California Construction News staff writer
The U.S. Army Corps of Engineers has awarded a $1.13 billion contract to Barnard Construction Co. Inc., headquartered in Bozeman, Montana, for the Prado Dam Spillway Modification Project.
The project will upgrade Prado Dam, a key flood-risk management facility on the Santa Ana River, protecting about 1.4 million people and more than $200 billion in property and infrastructure between the dam and the Pacific Ocean.
Prado Dam, completed in 1941, is considered a “dry dam,” with typically low water levels behind its reservoir. Its main features include a large earthen embankment, auxiliary dike, concrete outlet for controlled releases, and a wide concrete spillway to handle excess flows.
Modifications combine two phases into a single project. The first phase addresses potential failure modes identified in a dam safety study, including the construction of a labyrinth-style spillway control structure, demolition and reconstruction of all spillway chute walls and slabs, and integration with the earthen embankments. The second phase raises the spillway’s crest by 20 feet to match the elevation of a 2005 main dam embankment raise.
Significant construction is expected to begin in spring 2027 and continue through 2033. The dam will remain fully operational and continue reducing flood risk during construction.
USACE is using Integrated Design and Construction, a form of early contractor involvement that leverages the expertise of both the Corps and Barnard to increase efficiency and value for taxpayers.
“Our ‘Building Infrastructure, Not Paperwork’ initiatives are about delivering results by prioritizing our nation’s highest priority projects,” said Adam Telle, Assistant Secretary of the Army for Civil Works. “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.”
Prado Dam has long provided flood protection, recreation, and water conservation for the region. The current upgrades are intended to modernize the facility in response to decades of urbanization and increased runoff.
