A senate inquiry has been told there needs to be serious changes to the way water is managed in the upper Darling River.

Hearings have been held in Broken Hill as part of a senate inquiry into the integrity of the water market in the Murray-Darling Basin, which was launched in the wake of allegations of water theft, over-extraction and government mismanagement of the system.

The inquiry’s deputy chair, Queensland Senator Barry O'Sullivan, said the senators had been faced with justifiable fears about the use of water upstream.

“They're all looking for equity in the distribution of this national wealth, being the water of the Murray-Darling river system,” Senator O'Sullivan said.

“They've bought into focus a whole series of issues that it's probably fair to say are unique to the lower end of the basin, that affect people in the western districts more, perhaps than they do in the top end [of the system].”

Among the suggestions was a call from the Pastoralists' Association of West Darling for restrictions to be placed on the amount of time irrigators can pump from the river, with previous restrictions on the size of their pumps having been removed in 2012.

The inquiry will now be taken upstream to Brewarrina, after hearing detailed evidence from the town's mayor Phillip O'Connor.

Cr O'Connor said he had to give evidence behind closed doors because he was making allegations about specific people and properties.

The evidence was enough for the senators to announce they would go to Brewarrina to hear more from locals.

“There's a lot of evidence which people have got the right to respond to, a lot of evidence that a lot of people have brought to me,” Cr O'Connor said.

“There were a lot of structures and a lot of things along the river which couldn't be discussed in public, which the senators want to come and investigate in a lot bigger way in our Shire.”

Former Murray-Darling Basin Authority staffer and water expert Bill Johnson said there is an urgent need for change, because the current situation threatened to destabilise the irrigation industry in the Murray-Darling Basin.

“The first thing that has to happen with the Barwon-Darling Water Sharing Plan is that limits on the extraction of low flows need to be imposed,” he said.

“They were in the draft plan and they were taken out in the final plan.

“There needs to be protection of low flows. The water just has to be allowed to flow through.”