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

Florence County's zoning ordinance goes one foot beyond FEMA's federal floor. Chapter 30, § 30-62(b) governs every zone A and AE parcel where FEMA has published base flood elevation data. New construction and substantial improvements of residential structures, including manufactured homes, must have the lowest floor elevated no lower than one foot above the base flood elevation, and basements are flatly prohibited. Commercial, industrial, and other nonresidential structures carry the identical one-foot freeboard requirement, though § 30-62(b)(2) lets them floodproof instead of elevate in A-zones if a registered professional engineer or architect certifies the structure is watertight below the required elevation.

Where solid perimeter walls are used to elevate a building, § 30-62(b)(4) requires flood vents: a minimum of two openings on different walls totaling at least one square inch of net area per square foot of enclosed area subject to flooding, with the bottom of each opening no more than one foot above grade. C. Code § 40-29-10 and the South Carolina Manufactured Housing Board Regulations. A registered land surveyor or professional engineer must certify the lowest-floor or floodproofed elevation to the local administrator under § 30-61(b)(2) before construction proceeds, and any work done before that certification is submitted is at the permit holder's own risk.