A lot of pundits believe that the future of water and Las Vegas is particularly bleak. Currently, the only source of water for Vegas is Lake Mead, whose water was allocated in the late 1920s during negotiations among the affected states before the construction of Boulder (now Hoover) Dam began. (Las Vegas is quite a bit different now than it was in 1928. Obviously.) Southern California gets the lion's share of Lake Mead; Arizona, New Mexico, even Baja get a bunch, while Las Vegas gets less than a bunch. And to change the allocations would create a huge political quagmire.
Exacerbating the situation is the fact that the watershed of the Colorado River is in a long-term drought. The last time Lake Mead was full was in 1998. Since then, the lake level has dropped 80 feet, erasing 200 miles of shoreline, to its lowest level since 1968. It would take years of above-average precipitation to just get back to "normal."
As far as underground wells are concerned, once upon a time, Las Vegas Valley was underlain by a huge artesian aquifer, which bubbled up to the surface at Big Springs. It was the only oasis in the Mojave Desert for a hundred miles in every direction, which is why Las Vegas (which, in Spanish, means "the Meadows") grew up as it did. But before Lake Mead was completed, the aquifer was Las Vegas' primary source of water, and it was sucked pretty much dry during the 30-40 years its water was mined. So the answer is no, wells are out of the question.
One thing that's happening lately is that northern Arizona agricultural water districts, which are allocated Lake Mead water but aren't using their allocations, are selling credits to Las Vegas. This deal is a little complicated and shadowy, but it looks like Las Vegas is building up a secondary allocation of water for emergency purposes.
Finally, a book called Cadillac Desert, written by Marc Reisner in 1986, describes a possible scenario for importing water to southern Nevada from the icefields of the Canadian Rockies in British Columbia and Alberta, via a pipeline the could run down the valleys of central Idaho and eastern Nevada, proposed by a group called the North American Water and Power Alliance (NAWAPA).
Who knows? With Las Vegas' bankroll and growing political power, such a solution to the water situation isn't so far-fetched.
