Unitywater Completes Waraba Milestone Sealing Off Five-Storey Underground Wet Well
In a significant development for Caboolture West’s future, Unitywater has successfully sealed a five-storey underground wet well as part of its Waraba Wastewater Network Project. The milestone was achieved by using a 350-tonne crane to lift a 35-tonne concrete slab into place—marking another step toward providing essential services for the region’s growing population.
Built for the Future
The new wet well and more than 4.5 kilometres of wastewater pipeline are designed to serve approximately 30,000 residential lots—supporting up to 70,000 future residents in Waraba over the next 40 years. Once complete, the network will be capable of handling the equivalent of more than three million toilet flushes every day, ensuring reliable wastewater management for decades to come.
How the Wet Well Works
Unitywater Principal Project Manager Victor Cabrera explained that the wet well is a 15-metre-deep storage chamber that regulates the flow of wastewater to the pump station during busy periods. This process helps maintain a steady downstream flow and breaks down any solids before the wastewater reaches the South Caboolture Wastewater Treatment Plant. There, it will be cleaned, disinfected, and safely released back into local waterways.
In extreme wet weather, the system will be able to process up to 381 litres of wastewater per second—keeping the community’s services running smoothly.
A Technically Challenging Build
Josh Pearson, Senior Project Engineer for delivery partner Killard Tallai Joint Venture (KTJV), said sealing the wet well was no small task. The slab was poured directly beside the wet well site for precision, then carefully lifted and placed by the 350-tonne crane.
Supporting Growth in the Region
Construction began in May 2024 and is expected to finish in late 2025. Unitywater’s $2 billion, five-year infrastructure investment will continue to provide essential water and wastewater services for the Moreton Bay, Sunshine Coast, and Noosa communities—supporting over 800,000 people today and the many more who will call the area home in the future.
For more information, visit the Waraba Wastewater Network Project page.
