New Castle County, DE Environmental Rules: Stormwater Management (2026)
Key Facts
- Permit required
- Sediment and stormwater management plan
- Standard adopted
- Delaware DNREC Sediment & Stormwater Regs
- Criminal penalty
- $500 misdemeanor fine, per day
- Civil penalty
- $500 to $5,000 per day
- Enforcer
- Department of Land Use Code Official
Summary
New Castle County requires an approved sediment and stormwater management plan, built to state DNREC standards, before any grading, clearing or other land disturbing activity can begin in the unincorporated County.
Except as provided in the Delaware Sediment and Stormwater Regulations, no person or entity may engage in any land disturbing activity until such person or entity has obtained an approved sediment and stormwater management plan. Lines and grades plans will not be approved for a parcel of land before approval of a sediment and stormwater management plan, except as exempted by the Delaware Sediment and Stormwater Regulations.
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 Code Chapter 12, Article 5 bars land disturbing activity, grading, clearing, excavating, filling, until the Department of Land Use approves a sediment and stormwater management plan meeting the Delaware Sediment and Stormwater Regulations, which the County adopts wholesale as its own standard (Sec. 12.05.001). Plans must address peak flow, TMDL nitrogen/phosphorus/sediment load reduction, pond depth and maintenance easements (Sec. 12.05.006). The chapter carries none of the incorporated-municipality opt-in language found in the Building Code or Property Maintenance chapter, so it governs unincorporated County territory only; Wilmington and Newark enforce their own separate building and stormwater rules.
Violations & Fines
Violating this chapter is a misdemeanor carrying a $500 fine, with each day a separate offense; the County can also impose civil penalties of $500 to $5,000 per day, plus stop-work orders and permit refusal.
Frequently Asked Questions
Does this stormwater rule apply inside Wilmington or Newark?
What happens if I disturb land without an approved plan?
What standards must the stormwater plan meet?
Sources & Official References
Other rules in New Castle County
Compare New Castle County to another location·View the Delaware environmental rules overview
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