New Castle County, DE Environmental Rules: Erosion Control (2026)
Key Facts
- Governing standard
- Delaware Sediment and Stormwater Regulations (DNREC)
- Permit required
- Before any land disturbing activity
- Applies in
- Unincorporated New Castle County
- Enforcement
- County as DNREC-delegated inspection agency
- Fee basis
- Set by UDC Appendix 2
Summary
New Castle County requires an approved sediment and stormwater management plan before any land disturbing activity begins, enforcing Delaware's DNREC erosion regulations through mandatory permits and site inspections across unincorporated parts of the 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
Under County Code § 12.05.001, New Castle County has adopted the Delaware Sediment and Stormwater Regulations, issued by DNREC, as its own erosion and sediment control standard. Section 12.05.003 bars any land disturbing activity until the applicant obtains an approved sediment and stormwater management plan, and grading (lines and grades) plans cannot be approved first. The County collects a permit fee set under Unified Development Code Appendix 2 (§ 12.05.002) and reviews sites as the state's delegated inspection agency (§ 12.05.007). This chapter and the Unified Development Code process it runs through govern unincorporated New Castle County; Wilmington and Newark are separately incorporated cities that administer their own building and land-use codes, not this chapter.
Violations & Fines
No grading or building permit issues without an approved sediment and stormwater plan. The County may withhold permits if DNREC finds the applicant violating 7 Del. C. § 4001 et seq., and inspectors periodically check active sites for effective erosion and sediment control under § 12.05.007.
Frequently Asked Questions
Does this cover Wilmington or Newark?
What do I need before grading a site?
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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