Stephen Cadogan: Seeing the power lines among the trees

Where naturally regenerated trees colonise ESB power line corridors, they must not be allowed to grow higher than three metres; the landowner is responsible for cutting or lopping the trees to ensure this. 

There have been calls around the country to update long-standing forest design requirements and legislation, in order to protect the electricity network where it goes through forestry land.

In the north west, several of the power cuts during recent storms were blamed on wires being brought down in forestry plantations. Now, the Department of Agriculture, Food and the Marine (DAFM) has said it will engage with the ESB to see if any further measures are required.

As it stands, the ESB are empowered to lop or cut any tree, shrub or hedge which obstructs or interferes with electrical wires, or interferes with the erection or laying of electrical wires, or with the survey of a proposed route for any transmission or distribution lines. Such works do not require a felling licence.

There is also an agreement between the Irish Farmers’ Association and the ESB on power lines interacting with grant-aided forest areas.

ESB power line corridors are intended to be left unplanted at the initial afforestation stage. Where naturally regenerated trees colonise these corridors, they must not be allowed to grow higher than three metres; the landowner is responsible for cutting or lopping the trees to ensure this. 

The landowner is also responsible for keeping a minimum corridor of at least four metres wide clear of regenerating trees, for ESB maintenance access.

Cavan Fianna Fáil TD, Brendan Smith, has called for adequate inspection of forests, both in public and private ownership, to deal with the recurring problems of fallen trees causing damage to ESB transmission lines, resulting in power outages and huge inconvenience, costs and hardship to communities.

Sligo-Leitrim Sinn Féin TD, Martin Kenny, said that the onus is on the ESB, forestry companies and forestry owners to ensure that trees are properly maintained and assessed to ensure that they are not a risk to power supplies.

“It is my understanding that ESB is given wayleaves to cut trees that are a danger to power lines in all new forest plantations. There may be older forest plantations that they don’t have wayleaves for."

He recommended that where the ESB does not have wayleaves, the forest companies or forest owners should be forced to grant the wayleaves, or else be responsible for cutting back trees from the power lines themselves.

It is believed power cuts for some households were longer because the ESB could not access some lands. Environmental group Save Leitrim have called for greater regulation of forestry, because trees close to power lines fell, leaving households without electricity for long periods.

At least 20% of Leitrim is afforested. Sligo-Leitrim independent TD Marian Harkin has called for tree removal up to 30 metres from power lines. One power line in Co Sligo was broken six times in 2024 due to trees falling on it.

According to the DAFM, the management of forestry plantations is ultimately the responsibility of the owner of the land. But if maintenance entails thinning or felling, the owner must apply to the DAFM for a licence (but it is not required by the ESB).

IFA-ESB agreement guidelines on power lines in forestry recommend unplanted corridors ranging from 20 metres for 10 kV lines to 74 m for 400 kV, but that low voltage lines only need clearance from branches and tree tops.

Corridor areas do not qualify for Forest Service grant assistance but may be used to satisfy the 15% biodiversity requirement and a corridor of 4m must be left totally clear for ESB maintenance access.

The agreement recommends that applications for compensation from the ESB for loss of forest premium can be made for areas suitable for afforestation but left unplanted because of power lines.

Cork North-West Fianna Fáil TD, Michael Moynihan, called for a major evaluation of the placing of power lines in forested areas, after falling trees were blamed for North Cork communities going without power several times recently.

The TD said power lines in wooded areas proved difficult to access for ESB crews, and he called for a clearance area of more than 20 metres between power lines and trees, wherever cables must be routed through forested areas.

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