The Mississippi River, rising from Lake Istasca in northern Minnesota to flow 2,340 miles to the Gulf of Mexico, "is heading toward an ecological precipice," says the Minneapolis Star Tribune in a special report. In five years, 400 square miles of forests, marshes and grasslands in the upper Mississippi have been converted to agriculture and urban development, "endangering the cleanest stretch of America’s greatest river with farm chemicals, depleted groundwater and urban runoff."
More than half the flow of rivers in the upper Colorado Basin is derived from groundwater, according to a study by the U.S. Geological Society. The study's authors hope it will compel state water managers to ask important questions, since rivers are a key source of irrigation and drinking water across the west. For instance, should a farmer’s use of a nearby river be limited if he or she is also pumping large amounts of groundwater?