What is a Tree Risk Assessment?

A tree risk assessment is the process of risk identification, risk analysis and risk evaluation followed up by risk treatment. Typically there are three main roles in a tree risk assessment. There is the Tree Risk Manager which could be the tree owner, property manager or controlling authority. The Tree Risk Assessor which needs to be an ISA Certified Arborist and be ISA Tree Risk Assessor Qualified (TRAQ). And finally the Arborist tree worker that will be commissioned with the tree risk mitigation work.




The job of the Tree Risk Manager is to:

  • have the duty of car responsibility

  • communicate the tree risk management polices

  • decide on the need to inspect the subject trees

  • establish a budget for the project

  • identify the geographical limits of the tree inspection

  • specify the desired level of assessment

  • determine or accept the scope of work, which should be shared with the tree risk assessor

  • decide on the level of acceptable level of risk

  • decide on the inspection frequency

  • verify target zone uses and occupancy rates

  • prioritize the work

  • decide among the risk mitigation options

The job of the Tree Risk Assessor is to:

  • develop a scope of work and share with tree risk manager

  • develop a time frame and share it with the tree risk manager

  • correctly identify the tree and site

  • correctly identify potential targets, their occupancy and the target zone

  • perform an assessment and determine the likelihood of a tree or tree part failure hitting a target

  • analyze and determine level of risk

  • determine if additional more advance assessments need to be conducted

  • develop mitigation options for risks

  • estimate the risk levels after mitigation work is done by a ISA Certified Arborist

  • recommend a inspection frequency

  • Write an arborist report containing all data collected

  • provide tree risk manager/client with report

The job of the Arborist/Tree Worker is to:

  • provide need services while following ISA best management practices

  • removal

  • pruning

  • support systems

  • lightning protection

  • tree replacements

  • transplanting

  • tree health management

Typically tree risk assessments are conducted on trees in urban environments as they are more likely to be a risk due to their target zones being occupied by people or valuable property. Browning Arborist Consulting provides tree risk assessments to the lower mainland of British Columbia. We are capable of providing level 1, level 2, level 3 aerial inspection, level 3 increment boring, level 3 root excavation using an air spade and other forms of in depth inspections.