Almost 200 households in Lilydale can now connect to a modern piped sewerage system thanks to work delivered by Yarra Valley Water using trenchless construction methods.
The project is part of the organisation’s Community Sewerage Program, which is progressively providing properties in Melbourne’s outer northern and eastern suburbs with the option to move off ageing septic tanks and onto a piped system.
Delivering the Lilydale upgrade was particularly complex, given the suburb’s steep topography, narrow roads and established tree canopy. To minimise environmental and community impacts, Yarra Valley Water and contractor Interflow relied on horizontal directional drilling (HDD) rather than traditional open trenching.
Technology in focus
Through HDD, crews were able to install pipes up to 5 metres below ground level with minimal surface disturbance. The method uses a specialised drilling rig to bore an underground path before pulling the new sewer pipe through.
Detailed geotechnical scans were carried out prior to construction, helping Interflow select the right equipment for each location. Interflow also deployed recycled water in a hydro-excavation process, blasting high-pressure streams into the ground to verify the location of any existing services that scanning alone might have missed.
Yarra Valley Water Project Manager Nova Irawati said the approach ensured accuracy and efficiency.
“By combining HDD with extensive pre-surveying, we were able to preserve Lilydale’s streetscapes, avoid service clashes and complete the project with minimal disruption. In fact, only three trees were removed across the entire alignment.”
Minimising risks, maximising outcomes
The trenchless method also reduced the risk of interfering with underground utility networks carrying gas, electricity, telecommunications and drinking water.
Yarra Valley Water General Manager Asset Services Bridie Fennessy said the project was a technical success with clear community benefits.
“Trenchless delivery allows us to overcome significant site constraints while achieving a great outcome for households,” she said.
“Managing septic tanks can often be a hassle. When tanks are too small or aren’t maintained,they can create unpleasant smells and can even leak waste onto other properties or into waterways.
“Connecting to sewerage is more convenient for property owners and better for the environment. While people still need to be mindful of what goes down the drain and maintain their household plumbing, sewerage offers a far cleaner and more reliable alternative to managing an aging septic system.
“We’re very pleased more people have the option to connect to sewerage now that we’ve completed the works in Lilydale.”
For more information about the Lilydale Community Sewerage Program visit www.yvw.com.au/lilydale-sewerage-project