No person may, without first having received a written permit issued by the Department of Transportation, in consultation with the Department of Recreation and Parks, place or maintain upon the ground in any street, lane, or alley, any stone, cement, or other substance or structure that will impede the free entrance of water and air to the roots of any tree without leaving an open space of ground outside the trunk of the tree, in area not less than 32 square feet. City Code, 1927, art. 45, §181 1950, art. 35, §99 1966, art. 26, §102 1976/83, art. 26, §107 Ord. 12-154 Ord. 46-396 Ord. 76-139 Ord. 77-310 Ord. 15-435