(A) The slope of all sidewalks in the city upon all streets where the grace and curb lines have been established or may hereafter be established shall be as provided by this section.
(B) The elevation of the sidewalk shall, in all cases, be a rise from any point on the line of the curb which is next to the line of the center of the street to a point on the property line directly opposite the point on the same side of the street and shall be at the uniform rate of three-hundreds of a foot vertical height per one foot horizontal distance on the walk.
(`90 Code, § 19-25)