Stormwater Management: Kapolei vs Urban Honolulu
How do stormwater management rules compare between Kapolei, HI and Urban Honolulu, HI?
Kapolei and Urban Honolulu have similar restriction levels.
Kapolei, HI
Honolulu County
Kapolei properties tied to the city's separate storm sewer system are regulated by ROH Chapter 43, Article 11, which bars non-stormwater discharges and enforces MS4 water quality standards.
View full Kapolei rules →Urban Honolulu, HI
Honolulu County
In Urban Honolulu's redevelopment zones from Kakaako to Ala Moana, ROH Chapter 43 Article 11 and Chapter 14 water quality rules require strict MS4 compliance, with illicit discharge prohibitions enforced at construction and operation stages.
View full Urban Honolulu rules →Key Facts Comparison
| Fact | Kapolei | Urban Honolulu |
|---|---|---|
| - | - | |
| Authority | - | ROH Ch. 43 Art. 11 |
| Connection rule | - | Sec. 43-11.12 |
| Illicit discharge | - | Sec. 43-11.22 |
| Receiving waters | - | Ala Wai, Kewalo, harbor |
| Projects | - | Kakaako, Ala Moana towers |
Highlighted rows indicate differences between cities.
Kapolei FAQ
Can I pressure-wash my Kapolei driveway into the gutter?
If the runoff carries soaps, oils, or other pollutants to a storm drain, it is a prohibited non-stormwater discharge under Sec. 43-11.22.
What is the MS4 system?
The MS4 is the city's municipal separate storm sewer system, which carries untreated stormwater to coastal and stream outfalls under federal and local water quality rules.
Urban Honolulu FAQ
Do Urban Honolulu tower projects need post-construction stormwater controls?
Yes. City water quality rules require permanent treatment such as bioretention, cisterns, or media filters for qualifying new and redevelopment projects, on top of construction-phase BMPs.
Can my condo discharge cooling-tower blowdown to the storm drain?
No. Sec. 43-11.22 prohibits non-stormwater discharges including cooling tower blowdown, which must be routed to sanitary sewer under a permit rather than the MS4.
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