With more than 17km of a total 33.5km in place, the Alkimos seawater desalination trunk, Western Australia’s largest water pipeline, is now half complete.
Part of the WA Government’s $2.8 billion Alkimos Seawater Desalination Plant project, the underground pipeline will connect the new desalination facility to Water Corporation’s Wanneroo Reservoir and ultimately the Integrated Water Supply Scheme, which supplies more than 2.5 million people.
With an internal diameter of 1.6m, the trunk main is one of the largest water pipelines ever constructed in WA and has been designed to support future expansion of the desalination plant.
The steel, cement-lined pipeline is being manufactured locally by Steel Mains in Kwinana using Pilbara iron ore and Cockburn cement, and is expected to have an operational lifespan of around 120 years.
Almost 1,600 pipe sections ranging from 6m to 12m in length have been installed so far, with each 12m section weighing close to nine tonnes.
Once complete, the Alkimos Seawater Desalination Plant will become WA’s third seawater desalination facility, initially delivering 50 billion litres of drinking water each year while supporting more than 1,500 jobs during construction.
The trunk main will transfer water from the plant via the Carabooda Tank, future Nowergup Tank and Wanneroo Reservoir before connecting to the broader water supply network.
Its large diameter has been designed to improve pumping efficiency, reducing energy demand and lowering greenhouse gas emissions by 21 per cent compared with a smaller pipeline.
The trunk main is being delivered by the Alkimos Pipeline Alliance, comprising Water Corporation, Georgiou Group and DM Civil, and is scheduled for completion in 2027. The route has been developed in consultation with local stakeholders to minimise impacts on the environment and surrounding communities.
WA Premier Roger Cook said the project showcased the benefits of the state’s Made in WA plan.
“Not only will it be built with products and materials sourced from local businesses, it will also be a key part of our Alkimos desalination plant, which when built will support hundreds of jobs while supplying households and businesses with water that is Made in WA,” Cook said.
