Site preparation begins for $2.8bn Alkimos Seawater Desalination Plant

The Western Australian Government is committing $2.8 billion to deliver Perth’s next major source of drinking water – the Alkimos Seawater Desalination Plant. 

Site preparation works have already commenced at the project site. Georgiou Group has been awarded a $29.8 million contract to prepare the site for major construction, with early works including 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. 

“Over the coming months, the site of Perth’s next major water source will begin to take shape, marking the early stages of this significant project for our growing city. 

“We’re feeling the effects of climate change right now – it doesn’t rail in Perth like it once did. 

“Where we used to receive an average of 420 billion litres of rainfall into Perth dams annually, today it is less than 70 billion litres. 

“Unlike other global cities that are facing significant water supply challenges, Perth has acted to ensure our water supply network is more resilient to the impacts of climate change,” Water Minister Simone McGurk said. 

Georgiou Group will commit to spending its entire contract value locally, with about $13 million directed to Western Australian subcontractors and up to 14 per cent to be spent with Aboriginal businesses. 

The preparation works are expected to support around 70 local jobs, including opportunities for apprentices and trainees. 

“This is a huge project for Alkimos and Perth’s north, with site works alone set to create around 70 local jobs and benefit local businesses. 

“It is a forward-thinking and innovative project that has been carefully designed with the protection of the surrounding environment and local community expectations in mind,” Butler MLA John Quigley said. 

The Alkimos Seawater Desalination Plant was announced last year, and the project secured environmental approval from State and Federal regulators in November this year as well as from an independent Development Assessment Panel. 

The desalination plant will supply up to 100 billion litres of clean, safe drinking water at full capacity, supporting the long-term water security for more than 2.5 million Western Australians who receive drinking water through the Integrated Water Supply Scheme. 

“This is a significant milestone for a project that is crucial to the long-term water security of more than 2.5 million Western Australians. 

“WA was the first State to introduce large-scale desalination and continues to be a world leader in the delivery of climate-resilient water sources. 

“The Alkimos Seawater Desalination Plant will help to secure long-term drinking water, support our economy, reduce dependence on groundwater, and meet the needs of our State’s growing population. 

“My Government’s $2.8 billion investment can be made thanks to our responsible Budget management, which will help secure not only Perth’s water supply but the future of those who will call out State home for many years to come,” Premier Roger Cook said. 

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

The $2.8 billion project will include: 

• A 50 billion litres a 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 take 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. We will incorporate this into the existing nature 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 

“Our string financial management and the surpluses we’re delivering have meant we’ve been able to support this desalination plant, which will be the third of its kind in WA. 

“This is an important project for our Government and crucial for the long-term water security of Western Australians, reflecting the Government’s $2.8 billion commitment toward this priority project,” Treasurer Rita Saffioti said. 

A contract to design, construct and operate the Alkimos Seawater Desalination Plant is due to be awarded in early 2024 and the first 50-billion-litre stage to be completed in 2028. 

During the plant’s construction and operation, it will have net-zero greenhouse gas emissions which will allow Water Corporation to reduce its groundwater allocation by 30 billion litres annually, helping preserve healthy wetlands, parks, forests and public open spaces in Perth’s north. 

Source: Government of Western Australia – Media Statements; Water Corporation (1, 2, 3)