Colorado Statewide Rule

Colorado Allows Limited Residential Rainwater Harvesting

Some RestrictionsApplies statewide across Colorado (2026)

Key Facts

Statute: CRS 37-96.5-103
Max Capacity: 110 gallons total
Max Barrels: Two barrels
Eligible Use: Outdoor on-site only

Last verified: September 5, 2026Source: C.R.S. 37-96.5-103 - Small-capacity rooftop precipitation collection permitted

Summary

Colorado law universally permits residential rooftop rainwater collection up to two rain barrels totaling 110 gallons, overriding the state's strict prior-appropriation doctrine that historically forbade private capture.

(a) No more than two rain barrels with a combined storage capacity of one hundred ten gallons or less are utilized; (b) Precipitation is collected from the rooftop of a building that is used primarily as a single-family residence or a multi-family residence with four or fewer units; (c) The collected precipitation is used for outdoor purposes including irrigation of lawns and gardens; and (d) The collected precipitation is used on the residential property on which the precipitation is collected.

Source: C.R.S. 37-96.5-103 - Small-capacity rooftop precipitation collection permittedView official code

Full Breakdown

HB 16-1005, codified at CRS 37-96.5-103, authorizes residents of single-family homes and multi-family buildings with four or fewer units to collect precipitation from rooftop downspouts in up to two rain barrels with a combined capacity of 110 gallons. Water must be used on the same property for outdoor purposes such as lawn irrigation or gardens. The statute applies statewide and supersedes any local rule banning residential rain barrels, though municipalities may add cosmetic standards. Larger cisterns and non-residential collection still require water court approval under Colorado's prior appropriation system.

Violations & Penalties

Exceeding the 110-gallon limit or diverting collected water off-property can be treated as an unauthorized water diversion under CRS 37-92-503, with state engineer cease-and-desist orders and civil penalties up to $500 per day.

Frequently Asked Questions

Can my Colorado city ban rain barrels entirely?

No. CRS 37-96.5-103 grants statewide rights to residential rain barrels meeting the 110-gallon cap. Municipalities cannot prohibit them but may regulate placement and overflow safety.

Can I use harvested rainwater for indoor use or drinking?

No. State law restricts harvested water to outdoor use such as gardens, lawns, and landscape irrigation on the property where it was collected. Indoor potable use is not authorized.

Sources

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