Note: AO-Zones involve more sand transport and hazard to property than other A-Zones. FEMA recommends Coastal AO-Zones be treated as V-Zones for design and risk analysis. In terms of sand transport and flooding, AO-Zones act more like V-Zones, with only a foot of sea-level rise (or lowering of the beach and dune profile) an AO-Zone will become a V-Zone.
Most coastal sand dune systems have been identified by the Maine Geological Survey (MGS) and are shown at 1:4,800 scale in Coastal Sand Dune Geology Maps dated 2023.
Note: Maine Geological Survey's most recently updated Coastal Sand Dune Maps are available for viewing or download at https://www.maine.gov/dacf/mgs/pubs/digital/dunes.htm.
or any portion of the coastal sand dune system that is mapped as an AO flood zone by the effective FEMA Flood Insurance Rate Map, which is presumed to be located in an Erosion Hazard Area unless the applicant demonstrates based upon site-specific information, as determined by the department, that a coastal wetland will not result from either (1), (2), or (3) occurring on an applicant's lot given the expectation that an AO-Zone, particularly if located immediately behind a frontal dune, is likely to become a V-Zone after 2 feet of sea level rise in 100 years.
06-096 C.M.R. ch. 355, § 3