Stormwater

Storm water runoff

What is stormwater?

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.

Green Infrastructure

Green infrastructure is a cost-effective, resilient approach to managing wet weather impacts that provides many community benefits. While single-purpose gray stormwater infrastructure-conventional piped drainage and water treatment systems-is designed to move urban stormwater away from the built environment, green infrastructure reduces and treats stormwater at its source while delivering environmental, social, and economic benefits.

Stormwater runoff is a major cause of water pollution in urban areas. When rain falls on our roofs, streets, and parking lots in cities and their suburbs, the water cannot soak into the ground as it should. Stormwater drains through gutters, storm sewers, and other engineered collection systems and is discharged into nearby water bodies. The stormwater runoff carries trash, bacteria, heavy metals, and other pollutants from the urban landscape. Higher flows resulting from heavy rains also can cause erosion and flooding in urban streams, damaging habitat, property, and infrastructure.

When rain falls in natural, undeveloped areas, the water is absorbed and filtered by soil and plants. Stormwater runoff is cleaner and less of a problem. Green infrastructure uses vegetation, soils, and other elements and practices to restore some of the natural processes required to manage water and create healthier urban environments. At the city or county scale, green infrastructure is a patchwork of natural areas that provides habitat, flood protection, cleaner air, and cleaner water. At the neighborhood or site scale, stormwater management systems that mimic nature soak up and store water.

Read more about Green Infrastructure for Wet Weather

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 Construction Stormwater Toolbox webpage.

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
Contact for this Page

DOW, Bureau of Water Permits
625 Broadway
Albany, NY 12233

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