The county board is hereby given the authority to lease all or any part of any such parking facilities, and to fix and collect the rentals therefor, and to fix, charge and collect rentals, fees and charges to be paid for the use of the whole or any part of any such parking facilities, and to make contracts for the operation and management of the same, and to provide for the use, management and operation of such parking facilities through lease or by its own employees, or otherwise; provided, however, that no lease for the operation or management of any such parking facilities shall be made for more than one year, except to the highest and best bidder after notice requesting bids shall have been given by at least one publication in some newspaper of general circulation published in the county, such publication to be made once each week for at least two weeks before the date of receiving bids therefor. All income and revenue derived from any such lease or contract shall be deposited in a separate account and used solely and only for the purpose of maintaining and operating the project, and paying the principal of and interest on any bonds issued pursuant to ordinance under the provisions of this Division. Further any contract or obligation involving the borrowing of money for such purposes, incurred by the county board in the maintenance and operation of any such parking facilities shall be payable solely and only from the revenues derived from the operation of the project.