The Council may, by ordinance, adopted by the affirmative vote of two-thirds of all of its members, establish a Board of Sewer Commissioners for the City, with general independent powers to acquire, establish, improve, operate, maintain and repair a municipal sewer system or system or systems, or to assess the users thereof with the cost thereof. The specific powers, duties and compensation of such Board shall be set forth in the ordinance establishing it, and such powers, duties and compensation may be amended and supplemented by subsequent ordinances, adopted by the affirmative vote of two-thirds of all of the members of the Council. The Board shall consist of five members, two of whom shall be the Manager and the Engineer ex officio. The other three members shall be appointed by the Mayor, subject to the approval of the Council, for terms of six years each; provided, that the first three members shall serve for terms of two, four and six years, respectively, thereafter, a member of the board shall be appointed each two years for a full six year term. The Council shall, by a vote similar to that creating the Board, have the power to abolish the Board; in such event the terms of its members shall be terminated, the property belonging to the said Board shall become the property of the City, and the powers and duties thereof shall pass to such person or board as the Council may designate.