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HomeMy WebLinkAboutThomas Bay Project Alaska 1965i , r \ , , , l-, A • t ,- \ ". C 0 _>; • " \ IN REPLY REFER TO: UNITED STATES 700 A:rnMAIL State Director Bureau of Land Management 555 Cordova Street Anchorage, Alaska 99501 Dear Sir: Enclosed for your information is one 'copy of my Interim R the potential Thomas Bay Project, dated June 1965, revise 'A.~'.V .. '\'.:, ._ 0. "' Div ~)r ".r"' ':l\ •...•.•... ............ ............... .. -. ! ..• ,:; ._ •..•...........•..........•. , '.:, F, D. ............. ,' ................. ',:.:~ :;. i~:!· ... (.~ •• 0 •••• n •••••.••••• _._ •••••• !',;'l' _ ••...•••.•.•.•.....••..•••. __ .$"'" Cist. I,\~r. or.t. ... OIl... ....•.. 0"" .. Novem- ber 1965. ---------' This project was investigated by the Bureau of Reclamation as a source of power to meet the urgent needs of Petersburg, Wrangell, KB.ke, Ketchikan and Metlakatla areas in Southeast Alaska and to supplement power supplies now being provided by municipally ovmed utilities in each of those cities. You will note that the report recognizes expressions which were received in 1964 fram the cities of Petersburg, Wrangell, Ketchi- kan and Metlakatla concerning their inte~est in the potential project and developments which have occurred subsequent to that date. The latter incluo,e initiation of action by the City of Petersburg to develop a project similar to the Thomas Bay Project at the Thomas Bay site to furnish power supplies for the City of Petersburg. They.alsoinclude"inftiation by the Bureau of Recla- mation of feasibility 1nvestiga,tions of the potential Lake Grace Project to furnish JjoWer 'supplies to the cities of Ketchikan and Metlakatla. A report on the Lake Grace Project, suitable as a basis of recommendations for Congressional authorization, is scheduled for completion in fiscal., year 1967. ..;- In light of th~ above-mentioned expr'6\ssions and developments, the Bureau of Reclamation has deferred further consideration of the Thomas Bay Project pending;" '. ", ," 1. CQrnPletion of our proposed feasibility report on Lake .' \ G~ace Project, " " ..' , . ' -\ , " l '" , •• 1,; -"/ 2. Completion of our planned investigation of an integrated Southeast Alaska Power System, and 3. Completion of" action by the City of Petersburg on its proposal for the Thanas Bay Development. Copies of the report are being transmitted to the cities of Peters- burg, Wrangell, Kake, Ketchikan and Metlakatla and to other concerned agencies and interests for their information. Enclosure 2 George N. Pierce District Manager THOMAS BAY PROJECT ALASKA ARLIS Alaska Resources LibralV & I nfonnation SelVices Library Uuih.llng, Suite 111 3211 Providence Drive Anchorage, AK 99508-4614 INTERIM REroRT Department of the Interior Bureau of Reclsmat10n Alaska District Office Juneau, Alaska June, 1965 Revised November, 1965 Location: Authority: Plan: SUMMARY SHEETS INTERIM REPORT THOMAS BAY PROJEcr ALASKA Near the mouth of Cascade Creek; 15 miles Northeast of Petersburg, Alaska. Act of August 9,1955 (69 Stat. 618) and Appropriation Acts authorizing expenditures by the Bureau of Recla- mation for engineering and economic investigations, and for related reports, for the development and util- ization of the water resources of Alaska. Construct a small concrete overflow structure at the outlet of Swan Lake. Drill a pressure tunnel 11,600 feet long and a penstock tunnel 2,275 feet long to convey water to a 34,500 kilowatt powerplant at tide- water. The tunnel intake, gate shaft trashrack, and surge tank are included in the waterway construction. A 40,OOO.kva switchyard would be located approximately 2,500 feet from the powerplant. Transmission facilities would include 158 miles of 138,OCO-volt and 98.5 miles of 34,500-volt transmis- sion line. Substations would be provided near Wrangell, Ketchikan, and Petersburg. Elentric service would be furnished to the communities of Petersburg, Ka.ke, Wrangell, Ketchikan, and Metlakatla. Project Features Swan Lake Reservoir Elevation of normal full-pool water surface, feet (msl) Area of reservoir at elevation 1,5l4,acres Elevation of minimum operating level, feet (msl) Area of reservoir at elevation 1,36 5 acres Initial active storage capacity, acre-feet Active storage after 50-year sedimentation, acre-feet (No allocation of reservoir space for sediment storage) Hydrology Drainage area, square miles Annual runoff, average (1947-]g62), acre-feet Annual runoff, maximum (1961), acre-feet Annual runOff, minimum (1951), acre-feet a Rev. ll-26-65 1,514 572 1,365 445 72,000 18.9 159,900 204,700 130,400 Pressure Tunnel Length, feet Inside diameter, feet Capacity, cubic feet per second Lining -Reinforced concrete, circular cross section surge Tank Diameter, feet Top elevation, feet Height, above tunnel invert, feet Inside diameter, feet Overall length, feet Number of units Installed capacity, kilowatts Design head, feet Penstock Powerplant Range of gross head, feet Annual firm output, kilowatt-hours x 106 Tailwater elevation, feet (msl) Switchyard Capacity, kilovolt amperes Transmission Lines Thomas l3a.y to Wrangell SUbstation voltage , volts Conductor Size, MCM-ACSR Overall length, miles Miles of steel tower sections Miles of wood pole H-frame sections Long span (1) feet b 11,600 7.5 390 8.0 1,570 325 6.0 2,275 2 34,500 1,408 1499-1350 166 15 40,000 138,000 336 64 15 48 7,100 Wrangell Substation to Ketchikan Substation Voltage, volts Conductor size, MCM-ACSR OVerall length, miles Miles of steel tower sections Miles of wood pole H-frame sections Long spans (3) feet Ketchikan Substation to Metlakatla Voltage, volts Conductor size -Substation to Herring Bay Herring Bay to Metlakatla Overall length, miles Miles of single 'WOod pole secti ons Miles of submarine cable Thomas Bay to Petersburg Substation Voltage, volts Conductor size -Overhead Submarine OVerall length, miles Miles of single wood pole sections Miles of submarine cable Petersburg Substation to Kake Voltage, volts Conductor size Overall length, miles Miles of single wood pole sections Wrangell Substation to Wrangell (Shoemaker Bay) Voltage, volts Conductor size Overall length, miles Miles of single wood pole sections Construction Costs -Costs as of October 1964 Swan Lake Control structure Powerplant Switchyard Substations Transmission Lines General Property Total Construction Cost Interest during Construction Total Federal Investment c " 138,000 336 93 11 80 12,800 34,5,00 397.5"MCM-ACSR 4/0 AWG-ACSR 29 28 0.9 34,500 397:.5 MCM-ACSR 4/0 Copper 19 14.8 4.2 34 500 4/0 AWG ACSR 41 41 34 /500 397.5 MCM ACSR 9.5 9.5 4> 624,000 22,770,000 1,554,000 2,036,000 12,115,000 2,066,000 $41,165,000 3,118,000 $44,283,000 Annual Revenue Deductions Operation and Maintenance Provisions for Replacement Total 407,000 102,000 $509,000 Rate for firm energy at 55 percent average annual plant factor 15.7 mills Benefit -Cost Ratio 1.49 to 1.00 Rev. ll/26/65 d In reply refer to: 700 AIRMAIL UNITED STATES DEPARn-mNT OF THE· INTERIOR BUREAU OF RECLAMATION Alaska District Headquarters P.O. Box 2567, Juneau, Alaska 99801 June 28, 1965 Revised November 26, 1965 To: Commissioner, Washington, D. C. From: District Manager SUbject: Interim Report on Thomas Bay Project, Alaska This letter With its supporting reports, constitutes my interim report on the potential Thomas Bay Project, which was investigated as a source of power to meet the urgent needs of Petersburg, Wrangell, Kake, Ketchikan, and Metlakatla areas in Southeast Alaska and to supplement power supplies now being provided by municipally owned utilities in each of those cities. The major features of the Thomas Bay Project include a pressure tunnel 11,600 feet long and a penstock tunnel 2,275 feet long to con- vey water fram Swan Lake on Cascade Creek to a 34,500-kilowatt power- plant at tidewater operated at an average annual plant factor of 55 percent. The powerplant, to be constructed in two stages, would be located on Thomas Bay near the mouth of Cascade Creek, about 15 miles northeast of the City of Petersburg. Transmission facilities include a swltchyard and 158 miles of l38,000-volt transmission line extending to a substation to be located near Ketchikan. A substation would be provided near Wrangell to serve that community. In addition, a total of 98.5 miles of 34,500-volt transmission line would be included in the system. This would consist of 19 miles of line from the Thomas Bay Sw.i tchyard to Petersburg, of which 4.2 miles would be submarine cable; 41 miles of line from Petersburg to Kakej 9.5 miles of line from the Wrangell substation to Wrangell; and 29 miles of line from the Ketchikan substation to Metlakatla, of which 0.9 miles would be submarine cable. Power would be delivered to all load centers at 34,500 Volts. The estimated construction cost of the Thomas Bay Project is $41,165,000, based on prices as of October, 1964. The average annual tangible bene- fits over a 100-year period are estimated at $2,903,000, and the average annual costs at $1,945,000, or a benefit-cost ratiO of 1.49. Benefits are based on the cost of the most likely alternative source or sources which would provide an equivalent amount of power at the load centers. This was determined to be diesel-electric units located at the load centers, or less econClD1cal small bydroeleetne developnents to serve the incU. v ... idual cities. Based on an all-Federal t1Pe of operation, an averaae rate ot 15.7 JD111s per 1d.lQwatt-hour of t1rm energy so14 voul.d be necusan" to ~ OJ)erating costs and to rep8¥ the fecte.ral investment all.ocated to _ch etase, at 3-1/8 percent interest, 'Within 50 years of the date such stage becanea revenue producing. 1b1s rate t'or firm energy would be the sane at all dellvery pe1Dts and 'WOUld apply to wholesale energy delivered at 34,500 vol.ts. The pertinent prQJect t1Dd1ngs were presented to Pe'tAu"sburg, Wran- "p., Ke1;ebJ.kall, and Metlakatla :1l'1 ~ 1964. A«U*1~ advice coilce~ the poteJ;lt1a1 aJ.teJlfta:~e SWan take and take GMc~ ".h-o",cta were presented to Ketchikan in July 1964. . b f'eu1b1l1W .,.... tS.nd:$.DgI coacezordDa a 15 .. ()()O.kUowa" SW8Il Lake Project were obtained by updating the f:l.nd1nss ot the 1962 ~~ OIl U-t Pl'OJeet! 'rbeJ'. 11lC1-.cated ;ba~ ... coet of ~to lCetcb1lmn and Metlakatla trail tJJat proJect would-be about the· .... as fran the Thomas Bay Project,. . Tne reconnaissance fin41ngs concerDing a potential 20, ()()()"Jd.lovatt Lake Grace Project ind1cated that the cost ot power to.~ and Metlakatla :tran that source would be sigrd.ftcantl¥ leu.· ~ fi"aIl the Thomas ~ ProJect. Also, the I.alraGrace poweI',plaDt voul4 be only 42 transmission line miles tJ."aa. Ketch1kaD, as eanpare4 v1th the 158 tnmsm1ssion line mUes to the 1bana8 Ba¥ poweI',plaDt. Petersburg and Wrangell intol'Jll8l.q expressed desire tor M1"'ly con- struction of the 'l!lQDas Bq Project al a Jedel"al 4eve1opnent to satiety forecast power needs. Metlakatla indicated des11"e to be 1nclu4ed 111 8l\Y Federal proJect propose4 to 1\1m1sh power suppl1es to the Ketchikan-Metlakatla area. The Ketchikan City COUncil, on the advice ot the Ketch1kan PUblic Utilitles AdviElO1'7 Board, iAcUeated that it considered the 1bomaa Bay Project tranan1llion di8tance to be exceSSive for the city's -.101" power supply. The Council, by resolution dated August 5, 1964, I'equeeted the Bureau of Reclamation to expedite its investi- gation of' the lake Grace Project so that power t.rcm that source may be avaUa.b1e to Ketchikan not later than 1973 ... 74. Consideration was given to a smeller !lhClD8s l!ay' Project to turnish POWI' to Petersburg, Wrangell and Kalte. It was concluded that developnent of' a 'lhaDa8 !lay Project without part1e1pat:1oD by Ket ... ch1kan ~d be t1Danc1ally inteasible. The potential pzoJect cities were so advised. 2 '-The City of Petersburg has since received from the Federal Power Commission a preliminary permit for preparation of plans for stage development of a project at the Thomas Bay site similar to the Thanas Bay Project. The city has retained a consulting engineering firm and obtained funds from the Hous1ng and Home Finance Agency for the contemplated studies. ",-.. In light of these circumstances, it is considered that the Thomas Bay Project still merits inclusion in long range planning of powr supplies for Southeast Alaska, but further consideration of the project by the Bureau of Reclamation be deferred pending: 1. Completion of our proposed Feasibility Report on Lake Grace Project, 2. Completion of our planned investigation of an integrated Southeast Alaska Power System, and 3. Completion of action by the Cit¥ of Petersburg on its proposal for the Thomas Bay Development. It is recommended that copies of this report be furnished to the Cities of Petersburg, Kake, Wrangell, Ketchikan and Metl.ake.tla for their information. Enclosure cc: Chief Engineer, Attn: D-700 3 SUPPORTING REPORT OF l3UREAU OF RECLAMATION June 1965 c c c Table of contents REPORT OF THE BUBFAU OF RECIAMATION CHAPTER I---------------------------------------------------------- INTRODUCTION------------------------------------------------------- Location-------------------------------------------------------- History of Investigations--------------------------------------- Acknowledgements------------------------------------------------ CHAPTER II---------------------------------------------------------GENERAL DESCRIPTION-----__________________________________________ _ The Project Area------------------------------------------------The Power Market Area __________________________________________ _ Petersburg __________________________________________________ _ Wrange11-___________________________________________________ _ Ketchikan-_______________________________________________ -__ _ Metlakatla Area---__________________________________________ _ Kake-Duncan Canal Area---------------------------___________ _ Climate ________________________________________________________ _ Population-____________________________________________________ _ 1 1 1 1 4 5 5 5 6 6 7 7 8 9 10 11 CHAPTER III---________________________________________________ -----13 AREA ECONOMY AND RESOURCES--_______________________________________ 13 Basic Resources and Industries--------------____________________ 13 Forestry .. ----------------------------------------------------13 Fishery _________________________________________________ -----15 TouriBm--------------------------------____________________ --16 Mining------------_______________________________________ ----17 Other Industries---------------------------------------------18 Secondary Industry----------------------------------------------18 Transportation-----------------------------------------------18 Business Services--------------------------------------------19 CHAPTER IV--------------------------------------------------------- POWER SUPPLY AND DEMANDS------------------------------------------- Ketchikan Area------------------------------------------_·------- Existing Power Facil1ties------------------------------------ Ketchikan Public Ut11ities .. ------------------------------- Ketchikan Pulp com~---------------------------------- Ketchikan Spruce ~ ---------------------------------- Estimated Power Requirements--------------------------------- Cost of Utility Power and Energy----------------------------- Interim Measures Proposed------------------------------------ Metlakatla Area--------------------. ---------------------------.. - Existing power F'aei1i ties--"-------------.. ------------------- Estimated Power Requirements----.. _ .. --.. ----------------------- Cost of Utility Power and Energy----------------------------- Interim Measures Proposed---------------.--------------------- i 21 21 21 21 21 22 23 23 27 27 30 30 31 33 33 c c Table of contents (continued) Page Petersburg-Wrangell Area-------------------.·--------------------~ Electric Utility Systems and Power SUpply--------------------34 Cost of Utility Power and Energy------------------------------35 Record of Power Use'by Utility CUstaners---------------------36 Non-Utility Requirements and SUpply---------------··----------38 Future Power Requirements of the Petersburg-Wrangell Area----39 Interim Measures Proposed------------------------··-----------41 Kake-Duncan Canal Area------------------.. ----.. ------.. -----------42 Utility System-SUpply, Demand, and Rates---------------------42 Future Power Requirements------------------------------------44 Total Projected Power Requirements and SUpply-------------------45 Load Characteristics--------------·------------------------------50 Non-Firm Energy Market------------------------------------------51 CHAPTER v----------------------------------------------------------52 WATER AND POWER-- - - -.• - - - - - - - - - - - - ---- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -52 Water Resources-------------------------------------------------52 Historical Runoff--------------------------------------------52 study Period Selection---...... --------.. -----.. --------------.. --.. 55 Water Supply for Power-------...... ----.. ----'"-------------------55 Available Reservoir Capacity-.. ~--.. ---.-.... --------------------.u 56 Sedimentation-----------------------.. ,. ----------------------.. ---59 Water Rights-----------------.. ----., --.. --------------------------59 Power Production-·· --------------.. c. - - -•• -•• - - - -•• - - - - - - - --., - --.-•• -- - -60 Power Load and Generating Capacity .. ---------.-----------------60 Operation study-.. -.. ----------.. --.. ---------.. ---------------." --62 Power Head---------.. ----.". --. -_ .. -------------------------------65 CHAPTER VI-------------------.. -----.. ----.. ---~ ----------------------66 PLANS AND ESTIMATES------------------------------------------------66 Plan of Development---------------------------------------------66 Project Works-------------.. --------------.. ----------------------67 Swan Lake------------------.. ---... -----------------------------67 Waterwa.ys-----------------.. ----.. ----.. -------------------__ a' --68 Powerplant .. -----------------------.. --.. -----------.. -----------69 Transmission Facilities------.. -----.. -.. --------------------.. -.. 69 other Facili ties----.. ---------.. ---------.. -----_ .. -.,-----------70 DeSign and Construction Problems--------------------------------71 Accessibility--------------_ .. -.. ----.. ----.. --------.... ----------72 Rights·· of-Way-----.. --u' --•• --•• - - ----- ---- -•• - - ---•• - - - - ----•• - -_ •• -72 Relocations-·. -.. --------..... " -"' --.' --" ---.... -----.. -.. --------------73 Communications----_ .. ---_ .. --.. ----.. ---------.. ----------------.. -73 Geology ----------.. ---------_ .... --_ .. -. ---............ _.-.... ------.. ---------73 Project costs------.... --.. ---.. -_ .. -----------.. --..... -.. ---------------74 Construction Cost-_ .... -----., ----_ ....... --------------------------75 Operation and Maintenance-...... ------.. -.... ---_ .. --------------.---75 ii c C c Table of Contents (continued) Page Provisions for Replacements---.. ----_.--_ .. --_ .. -----------------75 Interest During Construction---------------------------------75 Project Formulation---------------------------------------------77 CHAPTER VII--------------------------------------------------------80 ECONOMIC AND FINANCIAL ANALYSIS------------------------------------80 No. T 2 3 4 5 6 7 8 9 10 11 12 ~3 14 15 16 17 18 Economic Justif1cation------------------------------------------80 Benefits-----------------------------------------------------80 Cost Al1ocation----------------------------------------------85 Annual Costs-------------------------------------------------86 Benefit Cost Ratio-------------------------------------------87 Financial Analysis----------------------------------------------87 Annual Revenues----------------------------------------------87 Revenue Deductions-------------------------------------------88 Repayment Analysis-------------------------------------------89 Tables Ketchikan Public Utilities-Generating Facilities--------------22 Energy Use-Ketchikan Area, 1936-1963--------------------------24 Estimated Load Growth, Ketchikan Area-----------------------··-26 Estimated Load Growth, Metlakatla Area--------------------··---32 Generating Facilities-Petersburg-Wrangell Areas---------------35 Estimated Population and Load Growth, Petersburg-Wrangell Area---------------------------.. -------------.. ----------------40 Estimated Population and Load Growth, Kake-Duncan Canal Area--45 Projection of Energy Requirements for Sales to Utilities from Thomas Bay Project (Unit: 1,000 kwh)--------------------47 PrOjection of Capacity Requirements of Sales to Utilities fram Thomas Bay Project (Unit: Ki1owatts)--------------------47 Requirements of Thomas Bay Powerplant-·-··----------------------50 Load Characteristics, Thomas Bay Project Power Market Area----51 Run-off of Cascade Creek near Petersburg----------------------53 Computed Run-off of Cascade Creek at Swan Lake OUtlet near Petersburg·· ---------------------------------------------------57 Monthly Load Distribution---·----------------------------------61 Annual Summary, Reservoir Operation Studies-------------------63 Summary of Construction Costs---------------------------------76 Summary of Load and Energy Requirements, Year 1983, and Esti- mated Cost of Generation by Diesel-Electric Units-------------83 Summary of Capacity and Energy Requirements for Sales to Utilities fram Thanas Bay Project··----------------------------88 iii c No. 945-906-11 945-906-7 945-906-6 945-906-2 945-906-8 Table of Contents (continued) Drawings General Plan· .,------------ ---- - - - - ---- -------preceding 1 Power Market-Requirements and SUpply, Energy-----------48 Power Market-Requirements and SUpply, Capacity---------49 Swan Lake Reservoir, Area and Capacity Curve-----------58 Reservoir Operation and Energy output------------------64 LETTER REPORT OF THE FISH AND WILDLIFE SERVICE---------------------1-5 Letter from Alaska Department of Fish and Game--------following 5 LETTER REPORT OF BUREAU OF OUTDOOR RECREATION ______________________ 1 LETTER REPORT OF NATIONAL PARK SERVIC~----------------------------1 iv 00 t-o I 00 00 '" RUTH U PREANOF AND GATE STRUCTURE-\ \ ---..... \ ----............. \ lUNlilJ--------.......... \ _-------......... .:t CAMP AREA CONSTRUCTION PLAN OF DEVELOPMENT 1000 0 1000 2000 3000 4000 SRRA A 1 SCALE OF FEET BULKHEAD TRASH RACK ,--STRUCTURE , (J THOMAS BAY PROJECT j '" LOCATION MAP RED ITEMS-NEW CONSTRUCTION • EXISTING POWERPLANT 5 0 H H H 5 '0 SCALE OF 1.11 LE S 'j UN I TED STATES DEPARTMENT OF THE I NTERIOR BUREAU OF RECLAMATION ALASKA D I STRICT 20 THOMAS BAY PROJECT-ALASKA GENERAL PLAN JANUARY e, 1965 945-906-11 CHAPTER I INTRODUCTION The Thomas Bay Project is a single purpose hydroelectric develop- ment to provide 34,500 kilowatts of power, at 55 percent average annual plant factor, to Ketchikan, Metlakatla, Petersburg, Wrangell, and Kake in Southeast Alaska. The authority for this report and for the supporting field investi- gations and office studies is contained in the Act of August 9, 1955 (69 Stat. 618). This Act authorizes the Secretary of the Interior to investigate and report to the Congress on the water resources of Alaska. Location The major features of the Thomas Bay Project would be on or near Cascade Creek on Thomas Bay, 15 miles northeast of the City of Peters- burg) Alaska. A transmission system would interconnect the project cities, aI shown on Drawing No. 945-906-11. History of Investigations Investigations for a hydroelectric developmunt to develop the waters of Cascade Creek were begun by Messrs. Hutton, McNear and Dougherty of San Francisco, who made application to the Federal Power Commission in 1922 for a license to construct the project. The license was issued but later terminated. .... -----. ----------------------------------- c In 1924, J. C. Dart of the Forest Service reported to the Federal Power Commission on potential waterpower sites in southeastern Alaska, including the Swan Lake site on Cascade Creek. This development is described in more detail in the 1947 joint report of the Federal Power Commission and the Forest Service, Water Powers, Southeast Alaska. The Corps of Engineers, in its Interim Report No. 1 on Southeast Alaska, dated February 15, 1952, discussed a potential development of Cascade Creek very similar to that described in this report. More re- cently, this plan is described in Geological Survey Water-Supply Paper 1529, Waterpower Resources near Petersburg and Juneau, Southeastern Alaska (1962) written by F. A. Johnson. John C. Miller also prepared c:; a report for the Geological Survey on the geology of Scenery, Cascade, and Delta .Creeks, dated September 1955. c The investigations on which this report is based were begun in fiscal year 1961 and completed the following year. Field surveys in- cluded topography of' the dam site and powerplant site, ties to geodetic coordinates, a profile of the penstock line, soundings of Swan Lake near the outlet, and soundings of Thomas Bay near the powerplant site. A surface geology examination of all project structure sites was supple- mented by three drill holes at the lake outlet and one drill hole at the powerplant site to indicate subsurface rock conditions. The geologic findings are summarized in the report, Thomas Bay Project, Alaska - Geology, by William I. Gardner, dated January 1962~ Studies were made 2 , c c c to determine potential energy output, to estimate the potential market for project power, and to select the optimum plan of develqp.ment. Estimates of construction cost were based on feasibility designs of major project structures. Economic studies were made to determine the justifiability and feasibility of the project development. A forecast of long range power needs in the power market area was obtained by interviewing officials of the Utility systems presentlY serving the five project cities. Data was obtained relative to their historic energy sales, types of loads, and their load growth pattern. Data on eXisting facilities was obtained as well as their future plans for rehabilitation or enlargement. These data, together with statistics on population increases, was the basis for estimating the project power requirements. 3 c c c Acknowledgments In the course of the investigations of Thomas Bay Project, assist- ance was received from many Federal, state, and local agencies, organ- izations and individuals. This help is gratefully acknowledged. Local groups or individuals who provided considerable information and assistance include city officials of Ketchikan, Petersburg, Wrangell, Metlakatla and Kake, and the Chambers of Commerce of Ketchikan, Peters- burg, and Wrangell. Officials of the Wrangell Lumber Company, Alaska Pacific Timber Co., Ketchikan Pulp Co., Ketchikan Northern Terminal Co., Ketchikan Cold storage, and others also furnished valuable information. The DiviSion of Marine Transportation and the Department of Health and Welfare of the State of Alaska supplied usef'ul help and Drs. George W. Rogers and Richard A. Cooley of the Division of state Planning made available statistical data prior to publication. Several Federal agencies also assisted in the investigations. The FOrest Service provided data on potential use of timber resources. The Fish and Wildlife Service and the Geological Survey transported camp facilities. The Geological Survey performed all the field survey work and made available unpublished records of Cascade Creek runoff. The letter reports of the Fish and Wildlife Service, the Bureau of Outdoor Recreation, and the National Park Service, are appended to this report. 4 c c c CHAP1'ER II GENERAL DESCRIPTION Southeastern Alaska comprises the large group of islands named the Alexander Archipelago and a narrow mainland strip lying between the northwestern part of British Columbia and the inne~ost tidal water courses. The islands are separated from each other and the mainlend by deep, narrow channels, and the mainland is dissected by numerous inlets and fiords. The entire area is extremely mountainous, with numerous peaks on the Canadian border rising to more than 8,000 feet above sea level. A dense forest cover, comprising princi~ western hemlock and Sitka spruce, extends fran tidewater to altitudes of from 1,800 to 3,000 feet. The potential Thomas Bay Project is located near the middle of this region and would deliver power in the southern half. The Project Area Cascade Creek, the waters of which would be used for Thanas l3a.y Project, heads in the Coast Range near the Canadian border and empties into the south arm of Thanas Bay near Petersburg, Alaska. In its westerly course, the stream flows through Swan rake and Falls rake. Swan Lake, the reservoir for the project, lies at elevation 1,514 feet, and its outlet is 2.8 river miles above the mouth of Cascade Creek. Falls Lake, at elevation 1,157, has a water surface area of only 20 acres, and its outlet is about 1.5 miles above the mouth of the stream. 5 c -------"------------------_ .. _-----------------p-- The drainage area, all. of which lies Wi thin the North Tongass National Forest, is remote and highly mountainous. Most of the area surrounding the lake is timber covered, but the higher slopes vary frem brush covered to bare rock. Tbe watershed around the lake rises to a maximum altitude of about 6,000 feet. The Pm,er Market Area The market area for project power would include the communities of Petersburg, Wrangell, Ketchikan, Metlakatla, and Kake. Petersburg is en Mitkof Island, about 15 air miles southwest of the proposed powerplant site. Wrangell is at the north end of Wrangell Island, about 40 miles southwest of the powerplant site. Ketchikan is about 125 miles south- e:; east on Revillagigedo Island. Tbe most distant part of the power market area, Metlakatla, is 14 miles south of Ketchikan on Annette Island. c Kake is on Kupreanof Island about 45 miles west of the power site and 40 miles northwest of Petersburg. A radio relay station on Duncan Canal is a potential load center for service from the transmission line to Kake. It is a.pparent that the power market area. is not a single cohesive unit but comprises five separate and isolated areas. Transmission of project power to these areas is a major item of project cost. Petersburg The incorporated town of PeterSburg, With a 1960 population of 1,502, is a fishing community inhabited primarily by persons of Scandi- navian descent. It is the supply center for several logging camps and 6 C headquarters for considerable sports fishing and hunting activity. Can- mercial fishing is the principal basic industry of the camnunity. Wrangell Wrangell 'Was incorporated in 1903, earlier than any other town in the power market area. It is a modern camnunity with a recorded popula- tion of 1,315 persons in the 1960 census. It is one of the main fishing centers of southeast Alaska, but its present economy primarily depends on timber resources. The Bureau of Indian Affairs maintains a boarding school for dependent elementary Native students at wrangell Institute, about 4i miles south of the town by hi~. The educational facil1 ties at the school are operated as an integrated part of the state school system. c:: Ketchikan c The baSis for Ketchikan's economy is reflected in its physical location. Almost every hane overlooks the sea, and most of the business district, including much of the city·s arterial street, is supported by piling. Thus the canmunity rests on and overlooks the fish-laden 'Waters that brought it prosperity for half a century, while the dense evergreen forest that crowds it closely fran behind betokens the source of future wealth. An indication of the importance of fishing to Ketchikan's economy is the three small boat harbors, which can accommodate over 1,100 small boats. The waterfront is packed with five fish canneries and three cold storage plants for fish processing. 7 ----------------------------------------------------------- c c c At Ward Cove, seven miles northwest of Ketchikan, is the large modern mill of the Ketchikan Pulp Company. A large lumber mill is located within the city. The city is modern in every respect, with up-to-date stores, shops, hotels, two banks, a daily newspaper, many churches, an excellent school system, and an efficient, well-equipped volunteer fire department. The city owns it own water, :,,)ower, and telephone services, which are operated through the Ketchikan Public utilities. Ketchikan city had a population of 6,483 in the 1960 census. Metlakatla Area Metlakatla is an Indian Village located on Annette Island Indian Reservation. The reservation was established on March 3, 1891 by Congress under the jurisdiction of the Secretary of the Interior, but the village was established in 1887. It is one of the most developed Indian villages in the State. Its 1960 population was 798 persons. Annette, on the FAA reservation, 7 miles to the south, had a 1960 population of 337 comprised of personnel from FAA, Weather Bureau, Coast Guard, Air Lines, Standard Oil of California, and school teachers. The total estimated 1960 population of Annette Island was about 1,500. Other than part-time employment with FAA, airlines and others, the principal economy of Metlakatla is derived f'ram their fish cannery, said 8 c c c to be the largest native fish cannery in the state. Municipal water and power is owned and operated by the Town Council. They have plans to re- habilitate or reconstruct the Annette Island Spruce Co. sawmill which has been inoperative since 1957. The FAA facilities include, besides a Flight Service station, Point to Point and Air-Ground radiotelephones, local teletype and inter- phone circuits with Air Carriers, VHF, radioteletype, standard SBRAZ Radio Range, Control Tower, Remote Receiver Site, Instrument Landing System, Communications transmitter site and VHF site, and VHF/UHF DF equipment, VHF peripheral. The surfaced airfield is maintained by the FAA, which has a complement of 32 persons. Kake-Duncan Canal Area Kake has almost no white population and, like Metlakatla, is con- sidered one of the better Indian communities in southeastern Alaska. The population in 1960 was 455 persons. The present economy is based prtmarily on fishing and fish processing. It was incorporated in 1952, and their electric utility system is community owned. Other community facilities include the general store and post office. The Bureau of Public Roads has completed a survey of a road on K'up-reanof Island from West Petersburg (across Wrangell Narrows from Petersburg) to Duncan Canal. '!his survey is to be eventually extended to Rake. '!he primary purpose of this road is to open new areas for log- ging operations. It would also provide access to the military ~ite 9 c c c ... ~ .. -.-.•.....• -.