(a) Any sidewalk heretofore laid shall not be raised or lowered without the approval of the City Engineer and all sidewalks hereafter laid shall be in accordance with the provisions of this chapter and under the supervision of the City Engineer.
(b) No curb line or grade for curb shall be changed, except by the direction and written consent of the Service Director or City Engineer.
(c) Any sidewalk laid on any public street or highway within the City in a manner inconsistent with the provisions of this chapter shall, upon the recommendation of the Service Director, be ordered relaid to the proper grade, upon the failure of the property owner to make the change so ordered within the time specified in the notice.