House Bill 16-1005, effective August 10, 2016, allows precipitation to be collected from the rooftop of certain residential properties.
GVM residences that are a single family house on an exempt household-use only well can use rain barrels as allowed under HB16-1005. There is a limit of two rain barrels with a combined storage capacity not to exceed 110 gal. The water must be collected from the roof of the building that is used primarily as the residence and may be used for outdoor uses, such as lawn and garden irrigation, on the property where the water was collected. The water cannot be used for drinking water or indoor household purposes.
Click here for the Rainwater Collection page from the CO Division of Water Resources
Click here for a Rainbarrel Fact Sheet from CSU