No person shall build, erect, construct or reconstruct any structure, barrier, obstruction or sidewalk in any public street, alley or public way; or fill, pave or repave the same or any part thereof, or construct, erect, install, change or replace any drain or drainage structures therein; or physically alter or change any public street, sidewalk, alley or public way; or change the elevation or grade thereof in the City, without first obtaining a permit therefor. (1967 Code §19-2)