Orangeburg County, SC Environmental Rules: Flood Elevation Requirements (2026)

Section 18-82 lists the specific construction standards that apply in special flood hazard Zones A, AE, AH, AO, A1-30, V, and VE once FEMA or the local floodplain administrator has provided base flood elevation data under Section 18-4 or Section 18-54. Subsection (1) sets the residential rule: new construction and substantial improvement of any residential structure, including a manufactured home, must have its lowest floor elevated no lower than one foot above the base flood elevation, and no basements are permitted at all. If solid foundation perimeter walls are used to elevate the structure rather than an open pier or column foundation, the owner must add flood openings sufficient to automatically equalize hydrostatic flood forces, sized and placed to meet the elevated buildings requirements in subsection (4).

The one foot cushion above the mapped base flood elevation is the county's freeboard, and it is verified twice: once at the development permit stage under Section 18-53, where the applicant must show the elevation the lowest floor will reach, and again after construction, when Section 18-53(b)(2) requires a registered land surveyor or professional engineer to certify the as-built lowest floor elevation before further vertical work proceeds. The local floodplain administrator, appointed under Section 18-51, reviews both submissions and can issue a stop-work order under Section 18-55(2) if the elevation requirement is not met, with violation of that order itself a misdemeanor.