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How does SDP fit in with Sydney’s wider water supply network?
Q: The Sydney Desalination Plant is the third largest desalination plant in Australia. What is SDP’s role in the Sydney Water drinking water supply network?
A: Sydney Water has access to a large network of dams around Sydney that collect rainwater, which is then treated to drinking water quality and distributed to customers via their network of pipes. The Sydney Desalination Plant (SDP) can currently provide up to about 15 per cent of Sydney’s drinking water needs.
The key difference is that SDP is Sydney’s only major source of rainfall independent drinking water supply. The water produced at SDP is transferred via an 18km pipeline that runs under Botany Bay and is then fed into the Sydney Water network in Erskineville. From here, the water is blended in with the water treated at the Sydney Water filtration plants before heading out to customers.
Q: What was the purpose of building SDP at the Kurnell site in Southern Sydney and why is SDP important?
A: Being located in Kurnell allows us to have safe, unrestricted and unlimited access to high quality seawater.
The Sydney Desalination Plant is Sydney’s only major rainfall independent drinking water supply. This means that in certain situations (extreme wet or dry weather, poor water quality, lower dam levels, or critical maintenance work on the Sydney Water system) there is a need for the Sydney Desalination Plant to be available and ready to assist. In these circumstances, having the Sydney Desalination Plant readily available reduces stress on the dams and allows Sydney Water more time to respond, ultimately benefiting the residents of Sydney. Also, key planned maintenance activities in the Sydney Water network can occur, meaning ageing assets can be renewed and maintained and therefore reduce the number of reactive situations that cause unplanned interruptions to customers.
Q: What are the major challenges and opportunities facing the drinking water supply network in Sydney over the next ten years and beyond?
A: The challenges in Sydney are the same challenges that are being seen all over the world. As populations grow, infrastructure must be developed to respond to that growth and more drinking water is required to meet this demand. Combined with that is the effects of climate change. We are seeing an increase in extreme weather events such as storms and droughts which puts additional stress on water networks.
Sydney will have ongoing challenges to increase its rainfall independent drinking water supply infrastructure due to its overreliance on storage dams which current supply over 80 per cent of Sydney drinking water needs. Desalination and purified recycled water will play a key role in maintaining Sydney drinking water system resilience.
Q: Does SDP have the potential to increase production quickly if there is an issue in the Sydney Water network and/or other sources of drinking water have problematic production?
A: The Sydney Desalination Plant operates in a ‘fully flexible’ arrangement with Sydney Water, whereby the plant is always operating and available to increase production if needed. The time to respond is dependent on how much water the Plant was already producing, but we can typically go from baseline (low flow) production of around 20 per cent capacity, to full production in a short period.
Q: How crucial will desalination plants be for Australia to address the impact of climate change, variable extreme weather events and population growth?
A: Having desalination as an available and reliable drinking supply is a big advantage to any water network. It is the benefits of having immediate, reliable, high quality drinking water which makes desalination critical to assist in combating the impacts of climate change, extreme weather events and population growth. It is no surprise that all of Australia’s five biggest cities have at least one desalination plant. This will likely increase in the future, and we are also starting to see smaller regional areas around coastal Australia such as Newcastle building their own desalination plants.



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Frequently Asked Questions
- Is the Sydney Desalination Plant operating?While the Plant was originally designed to operate only in times of drought, it has remained operational since 2019 to help address several storage dam water quality issues arising from bushfires, flooding and significant maintenance tasks in Sydney Water’s supply network.
The Sydney Desalination Plant’s WICA Network Operator’s Licence enables the Plant to remain operational, recognising that the Plant has always been, and will continue to be, an essential component of Sydney’s water management and an integral part of our city’s water-resilient future. - How much water does the Plant produce?The Plant can provide up to 15 per cent of Sydney’s average drinking water needs without any reliance on rainfall.
It treats, filters and re-mineralises seawater to produce up to 91.25 gigalitres per annum of high-quality drinking water.
Under our WICA Network Operator’s Licence, the Plant will operate on a “flexible full-time basis”, producing between about 20 gigalitres to 91.25 gigalitres every year. - What does desalinated water taste like?Sydney Desalination Plant water is treated to taste the same as Sydney’s other drinking water.
Like dam water, water from the desalination plant is treated to meet Australian Drinking Water Guidelines, which makes it among the best in the world. - Who owns the Plant?Sydney Desalination Plant is jointly owned by the Ontario Teachers’ Pension Plan Board and the Utilities Trust of Australia, which is managed by Morrison & Co. Find out more on our About Us page.
- Why is desalination important?The Sydney Desalination Plant is Sydney’s only major sources of non-rainfall dependent drinking water. It is one effective way of securing Sydney’s water supply against the effects of climate change and natural disasters and the increase in demand due to population growth, warmer weather and urban greening projects.
While the Plant was originally designed to respond to Australia’s severe millennium drought, recent experiences have demonstrated that drought is only one type of event that requires support from the Plant to ensure clean and safe drinking water for Greater Sydney.
The Plant has been a reliable drinking water supply during floods and bushfires, which caused water quality challenges from time to time in Sydney’s storage dams. - Where does the water go?The Plant can supply water to homes and businesses south of Sydney Harbour and as far west as Bankstown, as part of all their water supply.
Sydney Water uses a variety of water sources to supply customer needs. Where your water comes from depends on demand and where in Sydney you live.
If you live in the blue-shaded area on this map, you may receive water from the dams, the Sydney Desalination Plant or a combination of both. The Plant's water proportion will change throughout the day due to variations in supply and demand.
Everyone will benefit from desalination because it allows more water to be left in the dams, which means a more secure water supply for Sydney. - How much energy does the Plant use?The Sydney Desalination Plant requires roughly 38 megawatts at full production and is 100 per cent powered by renewable energy.
The average energy needed to provide drinking water to one household is about the same as the energy used to run a household fridge. - What’s the impact on the environment?Sydney Desalination Plant places a high priority on minimising any environmental impacts – both on land and in the water.
To support this, the Plant has put in place a world first stringent six-year marine environment monitoring program. The marine environment was monitored for three years before construction and three years after the Plant became operational. It demonstrated that the Plant has minimal effect on the marine environment.
On land, a third of the Plant site at Kurnell has been maintained as a conservation area. This area is protected, and native species of flora and fauna are regularly monitored. This includes a program to survey the numbers of grey-headed flying foxes and green and golden bell frogs in the area.