Milpitas, CA Landscaping Rules: Rainwater Harvesting (2026)

There is no Milpitas Municipal Code provision banning residential rainwater catchment, and the City promotes water conservation through its Save Water Milpitas program. California's Rainwater Capture Act of 2012 (Public Resources Code Section 10574) confirms a property owner may capture and use rainwater that falls on their parcel without obtaining an appropriative water right from the State Water Resources Control Board. Under the California Plumbing Code, rain barrels and simple gravity systems under 360 gallons used for outdoor, non-potable purposes generally do not require a plumbing permit; larger cisterns or any system plumbed for indoor non-potable use (such as toilet flushing) trigger plumbing-permit review. Because Milpitas restricts outdoor irrigation to four designated days under its Water Conservation Ordinance, captured rainwater is a practical way to supplement landscape watering between allowed days. Harvested rainwater should be used in line with the City's conservation rules and should not create standing water that breeds mosquitoes. Residents installing larger systems, or connecting any catchment to an irrigation or building system, should confirm permit requirements with the Building Division before installation.