All powers of any public body created under this subchapter shall be exercised by, or under the authority of, and the business and affairs of the public body managed under the direction of, its board of commissioners, subject to any limitation set forth in the public body's certificate of incorporation or interlocal agreement. The duties of the board of commissioners shall include, but not be limited to:
(1) Appointing a chief executive officer, who shall not be a member of the board of commissioners, and shall set compensation and other terms of employment for the chief executive officer;
(2) Approving all budgets of the public entity;
(3) Adopting such rules and bylaws as the board of commissioners may deem necessary and expedient for the proper ownership and operation of the consolidated waterworks system, and altering, changing, or amending the rules and bylaws at its discretion; and
(4) Performing such other duties as shall be set forth in the interlocal agreement.