The purpose of the Marin City Pond Flood Reduction Project is to make several improvements to the stormwater drainage and pond system . This includes a new pump station near Highway 101 to improve drainage out of the pond to the bay.
The initial plan was for a trenchless installation of the culvert. After further geotechnical analysis in August 2021, this approach was found to be technically infeasible. Issues around the subsurface soils make trenchless installation risky and prone to failure.
The project team developed a new design with a pump station and flood wall at the edge of the pond that uses the existing pipe under US 101 to drain flood waters. These proposed improvements reduce flood risk under current and sea level rise conditions as compared to existing conditions
A contract for design, permitting and environmental analysis was awarded in March 2021. The District has requested CalOES extend the design timeline from March 2023 to 2024.
The District anticipates conducting a wetlands assessment, topographic survey and a geotechnical boring for the pump station project component in January 2023.
The budget for design, permitting and environmental analysis contract is $773,000.
The cost for the new design approximately $9 million. This is more than double the original amount. To fill this funding gap, we requested a scope change from the Federal Emergency Management Agency (FEMA) to increase the grant amount. In the same request, we also asked for $2 million to dredge the pond.
Before we can proceed with design, we need confirmation from FEMA that they will increase the grant. FEMA has not provided a timeline for review and approval of the proposed grant scope and budget change.
Agencies and partners
- Marin County Flood Control & Water Conservation District
- California Office of Emergency Services (CalOES)
- Federal Emergency Management Agency (FEMA)
- Audubon California
- Marin City Climate Resilience and Health Justice
- Marin City Community Service District