According to Scientific America "much of the U.S. Southwest is a desert—at least it was at one time in the past. But about 90 percent of the Colorado River's water is today diverted into these parched lands for agricultural irrigation. Perhaps half of this regional resource does not even reach the intended crops because it is lost to evaporation and seepage during pumping and transport, according to a 1997 Cornell University study that appeared in the journal BioScience. Many farmers rely on flood irrigation, which, though inexpensive, is a highly inefficient means of delivering water to thirsty plants. The Colorado's dwindling water flow threatens the supplies of seven states and has spawned a plethora of lawsuits regarding water rights. As the Scientific America featured article on water points out, shaving irrigation water by 10 percent would save more than is used by all other water consumers put together. A prime example of this ill-advised approach is growing alfalfa in the desert."
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