Houston, TX Environmental Rules: Flood Elevation Requirements (2026)
Key Facts
- Standard
- 500-year elevation + 2 feet
- Governing code
- Code of Ordinances Ch. 19
- Effective
- Sept 1, 2018 (post-Harvey)
- Critical facilities
- 3 feet above 500-year level
- Enforcer
- City engineer, Houston Public Works
Summary
In Houston's 0.2% annual chance (500-year) floodplain, new homes and substantial improvements must sit at the minimum flood protection elevation: the 500-year flood elevation plus two feet. The Hurricane Harvey-driven rule took effect September 1, 2018.
Minimum flood protection elevation means the 0.2 percent flood elevation, plus 2 feet. ... (b) The following additional requirements apply in an X Shaded Zone: (1) Any addition to, and new construction of any residential structure shall: a. Have the lowest floor and all utilities elevated to at least the minimum flood protection elevation ...; (2) Any addition to, and new construction of nonresidential structure: a. Shall be elevated to at least the minimum flood protection elevation measured to the lowest floor; or b. Shall ... be floodproofed to the minimum flood protection elevation.
Full Breakdown
Chapter 19 defines the 'minimum flood protection elevation' as the 0.2 percent flood elevation plus 2 feet (Sec. 19-2). Section 19-33(b) applies this to the X Shaded Zone: the 500-year floodplain: any new residential structure must have its lowest floor and all utilities elevated to at least that height, and new nonresidential buildings must be elevated or floodproofed to it. Critical facilities must reach 3 feet above the 500-year elevation (Sec. 19-33(e)). The city engineer at Houston Public Works issues the required floodplain development permit, and the 2018 amendments also extended the zero-net-fill rule to the 500-year floodplain.
Violations & Fines
Construction below the minimum flood protection elevation is denied a floodplain development permit; the city engineer can revoke an issued permit under Sec. 19-23 and halt work until the structure meets Chapter 19 elevation standards.
Frequently Asked Questions
Does the 2-foot rule apply outside the FEMA 100-year floodplain?
Can a nonresidential building be floodproofed instead of elevated?
When did Houston change this elevation requirement?
Sources & Official References
Other rules in Houston
Texas rules heatmap·Compare Houston to another location·View the Texas environmental rules overview
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Flood Elevation Requirements in Nearby Cities
How other cities in Harris County handle flood elevation requirements.