The owner or developer shall, prior to review of the plans and construction, deposit with the Village a sum of money as prescribed by the Manager to defray the cost of engineering and inspection services to be provided, and any expense incurred by the Village due to review of the plans and installation of the improvements. Should the amount of such deposit be insufficient to pay the cost thereof, the owner or developer shall immediately, upon demand, deposit such additional sums as are estimated by the Manager to be necessary. Upon satisfactory completion of the improvement any unexpended balance remaining from such deposits shall be refunded.