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HomeMy WebLinkAboutChakachamna Project Alaska 1962L A s K STATUS UNITED STATES I I I \ \ A \ - i\ lasi<(l CCl n,] d a REPORT DEPARTMENT OF THE INTERIOR BUREAU O-F RECLAMATlOf'J L ,...... 0) ..q ,...... ..q LD 0 0 0 LD LD ,...... ('I') ('I') r ~, PrtJpu'fy (if" Rm / 1"-. R.1 ;. ,; AK: RESOURCES LIBRARY "~'''' . -,,,.-.-"" CHAKACHM1NA PROJECT ALASKA STATUS REPORT MARCH, 1962 BUREAU or RECLA!1ATION ALASKA DISTRICT OFFICE JUNEAU, ALASKA JUl 1 5 1974 ....,-.v { ;' '-..-., / r / I~ , !\ ~, I' ...-, ( -i .) ._ TAB L E INTRODUCTION • PROJECT INVESTIGATIOlIS POHER ~lARKET WATER SUPPLY POWER DRAINAGE AREA • RUNOFF OPERATION Power Head Sediment Evaporat ion () F CON T 1:: N T S Reservoir and Power Operation Studies PLANS AND ESTI MATES RESERVOIR TUNNEL SURGE TANK PENSTOCK POHERPLANT ACCESS ROADS TRANSMISSION LINE SUBSTATION CONSTRUCTION PERIOD ~OVERNMENT eMP General Property • Service Facilities i Page No. 1 1 2 4 4 5 5 6 6 7 7 7 8 8 9 9 9 9 10 10 10 10 11 11 11 TAB LEO F CON TEN T S ( Cont i nued ) CONSTRUCTION MATERIALS • • • • • · . DESIGN AND CONSTRUCTION PFOBLEt·~S •• · . . . . . . Access ibi li ty . . . . . . . Communications • · . . · . . · . . PROJECT COSTS · . . . . . . . . Construction Costs • . . . . · . . Operation and Maintenance Costs · . . Provisions for Replacements · . . · . . . FINANCIAL ANALYSIS REPAYMENT · . · . BENEFIT-COST ANALYSIS . . . Alternative -Coal-fired Steam Plant •• Direct Benefits · . . . . . Direct Costs · . . . . . . . Benefit-Cost Ratios . . . . SUMMARY · . · . . PLAN FORMULATION CONCLUSIONS • • • ACJ(NOWLEDGEt1ENT • • . . . . . . . REPORT OF FISH AND WILDLIFE SERVICE • · . . ii Page No. 11 11 12 12 12 12 13 13 14 14 15 15 15 15 16 16 17 17 18 19 939-906-3 939-906-2 Figure 1 Table 1 Table 2 Table 3 LIS T 0 F D RAW I N G S General Map • • • • PrecedinR Page 1 Area and Capacity Curves . . • ~ollowinp Page 8 Total Head Loss • • • • Following Pap,e 7 LIS T 0 f TAB L E S Runoff in Acre Feet, Chakachatna River Following Page 5 Near Tyonek, Alaska Annual Summary, Reservoir Operation Following Page 8 Study Sunnnary, Construction Costs Page 13 LIS T 0 F P HOT 0 G RAP H S P-939-906-20 Proposed Powerplant Area • . . Followin~ Page 1 P-939-906-2l Chakachamna Lake . • • • • Followinp, Page 1 iii I I J I I I I • I I I i I I I I I I t ~ I I \" \ "::1 \ -:- \~ '.0 \, -? , -Harpoon r ~ ~ .. ~ ~--,- LAKE '~ \ \ , ..--...--: ,'" -j'" ~ , ( -~ /' -' I r,' ~/ \ ~ ( ( I' " ( / / Glacier 5 /' ,--' ...... \ " ' I I HArv'''-JA LANT KW I ....:0- r 1 \ " Capps Glacier / ) , \ , \ I -',I __ _ -:I ---__ , -----.... -.....I~ -' -, \ , \ \ \ " 11 \'-::,~ \ \ / I '" ~C'~ '--G- "-""1// ", • I I 'I ~. IWkie I~dian Ise"OI~ I rk-~~ I I 2 30 K V DO U B LEe IRe U T 5 TEE L TOWER TRANSMISSION LINE ARCTIC f)CE4N KEY MAP .;\-. f --',11-f I ) , ,/ COO K INLET I ,~ :iJ8i 9 Lake "~ I I I I ~' EXISTING 1:5 TRMJSMISSION I /t'1 Wo sill a~J ffl.-rl_'_' __ I''>~''//~---'' '-, 1"-" I I \ \ -""r--.~ ___ <:<'0 G len I" \.9:t<> I __ -~ I \ I RlcttPRR;SON I \~ ! Mill cARY \~ \~. RESERvATION I ~ '-\ IXlsTIN~~'c-HORA~ \ SUBSTATION I I I NO.2 ,; • J3 -6, 906 JR6 CHANGED rRAvt;\I/S_~/OfY LINE , 16 ' 61 906 JFlB C'fANGED TR4NSo./15SION LINE UN/TED S TA TES DEPARTMEN T OF THE INTEIT/OR BuREAU OF RECLAMATION ROUTE: ROUTE CHAKACHAMNA PROJECT -ALASKA GENERAL MAP ORAWN ___ J,'lJL,_ SuBMITTEO ___________ , __ _ T R ACE 0 __ J_ fJ _B ____ q E COM MEN D E 0 _ _ _ _ _ _ _ _ _ _ _ _ , CHECKEO _______ ' APPROVEO ___________ . ______ _ APPROVdrlG OFFICIAL JUNEAU, ALASKA DEC 1,1960 939-906-3 CHAKACHAMNA PROJECT, ALASKA STATUS REPORT I N T ROD U C T ION The Chakachamna Project is a transmountain diversion and a single- purpose project for power development. Chakachamna Lake, located about 85 air miles west of the City of Anchorap,e, would be utilized as a stora~e reservoir. Water would be conveyed through a pressure tunnel and penstocks to a powerplant located en f1cArthur River. The power output would be transmitted to Anchora~e, the principal outlet for the sale of electrical energy. The location of the major features of the project are shown on r.eneral Map, Drawin~ No. 939-906-3. PROJECT INVESTIr.ATIONS Field investigations of the water-power potential of Chakachamna Lake were first made in 1948 by Mr. Arthur Johnson of the U. S. Geological Survey. The results of his brief study were published in "Report on Reconnaissance of Lake Chakachamna, Alaska" dated January 1950. Previous studies of the project by the Bureau of Reclamation are discussed in its report "Reconnaissance Report on the Potential Development of Water Resources in the Territory of Alaska" dated January 1952. In addition, the Corps of Enj:!ineers mentions the project in their "Survey Report on Harbors and Rivers in Alaska, Interim Report No.2, Cook Inlet and Tributaries" dated January 20, 1950. In July 1960, the Geological Survey at the request of the Alaska District Office, Bureau of Reclamation, established a survey camp on Chakachamna Lake and obtained underwater topop,raphy of the Lake. This mapping is controlled by the Coast and Geodetic triangulation net established around the Lake in 1953. The underwater topography of the Lake, as well as above water topography, to elevation 1,240 is shown on Geological Survey r1ap "Chakachatna River and Chakachamna Lake, Alaska", Sheets 1 and 2. In July of 1960, the Bureau of Reclamation established a survey camp on McArthur River near the proposed powerplant site and tunnel out- let portal. Horizontal and vertical control for these surveys was extended from the Coast and Geodetic triangulation stations by a triangulation net. Topography of the proposed powerplant site was taken on a scale of 1:1,200 with 10-foot contour intervals and is shown on Drawing No. 939-906-1. P-939-906-20. General view of HcArthur .