Interim basin inspector-general Mick Keelty was tasked with reviewing how water is managed after irrigators protested at Parliament House last year.

His report released on Friday did not find changes were needed to the way water allocations are carved up between the states.

Instead, Mr Keelty's central finding was dramatic reductions in water coming into the river system during the past decade were having a major impact.

"This remains the primary driver of reduced water availability, and there is little anyone can do to influence when and how much it rains," his report said.

The interim inspector-general found uncertainty, misinformation and misperceptions of available information had created an increasingly toxic public debate.

That had created division between communities and states, he said.

"In the absence of strong, basin-wide leadership, there is a perception that some parties are too busy 'playing politics' and are ineffectual at making any tough decisions," Mr Keelty said.

"Especially when it comes to making decisions in the national interest and at the whole-of-basin level."

Murray-Darling Basin Authority chief executive Phillip Glyde said the report showed how climate change was affecting inflows and state water shares, particularly in NSW.

He said some irrigators would be disappointed the report did not find new water for drought-affected communities.

"However, it does show that every drop is accounted for and is made available to the state governments to manage and allocate according to their rules," Mr Glyde said.

"We've been working hard to increase the transparency and accessibility of water management information but we know there is always more that can be done."

Labor's water spokeswoman Terri Butler said the report was a scathing assessment of the lack of transparency across the basin.

"This is an indictment on the Morrison government's absence of leadership in the management and governance of Australia's precious water resources," she said.

Federal Water Minister Keith Pitt accepted all Mr Keelty's recommendations, including:

* The MDBA should provide more transparent information about water that is not used and how water is accounted for.

* The MDBA should do more analysis of what is causing less water coming into the northern basin and how that affects water sharing.

* There should be a single authoritative platform combining water information available across federal and state government websites.

* States and agencies should work with secondary schools and TAFEs to provide more water education.

Australian Associated Press