BMP - Tree Risk Assessment - 43

Matrix 2. Risk rating matrix showing the level of risk as the combination of likelihood of a tree or tree part failing and impacting a specified target, and severity of the
associated consequences.
Likelihood
of Failure
& Impact

Consequences of Failure
Negligible

Minor

Significant

Severe

Very likely

Low

Moderate

High

Extreme

Likely

Low

Moderate

High

High

Somewhat likely

Low

Low

Moderate

Moderate

Unlikely

Low

Low

Low

Low

Risk Perception and Acceptable Risk
How people perceive risk and their need for personal safety is inherently
subjective; therefore, risk tolerance and action thresholds vary among tree
owners/managers. What is within the tolerance of one person may be unacceptable to another. It is impossible to maintain trees completely free of
risk-some level of risk must be accepted to experience the benefits that
trees provide.
Acceptable risk is the degree of risk that is within the owner/manager's or
controlling authority's tolerance, or that which is below a defined threshold.
Some countries have a framework directive, which defines thresholds of risk
tolerance and acceptability. Municipalities, utilities, and property managers
may have a risk management plan that defines the level of acceptable risk.
Safety may not be the only criterion used by the risk manager to establish
acceptable levels of risk; budget, a tree's historical or environmental significance, aesthetics, and other factors also may come into the decision-making
process. Tree risk assessors may also assess risk within a population of trees
and use that information to prioritize remedial action.
For extreme-risk trees, the tree risk assessor should notify the owner/
manager as soon as possible and, in some cases, recommend or implement
immediate restriction of access to the target zone to avoid injury. For lower
levels of risk, however, some discussion is usually required to understand
the client's risk tolerance and to determine appropriate mitigation treatments.
In considering risk and mitigation measures, tree risk assessors should communicate the benefits of trees as well as the consequences of losing them.
People often use the terms " hazard " or " hazardous " when discussing risk
assessments. A hazard tree (hazardous tree) is a tree identified as a likely
source of harm. Hazardous trees are those that have been assessed and have
43



BMP - Tree Risk Assessment

Table of Contents for the Digital Edition of BMP - Tree Risk Assessment

Table of Contents
BMP - Tree Risk Assessment - Cover1
BMP - Tree Risk Assessment - Cover2
BMP - Tree Risk Assessment - i
BMP - Tree Risk Assessment - ii
BMP - Tree Risk Assessment - Table of Contents
BMP - Tree Risk Assessment - iv
BMP - Tree Risk Assessment - 1
BMP - Tree Risk Assessment - 2
BMP - Tree Risk Assessment - 3
BMP - Tree Risk Assessment - 4
BMP - Tree Risk Assessment - 5
BMP - Tree Risk Assessment - 6
BMP - Tree Risk Assessment - 7
BMP - Tree Risk Assessment - 8
BMP - Tree Risk Assessment - 9
BMP - Tree Risk Assessment - 10
BMP - Tree Risk Assessment - 11
BMP - Tree Risk Assessment - 12
BMP - Tree Risk Assessment - 13
BMP - Tree Risk Assessment - 14
BMP - Tree Risk Assessment - 15
BMP - Tree Risk Assessment - 16
BMP - Tree Risk Assessment - 17
BMP - Tree Risk Assessment - 18
BMP - Tree Risk Assessment - 19
BMP - Tree Risk Assessment - 20
BMP - Tree Risk Assessment - 21
BMP - Tree Risk Assessment - 22
BMP - Tree Risk Assessment - 23
BMP - Tree Risk Assessment - 24
BMP - Tree Risk Assessment - 25
BMP - Tree Risk Assessment - 26
BMP - Tree Risk Assessment - 27
BMP - Tree Risk Assessment - 28
BMP - Tree Risk Assessment - 29
BMP - Tree Risk Assessment - 30
BMP - Tree Risk Assessment - 31
BMP - Tree Risk Assessment - 32
BMP - Tree Risk Assessment - 33
BMP - Tree Risk Assessment - 34
BMP - Tree Risk Assessment - 35
BMP - Tree Risk Assessment - 36
BMP - Tree Risk Assessment - 37
BMP - Tree Risk Assessment - 38
BMP - Tree Risk Assessment - 39
BMP - Tree Risk Assessment - 40
BMP - Tree Risk Assessment - 41
BMP - Tree Risk Assessment - 42
BMP - Tree Risk Assessment - 43
BMP - Tree Risk Assessment - 44
BMP - Tree Risk Assessment - 45
BMP - Tree Risk Assessment - 46
BMP - Tree Risk Assessment - 47
BMP - Tree Risk Assessment - 48
BMP - Tree Risk Assessment - 49
BMP - Tree Risk Assessment - 50
BMP - Tree Risk Assessment - 51
BMP - Tree Risk Assessment - 52
BMP - Tree Risk Assessment - 53
BMP - Tree Risk Assessment - 54
BMP - Tree Risk Assessment - 55
BMP - Tree Risk Assessment - 56
BMP - Tree Risk Assessment - 57
BMP - Tree Risk Assessment - 58
BMP - Tree Risk Assessment - 59
BMP - Tree Risk Assessment - 60
BMP - Tree Risk Assessment - 61
BMP - Tree Risk Assessment - 62
BMP - Tree Risk Assessment - 63
BMP - Tree Risk Assessment - 64
BMP - Tree Risk Assessment - 65
BMP - Tree Risk Assessment - 66
BMP - Tree Risk Assessment - 67
BMP - Tree Risk Assessment - 68
BMP - Tree Risk Assessment - 69
BMP - Tree Risk Assessment - 70
BMP - Tree Risk Assessment - 71
BMP - Tree Risk Assessment - 72
BMP - Tree Risk Assessment - 73
BMP - Tree Risk Assessment - 74
BMP - Tree Risk Assessment - 75
BMP - Tree Risk Assessment - 76
BMP - Tree Risk Assessment - 77
BMP - Tree Risk Assessment - 78
BMP - Tree Risk Assessment - 79
BMP - Tree Risk Assessment - 80
BMP - Tree Risk Assessment - 81
BMP - Tree Risk Assessment - 82
BMP - Tree Risk Assessment - 83
BMP - Tree Risk Assessment - 84
BMP - Tree Risk Assessment - 85
BMP - Tree Risk Assessment - 86
BMP - Tree Risk Assessment - Cover3
BMP - Tree Risk Assessment - 88
https://www.nxtbookmedia.com