Honolulu vs Kaneohe
How do rainwater harvesting rules compare between Honolulu, HI and Kaneohe, HI?
Honolulu and Kaneohe have similar restriction levels.
Honolulu, HI
Honolulu County
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.
View full Honolulu rules →Kaneohe, HI
Honolulu County
Kaneohe's high rainfall makes rainwater collection practical; exterior systems up to 360 gallons need no permit, and BWS offers rain barrel rebates.
View full Kaneohe rules →Key Facts Comparison
| Fact | Honolulu | Kaneohe |
|---|---|---|
| County ordinance | None | - |
| Permit threshold | Up to 360 gallons exempt | 360 gallons storage |
| Rebate program | Board of Water Supply | - |
| Guidelines | UH CTAHR catchment program | - |
| State restrictions | None | - |
| Code reference | - | Hawaii Plumbing Code Ch. 16 |
| Rebates | - | BWS rain barrel program |
| Indoor use | - | Requires plumbing permit |
Highlighted rows indicate differences between cities.
Honolulu FAQ
Do I need a permit for a backyard rain barrel on Oahu?
Usually no. Exterior catchment up to 360 gallons for outdoor irrigation is exempt under the Hawaii Plumbing Code, and Honolulu County has no separate ordinance.
Are there incentives for catching rainwater?
Yes. The Honolulu Board of Water Supply runs a rain barrel rebate program encouraging conservation. Details and eligibility are posted on the BWS website.
Kaneohe FAQ
Should Kaneohe homeowners size rain barrels larger than 360 gallons?
Often yes, given local rainfall. Tanks over 360 gallons or plumbed indoors need permits and backflow devices, but the extra storage pays off quickly.
Can I water my Hoomaluhia-adjacent yard from catchment?
Yes. Outdoor irrigation from rainwater is unregulated by ROH, and BWS encourages it as a drought-resilient source for windward gardens.
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