70 ILCS 2805/25
When, in making any improvements which any district is authorized by this Act to make, it shall be necessary to enter upon and take possession of any existing drains, sewers, sewer outlets, plants for the purification of sewage or water, or any other public property, or property held for public use, the board of trustees of such district shall have the power to do and may acquire the necessary right of way over any other property held for public use in the same manner as is herein provided for acquiring private property, and may enter upon, and use the same for the purposes aforesaid: Provided, the public use thereof shall not be unnecessarily interrupted or interfered with, and that the same shall be restored to its former usefulness as soon as possible.
70 ILCS 2805/25