·Rive rand proposed power- plant area, looking upstream, The powerp L3nt would be located at the base of the cliff shown in the right center of fore g round. Chakachamna Lake lies to the-~1e ft ':of snow-capped Mt. Spurr seen in the rig ht backg r ound. P-939-906-21. Chakachamna Lake lookinp-west. The outie t -of the lake is in the left foreground '. The tunnel p o r tal would be a bout 1/2 mile up the left side' of the lake. The ridg e seen in the f ore- g round is the snout of Barrier r,lacier. In March 1961, t1r. Bruce La Jackson of the t::eological Survey completed an open file report "Potential Hater Power of Lake Chakachamna, Alaska". In Au~ust 1961, the qeolo~ical Survey conducted additional studies for the Bureau of Reclamation on Barrier qlacier and obtained sound- ings at the lake outlet. The investioations of Barrier Glacier at the outlet of the Chakachamna Lake consisted of establishin~ four ablation stakes. A base line was established for trian~lating the position of the ablation stakes and also for obtaininf! terrestial photographs. From these rhotop,raphs a map of the lower portion of the ~lacier can be compiled at some future time for comparative purposes. In September mission line at irregular structures. 1961, the Bureau of Reclamation restudied the trans- route by helicopter; with auger holes beinp nut down intervals to determine foundation conditions for Profiles were taken at the major river crossings. POW E R MAR K E T The market for project newer would be the Anchora~e-Palmer area. This is part of the market that would be served by the Devil Canyon Pro~cct. Its economy and pOHer requirements are discussed in con- siderable detail in the Feasibility Report on the Devil Canyon Project, nublished by the Bureau of Reclamation in ~1ay 1960. The 1960 census for this area was approximately 96,950. This Has nearly 145 percent greater than the po~ulation of 1950. Power requirements in the area have been growin~ at a prodi~ious rate. In 1951, the approximate load was 59,400,000 kilowatt-hours. By 1955, it had increased to 129,900,000 kilowatt-hours; and in 1960, about 225,380,000 kilowatt-hours were used. The market study for the Devil Canyon report forecasts a non-military load in this area in 1970 of 610,000,000 kilowatt-hours with a peak requirement of about 126,000 kilowatts. Projections beyond 1970 assume that some major hydro power source will be orerating, and estimated loads reflect an acceleration in use. On that basis, the non-military requirements of 1980 may exceed 1,600,000,000 kilowatt-hours. The Federal Power Commission forecast loads for this same area in their Alaska Power Harket Survey of Hay 1960. Their nrojections compare with the Devil Canyon Pro4ect forecast and recorded use as follows: 2 F. P. C. Projections Devil Canyon Recorded Normal ~1inimum ~Taximum Pro;ection Use 1960 (1000 KWH) 215,492 204,130 224,430 221,000 225,380 1970 (1000 KiiH) 507,730 411,270 597,870 610,000 1960 (KW) 48,955 46,390 50,995 47,600 48,950 1970 (KW) 110,770 89,850 130,410 126,000 The above tabulation illustrates that for the year 1970 both the Devil Canyon forecast and the F.P.C. "maximum" forecast compare very closely. It also shows that all forecasts of 1960 ener~y requirements were below recorded use. The installed firm capacity of all utility systems in the power market area in 1961 was 72,470 kilowatts. Approximately 62 percent, or 45,000 kilowatts of this total was hydro power, 14,500 kilowatts was coal-fired steam generation and 12,970 diesel. Completion of the Cooper Lake -Anchorage transmission line will increase the area's potential capacity to 72,470 KW. This total is not expected to be sufficient to meet area requirements beyond 1964. A 20,000 kilovolt-ampere intertie between Anchorage military bases and non-military systems provides for a small quantity of additional capacity in emergency situations, depending on military needs at the time. The military bases of Elmendorf, Fort Richardson and I-lildwood had a generating capacity of 62,240 kilowatts in 1959. Approximately 90 percent of this was in coal-fired steam plants. In addition, a 6,500 kilowatt steam plant is located at the military port of Whittier. The Army curtailed its operations at Whittier in September 1960 and the bulk of its supplies for interior bases is now landed at Seward. Although no lonp,er required by the military, the Whittier power plant is not yet available for non-military uses. Considering its isolated location, it would be difficult and expensive to tie into other systems in the power market area. The port will continue to be used by private firms operating there, such as a sawmill and a wood treatment plant. Also the Union Oil Co. has its own oil dock, tanks and car-loading facilities at Whittier. These industries furnish their own power. 3 W ATE R SUP PLY The water storage reservoir for the :--T'orosed development is Chakachamna Lake. This is a glacier-formed lake surrounded by precipitous high mountains rising abruptly from the shores. The lake is the source for Chakachatna River. The area of the water surface of the lake at elevation 1,127 feet is 22.7 square miles. It is 17 miles in lenRth, averages three miles in width and has a maximum depth of 365 feet. The total contributing area above the mouth of the lake is 1,120 square miles. The average annual runoff available for project development is estimated to be 2,684,200 acre-feet. DRAINAGE AREA The entire drainage area is one of scenic grandeur and it has been said to be the most picturesque in Alaska. It contains lofty, rugged mountains with numerous large glaciers in the valleys and perpetual ice fields in the higher elevations. These glaciers and ice fields comprise 20 percent of the 1,120 square miles of drainage area. Mountain peaks are in the ran~e of 6,000 to 10,000 feet in elevation, with the highest peak being ~·1t. Torbert at elevation 10,600. Mt. Spurr, an active volcano just outside the drainage area and about eight miles northeast of the mouth of the lake, rises to elevation 11,070 feet. 