70 ILCS 3705/28
Within 20 days after receiving a copy of such order, the chairman of the board of trustees of the public water district shall call a meeting of the board to consider the question of annexing the territory described therein to the district. A two-thirds vote of the board is required to annex such territory to the district and action of the board shall be by ordinance of annexation and the vote on such ordinance shall be entered upon the records of the district. If the vote of two-thirds of the members of the board is favorable to annexation of such territory the secretary of the board shall file a certified copy of the ordinance of annexation with the court that ordered the consideration of such question, which ordinance shall be filed in the records of such court.
70 ILCS 3705/28