65 ILCS 5/9-3-23
All contracts awarded by any municipality for the construction of any improvement authorized and provided for under this Division 3 shall be payable solely and only out of the assessment levied to pay the cost of the construction thereof. No person taking any contracts for the construction of any improvement provided for under this Division 3 shall have any claim or lien upon such municipality in any event except from the collection of the special assessments levied for the payment of the cost of the work. If it appears that such assessment cannot be levied or collected, such municipality shall not be in any way liable to any such contractor in case of failure to collect the same, but shall so far as it can legally do so with all reasonable diligence cause a valid assessment to be made to defray the cost of the work until any such contractor has been fully paid. Any contractor shall be entitled to summary relief or mandamus or injunction to enforce the provisions hereof.
The treasurer of any such municipality shall keep a separate account for each special assessment.
65 ILCS 5/9-3-23