Common misconceptions

Understanding more about the Great Artesian Basin(s)

Australia is the driest inhabited continent in the world.

Fortunately, it is also home to the world’s largest artesian underground water source, the Great Artesian Basin, which underlies about a fifth of Australia.

But its waters are finite. Each year, more is used than is replaced.

With an enormous number of Australian industries and communities dependent on continued access to its waters for survival, Australia has been active in rolling out innovative programs to manage use of the GAB so it is available for many generations to come.

It is imperative to understand how it works so the extraction of water can be managed in the most sustainable way. This is difficult because all of the action happens underground.

The good news is that our understanding of the basins' systems is increasing all the time due to new studies and investigation techniques. While there is still a lot yet to discover that could improve our understanding and management of the precious resource, dispelling the huge number of commonly held misconceptions and myths about the GAB could lead to important improvements in how it is currently being used.

Common misconceptions about the GAB

The GAB is an infinite source of water
  • In certain places in the GAB, water comes to the surface naturally and collects in creeks and rivers. In some areas they create a permanent water source. We call these springs and First Australians used these throughout time as a critical source of fresh water. They supported valuable food sources including birds, mammals, reptiles, crustaceans and insects, creating an abundant hunting ground. They were hubs of activity and great cultural importance.  
  • The springs of the GAB are home to an array of unique and endangered animals (such as the Endemic Snail (Jardinella sp), and a number of gobi fish species such as the red-finned blue eye) and plants (such as the Salt Pipewort (Eriocaulon carsonii)) that are found nowhere else in the world.
  • Around 140 years ago, in 1878, a shallow bore sunk near Bourke produced flowing water, which marked the start of commercial extraction of the GAB. Hundreds of wells quickly became thousands as access to water opened up tracts of Australia’s arid inland.
  • Not realising the resource was finite, the early bores were constructed to allow water to gush freely. Water was wasted and evaporated.
  • Within four years there were reports of decreases in groundwater levels and spring flows.
  • Any changes to the water flow or water quality can be detrimental to the GAB's ecosystems, and there were reports of changes spreading along the network of bore drains which provided passage for feral animals and prime conditions for exotic plants, changing the landscape and putting pressure on native animals and habitats.
  • These worrying trends continued, then in 1912, within 34 years of the first bore, the states held the first meeting to discuss decreased groundwater flows. This sparked investment in specialised research and the introduction of the first of many management strategies to address the issue.
  • Over the next 100 years, research, improved regulation and management practices, and collaboration between governments and between government and landholders, made a substantial difference.  A major focus has been to stop wastage of the groundwater by stopping the uncontrolled flow of bores and removing open drains.     
  • This is of enormous importance to the many industries and communities which rely on the water.
It's one big basin 
  • The name Great Artesian Basin is misleading, it should be plural - Great Artesian Basins - as it is not one basin but several. Starting by correcting this would help to reset our thinking to stop talking about it as one entity – as in reality it is a complex jigsaw of four semi-connected hydrogeological basins.
  • These basins have different characteristics which can help inform how to manage its use. These include the size, depth, flow rates, layers, directions, geology, quality, and hugely varying level of connection and disconnection.
It refills quickly every time it rains
  • There are only small areas of the basin where rainfall can get down to the aquifers.
  • These areas are called recharge areas, and account for about 4% of the GAB's area.  Furthermore, it is estimated that only 2-3% of rainfall falling on these recharge areas makes it down to the aquifers.
  • Rainfall outside of these areas does not affect groundwater volumes, but contributes to river flows and soil moisture.
  • As you would imagine, water moving through rock goes very slowly - at a rate of around just 1 to 5 metres a year - and that’s when it’s moving easily!
  • Some of the water in the GAB is millions of years old.
The GAB is like an underground lake
  • The way groundwater is stored in the basins is actually very different to what many people imagine.
  • Many think of it as a large underground lake, but instead of a body of water, think of large layers of porous rock such as sandstone which holds water in tiny spaces between the sand grains.
  • We call this an aquifer – when samples of this layer are brought to the surface they often look like pieces of concrete and it is very hard to imagine how water can flow through this material.
  • There can be many layers between the surface and the basement rock of the GAB and they don’t neatly stack up on top of each other. This means the flow of the groundwater can change direction, or even almost totally stop due to the barriers.
  • New research shows that in large areas there is little evidence of connection between basins, so we should not expect changes in one location to necessarily spread to the other areas. Other areas have high levels of connection. This is important information in understanding the level of impact that might result from any development in a specific area.
The GAB water level cannot recover 
  • A large amount of money has been invested in water saving technology.
  • These days a huge amount of water is conserved by capping the once free-flowing bores, and piping the water to tanks to be stored and used as needed. 
  • This program is very expensive to implement and has only been achieved through a combination of government subsidies and landholder contributions.
  • There has also been an increase in metering and monitoring bores over time. This is mandatory for industry, which accounts for 20% of the GAB’s use. The introduction of industry has actually brought with it much new data, which is collected during the extensive impact assessment processes and ongoing monitoring that must be undertaken by any large extraction user.
  • There is no regulatory requirement to monitor the volume of water used for stock and domestic purposes. However, in recent years an increasing number of bore owners have been monitoring the volume of groundwater they extract. Bore owners have installed meters for their own information, or participated in research projects, or citizen science initiatives, e.g., local monitoring groups. Citizen science monitoring initiatives increase the amount of publicly available bore level data, which can be collated to show performance of sustainability initiatives.  
  • There continues to be improvements in how we can monitor, assess and manage springs and associated health of the ecosystems.


Lead researcher on the GAB project, Dr Carlos Miraldo Ordens with a copy of the Hydrogeology Journal, which delivered 26 papers for the project's technical audience. Public resources will be developed during phase two of the project.