Tunnelling work to build Melbourne’s newest sewer pipeline has begun.

‘Lucey’ - Melbourne Water’s tunnel boring machine - is doing the hard work of replacing 65-year-old sewers responsible for the transfer of 30 per cent of Melbourne’s wastewater.

The new 670 metre Hobsons Bay main sewer stretches from Westgate Park, Port Melbourne to Scienceworks in Spotswood, under the Yarra River.

The $206 million Melbourne Water-funded critical sewage infrastructure project allows sewage to continue to flow to its Western Treatment Plant while the existing sewer - which is reaching the end of its service life - is upgraded.

Lucey, the tunnel boring machine, was named by the students at the nearby Spotswood Primary School after Lucey Alford, the first female bacteriologist and scientist employed by the Melbourne Metropolitan Board of Works - now known as Melbourne Water.

“The Hobsons Bay main sewer project forms part of a broader Melbourne Water capital infrastructure program that will enhance the reliability of our sewerage network and services for the benefit of Melburnians today and for generations to come,” Melbourne Water Managing Director Dr Nerina Di Lorenzo said.

“We’re looking towards the future and anticipating the evolving needs of a growing Melbourne - which is projected to nearly double in population by 2050. This project ensures our infrastructure is keeping up with future demand.”

The Hobsons Bay main sewer pipeline, which aims to achieve a net zero carbon footprint, will be located at depths between 24.5 and 27 metres below the surface of the Yarra, will be positioned alongside its existing twin and will provide a significant increase in sewer capacity.