Stormwater Management

Stormwater Regulations and the Construction Industry

How To Be In Compliance

If your project will disturb one acre or more of ground, site owners and/or operators are required to:

  • Develop a Stormwater Pollution Prevention Plan (SWPPP) and follow it. The SWPPP is a plan for controlling runoff and pollutants from a site during and after construction.
  • Once a SWPPP is prepared, you must file a NOI( Notice of Intent)with the DEC to obtain a Stormwater General Permit from the NYSDEC. You can obtain help from the NYSDEC or your County Soil and Water Conservation District about permit requirements. You can also visit the NYSDEC website for detailed stormwater information (

Note - It could take up to 60 business days to get a permit, but often only takes 5 business days. Plan ahead!

  • Certify, under penalty of law, to follow the SWPPP. Landowners and contractors must sign a statement that they understand and agree to comply with terms and conditions of the SWPPP
  • Have a qualified professional* perform inspections after 1/2 inch of rain, as well as weekly, to determine compliance with water quality standards and adherence to the SWPPP. *As specified in the permit. See the NYSDEC website for more information.
  • Maintain erosion and sediment control practices and update the SWPPP regularly.
  • Install permanent stormwater management practice.
  • Keep all SWPPP and inspection forms in a logbook on the construction site.
  • If you begin construction before filing a NOI and obtaining coverage, you may be subject to a penalty of up to $37,500 per violation per day.

What Contractors Can Do At The Site

Soil erosion prevention and sediment control:

  • Minimize the area of exposed soil on-site: Plan tthe project in stages if possible; seed and mulch disturbed areas with permanent or temporary groundcover immediately upon reaching final grade; seed or cover stockpiles that will not be used immediately.
  • Reduce the velocity of stormwater: Use ESC practices such as vegetated buffers and check dams to slow down stormwater as it travels across and away from the project site; don't use silt fences or other types of perimeter fillers to reduce the velocity of runoffs and never install them in streams or ditches.
  • Keep sediment on-site: Maintain a minimum 50-foot length of clean stone at access points to accommodate large vehicles; sweep the construction entrance road often to prevent soil and debris from entering storm drains; do not hose paved areas; use temporary sediment traps and basins with other permanent measures to retain sediment.
  • Divert clean water from disturbed soil: Use interceptors and diversion structures to direct flow away from exposed areas toward stable portions of the site.
  • Maintain all ESC practices to ensure their effectiveness during the life of the project: Regularly remove collected sediment from the silt fences, berms, traps, and other practices; maintain sediment controls that protect sensitive areas such as diversion structures and silt fences; keep geotextiles and mulch in place until vegetation is well established.
For more information please visit the   NYS Department of Environmental Conservation website at and link to the Stormwater Program, or call the Nassau County SWCD at 516-571-6863