New South Wales' Natural Resources Access Regulator (NRAR) says it is investigating claims that irrigators in the Namoi Valley pumped water out of the river system during a recent embargo.

Key points: The NSW Department of Industry - Water gazetted an enforceable embargo on water pumping in Namoi Valley on Sunday

The NSW Department of Industry - Water gazetted an enforceable embargo on water pumping in Namoi Valley on Sunday The water regulator says it received several complaints that pumps were operating after the embargo came into effect

The water regulator says it received several complaints that pumps were operating after the embargo came into effect The area's industry group for irrigated agriculture said irrigators were not sent proper notification or communication of an official embargo

A voluntary pumping embargo was issued by the area's industry group for irrigated agriculture, Namoi Water, following good rainfall in the valley last Sunday.

The NSW Government then gazetted an enforceable embargo later that day.

NRAR says it received several complaints that pumps were operating after the embargo came into effect, but Namoi Water said the allegations are unfounded and irrigators were never notified of the Government embargo.

Chief regulatory officer for the NRAR, Grant Barnes, said irrigators were made aware of the embargo conditions.

"NRAR has received reports of pumping in the Namoi Valley, near Tamworth, on Monday, April 1, after the embargo was officially communicated," Mr Barnes said.

"We've had calls subsequently from concerned people in the Namoi Valley regarding pumping and we take those allegations seriously and have commenced an investigation.

"We understand that communication had gone out to water users, and we reiterate it is the obligation of all users to ensure that they understand whether pumping is permitted at any time they turn the pumps on."

Mr Barnes said in conducting the investigation the first step was to determine whether the water users should have reasonably known about the embargo prior to pumping.

'Failure of Government, not irrigators'

Irrigators have told the ABC they did not receive proper notification of an official embargo. ( ABC News: Dominique Schwartz )

Sorry, this audio has expired Water watchdog to investigate claims Namoi irrigators were pumping despite embargo

Namoi Water has labelled the pumping allegations unjust, and said irrigators were not sent proper notification or communication of an official Government embargo.

While there were local radio announcements of the changes, Namoi Water executive officer Jon-Maree Baker said there was no other form of correspondence to irrigators.

Ms Baker also said there had never been an unregulated pumping embargo in the Namoi before, and irrigators in the valley were still yet to receive any formal notification of the pumping embargo.

"This is a failure of Government. This isn't a failure of irrigators to adhere to a new condition that's been applied as a temporary restriction. This is a failure of proper notification," Ms Baker said.

"It's not fair to prosecute irrigators for illegal pumping if they have not been properly notified."

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Ms Baker added that stock and domestic users were still allowed to pump during the embargo and that may explain why pumps were running after the embargo came into force.

She also said her organisation made members aware of the official embargo around midday on Monday, and she was not aware of anyone breaking the embargo once they knew about it.

"I find it extremely implausible that an irrigator would be illegally accessing flows in the Namoi now," she said.

NSW Irrigators Council CEO Luke Simpkins also agreed that he found it hard to believe someone would knowingly do the wrong thing.

"Irrigation farmers want everybody doing the right thing and everyone operating under the same set of rules," he said.

A spokesman for WaterNSW said the organisation conducted a regional media campaign throughout the day, and a website link to the Department of Industry - Water department gazettal details also appeared on the WaterNSW website.

The Department of Industry - Water has been contacted for comment.