ""' ...... 49.76' " •• 37 27 27 36.884 42.'71 2. 161 2.'36 If" 1.2'2 ........ ..,"" ..... '" .., .... ""..,"" ......... 40.010 46.3''9 2a 22 .-------------IB3.06' 20B.470 Nt,. 4/84 Jlt2 Table 2a. END OF CALENDAR YEAR STATISTICS --~--~-~----------------------------------------. +++++++++++++++ A E L 1& P +++++++++++++++ Re-sidential Qeneral Hot Water All Electric 198:2 4,470 :2,008 1,344 1983 4,:221 1,959 1,967 X Chg. -5.6 -2.4 46.4 1982 :28,439 :25,647 :29,727 1983 :28,258 :25,743 39,857 X Chg. -0.6 . " 0.4 34. l' --------------~--------------------------- Subtotal 7,822 8, 147 4.2 83,813 Comm.rci.l 1, 186 1,250 5.4 46,925 54,037 Qovernment :237 264 11.4 36,884 42,571 Outside Lighting 79 74 -6.3 187 145 Str •• t Lighting 120 121 0.8 778 1,021 -=-==== -=----= ----=== ---=-----====-AEL&P Total 9,444 9,856 4.4 168,587 191,632 +++++++++++++++ o H E A +++++++++++++++ Residential Commercial Government Street Lighting 1,018 1, 144 47 50 52 3 3 12.4 25. 5 4.0 0.0 10,477 1,840 2, 161 73 12,316 1,900 2.536 86 12. C" 15.2 31. 2 17.6 3.3 17.8 ----=----------------_.-=-------=_. ____ a_a. QHEA Total +++++++++++++++ CO'" BIN E D +++++++++++++++ R •• idential Oo"e..,.n.ent Out.ide Lighting .JUNEAU Total 1, 118 8,840 1,233 287 79 123 1,258 9,291 1,309 316 74 124 12. 5 5. 1 6.2 10. 1 -6.3 0.8 14,551 16,838 94,290 106,174 39,04~ 187 851 5~,937 45, 107 145 1, 107 15.7 12.6 14.7 15. 51!" -22.5 30. 1 -----=-------------_. ---=-----=-=-= --_ .. 10,562 11, 114 5.:2 183,138 :208,470 13.t1!1f' APA 4/84' Jl4 " - ... AEL&P Octbber through Aeril Sales {million kWh} Class Residential Customer 1980 1981 1982 1983 1984* General 18.6 18.1 18.5 17.8 18.2 Hot Water 11.0 12.9 15.7 15.7 16.2 All Electric 1.3 6.5 19.1 24.0 32.7 TOTAL 30.9-37.5 53.3 57.5 67.1 *Apri 1 sales estimated. The trend toward all-electric homes through 1983 is further shown by the shift in the number of AEL&P customers from the general class to the hot water and all-electric class . Number of AEL&P Customers Class of Residential Customer Dec l 80 Dec l 81 Oec'82 Dec l 83 Genera 1 4,829 4,327 Hot Water 1,753 1,886 All Electric 348 872 4,470 2,008 1,344 4,221 1,959 1,967 4,256* 1,998 2,130 TOTAL 6,940 7,085 7,822 8,147 8,384 *As of March 1984, approximately 800 customers are boat slips with 150 live aboard. -This results in less than 50% of the total customers now in the General class. AEL&P data was presented above since GHEA does not report residential classes in this form. AEL&P serves 90 percent of the area customers and ;s considered representative of GHEA customers. . The shift in the residential sector to the hot water and all-electric classes caused the use per customer in the sector to increase. Tracking this energy use for both AEL&P and GHEA for the last several calendar years shows: Residential Customer Energy Use CYl979 CY1980 CY1981 CY1982 CY1983 Average No. of Customers 7,197 7,490 7,801 8,493 9,074 Residential Energy Sales 51.2 58.2 72.3 -94.3 106.2 ( m i 11 ion kWh) Use per Customer (kWh) 7,110 7,770 9,270 11,100 11,700 The increases in use per customer can be attributed primarily to new electric heat and hot water use, however, part of the 1982 increase is due to the cold weather during that year's heating season. A summary of heating degree days for the past 25 years is shown in Table 3. ~ Economic and construction information was obtained from contractors, utilities, and Borough officials. A summary of the major points revealed: 5 .... Tabl. 3. ,JUNEAU AIRPORT HEATING DEQR'EE DAYS ~ . FY Oct Nov Dec "'an F.b Ma,. Ap,. I'IAV "'un "'ul Aug Sep -: .. 1 •••• .-~-----=----.-== .. =.=--.-----.. -======-.-=--=---======.-------.-19~9 736 928 1076 1449 1022 959 781 :.92 285 328 378 498 90 2 1960 7~7 911 926 1146 911 1019 713 470 409 321 3'5 466 84'V4 1961 660 915 956 1062 932 938 746 S38 371 262 339 '11 82" C 1962 760 1027 1246 1182 1097 1095 756 627 447 250 305 486 92tE 1963 645 810 1132 1147 885 1023 846 SOO 431 288 244 375 832~ 1964 625 1093 993 1098 835 1118 ·785 610 336 324 341 453 8/:l~7 1965 614 980 1496 1291 1154 923 813 693 481 292 291 435 94. ~ . 