The Hobsons Bay Main Sewer is a critical part of Melbourne’s sewer network, transferring around 30 percent of Melbourne’s wastewater to the Western Treatment Plant. The existing sewer was first constructed in the 1960s, it is now reaching the end of its service life and requires rehabilitation.

About the project

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The sewer is located under the Yarra River between Westgate Park in Port Melbourne and Scienceworks in Spotswood. To rehabilitate the existing sewer, we are building a duplicate sewer which will allow sewage flows to be diverted during rehabilitation works. These critical works form part of a broader Melbourne Water sewer program on a number of ageing sewers around the city.

The current sewer is still functioning and there is no immediate environmental danger, however these critical sewer works are necessary to protect our future and will provide a significant increase in system capacity to cater for Melbourne’s growing population.

This project is part of Melbourne Water’s commitment to protecting Melbourne’s bays and waterways from environmental harm and ensuring the reliability of our sewer network.

Major works are underway from June 2022 to late 2024

Since February 2022, the project team has established two construction sites at Scienceworks and Westgate Park. Tunnelling works have now been completed with tunnel boring machine 'Lucey' completing her 670 metre journey under the Yarra River in November 2023.

Over the coming months works will include:

  • Tunnel grouting works
  • Sewer connection works to connect the new sewer to the existing network
  • Treatment and removal of spoil from site
  • Permanent rehabilitation works.

When are we working?

Works will take place from June 2022 to late 2024 (subject to weather and ground conditions).

From December 2023, construction hours will be 24 hours Monday to Friday at both the Spotswood and Port Melbourne site.

What to be aware of

Photography:  TJ Garvie Photography / Designs: GrowCreative  - The images supplied (copyright 2023)
  • ​​​​Noise levels will be low to moderate for businesses directly neighbouring the works areas during tunnelling. We do not expect local residents or businesses beyond this to be impacted by noise.
  • Low level construction related traffic is expected with no impact anticipated for nearby businesses or residents.
  • Site vehicle access will be via Booker Street with occasional access via Craig Street in Spotswood and via Kooringa Way in Port Melbourne.
  • Local access for residents, businesses and visitors will be maintained at all times and we do not anticipate any impacts to your water or sewerage services throughout these works.

Project Timeline




September 2021 - December 2021

Early works and final geotechnical investigations


January 2022 - May 2022

Site mobilisation


June 2022 - April 2023

Main works - piling and shaft construction


May 2023 - August 2023

Main works - shaft excavation


August 2023 - December 2023

Main works - tunnelling works

Not Started

late 2024

Permanent works and reinstatement of construction areas.

The works area

Works will take place on both the east and the west sides of the Yarra River.

HBM Truck Routes
Truck routes during site works.

Contact us

For more information, please contact the Hobsons Bay Main Project Team: 

[email protected]

1800 512 313

Last updated: