70 ILCS 605/4-7
In all districts which, at the time this Act goes into effect, were operating and existing under the provisions of the Levee Act, or under the provisions of any other act repealed by this Act except the Farm Drainage Act, the commissioners thereof shall hereafter be appointed in the same manner and with like qualifications as though the districts had been originally organized under this Act unless the landowners have elected to change from the appointment to the election of commissioners in the manner provided in Section 4-8. The commissioners in office at the time this Act goes into effect shall continue as commissioners of the district under this Act until the expiration of their terms of office and until their successors are selected and shall have qualified as provided in this Act. Commissioners appointed under this section shall, within 20 days after their appointment, qualify by subscribing to an oath of office and giving bond, in the manner provided in Section 4-4.
70 ILCS 605/4-7