Rainwater Harvesting: Kailua vs Kapolei
How do rainwater harvesting rules compare between Kailua, HI and Kapolei, HI?
Kailua and Kapolei 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 →Kapolei, HI
Honolulu County
Kapolei residents may install residential rain barrels without a Honolulu ordinance permit; small catchment up to 360 gallons is exempt under state plumbing code.
View full Kapolei rules →Key Facts Comparison
| Fact | Kailua | Kapolei |
|---|---|---|
| Permit threshold | 360 gallons storage | - |
| Code reference | Hawaii Plumbing Code Ch. 16 | - |
| Rebates | BWS rain barrel program | - |
| Indoor use | Requires plumbing permit | - |
| City code | - | No specific ordinance |
| Plumbing code | - | Up to 360 gallons exempt |
| Incentive | - | BWS rebate programs |
| Climate fit | - | Dry leeward offset |
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.
Kapolei FAQ
Do I need a Kapolei permit for a rain barrel?
No. Residential outdoor catchment under 360 gallons is exempt under Hawaii Plumbing Code, and Honolulu has no specific ordinance for Kapolei residential catchment.
Can Kapolei businesses install large cisterns?
Yes, but larger commercial systems may require plumbing permit review if they exceed the 360-gallon exterior irrigation exemption under the Hawaii Plumbing Code.
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