Yes, with limits. Rainwater collection is legal in Colorado, but the state caps how much you can store.
What Colorado law says
Colorado allows residential rainwater collection with specific limits: Max two rain barrels (55 gal each). Rooftop only, outdoor non-potable use, on-property only. HB 16-1005. A standard rain barrel setup fits comfortably inside these rules, so for most homeowners the cap never becomes a practical problem.
How much water a Colorado roof can collect
Colorado averages about 16 inches of rain per year. On a typical 1,200 square foot roof at 85% collection efficiency, that works out to roughly 10,200 gallons a year currently running into your storm drain. A single one-inch storm delivers about 635 gallons, enough to fill 13 standard 50-gallon barrels.
Average annual rainfall in Colorado.
Gallons per year from a typical 1,200 sq ft roof.
Approximate annual value at municipal water rates.
Your roof and rainfall will differ; run your exact numbers in the rainwater calculator.
The right setup for Colorado’s climate
With about 16 inches of rain a year, Colorado is a dry-climate state where storage capacity matters most. Storms are rare, so when one comes you want to catch as much as possible: a 65-gallon barrel, or two linked 50s, beats a single small barrel that overflows in the first hour.
Rain Wizard 65 Gallon, reviewed against our independent testing criteria. See all six models side by side.
Common questions
Is it illegal to collect rainwater in Colorado?
Do I need a permit for a rain barrel in Colorado?
Does Colorado offer incentives for rainwater harvesting?
Sources
- Rainplan, 50-State Rainwater Collection Guide (2026)
- State statutes and water agency guidance for Colorado
- NOAA National Centers for Environmental Information, annual precipitation normals
- US EPA WaterSense, Outdoor Water Use fact sheet
Educational content, not legal advice. Laws change; confirm current rules with your state water agency.