Vegetation management: A clear path for reliable electricity
One tree. 55 million people without power. A $6 billion economic hit.
In 2003, one single tree touching a transmission line in Ohio is all it took to bring about the largest power outage in U.S. history. Within five hours on a hot August day, power was down in eight northeastern states and parts of Canada.
Fifteen years later, California’s deadliest and most destructive fire in history was the result of a utility’s failure to keep power lines clear of trees or vegetation. The 2018 Camp Fire, as it was called, ravaged Northern California, killing at least 85 people, destroying nearly 19,000 buildings, and charring an area the size of Chicago. Total damage is estimated at $16.5 billion.
Closer to home – in Basin Electric’s service area – South Dakota’s 2017 Legion Lake fire started in the Black Hills when a 35-foot tree fell across a power line owned by a non-cooperative utility. The fast-spreading fire burned 84-square miles before its containment.
All of these incidents demonstrate the importance of keeping the area around transmission lines clear.
Trees and power lines don’t mix
High-voltage transmission lines are the backbone of how Basin Electric keeps electricity flowing. The co-op’s vegetation management program, which maintains the areas around power lines, helps prevent unnecessary power disruptions, and keeps people and property safe.
Basin Electric conducts vegetation management (of trees and shrubs) for three reasons:
- Ensure a safe, reliable electric system.
- Prevent fires.
- Be compliant with federal requirements. Violations can result in fines of up to $1 million per day.
“We’re not cutting down trees because we like to cut trees,” says Paul Kaiser, Basin Electric assistant line superintendent for North Dakota. “We’re doing it for the reliability of the power lines, and to make it safer for the landowner and for the land itself. We’re helping landowners save their million-dollar crop – or other property – so it doesn’t start on fire. We’re here to help.”
The foundation of vegetation management starts with a right-of-way, which is the area of land that a power line passes through.
In these areas, Basin Electric has acquired a property right from the property owner to install, operate, and maintain transmission lines and related equipment.
All of Basin Electric’s easements, even the older ones, have the right for vegetation management, says Shauna Laber, Basin Electric senior property and right-of-way specialist.
“Since (high voltage) electricity began being run through transmission lines, we’ve known that vegetation and electricity don’t make a good combination,” Laber says. “Many people don’t realize it’s a hazard, or know about restricting trees or buildings being in the easement.”
Compliance plays a huge role in vegetation management, Kaiser says. After the 2003 power outage in the northeastern United States, the federal government started to clamp down on its checks and balances for vegetation management.
According to federal regulations, trees have to be monitored once every 18 months through the MinMax program, a computer program specifically designed and maintained for compliance, and audits can be conducted by the federal government randomly. However, Basin Electric goes above and beyond the 18-month requirement.
Basin Electric’s line crews monitor vegetated areas by ground patrol once per year. Aerial patrol of all lines using a fixed-wing aircraft and/or drones is conducted three times per year. Monitoring is done year round.
“Trees grow,” Kaiser notes. “When the line crews do their annual inspections through the MinMax program, they document what the conductor-to-tree clearance is.”
Laber also notes that some trees and shrubs are volunteer and just happen to grow in the right-of-way. “A seed blows in, and the tree or shrub happens to grow in that area because it’s conducive for that type of vegetation,” she says.
If a tree or shrub needs to be removed from a right-of-way, Basin Electric’s line crew will cut it at the ground line, called clear cutting. The landowner can elect either to have the tree chipped and mulch spread in the area removed, the tree chipped and mulch hauled away, or have the tree cut into eight-foot sections and hauled to an area within a one-half mile radius.
“When landowners choose to have the wood left for them to use, they can still use the resource that grew on their property,” Laber says.
Safety at all times
Of all job duties a line worker has, cutting trees is the toughest and perhaps least desirable, according to Kaiser.
“It’s a very physical and dangerous task,” he says. “From a safety perspective, you’re dealing with sharp, fast-moving objects.”
From head to toe, line workers are geared up for safety at all times, but even more so when cutting trees. Their gear consists of cut-resistant chainsaw boots, chaps, and gloves; a hard hat, face shield, and sound-proof earmuffs, in addition to their standard fire-resistant clothing.
A person can get very warm wearing all of this gear. To avoid heat exhaustion, fall and spring are the target cutting times. Tree cutting is only done in the summer if a dire situation warrants it.
Most of Basin Electric’s line workers are certified tree fallers, having received training from one of the top five tree cutters in the world. During the training, they learn how to properly fall a tree: making it go where you want it to, and how to consider the tree’s height and lean, into the decision.
Safety around machinery is vital, too, as Basin Electric’s line crew operates one of the biggest wood chippers made by Vermeer Corporation.
After an incident when a line worker’s hard hat and safety glasses were sucked into the chipper as tree limbs were fed into it, Basin Electric purchased a different chipper featuring an upper safety bar, in addition to the standard front safety bar.
The line crew also redesigned its procedures to safely chip trees. “We position ourselves outside the feed shoot when feeding tree limbs, and we also have an employee at the controls at all times during this task,” Kaiser says.
A collaborative approach
Vegetation management is a collaborative approach between Basin Electric's right-of-way team, its line crews, and the property owners.
Laber notes that from a right-of-way perspective, Basin Electric understands people’s needs or desire for shelter belts, or their emotional attachment to their trees.
“It’s hard for them, and we recognize that,” Laber says. “We do our best to help them work through the situation by communicating up front, having discussions, and giving them time to work through it. Ultimately, we just don’t want the prairie to catch on fire.
”Just like landowners have to be good stewards of the land, Basin Electric is an organization that is being a good steward of its assets,” she says. “It’s just all of us working together.”