'ferril Pass, the "flyway" to \'/estern Alaska lies 18 miles to the west of Chakachamna Lake at an elevation of about 2,900 feet. The penerally southeastern exposure of the drainage area receives moisture from the storms moving inland through Cook Inlet. The principal streams contributing to Chakachamna Lake are the Neacola and Chilligan Rivers, each about 24 miles in length. Other streams are the Nagishlamina, Igitna, and Another River. Three of these streams terminate in Kenibuna Lake located directly to the west of Chakachamna Lake. Kenibuna Lake in turn empties into Chakachamna Lake. All streams except the Chilligan River originate in ~laciers. The Shamrock Glacier at the \.Jestern and upper end of the lake has its terminus near the shore. There is no vegetal cover in the drainage area other than low brush and alders that p,row in the floodplain of the river bottoms. RU~OFr The U. S. Geolop,ical Survey established a recordinq stream gaging station in Chakachatna River near the mouth of the lake on June 14, 1959. This station identified by the U. S. ~eolo~ical Survey as "Chakachatna River near Tyonek, Alaska" has been in continuous operation since that date, and the record of runoff is included in Table 1. To extend the record over a lonp,er period, the recorded runoff for the Newhalen River near Iliamna, '1atanuska River at Palmer, Susitna River at Gold Creek, Susitna River near Denali, Kasilof and Bradley Rivers near Homer were each examined for possible correlation. The cumulative plot of the recorded monthly runoff of the Matanuska River at Palmer, for the period of concurrent records, shows similar trends to the Chakachatna River, and was therefore used in extending the Chakachatna River records. Runoff data for the Matanuska River is continuous through water years 1950-1961, and this is taken as the period of study for this report. The averaRe annual runoff of Chakachatna River obtained from the 28 months of record was found to be 92.7% of the recorded runoff of the Matanuska River for the same period. This percentage was used to determine the annual runoff of Chakachatna River ~rior to water year 1960. The annual totals were then distributed monthly by the percent of annual as obtained from the period of record for the Chakachatna River. The minimum annual runoff of 2,320,200 acre-feet occurred in 1960, and the maximum was 3,231,700 acre-feet in 1957. The estimated average annual runoff for the period of study, 1950 throuqh 1961 water years, is 2,684,200 acre-feet. The recorded and reconstructed monthly and annual runoff for the period of study is shown in Table 1. P 0 HER The initial and ultimate capacity of the Dowerplant would be 320,000 kilowatts at an average annual load factor of 63.5 percent. It is capable of producing 1,780,000,000 kilowatt-hours of firm energy each year. The maximum amount of non-firm enerp,y that could have been generated in anyone period would have been 193,000,000 kilowatt- hours. This would have occurred during August and September of 1957. During the twelve-year period, there were seven years when water was available for non-firm output. The average annual non-firm ~otential is equivalent to 80,000,000 kilowatt-hours each year. 5 =@!$ _~""'~"'~--I2~-'-'-l-i -.-_-------:::~::::-=:-:.:2:--==--;;;---;;---;-·-I-.---R } 0'-R[ -A..,I.:.Ti:JN Ta... D! c: . . r ((: (l. t ,_! n e (l.. ~'. I Y t::. (c. ( ..... YF ..• R 1_MAh .J ! -". ,;;, I ",-, D ' 1 .. ",... . c!·.:.;-I r" NOV. D~C JAr-;, I FE fS I I ~ -r t-~_..s 4~ 4-" z. j 3 4,. I c ;.. _'lD 2 7 , _ .J.. __ ""-/ ~ ; L ..; ,:, ..,..<.c 7 -j' ! 1 .;.-.' ' .. .:f-.:; .3 ) c. 3 '- ., .., --.-. ,}S 3 TorAL PERCENT. ~-'!U".;"'''J'f ~~ gJ A,,,"'~a.1 ·t-",K .. ", f .......... 2.8 ,.." .. !..." .... ,~ Q+ r-ec.,,,c:led Ch ... lc:.q,cJ"~.-f",,,-;t?,vt:;-neal-T yo "eK.;}>':·,J •• l7 A "r", .... i -r" .... "" . .; ';""'" " ;.., ,9"0 Cni4ka..ch,,-+n.o.. R ,..:. JV1Q+<A.."u~k,. (2. ""t-P""i ...... <:...-' 2...5"2.4.8 ':IZ.77' ... "'f-"~co~d ... c! """'~+,",,,u,.t:::. ... r:'..:r~~ A "'-.v....J s, .J :z.7i';r~r ... OPERATION The load characteristics of the power market area were used in scheduling Chakachamna Power Production. The following is the monthly load distribution that would anply: January 9.3 percent February 8.1 " March 8.3 " April 7.7 " May 7.6 " June 7.2 " July 7.4 " August 7.7 " September 8.0 " October 8.9 " November 9.4 " December 10.4 " Water would be released through the powerolant to provide energy in accordance with this monthly load distribution. Releases required for firm energy are based on an 80 percent efficiency of the powerplant for all heads. Power Head The maximum recorded water surface elevation of Chakachamna Lake was 1,147.5 on August 6, 1961. Soundings in Chakachatna River at the lake outlet show a constriction at about elevation 1,127 which is the controlling elevation of the streambed used in this study. With no dam and with all water except occasional spills, diverted through the tunnel to the powerplant, the top of the active con- servation space would be about 1,127 feet. This elevation would correspond to an uncontrolled sryillway crest of a dam and is the elevation used as the normal full 0001 elevation in the operation studies. The minimum water surface elevation would be 1,014 feet. The elevation of the water surface in l1cArthur River on July 26, 1960 was 183.7 feet, and the average tailwater elevation is taken as 185 feet. Based on averap,e monthly head losses, the maximum effective head on the turbines would