What is Stormwater Runoff?

Stormwater is water that originates during precipitation events or snow/ice melt that runs off surfaces such as rooftops, paved streets, highways, and parking lots. It can also come from hard grassy surfaces like lawns, play fields, and from graveled roads and parking lots.

What is Stormwater Pollution?

When stormwater runoff flows over surfaces it picks up and carries with it many different pollutants such as:

• Garbage
• Oil and grease
• Gasoline
• Sediment from construction sites and urban runoff
• Metal flakes from rusting vehicles and brakes
• Road salt
• Lawn pesticides
• Agricultural herbicides
• Heavy metals from roof shingles
• Pet waste
• Leaves
• Grass clippings
• Bacteria
• Nutrients such as phosphorus and nitrogen
• Other chemicals
• Illicit discharges such as paints, cleaning solution products and used motor oil

These pollutants cause stormwater runoff to be the number one cause of stream impairment in urban areas.  Specific to Norwalk, these pollutants can close our beaches, shellfish industry, and other recreational water activities.

What is Stormwater Management?

The intentional capture, placement, or movement, and treatment of stormwater runoff in order to minimize pollution and/or flooding.  The City of Norwalk manages and maintains the stormwater system as required under the Connecticut Department of Energy and Environmental Protection’s (CT DEEP) General Permit for the Discharges of Stormwater from Small Municipal Separate Storm Sewer Systems (MS4).  The purpose of the MS4 general permit is to protect waters of the state from urban stormwater runoff through municipal stormwater sewer systems. The permit outlines a program of the following six Minimum Control Measures:

• Public education and outreach
• Public involvement / participation
• Illicit discharge detection and elimination
• Construction site stormwater runoff control
• Post-construction stormwater management
• Pollution prevention/good housekeeping

City Stormwater Management Plan and Annual Reports:

• 2004 Stormwater Management Plan
• 2015 Annual Report
• 2016 Annual Report
• 2017 Annual Report
• 2018 Annual Report
• 2019 Annual Report
• 2020 Annual Report
• 2021 Annual Report
• 2022 Annual Report

Customer Service Center:

If you have questions, comments, or would like to report water pollution, please contact our Customer Service Center at 203-854-3200. 

• Customer Service Center - Help Desk

Stormwater Educational Materials:

• "After the Storm" - Citizens Guide to Understanding Stormwater by EPA
• "The Solution to Pollution" – A homeowner’s guide to health habits for clean water by EPA
• “When It Rains, It Drains” – Understanding Stormwater and How It Can Affect Your money, Safety, Health, and the Environment by the PADEP
• Fact Sheet: City of Norwalk Water Quality and Stormwater Summary – CTDEEP
• Fact Sheet: MS4 General Permit – CTDEEP

Related Information:

• Harbor Watch 
• East Norwalk Blue 
• Norwalk River Watershed Association
• The Maritime Aquarium – Conservation & Research
• On the Pathway to Long Island Sound 
• CTDEEP Stormwater Management
• EPA Facility Stormwater Management
• UCONN-NEMO MS4 Public Education and Outreach