14 DAY TRIAL // On account of global warming, much of Australia's surface waters may decline over the decades, environmentalists warn. Luckily, the underground basin that was formed under the continent contains some 65 million gigaliters (109 L) of water, which means that it would suffice to sink all of the Earth's land mass by about half a meter. Estimates say that the water source could be enough to meet Australia's demands for the next 1,500 years. The basin alone holds about 820 times more water than the continent has on its entire surface.
The Great Artesian Basin Coordinating Committee, in charge of supervising the precious resource, says that about 1 million megaliters (106 L) of water add to the basin every year, on account of rain water filtering down through the permeable stone layers that cover it. In some places, the artesian reservoir is buried as deep as two kilometers (1.2 miles) beneath the ground, and its own depth is estimated to reach as much as 3 kilometers in some places.
The main problem that the basin poses is the fact that it relies on artesian pressure to bring the water to the surface. This means that water can be extracted through boreholes and wells only if there are not many such places through which it can exit the basin. If more of these watering holes are made, then the pressure inside the basin will be released, and the water will no longer rise up on its own.
This would be devastating news, as then authorities would have to resort to costly drilling and build an extensive network of tunnels underground, in order to capture the water at the bottom of the basin. And seeing how the water layers are separated by various types of rocks, drilling to reach the bottom of the reservoir, some 4 kilometers below the surface, might not prove to be such an economically-sustainable initiative.