Electrical Power for Valdez and the Copper River Basin-1981

turbine. The penstock would bifurcate into two penstocks immediatelyupstream of the Alternate No.2 powerhouse valve room. Each penstockwould connect to a turbine. Some of the water discharged from theturbines would be diverted into the existing weir on the creek forA1yeska's water supply and for the Department of Fish and Game salmonhatchery f ac i 1 it i es.pm~ERPLAN TTwo alternative sites of the aboveground powerhouse would be locatednear the channel of the Allison Creek. The centerline of the bifurcationwould be at the same elevation as the powerp1ant. The powerhouse wouldcontain two synchronous generators driven by Pelton wheel turbines withdesign heads of 1,220 feet for the alternate Site No.1 and 1,170 feetfor the alternate Site No.2. The turbines would have nameplate ratingsof 4.0 MW each. The powerhouse structure would house the generators,turbines, a 15-ton bridge crane, and all other equipment required foroperation and maintenance. Remote control of the powerp1ant would befrom Valdez accomplished through the use of a carrier communicationsystem. The tailraces of the alternate powerhouse No.2 are longer inlength than that of the alternate powerhouse No.1. On both alternatives,stoplogs would be installed near the upstream end of the tailracepipes to regulate flow during the summer and winter operations. Energydissipators at the Allison Creek end of the tailraces would be ofconcrete construction.TRANSMISSION SYSTEMThe Valdez project power would be delivered to Solomon Gulch substationand then transmitted over the Copper Valley Electric Associationsystem for distribution. The transmission line route was located in thefield based on aerial and map reconnaissance. The route runs along thesouth side of the existinq road Qetween Allison Creek and Solomon Gulch.The terrain is of a moderate ro11inq mountains and close to tidewater ofthe Port of Valdez.The project installed capacity is 8.0 MW and the transmission systemcapacity would be 10 MVA. The transmission line from Allison Creekpowerp1ant to Solomon Gulch sUbstation would be a 115 kV line. Therewould be approximately 3.0 miles of single wood pole construction. Theoverhead conductors would be #1/0 ACSR with no overhead ground wires.The 115 kV system was chosen for power transmission to match existingfacilities. Vo1taqe regulation from Allison Creek powerplant to SolomonGulch substation is 2.5 percent and is acceptable. An addition to theSolomon Gulch sUbstation is proposed to provide switching and powerenerqy to the existing system. An oil filled circuit breaker would beremotely controlled from Valdez via a carrier communication system.The proposed right-of-way would be a 50-foot wide corridor and wouldrun over lands administered by the U.S. Forest Service. Based on USGSmaps with vegetation overprint, the entire line would require essentiallycontinuous clearing. Small shrubs and bushes would remain and all othermaterials would be burned, chipped or left in place as determined by theD-3