Bexar County, TX Environmental Rules: Flood Zones (2026)

Bexar County is a participating community in the National Flood Insurance Program and has adopted a Flood Damage Prevention Order to meet FEMA and Texas Water Code Chapter 16 floodplain management requirements. In unincorporated Bexar County, any development in a FEMA Special Flood Hazard Area (Zones A, AE, AO, and the floodway) requires a floodplain development permit from Bexar County Public Works before construction. Residential structures must have their lowest floor, including basement, elevated at least 1 foot above the base flood elevation; Bexar County effectively requires 1 foot of freeboard above the BFE. Non-residential structures may be elevated or dry-floodproofed. Encroachments in the regulatory floodway that would increase the base flood elevation more than the allowable 0 foot rise are prohibited without a Conditional Letter of Map Revision from FEMA. Bexar County has extensive flood risk along the San Antonio River, Cibolo Creek, Salado Creek, and Leon Creek, and flash flooding from Hill Country thunderstorms is a major regional hazard. Property owners can request Elevation Certificates and Letters of Map Amendment where mapping overstates risk. NFIP Community Rating System participation can reduce flood insurance premiums for policyholders.