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Rainwater, Graywater, and Stormwater 
DWR > Surface Water > Water Rights > Rainwater, Graywater, and Stormwater

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 completing and submitting an Application 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.

Graywater Reuse

Colorado Water Law typically does not permit most residential properties to reuse graywater, water already used once for showers, laundry and dishwashing.  The Colorado Department of Public Health and Environment Water Quality Control Division (CDHPE WQCD) administers requirements and minimal standards.  Many city and county regulations further prohibit the issuance of any type of individual sewage disposal system permit within a certain distance of service by a municipal or community sewage treatment facility, so please contact your local government office for specific details.

Stormwater Management

Precipitation that falls on a site and becomes concentrated in a detention or infiltration area may not be diverted for any beneficial use.  Landscaping that is planted on roofs (green roofs) is allowable as long as the landscaping intercepts only precipitation that falls directly onto the landscaping. The landscaping may not intercept and consume concentrated flow and may not store water below the root zone.  Please see the administrative position for additional details.