The Great Artesian Basin
What, Where & How.
Oceania is known to have fresh groundwater reserves, found mainly in aquifers which allows it to store and transfer water. Australia’s geological formations being hundreds or thousands of years old makes it even more diverse. One very popular aquifer is the Great Artesian Basin, found in Central Australia and is known to be the largest and deepest of its kind in the whole world. It covers 22%, almost one-fourth, of Australia, and is 660,000 square miles and has a depth of 9,800 feet at some points [3].
According to historians and geologists, when the ocean level in Australia massively dropped, around two million years ago, the sediment that was left above the water basin solidified into sandstone and rock, covering the remaining water. It was called the “Unknown Sea Under the Desert of Australia” [4]. It was discovered by Europeans in 1878 when a bore was sunk and produced flowing water.
Covering more than 1.7 million square kilometres, the GAB underlies parts of Queensland, New South Wales, South Australia, and the Northern Territory. The GAB contains a vast volume of underground water (estimated at 64,900 million megalitre) and is the largest groundwater basin in Australia [1]. It has become one of the major sources of water on the continent. It sustains water for a wide range of groundwater-dependent domestic, rural, agricultural, and industrial use. According to Frontier Economics 2016, it supported at least $12.8 billion economic activity yearly. The daily free discharge of water, from more than 18,000 boreholes, averages 350,000,000 gallons (1,300,000,000 litres) [2]. The distribution of fresh groundwater is done mainly by open earth channels or naturally through mound springs. Wells are drilled down enough for the water pressure to push the water out without the need for pumping motors.
In the beginning, water could free flow from most bores. It was later realised that the use of water from the basin was wasteful and unsustainable. A rehabilitation project for the Great Artesian Basin was launched in 1989, which aims to improve the sustainability of the popular aquifer. Also, the Australian government has shown great backing. In 1999, they introduced the Great Artesian Basin Sustainability Initiative, where bore-owners were offered government assistance to cap uncontrolled bores and the replace open bore drains with piped water reticulation systems [3]. At the time of writing, it is still argued to whether the groundwater is sustainable. Will it take several years to replenish, or will it not replenish at all? Whatever it is, the remaining water in the Great Artesian Basin in Australia must be protected for as long as possible.
References:
[1] http://www.ga.gov.au/scientific-topics/water/groundwater/gab
[2] https://www.britannica.com/place/Great-Artesian-Basin
[4] https://www.slideshare.net/EWomersley/the-great-artesian-basin