be 922 feet and the minimum effective head 805 feet. Under a condition of maximum release at maximum drawdown, the computed minimum head would be 767 feet, and the design head is taken as 780 feet. The average head com- puted from the operation studies is 870 feet. An allowance fo~ 6 loss of head due to friction was made fer each monthly release. The values for head loss are shown on Figure 1, "Total Head Loss". Sediment A reconnaissance estimate of the 100-year sediment inflow to the lake has been determined as 1,350,000 acre-feet. Of this total, about 70,000 acre-feet would be deposited in the active conserva- tion space. Since this is less than five percent of the active conservation capacity, no allowance is made for sediment deposition in this report. Evaporat ion The annual loss due to evaporation is estimated to be not more than one-half foot for a full reservoir. At elevation 1,127 this would amount to about 7,250 acre-feet per year or 0.5 percent of the active conservation capacity. As this is not within the accuracy of the water supply studies, no allowance was made for this loss. Reservoir and Power Operation Studies Releases from the reservoir would be for power production only and would be in accordance with the monthly load distribution. The reservoir and power operation studies were started 'tli th a full reservoir havinR a water surface elevation of 1,127 feet. Controlled releases would permit a maximum drawdown of 113 feet to elevation 1,014. During the 1950-1961 period of study, the reservoir was drawn down to this elevation only in Hay 1961. The minimum drawdown occurred in May 1957, when the reservoir reached an elevation of 1,043 after a full reservoir at the end of the previous September. Considering only the production of firm energy, the reservoir would have filled and had spills in Au~ust and September of 1951, 1953, 1954, 1956 and 1957, and in September only of 1950 and 1955. The maximum spill for anyone month would have occurred in August 1957, amounting to 520,700 acre-feet. AT the end of the period of study, September 1961, the reservoir lacked 118,500 acre-feet of recover- ing, but this was considered as being normal, as the maximum draw- down occurred durinp that year. 7 , i I , i ITE I'V! ~~a_'~:!~f ' E t Le-oith, fl. .. --, -.. h. t_ -+-----i ! t------------ ; TUNNEL ---------' . 25 57,10_0 -0-013 ~ ___ -,-____ 2..B_p.o1t ~.t1Qnth'" 1 I ~O Do) 'y'1onlh "" J! " "-, 3 I Do ;I ~';'on I h " PEN':>loCK 1,21.Q_ O.{)H , / . I •• / I / /, I I / r--' . 1 ( " r; -, ,~ --r --: -/,..~ ~ r-_. I FIS'JRE 1 , -.J --r I -- I I . ' .+-p2E)-) ___ .I--o. .I.U ~J.N EL " 1 I . : I W I I : LJ lJ.., ! I 0 I :.t W 1: u... 0 i-UlIO-;---- I UJ I .L .. _ t---o9:- 1-,-1 ------1.--~8: I ~ I 1--'1 1 __ - I _ -__ ---... t-I--;1 -. --! I a . . ~ , :1 l'-! , /)1 I '/ ,. , 5P I i I· -'- i . _ t ( I .. f I' f I I / ,.' / (. / . 'f / / . ( ( . I .; -; I I . _ .. -f _._. y-- Sl/2 ~ ~ • 0.463 a 8 /J F'E\lSTOCK; o ")4V L"I hf --'--. -D 1.1 . I per 1000 ft. l. OS-:'lRUCTlONS ' h K'£' t. -, 2g- CHAK~CH4~v'l.\lA_ PROJECT -. -.. AL':"SKA ...., TOTAL HEAD LOSS 2-7-61 -f 100 ~Oc 300 500 I' MONTHLt RELEASE -1000 AC~E FEET I-.l--------.------· ----1._ I _ l -~- With this operation, the maximum monthly release was in December 1961 and averaged 4,246 cu. feet ~er second for the month (261,100 acre-feet). The minimum monthly release averaged 2,966 cu. feet per second durin~ August 1957 (182,400 acre-feet). The average flow through the tunnel for the period of study is 3,440 cu. feet per second. The active storage capacity required for the operation study is 1,606,300 acre-feet. The total storage capacity of the reservoir below elevation 1,127 is 4,015,000 acre-feet. The annual summary of the operation study is shown in Table 2. P LAN SAN DES TIM ATE S The proposed plan of development for the Chakachamna Project pro- vides for the construction of a transmountain diversion tunnel from Chakachamna Lake, surge tank, penstock, powerplrtnt, trans- mission line, substation and access roads. Chakachamna Lake is 85 miles west of the city of Anchorage and the powerplant would be located on McArthur River 10.8 miles southeast of the lake. The proposed location of these features is shown on the General Man, Drawinp, No. 939-906-3. RESERVOIR The storage reservoir, Chakachamna Lake, would have a normal water surface elevation of 1,127 feet, and a maximum water surface elevation of about 1,148 feet. At elevation 1,127 feet the surface area of the lake is 15,250 acres. Operation studies indicate that 1,606,300 acre-feet of active storage space will be required. This would provide about 93 percent regulation of the Chakachatna River at the lake outlet. It is estimated that there is a total of 4,300,000 acre-feet of space within the lake below elevation 1,148, and 4,015,000 acre-feet below elevation 1,127. The lowest elevation obtained from the soundinos was 762 feet. A drawdown of 113 feet will give the required active storaQe. The minimum water surface elevation would be 1,014 feet and would have a surface area of about 13,500 acres. The reservoir would contain 2,408,700 acre-feet of dead and inactive storage below elevation 1,014. The area and capacity curves for Chakachamna Lake are shown on Drawing No. 939-906-2. 8 <t w If) Z <t W ~ I If) z o I- <t > W ..--l W 1160 I! 10 1060 1010 960 910 860 810 760 14 13 ,I I ARE~ 10 9 8 7 IN THOUSANDS OF I t- \ -__ .i-______ . -l-----t---+----t----1 I I , I i ---i- I ! I ! I ----+-----L------i- ! I I I -t---t---------+------+--+------~---l -~ i CAP A C i I I , I -I--l----~ I i I --l-r·-T . I -t-- I i -----~---I --------!------1 I ---t J-I -L--- I -f-- f-------t-----+--+-. i~ r . 