The NSW Government will prosecute several people over alleged water theft on the Barwon-Darling, eight months after Four Corners investigated the issue.

WaterNSW has named the people it is taking to the Land and Environment Court over alleged breaches of water management rules.

They are prominent irrigator Peter Harris and his wife Jane Harris, who own a major cotton farm near Brewarrina in the state's north-west and were named in the Four Corners story.

The couple have been accused of taking water when the flow conditions did not permit it, and breaching licence and approval conditions.

Three members of another prominent family are also facing charges: cotton grower Anthony Barlow from Mungindi near Moree and Frederick and Margaret Barlow.

The Barlows have been accused of pumping during an embargo and pumping while metering equipment was not working.

WaterNSW gave false figures: Ombudsman

WaterNSW announced the prosecutions an hour before the NSW Ombudsman released a scathing report saying the agency had given the Government incorrect figures on its enforcement actions.

Murray-Darling lifeline pumped out Water purchased by taxpayers to save Australia's inland rivers is being harvested by irrigators. Read more Read more

The state's ombudsman, Michael Barnes, found WaterNSW gave incorrect figures when it provided statistics that showed there had been a significant increase in enforcements between July 2016 and November 2017.

"The information provided to us indicated that the updated statistical information from WaterNSW that we'd published was significantly incorrect," he said.

"There had, in fact, been no referrals for prosecutions and no penalty infringement notices issued in the relevant period."

Mr Barnes said he initiated a separate investigation after his office received complaints about the figures, and he found WaterNSW had inflated the statistics.

"As part of our investigation, we confirmed with Revenue NSW that no penalty infringement notices were issued by WaterNSW in the relevant period," he said.

The ombudsman said he raised the issue with WaterNSW, which has admitted to the mistake and apologised.

Mr Barnes also said he believed the error was unintentional.

The agency's CEO, David Harris, said staff have now manually reviewed all actions taken.

"Some of the detail WaterNSW provided was incorrect and, although it was revised, it is not acceptable and we are acting to ensure it does not happen again," he said.

Harris to 'vigorously defend' allegations

Irrigator Peter Harris confirmed he was issued a summons by WaterNSW to appear in the Land and Environment Court of NSW.

"We look forward to an opportunity to vigorously defend these allegations in a legitimately constituted forum where the rule of law applies," Mr Harris said in a statement.

"We have always believed we acted in accordance with the conditions of our Water Access Licences. While these allegations relate to events that happened more than 21 months ago, this is the first time Water NSW has raised this matter with us.

"The prosecution announced today appears to cover issues raised in proceedings commenced late last year by the Inland Rivers Network which is also before the same court."



More water thefts under investigation

One of the cases under investigation by the former Strategic Investigations Unit involved a prominent cotton grower Anthony Barlow. ( Four Corners )

The proceedings against the five people facing charges began in the Land and Environment Court this week.

WaterNSW is investigating other alleged water thefts in the Barwon-Darling and other areas, and said it should be able to update the public on that soon.

NSW Primary Industries Minister Niall Blair said the Government had taken action since the explosive allegations aired on Four Corners.

"In November, the Government legislated to establish a new independent Natural Resources Access Regulator (NRAR) dedicated to building first-class compliance and enforcement regimes for water in NSW," he said.

But Greens MP Jeremy Buckingham said the Government has been "dragged kicking and screaming" to make changes.

"It's a smokescreen that these prosecutions have been announced on the day when the ombudsman will table a damning report on how WaterNSW provided false figures in an effort to cover up the lack of enforcement," he said.

South Australia laments 'upstream theft'

Four Corners investigated whether a small number of irrigators along the Barwon-Darling were exploiting the Murray-Darling Basin Plan to benefit their farms, at the expense of towns downstream and the environment.

After the report aired, Prime Minister Malcolm Turnbull ordered a review of the states' compliance with the basin rules.

It found both NSW and Queensland had low levels of compliance, with NSW having just one compliance officer for 355 gigalitres of water diversions.

South Australia, by comparison, had one compliance officer for every 56 gigalitres, prompting Premier Jay Weatherill to criticise the NSW Government.

"What it documents is theft by the upstream states, theft by NSW and Queensland, of water that should be put back in the river to restore the river to health," Mr Weatherill said in November.