As a result of the recent high rainfalls and subsequent flooding Melbourne Water is working with emergency services and other relevant agencies to review the impacts to our waterways and assets. 

For flood or storm emergency assistance, contact the VIC SES on 132 500 and for life threatening emergencies call 000. 

You can access current emergency information by calling the VicEmergency Hotline on 1800 226 226 or sign up to receive regular updates regarding flooding via the emergency.vic.gov.au website and app.

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 and has deteriorated to the point it needs rehabilitating.

Due to the volume of sewage carried by the Hobsons Bay Main Sewer, a second sewer will be built under the Yarra River and connected into the existing sewer located at Scienceworks. This will allow sewage flows to be diverted and rehabilitation works can then be undertaken on the existing sewer. These critical works form part of a broader Melbourne Water sewer program on a number of ageing sewers around the city.

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 mid-2024

Works to establish two construction sites at Scienceworks and Westgate Park have been completed and major works are now commencing. These works include:

  • Delivery and establishment of plant and equipment including piling rigs
  • Construction of 35m deep shafts to launch the tunnel boring machine
  • Tunnelling works under the Yarra River
  • Removal of spoil from site.

When are we working?


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

Construction hours for the Spotswood site are 7:00am to 6:00pm Monday to Fridays and 7:00am to 1:00pm Saturdays.
Construction hours for the Port Melbourne site are 6:00am to midnight Monday to Friday and 6:00am to 6:00pm Saturdays

Some works are required to take place out of normal construction hours.

What to be aware of

  • ​​​​Noise levels will be moderate to loud for businesses directly neighbouring the works areas during piling and excavation from June 2022 to April 2023. We do not expect local residents or businesses beyond this to be impacted by noise.
  • Low level construction related traffic is expected with minimal 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.

Project Timeline


    September 2021 - December 2021

    Early works and final geotechnical investigations


    January 2022 - May 2022

    Site mobilisation


    June 2022 - September 2022

    Main works - Shaft construction 

    Not Started

    May 2023 - October 2023

    Tunnelling beneath the Yarra River

    Not Started

    October 2023 - March 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: 

    Last updated:
    5 September 2022