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Desalination

Groundwater desalination

There are desalination plants across South Australia that treat groundwater to remove salt and impurities, and provide safe, clean drinking water to remote Aboriginal communities in South Australia and the people of Hawker and Leigh Creek in the Flinders Ranges.

Ten desalination plants are operated by SA Water to provide drinking water to regional communities. The plants are located at Marla, Oodnadatta, Hawker, Leigh Creek, and the rest in APY Lands and Yalata.

Private companies including horticulturalists and miners also operate groundwater desalination plants.

Seawater desalination

Desalinated seawater is a key water source for South Australia. Desalinated seawater and recycled wastewater are the only water sources that are fully independent of climate, so they will become increasingly important in the future with changing rainfall patterns due to climate change.

When combined with the renewable energy under the State Government’s Zero Cost Energy Future, seawater desalination and treated wastewater will provide sustainable water sources for South Australia’s future.

Regional seawater plants

SA Water operates two seawater desalination plants, one at Lonsdale in Adelaide and the other at Penneshaw on Kangaroo Island.

A third plant is planned for Billy Lights Point south of Port Lincoln to provide water for the Eyre Peninsula. SA Water is also planning a new plant at Penneshaw on Kangaroo Island that will provide 2 million litres per day to support future population growth on the Island.

A number of small-scale desalination plants operate around South Australia. For example, Yorke Peninsula Council operates a small seawater desalination plant at Marion Bay capable of producing 65 kilolitres per day. The use of desalinated water improves the quality of water supplied to the Marion Bay Caravan Park, businesses, residents and visitors to the area.

Sundrop Farms near Port Augusta is an example of a privately operated solar powered seawater desalination plant that supplies freshwater for horticulture.

Adelaide Desalination Plant

South Australia's largest desalination plant. it was constructed to safeguard water supplies for Adelaide and to ensure enough water is available in extremely dry years. The plant can supply up to 300 ML per day with an annual production of 100 billion litres, which is about half of Adelaide's water needs.

The volume of water supplied from the plant is balanced with water available from the reservoirs of the Mount Lofty Ranges and the River Murray. Most years the plant operates in a reduced capacity because of reduced demand and the relatively higher costs of producing desalinated water.

Further information is available on the SA Water website.

The Environment Protection Authority (EPA) issues environmental licences for seawater desalination plants with strict requirements for compliance and monitoring. Details of the Adelaide Desalination Plant licencing and a summary of the monitoring data collected as part of the licence conditions is available on the EPA website.

Why was the plant built?

The plant was built following the Millennium Drought to provide a source of water not dependent on the climate, to supplement water from the state’s reservoirs, stormwater, wastewater and the River Murray.

The combination of these sources of water provides the necessary water security to underpin South Australia’s economic and population growth to 2050.

How is the plant factored into water allocation decisions?

The plant makes a major difference to how water is shared between South Australian water entitlement holders of the River Murray in dry years.

By reducing Adelaide’s reliance on the River Murray in dry years, up to an additional 50 GL of available River Murray water is then able to be released to holders of irrigation licenses, which would not be possible without the insurance provided by the plant.

This boosts irrigation allocations by up to 8 per cent and applies when irrigators are on less than 100 per cent and critical human water needs have been secured.

How is the plant used to help with the impacts of drought?

When South Australian irrigators are on allocations of less than 100 per cent, the insurance provided by the Adelaide Desalination Plant enables these allocations to be increased by up to eight percentage points.

The plant is also able to provide a benefit to severely drought affected farmers in this time of national need.

In a historic agreement between the South Australian and Australian Governments, Adelaide’s Desalination Plant increased production and provided 40 GL of water in 2019-20. This enabled the Commonwealth Government to release the equivalent volume to help drought-affected farmers through its Water for Fodder program.

The Australian Government meets all costs associated with increased use of the desalination plant and provides the extra water to farmers at less than market rates. Details on how this water will be made available to drought affected farmers is available from the Commonwealth Government.

As part of this deal, a $10 million South Australian Drought Resilience Fund was established.

Key components of the Agreement are:

No adverse impact on Adelaide’s water security
No adverse impact on Adelaide’s water prices
No adverse impacts on flows to South Australia
Up to 40 GL of water to be provided this financial year, with up to an extra 60 GL to be provided in 2020-21 dependent on a review.
The review will commence prior to 2020-21 and assess the effectiveness of the 40 GL, water availability in the Basin, South Australia’s water security and costs
The arrangement is a one-off, recognising the severe impact of current drought conditions.

You can also read the story on our news page.

Letter from the Prime Minister and copy of the arrangements for the provision of water to the Commonwealth through increasing production from Adelaide’s Desalination Plant.

Has the review of the 40 GL been completed?

The South Australian and Commonwealth governments have completed the review of the 40 GL produced in 2019-20. Two reports were prepared as part of the review:

A decision was made not to proceed with producing a further 60 GL in 2020-21.

Are there any environmental impacts?

The Adelaide Desalination Plant has one of the smallest carbon footprints of any desalination plant in the world.

Independent reviews of the plant's environmental impact show that it has caused no harm to the environment.

This has been achieved by:

using energy from renewable sources
harvesting rainwater on-site for use within the plant
capturing stormwater and surface water run-off in local wetlands as this process naturally cleans the water before it goes out to sea
growing Indigenous plant species and encouraging animals to return to the site
continually monitoring the environmental health of Gulf St Vincent.

Does the plant contribute to Basin Plan outcomes?

At the December 2018 Murray-Darling Basin Ministerial Council, the Minister for Environment and Water agreed to investigate whether the Adelaide Desalination Plant could make a contribution to the recovery of the final 450 gigalitres through efficiency measures under the Basin Plan. This investigation built on a report provided by EY to the Ministerial Council in January 2018.

SA Water and the Department for Environment and Water contracted Aurecon Australasia Pty Ltd to undertake the feasibility study.

The feasibility study concluded that through the operation of the Adelaide Desalination Plant it is technically feasible to maintain Adelaide’s water security while reducing the volume of water taken from the River Murray by up to 30 gigalitres on average per year in perpetuity. The cost of achieving this however, significantly exceeds the Commonwealth government’s current funding multiplier of 1.75 times the market value of water rights. Proceeding with this measure would also reduce the capacity for the desalination plant to be used to further support regional communities in times of extreme drought.