Bart Doohan wraps an arm around his teenage daughter, Hayley, as they look out across their empty dairy. Hayley lets the tears flow. At 17, this is her first harsh taste of injustice.

The Doohans have put their farm near the small Southern Riverina town of Blighty, New South Wales, up for sale after gradually destocking in recent months.

The last of their cows were loaded onto a truck and sent to the meat works in a crushing blow to a family that's already in "dire straits".

"The dairy industry is in such turmoil there was no option to send our cows to other dairy farms," Bart said.

Bart Doohan has had to put the family's farm up for sale after de-stocking it. (A Current Affair)

The last irrigation season was the nail in the coffin for the Doohans' operation. Under the Murray Darling Basin Plan, they were on zero water allocation, meaning they didn't receive any water under their fixed entitlement.

And with losses of up to $3 million over the past 18 months, they couldn't afford to buy water on the temporary market to keep the operation running.

"Every dairy farm in this area is going backwards and we just can't keep sustaining that," Bart said.

There's a cruel twist to the water crisis on the Murray. They may have been impacted by drought over the past 12 months, but at the height of the last irrigation season there was an abundance of water in the region. The two main dams were more than 50 per cent full while the Murray itself was flowing fast past their properties.

Bart Doohan comforts his daughter Hayley. (A Current Affair)

But under the MDBP, that water was pushed downstream to South Australia where landholders received 100 per cent of their allocations, leaving NSW Murray farmers high and dry.

According to Murray Dairy, 72 dairy farms are operating in the NSW Murray region, down from 89 during the 2017-18 irrigation season. But farmers who are more acutely aware of operations in the regions, say that number is more likely to be around 30.

And on July 1, South Riverina dairy farmers received the unsurprising news that “due to the severity of the drought” they've once again been denied an allocation for the next season, which for many will be their last.

The Murray Darling Basin Plan is driving a key agricultural sector to extinction as New South Wales dairy farmers, like Bart Doohan, walk off their properties at record rates.

The Murray Darling Basin Plan has been criticised by farmers. (A Current Affair)

Accusations of mismanagement and misleading science have dogged the Murray Darling Basin Authority and the evidence is piling up against them.

In a report released last month , The Australia Institute outlined how the Murray Darling Basin Authority failed to comply with its own objectives by denying an allocation to NSW Murray general security holders, while flooding the Barmah-Millewa forest and draining the Menindee Lakes.

"While everyone else in the Basin was dealing with drought, the MDBA created a flood and lost large volumes of water," said Maryanne Slattery, senior water researcher at The Australia Institute.

The farmers I met in the Southern Riverina are beyond the tipping point. They're desperate and living on borrowed time. They want the 2012 Plan to be paused for the sake of their survival. But governments are staying the course, promising to deliver the plan in full.

Drought and water shortages have hurt farmers in different regions in recent years. (A Current Affair)

Making matters worse, city-based traders who don't own agricultural land are pricing farmers out of the temporary water market.

Lachlan Marshall uses a poker analogy to describe his family's dilemma.

"Four generations of the same family and we're all in," he said.

Lachlan, 38, and his brother Adam, 36, are milking 900 cows three times a day on their property near the Doohans.

Lachlan and Adam Marshall run a 900-cow dairy in the Riverina. (A Current Affair)

They're only just holding on, but at a huge price.

Between October and late December last year the Marshalls spent $1 million on water on the temporary market, where prices are at record highs.

"The price has gone up exponentially and it’s been driven up by speculators and traders ... who are making astronomical profits off the hardship of people who are trying to make a living," said Lachlan Marshall.

They say water on the temporary market reached a spike of $650 per megalitre last year; up from $30 dollars per megalitre when they moved to the region in 2006.

The dairy industry is facing extinction as farmers exit. (A Current Affair)

"These people are leaving the industry and they're leaving burnt and jaded and angry and they're not coming back," Lachlan Marshall said.

"There's a real concern for our nation's food security unless we're happy as a nation to be buying overseas food."

Another season on zero allocation will likely spell the end for this fourth-generation operation. But they won't walk off their farm without a fight, which is why the brothers have joined a class action.

Barooga farmer, Chris Brooks, is leading the action, accusing the MDBA of negligence and mismanagement, which has cost up to 1800 landholders a total of $750 million.

Farmers in the Murray region say just around 30 dairies are still operating. (A Current Affair)

"The payout will compensate for the losses last year but the main objective is to take the MDBA to account," said Brooks.

The MDBA claims water was sent downstream to South Australia to meet environmental commitments. But severe erosion at the Barmah Choke and along the banks of the Murray River are evidence that the Basin Plan is causing major environmental damage.

The Australia Institute report shows that 1700 gigalitres of water was wasted by flooding the Murray system, which would have been enough to provide an allocation to Southern Riverina dairy farmers.

It’s no wonder calls for a royal commission into the MDBP are growing louder. An independent review, at the very least, is critical to the survival of yet another endangered Australian industry.

Severe erosion has been shown along the banks of the Murray. (A Current Affair)

The plan is a mess. It's based on questionable science. And by failing to act, the federal government is allowing wealthy traders to reap enormous profits at the expense of farmers who can’t make ends meet.