The New York City (NYC) reservoirs in the Delaware River Basin are an essential source for goods and services, such as drinking water supply to the cities, recreation, transportation, power generation, and a host of ecosystem services. The reservoirs are located at the headwaters of the Delaware River, which supplies water to New York, New Jersey and Pennsylvania, as well as the world's largest freshwater port. However, the river is vulnerable to water shortages under changing climate conditions and needs to be managed wisely. This study developed a hydrologic model within the Stella modeling software for the NYC reservoirs to determine how historical reservoir management policies perform at meeting water demands in the basin and out-of-basin. Moreover, the model helps to better understand the interconnected effects of the water use sectors under different climate conditions and to address water shortages and water quality problems under water-stressed conditions. The model predicts reservoir releases based on inflows to reservoirs, water demand by sector and historical reservoir management policies. The model predictions are compared with historical data to assure that the model is operating in the designed manner. The impact of this study extends directly to decision makers, and stakeholders who rely on water resources in the basin. Moreover, running simulation over the period of fifteen years record and analyzing the main droughts in the basin shows how the different operations manage drought over the historical record. These simulations will help for comparing the various operations for future scenarios.