Risk / hazard assessment is the ideology that a tree poses a risk of failure and that failure has some consequence.  A hazardous tree is defined as any defective tree, or tree part, that poses a high risk upon its failure or fracture to cause injury to people or do damage to property.  A hazardous tree has one or more defects which decreases its structural integrity and gives it an increased potential for failure. Defects that are visible or detectable include cracks, decayed wood, weak branch unions, cankers, poor tree architecture, root problems, and dead tree or branches.

 

A defective tree is not considered hazardous unless there is a nearby target that it could hit.  A target could be a person, vehicle, building or any other object likely to sustain damage.  The term target area is used to describe an area where people or their equipment are likely to congregate.  By definition, a hazardous tree = a defective tree plus a target.

 

All hazardous trees can not be detected, corrected or eliminated.  However, a trained tree inspector implementing a hazardous tree management program can help make an unsafe environment reasonably safe again.  There are guidelines by which defective trees are judged, a process for rating the trees and sites, and corrective actions to remedy identified hazardous situations.