Producer Andrew Pursehouse said irrigators expected the cut, after carryover allocation had over-extended sustainable usage during the past three years.

"Sustainable extraction has been assessed at 16,000 megalitres and for the last three years we have been taking 20,000ML by using carry-over allocation," said Mr Pursehouse. "This is about bringing that back into alignment.

"It is better to have this decision made now rather than in September when we would be planning for a summer crop. We will adjust our program, maybe grow less corn or switch to sorghum, which uses less water, or maybe plant cotton using a single skip-row rather than a full paddock or we may choose to leave more country for fallow."

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Mr Pursehouse said it followed that there would be increased water saving measures like further laser levelling of paddocks along with the uptake of unused off-river storage.

"The last thing we want is this resource to be mined," he said, noting that water quality was good enough for bottling. "In the 1980s we pleaded with government to stop issuing extraction licences."

While Namoi Valley zones two and five, around Narrabri, have minimal cutback to 95 per cent allocation, zone 1 around Quirindi will have an increased 230 per cent allocation after Liverpool Plains Shire Council handed back 500ML of groundwater following state government works to increase the capacity of Quipolly Dam.

Namoi Valley Irrigators chief executive Jon-Maree Baker said the increased allocation to zone one could be regarded as just reward for the four or five active irrigators in that district following the heavy 95 per cent allocation cut following the 2004 water sharing plan, which rendered most opertations unviable.

Meanwhile, groundwater hydropgraphs showed "pretty good" reserves and users in zone eight looked forward to a reassessment by Minister Melissa Pavey in August after final meter readings.

"We welcome increased transparency around these ministerial decisions," said Ms Baker.

The Land