Storm Water Pollution Prevention
General Permit
In 2004, the Town of Manchester developed a townwide Stormwater Management Plan. This plan is a required component of the Connecticut Department of Energy & Environmental Protection (CTDEEP, formerly known as DEP) General Permit for the Discharge of Stormwater from Small Municipal Separate Storm Sewer Systems, more commonly known as the "MS4" permit. The goal of the MS4 permit program is to improve overall water quality by reducing the amount and potential for pollutants to enter our water system.
The Stormwater Management Plan identifies measurable goals in each of the following six control measures:
- Public Education and Outreach
- Public Participation and Involvement
- Illicit Discharge Detection and Elimination
- Construction Site Runoff Control
- Post-Construction Runoff Control and
- Pollution Prevention/Good Housekeeping
The overall purpose of the program is to protect the quality of our natural resources by reducing the discharge of pollutants to wetlands and watercourses. If you have any comments regarding this plan or annual report, please contact Jeff LaMalva, Town Engineer at (860) 647-3158 or via email.
2004 Stormwater Management Plan(PDF, 376KB)
Annual Reporting
CTDEEP requires that towns annually submit reports documenting their progress towards achieving the goals for each control measure that were originally identified in the 2004 Stormwater Management Plan. They also require that towns sample and test stormwater runoff from predetermined representative locations and submit the results to CTDEEP. The Town has made considerable progress towards the goals originally identified in the 2004 Plan, as documented below across the previous annual reports submitted to CTDEEP:
Manchester's Annual Reports
Stormwater Data
Impervious Cover
CT NEMO acquired the 2012-statewide high resolution (1 foot) imagery and impervious cover data in September 2017. This data includes the percent impervious cover for each town and each basin. Using this information, it was determined that Manchester has a significant amount of watershed basins with greater than 11% impervious cover. In 2020, the Town produced a map for the public identifying impaired water bodies, impaired water courses, and which watershed basins have greater than 11% impervious cover. A link to the map is provided below:
Watershed Basins with Impervious Cover Greater Than 11 Percent (2012)(PDF, 2MB)
Storm Drainage System
The Town of Manchester's Stormwater Drainage System has been extensively mapped as part of the Town's GIS asset data. It is routinely updated when changes or additions are made as a result of Town-initiated projects and also private development projects. A snapshot map of the system from 2020 was produced as part of the Town's permit. A link to the map is provided below:
Manchester Storm Drainage System MS4 Map (2020)(PDF, 4MB)
Priority Ranking of Watershed Basins
As part of the 2024 Annual Report, the Town reviewed its Townwide catch basin and outlet mapping and developed a Priority Ranking System to be used for targeting Illicit Discharge Detection and Elimination (IDDE). The Ranking addresses Part III: Additional IDDE Program Data Item #1 Assessment and Priority Ranking of Catchments data (Appendix B (A)(7)(c) of the MS4 Permit). Points were assigned to Subregional Basin areas (areas are defined by CTDEEP) as recommended by CT NEMO. All catch basins within a given watershed Subregional Basin area are assumed to have the same ranking.
Four primary criteria are established and scored for the ranking:
- Is impervious coverage greater than 11%?
- Is directly connected impervious area greater than 11%?
- Does the discharge point or outlet discharge into a CTDEEP designated impaired waterway or waterbody?
- Is the CTDEEB Subregional Basin area designated as a Priority Area?
The results are summarized in the map linked below:
Basin Assessment and Priority Rankings (2024)(PDF, 452KB)
Best Management Practices
The MS4 permit mentioned above contain Best Management Practices (or BMP's) for the Town's operations. Reducing the amount of pollutants entering our watercourses is important because it affects plants, fish, animals and people. After it rains, stormwater runoff can pick up chemicals, debris, sediment and other pollutants from the ground as it flows untreated into the water bodies we use for recreation purposes and sources of our drinking water. Everyone can play a part in reducing these pollutants from entering our water bodies.
Below are some brochures and links that show ways you can help.
Education
U.S. Environmental Protection Agency National Pollutant Discharge Elimination System (EPA NPDES) provides more information on MS4 programs at the federal level. For more information see: EPA NPDES Webpage
For a glossary on terms used on this page and throughout those linked and to learn more, see Water Cycle Glossary (Thanks Jenae!)
