The Service Department of this City shall consist of a Service Director and such employees as the Mayor shall from time to time deem necessary. The Service Director shall be the head of the Service Department, under the direction of the Mayor. He or she shall have such powers and perform such duties as are provided by ordinance of the City for a Street Commissioner, if any, and shall be responsible for the maintenance and repair of all streets, public sewers, the removal of snow and ice from the streets, the collection and disposal of rubbish and garbage and all matters incidental to the foregoing.