http://news.moneycentral.msn.com/provider/providerarticle.aspx?feed=FT&Date=20070222&ID=6522582

Scientists warn of US water shortages

Severe water shortages are likely to constrain future expansion of population, agriculture and industry in the south-western US, the fastest growing part of the country, according to a report by the National Academy of Sciences.

The study focused on the Colorado River, which supplies water to about 25m people and millions of acres of farmland in seven states. It concluded that droughts would be longer and more serious than had been previously assumed.............

.........."Severe drought conditions have affected much of the region since the late 1990s, with 2002 and 2004 being among the 10 driest years on record in the upper basin states of Colorado, New Mexico, Utah and Wyoming," the report says. "Water storage in the basin's reservoirs dropped sharply during this period due to low streamflows; for example, 2002 water year flows into Lake Powell were roughly 25 per cent of average."

Meanwhile the population is growing rapidly. Arizona saw a 40 per cent rise during the 1990s, while Colorado's population grew by 30 per cent. In spite of successful conservation efforts, urban water use in the region has increased significantly along with the growth in population. Consumption in Clark County, Nevada, which includes Las Vegas, doubled between 1985 and 2000.

There is limited scope for satisfying the cities' and suburbs' thirst by reducing agricultural irrigation, the NAS says. It urges federal, state and local governments to undertake a "comprehensive, action-orientated study" of water practices in the Colorado basin and devise a strategy for coping with long-term drought.............