A doubling in capacity of Sydney’s Desalination Plant will allow it to produce 500 ML of fresh water per day. Photo: Sydney Water.
The NSW Government is investigating options to double the capacity of Sydney’s Water Desalination Plant to help make the growing city more drought-resistant.
Built on the historic Kurnell Peninsula adjacent to the Ampol oil terminal and opened in 2010, the ‘Desal’ was considered a white elephant when it was mothballed between 2012 and 2019 after Sydney’s dam levels recovered from the severe drought.
The NSW Government says 85 per cent of Sydney’s water supply is dependent on the rainfall collected in the city’s five major water catchments and household water tanks, and says the plan to upscale the desalination plant will help diversify those water supplies and make the city better able to withstand future droughts.
The plant can currently deliver 250 megalitres per day, but an initiative of the Greater Sydney Water Strategy, which identified the need to invest in non-rain-dependent alternatives, says the planned 500 megalitre capacity will enable the plant to cover 30 per cent of the city’s water requirements.
The desalination process draws seawater through four caged intake pipes located about 300 metres offshore and 25 metres below the surface. First, the water goes through a pre-treatment filter to screen out rubbish, plant and animal life and sand or dirt and is then further filtered through layers of anthracite and sand.
Next, the reverse osmosis process passes the seawater through 36,000 membranes at high pressure to remove the salt and other minerals.
A post-treatment process on the now freshwater adds the required minerals, fluoride and chlorine to make it suitable for drinking before it is fed into Sydney’s water supply at Erskineville via an 18 km long pipeline underneath Botany Bay.
NSW Minister for Water Rose Jackson said the planned upgrade was about safeguarding Sydney’s water future so it can continue to meet demands in a changing climate.
“We’re kicking housing expansion in Greater Sydney into high gear and to ensure this growth is sustainable, we must also expand vital water infrastructure,” she said.
“In a drought, Warragamba Dam can go from full to empty in five years, so it is crucial that we actively explore options to expand our water sources, which will take pressure off Sydney’s dams.
“Melbourne and Adelaide have already turned to desalination plants for nearly half their water use, so it is high time we joined their ranks and move forward with boosting our supply options, so we’re better placed for future dry periods,” she added.
“As part of our commitment to a greener future, any upgrade to the plant will be 100 per cent powered by renewable energy, providing a sustainable and secure solution.”
Sydney Water managing director Roch Cheroux said the agency was preparing for the future by exploring all options as part of the Greater Sydney Water Strategy, including increased production of water supplied by the desalination plant.
“We can no longer rely on rainfall alone, so this investment allows us greater flexibility to diversify our water sources to meet Greater Sydney’s future demands,” he said.
“We have also released our first ever long-term investment plan, which addresses the challenges facing Greater Sydney, such as significant population growth, climate change and our own ageing infrastructure.”
Work on the first stage of planning for the upgrade will get underway by the end of this year and be finalised in 2024.
