Collecting rainwater may seem like a global common, now it depends on where you live: By capturing rainwater, some homeowners are breaking the law.
For example, in the state of Colorado it is illegal for residents to divert rainwater that falls onto the ground they own unless they have permission to do so. Collecting rainwater in a backyard barrel can technically be considered a violation of the law.
Up until 2009,the water rights laws of Colorado was almost completely restricted the harvesting of rainwater. The person caught capturing rainwater were said to be stealing it from those who have rights to take water from the watershed. Now, residential well owners that meet certain criteria may obtain a permit to install a rooftop precipitation collection system (SB 09-080)
In Oregon all water is publicly owned. Therefore, anyone who wants to collect and store any type of water on their property must first obtain a permit from state water managers.