Friday, March 13, 2009

Confronting the Global Water Crisis

Further to Christina Madden's Policy Innovations article "Managing Water Well," Peter Rogers recommends some technical and managerial adaptations in Project Syndicate this week:
- Trade virtual water—the amount of water that is embodied in producing a product (usually food) and shipping it somewhere else to be used. This saves the recipient from using his own water, which can be saved for higher-value activities;

- Conserve irrigation water. Because agriculture routinely accounts for 75 to 90 percent of all water consumed in a country, a 10 percent efficiency gain would save as much water as all the water used by the country's municipalities and industry. Another way of improving irrigation efficiency is by developing crops that produce more food with the same, or less, water. Research on such genetically modified (GM) foods is well advanced in several of the largest water-scarce countries, such as China and India;

- Exploit advanced desalination. Modern developments in desalination have brought the cost per unit of desalinated seawater to levels comparable to obtaining fresh water from natural sources (approximately $0.05 per cubic meter).

- Expand wastewater recycling. Urban areas typically dispose of about 85 percent of their fresh-water intake as wastewater, often in neighboring water bodies. The wastes could be treated and used to replenish groundwater. Emerging low-water-using sanitation technologies such as urine-separating dry-composting toilets could also significantly reduce urban water demands if properly developed;

- Develop creative pricing policies for urban water and wastewater. Protecting human and ecosystem health are difficult to price, because they form part of the pervasive externalities associated with water use. Nevertheless, many water uses would respond well to more efficient prices.

Although avoiding a global water crisis will not be easy, we have at hand policies and technologies that, if properly applied, could see us safely through the next several decades, even in the face of increasing—and increasingly wealthy—populations.

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