No sidewalk, curb or gutter shall be installed unless a grade and line are established therefor. If no grades or lines are available, sidewalks, curbs and gutters may be installed (provided a permit is obtained), but they shall be removed, modified or replaced to conform to grades and lines when established by the city at the sole cost of the property owner abutting the sidewalk, curb or gutter. (Ord. 416, 1-3-1994)