The water rule which governs the current division of Colorado River waters is called Prior Appropriation, or First-in-Time, First-in-Right. This rule originated in the California and Colorado gold fields, where fortune-seekers needed water to extract gold ore from rock. Before they sank their sweat and treasure into deep mineshafts and long flumes, miners needed a rock-solid claim to water with which to extract their gold. They posted signs along creeks claiming a specific amount of water for their use. The first to post had the first and best right to the creek’s water, with the second and third person to post getting whatever was left after the others before them had taken theirs.

For the Anglos who settled the arid West, this First-in-Time rule exactly fit their extractive mindset. Huge amounts of sweat, treasure and water were needed to build their towns and agrarian economies. They needed rock-solid claims to water before paying shovel crews to cut miles-long irrigation ditches in 1860, or before pledging millions to build the Hoover Dam in 1931. Over the last 175 years, Prior Appropriation has become the water law of the West.

But long before the Anglos settled the West, the Hispanos brought their own water rules to settlements in New Mexico, Colorado, California and Arizona. Hispanic water rules come from the arid Arab world and govern acequias (irrigation ditches) in New Mexico today. Rather than treating water as something to extract the earth’s resources with, the acequia tradition sees water as life, a community asset upon which everyone depends. During a drought, acequias rotate the scarce water between all users, giving priority first to people, then animals, and then human-food crops. Under acequia rules, irrigated pasture and industry are usually the lowest priority and may not get any water during a severe drought.

Acequia water-sharing traditions are the historic precedent for the third option the Bureau of Reclamation is proposing for how to distribute Colorado river-water cuts. The bureau’s first two options, doing nothing or following Prior Appropriation rules, would decimate water supplies for Arizona and Nevada, potentially drying up the cities of Las Vegas, Phoenix and Tucson. The bureau’s third proposed option, distributing water cuts equally among all member states, flies in the face of Prior Appropriation law, but recognizes that everyone needs water to live, just as acequia traditions do. Under the bureau’s third option, California, Nevada and Arizona would each face less painful cuts, since cuts would be spread between all of their users: their cities plus Imperial Valley and Central Arizona Project agriculture.

The current water crisis on the Colorado River calls for a reevaluation of our modern attachment to Prior Appropriation. An Anglo extractive mentality may no longer be appropriate in the face of climate change and mega-droughts. Rather, the older Hispano acequia rules for water-sharing during droughts will better protect people, communities and food supplies when there is no longer sufficient water to fulfill everyone’s claims.

Elizabeth Black runs the Citizen Science Soil Health Project and farms Christmas trees in Boulder. She produced The Ditch Project, a show and website about western water and Boulder’s irrigation ditches.