This act shall be construed as granting cumulative authority for the exercise of the various powers herein conferred, and neither said powers nor any bonds 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 herein, it being the purpose and intention of this act to create full, separate and complete additional powers. The various powers conferred herein may be exercised independently and notwithstanding that no bonds are issued hereunder.