Irrigation is the largest user of freshwater - around 70% of withdrawals are for
irrigation. Irrigation produces 30 to 40% of the world's food crops on 17% of all arable land (Seckler et al., 1998). To meet future demands for food with an increasingly scarce
water supply, we must manage our water resources better. When water supplies are
abundant and environmental pollution and degradation is no issue, water managers can
afford to be lax in its management. But, with growing population and subsequent need for
water for food, health and environment, there will be few places in the next century where
we have this luxury. Management and planning requires good information, and reliable
information on water resources use is also at present a scarce resource.