How did The Great Artesian Basin form?

The Great Artesian Basin (GAB), one of the world’s largest groundwater reservoirs, formed over millions of years through geological processes. During the Triassic and Cretaceous periods, vast sedimentary layers accumulated in an inland sea that covered parts of eastern Australia. These layers consisted of porous sandstones and impermeable rocks like shale and clay.

As tectonic forces shifted, these sedimentary layers were compressed and buried deeper beneath the Earth’s surface. The sandstone layers became aquifers, holding water from rainfall that seeped into the ground over time. The impermeable rock layers around the sandstone, trapped this water, preventing it from escaping and forming the pressurized basin we have today.

How big is The Great Artesian Basin?

The basin ranges from 100m near the Bowen Basin and down to to 3Km deep in the Eromanga Basin.
It has an underground area of 1.7 million square kilometers which is about 23% of the entire Australian Landmass. It is also the largest artesian basin in the world!
It holds 64,900 million megalitres of water, which is enough to fill Sydney Harbour 130,000 times over!

Water that falls as rainfall around the edges of the basic (especially on the east coast) filters through the rocks between 1 to 5 meters a year and can take 2 million years to reach the oldest section which is the SW of QLD in the Cunnamulla region!

When was The Great Artesian Basin Discovered?

Traditional owners have known of water and mud springs bubbling up from below for tens of thousands of years.
Artefacts and oral histories show that natural springs were often places for making and collecting tools and plant products. These could be traded with other tribes along trade routes following the chain of springs.
Early white explorers used the water from the springs in their early travels in the 1850’s and the first artesian bore was sunk near Kallara Station, near Bourke in 1878. The first substantial flows were from QLD near Noorama Station just south of Cunnamulla in 1886.

Why is The Great Artesian Basin important?

By 1915 1,500 bores had been sunk, those bores provided water for livestock, farming, the Ghan Railway, even powering mills and electrical generators.
The Great Artesian Basin bores opened up a lot of Outback Australia to development.

The mud springs of the basin also support a lot of native and endemic wildlife, the Desert Goby (Chlamydogobius eremius) is the primary fish associated with GAB springs. The can live in water with a wide range of temperatures, pH, salinity and oxygen levels. The can also change colour to blend in with their environment.

Is The Great Artesian Basin about to run out of water?

No, but a lot of water was wasted!
In 1952 the government set up schemes to rehabilitate bores and replace open drains.
As at 2022, more than 775 bores have been rehabilitated and 450 bores piped. Around 15,000km of open drains have been decommissioned over the years. This has saved more than 228,000 megalitres of water with investment of over $243 million from the Australian and Queensland governments, industry and landholders.

The current aim of the plan is to have all eligible stock and domestic bores watertight by 2032.

What is The Great Artesian Basin used for?

Today, the Great Artesian Basin remains a primary water source for 120 towns, 7,600 businesses and approximately 180,000 people. In 2018, the Australian Government pledged a new program of investment in GAB Management and the Great Artesian Basin Strategic Management Plan was released in 2019.

The artesian springs are now recognized as an important part of QLD Tourism and artesian bathing has many health and social benefits.
The Wellness Way is a drive trail that can take you to 24 different artesian locations throughout QLD, all with their own unique experience.