1 1 ---- , I -L --1_ ---~----l---t- o 500 --I . I I I I I ! '~-----+--- 1000 I I 1500 1----- I I ---. - I ---r-- I --1--- -I - I 2000 2500 CA PACITY IN THOUSANDS OF i I 6 5 4 3 2 o AC R ES I I.! ! I 1 . ill -----t------+ -~ -+_--t ------t----T-------T---- , i I iii , ( I : I I , ----r -;------!~. iii ! I ! ! I ·-r--+--~----}-----+----I , 1 I ' I I ! I I : I' -----1------1--------r----L--- -! i i ; I .----4-·--------L-------l----L----L-~_t-- I I Iii i I t----+-----I -----+ -------t-------l-----t ----+----------t-I ! ! ' I J ---+----1 ! I I -+-l-~- I I: i ·--t --i --+----t--- I· " I I -f ! I : --+ ---f---- -1----\ ~--+ ; ----t--- : I I : i I I J': I I !--r------l----t--~-t_~L -;--r-j -I--t--i i f-- 3000 ACRE-FEET 3500 1 I 1 _ -__ 4000 4500 CHAKACHAMNA AREA ELEV. M.S. L IN 760 765 770 780 800 20 40 60 80 900 20 40 60 80 1000 20 40 60 80 1100 20 40 42 LAKE 8 CA PAC ITY DATA AREA ACRES 0 810 1,300 2,690 5,670 7,320 8,270 9,280 10,400 11,590 11,960 12,320 12,650 12,980 13,280 13,520 13,740 13,960 14,170 14,390 14,620 16,100 16,780 CAPACITY ACRE FEET 0 2,025 7,300 27,200 111,000 241,000 397,000 572,000 769,000 988,000 1,224,000 1,467,000 1,717,000 1,973,000 2,236,000 2,504,000 2,776,000 3,053,000 3,335,000 3,620,000 3,910,000 4,218,000 4,250,000 UNITED STA TES DEPARTMENT OF THE INTERIOR BUREAU OF RECLAMATION CHAK ACHAMNA PROJECT -A LASK A AREA a CAPACITY CURVES CHAKACHAMNA LAKE DR AWN __ ,._R~ {;~ ____ SUBMI TT EO _____________ _ TR ACE D_.f_ f!.._~ ____ RECOMME NOEO ____________ _ C HEC K E 0 _____ - - ___ A P PRO V E 0J.PfSIfIN·r~~-OTT'/C fA, JUNEAU, ALASKA FEB.I,196Il 939-906-2 'c'C ~f-. .1 ~'J ~, <..;,:.'"10 • cm,,1PUT t~ T ieN SHEET ~ ._,) p ~ (' .;t + , • "I I -J... 'I' (~I --~---_. --r---_.----.-----i-' .---.. ---r---.---. 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"-" 2.:/ 0." 2(,'~'o) Z.'::-473 4603, I '-I,C) (s C) 4,:, IS-[) 4-0 f S (j 4<!) /5 0 'f-!) ,r 'u I:) 3 888 E3 3 '3 4 3 c;., .3 7S2 :J 3 8 '.Jr. 5 2C;84.2 2492.2. /lnG 33";:;'/ i P 7 ,.) ,-, , i 8 ,7 ,~ I 8 7':"- A ., I , .£' '7 4-, ~ ~ .~) ,3~ ') B,:., :3 <'3 <> 4- .' z_ '--- 3 7~) i (0 ;:I'-'~ ! )j""., h"",.1 .. , J\e,le:,~-.e ;-! I'· 1 .,. ,-. .j ~l r------· ;" ------, ,.,., Pi -t-I'-) J ( .' il~' ,) ! 180 ! ! i ,~ 32 .3 L) 3 2_d 6' .,~' 8 .. -to. 8/"" '-.s ! 'j dr'''' ---.. ·_·1-----,,··- I 1".10.'( Jvf I ',,, I ~/1;.;. x: -r------+ -- ~) 2~~/_ }221 I ~/2 0 ) Z I ! , :jz Z. :j .' z.. ! Y 7 /8 3. /:9 s: I (3 '" I C ,) ,'- .q ;: '-I '7 . 186. I 2' ~,. ,--, ~4. / -, ~ >D <-t-2-~-i ") 'j l S S', ;Z :3 L S J: , '- Z -~ , ~ '1 8 £. 0-R -~ i 2 S 7 d !---! • ~ .- .) : ~." -' ~ I TUNNEL It is proposed that the transmountain diversion would be through a circular pressure tunnel 10.8 miles in lenQth. It would have a diameter of 25 feet, be concrete lined, and terminate at a surge tank. The average flow would be 3,440 cu. feet per second. The entire tunnel would be in rock, including the portals. Heavy reinforcement is proposed for the ends where the hydraulic head exceeds the depth of rock cover. The maximum thickness of cover over the tunnel is about 5,000 feet, with 8.33 miles having a cover of 1,000 feet or more. The inlet portal of the tunnel is located 2,500 feet from the lake outlet. The area is solid rock and steep and access to the portal and gate shaft would be expensive. The outlet portal and surge tank could be reached by constructing an access road two and one- half miles in length from McArthur River. In addition, there would be an access adit about 2.2 miles upstream from the outlet requir- ine an additional 2.5 miles of access road. SURGE TANK A 50-foot diameter surge tank, 400 feet hiph, would be located at the downstream end of the tunnel. It would be embedded in the mountain side and an access shaft is included to eliminate a large open cut. PENSTOCK A steel penstock 23 feet in diameter would be located within an inclined tunnel and would branch to the four turbines near the powerplant • POWERPLANT The proposed powerplant would be located on the left bank of McArthur River, some 34 miles by road from tidewater. The powerplant would have an installed capacity of 320,000 kilo- watts at a design head of 780 feet, and an average annual load factor of 63.5 percent. Four 80,000 kilowatt units would be installed. 9 The maximum head on the turbines is 922 feet, and the minimum head 805 feet. The average head from the reservoir and power operation studies is 870 feet. The annual firm output of the powerplant is estimated to be 1,780,000,000 kilowatt-hours. ACCESS ROADS The remoteness of the powerplant would necessitate the construc- tion of 34 miles of access road from tidewater. It would have a gravel surface with very little grade. A bridge 400 feet in length would be required to cross the Chakachatna River. For access to the lake and inlet portal, an additional 17.5 miles of road would be provided, which would require two bridges. TRANSMISSION LINE Power transmission would be at 230,000 volts over a double circuit line, 113.5 miles in length, and terminatin~ at a substation near Anchorage. Submarine cables would be used to cross Cook Inlet near Anchorage, a distance of about 1.5 miles. There would be III miles of standard overhead steel tower construction and one mile requiring special towers for crossing the Chakachatna and Susitna Rivers. Overhead construction would include ~round wires and 6 -954 MCM ACSR conductors. SUBSTATION The Anchorage Substation No. 2 would be located three miles east of the existing Anchorage Substation and just outside the Fort Richardson Military Reservation. This location allows ample room for customer service lines. It would be rated at 350,000 kilovolt-amperes. CONSTRUCTION PERIOD The time required to construct the tunnel sets the construction period estimated to be 5 years. All other features would be completed in this time. 10 GOVERNMENT CAMP There are no housing facilities near the proposed powerplant site