Rice is a water hungry crop, and not naturally suited to being grown in Australia, a dry continent. 1 kg of rice needs approximately 3400 litres of water (www.waterfootprint.org).
Most Australian rice is grown in the Murray-Darling River Basin, and draws a significant amount of water from that river system. Australian Bureau of Statistics in 2005-6 estimated to create one dollar of product, the rice sector consumes 4569 litres of Murray-Darling water. 90% of Australian rice produced is for export.
That said, the Australian Rice industry is one of the most efficient in the world, having improved water use efficiency by 60% over the past 10 years and now using use 50% less water to grow one kilo of rice than the world average.