Desalination key to securing sustainable water future for Lower Great Southern

• Low-impact desalination will form part of the region’s longer-term water supply
• No alternative water source can meet future demand with constraints on existing groundwater sources
• New areas of investigation identified for future desalination plant

Nanarup and Sandpatch within the City of Albany are the new areas under consideration for a proposed seawater desalination plant to help secure a sustainable and reliable water supply for the Lower Great Southern beyond 2030.

While a new groundwater source within the Albany area is still being investigated, climate-resilient desalination will need to form part of the solution, with no alternative water source able to meet long-term demand within the required timeframes.

Water Corporation’s Great Southern Regional Manager Adrian Stewart explained why groundwater alone will not be sufficient.

“Due to declining rainfall, we can’t rely on our existing groundwater sources and dams to meet our long-term water needs. Groundwater will continue to play a part but it won’t be enough. That’s why seawater desalination needs to be part of the long-term plan.

“We’ve explored different ways to find more water, like using recycled wastewater and stormwater or expanding dam catchments, but none are sufficient to bridge the gap, with an extra 1.8 billion litres required by 2050.”

Desalination is a proven technology that can operate with minimal environmental impact. Water Corporation is commencing initial engagement on the new locations, following King George Sound being ruled out.

Adrian Stewart explained the two areas were selected due to their proximity to the city and existing water infrastructure.

“We need to keep a future plant close to Albany, which accounts for the bulk of water demand within the region, and existing water infrastructure. This helps reduce the environmental and social impacts of long pipelines, which otherwise add to the complexity and timeframes for delivery.”

Environmental values informed the new areas with both located outside protected national parks and nature reserves.

To help inform its options analysis, Water Corporation will now engage with dozens of key stakeholders, including the City of Albany and Traditional Owners. Feedback and insights will be gathered through its new community consultation group and other channels, including drop-in information sessions.

A new source is required by 2030 to respond to the growing pressure on existing sources and to meet increased demand to support population and economic growth.

Mr Stewart said: “A desalination facility in Albany will be small, sympathetic to the locality and will operate with minimal environmental impact. It’s the sustainable water source required to support the Lower Great Southern, so we need the community and other stakeholders to help us deliver this vital project.”

Climate projections for Albany indicate average annual rainfall will decline by up to 21 per cent by 2050. This will mean less water to replenish underground aquifers, dams and river sources. Groundwater currently supplies around 90 per cent of the region’s drinking water.

The inaugural community consultation group meeting was held on Tuesday, 1 July, and Water Corporation will host a drop-in information stand at City of Albany’s All at Sea Saturday event on 5 July. 

For project updates and FAQs, visit Future water source planning in Great Southern Region.

Lower Great Southern seawater desalination fact file

• Desalination is a proven and low impact water source, not reliant on rainfall, that provides a sustainable and reliable supply of drinking water.
• A future plant in the Lower Great Southern will be relatively small and visually more discreet with an expected 3GL (billion litre) capacity, subject to further design and modelling, vs 100GL at WA’s largest desalination plant.
• Seawater desalination uses very fine membranes, acting like microscopic strainers, to separate water molecules from seawater in a process called reverse osmosis. About 40-45% of the seawater becomes freshwater for drinking and the remaining 55-60% is brine (concentrated seawater).
• A special diffuser is used to gently disperse the brine back into the ocean.
• Water Corporation has successfully operated desalination plants for almost 20 years, demonstrating it can be delivered with negligible environmental impact.