The Bureau of Reclamation awarded a $16 million contract Oct. 1 to Kiewit Pacific Co. of Concord, Calif., for construction of an auxiliary spillway at 198.72-MW Folsom Dam and Reservoir.
The auxiliary spillway is being built as a Joint Federal Project by BuRec, the Corps of Engineers, the California Department of Water Resources, and the Sacramento Area Flood Control Agency. The spillway is to address the hydrologic risk to Folsom Dam identified through BuRec’s Safety of Dams program. It also is to achieve the Corps’ objective to increase flood control protection for the city of Sacramento.
The work consists of an approach channel, control structure with six submerged tainter gates, concrete-lined spillway chute about 3,000 feet long, and stilling basin to dissipate energy before water is discharged into the American River below the main dam.
The project will be constructed in three phases. The Phase I contract to Kiewit Pacific includes initial spillway excavation, construction of a roadway, and modifications to two wing dams. Work is to begin in late fall 2007, and will be completed by 2009. Contracts for Phases II and III are pending. Completion of the spillway is expected by 2015.
As part of the same project, BuRec is to complete dam safety work on Dikes 4, 5, and 6, and Mormon Island Auxiliary Dam. Once the Folsom spillway is complete, the Corps will proceed with other flood control improvements, including a 3.5-foot increase in the height of the earthen embankments and modifications to emergency spillway gates.
The Water Resources Development Act of 2007 passed by Congress and sent to President Bush authorizes $444 million in federal money for the flood damage reduction work at Folsom. (HNN 9/26/07)