There are growing calls for federal Water Minister Barnaby Joyce to be stripped of his portfolio after he was recorded telling farmers he took control of water to stop "greenies running the show".
Mr Joyce is heard telling those at a Shepparton pub on Wednesday night that an ABC Four Corners investigation into alleged water rorting in the Murray Darling Basin was trying to "create a calamity".
"It's about them trying to take more water off you... shut more of your towns down," he says in the recording.
He admits the National Party took responsibility for water from the environment portfolio and into his agriculture portfolio to "look after" farmers.
"We've taken water and put it back into agriculture so we can look after you and make sure we don't have the greenies running the show basically sending you out the back door.
"That was a hard ask but we did it."
Responsibility for water was handed to the Nationals as part of the party's coalition agreement with the Liberal Party in 2015.
Environment groups raised concerns at the time, warning the Nationals would prioritise the interests of irrigators over environmental concerns for the Murray River.
South Australian Greens senator Sarah Hanson-Young said Mr Joyce's comments showed he was not fit to be federal water minister.
South Australian Water Minister Ian Hunter has also called for Mr Joyce's removal.
"He is absolutely incapable of doing the job he has been given," he said.
South Australia also criticised the NSW government's probe into the matter as "absolutely inadequate".
The former head of the National Water Commission, Ken Matthews, was this week appointed to head up the NSW investigation into the allegations.
The investigation's terms of reference include investigating water theft at specific properties in northern NSW.
It will also examine whether a senior official helped irrigators undermine the Murray Darling Basin Plan, and whether a major investigation into water management breaches was stymied.
But Mr Hunter doubts it will get to the bottom of alleged long-term gaming of the water rules, and wants NSW Regional Water Minister Niall Blair to broaden its scope.
"Mr Blair needs to restore public confidence in his state's water compliance regimes that provide the drinking and irrigation water for millions of Australians," Mr Hunter said.
"This inquiry won't do it."
A spokeswoman for Mr Blair said any issues outside the terms of reference will be referred to the appropriate authorities for review.