Before the issuance of any bonds under the provisions of this article, the authority shall, by resolution, provide for a sinking fund for the payment of the bonds and the interest thereon, and the payment of the charges of banking institutions or trust companies for making payment of such bonds and interest, out of the net revenues of said system, and, in this connection, shall set aside and pledge a sufficient amount of the net revenues of the system for such purpose, such net revenues being hereby defined to mean the revenues of the system remaining after the payment of the reasonable expense of administration, maintenance, repair and operation, such amount to be paid by such authority into the sinking fund at intervals, to be determined by resolution adopted prior to the issuance of the bonds, for: (a) The interest upon such bonds as such interest shall fall due; (b) the necessary fiscal agency charges for paying bonds and interest; (c) the payment of the bonds as they fall due, or, if all the bonds mature at one time, the proper maintenance of a sinking fund sufficient for the payment thereof at such time; and (d) a margin for safety and for the payment of premium upon bonds retired by call or purchase as provided in this article. Such required payments shall constitute a first charge upon all the net revenues of such authority. Prior to the issuance of any bonds, the authority may, by resolution, be given the right to use or direct the West Virginia Municipal Bond Commission to use such sinking fund, or any part thereof, in the purchase of any of the outstanding bonds payable therefrom, at the market prices thereof, but not exceeding the price, if any, at which the same shall in the same year be payable or redeemable, and all bonds redeemed or purchased shall forthwith be cancelled, and shall not again be issued. In addition to the payments into the sinking fund provided for above, the authority may at any time in its discretion transfer all or any part of the balance of the net revenues, after reserving an amount deemed by such authority sufficient for maintenance, repair and operation for an ensuing period of not less than twelve months and for depreciation, into the sinking fund.

The amounts of the balance of the net revenues as and when so set apart shall be remitted to the West Virginia Municipal Bond Commission at such periods as shall be designated in the resolution, but in any event at least thirty days previous to the time interest or principal payments become due, to be retained and paid out by said commission consistent with the provisions of this article and the resolution pursuant to which such bonds have been issued. The West Virginia Municipal Bond Commission is hereby authorized to act as fiscal agent for the administration of such sinking fund under any resolution adopted pursuant to the provisions of this article and shall invest all sinking funds as provided by general law. Notwithstanding the foregoing, payments of principal and interest on any bonds owned by the United States or any governmental agency or department thereof may be made by the authority directly thereto.