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

The county's Flood Damage Prevention and Building Regulations apply countywide to unincorporated land only (Art. 3 § A) and adopt by reference FEMA's Flood Insurance Study for Cameron County and its Flood Insurance Rate Maps and Flood Boundary-Floodway Maps (Art. 3 § B) as the basis for mapping the special flood hazard areas. A Building Permit is required for any development in a mapped area before work starts (Art. 3 § C), and no structure or land use may change without full compliance with the order (Art.

3 § D). Article 5 § A sets the elevation standard: the finished floor must sit 12 inches above the Base Flood Elevation, the estimated BFE, or the FIRM depth number, or 24 inches above the highest adjacent natural grade, whichever is higher; where the FIRM lists no depth number, 24 inches above natural grade governs. Fill compaction must follow TxDOT Item 132, footings must extend at least 12 inches below undisturbed soil, and elevated foundations must be engineered to resist hydrodynamic and hydrostatic forces.

Article 5 § B adds that in mapped special flood hazard areas, new residential construction must have its lowest floor elevated to or above the base flood elevation, certified by a registered professional engineer, architect, or land surveyor to the Floodplain Administrator; nonresidential structures may instead be floodproofed and certified watertight below the base flood level. Requests to change the mapped floodplain (LOMA/LOMR) go through the Floodplain Administrator or Building Official before FEMA review (Art. 4 § L).