16. Drought and Climate Change in the Murray-Darling Basin: A Hydrological Perspective

The Murray-Darling Basin experiences frequent droughts and, at the time of this writing, parts of it are in the grip of the worst drought in the 110 years of comparatively high-quality records. In this chapter, we consider the term drought to be several years with less than median rainfall. The combined impacts of drought and over-allocation of water for irrigation use have led to severe stress on floodplains and wetlands. Climate change projections suggest that the Murray-Darling Basin will be on average drier in the future. The recent drought period has experienced lower autumn and winter rain and higher temperatures than past droughts, resulting in the lowest runoff totals on record in recent years. While these features may be associated with climate change, they may equally be a result of large, long-term climate variability. The recent drought and declining river health have exposed the inadequacy of current water management to cope with the variability of water availability in the Murray-Darling Basin. Future water management strategies should involve consideration of a range of scenarios, including those incorporating climate change.