New Castle County, DE Environmental Rules: Coastal Development (2026)

New Castle County's Delaware River frontage and the lower reaches of the Christina River fall within the Delaware Coastal Zone regulated under the landmark Delaware Coastal Zone Act (CZA, 7 Del.C. Chapter 70, enacted 1971 by Governor Russell Peterson). The CZA bans new heavy industry within the coastal zone and strictly regulates other development through DNREC Division of Water. The coastal zone encompasses a 2-mile-wide strip along the Delaware River and Bay from the Pennsylvania line south to Cape Henlopen. Within New Castle County this includes the Port of Wilmington, Edgemoor, the Wilmington waterfront, and downriver areas through Delaware City toward the Chesapeake & Delaware (C&D) Canal. Wetlands (tidal and freshwater) are protected under 7 Del.C. Chapter 66 (Wetlands Act), which prohibits dredge or fill without a DNREC permit and maintains buffer zones. The Subaqueous Lands Act (7 Del.C. Chapter 72) regulates any activity below mean high water on rivers, bays, and tidal waters, requiring permits and typically a submerged lands lease. Waterfront construction (piers, bulkheads, marinas) requires coordinated approvals from DNREC, US Army Corps of Engineers (Section 10 Rivers and Harbors, Section 404 Clean Water Act), and the US Coast Guard for navigation. Coastal development approvals under the Coastal Zone Management Act federal consistency review apply to federal projects and permits. Sea level rise and climate change planning under DNREC guidance increasingly affects approval conditions. Public access to the waterfront is a statutory policy goal.