Great Artesian Basin water surfacing in new places

After years of drought, water is emerging from the ground across outback Queensland. Free-flowing bores are being capped and piped to minimise water wastage across the Great Artesian Basin. Emerging springs are being found with potentially new species in them.

After years of drought, water is emerging from the ground across outback Queensland. Free-flowing bores are being capped and piped to minimise water wastage across the Great Artesian Basin. Emerging springs are being found with potentially new species in them.

The Great Artesian Basin is one of the world’s biggest water reservoirs. Much of its precious water source has been wasted through unregulated bore drilling for over 150 years. Scores of potential new species are being uncovered as water springs emerge in places never seen before in outback Queensland.

Now, thanks to the success of a decades-long rehabilitation program, water pressure in the basin have 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, several potentially unidentified macroinvertebrate species have been discovered at the springs.

“We’re excited that they’re so unique that there may be unknown species in them,” Pearce said.

Water wasted from the Great Artesian Basin

The Great Artesian Basin covers 22 per cent of Australia’s land base. It 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. By the 1960s, more than 3,000 bores across Queensland had been left as free-flowing water points.

The Queensland government introduced new laws to protect the basin in the following decade 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 to have all uncontrolled bores capped and bore drains replaced by September 2027.

Since 1989, more than 700 bores have been rehabilitate. 14,000 kilometres of bore drains have been decommissioned. It has saved an estimated 214,000 megalitres of water each year.

Emerging springs

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 unique techniques even to find many of these new springs,” 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 flourishing, thanks to ecological surveys identifying a growing presence in the springs.

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 Great Artesian 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 we’ve had over the past six months is recharging the groundwater systems across the entire region,” Robinson said.

“Many dry dryland rivers suddenly start to flow, and they will channel water across the earth’s surface.

“At various points along their journey, some water will leak into these shallow aquifers … they’re recharging groundwater at different layers.

“That does vary from location to location … so, 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 Pearce explained, protecting them was crucial.

“We 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. The important thing is that there does need to be some management.

“They shouldn’t be locked up and forgotten about … they need to be actively managed.”

Pearce said the threat of weeds and pests often obstructed the development of the springs. 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 threats — weeds and pigs,” she said.

“The weed control works … it’s been critical to the health of the emerging springs.”

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