Second Culvert Project on US-101 in Marin City

Project Overview

Flooding affects the entire California Highway System, and Caltrans is looking for ways to mitigate the issue, especially with sea-level rise expected to affect the region in the next 100 years.

With the Second Culvert Project on US-101 in Marin County, Caltrans proposes to build a 6-by-4 culvert that will help mitigate flooding in the Marin City area. The location is near Marin City from Donahue Street to 0.3 miles north of Donahue Street.

The Draft Environmental Document (DED) for this project is scheduled to be circulated externally in June, 2025.

Caltrans will host a hybrid (in-person and virtually via Zoom) public meeting on Wednesday, June 18 from 6 to 7:30 p.m. (doors will open at 5:30 p.m.) at the Marin City Senior Center, 640 Drake Ave, Marin City, CA. 94965.

At this meeting, attendees will have the opportunity to learn about the project and ask questions. Join us in person, or go to CaltransD4Environmental.com for information on how to join virtually.

Submit a comment in writing during the public comment period, from Wednesday, June 4 to Monday, July 7, 2025. Send by mail to Caltrans District 4, Office of Environmental Analysis, ATTN: Christopher Pincetich, P.O. Box 23660, MS 8B, Oakland, CA 94623-0660, or by email to Marin_City_Second_Culvert_Project@dot.ca.gov.

Project Schedule

The project is scheduled to go into construction in 2027.

Caltrans is coordinating with Marin County and the Marin City Stormwater Task Force, which includes a county project, permanent pump station and floodwater within project limits.

Please send questions to marin_city_second_culvert_project@dot.ca.gov

Project Contact

Matt O’Donnell
Marin County Public Information Officer
Email: matt.odonnell@dot.ca.gov