-------------------------------- Alice" station on Imlcan Canal. A ferry 'WOuld be the most likely means of connection between Petersburg and West Petersburg. Actual construction of the road has not yet been scheduled. Although Kake now offers little of modern comfort or convenience, the City Council is progressive in thought and is trying to improve the general living conditions. It hopes that this action, together with more jobs resulting fran expansion of local industries, Will en- courage more young people to remain in Kake. An adequate supply of lower cost power would greatly benefit this forward-looking ccmnunity. Climate The cl1ma.te of the power market area is characterized by heavy pre- cipi tation, relatively mild temperatures, and much cloudiness. Precipi- tation results fran the warm, moist winds from the Pacific Ocean rising over the mountain barriers of the islands and the mainland. The same Pacific Ocean provides a warming effect on the area, and keeps the air temperature much higher than would be expected for this northerly lati- tude. Cloudiness, fog and precipitation, and temperature to a much lesser extent, are greatly influenced by local topography, of'ten result- ing in considerable variation within a distance of only a few miles. Furthemore, precipitation in the mountains is much heavier than at sea level, and winter temperatures are lower. The bulk of the winter precip- itation in the mountains is snowfall, as shown by the low runoff during the winter months, when sea level precipitation is substantial. The 10 c following monthly distribution of precipitation as a ~ercentage of the annual total at Petersburg is typical of the entire area: January February March April May June 8.6 percent 6.6 6.6 6.8 5.6 4.5 July August September October November December Total Population 5.0 percent 7.6 10.2 17.1 11.1 10.3 100.0 percent The total population of the potier market area in 1960 'WaS approxi- mately 14,300 which 'WaS a 22.8 percent increase over the population in 1950. The area showed about a 17.5 percent increase in each of the pre- ceding decades. About 68 percent of the total population is in the four c:; incorporated towns constituting the major project load centers. About 22 percent is in small unincorporated communities near the larger towns, primarily northwest and southeast of Ketchikan. The remaining 10 percent are rural inhabitants that can be supplied with ~roject power. The following table summarizes the 1960 population data for the power market area: Number of inhabitants Petersburg Area 1,800 Petersburg 1,502 Small ccnmuni ties 26 Rural 272 Y Wrangell Area 1,830 Wrangell 1,315 C Rural 515 Y 11 C Ketchikan Area 8,730 Ketchikan 6,483 Small Communities 1,655 Rural 592 Y Kake Area 460 Ka.ke 455 Rural 5 Metlakatla Area 1,500 Metlakatla 798 FAA Reservation 337 Rural 365 Y Total 14,320 ~ -Approximate C 12 c c c CHAPTER III AREA ECONOMY AND RESOURCES The economy of the Thomas Bay Project power market area is influ- enced to a large degree by its geography and climate. The fishery re- source provided by th~ sea has long been the basi s for an important industry. More recently, the heavy timber grollth that is nourished by the abundant precipitation of the area has encouraged an increasing interest in harvesting and processing timber for :pulp and lumber. The inauguration at the Alaska Marine Highway in January 1963 has made the area more accessible to an ever-increasing number of tOurists, who are attracted by the magnificent scenery and plentiful wildlife resources of southeastern Alaska. Basic Resources and Industries Forestry The 16 million acres in the Tongass National Forest of southeastern Alaska are estimated to contain about 83 billion board feet of inventoried accessible commercial forest timber. Based on allowable cut, this timber resource could produce about 820 million board feet annually. The pre- sent annual cut from the Tongass National Forest is about 400 million board feet. Western hemlock is the predominant species, representing about 63 percent of the total forest volume and is particularly valuable as a pulping wood. Sitka spruce, comprising about 31 percent of forest 13 c c c volume, is the principal lumber tree of the area. Western red cedar and Alaska cedar occur individually or in small groups and have special uses such as for poles, shingles, and furniture. The Forest Service has divided the Tongass National Forest into five units called working circles. One of these is centered at Ketchi- kan and a second surrounds Petersburg and Wrangell. Within the Ketchi- kan-Craig and the Petersburg-Wrangell working Circles, there is an esti- mated allowable cut of 490 million board feet annua.lly, of which only 290 million board feet is being harvested. An additional 200 million board feet could be utilized each year if facilities were available. The Ketchikan Spruce MillS, the oldest continuous mill in Alaska, is located in the Ketchikan area. It has an annual capacity of 20 million board feet of lumber. In 1954, the Ketchikan Pulp Company placed in operation its $60 million mill with a daily capacity of be- tween 550 and 600 tons of high grade dissolving pulp. Wi thin a year after Ol>ening of the Ketchikan Pulp Co. mill, the Forest Service entered into two additional long-ter.m timber sale agree- ments in Alaska, one of which is within the Petersburg-Wrangell area. The Wrangell Lumber Company, at Wrangell, has a mill capacity of 50 million board feet annually with a one-shift operation. Its output of sawed timbers are shipped directly to Japan, and very li tUe :finished 14 c c c lumber is produced. They are considering the construction of a plywood plant to be operated in conjunction With their mill. The Pacific Northern Timber Company, also located at Wrangell, has remodeled its mill to permit more efficient manufacture of green lumber for export to Japan. The mill has an annual capacity of 40 million board feet. Future expansion of operations, contemplated by its Forest Service agreement, will include the construction of a dry-kiln, plywood plant, and pulp mill. Fishery Until recent years, commercial fishing has been the basis of the regional economy. Although still an important factor, it is gradually giving place to lumber and pulp production. Since the Ketchikan Pulp Co. mill began operation in 1954, the value of fishery products has been exceeded by that of the expanding forest industries. Salmon has been the backbone of the fishing industry, with all five species of Pacific salmon being taken. Two species, the king and coho, are taken chiefly With trolling gear and are preferred for sale as the fresh, frozen or mild-cured product. Pink, chum, and red sa.lmon, Which constitute the vast majority of all salmon taken, are processed in canneries. The number of canneries in the area has dropped sharply over the past few decades and may reduce still further with increased use of freezer ships. Halibut is the next most :inJ±lortant fishery re- source, followed by herring, crab, and shrimp. 15 c Ketchikan has five canneries and three cold storage plants for fish processing. A cold storage plant and three small shrimp canneries cur- rently operate at Wrangell. The fishing industry at Petersburg has ex- panded in recent years, due largely to diversification to shellfish processing. Petersburg now has two large canneries (one of which has cold storage facilities), two smaller canneries, and a large cold stor- age plant. Kake has a community-o-wned salmon cannery and a small crab cannery. The city plans to install a cold storage plant and to develop a shrimp industry. The largest native fish cannery in the State is located at Metlakatla. Diversification into processing specialty products such as salmon C egg baits, canned fish balls, salmon egg caviar, smoked salmon, and smoked black cod, may play an important part in the future of the area's fishing industry. Tourism The spectacular scenery of southeastern Alaska and the opportunities for activities such as boating, hunting, fishing, mountain climbing, and skiing provide a varied and bountiful recreation resource. The Alaska Marine Highway fram Prince Rupert, British Columbia, to Haines, Alaska, makes it possible for tourists, 'Who formerly would have made a round trip via the Alaska Highway, to travel one direction through southeastern Alaska. 16 c According to the Alaska state ~partment of Economic Development and Planning, Planning and Research Division, 60 percent of all travel to and from Alaska during the summer of 1964 was by tourists. Of the total number, 29 percent traveled through Southeast Alaska by either Cruise ships or the Marine Highway. With this amount of travel, there is good reason to e~ect that tourism will develop into a major industry. Mining Several mineral deposits of possible commercial significance are currently under investigation or development in the southern part of southeastern Alaska. The most plausible developments are the iron and c:: copper deposits on the Kasaan Peninsula of Prince of Wales Island, the limestone deposits on tall Island, the lar~e Granduc copper deposit in British Columbia, now being developed on the headwaters of the Leduc River near the Alaska border, and major deposits recently announced and being extensively explored on the Stikine River near the Alaska-Canadian border • .. A small amount of uranium production has been resumed at Kendrick Bay on Prince of Wales Island, 35 miles southwest of Ketchikan. This deposit was discovered in 1955, but after a short period of operation, production was temporarily suspended. c· 17 c other deposits which might affect the economy of Ketchikan are the Riverside lead-silver-tungsten deposit and the Mountain View silica deposit, both of which would be reached from Hyder at the head of Port- land Canal, the southeastern border between Alaska and British Columbia. The deposits mentioned above by no means indicate the total mineral potential of the power market area. There are many other deposits that may be economic to develop if conditions becoille favorable. other Industries No other basic resource industries are of major importance to the power market area. FUr trapping and agriculture are of minor local C significance, and no change in this status in the near future is foreseen. c· Secondary Industry Transportation Transportation is an important factor in the economy of the power market area because of the relative isolation of the established com- munities. Excellent passenger service to the area is provided by the Alaska Marine Highway and by air. Pacific Northern Airlines makes a daily flight between Seattle-Tacoma airport and Annette Island airport, only l! hours apart by jet; this flight continues on to and returns fran Juneau and more northerly cities. Alaska Coastal Ellis Airlines pro- vides connections for these :flights fran Ketchikan, 19 miles away, and twice daily service between Ketchikan and Juneau with regular 16 c stops at Petersburg and Wrangell. 'lliis airline also serves Kake regularly. Several steamship canpanies serve the area. The Alaska steamship Company is the principal freight line whose ships ply between principal Alaskan ports and Pacific coast cities. Passenger vessels of the Cana- dian Pacific and the Canadian National lines, as well as those of several smaller companies, visit southeastern Alaska ports during summertime tourist cruises. Many national and foreign freighters arrive and depart on an unscheduled basis. Ketchikan is the terminous of a rail-barge system of transportation. c Loaded railway cars are barged direct fram Seattle and Vancouver. The Alaska Marine Highway fran Prince Rupert, Br1 tish Columbia, to Haines, Alaska, provides daily year-round transportation for freight vehicles, passengers, and autanobiles, and makes the power market area more accessible to the "Southern 48." A road fram Petersburg up the Stikine River basin through British Columbia is being actively considered. Business Services The three major cities in the power market area have adequate busi- ness services to fulfill their needs. This is especially true of Ketchi- kan, which boasts a level of services and facilities found only in much larger cities in other states. Enterprises such as retail stores, banks, 19 c c c· entertainment, and personal and professional services are available. As the area develops and the population grows, the need for all types of business facilities will also expand. 20 c c c CHAPTER IV POWER SUPPLY AND DEMANDS The Thomas Bay Project would supply residential, commercial, and small industrial loads to the five communities of Ketchikan, Metlakatla, Petersburg, Wrangell, and Kake. Electric utility service is now pro- vided to the communities by municipally operated S,Ystems. In addition to the utility systems, there are Within the project power market area several self-supplied power users. The power market evaluations summar- ized below are based upon data obtained fram the concerned electric utilities and industrial power users. Ketchikan Axea The Ketchikan area is that area which is, or is likely to be, served by the Ketchikan Public Utilities System. It includes the City of Ketchikan and environs accessible by road. Existing Power Facilities The existing power facilities in the Ketchikan area, besides the Ketchikan Public Utilities, are the Ketchikan Pulp Company and the H;II~ Ketchikan Spruce 9cmp~. 2 Ketchikan Public Utilities -This utility system has been owned and operated by the City of Ketchikan since 1935. Its sources of power supply are two hydroelectric installations, Ketchikan Lakes and Beaver 21 ,,4,--., ~ Falls (Silvis Lakes), and a diesel installation at the Ketchikan Lakes ........., plant. A third hydroelectric plant, Lake Whitman, was acquired in 1957 for the water ~ights, but it is inoperable. These hydroelectric develop- ments are indicated on Drawing 945-906-11. The operable hydro-plants have a. peaking capacity of 9,600 kilowatts and can produce 53,240,000 kilowatt-hours of firm. energy each year. The diesel installation has a capacity of 900 kilowatts. The peak system demand in 1963 was 9,200 kilowatts, which is an increase in demand of 11 percent aver 1962. The generating facilities of the Ketchikan Public utilities are summarized in Table 1. Table 1. Ketchikan Public utilities -Generating Facilities Annual CaE8citx -Kilowatts Firm Name Energy Plant Type Plate Firm Peaking MWH - - Ketchikan Lakes Hydro 4,200 3,600 3,600 17,750 Ketchikan Lakes Diesel 873 837 900 2,250 !eaver Falls Hydro 5,000 4,000 6,000 31,500 Ketchikan Pulp Company -The largest power user in the power market area is the Ketchikan pulp mill. Although located within the service area of the Ketchikan Public Utilities System, this load is completely self-supplied. The mill uses a chemical process that produces a large volume of waste liquors. These liquors are disposed of by burning, which provides the means for producing the steam for its 20,000 kilowatt 22 Rev. 11-26...65 c c steam generating plant. The energy requirements are not known, but they probably approach 140,000,000 kilowatt-hours annually. The mill does not supply power or energy to other users in the area. Ketchikan Spruce ~ny -A second industry ~th its own electric M,J/s. generating facilities is the Ketchikan Spruce Gom~QflY, a large saw.mill. ~a~.;11 The Geml'e:tlY uses waste wood as fuel in its steam powerplant 'Which has a generating capacity of 850 kilowatts. Most of the power requirements of the mill are met by thi s powerplant; however, some of the lighting load is supplied by Ketchikan Public utilities. Total electric energy requirements of the mill are estimated at about 2,500,000 kilowatt-hours per year. Estimated Power Requirements Over the past 27 years, the utility energy sales have increased at an average annual rate of about 6.6 percent. In 1936 the system supplied customers ~th 7,267,358 kilowatt-hours. In 1963 total energy sales were 38,841,630 kilowatt-hours. Annual load growth during this 27-year period fluctuated a great deal. Individual yearly changes in total customer requirements ranged from a high of 19. 2 percent in 1937 to a lO'tf of -4.1 percent in 1942. This load growth is presented in Table 2. No one year or group of years can be considered as typical or nor- mal. Each series of ups and downs can be correlated with specific events C 23 occurring in the local area. For example, the substantial load increases c:; in 1952 and 1953 were coincident with the construction of the Ketchikan Pulp mill. The first few years following completion of the mill are c c marked by a very slow rate of load growth. This can best be explained as a readjustment period following the construction boom. Since 1957, the average rate has been about 4.4 percent. This recent rate of load increase is lower than observed in every other major Alaska ccmmun1ty. Year 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 Table 2. Energy Use -Ketchikan Area, 1936-1963 Sales of Electric Energy Aimual (1,000 kwh) Increase (i) 7,267 8,662 9,95 0 11,418 11,739 12,106 11,610 12,554 14,119 15,636 15,686 16,382 16,614 18,105 19,585 20,949 23,039 26,894 27,595 28,254 29,951 30,011 31,753 33,478 34,082 35,306 37,668 38,842 41,802 19.2 14.9 14.8 2.8 3.1 (4.1) 8.1 12.5 10.7 0.3 4.4 1.4 8.8 8.0 7.0 10.1 16.7 2.6) 2.2 6.0 0.3 5.4 5.4 1.8 3.6 6.8 3.1 7.6 24 Gross Generation (1,000 kwh) Unknown UnknO'WIl 12,217 13,705 14,113 14,08 7 13,277 14,105 15,617 16,707 16,908 17,831 19,082 20,732 22,3 88 23,975 26,795 30,885 31,53 6 32 ,366 33,562 34,606 35,900 37,377 37,908 39,723 42,328 44,521 47,15 8 Peak Demand (KW) 2,300 2,600 2,700 3,000 3,000 3,000 2,700 3,100 3,45 0 3,200 3,400 3,650 4,000 4,440 4,650 5,320 5,700 6,000 6,600 7,100 7,200 7,000 7,5 00 7,5 2 0 7,800 8,000 8,300 9,200 10,050 c c c An analysis of customer use during the period 1957-61 indicates that this growth probably did not reflect a normal condition. During this five-year period, several incendiary fires occurred in the heart of the business district. The almost annual loss of major business buildings undoubtedly adversely effected the commercial class use. This conclusion is confirmed when commercial customer use is isolated from all other use. The remainder of the system loads increased at an average annual rate of 5.1 percent from 1957 through 1961. On the other hand, commercial loads in 1961 were still 1.8 percent below those of 1956. Use of electricity by individual customers is relatively high in the Ketchikan area. In 1960, residential customers used an average of 6,420 kilowatt-hours each, connnercial customers an average of 20,148 kilowatt-hours, and small industrial customers an average of 320,304 kilowatt-hours. If electricity were in plentiful supply, it is expected that average use would increase quite rapidly. Considering the long term gain, the possible future developments, and the analysis of local growth in recent years, it seems reasonable to forecast a future increase in the Ketchikan area at an average annual rate of 5.5 percent until a major block of reasonably priced power should became available. At such time, it is considered that the use of energy would increase by 7.0 percent annually. Thus assuming that Thomas Bay Project deliveries could become available by 1974, the power requirements of 1974 are esti- mated to be 81,000,000 kilowatt-hours and 16,810 kilowatts. These 25 c requirements would exceed the fir.m capability of the Ketchikan Public Utilities System. The projected loads are summarized in Table 3. If the Thomas Bay Project were the source of power for these future loads, the transmis- sion losses would be in addition to the requirements shown. Table 3. Estimated Load Growth, Ketchikan Area Energy Capacity Year Requirements {1000 kwh) Requirements (kw) 1· . 1963 44,521 9,200 1964 46 , 900 1./ 7; I~-a ~ 1~~.>-tD 1965 49,500 10,270 1966 52,200 10,830 1967 55,100 11,440 C 1968 58,180 12,060 1969 61,300 12,720 1970 64,600 13,410 1971 68,100 14,130 1972 n;800 14,900 1973 75,700 15,710 1974 B81,ooo 16,810 1975 86,700 17,990 1976 92,700 19,250 1977 99,200 20,590 1978 106,200 22,030 1979 113,600 23,580 1980 121,600 25,230 1981 130,100 26,990 1982 139,200 28,880 1983 148,900 30,900 1984 159,300 33,070 1985 170,500 35,380 1986 182,400 37,860 1987 195,200 40,510 1988 208,900 43,350 1989 223,500 46,380 1990 239,100 49,630 c 26 c c c cost o~ Utility Power and Energy A decade ago the average cost o~ firm energy generated by the Ketchikan Public Utilities System was about 10 mills per kilowatt-hour. Subsequent plant expansion and rehabilitation have gradually increased this unit cost to nearly 12 mills. It has long been the policy o~ the Ketchikan Public Utilities to retail power at the lowest possible rates. As a result, the average residential use in 1960 was 6,420 kilowatt-hours. If power were not chronically in short supply, it is likely that this use would be sub- stantially greater. Present rate schedules incorporate an end rate designed to discourage electric house heating. The residential rate in e~fect ~or the past several years is as ~ollows: First 50 kwh per month Next 100 kwh Next 1,050 kwh All over 1,200 kwh 5.00¢ per kwh 3.00¢ per kwh 1. 