When the Rivers Run Dry: Water—The Defining Crisis of the Twenty-First Century.
Pearce, Fred (author). Maps by Hardline Studios UK.
2006. 324p. Beacon Press, hardcover, $26.95 (0-8070-8572-3).

333.91 Water supply

If you take away nothing else from this book, please try to remember the concept of “virtual water.” Economists coined this term to describe the water needed to grow and manufacture products traded globally. It’s about as technical as this book gets. Author Fred Pearce is a journalist who can take complex scientific concepts and put them in terms that readers with perhaps a high school or college education should easily grasp. He writes for the New Scientist magazine, Time and the Boston Globe, among other publications. He has also written several other books on the environment.

As you read some of the horror stories of gross mismanagement that Pearce has assembled here, it might also help for you to know one technical term, “acre-foot.” Pearce uses the term but doesn’t define it and doesn’t mention it in his index. From my days editing and writing a monthly newsletter about ground water, I remembered that an acre-foot is the amount of water it takes to cover an acre of land with a foot of water. An acre-foot contains about 326,000 gallons of water.

As an aside, I have my own horror stories of editing the ground water newsletter, and many other newsletters with no news or even any useful information in them. One person who edited the ground water publication before me described it as “an albatross around the neck of whoever gets stuck with it.” And for all of my troubles, there is almost no evidence on the Web that the publication ever existed. The only proof I could find were a few one-line mentions at various sites. Apparently, it was folded into another enviro pub before being sold to a competitor, traded like an aging shortstop with bad knees.

But that is another story for another time. Suffice it to say that the publisher of that sad little journal could not have cared less whether the water you drink is clean or dirty, or whether you even have any water to drink at all, as long as he could make money off of it.

Not so with Fred Pearce. He shows emotion and uses it to help make the argument that heavy-handed efforts to control nature usually fail, sometimes with horrendous consequences. He is aghast at the ways we humans have treated the rivers that sustain us—choking them off with dams and dykes; bending them to our will with artificial banks that try to redirect their flows or keep them from overflowing; poisoning them with industrial and human waste. In the process, we have destroyed or crippled many of the wetlands and inland seas these rivers used to nourish, as well as the human and animal communities that used to depend on them.

Pearce displays weariness at the ways in which cultures and governments through the ages have tried to fix the mistakes they’ve made in managing water. He cites the example of Los Angeles. The city, and much of the American Southwest, now depends largely on water piped in from the Colorado River. The salt content of the river is increasing. Evaporation is reducing water levels in the reservoirs created by the dams on the Colorado. So what should L.A. do?

In 2003, President Bush suggested that California and other states in the Southwest might turn to Canada to meet the needs of farmers, industries and private homes. For Pearce, the proposal had a familiar ring. In the 1960s, the Los Angeles water department devised a scheme that would have met the city’s needs by importing water first from the Columbia River, and then from several rivers in the Canadian Northwest. Pearce says that proposal is off the table, but water officials in Canada say they have fielded U.S. requests to export small amounts of water from the Great Lakes and elsewhere.

Russia and China have also toyed with the idea of transporting water over vast distances, from wet regions to arid ones, at costs in the hundreds of millions of dollars. In the U.S., the Middle East, and elsewhere, governments have invested in or are considering various techniques to take the salt out of seawater. Again, the costs are high. In addition, the process also consumes a lot of energy. It also leaves behind not only a lot of salt, but also a lot of chemicals used both during and after the desalination process.

And now for the happy ending: We have many low-cost alternatives to transcontinental pipelines and desalination plants at our disposal. Pearce saves this good news for last, after recounting in excruciating detail the slow death of the Aral Sea in Central Asia, the water wars going on within and among nations, and the general folly of dam building. The cheap and simple methods Pearce outlines include many different ways to collect and store rainwater, building ponds to catch dew, and even using nets to collect water from fog.

In the final section of When the Rivers Run Dry, Pearce advises us to “go with the flow,” and stop trying to literally bend rivers to our will. He advocates redesigning urban areas to capture more stormwater runoff. We shouldn’t try to prevent floods, but should look more closely at natural ways to reduce their intensity, such as restoring wetlands.

We should also find ways to use less water for farming, which brings us back to the concept of “virtual water.” It takes more water to grow some crops than others. It takes 65 gallons to grow a pound of potatoes, twice that much to grow a pound of wheat. How much water does it take to grow a pound of rice? Up to 10 times what it takes to grow a pound of wheat—650 gallons. How much water does it take to grow a pound of coffee? 2,650 gallons.

If we keep going in this direction, pretty soon we’ll be talking about those acre-feet again. About a third of the 28 trillion acre-feet of freshwater on Earth is liquid. Most of it is very hard to get to, however, because it is either in dense jungles or in the Arctic zone. For that and many other reasons, we humans must get by on about seven billion acre-feet of river water at any given time.

Remember, I said an acre-foot equals about 326,000 gallons. If each of the 6 billion people or so people on this planet needed about an acre-foot of water a year to meet their needs, we would be in relatively good shape. In fact, Pearce calculates that each of us would now have about 370,000 gallons per year to do with as we see fit. But, as a Westerner, he puts his own annual water consumption at between 400,000 and 530,000 gallons. “I imagine most of the world would like to live as well as I do,” he says. “So we have a problem.”

So we do. And right now, the solution is up in the air. Or maybe on the ground. Or maybe under it.