The system of scenic water bodies created by Central Park's designers, Frederick Law Olmsted and Calvert Vaux, is a defining feature of the Park's north end. Through excavation, the introduction of dams and weirs, and piping from the Croton Aqueduct system, Olmsted and Vaux converted an existing stream and marshland into the Pool on the west side of the Park at 100th Street. The Pool flows through the picturesque Ravine in the North Woods, continues along a series of small pools and cascades known as the Loch, and empties into the Harlem Meer at the northeast corner of the Park.
While the Pool, the Loch, and the Harlem Meer still form an interconnected system, they are fed continuously by City water that empties into a sewer system on Fifth Avenue. In the 1960s, the original watercourse was also diverted into a culvert, disrupting the flow of water and diminishing the recreational value of the landscape.
Several years ago, the Central Park Conservancy and the New York City Department of Environmental Protection (DEP) began to explore the possibility of water recirculation in the Park’s lakes and ponds to conserve potable water and reduce outflow to the City’s sewers. The proposed recirculation system will capture stormwater from 205 acres of the north end of the Park (nearly a third of the Park's total area). This water currently drains to combined sewers in Harlem and East Harlem; instead, the system will pump the water from the outflow at the Harlem Meer to a manhole just south of the 100th Street Pool. From there, water will flow by gravity into the Pool and back through the water body system.
Modeling shows the proposed system will save a significant amount of potable water per day and keep a considerable amount of stormwater out of the City’s sewers during rain events. The system will also address water quality by reducing nutrients that contribute to harmful algal blooms.
The project is currently in design, with a target to start construction in 2025.