NSW Deputy Premier John Barilaro has raised questions over the state's long-term commitment to the Murray-Darling Basin plan following a disagreement at Sunday's water ministers' meeting in Canberra.
He said NSW was considering its options in relation to the basin plan after the meeting.
He said the Murray-Darling Basin Plan Ministerial Council had missed an opportunity to deliver "some real certainty and transparency for regional communities on their knees".
"The Murray-Darling Basin Plan is untenable for NSW," he said.
NSW Water Minister Melinda Pavey said drought had heightened concern in regional communities and there was a level of distrust about the ability of authorities to deliver the basin plan.
"Our communities deserve nothing less than to open the books, have a look at the work, analyse it, independently peer review it so that we can restore faith in the processes," Ms Pavey said.
She criticised the federal and South Australian governments for refusing to back an independent review of the plan's target.
Ms Pavey said NSW and Victoria would jointly conduct their own review to examine "what can actually be achieved".
Mr Barilaro said the meeting was an opportunity to deliver "real certainty".
"Instead, we got served up the threat of more water buybacks from the Commonwealth, and South Australia refusing an independent review," the Nationals' leader said.