Groundbreaking Marks Largest Floodplain Salmon Rearing Habitat Project in California History


The ceremonial first shovel at the Big Notch Groundbreaking ceremony at the Fremont Weir Wildlife area in Yolo County.

The ceremonial first shovel at the Big Notch Groundbreaking ceremony at the Fremont Weir Wildlife area in Yolo County.

SACRAMENTO, Calif. – Federal and state agencies broke ground today on a project that will become the single largest floodplain salmon rearing habitat restoration in California history. The Department of Water Resources (DWR) and U.S. Bureau of Reclamation (Reclamation) are partnering on the “Big Notch Project,” a 30,000-acre floodplain habitat restoration and fish passage project in the Yolo Bypass in Yolo County.

The project will expand floodplain rearing habitat for juvenile salmon and improve access through the bypass for salmon and sturgeon, which is pivotal to the recovery of these threatened and endangered fish species.

“As California experiences a third year of dry conditions, the State and its federal partners are committed to supporting wildlife during this extended drought,” said DWR Director Karla Nemeth. “This project is part of a decades-long plan that has been recognized as critical for the recovery of threatened and endangered salmon.”

“Big Notch is a pivotal project for ongoing operations of the water projects that are critical to the State,” said Ernest Conant, California-Great Basin Regional Director for Reclamation. “Big Notch is an example of the collaboration it takes to implement a complex and expensive project, and everyone came together to make it happen.”

The Big Notch Project is located in the Fremont Weir State Wildlife Area in Yolo County. Part of the project includes the removal of a section of the Fremont Weir, the installation of three gates, the excavation of 180,000 cubic yards to carve a new path for salmon, and construction of a control building and pedestrian bridge.

When the project is finished in late 2023, the gated passage, or notch, will be opened when the Sacramento River is high enough to flow into the Yolo Bypass floodplain. The water will enter the bypass through the notch at Fremont Weir and create shallow-water habitat for fish to easily migrate through the area. Juvenile salmon will be able to feed in a food-rich area for a longer time, allowing them to grow more rapidly in size, improving their chances of survival as they travel to the Pacific Ocean. Adult salmon and sturgeon will benefit from improvements that will reduce stranding and migratory delays due to passage barriers.

The Big Notch Project is being implemented in conjunction with the State Water Project and federal Central Valley Project. The State Water Project provides water to 27 million Californians, 750,000 acres of farmland, and businesses throughout the state. The Central Valley Project provides an annual average of 5 million acre-feet of water for farms, 600,000 acre-feet of water for municipal and industrial uses, water for wildlife refuges, and reduces Central Valley flood risk.

Additional Resources:

For more information about the Big Notch Project, visit:


Sabrina Washington, Information Officer, Public Affairs, Department of Water Resources

916-820-7664 |

Gary Pitzer, Public Affairs Specialist, U.S. Bureau of Reclamation

916-223-5137 |