Austin, TX Hurricane Preparedness: Flood Elevation (2026)

315 of the Texas Water Code, which let local governments regulate to minimize flood losses. Section 25-12-54(C) requires design and construction of buildings and structures in a flood hazard area, and of additions and alterations to them, to follow ASCE 24, Flood Resistant Design and Construction. The core elevation rule sits in Subsection (C)(1)(a): unless Title 25 (Land Development) specifies otherwise, the lowest floor of a building or structure must be elevated at least two feet above the design flood elevation, the two-foot margin functioning as Austin's freeboard requirement above the base flood level.

The flood hazard area itself is defined by reference to FEMA's Flood Insurance Studies for Travis, Williamson, and Hays counties and their accompanying Flood Insurance Rate Maps, plus the 100-year and 25-year floodplains defined in the Austin City Code. The rule reaches more than new houses: Section 25-12-54(C) applies to subdivision of land, site improvements, utility installation, placement of manufactured homes and recreational vehicles, new construction, repair and rehabilitation, substantial improvement of existing buildings, and tank installation. All elevation compliance must be documented on FEMA's Elevation Certificate, form FEMA 086-0-33, certified by a registered professional engineer, surveyor, or architect, and filed with the Floodplain Administrator before work is approved.