Delaware River Basin States And New York City Announce One-Year Reservoir Operating Plan Agreement

CONTACTS: Robert Mason or Marie Stewart, Office of the Delaware River Master, (570) 296-7213


MILFORD, Pa. (May 31) – New York State, Pennsylvania, New Jersey, Delaware, and the City of New York today announced that they have unanimously approved a one-year extension of the current Flexible Flow Management Program (FFMP) intended to meet water supply demands, protect fisheries habitat downstream of the New York City (NYC) Delaware Basin reservoirs, enhance flood mitigation, and repel the upstream movement of salt water in the Delaware Estuary.

Releases of water from the three City reservoirs (Pepacton, Cannonsville, and Neversink) located in the headwaters of the Delaware River, and out-of-Basin diversions, are managed according to procedures unanimously agreed to by the four states and NYC under the terms of a 1954 U.S. Supreme Court Decree that settled an interstate water dispute between New York State and New York City, and the lower basin states.

The Decree Parties (four basin states and NYC) will use the next year to further evaluate this interim reservoir management plan and use the experience to help guide ongoing negotiations to develop future multi-year agreements.

The FFMP, which will be in effect through May 31, 2014, will continue to rely on use of the City’s Operations Support Tool (OST) to manage water forecasted to be available in the three NYC reservoirs and help guide selection of reservoir release rates. The OST is a sophisticated monitoring and modeling system that allows for better predictions of reservoir-specific water storage levels, quality, and inflows than previous tools. The progressively evolving OST has proven to be a very useful tool in managing the FFMP. Its development continues on schedule with the complete version planned to be fully operational in late 2013.

Release rates in the renewed one-year agreement are patterned after recommendations provided in a January 2010 joint fisheries paper prepared by the New York State Department of Environmental Conservation and the Pennsylvania Fish and Boat Commission.

NYC will continue to create a higher potential to achieve a 10 percent storage void in its Delaware Basin reservoirs from Sept. 1 to March 15, as well as an average 5 percent void from July 1 to Sept. 1 and from March 15 to May 1. This program may help reduce peak spill rates during periods of high inflows and heavy snow melt. A significant fraction of the snow pack present in the watershed of the NYC reservoirs is included when calculating void promotion releases. Snow pack during the past winter was below normal.

In addition, reservoir releases will continue to be adjusted as needed to assist in repelling the upstream migration of salt water from the Atlantic Ocean that moves up the tidal Delaware River during low-flow conditions. As salt water moves upriver, the City of Philadelphia and other public water suppliers can be adversely affected, along with industrial surface water users and ecosystems.

The renewed FFMP maintains New Jersey’s increased maximum diversion from the Delaware River Basin through the Delaware and Raritan Canal to a daily running average of 85 million gallons per day when the basin is in a drought emergency.

Additional details, including the FFMP agreement and OST background information, can be viewed on the web site of the Office of the Delaware River Master, which administers the provisions of the 1954 U.S. Supreme Court Decree, at

For questions and information, contact DGS at, 302-831-2833

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