Twenty years ago, the Colorado River Basin’s hydrology turned persistently dry, reservoir levels plummeted and a river system relied upon by nearly 40 million people, farms and ecosystems across the West was in trouble. So key players across the Basin attacked the problem. The result was a set of Interim Guidelines adopted in 2007 that, according to a just-released assessment, mostly worked to prevent forced water supply cuts. With the guidelines expiring in 2026, that assessment is expected to aid discussions as key players begin writing a new set of river operating rules.