23 July 2008

Peak oil is the point in time when the maximum rate of oil extraction is reached.

Peak water? Just substitute "freshwater" for "oil" above.

The Ogallala Aquifer in the United States is one of the largest reservoirs of fossil water in the world. This is water that has been accumulated and trapped underground for thousands and perhaps even millions of years. Part of the aquifer lies beneath the Grain Belt of the United States. Unfortunately, it is being rapidly depleted. The importance of this aquifer to agriculture can hardly be exaggerated.

America is the world's largest exporter of soybeans, corn and wheat. Water shortages in the Grain Belt due to excessive water mining of aquifers can only mean disaster for global food supplies.

U.S. faces era of water scarcity

July 9, 2008

While agriculture in the Colorado Basin faces shortages, farmers to the east in the high plains — tapping the Ogallala Aquifer — have progressively seen their wells dry up. The aquifer is the largest in the United States and sees a depletion rate of some 12 billion cubic meters a year, a quantity equivalent to 18 times the annual flow of the Colorado River. Since pumping started in the 1940s, Ogallala water levels have dropped by more than 100 feet (30 meters) in some areas. Full Report