Rainwater Harvesting: Honolulu vs Pearl City
How do rainwater harvesting rules compare between Honolulu, HI and Pearl City, HI?
Honolulu and Pearl City have similar restriction levels.
Honolulu, HI
Honolulu County
Honolulu County has no ordinance restricting residential rainwater harvesting; the Board of Water Supply encourages it countywide through a rain barrel rebate program and CTAHR catchment guidelines.
View full Honolulu rules →Pearl City, HI
Honolulu County
Pearl City allows residential rainwater harvesting with no ordinance restriction. Rain barrels are practical for yards in Pacific Palisades and Manana, with BWS rebates available.
View full Pearl City rules →Key Facts Comparison
| Fact | Honolulu | Pearl City |
|---|---|---|
| County ordinance | None | - |
| Permit threshold | Up to 360 gallons exempt | - |
| Rebate program | Board of Water Supply | - |
| Guidelines | UH CTAHR catchment program | - |
| State restrictions | None | - |
| Ordinance | - | None specific to harvesting |
| Permit-free limit | - | Up to 360 gallons outdoor |
| Rebates | - | Board of Water Supply offers |
| Guidance | - | UH CTAHR catchment program |
Highlighted rows indicate differences between cities.
Honolulu FAQ
Do I need a permit for a backyard rain barrel on Oahu?
Usually no. Exterior catchment up to 360 gallons for outdoor irrigation is exempt under the Hawaii Plumbing Code, and Honolulu County has no separate ordinance.
Are there incentives for catching rainwater?
Yes. The Honolulu Board of Water Supply runs a rain barrel rebate program encouraging conservation. Details and eligibility are posted on the BWS website.
Pearl City FAQ
Do Pearl City HOAs allow rain barrels?
Rules vary by association. Many allow screened rain barrels; check your specific condo or townhouse association's architectural guidelines before installing.
Is BWS rebate available for Pearl City rentals?
Rebates are typically issued to the account holder; renters should coordinate with landlords since the BWS account holder receives the rebate.
Compare other topics
See how Honolulu and Pearl City 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