I just returned from a brief family holiday in Las Vegas, where a surprising number of people spend Christmas.  While strolling along the Strip Monday taking in the sights, I was intrigued by the abundant use of water in the landscaping decorating the casino hotels.  Isn't this the desert? I wondered.  And isn't southern Nevada in the grip of a long-term drought?  

Yes, and yes, are the answers.  Las Vegas gets its water from the Colorado River, which is enduring its worst drought on record.  Lake Mead, the reservoir for the region, is about 100 feet lower than it was in 2000.  The Southern Nevada Water Authority has imposed water-use restrictions and promotes water efficiency and "water-smart" landscaping to ease the region's thirst.

Outside the Venetian Hotel, with its faux canals, I saw plaques explaining that the water features there are in compliance with official drought restrictions.  The ornate fountains were dripping rather than spraying, and the pool-clear water on which the gondolas floated appeared only a few feet deep - perhaps another sign of restraint.  I didn't see any signs about water-use restrictions outside the nearby Mirage, with its gushing waterfall and big, manmade lake.

Extravagant as the casinos' water use seems, it's apparently only a small fraction of what's consumed in Vegas, one of the fastest growing metropolitan areas in the country.  The population increases by nearly 70,000 residents a year in an area that receives only about 3.5 inches of rain annually.  Residential development, particularly sprinkling or irrigating lawns, gobbles up far more water. 

Conservation efforts have paid off, as consumptive water use has declined significantly in the region.  But with no letup of the drought in sight, some officials are pushing a plan to ease reliance on the Colorado by pumping water from underground aquifers to the north.  Only problem is, ranchers and farmers rely on those aquifers for irrigation, setting up a tug-of-war over the precious resource between people and agriculture.

A recent study by the Pacific Institute found, though, that while Las Vegas has taken steps to use water more efficiently, it's falling behind other Western cities in cutting wasteful uses of water.  Greater conservation efforts could defer or eliminate the need for new water supplies.  

Growth continues apace in Las Vegas, meanwhile.  My hotel TV devoted one entire channel to a glowing promotion for the new CityCenter project, a 76-acre "city within a city" being developed by MGM Mirage.  The $7.4 billion project is being designed to meet LEED certification by the U.S. Green Building Council.   So it goes.