East Honolulu vs Mililani Town
How do rainwater harvesting rules compare between East Honolulu, HI and Mililani Town, HI?
East Honolulu and Mililani Town 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 Town, HI
Honolulu County
Mililani Town residents can collect rainwater for outdoor use without a permit up to 360 gallons; HOA rules may affect visible barrel placement.
View full Mililani Town rules →Key Facts Comparison
| Fact | East Honolulu | Mililani Town |
|---|---|---|
| Ordinance | None specific to harvesting | - |
| Permit-free limit | Up to 360 gallons outdoor | - |
| Rebates | Board of Water Supply offers | BWS rain barrel program |
| Guidance | UH CTAHR catchment program | - |
| Permit threshold | - | 360 gallons storage |
| Code reference | - | Hawaii Plumbing Code Ch. 16 |
| HOA layer | - | MTA architectural rules |
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 Town FAQ
Does Mililani Town Association allow rain barrels?
Generally yes, with placement and color guidelines. Submit an architectural application to the MTA before installation to avoid compliance letters.
Can I plumb rainwater to my Mililani washing machine?
Only with a plumbing permit and proper backflow protection. Non-potable indoor use is regulated under the Hawaii Plumbing Code.
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