Construction on what has been described as New York City’s longest-running and most expensive construction project — a tunnel to expand the capacity of the water supply system — reached a new milestone yesterday. And it was ahead of schedule.
Work on Manhattan sections of the tunnel have been taking place seven days-a-week — on multiple shifts.
The project is one arm of the extensive network of tunnels, aqueducts and reservoirs that comprise the city's remarkable water supply system.
Approximately 2,750 feet of new trunk water mains have been installed on the Upper East Side, along with upgrades to existing mains. The work was executed by the city’s departments of Environmental Protection and Design and Construction, who report that the $38 million construction project was completed five months early.
According to the DEP, trunk water mains range in size from 30 to 48 inches and “serve as a conduit between the large water tunnel shafts and the smaller water mains that make up the local distribution networks."
The agency says that completion of the project marks an important step towards the activation of the Manhattan section of water tunnel no. 3, which is scheduled to take place by the end of the year.
The city is in a race against time to complete tunnel no. 3 before tunnels no. 1 and no. 2 must be de-commissioned for inspections and repair. Both tunnel no. 1 (completed in 1917) and tunnel no. 2 (completed in 1936) have been in continuous operation since their construction. Both tunnels are reportedly leaking.
When it is finally completed in 2020, tunnel no. 3 will be 60 miles in length and will supply drinking water to all five boroughs.
Construction on the tunnel began in 1970. The Bloomberg administration has committed $4.5 billion to its construction. The DEP reports that since 2002 the agency has invested $10.5 billion in the city’s water supply and distribution systems.
The city’s water supply system delivers one billion gallons of drinking water to New York City and surrounding suburbs every day.
Image of water tunnel no. 3 courtesy of the DEP.