The Colorado River carries some 38,000 MCM/year of water 2,330 kilometers, from the Rocky Mountains, just west of the Continental Divide, south into the Gulf of California. Along the way, it carves out the Grand Canyon, and one of its tributaries, the San Juan River, goes down into Chaco Canyon, once center of the Anasazi civilization. Today, Chaco Canyon is a national park and a world heritage site, “[r]emarkable for its monumental public and ceremonial buildings, engineering projects, astronomy, artistic achievements, and distinctive architecture, it served as a hub of ceremony, trade, and administration for the prehistoric Four Corners area for 400 years—unlike anything before or since.”¹ But, by the 1200s, Chaco Canyon was deserted, and the Anasazi civilization collapsed. The Pueblo people of today—including the Hopi, Zuni, Taos and Acoma—are the descendants of those Anasazi who created a more sustainable, less complex way of life. What was the crisis that brought down the Anasazi, though? There are, of course, many possibilites, and the ultimate cause is always the diminishing returns on complexity, but the proximate cause may very well have been water.

The cohesive system that characterized Chaco Canyon began to break down about 1140, perhaps in response to a severe region-wide drought, to water management that led to arroyo-cutting, and to deforestation.²

Today, the Colorado no longer reaches the Gulf of California. Overuse has left its lower reaches dessicated; it is entirely used up before it reaches the sea. It takes little imagination to wonder why: the river provides the primary source of water for the entire American southwest. Ongoing feuds between the several states that use the river have led to the looming possibility of federal intervention.

The states insist they are making progress on a plan aimed at avoiding shortages and don’t intend to let the government take over. Representatives of the seven states have met several times and believe they can move quickly now.

“People ask why we don’t already have a plan,” said Sid Wilson, general manager of the Central Arizona Project, which carries Colorado River water to Phoenix and other cities. “Well, all the information the states have relied on is based on about 100 years of record, and now we’re in a drought more severe than anything in those 100 years would indicate.”

“We always thought we wouldn’t have to worry about a shortage for 20 or 30 years,” Wilson added. “It’s a whole new ballgame.”

Hydrologists say that if the drought persists and runoff into the Colorado continues at such low levels, Lake Powell could virtually dry up by the end of 2007. That would pit the seven states against each other in a bitter water war.³

These concerns are not new, either. As early as 1898, California’s use of the Colorado River for Los Angeles sparked a series of confrontations explicitly called “California’s Water Wars,” leading right into the present day.⁴

The energy crisis temporarily may have taken center stage, but is seen by state policymakers as a harbinger of tomorrow’s dry spells if no corrective action is taken. California’s population is growing rapidly, yet the state will have to reduce its dependence on Colorado River water by 20 percent. With water shortages looming, managing California’s water resources has taken on a new urgency.⁵

Nor is the struggle over the Colorado simply domestic within the United States. Randal Archibold suggests that the current border disputes between the United States and Mexico may have a great deal to do with precisely this shortage.

To slake the ever-growing thirst of San Diego, 100 miles to the west, the United States has a plan to replace a 23-mile segment of the earthen All-American Canal, which the federal government owns and the Colorado River feeds, with a concrete-lined parallel trough.

The $225 million project would send more water to San Diego, by cutting off billions of leaked gallons—enough for 112,000 households a year—that have helped irrigate Mexican farms since the 1940’s.

But Mexican farmers and their advocates say the lined canal would effectively turn off the spigot for 25,000 people, including 400 farmers whose wells rely on the seepage that has helped turn the powdery fields east of Mexicali, an industrial city, into one of the biggest Mexican producers of onions, alfalfa, asparagus, squash and other crops.⁶

Like the Anasazi, the United States faces a severe drought that threatens the ephemeral complexity built up on the banks of the Colorado River. The situation is exacerbated by the recent trend of southwestern cities like Phoenix and Los Angeles to sprawl out.

Over the last decade, studies have linked suburban sprawl to increased traffic and air pollution as well as the rapid loss of farmland and open space. Sprawl also threatens water quality. Rain that runs off roads and parking lots carries pollutants that poison rivers, lakes, streams, and the ocean. But sprawl not only pollutes our water, it also reduces our supplies. As the impervious surfaces that characterize sprawling development – roads, parking lots, driveways, and roofs – replace meadows and forests, rain no longer can seep into the ground to replenish our aquifers. Instead, it is swept away by gutters and sewer systems.⁷

As World Water Week comes to a close, this should be a startling reminder that conflicts over water are not simply the concern of Third World or developing countries. Even in the most complex nation-state on the planet, there are water shortages that carry the threat of significant socio-political breakdown. Tensions over water will likely become flashpoints in decades to come, as cities continue to grow beyond the means to support themselves and states begin escalating their feuds against one another. As collapse progresses and more power is given to individual states, we may see the southwest torn apart by civil war as states fight for access to the river: just like the grisly warfare that wiped out the last of the Anasazi. When it is all over, what will remain in the southwest will be whatever that ecology can reasonably sustain. Predicting its precise details would be impossible, but we can guess what it will generally look like, regardless of who wins the intervening wars: it will look like the Hopi, or the Zuni, or the Taos, or the Acoma.