http://cals.arizona.edu/AZWATER/awr/dec99/Feature2.htm
"Consider: More than a dozen nations receive most of their water from rivers that cross borders of neighboring countries viewed as hostile. These include Botswana, Bulgaria, Cambodia, the Congo, Gambia, the Sudan, and Syria, all of whom receive 75 percent or more of their fresh water from the river flow of often hostile upstream neighbors."
"The World Bank reports that 80 countries now have water shortages that threaten health and economies while 40 percent of the world — more than 2 billion people — have no access to clean water or sanitation"
"Meanwhile many countries suffer accelerating desertification. Water quality is deteriorating in many areas of the developing world as population increases and salinity caused by industrial farming and over-extraction rises. About 95 percent of the world's cities still dump raw sewage into their waters. "
Can desalination help? Yes. but it also has MAJOR drawbacks. Mainly energy usage by a desalination plant is huge.
"Energy use requirements for desalination plants are high. For example, an estimated 50 million kWh/yr would be required for full-time operation of the City of Santa Barbara's desalination plant to produce 7,500 AF/yr of water. In contrast, the energy needed to pump 7,500 AF/yr of water from the Colorado River Aqueduct or the State Water Project to the Metropolitan Water District (MWD) of Southern California is 15 to 26 million kWh/yr. These energy requirements may be compared to the energy use of a small- to medium-sized industrial facility (such as a large refinery, small steel mill, or large computer center) which uses 75,000 to 100,000 kWh/yr."
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http://www.coastal.ca.gov/desalrpt/dchap1.html
And with global energy sources decreasing, thus driving up costs, it becomes more and more difficult for desailnation to meet the demands for providing potable water in the developing world.
