The U.S. Army Corps of Engineers Sacramento District awarded a $114.4 million contract for the Folsom Dam Raise project to Folsom Dam Constructors (FDC), a joint venture of California Engineering Contractors Inc. and Shimmick Construction Company.

Folsom Dam Constructors will raise the main dam and left and right wing dams – on the American River in California — up to 3.5 feet and modify the eight spillway gates by adding top seals, strengthening the gates and raising the gate piers. Together, these measures will allow greater control of releases from the dam during large flood events and increase the temporary storage capacity of Folsom Lake that can be used to mitigate flooding for the greater Sacramento area. This will reduce the flood risk for 500,000 residents and $58 billion of assets downstream.

“Although there’s much work left to be done, this award represents the culmination of several years of effort from our dedicated team,” said Elvan Childs, USACE project manager. “We’re excited to continue push this project forward.”

The Folsom Dam Raise carries on the work begun by the Joint Federal Project (JFP) between USACE and the Bureau of Reclamation, which operates the Folsom Dam facility. The primary component of the JFP was construction of the Folsom Dam auxiliary spillway, which was completed in 2017. Dike 8, on the southeastern side of Folsom Lake, was raised 3.5 feet in 2020 as part of the project’s first component. 

Follow-on work will include raising the remaining seven dikes and Mormon Island Auxiliary Dam and reconfiguring the Folsom Dam penstock gates with modernized temperature control shutters.

The Folsom Dam Raise project is scheduled for completion in 2027.