In virtually all countries, climate change is changing the capacity to save water, so that in the medium term many regions that are currently water-rich could also experience water shortages. Therefore, a high level of efficiency in water use should actually be ensured everywhere.

Water development underpins food security, people’s livelihoods, industrial growth, and environmental sustainability throughout the world. In 1995 the world withdrew3,906 cubic kilometers (km3) of water for these purposes. By 2025 water withdrawal for most uses (domestic, industrial, and livestock) is projected to increase by at least 50 percent. This will severely limit irrigation water withdrawal, which will increase by only 4percent, constraining food production in turn. About 250 million hectares are irrigated worldwide today, nearly five times more than at the beginning of the 20thcentury. Irrigation has helped boost agricultural yields and outputs and stabilize food production and prices. But growth in population and income will only increase the demand for irrigation water to meet food production requirements. Although the achievements of irrigation have been impressive, in many regions poor irrigation management has markedly lowered groundwater tables, damaged soils, and reduced water quality.

In severely water-scarce basins, however, relatively little room exists for improving water use efficiency, and food production and farm incomes could fall significantly if water for irrigation is transferred to other uses. In these basins, governments will need to compensate for the negative impact of growing water scarcity on agriculture by alternative means, such as investing in agriculture to obtain more rapid growth in crop yields, promoting the diversification of farming into less water-intensive crops, and diversifying the economy to reduce the economic role of agriculture over time. Therefore, a high level of efficiency in water use should actually be ensured everywhere.

Dear Naresh,

The distinction between water rich and water shortage country is a matter of perception and subjectivity. Since the climate change is a global phenomenon, any good practice on water productivity needs to be adopted irrespective of any man-made classification.