Impacts of Water Use
With the global increase in population and mushrooming of industries, the demand for water has rose to an alarming level. The rapid consumption of water has led to significant fall in the water table. Many a major rivers of the world like Amu Dar'ya, Colorado, Ganges, Indus and Rio Grande runs dry in many catchment areas for a significant portion of the year. Worldwide, freshwater wetlands have diminished by half in area. There are almost 20,000 Species of fish that breathes in fresh water. Out of this, 20 percent are at risk of extinction and many of them are already extinct.

Dam-Building Frenzy
The number of large dams climbed from 5,000 in 1950 to more than 45,000 today-an average construction rate of two large dams a day for 50 years. This phenomenal increase in the number of dams at this rate will adversely effect the demand of water.

Rising Uneven Distribution
Just six countries-Brazil, Russia, Canada, Indonesia, China, and Colombia-account for half of Earth's total renewable freshwater supply. Canada ranks near the top of water wealth, with more than 92,000 cubic meters of water per inhabitant. At the water-poor end of the spectrum are Jordan with annual renewable supplies of 138 cubic meters per person, Israel with 124, and Kuwait with essentially none.

Agricultural Water Use
Agriculture uses about 70 percent of all the water extracted from Earth's rivers, lakes, and underground aquifers, and as much as 90 percent in many developing countries. Recent projections indicate that by 2025 numerous river basins and countries will face a situation in which 30 percent or more of their irrigation demands cannot reliably be met because of water shortages.

Cities and Homes
With nearly half of the global population now living in urban areas, a figure that will increase to 60 percent by 2030, meeting the growing water desires of the rich and the water needs of the poor is now a significant challenge

Industrial Water Use and Material Goods Consumption
Industrial demands in developing and emerging economies are growing rapidly and will compete for scarce water supplies with both cities and farms.

Industries account for about 22 percent of the world's total freshwater withdrawals, but they claim a far higher share in industrial countries (59 percent on average) than they do in developing ones (10 percent). In addition to using rising quantities of water, industries generate large volumes of wastewater; in developing countries, much of this is currently released untreated into nearby rivers and streams, polluting scarce supplies.

(Source: Worldwatch Institute )