Long-distance water transfer

WATER is used for a wide variety of purposes, chief among which are domestic use, industrial use (including mineral extraction and processing), irrigation, hydroelectric power generation, navigation, recreation and fisheries development. The extent of water use for any one purpose varies from one country to another, and is dependent on a variety economic development, i factors like state of t, including standard of living; importance and extent of a specific sector like industry or agriculture in the national economy; efficiency of water use; socio-cultural practices, so on. For example, for two industrially advanced countries like Japan and the United States, industrial water use in terms of per capita per day varies from 4,500 litres for the former to 9,600 for the latter, a figure that is more than twice the usage rate for Japan. Similarly for the United States, total agricultural and industrial water demands are somewhat similar: approximately 40 per cent of total water requirements. On a global basis, however, the situation is very different: agriculture is the largest user of water and accounts for nearly 80 per cent of total consumption.

Water is a renewable resource and, unlike non-renewable resources like oil or natural gas, there is no danger that the world is going to run out of water. The principal problem with water is that its distribution varies tremendously both with respect to time and space, and accordingly its rational management

is of paramount importance for the welfare of mankind.