On a sage-infused summer morning in the San Luis Valley, Robert Quintana steps from his worn silver pickup truck to check the acequia. Quintana relies on the historic ditch to irrigate his alfalfa fields—but it’s empty, only a trickle of water smudging the dirt along its cracked concrete base.

He’s certain someone has stolen his water, which the fourth-generation rancher needs to soak the 1,700 acres of hay and alfalfa he sells and feeds to 200 cattle. “This is a daily thing … when we are in a drought,” Quintana says. “Most people on these ditches are friends and family, but there’s no love when it comes to water.”

The 169-year-old San Luis Peoples’ Ditch holds the oldest water right in Colorado.