New Castle County, DE Environmental Rules: Flood Elevation Requirements (2026)
Key Facts
- Freeboard requirement
- Base flood elevation plus 18 inches
- Governing amendment
- IBC § B1612.2 amended by Sec. 6.04.002
- FIRM maps effective
- January 22, 2020
- Map range
- 10003C0035L through 10003C0437K
- Jurisdiction
- Unincorporated county plus opt-in municipalities
Summary
New Castle County's Building Code amendment to IBC Section B1612.2 requires the lowest floor or crawlspace of new construction to sit at or above base flood elevation plus 18 inches of freeboard.
Section B1612.2, Design and construction, is amended at the end of the paragraph by adding the phrase "and shall have the lowest floor or crawlspace elevated to or above the base flood elevation plus 18 inches".
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Code of Ordinances: Supplement 5).
Full Breakdown
New Castle County's amended Building Code (adopting the 2024 International Building Code) raises the state minimum freeboard standard: Section B1612.2 now requires the lowest floor or crawlspace of buildings in flood hazard areas to be elevated to or above base flood elevation plus 18 inches, rather than to BFE alone. The Code Official enforces this through the building permit and inspection process. Effective FIRM maps date to January 22, 2020, covering Map Numbers 10003C0035L through 10003C0437K. The chapter applies to unincorporated New Castle County and to any incorporated municipality whose governing body opts in, per Appendix 6; Wilmington and Newark, which enforce their own building codes, are not covered here.
Violations & Fines
Code Official withholds permit approval and certificate of occupancy for noncompliant construction, issues a violation notice, and can call a show cause hearing before penalties or license action follow.
Frequently Asked Questions
Does this apply inside Wilmington or Newark?
How much higher than base flood elevation must the lowest floor be?
What FIRM maps set the flood zones used to enforce this?
Sources & Official References
Other rules in New Castle County
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