San Bernardino County, CA Environmental Rules: Flood Zones (2026)

San Bernardino County participates in the National Flood Insurance Program (NFIP) and enforces floodplain development standards through the Floodplain Management Ordinance and FEMA Flood Insurance Rate Maps (FIRMs). Properties in Special Flood Hazard Areas (SFHAs) designated Zones A, AE, AH, AO, AR, A99, V, or VE face specific construction requirements. New residential construction and substantial improvements (50 percent or more of market value) must have lowest floor elevated at least 1 foot above Base Flood Elevation (BFE) to meet County freeboard standards. Elevation Certificates signed by a licensed surveyor or engineer are required. Non-residential structures may use flood-proofing alternatives with engineer certification. Mandatory flood insurance applies to federally-backed mortgages on SFHA properties. Fill in floodways is prohibited without engineering studies showing no increase in BFE under Title 44 CFR 60.3. The San Bernardino County Flood Control District maintains major drainage infrastructure and enforces easement protections. Desert and mountain areas have alluvial fan flooding hazards not always mapped on FIRMs, requiring site-specific analysis. Community Rating System (CRS) participation may provide premium discounts for flood insurance in participating communities.