FEMA updates floodplain designations periodically for communities in the
National Flood Insurance Program. Although these maps are accurate at
the time they are updated, it may be several years between these
updates. In that time, new development in and around floodplains can
alter the areas at risk of flooding through the creation of more
impervious surface. Therefore, existing or new homes built near the
floodplain boundaries may actually be at greater risk of flooding than
is assessed in the most recent flood map.
Some communities have done analyses of the effects of increased
development in and around the floodplain and have created their own
updated flood risk maps between FEMA updates. Mecklenburg County, North
Carolina provides a good example of this process
Has anyone else taken such progressive approaches to updating their local floodplain designations?