Heavy Rains Flood Marin County Highways
A series of storms has brought heavy rainfall to Marin County, with some areas receiving over four inches since Sunday. The downpour has led to significant flooding on parts of Highway 101, disrupting commutes in the Bay Area.
- This series of storms is not an isolated event; in early January 2026, a combination of an atmospheric river and king tides caused the worst coastal flooding in the county in nearly three decades, submerging parts of Highway 101 in 2 to 3 feet of water. - The recent downpour included 2.75 inches of rain recorded at the Marin Civic Center and 2.53 inches in Mill Valley, contributing to already saturated ground from a wet winter. - Flooding of Highway 101 is a recurring issue, particularly around the Lucky Drive and Seminary Drive exits, which also experienced closures during the major floods in January 2026. - Marin County has a history of severe flooding, including a major storm in January 1982 that triggered thousands of debris flows and caused an estimated $280 million in total storm-related losses. - To combat recurring floods, the Marin County Flood Control and Water Conservation District has initiated several projects, including the Corte Madera Creek Flood Risk Management Project and the 2024 installation of a portable pump station in Marin City to protect Highway 101 ramps. - While causing hazardous conditions, the intense rainfall has significantly boosted local water reserves; as of mid-February 2026, Marin's reservoir storage levels were at 117% of the historical average for the date. - The current weather is characteristic of an "atmospheric river," a concentrated plume of moisture. Forecasters warn that these systems, combined with saturated soils, increase the likelihood of downed trees, landslides, and widespread power outages.
