Central Valley Flood Management

Many communities in California’s Central Valley face a greater risk of flooding than almost anywhere in the nation.  Larger storms, urbanization, and catastrophic levee failures threaten thousands of lives, water supply for 25 million people, a unique ecosystem, and an agricultural economy critical to the state. By actively working with local, regional, and state agencies and stakeholders to promote sustainable flood management strategies American Rivers is working to reduce risk, enhance public safety, and restore ecosystems.

Flood risk is growing in the Central Valley because the current flood conveyance system is insufficient to contain existing or future floods. Overreliance on technical strategies like dams and levees (which can fail catastrophically) has increased flood risk by constraining rivers and sending more water to downstream communities. Levees have also increased risk because the perception of safety incentivizes local governments and individuals to place valuable human life, property, and development on low-lying lands that are flood-prone.

Levees have failed in the past and will fail in the future.  In the Central Valley, the likelihood is even greater because many of them were built over 150 years ago by individual landowners and farmers piling up dirt—not by geotechnical engineers. Managing risk on these levee protected lands is now more important than ever. Consequences of levee failure could cause significant loss of life and could destroy property, infrastructure, and the vitality of the region as a whole.

Rivers need more room, and communities need greater awareness and better protection.  Moving people out of harms way, and creating flood bypasses and levee setbacks are great strategies for protecting public safety and restoring rivers for communities.

American Rivers Conservation Director for the Bay Delta Central Valley, John Cain, is author of this comprehensive report on the San Joaquin river and its tributaries. It describes the ecological importance of a natural flow regime and identifies opportunities to reoperate reservoirs to better meet ecological objectives while minimizing impacts on farmers who currently use the SJ River for irrigation.

To learn more, check out our Central Valley flood management factsheets:

American Rivers’ work in the Central Valley includes: