70 ILCS 1250/2
Whenever any such board of park commissioners shall determine to extend any such boulevard or driveway under this Act, said board shall prepare a plan of such proposed extension, and make an estimate of the cost thereof, and shall obtain the consent in writing of the owners of at least two-thirds of the frontage of all of the lands not appropriated to or held for public use abutting on such public waters, in front of which it is proposed to extend such boulevard or driveway for the making of such extension, and shall also obtain the consent of the supervisor and assessor corporate authorities of the town or towns in which the lands abutting on such public waters in front of such proposed extension may lie, to the making of such extension. The riparian or other rights of the owners of lands on the shore adjoining the waters in which it is proposed to construct such extension, the said board of park commissioners may acquire by contract with or deeds from any such owner; and in case of inability to agree with any such owner, proceedings may be had to condemn such rights according to the provisions of the Eminent Domain Act .
70 ILCS 1250/2