It allowed the City to purchase watershed land in the Catskill Mountains and to create new reservoirs by damming streams and rivers. The residents of several villages were moved and the towns flooded to create reservoirs. In this way, the City developed the Catskill and Delaware reservoir systems, which were completed in 1927 and 1965, respectively. The system today The watersheds of the three systems cover an area of almost 2,000 square miles, approximately the size of the State of Delaware. The reservoirs combined have a storage capacity of 550 billion gallons.
Chlorine is added to the water to kill bacteria, and fluoride is added to help prevent tooth decay.
Located in Westchester, Putnam and Dutchess Counties, the Croton system has 12 reservoirs and 3 controlled lakes. The largest, the New Croton Reservoir, can hold 19 billion gallons of water. The system normally supplies 10 percent of the City s drinking water, but can supply more when there is a drought in the watersheds farther upstate. The Catskill system includes 2 reservoirs and supplies up to 40 percent of the City s daily needs. The Catskill watershed is located in parts of Greene, Ulster and Schoharie Counties, about 100 miles north of New York City and 35 miles west of the Hudson River.