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

Lake County does not have an ordinance restricting residential rainwater catchment, and the County and UC Cooperative Extension encourage water-wise practices. The governing rules are statewide. The California Rainwater Capture Act of 2012 (Cal. Water Code Section 10574, AB 1750) provides that capturing rainwater from rooftops does not require an appropriative water right from the State Water Resources Control Board. For tanks and cisterns, the County applies the California Plumbing Code and California Building Code as adopted in County Code Chapter 5 (Building Regulations). Under the standard Plumbing Code framework, simple non-potable rain barrels and cisterns used for non-spray landscape irrigation are generally exempt from a building permit when they are below the code threshold (commonly 5,000 gallons), sit on an adequate foundation, and have a height-to-width ratio under 2:1. Larger, elevated, or potable-use systems require permits and must meet California Plumbing Code Appendix K for non-potable rainwater catchment, or the potable-water provisions where drinking water is intended. Because much of the county sits in the fire-prone Clear Lake watershed, stored water can also support defensible-space and emergency needs.