New York City Water Tunnel No. 3
New York City Water Tunnel No. 3 is a water-supply tunnel forming part of the New York City water supply system. It is being built by the New York City Department of Environmental Protection to provide New York City with a third connection to its upstate water supply. Water Tunnel No. 3 is the largest capital construction project in New York City history. The tunnel will be more than long, travel below street level in sections, and will cost over $6 billion. Construction began in 1970 and is expected to not  be completed until at least 2026. The tunnel will serve as a backup to Water Tunnel No. 1, completed in 1917, and Water Tunnel No. 2, completed in 1936. Stages. One. The project was authorized in 1954 and was imagined as "the greatest nondefense construction project in the history of Western Civilization". The city determined that it needed a third water tunnel so that Tunnels 1 and 2 could be closed for inspection and repairs. Stage One construction of Tunnel 3 began in 1970 and completed in 1993. This portion was put into service in 1998 and cost about $ 1 billion. This first section was bored through bedrock between underground, using drilling and blasting techniques. Section one is long and starts at Hillview Reservoir in Yonkers, New York then crosses under Central Park in Manhattan, to reach Fifth Avenue at 78th Street. From there it runs under the East River and Roosevelt Island into Astoria, Queens. It is a concrete-lined tunnel that is in diameter and reduces to in diameter before connecting to 14 vertical shafts. Two. Stage Two was built using tunnel boring machines and comprises two sections. The Brooklyn and Queens section runs and begins in  Red Hook, Brooklyn, where it connects to the Richmond Tunnel for Staten Island. It passes through Park Slope, Bedford-Stuyvesant, and Bushwick before reaching Maspeth, Queens. From Maspeth it runs through Woodside and Astoria, where it connects to the end of the Stage One section. The Brooklyn section is in diameter, and the Queens section is . The Manhattan section is in diameter and runs for . It begins at a valve chamber in Central Park, runs south along the west side of Manhattan, and curves around the southern end of the island to come partway through the Lower East Side. A  spur of the Manhattan tunnel begins on the west side at approximately 34th Street, goes to the east side and then turns north under Second Avenue to about 59th Street. The tunnel itself was completed in 2008, and after the construction of riser shafts was completed, the tunnel opened in 2013. Three. What used to be called Stage Three is now being referred to as a separate project, the "Kensico–City Tunnel". It will be in diameter, running from the Kensico Reservoir in Westchester to the Van Cortlandt Valve Chamber complex in the Bronx. Four. Stage Four is a proposed  tunnel that would start at the Hillview Reservoir, pass through the eastern Bronx and then through Queens, where it would eventually meet the Stage Two section. Valve chambers. The largest valve chamber is in Van Cortlandt Park. It is built below the park surface. It controls the flow of water from the city's Catskill and Delaware systems. These systems provide 90 percent of the city's current drinking water. The Van Cortlandt Park Valve Chamber is long, wide and high. The complex has nine vertical shafts; and two manifolds. Each manifold is long and in diameter and is currently  in operation. Additional, though smaller, valve chambers are in use under Central Park at 79th Street, under Roosevelt Island, and in Jackson Heights. Deaths. Since 1970, when construction on the tunnel began, twenty-four people have died in construction-related accidents. The deaths have included twenty-three workers and a 12-year-old boy, Don-re Carroll, who died while exploring uncapped water pipes in the Bronx. No deaths have occurred since 1997. Progress. In 2002, New York City mayor Michael Bloomberg made completion of the tunnel a priority, and set a goal date of 2021. Commissioner Christopher O. Ward  helped move this project along for the Mayor. A "New York Times" report in 2016 stated that mayor Bill de Blasio was postponing completion of the project indefinitely, but he subsequently stated that this was a miscommunication between his press office and the "Times", and that the completion date was actually being pushed up to 2020.