McKinney, TX Environmental Rules: Flood Elevation Requirements (2026)
Key Facts
- Residential freeboard
- 2 ft above base flood elevation
- Pad elevation
- At least 1 ft above flood
- Non-residential option
- Elevate 2 ft or floodproof watertight
- Floodplain basis
- FEMA FIRM dated June 7, 2017
- Enforcement
- City Engineering Department / Director
Summary
In McKinney's mapped floodplain, new homes and substantially improved homes must have their lowest floor at least two feet above the base flood or fully developed 100-year flood elevation, whichever is higher: a full two feet of freeboard enforced by the city Engineering Department.
New construction in reclaimed floodplain areas and substantial improvements of any existing residential structure in floodplain areas shall have the lowest floor, including basements or fully enclosed areas, elevated to at least two feet above either the base flood or the fully developed 100-year flood elevation, whichever elevation is greater. Pad elevations for residential lots raised out of the floodplain shall be at least 1 foot above the elevation of either the base flood or the fully developed 100-year flood elevation, whichever elevation is greater.
Full Breakdown
UDC §705 governs building in McKinney's floodplain, defined by FEMA's June 7, 2017 flood insurance study and rate maps plus the fully developed 100-year flood limits. Residential lowest floors, including basements and fully enclosed areas, must be elevated at least two feet above the base flood or fully developed 100-year elevation, whichever is greater, and pads raised out of the floodplain must sit at least one foot above that elevation. Non-residential structures meet the same two-foot mark or are floodproofed watertight to two feet above the design flood elevation, certified by a registered engineer. Substantial improvement means cumulative work reaching 50 percent of market value.
Violations & Fines
Building or substantially improving a floodplain structure below the two-foot elevation, or floodproofing that fails engineer certification, violates UDC §705; the Director of Engineering withholds plat and permit approval until lowest-floor and pad elevations comply.
Frequently Asked Questions
How much freeboard does McKinney require?
Can I build a house in McKinney's floodplain?
What counts as a substantial improvement?
Sources & Official References
Other rules in McKinney
Texas rules heatmap·Compare McKinney to another location·View the Texas environmental rules overview
See something wrong?
Help us keep this page accurate. If you notice an error or outdated information, let us know.
Flood Elevation Requirements in Nearby Cities
How other cities in Collin County handle flood elevation requirements.