Wilmington, DE Environmental Rules: Flood Elevation Requirements (2026)
Key Facts
- Freeboard required
- Base flood elevation + 18 inches
- Applies to
- Zones A, AE, AO
- Enforced by
- Floodplain administrator
- First offense fine
- $250-$1,000 per day
Summary
New buildings in Wilmington's special flood hazard areas must elevate the lowest floor at least 18 inches above the base flood elevation, a freeboard buffer beyond FEMA's minimum flood map standard.
(a)Elevation requirements.(1)The lowest floor (including basement) shall be elevated to or above the base flood elevation plus 18 inches.(2)In areas of shallow flooding (Zone AO), the lowest floor (including basement) shall be elevated at least as high above the highest adjacent grade as the depth number specified in feet on the flood insurance rate map plus 18 inches, or at least two feet plus 18 inches if a depth number is not specified.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Code of Ordinances: Supplement 72).
Full Breakdown
Under Section 48-587 of the Wilmington City Code, new construction and substantially improved residential buildings in special flood hazard areas (Zones A, AE, AO) must have the lowest floor, including any basement, elevated to or above the base flood elevation plus 18 inches of freeboard. In Zone AO shallow-flooding areas, the floor must sit above the highest adjacent grade by the map's depth number plus 18 inches, or at least two feet plus 18 inches if no depth number is listed. Manufactured homes face the same elevation standard, and any enclosed space below the required floor level is limited to parking, access, or storage with flood-vented openings.
Violations & Fines
Violating the elevation standards is a misdemeanor under Section 48-597: fines run $250-$1,000 for a first offense, up to $2,500 for a second, and up to $5,000 for later offenses, with each day counted separately.
Frequently Asked Questions
How high above base flood elevation must I build in Wilmington?
Does the elevation rule apply to home additions?
Can a nonresidential building skip elevating instead?
Sources & Official References
Other rules in Wilmington
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