25¢ per kwh 2.oo¢ per kwh A monthly use o~ 300 kilowatt-hours would cost the reSidential customer $7.38, or an average o~ 2.46 cents per kilowatt-hour. Interim Measures Proposed The Ketchikan Public utilities recognizes the city's urgent need for additional power supplies. It has made two applications to the Federal Power CommisSion for license to construct additional hydro- electric improvements. These concern the Lake Whitman and Beaver Falls sites. 27 •. J I i The Lake Whitman license was granted effective August 1, 1963. It would provide for rehabilitation of the Lake Whitman dam and construc- tion of a powerhouse and related works with an installed capacity of about 4,000 kilowatts. Due to the limited water supply, it would pro- duce only 7.3 million kilowatt-hours of energy annually. It was pro- posed as a two-stage peaking plant with a load factor of 20.8 percent. Subsequent to filing for this development, the Ketchikan Public utilities concluded that enlargement of its Beaver Falls installation to provide a larger amount of capacity and energy than was possible at Lake Whitman was desirable. Plans for a Beaver Falls development involving construction of a new 2,OOO-kilowatt installation on Lower Lake Silvis, utilizing the flow and powerhead from Upper Lake Silvis, and a 4,OOO-kilowatt enlargement of the existing Beaver Falls development were formulated. These would provide an additional peEking capacity of about 6,000 kilowatts and additional annual firm energy of about 19.8 million kilowatt .. hours. With these additions, the peaking capacity of the Ketchikan Public Utilities System would be 16,500 kilowatts, and the system would be cap- able of producing about 74.8 million kilowatt-hours of firm energy annually. It is estimated that this would satisfy their power needs through calendar year 1973. Additional diesel reserve capacity may be required after 1972. This proposal was submitted to the electorate of the City of Ketchikan in May 1964 and again in October 1~4. It 28 Rev. 11-26-65 " : .......... was de:feated both times. The application for amendment of' the City of' Ketchikan's Beaver Falls Federal Power Commission license to provide for accomplishment of this plan remains pending. The electorate of Ketchikan on April 13, 1965 approved a bond pro- posal which would provide f'or construction of a diesel powerplant with a capacity of 2,000 kilowatts and reconstruction ot the existing dam at Upper Silvis Lake in accordance with the overall plan for enlarge- ment of its Beaver Falls development. The new diesel installa.tion is to be located 8 miles north o:f th6 city to provide improved electric service for the area north ot Ward Cove. The city administra.tion also expects to submit to the electorate in the fall of 1965 a new bond proposal to provide for reconductoring of' the existing transmission line and for construction of the new 2,000 kilowatt hydroelectric install- ation on Lower Silvis Lake. It is reasonable to presume that, if power requirements so merit, further consideration would be given by the city administration to com- pletion of the Beaver Falls enlargement. This report, therefore, pre- sumes that the present hydroelectric capacity of the Ketchikan Public utilities would be expanded to include an additional 6,000 kilowatts with an increased firm energy production of 23.3 million kilowatt-hours by the time the Thomas Bay Project power would be available. Rev. 11-26-65 29 c· Metlakatla Area The Metlakatla area is that area served by the Metlakatla Power and Light Company. This includes the City of Metlakatla, which is the seat of Government for the Annette Island Indian Reservation, the Coast Guard station, the Annette Island Airport, and the adjoining residential area for airport-related personnel. The 1960 population of the Metla- katla area was about 1,150, of which 800 were in Metlakatla. Existing Power Facilities The only existing power facilities in the Metlakatla area are those of the Metlakatla POlIIel' and Light Company, which has been serving the area since 1929 as a municipal entity. These facilities are indicated c:: on Drawing 945-906-11. The power supply of the Metlakatla Power and Light COJl'I!lany consisted of a diesel unit and a hydro-plant at Chester Lake in 1957. When their Rural Electrification Administration-financed Purple Lake hydroelectric development began operating in 1957, with an installed capacity of 3,000 kilowatts, the Chester Lake plant was taken out of service as being obso- lete and the diesel plant was put on standby service. The Company's present power load includes an RCA early warning ~stem, and the Annette Island Airport in addition to the village of Metlakatla and the Metla- katla cannery. 30 c c c Estimated Power Requirements The Metlakatla Power and Light Company has kept records of power and energy use from their system since 1959. These records show that annual energy requirements increased from 5,842,000 kilowatt-hours in 1959 to 9,982,000 kilowatt-hours in 1962, with a decrease in 1963 to ~ 9,841,000 kilowatt-hours. The peak load was 2,120 kilowatts in January 1963. Future long term power requirements are not expected to increase at this rate, but :s.t seems probable that they will increase rapidly. Plans are under consideration for deve1~ent of a new sawmill with a capacity of 100, 000 board feet per day to saw cants for export. The sa'WIIJ.ill would generate i t·s o'WIl power from mill waste. However, the additional employment that would result from this new industry in Metlakatla would be reflected in additional domestic and other power requirements. Thus, when additional power becomes available at a favor- able rate, the power demands can reasonably be forecast to increase in the Metlakatla area by at least seven percent each year. On this baSiS, and on the premise that the Thomas Bay powerplant would be on the line in fiscal year 1974, the forecast load demand of the Metlakatla area by FY 1974 would be 3,700 kilowatts. The projected loads are summarized in Table 4. 31 c c c Year 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 Table 4. Estimated Load Growth, Metlakatla Area Energy Requirements (1000 kwh) 9,84~ 9,770 10,250 10,785 11,300 11,870 12,430 13,100 13,710 14,410 15,150 16,210 17,340 18,570 19,930 21,330 22,820 24,440 26,190 28,080 30,090 32,190 34,470 36,920 39,550 42,310 45,200 48,400 Capacity Requirements (kw) 2,120 2,230 2,340 2,460 2,580 2,710 2,840 2,990 3,130 3,290 3,460 3,700 3,960 4,240 4,5~0 4,870 5,210 5,580 5,980 6,410 6,870 7,350 7,870 8,430 9,030 9,660 10,320 11,05 0 Cost of utility Power and Energy The annual generation, distribution, and transmission costs of the Metlakatla Power and Light Company have varied from a maximum of 22 mills per kilowatt-hour in 1960 to a minimum of 12.9 mills per kilowatt- hour in 1962, With a 1$63 cost of 14.0 mills. The present residential rate is very low for Alaska and is desigxed to encourage residential use, With the reverse being true of commercial use. The rate schedule is as follows: Residential. First 200 kwh per month Remaining kwh per month Commercial Large Small Interim Measures Proposed 2. oo¢ per kwh 1.OO¢ per kwh 3.50¢ per kwh 6.50¢ per kwh The Metlakatla Power and Light Company is constructing a new 3,000 kilowatt diesel power house with an initial installed capacity of 1,500 k.ilowatts, This initial. unit "shoul.d be in operation by January l.966, and the second 1,500 kilowatt unit Will be installed when required to satisfy area requirements. The company expects these units to satisfy area requirements through 1975. This report, therefore, assumes there will be no expansion of Metlakatla's hydroelectric capacity before that date. 33 Rev. 11-26-65 Petersburg-Wrangell Area The Petersburg-Wrangell Area is served by two completely separate utility systems, Petersburg Municipal Light and Power and Wrangell Light Department. Unless a large power source is developed to supply both systems, it is unlikely they will be interconnected in the fore- seeable future. The two communities have been considered together here because of their complementary relationship in economic development and their usual treatment as a political subdivision unit. Electric utility Systems and Power SupplY The power systems of both Petersburg and Wrangell are quite small and without competition. Each supplies electric service to contiguous rural areas, as well as to the community itself. Petersburg has both a diesel and a hydro plant with the hydro supplying all power requirements under normal operations. The total installed capacity of the two systems is 4,985 kilowatts. They also have employed a private consulting firm to develop proposals for expan- sion of their power production facilities. 34 Rev. 11-26-65 c The present power supply problem at Wrangell is much more acute than at Petersburg. The only source of utility power is a diesel- electric plant with a firm capacity of 1,735 kilowatts. Table 5 summarizes the present and programed firm generating facilities. Table 5. Generating Facilities -Petersburg-Wrangell Area Installed Capacity (Kilowatts) Petersburg Wrangell Total Hydro 1,600 400 0 2,000 DieseL 1,000 735 250 500 500 c Total 3,250 1,735 Cost of Utility Power and Energy The costs of power production are not available for Petersburg and Wrangell. It is probable, however, that the hydro averages around 15 mills ~~ki1owatt-hour and the diesel 20 mills or more. Considering the size of present loads, it is not likely that either community will be in a position to develop relatively low-cost power for many years. 35 - c c c . Retail rates are considerably higher at Petersburg and Wrangell than at Ketchikan. Petersburg has a single residential schedule while Wrangell has two --general and all-electric. The lowest o~ the resi- dential schedules for the two communities are currently as follows: Petersburg First 50 kwh per month Next 50 kwh Next 100 kwh Allover 200 kwh Wrangell First 100 kwh per month Next 200 kwh All over 300 kwh 10.00¢ per kwh 5.00¢ per kwh 3.00¢ per kwh 2.l0¢ per kwh 8.00¢ per kwh 3. OO¢ per kwh 2.50¢ per kwh A monthly use of 300 kilowatt-hours would cost the consumer $12.60 at Petersburg and $14.00 at Wrangell. Record of Power Use by Utility Customers Excellent records of power use and requirements have been maintained for Wrangell. For Petersburg, however, they are less complete. This ~s especially true of data on number of customers, gross generation, losses, plant use, and peak demand. Power losses at Wrangell average between 5 and 6 percent of gross generation, which indicates a rather efficient system. At Petersburg, the average losses for years recorded have been about 23 percent of generation. This unusually high figure is due in part to the practice of not metering municipal use. There is also evidence that other uses C c· may be only partially metered. It is quite probable that these unrec~ed uses represent 35 to 40 percent of the total so-called losses. A review of the power load growth of the two communities shows them to be somewhat complementary. In each year since 1956, a decrease in the rate of load growth for one system has been offset by a rise in the rate for the other. This situation is demonstrated in the following tabulation of annual percentage increases in total Sales: Annual Rate of Load Growth (~~ Year Petersburg Wrangell Total 1957 4.5 7.7 5.6 1958 3.6 9.7 .5.8 1959 7.9 6.6 7.4 1960 3.0 11.6 6.2 1961 16.7 7.0 12.9 1962 4.7 11.2 6.7 1963 7.6 4.0 .5.2 Ave. 6.9 8.3 7.1 The trend of the composite result is toward an increasing rate of growth with a strong average annual rate. Combined statistics for the two utility systems show that 1,079 residential customers used a total of 3,416,144 kilowatt-hours in 1960, for an average use of 3,166 kilowatt-hours per customer. In the same year, 207 commercial customers used 2,384,731 kilowatt-hours, an average of 11,520 kilowatt-hours. The number of small industrial customers is not listed, but the total kilowatt-hour use in this classification in 1960 was 2,160,825. ... - 3i c The combined kilowatt-hour sales for the period 1954 through 1962 has been: 1954 -5,841 1955 -6,413 1956 -6,357 1957 -6,713 1958 -7,105 1959 -7,634 1960 -8,110 1961 -9,157 1962 -9,763 The Wrangell Cold storage Plant was served entirely by the utility system prior to 1961. The approximate total use of the plant in 1961 is included in the above sales, although the plant generated a portion of its own requirements in that year. Wrangell Cold storage Plant require- ments are not included in 1962. Total generation in 1962 was 11,669,000 kilowatt-hours with a non- coincidental peak demand of about 2,360 kilowatts. The resultant rather c:; high utility load factor is due to the substantial summer requirements of fish processing plants. Non-Utility Requirements and Supply At the present time the only significant non-utility load in the area is that of the Wrangell Lumber Company mill. This self-supplied operation uses waste wood for fuel in its steam generating plant. The actual power requirements of the mill are not lmO'l'lIl. It is estimated that the 1961 power use was 3,080,000 kilowatt-hours with a 600-kilowatt peak demand. The resulting load factor is rather high for a sawmill, probably partly due to its year-round operation. 38 '." c c c c In 1961 the Wrangell Cold storage Plant installed two lOO-kilowatt diesel generators. These units were used to carry the bulk of the power requirements through the summer, the rest being supplied by the utility system. Since this entire load had been a utility one in prior years, it has been so included in 1961 in this analysis. The estimated total requirement of the plant in 1962 was 350,000 kilowatt-hours and 150 kilowatt peak demand. Future Power Requirements of the Petersburg-Wrangell Area As mentioned earlier, the total requirements of the Petersburg- Wrangell area in 1962 were only about 11,669,000 kilowatt-hours. With so small a base to start from, a forecast predicated on an average annual rate of increase would have little meaning. Therefore, load projections for this area were formulated from forecasts of economic development, population increase, and average customer usage through the year 1975. From 1976 through 1990, total loads were increased at an average annual rate of 7.0 percent. In projecting the power requirements, it was assumed that the power from Thomas Bay Project would be available in 1974. No allowance was made for the construction of a pulp mill in the area although this is a distinct possibility. Table 6 summarizes the load forecasts for the Petersburg-Wrangell Area. 39 () o o Table 6. Estimated Population and Power Load Growth, Petersburg-Wrangell Area Calendar Year 1961 1965 1970 1975 1980 1985 1990 Population 3,630 4,190 5,300 6,500 customer Class Use (1000 kwh) Residential 3,623 5,050 7,850 11,900 Commercial 2,550 3,330 4,920 6,590 Small Industrial 2,466 3,350 4,280 15,890 ~ All Other (Including MUnicipal) 375 480 600 740 0 Subtotal Sales 9,014 12,210 17,050 35,120 Distribution Losses 1,915 2,145 3,080 4,360 Subtotal 10,929 14,355 20,130 39,480 55,374 77,666 108,930 Small Industrial (Self-supplied) 3,080 5,610 7,850 Total Energy Requirements (1000 kwh) 14,009 19,965 27,980 39,480 55,374 77,666 108,930 Total Capacity Requirements (kw) 2,870 4,300 6,000 8,460 11,865 16,642 23,341 C Interim Measures Proposed c The City of Petersburg was issued a preliminary permdt, effective June 19, 1964, by the Federal Po't-rer Commission for the Kupreanof Hydro-- electric Project on Kupreanof Island, 17 air miles west of Petersburg. The ultimate development of this potential project, as stated in the Permit, would involve the construction of four low dams for storage and diversion of water from adjacent drainages, under a three-stage construc- tion program. The powerplant on Towers Bay, on Seymour canal, would have an initial capacity of 7,200 kilowatts and an ultimate capacity of about 21,600 kilowatts. It would be situated about mid'W8JT between Petersburg and Kake, and transmission lines would extend to both load centers. Subsequent to the issuance of the 1964 permdt, studies accomplished by the city's consulting engineers indicate that the Kupreanof project would be less desirable than other alternates being considered. These include immediate installation of about 1,000 kilowatts of additional diesel capacity, and possible municipal stage development of the Thomas Bay Project potentialities to serve the City of Petersburg. These studies contemplate extensive industrial load growth in the Petersburg area in addition to that previously discussed. The City of Wrangell has made an Application for Preliminary Per- mit for the Virginia Lake Hydroelectric Project on the mainland, 8 air miles east of Wrangell. As stated in the Application, a dam on Mill Creek would raise the water surface of Virginia Lake from elevation 105 feet to 140 feet, and would provide for 40,000 acre-feet of power 41 c c storage between elevations 95 and 140. Hater would be conveyed about 2,200 feet to a powerplant at tidewater 'Which would contain a 3,000 k:va generator. Power would be transmitted to Wrangell by a two-m11e sub-- marine cable and about five miles of 13,5~vo1t transmission line. The City of Wrangell submitted an application to the mIFA for planning funds for the project, but in March 1964 the HHFA returned the application and no further action has transpired. Kake·· Duncan Canal Area The Kake-Duncan Canal Area has been treated separately fran the Petersburg-Wrangell Area for tw reasons. One 'WaS consideration of the economic justification of prOViding the transmission facilities needed to service it. The second 'WaS the dissimilar nature of its popu- lation and power use. utility System -SUP,Rll, Demand and Rates The community-owned power system of Kake is the only power utility. system in the area. The system consists of eight e1ectricaJ.l.y connected diesel generating units situated at various sites in the village. These eight units have an aggregate name plate capacity of 605 kilowatts, of 'Which four units comprising a total of 255 kilowatts are reserved for standby purposes. The cammuni ty also owns a 75-kilowatt hydroelectriC plant situated on Gunnuk Creek; however, this plant is inoperable at the present time and has been treated as such in this report. In