70 ILCS 1835/6.1
The District may lease to others for any period of time, not to exceed 99 years, upon such terms as its Board may determine, any of its real property, rights of way or privileges, or any interest therein or any part thereof, for industrial, manufacturing, commercial, or harbor purposes, which, in the opinion of the Port District Board is no longer required for its primary purposes in the development of port and harbor facilities for the use of public transportation, or which may not be immediately needed for such purposes, but where such leases will in the opinion of the Port District Board aid and promote such purposes, and in conjunction with such leases, the District may grant rights of way and privileges across the property of the District, which rights of way and privileges may be assignable and irrevocable during the term of any such lease and may include the right to enter upon the property of the District to do such things as may be necessary for the enjoyment of such leases, rights of way and privileges, and such leases may contain such conditions and retain such interest therein as may be deemed for the best interest of the District by such Board.
70 ILCS 1835/6.1