Alkimos to be home of WA’s new desalination plant

The new desalination plant will be delivered in two stages. Graphic: Water Corporation

A NEW desalination plant to be delivered in two stages has been announced for Alkimos with the first stage due to be completed and operational in 2028.

A McGowan Government spokesman said it was estimated the cost of the first stage (with a capacity to produce 50 billion litres of drinking water) would be $2 billion.

The government said a detailed environmental review document for the Alkimos seawater desalination plant was with the WA Environmental Protection Authority for assessment.

Environmental Protection Authority (EPA) chairman Matthew Tonts said the Alkimos seawater desalination plant would be assessed at the public environmental review (PER) level.

Professor Tonts said the EPA assessment was for the construction of a desalination plant, implemented in stages, capable of supplying 100 gigalitres per year of drinking water.

“The next key step is for the proponent, Water Corporation, to submit its environmental review document,’’ he said.

Once approved by the EPA this document will be published on the EPA website for a four-week public review.

“The EPA expects to complete its assessment of the Alkimos seawater desalination plant in the first half of 2023.’’

The EPA’s report and recommendations will then be given to the Environment Minister Reece Whitby.

Premier Mark McGowan said a new plant would cater for the growing drinking water needs of Perth, Peel, parts of the South-West and Kalgoorlie-Boulder and support future economic development.

“Importantly, the new desalination plant will be renewably-powered, and with the existing initiatives, will support the new 2030 government emissions target,’’ he said.

Water Corporation information about the Alkimos seawater desalination plant says modelling has shown any water returned to the ocean through the desalination process will mix with surrounding seawater quickly and have minimal impact on marine habitats.

The government said the new desalination plant would be sunken behind big, vegetated sand dunes to shield it from view and buffer noise, while a special tunnel boring technique would limit seabed and beach disturbance during construction.

Renewable energy will be used to match the plant’s energy requirements as the Water Corporation works towards net-zero greenhouse gas emissions across its operations by 2035.

Water Minister Dave Kelly said as well as eventually providing 100 billion litres of drinking water annually the Alkimos desalination plant would reduce reliance on groundwater to help protect lakes, wetlands, bushland and parks.

“Desalination is energy intensive, that’s why it’s significant that Water Corporation has set itself a target of net zero by 2035, which will include having all three desalination plants powered by renewable energy,’’ he said.

But he said new water sources were just one element in a much larger and more complex supply planning process.

“It’s absolutely vital we all remain as waterwise as possible to help protect WA’s most precious resource.”

The McGowan Government has already allocated $1.4b towards the desalination project.

Food producers unlikely to gain from any net water benefit