Water reuse introduces the need to integrate both water supply and wastewater management at local and regulatory levels.

Growing population and increasing urbanization is resulting in shortages of water supply for communities even in water-rich areas of the world. An approach to addressing this problem has been the introduction of wastewater reclamation and reuse for nonpotable purposes through dual distribution systems in municipalities in the United States on a significant scale in the 1970s and more recently in Japan and Australia. Many hundreds of communities, some very small and others very large, have adopted dual systems to add to their water resources and to reduce the burden of water pollution. Two issues deserve attention. The first is that the provision of water supply and its regulation by government is generally entirely separated from the provision of sewerage and wastewater treatment, so that the management of a reclaimed water service requires new arrangements both on the part of communities and of the government agencies that are concerned with the oversight of water supply and pollution control. The second issue is that the availability of new technology for treating waters drawn from polluted sources has led to proposals for purposefully using reclaimed water for potable purposes. The integration of water supply and wastewater disposal functions in professional organizations, such as IWA, is a useful step towards integrating water management in practice.