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

Section 16-122 sets the specific construction standards that apply once a parcel's base flood elevation (BFE) has been established under Section 16-32 or 16-83(9). For residential construction, including manufactured homes, the lowest floor must be elevated no lower than three feet above the BFE, and basements are not permitted at all (Sec. 16-122(1)). That three-foot freeboard is the same figure the code's definitions section calls 'freeboard,' a safety margin meant to cover unknowns like wave action, bridge openings, and watershed urbanization that could push flood heights above the calculated base level (Sec.

16-31). Commercial, industrial, and other nonresidential structures face the identical three-foot elevation standard, but may floodproof instead of elevate in zones A and AE, provided a state-registered engineer or architect certifies the structure is watertight below the required elevation and the owner keeps an approved, annually exercised maintenance plan (Sec. 16-122(2)). Where solid perimeter walls are used to reach the elevation instead of piers or open foundations, the walls need flood-vent openings sized to let water pass through automatically, per the elevated-buildings criteria in Sec.

16-122(5). An as-built elevation certificate from a state-registered surveyor or engineer must be filed with the floodplains manager as soon as the lowest floor is complete and before any further vertical construction proceeds (Sec. 16-82(6)).