The boat launch jutted out into thin air. 30 meters below, a pair of coyotes slunk through the weeds. An old fishing boat lay half buried in the dry earth. A road sign read like a bizarre joke: 'No fishing in harbour'. You would need to have a very long cast to fish from this spot where there was once water. Today, the desert reigns.

Lake Mead is one of the main reservoir lakes on the Colorado River system. It is right beside the Hoover Dam, just a 30 minute drive from Las Vegas. The region is entering its eighth year of drought. The lake is at 49% capacity. A visible 'bathtub' ring clearly marks a 30-meter drop on the brown and ochre cliffs which ring the blue waters of this man made oasis.

Scientists call what's happening in the Lake Mead area and throughout much of the south west US an example of the 'other water problem' arising from global warming. Yes, sea levels are rising and are forecast to rise further. But dry parts of the world are experiencing longer periods of drought.

Pat Mulroy is the General Manager of the Southern Nevada Water Authority. She's one of the most powerful public officials in what has been the fastest growing region of the US for much of the past 20 years. In her Las Vegas office is a carved sculpture of the head of a native American woman. The inscription at its base aptly reads: 'Praying for rain'.

The native American's should know. The Anasazi were a tribe who once lived in this region and developed an advanced desert society. They are a puzzle to archaeologists as they 'disappeared' sometime around the 13th century. Some experts believe they may have been forced southwards by a long-lasting drought.

The booming two million population of Las Vegas is not about to move but according to Ms Mulroy, their way of life is and already has begun to change radically.

She believes it's academic whether the eight-year drought in the region today is being caused by climate change. In stark terms she declares that the city and the wider region is fast 'coming up against the wall' where a whole mindset is going to have to change. By 2010, if things remain as they are, the Hoover Dam will cease producing electricity.

The Authority she runs is looking at all options to source water. That includes everything from desalination plants on the west coast to sourcing natural springs deep in the desert.

grassIt has also spent $90m buying grass off people. That's right, if you sell the city your front lawn, they will pay you and return it to more 'suitable' desert vegetation. And if you opt to keep your lawn, you will pay dearly to water it as the city's supply is strictly metered.

In fact the change in mindset extends to that unique slice of Americana in the desert known as the Vegas Strip. Beneath each of those monstrous hotel-casinos are state-of-the-art water treatment plants. Each hotel is double plumbed to capture leaks ensuring that 100% of their 'grey water' is recycled. Best stick to the cocktails when thirsty.

The seven states which draw their water supply from the Colorado river basin have just this week signed an agreement on how to allocate water from the system if this drought worsens. It's billed as a landmark agreement but it won't refill the dry cliff walls of Lake Mead.

- Robert Shortt

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