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Tree Risk Assessment

Unhealthy and damaged trees can often pose a significant risk to people and property, which is why a tree risk assessment is so crucial to ensuring the safety of your employees, visitors and guests. We perform industry standard tree risk assessment. Following the American National Standard for Tree, Shrub, and Other Wood Plant Management – Standard Practices (Tree Risk Assessment a. Tree Failure), also known as ANSI A300 Part 9. We assess trees using the formula Probability x Consequences = Risk.

Tree Risk Assessment chart

Table 1 – Tree Risk = Probability x Consequences

tree risk assessment levels chart

The 3 Levels of Risk Assessment

  • Level 1: Limited Visual Tree Risk Assessment
    This is used when the tree will be viewed from a defined, limited perspective. It consequently has limitations as to which risks it may detect. This view may include an aerial patrol, a drive by windshield survey, a foot patrol or photographs.
  • Level 2: Basic Tree Risk Assessment
    This level involves looking at the tree’s roots, trunk and crown to detect structural defects. It is a 360 degree, ground-based visual observation of the tree.
  • Level 3: Advanced Tree Risk Assessment
    This level is anything in excess of level 2. It may include tissue testing, drone inspection and resistance drilling.

Our tree risk assessments are usually part of a Tree Management Plan for residential, business or academic campus properties. We have a number of ISA Tree Risk Assessment Qualified Consultants ready to perform industry standard tree risk assessments.

Tree Risk Mitigation

After potential targets are identified, our consulting arborists will provide a range of options to mitigate damage risks. There are essentially four options – removing the target, treating the tree and treating the target. Removal is always a last resort if no other options are available.

Tree Canopy Assessment

We use high resolution remotely sensed imagery fused with LiDAR data to provide sub-meter high resolution land cover maps. We can combine these with other datasets to assess the existing and potential tree canopy at a variety of scales from the parcel to the jurisdiction and beyond.

tree risk assessment chart

Tree Risk Targets

Photo 1 – A tree fails; the area impact is a radius equal to the height of the tree.

Photo 2 – The yellow arrow points to a large area of impact. The red arrow shows a smaller tree with an equal risk rating because it is located near walkways, structures and a parking lot.

Tree Risk Assessment Clients:

The Maryland National Capital Park and Planning Commission
The Maryland-National Capital Park and Planning Commission

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Whiting-Turner

town of bedford ny logo
Town of Bedford

city of aurora CO logo
City of Aurora

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Gorman & Williams

Village of Addison IL logo
Village of Addison

village of morton grove il logo
Village of Morton Grove

the peddie school logo
The Peddie School

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Town of Winchester

Contact us today to find out how our Consulting Group can help protect your property.

For more information on Tree Risk Assessments, please watch this informational video from Mike Galvin, SavATree Consulting Group Director.