Environmental Rules in Delaware (2026)
23 rules on the books across Delaware, 4 cities and counties. Select a rule to read the full details.
Severity: Few Restrictions · Light Restrictions · Some Restrictions · Significant Restrictions · Heavy Restrictions
Stormwater Management
Requirements for managing rainwater runoff on your property, including retention basins, permeable surfaces, and drainage plans.
Kent County
Some RestrictionsKent County's Drainage Code, Chapter 116, requires an approved sediment and stormwater management plan and permit…
Read full rule →New Castle County
Some RestrictionsNew Castle County requires an approved sediment and stormwater management plan, built to state DNREC standards, before…
Read full rule →Sussex County
Some RestrictionsBefore issuing a building permit that requires stormwater management, Sussex County makes the applicant sign a recorded…
Read full rule →Wilmington
Some RestrictionsWilmington requires a sediment and stormwater management plan for any land-disturbing activity over 5,000 square feet…
Read full rule →Erosion Control
Rules to prevent soil erosion during construction and landscaping, including required sediment barriers and ground cover standards.
Delaware: statewide
StatewideHeavy RestrictionsDelaware Code Title 7, Chapter 40 mandates statewide erosion and sediment control standards for any land disturbance…
Read full rule →Wilmington
Significant RestrictionsAny land-disturbing activity over 5,000 square feet in Wilmington needs a sediment and stormwater management plan…
Read full rule →Kent County
Some RestrictionsKent County bars anyone from disturbing land, whether by grading, excavating, clearing, or filling, without an approved…
Read full rule →New Castle County
Some RestrictionsNew Castle County requires an approved sediment and stormwater management plan before any land disturbing activity…
Read full rule →Sussex County
Some RestrictionsSussex County won't issue a building permit until the Sussex Conservation District approves a sediment control and…
Read full rule →Coastal Development
Building restrictions near coastlines, including setbacks from the water, dune protection rules, and coastal commission permits.
Delaware: statewide
StatewideHeavy RestrictionsThe 1971 Delaware Coastal Zone Act (7 Del.C. Chapter 70) prohibits new heavy industry within the designated coastal…
Read full rule →New Castle County
Significant RestrictionsNew Castle County's Unified Development Code blocks any new Heavy Industry (HI) zoning district from being created…
Read full rule →Flood Zones
Building requirements for properties in FEMA flood zones, including elevation standards, flood insurance mandates, and construction limits.
New Castle County
Significant RestrictionsNew Castle County requires a floodplain development permit from the Department of Land Use before any construction…
Read full rule →Wilmington
Significant RestrictionsAny construction, fill, or utility work in a Wilmington special flood hazard area needs a floodplain development permit…
Read full rule →Kent County
Some RestrictionsKent County bars any construction, grading, filling, subdivision, manufactured home placement, or storage tank…
Read full rule →Sussex County
Some RestrictionsSussex County requires a floodplain development permit before any construction, filling, grading, subdivision or…
Read full rule →Boat Dock Permits
Permits required to build or modify boat docks, lifts, and davits on waterfront properties, including size limits, setbacks, and environmental reviews.
Wilmington
Significant RestrictionsWilmington requires a license from the city before anyone builds, extends, or repairs a wharf, pier, or dock structure…
Read full rule →Kent County
Some RestrictionsKent County requires private piers, wharves, moorings, pilings and buoy installations to comply with Delaware DNREC and…
Read full rule →Sussex County
Some RestrictionsSussex County caps boathouses at 25 feet tall, 25 feet wide and 50 feet deep, and limits any dock, pier or wharf to no…
Read full rule →Vehicle Idling Restrictions
Limits on how long heavy-duty vehicles, buses, and passenger cars may idle, including bans near schools and residential areas.
Flood Elevation Requirements
FEMA NFIP minimum base flood elevation (BFE) construction standards for properties in mapped flood zones, including freeboard requirements above BFE.
Kent County
Some RestrictionsIn Kent County's non-coastal special flood hazard areas, Zones A, AE and AO, Chapter 188 requires the lowest floor of a…
Read full rule →New Castle County
Some RestrictionsNew Castle County's Building Code amendment to IBC Section B1612.2 requires the lowest floor or crawlspace of new…
Read full rule →Sussex County
Some RestrictionsSussex County requires the lowest floor of new and substantially improved residential structures in a special flood…
Read full rule →Wilmington
Some RestrictionsNew buildings in Wilmington's special flood hazard areas must elevate the lowest floor at least 18 inches above the…
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