German efficiency and Kiwi initiative have combined to help reduce power outages in rural and northern Hawke's Bay, by creating buffer zones for a major power line supply.

Trees are the number one cause of unplanned power outages across New Zealand, and lines company Eastland Network, which distributes electricity to homes and businesses in Wairoa, has partnered with Germany-based company Grandy Lake Forest's Wairoa-based management consultants, Merrill & Ring, on a long-term solution to tackle the issue.

Eastland Network general manager Brent Stewart said during a storm, trees and branches that touched or fell through power lines caused widespread cuts to the electricity supply, and often require expensive and extensive repairs.

"As the lines company for Gisborne, Wairoa and the East Coast, we cover nearly 12,000 square kilometres of mainly rural land, which includes many large areas of forest.

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"Under current regulations, all landowners must keep trees away from power lines but the reality is that pine trees can grow to 40 metres in height, and in bad weather they regularly damage lines. So, we've worked with Merrill & Ring at Grandy Lake's Ika nui Forest to create the region's first ever 80-metre wide corridors."

Trees border Eastland Network's 33kV line near Wairoa, before an initiative to create a new buffer zone. PHOTO / SUPPLIED
Trees border Eastland Network's 33kV line near Wairoa, before an initiative to create a new buffer zone. PHOTO / SUPPLIED

There are two separate corridors, extending a total of four kilometres.

Eastland Network project manager Earl Walker, who regularly talks to forestry companies about considering widening corridors after harvest, before the replanting takes place, said Merrill & Ring forest manager Graham Douglas suggested teaming up on the initiative.

More than 1500 pine trees were felled to make the new 80-m-wide buffer zone near Wairoa. PHOTO / SUPPLIED
More than 1500 pine trees were felled to make the new 80-m-wide buffer zone near Wairoa. PHOTO / SUPPLIED

"This 33kV line is a main sub-transmission line which supplies multiple 11kV feeders," Walker said.

"It's in a high wind zone through the forest and the original corridor, at a standard 40-metres wide, made it vulnerable to bad weather. If a pine tree took this line down, a major outage would occur, with all of Mahia, Nuhaka, Tahenui and Morere (1700 connections) losing power.

"With the new corridors in place, this risk to the local communities has been minimised.

"Merrill & Ring not only appreciate the benefits, they proactively approached us to work together on a solution."

More than 1,500 seven-year-old pine trees were felled to create the corridors.

The nine-month operation was a short-term investment that would more than pay for itself over time.

"Our forestry management company, and Grandy Lake Forest, have a long-term view of forestry. For us, it's a matter of taking a responsible approach and considering everyone who could be affected. We believe that creating effective buffers like this benefit absolutely everyone, from the forestry owners to the lines companies and the surrounding communities.

"With easy access well away from the power lines, the costs and challenges at harvest time will be significantly reduced. Compliance, risk management, and health and safety will all be improved. The power won't need to be turned off for harvesting, and it will be a safer environment for our workers."

Stewart said the Gisborne-based company would like to publicly acknowledge Merrill & Ring and Grandy Lake Forest for their foresight.

"We hope that the demonstrable advantages for lines companies and forestry companies alike – not to mention the workers and local communities – will see these 80-metre wide buffers become the norm, not the rare exception."