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HomeMy WebLinkAboutBradley Lake Hydroelectric Project Information Brochure 1979I '\ ',?/.~.~) C~.'# INFORMATION ~1 BROCHURE BRADLEY LAKE HYDROELECTRIC PROJECT ~United States Army 1t,_PI. ,II 5 Corps of I;ngineer& ~, .• ,Stmllng the Army , ."Set:l'Ing tJw Nat'"n AI"skaDistrict , 707 A STREET ANO-IOAAGE, AX 99501 , ! Sept~mller 1979' " " ~' . ~, ~ , , L% ....... ::: .... . THE NEED The fast approaching obsolescence of current fossil fuel fired power plants as well as a tremendous increase in the growth of industries and population of. the Kenai Peninsula signals a need to develop new sources of energy. Construction of a new generation of oil and gas fired power plants is a definite alternative in accommodating the future needs of j" the area •. H~Wever; .trends in the price as ,well as the politics involved in insuring oil and gas supply makes total dependence on fossil fuel generators . less inviting and more risky. Other sources of energy such' as nuclear. solar, geothermal, tidal and wind are as yet not economically feasible or not suitable for the area. Although hydropower as a sole source of energy is not the answer, hydropower can be used to augment the current power generating capacity of the area. Hydropower together' with gas and oil fired generating plants can accommodate the future requirements of the area, at least until such time as other alternatives ' become. viable as sources of energy. HISTORY The Bradley Lake Project was authorized by'Congress in the Flood Control Act of 1962. However, because of an outlook of cheap long term power supplied from locally available natural gas, the development of the project was halted short of the design stage. In 1968, a reevaluation· of the project was initiated because of indications of a greater water availability than initially estimated. Additionally, the 1973 oil crisis highlighted the need to develop other than fossil feel energy sources. A feasibility study was thus undertakened by the Corps of Engineers and was concluded in 1975. Furthermore, a reanalysiS of the Kenai Peninsula Power Market, alternative power sources.and general design features of the project was made and concluded in 1978. The results of these studies as well as those of the Alaska Power Administration surveys on power demands of the area confirmed the economic feasibility as well as the desirability of the project. A'RLtS AIub~Ubl!'1 &: JnfonnadoDScrdceI . UbrarY .Bu11dins. Suite 111 ~~4 Since then several studies and investigations have been undertaken toward the design and construction of the project. An environmental study was made to insure ~hat any drastic changes on the ecology as well as the aesthetic qualities of the area that may possibly result from the project are minimized or avoided. An archeological study has been initiated to insure that none of the historical and cultural resources of the area' are obliterated. Aerial and ground surveys, geological studies, extensive mapping, and hydrologic investigations are well under way to collect data for incorporation into the design of the various facilities. Although data collection, investigations and planning are expected to continue throughout the project duration,' enough information will have been compiled by 1982 to insure that a design compatible to the rteeds and the desires of the region is accomplished. The entire project itself is expected to be finished in 1988 at a projected cost of $174,000,000. Moreover, power transmissions may start as early as September 1987. Upon completion, the project will be turned over to the Alaska Power Administration for its operation and maintenance. LOCAT:lON Bradley Lake occupies a glacially carved basin in the scenic Kenai Mountains, 36 airmiles northeast of Homer, Alaska. Perched 1090 ft. above sea level, Bradley Lake collects water from many glaciers as well as p:tiecipitation over a drainage basin 54 square miles in area. From· the lake, water eventually empties into the head of Kachemak Bay via the swift currents of Bradley River. 2 '.'"-~ --#~~ -:' !f.;~ ~!.,. ;.:"" . t-l?f .;_".~',,~ ;_: .t'~ ~ "~~~>,,,~:, .. , KENAI I11II'I' \'MIll ~ _ ON "'u. .... . «:111'" tID. .... D 11. ..... . ....,.. .1._ CI, Ca. It. I II. 3 • PENINSULA flUt.TlPLI I'UllPOU tNCLUDlIIII POWIII BRADLEY LAKE ALASKA 1178 lCAL! IN tEET 4000 j I . i I DEHSTOCK .C' ':;1.1,,1 "EEL L "r_ KE Dltc" ~(I • -0 ............ I ••• " FLOW ...;..----11 ~ "' ~,,7.~~~.~-----~~~~~vJ.