§ 91.063  MANNER OF EXCAVATING.
   (A)   It shall be unlawful to make any opening excavation or tunnel in any way contrary to or at variance with the terms of the permit therefore. Proper bracing shall be maintained to prevent the collapse of adjoining ground; and in openings or excavations, the excavation or opening shall not have anywhere below the surface, any portion which extends beyond the opening at the surface.
   (B)   No injury shall be done to any pipes, cables or conduits in the making of the openings, excavations or tunnels and notice shall be given to the city department or officer charged with the care thereof, which are or may be endangered or affected by the making of any excavation or tunnel before the pipes, cables or conduits shall be disturbed.
   (C)   No unnecessary damage or injury shall be done to any tree or shrub or the roots thereof.
(1980 Code, § 14.309)  Penalty, see § 91.999