Major milestone reached on $2.8bn Alkimos Seawater Desalination Plant

The development of Perth’s next major source of drinking water is ramping up with the announcement of a preferred proponent that will design, build and operate $2.8 billion Alkimos Seawater Desalination Plant (ASDP). 

A consortium comprising of Acciona Agua Australia Pty Ltd and Jacobs Group Australia Pty Ltd has been named as the preferred proponent for the project and, subject to further negotiations, the companies will form an alliance to be known as the Northern Water Partnership (NWP) prior to the beginning of construction mid this year. 

The two companies boast credentials in undertaking projects similar to the future Alkimos Seawater Desalination Plant. 

Acciona Agua Australia has significant experience in delivering and operating drinking water infrastructure, including the Adelaide Seawater Desalination Plant that it built and now operates as part of a consortium. 

Jacobs Group, on the other hand, has similar expertise as the company partnered with Water Corporation to deliver vital water supply and wastewater projects across Western Australia. 

Alkimos Seawater Desalination Plant concept illustration (source: Water Corporation)

The proposed scope of the $2.8 billion program of works include: 

• A 50 billion litres per year desalination plant within the Alkimos Water Precinct, with the possibility of a future 50 billion litres per year expansion 
• An ocean intake pipeline below the seabed that brings seawater into the plant 
• An ocean discharge pipeline below the seabed that safely takes brine (salty water) away from the plant 
• A 33.5-kilometre pipeline to convey drinking water produced by the plant to Wanneroo Reservoir for supply into Perth’s Integrated Water Supply Scheme 
• Built-up, vegetated sand dunes on the western side of Alkimos Water Precinct, which will be incorporated into the existing natural dune system to minimise potential visual and noise impacts from the plant 
• Provision for a 4.9 billion litres per year groundwater treatment plant and local bores 

The Alkimos Seawater Desalination Plant will eventually produce 100 billion litres of climate-resilient drinking water annually, helping secure water supply to over 2.5 million Western Australians. 

The delivery of this project was made possible by the Western Australian Government’s Budget surplus. 

An alliance contract is anticipated to be awarded in March 2024, depending on successful negotiations with the preferred proponent. 

“The Alkimos Seawater Desalination Plant and associated projects are a significant investment in the future water security for millions of people across Perth and regional areas. 

“With siteworks well underway, and now the announcement of the preferred proponent, we’re on track for construction to begin mid-2024. 

“Western Australia was the first State to introduce large scale desalination, and this is a key milestone in the delivery of our next climate-resilient water source,” Water Minister Simone McGurk said. 

Project site within Alkimos Water Precinct (source: Water Corporation)

Preparation work on the Alkimos Water Precinct project site is well underway. Georgiou Group was awarded a $29.8 million contract to undertake early works, which includes sinking the site into the landscape and extending a large, vegetated sand dune to shield the future facility from view along with the establishment of a noise buffer. 

The early works will support up to 70 local jobs, including opportunities for apprentices and trainees. Georgiou Group is also committed to spending its entire contract value locally, with approximately $13 million directed to Western Australian subcontractors and about 14 per cent to be spent with Aboriginal businesses. 

Source: Government of Western Australia – Media Statements; Water Corporation (1, 2)