Winter Weather Storms & Flooding
Flood History
In recent history, the winter storms of 1970, 1973, 1982, 1983,1986,1998, 2005 and 2006 caused significant damage. Novato Creek in the northern part of the county historically caused damage to large numbers of homes in the 1960’s until the Novato Flood Control Project was completed in the 1980’s.
Corte Madera Creek has had a history of flooding with the largest recorded flow in the winter of 1982 and more recently in December 2005 and January 2006, causing severe damage to the surrounding communities. Widespread localized flooding occurred in almost all areas of the County in this past winter storm. San Anselmo, Ross, Fairfax, and Mill Valley were the most heavily impacted. Power outages peaked at 10,000 customers in January. Nine schools closed due to mud, water and road damages and over 20 major roads were closed during the early part of the storm. Two levies in the Novato area were damaged. Over a thousand homes, apartments and businesses were damaged or destroyed.
Types of Flooding
- Waterways
Floods are generally classed as either slow-rise or flash floods. Slow-rise floods may be preceded by limited warning time. Evacuation, sandbagging and other preventative measures for a slow-rise flood may lessen flood-related damage. Conversely, flash floods are difficult to prepare for due to extremely short warning time. Flash flood warnings usually require immediate action within the hour. Flood waters can cause road closures and sweep away objects and people. - Debris Flow
In Marin County, flash flooding is not as critical a threat as is the debris flow including landslides caused by excessive rainfall that can cause serious damage. - Coastal Flooding
Winter storms can generate heavy wave action along the coastal areas which, combined with high tides, can initiate flooding along the ocean and bay coastlines. - High Tides
High astronomical tides over 7 feet are known to occur during winter storm weather causing flooding along the coast and impacting lands adjacent to Bay and River fronts.
NWS – San Francisco Bay Area Office
Marin County Real-Time Rainfall, Creek Data, & Weather Stations
Marin County Winter Storm Information Sheet
