Melbourne Water is planning to build a new sewer in the suburb of Maidstone to improve the transportation of wastewater to where it’s eventually treated at the Western Treatment Plant in Werribee. The two-year project is planned to start in late 2021.

Why this project is important

The Maribyrnong River Main (MRM) Sewer, which follows the Maribyrnong River from Thompson Street Reserve in Avondale Heights to Epsom Road in Ascot Vale, is one of the main sewers in Melbourne Water’s network. Population growth and more extreme rainfall events have resulted in substantial increases in sewage flows, and the MRM Sewer is running out of capacity to carry these higher flows.

The MRM to North Western Sewer Connection project will provide a world-class sewerage system to manage future flows by increasing the capacity of the system, and improving the transfer of wastewater from the area. The new sewer will transport approximately 24 million litres of sewage each day from 36,000 properties in Essendon West, Airport West, Tullamarine (including Melbourne Airport), Avondale Heights, Keilor East, Taylors Lakes and Sydenham to where it’s treated at the Western Treatment Plant in Werribee.

Improving the sewerage system is an important initiative for the residents of the north-western suburbs as it will ensure the community continues to be provided with a secure and reliable sewerage service for decades to come.

What are we doing?

A new 1.2 kilometre gravity sewer will be built to divert sewage flows from the MRM Sewer into the larger North Western Sewer in Maidstone, which transports wastewater to the Western Treatment Plant.

The new sewer will connect from the MRM Sewer on the northern side of the Maribyrnong River, crossing the river via a new pipe bridge, with a buried sewer to be constructed from Medway Golf Club to Hampstead Road.

800 metres of the new sewer will be constructed by a tunnel boring machine (TBM) from the eastern end of Medway Golf Club to the North Western Sewer near the corner of Hampstead Road and Williamson Road. The sewer will be located at depths of up to 30-40m below ground. 

The remaining section of the new sewer will be constructed by open-cut trenching methods at a depth of 2-4 metres below ground.


Location map showing sewer map from Maribyrnong



Planning and functional design and site investigations

Early 2019 to late 2020


Design and construct tender period

January 2021 to May 2021


Tender award

July 2021


Further site investigations, planning and approvals

January 2021 to November 2021

Not Started

Detailed design

July 2021 to November 2021

Not Started

Construction start

November 2021

Not Started

Construction end

late 2023

These dates may be subject to change as the planning and design progresses and more information becomes available.

Community and environmental benefits – leaving a long lasting legacy

The MRM to North Western Sewer Connection Project will provide an improved sewerage system with capacity for future flows whilst ensuring local amenity, environment, heritage and community interests are protected and enhanced during the delivery of the project.

Improving connectivity and amenity for the lower Maribyrnong River

We’re working closely with Maribyrnong and Moonee Valley City Councils to plan a legacy project which will deliver long-term benefits for the Maribyrnong River and for the community.

  • A new pipe bridge over the Maribyrnong River will be located approximately 100 metres to the east of the existing water pipe (M102) bridge. The new bridge will be designed to cater for active transport connection and accessibility (eg. for bikes, pedestrians, prams, wheelchair access).
  • A section of land next to the Maribyrnong River, which is currently inaccessible, will be opened up for the community to enjoy continuous views and access along the river.
  • Extensive weed removal will be undertaken through this reserve and native grasses, trees and shrubs will be planted in their place.
  • A new 300 metre shared path will be created and will join up to existing shared paths on either side, creating a key link in the western active transport corridor.

The continuation of the shared trail between the M102 water pipe bridge and Saltwater Crescent in Maidstone is the final missing link in the north of the city. This is part of Maribyrnong City Council’s key objective to achieve continuous public access along the river.

Connecting this path network will also improve linkages to the other side of the Maribyrnong River and to shared paths within Moonee Valley City Council.

Managing impacts

Like any major project, there will be impacts associated with the construction of the new sewer. We are working closely with Maribyrnong City Council, Moonee Valley City Council and other key stakeholders to plan for and manage these impacts.

There may be some temporary changes to local traffic conditions, parking and access, including speed limit reductions, lane closures and some road closures. A traffic management plan will be developed to manage these impacts.

There may also be reduced access to the Maribyrnong River Trail in some locations, with temporary diversions in place for cyclists and pedestrians around construction areas.

Vegetation removal

The project is being carefully designed to avoid as many trees and shrubs where possible; however, not all vegetation can be avoided. Some vegetation, including large trees, will need to be removed to undertake these essential infrastructure works. We may also need to trim branches where trees are located in close proximity to work areas. We have been working with independent ecologists, arborists, and Moonee Valley and Maribyrnong City Councils to avoid and minimise vegetation loss where we can. 

All trees to be removed have been identified and assessed by a qualified arborist. Wherever possible, suitable logs will be kept for habitat along the banks of the Maribyrnong River, and remaining material will be mulched for re-use in local garden beds.

After the works have been completed, we will replace all vegetation that was removed by re-planting in the local area, and disturbed areas will be restored in accordance with reinstatement plans approved by Moonee Valley and Maribyrnong City Councils.

Keeping you informed

We will provide more information, including the timing of activities, as the detailed design progresses and more information becomes available.

We will make contact with directly affected residents and businesses through door knocks and notifications to ensure they are appropriately informed prior to upcoming work.

Contact the project team

 131 722

Community bulletins

Last updated:
12 August 2021