addition to the above 42 c:: community-owned generating facilities, there are numerous small indivi- dual-owned auxiliary units situated throughout the village. ~ a very sketchy record of power use is available for this can- mum ty • In 1960 and 1961 it served 102 custaners with an actual sales of 59,647 kilowatt-hours and 102,026 kilowatt-hours respectively. The above sales do not include the fish cannery, crab cannery, and related. facili ties which are now interconnected with the community system. It is estimated that the total requirement for the community of Rake in 1961 was 330,000 kilowatt-hours. The residential rate schedule consists of two steps: 10 cents per kilowatt-hour for the first 100, and 5 cents per kilowatt-hour for all over 100. At these rates, a customer using 300 kilowatt-hours in a c:; month would pay $20.00. The community-owned power system is overloaded at present and the community is investigating the most expedient means of developing hydro- electric facilities to supplement their existing high cost diesel generation. Same immediate steps must be taken to alleviate the present overloaded situation. It is believed that any small hydro facilities developed for this immediate and interim period will have very little significance to the overall project; and therefore, the report is written on the assumption that the total Rake community requirements would be supplied by the Thomas Bay Project at such time as the power becomes available to them • . - C PUture Power Requirements The citizens of Kake are highly regarded as an industrious people. They are interested in the progress of their community and have set up a program of civic improvement and industrial expansion. They hope to expand their fishing and fish processing operations, including the installation of cold storage facilities. They are also considering a sma.ll sawmiU for the area. Completion of the proposed road fran West Petersburg to Kake woul.d greatly benefit the area. The principal objective of this road is to provide access to substantial volumes of commercial timber. The ha.r- vesting of these forests is expected to play an important part in the area economy of the future. c The projection of Kake1s power requirements has been made by fore- casting econanic and population growth and customer use. It has been assumed that project power would be available in 1974. The power requirements of the radio relay station at Duncan Canal are estimated to have been about 1,260,000 kilowatt-hours in 1961. They would probably not increase to any appreCiable extent in the future. It is believed, however, that project power woul.d be used if available. Table 7 summarizes the load forecast for this area • • 1 '. ~:". "'t 44 c C Table 7. Estimated Population and Load Growth Kake-funcan Canal Area Year 1961 1965 1970 1975 1980 1985 1990 Popul.ation (civilian) 472 523 595 6rr Utility Sales (1000 kWh) 102 250 410 680 All other (1000 kwh) 1,488 1,660 1,860 2,440 TOtal Energy Requirements (1000 kwh)' 1,590 1,910 2,270 3,120 4,370 6,135 8,600 Total Capacity Requirements (kw) 250 330 420 600 840 1,180 1,650 Total Projected Power Requirements and Supply Individually, none of the four separate power market areas demon- c:; strates the need for a project the size of Thomas Bay. Collectively, however, the,y do show a satisfactory utilization of the project potential. c Existing and scheduled generating facilities of the utility systems in the area will be capable of meeting a firm power peak load of about 25,300 kilowatts. Thanas Bay Project power 'WOUld probably supplant 5,100 ki1o'Watts of this. It is expected that Ketchikan would continue to use its 15,600 kilowatts and 73,000,000 kilowatt-hours of firm hydro power and energy. It seems probable that Petersburg would also continue to utilize its 1,600 ki1o'Watt hydro plants and 8,000,000 kilowatt-hours of firm energy. In addition, the 3,000 kilowatt hydro plant at Metlakatla would be expected to continue in operation, supplying about 13,000,000 kilowatt-hours annually. c Tables 8 and 9 demonstrate the remaining market available to Thomas Bay Project. These tables show the anticipated sales to utUities in the power market area; transmission losses from the SWitchyard to delivery point are not included. When the powerplant becomes fUlly loaded, total project transmission losses would be about 7 :percent. The possibility of divers:1ty between the individual load areas has been neglected for the purpose of this report. The power market has been developed from essentially utility and small industrial-type requirements. The individual area load requirement characteristics were assumed to be comparable since the manner of livelihood is similar. Drawing No. 945-906-7 illustrates the projected power market energy requirements and the probable supply from other sources and from Thanas Bay Project. Drawing No. 945-906-6 shows corresponding data for projected capacity requirements. When Thomas Bay Project power becomes available and produces adequate, reliable, and economical power, it is assumed that the self-supplying industries, With the exception of the pulp mill, will purchase their load requirements from the project. 46 Table 8. Projection of Energy Requirements for Sales C to utilities from Thanas Bay Project (Unit: 1000 kwh) Petersburg-Kake-Total Ketchikan Wrangell Metlakatla. Duncan CansJ. Market Year Area Area Area Area Area 1974 8,000 28,900 3,210 2,920 43,030 1975 13,700 31,480 4,340 3,120 52,640 1976 19,700 34,240 5,570 3,340 62,85 0 1977 26,200 37,200 6,930 3,570 73,900 1978 33,200 40,360 8,330 3,820 85,710 1979 40,600 43,750 9,820 4,090 98,260 1980 48,600 47,370 11,440 4,370 1l1,780 1981 57,100 51 ,250 13,190 4,680 126,220 1982 66,200 55,400 15,080 5,010 141,690 1983 74,060 59,010 16,730 5,300 155,100 Table 9. Projection of Capacity Requirements of Sales C to Utill ties fran Thomas Ba\Y Project (Unit: Ki10wattsl Petersburg-Kake-Total Ketchikan Wrangell Metlakatla Duncan Canal Market Year Area. Area Area Area Area - 1974 1,210 6,320 700 560 8,780 1975 2,390 6,860 960 600 10,810 1976 3,650 7,450 1,240 640 12,980 1977 4,990 8,090 1,550 690 15,320 1978 6,430 8,7(jO 1,870 740 17,800 1979 7,980 9,490 2,210 790 20,470 1980 9,630 20,260 2,580 840 23,310 1981 11,390 11,100 2,980 900 26,370 1982 13,280 11,980 3,410 960 29,630 2983 14,790 12,690 3,750 1,010 32,240 ; ". c ~ (J) <D ~ U1 I <D 0 m I --.J 260 250 240 230 220 210 ~ 200 6 190 II80 I I-170 ~ <! 3:: 160 0 150 .....J ~ 140 u.. 130 0 (f) 120 z 0 110 -.....J 100 .....J ~ 90 80 70 60 50 40 30 20 10 THOMAS BAY POWER MARKET REQUI RMENTS AND SUPPLY ENERGY ( Individual load centers separated prior to Thomas Bay \ / / / --. / ." / "~ Total Energy Requlrements-, ..... Thomas Bay Project EnergyatLoad----,-~ Slcge 2 -" ~ CI) u_ 0;:: u o CI) -0"'" III 0 0-~ J:a.. _____ 1 I Existing and Scheduled Diesel I I ~------L_---1---,.'-----------_._-.. -.--~ ---_ Sl Gg e I Future Hydro Generation ,..---------+----'---------._-------- Area Existing Hydro Generation CALENDER YEAR 1955 5657 58596061 6263646566 6 68697071 7273 747576 77 78798081 8283848586 60 55 50 en 45 l- I- <[ 3 40 0 ---1 :£. 35 l~ () c. 30 ::.::J Z <1 ~jl 25 :~) 0 I ~ 20 15 10 5 THOMAS BAY POWER MARKET REQUIRME NTSand SUPPLY CAPACITY r------------ (I ndlvldual load centers seperated prior to Thomas Bay) I Stand-By I Die sel I T']'ol Area Peok Requlrement-_... ~, o~ _____ Thomas Bay Project / Kilowatts at Load---------':;,t ~ ~-----~ : Stand-By I Diesel I --! \::l o <lJ v+-- -v o <lJ I ~~ __ -----'-+--__ S ta g e 2 I :n. ~ r-- - - - - - - - - -i/a.. ._..1 E)(lsting and I Scheduied Cliese I Stage I Future Hydro Generation Area Existing Hydro Generation CALANDER YEAR c c The est:iJna.ted power and energy requirements of' the "Thomas Bay Project, with an allowance of' 7 percent f'or transmission losses, is shown in Table 10. Table 10. Requirements of Thomas ~ Powerplant Fiscal Year 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 Kilowatts 9,390 11,570 13,890 16,390 19,050 21,900 24,940 28,220 31,700 34,500 Load Characteristics 1,000 Kilowatt-hours 46,040 56 ,320 67,250 79,070 91,710 105,140 119,600 135,060 151,610 166,000 Table 11 summarizes the anticipated chara.cteristics of' the load that would be supplied by Thomas Bay Powerplant. 50 c c --_._ .. _,------------------------------------ Month January February March April May JUne July August September October November December Table 11. Load Characteristics, Thanas Bay Project Power Market Area Monthly Energy Distribution (Percent of annual total) 9.0 8.1 8.4 7.9 7.8 7.4 7.6 7.9 8.3 8.9 9.0 9.7 Non-Firm Energy Market Monthly Peak wad (Percent of annual peak) 96 89 87 82 81 77 79 80 80 86 95 100 Following full utilization of Thomas Ba.y Project firm energy, it is probable that a market for non-firm energy would slowly develop. It is estimated that this market would not materialize until about 1984 (the 11th year of Project operation). Non-firm use is then assumed to increase at an annual rate of 2,000,000 kilowatt-hours until the average annual net of 15,900,000 kilowatt-hours is required. 51 c CHAPTER V WATER AND POWER The water supply available for power production at Thomas Bay Power Plant was estimated using runoff records of Cascade Creek. Power operation studies were made to estimate the potential energy output, fram which installed and dependable powerplant capacities were also determined. Water Resources Cascade Creek heads on the western slopes of the Coast Range. It drains about 23 square miles of mountainous country before flowing into the southern arm of Thomas Bay. About 18.9 square miles of drainage area lie above the outlet of Swan Lake. Historical Runoff The Geological Survey operates a stream gaging station on Cascade Creek, located about one-fourth mile fram tidewater. Continuous records of runoff were available for this report for the periods October 1917 through November ~928 and October ~946 through September ~962. This period of record is one of the longest for Alaska streams. The monthly recorded runoff of Cascade Creek is shown on Table 12. For the 27 years of record, the average discharge of Cascade Creek was found to be 181,000 acre-feet or 248 cubic feet per second. Annual runoff has varied fram 80 percent (1921 and 1951) to 126 percent (1918 52 VI W FORM 7-223,A (JULY;;) BURL )F nC:CLAt,lATlON Ta6/(~ 12 Run-off of YEAn OCT. N -.-13/"'_ ;:"(;;.?oa 39.100 l!1Ii~ ~3.1{.o llJOOO 10/;:::, ?f2;'JQJ) f---4f1la 1121 9.720 ~-1--_4 620 1'122. '!3<:t:,.O() 7.tBO 19.?~_ . .!,.!jJj~Q ~1{2(l J!i?d... __ .23,700 J."1;Mtl -.L£25 __ _ ?.2:epQ r-1-t-L'l.9_ -'926_ ~28 .. C!t2_ J_12/?(1) 192~ _1!J~So()_ 'r-_~40 1928 __ 18.(::;0 _."L,c_ f)('X"o -',I--~-, "-,, ~7 /l5~o "'-.F".'J -:,-~fi!lo.. .1!l.48 1~!tZ()_ I--t S 2"rd. /'149 /3. 3 {'.o B€Ro Irr!lO 23 (~Jl ~tJ2!:>.. ---'!l5~ .... 86'10 -J-.. 5t:J'10 f---:J-:::-L.::- --'!l5L-r-L~OM!.. _',66Q. 195.3 29.()7~ 9.14(1 /QS4 24190 7.890 TOTAL_ f---.. MEAN~_ _ .. PERCENT. ~ -" - DEC. JAN. ~54Q ~o~q --C;, 'i8 0 g...2~c2 ,£460 ~~Z2.{:L 2140 .?o:to 9.o~o ... to7o ~9!1o 17dO :!l~,,!2... _g,?40 .. .~2.4'!... 1,142 g~~()O Z!L.1OQ iJrtoa .3320 1.9::;;0 .",-'J-!-!-~ f-~(iZ'!.. 23"'l0 ~I-'--.-4P.!lQ- A~~.j, 'r-!h 2 lltL 2960 ;{ 79a ~17fJSL f-/, S "10 ---3E-~o _~S70_ _4.llQ._ f-Z ... 04Q.. 3,080 r-~oS_~ _4;:J!Lo 3.120 HYDROGHAPHIC 3CHf\RGE D/'\Tf.\ >, . ::-. ~----... ~--" -.. " .' . ." ---,-- ,,,_._,, "==-r== ! r,,1J).R. f'R. Jur~E .'ULY TOTAL PERCENT SAN -"---.. __ ." .--' ~~I~~~CL 62';1:L _~:tI2,:; I~oc,.1 ·J2.J()O ~'LZt)o <,,1..::;06 i,! ::,:,(~ (oJ Z2.'1.ICiO /,~6 f--.1.fi12tL c--J~JL ~~4' ~,3(' -'.""-'--12..~llQ .".:0}. :~:tJ2 M,I{;"~ 7.0(' , I7r 330 '-J---.-" 11 ~/:5" _~',/1.._~ Y~t11f:L_ _GO;:Jo 6,110 ,-'z~.!2{l _tl2!l<:>.Q 4UiQ.fj -'2!.~· (;.2. -'Lo,1J?~ .. " 91/ 2290 ~"1!l(J ~O/l{! -'~;:l(2Q .?J.g ~. r,to" 24,6oq 2:;~ _:=./OJZ l240.QQ _l:~~4(L __ f!t.o_ 1.390 j2.ZJo 3 Oro 11100 18.4o~ ~l!Ma .JJ()/l~!!... :?~ ~-.. ·.1'L~ -/7'31{]o r-c-:!!:..J .• -=-=-910 2:2.00 "~.~,, _~37o_ ~3~ .L~2(JQ ~.J?,1-o~ ~7:700 3Lzo.g 3~~ ItJ A iGo "-~J-'-"'-.<-/02- 1.440 .. ~7~<l .A-f;l7!L /tlA()Q-1-~3.!M. _3?,ri~JL _31..t2cHi 40.700 _311l}g() 11 ,,-'J-",---C_ ,--'-'-,,-"- ~1I0 1,2£(£ I. '1.,"'1 -~-~ _20,5ao_ l-~o.().Q .3f1:!J05 -.. ~ .. ~".~---~ 2.7700 -~---•.. ", .1/1.700 ..J1.9,_30~ ~q- ...!il.i1.0 __ 8550 J~J!.(Jt2 17.7(;0 24..lfo[) '2."3 'Pc: "0 I'l ~ ... IOd~e ,lp.%!17P __ I/O _ ... ,,-----",-,>---, r~-'-f-=';; .. ::;A'~_~.I<c!.~","-;' C-"--- /,110 --b_'l?JJ I. 9So I (),1 00 . };/;:,D (J 1:1 29.6qo 25 (Joo 3I.CjQQ.. /71. 92..0 9'1 §.§.oo 4:060 4.?.IQ. ... 2~1..o:; _3~OG:~£?,,?OQ ~ZgQQ g.§;go"Q _L~o.220 105 ,,,--f-... ~ .. -" -£28J2 j~.JjJO. _%Z3..Q. _Z,qlQtL .atz~,2tl ~9~Q 2~61a l1t34() -'-SlS-li!:L /0/ r-"-' _g310 J./_61to 1.510 ~j4{'2. ~~C:Jo_ 2.!f1-81tL 2J/:L70 2tl8()o /G~/l~ jo __ /.880 2.140 J.&ICJ IUdiQ ZG:;"t:10 ,3()450 2B.3()o 2llo0 /65 1ft:} 'II l)IIO 1400 ~!f9'!..... ~OlJi? 3(){J'5() r-"'-'/~' 30970 ~~60 2'5.480 /75,960 9",7 J..42~ ... ~790 2'70 l~tJlo 3~~ 2~1J<;t 204(~(} c"c~ ... -. /6.960 .1~D3fL r--fio- 1870 .:;}-_ .. , ~_8So 2700 1.f,.8.6Q _l{c,,05c ~1.81!t ~EJO .B.ll!~ J73,130 96 !.Jo~ j~83(,-r---g,i~ ..2.1)l20 . e7,g(}~ z,z/lifJ. ,·.~.!i,,'3..J.o .. z...z:r.z.Q. _-'7J./UJ 9.5. II ()'3o Z 110 /780 12.060 '2.7,110 24010 (7310 It:;f::lio 155.040 8~ .. ~ "" . ... -~ ... --, c GPO 845Z47 FOAM 7-2e3A (..IUL.~ 'i',1 BURl{ • )F REOL.AMAT10N . HYDROGRAPHIC 3CHARGE DATA ) 7Q 61e 12 (Continued) Run-off of C 6scade {',.eel: nee,,' Pt!!ttU".sbutt;J. YEAR 1'155 1'156 /'151 1'158 195' 1'160 1961 '962 - "47 -b2. rofp./ 27-yr ').7-Yr A Ife. TOTAL_ MEAN PEROENT OOT. 15.870 /3 ~1t1 # 1432t1 1£&10 28.'70 25.o~1l 37.7()O S4.5!io $g.180 2g~ NOV. DEO. 13 Z60 9.1'10 8,170 2..4b0 1%220 1/ 'leo 15obo 5.360 8420· '470 8710 12:'320 II "50 IQ 8,0 9.ls8o 3390 .3Q~990 /14£)...510 -~.:'!!Q -§~ JAN. FEB. MAR. 4.120 2.5'J(} 2200 1.4-00 /"/60 '(,0 42$0 2.310 %'0'0 6240 2.J90 2.'60 2.'60 3 ISO 2"0 4.250 2930 3110 4.Qzo 4850 2110 BISSo ~960 '2590 , , 124520 72.150 73510 4.(DIO ;?'JG70 Z-J 720 . .sheet 2 J 2 Unit Acl"t!!-Fee::1 Drainoge Area 23 () Sq Miles . . . APR. MAY JUNE JULY AUG. SEPT. TOTAL PEROENT MEAN 2.96D 8:1/'0 25.230 2A. ..... o"" .~.;t 740 2~(J9" 111~4tJ 98 .. _ ... 2090 .22 12.0 2!5./.AO 3a.310 40.1JJ" /7.910 Ib8.6~o. 9'3 3070 18510 2'.200 27.310 ~/680 2.8.640 115.580 '11 5'.34<:) 18.52_0 28870 2.5.860 167/0 12380 "~8oo '2- 3510 "aZO 30 '-So 4o.58(J 29.260 "'220 IS8.91() 104 7.'650 ,,'20 26060 ~4710 30'40 Z5160 19'1.910 lI0 "/0 ... LB.4«> 34.380 32.'150 39.340 23.'110 22.7.750 12.6 3460 12..470 J/Z'" .37.81tJ 29.480 3{)570 2.10860 "'- 1~845.9So 178000 I09L970 425(;10 77/,9/0 833'3lJ 774,~ (#"7.17C '~B8~}750 I 4,07Q "5,170 2~S90 !JD.880 .2~~9..Q 24.110 181,,000 OPO 845141 - c c and 1961) of this average. About 83 percent of the flow occurs in the May through October months. For the 1947-1962 period, average recorded flow was 178,000 acre-feet. Study Period Selection The two periods of record (1918-28; 1947-62) are very similar in their extremes. For the four year period 1948 through 1951, the runoff average was a little less than 90 percent of the 27 year average. This period is the most critical recorded runoff period for Cascade Creek. An inspection was made of the recorded precipitation at Petersburg and Wrangell to aid in the study period selection. Minimum recorded precipitation at both stations occurred in the 1950·s. A relatively dry period is indicated during the years 1940-1946, but the dry years in the 1950' s appear to be more critical. The 1947-1962 years were selected as the study period for determining the project power production. Water Supply for Power The tributary drainage area above the SWan Lake outlet is 18.9 square miles, with a weighted mean elevation of 3,285 feet. The recorded runoff at the Cascade Creek gage reflects a weighted mean e1e- vation of 3,093 feet and 23 square miles of drainage area. Experience in Southeast Alaska shows that precipitation and runoff rates increase substantially With increase in elevation, although canparative data are usually not available to test this relationship for a specific area. 55 In this ease, recorded flows are available for Scenery Creek, which lies immediately adjacent to the Cascade Creek drainage. The two drain- age areas are quite similar, but that of Scenery Creek has a somewhat lower elevation. The elevation and runoff data for these two streams were compared and an increase of 5.0 percent in the unit runQff was found for each increase of 100 feet in weighted mean elevation. Using this relationship, the runoff at Swan Lake Outlet was found to be 89.9 percent of the runoff at the Cascade Creek gage. Computed flows at Swan Lake Outlet for the study period are .hewn on Table 13. For the 1947-1962 period~ the average flow is 159,900 acre-feet per year or about 220 cubic feet per second. Mure lake evaporation will be substantially the same as that ~ reflected in the runoff records, and seepage lOBS from the lake was reasoned to be negligible. Thus, all of the computed flow at Swan Lake Outlet is assumed potentially available for power production. Available Reservoir Capacity The area capacity data for Swan Lake are shown on Drawing 945-906-2 • The curves begin at elevation 1,300 feet, the lowest elevation at which the available soundings permit drawing of the underwater contour. The total volume of the lake between the present water surface elevation of 1,514 feet and the 1,300 foot level was found to be 97,500 acre-feet. The area of the lake at the 1,360 foot level is 365 acre-feet. 56 Mv. U .. 26-65 FO"' ... 7-223A (JULY 1953) BUREAU OF RECLAMATION HYDROGRAPHIC DISCHARGE DATA Table 13 Computed Run off of-ea a c . ~ L 1 01 tl i UniLJOOO ~H'i Drainage Area~ Sq Miles -sea c' r,~.Y· . ran -.a ~e l e --~ YEAR OCT, NOV. DEC. JAN. FEB. MAR. APR. MAY JUNE JULY AUG. SEPT. TOTAL PERCENT MEAN 1947 10.4 12.2 2.1 2.4 2.0 10.3 8.7 18.1 27.3 21.5 20.4 28.2 163.6 , aL.R 10 L. 8 (, !l.O 4 7 ~, :I I) 1 h '0. ~ ~(, I) ~~.~ 10.8 ~I)O '14tS I) ~a 1 ~ 0 7.R ~ 7 ~ c; 1 .~ 1.0 ~.2 '(,0 ~~ P, ~7 h ~c; h ~h h 1 hP, ~ lOI)() ~() P, 10.0 ~.4 1.4 1.0 l.i 1.4 0.1 277 ~7 8 ~1 • c; ~~ 0 , c;R ~ \ -- ., ,... ... ., 7 7 It (, ~ 7 ~ ~ 1 ~ 1(, ~ h 1 (, 1 ~, 0::> 0::>(, a ,p it , c; 0::> , ~n h' .... ././ ~ ~ "7 -.- 10S2 1~.5 Q.O ~. 7 1.8 1.7 1.7 2.5 14.~ 2i.4 34.Q. J5J.. ~O Is6.2 , , at;~ 2(, , -Eo::> 3..-t; , P, , t; , h ~ ~ , O.?' 2ll.. t; 0::>1 c; 22.B. 12Q.1i-~5~1 . .,. ., 10s4 21.7 .7.1 4.i 2 8 0.0 1.0 1.6 10.8 24 h 21 6 1') 6 --.lLL t--139.1.~ , 1955 14.~ 11 5L 8.i i7 2.i 2.0 2.7 7 S 22.7 ~O.(, ~O.~ ~~ S ] sO.8 19S6 11.9 71 2 2 11 1.0 OL9 1.9 19.9 22 6 20.0 ~6 6 ]6.1 1')1 6 , Ot;7 J2..9--~--() , () 7 ~ g ~, 10 ~8 1h7 ~h ~ 0::>1.t (, ~_c; o::>t; 7 , <:;8.0 ~ 10s8 14.0 11.') 