The $13 billion scheme, introduced in 2012, sought to restore Australia’s largest and most complex river system to a sustainable level following years of drought.

But last month, the independent authority overseeing the plan admitted it would not reach legislated targets by the June 2024 deadline.

The Debasing the Basin Plan report, released on Thursday by Environment Victoria, claimed Victoria was the state most to blame for “sabotaging” the national scheme.

It said successive Victorian governments had delayed and curtailed the water act, promoted unproven water-saving infrastructure and lower water targets, instigated an off-set scheme and implemented an unworkable socio-economic test.

“Other states might have been more blatant in their sabotage but Victoria’s insidious undermining of the Basin Plan has been ultimately more damaging,” Environment Victoria policy and advocacy manager Bronya Lipski said.

“If the failure to recover enough water for rivers ahead of the next drought results in more mass fish kills and massive toxic algal blooms, the Victorian government will deserve a large share of the blame.”

The national plan sets a target of 2750 gigalitres of water to be recovered per year over a long-term average annual yield, along with 450GL for critical environment outcomes.

The report said Victoria pushed for lower targets despite initial advice suggesting a range of between 3000GL and 7600GL would better protect the Murray-Darling Basin’s biodiversity.

The state also supported a cap on water buybacks, or paying farmers to reduce their water take, which the report said dramatically reduced the amount of water that could be recovered.

“Since it was elected in 2014, the Andrews government has refused to support water buybacks from willing sellers as the most cost effective way to return environmental water to the rivers,” Ms Lipski said.

“(It) has remained fixated on ineffective water offset schemes, resulting in wetland engineering projects that are often being carried out without Traditional Owner consent.”

Victorian Water Minister Harriet Shing has been approached for comment, while Federal Water Minister Tanya Plibersek declined a request.

Victorian Greens water spokeswoman Sarah Mansfield said the report showed the state government was prepared to sit back and watch the basin dry up.

“The Victorian Labor government now has a clear choice – to continue to put off their obligations at the cost of this precious ecosystem or show leadership and ensure the Murray and regional communities can thrive for generations to come,” she said.

-AAP