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

There is no Lake Forest ordinance prohibiting or specially restricting the capture of rainwater for landscape irrigation, and rain barrels and small cisterns are effectively unregulated. Rainwater harvesting in California is authorized by the statewide Rainwater Capture Act of 2012, which lets residential, commercial, and institutional property owners install and operate rooftop rainwater capture systems without a State Water Board water right. The City's own water conservation efforts and its Water-Efficient Landscape regulations align with the state Model Water Efficient Landscape Ordinance (MWELO), which expressly encourages alternative water supplies, including harvested rainwater, graywater, and onsite stormwater capture, for irrigating new and renovated landscapes. In practice, a typical rain barrel needs no City approval. A large above-ground storage tank, an elevated tank platform, or a system plumbed into the home's potable plumbing can trigger a City building or plumbing permit and must avoid any cross-connection that could contaminate the drinking-water supply. Because Lake Forest sits in a semi-arid Southern California climate with most rainfall concentrated in winter, captured rainwater is most useful for offsetting summer irrigation demand, which complements the district and state conservation rules.