Water security

Eyre Peninsula’s water security challenges

In 2007, we began working with the Eyre Peninsula community as we prepared a long-term water plan for the region. The plan identified seawater desalination as the preferred future water supply option to supplement existing groundwater sources and ensure water security for 35,000 local customers.

Uley South Basin is the last remaining major productive groundwater source on Eyre Peninsula, currently supplying approximately 75 per cent of the region’s drinking water. The basin refills when rain seeps through the soil and ground into the underground aquifer – a process known as groundwater recharge. Extensive monitoring of water levels in different parts of the basin has shown a long-term trend of reduced recharge.

Continued extraction from the Uley South borefield at current levels, in combination with the long-term trend of reduced recharge, is predicted to cause water levels in parts of the basin to reach historically low levels by the mid-2020s. Sustained over-extraction risks the freshwater in the basin becoming more saline, as well as seawater intrusion – which would permanently decrease the size of the freshwater aquifer.

Data for 2021-22 indicates that despite being an above average period for rainfall, Uley South Basin experienced only average recharge with water levels remaining stable. To ensure the basin remains a viable resource for the long term, it is essential that a climate-independent desalination plant is delivered.

The timeframe for delivery is critical, with a very real risk of irreversible damage to the Uley South Basin if current extraction rates continue beyond 2025-26. Without a desalination plant, we are unlikely to be able to supply water to Eyre Peninsula at current demand, and significant delays would likely lead to water restrictions.