McConnell Dowell has delivered the final 3.6 km of the 31 km Hūnua 4 water pipeline which is part of the biggest-ever water project undertaken by our customer, Watercare.
Our team worked with Watercare to develop a design that allowed for 80 per cent of the alignment to be tunnelled, minimising disruption to neighbours and traffic in the busy city centre.
“Hūnua 4 has been a technically challenging project so it’s incredibly satisfying to see the work completed,” says Project Manager Richard Atkin
“The hard work and perseverance of the team has been phenomenal, and we are all very proud to have helped deliver this important new water pipeline.”
The team set two pipe-jacking records for the longest single drives in the Southern Hemisphere by a TBM greater than 2.6 metres in diameter in 2020. The longest was a 1,296-metre record set by the Herrenkenecht AVN2500 mTBM during the third drive.
Watercare chief infrastructure officer Steve Webster says the colossal project caters for our growing population and provides resilience in the event of a natural disaster.
“As far as water pipes go, Hūnua 4 is massive. With a diameter ranging from 1.6 m to 1.9 m, it carries huge volumes of water – up to 3000 litres per second – or 19 bathtubs per second.
“Hūnua 4 does all this beneath our feet, without us even realising it – she’s a bit of a quiet achiever.”
Take a 3D tour and virtually visit the project’s four sites at milestones like TBM being set up, go down inside the shafts and trenches, the TBM’s first breakthrough, and look around the completion of the first drive.