1966 654 1045 1182 1146 1090 1011 805 661 355 265 382 466 9111f e 1961 812 1191 1188 1291 963 1261 824 592 300 340 303 444 95. C; 1968 671 973 1162 1432 1043 984 808 S08 374 248 281 516 900C 1969 802 920 1405 1801 1219 1054 727 464 218 343 448 521 99;:~ 1970 724 975 921 1329 830 876 770 601 422 387 405 553 87 :::: • 1971 783 1110 1343 1607 1029 1112 784 658 346 227 290 504 97~'::. 1972 811 1001 1360 1519 1315 1186 906 618 432 207 293 535 101 :::: 1973 810 907 1275 1423 1126 986 752 584 404 343 404 505 951C; 1974 732 1253 1143 1550 1006 1242 765 556 437 349 315 437 918~ 1975 690 851 957 1296 1129 1063 791 541 402 281 337 402 87C 1976 712 '1088 1244 1132 1131 1006 706 597 384 280 215 427 8<1S: 1977 679 717 938 918 690 893 673 531 320 243 196 428 1'?/; 1978 695 1062 1423 1233 922 954 683 525 317 298 262 427 8a 1 1979 612 1037 1134 1310 1505 904 712 528 378 251 205 415 9051 1980 609 830 1187 1404 895 949 678 477 278 283 308 472 83FC <,. 1981 628 783 1333 843 899 786 772-392 316 257 275 469 775::: 1982 682 841 117' 1584 1213 1011 816 627 257 220 310 435 91;ri 1983 699 1027 1029 1073 924 931 663 470 272 235 311 502 81 : ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~- Ii' 25-Vea,. Av.,.ag. 704 971 1169 1317 1031 1014 763 558 359 285 315 467 89",:; ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ '" 1984 701 989 1425 1015 839 794 Sou,.ce: Climatological Data, National Oc.anic and Atmosphe,.ic Admin. 6 o Residential Sector Plans: Essentially all new housing in 1982 was all- el ectric. The 1983 constructi on showed a trend back to fuel oil heati ng systems with about 50 percent of homes being built at the start of the 1984 season being all-electric. Basically, most single-family residences being built were oil-heated while multi-family units were all-electric. About 75 percent of new residential units are multi-family and 25 percent single-family. A number of re-conversions back to oil systems were also noted by heating contractors. o Commercial Sector Plans: Growth in this sector should continue strong this year with completion of the Fred Meyer store, Jordan Creek Mall, expansion of Nugget and Mendenhall Malls, and construction of numerous office and other buildings throughout"the city. The Gold Creek Development should contribute significantly to, growth in the downtown area. o Government Sector Plans: Moderate growth should continue in this sector to meet new programs and maintain existing state positions in Juneau. Federal employment should continue at its present level. Nearly 300,000 square feet of additional space requirements, at a minimum, have been identified by 1991, and an additional 300,000 square feet of optional office space according to load forecasts by AlE&P. o Noranda Mining Corporation is continuing plans for operation of its' Greens Creek site on Admiralty Island by about 1987. Approximately 300 employees would be involved, with most living in Juneau. o Evaluation of future mining at the AJ and Treadwell Mines is continuing. It is estimated that AJ could process 10,000 to 20,000 tons of ore per day and Treadwell about 1,000 to 2,500 tons a day. This would require an electrical supply of about 22.5 mw. These loads are not included in the forecasts. 7 EVALUATION OF BASIC DATA This section evaluates the basic historic data, explains the recent growth, and looks for trends that could affect future growth. Residential Sector A summary of October through April AEL&P residential sales and number of customers for the past five seasons was presented in the previous section. Examination of this data shows the following trends: Residential Sa 1 es bl Cl ass of Customer . Oct-Apr Oct-Apr Oct-Apr Oct-Apr* FY 1981 FY 1982 FY 1983 FY 1984 Increase Increase Increase Increase Class Gwh % Gwh .