Roosevelt Island Water Tunnel #3
Futures of Brooklyn & Queens Hinge On Shaft 15B
Roosevelt Island’s critical role in New York City Water Tunnel #3 is not well-known. It’s the largest capital construction project in City history, and we’re in the middle.
We reported in 2017 that two temporary roads were being built to support the project. But that’s only the surface.
“New York’s City Tunnel No. 3 is one of the most complex and intricate engineering projects in the world,” says an article in Water Technology.
Built by the Department of Environmental Protection (DEP), the 60 mile tunnel has a 2021 finish date. That’s iffy, though, as Mayor de Blasio hasn’t made a clear commitment.
The future of the City, especially Brooklyn and Queens hinges on Water Tunnel #3. Mayor Michael Bloomberg saw it as the most urgent concern of his time in office.
Roosevelt Island and Water Tunnel #3
Water Tunnel #3, when finished, carries water from the Croton Reservoir into Manhattan, Brooklyn and Queens. The Manhattan section is complete, but the spur eastward depends on finishing three shafts or valve chambers.
Each holds “a series of 96-inch diameter conduits with valves and flowmeters to direct, control and measure the flow of water in sections of the tunnel.”
Shaft 15B, right under Roosevelt Island, is the last before water can flow into Astoria and beyond.
Why Does This Matter?
Pricey and critical as it is, Water Tunnel #3 serves only as a backup for a pair of earlier tunnels. #1 is 102 years old, and #2 is a mere 80. But they can’t be tested because they can’t be shut down without an alternative.
No one knows the condition of the old tunnels, and that’s where Roosevelt Island and Water Tunnel #3 come in.
“Collapse of one of the two water tunnels that would make half the businesses and residences inside the city of New York uninhabitable.”Kevin Sheekey, a former deputy mayor, quoted in the New York Times.
In 1954, the City tried shutting down Tunnel #1, but a giant valve under Central Park started to crack. That’s the last time a thorough inspection was even considered, and Tunnel #3 was quickly approved.
Do the math. That’s 65 years, a collapse of Water Tunnel #2, for any reason, would leave 5 million New Yorks without water for up to three months. That’s how long an emergency activation of Tunnel #3 would take.
That’s a disaster too big to get your head around.
Finish Line for Roosevelt Island and Tunnel #3
Earlier this year, DEP finished both planned access roads for Shaft 15B.
The emergency road cutting behind the Octagon and a main access between Jack McManus Field and the Community Garden considered esthetics in ways rarely seen in government work.
Both actually look nice and inconspicuous. Not what you’d expect and a plus for Roosevelt Island.
The 2021 Tunnel #3 finish date is in sight. Queens and Brooklyn depend critically on Roosevelt Island Shaft 15B .