The following info comes from the Colorado Division of Water Resources web page:
Rooftop Precipitation Collection
Although it is permissible to direct your residential property roof downspouts toward landscaped areas, unless you own a specific type of exempt well permit, you cannot collect rainwater in any other manner, such as storage in a cistern or tank, for later use. Please review our publications below, as well as links to CSU Extension's information on this topic and Colorado law on the subject as written in the Colorado Revised Statutes, before applying for a Rooftop Precipitation Collection System Permit. If your well has not been registered, you will also need to Register an Existing Well before applying.
Rainwater Harvesting Pilot Projects
House Bill 09-1129 allows for Pilot Projects for the Beneficial Use of Captured Precipitation in New Real Estate Developments. The Colorado Water Conservation Board (CWCB) has developed criteria and guidelines for applications and the selection process for new development pilot projects to evaluate the feasibility of rainwater harvesting as a water conservation measure in Colorado, when paired with efficient landscaping and irrigation practices.
It did last year... people on domestic wells with no access to city/municipal water systems can now collect their rooftop melt/rain for later use in a garden, landscaping, etc.
City dwellers-no-go.
People living in any city will still not be allowed to collect their rain water.... at least at this time.
I say lets all remove the warning labels and let nature take its course.
My Feedback
"When law and morality contradict each other, the citizen has the cruel alternative of either losing his moral sense or losing his respect for the law." -Frederic Bastiat
"I am a conservative. Quite possibly I am on the losing side; often I think so. Yet, out of a curious perversity I had rather lose with Socrates, let us say, than win with Lenin."
― Russell Kirk, Author of The Conservative Mind