% Gwh % Gwh % Genera 1 -0.5 -2.7 0.4 2.2 -0.7 -3.8 0.4 2.2 Hot Water 1.9 17.3 2.8 21.7 0.0 0.0 0.5 3.2 All Electric 5.2 400.0 12.6 193.8 4.9 25.6 8.7 36.2 TOTAL 6.6 21.4 15.8 42.1 4.2 7.9 9.6 16.7 *April sales estimated. General Class Sales have decreased slightly the past few years to users without electric hot water heating and have increased to those with electric hot water heaters. Overall, the net increase has been about 3.8 per- cent annua 11y. Number of customers has declined 5 percent between December 1980 and March 1984. Use per customer has increased about 3 percent annually the past few years. All Electric Class Almost all homes built from 1979-1983 were in the all-electric class. This trend is diminishing with about 50 percent of new residences presently being all-electric. For FY 1981 through FY 1984, 87 percent of the increase in October to April AEL&P residential energy use occurred in the all-electric class. October to April energy use during the past five years increased from 1.3 million kWh (4 percent of total residential use) to 32.7 million kWh (49 percent of total residential use). 8 .. ... Commercial and Government Sectors Commercial Sales have increased about 11 percent,annually since 1979, however, the increase for 1983 alone was 15 percent. This sector accounts for 27 percent of energy sales. Government Sales have increased about 10 percent annually since 1979, however, the 1983 increase amounted to 16 percen.t. This sector accounts for about 22 percent of energy sales. Residential Energy Use Per Customer Residential customer use increased 4,590 kWh per customer (65 percent) between 1979 and 1983, primarily because of the trend to all-electric heating. A breakdown in energy use in the various classes for the past five years show: General Hot Water All Electric CY1979 5,.850 11,070 23,560 Kwh per Customer Class CY1980 5,970 11,520 24,530 CY1981 6,070 12,120 23,760 CY1982 .6,460 13,060 26,590 CY1983 6,500 12,980 24,075 A summary of recent trends in electrical use in the Juneau area is shown in Table 4. Weather Influence on Energy and Capacity Juneau power demands have always been sensitive to weather and this is clearly shown on Table 1. where the 1981, 1982, and 1983 generation and peak figures are shown. The cold 1982 season resulted in increases in energy and peak demand of 21.7 percent and 29.2 percent respectively while the' warm 1983 season following the cold 1982 season resulted in an energy increase of only 12.4 percent and a decrease in the peak of 3.6 percent. It is then possible to adjust the ~nergy usage during cold and mild winters to annual heating degree days to determine what that usuage would have been during an "average" winter. Table 5. presents a surrmary of adjusted, net generation figures for the past winter. It shows that an tlaverage" winter would have required about 4 million more kWh of energy than was actually generated. If the past winter had been colder than normal, calculations show that about 12-15 million kWh of additional energy would have been required. FV79 ... --_. Population 19, 174 Re.identi.l Cu.tom.r. 7, 197 All-Electric Cu.tomer. 69 Re.identi.l a.l •• U1WH) :U, 168 :::l Commerci.l aal •• (HWH) 37,137 Government 8.1e. CHWH) 31,303 Re.identt.l Sal •• 43 X of Total Commercial Bal •• 31 X of Total Oov.rnment B.l •• 26 X of Total T.ble 4. JUNEAU AREA. RECENT ELECTRIC TRENDS Ch.nge Change Ch.nge (--x--) FVBO <--x--) FVBl <--x--> FV82 .. -... -. -_ .... ----==--....... =--........... :a=c ..... 2 19,'00 3 20,08' 7 21,49' 4 7,490 3 7,725 7 8,267 110 14' 259 '20 101 1,043 14 :58,31:5 24 7';1.,';1.89 30 94,';1.90 ';/. 37,867 7 40,371 21 48,76:5 6 33,318 7 3',:566 12 40,010 45 9 49 '2 -6 29 -7 27 ° 27 0 26 -8 24 -13 21 Ch.nge <--X--) _ ....... 6 6 60 13 1:5 16 -2 ° FV83 ._.-._- 22,880 8,800 1,670 106, 174 :5',937 46,3'9 '1 27 22 APA 4/84 Jlt4 ....... ....... T.ble :So ~NEAU NET GENERATION ADJUSTED DEGREE DAY S ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Va"i.tion '"om Ave"age 2S-Vea" ~~~~~~~~~~~~~~~~~ Month Actual Ave"age Deg"ees ( OX) -----------------------------_ ....... - Oct 701 704 -3 -0.4 Nov 989 971 18 1.9 Dec 1,425 1,169 256 21. 