The Catskill Aqueduct, part of the New York City water supply system, brings water from the

Catskill Mountains The Catskill Mountains, also known as the Catskills, are a physiographic province of the larger Appalachian Mountains, located in southeastern New York. As a cultural and geographic region, the Catskills are generally defined as those areas cl ...

to Yonkers where it connects to other parts of the system.

History

Construction commenced in 1907. The aqueduct proper was completed in 1916 and the entire Catskill Aqueduct system including three dams and 67 shafts was completed in 1924. The total cost of the aqueduct system was $177 million ().

Specifications

The aqueduct consists of of cut and cover aqueduct, over of grade tunnel, of pressure tunnel, and nine miles (10 km) of steel siphon. The 67 shafts sunk for various purposes on the aqueduct and City Tunnel vary in depth from 174 to . Water flows by gravity through the aqueduct at a rate of about . The Catskill Aqueduct has an operational capacity of about per day north of the

Kensico Reservoir The Kensico Reservoir is a reservoir spanning the towns of Armonk (North Castle) and Valhalla ( Mount Pleasant), New York, located 3 miles (5 km) north of White Plains. It was formed by the original earth and gravel Kensico Dam constructed in 18 ...

in Valhalla, New York. Capacity in the section of the aqueduct south of Kensico Reservoir to the Hillview Reservoir in

Yonkers, New York Yonkers () is a city in Westchester County, New York, United States. Developed along the Hudson River, it is the third most populous city in the state of New York, after New York City and Buffalo. The population of Yonkers was 211,569 as en ...

is per day. The aqueduct normally operates well below capacity with daily averages around 350– of water per day. About 40% of New York City's water supply flows through the Catskill Aqueduct.

Geography

The Catskill Aqueduct begins at the Ashokan Reservoir in Olivebridge, New York, located in Ulster County. From the Ashokan Reservoir, the aqueduct traverses in a southeasterly direction through Ulster, Orange, and Putnam counties. It tunnels first beneath the Rondout Valley and Rondout Creek in the town of Marbletown, then beneath the Wallkill River in the town of Gardiner in Ulster County before flowing toward

Orange County, New York Orange County is a county located in the U.S. state of New York. As of the 2020 census, the population was 401,310. The county seat is Goshen. This county was first created in 1683 and reorganized with its present boundaries in 1798. Orang ...

. It crosses below the Hudson River bed at Storm King Mountain in Orange County before reaching Putnam County on the east side of the river at Breakneck Mountain. The aqueduct transports water from Ashokan as well as the Schoharie Reservoir, which feeds into Ashokan.The Hudson River Guidebook By Arthur G. Adams
/ref> The aqueduct then enters Westchester County, New York, and flows to the

, which also receives water from the City's

Delaware Aqueduct 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, then into ...

. It continues from the Kensico reservoir and terminates at the Hillview Reservoir in Yonkers. The Hillview Reservoir then feeds City Tunnels 1 and 2, which bring water to New York City. If necessary, water can be made to bypass both reservoirs.

History

Specifications

Geography

References

See also