Kailua vs Waipahu
How do rainwater harvesting rules compare between Kailua, HI and Waipahu, HI?
Kailua and Waipahu 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 →Waipahu, HI
Honolulu County
Waipahu allows residential rainwater harvesting with no ordinance restriction. Rain barrels suit tight plantation-era lots, and the Board of Water Supply offers rebates.
View full Waipahu rules →Key Facts Comparison
| Fact | Kailua | Waipahu |
|---|---|---|
| Permit threshold | 360 gallons storage | - |
| Code reference | Hawaii Plumbing Code Ch. 16 | - |
| Rebates | BWS rain barrel program | Board of Water Supply offers |
| Indoor use | Requires plumbing permit | - |
| Ordinance | - | None specific to harvesting |
| Permit-free limit | - | Up to 360 gallons outdoor |
| Guidance | - | 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.
Waipahu FAQ
Can a Waipahu rental property install a rain barrel?
Only with landlord permission. No ordinance prohibits it, but tenancy and any HOA rules govern yard additions on rental properties.
Is catchment water safe for a Waipahu backyard garden?
Yes for irrigation of non-root, non-leaf-eaten crops. Follow UH CTAHR guidance for safer watering of vegetables meant to be eaten raw.
Compare other topics
See how Kailua and Waipahu 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