* Construction of the bypass tunnel to begin in 2015 and be completed in 2019. The new three-mile segment of tunnel will bypass the leaking portions of the existing tunnel in the Roseton area. DEP's ongoing testing program - including two AUV inspections of the interior of the tunnel and extensive geological investigations - has confirmed the location of primary leakage in this area. A tunnel boring machine will be used to drill the 22-foot diameter bypass tunnel. This segment of the tunnel will extend from a tunnel launching shaft to the tunnel reception shaft, each located approximately 150 feet away from the existing tunnel alignment. The machine is expected to advance at up to 50 feet per day.
The existing tunnel will continue to operate while the bypass tunnel is under construction. When the new bypass tunnel is nearly complete and the water supply augmentation and conservation measures are in place, the existing tunnel will be taken out of service and excavation will begin to connect the new bypass section to the existing tunnel.
About eight to 12 months are anticipated to complete the bypass connection. To make the connection, additional rock will be excavated to break through to the existing tunnel; two plugs will be installed to isolate the existing leaking portion of the tunnel; a connection chamber will be excavated and lined at the two connection points, and each of the construction shafts will be plugged. When that work is complete, the tunnel will be refilled and returned to service.
* Eliminating the leaks in Wawarsing. During the construction of the bypass tunnel, the Delaware Aqueduct will be shut down, enabling DEP to enter upstream portions of the tunnel and fix cracking at three segments totaling nearly 500 feet in Wawarsing by injecting grouting from the inside of the tunnel near the affected areas.
DEP has been investigating the potential leak impact in Wawarsing since the day it was first observed. While the investigation was underway, DEP, with the Ulster County Health Department, has taken water samples, photographs, met with homeowners, and, with the United States Geological Survey, created an extensive monitoring network and began hydrogeological mapping.
DEP has also attended public meetings on the issue as well as forming a Public Advisory Committee to help keep the community informed about efforts to monitor and repair the tunnel. While studies have been ongoing, New York City has assisted homeowners with sump pumps, ultraviolet disinfection, bottled water, and funds for stormwater improvements.
* Preparing the water supply system to handle the repair. Before the repair is performed, DEP is building or upgrading several key pieces of crucial infrastructure that will help maintain the city's water supply capacity during the construction of the bypass tunnel, including: completing the construction of the Croton Filtration Plant in the Bronx, which will provide up to 290 million gallons per day of filtered water - up to 30% of the city's water needs; upgrading the Cross River and Croton Falls pumping stations to provide increased water capacity; upgrading the New Croton Dam, which will allow for increased water storage capacity; and the connection of the Catskill Aqueduct and Delaware Aqueduct, which will allow the city to send water from the Delaware Watershed system into the Catskill Aqueduct, providing increased capacity and flexibility for the water supply. The city is also upgrading its groundwater system in Queens to increase the water supply for the future, as part of its program for long-term reliability and sustainability of the water system.
Mayor Bloomberg has made planning for the repair of the Delaware Aqueduct a pivotal part of the PlaNYC goal to improve the reliability and long-term sustainability of New York City's water infrastructure. Mayor Bloomberg has made a larger commitment to maintaining and improving the City's water system than any administration in history. Approximately $21 billion has been allocated for water system capital projects, including:
* $2.5 billion invested and committed to City Water Tunnel No. 3 - more funding for the tunnel than the previous five administrations combined;