Tree Safety

Tree Safety Management Plan (2012)

The current plan (TSMP) published as part of the Nottingham Urban Forest Strategy (2012, NCC) defines the current tree safety management processes for trees maintained by Tree Services, Resident Services. The main features of this plan are:

1. Trees will be inspected on a schedule of 1-5 years, depending on the type of site and its usage or occupancy. Trees in areas with negligible use will only be inspected reactively.
2. As part of a tree inspection an individual tree risk assessment is made that defines
   1. The size or impact of the failure of a tree part (the hazard).
   2. The likelihood of a hazard being realised.  
3. A numerical risk rating is generated from a calculation based on
   1. The target-use of the site; 
   2. The size or impact of the failure of a tree part (the hazard); and 
   3. The likelihood of a hazard being realised. This calculation is based on a THREATS type system of tree risk assessment.
4. In tree risk management, risk ratings are categorized to assign target deadlines (priorities) for completing risk-reducing actions. Trees identified with intolerable risks are grouped into batches, with the urgency of the required work determined by the level of risk they pose.

Future Tree Risk Management Plan (2024)

The revised Plan (TRMP) has been assessed, and the following improvements have been proposed to increase the effectiveness of the system used and reduce unnecessary inspections where possible.

1. All NCC portfolios will be assessed for un-surveyed trees using the National Tree Map data. These trees will be incorporated into future inspection schedules.
2. The target-use (of the area that a failing tree may affect) of all NCC land will be defined by a process of GIS ‘buffering’ from plotted use-features.
   • These use-features will be either area, line or point features (paths, drives, entrances, picnic benches, playgrounds, woodlands etc.) and will be plotted with premises managers based on site knowledge using GIS tools.
3. The target-use plans of a site will be used to categorise individual trees with a prioritised re-inspection interval of between 1-5 years. Other less used parts of a site may be given a ‘negligible’ target-use and inspections will be reactive-only in these areas.
4. The overall effect of this change, will often be to relatively lower the reinspection interval for large areas of a site and reduce inspection needs.
   • For instance, a park with an overall target-use rating of 'moderate' (resulting in a three-year reinspection interval) could, after the proposed changes, have certain high target-use areas identified. Meanwhile, other large areas (such as Wollaton) might be classified as 'low' target-use, leading to a five-year reinspection interval. Additionally, negligible target-use areas will be defined and excluded from the inspection schedule.
5. The TRMP will include a council-wide high wind policy to guide the management of sites with trees, before, during, and after high winds.

Alongside the TRMP, tree works will be prioritised to

• Meet the requirements of the Highways Act to prevent encroachment.
• Reduce the financial and reputational risks from actionable nuisances.

Zonal rating map - Click to view