The defining issues of the twenty-first century may well be the control of water resources. In the next 30 years it is likely that water shortages will increase dramatically. While water supplies are dwindling because of groundwater depletion, waste, and pollution, demand is rising fast. Currently 338 million people are subject to sometime severe water shortages, and by 2025 this number is projected to jump to about 3 billion. The worsening scarcity of water threatens agricultural growth and industrial production and is likely to increase water-related health problems and degrade the environment. In light of these prospects, water issues have been a central theme of IFPRI’s 2020 Vision initiative, which seeks to develop an international consensus on how to meet future world food needs while reducing poverty and protecting the environment. In this paper, Mark W. Rosegrant assesses global water supply and demand, describes in detail the forces contributing to water scarcity, and lays out a number of strategies for managing water in the future. Any solution, Rosegrant asserts, will need to involve both the careful exploration of new sources of water and strong measures to stimulate more efficient use of water. Policies must treat water not as a free good as they often do now, but rather as a scarce commodity that comes at a price. Cooperation’s between countries sharing the same water basin will also become increasingly important as water becomes more scarce. As Rosegrant points out, sensible and far-sighted methods of managing water resources have been adopted in some areas and have been successful in helping alleviate water shortages. Bit such methods will need to become much more widespread if the world id to avoid large-scales conflicts and catastrophes stemming from water shortages and competition for the scarce resource. The principles described here offer guidance on strategies to help avert these disasters.