In all cases where any street, avenue, alley or roadway within the corporate limits of the city is improved with hard-surface pavement, but no curb placed at the side or edge of such pavement, the same shall be drained by an open ditch or other proper and adequate drain placed on either side of such street at least four feet from the edge of such pavement, the same to be fixed and established upon property grade and of sufficient depth, size and capacity to carry away all surface water and properly drain said pavement with proper slope from the edge of the pavement to such ditch or other drain. The same shall be kept in repair and maintained from time to time without obstruction thereof so as to properly or adequately drain all such pavement. The slope for at least two feet in width on either side of such pavement shall be filled for a depth of not less than four inches with either gravel or crushed rock. (Ord. 1609 §1, 1925).