Management of Murray-Darling Basin, Australia

The Murray-Darling Basin covers parts of four States of Australia and the whole of the Australian Capital Territory. As at 2002, its water management was well regarded internationally. Basin flows are low and variable. The most reliable streams show variations of about 12:1 between maximum and minimum annual natural flows. The longest tributary, the Darling, has a ratio of infinity. It was recognized in the 1980s that extractions from the system, largely for irrigation, had to be constrained. That led to the introduction of the Murray-Darling Basin Cap which limited extractions and recognized the probability of average inflows declining, which was already being predicted by climate change modelling. The millennium drought of 2000-2009 was very severe and led to fears that the drop in inflows was happening faster than modelling was predicting. In 2007, the National Government, on the eve of an election, declared that the Basin had been mismanaged for a century by the States and legislated to transfer management powers from the States to the Commonwealth. That transfer has been pursued since then by National Governments of both major parties. Government claims to have taken the politics out of Basin management and returned to the science. The evidence is that the exact opposite has occurred. The paper traces the history of water management in the Basin. (c) 2020 John Wiley & Sons, Ltd.