Whenever an excavation for any purpose is made or permitted in a public street under or by the order of the department having power to grant such permit, the street shall be restored to its normal condition by the person or department making the excavation, without unnecessary delay, and if it is not restored in a manner satisfactory to the superintendent of streets, although it may not be dangerous to public travel, the superintendent of streets shall notify the person who made the excavation forthwith to make such further restoration as the superintendent deems necessary, and if such person neglects so to do within five days after such notice, the superintendent shall cause such restoration to be made and shall charge such person therefor. Until such restoration is completed, he shall protect the public from injury by reason of such defect. (Prior code § 21-30)