Tree Management Policy 2025 - Service scope and standards - objectives

This policy does not cover trees on privately owned land.

Trees can occasionally cause direct or indirect root damage to structures. Direct damage may be caused by the increasing diameter as roots grow which can affect light structures with shallow foundations. The usual solution is to modify the affected structure allowing for any future expansion of the root. Root pruning should be avoided wherever possible as this can introduce disease or deny the tree of vital food reserves or make the tree unstable. 

Roots may also grow into and block cracked or leaking drains. Roots will not enter below ground services if those services are not already leaking. To remedy root growth ingress, drains should be repaired and made watertight.

Indirect root damage, often referred to as subsidence or heave, can occur when the fibrous roots of shrubs and trees extract moisture from shrinkable soils, which are usually clay. If this occurs beneath the foundations of larger structures such as houses, movement and damage may occur.

Regardless of shrub or tree roots, shrinkable soils expand and contract dependant on the moisture content. During the dryer months of the year shrinkable soils contract and through the wetter months rehydrate and expand. This seasonal movement alone can cause damage to structures.  The policy addresses direct and indirect root damage in the 'Indirect and direct root damage' section of this policy.

The Council will not prune trees for the following reasons, for example:

• Disruption of surfaces and light structures such as footpaths, patios, driveways and fences
• Reduced light levels
• Interference with television and/or satellite reception
• To alleviate the inconvenience of a tree’s seasonal and/or natural processes such as:
  • Leaves
  • Twigs/small dead branches
  • Pollen
  • Fruit and seeds
  • Bird droppings
  • Honeydew from insects
• Drains blocked by leaves or roots
• Branches overhanging boundaries
• Trees impacting on planning permissions on third party land
• Personal medical complaints

The objectives for tree management must strike a balance between the level of risk, the benefits and the resources available to the duty-holder. For a tree risk strategy to be effective, the following objectives, taken from the National Tree Safety Group's Common sense risk management of trees, must be applied:

1. To enable corporate objectives to be achieved.

2. To identify and manage the risk

3. To comply with relevant legal and regulatory requirements

4. To assure the public that trees on public land are appropriately managed.

The Council is responsible for a significant number of trees. To identify and manage the risk the Council will inspect our trees on a frequency determined by zones. The zones are categorised as high, medium and low according to the level of occupancy of people and/or value of property within striking distance of trees.