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, which means that they are likely to become increasingly important in the future with changing rainfall patterns as a result of climate change. When combined with the renewable energy development of State Government’s Zero Cost Energy Future seawater desalination and treated wastewater will provide sustainable water sources for South Australia’s future.

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

A third plant is planned for south of Port Lincoln to help provide for the water needs of the Eyre Peninsula including Port Lincoln. SA Water is also planning for a new desalination plant at Penneshaw that will provide 2 million litres per day to support future population growth on Kangaroo Island and to provide a new secure drinking water supply.

The Adelaide Desalination Plant (ADP)

The Adelaide Desalination Plant (ADP) is the State’s largest. It was constructed to safeguard water supplies for Adelaide and to ensure that sufficient water is available in extremely dry years. The ADP can supply up to 300 ML per day with an annual production of 100 billion litres, which is about half of the water needs for the city.

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

Further information relating to the ADP is available on the SA Water website.

Other seawater desalination plants

There are a number of small scale desalination plants operated 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.

Monitoring the environmental impacts of seawater desalination

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.

Desalination of groundwater

In addition to the seawater desalination plants, SA water operate eight desalination plants that treat saline groundwater to provide safe, clean drinking water to remote Aboriginal communities in South Australia and the people of Hawker and Leigh Creek in the Flinders Ranges.

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