DeSoto, TX Environmental Rules: Coastal Development (2026)

Dallas County has no coastline, so Tex. Nat. Res. Code Ch. 61 (Open Beaches Act) and General Land Office coastal-construction rules do not apply. Dallas County participates in the National Flood Insurance Program and administers floodplain rules through the Department of Unincorporated Area Services (DUAS) and Public Works. A Floodplain Development Permit is required before any grading, fill, structure, fence, or accessory building in a FEMA SFHA in unincorporated areas — and per DUAS, most unincorporated Dallas County land sits in the Trinity River floodplain, so a permit (or a verification letter showing the site is outside the SFHA) is the default starting point for any project. Floodway encroachment is prohibited unless FEMA issues a Conditional Letter of Map Revision (CLOMR) confirming no rise in the base flood elevation. Required submittals typically include an Elevation Certificate, topographic survey, and engineered no-rise analysis. Dallas County also participates in the Trinity River Common Vision Program coordinated by the Trinity River Authority. Inside city limits (Dallas, Garland, Mesquite, Irving, Richardson, etc.), the city's floodplain administrator — not the county — issues permits. Confirm jurisdictional waters and floodplain status with DUAS at 214-653-6565 or development@dallascounty.org.