This article shall be construed as granting cumulative authority for the exercise of the various powers herein conferred, and neither the powers nor any bonds or notes issued hereunder shall be affected or limited by any other statutory or charter provision now or hereafter in force, other than as may be provided in this article, it being the purpose and intention of this article to create full, separate and complete additional powers. The various powers conferred herein may be exercised independently and notwithstanding that no bonds or notes are issued hereunder.