A.   It shall be unlawful for any person to cause, create or maintain any obstruction to any street, alley, sidewalk or other public way, except as may be specifically authorized by ordinance or by the Committee on Streets and Alleys when necessary in an emergency or in connection with any lawful construction, repair or removal work. It shall further be unlawful to obstruct any drain in any public street or alley.
   B.   It shall be unlawful to erect or maintain any building or structure which encroaches upon any public street or property. (1979 Code § 7-1-8)