It is the legislative intent of the City of Louisville to discourage the survival of nonconforming uses, to prevent their enlargement or expansion, and to prevent their establishment elsewhere in the same Zoning District. The purpose of this chapter is to provide for the continuation and termination of nonconforming uses, structures, and lots that do not conform to the existing zoning, but which were legally in existence or operation prior to the enactment of this UDO or amendments thereto.