or Chakachamna Lake. A permanent camp as well as a temporary camp to house government construction workers would be required. General Property Residences for a staff of 50 persons, together with the necessary streets and utilities, would be required for operatinp personnel. These facilities would be completed early and used to house a part of the construction workers. An access road about one mile in length would be required from the camp to the powerplant. In addition, an airstrip would be provided near the nowerhouse area and an unloading ramp for amphibious planes would be con- structed at Chakachamna Lake. A barge dock would be provided at the terminous of the major access road. Service Facilities Temporary facilities, in addition to the permanent community, would be required to serve an estimated total of 100 government employees during the peak of construction. Additional housing would be supplied by trailer and transa-houses. Major buildings needed would include an administration buildinp" laboratory, warehouse and fire station. Transnortation facilities and all working tools and equipment are included. CONSTRUCTION MATERIALS There has been no sampling or testing of construction materials for the project. Concrete aggre?ate could probably be obtained from the large beach area near the outlet of Chakachamna Lake. Another source might be the wide flood plain of the McArthur River one to three miles upstream from the powerplant site. An alternate source may occur in the talus slopes about one-half mile below the powerplant site and on the same side of the river. DESIGN AND CONSTRUCTION PROBLEMS The project is located in a remote area of Alaska. Problems of access, housinp, communications and climate require ~Der.i;:!l c()n- sideration. 11 Accessibility There are no roads or trails in the vicinity of Chakachamna Lake. A total of 51. 5 miles of access roads would be required leading: from tidewater. r·1aterials and equipment would probably be baroed from Anchorage or Seattle to the Government dock, then transported over- land to the job site. During winter months this could be by "cat train" over the frozen rround. Amphibious-tyne olanes could operate between Anchorage and Chakachamna Lake. A sea-plane ram~ at the lake would be necessary for unloading. A landinp strip for wheel planes would need to be constructed in the vicinity of the powerplant. Communications Communications to and from all project works would be by radio or radio-telephone. PROJECT COSTS Project costs are composed of the Federal investment in project features, the annual costs of operation and maintenance and nrovi- sions for providing replacements of equipment whose useful life is less than 100 years. Construction Costs The estimated construction cost of the plan of development selected for this report is $325,239,000, based on October 1, 1961 price levels. Interest durinr construction would amount to an additional $20,327,000. The construction costs associated with this development are summarized in Table 3. 12 fPC No. 331 332 333 334 335 336 350 351 352 353 354 356 358 Table 3. Summary, Construction Costs Description Structures and Imnrovements ~eservoirs, Dams and ,{aterwavs Turbines and ~enerators Accessory Electrical Equipment Miscellaneous Equipment Roads, Railroads and BridQes Land and Land Ri~hts Clearing Land and RiClht of ',Jay Structures and Improvements Station Equipment Towers and r'ixtures Overhead Conductors and Devices Underp,round Conductors and Devices r,overnment Camp TOTAL Operation and ~1aintenance Costs Cost $ 21,765,000 223,729,000 20,592,000 2,574,000 1,263,000 10,949,000 52,000 447,000 617,000 13,027,000 13,344,000 5,780,000 2,332,000 8,768,000 $325,239,000 The annual cost of operation, maintenance, administration and ~eneral expense associated with this development is estimated to be $610,000. This cost for each major division is as follows: Annual Operation and Maintenance Powerplant Transmission Administration and General EX,)ense Total $316,000 214,000 _8.2.,000 $610,000 Provisions for Replacements Provisions for replacements are computed on a strai.,-ilt ::::inkin?:-fllnri basis at 2 1/2 percent interest. This annual char~e, estimated to be $355,000, is summarized as follows: Government Camp Chakachamna Powerplant Switchyard & Substations Transmission Lines Total Rounded 13 $ 53,700 118,600 107,800 75,200 $355,300 $355,000 FIN A N C I A L A 1 A L Y SIS The cost of nroject power would be some,..rhat hip-her than the 7.89 mills estimated for the Devil Canyon P~oject. For this reason it is con- sidered as a supplement to Devil Canyon rather Lhnn an alternate. This consideration led to the followinr-assumptions in making this preliminary economic analysis of the project: (1) The market for ryower is ne~lected, it beinq assumed that all power can be diSDosed of immediately. (2) The project \-1ould be a sinRle-staoe development. (3) Repayment of all project costs would be in 50 years at 2 1/2 percent interest. Annual revenues must be sufficient to pay annual operation and main- tenance costs, nrovide for periodic replacements and repay the Federal investment in 50 years at 2 1/2 percent interest. These costs summarize as follo\O;8: Operation and Haintenance Provision for Replacements Equivalent annual repayment ($345,566,000)(.03526) = Total Annual Costs $ 610,000 355,000 12,185?000 $13 ,150 ,000 The only revenue source considered in reoayment is the sale of firm energy. The possible sale of a limited amount of non-firm energy was neglected as being too indefinite. \~ater su':>oly studies show it available seven years out of twelve. The amount of firm ener~y available annually is 1,780,000,000 kiloevatt-hours. Allowing about eight percent for losses, there would be 1,638,000,000 kilowatt-hours saleable each