The Jacqueline Kennedy Onassis Reservoir — originally and sometimes still known as the Central Park Reservoir — is a decommissioned reservoir in Central Park in the borough of Manhattan in New York City, USA.
The JKO Reservoir covers 106 acres (43 ha) and holds over 1,000,000,000 US gallons (3,800,000 m3) of water. Though no longer used to distribute New York City's water supply, it provides water for the Pool and the Harlem Meer. It is a popular place of interest; there is a 1.58-mile (2.54 km) jogging track around it and it is also encircled by the park's bridle trail. It is often visited by tourists, especially when its double pink "Yoshino" cherries (Prunus x yedoensis), followed by Prunus serrulata "Kanzan" cherries, are blooming. The rhododendrons along the "Rhododendron Mile" were a gift to the city from Mrs Russell Sage, in 1909. It is one of the main ecological sanctuaries in the Park, housing more than 20 species: aside from the familiar mallards and Canada geese, there may also be seen coots, loons, raccoons, cormorants, wood ducks, grebes, herons and egrets, both in migration and overwintering, making it a favorite venue for birdwatchers.