Kensico Reservoir

Kensico Reservoir covers 870 hectares (2,145 acres) between the towns of Armonk and Valhalla, storing water channeled from the Catskill Mountains through aqueduct systems. The large granite dam forms the southern boundary of the body of water and defines the overall appearance of the facility.

The current dam was built between 1913 and 1917, replacing an earlier earth structure dating from 1885 to expand the water supply for New York City. This expansion formed part of a larger project to secure sufficient drinking water reserves for the growing urban population.

The body of water takes its name from Chief Cokenseko of the Siwanoy tribe, who sold the surrounding territory to English colonists during the seventeenth century. This connection to indigenous history remains visible through the name itself.

Anyone wishing to enter the grounds needs a free access permit from the New York City Department of Environmental Protection, available online or on site. The paths around the body of water suit walking and observation, although certain areas may remain closed year-round.

Nearly all the water comes from external sources, with only about two percent flowing from the facility's own 34-square-kilometer (13-square-mile) watershed. This characteristic makes the installation a pure relay and storage system within the municipal water network.