4 8 S_~ ~O 2 4 4 8 16 6 26 0 2~ 2 24 0 11.] 148.0 1959 21).8 7 6 s.8 2.7 2.8 2.4 1 2 14.7 27.6 ~6'i 26.i Ih.6 170,0 10(,0 ~~.C; 7,8 " ., ~.R 2.h 2.8 6.0 ~'7 .... 2 ~~ It 31..2-~7 P, ~~ 6 170 ... 7 1061 i~.9 10.1) 9.7 4'4 4.4 2 0 S.O ] 6. 'i iO.O 20.6 ~s h ?1 I) ~Oh.7 1962 31.1 8.7 3.0 7.7 6.3 2.~ 3.1 112 28~1 i4.0 26.s 21...5_ -~82 .1) .;-'~" .' TOTAL ~ MEAN :I 8.] o S 'i 1 q' q 28 211 ~ 4 1 c; ~ 0::>(:.. () 0::>7 7 o::>h A 0::>1 h ' , c;o a '.,. PERCENT GPO 8-152-17 en z -.J 0 I.f) -~ ~ <t > r lLJ w W -J LL LAJ SURFACE AREA, ACRES 1.700 I 300 -----+--~ CAPACITY-1000 ACRE FEET NOTE S: Area data taken from U.S.G.S. Topo.sheet "Cascade Creek and Vicinity" 1952 S I II'. I cae I ~ 2,0 00. Top 0 f con s e r v a 1 Ion spa c e, e I e v. I 5 I 4, c 0 inc ide s wit h pre sen t lake elevation. Contours below elev. 1514, are based upon 'underwater soundings. Lowest measured contour is at elev .. 1'300 and volume of the 10 ke below this level is unknown. 58 ELEV AREA CAPACITY FEET ACRES AC. FT. 1300 365 '0 1340 400 15,200 1380 430 31,800 1420 465 49,800 1460 500 69, 100 1500 530 89,700 15 14 572 97,500 1520 590 100,900 1560 740 127,500 1600 885 160,000 1640 965 197,000 1680 1040 237,100 UNITED STATES DEPARTMENT OF THE INTERIOR CURE AU OF RECLAMATION THOMAS BAY PROJECT-ALASKA SWAN LAKE RESERVOIR AREA AND CAPACITY DRAWN -__________ SUBMITTED- TRACED ______ RECOMMENDED __ _ CHECI<ED___ __ APPROvED_ JUNEAU,ALASKA, JAN.196519~5-906-2 c c c .J. • J Sedimentation An a.na.lysis of potential sediment inflow to Swan Iake has been prepared on the basis of experience in other areas. Over a one hundred year period, the est1lnated sediment inflow to Swan Lake is 4,000 acre- feet. Of this, about 3,000 acre-feet is the estimated portion 'Which 'Would be deposited in the active storage capacity. This is less than 5 percent of the planned active capacity of 72,000 acre-feet, so no allocation of reservoir space to sedimentation was made. Water Rights The Constitution of the state of Alaska provides that surface and subsurface waters are reserved to the people for camnon use, except mineral and medicine.l waters, and are subject to appropriation. "Priority of appropriation shall give prior right. Except for public water supply an appropriation o'f W8~r shall be limited to stated purposes and subject to preferences among beneficial uses, concurrent or otherwise, as pre- scribed by law, and to the general reservation of fish and wildlife." Pending 1egislation assigns to the State's Department of Natura1 Resources the responsibility for determining and adjudicating water rights. The proposed new state water code is based on the appropriation doctrine, with water rights obtained through the application process. A water right application to the Department of Natural Resources will be required prior to the construction phase. 59 ~ ~.~.--.... ~ •... ~~ .• ~-----------_~ •• !!!"' .............. D -..---------- C' A license for Federal Power Camnission Project No. 275 was issued in November 1923, to Messrs. Hutton, McNear, and Dougherty of San FranCiSCO, California, to develop power for a pulp mill. The license was conditioned upon obtaining a timber contract. A contract was not subsequently awarded and the license was terminated in June 1926. The project is now withdrawn as a Geological Survey Power Site Classification and as a Federal Power Commission Power Withdrawal. These withdrawals are for the land only and do not reserve the water of Cascade Creek, unless it were for a higher purpose; however, any use of Cascade Creek water that would involve use of withdrawn lands or other national forest lands would undoubtedly have to be consistent with the power withdrawals. No prior rights for public or private use of water fran Cascade c:; Creek have been established. c Power Production Power Load and Generating Capacity The load characteristics for the market area were discussed pre- viously. Through trial operation studies and mass diagram a.naJ.yses , it was determined that a firm power load of 166 million kilowatt-hours wou1d be appropriate for the Thomas ~ Project. A powerpl.ant capacity of 34,500 kilowatts was selected, for -which the 166 million kilowatt- hours of firm generation represents an annual load factor of 55 percent. Distribution of the annual load is shown on Table 14. 60 C Table 14. Monthly Load D1stribution Month Monthly Ener~ Distr1b~on % of Total KWH x 1 {mo. January 9.0 14.9 February 8.1 13.4 March 8.4 13.9 April 7.9 13.1 May 7.8 1.2.9 June 7.4 12.3 July 7.6 12.6 August 7.9 13.1 September 8.3 13.9 October 8.9 14.8 C November 9.0 15.0 December 9.7 16.1 Total 100.0 166.0 61 c " """""""---" --------------------..---------------- C Operation study A monthly reservoir operation and power study ws prepared to determine the needed reservoir capacity and to describe power production throughout the study period. An annual summa.ry of the study is shown on Table 15, and the reservoir operation and power production are shown graphically on Drawing 945-906-8. In add! tion to the firm energy of 166 million kilowatt-hours per year, secondary generation averaging 17 million kilowtt-hours per year was determined in the study. Most of the secondary generation was found in the August through November months, with same secondary generation being indicated in 15 of the 16 study years. Power water spills, averaging about 3 percent of the inflow, occurred in seven of the study years. C The reservoir was assumed :t\Ul (97,500 acre-feet) at the beginning c of the 1947 water year. The minimum reservoir content of 29,500 acre- feet was reached at the end of April, 1952. A maximum storage use of 68,000 acre-feet is thus shown in the monthly operation study. The deSigns and estimates are based upon a minimum reservoir water surface elevation of 1,365 feet, which provides 72,000 acre-feet of active cap- acity below the present lake level. The added capacity over that used in the operation study 'WOUld allow for daily variations of inflow which are not apparent fran. the monthly records and might perm! t a slight increase in the firm power load. 62 ,,--.. " Tab/t! 15 ;~~ r •... I 0-17·'~ .... -~. ~ ( ," •• /0 '\ , .-:, ~ (") f ' ......... _. _ . ___ ,_ . : -1 .. ;: :' 1. h: \'::, ' I i ,\ --. I I ; ; \ ; ANNUAL SUMMARY; 7." '175' -. o Cf7S :f484! 1470 . o ' '11.C5 o 97.5 o 85.7 o Q7.S' 4.b;.9'.5, o 1 8'.8 o i 97.5, a i 9'f.'S J .5.0, '1?5 i • f1-6~· '14~/1' :,45/ i :/4451 ___ . '/4'7; _ ;/470; :1464 ; it4~'" , .14871 1 14 /~ 12. /~ 14 I~ 14-I~ IZ IS I~, i I~ 14 ,-'~ 15 I~ 15 15 13 I~ I') 15 i lS_ I ! 15 '455 "'.0 20.1 '86.1' .,4.,.3 "6'.0 7.3 173.'3'. 11f37 -"".0' 8.7 /14.1- 1440 : "".0 ~o.e /86.8 14l.4 : "b.o· 0 : "'.0: }414 : "6.0 1.4-"7.4-; /4-38 I~'.D: '0.' 17{,.t:t . '/44() "'.0; I~.o 17'.0 : . 1+$4-· (,-".f) 9,t. i 175.Z: . 11436: /66", 12.5.178.51 Y+5.6 , 1"'.tJ: 1~.6 :/8%.6 I , i : I , : '/4S7 I/~~.~: /2.2.: 178.2 i '/HS j~~",: '21-3 19.1.3 , v4S3: I~~.D! .3;'~~3,~· ,-I-S5 :/"~! 4d'.$ '''/2//.5 . 1.tIt9'1 j,,~: ,J4.4.24~ • .,., . i .. - I I , ., i . --1 _ .... __ ., I .-------------_._ ... ---_._---.--_. ------- 40 ~ OI ~I- IL.z Zo 30 -~ 20 I.&J, ~lL. «c::r 10 ~o z8 <l' ---0 ~ CJ) 90 lL.. 80 « I.&JO 70 ~o <l'Q -.II 60 I-zz <l'w 50 ~f- CJ)Z 0 u 40 30 30 ZO O~ 20 ~ «9 a::: x I.&JI z3 I.&J~ 10 (!) 0 SPILIL RESE RVO'fl INFLOWAN P SPI LLS ~ --------~---~.-. _._._. . -t-f .----. ."" •• ____ 0'. on • n ~ ~ ~ ~ .. ~ X " 11--~ .~ 'I X 1---... _. ... -~ . -----\ ... -_. X ._- ~9l~ ~ ')/ i'IJ ~ .. ~ --._-f--.l( .~ ~ X tl--~ 1 ~ ~t ~ ~~ xx: ~ ~~ lJ ,~ ~ ~z j( ~x x~ hl ~ ~ ~~i'1 ~ M .X I)(X n TOP OF CONSERVATION POOL)ELEV.1514 STORAGE 9~500 A. F RESERVOIR CONTENT SECONDARY ENERGY ! \., .,., FIRM ENERGY I I 1947 1948 1949 ----T---- GENERATION I ! ~rtl ...n a-' - - -1-----. -+------r---_----+-__ -+ __ ~_r_t,------+--.-.---t·----+-----.--- ! I ! ! ' I 1950 1951 1952 1953 1954 1955 1956 1957 1958 [959 1960 I .. !------I ,-----------------------1 UN I TED STATES DEPARTMENTOF THE INTERIOR BUREAU OF RECLAMATION THOMAS BAY PROJECT RESERVOIR OPERATICWANO 1961 1962 ENERGY OUTPUT DRAWN ____ SUBMI TTED -------t TRACED __ RECOMMENDED ____ I CHECKED. APPROVED ____ _ Juneau,Alasl<a,Jan. 14,1965 945-906-8 ________ .. ___ .. ____ .... _________________________________________________ ----'L--_-'---_--'----_---'-_~ _____ ____' 64 Power Head The normal maximum and minimum water surface elevations are 1,514 feet and 1,365 feet, respectively. The impulse turbine runner install- ation used in the design was based upon equivalent nozzle settings at 15 feet elevation. Gross head range for the facility is then 1,350 feet to 1,499 feet. To develop the rated power of 34,500 kilowatts at minimum water surface elevation and 80 percent plant efficiency, tunbine discharge would be 390 cubic feet per second, tunnel and penstock losses would be about 50 feet, and the net head would be l, 300 feet. Average tunnel and penstock losses would be about 16 feet, so the maximum net head would be about 1,483 feet. The range in net head is about93',percent to 105 percent of the design head used in the feasibility designs and estimates, which is 1,408 feet. Rev. 11-26-65 65 c o c CHAPTER VI PLANS AND ESTIMATES The selected plan of development for Thomas Bay Project is based on detailed field surveys and office studies. Designs and estimates of project structures were prepared to provide a reasonable estimate of the total cost of constructing the project. Estimates were also made of annual costs to operate and maintain the project and to pro- vide a sinking fund for replacements. Plan of Develgpment Thomas Bay Project would develop the runoff of Cascade Creek and the head between SWan Lake and tidewater to generate electrical energy. A small control structure would be constructed at the lake outlet to establish the top of conservation storage at elevation 1,514 feet. Con- servation storage capacity would be developed by means of a drawdawn tunnel. The tunnel and underground penstock would convey water to a 34,500-kilowatt powerplant located on tidewater near the mouth of Cas- cade creek. Transmission faci1ities wou1d de1iver power to project load centers. The general plan of development is shown on Drawing No. 945-906-11. The project would be a single-purpose power development. Consid- ering the climate, topography, isolation, and inaccessibility of the project area, there is no opportunity to use the water of Cascade Creek for agricultural, municipal, industrial, or recreational purposes. No 66 c c c property or improvements in the area are subject to flood damage. The project would have no significant effect on the fish and wildlife re- sources of the area or on use for recreation. Because Cascade Creek flows directly into the ocean and is an independent river basin, development of Thomas Bay Project would not directly effect any other river basin or project. Project Works The following brief description of the project works is based on feasibility designs prepared for estimating the total project cost. More detailed planning and more thorough design studies might indicate that some reviSions in design would be desirable. Such changes would not be expected to have a Significant effect on the total project cost. Swan Lake A small concrete overflow structure would be constructed in the outlet channel of Swan Lake. The crest would be at elevation 1,514 feet, the present water surface elevation of the lake. The water sur- face would be lowered sufficiently by the drawdown tunnel to permit building the control structure in the dry. About 72,000 acre-feet of conservation capacity would be provided in Swan Lake between the maximum and m:inimum 'Water surface elevations of 1,514 feet and 1,365 feet, respectively. Because all the reservoir capaci ty will be obtained below the present lake surface, no clearing will be necessary. 67 ________________ ' ____ ...... __ ........... w'.'"ffl .. '~~"" __ ""~""'>,... ... "'_._. ___ ~_~"'_ ......... _ ... _ "!Ii ~~~ QJ '" , C Waterways c o The main feature of the waterways vTOuld be a concrete-lined pressure tunnel through which water would be withdrawn fran Swan I.e.ke. The invert of the tunnel at the inlet end would be at elevation 1,345 feet, 169 feet below the top of conservation capacity. The tunnel would be 11,600 feet long between the intake and the surge tank. The inside diameter would be 7.5 feet. Two shafts to the tunnel would be located far enough fran the intake to be operable above high water in Swan Lake. The upstream shaft would contain a bulkhead and trashrack structure. The downstream shaft would include a gate that could be opened or closed against unbalanced head. Venting and access to the tunnel downstream would be provided for in the portion of the open shaft behind the gate. An 8-foot diameter, reinforced-concrete surge tank would be located at the downstream end of the tuImel. It would extend 325 feet above the tunnel invert to a top elevation of 1,570 feet. The penstock would be located underground with an inclined section followed by a horizontal section. The total length would be about 2,275 feet. The penstock would consist of a single 6-foot diameter steel liner encased in concrete. It would bifurcate into two 5-foot diameter sections just upstream from the powerplant. A construction adit in the vicinity of the surge tank would be necessary to provide permanent access at the downstream end of the tunnel, provide for drainage of the tunnel during construction, and 68 c to facilitate installation of the steel penstock liners. The adit would also provide access for transporting construction materials into the twmel. c o Powerpla.nt The reinforced concrete powerplant would be located at tidewater about 3,000 feet northwest of the mouth of Cascade Creek and would discharge directly into Thomas ~. Two generating units would be housed in the structure with all accessory electrical and mechanical equipment. Each unit would consist of a vertical-shaft, 4-nozzle im- pulse turbine connected to a 17,250 kilowatt generator, for a total powerplant capacity of 34,500 kilowatts which would produce 166,000,000 kilowatt-hours of firm energy annually. Adequate service facilities would also be provided. Transmission Facilities 'nle sw1 tchyard would be located just north of Cascade Creek, about 2,500 feet from the powerplant. It would have a step-up transformer capacity of 40,000 kilovolt-amperes. A l38-kilovo1t line, including both H-frame wood-pole, and steel-tower sections, would transmit energy about 158 miles from the switchyard to the Ketchikan substation to be located near the Wh1 te R1 ver on George Inlet, about 10 miles northeast of Ward Cove. The substation would transform the l38,ooo-volt trans- mission voltage down to 34,500 volts for delivery to the Ketchikan Public Utilities. From the Ketchikan substation, a 34,500-volt, wood-pole --------------------------------------------------,-,--------~------------------------- c c c transmission line would extend 29 miles to Metlakatla. This line would cross Revillagigedo Channel near Mountain foint as a submarine cable 0.9 miles in length. The Wrangell substation, an intermediate substation on the 138,000. volt transmission line, would be located near Blake Channel, on Wrangell Island, for service to Wrangell. A 34,500-vo1t transmission.' line would extend 9.5 miles to a terminal station on Shoemaker Bay, four miles south of Wrangell. At the switchyard, the voltage would be reduced to 34,500 volts for transmitting power to Petersburg and Kake. The line to Petersburg would be about 19 miles long, of which 14.8 miles would be wood-pole construction and 4.2 miles would be submarine cable across Fredrick Sound. The Petersburg SUbstation would be located at West Petersburg, across Wrangell Narrows from Petersburg. The 34,500-vo1t wood-pole line would continue another 41 miles to Kake. Any reduction in voltage below 34,500 volts would be the respon- sibility of the utilities. It is expected that the terminal facilities of Petersburg, Metlakatla, Wrangell, and Kske would be provided by these cities. Other Facilities Because the powerp1ant would be isolated from Petersburg by 25 miles of water, permanent housing for operating personnel would be required. It would be located on a low bench just south of the mouth of Cascade Creek. Permanent facilities would include houses for a Rev. U-26-65 ~ staff of 27 persons, together with the necessary service buildings, streets, utilities, and communications and transportation equipment. Facillties would be required to serve an estimated 76 Government workers during construction of Thomas ~ Project. The permanent com- munity would be used and trailer-type houses would be provided for the remaining employees. Temporary structures and all necessary equipment and supplies are included in the construction cost. An access road less than a mile long would be constructed from the camp area to the powerplant site. A bridge across Cascade Creek would be included. A 1/4th-mile road would lead to the sw1tchyard. A road about 2-1/2 miles long would be needed to provide access to the adit at the lower end of the tunnel. A dock located near the service yard at the powerplant would be C provided to unload materials and equipment :fran barges and ocean-going vessels. A float for small boats and float planes would be located c near the permanent camp. Design and Construction Problems The general plan of developnent of Thomas Bay Project is not can- plex. Sane problems of design and construction that may be encountered are discussed below. 71 ~ Accessibi1itr Al.though only 15 airline miles fran Petersburg, the power site is in a remote area. Travel between Petersburg and the construction camp must be by float plane or a 25-mile boat trip. The beach at the camp site is suitable for constructing a float for small boats and planes. Construction materials and equipment could be delivered by barge and unloaded at a barge dock. A deepwater dock would be constructed for ocean-going vessels. There are no roads in the construction area. Access to construction sites must be by road, tramway, or high11ne. Swan rake can now be reached only by small float planes, or on foot. Petersburg is a deepwater port that can accommodate ocean-going ships and large float planes; there is no landing field for Wheel planes. A road fran Petersburg up the Stikine River basin through British Col- e um.bia is currently under active consideration; however, a completed roa~ ms:y not be a reality for years to cane, and in any event, would probably not be connected to the project. c Rights-of-Way All project works, except for receiving substations and Short sections of the transmission lines, would be located on lands of the Tongass National FOrest and Annette Island Indian Reservation. A por- tion of the lands required for development of the project as proposed under Federal Power Commission Project No. 275 have been withdrawn as a Federal Power Commission withdrawal dated November 12, 1922, and under Geological Survey Power Site Classifications No. 9 and 192, dated 72 ---------------------,--"'---..... , -,..