Since 1954, the Delaware River has been managed under the framework of a Supreme Court decree and the subsequent concomitant intergovernmental collaboration between New York State, New Jersey, Pennsylvania, Delaware, New York City (NYC) and the US federal government. Taking an environmental perspective, we review the evolution of water release policies for three NYC reservoirs from the issuance of the 1954 decree through the implementation of the Flexible Flow Management Program (FFMP) of 2007–2015 and examine the policies' impact on the upper Delaware River. We describe governmental and institutional constraints on the development of Delaware water policy and show how modifications of release policies have enhanced aquatic habitat and ecological health in the upper Delaware while reliably delivering water to NYC and the Delaware's other principal stakeholders. We describe the development of the FFMP in 2006, its subsequent modification, and its augmentation by NYC's Operations Support Tool in 2012. Finally, we discuss the negative ecological consequences of the 2010–2016 stalemate on Delaware water policy resulting from conflicts between the decree parties about current and future water rights, and how the stalemate derives partially from the decision structure imposed by the 1954 decree and the Good Faith Agreement of 1983.
Hydrogeology of the West Branch Delaware River basin, Delaware County, New York