Great Artesian Basin

Extent and physical characteristics

Covering roughly 1,711,000 square kilometres, the basin underlies parts of several Australian states and territories. Much of northern and central Queensland lies above the system, along with northern New South Wales, the south‑east corner of the Northern Territory, and sections of north‑east South Australia. In places the sedimentary rocks that contain the water reach depths around 3,000 metres. Estimates suggest the formation holds on the order of tens of thousands of cubic kilometres of water, and temperatures in deeper zones can rise from about 30°C to approaching 100°C.

Geology and hydrology

The basin is a layered sequence of porous sandstones and low‑permeability seals that trap and transmit groundwater under pressure. Rain that falls on recharge areas at higher elevations gradually percolates into porous rock and moves slowly through the system toward lower‑pressure discharge zones, sometimes emerging naturally as artesian springs. Because the water is confined and under pressure, wells can flow without pumping where the pressure exceeds the land surface.

Uses and importance

For many inland communities and pastoral operations the basin is the only dependable water supply. It supports domestic use, stock watering, small‑scale irrigation and tourism associated with natural springs. Some of the water is hot and mineralised, and in isolated cases has been used for bathing or local heating. More broadly, the Great Artesian Basin underpins ecosystems that depend on permanent or semi‑permanent springs, which are often biologically unique and culturally significant.

Environmental and management issues

• Uncontrolled artesian bores and leaks from poorly maintained wells have historically caused large, avoidable losses of pressure and freshwater, reducing flow to natural springs.
• Water quality varies across the basin; in some areas salinity or dissolved minerals limit suitability for some uses.
• Extraction must be balanced with recharge rates, which are slow; unsustainable use can lower pressure and reduce natural discharges.

To address these challenges, governments and communities coordinate management efforts. Organisations such as the Great Artesian Basin Coordinating Committee help plan bore rehabilitation, meter and regulate extraction, and work on conservation of springs. Research and monitoring also inform improved practices for sustaining the resource and the ecosystems that depend on it.

History, culture and research

European settlers relied on the basin early in inland pastoral expansion because it made reliable water available beyond the river systems. Indigenous Australian groups have longstanding cultural connections to many springs and groundwater features; those places often carry significant ecological and spiritual values. Scientific study of the basin spans geological mapping, hydrogeological modelling, and ecological surveys of spring communities, and continues to inform water policy, land use planning and conservation projects.

For further technical or regional information consult resources on the basin as an aquifer system (aquifer) and specialised sites covering groundwater science (groundwater). Additional jurisdictional references and management programs are available through regional portals in Queensland, Northern Territory, South Australia and New South Wales.