In many areas of the world, growing water scarcity and the misuse of freshwater pose serious threats to sustainable development. With more than two-thirds of the water withdrawn from the earth's rivers, lakes and aquifers being used for irrigation, agriculture is increasingly seen as the system's safety valve. This year's special chapter, Water polices and agriculture, examines the policy implications of increasing competition, conflicts, shortages, waste, overuse and degradation of water resources. It goes on to assess the various water policy options open to agricultural policy-makers.