The portable pump station project is designed to reduce the severity of localized flooding along Donahue Street, a key thoroughfare in the unincorporated neighborhood that has been chronically impacted by roadway flooding during storms and high tides. Marin City, which is adjacent to Richardson Bay, often becomes flooded during heavy storms, especially when those storms coincide with high tides. The localized flooding impacts Donahue Street and impedes access to the Highway 101 ramps, restricting mobility for Marin City residents and visitors who must wait until the stormwater slowly drains out to Richardson Bay after a storm.
This project includes constructing two temporary, underground sumps with two trailer-mounted portable pumps, and connecting the existing storm drainage system along Donahue Street to the sumps via new drainage structures and pipes. The portable pumps are intended to be deployed prior to significant storms and pump stormwater through two pipes approximately 1,400 feet to a stormdrain structure adjacent to the Marin City Pond, located northeast of the Gateway Shopping Center. The stormwater will then be discharged into Richardson Bay.
The functional benefit will be a reduction in the depth and duration of flooding on Donahue Street and the Highway 101 ramps (which are owned and maintained by California Department of Transportation). The improvements will allow vehicle access following storms to return faster than before. However, the portable pump station’s system will not be large enough to fully prevent roadway flooding at the location after storms and high tides. This is a first step in a series of projects in Marin City, and more improvements are planned to further reduce the flooding on Donohue.
Timeline
Late September 2024
October 2024
- Operations management contract expected.
Mid-Winter 2024/25
- Expected project completion, pumps operational.
Public Impacts
Construction of the pump station’s sumps and related underground work will take place on weekdays during daytime hours with traffic control measures. Some lane closures may be required for specific construction activities, so traffic delays are possible, but access will be provided for the Gateway Shopping Center businesses and for emergency service vehicles.
Funding
The total estimated cost of the portable pump station project is $2.5 million (including $1.37 million for the underground work) which is funded under the Zone 3 (Richardson Bay) budget. The project is supported with state funding secured by State Senator Mike McGuire and administered by the Transportation Authority of Marin.
Zone
Zone 3: Richardson Bay
