Aheavy monsoon season hit the Chihuahuan Desert in September. It flooded city streets in northern Mexico, overflowed some Mexican reservoirs and sent raging water down the Rio Grande through snaking canyons on the West Texas border, which months before had run totally dry for the first time on record.
In the Mexican state of Chihuahua, a massive area with a flourishing commercial nut export sector, residents rejoiced. Just a few weeks before they had drifted so near the brink of disaster that they had caught sight of the terrible hazards ahead.
In mid-August, Chihuahua’s largest reservoirs had dropped to critical levels after years of widespread drought. The largest city in northern Mexico, Monterrey, had been rationing water to its 5 million people all summer. Yet Mexico owed water to Texas. It was 20 months behind on a five-year payment schedule under a 1944 U.S.-Mexico treaty.
Along the Rio Grande, which forms the international border, residents of Texas cities were also confronting the prospect of severe shortfalls. This broad, regional crisis didn’t just result from a single summer’s searing heat and drought. The desperate predicament had been creeping for a century down long rivers and across vast deserts that connect the mountains of northern Mexico to the Rio Grande, South Texas, and the Gulf of Mexico.
When September’s monsoon arrived, it brought only temporary relief from a trend towards scarcity and conflict that spans two countries and affects millions of people.
Most of this vast region’s water problem comes down to the Rio Conchos, the largest single water source and, effectively, the headwaters of the Texas river. It flows—or lately, it doesn’t—from the Western Sierra Madre of Chihuahua into the Rio Grande between Ojinaga, Mexico, and Presidio, Texas.
These days a meek Conchos dribbles into the Rio Grande’s dry bed in a dusty, yellow grassland. Farmers around here grow mostly hay now.
Yet, this valley used to teem with muddy wetlands, back when the two rivers that nursed it were so mighty that Spanish explorers in the 16th century dubbed this La Junta de los Rios—The Meeting of the Rivers. They found some 10,000 people in a dozen villages of two-story mud brick homes raising crops along a 50-mile stretch of fertile floodplain.
“This has been farming country for thousands of years,” said Enrique Madrid, an Indigenous historian with long gray hair and a mustache, thumbing through published English translations of Spanish explorations.
As he speaks, Madrid, the son of the town librarian, pulls books
