Ross Valley flood project gets new $1.6M influx

A multifaceted flood control project in the Ross Valley has received $1.6 million in federal funding for creek work slated to start next year.

The grant is a second installment authorized by the California Coastal Conservancy, bringing the funding total to $2.2 million. The funds will support work to remove 1960s-era concrete walls from the Corte Madera Creek and restore wetlands near the College of Marin campus in Kentfield.

Marin County planners are planning a public forum on Tuesday, Oct. 15, to discuss the construction that is set to begin in the summer. The event is from 6:30 to 8 p.m. in the student center at Marin Catholic High School at 675 Sir Francis Drake Blvd. in Kentfield.

“The open house is a great opportunity to talk with community members one on one and answer their specific questions about the upcoming work,” said Berenice Davidson, the county’s assistant director of public works.

Participants will be able to meet with district staff to get an overview of the project, the progress made so far and what’s coming. Project maps and renderings will be on display.

Corte Madera Creek is an important part of the estuary in the Ross Valley. The creek has been degraded by a concrete channel that was constructed in the 1960s by the U.S. Army Corps of Engineers for flood control.

Sandy Guldman, president of the nonprofit Friends of the Corte Madera Creek Watershed, said the project “is an important first step in reversing some of the environmental damage done when the concrete channel was constructed.”

Friends of the Corte Madera Creek has been working with flood planners to get the project going for years.

“This will restore some tidal wetland, transition zone and upland habitats and promote more natural movement of sediment and better connection with groundwater, while accommodating the floodwater delivered from upstream,” Guldman said.

The project is part of the larger $18 million Corte Madera Creek flood risk reduction project. The project area is from Lagunitas Road in Ross to the earthen channel in Kentfield.

The effort aims to reduce the frequency and severity of flooding, protecting the community from 25-year flood events. The modifications to the concrete channel are designed to improve the way the creek functions.

Work began in 2022 with construction of a maintenance access ramp. Construction on a pump station in the Granton Park neighborhood of Kentfield began in 2023 and wrapped up this year.

“The new stormwater pump station will be able to actively pump water into the Corte Madera Creek concrete channel that was previously unable to drain by gravity when there were high flows in the creek channel,” said Tracy Clay, the county’s flood control and water resources division manager.

After the creek work in 2025, the final phase of the project is expected to begin and wrap up in 2026.

That phase involves improving fish resting pools along the bottom of the concrete channel. A portion of the fish ladder in the section of the creek that runs through Ross will be removed to transition to an earthen channel upstream. Sections of concrete channel walls in Ross and Kentfield also will be raised.

Marin County Supervisor Katie Rice, whose district includes the Ross Valley, said the project is “critical for increasing the viability of the watershed to support native fish populations.”

“This project — being multiphase and occurring over multiple years, and much of it out of sight of the majority of residents — is likely not on the radar of most folks,” Rice said.

The public forum will offer a chance for residents to become reacquainted with the project, and for some to learn about for the first time.

“It’s also an opportunity for residents to be reminded of the significant flood risk the Ross Valley faces every winter, and the projects underway to reduce that flood risk,” Rice said.