The "1% annual chance flood" is a new definition for the 100-year flood.
The "0.2% annual flood" is a new definition for the 500-year flood.
The "Base Flood Elevation value" is shown as a number within a wavy line; this number is the approximate elevation of the 1% annual chance of flood rounded off to the nearest foot, referenced to the North American Vertical datum of 1988.
No elevations are shown on the maps for the 0.2% annual chance of flood.
The lettered Cross section lines correspond to the profiles in the Flood Insurance Study, where additional and more accurate elevations are available.