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)

The Town prepared a Stormwater Management Plan (SWMP) that outlines the steps the Town is taking to ensure compliance with the permit.  The SWMP is a living document that is updated annually.

Public Education Material

Annual Reports

  1. 2019-09-26 MS4 Permit Year 1 Annual Report_Winchester
  2. 2020-09-28 - MS4 Permit Year 2 Annual Report_Winchester
  3. Winchester, MA - Year 3 MS4 Annual Report - Final
  4. Winchester, MA - Year 4 MS4 Annual Report - Final