Great Artesian Basin

The Great Artesian Basin is Australia’s largest artesian groundwater basin. Underlying an area of approximately 1.7 million km2, the Great Artesian Basin extends beneath the arid and semi-arid regions of Queensland, New South Wales, South Australia and the Northern Territory to depths of up to 3000m.

The Great Artesian Basin consists of a multi-layered, confined aquifer system with aquifers occurring in continental quartzose sandstones deposited during the Triassic, Jurassic and Cretaceous periods (225-65 million years ago).

A small groundwater spring in a field just below a ridge.

Groundwater spring from the
Great Artesian Basin

The Great Artesian Basin comprises the Eromanga, Surat and Carpentaria sedimentary basins and parts of the Bowen and Galilee Basins. The hydrostratigraphic units, i.e. aquifers and confining beds, generally correlate across the basin and are mostly identical to the lithostratigraphic or rock units. Most of the sandstone units that form the aquifers within the Basin contain minor interbedded siltstone and mudstone facies that are impermeable and have a variable distribution. Aquifers within the Great Artesian Basin can reach thicknesses of up to 400m, with average thicknesses in the order of 150–200m for the main aquifers.

Topic contact: groundwater@ga.gov.au Last updated: July 5, 2013