7.10 Utilities and trees

Conflict between tree roots and underground utilities is a common issue but can be easily mitigated through good design and construction practices. Best practice is set out in the latest National Joint Utility Group (NJUG) guidance , and the TDAG publication Trees in Hard Landscapes. The following requirements should also be followed:

Co-ordination of services with tree planting proposals must be undertaken at an early stage. Consideration should be given to the layout of services near trees, shrubs and pinch points within the carriageway.

Excavation for the maintenance of services can disturb trees. Common utility corridors must be provided and that services are laid in ducts to reduce the need for excavation later.

Where there is a risk of tree and vegetation related subsidence, flexible construction of pipes should be used to accommodate any ground movement.

Where existing trees are present, services should not be laid within root systems. Where this is unavoidable, they must be laid in ducts beneath the root system to avoid future excavation and subsequent damage to trees.