65 ILCS 5/9-3-20
The judgment of the court shall be final as to all issues involved and the proceedings in such case shall be subject to review by appeal, as hereinafter provided, and not otherwise. However, by mutual consent the judgment may be vacated or modified notwithstanding the expiration of 30 days of the rendition of such judgment, except as hereinafter provided.
Such judgments shall have the effect of several judgments as to each tract or parcel of land assessed. No appeal from any such judgment shall invalidate or delay the judgments except as to the property concerning which the appeal is taken. Each installment of each judgment, shall have the effect of several judgments. Foreclosure or sale of the property, to enforce the collection of any one installment, shall not affect the lien for any subsequent installment.
Such judgments shall be liens on behalf of the municipality making the improvements and for the payment of which the special assessment is levied on the property assessed from the date thereof until paid, to the same extent and of equal force and validity as a lien for general taxes, or until the property against which any such judgments or installment thereof has been entered is sold to pay the same, as provided in this Division 3.
Nothing in this section shall interfere with the right of the petitioner to abandon the proceedings, and for that purpose to vacate such judgments at any time before commencing the actual collection of such assessment. The court in which the judgment is rendered may enter an order vacating or modifying such order of confirmation on motion of the petitioner entered at any time after the expiration of 30 days from the rendition of such judgment of confirmation upon a showing by the petitioner that no contract was let or entered into for the making of such improvement within the time fixed by law for the letting of the contract, or that the making of such improvement under the original proceeding was never commenced, or that the making of such improvement under the proceedings was abandoned. No judgment entered in such proceedings so dismissed and vacated, shall be a bar to another like or different improvement. However, after the contract for the work is entered into, or bonds herein provided for in this Division 3 are issued, no judgment shall be vacated or modified or any petition dismissed, nor the collection of the assessment, in any way stayed or delayed, without the consent of the contractor and bondholders.
65 ILCS 5/9-3-20