Salt Water Foreseen As Vital to Southwest
By Tony Davis, The Arizona Daily Star, Tucson
Jun. 25–PHOENIX — It’s 2048 in the Sonoran Desert. Do you know where your water will come from?
Thomas McCann, a top official with the agency that runs the Central Arizona Project, laid out a vision in response to that question Tuesday at a conference on the future of the Colorado River:
–Three desalination plants are on line by that year to increase the supply of CAP water flowing to Phoenix and Tucson. One is removing salt from seawater along the Gulf of California in the Mexican state of Sonora, and its booty is shared by Arizona, California, Nevada and Mexico.
–Two others are treating salt-laden groundwater in the areas of Buckeye and Gila Bend.
–A huge nuclear power plant is humming along the Gulf of California in Sonora, producing 600 megawatts of power to provide the juice for the adjoining seawater desalination plant.
–Construction is under way to expand the size of the concrete CAP canal running from the Colorado River to Tucson to deliver up to 2.2 million acre-feet of water a year. An acre-foot — 325,851 gallons — will supply enough water for two to three families for a year. Currently, the aqueduct can deliver 1.8 million acre-feet.
–The Colorado River, over- allocated by 1.5 million acre-feet a year to the seven river-basin states and Mexico, has been boosted in supply by about one-third that much through cloud seeding and other forms of weather modification.
McCann, resource-planning manager for the three-county Central Arizona Water Conservation District, which oversees the CAP, was looking at how the state could furnish water to support a 2048 population of 11.5 million in Pima, Pinal and Maricopa counties, compared with less than 6 million today.
It was a controversial vision, with many conservationists, led by Sierra Club members and others in the crowd of more than 300, attacking it as a fantasy. They questioned whether the money would be available for such a large number of projects and whether the increased energy use for desalination would make it economically and environmentally unfeasible.
The critics also said leaders should concentrate on conserving water rather than simply searching for more water to serve population growth.
And they questioned whether solutions would ever be found to handle the waste produced by the nuclear plant.
Bob Cook, a planner and economist active in Sustainable Tucson, an environmental group, said the presentation ignored the rising costs of energy that already are causing crises in the airline and trucking industries.
“People will migrate to where the water is,” Cook said. “There’s no real analysis here of the factors behind our population growth — cheap water, cheap land and cheap energy — and how they are changing.”
It’s good that CAP officials are looking that far ahead, but “I didn’t get a sense of the problems to be overcome, so we can do all the things to get us where we need to be,” said University of Arizona professor Karl Flessa, head of the geosciences department.
But the CAP’s top official predicted that at least some of the ideas in McCann’s vision will come to pass, although the agency has no formal blueprint for turning them into reality.
“Every element of what Tom talked about will be addressed by 2048, although I’m not sure how large of a scale,” CAP General Manager Sid Wilson said to the crowd immediately after McCann’s talk. “I’m absolutely sure he hit the right buttons.”
The ideas also had many supporters in the audience.
One was Sahuarita-area pecan farmer Richard Walden, whose father, Keith Walden, pushed for congressional approval of the CAP 40 years ago.
Walden said it’s realistic to start looking at desalination now, given that water projects are something that needs planning 40 years in advance.
“We built CAP and started getting water from it (nearly) 25 years ago, and for a while we had more water than we needed,” said Walden, of Farmers Investment Co. “Years later, we have to start looking for more.”
The CAP has four Pima County representatives on its board and runs the day-to-day operations of the country’s largest water project.
Educators, activists, economists, planners, consultants and researchers came to the Colorado River conference from at least 45 cities and towns around the state, including a substantial contingent from Tucson. The conference, held at the Arizona Biltmore, was sponsored by the University of Arizona Water Resources Research Center and a host of other parties.
The prospect of desalination has in recent years gained more currency among water leaders in Arizona and the West as they try to deal with the twin pressures of population growth and drought that have kept flows in the river below normal for seven of the past 10 years.
State and Mexican officials have started preliminary talks on possibly building a plant along the Gulf of California.
The CAP agency has hired a consultant to explore the feasibility of desalinating salt-laden groundwater inside Arizona.
After his speech, McCann said his ideas were based on population projections for Pima, Maricopa and Pinal counties for the late 2040s. His vision also assumed that people would reduce their water use by about 5 percent per person by then, that local governments increase the amount of sewage water captured from homes by 5 percent, and that they increase the re-use of wastewater by the same amount.
He also assumed that the river would have minor shortages of water in 2018-19 and in 2025, but nothing affecting urban users until a major five-year shortage hits in the 2030s. He acknowledged, however, that those projections were based on simple speculation.
DID YOU KNOW: The Central Arizona Project is a large system of canals that sends Colorado River water 336 miles from Lake Havasu City to Tucson.
The system provides nearly 3 million acre-feet of water annually for farming and municipalities in the Phoenix and Tucson regions. It also supplies 12 Indian tribes.
Construction of the project took 20 years and cost $4 billion. While construction began in 1973, planning and lobbying for the project began more than 50 years earlier.
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Copyright (c) 2008, The Arizona Daily Star, Tucson
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