Honolulu County has no ordinance restricting residential rainwater harvesting; the Board of Water Supply encourages it countywide through a rain barrel rebate program and CTAHR catchment guidelines.
The City and County of Honolulu does not regulate individual rainwater catchment systems. Hawaii law permits rainwater collection statewide, and the Department of Water Supply and Department of Health do not regulate personal catchment. Under the Hawaii Plumbing Code (2018 UPC Chapter 16), exterior rainwater catchment for outdoor irrigation with storage up to 360 gallons does not require a plumbing permit. Island-wide, the Honolulu Board of Water Supply offers rain barrel rebates, and the University of Hawaii CTAHR Rainwater Catchment Systems Program publishes design and sanitation guidelines used especially on Big Island and rural Oahu.
No ordinance violations apply specifically to harvesting; systems over 360 gallons or tied into potable plumbing may trigger standard building and plumbing code requirements.
Honolulu County, HI
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Honolulu County, HI
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Honolulu County, HI
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Honolulu County, HI
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Honolulu County, HI
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Honolulu County, HI
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