Office of the

Delaware River Master


In 1954, the U.S. Supreme Court issued a Decree in State of New Jersey v. State of New York and City of New York in which the Court established the position of the Delaware River Master. The Court directed that the River Master perform multiple duties and functions including administering the provisions of the Decree relating to yields, diversions, and releases; conserving the waters of the river; compiling data on the water needs of the parties; checking and correlating streamflow measurements and records; observing, recording, and studying the effect of developments in the watershed on water supply and other uses; and making periodic reports to the Court.

Since 2007, the Decree Parties have unanimously agreed to a series of Flexible Flow Management Program agreements. On October 21, 2017, the Parties to the Decree (DE, NJ, NY, NYC, PA) signed the 2017 Flexible Flow Management Program (FFMP2017). FFMP2017 is a two-part, ten-year agreement, which guides the current operations of the ODRM.

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Montague Data

Last 30 days.

Current Diversions

New York

The Decree authorizes the City of New York to divert water from the Delaware River watershed. At no time during any twelve-month period, commencing June 1, shall the aggregate total quantity diverted, divided by the number of days elapsed since the preceding May 31, exceed the applicable permitted rate of diversion.

New Jersey

The Decree authorizes the State of New Jersey to divert outside the Delaware River watershed. The diversion is not to exceed 100 m. g. d. as a monthly average, with the diversion on any day not to exceed 120 million gallons.

Current Data


Total Storage Capacity

Based on new values in use June 1st 2018

Cannonsville Reservoir

Available Storage: 89.45%

Pepacton Reservoir

Available Storage: 94.11 %

Neversink Reservoir

Available Storage: 96.30 %

Data presented on the Office of the Delaware River Master website are reviewed periodically to ensure accuracy. The data are considered provisional, however, until they are published in the annual report of the River Master. Data users are advised to carefully consider the provisional nature of the information before using it for decisions that concern personal or public safety or the conduct of business that involves substantial monetary or operational consequences. Information on the accuracy and appropriate uses of the data can be obtained by contacting the Deputy Delaware River Master.

Contact Us

Robert R. Mason Jr.
Delaware River Master
(703) 648-5305
rrmason@usgs.gov
Kendra Russell
Deputy Delaware River Master
(703) 648-5323
klrussell@usgs.gov
Vin Difrenna
Staff Hydrologist
(570) 296-7213
vdifrenna@usgs.gov

Office of the Delaware River Master ∙120 Route 209 South ∙ Milford, PA 18337