History Made Every Day™

Water Tunnel #3

Water Tunnel #3

The people who live and work in New York City use 1.3 billion gallons of water every day. That water travels from upstate reservoirs through City Water Tunnel #1 (completed in 1917) and City Water Tunnel #2 (completed in 1936). Unfortunately, these aging, leaky tunnels are in such bad shape that they can't be repaired or even inspected: Officials worry that the valves in the old tunnels are so corroded that closing them for repair might be disastrous. What if they got stuck and couldn't be re-opened? In that case, or in case of an earthquake or a terrorist attack, New Yorkers would have no access to safe drinking water.

In 1954, city officials decided to build a third, more high-tech tunnel, City Water Tunnel No. 3. They worked for almost two decades to find a design that would take some of the everyday pressure off of the older tunnels and would also be able to withstand a nuclear attack. Finally, in 1970, the Sandhogs began to dig.

At first, they used a plodding "drill-and-blast" method that, because it required workers to rig hundreds of tiny explosives every day, was incredibly unsafe. Today, the Sandhogs use a machine called "the Mole," a 450-ton, 70-foot-long drill that grinds 100 feet of bedrock every day. By the time they finish the project, in 2020, the sandhogs will have dug 60 miles of tunnel
in all.

Danger! Working Underground

Each day, a steel elevator cage called the Alimak carries nearly 200 Sandhogs deep underground. It takes about four minutes to ride all the way down into the tunnel—it's 600-800 feet below the city! (By contrast, subway tunnels run 30-50 feet underground; sewers are even shallower than that.) Even with the Mole and other advances in tunneling technology, the Sandhogs' job is still incredibly dangerous. Twenty-four men working on Water Tunnel No. 3 have been killed so far—that's almost one fatality per mile of tunnel completed. The air is filled with toxic dust and the tunnel's walls and ceiling could crumble at any time. In the dark, it's easy to get hit by trains and other equipment. But the pay is good—around $100,000 a year—and the Sandhogs are a close-knit bunch who work hard to keep one another safe.

At A Glance: New York City's Water Tunnel No. 3

– Year digging began: 1970

– Year tunnel will be completed (projected): 2020

– Total cost (projected): $6 billion

– Length of tunnel when it's finished: 60 miles

– Depth of tunnel: 600-800 feet (60-80 stories)

– Diameter of tunnel: 10-24 feet

– Number of sandhogs who have worked on the tunnel so far: more than 5,000

– Number of sandhogs who have died in construction accidents in the tunnel so far: 24