Water scarcity in US west gets serious

David A. Gabel in Environmental News Network: Water scarcity has always been a problem in the southwestern desert, with practically everyone relying on one river, the Colorado, to quench their thirst and the thirst of their crops. Increased water demands coupled with a long protracted drought in the Upper Colorado River Basin has created a potentially dire situation. The effects can be seen in Lake Mead, the giant lake along the border of Arizona and Nevada. Lake Mead has reached its lowest levels since 1937, the year the Hoover Dam was completed.

…The fastest growing region in the US is the southwest.. Unfortunately, it is the region that can least afford massive population increases. Places like the Las Vegas metropolitan area in Nevada and the Valley of the Sun in Arizona have grown by leaps and bounds in past few decades. Phoenix is now the nation's fifth largest city. Recent economic turbulence may have put a damper on that growth, but the higher water demand is still there.

Increased demand is a key factor, but perhaps not as important as the lack of rainfall across the southwest which feeds Lake Mead. According to the US Department of the Interior's Bureau of Reclamation, the Upper Colorado River Basin has had only 89 percent of its average precipitation for 2010. They predict that this autumn, the temperature will remain above average and precipitation below average, leading to worsening conditions.

The current drought began way back in October 1999. At that point, Lake Powell, the second largest reservoir in the US located along the Arizona-Utah border, was near full capacity. Over the next five years, inflow into the lake was about half of the average. It has increased somewhat since then, but remains low.

At this point, nobody is able to predict when the drought will end. Normally, droughts occur as a natural climate variation, and the pendulum always swings back towards a wetter climate. However, the current drought has lasted much longer than normal, and local residents have become concerned with possible consequences….

Lake Powell with the "bathtub ring" from receding water visible. Shot by Davejenk1ns, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license