The Fire Hazard Severity Zone (FHSZ) maps are developed using a science-based and field-tested model that assigns a hazard score based on the factors that influence fire likelihood and fire behavior. Many factors are considered such as fire history, existing and potential fuel (natural vegetation), predicted flame length, blowing embers, terrain, and typical fire weather for the area. There are three levels of hazard in the State Responsibility Areas: moderate, high, and very high.
Fire Hazard Severity Zone maps evaluate “hazard,” not “risk”. They are like flood zone maps, where lands are described in terms of the probability level of a particular area being inundated by floodwaters, and not specifically prescriptive of impacts. “Hazard” is based on the physical conditions that create a likelihood and expected fire behavior over a 30 to 50-year period without considering mitigation measures such as home hardening, recent wildfire, or fuel reduction efforts. “Risk” is the potential damage a fire can do to the area under existing conditions, accounting for any modifications such as fuel reduction projects, defensible space, and ignition resistant building construction.
Government Code 51178
The State Fire Marshal shall 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 shall be 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.
CAL FIRE’s office of the State Fire Marshal (OSFM) has updated the State Responsibility Area (SRA) Fire Hazard Severity Zone (FHSZ) maps effective April 1, 2024.
Local Responsibility Area (LRA) 2025 FHSZ Map Changes Under State Law, Government Code Section 51179 (b)(3), a local agency (BSFPD) SHALL NOT decrease the level of the LRA FHSZ recommended by the OSFM.
A local agency (BSFPD) can make additions to, or increase the level of the LRA FHSZ recommended by the OSFM. BSFPD is not proposing any additions or increases in the LRA FHSZ during this adoption process. The BSFPD is required by state law to adopt by ordinance, the OSFM recommended LRA FHSZ maps within 120 days of release by the OSFM.
The Office of the State Fire Marshal website link below has more information regarding fire hazard severity zones, including videos, FAQ’s, and a map viewer.
Please note, if your property address is in the jurisdiction of the Bonita-Sunnyside Fire Protection District and you would like to submit a comment to Office of the State Fire Marshal on the proposed maps, you may do so at: