(A) No person may cause or allow any fence, shrubs, bushes or other plantings on property owned by him or her or under his or her control to substantially obstruct vision between a height of two feet and a height of ten feet measured above the average elevation of the existing surfaces of the intersecting streets at their centerlines within the area formed by joining points on the property lines measured as follows.
(1) On property lines abutting streets 50 feet or less in right-of-way width, the points on the property lines shall be 25 feet from the lot corner.
(2) On property lines abutting streets more than 50 feet in right-of-way width, the points on the property lines shall be 40 feet from the lot corner.
(B) The requirements of this section shall not be deemed to prohibit obstructions caused by natural grade or by retaining walls.