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🌿 Landscaping Rules/Rainwater Harvesting

East Honolulu vs Kailua

How do rainwater harvesting rules compare between East Honolulu, HI and Kailua, HI?

East Honolulu and Kailua have similar restriction levels.

East Honolulu, HI

Honolulu County

Few Restrictions

East Honolulu permits residential rainwater harvesting. No Honolulu ordinance restricts collection, and the Board of Water Supply offers rebates attractive for large Hawaii Kai and Aina Haina lots.

View full East Honolulu rules β†’

Kailua, HI

Honolulu County

Few Restrictions

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 β†’

Key Facts Comparison

FactEast HonoluluKailua
OrdinanceNone specific to harvesting-
Permit-free limitUp to 360 gallons outdoor-
RebatesBoard of Water Supply offersBWS rain barrel program
GuidanceUH CTAHR catchment program-
Permit threshold-360 gallons storage
Code reference-Hawaii Plumbing Code Ch. 16
Indoor use-Requires plumbing permit

Highlighted rows indicate differences between cities.

East Honolulu FAQ

Do I need a permit for a rain barrel in Hawaii Kai?

No. Outdoor catchment for irrigation with storage up to 360 gallons is exempt from plumbing permits and no Honolulu ordinance restricts it.

Can I use collected rainwater for drinking?

Potable use systems must meet Hawaii Department of Health standards and typically require treatment. Most East Honolulu residents use catchment only for landscape irrigation.

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.

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