Rivers Running Dry

Remember last fall when the city of Atlanta was said to be just weeks away from running dry? It's getting warm in the Southeast again, and Lake Lanier, which supplies water to parts of three states (Georgia, Alabama and Florida) is still down 13 feet from where it should be this time of year. Part of the fault lies with the Army Corps of Engineers, which regulates the outflow from the lake down the Chattahoochee River and sent billions of gallons into the Atlantic to protect the endangered sturgeon population, based on a plan that had not been updated since 1989. It also lost an additional 22 billion gallons, owing to a broken gauge. But the bigger problem is the lack of a coherent policy for collecting, conserving and using fresh water there, or in much of the rest of the United States, or, for that matter, the world.

Environmentalists have long warned about the crisis in nonrenewable resources, such as oil. Water, of course, is the ultimate renewable resource—it falls from the sky—and therefore has been of less concern. But where and when rain falls, and what happens to it after it hits the ground, are crucial in determining the health and prosperity of human societies, says Jeffrey Sachs, director of Columbia University's Earth Institute and special adviser on environmental policy to an impressive number of foreign leaders including U.N. Secretary-General Ban Ki-moon, various governments, even rock stars (Bono is a friend). In his new book, "Common Wealth: Economics for a Crowded Planet," Sachs describes the worldwide water shortage as "one of our most daunting challenges." A six-year drought in Australia has virtually wiped out that country's rice crop, contributing to food riots in countries from Haiti to Indonesia this month. "Much of the world is already in water crisis," Sachs says. "And that crisis will only continue to grow."

Economists and geologists have identified one culprit in the water-management problem, a mind-set they call "stationarity"—the belief that natural systems fluctuate within a narrow, predictable range, even over long periods. "Stationarity is dead," says Chris Milly, author of a recent Science paper on the issue—done in by population growth, climate change and economic development. But the effect of the stationarity fallacy has been to leave water policy in the hands of relatively shortsighted municipal and state authorities, while the federal government has been looking the other way. This problem is especially acute in the Southwest. In February, one study found that Lake Mead, which supplies a stretch of the Colorado River that snakes through northern Arizona, could run dry in a decade or so, if current water use rates persist. Each year, the study found, the lake loses enough water for 8 million people. "Just like we have peak oil, we have peak water, and when it comes to the Colorado River, we are at that peak," says Tim Barnett, a scientist at the Scripps Institution of Oceanography in La Jolla, Calif., and coauthor of the Mead study. "The whole West is under the gun here." And while the threat may be less immediate in regions such as the Northeast, less water in one area can mean less food and more illness in another.

Sachs poses several technical and economic strategies that may help avert disaster. And unlike the ultrahigh-tech fixes to the energy crisis, many of these are relatively uncomplicated, low-cost and already proved. For example, digging ponds or underground receptacles to store rainwater for irrigation during dry spells has increased crop yields for some Chinese farmers by 20 to 50 percent. Cities such as Las Vegas are recycling wastewater. And a handful of states around the country, and countries around the world, have begun manually replenishing natural underground aquifers with treated wastewater or storm runoff, hoping to protect against droughts.

Sachs advocates using a combination of these and other similar strategies, depending on the needs of each region. In combination with economic incentives, he says, they can lessen the severity of the water problem without exceptional cost to the environment or the economy.

But implementing any of these takes planning, organization and leadership. "Politicians don't want to bear the costs of adjustment," Sachs says. "So they ignore the problem and continue the same unsustainable practices." There is no single solution. Governments, industries and individuals will collaborate or suffer the consequences. However responsibility is divided, we can no longer take our most renewable resource for granted.

© 2008