Marin City area flood board mulls stormwater survey

Over 20 projects were presented to more than 200 respondents and given report-card style scoring. 

High capacity inlets, more bypasses, and upgraded pipes are among the solutions proposed to reduce persistent flooding in Marin City.

County staff presented the results of an in-person and online survey conducted throughout June at a Marin County Flood Control District 3 meeting on Tuesday. Over 20 projects were presented to more than 200 respondents and given report-card style scoring.

“I think this all looks really promising,” vice chair Kevin Conger said.

The stormwater project aims to help to address an ongoing problem in Marin City, which has experienced notorious flooding for decades. Judd Goodman, a senior engineer with the county and the project manager, said the final product will be a hybridization of the proposed projects.

Each concept was evaluated for its effectiveness in reducing flooding and how well it meshed with residents’ environmental and health values, which was collected through community surveys and meetings. It was then given a GPA and grade between A and F. Goodman said more survey results need to be analyzed and included.

Some baseline projects are already underway and currently in the design phase, including a permanent floodwall along Highway 101, a pump station at the stormwater pond, and upsizing drainage pipes at the shopping center.

These projects alone, which staff hope to have under construction by 2026, could elevate the area’s flooding score from a D+ to a C+.

“That’s just our starting point, with the Marin City Stormwater Plan we’re looking to go above and beyond that,” Goodman said.

The proposed concepts are in the upper watershed — the higher, more natural landscape — and the lower watershed, which is the flatter and flood-prone area.

Performing maintenance and repair to existing infrastructure in the upper watershed could bring the overall grade to an A, and adding higher-capacity inlets at Waldo Court, trash racks in ditches, and connecting pipes all score within the B+ to A range overall on the draft report card.

Proposals that could improve flooding in the lower watershed include a bypass to a new outfall to the bay along Phillips Drive, a bypass from the library to the bay, a watershed detention area near Drake Avenue, and elevating Drake Avenue and Donahue Street.

Raising Drake Avenue and Donahue Street did not score well — either in flood reduction effectiveness or in reflecting community values, earning a C+ overall.

During the meeting, activist Terri Green resigned from the board, saying she felt there was discrimination and unfair treatment toward Marin City residents. She said staff needed to do more to include residents.

“There’s no place for anybody to go and ask questions,” Green said. “You don’t treat us like we’re real human beings, like we matter. I’m not feeling really good about this process.”

A task force meeting is scheduled for September and a community meeting in October. Staff hope to publish the plan by fall.