Middle Fork Surge Shaft Phase 1 and 2

The headrace tunnel runs from the Hell Hole Reservoir to a powerhouse located on the Middle Fork of the American River. The hydroelectric facility generates approximately 175 millivolts of electrical power. Kiewit Pacific Co., a subsidiary of Kiewit Corporation, is constructing the existing surge shaft in two phases to install 550 vertical feet steel pipe 96 inches in diameter.

Major quantities include 40,000 tons of road-base aggregate on five miles of U.S. Forest Service roads, 148 tons of shoring steel, 300 tons of 550-foot-long, 8-inch diameter steel liner and 535 cubic yards of structural tremie concrete.

The team engineered and performed the water treatment, collection system and road improvements.