A severe and long-lasting drought gripped the Southwest in the 13th century. Even for the Anasazi, who developed ingenious ways to grow corn and build architectural wonders in the desert, the Great Drought was too much to take.

The Anasazi migrated south, to places where there was more water, building new communities or joining existing ones. And they never really vanished. They are the ancestors of the Hopi in Arizona, the Zuni in New Mexico, perhaps the Tarahumara in northern Mexico.

The prolonged drought that drove the Anasazi out of their homes is, I believe, a cautionary tale for Las Vegas.

Las Vegas is a city built in defiance of its location and its climate. Without feats of modern engineering, Las Vegas could not support anywhere near its current population of 2 million people.

And yet, Las Vegas remains vulnerable to the whims of the climate.

When people started settling in Las Vegas in the 19th century, water bubbled out of the ground. Spring-fed pools near modern-day U.S. Highway 95 and Valley View Boulevard prompted Spanish travelers to call this place Las Vegas -- "the meadows." It was a relatively wet time in the Mojave Desert.

But the groundwater feeding the Las Vegas springs could support only so many people. By the 1950s, it was clear to local officials that a new water source would be needed if Las Vegas wanted to continue growing.

Enter the Colorado River. U.S. Sen. Alan Bible, D-Nev., worked in the 1960s to secure federal funds for a pipeline to draw water from the river's nearby reservoir, Lake Mead. The Southern Nevada Water Project started delivering water to Las Vegas in the early '70s, allowing Las Vegas to become the unlikely metropolis we inhabit today.

But the Colorado River is limited, too. Besides the federal law allowing Nevada to draw a maximum of 300,000 acre-feet of water from the Colorado each year, the river's volume depends on the climate.

The American West is in its eighth year of drought. You don't really notice it in Las Vegas, where it's always hot and dry. But look to the Rocky Mountains, which are the source for the Colorado. When the snowpack in the Rockies dwindles, less water runs into the river. The Colorado is at its lowest level in more than a century.

Nobody knows how long the drought will last. It could end next year or it could linger for another decade or more, creating big problems for all the Southwestern cities that depend to varying extents on the Colorado. Some scientists speculate that this isn't really a drought at all, but a return to a drier normal after several hundred years of unusually wet weather.

Some experts worry that the odds of a longer drought are increased by climatic changes elsewhere. Arctic ice is melting at an alarming rate, and a growing chorus of scientists theorizes that this could dramatically reduce rainfall in the American Southwest.

In other words, the Great Drought that pushed the hardy Anasazi out of the Four Corners could be kid stuff compared with what the Southwest could see over the next several decades.

Las Vegas is not designed to cope with this sort of climatic change. It is not, in popular parlance, a sustainable community. But unless we want to suffer the same fate as the Anasazi did 800 years ago, maybe we ought to start working on that.

Instead, of course, our business "leaders" remain focused on short-term financial strategies. In an astounding case of bad timing, members of the Las Vegas Chamber of Commerce traveled to Washington earlier this month to lobby for expanding the amount of federal land for sale around Las Vegas.

This came at a time when an unprecedented 28,000 houses are for sale in the Las Vegas Valley. Forty percent of them are unoccupied. In addition to these existing structures, thousands of acres of private land remain undeveloped within the valley, as well as 20,000 acres of federal land on the edges that still have not been auctioned off.

There is no pressing need to subject even more public land outside Las Vegas to the bulldozer's blade.

But more important, Las Vegas may not have enough water to provide for a significantly larger population. Plans to pump water from rural Nevada are in the earliest stages of development and still face the possibility of being derailed by opponents.

And even if rural water starts flowing to Las Vegas 10 years from now, it may not increase the overall supply but merely compensate for possible drought-induced, stricter limits on water withdrawals from the Colorado.

Who knows? Predicting the future is a dangerous game. But it's more foolhardy to ignore future possibilities in the quest for immediate gratification.

The rising real estate crisis and uncertainty about the water supply are cause for caution, not profligacy. It's time to improve the sustainability of our community, not recklessly push ourselves into a new type of crisis.

Las Vegas is one of the world's most amazing cultural centers -- equaling the Anasazi's marvelous cultural mecca, Chaco Canyon in northwest New Mexico. Let's learn from the Anasazi story by figuring out how to keep Las Vegas going strong through the drought and beyond.

Geoff Schumacher (gschumacher@ reviewjournal.com) is Stephens Media's director of community publications. He is the author of "Sun, Sin & Suburbia: An Essential History of Modern Las Vegas" and, coming in February, "Howard Hughes: Power, Paranoia & Palace Intrigue." His column appears Sunday.