Bolinas Road Slide Repairs – mileposts 1.27, 2.12 & 2.19

Overview

The March 2023 storms triggered multiple landslides and roadway damage along Bolinas Road. The damaged locations have been receiving repairs in order of urgency. The road is the sole route for hundreds of homes and provides critical access for wildland firefighting. The road is also the only way to reach water treatment facilities that supply drinking water for one-third of Marin Water’s customers.

This project will address three landslide locations: Mileposts 1.27, 2.12, and 2.19. The scope will generally include construction of retaining walls to stabilize the roadway at each damaged section and repair related road damage. These locations are about 1.5 to 2.5 miles west of downtown Fairfax, approximately 1000 feet south of the intersection of Sky Oaks Rd, and extending north to the Meadow Club.

Funding

The combined construction total for each location is expected to be $2.8M although total costs are subject to change with continued geotechnical review and investigation. The County has reported the damages to the Federal Highway Administration (FHWA) and is expected to receive an 88% reimbursement through an FHWA grant.

Traffic impacts

• The Westbound lane of Fairfax Bolinas Road will be fully closed for the duration of the project from approximately MP 2.10 to MP 2.21 (Between 900 and 955 Bolinas Road).
• One-lane, two-way traffic will be in effect, controlled by temporary traffic signals.
• Maximum wait time/delay of 5 minutes to be expected 24 hours, 7 days a week, through the end of the project.
• Road closures are not anticipated at this time. If a road closure during the day becomes necessary for select tasks, notification will be issued at least 7 days in advance.

For the safety of motorists, bicyclists, and the construction crew, please be patient.  

Timeline

2024

• Design phase
• September 25 and 26: On-location data collection activities. Intermittent traffic delays of up to 5 minutes.

Fall 2025

• Construction of an approximate 70-foot-long  retaining wall at milepost (MP) 2.12 and an approximate 120-foot-long retaining wall at MP 2.19 on Fairfax Bolinas Road in unincorporated Fairfax began on November 10, 2025.
• The site is approximately located 0.1 miles west of Fresa Avenue and .01 miles east of Meadow Club Road, and work is expected to extend through January 2026.
• Construction hours will be from 7 AM to 5 PM (Monday to Friday). Some work from 9 AM to 5 PM on Saturdays may also be necessary to protect certain construction phases from rain.
• There will be no work on Thanksgiving Day, the day after Thanksgiving, Christmas Eve, Christmas Day, or New Year's Day.

For questions, please reach out to:

Rachel Calvert, Project Manager
Marin County DPW
415-246-5017

Dan Valley, Resident Engineer
MNS Engineers
408-404-4964

Mark Shinn
Advanced Geotechniques, Inc.
916-768-3955