In Colorado, landowners must obtain a permit to drill a well on their property. The state has strict water rights regulations, and landowners must prove that they have access to water before building on the land. Groundwater laws require permits to dig a well on a property, with limits on how much water can be pumped per minute. Sustainability practices, such as rainwater harvesting and greywater recycling, are legal with regulations. House Bill 1005 allows up to two rain barrels with a combined capacity of 110 gallons for outdoor use only. Although Colorado has no zoning laws in some counties, statewide building codes still apply, and sustainability practices must meet regulations to be legal.