The City Manager shall forthwith cause an investigation of the application to be made; if the grade and line for the walk or curb have not already been established, or if in the opinion of the City Manager the grade and line of the walk or curb or either of them should be changed, then he shall establish the grade and line for the walk or curb. The grades and lines shall be deemed established and in force as soon as the City Manager shall have prepared a plan therefor showing the location, width, elevation, and grades of the walk or curb and the plan has been approved by the City Manager. The grade and line of any curb or sidewalk heretofore laid shall not be changed without the written permission or order of the City Manager.
(1980 Code 97.07)