65 ILCS 5/11-15.2-1
If authorized by an agreement approved by the court pursuant to notice as required by Section 4-22 of the Illinois Drainage Code (70 ILCS 605/4-22), a municipality and a drainage district may enter into an implementing agreement to provide for the automatic detachment of land from the drainage district when the land is annexed to the municipality. An implementing agreement shall not be required to comply with the provisions of Sections 4-19 through 4-24 of the Illinois Drainage Code (70 ILCS 605/4-19 through 605/4-24) and may authorize the filing of certificates as provided in this Section.
Upon the filing of a certificate, executed by a drainage district in compliance with Section 4-11 of the Illinois Drainage Code (70 ILCS 605/4-11) and by an annexing municipality, the land described in the certificate shall be detached from the drainage district and annexed to the annexing municipality as of the date of filing. The certificate shall be filed with the drainage district clerk and the county clerk where the land is located. The legal effect of the filing of a certificate shall be the same as a court order entered pursuant to Section 8-20 of the Illinois Drainage Code (70 ILCS 605/8-20).
65 ILCS 5/11-15.2-1