Prime Minister Scott Morrison has urged state and federal politicians not to blow up the consensus on the Murray-Darling Basin Plan, as governments weigh the scathing findings of a royal commission.
The South Australian royal commission's report found river allocations were driven by politics and called for a complete overhaul of the plan.
It accused the Murray-Darling Basin Authority of acting unlawfully, committing gross maladministration and taking a "head in the sand approach" to climate change.
Mr Morrison warned against abandoning an agreement to advance the plan, calling for state governments and his federal opponents to stay the course.
"It's very important that as we continue to manage what is a very difficult, sensitive and complex issue, that we maintain the bipartisanship in how continue we progress that matter," he said.
Authority chief Philip Glyde rejected "in the strongest possible terms" any suggestion the authority had broken the law.
He said the accusations stemmed from a difference in opinion about the intent of water reform policy, and insisted the authority has been guided by the best available scientific advice.
"We are half-way into implementing the plan," he said.
"We can't overturn the impacts of 100 years of water overuse in a few short years."
Labor leader Bill Shorten described the royal commission as a "rocket" up the plan, saying the headlines were damning.
"This is an ecological disaster in the Murray-Darling Basin, and ultimately the buck stops with the federal government," Mr Shorten said.
"They've been in power for the best part of six years, and the conditions there have got worse, not better."
Both leaders said they would carefully consider the 746-page final report which has 111 findings and 44 recommendations.
The basin plan was signed into law in 2012 by the federal Labor government and basin states and aimed to return water to the water system for the benefit of the environment.
Mr Morrison appeared to throw cold water on South Australian Liberal Premier Steven Marshall's request for a meeting of federal and state governments to look at the inquiry findings.
Ministers won't meet ahead of schedule to discuss the report, with the prime minister only committing to the normal schedule.
"The people responsible on the ground for running the plan, taking advice on how the plan can be better implemented, that's where the focus needs to be now," Mr Morrison said.
"I don't want politics to distract them."
Greens environment spokeswoman Sarah Hanson-Young wants a federal royal commission into the management of the river system, and called for Mr Glyde to be sacked.
