70 ILCS 1205/3-4
Any park districts, may be annexed to and become a part of any other adjoining park district in the manner following:
Upon the filing of a petition in the office of the circuit clerk of the county in which the annexing district or the greater or greatest portion thereof is located, signed by voters in number equal to at least 5% of the legal voters voting at the last general election in the district proposed to be annexed and by voters in number equal to at least 5% of the legal voters voting at the last general election in the district to which such annexation is proposed to be made, the circuit court for such county shall order the question of such annexation to be submitted to the legal voters of both park districts, in the manner prescribed in Section 3-3 hereof. The debts and obligations of the annexed district shall be transferred as provided in Section 3-5 hereof.
70 ILCS 1205/3-4