By rosebell
As part of the Midtown Wastewater Diversion project, using a micro TBM tunneling has started beneath Auckland’s CB.
This machine is digging a 600m tunnel under Queen Street in New Zealand’s largest city to lay a new wastewater pipe.
According to Watercare’s acting chief program delivery officer, David White: “The new 1.2m diameter pipe would connect to the Ōrākei Main Sewer and capture wastewater flows from the city centre.The start of tunneling is an important milestone in our NZ$115m (€58.5m) 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.”
He also added: “We began construction in October last year and it’s good to see tunneling getting under way. We chose this method of construction as opposed to open trenching to minimise disruption to pedestrians and businesses.”
The location of commissioning m-TBM was a shaft at the junction of Queen Street and Mayoral Drive, and tunneling is due to be done in two drives. The path of excavation by TBM will be through the ground at depths of 15m to a shaft at the corner of Wellesley Street East and after a cutterhead inspection, it is slated to continue boring to reach the final shaft at the junction of Victoria Street East towards the end of the year.
With the aim of laying the glass-reinforced plastic pipe in 6m-long sections, the m-TBM will employ pipe-jacking.
While the first stage of the Midtown Wastewater Diversion project is tunneling, stage two of works is in design and will involve laying new wastewater pipes from Vincent Street to Greys Avenue carpark. The scheduled date for completing work is 2027.
In order to enabling new housing, improving the reliability of services and protecting the environment,this project is part of Watercare’s NZ$13.8bn (€7.06bn) infrastructure investment program being delivered over the next decade. Additionally, as part of the Auckland Council group’s midtown regeneration program, it is transforming the streets, spaces and underground infrastructure ready for the City Rail Link opening.
