The Lonsdale Street Sewer Upgrade is the second stage of City West Water’s (CWW) four-stage $80 million program to expand Melbourne CBD’s sewer system capacity, with the new pipe linking to a new sewer under Spencer Street that was installed as part of stage one in December 2018.
Contractor Rob Carr installed the new 1.5 m diameter sewer pipe under Lonsdale Street using a 6.3 m, 16.3 t microtunnel boring machine (MTBM), which worked at depths ranging between 10 and 23 m.
The MTBM had tunnelled 24 hours a day from March to September this year and encountered a variety of hard and soft ground conditions throughout.
To support tunnelling activity, a 23 m deep launch shaft was excavated at William Street as well as two 10 m deep retrieval shafts at Elizabeth Street and Spencer Street.
Each of the three shafts have now been filled in, closed and replaced with manholes.
CWW Managing Director Maree Lang said the new pipe formed part of the biggest upgrade to Melbourne CBD’s sewer network in more than 120 years.
“With the existing sewer over 120 years old, the new sewer pipe will help cater for the growing demands of the Melbourne CBD now and into the future,” she said.
“We sincerely thank the thousands of city residents, workers and commuters who adapted to the changed conditions while we carried out construction along Lonsdale Street.
“Your patience and understanding allowed us to provide this vital piece of infrastructure for Melbourne’s CBD.”
The next phase of works will include a new sewer along Elizbeth Street, with construction expected to begin in mid-2021.
For more information visit the CWW website.
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