A column in the Denver Post this morning by Daniel Fitzgerald asked that very question. Can you own the rain? Kris Holstrom lives on the western slope of Colorado and wanted to capture the rain that fell off her roof to be able to water her yard and her burgeoning organic farming business. It wouldn't have been that much and she applied to do that through the State of Colorado.
But the State Engineer said no and the Water Court of Colorado agreed. They ruled that the rain that fell on her house was tributary to the San Miguel River and thereby previously appropriated. She can't capture rain and use it on her garden.
This is the same thinking that is causing water problems in the western United States, prior appropriation or otherwise known as first-in-time, first-in-right. This is the same rule that has applied to water appropriation since the west was settled.
Since there is a tremendous increase in population the consumption and need of water is ever-growing. We (the residents of Colorado and the West) need to start planning and developing innovative solutions to water management. Being stuck in the same ol' ways will not help us, but hurt us.
Studies have been done in capturing water that runs off the roofs and used to water gardens and also for waste supply (like toilets) and it will save a lot of water while still returning it to the river or transpired into the air to fall as rain somewhere else.
Most likely, the water from this persons roof would not make it to the river. It would have either evaporated or transpired through the vegetation.
We in the West need innovative technologies and a new thinking of water management. If we don't the water crisis will only get worse.