Lessons from adaptation to sustain freshwater environments in the Murray–Darling Basin, Australia

摘要

Governance of Australia's Murray–Darling Basin (the Basin) is frequently lauded as an example to other river managers globally. Freshwater environments in the Basin are particularly vulnerable to water scarcity and change. In this paper, governmentalresponses are assessed to draw global lessons on climate change adaptation for rivers. A range of climate change adaptation measures for freshwater ecosystem conservation in the Basin are outlined namely: higher, long-term allocations of water to the environment; reviewing water allocation on a cyclical basis; allocating an equal or greater share of available water to the environment in dry years; and environmental works and measures to use less water to conserve wetlands. Examples of poor translationof science into policy that do not adequately consider the risks, costs, and benefits of adaptation interventions are explored. Adaptation policy in the Basin illustrates the risks of heavy reliance on infrastructure, of the high costs of trade-offs between environmental measures versus socio-economic and political concerns, and of dependence on too few measures. Lessons include the need for rigorous evaluation of risks, costs, and benefits to minimize perverse outcomes, and for adequate incentives andpenalties for implementation of adaptation policies across governance scales. It is concluded that rather than a focus on only a few interventions, such as environmental flows, better adaptation practice requires deployment of a suite of different but complementary measures that spreads risk and maximizes resilience to climate variability and change.