Arguably the most critical part of new infrastructure needed for Greater New York was an increase in the water supply system. New York struggled with fresh water supply from its founding until the mid-1800s: being surrounded by salt water (the East River) and brackish water (the Hudson River) did nothing to ease the need for potable water, and the supply from streams and wells on Manhattan island was limited and, eventually, polluted. The construction of the Croton system – a dam on the Croton River (a small tributary of the Hudson about 40 miles north of Manhattan) to create a storage reservoir, an aqueduct to the city, and distributing reservoirs in Manhattan – provided a supply of clear water that greatly exceeded the demand in 1842, when it first opened. That supply was no longer adequate fifty years later.
The New Croton system, as shown in the photos above at the beginning of the Scientific American New York article on water supply consisted of a new dam and an enlarged aqueduct. The new dam was downstream of the old dam and higher, so when completed it encompassed the old system and its surroundings, increasing the storage. The new and bigger aqueduct allowed for a greater supply, and two new distributing reservoirs in the Bronx allowed for more efficient last-mile handling. The new system opened in 1890 and was not adequate for the continued growth in demand. A view of the New Croton dam from its HAER report is below.
The area west of the Hudson came next. The Catskill system, consisting of two damn on the Esopus Creek (another Hudson tributary) west of Kingston, a 90-mile aqueduct, and a new reservoir at Kenseco, just south of the Croton watershed, was in construction in 1908 when the article was published, and opened in stages starting in 1916.
That wasn’t enough either, and in the 1930s a third system, tapping the far northern branches of the Delaware River and its tributary the Neversink River. The Delaware system provides about half of the city’s water today, and the Catskill system about 40 percent. Since the Delaware system came into operation, efforts have focused on reducing system waste (for example, leaking pipes) and careless waste (by metering) rather than new sources.