Earth Equity News

The Colorado River Runs Dry. By Sarah Zielinski, Smithsonian magazine, 10/10 issue. “From its source high in the Rocky Mountains, the Colorado River channels water south nearly 1,500 miles, over falls, through deserts and canyons, to the lush wetlands of a vast delta in Mexico and into the Gulf of California. That is, it did so for six million years. Then, beginning in the 1920s, Western states began divvying up the Colorado’s water, building dams and diverting the flow hundreds of miles, to Los Angeles, San Diego, Phoenix and other fast-growing cities. The river now serves 30 million people in seven U.S. states and Mexico, with 70% or more of its water siphoned off to irrigate 3.5 million acres of cropland. The damming and diverting of the Colorado, the nation’s seventh-longest river, may be seen by some as a triumph of engineering and by others as a crime against nature, but there are ominous new twists. The river has been running especially low for the past decade, as drought has gripped the Southwest… some 130 feet lower, as it happens, since 2000. Water resource officials say some of the reservoirs fed by the river will never be full again. Climate change will likely decrease the river’s flow by 5 to 20% in the next 40 years, says geoscientist Brad Udall, director of the University of Colorado Western Water Assessment. Less precipitation in the Rocky Mountains will yield less water to begin with. Droughts will last longer. Higher overall air temperatures will mean more water lost to evaporation.” Note water levels of Lake Mead.