LOS ANGELES --
The U.S. Army Corps of Engineers Los Angeles District and the Orange County Flood Control District are pleased to announce the signing of an amendment to use Bipartisan Budget Act of 2018 funds for select features of the Santa Ana River Mainstem project, designed to improve flood protection for more than 1 million people.
The $2.83 billion Santa Ana River Mainstem project is aimed at reducing risk of flood damage along the Santa Ana River’s 96-mile journey, from Seven Oaks Dam near San Bernardino to Huntington Beach, where it flows into the Pacific Ocean.
The amendment to the project cooperation agreement between the two agencies was signed Oct. 7 by Col. Julie Balten, LA District commander, and Oct. 6 by Michelle Steel, chairwoman of the Orange County Board of Supervisors.
The amended agreement allows the Corps to use federal funds under the Bipartisan Budget Act to complete select remaining features, which include raising the Prado Dam spillway by 20 feet, from an elevation of 543 feet to 563 feet; completing the lower Norco Bluffs toe protection project, and the Alcoa Phase 2 and River Road dikes; and ongoing mitigation responsibilities associated with the Prado Dam project features.
“We are excited about our continued partnership with the Orange County Flood Control District on this extremely important project,” Balten said. “The Prado Dam reduces the risk of flooding for more than 1.4 million people living and working downstream of the dam in 29 cities in Riverside and Orange counties and protects more than $61 billion in property.
“Additionally, the Prado Basin – which encompasses the tri-county areas of Riverside, San Bernardino and Orange counties – provides recreation, water conservation, environmental stewardship and other opportunities that will benefit the surrounding communities for years to come.”
Design for the spillway, Norco Bluffs toe projection and dikes are underway. The Corps estimates construction contracts will be awarded in federal fiscal year 2021.
Completing the basin dikes and raising the spillway will provide an additional 142,000 cubic feet of flood water storage, for a total of 362,000 cubic feet, which will increase the dam’s capacity to retain water and provide two significant benefits – reducing the likelihood of downstream damage from flood waters and could potentially increase the ability to retain additional water to recharge underground storage supplies.
“Through this partnership and collaboration, we have taken one more step toward greatly improving the safety of our communities’ homes, schools, businesses, parks and more,” Steel said. “We have made significant progress in addressing the Santa Ana River improvements, and this agreement will take us to the finish line in completing the elements necessary to raise Prado Dam.”
Completion of construction in what is referred to as “Reach 9” of the Santa Ana River, which includes a levee downstream of Prado Dam in the City of Yorba Linda and the BNSF railway bridge protection, are underway and are not part of the BBA funds. The levee is intended to provide erosion protection for the north bank of the Santa Ana River and flood risk management for portions of East LA Palma Avenue, the Santa Ana River Trail/Bikeway, industrial facilities, commercial development and residential housing. Additionally, initial funds from the BBA have been provided to identify a construction-ready project for the Santiago Creek feature.
ABOUT THE SANTA ANA RIVER MAINSTEM PROJECT
Construction of the Prado Dam was completed in May 1941. Section 401 of the Water Resources Development Act of 1986 later authorized a comprehensive project for flood risk management in the tri-county areas of San Bernardino, Riverside and Orange counties, including improvements to the Prado Dam that provided for raising the dam and the construction of eight dikes along the basin boundaries. This expanded and enlarged effort is referred to as the Santa Ana River Mainstem project.
The project includes many features that have already been completed, including improvements to Seven Oaks Dam, 30 miles of levees and modifications to original project features, including raising the Prado Dam embankment and installation of a new larger capacity outlet works.