Leander, TX Environmental Rules: Flood Elevation Requirements (2026)

072(1) requires that new construction and substantial improvement of any residential structure "have the lowest floor (including basement) elevated at least two feet above the base flood elevation," with a registered professional engineer, architect, or land surveyor certifying to the floodplain administrator that the standard is met. 072(2) gives nonresidential buildings, commercial, industrial or otherwise, a choice: elevate the lowest floor the same two feet, or floodproof the structure watertight with walls substantially impermeable to water and components able to resist hydrostatic and hydrodynamic loads, backed by an engineer's or architect's certified design kept on file with the floodplain administrator.

072(3) requires flood vents that automatically equalize hydrostatic pressure: a minimum of two openings on separate walls providing at least one square inch of net area per square foot of enclosed area, with the bottom of every opening no higher than one foot above grade, unless an engineer or architect certifies an equivalent design. 072(5) only if they stay on site fewer than 180 consecutive days or remain licensed, wheeled, and ready for highway use with no permanent additions; otherwise they must meet the same manufactured-home elevation and anchoring requirements. 073(c) if it isn't otherwise available, so the two-foot freeboard can be verified before lots are even platted.