County of Marin - News Releases - Hillside Failure

For Immediate Release
March 23, 2023

Marin County Monitoring Hillside Slope Failure

Erosion event near Novato prompts multi-agency response to monitor, stabilize

The following is a joint news release between the Marin County Fire Department and the Novato Fire District

San Rafael, CAThe County of Marin is actively monitoring a mudslide that occurred Tuesday evening, March 21, on a slope above Redwood Boulevard, just west of Marin County Airport (Gnoss Field). The site is state property within unincorporated Marin and the Novato Fire Protection District boundary.

The slip caused significant erosion on the hillside, uncovering one of two PG&E natural gas main lines and possibly creating pressure on a North Marin Water District aqueduct that runs from Sonoma County to Marin. No gas line or water line breech has occurred to date. No observable movement has occurred since Tuesday night and there is no immediate threat to residents.

PG&E and North Marin Water are on site assessing and determining options to stabilize the hill and prevent further slip to protect infrastructure. PG&E is also de-pressuring lines out of an abundance of caution.

In addition, the slide moved a significant amount of water and mud in the immediate area and caused parts of the road below to buckle and break between an approximate 100 foot stretch of road. That portion of the frontage road, which runs adjacent to southbound Highway 101, will remain closed until further notice. There is no threat to, or closure of, Highway 101.

There are no residential structures in the immediate area. Current conditions do not warrant evacuation of the broader area.

Marin County Office of Emergency Management will continue to coordinate with PG&E to gather updated information about the incident and any change in conditions that may threaten the safety of residents. If conditions change, the Office of Emergency Management will send emergency alerts via AlertMarin.



Steven Torrence
Marin County Fire Department, Office of Emergency Management

Emergency Operations Facility
1600 Los Gamos Drive
San Rafael, CA 94903
(415) 473-6584
Email: Steven Torrence
Fire website