9 J.n 1,015 1,317 -302 -22.9 Feb &39 1,031 -192 -18.6 M." 794 1. 014 -220 -21.7. [1] Deg"ee Dav. pe"cent va"i.tion time. 0.5 [2] AdJu.tment pe"cent time. net gene".tion. <FV84> Net Oene"ation OWH -----.. 20.4 22.4 27.3 24. 1 21. 8 21.5 -------137.5 FOR WEATHER Tempe".tu"e AdJustment ~~~~~~~~~~~~~~~~~~ OX [1] OWH [2] , -------.... _---- 0.2 0.0 -0.9 -0.2 -10.9 -3.0 11. 5 2.& 9.3 2.0 10.8 2.3 AdJusted Net Gene"ation GWH ------- 20.4 22.2 24.3 26.9 23.& 23.& -------141. 5 APA 4/84 Jlt5. ESTIMATE OF FUTURE DEMANDS Estimates for future loads were made for three cases which are identified as low, medium, and high projections. Assumptions The FY 1984 estimated loads were based on net generation data for the first six months of the fiscal year and were extended to a 12 month period by assuming that the growth rate for the second half of the year would be essentially the same as the rate for the first half. 'Additiona1 assumptions include: All cases Population Growth (based on estimates in the April 1983 !lJuneau Economic study" by Homan-McDowell and forecasts. for AEL&P prepared by CH2M Hi 11 ) . 1983-1990 1990-2000 Population per residential customer Residential Use per Customer~ Single Family General Class Hot Water All Electric Multi -Fami 1y General Class Hot Water All Electric Low Projection Case Residential Sector 3% annually 2% 2.6 7,500 kWh annually 12,900 kWh annuallY1/ 26,000 kWh annually- 6,000 kWh annually 12,900 kWh annual1Y2/ 22,000 kWh annua1ly- General Class: About 40 percent of new customers are going into this class in 1984. This is assumed to increase to 80 percent by 1990 and hold constant thereafter. Hot Water Class: About 10 percent of new customers in 1984 are going into this class and this percentage is assumed to remain unchanged for future years. All Electric Class: About 50 percent of new customers are going into this class in 1984. This is assumed to decrease to 10 per- cent by 1990 and hold constant thereafter. 1/ From a sample of individual residential use in the Lakewood area. (AEL&P) g; From a sample of users in the Parkshore Condominiums. (AEL&P) 12 ,... New residential construction is about 75 percent multi-family in 1984. This is assumed to increase to 90 percent by 1990 and hold constant. Annual increases in use per customer are assumed to decrease to o percent by 1986. Use per customer will then decrease starting in 1988. This decrease is assumed to reach 2 percent annually by 1995 and remain at that figure thereafter. Commercial Sector Loads in this sector were assumed to increase by 12 percent in 1984; 8 percent in 1985; and 4 percent annually for all following years. Government Sector Loads in this sector were assumed.to increase by 10 percent in 1984; 6 percent in 1985; and 3 percent annually for all following years. Medium Projection Case Residential Sector General Class: About 40 percent of new customers are going into this class in 1984. This;s assumed to increase to 70 percent by 1990 and hold constant thereafter. Hot Water Class: About 10 percent of new customers in 1984 are going into this class and this percentage is assumed to remain unchanged for future years. All Electric Class: About 50 percent of new customers are going into this class in 1984. ThiS is assumed to decrease to 20 per- cent by 1990 and hold constant thereafter. New residential construction is about 75 percent multi-family in 1984. This figure is assumed to remain unchanged for future years. Annual increases in use per customer are assumed to decrease to o percent by 1988. Use per customer will then begin to decrease. This decrease is assumed to reach 2 percent annually by the year 2000. Commercial Sector Loads in this sector were assumed to increase by 12 percent in 1984; 10 percent in 1985; and 5 percent annually for all following years. Government Sector Loads in this sector were assumed to increase by 10 percent in 1984; 8 percent in 1985; and 4 percent annually for all following years. 