When bonds shall have been issued by the city as provided under section 16-676, the mayor and city council shall have power to levy annually upon all taxable property of the city such tax as may be necessary for a sinking fund for the payment of accruing interest on such bonds and the principal thereof at maturity, and to provide for the office of water commissioner, power commissioner, light commissioner, or heat commissioner, and to prescribe the powers and duties of such officers.