Scores of potential new species are being uncovered as water springs emerge in places they have never been seen before in outback Queensland.
The Great Artesian Basin is one of the world’s biggest water reservoirs, but much of its precious water source has been wasted through unregulated bore drilling for more than 150 years.
Now, thanks to the success of a decades-long rehabilitation program, water pressure in the basin has increased, leading to the re-emergence of natural springs.
“Without all of the capping and piping of the bores, I don’t think it’s likely that there would be the number of springs emerging at the rate they are,” said Natalie Pearce, a senior project officer at Desert Channels Queensland.
To the delight of scientists, a number of potentially unidentified macroinvertebrate species have been discovered at the springs.
“We’re really excited that they’re so unique that it is possible there are unknown species in them,” Ms Pearce said.
The Great Artesian Basin covers 22 per cent of Australia’s land base and holds more than 130,000 times more water than Sydney Harbour.
About two-thirds of the basin lies within Queensland, across an area of more than 1 million square kilometres, and it’s the only reliable source of fresh water throughout much of the state’s inland.
More than 150 years ago, early settlers began drilling bores into the basin to take advantage of the valuable and previously untapped water source.
But it was largely unregulated and by the 1960s, more than 3,000 bores across Queensland had been left as free-flowing water points.
In the following decade, the Queensland government introduced new laws to protect the basin through the Great Artesian Basin and other regional aquifers (GABORA) plan.
It looked at managing water flow through rehabilitating or replacing bores and capping and piping open bore drains, with the aim of having all uncontrolled bores capped and bore drains replaced by September 2027.
Since 1989, more than 700 bores have been rehabilitated, 14,000 kilometres of bore drains have been decommissioned and an estimated 214,000 megalitres of water has been saved each year.
With the success of the rehabilitation program, the natural resource management group Desert Channels Queensland (DCQ) has worked for the past 18 months to identify and protect springs within its coverage area in western Queensland.
So far, it has identified 95 springs, only 10 of which were previously known.
But they were not easy to find.
“It’s required a lot of really unique techniques to even find a lot of these new springs,” Ms Pearce said.
“When they’re brand new, they don’t look like much at all.
“Sometimes they’re a little puddle of mud about the size of a shoe print, which is why they can be so difficult to find … a lot of them were found just by stumbling across them.”
More than 70 macroinvertebrate species have been found flourishing, thanks to ecological surveys that identified a growing presence in the springs.
Ms Pearce said she and the rest of the team were delighted to find a small number of those species that were potentially previously unidentified.
Aquatic macroinvertebrates, like dragonfly larvae, mosquito larvae, beetles and snails, are small insects in their nymph and larval stages that live in water for all or most of their lives.
She said further work was being done to identify those species.
“It’s really important to look after them,” she said.
Flood and rains replenishing basin
The Great Artesian Basin is usually replenished, or recharged, on the eastern side of the basin, west of the Great Dividing Range, where water permeates through the surface to the deepest parts of the basin.
David Robinson, Geoscience Australia’s head of basin systems, said there had been significant recharging this year.
“The high levels of rainfall that we’ve had over the past six months is absolutely recharging the groundwater systems across the entire region,” Dr Robinson said.
“Many dryland rivers that are dry suddenly start to flow and they will channel water across the surface of the earth.
“At various points along their journey, some water will leak down again into these shallow aquifers … they’re recharging groundwater at different layers.
“That does vary from location to location … so, in order to get to the deeper part it has to be rainfall on those mountains [Great Dividing Range].”
Protecting the springs
There’s no guarantee, however, that the emerging springs will remain viable so, as Ms Pearce explained, protecting them was crucial.
“We ourselves are in a strong learning process because this is such a unique occurrence,” she said.
“We’re still getting to understand the best way to manage the springs, but the important thing is that there does need to be some sort of management.
“They shouldn’t be locked up and forgotten about … they do need to be actively managed.”
Ms Pearce said the threat of weeds and pests often obstructed the development of the springs, but control work done by DCQ had helped to find springs where they otherwise would not have been seen.
“Some of them have grown and developed quite quickly as we’ve removed some of the threats — weeds and pigs,” she said.
“The weed control works … it’s been really, really critical to the health of the emerging springs.”