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

5's Division 3 flood hazard reduction standards apply throughout the county's mapped Special Flood Hazard Areas, layered on top of whatever the underlying zoning designation allows. In the floodway fringe, Sec. 5-72 sets the freeboard: new construction and substantial improvements to a residential structure must have the lowest floor, including any basement, elevated no lower than two feet above base flood elevation, and the same two-foot standard applies to commercial, industrial, and other nonresidential buildings. Manufactured homes get their own version of the rule: whether the home is going into a new park, an expansion of an existing park, or a park where a unit was substantially damaged by flood, it must sit on a permanent foundation with the lowest floor two feet above base flood elevation, and the park operator must file an evacuation plan with the local administrator and the emergency management coordinator.

Recreational vehicles are exempt only if they stay on site fewer than 180 consecutive days, remain licensed and ready for highway use on wheels, and are not permanently attached to the site; otherwise they must meet the same elevation standard as a manufactured home. After construction, Sec. 5-52(7) requires the permit holder to submit a FEMA elevation certificate, prepared by a registered surveyor or engineer, to the local administrator within 21 calendar days of the lowest floor being set; work done before that certificate is filed is at the permit holder's own risk, and a deficient survey can trigger a stop-work order.

Where base flood elevation data have not been mapped, Sec. 5-74 still requires the lowest floor at least two feet above the highest adjacent grade.