Flood Zones: Mililani Mauka vs Urban Honolulu
How do flood zones rules compare between Mililani Mauka, HI and Urban Honolulu, HI?
Mililani Mauka has fewer restrictions than Urban Honolulu.
Mililani Mauka, HI
Honolulu County
Most Mililani Mauka parcels sit on elevated terrain outside special flood hazard areas, but ROH Chapter 21A still governs any properties mapped within FEMA flood zones.
View full Mililani Mauka rules →Urban Honolulu, HI
Honolulu County
Urban Honolulu's Mapunapuna, Waikiki fringe, and Kakaako makai properties lie in FEMA special flood hazard areas adopted under ROH Sec. 21A-1.5, with elevation and floodproofing required under Sec. 21A-1.8.
View full Urban Honolulu rules →Key Facts Comparison
| Fact | Mililani Mauka | Urban Honolulu |
|---|---|---|
| - | - | |
| Authority | - | ROH Chapter 21A |
| Map source | - | FEMA FIRM |
| Elevation rule | - | Sec. 21A-1.8 |
| Variance | - | Sec. 21A-1.12 |
| Urban hot spots | - | Mapunapuna, Waikiki, Kakaako |
Highlighted rows indicate differences between cities.
Mililani Mauka FAQ
Is my Mililani Mauka home likely in a flood zone?
Most upland lots are in Zone X, but parcels near stream corridors can fall within mapped flood zones; verify using the FEMA FIRM or ask DPP.
What if my project is near a drainage easement?
Drainage easements often carry mapped flood zones, so Chapter 21A elevation and construction standards may apply to any new construction nearby.
Urban Honolulu FAQ
Is Mapunapuna really in a flood zone?
Yes. FEMA FIRMs adopted under Sec. 21A-1.5 place much of Mapunapuna in a special flood hazard area, with chronic tidal flooding driving elevation and floodproofing requirements.
Can a Waikiki tower project get a flood variance?
Only under Sec. 21A-1.12 hardship standards, which are narrowly applied. Urban Honolulu variances are rare, and denials preserve NFIP insurance rating for surrounding structures.
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