Expanding Flood Protection Capacity

The Sacramento River Weir Widening is a component of a larger $320 million U.S. Army Corps of Engineers (USACE) American River Common Features Project. The “Sacramento Weir - North” will increase the capacity of the existing “Old Sac Weir” floodway to 177,000 cubic feet per second and allow for a greater volume of floodwaters to be shunted around the city of Sacramento, north of downtown.

HDR provided civil, geotechnical, structural, mechanical, permitting, and fish passage support during the design phase and is currently providing construction support to the USACE, including inspection of pile driving and fish passage structure, engineering services related to submittals and requests for information, and coordination with local agencies involved in the project. We are also providing technical expertise to implement an enterprise database system to track compliance with sampling and testing requirements for the project.

The project includes the construction of a passive weir, vehicle bridge, county road, fish ladder, levees, canals, utility relocations, and a retrofit of the old weir. The passive concrete weir is integrated with the bridge structure to provide a dual-purpose facility and is being constructed in challenging geotechnical conditions.

The fish ladder will be built in phases and is designed to accommodate both salmon and sturgeon. It includes large gates to manage flows into the bypass, along with a SCADA system and fish‑monitoring systems such as high‑grade sonar cameras, hydroacoustic receivers and passive integrated transponder tags.

We have also supported USACE with a robust data management system for tracking the progress of the construction on the Sacramento River. We led several workshops to collect requirements for the data management system and designed a solution that included leveraging enterprise Esri GIS on the Azure cloud and Safe Software FME to automate the collection, evaluation and aggregation of dozens of construction tests. The test data are linked to features in the CAD design and made available to USACE via REST services.

USACE, the Sacramento Area Flood Control Agency, and the Central Valley Flood Protection Board, supported by the California Department of Water Resources, partnered to construct this project, with an estimated completion date for flood features by 2027. Final site cleanup and erosion control planting are scheduled to be completed in 2028.