When a substantial portion of the required improvement has been completed to the satisfaction of the director of public works and the completion of the remaining improvements is delayed due to conditions beyond the owner's control, the director of public works may accept the completed portion and consent to a proportionate reduction of the surety bond or the cash bond in an amount estimated and determined by the director of public works to be adequate to assure the completion of the required improvements remaining to be made. (Ord. 2017-0009 § 11)