We’re upgrading the Western Trunk Sewer, which runs from Brooklyn Pumping Station to the Western Treatment Plant in Werribee. The 4.5-metre diameter sewer is an important part of our sewer network, carrying over 60 per cent of Melbourne’s wastewater for treatment in Werribee.

The Western Trunk Sewer was constructed in the late 1980s and is at the end of its service life. The sewer main consists of 15.2 kilometres of deep tunnel from Brooklyn Pumping Station to Hoppers Crossing Pumping Station, and 7.3 kilometres of shallow tunnel from Hoppers Crossing Pumping Station to the Western Treatment Plant.

What’s happening and when

Our regular inspection program identified six manholes and three sections of sewer at the end of their service life, which need to be upgraded.


Western Trunk Sewer Upgrade Project map

The three sections of sewer that need upgrading are:

  • Wattle Avenue to Duncans Road, Werribee (next to the Princes Freeway)
  • Nunniong Street to Kiely Avenue, Werribee (next to the Princes Freeway)
  • Main Drive, Cocoroc (located on Melbourne Water land)


Upgrading sewers is complex. In October 2019, we completed preliminary investigation works to explore the best options for the sewer’s rehabilitation. The investigation results will ensure the sewer is upgraded efficiently and safely while minimising the impacts to the community as much as possible.

Construction is due to start in 2021 and be completed by late 2022.

Contact us

For more information, please contact the project team:

 1800 841 444

 [email protected]

Last updated:
22 September 2020