13 High Projection Case Residential Sector General Class: About 40 percent of new customers are going into this class in 1984. This is assumed to increase to 50 percent by 1990 and hold constant thereafter. Hot Water Class: About 10 percent of new customers in 1984 are going into this class and this percentage is assumed to remain unchanged for future years. All Electric Class: About 50 percent of new customers in 1984 are going into this class. This is assumed to decrease to 40 percent by 1990 and hold constant thereafter. New residential construction is about 75 percent multi-family in 1984. This figure is assumed to decrease to 60 percent by 1990 and hold constant thereafter. Annual increases in use per customer are assumed to decrease to o percent by 1990. Use per customer w'j 11 then begi n to decrease. This decrease is assumed to reach 1 percent annually by the year 2000. Commercial Sector Loads in this sector were assumed to increase by' 12 percent in -1984 and 1985; and 6 percent annually all following years. Government Sector Loads in this sector were assumed to increase by 10 percent in 1984 and 1985; and 5 percent annually for all following years. Tables 6. through 8. present the load forecasts for the three cases through the year 2000. /I T.~h •. E8T1HATE OF FUTURE DEHAND LOW PROJECTI ON Ac'ual lie: tual FV FV FV FV FV FV FV FY FY FV FY 1982 1983 1984 1985 1"8. 1987 1988 1989 1"0 1995 aooo ... _--...... • ••••• ._ .... ._----_._ .. -... _.-____ a. ---_.-•••••• .. _.-. Popul.Uon al.495 22.880 23.'66 a4.273 25.002 a,. 752 a •• 524 27.3ao 27.86. 30.'.' 33.9.9 P.o,l. ,.r Cu.'a •• r 2 .• 2 .• 2 .• a .• 2 .• 2 .• 2 .• a .• a.6 2.6 a.6 R.,ld.n".l Cu,'o •• rs a.a., 8.800 9.064 9.336 9.616 9.904 10.20a 10.508 10.718 ".833 13.06' (Av.".,.) R.,ld.n'I.1 a.l., (H .. hrlc 45'X) O.n.ral Cl •••• Cueto •• r, ,.289 5.169 5.a75 5.41 I 5.565 ,.738 5.931 6 •• 45 6.313 7.206 8. I'll KWH/Cue'o •• r 7.052 6.500 6.562 6.591 6.586 6.578 6.537 6.462 6.356 5.71a 5.138 Million KWH 37.3 33.6 34.6 35. 7 36.6 37.7 38.8 39. 7 40. 1 41.a 42. 1 Ho' W.'.r Cl •••• Cue'o •• r, 1.935 1.961 1.987 a.015 .,.043 2.071 2.101 2. 13a 2.153 a.264 a.387 KWH/Cu,to •• r 13. 100 la.900 13.029 13.0'4 13.094 13.094 13.029 12.998 12.705 11.484 10.381 Million KWH 25.3 25.3 a,. 9 26.4 26. 7 27. I 27.4 27. 5 27.4 26.0 24.8 t-' <.n All El.c'rlc CI •••• Cu.'o •• r, 1.043 1.670 . 1. soa 1.911 2.009 .,.095 a.170 2,231 2.252 a.363 a.4.7 KWH/Cu,'o •• r a6.7oo a4.500 a4.634 a4.670 24.595 24.530 24.354 24.065 a3.689 .U.343 ".230 Million KWH a7.8 40.9 44.4 47. 1 49.4 :11.4 52.8 53. 7 53. 3 50.4 47.8 Sub'o'.l R •• ld.n'I.I. Million KWH 90.' 99.9 104.9 109. a l1a.8 116.3 119.0 laO.9 120.a 117.6 tt4.7 Co ... rcl.l 8al •• (H .... rlc 3O'X) Bub'o'al Co ... rcial. Million KWH 46. 7 53. 5 59.9 64. 7 .7.3 70.0 72.8 75.7 78. 7 95.a 116.' Gov.rn •• nt a.l., (Hhbrlc 25X' Bubtot.1 Gov.rn •• n'. Million KWH 37. I 43.7 48. I 51.0 53.8 55.4 57.1 58. 8 60.5 7a. 7 84. a Stl' •• t LI,btln,.R •• ld.ntial .. Gov.rn •• nt. "'Ilion KWH 1.0 1. a 1.2 I.a 1.2 1.3 1.3 1.3 1.4 I. , Tot.l Bal.,. "Illlon KWH 174.2 198.0 a14. I aa6.0 a35. 1 24.,.9 a50. I a56. 7 a61. 4 287. 5 317.0 H.t Gen.ra'ion. "ill ion KWH ( U 5X 0' 8al .. ) a02." aa4.0 a46.2 260.0 a70.3 a79.3 aS7.7 295.2 300 .• 330.6 364.' BWI"'. C.p. F.ctor • II 55.0 63.0 68.0 55.0 55.0 55.0 55.0 55.0 55.0 55.0 55.0 P ••• D •• and. HW 42.0 40. 1 41. 3 54.0 56. 1 5S.0 59. 7 6l. 3 62. 4 68.6 75. 7 11 MUd wln'.r. caue.d 1983 an' 1984 to '''''I'. ItPA 4/84 Jlt6 Tab .. 7. ESTIMATE OF FUTURE DEMAND ttEDIut1 PRO..JECTJON At'u.l Attu" FV FY FV FV FV FV FV FY FV FV FY 198iI 1983 1984 1985 1986 1987 1988 1989 19'90 1995 gooo ____ e. -.... • ••••• '!fII ••• -. • ••••• •••••• • ••••• .... -. • ••••• •••••• --.... Popul.Uon 21 •• 'D 22.880 ·23.566 :'!l4.273 25.002 25.752 26.524 27,320 27.866 30.767 33,'6' P.o,l. ,.~ Cu.'o •• ~ 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 R •• '~.nt'.1 Cu.to •• ~. 8.267 8.800 ,.064 9.336 9.616 9.904 to. 202 . 10.508 10.718 11.833 13.065 'Av.~ ••• J R •• ".n, •• 1 a.a •• CHhh~ic 45'1' Q.n.~.a Cl •••• Cu.to •• ~. S.aet 5. 169 D.27:1 5.397 5.537 5,696 5.874 6.073 6.220 7.001 7.863 KWH/Cu.to •• ~ 7.052 6.:100 6.627 6.724 6.788 6.819 6.815 6.7-77 6.707 6.207 '.602 Million KWH 37.3 33.6 35.0 36.3 37.6 38.B 40.0 41.2 41.7 43.' 44. I Hot ....... ca •••• Cu.'o •• ~. 1.935 1.96& 1,987 2.015 2.043 2.071 2. 101 2. 132 2.1'3 2.264 2.387 KWH/Cu.h •• ~ 13. 100 12.900 13. 15S 13.355 13.4B9 13.556 13.556 13.4S9 13.354 12.3IY.Z II. 192 Million KWH 25.3 25.3 26.2 26.9 27.6 28. I 2S. 5 29.S :ilB. 7 :ilB.0 26.7 ...... All EI.c'~'c ca •••• O"! Cu.'o •• ~. 1.043 1.670 1.802 1.924 2.036 2.137 2.227 2.303 2,345 2.&68 2.814 KWH/Cu.h •• ~ 26.700 24.:100 24.S79 25. &60 25.336 25.402 25.353 2:5. &97 24.915 :l3.012 20.727 M'lilan KWH 27.B 40.9 44.B 4B. 4 :51.6 54.3 :56. 4 :5S.0 :J8. 4 '9. I sa. 3 Subtot.1 R •• I~.n'I.I. HUlion KWH 90. 5 99.B 105.9 111.6 116.7 121. 2 125.0 liil7. 9 H!8. 9 130.6 129. I Co ... ~el.1 Bal •• CHhh~ic 3OX' Subtot.l Co ... ~c'.I. Million KWH 46.7 :53.S 59.9 65.9 69.2 72.7 76.3 80.1 84. I 107 .• 137.0 Oov.~n •• nt a.l •• CHhh~lc 2S'U Subto'.1 Qov.~n •• nt. HUUon KWH 37. I 43. 7 48. 1 :51.9 5S.3 :57.5 59.S 6ii1.2 64.7 81. 2 98.8 Btr •• ' LI""n.,R •• I'.ntl.1 .. Oov.rn •• nt. MUllan KWH 1.0 1.2 I. 2 1.2 l.2 1.3 1.3 1.3 1.4 I. S Tohl a.h •. MUUon KWH 174.2 198.0 ~IS. I 230.6 24ii1.4 252.6 262.4 271.5 279.0 320.6 366. 4 N.' O.n.~.Uon. MUllon KWH C 115'1 0' B.I .. ' 202.9 224.0 247.4 26:5.2 27B.B 290.' 301.7 312. 3 320.B 368.6 421.4 SV.' •• C.p. Facto~ '1 II 5:1.0 63.0 68.0 55.0 55.0 55.0 5:1.0 55.0 55.0 55.0 55.0 P ••• D._n'. HW 42.0 40. I 41. 3 5:5. & 57. 9 60.3 62. 6 64.S 66.6 76.5 B7.S 11 HI U wlnhr. eau •• ' 1983 .nd 1984 to 'iffer. APA 4/84 "U7 .. T.U. 8. E8TlKATE OF FUTURE D£KAND HIOH PRO..JECTlOH Actu.l Actuel FV FY FV FV FY FV FV FY FV ,.., ,.., 1982 1983 1984 198' 1986 19B7 1988 1989 1990 I"' aooo •••••• _ .. -. .. _.-. • ••••• •••••• • ••••• • ••••• • ••••• ..--.. •••••• • ••••• Popul.Uon al.49' ZI.880 23.866 a4.a73 a5.ooa a'.7,a a6.'Ol4 a7.320 Ol7.86. 30.767 33 •• '. P.op •• p.r Cu.t ••• r a.6 2.6 2.6 a.6 2.6 2.6 2.6 a. 6 Ol.6 2.6 2.6 R •• ld.nt, •• Cu.to •• r. 8.a67 8.800 9,064 9.336 9.616 9.904 10.20a 10.508 10.718 It. 833 13.065 CAv.r ••• ' H •• ld.n.l.l B.l •• CHhtoric 451.' G.n.r.l Cl •••• Cu.to •• r. '.289 5. 169 '.27' ,.389 5.509 5.639 ,.779 '.9a6 6.031 6"ea 7.204 KWH/Cu.to •• r 7.0'2 6.,00 6.627 6.7'8 6.B9Ol 6.996 7.061 7. 104 7. 106 6.939 '.607 "&111on KWH 37.3 33.6 3'.0 36.4 38.0 39.4 40.8 42. 1 4Ol.9 4'.7 47.6 Ho' W.t.r Cl •••• Cu.to •• r. 1,93' 1.96l 1.9B7 2,01' Ol.043 a.071 Ol.IOI Ol.132 a.153 2,264 Ol,381 KWH/Cu.to •• r 13. 100 12.900 13. I'S 13.4OlI .3.690 13."5 14.034 14.104 14. 104 13.1" 13.09. "tliion KWH a,. 3 a,. 3 26. a a7.0 2B.0 OlB.B a9.' 30.1 30.4 31. I 31.2 ...... All El.ctrlc Cl •••• -.....,j Cu.to ..... 1.043 1.610 I. Boa 1.933 2.064 Ol. 194 Ol.3Ola a.450 2.'34 2,981 3.473 KWH/Cu •• o .... a6.700 a4.,00 24,878 a,. 286 Ol'.717 26.04' 26.a,B 26,354 26.336 Ol',606 Ol4,292 "UUon KWH a7.B 40.9 44.8 4B.'( '3. I '7. I 61. 0 64,6 66.7 76.3 B4. 4 Bubtot.l R •• I'.ntl.l. "'l1lon KWH 90. , 99.B 10'.9 Ita. 3 119.0 la,. 4 131.3 136. 7 140.0 1'3.Ol 163. a Co ..... cA •• B.l •• CHhto .. lc 301., Sub'ot •• Co ..... cl.l. "Ullon KWH 46.7 53. 5 89.9 67. I 71. I 75.4 79.9 B4. 7 89.8 lOlO.Ol 160.1 Gov ... n •• nt 8 •••• (Hhh .. lc Ol5X' 8ubtot •• ~v ... n •• nt. "'ilion KWH 37. I 43. 1 48.1 52. 9 56.B '9. 7 6Ol.6 6'.B 69. I 90.6 115.7 8t .... t Li.,t'n,.R •• id.nt, •• .. Gov ... n •• nt, "illion KWH 1.0 I. Ol I. a 1.2 l.Ol 1.3 1.3 1.3 1.4 1.5 Tot •• 8 ..... "'Ilion KWH 174.2 19B.0 21'. I Ol33. , Ol4B.Ol Ol61.6 27'.2 aOB. \') 300. I 365.4 441. Ol N.t G.n .... tlon. "' .. Ion KWH "151. ., e.l .. , Ol02.9 aOl4.0 247.4 26B. , 2B'.4 300.9 316.4 331.0 345.2 4OlO.Ol S07.4 BII.t •• C.p. F.ctor X 'I ". 0 63.0 6B.0 55.0 ".0 5'.0 55.0 550 ".0 55.0 55.0 P ••• D ••• nill • ..... 42.0 40. I 41.3 '5. 