Determining the size of the world’s great aquifers isn’t easy, Guinness, however, lists the Great Artesian Basin, which underlies over one-fifth of Australia, as the world’s largest aquifer.
Underground layers of porous material containing vast reservoirs of water can be tricky like that. Even experts who have surveyed them in detail (like Dr Stephen Short of Ecoengineers) say it’s a hard call.
Guinness, however, lists the Great Artesian Basin, which underlies over one-fifth of Australia, as the world’s largest aquifer.
Dr Short reports that it’s probably the most intensely studied and the age of its water is the most accurately known. Around 3km deep in places, its porous rock formed an impressive 65 to 248 million years ago and holds enough water to fill 32,000 Olympic swimming pools (around 64,900 megalitres).
Its various outlets are its only visible aspects, and they occur in two ways: natural springs and manmade boreholes. The boreholes are marginally interesting for their curiosity factor, but the mound springs offer a great diversity of rare and endemic plants – a true horticulturist’s paradise. With the aquifer underlying the southeast corner of the NT, the northeast of SA, across northern NSW and most of Qld, you really have no excuse not to check out one of its outlets – even if it’s only a borehole.
A line of mound springs stretches from the northeast edge of the Flinders all the way to Alice Springs, and some of the aquifer’s hot water springs have been made into bona fide spas. No scientific exploration has ever been this relaxing.
Where // The Great Artesian Basin lies beneath about 23 percent of Australia. Lightning Ridge has terrific examples of the aquifer’s thermal pools, as does Thargomindah in southwest Qld and SA’s Dalhousie Springs.
Did you know? // When Thargomindah’s Hydro Power Plant came online in 1898, it became only the third town in the world (after Paris and London) to produce hydroelectric power. It’s thought to be the oldest still-working plant of its kind in the world.
SEE THE FULL LIST: 100 Things you can only do in Australia