San Angelo, TX Environmental Rules: Flood Elevation Requirements (2026)

Sec. 008(b)(1) sets San Angelo's residential freeboard: in any area of special flood hazard where base flood elevation data exists, new construction and substantial improvement of a residential structure, including any basement, must have its lowest floor elevated to whichever is more restrictive of two feet above the base flood elevation, one foot above the fully developed 100-year flood elevation, or one foot above the 500-year flood elevation. A registered professional engineer, architect or land surveyor must certify the elevation to the floodplain administrator, a duty assigned to the city engineer under Sec.

003. Subsection (b)(2) holds nonresidential buildings, such as commercial or industrial structures, to the same two-foot freeboard unless the owner instead floodproofs the structure watertight below that level with an engineer's certified design. Enclosures below the elevated lowest floor used only for parking, building access or storage must equalize hydrostatic pressure with at least two one-square-inch openings per square foot of enclosed area, with the bottom of each opening no higher than one foot above grade, under subsection (b)(3). Manufactured homes placed in zone A must be elevated and anchored to resist flotation under subsection (b)(4), and recreational vehicles in special flood hazard zones must either stay fewer than 180 consecutive days, remain licensed and ready for highway use, or meet the same elevation and anchoring standards.

Subdivision proposals larger than 50 lots or five acres must generate their own base flood elevation data under subsection (c)(2), and the floodway itself bars new fill, construction or other encroachment under subsection (e)(1) unless engineering analysis shows no increase in flood levels.