7 59.2 6a. , 65. 7 68. q 71.6 B7.Ol 10'.3 II Mtld wlnhr. c.u ••• 19B3 .nd 1984 to d""r. APA 4/B4 JUB RESULTS AND CONCLUSIONS Considerable increases in electric power use have been experienced in Juneau in the past few years. These increases reflect substantial growth in the area's economy and the shift from oil to electricity for a significant part of space heating. Weather related factors have also played a role in creating large increases during certain years. This is shown by the increases in energy use in 1981; 1982, and 1983 of 16 percent, 22 percent, and 10 percent, respectively. These three years consisted of a warm weather year followed by a colder year, followed by a warm year again. Adjusting those years for weather would result in increases of about: 1981-18 percent; 1982-17 percent; and 1983-15 percent (if the interruptible customers were not shut off, 1983 would have been about 17 percent). The first six months of fiscal year 1984 indicate that this high growth has started to decrease as energy use was only about 10 percent higher than the same period in 1983. This can be attributed to a number of things; the first being the stabilization of oil prices and hydro shortages during winter months have made oil heating systems attractive again. Also, the tremendous spurt in construction activity following the capital move vote has started to subside. Home building permits numbered over 900 in 1983 whi.le 1984 is expected to see fewer than 500. The three forecasts prepared for this study included low, medium, and high projections. The following general statements relating to annual electric growth under the latest estimates can be made: Low Projection -Future annual growth decreases from the 9.9 percent projected for 1984 to about 1.8 percent by 1990. Annual growth from 1984 to 1990 is about 3.4 percent and about 1. 9 percent from 1990 to 2000. Annual growth from 1984 to 2000 is about 2.5 percent. Medium Projection -Future annual growth decreases from the 10.4 percent pro- jected for 1984 to about 2.7 percent by 1990. Annual growth from 1984 to 1990 is about 4.4 percent and ab04t 2.8 percent from 1990 to 2000. Annual growth from 1984 to 2000 is about 3.4 percent. High Projection -Future annual growth decreases from the 10.4 percent pro- jected for 1984 to about 4.0 percent by 1990. Annual growth form 1984 to 1990 is about 5.7 percent and about 3.9 percent from 1990 to 2000. Annual growth from 1984 to 2000 is about 4.6 percent. Figure 1. graphically compares this year's forecast and those completed previousl y. A comparison of Juneau area hydro power resources and forecasted demands is shown on Table 9. The firm energy deficit which began in 1983 increases each year and by 1988 amounts to a shortage of 67 million kWh for the low projection case, 81 million kWh for the medium projection case, and 95 million kWh for the high projection case. Deficits would also occur under average energy conditions since the Juneau area load is not large enough to utilize the large portion of this average energy occurring in the fall. Colder than normal winters will also have a serious effect on energy deficits. 18 " ". .. APA presently has plans to temporarily increase the storage capacity at Long Lake by installing a small timber dam structure at the outlet. Modifications are scheduled for the summer of 1984 and could result in an increase in average annual generation of about 4-6 GWH. AEL&P is presently underway with the rehabilitation of the lower Salmon Creek Power Plant._ This work could result in an increased average annual generation capahility of 15-19 GWH. However, due to timing of the runoff, this total amount may not be available each year. Although increased costs of energy (rate increases) were not evaluated for this study, it is obvious that consumers are more conscious of their energy usage and try to conserve where possible. As rates continue to increase, price elasticity will become an important factor in future load