The coal-fired power plant that sat on Navajo Nation land in the northeastern corner of Arizona did not just generate electricity. It also drew water from the Colorado River, an essential input for cooling the plant’s machinery. What happens to that water now that the plant is being decommissioned? Who gets to decide how it is used? In a drying region in which every drop of water is accounted for and parceled out, the stakes are high and the legal claims are unresolved.