With such a massive population, New York City’s water supply has it’s work cut out which is why the city’s internal system still stands as one of the most intricate. The Big Apple’s water supply serves a span of 125 miles while delivering one billion gallons of drinking water to over nine million people.

As far as the origins of the city’s water system – in 1842, the City decided to impound water from the Croton River via the Old Croton Aqueduct. The aqueduct had a capacity of about 90 million gallons per day. In 1883 the city then formed a commission to build a second aqueduct from the Croton watershed in addition to more storage reservoirs.

The Board of Water Supply was established in 1905 by the State Legislature as well as the Catskill region developed to be an additional water source for the city. The Board of Water Supply proceeded to plan and construct facilities to impound the waters of the Esopus Creek to deliver the water throughout NYC.

Water for this system is impounded in three upstate reservoir systems that ultimately house 19 reservoirs and three controlled lakes. Overall, the system has a storage capacity of about 580 billion gallons. The three water collection systems were structured to be interconnected so that water transitions easily from one system to another.

Although New York City’s latest addition to their water supply system stands to be their biggest step forward yet. The U.S. Environmental Protection Agency ordered that the city filter its water and NYC had to make that upgrade at the cost of $3.5 billion. Located in the Bronx at Van Cortlandt Park, the Croton Water Filtration Plant is currently filtering 10% of the city’s drinking water and it plans to take on a bigger load.

The filtration plant was a must-needed upgrade as the city’s population continues to grow. But the most interesting aspect of the water system still stands even from system’s 1842 inception. 95% of the total water supply is generated by gravity and just 5% requires a pressure pump to continue the water flow.

New York City’s goal is to increase their new filtration system’s capacity to the point where it plays a hand in all of the water consumed throughout the five boroughs and with their $3.5 billion dollar addition, they are in clear route towards that goal.