Union County, NC Environmental Rules: Flood Elevation Requirements (2026)

Union County's Unified Development Ordinance (UDO) Article 65, Flood Damage Prevention, sets the elevation floor for building in a special flood hazard area outside every municipality's corporate limits and extraterritorial jurisdiction unless a town has opted in by resolution. 020-B1, Residential Construction, requires that new construction and substantial improvement of any residential structure, including manufactured homes, have the reference level, including any basement, elevated no lower than the regulatory flood protection elevation. 020-B2 and may floodproof to that same elevation instead of physically elevating, but only with a registered professional engineer's or architect's certification that the structure resists hydrostatic and hydrodynamic loads below that line.

The UDO's definitions article fixes what 'regulatory flood protection elevation' means in numbers: where FEMA has established a base flood elevation (BFE), it is the BFE plus 2 feet of freeboard; where no BFE has been set, it must be at least 2 feet above the highest adjacent grade. 020-B3: the reference level of the chassis can be no lower than the regulatory flood protection elevation, and if the elevation is met by a chassis height of 36 inches or less above grade, the chassis must sit on reinforced piers or an engineered foundation; above 36 inches requires an engineering certification.

030 covers the same construction in floodplains where FEMA has not yet provided BFE data, requiring the applicant to obtain and use the best available BFE data before building. The floodplain administrator, appointed under Article 65's administration section, reviews floodplain development permit applications and can require elevation certificates documenting the as-built reference level before a certificate of compliance issues.