Portable Pump Station Proposed for Marin City

For Immediate Release –

San Rafael, CA –

State funding to reduce flooding severity on Donahue Street

Marin City residents and visitors, chronically hampered by roadway flooding during severe storms and high tides, could find some transportation relief by next winter if a proposed portable pump station is approved on March 21. The planned project is designed to reduce the severity of localized flooding along Donahue Street, a key thoroughfare in the unincorporated neighborhood.

Staff from the Marin County Flood Control and Water Conservation District will present the project to the District’s Board of Supervisors during the public session next Tuesday. If approved, District staff would then move forward with next steps, including working with Caltrans on the environmental permitting phase. It is anticipated that construction could begin sometime in fall/winter 2023.

The estimated cost of the project, which includes operations and maintenance for three years, is $2.1 to $2.8 million. It will be covered by the $10 million in state funding secured by state Senator Mike McGuire in 2022.

Marin City, which is adjacent to Richardson Bay, can become flooded during significant storms, especially when those storms are occur during high tides. The localized flooding impacts Donahue Street and impedes access to the Highway 101 ramps, restricting mobility of Marin City residents and visitors who must wait until the floodwater slowly drains out to Richardson Bay after a storm.

This project includes installing a sump at the low point elevation along Donahue Street at the Drake Avenue intersection, which will be pumped by portable pumps that are brought to the location in advance of major storm events. During and after the storms, the portable pump station would convey floodwater through an above-ground pipeline along Donahue Street, ultimately discharging the floodwater into Richardson Bay.

The pump system will not be large enough to prevent roadway flooding at the location following significant storms and high tides. The functional benefits would be to reduce the depth and duration of the flooding on Donahue Street and the Highway 101 ramps (which are owned and maintained by Caltrans). The improvement would allow vehicle access after storms to return faster than before the pump system was installed.

The project on Donahue is intended to provide an immediate positive impact while the District pursues several other flood mitigation elements to be installed near the Marin City Pond. Those potential projects are awaiting federal funding and the current grant request is for approximately $10 million. The proposed improvements are a larger, permanent pump station, a floodwall and storm drain upgrades.

Separately from the efforts detailed above, the District is also initiating a watershed-wide Marin City Stormwater Plan to identify an updated list of other projects that could be constructed in Marin City by local and state agencies to alleviate flooding impacts. The Stormwater Plan is distinct from the prior studies in that it will result in a public stormwater infrastructure plan developed with direct input from Marin City residents and organizations in partnership with the various public agencies that have responsibilities within the watershed. More information will be available on the Stormwater Plan as the work progresses.