America's Water Future: Legalization of Rain Barrels in Colorado Highlights Western Water Rights Debate

Tom Cech, Director, One World One Water (OWOW) Center for Urban Water Education and Stewardship at the Metropolitan State University of Denver in ColoradoTom Cech, Director, One World One Water (OWOW) Center This is the latest in a series of guest posts Tom Cech, the director of the One World One Water (OWOW) Center for Urban Water Education and Stewardship at Metropolitan State University of Denver in Colorado. Born and raised on a farm in Nebraska, Tom graduated from Kearney State College with a Bachelor of Science Degree in Math Education and later received a Master’s Degree in Community and Regional Planning from the University of Nebraska-Lincoln. He was Executive Director of the Central Colorado Water Conservancy District in Greeley and taught undergraduate and graduate level water resources courses at the University of Northern Colorado and Colorado State University before becoming the OWOW Center Director. Tom is the author of Principles of Water Resources: History, Development, Management and Policy, co-author with Dr. Karrie Pennington of Introduction to Water Resources and Environmental Issues  and co-author with P. Andrew Jones of Colorado Water Law for Non-Lawyers.

Next month, residents of Colorado will be able to do something they’ve never legally done before: collect rain water for outdoor irrigation. With the recent passage of HB 16-1005, Coloradans can have up to two 55-gallon rain barrels to use on their gardens or landscape plants. Rain barrels are allowed only at single-­family homes or at multi-­family residences with four or fewer units, and the rain water cannot be used for direct human consumption.

Rain barrel (photo courtesy of barrel at a home Until now, opponents of rain water harvesting had won the day, arguing that state water law prohibited the capture and use of rainfall that would naturally move back into groundwater or nearby surface streams. That argument strove to protect the purity of the Doctrine of Prior Appropriation (first in time, first in right) regulation of water rights. In theory, the capture and use of rainwater could injure downstream senior water rights as old as the 1860s (when irrigation systems were first developed in northeastern Colorado).

However, last summer, the Colorado Legislature’s Interim Water Resources Review Committee reconsidered the issue. They focused on a Colorado State University study that found that 1,200 gallons of rainwater could be captured per household per year with little to no negative impact. Research indicates the following:

  • There is no measurable difference in the amount of storm water runoff at homes with rain barrels and those without.
  • Home owner rain barrel adoption and rates are under 10 percent in other parts of the United States.
  • Development of vacant land has a far greater impact on water use.
  • Rain barrel usage can lead to improved understanding and benefits of other water conservation practices.

Rain barrel proponents used those points to emphasize the minimal risk and potential benefits of rainwater harvesting. In addition, proponents argued that the opportunity for water education—and in particular an improved awareness of the need for water conservation in a semi-arid region—far outweighed the theoretical potential for downstream injury to senior water rights.

In the end, after considerable debate, the rain barrel legislation was passed by both the Colorado House and Senate and was signed into law by Governor John Hickenlooper. Whether the acceptance of rain barrels indicates a larger willingness to examine the West’s complicated water rights regime remains very much an open question.

Related: America’s Water Future: Where Will We Find New Water for Newcomers Moving to the West? (Part 1)

America’s Water Future: Where Will We Find New Water for Newcomers Moving to the West? (Part 2)

Americas Water FutureUrban water is part of America’s Water Future. Find out how you can support education about water in cities and other vitally important water topics by visiting the America’s Water Future web page.


First in time, first in what? If you need to know more about water rights, check out the classic Project WET activity “Pass the Jug” in the Project WET Curriculum and Activity Guide 2.0

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