The governing body or bodies may provide by the said ordinance or ordinances authorizing the issuance of the bonds or in the trust indenture hereinafter referred to, that additional bonds may thereafter be authorized and issued at one time, or from time to time, under such limitations and restrictions as may be set forth in said ordinance or ordinances, or trust indenture, or all of these, for the purpose of improving, renovating, extending, enlarging, increasing, equipping or repairing (including replacements) the works when deemed necessary in the public interest, such additional bonds to be secured, and be payable from the revenues of the works, as provided for in section nine of this article.