Mayor Michael R. Bloomberg and Department of Environmental Protection (DEP) Commissioner Christopher O. Ward announced the start of the Manhattan leg of Water Tunnel No. 3.  The Manhattan section, originating from 30th Street on the West Side of Manhattan, will run downtown to the Holland Tunnel.  A second section will then loop north from that point up the West Side to Lincoln Center.  Both of these sections will be activated by 2011.

The Tunnel, started in 1970, is being constructed in four stages and completion of the 60-mile Tunnel is not anticipated until 2020.   Stage 1, completed in 1998, runs 13 miles from the Hillview Reservoir in Westchester, through the Bronx, Northern Manhattan and Queens.   It cost approximately $1 billion and is already delivering drinking water to parts of these boroughs. Eventually, the Manhattan leg will be connected into the Stage 1 portion of the tunnel.  The first section of Stage 2, the Brooklyn-Queens portion, is complete and will be activated by 2007. This 10.5-mile leg of the tunnel runs from Red Hook, Brooklyn to Woodside and Astoria, Queens.

Starting in 1991, the Brooklyn-Queens section was constructed in two segments.  For 5.5 miles, the Brooklyn tunnel runs from Red Hook, Brooklyn to Maspeth, Queens, followed by the 5- mile Queens’ leg, which runs from Maspeth through Woodside and Astoria in Queens.  In 1997, these two segments were joined.  It is anticipated that water will start to flow through the Brooklyn-Queens leg by 2007, thereby building in a solid redundancy into the water supply system. It will also connect to the Richmond Tunnel in 2006, providing drinking water to Staten Island.

 “It is important for the public to understand the significance of what’s taking place in the lower depths of our City as we build new infrastructure for the 21st Century,” said Mayor Bloomberg.  “This is the largest public works project the City has ever undertaken and is an engineering feat of gigantic proportion.  Though rarely seen by the public, this project will increase our water systems reliability and will instill a sense of security in our City’s ability to provide essential services for future generations.”

“We’re now concentrating our tunneling schedule on completion of an 8.5-mile section of Tunnel No. 3 that will deliver water throughout Manhattan by 2011 at a cost of $750 million,” said Commissioner Ward. “The activation of Stages 1 and 2 of Tunnel No. 3 will provide the system with the ability to bypass one or both of City Tunnels No. 1 and 2.  Operation of the new Tunnel will allow for inspection of the older tunnels for the first time since they were put into operation in 1917 and 1936 respectively.”

Construction of Stage 2 was greatly accelerated using a mechanical rock excavator called a tunnel-boring machine (TBM). The TBM, affectionately known as “the mole,” is lowered in sections and assembled on the tunnel floor, chips off sections of bedrock through the continuous rotation of a series of steel cutting teeth.  The TBM replaces conventional drilling and blasting methods and allows for faster and safer excavation.  The TBM can clear from 55 to 75 feet of rock a day, twice as much as the old method that cleared between 25 and 40 feet a day.

City Tunnel No. 3 is the largest capital construction project in New York City’s history, and it is anticipated to cost from $5.5 to $6 billion. The DEP’s $16 billion Capital Improvement Program is committed to emphasizing the water delivery system.  The program is financed through the sale of water bonds and the collection of water and sewer charges.

Water Tunnel # 3 Facts:

• The amount of rock displaced during excavation of 8.5 miles of tunnel is approximately the size of a football field piled two hundred fifty feet high.  (300’ x 250’);
  
  
• 79,000 tons of concrete will be used in the Manhattan Tunnel;
  
  
• Tunnel depths range to as deep as 800 feet below Roosevelt Island.