Tree Risk Management

While trees provide numerous benefits to the City and to a property, trees sometimes need to be inspected and managed to keep them adequately safe.  See below for some signs that a tree might need an inspection by a qualified arborist, the types of risk mitigation actions that your arborist may recommended, and some conditions typically not associated with an elevated risk rating. Property owners are responsible for maintaining their trees in a safe manner and engaging with professional assistance when necessary.

Conditions that may warrant inspection by a qualified arborist:

• A split in the bark or wood
• Mushrooms growing on the roots, trunk or branches
• A cavity/hollow in a trunk or branch
• A sudden increase in a tree’s lean associated with heaving/lifting of the soil or roots
• Sizable deadwood hanging over objects or people that could be damaged or injured
• A documented pattern of recurring failure of substantial live branches with no previously identifiable defects
• Recent root loss due to excavation or other impact

Risk mitigation actions your arborist may recommend following inspection:

• Prune to remove a branch or trunk with a defect
• Prune to reduce the weight on a branch or trunk with a defect
• Prune to provide clearance from a structure or utility wire
• Install a support cable between two branches or trunks
• Remove the tree

Tree conditions typically not associated with elevated risk:

• A tree growing at a stable lean with no associated defects, which may be due to its growing towards the sun
• Healthy branches without any identifiable defects or concerning patterns of failure
• Smaller diameter dead or defective branches for which the consequences of striking a target are minor
• Dead or defective material on a tree that is far away from potential targets

Unfortunately, the City is not able to offer tree consultation services for private properties so you will need to work with a private arborist for this service.  If you determine that you intend to remove a tree or prune more than 10% of the living crown of a tree you will need to apply for the appropriate Tree Removal Permit or Tree Impact Assessment

Also, please see the City’s webpage covering City Tree Regulations, to read about the requirements pertaining to hazardous trees.