The steady increase in water use has occurred due to population growth and rising standards of living. The world's population reached 5 billion in 1988, which was nearly twice that of 1950. By the year 2000, the world population is likely to increase to more than 6 billion. The agricultural sector is the largest consumer of water resources. Agriculture is usually considered the engine of growth in developing countries.
Water is recognized as an essential component of sustainable agricultural development.
Without appropriate and reliable water control and management, sustainable agricultural development is simply not possible. Since 1950, the irrigated area world-wide has nearly tripled and now totals about 275 million hectares. In the drive to expand irrigation, however, comparatively little attention has been paid to the efficiency with which irrigation systems operate. Much water is lost as it is conveyed from reservoirs to farmlands, distributed among farmers, and applied to the fields. Much of the losses are rendered unproductive or become severely degraded in quality as the water picks up salts, pesticides and toxic elements from the land.