The next time you fly into a parched, western sprawl such as Phoenix, glance down at the amorphous blots of green and the splattering of aqua blue rectangles. Squint into the blinding sun and behold the glories of irrigation.
But along with the golf courses and swimming pools made possible by a seemingly endless flow of H2O came people — and lots of them. Between 1920 and 2000, the seven states that share the Colorado River grew from 5.7 million to almost 50 million people. Peter Gleick, co-founder and president of the Pacific Institute for Studies in Development, Environment, and Security, says 23 million more people will be added by 2030 amid mounting evidence that our current practices in water use and management are unsustainable.
As Gleick points out in "Roadmap for Sustainable Water Resources in Southwestern North America," it's not land, energy, mining or climate, that is going to be most difficult issue to address in the Western United States — it's water.
So given the International Panel on Climate Change's warnings about anthropogenic global warming and a well-documented expanding drought, residents of the West are not just living on borrowed water, they're also living on borrowed time.
Glen MacDonald is the director of the UCLA Institute of the Environment and Sustainability and an international expert on the effects of climate change and drought. He says that the best climate models that exist predict the 21st century is likely to be increasingly arid if greenhouse gases increase. But discounting that, MacDonald says we can expect more severe and longer-lasting droughts than occurred in the 20th century.
"It all adds up to the fact that we have to do some very, very serious long-range water resource planning," he says.
More on that later. But first, how do predictions offered in Mark Reisner's quarter-century-old call to action, Cadillac Desert, stack up?
John Sabo, an Arizona State University professor specializing in risk assessment and statistical issues in ecology says there was only one major result inconsistent with Reisner's thinking: the infilling of reservoirs with sediment. Sabo thought, like Reisner, that this sediment would ultimately lead to water scarcity. But as he writes, "a complete loss of storage function ... will not likely occur for most large reservoirs in the foreseeable future." (And many smaller reservoirs are being dismantled for habitat restoration or seismic safety anyway.)
As for the effect of "salt loads" from repeated applications of irrigation degrading cropland, Sabo's study found that fruit and vegetable output and revenue have been disproportionately affected in the West with annual losses of $2.8 billion compared to $267 million in the East.
This is the second part of a three-part series looking at the legacy of the groundbreaking story of water use and abuse in the Western United States, "Cadillac Desert":
Part I — Greening the Desert? Not So Fast!
Part II — Water Shortages Threaten the American West Lifestyle
Which brings us to the battle over water between farmers and residential users. Currently irrigated agriculture sucks up 80 percent of available water, leaving the rest for residential, commercial and industrial use. While urban areas are taking their water use — and abuse — more seriously, as California's 2020 Water Conservation Plan attests to, more and more urban areas and municipalities look toward farmers to help pick up the slack. Some have suggested crop shifting or "growing local" to remedy the situation.
"Changing crop types is really a sensitive issue for farmers," Gleick says. "They don't want to be told what to grow by some academic or some think-tank person who doesn't have his hands dirty. I respect that."
That said, in the last decade, Phoenix crossed the point where more water is being used for domestic than agricultural uses. Though MacDonald concedes this is an anomaly, with increasing populations and demands for food it's more likely, he believes, that pressure will build to shift water away from agriculture.
"If we say, 'OK, we are generating much more GDP from urban/suburban and industrial uses rather than agriculture. Let's shunt it out of ag,' what will then be the long-term sustainability costs of doing that? And that worries me."
Luckily, MacDonald says there is a buffer: "A lot of our water being consumed in today's Southwestern cities and suburbs is for landscaping and pools — 70 percent in some places. It's not like we're suddenly gonna have no tap water."
But far more important than xeriscaping or other water-saving measures is the politics of climate change. The federal climate bill failed to pass because of the belief that it's too expensive to decrease CO2 emissions.
MacDonald's response? "Take a look at maps of projected increasing temps and aridity going into 21st century. You'll see that the Southwest is a real bull's eye, meaning that the region is drying out at a remarkable magnitude compared to other parts of the country. The real question is can we afford NOT to work at mitigation?"
As Gleick points out, our water-management strategies and infrastructure were conceived under the mistaken assumption that the climate of the future will mimic that of the past.
"That means we need to start thinking about tomorrow's climate in planning how we manage our water," he says. "We have a limited window of opportunity here before things start to get really bad."
In the third part of this series, various entities have made efforts to reverse what once seemed inevitable.