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Interbasin Diversions & Registration

An interbasin diversion is a transfer of water or wastewater from one major drainage basin to any other drainage basin. New York State has 17 major drainage basins (PDF) identified by various US Geological Survey (USGS) Hydrologic Unit Codes (HUC), a standardized watershed classification system developed by the USGS)

Great Lakes-St. Lawrence River Basin

Diversions of any quantity from the Great Lakes-St. Lawrence River Basin are prohibited by the Great Lakes-St. Lawrence River Basin Water Resources Compact (PDF), as enacted in ECL Article 21 Title 10. Limited exceptions for public water supply systems may be considered when in compliance with the Compact as set forth in 6 NYCRR Part 601.10(n) (leaves DEC website).

All Other Basins

Outside of the Great Lakes-St. Lawrence River Basin, interbasin diversions in New York State that are in excess of an average of 1,000,000 gallons per day must be registered with DEC (PDF) in accordance with 6 NYCRR Part 601.18 (leaves DEC website). No registration is required If the diversion is already operating as part of a water withdrawal permit from the DEC or the Delaware River or Susquehanna River Basin Commissions. A new or increased interbasin diversion will not be approved if it results in a significant adverse impact on the water quantity in the major drainage basin that is the source of the diversion and from which waters are diverted.

Annual Renewal of Interbasin Diversions

Renewals of interbasin diversion registrations shall be submitted by March 31 of each year.

Transfer of Ownership

Interbasin diversion registrations must be obtained within 60 days of transfer of ownership of the facilities which create an interbasin diversion.

Information Required for Interbasin Diversion Registration

In order to be deemed complete, an interbasin diversion registration or renewal requires the following information:

  1. The information requested on the Interbasin Diversion Registration Form (PDF)
  2. General map. Maps shall be USGS topographic maps, or equivalent, and must indicate the location of the withdrawal, the diversion, and the discharge or return flow. The map shall include the line of divide between New York major drainage basins, and the locations of all inter-connecting pipelines, canals, streams or tunnels.
  3. Engineering report signed and stamped by a New York State registered Professional Engineer. The Engineering report shall contain the following information:
    1. a general description and the engineering features of the existing or proposed interbasin diversion;
    2. a listing of all related Departmental permit applications or permits;
    3. a description of the amounts of water or wastewater diverted on a daily, monthly and annual basis; and
    4. an evaluation of the impacts of the diversion on the quantity of water in the New York major drainage basin that is the source of the diversion and from which waters are diverted.
  4. Annual Water Withdrawal Reporting Form (PDF) completed for the previous calendar year. Reporting forms are available for agricultural water withdrawals and for non-agricultural withdrawals.

For more information, please review the regulations for interbasin diversions (leaves DEC website).