Reports say NSW sought to increase its Basin Plan water limits, and caused concern about the fallout. 

The Greens have obtained emails that show discussion of ways more water could be extracted from the basin while still remaining below 1995’s ‘baseline diversion limit’.

The emails suggest the NSW government wanted to increase the amount of water permitted to be extracted from the Murray-Darling Basin. 

Another email said that the Commonwealth body in charge was “desperately afraid” of the media coverage if the plan became public.

“The [Murray Darling Basin Authority] is desperately afraid of the media coverage when it becomes apparent that the number for [the Baseline Diversion Limit] has gone substantially up,” wrote Andrew Brown, the principal water modeller with the Department of Planning, Industry and Environment, in an email dated July 22, 2018.

“There will be immediate claims that NSW is fiddling the figures, closely followed by questions about why MDBA isn’t stopping this from happening,” Mr Brown said.

He predicted that the authority would struggle to address key questions after its “initial shock phase”, including how they got it “so wrong”.

The emails were obtained ahead of hearings of the NSW parliament’s Floodplain Harvesting Inquiry, which is looking at the state’s efforts to meter and monitor water captured in dams as floodwaters flow overland.

That water usage did not appear in the original cap on water extraction under the $13 billion Murray-Darling Basin Plan.

NSW Greens water spokesperson Cate Faehrmann said the emails raise “red flags”.

“These models are being used to grant compensable floodplain harvesting entitlements worth hundreds of millions of dollars. They must be held to the highest standards possible,” Ms Faehrmann said. 

“If these models result in the over-allocation of water, it will have long-lasting and disastrous impacts on the Murray Darling Basin.”

Former Basin official Maryanne Slattery says the emails show the government and the Basin Authority “trying to hoodwink everybody” into allowing caps to be exceeded.

“If they implement this as planned, there are no volumetric limits,” Ms Slattery said. 

“It’s all just a circus.”

The NSW water minister says the state has been unfairly treated. 

“South Australia, Victoria, the ACT and Queensland have all adjusted their [baseline diversion limit] estimates with best available science,” a spokesperson for Water Minister Melinda Pavey said. 

“NSW expects to have the same opportunity.

“We expect the inquiry to clear up a number of misconceptions this week and put us in a position to be the first state to measure and license floodplain harvesting by the end of next week,” the spokesperson said.

Jamie Pittock, acting director of the Wentworth Group of Concerned Scientists, says the emails demonstrate “the cavalier manner in which it is managing water”, exploiting every loophole to allow more water to be extracted for irrigation at the expense of the environment, Indigenous nations, and downstream communities and industries.

“It is time that the federal government nationalised and published Basin water modelling to prevent state governments hiding behind their private modelling to abrogate their responsibilities,” he said.