No proceedings for the construction or repair of sidewalks, curbings, and gutters, and levying assessments therefor, shall be necessary other than the proceedings required under this and the preceding section. In any case in which special assessments may be made on property for all the cost of constructing or repairing sidewalks, curbings, or gutters, such assessment within the limit of thirty-three and one third percent (33-1/3%) of the real value of the property shall be a valid assessment thereon except as provided in Section 88 of this Charter.