Folsom Dam is a concrete gravity dam on the American River of Northern California in the United States, about 25mi northeast of Sacramento. The dam is 340ft high and 1400ft long, flanked by earthen wing dams. It was completed in 1955, officially opening the following year.Located at the juncture of the north and south forks of the American River, the dam was built by the United States Army Corps of Engineers, and was transferred to the United States Bureau of Reclamation upon its completion. The dam and its reservoir, Folsom Lake, are part of the Central Valley Project, a multipurpose project that provides flood control, hydroelectricity, and irrigation and municipal water supply. In order to increase Sacramento's flood protection to 200 year flood protection (meaning that the area is protected from a flood that has a 0.5% chance of occurring in any given year) the US Army Corp of Engineers is constructing an auxiliary spillway. The spillway is scheduled to be completed by October 2017, and will enable Folsom dam to release water before it reaches the height of the gates already in place.Another Central Valley Project dam, Nimbus Dam, is located further down river.
