Los Angeles, CA Landscaping Rules: Rainwater Harvesting (2026)

Los Angeles does not run a separate rainwater-harvesting ordinance; it regulates the practice through the city's own Plumbing Code, part of Chapter IX of the Municipal Code. Division 16, titled "Nonpotable Rainwater Catchment Systems," consists of a single section, SEC. 0, last amended by Ordinance No. 187,719 effective January 23, 2023. " That means Los Angeles has folded the California Plumbing Code's entire rainwater-catchment chapter, covering system design, filtration, storage tank construction, labeling, and cross-connection safeguards for nonpotable reuse, into local law wholesale, rather than writing bespoke city standards.

Any property owner installing a catchment system that ties harvested rainwater into piping for irrigation, toilet flushing, or other nonpotable uses must build to that adopted chapter as the governing city standard. 1, a voluntary residential measure: "An approved rainwater catchment system is designed and installed to use rainwater generated by at least 65% of the available roof area. " This appendix item is optional, one of the checklist measures builders can select toward CALGreen's voluntary tiers, and it still funnels back to the same Plumbing Code standards adopted in Division 16, not a separate landscaping rule.