While it is often suggested that water pricing and trading offers the best mechanism to allocate water between users in changing circumstances, this often fails to take account of the long-term nature of water uses and the challenges of, and limited opportunities for, moving water from one group of users to another to deal with short term variability . During the recent multiyear drought in Australia’s Murray-Darling Basin, economic damage was limited by the way water was prioritized between users in their water allocation system.