Water-Smart Growth: Rainwater Collection Under Colorado Law

In my previous article, “Water Smart Growth – the Key to Colorado’s Future”, I discussed methods for supporting Colorado’s water conservation efforts, including the collection and use of rainwater.



This method collects rainwater from rooftops and captures it into cisterns or rain barrels and is utilized to water lawns and for other outdoor uses. This then reduces the need to tap municipal water sources for outdoor watering while at the same time puts to use the thunderstorm deluges that pound Colorado during the monsoon season.

Not so fast.

Unfortunately, here in Colorado, it isn’t as easy as just sticking your rain barrel out and capturing the rainwater. Currently, Colorado law states that you can only apply for a rooftop collection permit if you are a single family household and you do NOT reside in a municipality or special district that supplies water to you. Sorry Denver Metro, that means you are excluded. According to the Colorado Division of Water Resources (see also C.R.S. § 37-92-602 and § 37-90-105), the proposed property must meet all the following criteria:

1) the property must be residential

2) the property must have a water well or be legally entitled to one

3) the well uses are consistent with those permitted by law, such as no more than 1 acre of irrigated lawns or gardens

4) there is no water supply available

5) the building where precipitation is collected is only used for residential purposes

6) the uses of the collected water are limited to those allowed for the well on the property.

Who CAN legally capture rain water in Colorado?

If you live in a rural or semi-rural area outside of a municipality or special district and you don’t currently receive municipal water, you may be eligible to collect rainwater from your roof and water up to one acre of lawns or gardens. That means, of the approximate 2 million households in Colorado, only 12%, or about 250,000 households are eligible.

During the 2015 Colorado state legislative session which recently ended, Colorado House Bill 15-1259 was introduced. This bill would allow collection of rainwater with up to 2 rain barrels having a combined storage of no more than 100 gallons, from rooftops on any structure used as a single family residence or multi-family structures with 4 or fewer units. Most importantly, HB 15-1259 would apply to urban residents who receive their water from municipalities. That would mean Denver Metro households would be included. The water collected could be used for lawn irrigation, gardening, or other outdoor uses. This would effectively remove most of the legal obstacles from rainwater collection, making it available to most Coloradans.

HB 15-1259 passed the state House of Representatives however it stalled in the State Senate and did not make it out before the end of the session. Therefore, there will not be any expansion of rainwater collection rights in Colorado before 2016.

With water conservation issues becoming increasingly important, you can expect that the legislature will revisit this issue in the future. I hope they do, as rainwater collection has significant potential to boost Colorado’s water conservation efforts.

ABOUT THE AUTHOR: Mike Downey is the Land Protection Specialist and Colorado Open Lands Fellow for San Isabel Land Protection Trust. When Mike is not working on protecting important and productive ranches, forests, and waters in our region, he can sometimes be found predicting the weather and informing San Isabel staff as to whether or not they should wear layers!



We have protected more than 42,000 acres through 134 conservation easements.

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