Stormwater Management Program

Stormwater discharges in the City of Manchester are regulated by the U.S. Environmental Protection Agency (EPA) National Pollutant Discharge Elimination System (NPDES) Phase II Stormwater Permit Program.  Under this program, Manchester was required to obtain NPDES permit coverage under the 2003 and 2017 "General Permit for Stormwater Discharges from Small Municipal Separate Storm Sewer Systems (MS4s)" for its stormwater discharges.  This permit program was created with the intention of improving the quality of the nation's waterways by reducing the quantity of pollutants that stormwater picks up and carries into stormwater systems and discharges to surface waters.

Under this permit, Manchester was required to develop and implement a Stormwater Management Program (SWMP), which identifies Best Management Practices the City will implement to address the following six "Minimum Control Measures":

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

Manchester prepared a written Stormwater Management Program (SWMP) Plan in 2019, summarizing its program.  The Plan is routinely updated throughout the permit period to document compliance with permit requirements. The Notice of Intent (NOI) was submitted in 2018 and outlines the program for the next five years. The most recent NOI and SWMP Plan can be viewed by selecting the links below:

• Notice of Intent
• Stormwater Management Plan Cover and Table of Contents
• Stormwater Management Plan Section 1-11
• SWMP Appendix A - Notice of Intent
• SWMP Appendix B - Relevant Maps
• SWMP Appendix C - Impaired Waters Update
• SWMP Appendix D - Regulatory Review
• SWMP Appendix E - Storm System Map
• SWMP Appendix F - Inventory and Ranking of City-Owned Properties
  • Inventory of City-Owned Property
  • Municipal BMP Retrofit
• SWMP Appendix G - BMPs Inventory and Inspection Reports
• SWMP Appendix H - SWPPP Facilities
• SWMP Appendix I - Catch Basin Cleaning Prioritization Plan
• SWMP Appendix I - Catch Basin Inspection and Cleaning Optimization Analysis Memorandum 
  • Memo Attachment 1 - Ward Map
  • Memo Attachment 2 - Catch Basins More than 50% Filled
  • Memo Attachment 3 - Catch Basin Inspection Matrix Map
  • Memo Attachment 4 - Catch Basin Sump Depths Map
  • Memo Attachment 5 - Direct Discharge Catchments Map
  • Memo Attachment 6 - Detailed Sediment Accumulation Rate Criteria
  • Memo Attachment 7 - Potential Catch Basin Cleaning Schedule
• SWMP Appendix J - Street Sweeping SOP
• SWMP Appendix K - TMDL and Impaired Waters Progress
• SWMP Appendix L - Annual Reports

Due to size, some of the documents that are referenced in SWMP sections above are routinely updated and have been provided as individual documents, in lieu of SWMP Appendices. These include the required Operation and Maintenance (O&M) Plan for City-owned facilities and MS4 infrastructure, the Illicit Discharge Detection and Elimination (IDDE) Plan, the Stormwater Pollution Prevention Plan (SWPPP) for the Brdige Street Maintenance Center and the Salt Reduction Plan. These stand-alone documents have been broken into separate sections for ease of use on this webpage. Please refer to the additional links below for these document sections:

Illicit Discharge Detection and Elimination (IDDE) Plan

• Illicit Discharge Detection and Elimination (IDDE) Plan Sections 1-11
• IDDE Appendix A - Impaired & TMDL Waters Updates
• IDDE Appendix B - Key Junction Maps
• IDDE Appendix C - SSO Inventory
• IDDE Appendix D - IDDE Outfall Ranking & Vulnerability 
• IDDE Appendix E - Dry Weather Screening S.O.P.
• IDDE Appendix F - Illicit Discharge Source Investigation S.O.P.
• IDDE Appendix G - Dry Weather Key Junction Screening
• IDDE Appendix H - Wet Weather Outfall Sampling S.O.P.
• IDDE Appendix I - Illicit Discharge Records and Outfall Inspection Data
• IDDE Appendix J - IDDE Training Records

O&M Plan for City-Owned Facilities and MS4 Instrastructure that are not covered under MSGP

• O&M - Cover and TOC
• O&M - Sections 1-4
• O&M - Municipal Infrastructure SOPs
• O&M - Vehicle Equipment and Storage Yard SOPs
• O&M - Spill Prevention, Response, and Reporting SOPs
• O&M  - Parks and Open Space SOPs
• O&M - Buildings and Facilities
• O&M - Construction Management SOPs
• O&M - Attachment A - Inventory of Permittee-Owned Facilities
• O&M - Attachment B - Ice and Snow SOPs

SWPPPs for City-Owned Facilities that are not covered under MSGP

• SWPPP - Bridge Street Maintenance Center

Salt Reduction Plan

• Salt Reduction Plan

Phosphorus Impairment Plan

• Phosphorus Impairment Plan - Cover & TOC
• Phosphorus Impairment Plan - Executive Summary & Sections 1-12
• Phosphorus Impairment Plan - Figures 1-15
• Phosphorus Impairment Plan Appendix A - Baseline Loads
• Phosphorus Impairment Plan Appendix B - Source Area Catchment Prioritization Tables
• Phosphorus Impairment Plan Appendix C - Existing BMP Pollutant Removal Memo
• Phosphorus Impairment Plan Appendix D - Flow Path Calculations
• Phosphorus Impairment Plan Appendix E - Catch Basin Cleaning Phosphorus Reduction Credit
• Phosphorus Impairment Plan Appendix F - Municipal Property BMP Retrofits Memo
• Phosphorus Impairment Plan Appendix G - Stormwater Pollution Prevention Operation and Maintenance Plan

As part of the MS4 permit requirements, the City of Manchester must provide public involvement and participation. This includes providing public access to review and comment on the SWMP document. If there are comments on the SWMP or for any other general stormwater inquires, click on the link below to contact the Environmental Protection Division (EPD) Stormwater Department and select "Stormwater" under the subject line:

Comments or Stormwater Inquiries

Hardcopies of the above-listed stormwater management documents can also be made available for viewing by contacting the EPD Stormwater Department at (603)621-7735 or by clicking the link above.

Other Resources and Information

• EPA NPDES MS4 Information
• NHDES MS4 BLOG