The Sacramento River West Side Levee District (SRWSLD), with funding from the California Department of Water Resources (DWR), is proposing this project, which would consist of constructing a 1.8-mile-long slurry cutoff wall in the existing Sacramento River West Bank Levee System (SRWBLS), encroachment remediation, waterside hardening, establishment of an operations and maintenance area, and restoration of approximately 11 acres of floodplain for salmonids. DWR investigations have determined that the section of the SRWBLS north and south of, and directly adjacent to, the town of Grimes in Colusa County is vulnerable to seepage. Currently, Grimes is not mapped within a Federal Emergency Management Agency (FEMA) special flood hazard area; however, FEMA has initiated a remapping process for Colusa County. Initial results indicate that without remediation of the Sacramento River levees, FEMA will model the area assuming no levees are present. The goal of the proposed project is to increase flood resiliency to a 100-year level of flood protection to the town of Grimes in a manner consistent with the 2012 Central Valley Flood Protection Plan and its 2017 update, including investments in multi-benefit flood projects (e.g., improvement of salmonid habitat). The construction phase will begin once SRWSLD secures a state or federal implementation grant.