Brazoria County, TX Environmental Rules: Flood Elevation Requirements (2026)

Brazoria County ties structure elevation to FEMA's Base Flood Elevation (BFE) through two provisions of its Subdivision Regulations, effective August 28, 2023. Appendix I, Item 2 requires every subdivision and re-subdivision plat that touches the designated floodplain to carry, on the face of the plat itself, the note that structures on those lots must be elevated to the FEMA Base Flood Elevation and that no development permits will be issued below the BFE. That plat note is mandatory wording, not something a surveyor can vary, and it directs anyone reading the recorded plat to contact the Floodplain Administrator's Office for the specific BFE that applies to that lot.

3, in the plat's engineering and surveying requirements, has the Floodplain Administrator set the minimum slab elevation for each subdivision based on the latest FEMA guidelines, so the elevation figure a builder actually uses is not a single countywide number but one the Floodplain Administrator calculates subdivision by subdivision. Because the county issues no zoning or general building permits, this BFE and slab-elevation requirement is the closest thing unincorporated Brazoria County has to a construction elevation standard, and it is enforced at two points: when the Engineering Department reviews the plat for the required note and slab-elevation figure, and again when the Floodplain Administrator's office issues, or refuses, the floodplain development permit itself.