Member for Murray Helen Dalton pledged support for a rally outside Minister for the Environment Tanya Plibersek's office

The currently-planned buybacks intend to buy $3 billion in water from the Murray-Darling Basin in an effort to fulfil environmental commitments outlined in the Murray-Darling Basin Plan.

Mrs Dalton said that the planned buybacks would devastate farms and livelihoods across the Riverina and Murray.

"Right now, the Murray-Darling Basin plan makes it illegal for these kinds of buybacks to take place because they will be so destructive to so many livelihoods," she said.

"And the price of these buybacks is $3 billion dollars. It's absolute madness. It will drive up the cost of food for all Australians while destroying tens of thousands of farms."

Mrs Dalton has pledged support to a planned rally outside the office of Minister for the Environment Tanya Plibersek, to be held later this month.

The federal Labor party has promised to introduce legislation in September, extending the Basin Plan timeline and potentially removing the 1500GL cap. Currently, under the cap, the Commonwealth government can only purchase another 225 gigalitres.

Ms Plibersek has promised that the Federal government would be delivering the Murray-Darling Basin Plan in full, and described the plan as crucial to preventing environmental disaster.

"Our government made a commitment to deliver the Murray-Darling Basin Plan in full and that's exactly what we are doing," she said in late August, announcing the proposed timeline extension and changes to the 2007 Water Act.

"Australia is facing an environmental emergency. The Murray-Darling pumps life into the heartland of our country."

The proposed Water Act changes include a provision to provide funding for community adjustments and assistance following any buybacks, in order to minimise any detrimental effects.

Mrs Dalton had doubts about whether the water purchased would actually benefit the environment at all.

"Labor is worried about losing votes in the city to the Greens so it's claiming these buybacks will help the environment. But the truth is that constraints in the river system won't allow this water to get to areas that might help the environment."