Strengthening water security in Cairns
At a glance
Cairns’ largest-ever infrastructure project is safeguarding the city’s long-term water supply through a robust, low-energy solution, delivering water security and affordability for the community.
The challenge
Cairns' growing population and reliance on its primary water source, Copperlode Falls Dam, built in 1976, placed increasing pressure on the city's water supply. The urgency of the situation became clear during Tropical Cyclone Jasper, when the city came within hours of running out of water. Cairns Regional Council needed a resilient, affordable and future-ready water supply system that withstanding tropical weather extremes while supporting the community's long-term needs.
Our response
GHD partnered with Cairns Regional Council and John Holland to deliver the Cairns Water Security Stage 1 (CWSS1) project. Our Cairns-based team — who live and work in the community — led the design, with support from GHD's national and global water specialists to bring the best of both local insight and technical excellence.
This significant water project is being delivered in stages to reduce upfront costs while allowing for future expansion. The solution includes a new 60 ml/day Water Treatment Plant along Jones Road, which can be expanded to 93 ml/day, integrating water from Behana Creek and a new river well intake at the Mulgrave River. For long-term affordability and operational efficiency, we recommended a cost-effective, robust and energy-efficient Dissolved Air Flotation and Filtration (DAFF) system. Advanced modelling and lifecycle cost analysis informed this decision, guiding the hydraulic configuration and placement of process units on site to optimise ongoing operational costs for our client. Throughout the project, our team prioritised delivery for affordability, resilience to climate extremes and community benefit, so that every decision supported a sustainable and secure water future for Cairns.
The impact
The Cairns Water Security Stage 1 project delivers a resilient and diversified water supply system that strengthens the city’s ability to respond to emergencies and climate extremes. By adopting low-energy technologies and a staged delivery model, the project reduces long-term operational costs while supporting local economic growth. This contributes to a sustainable water future for the Cairns region for generations to come.