year. The averaqe power rate that would be necessary to assure full re- payment of all generation and transmission facilities and r81ated costs would be 8,03 mills Der kilowatt-hour. 14 BENEFIT-COST ANALYSIS Benefit-cost analyses, based on 50-year and 100-year economic lives were prepared assuming the alternative to be a mine-mouth, coal-fired steam plant in the Matanuska fields. Alternative -Coal-fired Steam Plant In this analysis it was assumed that a 320,000-kilowatt steam power plant would be located at the mine mouth in the Matanuska fields. It is assumed to operate at an annual load factor of 63.5 percent and ryrovide a net of 1,638,000,000 kilowatt-hours per year. Approximately 50 miles of 230,000-volt, double-circuit, steel tower lines are assumed required to deliver the power to the vicinity of Anchorap,e. Switchyard and substation facilities would also be required. The cost of fuel was evaluated on the basis of the 1960 average orice paid per ton for coal at the mine. Pertinent assumptions are summa- rized as follows: Plant capacity -KW Plant factor -% Annual net saleable energy -K:JH Fuel heat rate -BTU/Pound of coal Cost of fuel -$/Ton Power plant Investment -$/KW Transmission plant investment -$/KW 320,000 63.5 1,638,000,000 11,000 11.45 262 50 Fixed costs were found to be 3.99 mills per net kilowatt-hour and fuel costs 5.18 mills per net kilowatt-hour for a total net energy cost of 9.17 mills. Di rect Benefi ts The primary benefits derived from the project are determined by the at-market cost of power and energy from the alternative source. This cost has been determined as 9.17 mills per kilowatt-hour. Since no load development period was assumed, the average annual sales of energy (1,638,000,000 kilowatt-hours) would be the same for both the 50-year and the lOO-year analyses. The average annual worth at 9.17 mills per kilowatt-hour provides an annual benefit of $15,020,000. Direct Costs Direct costs are made UD of operation and maintenance, replacements and amortization. For purposes of benefit-cost analyses, investiga- tions costs are not amortized. Average annual costs of the project for the two periods of analysis can be summarized as follows: 15 50-yr. life Avera~e annual operation & maintenance $ Average annual provisions for replace- ments Average annual payment to interest and principal 610,000 355,000 12,175,000 Total average annual costs $13,140,000 Benefit-Cost Ratios 100-yr. life $ 610,000 355,000 9,430,000 $10,395,000 The benefit-cost ratios for 50 and lOO-year economic lives are determined as follows: Total average annual benefits Total average annual costs Benefit-cost ratio 50-vr. life $15,020,000 13,140,000 1.14 to 1.00 SUt1MARY The financial analysis can be summarized as follows: Project Construction Cost Interest Durin? Construction Total Project Costs Annual O&M Cost Annual Replacement Cost Averae,e Annual Payment to Principal and Interest -50 years Total Average Annual C')sts for Repayment Annual Firm Energy Output (KWH) Less Losses and Project Use (KWH) Annual Firm Saleable Output (KHH) Averar,e Rate for Project Firm Energy Cost of Generation (~ills/K\-m) Cost of Transmission (!-~ills/KvlH) Total Cost Delivered (Mills/KWH) Cost of Alternate Source Steam POHer U'ills/Kt-lH) Ratio of Benefits to Costs -50-year period 1.14 to 1.00 Ratio of Benefits to Costs -100-year period 1.44 to 1.00 16 100-yr. life $15,020,000 10,395,000 1.44 to 1.00 $325,239,000 20,327,000 $345,566,000 $ 610,000 355,000 12,185,000 S 13,150,000 1,780,000,000 142,000,000 1.638.000.000 6.40 1.63 8.03 9.17 PLAN FO~truLATION During the investigations an alternative site for the powerplant was studied. This alternative site is about two miles upstream from that proposed in this report. The tunnel would be 2.5 miles shorter, but the tailwater elevation would be 90 feet hip.her, resulting in an annual decrease of about 175,000,000 kilowatt- hours of firm energy. An examination of the terrain alon~ this reach of McArthur River indicated an unfavorable location for the tunnel portal and penstock. In addition, the transmission line and access road would have had to cross over an objectionable slide area. Considerin~ the Rain in powerplant canacity, and sound enpineering logic, the proposed location of the powerplant was adopted. CONCLUSIONS The project evaluation developed in this report status indicates that the cost of Chakachamna power would slip,htly exceed that of the Devil Canyon Project. The Devil Canyon Project would supply a substantially greater power market area as well as provide a transmission grid between Anchora~e and Fairbanks. In addition, it is expected to meet the pO\Oler demands of this area through about 1982. The water supply for project use is based on only two complete years of actual records, and a correlation with the ~~atanuska River at Palmer. The potential firm enerry output is based on estimated runoff information and is subject to revision. For these reasons a full scale feasibility investiRation of the project should be deferred until additional stream flow records are available. RECOHI1EN DATI ONS 1. Continue the stream gapinp program for the purpose of substantiating the hydro pm-ler potential based on a longer period of water record. 2. As comparable construction cost data becomes available for tunnel work in Alaska, reassess project development expense. 17 ACKUO\'lLEDGE~rr:NT The cooperative efforts of the lI. S. ~eological Survey and the U. S. Fish and Wildlife Service have been very instrumental in making possible the findin~s of this report. The appended letter by tir. Harry L. Rietze, ReP.ional Director, Bureau of Commercial Fisheries reports on studies conducted by that agency. His recommendations for future studies needed to more accurately assess the magnitude and value of the fish and wildlife resources are included. 