Delaware
The stormwater permit for construction in Delaware
Delaware runs its own NPDES programme, so a state issued construction general permit governs. Below is what our engine can say about it, and where we have not read that permit, what it will not say.
Governing permit
General Permit Authorization for Discharges from Construction Activities Under the NPDES and the Laws of the State of Delaware
- Issued by
- Delaware Department of Natural Resources and Environmental Control (DNREC), Division of Watershed Stewardship, Sediment and Stormwater Management Program
- Permit number
- WPCC 3082/20 (state); DE 0051268 (NPDES)
- Version determined against
- as published by the state agency
- Effective
- 2026-03-11
- Expires
- 2031-03-10
Who may prepare the plan
A credentialed preparer is requiredDelaware requires a credentialed preparer. Treat the generated document as a complete draft for that person to review, adopt and sign. It is not by itself a compliant filed plan.
Qualifying routes
- Licensed landscape architect
- Licensed surveyor
- PE
Must sign and seal. The section 3.7 Standard Plan path is an alternative for qualifying small sites.
Does a site in Delaware need coverage
Worked for a one acre site as a reference point. Change the acreage in the tool below and the answer, and its reasoning, change with it.
Coverage
Permit coverage required
The project disturbs 1 acres, at or above the 1 acre threshold, so it needs permit coverage.
Determined against dataset version 2026-07-19.
Read these before you act on the answer
- Requirements below are what we have read and cited directly from General Permit Authorization for Discharges from Construction Activities Under the NPDES and the Laws of the State of Delaware, not the federal CGP. A category we have not yet transcribed from this permit is omitted here rather than assumed to match EPA's rule.
- This is Delaware's 2026 CGP (effective March 11, 2026; expires March 10, 2031). Delaware's permit contains no numeric turbidity/pH/TSS benchmarks -- DNREC relies on BMP-based performance standards instead, so numericLimitsAndBenchmarks is omitted entirely. Delaware requires weekly maintenance inspections plus separately-cadenced 7-day 'construction reviews' uniformly, with no reduced/increased frequency tied to arid conditions or 'sensitive waters' -- inspection.routine.biweeklyPlusRain, inspection.increased.sensitiveWaters, and inspection.reduced.aridSemiAridDrought are all omitted. Delaware's 14-day stabilization-completion deadline does not vary by disturbed acreage, so a custom id (state.de.stabilization.complete.allSites) was used rather than force-fitting the acreage-tiered federal ids. No fixed calendar-day NOT deadline was found -- it is event/condition-triggered, not day-count. No distinct corrective-action 'identify' documentation deadline separate from the minor/major-fix deadlines was found.
- Delaware requires a credentialed preparer. Treat the generated document as a complete draft for that person to review, adopt and sign. It is not by itself a compliant filed plan.
- Basinwise does not perform the physical site inspections the permit requires. Those must be carried out on site by a qualified person.
How this answer was reached, step by step
- 1
Coverage threshold
The project disturbs 1 acres, at or above the 1 acre threshold, so it needs permit coverage.
- 2
Permitting authority
Delaware. The state runs its own programme under WPCC 3082/20 (state); DE 0051268 (NPDES).
- 3
Preparer credential
Delaware requires a credentialed preparer. Treat the generated document as a complete draft for that person to review, adopt and sign. It is not by itself a compliant filed plan.
What to do next
- 1. Confirm the governing permit. Read General Permit Authorization for Discharges from Construction Activities Under the NPDES and the Laws of the State of Delaware directly. It is linked above, and it is the document an inspector will hold you to. Delaware Department of Natural Resources and Environmental Control (DNREC), Division of Watershed Stewardship, Sediment and Stormwater Management Program
- 2. Settle the preparer question before you draft. Getting this wrong costs a redraft at best. The detail is on the credential page for this state. Preparer credential in Delaware
- 3. Screen the site. Run the real acreage and receiving water facts through the tool below. You get the inspection frequency, the stabilisation deadlines and the filing path with the permit section behind each.
- 4. Read the requirements in full. SWPPP requirements in Delaware
Screen a Delaware site now
Runs in your browser. Nothing about the site is transmitted.
What people ask about the Delaware construction stormwater permit
Do I need a stormwater permit for a construction site in Delaware?
Permit coverage is triggered at one acre of land disturbance, and below one acre if the project is part of a larger common plan of development or sale that will ultimately disturb an acre or more. The project disturbs 1 acres, at or above the 1 acre threshold, so it needs permit coverage.
Who issues the construction stormwater permit in Delaware?
Delaware Department of Natural Resources and Environmental Control (DNREC), Division of Watershed Stewardship, Sediment and Stormwater Management Program issues General Permit Authorization for Discharges from Construction Activities Under the NPDES and the Laws of the State of Delaware.
Does Delaware require a qualified preparer for the plan?
Delaware requires a credentialed preparer. Treat the generated document as a complete draft for that person to review, adopt and sign. It is not by itself a compliant filed plan.
Keep the record Delaware will ask you for
The screening is free. Holding the written plan and the retained inspection log is what the permit actually demands.