Serious doubts have been cast over the future of the rescue plan for the Murray, with Deputy Prime Minister Barnaby Joyce declaring it "bleeding obvious" extra environmental flows can't be delivered under the current deal.
Mr Joyce met with state water ministers in Adelaide on Friday and said the commonwealth remained hopeful of finding a solution.
But he said it was clear the promised 450 gigalitres in extra environmental flows could not be provided under the legislation which required there be no detrimental social or economic impacts.
"I'm just stating the bleeding obvious," Mr Joyce told reporters.
"But If someone has a solution, I'm all ears."
Friday's meeting also came after a more informal gathering of the ministers and their staff on Thursday night during which it was believed South Australian Water Minister Ian Hunter levelled insults at the deputy PM and others in the room and stormed out.
Mr Joyce said "what was in the room will stay in the room" but called on Mr Hunter to apologise to some of those involved.
"It's quite obvious you can't go through a room full of staff screaming at them," he said.
Mr Hunter declined to comment on his actions or what was said but described it as a "distraction".
"I'm not going to talk about what I might have said in a private meeting, that's not what I do," he said.
"But I would say I will stand up for South Australia at every opportunity. I will fight for the water that's been promised to South Australia.
"I'm very pleased to be standing up for my state and I will do so in the most forthright manner."
Mr Hunter said the federal government was trying to deflect attention from the fact that the Mr Joyce had flagged a willingness to walk away from the government's legislated and mandated plan for the River Murray.
In a letter to Mr Hunter ahead of Friday's meeting Mr Joyce said the inability to execute the Murray-Darling Basin Plan without causing harm to local communities along the river would lead to an "unsolvable stalemate".
"Just as you have an understandable desire for one outcome, your colleagues in other states have an equally understandable desire for another regardless of what side of the political fence they are on," he told Mr Hunter.
Despite the impasse, Mr Joyce said the funds to deliver the extra environmental flows were still on the table.