Thousands of people converged on Canberra in December to call for the controversial Murray-Darling Basin Plan to be abandoned.

"We are extremely concerned about Keith Pitt's appointment as new water minister, although we are hoping he proves us wrong," rally co-organiser Jan Beer said.

"It appeared some progress was being made, at long last, with David Littleproud, the previous water minister. So is this a ploy to get Mr Littleproud out of the firing line and further stall any efforts to fix the basin plan?"

Mrs Beer said campaigners would have preferred that Member for Nicholls Damian Drum took on the role, as he already had an understanding of the issues surrounding the basin plan.

Mr Pitt was appointed after a cabinet reshuffle prompted by the resignation of former Agriculture Minister Bridget McKenzie.

Mrs Beer said she had heard that the water minister's portfolio had been described as "a poisoned chalice" in the National Party.

"That does not have to be the case. There are achievable solutions, if only government ministers would work with us," she said.

"We will not accept another lengthy period trying to get our messages across; we will be rallying again if Mr Pitt does not immediately come down to our region, learn about the unnecessary economic and environmental damage, and take steps to fix it."

Southern Riverina Irrigators chairman Chris Brooks said in recent months progress had been made in discussions with Mr Littleproud, in particular through his appointment of Mick Keelty as the Inspector-General of the Murray-Darling Basin.

"We have been working closely with Mr Keelty through his inquiry, and a vast range of organisations across our region collaborated to present a united submission highlighting our issues and presenting solutions," Mr Brook said.

"I am disappointed that David Littleproud has made no real attempt to make much needed changes to water management, and now has not seen the Keelty process through, which was his promise to engage with us.

"It is important that Mr Pitt is across the unintended consequences of the basin plan, and most importantly the positive steps which can be taken to fix some of the problems which it has caused, in particular to my members and communities."