A Western drought that began in 1999 has continued after the respite of a couple of wet years that now feel like a cruel tease. But this time people in the driest states are not just scanning the skies and hoping for meteorological rescue.
About $2.5 billion in water projects are planned or under way in four states, the biggest expansion in the West's quest for water in decades. Among them is a proposed 280-mile pipeline that would direct water to Las Vegas from northern Nevada. A proposed reservoir just north of the California-Mexico border would correct an inefficient delivery system that lets excess water pass to Mexico.
In Yuma, Ariz., federal officials have restarted a desalination plant, long seen as a white elephant from a bygone era, partly in the hope of purifying underground water for neighboring towns.
The scramble is driven by the realities of population growth, political pressure and the hard truth that the Colorado River, a 1,400-mile-long lifeline for more than 20 million people in seven states, is providing much less water.
According to some projections, mountain snows that feed the river will melt faster and evaporate more with rising global temperatures, providing stress to the waterway even without drought. This year, the spring runoff is expected to be about half its long-term average.
Everywhere in the West, as officials search for water to fill current and future needs, tempers are flaring among competing users, rivalries are hardening and states are waging legal fights.
In one acrimonious dispute, Montana filed a federal lawsuit in February accusing Wyoming of taking more than its share of water from the Tongue and Powder rivers, tributaries of the Yellowstone River that supply water for farms and wells in both states.
Preparing for worst-case outcomes, the seven states that draw water from the Colorado River - Arizona, California, Colorado, Nevada, New Mexico, Utah and Wyoming - and the U.S. Bureau of Reclamation, which manages the river, are considering plans that lay out what to do if the river cannot meet the demand - a prospect that some experts say will occur in about five years.
"What you are hearing about global warming, explosive growth - combined with a real push to set aside extra water for environmental purposes - means you got a perfect situation for a major tug of war," said Sid Wilson, general manager of the Central Arizona Project, which brings Colorado River water to the Phoenix area.
New scientific evidence suggests that periodic long, severe droughts have become the norm in the Colorado River basin, undermining calculations of how much water the river can be expected to provide and intensifying pressures to find new solutions.