If you have driven past Bald Hill recently, you’ve likely noticed a significant change to the skyline. Greater Western Water (GWW) is nearing the completion of its $29 million Sunbury and Diggers Rest Water Storage Project, a massive infrastructure leap designed to support one of Melbourne’s fastest-growing corridors.
As we move through 2026, these two new enormous steel tanks, each standing nine metres high, are being integrated into our local grid. But what does doubling our region’s storage capacity actually mean for your daily life?
The Project at a Glance
- Infrastructure: Two 10-megalitre steel tanks (the equivalent of eight Olympic-sized swimming pools).
- Reach: Designed to secure water supply for up to 10,000 local properties.
- Connectivity: A new dedicated water main links these tanks directly to Melbourne’s broader supply network, including the recently ordered 150 billion litres of desalinated water.
Why Extra Capacity is a Win for Homes & Businesses
1. Stability During Peak Demand
In a growing suburb like Sunbury or Diggers Rest, peak hour isn’t just for traffic; it’s for water. On hot summer mornings and evenings, thousands of households turn on showers, dishwashers, and sprinklers simultaneously.
- The Impact: Extra tank capacity acts as a buffer. It allows the network to maintain steady water pressure during these high-use windows, ensuring that your shower doesn’t turn to a trickle just because the neighbourhood is watering the garden.
2. Emergency Resilience
Water infrastructure is the backbone of community safety. Having 20 million litres of water stored locally at Bald Hill provides a critical reserve for:
- Firefighting: Sunbury and Diggers Rest are in bushfire-prone regions. These tanks provide the high-volume, high-pressure supply needed for CFA operations.
- Maintenance Windows: If a major water main bursts elsewhere in the city, these local tanks can keep our suburbs running for hours while repairs are made, preventing total outages.
3. Managing the Desal Mix
With Melbourne ordering record amounts of desalinated water in 2026 to combat falling reservoir levels (currently at 67%), these tanks serve as a vital holding zone. They allow for more efficient blending of desalinated and catchment water before it is distributed to your home, helping to maintain a more consistent water profile.
The Expert Angle
At PureFlow, we view these storage upgrades as a massive win for our region’s reliability. Greater Western Water is doing exactly what is needed to ensure we don’t run dry.
However, it is important to remember that as the storage capacity grows, so does the travel time of the water. When water sits in large tanks or travels through new mains to reach growing suburbs, two things can happen:
- Sediment Disturbance: New infrastructure connections and pressure changes can occasionally stir up microscopic legacy particulates in older street pipes.
- Disinfection Balancing: To keep 20 million litres of water safe in the sun, treatment levels must be precisely managed. This can sometimes lead to a more noticeable scent of chlorine at the tap.
How Filtration Complements the Upgrade
A whole home filtration system is the final, logical step in Sunbury’s water modernisation. While the Bald Hill tanks manage the volume, a filter manages the refinement:
- The Final Polish: It catches any fine sediments stirred up by the new high-pressure system.
- Taste Consistency: It removes the variable scent of chlorine, ensuring that your water always tastes like a fresh mountain spring, regardless of how long it spent in a storage tank.
- Appliance Longevity: By smoothing out the mineral and sediment profile of the new water mix, you protect your hot water systems and coffee machines from the variables of a growing grid.
The Bottom Line
The Sunbury and Diggers Rest storage upgrades are an investment in our future. They mean we can keep building, keep growing, and stay safe. By adding a professional filtration system to your home, you are simply ensuring that this high-tech supply system delivers the highest possible quality to your glass.
