Santa Clara County, CA Environmental Rules: Flood Zones (2026)

The County Floodplain Administrator, in the Department of Planning and Development, enforces Division B17 Flood Damage Prevention regulations consistent with 44 CFR 60.3. FEMA Flood Insurance Rate Maps for Santa Clara County show Zone A, AE, and AO Special Flood Hazard Areas along Coyote Creek through south San Jose and Morgan Hill, the Guadalupe River and Los Gatos Creek, Uvas Creek near Gilroy, and the Pajaro River at the county line. New construction and substantial improvements in SFHAs must have the lowest floor including basement elevated to at least 1 foot above Base Flood Elevation, commonly called 1 foot freeboard. Non-residential structures may be dry floodproofed instead. Manufactured homes must be elevated on a permanent foundation with anchoring. Substantial improvement means any reconstruction, rehab, addition, or repair equal to or greater than 50 percent of the pre-improvement market value, and triggers full compliance with current standards. Elevation Certificates prepared by a licensed surveyor are required for permit issuance. Mandatory flood insurance applies to federally backed mortgages in SFHAs under the Flood Disaster Protection Act. Valley Water, formerly SCVWD, manages creek and levee systems and runs voluntary floodplain remapping projects that can remove properties from SFHAs through Letters of Map Revision. Violations of Division B17 can result in loss of NFIP participation and administrative fines up to 500 dollars per day.