When nonconforming use of property is discontinued through vacancy, lack of operation, or other similar condition, and upon a showing of intent of the owner or holder of the nonconforming use status to discontinue said use, for a period of 6 months or more, thereafter no right shall exist to maintain on that property a nonconforming use unless the Board of Zoning Appeals grants that privilege within 6 months after the discontinuance. No nonconforming use, if changed to a use permitted in the district in which it is located, shall be resumed or changed back to a nonconforming use.