Kailua vs Urban Honolulu
How do rainwater harvesting rules compare between Kailua, HI and Urban Honolulu, HI?
Kailua and Urban Honolulu have similar restriction levels.
Kailua, HI
Honolulu County
Kailua residents can collect rainwater for outdoor irrigation without a permit; the Board of Water Supply offers rebates for rain barrels on windward lots.
View full Kailua rules →Urban Honolulu, HI
Honolulu County
Urban Honolulu has no ordinance restricting rainwater harvesting; Board of Water Supply rebates target rain barrels at single-family homes in Kaimuki, Manoa, and Palolo rather than high-rise condos.
View full Urban Honolulu rules →Key Facts Comparison
| Fact | Kailua | Urban Honolulu |
|---|---|---|
| Permit threshold | 360 gallons storage | - |
| Code reference | Hawaii Plumbing Code Ch. 16 | - |
| Rebates | BWS rain barrel program | - |
| Indoor use | Requires plumbing permit | - |
| City ordinance | - | None |
| Permit exemption | - | Up to 360 gallons |
| Rebate program | - | Board of Water Supply |
| Best fit | - | Single-family neighborhoods |
| Guidelines | - | UH CTAHR catchment program |
Highlighted rows indicate differences between cities.
Kailua FAQ
Can I install rain barrels on my Kailua home?
Yes. Exterior barrels up to 360 gallons for outdoor irrigation are allowed without a permit. BWS offers rebates to offset purchase costs.
Can I plumb harvested water into my Kailua kitchen?
Only with a plumbing permit and proper backflow protection. Indoor use is treated as a non-potable supply under the Hawaii Plumbing Code.
Urban Honolulu FAQ
Can I install a rain barrel at my Manoa home?
Yes. No permit is required for outdoor catchment under 360 gallons, and the Honolulu Board of Water Supply offers rebates for qualifying single-family installations.
Why are condos a poor fit for rain barrels?
High-rise towers in Waikiki, Kakaako, and Ala Moana lack private rooftop downspout access and association rules often preclude barrel placement on common areas.
Compare other topics
See how Kailua and Urban Honolulu compare on other ordinance categories.
Want to add a third city?
Use our full comparison tool to compare up to three cities.
Open Comparison Tool