Dallas, TX Environmental Rules: Flood Zones (2026)

Sec. 105(a)(1) requires a person to obtain 'a fill permit or a floodplain alteration permit from the director of water utilities' and all other county, state, and federal permits before depositing or storing fill, placing a structure, excavating, or engaging in any other development activity in an FP area. A fill permit lets the property be developed at a specified elevation; the director maintains a record of every fill and floodplain alteration permit issued. Subsection (b) lets the director issue a floodplain alteration permit only if the alteration does not remove the FP designation and meets the engineering requirements in Subsection (g), and the director may require hydrologic or hydraulic modeling for projects such as pools, decks, retaining walls, or fences that could block the flow of flood water during a 100-year flood event.

Larger projects trigger a preapplication conference under Subsection (d), where water utilities staff determine what vicinity maps, acreage figures, hydraulic analysis, and drainage area maps are needed. Applications that seek to remove an FP designation entirely go through additional review under Subsection (e): the director circulates the application to development services, the chief planning officer, and parks and recreation for comment on environmental impacts, zoning concerns, and whether the property should instead be considered for public acquisition, and the water utilities department must schedule a virtual or in-person neighborhood meeting, with written notice sent at least 10 days ahead to every owner within 500 feet of the property.

This permit system sits alongside the separate 500-year flood construction standards elsewhere in Article V, and a FEMA Letter of Map Change is additionally required before an FP prefix can be removed from the official zoning map.