With the spectre of more dead fish looming over NSW, one state minister has warned against an emergency meeting of stakeholders becoming an ineffective talk-fest.
Up to a million fish are dead in the Darling River at Menindee and more are likely to perish in coming days as temperatures rise.
Despite criticism from scientists and environmental advocates who say mismanagement of water is to blame, the federal and NSW governments are adamant that drought is behind the deaths.
Federal Water Minister David Littleproud has asked the Murray-Darling Basin Authority to convene a meeting of water managers and environmental water holders this week.
The federal government wants states to agree to use $5 million from Murray-Darling Basin funds for a strategy to look after native fish.
The meeting will look at the immediate risk of further fish kills and how to mitigate that possibility including through the release of environmental water.
But Mr Littleproud says the government couldn't have planned for the severe drought affecting eastern Australia.
"The only thing that will fix this is rain," he told reporters in Brisbane on Monday.
NSW Primary Industries Minister Niall Blair called for an end to blame-shifting, saying the Murray-Darling Basin Plan was settled in December.
"Holding a talk-fest that does not identify any new water solutions to help the Menindee community, does not help anyone," Mr Blair told AAP.
He said managers should look at options in southern NSW, where there may be water in environmental accounts.
The clean-up at Menindee begins this week, with scientists saying rotting fish need to be urgently removed from the Darling River or the carcasses will trigger even more deaths.
Mr Blair said fish were killed by a "perfect storm" of factors including severely low water flow, algal blooms and a sudden drop in temperature.
Prime Minister Scott Morrison said he was concerned some may attempt to "play politics" with the bipartisan Murray-Darling Basin Plan.
"It's a devastating ecological event," Mr Morrison told ABC News Breakfast.
Labor leader Bill Shorten wants an emergency task force to investigate the ecological disaster.
Opposition water spokesman Tony Burke was recalled from holidays and sent to Menindee on Monday.
"We need to have the scientists out here doing the work," Mr Burke told reporters.
NSW Premier Gladys Berejiklian said her government is being led by experts in its response to the issue.
"We've had scientists advising us the whole way through, not just in recent months, but over many years and that will continue," she told reporters in Sydney.
NSW Labor leader Michael Daley has promised to establish a special commission of inquiry into water management with royal commission-like powers, if elected at the March state election.
Australia Institute research director Rod Campbell believes there needs to be a serious process towards overhauling how the basin is managed.
"For the prime minister to blame the drought is a cop-out. We need an inquiry into how the managers of the Darling River have got it so wrong for so long," he said.