Australia is a generally dry continent that experiences highly variable rainfall. Since colonisation urban settlements have been regularly subjected to droughts, floods and water shortages. Rapid population growth with subsequent economic growth in industry and commerce resulted in dramatic increases in demand for water. The traditional approach to urban water supply largely focused on developing external water sources to meet growing water demands. Concurrently, urban stormwater and wastewater infrastructure is designed on a philosophy of rapid conveyance to receiving environments with reliance on "dilution" in those waters to assimilate wastes. These concepts have limited the capacity of upstream environments to meet urban water demand and of receiving environments to assimilate contaminant loads. As shown in this chapter, the 'big pipe' and 'end of pipe' solutions to water management are gradually being replaced by new integrated water cycle management approaches that aim to be more sustainable and may include small scale and decentralised infrastructure for managing the urban water streams. This chapter discusses the potential for utilising roofwater, stormwater, greywater and treated wastewater to improve management of the urban water cycle.
Australian Runoff Quality: a Guide to Water Sensitive Urban Design p. 6.1 - 6.15