Tree Risk Assessment

It is generally accepted in the utility vegetation management industry that all utilities should have defined expectations for the assessment of tree risk as part of their program.

Trees cause outages in two ways: electrical modes of failure (part of a tree causing a short circuit and causing a protective device to operate) and mechanical modes of failure (parts of trees or entire trees failing, causing damage to electric facilities). To a large extent, successfully assessing a tree’s probability of failure can have a significant impact on reducing mechanical modes of failure as well as reduce the probability of wildfire ignition and other risks. These mechanical modes of failure typically make up 70-80% of all electric service interruptions.

Obvious defects, such as a dying or dead tree, are some of the easier threats to identify. However, more subtle defects like cracks, weak branch unions, cankers/fungal bodies, and poor architecture can be harder to identify for the untrained eye. Environmental factors such as root damage, changes in exposure (e.g., creating a new right-of-way edge), slopes and grades should also be taken into consideration.

We help our utility clients find that sweet spot in terms of what level of inspection should be implemented, the potential defects that should be considered for your area of operation, implementing well defined processes and training personnel to confidently execute your tree risk assessment needs.

We have professionals on staff who have TRAQ (Trees Risk Assessment Qualifications) and who have decades of experience with establishing and maintaining tree risk assessment programs for utility vegetation management.