“I went to the woods because I wished to live deliberately, to front only the essential facts of life, and see if I could not learn what it had to teach, and not, when I came to die, discover that I had not lived.”
- Henry David Thoreau

Tree Risk Management

1. Tree Risk Uncertainty

The risk of trees causing actual damage in a complex natural environment is uncertain and unpredictable.  However, consistent and recurring factors serve as indicators of significant risk. Therefore some risk is reasonably foreseeable.

2. Legal Requirements

The statutory duty of care  requires that duty holders identify and control reasonably foreseeable risk. Case law  shows that having in place a system and procedure to identify and control reasonably foreseeable tree risk is expected of the prudent landowner. Reasonable conduct requires risks to be controlled in proportion to costs, resources and benefits.  Health & Safety law  places an additional duty on a business, to manage risks from their undertaking to employees and the public.

3. Risk to the Duty Holder

The risk of trees actually causing death is expressed as 1 in 10 million.  This is very low, but consideration must be given to the millions of pounds spent  on tree risk management every year; proactive tree risk management and very low risk of death are clearly inter-linked.  The statutory duty is concerned with risk of damage and injury as much as death; these claims are often settled out of court and are unknown.

If a tree causes damage it could result in significant inconvenience, costs and loss. If it results in harm to a 3rd party, a claim for negligence or breach of statutory duty might arise. It may also trigger an investigation by HSE, the Police or Local Authority. Serious procedural failings could be prosecuted in the public interest - even if harm was not reasonably foreseeable - and could result in significant costs, stigma and censure. In the worst cases, imprisonment for negligent manslaughter is possible.

Duty holders with high numbers of trees will benefit from a system that prioritises risk. This will help spread costs in proportion to risk and benefits over a predetermined period, in recognition of the risk uncertainty. This would help the duty holder to demonstrate reasonable conduct in controlling risk.

4. Procedures Not Required

Duty holders are not required by law to guarantee tree safety, or embark upon an onerous and detailed inventory of every tree under their care. Neither is tree work or detailed tree investigation necessary, unless significant nuisance or hazard are obvious, or have been visually identified by a competent person.

5. Competent Tree Risk Management

Competence is fundamentally important to recognising and controlling tree hazards and risk in a reasonable and proportionate way. Resources can be wasted and benefits lost by undertaking expensive and unnecessary tree work. Competent tree inspectors will have experience and preferably appropriate qualifications. Independent advice should be covered by professional indemnity insurance.