In 1993 the United Nations General Assembly designated March 22 as World Water Day. The theme for World Water Day 2011 is Water for Cities, calling attention to the growing demand for clean water in the world’s cities. A few relevant factoids:
Every month the world’s cities grow by 5 million new residents;
In Africa and Asia, the urban population will double by 2030;
827 million people live in slums where sanitation is inadequate and clean drinking water is hard to find.
Worldwide, nearly 500 million people share their sanitation facilities. In 1990, that number was only 250 million;
Poor sanitation causes cholera, malaria and diarrhea.
The opportunity that is presented by this situation is something called “integrated urban water management,” such as increased recycling and reuse of water and wastes. While our cities have many ecological advantages, such as the availability of mass transit, they are clearly unsustainable without the infrastructure necessary to distribute water and to safely remove wastes.