---------------'-... -"'~' ..... - C August 20, 1921, and November 14, 1927, all in accordance with Section 24 of the Federal Wa.ter Power Act. The withdrawn area includes all lands below elevation 1,650 feet that drain into swan Lake, a strip of c o land one mile wide on the south side of Cascade Creek from Swan Lake to Thomas Bay, and a similar strip 1/8 mile wide on the north side of cas- cade Creek. This withdrawn area excludes most of the tunnel line and all the penstock line and powerplant site. Prior to construction, public lands required for transmission lines would be withdrawn. It may be necessary to obtain easements or acquire right-of-war for a very small amount of privately-owned land. Relocations There are no existing facilities that would have to be relocated because of project construction. CClllDlWlications Communication between the project facilities would be by carrier current, radio, or radio-telephone. The ThClllas Bay Project is in an area of hard, crystalline rocks, mainly quartz diOrite, with sane gneiss. Lofty, precipitous mountains are deeply scored by glaciation. Barren rock lies above the heavily forested zone that disappears in general above elevation 2,000 • . :: .. 73 c Swan Lake outlet, located in quartz diorite, is suitable for either a rock-fill or arch dam. Hard rock crops out on both abutments a short distance above stream level. Talus has filled the gorge to an estimated depth of 100 feet. Preliminary studies indicate that the con- struction of a dam would not be economically justified. Reservoir seepage loss is expected to be low and of no Significant effect. The tunnel line is predominantly in quartz diorite, interspersed with coarse-grained gneiSS, schist, and probably some marble. The line cuts across the "grain of the country" and generally excellent cOIld1- tions will prevail. No squeezing ground is anticipated. The flow of water along the entire line may not exceed 8 cubic feet per second. The powerplant would be in a hard granite gneiss. JOinting is blocky but not praninent. The rock is suitable for an underground C powerplant. c There are several possible nearby sources from which to obtain an adequate ~ly of sand and gravel for concrete aggregate. Project Costs Project costs include the construction cost, interest during construction, and the annual cost of operating and maintaining the project and providing for periodic replacements. 74 c Construction Cost Feasibility cost estimates have been prepared for all project fea- tures. Total construction cost, based on October 1964 prices, is estimated at $41,165,000, as summarized in Table 16. Included in this total construction cost are investment in project features, cost of service facilities required during construction, cost of permanent facil- ities ... required to operate the project, and the cost of project investigations. Operation and Maintenance The annual cost of operation and maintenance of all project features is estimated at $407,000. This estimate is based on fully attended powerplant operation, with a personnel requirement of 27 employees at the plant, including all transmission line crews. C PrOvisions for Replacement c· The cost of providing provisions for replacements 'WaS based on a straight Sinking fUnd, using a 3-1/8 percent interest rate and a 50- yee:r period. The estimated annual cost is $102,000, of which $93,000 is for Stage 1 construction. Interest During Construction An orderly scheduling of preconstruction activities is essential to selecting the optimum plan of development and the best designs for project structures. About one year 'WOuld be required for advance planning, preconstruct1on, and design activities. 75 • C Table 16. SUmmary of Construction Costs Feature Construction Cost {f:!z 000 1 stage 1 Stage 2 Total Reservoir and tam 624 624 Powerplant (20,984) (1,786) (22,770 ) structures and Improvements 2,071 2,071 Wate1"W8\Ys 15,002 15,002 Turbines and Generators 2,004 1,707 3,711 Accessory Electrical Equipment 923 79 1,002 Miscellaneous Equipment 147 147 Roads and Bridges 837 837 Thanas ~ Sw1 tchyard 1,239 315 1,554 Petersburg Substation 334 334 Wrangell Substation 1,101 1,101 Ketchikan Substation 601 601 C Transmission Lines (12,115) (12,115) Thanas Bay to Wrangell Sub. 3,545 3,545 Wrangell Sub. to Ketchikan Sub. 4,519 4,519 Ketchikan Sub. to Metlakatla 1,100 1,100 Thanas Bay to Petersburg Sub. 1,367 1,367 Petersburg Sub. to Kake 1,257 1,257 Wrangell Sub. to Wrangell 327 327 General Property ( 2,066) ( 2,066) Permanent Operating Facilities 710 710 O&M Housing 1.z35 6 1.z356 Total Project $39,064 $2,101 $41,165 c c I iii' It is expected that Thanas Bay Project would be constructed in two stages. The first stage would include all project facilities except one of the generating units, With its associated accessory and switching equipment. It is est:l.ma.ted that 3-1/2 years would be re- quired to construct these facilities after award of the prime construc- tion contract. The cost of the first stage is est:l.ma.ted at $39,064,000. The second stage would require a two-year construction period and include the second generating unit and associated facilities, at an estimated cost of $2,101,000. It 'WOUld be installed when required to meet the growing power 1oe.d. The estimates of future load growth in- dicate that it would be on the line at the beginning of the fifth year of operation. The interest during construction and total investment computed at C 3-1/8 percent simple interest is summarized below: c Construction Interest During Total Stage Cost Construction Investment 1 $39,064,000 $3,05 2,000 $42,116,000 2 2 z101 z000 66,000 202 16702 000 Total. $4~,~65,000 $3, ll8, 000 $44,28 3,000 ProJect Fbrmulation Three comparative studies were run to determine whether or not it would be justifiable to raise the 'Water surface elevation of SWan lake. One study 'Was based on the adopted plan of development described in this report, with the top of conservation storage at elevation 1,514 feet, 77 C the present lake J.eve!. A second plan included a dam at the outlet of Swan Lake to raise the top of conservation storage to elevation 1,625 feet. The dam in a third study would raise the water surface elevation to 1,667 feet. These three studies indicate that the optimum elevation of the top of conservation storage is approximately at the present lake level of 1,514 feet. A major factor in the conclusion is that a dam to raise the water surface any significant amount 'WOUld require the removal of about 100 feet of talus to reach a bedrock foundation, as well as this much extra height on the dam. The large increases in cost for the dam and other larger project features do not justif,y the additional benefits obtained from the higher head and better regulation of Cascade Creek runoff. Comparative studies 'Were also made of a surface powerpla.nt and an C underground powerplant. The surface plant was shawn to be less costly, and this design was used in estimating project construction costs. c Incremental analyses were made to determine the economic justi- fication of including the Ketchikan and Kake-lUncan Canal areas in the project power market and supplying them. 'With project power. In a.nalyzing the inclusion of the Ketchikan area, a reconnaissance cost estimate was prepared for a project including only the Petersburg-Wrangell and Kake- Duncan Canal areas. The project features were sized to fit the smaller power market. The annual incremental benefits of including the Ketchi- kan area 'Were much greater than the annual incremental costs (including OM&R costs), showing that inclusion of this area in the project power market is well justified. 78 c c· A similar analysis was made for the Kake-Duncan Canal Area. Because of the small load in this area, however, it was assumed that only the Petersburg-Kake transmission line would be omitted, with no change in the size of any other project features. This analysis showed the tangible incremental benefits to be larger than tangible incremental costs, thus indicating that this increment is econom1ce.lly justified. Furthermore, an adequate supply of power would greatly benefit this forward-looking canmunity by providing an important ingredient to the expanSion of its social and economic structure. The proposed plan of deve~ent is considered to be the optimum for Thomas Bay Project. 79 c CHAPrER VII ECONOMIC AND FINANCIAL ANALYSIS As the Thomas Bay Project is a single purpose hydroelectric power development, all project costs would be reimbursable fran net power revenues. Similarly, the project benefits were considered limited to those assignable to the delivery of power to the project cities. Economic Justification The physical life of the potential project works would probably exceed 100 years. However, because of the difficulty of defining remote future conditions and the discount of long-deferred values, direct project benefits and costs were analyzed for a lOQ...year period. ~ Benefits c Tangible benefits of 'nlomas Bay Project, as evaluated in this report, would equal the market cost of a similar block of energy from the most likely alternative source or sources. Studies of alternative sources of power far the project market area indicate that diesel-electric units located at the load centers, or less economically small hydroelectric developments to serve the indi- vidual cities, would be the most likely alternatives to the developnent of Thomas Bay Project. These would not provide for interconnection of the load centers. 80 C Ketchikan would be in a position to achieve the greatest economies with diesel generation. Utility loads are of sufficient magnitude that new diesel units could be of large capacity and permit purchase of' low- grade fuels in large quantities. Without the Thomas Ba\Y Project, it is unlikely that Petersburg and Wrangell will be electrically tied together within the foreseeable future. Also , it was considered that it would be quite some time before either would be in a position to use large diesel electric units. This situation coupled with a lesser fuel requirement would reflect higher generating costs than those attainable by Ketchikan. Kake and Duncan Canal would continue to ~ a very high premium for power under the alternative to the Thanas Ba\Y Project. Here again it is improbable that the two load centers would be tied together. C There would probably be very little expansion of facilities at l)mcan Canal. The community of Kake would have to add units periodically as c the loads grow. However, these incremental addi tiona would be provided in small units. Metlakatla has investigated other hydroelectric potentials in that area, but it has f'ound them unduly costly. Here again, sma.ll diesel generating units are expected to be added as required. The Ketchikan Public Utilities in connection with its submittal of a bond proposal for reconstruction and enlargement of its Beaver Falls hydroelectric developnent, prepared estimates of the costs of obtaining needed additional power supplies by installation of additional diesel 81 ~~--~--.--~-.----------~-----~---""'J -. -------- C units. The estimates were based on use of' Fairbanks Morae 2,000-k:l.1o- watt package units with 5,000,000 kilowatt-hours per year energy produc- tion, 30 year operation, an interest charge equal to 60 percent of' the C c estimated construction and installation charges, and fuel costs reflect- ing anticipated savings from bulk purchases and continuing general price increases. These estimates are summarized below: Item -Year -1963 Cost in Mills per Kilowatt-hour 1968 1973 1978 Insta.l1ation 1.787 1.787 1.787 1.787 Interest 1.072 1.072 1.072 1.072 Maintenance 1.378 1.378 1.378 1.378 Operation 2.361 2.361 2.361 2.361 Fuel 8.571 y 10.337 12.017 13.868 Total. 15.169 16.935 18.615 20.466 Y Based on 12 cents per gallon, adjusted :from 1963 contract price of' 14.63 cents per gallon. The above estimate f'or year 1963 conforms to a total cost of' generation of 18.2 mills per kilowatt-hour as estimated by the Alaska District Office for a diesel-electric plant of 15,000 kilowatts located at Ketchikan. Similar estimates of' cost of generation were made f'or the other project areas based on the capacity required for each at the time the Thomas Bay Project became fUlly loaded. In preparing these estimates, 82 c it was assumed. that all ex1i!:lting diesel un1.ts would have been retired or put in standby service. It was al.so assumed that all future in- stalled units would be larger more efficient units than presently eXisting, and all hydro would remain in service except the very small units. An allowance has been made for the cost of terminal facilities at Petersburg, Metlakatla, Wrangell, and Kake, which under the project plan would be required to reduce the voltage from 34,500 volts to their distribution voltage but would not be required for diesel-electric units: A summary of the size of plant, energy requirements, and cost of gener- ation at each load center is shown in Table 17. Table 17. Surrmary of Load and Energy Requirements Year 1983 and Estimated Cost of Generation by Diesel- Electric Units Requirements of Estimated Cost New Diesel-Electric Sets of Generation. Load Center Kilowatts Kilowatt-Hours Mills per kwh Ketchikan 14,790 74,090,000 18.2 Petersburg 7,000 35,560,000 22.9 Wrangell 5,690 23,460,000 23.0 Metlakatla 3,750 16,730,000 22.4 Kake-Duncan Canal 1,010 5,300,000 24.5 Tangible benefits of Thomas Bay Project would equal the market cost of a similar block of energy from the most likely alternative source. In this instance several sources and costs would be involved; therefo~, 83 Rev. 11-26-65'· c benefits accruing to each segment of the overall area would vary. The block of energy used by each of these segments t at the time the Thomas Bay Project would be fully loaded, constitutes the base for determinins the differing benefits from sale of firm energy. Benefits from sale of non-firm energy are assumed to accrue only to the Ketchikan and Peters- burg-Wrangell areas. Adjusting for load build-up, the average annual kilowatt-hour sales over the 100-year period are slightly lower than the amounts shown in Table 17. Discounting each year's sales to a present worth value in year one, and then determining the annual equivalent value for the present worth of total sales, the average annual kilowatt-hour sales of firm energy for a 100-year period at each load center, would be as follows: c Average Annual Load Center Sales -kwh Ketchikan 65,746,000 Petersburg 31,497,000 Wrangell 20,769,000 Metlakatla 14,855,000 Kake-Duncan Canal 4 2676,000 Total 137,543,000 On the same basis, the non-firm power sales would average 7,040,000 kilowatt-hours in the Ketchikan area, and 3,230,000 kilowatt-hours in the Petersburg-Wrangell area, for the lOO-year period. Rev. ll-26-65 84 -\.., c For the Ketchikan area, the 1OO-year average annual sale of 65,746,000 kilowatt-hours of firm energy at 18.2 mills would provide annual benefits of $1,196,000. An average annual sale of 7,040,000 kilowatt-hours of non-firm energy at 6 mills would yield benefits of $42,000. At Petersburg, average firm energy sales of 31,497,000 ki1owatt- hours at 22.9 mills would provide $721,000 in annual benefits, and the sale of 20,769,000 kilowatt-hours at Wrangell at 23 mills would provide $478,000 in annual benefits. For the Petersburg-Wrangell area, additional benefits of $19,000 result from the average annual sale of 3,230,000 kilowatt-hours. For the Metlakatla area, the sale of 14,855,000 kilowatt-hours at 22.4 mills would provide $333,000 in annual benefits. Benefits from sale of an average of 4,676,000 kilowatt-hours at a rate of 24.5 mills would amount to 114,000 in the Kake-Duncan Canal area. The average annual total of all tangible benefits would be $2,903,000. Cost Allocation The total investment cost, including interest during construction as previously derived, is $44,283,000 and considered assignable to power. It consists of $42,116,000 for the first stage development and $2,167,000 for the second stage development. 85 ,-, .. ,-.'- Since the project is to be developed in stages, a proportionate share of construction costs of features mutually necessary to both stages is allocated to each stage. The deferred cost allocated to the second stage is then carried at compound interest until this stage is transferred to p1ant-in-service status. It is then amortized within a 50-year period at compound interest in the repayment analysis. The costs allocated to each stage are derived below: Pro,iect Investment Total Interest Total Federal Deferred Allocated on Allocated Stp.ge Investment Costs Costs Deferred Costs Costs 1 $42,116,000 -$19,974,000 $22,142,000 0 $22,142,000 2 2 z167 2000 19·274 zooo 22 zl41.000 ~2 .616 :°°01/ 243757z000 $44,283,000 $44,283,000 $2,616,000 $46,899,000 11 4 years compound interest at 3-1/8 percent. Annual Costs For purposes of project justification, all costs were converted to a 100-year economic life from which average annual costs were obtained. The average annual costs are summarized as follows: Average annual operation and maintenance Average annual proviSion for replacements 86 $ 402,000 101,000 Average annual payment on interest and principal $44,032,000 gJ X 0.03276 Total average annual costs gJ Present worth of total allocated costs Benefit,Cost Ratio $1.442.000 $1,945,000 The ratio of average annual primary tangible benefits to average annual costs is 1.49 to 1.00. Financial Analysis When fully developed, the project would generate 166,000,000 kilowatt-hours of firm energy each year. With an allowance of 7 percent for station service and transmission losses, the saleable energy would c:: amount to 155,100,000 kilowatt-hours. The power market study indicates a probable 10-year development period before this would become fully utilized. Annual Revenues The main source of revenue would be derived from the sale of firm energy. After allowing for station service and transmission losses, net annual saleable firm energy is estimated to be 155,100,000 kilowatt- hours. In the repayment analysis, the fiscal year sales are taken as being identical to the calendar year requirements. The estimated project firm energy sales are summarized in Table 18. 