Watercare Begins Tunnelling In Queen Street For $115m Wastewater Upgrade

Watercare’s micro-tunnel boring machine (m-TBM) today begins its 600-metre journey under a stretch of Queen Street to lay a new wastewater pipe as part of the Midtown Wastewater Diversion project.

Watercare acting chief programme delivery officer David White says the new 1.2-metre diameter pipe will connect to the Ōrākei Main Sewer and capture wastewater flows from the city centre.

“The start of tunnelling today is an important milestone in our $115m wastewater upgrade for the city centre. This project will reduce wet weather overflows into the Waitematā Harbour, improve the resilience of our network and allow for growth.

“We began construction in October last year and it’s good to see tunnelling getting underway. We chose this method of construction as opposed to open trenching to minimise disruption to pedestrians and businesses.”

The m-TBM was launched from a shaft at the junction of Queen Street and Mayoral Drive. Tunnelling will be done in two drives. It will bore through the ground at depths of 15 metres to a shaft at the corner of Wellesley Street East.

“Then, once we’ve inspected the cutterhead, the m-TBM will continue on, reaching the final shaft at the junction of Victoria Street East towards the end of the year,” White says.

The m-TBM will lay the glass-reinforced plastic pipe in six-metre-long sections. A pipe-jacking method of tunnelling is being used in which hydraulic jacks braced against a shaft wall push pipes through the ground.

“We’re doing everything we can to minimise disruption for residents and local businesses. All the activity will take place behind solid fencing, designed to minimise noise and dust, as well as keep pedestrians, motorists and construction crews safe,” White says.

“We’ve retained pedestrian access and installed signage to let people know businesses are still open.”

Tunnelling is part of the first stage of the Midtown Wastewater Diversion project.

Stage two of works is in design and will involve laying new wastewater pipes from Vincent Street to Greys Avenue carpark. The work is due to be completed in 2027.

The project is part of Watercare’s $13.8b infrastructure investment programme being delivered over the next decade to enable new housing, improve the reliability of services and protect the environment.

It forms part of the Auckland Council group’s midtown regeneration programme which is transforming the streets, spaces and underground infrastructure in midtown ready for when the City Rail Link opens and brings many more people into the city centre.

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