To learn more, see the following links:
- Protecting Water Quality from Urban Runoff(PDF, 231KB)
- Think Green, Stay Blue: Clean Water Starts with You!(PDF, 217KB)
- Stormwater Pollution Prevention Guide for Homeowners(PDF, 676KB)
- Disconnecting Impervious Areas at Home: Driveways(PDF, 3MB)
- Disconnecting Impervious Areas at Home: Rooftops(PDF, 4MB)
- Reduce Stormwater Pollution: Pet Waste(PDF, 500KB)
- Clean Water Campaign Pet Waste Poster(PDF, 232KB)
- Nonpoint Source Water Pollution(PDF, 66KB)
- Stormwater Information Brochure(PDF, 2MB)
- Impacts of Development on Waterways(PDF, 635KB)
- Reduce the Need for Pesticides and Herbicides(PDF, 2MB)
- Organic Fertilizer Fact Sheet(PDF, 1MB)
Residential Low Impact Development
Low Impact Development (LID) is an ecologically based stormwater and land use management approach which favors management of rainfall on site through a mostly vegetated treatment network. The goal of LID is to mimic natural hydrologic conditions by using techniques that infiltrate, filter, store, and evaporate stormwater runoff close to it's source. To learn more about helping at home see Residential Best Management Practices(PDF, 740KB) and the Sustainable Design and Low Impact Development Guidelines(PDF, 2MB).
The following links provide additional information on some of the treatments mentioned in the Guidelines:
UConn Climate Corps
For the 2025–2026 academic year, the Town of Manchester partnered with University of Connecticut students participating in the Climate Corps program. Climate Corps is a collaborative initiative involving the Environmental Studies, Environmental Sciences, and Environmental Engineering programs, the Connecticut Sea Grant Program, and the UConn Center for Land Use Education and Research (CLEAR).
The documents below were developed by UConn Climate Corps students and are provided for informational and educational purposes only. The content does not constitute official Town of Manchester analysis, findings, recommendations, or policy. The Town assumes no responsibility for the accuracy, completeness, or use of the information contained in these materials.
Town of Manchester, Public Act 25-33 & MS4
In April 2026, Katharine Batchelar, a student in the University of Connecticut Climate Corps, prepared their Honors Thesis "Assessing the Town of Manchester's Compliance with PA 25-33 and MS4".
Abstract
This report aims to analyze the compliance of five policy documents from the Town of Manchester with two state laws. It summarizes Connecticut State General Stormwater Permit and Connecticut Public Act 25-33. It discusses the Town of Manchester’s Plan of Conservation and Development, Zoning Regulations, Subdivision Regulations, Stormwater Management Plan, and Public Improvement Standards in comparison to the requirements set out in these state policies. It identifies the largest places for growth being within discussing vulnerable populations and environmental justice, as well as incorporating long-term data projections. Recommendations for filling these policy gaps are outlined within the report, such as a climate vulnerability assessment and adding quantifiable pollutant goals to documents.
The findings of the study are summarized in the following UConn Research Poster and represent a snapshot of the Town's efforts as of April 24, 2026.
Thesis Report Summary Poster(PDF, 129KB)
A small presentation was made to Town Staff with additional summaries and graphics. The slides are available in PDF format below:
Thesis Report Presentation(PDF, 621KB)
Read the full thesis document below:
Assessing the Town of Manchester's Compliance with PA 25-33 and MS4(PDF, 335KB)
Disclaimer: These documents were developed by UConn Climate Corps students. This material is provided for informational purposes only and does not represent official Town analysis, findings, or recommendations. The Town assumes no responsibility for the accuracy or use of the information contained herein.
Best Management Practices for Lawn Care
The brochures below, developed by UConn Climate Corps student Hector Meza, were developed to help support the Town of Manchester's public education and outreach. The following are common sources of pollutants found in our waterways that are generated in typical households in Town.
Disclaimer: These documents were developed by University of Connecticut Climate Corps students. This material is provided for informational purposes only and does not represent official Town analysis, findings, or recommendations. The Town assumes no responsibility for the accuracy or use of the information contained herein.
Educational Outreach for Public Schools
Attached are four lesson plans developed by UConn Climate Corps students Olivia Wheeler and Ella Rogers on a variety of environmental topics, including sustainable design solutions, climate change impacts on weather and soil, ecosystem services, and environmental messaging through Silent Spring and Big Yellow Taxi.
This project was intended to provide the Manchester Public Schools with educational materials focused on human development, land use, and impacts on Earth systems, while supplementing the Grade 6 and 7 Earth and Space Science Survey (ESSS) curriculum. The lesson plans incorporate activities, videos, and discussion materials designed to introduce students to concepts related to sustainable development and land use and align with topics already included in the existing curriculum. The lesson plans can be downloaded using the link below. The included PDF files contain additional links to other resources that are part of each plan.
Sustainable Development & Land Use Educational Materials(ZIP, 406KB)
Disclaimer: These documents were developed by UConn Climate Corps students. This material is provided for informational purposes only and does not represent official Town analysis, findings, or recommendations. The Town assumes no responsibility for the accuracy or use of the information contained herein.
Illicit Discharge
Help keep our water clean: if you see illegal dumping into storm drains, please call (860) 647-3067 or (860) 647-5235.