The city may own and operate any gas, water, heat, power, light, telephone or other public utility for supplying its own needs for utility service or for supplying utility service to private consumers or both. It may construct all facilities reasonably needed for that purpose and may acquire any existing utility properties so needed; but no proceedings to acquire any such public utility shall be consummated unless the city has the money in the treasury to pay for acquisition or has made provision for paying for the property proposed to be acquired. The operation of all public utilities owned by the city shall be under the supervision of the city council.