The City Commission shall at all times control the distribution of space in, over, under or across all streets or public grounds occupied by public utility fixtures. All rights granted for the construction and operation of public utilities shall be subject to the continuing right of the City Commission, to require such reconstruction, relocation, change or discontinuance of the appliances used by the utility in the streets, alleys, avenues or highways of the City, as shall in the opinion of the City Commission be necessary in the public interest.