Stormwater Management: East Honolulu vs Urban Honolulu
How do stormwater management rules compare between East Honolulu, HI and Urban Honolulu, HI?
East Honolulu and Urban Honolulu have similar restriction levels.
East Honolulu, HI
Honolulu County
East Honolulu's coastal drainages to Maunalua Bay and Hawaii Kai waterways fall under ROH Chapter 43, Article 11 stormwater rules prohibiting non-stormwater discharges to the city's MS4 system.
View full East Honolulu 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 | East Honolulu | 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.
East Honolulu FAQ
Is it okay to drain my Hawaii Kai pool into the street?
No. Pool water typically contains chlorine and other chemicals and is classified as a non-stormwater discharge prohibited under Sec. 43-11.22 without special handling.
What should I do with wash water from my driveway?
Direct wash water to landscaped areas or capture it, as soapy or chemical-laden wash water entering a storm drain is a prohibited discharge under city stormwater 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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