Stormwater Plans

Stormwater Master Plan (2014)

The Stormwater Management Program Master Plan is the strategic and operational guidance document for the Town of Chapel Hill’s Stormwater Management Program. Developed through a collaborative, stakeholder-inclusive process, the Master Plan builds upon the program mission and stakeholder-defined goals to articulate strategic objectives.

Stormwater Management Plan

While the Master Plan guides our program through the years, the Town’s Stormwater Management Plan (SWMP)(PDF, 2MB) provides information for how:

  • we're complying with the requirements of its National Pollutant Discharge Elimination System (NPDES) Municipal Separate Storm Sewer System (MS4) Permit and
  • the applicable provisions of the Clean Water Act to reduce pollutants in stormwater runoff to the maximum extent practicable. 

In preparing this SWMP, we've evaluated our MS4 and the permit requirements to develop a SWMP that will meet the community’s needs, address local water quality issues, and provide the minimum measures necessary to comply with the permit.  We evaluate and update the SWMP annually to ensure that the elements and minimum measures it contains continue to adequately provide for permit compliance and the community’s needs.

The six minimum measures we're required to address are:

  1. Public Education and Outreach
  2. Public Participation and Involvement
  3. Illicit Discharge Detection and Elimination
  4. Construction Site Runoff Control
  5. Post-Construction Runoff Control
  6. Pollution Prevention and Good Housekeeping for Municipal Operations

The North Carolina Department of Environmental Quality approved this SWMP in 2025.

National Pollutant Discharge Elimination System (NPDES)

The Basics

NPDES is a federal Environmental Protection Agency (EPA) program. Its goal is to reduce pollution in our waterways through the use of permits for facilities and municipalities/tribes/states that discharge effluent and/or stormwater into waterways. The Town of Chapel Hill has an NPDES Phase II permit.

EPA requires six minimum measures called Best Management Practices (BMPs) for NPDES Phase II permitting. Each of these management practices must have measurable goals defined to evaluate their effectiveness in the removal of pollutants from stormwater runoff:

  1. Public education and outreach
  2. Public involvement and participation
  3. Illicit discharge detection and elimination (IDDE Ordinance(PDF, 291KB))
  4. Construction site stormwater runoff control: Orange County Erosion and Sedimentation Control performs
    permitting, inspection, and enforcement in Chapel Hill.
  5. Ensuring post-construction stormwater management in new development and redevelopment
  6. Pollution prevention/good housekeeping for municipal operations

Background

Although previously applied only to industrial and commercial dischargers and sewage-treatment operations, permits through the program are now also required for municipal stormwater, or non-point source, discharges. Water Permitting 101 explains the history of water quality legislation, NPDES, and the use of permits.

NPDES - Phase I permitting was required in 1989 for North Carolina for:

  • Large state facilities and municipalities with stormsewer systems;
  • Eleven categories of industrial activity; and
  • Construction activity that disturbs more than 5 acres of land. 

NPDES - Phase II permits, which went into effect in 2005, apply to medium and small municipalities with stormsewer systems, such as Chapel Hill's, and construction activities that disturb from 1 to 5 acres of land.

In North Carolina, the Department of Environmental Quality- Division of Energy, Mining and Land Resources (DEMLR) oversees NPDES permitting through its Stormwater Permitting Program.

Our Permit

You can review our current NPDES permit(PDF, 1MB), which became effective on August 1, 2023. 

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