Drying of West brings new era of water wars

The Press Democrat via the Economist: …The main reason why Lake Mead, currently only 40 percent full, has been getting emptier is a decade-long drought. Whether this is a cyclical and normal event, or an early sign of climate change, is unclear. But even if the drought ends, most scientists think global warming will cause flows on the Colorado River to decrease by 10 percent to 30 percent in the next half-century, says Douglas Kenney, the director of a water policy program at the University of Colorado Law School.

The other reason, says Kenney, is the rapidly increasing demand for the river's water. The Colorado provides much or most of the water for many cities and farms in seven states — Colorado, Wyoming, Utah, New Mexico, Nevada, Arizona and California — before it peters out in the sands of Mexico.

…That is why Las Vegas is a canary in the mine shaft, as Pat Mulroy, the boss of the Southern Nevada Water Authority, puts it. The Las Vegas valley gets its water through two long channels drilled through the rock. The first taps the lake at 1,050 feet above sea level, the second at 1,000 feet. Lake Mead's water level is now near its record low, at 1,086 feet. Within a few years, it could leave Las Vegas' first intake, or even both, dry.

The threat to Sin City is a good example of the four dimensions — physical, legal, political and cultural — of water in the West. For the physical, the standard response is to summon the engineers. Mulroy already has them digging a third intake at 890 feet. Given the weight of the water on top, this is fiendishly difficult, and it will not be ready until 2014. Mulroy also wants to pipe ground water from the rural and wetter northern counties of Nevada to Las Vegas, but that has caused a vicious row.

Another response is to call in the lawyers. This was the preferred approach a century ago, in the era of the “water wars.” Starting with the Colorado River Compact of 1922 and continuing with statutes, a treaty with Mexico and case law until the 1960s, a truce was achieved. Called the Law of the River, the resulting regime determines who along the river has what right to how much water....

Lake Mead, bathtub ring, this time by Cmpxchg8b, who has released the image into the public domain