MS4 Stormwater Permit

The Town of Winchester is required to comply with the requirements of the 2016 NPDES Phase II Municipal Separate Storm Sewer System (MS4) General Permit.  The Permit requirements include the development, implementation, and enforcement of a Stormwater Management Program to reduce the discharge of pollutants to the MS4 to the maximum extent practicable.  The 2016 MS4 Permit became effective on July 1, 2018. 

The objectives of the permit are accomplished through the implementation of Best Management Practices (BMPs) for the following six minimum control measures.

  • Public education and outreach;
  • Public involvement and participation;
  • Illicit Discharge Detection and Elimination (IDDE) Program;
  • Construction site stormwater runoff control;
  • Post-construction stormwater management in new development or redevelopment; and
  • Good housekeeping and pollution prevention for permittee-owned facilities

Stormwater Management Plan (SWMP)

Public Education Material

Annual Reports

  1. Annual Report 9 (PDF)
  2. Annual Report 10 (PDF)
  3. Annual Report 11 (PDF)
  4. Annual Report 13 - Winchester - May 2016 (PDF)
  5. Annual Report 14 - Winchester - September 2017 (PDF)
  6. Annual Report 15 - Winchester - May 2018
  7. 2019-09-26 MS4 Permit Year 1 Annual Report_Winchester
  8. 2020-09-28 - MS4 Permit Year 2 Annual Report_Winchester
  9. Winchester, MA - Year 3 MS4 Annual Report - Final