Tree Risks and Assessments

Tree Risk Management

The context in which the trees are surveyed should be addressed prior to assessment, it is important to understand the site usage, demographics and frequency of visitors within falling distances of trees. Things to look out for include the storage of plant and machinary, site boudaries and recreational areas. Areas such as these could call for a more detailed surveys and made a priority in the survey schedule, to be listed as ‘Target Zones’. Personal safety should also be taken into account, the condition in which the tree(s) are situated could pose other risks to the surveyor, such as slope, tree lean, tree density and weather etc. Appropriate PPE should be worn and adherence to the particular sites specific risk assessment.

Tree Assessment

The assessment itself will be a ‘Visual Inspection’ looking into the physical signs of failure and making observations in the context of the local environment.  The local environment can play an important part in the trees current condition.  An idea of historical site use, soil conditions, local climate, previous tree works or previous human constructions and any land use change can lend a hand in accuratly assessing the potential failures within a site. This assessment utilizes the surveyor’s knowledge and experience of tree biology and structure to assess the overall condition of the tree.  To assess the trees overall condition, signs and features associated to tree failure as well as an assessment of the risks are inspected from ground level, noting variations against what would be expected from a healthy tree.

Reporting

Data collected should be filled into the appropriate spaces within the Basic Tree Safety Survey Form systematically during the survey of each tree; ensuring notes are easy to follow and are written in laymen terms for those who may have less knowledge concerning tree surveys. Once a report has been written into a computerized format and the original copy scanned or kept in a safe location, a PDF/read only document should be sent to the client outlining your observations and possible recommendations dependent of aboriocultural knowledge.  Copies of this should also be sent to Head Office to be stored for a minimum of five years, to ensure that the surveyed trees were dealt with appropriately.

Tree SurveyPhoto: Member of IWA Head Office undertaking a tree survey

Further Guidance

More information regarding the necessity of tree safety can be found from the Forestry Commission's National Tree Safety Group

Advice

For advice on hazardous trees on your restoration site contact Alex Melson at alex.melson@waterways.org.uk

Resources

Tree Survey Form

Example Risk Assessment

OPAL Tree Identification Guides