The Restoring Our Rivers bill faces a tough road ahead as the Opposition calls for an inquiry into the contentious plan that involves buying more water licences back from irrigators to protect the River Murray’s future.

Plibersek told parliament that an historic agreement was struck with New South Wales, Queensland, South Australia and the ACT two weeks ago to deliver 450 gigalitres of environmental water to the River Murray “after a decade of sabotage and delay”.

Victoria refused to sign the Murray Darling Basin deal despite only two gigalitres of 450 gigalitres promised under the plan being returned to the river system in nine years, with this figure rising to 26 gigalitres in the past year.

South Australia’s Deputy Premier Susan Close has backed the plan, saying SA has most to lose if environmental water is not returned to the lower reaches of the River Murray and vowing to hold other states to account.

Plibersek told parliament there is still $1.3 billion of unspent funding in the nation’s Water for the Environment Special Account that will now target a suite of water recovery options across the basin.

This includes investing in on-farm water infrastructure along with water purchases from willing sellers, with the bill pushing back the original June 2024 water-saving deadlines agreed to by all states under the Murray Darling Basin Plan.

The timeline to recover the water has now been extended to the end of 2027, with the water infrastructure project timeline pushed out to the end of 2026.

Plibersek said only 16 of 36 water-saving projects meant to keep 605 gigalitres of water in productive use have been completed, and the remainder were unlikely to be finished by next year’s deadline.

The bill will also make “substantial and overdue reform to Australia’s water market”. Plibersek said the markets were important to the nation’s agricultural system “but as things currently stand, they lack integrity and transparency.”

“There are no laws against market manipulation. The insider trading prohibition is too narrow. And the legal requirement to maintain proper records is far too weak,” Plibersek said.

She said the new bill will introduce a framework to create an enforceable, mandatory code for water market intermediaries along with civil penalties for market manipulation and doubling the penalty for insider trading.

And as the code and conduct regulator, Plibersek said it will allow the Australian Competition and Consumer Commission to monitor water prices and investigate misconduct allegations bringing water markets into line with the standards in other markets.

“These changes will penalise bad behaviour. And they will also increase public transparency,” she said.

Opposition water spokeswoman, Nationals senator Perin Davey, wants the legislation sent to an inquiry and a committee to visit affected communities.

Dredgers operating in lower water flow times to keep the Murray Mouth open. The Murray Darling Basin Plan will deliver environmental water. Photo: Environment Department

The Greens are supporting the move for an inquiry, saying they cannot sign up to the plan in its current form.

Davey is also set to push the government to release the modelling underpinning the new plan, after the minister remained coy on the amount of money allocated to water buybacks saying those details could distort the market.

Davey said the secrecy surrounding the legislation and its potential impacts showed “a disappointing level of disrespect and contempt for regional communities”.

“The Nationals will be fighting for the Senate to put this legislation to an inquiry so that these communities can hear first-hand the good, the bad and the ugly of what is being proposed,” she said.

The Greens are in contrast pushing for more stringent oversight mechanisms to ensure all 450 gigalitres earmarked for the environment are recovered.

SA Greens Senator Sarah Hanson-Young said the party wanted to be sure the water would be recovered this time and not see the states “just kick the can down the road”.

“In order to get Greens’ support for delaying the plan, we need a guarantee that water – real water – is delivered for South Australia, the environment and the health of the river,” she said.

-with AAP