\{ TYPICAL SECtiON -SPllLWA' 110 "tALI ·SWISs" TYPE SYSh ... scaLf MO." ,-'100'- vlA' (',ISO' I rl.I" ... G '-ouND ~11iII( "IOv, .... _~ H-¥ttl V(MleLI &':ct$' 'ulirII .. r • ..... , ~r"''''''''~ I accUS ....,T CO"'O:ICT( LIN(D p[h:STOC. \ , , , , , ...... "-~ " , "-"- P tc:'"lSTAUCT1ON &OIT " ". POW!" TIJIIftE&. (""INED) , , ~ECT'O" II-A ~: ~.::,,-[ [·F' ~ .,,'lAOi.l , .... PROPOSED FACILITIES, At the point where Bradley Lake empties into Bradley River, ,a dam will ,beb~i1t to anel.e:Vationof 1180 ft. MSL. It will have a crest length of 300 ft., The spillway itself will be about 200 ft. northeast of the dam. It f S crest will be 180 ft. in length at an elevation of 1170 ft. In this configuration, the dam will be able to impound 342,000 acre .... feet (1 acre feet = 325,849 gallons) of water above the existing lake elevation of 1090 ft. To'insure that enough water is stored in the dam for uninterrupted power generation, a creek north of the lake that currently empties into Bradley River downstream from the dam may be diverted into Bradley Lake. A dam may also be constructed across Nuka River, 10.2 miles from the Bradley Lake dam. The construction of these diversions could increase the'drainage basin of the reservoir by 32 sq. mi1es~ All the': faciiities ,described so far are above ground. Aside from access , . roads and transmission lines, all other facilities will be underground tomiriimize the effects on the visual qualities of the area. From a point 70 ft. below the existing lake surface, a iake tap will convey water into a 16 foot diameter tunnel. This tunnel will run underground for approximately 12,000 feet to a point where it intersects an 11, foot diameter tunnel called a penstock. The penstock is where the energy of the water by virtue of height (potential energy) is converted into energy by virtue of motion (kinetic energy). At the end of the 1800 foot penstock, the kinetic energy gained by the water will then ,be used'to turn three turbines. ,These turbines will in turn run the generators : located in an underground piowerhouse. From the turbines, the energy- dissipated water will be conveyed by a 16 foot diameter tailrace tunnel through a distance of 5,200 feet into Kachemak Bay. 5 The powerhouse itself will be designed to provide a total capacity of 118 MW (lMW • 1,000,000 watts). However. only 70 MW of power will be initially generated to satisfy the immediate power needs of the Kenai Peninsula. With the expected increase in future peaking requirements of the area, the powerhouse will then be developed to its full power generation capacity. A switchyard wiil be constructed between the tailrace outlet and the existing Bradley River channel. Power will be distributed to the Kenai Peninsula by connecting the switchyard to transmission lines owned ~y Homer Electric Association at the head of Kachemak Bay. This will entail construction of 10 miles of 115 KV transmission line. A road network will have to be constructed to tie together the different features of the project and to provide access to the area (see road map on next page). Although a definite scheme has not been decided, there are four legs being considered. Leg "A", the road connecting the clam area to the powerhouse-switchyard complex, will provide the necessary maintenance-route within the area. Legs "B", "e", and "D" are the three alternatives being considered to provide the necessary access.to the area. The decision on which one of the three roads will be built is dependent on cost and environmental effects as well as the desires of the region. 6 CONCLUSION As with other projects of similar magnitude, Bradley Lake Hydroelectric Project will not be without unwanted effects. Built into the Corps of Engineer planning process however, is a conscious effort to avoid or minimize these effects. A very detailed environmental study is underway to insure that potentially adverse impact on the ecology is identified and avoided or minimized through sound design. Also an integral part of the Corps planning process is public involvement. Through public meetings, the desires. and needs of the public are made known and are thus considered in the decision making process. The Alaska District, Corps of Engineers, with the support of the people of Kenai Peninsula and Alaska, can, through careful planning and design, insure that the cost of increasing the quality of life of the area is as little as poss~ble. 8 I ~ j I i . All interested individuals, groups, .and agencies are also being invited to be present or be represented at this meeting. Everyone will be given an opportunity toexp~ess their view and furnish data on the technical, economic, social and environmental aspects of the project. All statements, oral or written, will become part of the official record of the study. Written statements may be given at the meeting or mailed to the Project Manager, Mr. Robert Oenbrink (phone 276-4722) at the District Office. Please bring this announcement to the attention of anyone you know who may be interested. ! LEE R. NUNN Colonel, Corps of. Engineers District Engineer 2 . : J , I ii I 'I ~I ! I