The flood plain issues are not the only water policy headache for the Berejiklian government.

The Murray-Darling Basin Authority wrapped up two days of meetings on Thursday by confirming that all of the remaining water resource plans put forward by NSW for assessment were likely to be at odds with the $13 billion Basin Plan. Four of the 20 plans have already been withdrawn.

“All proposed NSW [plans] appear to be inconsistent with Basin Plan requirements,” an authority statement, said. “Some of these inconsistencies are policy related and others are technical in nature.”

Maryanne Slattery, director of Slattery & Johnson, a consultancy specialising in water policy, said the NSW government was quietly heading for the exit.

“There’s nothing left in the Basin Plan,” she said. “NSW has effectively walked away from the plan without saying so.”

Ms Slattery said Ms Pavey would need to legislate water sharing plans that include floodplain harvesting volumes, and would need concurrence from NSW Environment Minister Matt Kean.

“In their current form, these plans are devastating for the environment and many people in the NSW Basin are hoping minister Kean will not sign off on them,” she said.

On the disallowed regulations, Helen Dalton, a Shooters, Fishers and Farmers spokeswoman on water, said Ms Pavey had “failed to properly consult, [and] many Lower Darling and Murray groups have been sidelined”.

Loading

“When she comes to the table with guarantees around downstream water targets, we can relook at the regulations,” she said, adding her party would support a proposal by Greens MP Cate Faehrmann for an upper house inquiry into the management of floodplain harvesting.

“We absolutely need this inquiry because the NSW government are using dodgy numbers to pretend floodplain harvesting is within legal limits,” Ms Dalton said.

Ms Faehrmann said her proposed inquiry, which might be voted on next week, is aimed at giving voice to groups including First Nations people along the Darling-Baaka River and would recommend how licensing should work.

“This inquiry will examine the legality of floodplain harvesting as well as the modelling underpinning the government’s claims that licensing floodplain harvesting won’t exceed the [Murray-Darling Basin extraction cap],” she said.

Clayton Barr, Labor’s water spokesman, said the inquiry’s terms would need to be modified before his party would sign up. “We do support it in principle,” he said.

Mr Barr said the floodplain regulations were trying to reconcile the 400 gigalitres of farm storage in the northern basin in 1994 against some 1500 gigalitres now.

“We’re trying to regulate an opportunity,” Mr Barr said. “We’re locking into concrete where, historically, it’s been the luck of the draw, the luck of the weather.”

Jim Cush, chairman of the NSW Irrigators Council, said his organisation was disappointed at the disallowance. “This was a way to increase flows back into the rivers,” he said.

“Environmentalists, are they for the river or are they for politics?” Mr Cush asked, adding the disallowance was “political bloody bastardry”.

He said that, with the rivers in high flow after recent good rains, there is still time to get the rules sorted before times turn dry again. “We have two years of supply in the Lower Darling,” he said.