Lubbock County, TX Environmental Rules: Flood Elevation Requirements (2026)

Article 5, Section B of the Flood Damage Prevention Order sets the county's one-foot freeboard: new construction and substantial improvement of any residential structure must have its lowest floor, including any basement, elevated to or above one foot above the base flood elevation, certified to the Floodplain Administrator by a registered professional engineer, architect, or land surveyor (Art. 5 § B(1)). Nonresidential structures must meet the same one-foot freeboard or, if floodproofed instead, be built watertight below that level with walls and components rated to resist hydrostatic and hydrodynamic loads, with the specific floodproofed elevation certified and kept on file by the Administrator (Art.

5 § B(2)). Enclosures below the lowest floor that are used only for parking, building access, or storage must have at least two openings on separate walls providing one square inch of net vented area per square foot of enclosed floor space, with the bottom of every opening no higher than one foot above grade (Art. 5 § B(3)). Manufactured homes placed in Zone A must be elevated at least three feet above adjacent grade and anchored against flotation and lateral movement, on top of any state and local wind-anchoring rules; homes placed in Zones A1-30, AH, or AE on a permanent foundation must instead meet the same one-foot base flood elevation freeboard as site-built homes (Art.

5 § B(4)). Where the county has not yet generated base flood elevation data, these freeboard standards apply once that data is produced for a subdivision of 50 lots or 5 acres or more, whichever is smaller (Art. 5 § C(3)).