Plight of Phoenix: how long can the worlds 'least sustainable' city survive? [View all]

[nitpicker]

https://www.theguardian.com/cities/2018/mar/20/phoenix-least-sustainable-city-survive-water

Plight of Phoenix: how long can the world’s 'least sustainable' city survive?


Joanna Walters
Tue 20 Mar 2018 07.00 GMT

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To look around Anthem would be to imagine there is no such thing as a water shortage. But the lush vegetation and ponds do not occur naturally. Phoenix gets less than eight inches of rainfall each year; most of the water supply for central and southern Arizona is pumped from Lake Mead, fed by the Colorado river over 300 miles away. Anthem’s private developer paid a local Native American tribe to lease some of its historic water rights, and pipes its water from the nearby Lake Pleasant reservoir – also filled by the Colorado.

That river is drying up. This winter, snow in the Rocky Mountains, which feeds the Colorado, was 70% lower than average. Last month, the US government calculated that two thirds of Arizona is currently facing severe to extreme drought; last summer 50 flights were grounded at Phoenix airport because the heat – which hit 47C (116F) – made the air too thin to take off safely. The “heat island” effect keeps temperatures in Phoenix above 37C (98F) at night in summer.

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What these cities want is water. The Phoenix area draws from groundwater, from small rivers to the east, and from the mighty Colorado. The Hoover Dam holds much of the Colorado’s flow in the vast Lake Mead reservoir, but the river itself is sorely depleted. That water has now dropped to within a few feet of levels that California, Nevada and Arizona, which all rely on it, count as official shortages. Lake Powell, the reservoir at the other end of the Grand Canyon, similarly averages half its historic levels.

And yet despite the federal Bureau of Reclamation reporting in 2012 that droughts of five or more years would happen every decade over the next 50 years, greater Phoenix has not declared any water restrictions. Nor has the state government decided its official drought contingency proposal.
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