City & County
of Honolulu

It depends on the SFHA. In Coastal VE and Floodway it requires a No-impact certification or a No-rise certification. There is no flood certification requirement if it is in the Flood Fringe.

Maui County

In Zone VE, solid walls are not permitted, but fences may be permitted. Solid walls or fences within a floodway would require a no-rise certification or LOMR. In a A zone without a floodway or not from coastal runup, compensatory storage may be required.

Kauaʻi County

In VE Zones it must be anchored securely on pilings or columns to prevent flotation, collapse, and lateral movement. In the Floodway (Zone AEF) a No-Rise Certification must be provided. In Zone AE (Flood Fringe) walls are permissible, but other requirements apply from Ordinance No. 808 with respect to ensuring existing drainage patterns are not adversely affected.

Hawai'i County

It depends on the SFHA and will be reviewed on a case-by-case basis.