Folsom Dam

Folsom Dam is a concrete gravity dam on the American River near the city of Folsom, California, United States. It is operated by the United States Army Corps of Engineers (USACE) and forms Folsom Lake, a multi‑purpose reservoir.

Location and Structure

• Situated in Sacramento County, approximately 18 mi (29 km) east of Sacramento.
• The dam is a concrete gravity structure with a height of 340 ft (104 m) above the riverbed and a crest length of 1,500 ft (460 m).
• The crest elevation is 525 ft (160 m) above mean sea level.

Construction History

• Planning for a flood‑control dam on the American River began in the 1940s.
• Construction commenced in 1950 and was completed in 1955.
• The dam was officially dedicated on June 26 1955.

Purpose and Operations
Folsom Dam serves several functions:

1. Flood Control – Regulates runoff from the Sierra Nevada watershed to protect downstream communities.
2. Water Supply – Stores water for municipal, industrial, and agricultural use in the Sacramento Valley.
3. Hydroelectric Generation – The Folsom Powerplant, operated by the Sacramento Municipal Utility District (SMUD), has a capacity of approximately 195 MW.
4. Recreation – Folsom Lake provides boating, fishing, swimming, and camping facilities.

Reservoir Characteristics

• Maximum storage capacity: about 979,200 acre‑feet (1.21 billion m³).
• Normal pool elevation: 492 ft (150 m) above mean sea level.
• Surface area at full pool: roughly 11,450 acre (46 km²).

Environmental and Management Aspects

• The dam and reservoir are subject to periodic drawdown for flood mitigation and water quality management.
• The USACE collaborates with state and local agencies on fish and wildlife habitat enhancement, including measures for salmonid migration.

Related Infrastructure

• Downstream of Folsom Dam is the Nimbus Dam, another USACE structure that further regulates flow.
• The American River Parkway, a regional recreation corridor, runs alongside portions of the river below the dam.

References

• United States Army Corps of Engineers, “Folsom Dam and Reservoir” (official project page).
• Sacramento Municipal Utility District, “Folsom Powerplant Overview.”
• California Department of Water Resources, “Reservoir Capacity and Operations.”