The council shall have the power to fix all rates and charges for water, light, heat, and all other utilities provided by plants owned by the city, but such rates and charges shall be just and reasonable. In like manner the council may prescribe the time and manner in which payments for all such services shall be made, and the manner in which water and electric current shall be computed or measured, whether by meter or flat rate, and make such other regulations as may be necessary, and may prescribe penalties for violations for such regulations.