Description: The California State Fire Marshal is required to identify areas in the state as Moderate, High, and Very High Fire Hazard Severity Zones based on consistent statewide criteria and based on the severity of fire hazard that is expected to prevail in those areas. Moderate, High, and Very High Fire Hazard Severity Zones are based on fuel loading, slope, fire weather, and other relevant factors including areas where winds have been identified by the Office of the State Fire Marshal as a major cause of wildfire spread.In 2007, CAL FIRE updated the FHSZs for the State Responsibility Area (SRA). Between 2008-2011 the department worked with local governments to make recommendations for the Very High Fire Hazard Severity Zones within Local Responsibility Area (LRA). The hazard maps are being updated to more accurately reflect the zones in California that are susceptible to wildfire. CAL FIRE used the best available science and data to develop, and field test a model that served as the basis of zone assignments. The model evaluated the probability of the area burning and potential fire behavior in the area. Many factors were included such as fire history, vegetation, flame length, blowing embers, proximity to wildland, terrain, and weather. CAL FIRE updated the Fire Hazard Severity Zones (FHSZ) for State Responsibility Areas (SRA) (maps effective April 1, 2024). Using these same processes and models, CAL FIRE updated the FHSZs for LRA, releasing the updated maps February 25, 2025. These updated maps were adopted locally, and ratified by the Marin County Board of Supervisors June 24, 2025.
Service Item Id: 7083bdf3f34a482abfd711e378f59812
Copyright Text: CAL FIRE recognizes the important contribution of various local government entities that contributed data, maps, and comments that were critical components of the FHSZ mapping process.