Rainwater systems are typically allowed, particularly for outdoor irrigation (and often without a permit) in much of the United States. Indoor, potable use of rainwater is the most challenging system to get a permit for. Rainwater tanks over 5,000 gallons typically require a permit, while smaller tanks don’t. When researching rainwater codes in your area check with agencies such as the zoning and fire department, as well as the building department and possibly the health department (although health departments typically are involved in permitting indoor systems, not irrigation).
Example rainwater codes:
- The American Rainwater Catchment Systems Association (ARCSA) developed ARCSA/ASPE 63: Rainwater Catchment Systems, a guidance document on proper design, installation, and maintenance for irrigation and potable rainwater harvesting systems.
- The International Association of Plumbing and Mechanical Officials (IAPMO), a code writing organization, has a rainwater code- find it in the UPC.
- California’s rainwater code (2016) is found in Chapter 16 of the California Plumbing Code.
- For a list of current state-by-state regulations visit ARCSA’s website here or Harvest H20’s site here.