The Senate is expected to vote next week on the abolition of the independent commission, set up by the Howard government in 2004 to advise state and federal governments on national water issues.

South Australia's Liberal Senator Simon Birmingham said the purpose of the commission had been fulfilled and its roles would be taken over the Productivity Commission, saving the budget $20.9 million over four years. Much of the savings will be absorbed by an aid agency to help other nations improve their water management.

"Nowadays it's nothing more than a government-funded commentary organisation," Senator Birmingham told Fairfax Media. The Productivity Commission will provide "more robust, more independent, more fearless criticism than the NWC has shown the likelihood to do to date".

But critics of the abolition plan point to submissions to a Senate inquiry that were overwhelming in support of retaining the AWC.

"It's complacency gone mad," said Adam Lovell, executive director of the Water Services Association of Australia, which supports the commission. "We'll have no focus at a national level on water."

Stuart Khan, an Associate Professor at the School of Civil Environmental Engineering at the University of NSW, said the government had "severely stripped" funding from the commission, undermining its role.

"Simon Birmingham's assertion that 'the purpose of the NWC has been fulfilled' is akin to saying 'water management in Australia is fixed and there's nothing more to do'," Dr Khan said. "This is a patently ridiculous assertion ... and the looming east coast drought will make that clear for all."

Stream flows into the Murray Darling Basin and most other river systems in eastern Australia are dwindling as rainfall levels over the region have been well-below average for the past two years.

The Bureau of Meteorology said low stream flows were recorded at 53 of 74 locations in October and the near-El Nino conditions in the Pacific may lead to more months of relatively dry conditions.

Dr Khan said the Baird government's infrastructure plan with $1 billion earmarked for water security unveiled on Tuesday underscored the need for an independent, specialist agency.

"The NSW government's vision for addressing projected water shortages is simply to build more dams and extract more water from stressed rivers," Dr Khan said. "This is while the report itself forecasts reduced rainfall in many areas of the state" because of climate change, he said.

"Inevitably, some of these increased NSW river extractions will affect other states such as Victoria and South Australia," Dr Khan said. "The National Water Commission could have played a valuable role in providing national oversight of this water planning."

Senator Birmingham said the Productivity Commission would conduct three-yearly audits of the National Water Initiative and five-yearly audits of the Murray Darling Basin Plan.

"I have good confidence that our management of the Murray Darling is in a sound position," he said.

Senator Birmingham also confirmed that the Department of Foreign Affairs and Trade is planning to fund the Australia Water Centre, at the cost of about $20 million over four years.

"It is a very logical progress to transition from a relatively inward-looking entity that the NWC has been to an outwardly looking body that helps Australia share our world-class capabilities with the world."