The Australian Financial Review reports today that the commission says there is a danger the Government could be purchasing the wrong water or the wrong amounts because the it has been buying water entitlements before the Murray-Darling Basin Authority has finalised its plan for sustainable water use in the river system.

The commission says the government has thus far been "operating under a broad 'no-regrets' presumption that the underallocation to the environment is so significant and widespread that the risk of purchasing the wrong water has so far been low". "But until the basin plan is in place, this risk will steadily increase."

The chief executive of the National Irrigators Council, Danny O'Brien, said it was "unusual that in this day and age a government program is spending hundreds of millions of dollars with no identified target, performance outcomes or measures of success".

A spokeswoman for federal Climate Change and Water Minister Penny Wong said the buyback was making use of the best available science to ensure the government was buying water for highest priority environmental needs.