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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 upon activities which lie in the path of the flow.

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 water bodies. 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 water bodies by making them unsafe for wading, swimming, boating and fishing. According to an inventory conducted by the United States Environmental Protection Agency (EPA), 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 automobiles 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.
  • Litter 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 sources of pollution, such as 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, or "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 in the first place and then our waterways.

Regulatory Requirements

The U.S.EPA and 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.

Public Involvement

The following information can be found on the Public Involvement web pages:

  • Dates of upcoming public meetings, agendas, background information and links to related information.
  • Draft permits are made available for public viewing and comment.
  • Responsiveness summaries are posted as the public comments are addressed.

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 Calendar.

Stormwater Interactive Map

The Stormwater Interactive Map provides information related to Stormwater General Permit program.

The interactive map includes information such as:

  • Coordinates needed to complete Notices of Intent
  • Regulated MS4 Areas
  • Watershed Improvement Strategy Areas
  • The 303(d) waterbodies included in Appendix E of the Construction Permit
  • AA and AAs Watersheds
  • DEC Regional Boundaries
  • Information on Authorized Construction Projects

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
  • Partners Available to Assist MS4s - MS4 Partners and other groups that may be available for assistance
  • Multi-Sector General Permit (MSGP) - The NYSDEC's general permit for stormwater discharges from industrial activities.
  • MSGP Toolbox - MSGP Tool Box