The New South Wales Irrigators Council has called on the Murray-Darling Basin Authority to recalculate and republish figures determining the average annual inflow to the Basin in light of the past two years of high water availability.

 

Council Chief Executive Officer Andrew Gregson says the Authority is to use “best available science” to draw the Basin Plan – and new inflow data could have a material impact on it.

 

“The MDBA has used 114 years of data to determine average annual inflows of 31,599 gigalitres. The period used was 1895 to 2009.

 

“We now have two further years of data available – 2010 and 2011. In light of that, we’re calling on the Authority to add that data to their work and to recalculate the average.

 

Gregson explains that the average annual inflows are critical in calculations to determine how much productive water the Basin Plan will remove from communities.

 

“They’re proposing the removal of 2,750 gigalitres of productive water. They took the average annual inflow and subtracted what their set of environmental assets “needs”. That portion left over is for productive use. They’ve determined it’s too high by 2,750 gigs.

 

“If the average available figure at the start is higher, then the reduction to productive water will be comparatively lower.”

 

“If, for example, inflows in the last two years were just 45,000 gigalitres – a low assumption given the flooding – that would raise the annual average to 31,830. That’s a rise of less than 1% to the average, but the volume involved is 231 gigalitres.

 

“If 231 gigalitres extra is available to the environment, we can subtract that from the 2,750 to be removed from productive use and get closer to a sensible Basin Plan without destroying communities.

 

“We understand it would require only a couple of weeks to undertake this work, so we’re calling on the MDBA to do it at the earliest opportunity.”