Kensico Reservoir in the context of "Byram River"

The Bronx River (/brɒŋks/), is a river that is approximately 24 miles (39 km) long, and flows through southeastern New York in the United States and drains an area of 38.4 square miles (99 km). It is named after colonial settler Jonas Bronck.

It originally rose in what is now the Kensico Reservoir, in Westchester County north of New York City, on a hill about 650 feet (200 m) above sea level in what is now New Castle, New York. The river originated in an area the Weckquasgeek called Quaropes, which means White Marshes. It was fed by the Fulton Brook, Manhattan Park Brook, Davis Brook, and Tompkins Brook. With the construction of the Kensico Dam in 1885, however, the river was cut off from its natural headwaters and today a small tributary stream originating from the reservoir as its source. The Bronx River flows south past White Plains, then south-southwest through the northern suburbs in New York, passing through Edgemont, Tuckahoe, Eastchester, and Bronxville. In the area known as the Aquehung, it is fed by Harts Brook and the north and south Fox Meadow Brooks. At Tuckahoe, it is fed by Troublesome Brook. At Bronxville, it is fed by Sprain Brook, its longest tributary system, which originates at Greenburgh Town Park.

The Delaware Aqueduct is an aqueduct in the New York City water supply system. It takes water from the Rondout, Cannonsville, Neversink, and Pepacton reservoirs on the west bank of the Hudson River through the Chelsea Pump Station near Beacon, New York, then into the West Branch, Kensico, and Hillview reservoirs on the east bank, ending at Hillview in Yonkers, New York.

Built between 1939 and 1945, the Delaware Aqueduct carries about half of New York City's water supply of 1.3 billion US gallons (4,900,000 m) per day. At 13.5 feet (4.1 m) wide and 85 miles (137 km) long, it is the world's longest tunnel.