LEADING scientists have walked away from the Murray-Darling Basin Authority because of serious concerns over changes being made to the volume of water to be returned to the river.

The Wentworth Group of scientists were advising the authority but have called on it to hold an independent review of the science that determined the volume of water to be returned to the river system after hearing that the proposed amount is now 2800 gigalitres.

A question of volume... the Murray Darling basin.

The original draft plan found that 3856 gigalitres would be a minimum volume of water that would need to be acquired from the 11,500 gigalitres of irrigators' entitlements to maintain the river.

Tim Stubbs, environmental engineer with the Wentworth Group, said the nearly 4000 gigalitres identified in the authority's guide had been widely accepted as an appropriate lower limit.