New York City skyline

New York City's Brick River

Old New York City sidewalk water pump.

In the 19th century, New York City residents got their drinking water from sidewalk pumps like this one. Initially, the water was so pure that the dispensers were called "tea-water" pumps.
In the early 1800s, residents of New York City got their drinking water from sidewalk pumps that tapped into the city’s aquifer. But as industry in the city grew, the water became contaminated with the runoff from breweries, tanneries, slaughterhouses, and waste (both livestock and human).

The city fathers recognized that, if the metropolis were to flourish, it needed a dependable source of clean water. Two seminal events spurred them to action: the cholera epidemic of 1832, during which the water-borne bacteria killed 3,515 residents, and the Great Fire of 1835, which burned for three days and destroyed 17 city blocks in part because of a lack of readily available water.

Map of the Croton Aqueduct.
It took from 1837 to 1842 to build the 41-mile Croton Aqueduct.
Receiving reservoir in Central Park, distributing reservoir in midtown, and the New York Public Library's main branch.
Top: The receiving reservoir in Central Park, now the location of the Great Lawn.

Middle: The distributing reservoir at 5th Avenue (left) and 42nd St. (right). It was a massive affair that held 20 million gallons of water and had a promenade along the top, popular with residents for Sunday afternoon strolls.

Bottom: In the late 1890s, the midtown reservoir was torn down to make way for the New York Public Library's main branch. This image was taken before the installation of Patience and Fortitude, the two marble lions that guard the library's entrance.
Photos © New York Public Library.
As a result, in 1837, work began on one of the most ambitious municipal projects of the era: an aqueduct that would bring water from the pristine Croton River 41 miles north of Manhattan into the city. Once there, the water would be stored in two reservoirs, a receiving reservoir in Central Park, and a distributing reservoir on 42nd St.
By any account, the aqueduct was an impressive feat of engineering. It was built of bricks and hydraulic cement, the latter being especially resistant to wet environments. It used no mechanical pumps—water flowed to the city by the force of gravity alone. To accomplish that, the aqueduct dropped 13 inches every mile.

Cross-section of the aqueduct pipe and supports.
The aqueduct is buried throughout its 41-mile length.
Rounded berm of the aqueduct trail.
Today, the aqueduct is a public trail, but you can still see its rounded earth covering.
Photo © ScubaBear68 via Flickr.

To meet that precise requirement, the horseshoe-shaped brick tunnel was secured on a stone foundation and topped by a dirt berm. The berm's telltale round top still marks the path of the aqueduct today.

A breather tube and inscription from a ventilator.
Beautiful stone ventilators prevented a vacuum from forming inside the aqueduct.
Photos © school 1106 via panoramio.
Ventilator inscription.
Ventilator shafts were sometimes inscribed with the section number of the aqueduct and signed by the builder, like this inscription from ventilator 8 in Ossining, NY.
Photos © Carlos Gee.
The aqueduct was far more than a giant brick sluice, however. To prevent a vacuum from forming inside it as water rushed downstream, 33 above-ground ventilators—giant stone “breather” tubes—were built about every mile.

The tunnel sent up to 90 million gallons of water to the city each day, and it needed regular care.

The weir in Ossining, NY.
The weir in Ossining, NY.
Photo © Peter McKie.
The valves and gates that stopped aqueduct water from flowing.
A view inside the Ossining weir. Turning the wheel in the left photo lowered the giant steel gate in the top right photo, preventing water from entering the aqueduct, and diverting the flow to a nearby river via a side pipe (bottom right).
Photos © Peter McKie.
To inspect, maintain, and repair the tunnel, caretakers had to empty the aqueduct. To that end, six stone structures, called weirs, were built along the conduit. They housed giant metal gates that, when closed, shunted the water in the aqueduct to nearby rivers. One of those weirs, in Ossining, NY, is open to the public a few times a year (go here for a tour schedule).

Keeper's house before and after renovation.
The keeper's house in Dobb's Ferry, NY, deteriorated over time. In 2001, a citizen's group cobbled together the money to save it.
Photos © Friends of the Old Croton Aqueduct.
Each weir required a caretaker, who was given the use of a “keeper’s house” near their secton of the aqueduct. Of the six houses built, only the one in Dobbs Ferry, NY, remains in its original location. In 2001, that rundown structure, built in 1857, was fully restored. It now serves as the aqueduct's museum.

Newly discovered keeper's house in Ossining, NY.
The recently discovered (2014) keeper's house in Ossining, NY.
Photo © Ossining Historical Society.
Until recently, the Dobb's Ferry building was thought to be the only remaining keeper's house. In 2014, however, a second house, in Ossining, NY, was identified and confirmed. It turns out that in 1928, the house was moved from its location next to the aqueduct to a residential street, where it is now a private home.

The aqueduct pipe inside the High Bridge.
Inside the High Bridge, the aqueduct water is carried by a giant pipe. Note that the pipe is held together by rivets, an indicator of how old it is; today, welds would replace the rivets.
Photo © shayna

Despite the distance the Croton water had to travel, only three bridges had to be built to span obstructions. The most noteworthy was the High Bridge, built in 1848 and modeled after the Roman aqueducts. It stretches 1/4 mile over the Harlem River in northern Manhattan.

The High Bridge in northern Manhattan.
The High Bridge rises 140 feet above the Harlem River.
Photo © H.I.L.T. via Flickr

The original Croton Dam.
The original aqueduct dam on the Croton River, in Croton-on-Hudson, NY.
Photo © Museum of the City of New York.
The new Croton Dam.
In 1906, a new, higher dam was built to meet the increased demand for water. Its design includes a flashy spillway, part natural (left) and part manmade (right), that complements the land below the dam, which has been turned into a state park.

The new dam sits slightly to the south of the old one, and in times of drought, you can see the remnants of old dam under the water.

Photo © John via Flickr.
The aqueduct cost $13 million to build and took 5 years to complete. Irish immigrants provided most of the labor at the rate of $1 a day.

Jay Gould's Lyndhurst estate.
The aqueduct trail goes through Lyndhurst, tycoon Jay Gould's 67-acre estate overlooking the Hudson River. The mansion is open to the public.
Photo © National Trust for Historic Preservation.
In 1968, New York State bought 26.2 miles of the aqueduct and opened it to the public as the Old Croton Aqueduct State Historic Park. The flat trail atop the aqueduct is ideal for walking, biking, and cross-country skiing.

The trail winds through commercial areas; residential areas (including people's back yards via easements still in place); the grounds of Lyndhurst, railroad tycoon Jay Gould's riverside mansion; and along the path of many old Hudson River estates.

While modern development means that the aquduct is no longer a contiguous 41 miles, trail maps show workarounds for inaccessible areas.