For years now, Coloradans have been fighting over the seemingly innocuous rain barrel. Environmentally conscious and thrifty residents say they should have the right to catch as much rain as they please, while agricultural interests argue that doing so is tantamount to stealing water from its rightful owners. The same battle has played out throughout the West, but Colorado is the last remaining state where barrels are banned outright—for a few more days, anyway. On April 1, the state legislature passed a bill to permit residents to catch rain in measured quantities, and Governor John Hickenlooper is expected to sign it.

Coloradans will no longer have to hide their downspouts and barrels for fear of being fined, but the issue is hardly settled. The forthcoming law keeps historical water law intact, while opening a crack in the once unbreakable water doctrine by allowing two 55-gallon barrels per residential property. It won’t be long before residents lobby for the right to collect more, and yet, water is only becoming scarcer in the West. Persistent droughts, exacerbated by climate change, and a rapidly expanding population will only intensify the debate over rain-catchment laws. The water wars have just begun.

“The controversy over the rain barrel proposal is not really about rain barrels,” said Douglas Kenney, director of the Western Water Policy Program at the University of Colorado, Boulder’s law school. “It’s about what some people see as a dangerous precedent in terms of changing the water rights regime. ... The stakes are very high.”

Colorado has a deeply rooted system of “prior appropriation”—finder’s keepers, essentially—which for over a century has governed how water is allocated in the state and much of the West. During the Gold Rush of the mid-1800s, miners flooded the West, settling next to rivers and streams to pan for gold. To ensure newcomers wouldn’t stake claim to the same water, the system of prior appropriation was established, creating the “first in time, first in right” standard that gave priority to “senior claims” over water. Those who arrived in the area more recently had “junior” rights, and newcomers were only permitted to use water left over after the first arrivals had their share. Settlers who held the most senior water claims were able to use as much water as they could put to “beneficial use”—essentially, not to waste it.

After the Gold Rush peaked, westward migrants moved in to establish agricultural communities, and prior appropriation—which was written into Colorado’s constitution and that of five other Western states—provided some level of risk protection. “No one would come out West and build a farm or a business, or anything, and invest all that time and effort if they thought someone else would come by ten years later and start using the water that the original settler had depended on,” Kenney said.

