Water Projects
Corps Awards $1.8B in Southern California Dam Safety Contracts to Barnard Construction
Prado Dam near Corona, Calif. will undergo a $1.13-billion spillway modification to manage flood risk.
The U.S. Army Corps of Engineers awarded $1.86 billion in contracts to Barnard Construction for dam safety upgrades at Prado and Whittier Narrows dams in Southern California. Both projects aim to mitigate flood risk for nearly 2.5 million people and $400 billion worth of infrastructure situated between the dams and the Pacific Ocean.
The $1.13 billion Prado Dam Spillway Modification project the Santa Ana River near Corona, Calif. will improve the holding capacity of a facility that has faced increased runoff due to regional urbanization since its completion in 1941. The “dry dam,” with generally low water levels behind the reservoir, features a main dam, consisting of a large earthen embankment, auxiliary dike, concrete outlet for controlled water releases and a wide concrete spillway to handle excess water flows.
"At Prado Dam, we’re pairing smarter contracting with the innovative engineering of a labyrinth spillway to provide a higher level of safety for 1.4 million Americans,” said Assistant Secretary of the Army for Civil Works Adam Telle in a release.
The project combines two project phases into one. The first phase fixes potential safety issues by replacing the old spillway with a labyrinth-style structure. Crews will demolish the existing walls and slabs, rebuild them, and then tie the new system into the dam’s earthen embankments. The second phase will raise the spillway’s crest by 20 ft to match the elevation of the 2005 main dam embankment raise.
Significant construction is expected to begin by the spring of 2027 and is anticipated to be completed by 2033. The dam will remain fully operational and continue to reduce flood risk during construction.
Concurrently, the Corps awarded Barnard a $735-million contract for the Whittier Narrows Dam, a three-mile-long structure that manages flows from the Rio Hondo and San Gabriel rivers in Los Angeles County. Completed in 1957, the dam is located about 11 miles east of downtown Los Angeles, making it the most urban dam operated by the Corps.
The dam is classified as high-risk due to its location in a densely populated urban corridor and the project will focus on critical safety improvements to the embankment and outlet structures.
Both projects will be delivered via integrated design and construction, which calls for early contractor involvement.
“When we considered the most effective way to deliver these projects, early contractor involvement was the clear choice because we could partner with Barnard earlier than in a traditional construction contract,” says George Sunny, project manager for the U.S. Army Corps of Engineers Los Angeles District. “Together, we have proactively identified innovations and resolved constructability issues before breaking ground."
Major construction on both the Prado and Whittier Narrows projects is slated to begin in the spring of 2027, with anticipated completion by 2033. The Corps says both dams will remain fully operational throughout construction to maintain flood-risk management for the region.
