Snake Eyes for Las Vegas?
By Bruce E. Johansen
Grand outdoor pools and ersatz waterfalls. Air conditioners humming in 120-degree heat. A chance to get lucky and beat the odds. Las Vegas, Nevada has always been a symbol of American indulgence and damn-nature ecological arrogance.
Water planners now realize that within a few decades this grand cultural artifact may run out of water. The Colorado River, the principal water source for a large part of the United States Southwest, is slowing to a muddy trickle in a drought that may be the worst in 1,250 years, since two dry centuries that felled the Anasazi and (further south) the Maya. The same warm spell lured the Vikings to Greenland, only to trap them in the Little Ice Age.
Of late, the city of Las Vegas, Nevada, has been pumping Lake Mead dry with a series of pipes, each one lower than the last. The lake’s level is close to a point at which water will have to be severely rationed in that city. People already are using each others’ recycled sewage water. And so what happens to Las Vegas real-estate values when the message finally sinks in that no one can run a major city without water?
All along, planners have acted as if the situation is cyclical, and will correct itself. It may not be. Global warming is reinforcing the drought by altering atmospheric circulation patterns, a subject left untouched in much of even the most thorough reporting on the drought. The reporting mentions global warming but misses the science.
Drought, Air Circulation, and Warming
The New York Times in January, 2014 carried an excellent report on the subject, but it missed the punch line: changes in worldwide atmospheric circulation aggravated by global warming. Near the equator, warm, moist air rises, cools and unleashes downpours. In the upper troposphere, the air spreads north and southward toward both poles, descending at about 30 degrees north and south latitude and creating deserts. For reasons that are not yet fully understood, as temperatures rise the “Hadley Cells” reach further north and south of the equator, expanding arid areas.
Droughts in regions where Hadley Cells favor descending air now span the globe, from Australia, to Spain, Iraq, Afghanistan, parts of China and the United States Southwest, including California, Nevada, New Mexico, Arizona and Texas. In China, the Gobi desert, also within the northern reaches of Hadley Cell range, has been expanding, sending occasional dust storms into Beijing, aggravating air pollution from coal-fired power plants that gives that city and others in China the dirtiest air on Earth.
Shrinking Lake, More Waterworks
Thus far, since 2008, water officials in southern Nevada have been dealing with the drought by constructing new waterworks that suck Lake Mead dry at ever-lower levels. John Entsminger, the senior deputy general manager of the Southern Nevada Water Authority, told New York Times reporter Michael Wines: “If Lake Mead goes below elevation 1,000” — 1,000 feet above sea level — “we lose any capacity to pump water to serve the municipal needs of seven in 10 people in the state of Nevada.”
The level of Lake Mead, at 1,106 feet above mean sea level in 2013, hovers just above 1,050 feet, where Las Vegas’ first intake runs dry. At 1,000, the second one can no longer pump water. The third intake is now being built at 860 feet. Meanwhile, temperatures rise, increasing evaporation rates, and rain and snowfall have continued an irregular decline.
As Wines reported: “Reservoirs have shrunk to less than half their capacities, the canyon walls around them ringed with white mineral deposits where water once lapped. Seeking to stretch their allotments of the river, regional water agencies are recycling sewage effluent, offering rebates to tear up grass lawns and subsidizing less thirsty appliances from dishwashers to shower heads.” By 2014, for the first time, federal authorities restricted the amount of water entering Lake Mead from Lake Powell, about 180 miles up the Colorado River. Lake Mead supplies water to about 40 million people, not only to Las Vegas, but also Los Angeles, and several millions of acres of irrigated farm and ranchland that produces 15 percent of the United States’ food.
Water is already becoming precious, Wines noted: “Virtually all water used indoors, from home dishwashers to the toilets and bathtubs used by the 40 million tourists who visit Las Vegas each year, is treated and returned to Lake Mead. Officials here boast that everyone could take a 20-minute shower every day without increasing the city’s water consumption by a drop.” The Las Vegas’ area’s water consumption did not increase between 2000 and 2012, even as it added 400,000 people.
These boasts come with the customary Vegas bravado—else why would a third intake valve be required at Lake Mead if the city has balanced demand and supply of water? Stay tuned.
Wines, Michael. “Colorado River Drought Forces a Painful Reckoning for States.” New York Times, January 5, 2014. http://www.nytimes.com/2014/01/06/us/colorado-river-drought-forces-a-painful-reckoning-for-states.html
Bruce E. Johansen is Jacob J. Isaacson Professor at the UNO and author of The Encyclopedia of Global Warming Science and Technology (2009).