Water managers and planners are slowly beginning to change their perspective and perceptions about how best to meet human needs for water; they are shifting from a focus on building supply infrastructure to improving their understanding of how water is used and how those uses can best be met. This review discusses definitions of water use, explores the history of water use around the world and in characteristic regions, identifies problems with collecting and analyzing water data, and addresses the question of improving water-use efficiency and productivity in different regions and economic sectors. There is growing interest on the part of water managers around the world to implement these approaches to lessen pressures on increasingly scarce water resources, reduce the adverse ecological effects of human withdrawals of water, and improve long-term sustainable water use.
