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What is stormwater?

Stormwater flowing arcoss a road, washing out parts of an adjacent field
Stormwater runoff carries pollutants into waterbodies

Stormwater is water from rain or melting snow that doesn't soak into the ground but runs off into waterways. It flows from rooftops, over paved areas and bare soil, and through sloped lawns while picking up a variety of materials on its way. The quality of runoff is affected by a variety of factors and depends on the season, local meteorology, geography, and land use.

What's the Problem

As it flows, stormwater runoff collects and transports pollutants to surface waters. Although the amount of pollutants from a single residential, commercial, industrial, or construction site may seem unimportant, the combined concentrations of contaminants threaten our lakes, rivers, wetlands, and other waterbodies. Pollution conveyed by stormwater degrades the quality of drinking water, damages fisheries and habitat of plants and animals that depend on clean water for survival. Pollutants carried by stormwater can also affect recreational uses of waterbodies by making them unsafe for wading, swimming, boating and fishing. According to an inventory conducted by the United States Environmental Protection Agency (USEPA), half of the impaired waterways are affected by urban/suburban and construction sources of stormwater runoff.

Examples of Pollution in Stormwater

  • Nutrients such as phosphorus and nitrogen can promote the overgrowth of algae, deplete oxygen in the waterway, and be harmful to other aquatic life.
  • Bacteria from animal wastes and illicit connections to sewerage systems can make nearby lakes and bays unsafe for wading, swimming, and the propagation of edible shellfish.
  • Oil and grease from spills during vehicle maintenance activities causes sheen and odor and makes transfer of oxygen difficult for aquatic organisms.
  • Sediment from construction activities clouds waterways and interferes with the habitat of living things that depend upon those waters.
  • Careless application of pesticides, herbicides, and fertilizers affect the health of living organisms and cause ecosystem imbalances.
  • Trash and debris damages aquatic life, introduces chemical pollution, and diminishes the beauty of our waterways.

What can be done?

Significant improvements have been achieved in controlling pollutants that are discharged from sewage and wastewater treatment plants. Across the nation, attention is being shifted to potential sources of pollution, such as polluted stormwater runoff, that are not normally treated by wastewater treatment plants. Stormwater management, especially in urban areas, is becoming a necessary step in seeking further reductions in pollution in our waterways.

The best way to control contamination to stormwater is usually at the source, where the contaminants can be identified, reduced, or contained before being conveyed to surface water. More often than not, it's more expensive and difficult to remove the combination of contaminants that are present at the end-of-pipe where stormwater is finally discharged directly to a receiving waterbody. Sometimes, significant improvements can be made by employing best management practices (BMPs). Proper storage of chemicals, good housekeeping, and just plain paying attention to what's happening during runoff events can lead to relatively inexpensive ways of preventing pollutants from getting into the runoff and our waterways.

Regulatory Requirements

The USEPA and New York State Department of Environmental Conservation (NYSDEC) are increasing their attention in several ways. There are three State Pollutant Discharge Elimination System (SPDES) general permits required for activities associated stormwater discharges.

Stormwater Management Training Calendar

NYSDEC posts a calendar of Stormwater Management Training Events, Regional and Statewide Conferences, and other learning opportunities on the Stormwater Management Training and Certification Training page.

Stormwater Interactive Map

The Stormwater Interactive Map provides information related to the CGP and MS4 GP.

The interactive map includes information such as:

  • Impaired waterbodies for the CGP, MSGP, and MS4 GP
  • Enhanced Phosphorus Removal Watershed
  • AA and AAs Watersheds
  • Rainfall Information
  • The location of MSGP covered facilities
  • Automatically and Additionally Designated MS4 Areas
  • Classified Waters
  • Waterbody Inventory/Priority Waterbody List (WI/PWL)
  • Adminstrative Boundaries
  • The CGP database of authorized construction projects
  • A tool to determine coordinates needed to complete Notices of Intent for CGP

More about Stormwater :

  • Stormwater Training and Certification - Calendar of Upcoming Stormwater Management Training Events including NYSDEC Co-Sponsored SUNY-ESF Continued Education Courses; Local Training Events In NYS; Regional & Statewide Conferences; and Other Learning Opportunities. Descriptions of training events and conferences are provided. Many corresponding Offsite Links are included in right column of page.
  • Stormwater Permit for Construction Activity - This page contains the General Permit for Stormwater Discharges from Construction Activity and the forms necessary to obtain coverage under that permit.
  • Construction Stormwater Toolbox - Links for Stormwater Information including a host of tools and sources of technical information related to the General Permit for Construction Activities and useful for the design of stormwater management practices.
  • NYC MS4 Permit and Forms - This page contains the General Permit for Stormwater Discharges from Municipal Separate Storm Sewer Systems for New York City and the forms necessary to obtain coverage under that permit.
  • Stormwater MS4 Permit and Forms - This page contains the General Permit for Stormwater Discharges from Municipal Separate Storm Sewer Systems and the forms necessary to obtain coverage under that permit.
  • MS4 Toolbox - Tools for MS4
  • Multi-Sector General Permit (MSGP) - The NYSDEC's general permit for stormwater discharges from industrial activities.
  • MSGP Toolbox - MSGP Tool Box