In any district heretofore organized or existing under the Levee Act in which, prior to the effective date of this Act, there has been levied an assessment of the "Annual Amounts of Benefits" upon the lands in such district for keeping the levees, ditches and other works in repair or to maintain in operation any pumping plant, such assessment of "Annual Amount of Benefits" shall continue as the annual maintenance assessment in such district under the provisions of this Act until the same shall be increased, reduced, abated or otherwise changed or a new annual maintenance assessment levied in lieu thereof by proceedings under this Act.
Any annual maintenance assessments due and unpaid at the time this Act becomes effective shall be collectible in the same manner as if this Act had not been enacted and, in addition, any remedies for the collection of annual maintenance assessments provided by this Act shall be available for the collection of any such annual maintenance assessments due and unpaid on the effective date of this Act.
70 ILCS 605/12-20