55 ILCS 5/5-32035
Any work or other public improvement to be paid for by special assessment shall be constructed by contract let to the lowest responsible bidder in the manner prescribed in this Division. Such contract shall be approved by the Committee.
Within 90 days after judgment of confirmation of any special assessment levied in pursuance of this Division has been entered, if there is no appeal perfected, or other stay of proceedings by a court having jurisdiction, or the judgment of confirmation as to any property is appealed from, then if the petitioner files in the case a written election to proceed with the work, notwithstanding the appeal, or other stay, steps shall be taken to let the contract for the work in the manner provided in this Division. If the judgment of confirmation of the special assessment levied for the work is appealed from, or stayed by order of court having jurisdiction, and the petitioner files no such election then the steps provided in this Division for the letting of the contract for the work shall be taken within 15 days after the final determination of the appeal, or the determination of the stay, unless the proceeding is abandoned as provided in this Division.
55 ILCS 5/5-32035