Plan

Nimbus Powerplant is a run-of-the-river plant and provides station service backup for Folsom Powerplant. Nimbus Dam forms Lake Natoma to reregulate the releases for power made through Folsom Powerplant. Nimbus Dam is a concrete gravity structure 87 feet high and 28 feet wide at the crest. The crest is 1,093 feet long. 

History

Nimbus Dam, 7 miles downstream of Folsom Dam on the American River, regulates releases made through Folsom Dam. Nimbus Dam forms Lake Natoma, with a surface area of 540 acres and a capacity of 8,760 acrefeet. Nimbus Dam is a concrete gravity dam 1,093 feet long and 87 feet high. Eighteen radial gates, each 40 feet by 24 feet, control the flows.

Nimbus Powerplant is located on the right abutment of the dam, on the river’s north side. Its two generators have a capacity of 7,763 kilowatts each. Water is supplied to the two 9,400 horsepower turbines that drive the generators through six 46.5-foot-long penstocks. Nimbus Dam and Powerplant began operating in 1955. Power generated by the Folsom and Nimbus Powerplants is marketed by the Western Area Power Administration.

General