East Honolulu vs Mililani Mauka
How do rainwater harvesting rules compare between East Honolulu, HI and Mililani Mauka, HI?
East Honolulu and Mililani Mauka have similar restriction levels.
East Honolulu, HI
Honolulu County
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 →Mililani Mauka, HI
Honolulu County
Mililani Mauka homeowners may install rain barrels without a Honolulu permit; small outdoor catchment up to 360 gallons is exempt under state plumbing code.
View full Mililani Mauka rules →Key Facts Comparison
| Fact | East Honolulu | Mililani Mauka |
|---|---|---|
| Ordinance | None specific to harvesting | - |
| Permit-free limit | Up to 360 gallons outdoor | - |
| Rebates | Board of Water Supply offers | - |
| Guidance | UH CTAHR catchment program | - |
| City code | - | No specific ordinance |
| Plumbing code | - | Up to 360 gallons exempt |
| Incentive | - | BWS rebate programs |
| HOA layer | - | Mauka design review |
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.
Mililani Mauka FAQ
Do I need a permit for a rain barrel in Mililani Mauka?
No. Residential catchment under 360 gallons is exempt under the Hawaii Plumbing Code, and Honolulu has no specific residential catchment ordinance.
Will the Mauka HOA let me install a rain barrel?
Usually yes with screening. Submit your plans to the Mililani Mauka Community Association architectural review to confirm placement and color requirements.
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