Saturday, March 19, 2011

Arizona challenge: Finding water for the next 100 years

Shaun McKinnon in the Arizona Republic: … "The big dams are all built," said Craig Kirkwood, an Arizona State University researcher who has studied water-resource issues. "You can reallocate water. You could augment water supplies, but that would probably be very expensive. Or you could say, 'We're living in the desert,' and just accept that." Still, most water experts agree that if the region continues to grow, its cities will need to find more water - or use less of what is now available - to avoid drawing too deeply on non-renewable groundwater supplies.

…Conservation is the cheapest and most direct way to stretch water resources, but it would require fundamental changes in the way people use water. "When you talk about conservation, people think about shorter showers or maybe reclaiming effluent," Gammage said.
To make a real dent in water use, Phoenix would need to change the entire landscape - the actual landscape, Gammage said. "If you quit watering landscape at the rate we do, just drop the per capita water use in Phoenix to what they use in Tucson. That's about a 40 percent increase in water supply right there."

…But the idea gaining the most attention right now is desalinating ocean water. Officials from SRP, the CAP and the state have met with private investors and officials from Rocky Point, Mexico, about building a desalination plant on that resort city's coast. The plant, built with money from both sides of the border, would produce water for Rocky Point and export the treated water to Arizona and California.

…But the cost would be enormous, as would the energy requirements. Even if those obstacles were overcome, the plant might not produce water for decades. "It might fill a small short-term immediate need, and maybe it's part of the solution mix, but these plants are incredibly expensive," said Brad Udall, director of the University of Colorado's Western Water Assessment. "And if you build them and the drought ends, you have a very expensive plant sitting there waiting for the next drought. It's not a silver bullet."…

The downstream side of the Glen Canyon Dam in Page, Arizona, shot by Brian Thomas, released by the author under the Creative Commons Attribution-Share Alike 3.0 Unported license.

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