The Northern Territory government is being accused of responding to the demands of new gas and cotton industries in the Beetaloo Basin by changing its rules so that it can give out more water than the environment can cope with.
A freedom of information request has revealed the government's most senior water planner warned it that using the new rules could negatively affect the environment and Indigenous communities.
The government has started to use rules from the territory's southern arid zone in the northern area of the Beetaloo Basin, which allows it to allocate 80 per cent of the water stored in aquifers to industry.
The Beetaloo Basin was earmarked by the previous federal government as key to the so-called "gas-led recovery" and drew millions of dollars in grants to fast-track exploration.
A freedom of information request by the NT Environment Centre has revealed the government's Director of Water Planning, Tim Bond, drew up and sent an 11-page memo to the director of water licensing two years ago.
The memo said allowing 80 per cent of the Mataranka Tindall Limestone Aquifer in the region to be extracted, could "cause water to flow in the opposite direction", and "potentially impacts on the environmental and cultural values" of the Roper River.
It also raises concerns about maintaining flows down the river.
"The aquifer behaves like a fill and spill aquifer with very limited capacity to store water which emphasises the reliance on more southern portions of the aquifer to store water and maintain through flow to discharge in the Roper River," Mr Bond said in the memo.
"Drawing down storage by 80 per cent as proposed … will not provide for the environmental and cultural water requirements supported by the aquifer.
"The lowering of the height of the upper surface of the aquifer after 100 years of extraction has the potential to … cause water to flow in the opposite direction towards Larrimah."
Mr Bond also cautioned that allocations needed to be conservative in the face of climate change.
"The last few years have been some of the driest on record and may indicate the start of a drier climate period. A precautionary approach would warrant allocating water on the basis of long term median values rather than the last 30 years," he said.
"Through flow across the northern boundary of the Tindall Limestone Aquifer decreases by 41.5 per cent in one ten year period."
'Water is everything to us'
On Cow Creek Station, near Larrimah in the Beetaloo's north, Carina James is one of the pastoralists already worried about where the planned new gas industry will get the large amounts of water it would need for fracking to go into full production next year.
"Water is everything to us," she said.
"These enterprises are pretty much 100 per cent reliant on groundwater.
The last few years have proven that even good dams will go dry."
Ms James said she was concerned the Northern Territory government had started to use water allocation rules, which used to only apply to the south of the territory, to give out more water in her area.
"I wouldn't like to see changes to our water take because we've slipped into some other kind of zone," she said.
Warning new rules could reverse aquifer's flow
NT Environment Centre director Kirsty Howey views potential changes to zoning as "troubling".
"The arid zone rules flip the rules that apply in the Top End, in that instead of being able to extract 20 per cent of the recharge of an aquifer which is sustainable, you're instead extracting 80 per cent of the storage of an aquifer over 100 years," she said.
"That means that you're extracting water at a greater rate than it's replenishing into the aquifer.
"It's extremely troubling that the government appears to be pursuing a policy of water mining that could impact territory waterways for fracking, cotton and other big industries that are zeroing in on the Northern Territory.
"The memorandum is quite shocking in that it reveals that the allocation rules that the department has been using, and proposes to use, could have very damaging, if not catastrophic impacts on iconic territory waterways including the Roper River and Mataranka hot springs."
No water licences for cotton have been granted in the region yet.
There are currently five water licences related to onshore gas exploration in the Beetaloo Basin, totalling less than 1000 megalitres per year.
NT government defends water planning as 'sustainable'
The NT government decided the new rules could be used without damaging rivers, aquifers and springs because the water level wouldn't drop anywhere by more than a metre and a half, and ecosystems could adapt.
In a written response to the ABC, the NT Environment Department chief executive Jo Townsend said: "The decision on whether the arid zone rules apply or whether the Top End rules apply is determined by a range of rainfall and recharge, catchment and aquifer criteria and characteristics".
Agriculture Minister Paul Kirby said the government's water allocation rules were sustainable.
"We will take advice, as we have with every other industry, to make sure we make the best decisions going forward, to make sure that those decisions are the best ones for the Northern Territory and they're sustainable going forward," he said.
Chief executive of the Amateur Fishermen's Association NT, David Ciaravolo, said the recreational fishers' peak body was not worried about the arid zone rules being applied on the Mataranka Tindall Aquifer, because he expected they would only be used until specific water plans were drawn up for each area of the Beetaloo.
"We have been advocating very strongly for strong environmental protection to the government, and we would have an expectation that when a plan is delivered it will protect the Roper River and it will protect the environment," he said.
But Griffith University geography professor Sue Jackson is calling on the NT government to stop using southern arid zone rules to supply new industries until it models exactly how much water can sustainably be given out in each area.
"We have a system at the moment where the Northern Territory government continues to hand out licences in the absence of robust scientifically informed water allocation plans," she said.
"The groundwater in this region moves very slowly, it might take 50 years to show the effects of extraction on some of these groundwater systems.
"And then the question becomes: what are governments prepared to do about it, because we know from many other parts of Australia that clawing back licences from those people that have been granted them becomes a a very expensive and very difficult exercise."
Ms Townsend said it would be "unlawful" for the government to delay making licence decisions until water allocation plans are finalised.
"In any event a declared plan is only one of the criteria for a decision about the granting of a licence under the Act," she added.
