Maui County, HI Environmental Rules: Flood Elevation Requirements (2026)

030 as the water surface elevation of the 100-year flood. Once the structure is finished, an engineer or surveyor must certify the actual lowest-floor elevation on FEMA's 'elevation certificate' form and give a copy to the director of public works. In zone AO, where the flood insurance rate map shows a flood depth rather than an elevation, the lowest floor instead has to sit above the highest adjacent grade by at least one foot over the mapped depth number, or three feet if no depth number is shown, again certified on the same FEMA form.

Nonresidential buildings may floodproof instead of elevating, but only if the walls below base flood level are made substantially impermeable, the structure can resist hydrostatic and hydrodynamic loads, and an engineer or architect certifies compliance on FEMA's floodproofing certificate. Manufactured homes get the identical one-foot-above-base-flood-elevation floor requirement under subsection D, and utilities, HVAC and other service equipment must be located at least one foot above the base flood elevation under subsection A(2)(c) so floodwater cannot enter or accumulate in them.