Connecticut Department of Energy & Environmental Protection

Department of Transportation (DOT) Separate Storm Sewer System General Permit

DEEP first issued the General Permit for the Discharge of Stormwater from the Connecticut Department of Transportation Separate Storm Sewer Systems (CTDOT MS4) on May 24, 2018 (effective July 1, 2018) under the EPA Stormwater Rule.

2025 Permit Issuance Package

DOT MS4 Stormwater Management Plan (2020).  Please note, this SMP will be updated in 2025 upon receipt from CT DOT.

**DOT MS4 General Permit**  (75 pages, uploaded 08/05/2025)

  • Issuance Date: 06/23/2025
  • Effective Date: 07/01/2025
  • Expiration Date: 06/30/2030

Fact Sheet for the DOT MS4 General Permit (21 pages, uploaded 08/05/2025)

Response to Public Comments for the reissuance of the MS4-DOT General Permit (2 pages, uploaded 08/05/2025)

For more information on: Permit Application, Stormwater Prevention Plan, and Annual Reports, please visit the CT Department of Transportation website.

For additional details on the permit please contact the Stormwater Permitting, Compliance, & Enforcement Program, email: DEEP.StormwaterStaff@ct.gov

The cornerstone of the MS4 permit is the Stormwater Pollution Prevent Plan

This plan outlines a program of best management practices (BMPs), measurable goals, responsible individuals or departments, and sets forth implementation schedules for the following six minimum control measures specified in the permit:

Six Minimum Control Measures
Six minimum control measures 

Impaired water monitoring

 

Additionally, the Stormwater Management Plan (SWMP) outlines the Department’s plan to monitor and improve the quality of stormwater runoff from DOT’s stormwater system to impaired surface water bodies. 

 

CT DOT Drainage Network

*Disclaimer: The following information is not generated by CT DEEP. Please visit the CT DOT website for more information. 

This service represents CTDOT’s Stormwater Drainage Network available for the Open Data Portal. The CTDOT Drainage Network for public viewing includes Culverts, Closed Conveyances, Open Conveyances, Virtual Drian Lines, Inlets, Headwalls/End Walls, Manholes, Blind Ties, Interconnections, Other Drainage, and BMP’s. Click the link here for more information on the CT DOT Drainage Network.

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. 

 

 

Content last updated August 20, 2025