Riverside County, CA Landscaping Rules: Rainwater Harvesting (2026)

Collecting rainwater is legal throughout California, and unincorporated Riverside County does not prohibit residential rain barrels or cisterns. The governing law is the California Rainwater Capture Act of 2012 (AB 1750, codified in the Water Code), which authorizes residential, commercial, and governmental landowners to install, maintain, and operate rainwater capture systems and confirms that capturing rooftop rainwater does not require a water-right permit from the State Water Resources Control Board. As a practical rule, simple rain barrels and cisterns that collect rooftop runoff for outdoor, non-potable uses (such as landscape irrigation) and are below roughly 360 gallons can be installed without state permitting.

Larger storage, systems connected (plumbed) into a building's interior plumbing, potable use, or systems serving non-residential or agricultural purposes can trigger local building, plumbing, or health-department permit review by the County. Harvested rainwater pairs well with the County's water-efficiency goals under Ordinance 859 (Water Efficient Landscape Ordinance) and with statewide conservation efforts, and using captured rain for irrigation also helps avoid State Water Board runoff prohibitions. Homeowners planning a large cistern, an underground tank, or any indoor-plumbed system should confirm building and grading permit requirements with Riverside County Building & Safety before installation, and should keep tanks screened and sealed to prevent mosquito breeding.