Monday, May 11, 2009 | Back in 2006, Tim Barnett sketched a grim future when asked about the impact climate change would have on San Diego’s water supply.

The warming climate, Barnett said then, would bring water cops, limits on lawn watering and trouble for salmon in the Sacramento River, one of San Diego’s major water sources.

“I believe the environment will eat it first,” said Barnett, a marine physicist at Scripps Institution of Oceanography. “Do you want to go thirsty or kill off the last salmon in the Sacramento River?”

Three years later, San Diego has adopted specific lawn-watering days, which start June 1. The city will spend $756,000 to hire 10 water cops. The salmon population on the Sacramento River plummeted to historic lows last year, prompting an unprecedented closure of commercial salmon fishing from the U.S.-Mexico border to Oregon.

The drier future that Barnett predicted is becoming reality. And today, Barnett is warning of worse things to come. As the climate continues to warm, the Southwest, from San Diego and Los Angeles to Las Vegas and Phoenix, will have to cope with less water, he said.

Barnett projects that in 40 years, the warming climate will reduce runoff into the Colorado River so much that shortages will be more common than surpluses. The seven states that rely on the Colorado, a major source of San Diego’s water, will have to handle shortages in as much as nine out of every 10 years. Shortages could hit in four out of every 10 years by 2025.

“Our water future is fraught with peril,” Barnett said.

The Colorado River is the lifeblood of the Southwest. It supplies 27 million people in the United States and Mexico. It irrigates 3 million acres of crops. Its water has been warred over and litigated for decades. And while the seven states that rely on the Colorado have entered a time of relative peace and cooperation, Barnett’s projections signal that a potentially litigious future lies ahead.

The Colorado’s annual flows were divvied up among California, Arizona, Nevada, Colorado, New Mexico, Utah and Wyoming in 1922. Those average flows were based on one of the wettest centuries in the last millennium. Without changes in how much water each state is allowed to pull out of the river each year, shortfalls “could become systematic,” Barnett and his colleague, David Pierce, wrote in their most recent report.

Lake Mead, a measure of the Colorado’s robustness, today sits at 1,099 feet of elevation behind the Hoover Dam. That’s the lowest it’s been since 1965. More water is pulled out of the vital reservoir each year than goes in.

The seven states that rely on the Colorado signed an agreement in 2007 that dictates how they’ll divide shortages. For now, Arizona and Nevada will bear the brunt of initial cutbacks, which begin when Lake Mead drops to 1,075 feet. (It’s projected to drop to 1,091 feet by the end of summer.) If the reservoir drops to 1,025 feet, the states are scheduled to renegotiate. That could be contentious.

Barnett takes a sour view of the future negotiations about the river, which he said will be inevitable.

“There will be a lot of scrambling and meeting and discussions — and then the lawsuits will hit,” Barnett said. “There we’ll sit for a couple of decades. The river may decide the lawsuits before any judge does.”

Barnett’s work has attracted a flood of media attention in the last two years. He is to Western water supplies what Nouriel Rubini, the New York University professor dubbed “Dr. Doom”, is to the financial markets. One Arizona newspaper annointed Barnett the Southwest’s Cassandra, the cursed Greek prophetess who had the ability to see the future but was ignored.

Barnett is nothing if not blunt, describing a bleak future in matter-of-fact terms.

“These things all seem to have a break point around 2030,” he said. “It’s going to be interesting. We’re not going to turn around and solve the global warming problem between now and 2030. Changing the industrial base of the country in 20 years? I don’t think there’s any way that’s going to happen. You’re in deep shit.”

He paused.

“Deep trouble would be a better quote.”

The 70-year-old Long Beach native has seven grandchildren. Though he technically retired in 1998, he said they’ve been his motivation to continue researching part-time. “I do not like the kind of world they’re going to live in,” he said.

Brad Udall, director of the Western Water Assessment at the University of Colorado, said Barnett’s work has been part of an important body of scientific research that’s altered the way water managers view the impact of climate change on water supplies. As the West warms, the amount of water going into the Colorado is projected to drop because more water will evaporate, plants will demand more and the climate will grow more arid.

In 2004, Udall gave a presentation to a group of water managers about climate change — “to absolute dirty looks,” he said. By 2007, he said, water managers were convening seminars on climate change and water. “What’s happened in the next five years is miraculous,” Udall said. “They get it.”

Water managers have criticized some of Barnett’s work, particularly a 2008 report entitled “When will Lake Mead go dry?” that said the massive reservoir near Las Vegas had a 10 percent chance of running dry by 2014 and a 50 percent chance by 2021.

Terry Fulp, deputy regional director of the U.S. Bureau of Reclamation, which manages the Colorado, said the paper had a catchy title, but had ignored important inputs, such as the 8 percent of flows that enter the river below Lake Powell, the other key reservoir on the Colorado. It similarly didn’t acknowledge that water managers would not allow current consumption to continue if Lake Mead kept dropping.

“When it appeared, it gave a lot of folks the feeling that no one in the basin knew there was this water supply imbalance,” Fulp said. “The assumption was that everyone was asleep at the wheel. That wasn’t at all the case. Water managers are not asleep at the wheel.”

Barnett admitted the title may have been too provocative. “Everybody jumped on our ass about that,” he said. He tried to address the other concerns in a follow-up report published in April that examined whether current deliveries from the Colorado would be sustainable in the future given climate change. The answer: No. The warmer it gets, the less reliable the river becomes.

But Barnett doesn’t shy away from provocation. He said the Southwest’s troubled water future is a political problem that no one wants to touch.

“The thing that bothers me most is the development going on,” he said. “Phoenix is the fourth-largest city in the country and it’s in the goddamn desert. The politicians so far have not wanted any of this. The congress people say it’s a local problem. The mayors say we can’t tell people not to live here. Once you get above my level, it’s politics, politics and more politics.”

Barnett plans to officially retire from Scripps this fall. He said scientific research is a young man’s quest, that he’s done what he can.

“I think I’ve made the point,” he said. “We’ve called out a serious problem. The probability that it will happen is very high. The solution is outside academia.”

Please contact Rob Davis directly at with your thoughts, ideas, personal stories or tips. Or set the tone of the debate with a letter to the editor.

Dagny Salas was web editor at Voice of San Diego from 2010 to 2013. She was an investigative fellow at VOSD from 2009 to 2010.

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