No modifications or additions to a nonconforming use shall be permitted
unless they are made in conformity with the provisions of this chapter
for the area of floodplain occupied. The words "modification" and
"addition" shall include, but not be limited to, any alteration, addition,
modification, structural repair, rebuilding or replacement of any
such existing use, structure or accessory structure or use. Ordinary
maintenance repairs are not considered modifications or additions;
these include internal and external painting, decorating, paneling
and the replacement of doors, windows and other nonstructural components
and the maintenance, repair or replacement of existing private sewage
or water supply systems or connections to public utilities.