A tree touching a live line is dangerous long before anything sparks or smokes. The tree itself can carry current into the ground around it. This page covers what to do when something is wrong, and how to make sure it never is.
A line is down, or a tree is on a line
Stay at least eight metres clear -that includes the ground, the tree and anything touching it. Keep children and animals away. Call 111 if there is fire or anyone is hurt, then call us on 0800 367 328, any hour of the day.
Don't trim near a live line
No ladders, pole saws or chainsaws within four metres of a conductor – that work is for approved utility arborists only. Electricity arcs across gaps, so you do not have to touch a line to be badly hurt by one.
Why trees near lines are dangerous
A green, growing tree is wet inside, and wet wood conducts electricity. When a branch bridges a conductor, current can travel down the trunk and energise the ground at its base – which is why we ask you to stay eight metres clear rather than simply avoid touching the tree.
Contact doesn’t always announce itself. A branch can rub against a line for weeks, wearing through insulation and heating up, with nothing to see from the ground but a few scorched leaves. In dry weather that same contact starts fires. Across our network, vegetation is the largest single cause of unplanned outages.
Wind makes everything worse. A branch that clears the line on a still day can be well inside the growth limit zone in a nor’wester, which is exactly why the zones are measured with movement in mind.