Overhead electricity lines are normally bare (uninsulated) and if an object gets too close it is possible that a ‘flashover’ can occur, where electricity will jump over a distance to reach earth via the object. Flashovers can kill or cause severe shocks and burns to any person nearby.
In order to prevent flashover there are minimum safety clearances between overhead lines and the ground, roads, or objects on which a person can stand.
A flashover to a tree can cause a loss of supply to customers, a fire in the tree, or can lead to the tree itself conducting electricity.
Despite the dangers, we cannot actually prevent trees and vegetation being planted beneath our overhead electricity lines, as we do not own the land.
We have a duty to make sure that no tree comes close enough to an overhead electricity line to cause a flashover.
We employ specialist contractors to undertake vegetation management beneath our overhead electricity lines to make sure safety clearances are not infringed over a number of growing seasons.
All vegetation clearance work beneath and adjacent to overhead electricity lines must be carried out by specially trained staff.
Planting trees near overhead power lines or pylons
Only low height, slow growing species should be planted beneath overhead electricity lines, conductors, and towers.
If you are proposing planting in the area around a pylon (tower) base, you should consider the need to maintain safe vehicle access to the tower base for overhead line maintenance activities, and to prevent unauthorised access to towers.
Tree roots can disturb and prevent access to maintain underground electricity cables. Our prescribed planting distances between trees and buried services must be observed.
Please contact us for detailed technical advice before you finalise any landscape scheme.