Finding the right approach to tree risk management
09/25/2022
Tree risk management requires striking a balance between preserving a treed environment for the public benefit, with the need to ensure trees do not present a risk of harm to people or property.
With an increasing number of local authorities declaring climate emergencies, there is a growing recognition of the crucial role trees play in carbon capture and storage. Equally, there is increasing acknowledgement of the importance of greenery in supporting health and wellbeing, particularly in urban areas.
Consequently, planting and preservation of trees is now increasingly being embedded in government policy. For example, the England Trees Action Plan aims to increase urban tree cover and introduce tree and woodland strategy requirements for local authorities , while the Scottish government has set targets to plant more than 10,000 hectares of new woodland every year.
What risks do trees pose?
While trees bring important benefits, they can also present risks to people and property. These risks include:
- Branches or whole trees falling as a result of disease or storm damage - on average, five to six people are killed each year as a result of falling trees or branches according to the Health and Safety Executive
- Structural damage to property caused by tree roots, e.g. subsidence – according to the Association of British Insurers, there were 27,000 domestic property subsidence claims in 2020, with tree roots often a contributory factor
What does the law say about tree safety?
If there are trees on land you own, under the Occupiers’ Liability Act 1957 you have a duty to take “such care as in all the circumstances of the case is reasonable” to ensure that visitors to your land are safe.
What constitutes a reasonable level of care will depend on factors including the location of the trees, what the land is used for and how easily it is accessed, but as a landowner or occupier, you must make some assessment of the potential risk presented by any tree on your land, and your duty of care must be satisfied using an appropriate, risk-based system of safety management.
This begins with a system for inspections that is proportionate to the risk posed. For example, a tree overhanging a busy footpath will present a far greater degree of risk than one growing in secluded woodland and this will affect the kind of inspection programme that is necessary and proportionate. Under the Highways Act 1980, private landowners may also be compelled, by any competent authority responsible for a highway, road or footpath to which the public has access, to remove or cut back within 14 days any tree (or hedge or shrub) that is dead, diseased or insecurely rooted and which is likely to cause danger.
Depending on how much land you own, it may be necessary to establish different zones to help categorise different levels of risk. Low risk zones, where there is no public access, may only require irregular inspections, if at all, whereas for trees in higher risk zones, such as near roads or buildings, a system of periodic and more frequent inspections may be required. The National Tree Safety Group provides guidance on how to categorise tree ‘risk zones’.
Why are tree inspections important?
While the risk of death or injury from a falling tree or branch remains extremely low, such incidents do happen. In the event of a legal claim, courts will consider whether the frequency of and type of inspection was proportionate to the risk posed, and if the person carrying out the inspection was suitably competent and qualified to identify signs of decay or other defects.
Record-keeping is a crucial aspect of claims defensibility. For example, if a ground-level, ‘walk-by’ inspection, looking only for obvious defects, is considered sufficient, the inspection record should clearly explain why. Conversely, if the inspector believes an aerial inspection may be required to check for defects that may not be visible at ground level, this should be recorded and actioned.
What to consider for tree inspections?
It’s important to ensure your risk assessment details your tree inspection regimes. It’s helpful to consider:
- The frequency of your tree inspections, based on factors such as the tree species, age, location, size, soil type and soil mapping (e.g. identifying trees that are on clay soil), claims history and the types of third parties that might be affected.
- How you will inspect all aspects of the trees (including long branches, cavities and roots).
- Proximity of trees to buildings, and the age of buildings near trees (older buildings are likely to have shallower foundations).
- The type of inspection that is appropriate for the type of trees you’re responsible for, and the risks they pose.
- How you’d respond to an emergency such as severe weather or falling trees or branches, and putting in place plans and procedures, just in case incidents happen.
Remedial action
In the event that damage or decay is found, the inspection record should note any remedial action required and then record when this remedial action was completed, and by whom. Remedial action could include treatment of disease, removal of dangerous hanging branches, or pollarding to restrict the tree’s growth.
It is always sensible to get an expert opinion when considering specialist work such as tree felling, or to establish whether pruning will actually reduce the impact of a tree or alternatively, stimulate new growth which could exacerbate existing risks.
If you need to get specialist advice from a tree surgeon or arboriculturists, it is worth thinking about:
- How they manage their risk assessments?
- Do they have appropriate insurance?
- Do they have the right qualifications and experience?
- Can they be available for out of hours emergency work?
- How can you monitor and review the work carried out by contractors?
Landowners should also establish whether a tree preservation order (TPO) is in place before considering felling. Although the Town and Country Planning Act 1990 makes clear that no TPO will apply to “the cutting down, uprooting, topping or lopping of trees which are dying or dead or have become dangerous”, landowners must still seek permission from the relevant local authority.
Finally, it is important to have a clear and consistent system for recording any notifications of tree-related damage that may come from your staff, visitors, user groups or members of the public. This could include visible signs of decay, or loose or fallen branches. You should then have a system to follow up with any remedial action required.
Zurich Resilience Solutions can offer customers a range of risk management services, such as a tree safety and liability review, facilitated workshops, document reviews and training. For more details on any of our risk services, please speak to your usual Zurich contact or email: zrs.enquiries@uk.zurich.com.
