by Stephen Janowsky

Created on: April 21, 2008

Less than one percent of water on Earth is found as fresh water in lakes and rivers. This water is vital to all land-living creatures. The world's rivers have forever been a source of life in continental areas. They have been the cradles of early civilizations, supporting the development of human communities, fertilizing lands for agriculture, and providing routes for trade and shipping. The progress of mankind was accompanied by a constant growth in water demands; consumption has multiplied more than thirty times during the past three centuries, and nowadays it still increases by two to three percent every year. Moreover, in the last decades, dam building, global warming, and pollution have seriously endangered our rivers.

As a result of damming and drought, the delta of the great Colorado River, once hosting some 400 species of plants and animals, has turned into a huge salt desert with loads of clamshells. The Rio Grande is currently split in two, as it virtually disappears on some 200 miles of its course, called by local people "the forgotten river". The famous slit-carrier Yellow River of China is hardly reaching the sea today because of intensive damming and drying out of its sources, the Tibetan glaciers. The Aswan High Dam, designed 40 years ago to prevent the recurring floods and droughts of the Nile, has reduced the flow rate of this world's probably longest river to only six percent of its previous level. Similarly, the Indus in Pakistan, Australia's Murray River, and Germany's River Elbe have run dramatically dry. The Amazon was affected by terrible drought a few years ago, but it is still largely devoid of dams. Salmons are endangered in Alaska's Yukon River because its waters are getting too warm. The water removed for irrigation from Central Asian rivers has shrunk the Aral Sea down to 20 percent of its volume in the past half a century. Because of global warming, the snow sources of the great rivers of the American west are expected to gradually decrease in the future decades. Examples may continue.

In 2006, the UN World Water Development Report pointed out that "we have hugely changed the natural order of rivers worldwide", seeing that "more than one half of the world's 500 major rivers are being seriously depleted and polluted". The reason is that "humanity has embarked on a huge ecological engineering project with little or no preconception of the consequences."

Starting with the Colorado Hoover Dam some 70 years ago, people worldwide have

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