San Luis Valley and the Acequias

The San Luis Valley in south-central Colorado is one of the highest large mountain valleys in the world. It sits at an average elevation of roughly seventy-five hundred feet, enclosed on the east by the Sangre de Cristo Mountains and on the west by the San Juan range. It is cold, dry, and remote. It is also the oldest part of Colorado to be continuously settled by people of European descent.

Hispanic New Mexican settlers began entering the valley in the eighteen thirties and forties, moving north from New Mexico during the final years of Mexican governance of the region. The town of San Luis, founded in eighteen fifty-one, is the oldest continuously inhabited town in Colorado. The San Luis People's Ditch, completed in eighteen fifty-two, is the oldest operating water right in the state.

These settlers brought with them the acequia tradition: community-managed earthen irrigation ditches governed by shared rules, shared labor, and a water master called a mayordomo. An acequia is not merely a ditch. It is a social institution. Members owe labor to its maintenance proportional to the water they receive. In times of drought, cuts are shared collectively. The system is explicitly communal and rooted in centuries of practice in Spain and the Middle East before it crossed the Atlantic.

Many San Luis Valley acequia systems are still operating today, maintained by the same families whose ancestors first dug them. They represent a living form of water governance that preceded American Colorado by centuries, and that has survived by being too useful to abandon.