70 ILCS 605/9-8
The merging of any district into a consolidated district shall not affect the obligation of any contract entered into by the merged district nor invalidate or otherwise affect the levy, extension or collection of any assessments upon property in such merged district. Such contracts shall be taken over and assumed by the consolidated district. All assessments shall be collected and the proceeds therefrom shall be expended or disposed of by the consolidated district in the same manner as such assessments might have been collected, expended or disposed of by the individual districts.
If an annual maintenance assessment has been levied in one or more of the districts so consolidated such annual maintenance assessment or assessments shall remain unimpaired by such consolidation and the commissioners of the consolidated district shall have the power to make and file a certificate of levy of an annual maintenance assessment in the same manner as is provided in this Act for other districts. If the commissioners of the consolidated district determine that (a) the annual maintenance assessment is insufficient or (b) is not properly equalized on the lands and other property in the consolidated district they may petition the court for leave to levy an annual maintenance assessment to supersede the former annual maintenance assessment or assessments levied by the individual district or districts. Any such petition shall be filed, set for hearing and heard after notice in the manner provided in Sections 4--19 to 4--24, inclusive. If the court finds that the existing annual maintenance assessment is insufficient or is not properly equalized on the lands or other property in the consolidated district then its order shall include a provision setting aside and vacating the former annual maintenance assessment or assessments effective upon the confirmation of the new annual maintenance assessment roll, but such order shall not in any way affect the collection of any annual maintenance assessments due and unpaid at the time of the confirmation of the new roll.
70 ILCS 605/9-8