(Roughly) Daily

Between AD 1275 and 1300, the Anasazi, a civilization that had thrived in the canyonlands of the Four Corners area of the American Southwest for a thousand years, simply vanished, abandoning their urban centers, their irrigated lands, their sacred enclosures. Their descendants, the Hopi and Zuni, tell of a time of drought, the end of the rains. Without food in the desert, one can live for a fortnight; without water, perhaps a day. The collapse of the Anasazi occurred in a single generation.

The drought in the American Southwest has now entered its twenty-third year– and as Wade Davis explains in an excerpt from his book River Notes: Drought and the Twilight of the American West, the historic drought of the last couple of decades is threatening the Colorado River (on which 40 million Americans and 5.5 million acres of agriculture depend) and raising that specter again…

… We are today in the third decade of a drought that, despite heavy snowpacks in California and parts of the mountain west, remains unrelenting.

Over the last century, the river’s flow has averaged roughly 15 million acre-feet a year, far less than the 17.5 million acre-feet that planners anticipated when water rights were apportioned to the seven states of the basin — Wyoming, Colorado, Utah, New Mexico, Nevada, Arizona, and California — in 1922. In that year, the population of Arizona was roughly 350,000, that of Nevada a mere 80,000. Between 2000 and 2022, the flow of the river dropped to an average of 12 million acre-feet; over the last three years the annual flow has been but 10 million acre-feet. Even as the volume of water coming down the Colorado has dramatically declined, the seven states of the basin continue to clamor for allotments based on flawed assessments established nearly a century ago, exerting rights to consume what the river cannot provide.

As a result, during a drought of historic severity, water consumption has consistently surpassed the total natural flow of the river; altogether since 2000, water use has out-stripped supply by 33.6-million acre-feet (an acre-foot is 325,851 gallons). To meet demand, water has been diverted from the major reservoirs. Lake Mead, last full in 1983, is today down to 28 percent of capacity, 1,040 feet above sea level, the lowest it has been since the floodgates closed in the 1930s. If the reservoir drops below 950 feet, the Hoover Dam will no longer generate hydroelectric power. At 895 feet, the reservoir becomes a deadpool; water can no longer pass through the dam. The river downstream ceases to exist.

The situation at Lake Powell is equally grim. Its capacity is now down to 22 percent. In February 2023, the reservoir dropped to 3,522 feet above sea level, the lowest since the Glen Canyon Dam became operational in 1963. Should the water level drop another 32 feet, which can readily occur in a year, it will no longer be possible to generate electricity that today powers and cools the homes and businesses of 4.5 million citizens. A power outage in Phoenix, coinciding with a two-day heat wave, could result in half the population — 800,000 or more — seeking emergency care in hospitals set up to handle but 3,000 patients. An estimated 12,800 would die. At 3,370 feet, Lake Powell will reach deadpool. The Glen Canyon Dam will be but a concrete plug. Water will cease to flow, cutting off the drinking supply of well over 25 million Americans, including most of those living in Phoenix, Las Vegas, Tucson, and much of the Los Angeles basin.

…ordinary American families are already experiencing shortages that would have been unthinkable in 2006. For decades, the Arizona city of Scottsdale has provided the Rio Verde Foothills, a community of two thousand homes, with access to its municipal water supply, sourced from the Colorado. On January 1, 2023, this supply was cut, a decision made by a city facing its own crisis, leaving the people of Rio Verde no option but to buy water by the truckload at prices that tripled overnight. Those who dug wells discovered that, after years of drought, the water table had fallen by hundreds of feet. Residents have turned to using paper plates and urinating outside, even while coping with monthly water bills as costly as their mortgage payments.

Cities such as Las Vegas have implemented strict conservation measures, banning ornamental grass, limiting water deliveries to golf courses, reducing the size of swimming pools, using recycled water whenever possible. Yet despite these efforts, Las Vegas still uses twice as much water as the average US consumption. Hedging its bets, the city is building a three-mile-long tunnel that will come up at the bottom of Lake Mead, a $1.4-billion drain to ensure that if the reservoir ever runs dry, Las Vegas will get the last drop.

In the end, what Las Vegas and other cities do hardly matters, for the elephant in the room remains agriculture. Fully 80 percent of the water drawn from the Colorado goes to irrigating some 5.5 million acres, most of which is used to grow alfalfa and grass to feed cattle, and not only in the United States. Alfalfa grown in Arizona is exported by the ton to fatten cattle in Asia and the Middle East…

Water, water– not a drop to drink? “The Climate Crisis Could Mean the Twilight of the American West,” from @authorwadedavis in @RollingStone. Eminently worth reading in full.

* Sylvia Earle

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As we dowse, we might spare a thought for Bjørn Helland-Hansen; he died on this date in 1957. A pioneering oceanographer, his studies of the physical structure and dynamics of the oceans and their interactions with the atmosphere were instrumental in transforming oceanography from a science that was mainly descriptive to one based on the principles of physics and chemistry.

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