Collecting rainwater is not illegal or a federal crime. Rainwater collection laws vary because of state water-rights doctrines, not federal environmental rules. Understanding prior appropriation and riparian rights makes the patchwork of state laws much easier to navigate. Who Owns the Rain? Water rights in the U.S. developed differently across regions, depending on climate and settlement patterns. These doctrines shape how states regulate rainwater collection: States With Strict Limits Prior appropriation states tend to impose tight restrictions. For example, Colorado caps rainwater collection at two barrels totaling 110 gallons for outdoor use only. The state’s complicated water rights system means that rainwater running off your roof is already claimed by someone downstream.…
