Brackish groundwater resources, which contain elevated salt levels, are alternative water resources that can be desalinated and used when freshwater sources are low or unavailable. Their use can secure water supply for communities, agricultural production, and other industrial uses where freshwater is scarce. Brackish water desalination offers several advantages over desalination of highly saline water, including higher water recovery rates, lower energy requirements, and reduced brine stream volumes.

Despite these potential benefits, research into brackish groundwater resources in Australia and their suitability for desalinisation has been limited. CSIRO has undertaken a study to identify and characterise brackish groundwater resources in Western Australia and evaluate further opportunities for their desalination and use.

This project, funded by the Australian Government through the National Water Grid, addressed key challenges facing brackish groundwater desalination, including:

  1. brackish groundwater resource characterisation (occurrence, chemical composition and suitability for desalination)
  2. available desalination technologies and inland brine management options, and
  3. energy source availability, including consideration of current and future climate conditions.

The project evaluated brackish groundwater in Western Australia (WA) based on its occurrence, potential availability, and suitability for desalination. The analyses conducted were based on available groundwater information and allocation data established by the state’s Department of Water and Environmental Regulation. These datasets contain inherent uncertainties; therefore, the project results should be considered as providing a high-level overview at a state scale.

The project took a closer look at a number of regional opportunities for the use of brackish groundwater. These were:

groundwater lake north of Perth

Perth Basin

In the Perth Basin, the total unallocated groundwater classified as ‘brackish and mainly brackish’ is approximately 57.0 GL.

Image of rockpool with rocky cliffs behind

Carnarvon Basin

The Carnarvon Basin, located in Western Australia’s Gascoyne region, is a geologically rich and complex area, stretching across both onshore and offshore zones.

Image of a wide river in the outback with a weir and sand bars downstream from this.

Canning Basin

The Canning Basin located in north-west WA has an onshore extent of about 530,000 km2 and is Australia’s second-largest sedimentary basin (after the Great Artesian Basin).

Fractured Rock, Palaeovalleys and Alluvial Aquifers

Groundwater resources from local to intermediate-scale aquifers across regional parts of Western Australia (WA) provide a crucial source of water for industry, livestock, domestic use, and community water supplies, particularly in areas where traditional sedimentary aquifers are limited or absent.

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Remote Communities

Across WA there are over 300 remote communities many of which occur in the north of the state spread across parts of the Kimberley region, and others dispersed across the centre of the state from the Pilbara region in the central-east to the Goldfields region in the central-west.