Lower Walnut Creek and Pacheco Marsh Restoration

The Lower Walnut Creek (LWC) Restoration Project, led by Contra Costa County Flood Control and Water Conservation District (District) restores a complex degraded estuarine landscape, creating a diverse range of habitats from tidal marsh to wetland and upland habitats. It integrates pre-existing habitat areas with recently restored landscapes providing sustainable flood protection.

ESA worked with the district for over eight years to implement this award-winning project in along Suisun Bay. From early feasibilty studies through final design and construction, ESA assisted the district navigate a complex permitting process that included extensive outreach and engagement with local businesses, landowners, utilities, governments, and community organizations. Key project elements included the breaching and lowering of USACE managed levees to reintroduce the tidal flows, constructing new setback levees for flood protection, and the grading of filled areas to create new tidal wetland areas. During the construction process, ESA developed and applied several innovative measures for the protection of sensitive species including salt-marsh harvest mouse and nesting marsh birds.

The project has proved a huge success with the contruction of wetland and upland habitats for native and special-status species. This multi-benefit restoration project has become a sustainable flood protection solution for the surrounding community and avoids significant maintenance or dredging. An added benefit is a trail extention corridor for future connections to the Iron Horse Trail and San Francisco Bay Trail. ESA also helped secure $2 million dollars of funding for the Project from CDFW and US EPA’s San Francisco Bay Water Quality Improvement Fund. The project has been recognized by the Northern California chapter of the American Public Works Association (APWA) as the Project of the Year Award in 2023.