Climate adaptation options for the 2026 MDB Plan: opportunities for managing climate risk

How water resources are defined, both conceptually and legally, is central to their efficient and equitable allocation. With climate change introducing significant uncertainties to water resources management, flexible allocation frameworks are needed that can adapt to changing conditions. This paper explores options for climate-adaptive water allocation in Australia's Murray Darling Basin. The 2026 revision of the Basin Plan may provide significant opportunities for proactive climate risk mitigation, but this depends on rigorous evaluation of policy options. The Water Act requires that the Plan's revisions use the best available science to inform strategies that minimise the impact of climate risks. The Act also enables the use of ratios and formulas as alternatives to using long-term averages as the basis of the Plan. However, there have been limited investigations into using these alternatives. Achieving more adaptive policies depends on rigorously assessing climate risk management options. Given the far-reaching consequences of climate change, rigorous investigations are needed into reforms to the established approaches to water resources planning and to existing water entitlements and allocation regimes. At minimum, this means reassessing the total resource pool and all subsidiary targets and investigating allocation frameworks that equitably share risks between extractive users and the environment.