Transforming wastewater into regional value

Unitywater provides water and wastewater services in the Moreton Bay regions and as part of the Wamuran Irrigation Scheme concept, needed to transform wastewater from its growing urban areas into a safe and reliable recycled water supply. The solution had to meet strict health and environmental standards while supporting agricultural needs, community growth and protecting sensitive waterways. This required designing a treatment solution that could deliver high-quality water and remaining reliable amid the region’s ongoing growth and development.

GHD partnered with Unitywater to design the Caboolture South upgrades as part of a broader consortium delivering the Wamuran Irrigation Scheme. This consortium includes the WIS Joint Venture (between Pensar, Twin View Turf and Piñata Farms), AECOM and Abergeldie Complex Infrastructure. 

GHD had long-standing experience in the region’s water supply planning and design, as demonstrated through the successful delivery of works at the Caboolture South Sewage Treatment Plant. This history gave our team strong insight into the existing plant’s operation and the treatment processes required to deliver a reliable recycled water supply. 

For the Wamuran Irrigation Scheme, we designed the new Caboolture South Recycled Water Treatment Plant to reinstate water recycling at the back end of the Caboolture South Sewage Treatment Plant. The plant produces beyond Class A quality water suitable for use on strawberry, pineapple and turf farms across Wamuran and nearby areas. The treatment process applies robust filtration to meet the project’s stringent quality requirements. Additionally, the adopted design strategically repurposes parts of a decommissioned water recycling plant at the site to minimise capital expenditure and reduce infrastructure required as part of the upgrade works and treatment system.

Working closely with Unitywater, Queensland Health and specialist partners, we guided regulatory approvals, supported validation and prepared key inputs to the Recycled Water Management Plan. The project also implements Queensland’s updated State Code 21 for chlorine facilities, an important step in achieving the required safety and performance outcomes for gaseous chlorine facilities.

To support long-term performance, we collaborated with stakeholders to develop the operating framework and create a clear pathway for reliable ongoing operation of the scheme.

Through deep technical experience, strong collaboration and a focus on regional outcomes, we help convert wastewater into a sustainable water source that supports local growers, protects waterways and enhances water resilience across the Moreton Bay Region.

Today, the Wamuran Irrigation Scheme delivers a reliable supply of quality recycled water to farms in the Moreton Bay Region, diversifying water availability for agriculture and reduces nutrient loads to nearby waterways. The scheme, enabled by the Caboolture South Recycled Water Upgrade, has been acknowledged for its innovation and collaborative approach, receiving the Infrastructure Project Innovation Award at the Australian Water Association Queensland Water Awards.

Infrastructure Project Innovation Award (METRO)
- The Wamuran Irrigation Scheme

Unitywater, WIS Joint Venture (Pensar, Twin View Turf and Piñata Farms), GHD and Abergeldie Complex Infrastructure