Refunding bonds shall be special obligations of the public body and shall be payable solely from and secured by a lien upon the gross revenues or net revenues of the enterprise, as shall be more fully described in the ordinance or resolution authorizing the issuance of refunding bonds, and the ordinance or resolution authorizing such refunding bonds shall provide for a special fund into which there shall be pledged a fixed amount or a fixed proportion of such revenues which shall be sufficient to pay the principal of and interest on the refunding bonds as the same become due.

In order to assure payment of the principal and interest on any refunding bonds it shall be the duty of the governing body of the public body to establish, levy, maintain and collect such fees, tolls, rentals, rates and other charges for the services of such enterprise as shall be necessary to produce revenues sufficient, after making due and reasonable allowance for contingencies and for a margin of error in estimates, to pay at all times principal of and interest on the refunding bonds as the same become due, to pay current expenses of operation and maintenance, to provide for depreciation, to provide for reserves for any of the foregoing, to comply in all respects with any contract or agreement with bondholders set forth in the ordinance or resolution authorizing such refunding bonds, and to meet any other obligations of the public body which by their terms are charges, liens, or encumbrances upon the revenues of such enterprise.

The ordinance or resolution authorizing any refunding bonds may contain such covenants with the holders of the refunding bonds as to the efficient management and operation of the enterprise; the collection, keeping and disposition of the revenues of the enterprise; the issuance of additional refunding bonds or revenue bonds; the carrying of insurance on such enterprise and the disposition of insurance proceeds; the keeping of books and records and the auditing thereof; the inspection by bondholders at reasonable times of the enterprise and the records, accounts and data of the public body relating thereto; limitations upon the sale or other disposition of integral parts of the enterprise; the discontinuance of the services and facilities of the enterprise upon failure to pay for such services and facilities; the appointment and duties of a trustee; the rights, liabilities, powers and duties arising upon the breach by the public body of any covenants, conditions or obligations contained in the ordinance or resolution authorizing the issuance of such refunding bonds; remedies of bondholders upon default in the payment of the principal of or interest on any refunding bonds, including the appointment by a court of competent jurisdiction of a receiver for the operation and management of the enterprise and the collection and disbursement of the revenues thereof, but such receiver or any court having jurisdiction in the matter shall not be permitted to sell, mortgage or otherwise dispose of any assets of the enterprise and useful in its operation or cause any of such assets to be sold, mortgaged or otherwise disposed of; and any other conditions, acts or pertinent matters as may be deemed necessary or proper by the governing body of the public body to assure efficient operation of the enterprise, payment of the refunding bonds and marketability of the refunding bonds upon favorable terms. Any agreement or covenant contained in the ordinance or resolution authorizing such refunding bonds shall constitute a contract with the holders of such refunding bonds.

All refunding bonds of the same issue shall be equally and ratably secured, without priority by reason of number, date or time of sale, execution or delivery, by a lien upon the revenues of the enterprise in accordance with the provisions of this section and the ordinance or resolution authorizing the issuance of such refunding bonds.

Nothing in this section or in any other section of this article shall be deemed in any way to alter the terms of any agreements made with the holders of any outstanding revenue bonds of the public body, or to authorize the public body to alter the terms of any such agreements, or to impair, or authorize the public body to impair, the rights and remedies of any creditors of the public body.

Nothing in this section or in any other section of this article shall be deemed in any way to authorize any public body to do anything in any manner or for any purpose which would result in the creation or incurring of a debt or indebtedness or the issuance of any instrument which would constitute a bond or debt within the meaning of any provision, limitation, or restriction of the Constitution relating to the creation or incurring of a debt or indebtedness or the issuance of an instrument constituting a bond or a debt.