The concept of sustainability has received much attention since the publication of Our Common Future by the World Commission on Environment and Development in 1987. Despite the institutionalisation of sustainability principles through legislation and policy around the world, progress in implementing sustainable development actions has been slow. The very open-ended definition of sustainable development provided in these documents, and the "language" used has made interpretation of what is required for implementation controversial. ''Principles" of sustainable development have been developed to provide further guidance for implementation, but sustainability remains a contested and value-laden concept. Yet there is increasing recognition that the present development paths around the world are clearly not sustainable into the future and that we need urgently to address this unsustainability. Water use has become a prominent issue through broad acceptance that its use in many situations, including southeast Australia and cities such as Sydney, is unsustainable. This paper provides a broad introduction to the development of the concept of sustainability, barriers to implementation of sustainable development, and the application of sustainable development principles to water provision for a city such as Sydney, with emphasis on the use of recycled water.