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

Tarrant County is subject to significant flood risk along the Trinity River, West Fork of the Trinity, Clear Fork, Big Fossil Creek, Mary's Creek, Sycamore Creek, and numerous smaller streams. The county participates in FEMA's National Flood Insurance Program (NFIP) and administers floodplain development in unincorporated areas through the Tarrant County Floodplain Administrator within Public Works. FEMA Flood Insurance Rate Maps (FIRMs) for Tarrant County identify Special Flood Hazard Areas (SFHAs, Zones A and AE) and floodways. Any development in the SFHA including new construction, substantial improvement (50% of market value), fill, excavation, and grading requires a floodplain development permit. New residential structures must have the lowest floor (including basement) elevated to or above the base flood elevation plus freeboard; Tarrant County typically requires 1 foot of freeboard. Non-residential structures may be floodproofed instead. The floodway is more restrictive: no development that would increase base flood elevations by any amount is allowed unless a no-rise certification is prepared by a Texas-licensed engineer. Substantial improvement triggers full code compliance and elevation even for older structures. Incorporated cities (Fort Worth, Arlington, Mansfield, Grapevine, etc.) administer their own NFIP programs with their own maps and may require more freeboard (e.g., Fort Worth and Arlington typically require 2 feet).