Lower Walnut Creek Restoration Project

Walnut Creek Watershed
The Walnut Creek watershed is the largest in Contra Costa County, draining over 150 square miles, and containing eight cities and over 300,000 residents. The lowest, or most downstream, portion of this watershed is called Lower Walnut Creek, and it consists of a wide trapezoidal earth channel with levees on one or both sides. It is populated with a diverse assortment of wildlife both in the water and in the adjacent marshlands.

Sediment Buildup & Restoration
The channel is heavily impacted by sediment and has partially silted up, which affects its flood carrying capacity. But removing the sediment also removes the habitat and wildlife, and the sediment would quickly return. Something needs to be done. But what is the best solution? The Flood Control District feels a restoration project is the answer.

This web page is focused on the Flood Control District’s Lower Walnut Creek Restoration Project, which re-evaluates the antiquated design and revisits the required maintenance practices of the Lower Walnut Creek flood control channel.

Long-Term Vision
The Flood Control District’s long-term vision is to have a sustainable channel that provides critical flood protection in a way that is more compatible with the plants and animals that call the creek home.

This can likely be accomplished by:
  • Creating additional wetlands, riparian habitat, and revegetation potential
  • Moving back the channel levees in the lower reaches to provide additional capacity for floodwaters
  • Reducing de-silting costs 

Other objectives include improving the level of flood protection and expanding recreation opportunities along the creek.

Additional Information
For more details about the watershed and the project, click on the menu choices to the left. If you have questions on this project or on other Flood Control District restoration projects, please contact Paul R. Detjens.