Global water use doubled between 1940 and 1980, and is expected to double again by 2000. Yet 80 countries, with 40% of the world's population, already suffer serious water shortages. There will be growing competition for water for irrigation, industry and domestic use. River water disputes have already occurred in North America (the Rio Grande), South America (the Rio del la Plata and Parana), South and Southeast Asia (the Mekong and Ganges), Africa (the Nile), and the Middle East (the Jordan, Litani, Orontes, and the Euphrates).
In most countries, agriculture is the main consumer of water, accounting for about 70% of world water use. The irrigated land area has almost tripled since 1950, and supplies one third of the world's food. But only 37% of the water supplied for irrigation contributes to the growth of crops; the rest is wasted. Farmers have little incentive to use the water efficiently because, in general, they pay only 10 to 20% of the cost of supplying it. In most countries, water policies and laws are inadequate to manage an increasingly scarce resource. Consequently they lose millions of dollars in wasted freshwater and crop production. Water is in many cases allocated inefficiently and inequitably and used inefficiently.