Colorado Allows Limited Residential Rainwater Harvesting

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.

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.