Retaining Walls: Ewa Gentry vs Waipahu
How do retaining walls rules compare between Ewa Gentry, HI and Waipahu, HI?
Ewa Gentry and Waipahu have similar restriction levels.
Ewa Gentry, HI
Honolulu County
ROH Sec. 21-4.40 controls retaining walls in Ewa Gentry, limiting fill-containing walls inside required yards to six feet and combining terraced wall heights for measurement.
View full Ewa Gentry rules →Waipahu, HI
Honolulu County
Waipahu retaining walls fall under ROH 21-4.40, capping fill-bearing walls in required yards at 6 feet with terraced heights combined, impacting stream-side and hillside plantation lots.
View full Waipahu rules →Key Facts Comparison
| Fact | Ewa Gentry | Waipahu |
|---|---|---|
| - | - | |
| Yard max height | - | 6 feet |
| Terraced rule | - | Heights combined |
| Code section | - | ROH 21-4.40 |
| Drainage overlay | - | Chapter 14 |
Highlighted rows indicate differences between cities.
Ewa Gentry FAQ
Can I build two stacked retaining walls to exceed the height limit?
No. ROH 21-4.40 combines terraced wall heights so stacking does not bypass the six-foot limit in required yards.
Do I need an engineer for a rear-yard retaining wall?
Most fill-retaining walls above the short-wall exemption require engineered drawings and a DPP permit.
Waipahu FAQ
How tall can a Waipahu retaining wall be?
Walls with fill in a required yard cap at 6 feet under ROH 21-4.40. Terraced walls are measured as combined height. Engineering review is required above the 30-inch permit threshold for taller installations.
Do old rock walls still comply?
Many legacy plantation-era rock walls are grandfathered. However, substantial alteration, repair, or replacement triggers current ROH 21-4.40 standards and may require engineered drawings plus drainage review.
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