A racist past and hotter future are testing Western water like never before

A two decade-long drought on the Colorado River is drying up reservoirs. Droughts there and in California are bringing new scrutiny to the way Western states decide whose water allotment gets cut back. (John Locher/AP)

As droughts strain water supplies across Western states, some cities and farmers have struggled with mandatory cutbacks. Determining who gets cut is decided by the foundational pecking order of Western water: the older your claim to water, created as the country expanded westward, the better protected it is.

When there's a shortage, those with newer water rights have to cut back first, sometimes giving up their water completely before older claims lose a single drop.