This mature city tree suffered a catastrophic failure during a storm. A section of the tree was blown out, causing an outage and
requiring Dyersburg, Tenn., to remove it to avoid another outage when the tree failed again. (Photo provided)

When it comes to identifying the root cause of power outages in the United States, it’s not going too far out on a limb to say that trees are responsible for approximately 30 percent of them. When one tree branch comes into contact with an electrical line, it can affect hundreds of homes and businesses. Multiply that number with a major storm, and you can see how these events cost the nation’s economy between $20 billion and $55 billion annually.

To reduce the risk of power outages before an event occurs, utility companies work hard to implement integrative vegetation management programs to keep their electrical lines clear of vegetation. An IVM program is defined by the Environmental Protection Agency as “the practice of promoting desirable, stable, low-growing plant communities — that will resist invasion by tall-growing tree species — through the use of appropriate, environmentally sound and cost-effective control methods,” including chemical, biological, mechanical and manual treatments. Through this approach, utilities can manage vegetation while balancing control, cost, public health, environment quality and regulatory compliance.

Dyersburg, Tenn., is a small community of 20,000 located in the northwest corner of the state. The municipally owned Dyersburg Electric System was established in 1902 and provides electricity produced by the Tennessee Valley Authority to the community and the surrounding area.

Jack Golio is the systems forester for Dyersburg Electric. Since 1998 it has been his job to oversee 350 miles of distribution and transmission lines, using his knowledge as an arborist along with the best practices in the industry.

These before-and-after pictures show a row of pine trees growing along a high voltage line. They were trimmed to a minimum of 10 feet, the OSHA-required clearance. (Photo provided)

“Maintenance is the biggest line item in my annual report,” he said. “We don’t want trees taking out our power lines and causing a dangerous situation for our residents, so we strive to be very proactive about it and mitigate those risks.”

Golio said that when he first came to Dyersburg Electric, it was obvious that a change was needed. The budget had spiraled out of control, and trimming methodologies of past were about to catch up with the community and create an even bigger problem. Although it would take a while to turn things around, he began laying the groundwork for what is a viable IVM program that remains to this day.

A beaver dropped this tree across a 69,000-volt transmission line. Look closely to see a red “X” on the trunk of the tree: Dyersburg, Tenn., had identified it as a potential hazard and marked it for removal, but the beaver got to it first and knocked out power to the entire community. (Photo provided)

“Of course, nothing you do will eliminate power outages 100 percent, (but) a solid plan can significantly reduce that percentage,” he said.

The first step was to create a 3–4 year trimming cycle in accordance with American National Standards Institute and Occupational Safety and Health Administration requirements. This practice is not only efficient at helping maintain the appropriate clearance between trees and power lines but also enables crews to be responsible in their pruning practices.

Another thing that made a difference was Dyersburg’s tree removal system and foliar herbicide program, which allowed it to remove offending trees, replace them with varieties that will not infringe on power lines in the future and spray the stumps to prevent any stray growth.

“Stumps can’t get into the electrical lines, so they cannot create outages,” Golio said.

He admitted that creating and implementing an IVM is not a one-size-fits-all proposition. Different areas of the country have different needs, but if leaders employ experienced arborists, they can explore the options and find the best solutions to their concerns.

“The more money you are able to put toward it the better, of course, so budgeting is a big issue. I know plenty of communities who extend their trimming cycle out five to six years thinking that they will save money, but they have more problems in the process. Putting the money toward developing an IVM will not only help you reduce the number of outages your community faces, but will also improve reliability and save you money in the long term.”