When required accessory off-street parking facilities are provided elsewhere than on the lot on which the principal use served is located, they shall be in the same possession, either by deed or long-term lease, as the property occupied by such principal use.  The owner of such property shall be bound by covenants filed of record in the office of the Recorder of Deeds of Cook County requiring the owner and his or her heirs and assigns to maintain the required number of parking spaces during the existence of such principal use.