“The last 3km of the pipe – between Newmarket and Khyber Pass and including a long section under State Highway One – was largely built by a tunnel-boring machine to minimise disruption in this high-traffic area,”

Auckland’s biggest-ever water project – a $400m water transmission pipeline from Manukau to Khyber Pass – has been completed after more than a decade in construction.

Work on the 31-kilometre watermain started in 2008 and has been carried out in 11 stages. As each stage has been completed, the pipe has been connected to its neighbouring suburbs, boosting resilience and providing for population growth.
 

https://www.watercare.co.nz/About-us/News-media/Auckland%E2%80%99s-biggest-water-project-finishes-construc