Introduction

Adelaide, South Australia, is a city of 1 million people on the southern coast of Australia with a Mediterranean climate, and where (as in Perth, Western Australia) climate change impacts on rainfall have been felt severely and are projected to be among the most severe globally. From its foundation in 1836 until 2010, Adelaide has relied almost exclusively on runoff from rural catchments for its water supply. It developed water treatment processes to harvest water from catchments – including the Murray–Darling Basin, used for agriculture, grazing, and forestry, and occupied by more than 0.5 million people and millions of cattle and sheep. As a result of climate change, the River Murray is suffering its lowest recorded inflows; unfortunately, adaptation of a massive irrigated agricultural industry takes time, and so the Murray's distal lakes are drying in an environmental crisis similar to the Aral Sea. Like Perth and other coastal cities, Adelaide has turned to seawater desalination for immediate substitute supplies. However, it is exploring many other options, which, if successful, could also become significant sources of supply, and the result might provide a model for other cities aiming to increase water security. For example, harvesting of urban stormwater and storing it in aquifers now forms a major plank of South Australia's water security plan. Domestic rainwater tanks and reuse of sewage effluent are other options, along with water conservation measures.