The Office of the Delaware River Master was established to ensure compliance with the provisions of the 1954 Supreme Court Decree, subject to modifications stemming from more recent Flexible Flow Management Programs, and compilation of data concerning related streamflow, reservoir releases, and water diversions.
Provisional Hydrologic Data:
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.
- Weekly Reservoir and Release Data: Table (PDF)
- Previous Weekly Reservoir and Release Data: Archive
- OST Summary Data
- Storage for New York City Reservoirs: Graph (PDF)
- Monthly Hydrologic Conditions for the Upper Delaware River Basin Summaries: Archive (PDF)
- Consumption of Water by New York City and Outside Communities, 1940 - 2014
As part of the FFMP agreement, the New York State Department of Environmental Conservation (DEC) monitored the releases program to evaluate its effectiveness in protecting the coldwater ecosystem below the reservoirs. This report, NYSDEC Tailwaters Temperature Monitoring Report for June 2011 through May 2015, prepared by the DEC, summarizes the summer water temperatures observed under the oneyear FFMP agreement extensions in effect between June 1, 2011 and May 31, 2015. Thermal data were obtained from eight permanent USGS gages and 21 Onset Optic “Stow Away” thermographs installed and maintained by DEC staff on the upper East Branch, West Branch, Delaware River, and Neversink River. The report concludes that:
- Overall, the FFMP releases program was effective in maintaining flow and temperature targets in the Upper East Branch, West Branch, and Neversink River tailwater reaches. No thermal stress days were recorded for the Upper East Branch or the West Branch and only 7 in 2012 in the Neversink River. FFMP summer base flows to the West Branch were inadequate in maintaining desirable summer water temperatures in the upper Delaware River but this was also true of all earlier releases programs. Directed releases to meet the Supreme Court mandated Montague flow target continue to exert the greatest influence on summertime temperature and flow conditions on the West Branch and upper Delaware River. Thermal stress days on the Delaware River for the summers of 2011 through 2014 ranged from 0 to 13 at Lordville (RM 321) and 5 to 67 at Callicoon (RM 303).