

Last month, we reported about Scripps Oceanographic Institute researchers' work on the impact of climate change on the Western water crisis. Now, the same researchers are back in a smaller scientific journal to answer a simple question posed in the title of their paper: "When Will Lake Mead Go Dry?"

Based on models constructed from the analysis of historical records from the Federal Bureau of Land Reclamation, the researchers, Tim Barnett and David Pierce, say there is a ten percent chance the reservoir will be dry in 2014, and a 50 percent chance no water will be left by 2021.

Lake Mead was created by the Hoover Dam's blockage of the Colorado River. The river is fed by snow pack from Rockies, which has been decreasing. The dam, of course, was one of the prototypical megaengineering efforts of the 20th century and a symbol of how human ingenuity could conquer any obstacle, including supplying water to a city the size of Las Vegas in the middle of the desert.

But the sheer amount of water that natural and manmade climate changes and human usage is drawing out of the Colorado River system is staggering. The researchers estimate that 1 million acre-feet, or 326 billion gallons, of water are being leached out of the system each year. They say that's enough to supply 8 million people. (Update: Hat tip to Keith for making me check my math; I had shifted a few decimal places in an earlier version of this post. Ah, the wisdom of crowd copyediting.)

Their conclusion is dire:

Today, we are at or beyond the sustainable limit of the Colorado system. The alternative to reasoned solutions to this coming water crisis is a major societal and economic disruption in the desert southwest; something that will affect each of us living in the region.

We've nudged what has been a naturally replenishing system into a downward spiral. While everyone hopes that there is a technological answer to generating fresh water–say, desalination, or wastewater recycling– those things cost money and energy, and will almost certainly drive up the cost of water.

But take a step back and look at the system, it defies reason to build huge cities in a desert that's getting even dryer. I have no doubt that as the price of water and air conditioning rise in Vegas and Phoenix, the low upfront housing costs and hot sun will start to lose their appeal. I just hope that happens before we permanently break the Colorado River water system.

See Also:

Study: Climate Change Escalating Severe Western Water Crisis

Making Water From Thin Air

New Purification Plant Answers California's Water Crisis