70 ILCS 1230/1
Every board of park commissioners existing under the laws of this state, which has now, or may hereafter have or acquire control over any public park, boulevard or driveway bordering upon any public waters in this state shall have the power to extend such park, boulevard or driveway over and upon the bed of such public waters, and that every board of park commissioners existing under the laws of this state, which now has, or may hereafter have or acquire, control over two or more separate public parks, whether they constitute a part of one park system or not, bordering upon any public waters in this state, shall have power to connect the same by constructing a park, boulevard, driveway or parkway, extending over and upon the submerged land and bed of such public waters, and over and upon any lands adjacent to or adjoining upon or penetrating into such waters, and may extend any such park by constructing a park, boulevard, driveway or parkway over any private property, and over any navigable river or any part thereof which lies within the territory, the property of which shall be taxable for the maintenance of the park under the control of said board of park commissioners, so as to connect such park, boulevard, driveway or parkway with any park, boulevard, driveway or parkway now or hereafter constructed, and connected with or forming a part of any other park system; and in extending such park or in constructing such park, boulevard, driveway or parkway, the said board of park commissioners may construct such viaducts, bridges or tunnels or parts of viaducts, bridges or tunnels, within its said territory as to it may seem necessary, and that every such board of park commissioners may acquire the lands, or the riparian or other rights of the owners of lands, or both, whether of individuals or corporations, on the shores adjacent to or adjoining the public waters or rivers in which it is proposed to construct any such park, boulevard, driveway or parkway, or extension or connection, also the title of the private or public owners, if any there be, to lands lying beneath, adjacent to or adjoining such public waters or rivers, also the title of any lands penetrating into such public waters and the title of any lands into, upon or over which it is proposed to construct any such park, boulevard, driveway or parkway or any such extension or connection, or any viaduct, bridge or tunnel forming a part thereof, by contract with or deed from any such owner or owners, whether individuals or corporations, or by condemnation: Provided, however, that no extension which shall be made shall interfere with the practical navigation of such public waters or rivers for the purposes of commerce, without due authority from the proper official of the United States government having control thereof. Said board of park commissioners and said riparian or adjacent owners are hereby authorized to agree upon a boundary line dividing such adjacent, adjoining, submerged and penetrating lands, acquired or to be acquired by said board of park commissioners, and such adjacent, adjoining, submerged and penetrating lands to be taken, owned and used by said riparian or other owners in lieu of and as compensation for the release of said lands and riparian rights to said board of park commissioners. In case said board of park commissioners are unable to agree with and such owner or owners or persons interested, either as to such boundary or dividing line and such lands to be taken by such riparian or other owners and persons interested as compensation for the release and granting of said lands and riparian or other rights or in case the compensation to be paid for or in respect of the property, riparian or other rights, the adjacent, adjoining, submerged and penetrating or other lands sought to be appropriated or damaged for the purposes mentioned in this act, cannot be agreed upon by the parties interested, or in case the owner of the property is incapable of consenting, or his name or residence is unknown, or he is a non-resident of the state, or, if in any event, the said board of park commissioners shall elect to acquire the riparian or other rights, or the adjacent, adjoining, submerged, and penetrating or other lands, or any such rights or lands, proceedings may be had to condemn the said riparian or other rights and the said adjacent, adjoining, submerged and penetrating or other lands, or any of them, according to the provisions for the exercise of the right of eminent domain under the Eminent Domain Act .
70 ILCS 1230/1