The Department of Natural Resources, upon the issuance of any permit under the provisions of Section 18 of this Act, shall have the right to enter into an agreement with any person, firm or corporation to whom a permit is issued, by the terms of which agreement the person, firm or corporation may take earth, stone, sand or gravel, or any combination of these materials, from the bed or below the bed of any public waters within the State at a price based upon the fair market value for any material or combinations of materials so taken.
     The Department of Natural Resources may however, permit any municipal corporation or political subdivision of the State of Illinois or any governmental unit or agency of the State, or the Federal Government or any agency of the Federal Government, to take the earth, stone, sand or gravel, or any combination of these materials, without compensation if the municipal corporation, political subdivision, or governmental unit or agency of the State, or the Federal Government or agency of the Federal Government, proposes to furnish the material in connection with any public project or construction work, and is not acting for or on behalf of any person, firm or corporation who is required to furnish the material.