Introduction

Australia is the driest inhabited continent and in many parts of the country – including the Murray–Darling Basin (MDB) – water for rural and urban use is scarce and is therefore a valuable resource. Climate change and other risks (including catchment development) to the availability of water make improved water resource data, understanding, planning, and management high priorities for Australian communities, industries, and governments.

In this context, in late 2007 the Australian government called on the Commonwealth Scientific and Industrial Research Organisation (CSIRO) to undertake (over an 18 month period) a comprehensive assessment of current and likely future water availability across the MDB, considering surface and groundwater resources and their interactions, and considering climate change and other risks. CSIRO reported progressively to the Australian government through this study, and a comprehensive set of study reports can be accessed at www.csiro.au/mdbsy. In this chapter, some of the key findings from this study relating to surface water resource use and environmental consequences are presented, together with a discussion of the implications of these findings for future water planning.

The Murray–Darling Basin

The MDB covers more than 1 million km2 of mainland Australia, encompassing parts of four states (Queensland, New South Wales, Victoria, and South Australia) and all of the Australian Capital Territory (Figure 21.1). The Basin is bounded by the Great Dividing Range in the south and east and the landscape is dominated by vast plains and large areas of undulating hills.