forecasts. The overall conclusion of this study is that the Crater Lake addition to Snettisham is needed regardless of which forecast is chosen as from 60 to 90 percent of the project's output could be utilized in 1988. APA will continue to monitor and assess energy use and changing economic conditions in order to determine the appropriate generation facilities beyond Crater Lake and the optimum timing for these facilities. Potential hydro sites beyond Crater Lake would include Long Lake Dam, Lake Dorothy, Sweetheart Lake, and Speel River. The two local utilities (AEL&P and GHEA) , APA, and the Alaska Power Authority are jointly sponsoring a contract study with Ebasco Services, Inc. to look into the future development of generation facilities in the Juneau area. This reconnaissance level study will assist in defining the best utilization of the area's hydro resources and is expected to be completed this summer . • 1'1 i 1 1 i Go r. K W H Comparison of Fi !tv.,.. 1.. ESTV'tATED EI£RGY REQUl:REr1EHTS ~ I I I I I I I I 4~o. I I I. I I I I I I 40()" I I I I I I I I I :3~0+ I I I I I I I I I :300" I I I I I I I I I 2~ I I I I I --------------------------_.--._------------------- I I 21 J l.~ot ~ I -I ./ I / I -I / I ...... -l.oo! /-I I- I ,./- 1 _/ 1/ I- I ~ I I I I I I I I I 0+ ... I / (. +----... -------------... -------+-+---------+--------_. -n ~ ~ ~ ~ ~ 0 YEA R 20 TABLE 9. COMPARISON OF JLNEAU AREA HYDRO RESOURCES AND ESTIMATED LOADS ======== Fir-m Arlnual Ener-,!!,,! GWH 5nettisham Lonq Lake 179 AEL&P 1-1'1' dr'o 42 stimat.~ Loads and De+icits (GWH =========================== FY .1.985 19.'3G 1987 1SS.S Low Pr'o Ject ion Estimate~ Loads De+icit 260 270 279 2S8 -39 -49 -58 -07 ====== 22.1. ME:'~ium Pr-o ject ic'n Estimate~ Loads De+icit 265 279 290 302 -44, -5.S -69 -81 High Projection Estimated Loads De+icit 268 285 301 316 APA 4/84 jlt9 -47 -64 -80 -95 EXHIBIT 14 UPDATED POWER VALUES CRATER LAKE PHASE SNETTISHAM PROJECT} ALASKA JULY 1982 FEDERAL ENERGY REGULATORY COM~1ISSION -.-:-;',. .... .-. -::-::: .... = Ap ri 1 15, 1982 Mr. Harlan E. Moore Chief, Engineering Division Alaska District, Corps of Engineers P. O. Box 7002 Anchorage, Alaska 99510 Dear Mr. Moore: Please refer to your letter (NPAEN-H-HY) of March 10, 1982, in which you re- quested updated power values for the Crater Lake phase of the Snettisham Project, and my letter to you of March 24, 1982. The at-market values of hydroelectric power delivered in the Juneau area are based on the estimated costs of power from an alternative source described as foll ows: A diesel engine-driven generating plant of 7,500 kW total capacity consisting of three 2,500 kW units, heat rate of 10,550 Btu/kWh, operating at a 40% plant factor; capital cost of $530 per kilowatt, service life of 35 years, and fuel and lubricating cost at $1.0795 and $5.00 per gallon, respectively. The following values are based on January 1982 price levels for federal financing at 3-1/3% and 7-5/8% interest rates. Real fuel cost escalation assuming a project-on-1ine date of 1986 is also provided. At Market Value of Dependable Hydroelectric Power Price Level -January 1982 Federal Financing $/kW 3-1/3% 40.17 7-5/8% 61.76 Without Fuel Cost Escalation mill s/kWh 95.04 95.04 With Fuel Cost Escalation mills/kWh 162.28 141. 53 These values include both hydro-thermal energy and capacity adjustments. The capacity value adjustments reflect only the relative reliability factors of the diesel plants. The hydrologic availability factor must be applied to arrive at the total adjusted capacity value. As mentioned in my letter of March 24, 1982, we have not performed a study to determine the usability and timing of the output from Crater Lake. As such, the above values are only applicable to the load-carrying capability of the project for power benefit evaluation purposes. Copy to North Pacific Div. Corps of Engineers Portland, Oregon. Attn: Mr. Nolan Folden -2- Sincerely, ?h~/.A~ ~: F. Kopf~~~ , Regional Engineer "