It shall be unlawful, as a normal practice, for any person, firm, or city department to top any street tree, park tree, or other tree on public property. "Topping" is defined as the severe cutting back of limbs to stubs larger than three inches (3") in diameter within the tree's crown to such a degree so as to remove the normal canopy and disfigure the tree. Trees severely damaged by storms or other causes, or certain trees under utility wires or other obstructions where other pruning practices are impractical, may be exempted herefrom at the determination of the city tree board. (Ord. 105, 7-6-1993)