West Marin Drainage Rehabilitation Mitigated Negative Declaration

Community Development Agency



The project location encompasses three road segments: (1) Point Reyes-Petaluma Rd between the intersections with Hwy 1 and Platform Bridge Rd; (2) Lucas Valley Rd between Big Rock and Nicasio Valley Rd; and (3) Nicasio Valley Rd between Sir Francis Drake Blvd and Lucas Valley Rd.


Environmental Review

Project Contact

Betsy Swenerton, Dept. of Public Works

Project Description

The County is proposing to conduct maintenance activities to rehabilitate existing road pass-through culverts and repair eroded roadside embankments (slip-outs). The proposed project would address culvert deficiencies using a variety of maintenance treatment types specific for each location. Culvert maintenance treatment types may include: extending culvert outfall pipes to avoid flanking or undermining; grouting or lining culvert interiors; paving culvert inverts; replacing damaged sections or failed pipes in-kind; installing larger diameter pipes where culverts are undersized; repairing existing inlet drop structures placing rock riprap at culvert inlets and/or outlets; constructing concrete headwalls; and improving fish passage.