70 ILCS 3110/19
(a) The rates, rentals, fees, and charges of the Service in connection with the project shall be so fixed, revised, and collected as to provide funds, with other funds available for such purposes, sufficient at all times:
(c) The revenues, or any part thereof, whether derived from the project or projects in connection with which the bonds of any issue shall have been issued or from other projects or sources, designated as security for such bonds by the authorizing resolution or in the trust agreement securing the bonds shall be set aside at such regular intervals as may be provided in such resolution or trust agreement in a special fund which is hereby pledged to, and charged with, the payment of:
(4) The redemption price or purchase price of bonds retired by call or purchase as provided in such resolution or trust agreement.
Any amounts set aside in such special fund which are not needed to provide for the payment of the items listed in paragraphs (1), (2), (3) and (4) may be used for any other lawful purpose, to the extent provided in such resolution or trust agreement. Such pledge shall be valid and binding from the time when the pledge is made. Such revenues or other moneys so pledged and thereafter received by the Service shall immediately be subject to the lien of such pledge without any physical delivery thereof or further act, and the lien of any such pledge shall be valid and binding as against all parties having any claims of any kind in tort, contract or otherwise against the Service, irrespective of whether such parties have notice thereof.
Neither the resolution nor any trust agreement by which a pledge is created need be filed or recorded except in the records of the Service, any State or local law to the contrary notwithstanding. The use and disposition of moneys to the credit of such special fund shall be subject to the provisions of the resolution authorizing the issuance of such bonds or of such trust agreement.
(from Ch. 111 1/2, par. 7119)
(Source: P.A. 84-1320.)