Croton Watershed

Spanning large swaths of Putnam and Westchester counties in far southeastern New York State, it represents the drainage, flow, and operating systems of some seven rivers, one dozen reservoirs, and three controlled lakes[1][2] falling within the Croton River watershed.

[b] Over 350 square miles (910 km2) in area, the Watershed holds some 100 billion US gallons (380,000,000 m3) of fresh water.

[c] The vast majority of this ends up at the Jerome Park Reservoir in the Bronx via the New Croton Aqueduct, from which it is distributed.

The Croton Watershed is a term describing a part of the New York City water supply system.

Excess water leaves the spillway at the New Croton Dam and empties into the Hudson River at Croton-on-Hudson, New York at Croton Point, about 30 miles (50 km) north of New York City.

Numerous small natural lakes and ponds, as well as large Lake Mahopac , are part of the Croton River 's watershed but not part of New York City’s supply system. A map of the actual Croton Watershed is found here.
The three branches of the Croton River are collected at the New Croton Reservoir . Flow in excess of New York City's needs goes over a spillway at the New Croton Dam there and discharges into the Hudson River