Wednesday April 9, 2025
DWR via Maven’s Notebook —
Since the 1950s, California’s salmon populations have dwindled due to lost habitat from a combination of factors, including human-made barriers such as dams, altered river flows, and climate change. These challenges mean DWR looks for opportunities to support salmon and other endangered species in its projects whenever possible. DWR’s Lower Elkhorn Basin Levee Setback (LEBLS) Project is a multi-benefit project where engineering, flood protection, and supporting nature all come together. While the primary goal of LEBLS is to reduce flood risk, the recently expanded bypass floodplain is producing zooplankton, an energy-rich invertebrate that’s a key part of the juvenile salmon diet. This food production is happening in significant quantities and sooner-than-expected.
LEBLS is located north of West Sacramento and just west of the Sacramento River. The primary construction feature of the project set back the east levee by approximately 1,500 feet for the 5 miles along the Yolo Bypass and 2 miles of the north levee along the Sacramento Bypass. The construction of the new setback levee was completed in October 2023. This work expanded the Yolo Bypass, which floods seasonally and includes rice fields. DWR scientists knew this area would be valuable habitat for juvenile salmon because the inundated fields would have shallow, slow-moving, food-rich water.