A structure or use of a structure or premises which lawfully
existed before the enactment of these provisions but which is not
in conformity with these provisions may be continued subject to the
following conditions:
A. Existing structures in the floodway area shall not be expanded or
enlarged unless it has been demonstrated through hydrologic and hydraulic
analyses performed in accordance with standard engineering practice
that the proposed expansion would not result in any increase in the
base flood elevation.
B. Any modification, alteration, repair, reconstruction, or improvement
of any kind to a structure and/or use located in any floodplain area
to an extent or amount of less than 50% of its market value shall
conform to the Virginia USBC and the provisions of this chapter.
C. The modification, alteration, repair, reconstruction, or improvement
of any kind to a structure and/or use, regardless of its locations
in a floodplain area, to an extent or amount of 50% or more of its
market value shall be undertaken only in full compliance with the
provisions of this chapter and the Virginia Uniform Statewide Building
Code.