70 ILCS 2805/32e
The trustees of any district, having been authorized by an election held pursuant to Section 32d, and being desirous of exercising such authority, shall have an estimate made of the cost of the acquisition or construction of the contemplated waterworks, and by ordinance shall provide for the method of financing such acquisition or construction. The ordinance shall set forth a brief description of the contemplated waterworks, the estimated cost of acquisition or construction thereof, the method of financing such acquisition or construction, the amount, rate of interest, time and place of payment, and other details in connection with the issuance of any bonds necessary therefor. If all or part of such financing is to be by issuance of revenue bonds, such bonds shall bear interest at not exceeding the rate permitted by "An Act to authorize public corporations to issue bonds, other evidences of indebtedness and tax anticipation warrants subject to interest rate limitations set forth therein", approved May 26, 1970, as amended, payable semi-annually, and shall be payable at such times and places not exceeding 30 years from their date as shall be prescribed in the ordinance providing for their issuance.
This ordinance may contain such covenants and restrictions upon the issuance of additional revenue bonds thereafter as may be deemed necessary or advisable for the assurance of payment of the bonds thereby authorized and as may be thereafter issued, and shall pledge the revenues derived from the operation of the waterworks for the purpose of paying all maintenance and operation costs, principal and interest on all bonds issued under the provisions of this Act, and for providing an adequate depreciation fund, which depreciation fund is hereby defined for the purposes of this Act to be for such replacements as may be necessary from time to time for the continued effective and efficient operation of the waterworks properties of such district, and such fund shall not be allowed to accumulate beyond a reasonable amount necessary for that purpose, the terms and provisions of which shall be incorporated in the ordinance authorizing the issuance of the revenue bonds.
70 ILCS 2805/32e