The commission shall at all times control the distribution of space occupied by public utility appliances and fixtures in, over, upon or under the streets, alleys, public ways, places and grounds of the city; and all rights granted for the construction and operation of any public utility shall be subject to the continuing right of the commission to require such reconstruction, relocation, change or discontinuance of the appliances and fixtures so used by the utility as, in the opinion of the commission shall be necessary to the public interest.