The Croton River was the main source of the city water supply from 1842 to the mid-20th century. Water was brought to the city through the Croton Aqueduct, later called the Old Croton Aqueduct.[3] The larger New Croton Aqueduct opened in 1890.[4] The Old Croton Aqueduct remained in service until 1955.[5]
Seeking to expand the city's water supply, engineers of the city Aqueduct Commission designed in 1884 a 275-to-300-foot-high (84 to 91 m) masonry dam spanning the Croton River near its mouth. The resulting storage reservoir, impounding a 16-square-mile (41 km2) watershed, would hold 14.2 billion US gallons (54,000,000 m3) at full capacity.[6] This dam, now known as the New Croton Dam, was completed in 1906. Further upstream, two tributaries of the Croton were dammed, creating the Croton Falls Reservoir, which was placed into service in 1911.
In the 1890s, rather than building an expensive filtration system, the city ordered the destruction or relocation of any village or hamlet in the watershed that was considered to be a potential pollution source for the Croton or its tributaries. Many were moved.[citation needed]
In the late 1990s, the city stopped using water from the Croton system as it became more and more unsuitable for drinking. In 2004, a project was started to rehabilitate the New Croton Aqueduct and build the Croton Water Filtration Plant, which came online in May 2015.[3][7] By the early 21st century the Croton system was supplying 10% of the city's water.[8]
^As a result of dam construction, the waters of the Middle and West Branches mingle in Croton Falls Reservoir before exiting as a brief stretch of the West Branch alone, which joins the East Branch at the confluence of the Croton River proper.
^Wegmann, Edward (December 1912). "Discussion on Design of Masonry Dams". Transactions of the American Society of Civil Engineers. New York, NY: American Society of Civil Engineers. 75: 163. Paper No. 1221.