87 Rev·.·ll-e6-65 " .. - \ •. " Table 18. Summary of Ca~acity and Energy Requirements for Sales to utilities from Thomas Bay Project Year of Fiscal Capacity Firm Energy Operation Year Kilowatts Megawatt-Hours 1 1974 8,780 43,030 2 1975 10,810 52,640 3 1976 12,980 62,850 4 1977 15,320 73,900 5 1978 17,800 85,710 6 1979 20,470 98,260 7 1980 23,310 111,780 8 1981 26,370 126,220 9 1982 29,630 141,690 10 thru 54 1983 32,240 155,100 Other project revenue would include rental from permanent operating facilities and sale of non-firm energy. A net annual average of 15,900,000 kilowatt-hours of non-firm energy would be available for sale. However, c:: a market for this type of energy would not be expected to develop until the 11th year of project operation. It has been assumed that this mar- ket would then grow at the rate of about 2,000,000 kilowatt-hours per year. Revenue Deductions Revenue d.eductions fall into three general classifications: Operation, maintenance, and proviSion for replacements. Operation and maintenance includes the cost of labor and material required to operate the project and keep it in good condition. This estimated cost is divided between generation plant, transmission plant, and administrative and general expense, and increases with each stage of construction: 88 ... " .. ",.,... '~ Generation Transmission Admin •. and Plant Plant Gen. E!I2. Total Year 1 through 4 $160,000 $156,000 $44,000 $360,000 Year 5 through 54 180,000 177,000 50,000 407,000 Replacement of major items of equipment would be provided for by a 50-year straight sinking fund at 3-1/8 percent interest: Year 1 through 4 $ 93,000 Year 5 through 54 102,000 Repayment Analysis An average rate of 15.7 mills per kilowatt-hour of firm energy sold at 55 percent annual plant factor, would be necessary to pay operating costs, and to retire the Federal investment within the re-e quired length of time. This rate would be the same at all delivery points and would apply to wholesale energy delivered at 34,500 volts. It would provide for the repayment, with interest at 3-1/8 percent, of the investment costs allocated to each stage within 50 years after that stage is placed on the line. The total accumulated revenues and costs and computed rate for firm energy for each repayment period are summarized as follows: c ft@tr. ll-e6-65 c c c At End of Repayment Period for First Stage (50 Years) Total accumulated firm power sales, MWH Total accumulated costs Less non-firm power sales & other income Less allowable unpaid balance Total costs to be repaid with firm power revenues Required firm power rate (X) 15,661,600 (X) $264,339,000 -9,523,000 -24,638,000 11 $230,178,000 = 230,178,000 15,661,600 = 14.70 mills per kilowatt-hour at 55 percent annual plant factor At End ~f Repayment Period for Second Stage (54 Years) Total accumulated firm power sales, MWH Total accumulated costs Less non-firm power sales & other income Total costs to be repaid with firm power 18,362,000 (X) $301,095,000 -u,848,ooo revenues Required firm power rate (X) = 289,247.000 18,362,000 Adopted rate $289,247,000 = 15.75 mills per kilowatt-hour at 55 percent annual plant factor II: 15.7 mills per kilowatt-hour at 55 percent annual plant factor !I Allocated cost to stage 2, plus 4-years simple interest on deferred costs. LETTER REPORT OF FISH AND WILDLIFE SERVICE c c o Mr. George N. Pierce District Manager UNITED STATES DEPAR'lMENT OF THE INTERIOR FISH AND WILDLIFE SERVICE Bureau of Commercial Fisheries Box 2481 Juneau, Alaska 99801 April 14, 1964 U.S. Bureau of Reclamation P. O. Box 2567 Juneau, Alaska Dear Mr. Pierce: 3ii Reference is made to your request of December 3, 1963 for the views and camnents of the U.S. Fish and Wildlife Service on the n:..amas l3a\Y pro- ject near Petersburg, Alaska. This letter constitutes the preliminary report of this Service and has been prepared under the authority, and in accordance with, provisions of the Fish and Wildlife Coordination Act (48 Stat. 401, as amended; 16 U.S.C. 661 et seq.). Swan Lake, which would provide storage for the project, is located about three miles east of Thomas Bay, and approximately 17 miles north- northeast of Petersburg. The lake lies at an elevation of 1,514 feet, 1/ and drains an area of slightly more than 17 square miles. - The proposed plan of development provides for a tunnel, penstock, power plant, and transmission line. The normal lake surface elevation at 1,514 feet w~uld be the maximum elevation of the conservation storage pool. The surface area at this elevation would be 540 acres. '!he re- quired active storage of 72,000 acre-feet would be obtained by drawing the lake down, by means of a tunnel, to elevation 1,365 feet. At this minimum 'Water surface elevation, it is est1lna.ted that the dead storage would exceed 88,000 acre-feet, and that the reservoir would have a sur- face area of 420 acres. A concrete-lined tunnel, 11,600 feet in length and 7.5 feet in diameter, would convey the wter to a surge tank located near Thomas Bay. The steel penstock would be 6.0 feet in diameter, 2,460 feet in length, and contained wi thin a tunnel. The power plant, Y All elevations in feet and refer to mean sea level datum. c c c located at tidewater, would have an installed capacity of 34,500 kilo- watts. The transmission system 'Would include the sw:ltchyard, a 34.5 kilovolt transmission line to Petersburg and Kake, a l38-kiloyolt transmission line to Ketchikan, a 34.5 kilovolt transmission line to Metlakatla, and substations at Petersburg, Wrangell, and Ketchikan. Water from the power plant, an average of 212 cubic feet per second, would discharge directly into Thomas Bay about 3,000 feet northwest of the mouth of' Cascade Creek. studies of reservoir operation for the water years 194.7-1961 showed that spills fran the reservoir would have occurred in all years except 1951 and 1952. These studies considered only the production of firm energy. 5.1 The drainage area of' Swan I.e.ke is mountainous and extremely rugged. Peaks rising to more than 5,000 f'eet elevation lie within 1.5 miles of' the lake margin; a few small glaciers and extensiYe snow fields persist all summer at these higher altitudes. Much of the valley walls consist of' steep, bare rock cliffs which give way to dense spruce-hemlock f'orest near the lake. Small patches of bog and muskeg occur on poorly drained si tes at the lower elevations. The fiat area extending up the valley beyond the lake supports moderately dense stands of' alder, with heavy willow growth along stream courses. The upper valley floor sustains an alpine coyer type, with sparse conif'er growth. Swan Lake lies in a solid rock basin and possesses depths in excess of' 500 f'eet. Surface water temperatures in midsummer range into the mid- fifties. The lake waters are colored a grayish green by glacial flour, and are f'ab'ly clear. Most of' the lateral inlet streams are yery steep and offer no spa'WIling areas, although one lateral stream near the head of' the lake contains a short section of' usable grave!. The stream entering at the head of' the lake is the largest inlet and contains the most extensive area suitable f'or spawning. Only the lower 1.2 miles of' the latter stream are accessible to fish, however, awing to the presence of' a 35-f'oot waterfall upstream from the lake. Upstream fran this water- fall, the bottom substrate consists predaninantly of coarse materials, and is largely unSUitable as spawning area. The only f'eatures of' human origin within the basin are a foot trail con- structed by the U.S. FOrest Service, extending from tidewater to SWan Lake, and a stream. gaging station maintained by the U.S. Geological Survey on the lower reaches of' Cascade Creek. Based on unpublished data provided by U.S.B.R. and canputed fran "Surf'ace Water Records of Alaska, U.S. Geological Survey, 1962." ··2·· c c c Swan Is.ke ws found to be barren of fish when surveyed in 1957; how- ever, the Fish and Wildlife Service stocked 20,000 rainbow trout fry on July 12, 1958. The Alaska Department of Fish and Game stocked an additional 20,500 rainbow trout fr.Y on July 16, 1959. SUrveys con- ducted during 1961 indicated that these stockings were successful and that natural reproduction had occurred. The rainbow trout taken ranged in length from 4 to 14 inches; their condition ws excellent, and the population appears to be thriving. It is probable that most spawning occurs in the two inlet streams previously mentioned although same spa.wning may take place in lake gravels near the shore that are per- meated by spring seepage. The outlet of Swan rake, Cascade Creek, possesses a very steep gradien-:t; and coarse bottom materials. Casca.de Creek flows first through a small sha.1low lake situated one-half mile below Swan lake, and thence through Falls Lake, a 2O-acre body of water lying at the 1,150 foot elevation. A falls near tidewter blocks the migration of e.nadromous fish into the basin. Investigations conducted during 1962 in the section of Cascade Creek between the SWan Lake outlet and the small shallow lake approx1mately one half the distance to lialls Lake, revealed rainbow trout throughout the entire distance. These fish have presumably became established as a result of movement downstream from Swan Lake, and probably cannot return to the lake owing to the steep cascade section below the SWan Lake outlet. Sportfishing pressure in the basin is at present very light, but is expected to increase in future years with the expanding human population. The foot trail to SWan Is.ke is more than 2 miles long and difficult to travel. A few fishing parties probably fly into the lake every year using float planes. The effects of construction and operation of the project upon fishery resources will disrupt the spawning that may occur near the shore, on gravel deltas, and in streams. The reservoir 'Will be fi1l1ng at the time the rainbow spawn (May and June) and during the periods of egg developnent and fry emergence (through July). Spawning in the two usable inlet streams is of primary importance and will be disturbed inasmuch as the reservoir level 'Will be below the natural lake surface elevation at the time spawning occurs. Because of the poor substrates, spawning will probably not take place in the lowe:nnost sections of the inlet streams Which will be newly exposed at below-capacity reservoir levels. Should the fish be denied access to the inlet streams and should they be unable to spawn successfully on the lake margin, the result would be the ultimate destruction of the Swan rake rainbow trout population. -3- c c c In addition, the drawdown will dew.ter Cascade Creek of all but incre- mental flow during the period December through June. This dew.tering will have serious effect on the rainbow trout inhabiting this area. At max1mum pool elevation, Swan Lake will have a surface area of' 540 acres. It is antiCipated that the ma.x1mum drawdown will be 149 feet. The latest engineering information available indicates that under normal load it is unlikely that the fluctuation will exceed 100 feet. Using the maximum drawdown of 149 feet, the surface area will be reduced to 420 acres. Concurrent with the winter drawdown there will be a subse- quent loss of productivity owing to the loss of area suitable for plankton production and disruption of the littoral zone. Together, these will reduce the lake's carrying capacity for trout. Project construction and operation probably will not improve access to Swan Lake Significantly because it is unlikely that a road will be built to the reservoir site. Without a road, the gradual increase in sport fishing and hunting that is expected to occur in future years, will be merely the result of enlarged human population. Black bear and moun- tain goats were seen in the basin during the surveys, and deer probably occur here also, although none were observed. Sma.ll game species include snowshoe hare, blue grouse, and ptarmigan. An aggregation of flightless Canada geese w.s observed here during July. No breeding geese were seen on Swan Lake, although the survey crew noted breeding goldeneye ducks and short-billed gulls. Hunting pressure in the basin is believed negligible, although Swan Lake serves as a base camp for a few goat hunters each year. In view of the engineering data provided by your office and our recon- naissance surveys of the fish and wildlife within the contemplated developnent, we conclude that the project will neither benefit the fish and wildlife nor offer significant opportunity for their improvement. If the project is constructed, the fishery present in Swan Lake and Cascade Creek would be subject to moderate adverse effects. Therefore, this Service does not recommend that the conservation, improvement, and development of the fish and wildlife resources be included as a purpose of the project. No detailed studies as to the possible effects the project would have on fish and wildlife resources of the basin have been conducted. If the project is authOrized, studies would be necessary to determine more preCisely (1) the magnitude of the rainbow trout population in Swan lake and Cascade Creek, (2) spawning areas and the time spawning occurs, (3) what effects the disruption of the littoral zone and reduction in area of the pelagic zone would have on productivity, and (4) the minimum -4- C now required to sustain the rainbow trout in Cascade Creek. c c This report has been coordinated with the Alaska Department of' Fish and Game and has the concurrence of' that agency as indicated in the letter dated April 8, 1964, Signed by Deputy Camnissioner E. S. Ma.rvich, a copy of' which is appended. It is recommended: That the f'ollowing language be incorporated in the recommendations of' the report of' the District Manager of' the Bureau of' Reclamation: 1. "'lhat additional detailed studies of' fish and wildlif'e resources af'f'ected by the project be conducted as necessary, after the project is authorized, in accordance with Section 2 of' the Fish and Wildlif'e Coordination Act (48 stat. 401, as amended; 16 U.S.C. 661 et seq.); and that such reasonable modifications in the authorized pro- ject facilities be made as may be agreed upon by the Secretary of' Interior and Secretary of the Army for con- servation, improvement, and development of these resources." 2. "That federal lands and project waters in the project area be open to public use for hunting and fishing so long as title to the lands and structures remains in the f'ederal government, except f'or sections reserved f'or safety, efficient operation, or protection of public property. 3. "That leases of federal lands in the project area reserve the right of public use of such land for hunting and fishing." 4. "'lhat the U.S. Fish and Wildlife Service should be advised of any changes in the engineering plan in order that such changes may' be reviewed 'With regard to their eff'ect on fish and wildlife, and adequate provision may be made as required f'or the projection of these resources in the af'f'ected areas." We appreciate the opportunity to comment on this project. Enclosure: as c1 ted Very truly yours, /s/ Harry L. Rietze Regional Director -5- c c c S T .. -A-;!r E. o F A LAS K A William A. Egan, Governor DEPAR'lMENT OF FISH AND GAME Office of the Commissioner Subport Building-Juneau April 8, 1964 Harry R1etze, Regional Director Bureau of Canmercial Fisheries U.S. Fish and Wildlife Service P. O. :Box 2481 Juneau, Alaska Dear Mr. R1etze: This Department has reviewed the revised report on the Thanas Bay project near Petersburg. We agree with the findings as to the effect of the project on fish and game and concur in the recommendations for the protection of these resources as outlined in the report. Sincerely yours, AIASKA DEPAR'lMENT OF FISH AND GAME /s/ E. s. M8rv1ch, Deputy Commissioner • LETTER REPORT OF BUREAU OF OUTOOOR REJREATION c c c UNITED STATES DEPAR'lMENT OF THE INTERIOR Bureau of OUtdoor Recreation Pacific Northwest Region U. S. Court House Seattle, Washington 98104 December ll, 1963 Mr. George N. Pierce, District Manager Bureau of Recl.ama.tion P. O. Box 2567 Juneau, Alaska Dear Mr. Pierce: Personnel of this office have reviewed your letter dated December 6, 1963, and the accanpanying Fish and Wildlife Service preliminary report dated May 3, 1962, on the Thomas Bay Project, Alaska. It will be noted that the Fish and Wildlife Service report indicates the project will not affect general recreation. The proposed develop- ment would neither create or destroy Significant recreation values and because of the relative unimportance to recreation, a far.mal reconnaissance report has not been prepared. We have no objection to or further comments on the Thomas Bay Project, Alaska. Sincerely yours, /s/ Fred J. Overly Regional Director LETl'ER REPORT OF NATIONAL PARK SERVICE In Reply Refer To: L7423-RBR Memorandum To: Fran: Subject: UNITED STATES DEPAR'IMENT OF THE INTERIOR National Park Service Western Reg10n 180 New Montganery street San Francisco, California 94105 January 16, 1964 Mr. George N. Pierce, District Manager, U. S. Bureau of Reclamation, P. O. Box 2567, Juneau, Alaska Assistant Reg10nal Director, Resource Planning Thomas l3a\Y Project, Swan rake, Alaska Your subject letter of December 6, enclosing a copy of the Fish and WilcU1fe Service's informative report of May 3, 1962, describing your Bureau's proposed :power development at Swan Lake, leads us to believe the public use potential will not be greatly enhanced by the prOject. Swan Lake's isolated location, surrounded by glaciated, precipitous tarrain and the probabil1 ty that access by road will not occur, leads us to conclude that public use of the lake will not be enhanced by the project. The lake area will undoubtedly experience some increased recreation use due to increases in population and use of float planes provided the lake becomes lmown as a good fishery. In regard to archeology, there may be prehistoric human remains in Thomas Bay at the mouth of Cascade-Creek where the :power plant is pro- posed. The area should be scientifically investigated before any con- struction activity occurs. We would suggest that the University of Alaska do the archeolog1cal investigations 'Which ms:y cost $500. Should an archeological excavation be required, the additional costs should not exceed $3,000. Although we have no further comments we will appreciate being informed of your further progress on this project. /s/ Leo J. Diederich Assistant Regional Director