The Sacramento Weir is more than 100 years old and the only manually operated weir on the Sacramento River system, officials say. The new section would be a passive weir, allowing high water to flow into a bypass during floods. The 48 manual gates on the existing weir will remain intact.

The project would add 1,500 ft to the width of the Sacramento Weir. Image courtesy of U.S. Army Corps of Engineers Sacramento District

 

The weir widening is the second of two projects being undertaken to upgrade its performance in deterring flooding in populated areas along the Sacramento River. The first project, the Lower Elkhorn Basin Levee Setback (LEBLS), is led by the California Dept. of Water Resources and scheduled for completion in June 2025. It involves the construction of about 7 miles of setback levees along the Sacramento Bypass, which runs between the weir and the Yolo Bypass, a 59,000-acre wildlife habitat bordered by levees.

Work on the LEBLS project, with contractors Forgen LLC, Sukut Construction and GSE Construction, began in 2020. 

Once both projects are complete, officials say they will allow a greater amount of flood water to flow from the Sacramento River into the Yolo Bypass. As ENR previously reported, the projects are designed to double the capacity of the Sacramento Bypass and add hundreds of acres to the floodplain, reducing the likelihood of flooding downstream.