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    State of Delaware

    Maintenance of Stormwater Management Systems

    7.1 Stormwater management systems constructed to comply with 7 Del.C. Ch. 40 and these regulations shall be maintained in accordance with the provisions of this section.

    7.1.1 Maintenance responsibility lies with the Owner until the time that a legal transfer of ownership has been executed. Prior notice of the transfer shall be provided to the Department or Delegated Agency 30 business days before the transfer occurs.

    7.1.2 The stormwater management system shall run with the land and be binding upon the landowner and any successors in interest. Maintenance of these systems shall ensure that the stormwater management system is performing in accordance with the approved engineered design, within the tolerances of the accepted post construction verification documents, and in compliance with these regulations.

    7.1.3 The Owner of a stormwater management system established in accordance with these regulations may offer for dedication to a delegated agency, public entity, municipality, stormwater utility, or private entity, a stormwater management system, together with the easements and appurtenances as may be reasonably necessary for the proper functioning of the system.

    7.1.4 All stormwater management systems must be designed so as to be accessible for maintenance. If required, a maintenance right-of-way or easement must extend to the stormwater management system from a public or private road. The easement or right of way shall specify the ownership and party responsible for maintenance.

    7.2 Owner Responsibilities

    7.2.1 The Owner shall ensure that the stormwater management system is functioning in accordance with the approved engineering design, within the tolerances of the accepted post construction verification documents, and in compliance with these regulations. The Owner will promptly repair and restore stormwater management systems. Such repairs, restoration, or maintenance shall be conducted in accordance with the approved Sediment and Stormwater Management Plan, the Operation and Maintenance Plan, Standard Guidelines for Operation and Maintenance of Stormwater Management Systems, and directions provided by the Department or Delegated Agency.

    Stormwater Management

    Stormwater Permit

    Under the Clean Water Act and the National Pollutant Discharge Elimination System (NPDES) program, the U.S. Environmental Protection Agency (EPA) regulates the water quality of stormwater runoff that discharges into local waterways. Stormwater runoff is transported through municipal separate storm sewer systems, referred to as MS4. To prevent harmful pollutants from being washed or dumped into an MS4, the EPA requires an NPDES permit and a Stormwater Management Program (SWMP) that includes the following program elements:


    1. Construction Site Runoff Control
    2. Illicit Discharge Detection and Elimination
    3. Pollution Prevention/Good Housekeeping
    4. Post-Construction Runoff Control
    5. Public Education and Outreach
    6. Public Involvement/Participation
    7. Program Effectiveness
    8. Total Maximum Daily Loads

    The MS4 program is divided into phases that are based on population. The 1990 Phase I regulations require that medium and large cities with a population of greater than 100,000 obtain NPDES permit coverage for stormwater discharges. The 1999 Phase II regulations require that small urban areas obtain similar NPDES permit coverage for stormwater discharges.

    DelDOT has a Phase I Permit that covers all of New Castle County, and a Phase II Permit that covers the urbanized areas of Kent and Sussex Counties.

    Construction Sites

    The Delaware Sediment and Stormwater (S&S) regulations require that sediment control and stormwater management practices be implemented and managed to prevent erosion and sediment runoff from construction sites.

    DNREC delegated DelDOT to administer its own Sediment and Stormwater Management program. This program requires all construction activities and development disturbing over 5,000 square feet to submit a Stormwater Management and Sediment Control plan. The Plan is required to include a summary of field conditions, hydrologic and hydraulic computations, a plan checklist, and details for sediment control and storm water management practices. DelDOT regularly inspects construction sites for compliance with the DNREC-approved plans.

    State of Delaware Additional Documents

    State of Delaware Stormwater Management Website

    Sediment and Stormwater Regulations

    Delaware Stormwater Best Management Practices