TBM on site for Melbourne CBD sewer upgrades

Dec 01, 2023

A microtunnel boring machine (TBM) has arrived on Elizabeth Street to help deliver one of the biggest upgrades to Melbourne CBD’s sewer network in more than a century.

As construction continues on the Elizabeth Street Sewer Upgrade, the TBM was lowered five metres underground during a recent site visit. The arrival of the 3.5m long TBM marks a milestone for the latest stage of an $80 million capital improvement program for the city’s sewer network, which is over 120 years old and nearing full capacity.

Greater Western Water (GWW) General Manager Growth and Infrastructure Amanda Smith said the investment in a second network for the CBD is ensuring safe and reliable sewerage services for Melburnians and city tourists. “We’re future proofing this vital community infrastructure to support population growth and meet the challenge of climate change so that Melbourne remains a liveable city for generations to come,” she said.

“After several months of careful planning and working closely with stakeholders to prepare for these works, we’re pleased to be ready to start tunnelling.” The TBM has now started a 700m long journey to construct a new sewer main under Elizabeth Street, from Lonsdale Street to Victoria Street, travelling 12m a day.

The eight-tonne, 85cm diameter TBM is big on efficiency and is expected to finish the job in 16 weeks, moving about 420 cubic metres of dirt to build the new sewer. Because this type of TBM emits low noise and vibration, Elizabeth Street pedestrians and commuters will barely hear or feel the machine at work underground.

Temporary traffic changes remain in place along Elizabeth Street to keep everyone safe in and around the site, including lane closures for northbound traffic as works take place. The Elizabeth Street Sewer Upgrade is scheduled for completion in late 2023, joining two new sewer mains constructed underneath Spencer and Lonsdale Streets.


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