(CTDOT's Stormwater Quality Management Program)



As of July 1, 2019, the Connecticut Department of Transportation (Department) is subject to the goals and requirements of a stormwater discharge permit that aims to reduce the amount of pollution discharged to the state’s surface waters and wetlands.

The "General Permit for the Discharge of Stormwater from Department of Transportation Separate Storm Sewer Systems” (General Permit) was issued by the Connecticut Department of Energy and Environmental Protection (CTDEEP) under the authority of National Pollutant Discharge Elimination System (NPDES) program.

Within the NPDES program, the Department of Transportation is considered a non-traditional municipality. As such, the Department’s drainage system is commonly referred to as the DOT MS4, which stands for Department of Transportation Municipal Separate Storm Sewer System.

The broad goals of the General Permit affect nearly every aspect of CTDOT’s operations, from design to construction to operations and maintenance. In order to address these goals, the Department has developed a Stormwater Management Plan (SWMP) that identifies best management practices for each goal. A copy of the SWMP will be available here on or before April 1, 2019.

Beyond the initial development and implementation of the SWMP, the Department will also produce annual reports to detail progress in implementing each of the best management practices specified in the plan. Links to any annual reports completed to date and to other Department and non-point source pollution topics are included below.

     Contact Us    

CTDOT has established a dedicated email address for the purpose of collecting public comments and concerns regarding CTDOT’s MS4 program. If you have questions, comments or concerns about the program, please contact us at DOT.MS4@ct.gov.

If you believe that you have observed an illicit discharge entering or leaving CTDOT’s storm sewer system please send an email to DOT.MS4@ct.gov. or call the CTDOT Customer Care Center (860) 594-2560. To the extent possible please include any details regarding the discharge such as location (address, nearest cross street, mile markers, etc.), the name of the receiving water and a description of what’s been observed (source, color, odor, etc.).

For all other transportation related comments or questions please use our contact us form.

Storm Outlet Example 1    Storm Outlet Example 2
DOT Related Links

2020 Annual Report

2021 Annual Report

2022 Annual Report

2023 Annual Report

2024 Annual Report


Water & Noise Compliance Webpage

Hydraulics and Drainage Webpage

Environmental Compliance Webpage

CTDOT MS4 GIS Database Maintenance Guide

CTDOT MS4 Drainage GIS Map

  Stormwater Outlet Example 5
Public Education / Outreach

CT NEMO MS4 Webpage


Non-Point Source Pollution

Engineering Directive

Designer Worksheet

Designer Worksheet Instructions

MS4 Water Quality Volume Worksheet

MS4 Designer Examples

BMP One-Pagers

BMP Matrix


EPA Non-Point Source Pollution