A number of farmers will be investigated after satellite imaging showed their dams, in drought-ravaged parts of New South Wales, were filled during a pumping embargo in parts of the Murray-Darling Basin.

Key points: Routine satellite checks identify a number of private dams in the Murray-Darling Basin that filled during a pumping ban

Routine satellite checks identify a number of private dams in the Murray-Darling Basin that filled during a pumping ban Some dams are considered to be a "high priority" for investigation, while others filled before the embargo began

Some dams are considered to be a "high priority" for investigation, while others filled before the embargo began The ban was in place to allow some of the first flows into these catchments in months

Routine satellite monitoring conducted by the Murray-Darling Basin Authority (MDBA) captured several filled private dams earlier this year.

The ABC has been told the state's water watchdog, the Natural Resources Access Regulator (NRAR), will investigate.

"In the Namoi, the MDBA found that 29 private storages appeared to fill or partially fill during the embargo," the MDBA said in a statement.

"In the Macquarie, another three private storages were found to fill during the embargo.

"There are many reasons why a farm dam could have filled quite legally, which is why it is important for follow-up work to be done on the ground by state compliance officers."

Some of the dams started to fill after the flow arrived but before the embargo began. ( Supplied: MDBA )

National Irrigators Council chief executive Steve Whan said the report was "premature" because there were legal ways for the dams to fill.

"I suspect that this report's been released a bit before it should have been," he said.

"I think it would have been better for all concerned if there had been exploration of whether there was any wrongdoing taking place first."

MDBA chief executive Phillip Glyde said the agency had been monitoring water that went into the system after Cyclone Trevor impacted northern Australia in March.

"At the time, the NSW Government imposed an embargo between April 1 and May 7, so we were able to watch what happened to that water," he said.

"We noticed as we were going along that a lot of the private storages would fill up, you could see that from the satellite imagery.

"That was interesting to us — that satellite image doesn't provide a basis for knowing whether or not something's legal or illegal, but we referred those images off to the NSW regulator."

Federal Water Minister David Littleproud and the Murray-Darling Basin's "top cop", interim inspector-general Mick Keelty, have warned of a crackdown on those tempted to steal water.

Mr Glyde said cooperation between state and federal agencies was what farmers, local communities and the broader public rightly expected of water managers, especially in times of water scarcity.

"Flows of this nature carry much-needed economic, cultural and ecological benefits right through the system, and in times of drought it is critically important the water is allowed to reach as far as possible downstream," he said.

The MDBA was tracking rainfall flows when it discovered water in private storages. ( ABC: Jessie Davies )

Member for Parkes Mark Coulton is calling on the MDBA to remove the information about farmers in his electorate until further investigations are completed.

"I am very disappointed with the insinuations that have resulted from a published document identifying private storages in the Namoi and Macquarie Valleys as alleged sites of illegal pumping during an embargo," he said.

"Without any charges being laid, and in the absence of any thorough investigations whatsoever, farmers in my electorate could be linked with illegal activity.

"The farmers in my electorate play a crucial role supporting not only the local economy, but also contribute to valuable export income for our country, and for them to be portrayed as being dishonest without comprehensive investigation is extremely insulting to them and their families.

"I call on the MDBA to remove this information until further investigations are completed."

View from above

The MDBA was monitoring first-flush flows into the Namoi, Macquarie and Warrego catchments which would have flowed into the Barwon-Darling and Menindee Lakes.

For some catchments, it would have been the first flows in months.

Mr Glyde said the embargo had been put in place to protect the environment during the extreme drought conditions.

"That was the intent, that was the message, and it's really quite an important thing, particularly in really dry catchments which these catchments were prior to this small rain event and obviously remain very dry now."

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In the course of its monitoring, the MDBA discovered 158 private storages in the Namoi had filled by at least 10 per cent after the flow arrived but before the embargo began.

It also discovered 29 storages had filled by at least 10 per cent during the embargo, with four of these considered a "high priority for further investigation".

In the Namoi, the storages represent 32 per cent of the mapped large (more than one hectare) storages in the region.

There were three dams in the Macquarie catchment that filled by more than 10 per cent during the embargo; all of them are considered high priority for investigation.