Sumter County, SC Hurricane Preparedness: Flood Elevation (2026)

Section 18-72 sets the specific construction standards that apply once FEMA has published base flood elevation data for a Sumter County site. Subsection (1) governs residential construction: any new residential structure, or one undergoing substantial improvement, including manufactured homes, must have its lowest floor elevated no lower than two feet above the base flood elevation, a two-foot freeboard margin built in specifically to absorb the unpredictable extra height a storm surge or hurricane-driven flood can add. Basements are prohibited outright in these structures. If solid foundation perimeter walls are used instead of piers to reach that elevation, Section 18-72(5) requires flood-vent openings sized to let floodwater flow in and out automatically, at least two openings on different walls totaling one square inch of net area per square foot of enclosed space, with the bottom of each opening no higher than one foot above the surrounding grade.

Manufactured homes get their own rule at Section 18-72(3): they must sit on a permanent, elevated foundation reaching the same two-foot freeboard and be anchored under the state Manufactured Housing Board's regulations to resist flotation and lateral movement during flooding, and an evacuation plan must be filed with the Floodplain Administrator and the county's emergency preparedness coordinator for any new or substantially damaged manufactured home park. A registered engineer, architect or surveyor must certify the as-built lowest-floor elevation before further vertical construction, under Section 18-54.