Murrieta, CA Fire Regulations: Wildfire Zones (2026)

4 to the California Fire Code, targeting new construction in fire hazard zones designated by the Director of Forestry and Fire Protection (CAL FIRE). Any new building constructed or installed within a High or Very High Fire Hazard Severity Zone must meet increased minimum fire-flow requirements: 500 gallons per minute above the standard requirement, delivered at a residual pressure of 20 psi, sustained for a minimum duration of two hours. The only exception written into the section applies where the entire project is built to comply with the current Insurance Institute for Business & Home Safety (IBHS) Wildfire Technical Standards; in that case, the project may use the standard fire-flow table in Appendix B without the added 500 gpm.

This sits alongside the base fire-flow table in the same appendix, which sets minimum required fire-flow and duration by building size and occupancy, for example requiring a 2-hour minimum duration for developments up to 2,500 square feet for multi-family, 3,000 for commercial, and 3,500 for industrial before the wildfire-zone increase is layered on top. 4 in the un-amended state Fire Code appendix. Because the increase is measured against water-system delivery capacity, it typically drives larger water mains, additional fire hydrants, or on-site storage for projects sited in the mapped zones, and compliance is verified by the fire code official during plan review before building permits are issued.