There are many hazards associated with trees, such as those produced
when trees fall during storms or die and begin to fall. However,
falling trees are not the only potential for problems.
Urban trees should never be allowed to grow in designated clear
zones for utility lines, pedestrian walkways, buildings, streets
and travel lanes. When trees are allowed to grow un-checked into
these areas they reduce clearance and sight distance and increase
costs to maintain public safety. Additionally, if the upper portions
of the tree are left to tower over property it can cause power outages,
damage to homes, vehicles and other property. There is also an increased
risk for personal injury.
An often overlooked liability is the root structure of the tree.
Tree roots that surface above ground can pose a tripping hazard
or damage equipment such as lawn mower blades.
In many cities, communities are finding themselves spending millions
of dollars to resolve conflicts caused when trees impose on sidewalks,
sewers, power lines and other elements of urban infrastructure.
Studies have shown that repair costs for sidewalk, curb and gutter
repair, tree removal and replacement and legal and liability costs
range from $0.75 to $2.36 per capita and up to $6.98 per resident.
When figuring in the additional costs of repairing damaged sewer
lines, pavement, building foundations and other damaged materials,
total costs add up to as much as $100 million per year in larger
Unfortunately, when these repairs become necessary municipalities
are sometimes forced to shift these costs to residents. Typically,
this leads to a downsizing in urban forests as small stature trees
are planted to replace the larger trees removed due to their damaging