When driving into Las Vegas for the first time, one wonders how the extravagant meetings mecca went from a desert to something more like Times Square or Miami. And indeed, many scientists believe the city can't sustain itself indefinitely with the amount of water available. "I have a feeling that Las Vegas' water demands are so incredible and increasing so much that it's not a sustainable situation," says Charles Goldman, a limnology professor at the University of California at Davis. Las Vegas' average rainfall is only four inches annually. Lake Mead, the man-made reservoir behind Hoover Dam which supplies most of the city's water, has been in a drought condition over the past few years, which has sparked a number of media reports of impending water doom.The hotel industry accounts for only three percent of the city's net water consumption, or intake of water that can't be treated and reused. However, hotels could feel the impact of water shortages and, since they are so greatly responsible for the city's growth, and and so greatly benefit from it, they should be part of a solution, according to Goldman. "They really need to look into the long-term science of sustainability for their operations," Goldman says. "And they need a lot of good civil engineering [to increase efficiency of water use]. It's a complex, multidimensional problem that requires a truly holistic approach."