18 UNITED STATES DEP.ART"lENT OF THE INTERIOR FISH AND WILDLIFE SERVICE BUREAU OF COm4ERCIAL FISHERIES Box 2481 Juneau, Alaska f1r. Dary 1 L. Roberts District r'lanager Alaska District Headquarters P. O. Box 2567 Juneau, P.laska Dear Mr. Roberts: March 24, 1961 Reference is made to your letter of 11arch 8, 1961, in which you request information on the fish and wildlife resources in relation to the pronosed Chakachamna Project. The data presented herein are based on limited studies which are considered to be reconnaissance in nature. Because of the above and the fact that your report on the Chakachamna Project is also a reconnaissance report, our comments are necessarily ~eneral and this letter does not consti- tute the report of the U. S. Fish and iHldlife Service and the Alaska Department of Fish and Game on the project within the meaning of the Fish and l,Hldlife Coordination A.ct, 48 Stat. 401, as amended, 16 U.S.C. 661 et seq. Chakachamna Lake is located approximately 85 air miles west of Anchorage, Alaska, in a deep valley of the Alaska Range surrounded by glaciers and high rugged mountains. The elevation of the lake is 1,145 feet and the watershed drains to the east and southeast via the Chakachatna River for 40 miles into Cook Inlet. The lake is approximately 13 miles in lenpth and varies from 1.5 to 3.0 miles in width. Inflow to the lake is largely of glacial origin, and the lake waters are quite turbid as a result. One of the lar~er p,laciers, Shamrock Glacier, divides Chakachamna Lake into two bodies of water; the small upper lake is called Kenibuna and is also turbid owing to its p,lacial tributaries. A small stream from this lake flows around the north side of Shamrock Glacier and into upper Chakachamna Lake. Barrier r,lacier partially blocks the outlet of Chakachamna Lake. A few small, sprinR-fed, clear water tributaries empty into the main lake, and the two main tributaries, Chillif7an and llapishlamina, enter from the north. 19 The present plan of development for this project consists of a transmountain diversion tunnel fran Chakachamna Lake to a pc:wer- plant located on the upper reaches of McArthur River to the south. The tunnel would be nearly 12 miles in length and approximately 25 feet in diameter with ·a 1.230 foot penstock leading to the powerplant. Installed capacity of the project would be approxi- mately 320.000 kilowatts. Steel tower transmission lines would traverse the upper portion of Cook Inlet and provide electrical energy to the Anchorage area. No dam is proposed for the outlet of Chakachamna Lake although the lake itself would form the storage reservoir. Populations of lake trout. whitefish and sculpins are present in Chakachamna Lake. However. due to the glacial water. the limited access to the lake. and the presence of more attractive fi$hing sites elsewhere in the area. sport fishing pressure is practically non-existent. During August. a run of red salmon arrives at Chakachamna Lake and spawns in the clearer sloughs and side channels of the lake's main tributaries. During 1952 2.000 red salmon were seen in Chilligan River about two miles upstream of the lake. About 1,000 salmon were noted in this drainage during the 1960 spawning season. Chakachamna Lake is undoubtedly used as a rearing area by the red salmon, although the time of seaward migration of the young fish has not yet been determined. Pink and red salmon are present in the lower reaches of the Chakachatna River. The McArthur River supports populations of Dolly Varden and whitefish as well as a red salmon run. Reportedly. certain other species of salmonids also utilize these two rivers. although our surveys did not reveal their presence. The tentative operation plan for the Chakachamna project would result in virtual dewatering of the upper Chakachatna River and would thereby eliminate the run of red salmon now utilizing the lake for spawning and rearing purposes. Reduced flows in the lower portion of this river could adversely affect other fish populations that may be present. At this time, the effect upon fish life of discharging tailrace flows into the McArthur River is not known. Big game species utilizing the Chakachamna Lake drainage are moose. caribou, and black and grizzly bear. Wolverine, beaver, mink. and spruce grouse are present in the area. Goldeneyes were the only species of nesting waterfowl observed to be present in 1960 although green-winged teal, redheads, and mallards w@re noted migrating through the area. 20 Fluctuating water levels would be detrimental to wildlife utilizing the lake perimeter. However, wildlife populations are relatively low and utilization of these resources is minimal at the present time. Project operation is not expected to affect seriously the game resources around the lake. As is the case of the fishery resources, dewatering of the Chakachatna River and the discharge of addi ti onal flows into the t'lcArthur River may affect fur bearers which utilize the habitat of these stream courses. The Fish and vlildlife Service and the Alaska Department of Fish and Game have not at this time formulated any specific recommenda- tions concerning the project in the interest of the fish and wild- life resources. Detailed studies are recommended to assess accurately the maP,nitude and value of the fish and wildlife re- sources and to develop specific recommendations for their mitipa- tion and (or) enhancement. The Fish and vJildlife Service and the Alaska Department of Fish and Game should be advised if the Bureau of Reclamation plans to start feasibility studies of the project in order that de- tailed fish and Hildlife investirations may be initiated. Very truly yours, /s/ Harry L. Rietze HARRY L. RIETZE Regional Director 21