The Colorado River has been severely diminished over the past century as seven Southwestern states expanded their claims on its water. The past 14 years have witnessed an extraordinary drought that has brought the river to crisis levels. Unfortunately, this may be more the norm going forward than many would hope to believe according to a recent article in the New York Times
But many experts believe the current drought is only the harbinger of a new, drier era in which the Colorado’s flow will be substantially and permanently diminished.
Though perhaps not yet catastrophic in its impact, the shrinking flow of the Colorado has widespread and material impacts on agriculture, livestock, and water for millions of people across the seven states.
These new realities are forcing a profound reassessment of how the 1,450-mile Colorado, the Southwest’s only major river, can continue to slake the thirst of one of the nation’s fastest-growing regions. Agriculture, from California’s Imperial Valley to Wyoming’s cattle herds, soaks up about three-quarters of its water, and produces 15 percent of the nation’s food. But 40 million people also depend on the river and its tributaries, and their numbers are rising rapidly.
In fact, the past century, during which claims on the River have radically increased, has seen rainfall that was well above normal. And that doesn’t even begin to factor in potential impacts from climate change.
Studies now show that the 20th century was one of the three wettest of the last 13 centuries in the Colorado basin. On average, the Colorado’s flow over that period was actually 15 percent lower than in the 1900s. And most experts agree that the basin will get even drier: A brace of global-warming studies concludes that rising temperatures will reduce the Colorado’s average flow after 2050 by five to 35 percent, even if rainfall remains the same — and most of those studies predict that rains will diminish.