For Immediate Release –
Marin City, CA –
The effort is designed to reduce flooding on Donahue Street and Highway 101 ramps
The Marin County Flood Control and Water Conservation District has awarded a $1.37 million construction contract for the underground components of a portable pump station in Marin City. The underground work is expected to start shortly after Labor Day and the project is expected to be completed by mid-winter. The completion will mark the first implementation in a series of new flood risk reduction infrastructure planned for Marin City.
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. The total estimated cost of the project is $2.5 million, including the $1.37 million in underground work, which is funded under the Flood 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.
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 installation of the 1,400 feet of pipes is included in this construction phase.
Construction of the pump station’s sumps 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.
Once the construction work has been completed, the two trailer-mounted portable pumps and related elements will be purchased. Depending on the availability of various components, it is anticipated that the portable pump station will be operational by mid-winter.
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, and more improvements are planned to further reduce the flooding on Donohue.
The portable pump station on Donahue Street will provide an immediate positive impact while the District pursues several other flood mitigation elements to be installed at or near the Marin City Pond. Those potential projects are awaiting federal funding and the current grant request is for approximately $12 million. The proposed improvements include a permanent pump station at the pond, a floodwall and multiple storm drain upgrades.
The proposed permanent pump station will be larger and significantly more powerful than the portable station that is being installed this winter. The portable station is currently funded for three years of operation or until the permanent pump station is operational.
Separate from the efforts detailed above, the District has a watershed-wide Marin City Stormwater Plan already underway. The purpose of the plan is to identify an updated list of projects that could be constructed by local and state agencies to alleviate flooding in the unincorporated neighborhood. The Stormwater Plan is distinct from prior studies in that it will result in a public infrastructure plan developed with direct input from Marin City residents and organizations. The in-depth effort is in partnership with various other public agencies that have responsibilities within the watershed.
Contact:
Berenice Davidson
Assistant Director
Public Works
3501 Civic Center Drive.
#304
San Rafael, CA 94903