Within the districts established by the Zoning Ordinance or amendments that may later be adopted there exists lots, uses of land, structures, and uses of structures and land in combination which were lawful before the Zoning Ordinance was passed or amended, but which would be prohibited, regulated, or restricted under the terms of the Zoning Ordinance or future amendments. It is the intent of the Zoning Ordinance to permit these nonconformities to continue until they are removed, but not to encourage their survival. It is further the intent of the Zoning Ordinance that nonconformities shall not be enlarged upon, expanded or extended, nor be used as grounds for adding other structures or uses prohibited elsewhere in the same district.