Sediment and Stormwater

Delaware’s Sediment and Stormwater Management Program operates within the Division of Watershed Stewardship’s Conservation Programs Section. The program employs a comprehensive approach to sediment control (both during and after construction) and stormwater management that includes monitoring of stormwater quantity and water quality control.

The Division of Watershed Stewardship held a virtual public hearing on Dec. 1, 2020, on proposed revisions to the Regulations Governing the Control of Water Pollution that would convert the Delaware Construction General Permit (CGP), under the NPDES program, from a permit by regulation to a stand-alone general permit. (Delaware Register of Regulations Notice).

The Sediment and Stormwater Program was created by the Delaware General Assembly in 1978 (7 Del. Code, Chapter 40, Erosion and Sedimentation Control). It oversees activities governed by Delaware’s Sediment and Stormwater Regulations (7 DE Admin. Code 5101). Projects begun prior to Jan. 1, 2014, are covered by an earlier version of the regulations.

Program responsibilities include:

  • Sediment control and inspection during construction
  • Post-construction inspection of permanent stormwater facilities
  • Stormwater quantity and water quality control
  • Education/training relating to stormwater.

Delegated Agencies

There are delegated agencies in all three Delaware counties, and in several municipalities who perform sediment and stormwater services including plan review, construction inspection, and maintenance inspection.

NPDES Construction Permits

The eNOI System — An online tool to submit NOIs and manage NPDES Construction Permits

Example Weekly Self Review Form

List of Notices of Intent

Delaware’s Regulations Governing the Control of Water Pollution provide for a general permit under the National Pollutant Discharge Elimination System (NPDES) for controlling stormwater discharges from construction sites.

For permit coverage, construction activities with land disturbing activities on 1 acre or more must submit a Notice of Intent (NOI) prior to plan approval, follow reporting requirements outlined in the Special Conditions for Stormwater Discharges from Construction Activities (7 DE Admin. Code 7201 Part 2). Permit coverage is required until conditions of terminating permit coverage are met.

Regulatory Guidance Documents

Delaware Erosion and Sediment Control Handbook

The Erosion and Sediment Control Handbook provides background information on erosion and sedimentation, information on Delaware’s regulatory program and standards and specifications for erosion and sediment control. The standard details to be used on Sediment and  Stormwater Plans are also available for download.

Post Construction Stormwater BMP Standards and Specifications

The Post Construction Stormwater BMP Standards and Specifications contains design guidelines, construction guidelines and maintenance recommendations for the various permanent Best Management Practices (BMPs) intended for both quality and quantity management of stormwater runoff.

Standard Guidelines for Operation and Maintenance of Stormwater BMPs

The Standard Guidelines for Operation and Maintenance of Stormwater BMPs summarizes the maintenance items and frequency from the Post Construction Stormwater BMP Standards and Specifications into a single document. Maintenance review checklists for a selection of those practices are also included.

Regulatory Guidance Memoranda

RGM-1 NOAA Rainfall Distributions

RGM-2 Procedure for Conducting a Downstream Analysis