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 to diverse range of native wetlands habitats that have almost entirely been lost along the southern shoreline of Suisun Bay. The Project reconnects and expands formerly fragmented wetlands, while providing sustainable flood protection and climate change resilience.

ESA worked with the district for over eight years to plan, design, permit, and implement this award-winning project along Suisun Bay. ESA led the design from concept through final bid documents, including feasibility studies, flood analysis, integrated restoration ecology, and grading and planting design.

Key project elements included extensive grading to create new tidal wetlands, breaching and lowering existing levees, and constructing new flood protection levees and native planting. ESA prepared the CEQA documentation and assisted the district navigate a complex permitting process that included extensive outreach and engagement with local businesses, landowners, utilities, governments, and community organizations. ESA performed engineering support and biological monitoring during the construction process, including applying innovative measures to protect sensitive wildlife including salt-marsh harvest mouse and nesting marsh birds.

ESA is performing post-construction monitoring, which confirms the project’s early success in achieving project goals. 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 extension corridor for future connections to the Iron Horse Trail and San Francisco Bay Trail. ESA also helped the District secure approximately 12 million of dollars of grant funding for construction from various public agencies.

The project has been recognized by the American Public Works Association (APWA) with 2023 Project of the Year Award in the Environment $5 million but less than $25 million category.