The Council may proceed to repair any such sidewalks, or to construct any sidewalks upon any street where the curb has been set, after first giving the property owner or his duly authorized agent, thirty days notice of its intention to do so, and may levy and collect the expenses of such work to the extent thereof, with one percent interest (1%) per month added after a demand of thirty days has been made by the Mayor or Recorder, for the payment thereof. Costs and interest shall be collected in the same manner and shall become a lien on the abutting property the same as taxes.