Harris County, TX Environmental Rules: Flood Zones (2026)
FEMA flood zone rules in Harris County, TX, also called floodplain regulations or special flood hazard area (SFHA) rules, determine flood insurance requirements and elevation standards for new construction.
Key Facts
- Minimum finished floor
- 12 in. above adjacent grade or street crown
- Permit authority
- Harris County Engineer
- Fill in 1% floodplain
- Prohibited for elevating structures
- Applies to
- Unincorporated Harris County only
Summary
New homes in Harris County's 100-year floodplain must sit above the base flood elevation before a development permit issues.
If the structure is a single family residence the finished floor shall be a minimum of 12 inches above the highest adjacent natural grade when measured 10 feet from the edge of the slab or 12 inches above the crown of the adjacent street which ever results in the highest elevation (an exception may be granted on sloping properties where the crown requirement is not achievable).
Full Breakdown
Harris County's Regulations for Floodplain Management require a development permit before any construction in a mapped Special Flood Hazard Area. In Non-Conforming Subdivisions, a single-family home's finished floor must be at least 12 inches above the highest adjacent natural grade (measured 10 feet from the slab) or 12 inches above the adjacent street crown, whichever is higher. Homes partly in the 500-year floodplain must elevate to that flood level. The County Engineer determines Class I (outside the floodplain) versus Class II (within it) permits, and no fill may raise structures inside the 1% floodplain. This applies in unincorporated Harris County only; Houston enforces its own floodplain ordinance.
Violations & Fines
County Engineer can refer violations to the County Attorney to sue to enjoin construction, file a Certificate of Non-Compliance in the Real Property Records, and ask FEMA to deny flood insurance on the property.
Frequently Asked Questions
Does this apply inside Houston?
Can I use fill dirt to raise my house above flood level?
Sources & Official References
Other rules in Harris County
Texas rules heatmap·Compare Harris County to another location·View the Texas environmental rules overview
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