A new 1.2km gravity sewer will be built to divert sewage flows from the Maribyrnong River Main (MRM) sewer in Avondale Heights, into the larger North Western Sewer (NWS) 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.
850m of the new sewer will be constructed by tunnel boring from the eastern end of Medway Golf Club to the NWS near the corner of Hampstead Rd and Williamson Rd. 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 2-4m below ground. On completion of the project a new shared user path will be installed along the sewer alignment on the southern side of the river, connecting previously inaccessible river bank with existing walking trails.
Scope of Work
- Construct a 1.2 km gravity fed sewer
- Tunnel bore approximately 800m with 1.8m diameter tunnel boring machine (TBM). Installing approximately 271 segments of 3m length GRP pipe
- Micro tunnel 80m with smaller diameter TBM. Installing 26 segments of 3m GRP pipe
- Open cut trench 170m for pipe installation along river frontage
- Construct 70m steel structure pipe bridge to support 750mm stainless steel pipes
- Construct five GRP maintenance hole structures
- Flow management of live sewer to ensure continued operation during tie in works
- Install approximately 1km of new shared user path
- Reinstate and make good work site areas
Innovation & Complexity
- Rock blasting through 30m of volcanic basalt to excavate TBM launch shaft (final depth 40m)
- Increased tunnel diameter to remove quantity of maintenance holes
- Maintenance holes pre-fabricated offsite using glass reinforced polymer
- Increased complexity to manually break into live sewer mains
- Implement best practice with fit for purpose equipment
- Compliance and innovation to ensure safety in confined spaces.
- Encourage a continuous and inherent safety culture.
- Clear traffic management around work sites, ensuring safety of pedestrians, cyclists and motorists.
- Design to ensure minimum 100 year life of asset.
- Improved bridge design to comply with accessibility standards.
- Reinstatement in accordance with stakeholder expectations
- Ensure environmental compliance.
- Protect native vegetation and trees from construction impacts.
- Reduce, reuse or recycle our waste materials to avoid landfill.
- Incorporate the use of sustainable materials in our processes.
- Extensive sedimentation controls to protect the river.
- Regular noise, vibration, surface water & groundwater monitoring
Create relationships with Maribyrnong City Council, Moonee Valley City Council, Medway Golf Course, Rivervue Retirement Village, Parks Victoria, DELWP and the Department of Transport to facilitate permits, approvals and to collaborate on mitigating project impacts.
Promote project purpose and outcomes to the community. This will be done by delivering presentations to interested community groups, residents and local schools. Community events will be organized towards the completion of the project to celebrate the connectivity of the river valley via the new bridge and shared pathway.
Develop and distribute communication collateral that keeps the community, residents, businesses, pedestrians, cyclists and motorists well informed of the works prior to commencement, with regular updates during construction.
Leave a legacy for the community and environment. Working with key stakeholders and community groups we will collaborate on the reinstatement outcomes to ensure more trees, shrubs and grasses are planted back into the river valley.
Senior Project Engineer