Tunnel proposed for leaking New York aquaduct

New York City is planning to construct an ambitious tunnel that will bypass the failing sections of the Delaware aquaduct which conveys water from upstate reservoirs to more than 50% of the city's inhabitants.
The 5km by-pass tunnel will be constructed between Newburgh and Wappinger. It will run at depths of 180-240m below the Hudson river and divert water around the leaking sections of the aquaduct.
In addition to deep launch and reception shafts at either end of the TBM-drive, it will also be necessary to construct connector tunnels as part of the works.
Repair work will also be undertaken on stretches of the existing aquaduct and will include sealing the cracked structure with pressurised grout injection.The total cost of the project, including land acquisitions and environmental reviews, is expected to be in the region of US$1.2 billion.

It is estimated that more than 150 million litres of water/day are being lost though cracks in the aqueduct’s 380-550mm-thick concrete liner. Leaks were first discovered in 1988 and have been severe enough to cause chronic flooding in Wawarsing, about 160km north of New York city.
So far, over US$27 million of investigation work has been carried out, including geological investigations, tunnel flow monitoring and automated underwater vehicle inspections.
The Delaware aqueduct is part of a drainage system built between 1936 and 1964, and extends up to 200km northwest of Manhattan. The system conveys water to New York via a series of reservoirs and tunnels.
Ground is expected to be broken in 2013, with aquaduct repair and bypass tunnel construction taking place between February 2015 and January 2018.