NYC DEP Begins Tunneling For Delaware Aqueduct Repair Project

Sep 11, 2017

The New York City Department of Environmental Protection has started a major phase of its largest repair project ever. Officials visited a shaft construction site in Orange County on Friday to mark the start of tunneling for a bypass tunnel across the Hudson River. Beginning this week, construction workers in Newburgh will start lowering the tunnel-boring machine that will make its way from Orange to Dutchess County.

The billion-dollar Delaware Aqueduct repair project is under way to address two leaks in the 85-mile Delaware Aqueduct, the longest tunnel in the world. The larger of the two leaks is on the western bank of the Hudson River, in Newburgh. DEP Acting Commissioner Vincent Sapienza says the effort to fix the aqueduct is the most complex his agency has undertaken.

“The Delaware Aqueduct, which was built in the 1940s, has a leak which we need to repair, and the solution that was come up with was to build a parallel tunnel right alongside the Delaware Aqueduct. And so this project here that we’re doing is to put a tunnel boring machine down a deep shaft to run parallel to the Delaware Aqueduct, the existing tunnel,” Sapienza says. “It’s going take about two years for this boring machine to make its way from Newburgh to Wappinger, about two-and-a-half miles. And, once the parallel tunnel is built, we can then connect that to the existing Delaware Aqueduct to basically bypass the leaking section.”

He says patching the leak would take too long and New York City would not be able to survive on the limited amount of water that would be deliverable. And the tunnel boring machine, which when assembled will be more than 470 feet long and weigh upwards of 2.7 million pounds, is named Nora, for the first woman in the U.S. to earn a civil engineering degree. Nora Stanton Blatch Deforest Barney earned her degree in 1905 from Cornell University and worked for the predecessor to the DEP. Coline Jenkins is her granddaughter.

“This is a real woman who’s a groundbreaker and this is a groundbreaking machine and so the, it was a very easy choice to make,” Jenkins says. “I think somebody proposed superwoman. But I’m a little tired of generic, fictitious women. Real women exist.”

Jenkins says Nora the human also was a suffragist and granddaughter of Elizabeth Cady Stanton.

“And I’m going to end with a suffrage saying. And it is ‘forward into the light,” Jenkins says. “And what I want to do is adapt it to today for tunneling: ‘Forward into the light at the end of the tunnel.’”

Orange County Executive Steve Neuhaus was on hand for the ceremony for the start of tunneling.

“I think it’s a great thing. A billion-dollar investment. Lots of men and women working on this job, and it’s an engineering marvel,” says Neuhaus. “This is what you watch on the History Channel that they did back in the day that you don’t think they can do anymore today. This is a modern marvel.”

The DEP’s Sapienza says while work goes on belowground, the public will notice the following aboveground.

“So, right now, we’re standing on top of basically an 800-foot deep shaft. And so, piece by piece, this is going, this tunnel boring machine is going to be lowered into the hole, pieced together and moving,” says Sapienza. “You won’t see any of this machine anymore, but what you will see is pulverized rock being brought to the surface every day, going onto trucks and then being brought offsite.”

Sapienza notes this is one of the largest public works projects taking place in the Hudson Valley, on the heels of the construction of the new Tappan Zee Bridge.

“The Tappan Zee Bridge is moving cars and we’re moving water.”

The finished bypass tunnel will be reinforced by 9,200 linear feet of steel and a second layer of concrete. DEP then will shut down the Delaware Aqueduct to connect the bypass tunnel to the Aqueduct. The about six-month shutdown is planned for October 2022. The project is expected to be finished in 2023.