(NaturalNews) Water resource experts have known for many years that current use of the Colorado River is not sustainable. Sixteen years of drought have made it clear that the river is overtaxed, and cannot indefinitely meet the demands of agriculture, hydroelectric generation, recreation and sustaining the populations of some of the fastest-growing cities in the nation.

This past spring was an unusually wet one, leading to higher-than-average runoff from river's source in the Rocky Mountains. Yet even at atypically high levels, the river still ran dry before reaching its outlet at the Gulf of California.

All of which suggests that the elaborate water distribution system that sustains the cities and farms of the Southwest may be collapsing sooner than anyone expected.

Will Phoenix be abandoned?

It's no surprise that the Colorado River is under enormous strain. The 1,450-mile river begins as snowmelt in the Rocky Mountains, crossing seven states on its path to what was once a flourishing delta just across the Mexican border, and is now a tiny marsh just a tenth of its former size. The marsh and river both run dry before reaching the sea.

The river is pumped continuously along its path to sustain, among other things, major cities including Denver, Las Vegas and Phoenix - cities that house approximately 40 million people. And that population is expected to double within 50 years.

Water from the Colorado also goes to water beef pastures in western Colorado, produce electricity at the Hoover and Glen Canyon Dams, and irrigate lettuce fields in southeast Arizona.

At some time in the next few decades, federal officials have warned, some of those uses will have to give. Never, since the signing of the 1922 Colorado River Compact, have any river users been forced to take allotment compacts. But that day is fast approaching.

Due to the idiosyncrasies of the compact, some users would be hit worse than others. California would take almost no cutbacks, due to a 1968 agreement in which California allowed Arizona to build a massive water diversion system (the Central Arizona Project). In exchange for that approval, Arizona agreed to suffer steeper water cuts in the event of a shortage.

Arizona officials are very concerned about this possibility, in spite of serious conservation measures taken in the 1980s. Cutbacks would likely lead to the fallowing (or even abandoning) of fields in central Arizona used to grow cotton and cattle field. The greatest fear is that water shortages might require placing caps on urban growth in the capital city of Phoenix. Arizona's economy is founded upon urban growth.

Growing lettuce in the desert

Due to another strange quirk of the Colorado River Compact, though, Arizona's lettuce-growing heartland would remain largely unaffected.

That heartland is the region around the city of Yuma, which produces nearly all of the lettuce found in U.S. stores during the winter. And not just lettuce: Any green salad eating between November and April probably contains some produce grown near Yuma.

Growing leafy greens in one of the driest parts of the country is only possible because Yuma gets an enormous Colorado River allotment: 1 million acre-feet, out of just 15 million acre-feet available for the entire river basin. In comparison, the cities of Phoenix and Tucson (total population 5 million) use only 1.5 million acre-feet; the entire state of California is entitled to 4.4 million.

Yuma agriculture gets such a massive allotment because it was one of the first (non-indigenous) users of the Colorado River water. The 1922 compact recognized those water rights as senior, and as a consequence the area would also be among the last to take cuts.

But as the river continues to dry up, something will have to give. Whether it will be winter lettuce, hydroelectric power, or some of the fastest growing cities in the country still remains to be seen.

(Natural News Science)

Sources:

http://www.latimes.com