WSP10956 - Laserfiche WebLink

Home Browse Search

21 OuZ258 . Plan 6 (Sierra Diversion to Southern California-East Side Division Exchange)--This plan proposes to divert 1,200,000 acre- feet from the major east side San Joaquin Valley streams, above about 3,000 feet elevation, by a series of tunnels of progressively larger capacity starting at the San Joaquin River above its junction with Big Creek, and intersecting the Kings, Kaweah, and Tule Rivers, and discharging into Isabella Reservoir. From Isabella Reservoir the water would be conveyed by tunnel to the east side of the Sierra Nevadas, and thence through Antelope Valley to join the California Aqueduct near the Cottonwood Powerplant. From that location it would be conveyed through the aqueduct to Perris Reservoir. Exchange water for the areas now being served by the east side streams from which tunnel diversions are contemplated under this plan would need to be provided. This tunnel diversion plan would require a series of tunnels totaling 140 miles in length from San Joaquin River to Isabella Reservoir on the Kern River. Associated with these tunnels would be 11 diversion dams for diverting water from each of the streams. From Isabella Reservoir a 34-mile tunnel would convey the water southeasterly through the Sierra Nevadas to Cottonwood Creek, about 20 miles north of the town of Mojave. From this location the water would be lifted 650 feet and conveyed by a 75-mile, 2,000 c.f.s. canal to join the California Aqueduct below the Cottonwood Powerplant near Fairmont, Los Angeles County. The aqueduct would be increased 2,000 c.f.s. to convey the water to Perris Reservoir. The capital cost of the Sierra diversion tunnels and conveyance facilities to southern California (exclusive of exchange and storage facilities) is estimated on a reconnaissance basis to be $1,010,000,000, and the annual OM&R $2,100,000, not including cost of pumping energy. The net cost of pumping is estimated to be zero. Exchange water for the areas now served below the points of diversion on the east side streams would be conveyed through East Side Division (enlarged). A 3,000 c.f.s. incremental increase would be made in these facilities to the Kern River. . The estimated capital cost (reconnaissance) for this incremental enlargement for exchange purposes is $200,000,000, including the esti- mated amount required to offset the adverse effect on existing power- plants below the tunnel diversions. The annual OM&R costs are estimated at $750,000. Pumping costs are estimated to approximate $5,600,000 annually. The additional water, 1,200,000 acre-feet, required for exchange purposes would he conserved in two storage reservoirs proposed on Trinity River. Helena Reservoir, with a gross storage capacity of 2,800,000 acre-feet, would be built on the main Trinity River down- stream from Lewiston Dam. This reservoir would develop an annual