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

Dallas County Code Sec. 42-32 makes the Regulations apply to "all areas of special flood hazard within the jurisdiction of Dallas County" and requires a Development Permit "to ensure conformance with the provisions of these Regulations or Court Orders." No structure or land in the mapped floodplain may be built, altered, or have its use changed without full compliance, including compliance with the county's Subdivision Regulations and County Road Construction Standards under Court Order 2017-1621.

Permit applications go to the Floodplain Administrator, a role assigned under Sec. 42-33 to the Director of the Dallas County Public Works Department. Projects larger than 50 lots or five acres, whichever is smaller, must submit duplicate scaled plans showing lot elevations, the location of proposed and existing structures (including manufactured homes), and their position relative to the special flood hazard area. Applicants proposing a nonresidential flood-proofed structure must also include an engineer's or architect's certification meeting the flood-proofing criteria in Article 5, Section B(2).

Before approving or denying a permit, the Floodplain Administrator weighs the danger to life and property from flooding, the site's susceptibility to damage, the effect on emergency-vehicle access, and the cost of maintaining streets, bridges, and utilities during and after flood conditions. Where no floodway has been designated, no fill or development is allowed in Zones A1-30 and AE unless it is shown the cumulative effect will not raise the base flood elevation more than one foot at any point in the community.