The New Croton Dam, across the Croton River, near Croton-on-Hudson, about 35 km north of New York City, was built between 1892 and 1906 to divert water from the Croton River into the New Croton Reservoir that supplies water to the residents of New York City. It was the first major water supply system for the city — one which played an important role in sustaining the early growth the city experienced, and without which New York City could never have grown to what it is today. The reservoir impounds about 19 billion gallons of water — now a small fraction of the New York City water system's total storage capacity of 580 billion gallons.

The original Old Croton Dam was built in 1842. The old reservoir had the capacity to supply about 90 million gallons of water a day to the city through a 66-km underground aqueduct. By the end of 19th century, it became clear that New York City needed more water. Consequently, work began on the New Croton Dam.

Photo credit