Cannonsville Reservoir

The Cannonsville Reservoir is a reservoir in the New York City water supply system in Delaware County, New York. It was formed by construction of the Cannonsville Dam on its west end, which impounded over half of the West Branch of the Delaware River. Lying on the western part of the Delaware Watershed, it is the westernmost of New York City\’s reservoirs. It was placed in service in 1964, and is the most recently constructed New York City-owned reservoir.

The town of Cannonsvile was destroyed to make room for the reservoir, which lies within the towns of Tompkins and Deposit.

Its 1,180 km2 drainage basin is the largest of all of the NYC reservoirs. Capacity is 362,000,000 m3. Water from the reservoir flows through the 71 km West Delaware Tunnel into the Rondout Reservoir, before joining the 137 km Delaware Aqueduct, which provides New York City with about 50% of its drinking water.