(a) Every municipality or county commission issuing bonds under the provisions of this article shall thereafter, so long as any of such bonds remain outstanding, repair, maintain and operate its waterworks or electric power system as hereinafter provided and shall charge, collect and account for revenues therefrom as will be sufficient to pay all repair, maintenance and operation costs, provide a depreciation fund, retire the bonds and pay the interest requirements of the bonds as the same become due. The ordinance or order pursuant to which any such bonds are issued shall pledge the revenues derived from the waterworks or electric power system to the purposes aforesaid and shall definitely fix and determine the amount of revenues which shall be necessary and set apart in a special fund for the bond requirements. The amounts as and when so set apart into said special fund for the bond requirements shall be remitted to the West Virginia Municipal Bond Commission to be retained and paid out by said commission consistent with the provisions of this article and the ordinance or order pursuant to which such bonds have been issued: Provided, That payment of principal of and interest on any bonds owned by the United States of America or any agency or department thereof may be made by the municipality or county commission directly to the United States of America or said agency or department thereof. The bonds hereby authorized shall be issued in such amounts as may be determined necessary to provide funds for the purpose for which they are authorized, and in determining the amount of bonds to be issued it shall be proper to include interest on the bonds for a period not beyond six months from the estimated date of completion.
(b) If the proceeds of the bonds, because of error or otherwise, shall be less than the cost of the property or undertaking for which authorized, additional bonds may be issued to provide the amount of such deficit and such additional bonds shall be considered to be of the same issue and shall be entitled to payment from the same fund without preference or priority over the bonds first authorized and issued.
(c) If the proceeds of the bonds shall exceed the cost of the property or undertaking, the surplus shall be converted into the fund thereon.