The regulations are so divisive that they were disallowed in the NSW Upper House for the fourth time last week, in a vote of 16 for and 15 against.

Mel Gray from Healthy Rivers Dubbo says the trigger points that manage the take of water in Mr Anderson's 'Water Sharing Plans' are too low to and will not stop environmental degradation.

"Because floodplain harvesting is being licensed for the first time, the triggers that they have come up with are so low that they will not protect the environment, and we believe they are not in line with the law," she said.

One example is Menindee Lakes where the trigger point is 195 gigalitres. This is far too low according to Ms Gray.

"That's less water than when the fish kills happened," she said. "It's very controversial."

"The trigger at Marebone Break upstream is [also] very low, so when the river's almost dried up is the only time they can stop floodplain harvesting."

Ms Gray along with four Traditional Owners and 17 representatives from groups such as the Australian Floodplain Association, Darling River Action Group, Menindee Lakes Stakeholder Group, and National Parks Association of NSW penned an open letter to NSW Premier Dominic Perrottet.

The open letter stated floodplain harvesting had "grown out of control" and called upon the Premier for action before it is "too late".

While the groups supported the licensing of floodplain harvesting, they said the Water Minister's plan failed to do it fairly, transparently, and while considering the impact on the environment and downstream communities.

A response from the Premier's office declined an invitation to meet with the group representatives and asked them get in touch with the Water Minister, stating the issue was more "relevant" to him.

"I hope you will appreciate that the Premier receives a significant number of diary requests and he is unable to accept them all. On this occasion, the Premier will be unable to accept your meeting request," a spokesperson for Mr Perrottet said.

Daily Liberal has reached out to the Water Minister for comments on the open letter.

Ms Gray said the open letter, which was sent to almost 20 members of parliament including the Water Minister Kevin Anderson, had either been unanswered or received automatic acknowledgment emails from offices.

The sole member to respond to the letter was Reverend Fred Nile.

"We got ignored... We got no meaningful response, except from Reverend Fred Nile who was supportive of our case," Ms Gray said.

Reverend Nile was one of the people who supported the disallowance motion in the Upper House along with Independent MP Justin Field, Greens MP Cate Faehrmann, and Labor. It was opposed by the coalition, One Nation and Shooters Fishers and Farmers party.

Gomeroi Traditional Owner Polly Cutmore took to Twitter to thank supporters of the disallowance motion.

A spokesperson for the Water Minister said if floodplain harvesting was not licensed, the practice would grow "unconstrained", as reported by The Land.

"By licensing floodplain harvesting and reducing the water drawn from floodplains to legal limits, water is returned to rivers and floodplains, including around 100 gigalitres per year to the Northern Basin, and three times that volume in wetter years," the spokesperson said.

However, Ms Gray said the Government was hurrying to issue floodplain harvesting licenses. She said Government should first make sure all the floodplain harvesting levees were legal.

"They shouldn't rush," she said. "...in the Macquarie, specifically, they seem to be rushing the licenses before they have worked out how many floodplain harvesting levees are illegal.

"...a lot of them might have to be levelled or reduced. They've been built over time and they're blocking critical flows to the Macquarie Marshes."