Beetle-Killed Trees Near Power Lines Bring Increased Wildfire Risk
As fire season starts to heat up in Montana, the threat of electrical power lines igniting dry forests is raising concerns. Power lines started the deadliest and most expensive fire in California history last November, the Camp Fire, which destroyed the town of Paradise and killed 85 people.
The threat of vegetation falling on Montana power lines has increased in recent years due to the rising number of beetle-killed trees.
“There was this massive accumulation of standing kill and new hazard trees,” Brad Johnson, the chairman of the Montana Public Service Commission said. “It’s a matter of recognizing the new threat and dealing with it.”
The Public Service Commission is the agency that regulates utility companies.
Much of the responsibility for those electric lines falls on NorthWestern Energy, Montana’s largest supplier of electricity.
“Who knows when that catastrophic fire is going to pop up that we aren’t able to get our arms around it,” Johnson said. “I can’t tell you when or if that is going to happen. So the best we can hope for is to mitigate that threat to the greatest extent possible, and I think NorthWestern is trying to do that.”
NorthWestern Energy said it is more than doubling what it spends on hazard tree removal this year, from a little over $3 million to $8.5 million. That spending is on top of the more than $83 million spent on electrical transmission and distribution operations, as well as maintenance, last year.
Some of the most expensive and visible work has been done in Gallatin Canyon, six miles north of Big Sky on U.S. Highway 191. The gorge narrows here, and evergreens and power lines compete for space on the steep, rocky terrain beside road and river.
And then, a helicopter emerges above the ridge. What looks like a large box dangling from its belly is called a Heli-Feller. Its metal claws wrap around the trunk of a tree as a saw cuts off the top.
What’s unique about the Heli-Feller is that it can hold the tree top until the pilot finds a safe place to drop it.
This is the first year NorthWestern Energy has hired the Oregon-based company, Heli-Dunn, to do this work. It’s part of the utility’s effort to protect 21,200 miles of overhead lines in Montana and prevent wildfires. That’s more than twice the distance between Nome, Alaska, and the southern tip of South America.
When power lines cause fires in Montana, more than half the time it’s because a tree has fallen on the line. Mike DeGrosky is chief of the Fire Protection Bureau at the Montana Department of Natural Resources and Conservation. He said 75% of power-line fires in Montana start in the more forested western region of the state.
“[We face] high to extreme fire danger for a good chunk of the summer,” he said. “And that right-of-way maintenance is just extremely important.”
Right-of-way maintenance refers to clearing a path in areas where trees could fall on power lines and potentially start a fire. The largest recent power-line fire in Montana was in 2014, burning more than 8,000 acres of mostly grasslands in Rosebud County.
DeGrosky said overall, power lines aren’t a major ignition source for wildfires in Montana, and the fires that do start are often brought under control quickly. But they’re still a source of fire and it is preventable.
Scott Bernhardt is NorthWestern’s vegetation manager, and was on site when the helicopter was working Gallatin Canyon. He said steep, rocky terrain such as the canyon’s has been the main challenge for his crews.
“We’ve done it all by hand in the past, but it’s just brutal, steep and physically challenging for the guys, and to get all their equipment up there to do the work and those sorts of things,” Bernhardt said.
He explained that in some areas it can take several hours just to hike in with ropes, climbing saddles and chainsaws from the nearest road.
“You know, they’re carrying hundreds of pounds of stuff up there,” Bernhardt said.
“Gear and ropes and climbing saddles and climbing gaffs and chainsaws and gas and oil: It’s just getting to the work in a lot of cases. That’s why we’re excited about the helicopter.”
Bernhardt said the helicopter can take care of the stuff in the steep and hard-to-reach terrain while his ground crews handle the easier work. With all of the recent tree kill-offs from insects, he said they have a lot to do.
“We think we have 1,100 to 1,200 miles that are affected just by the mountain pine beetle,” Bernhardt said. “We’re looking at a different forest today. This is all spruce budworm damage and it’s killing our fir trees down here.”
NorthWestern executive Mike Cashell addressed the bigger picture.
“You asked if the situation in California has heightened awareness: It certainly has, but I guess I’d stress the fact that we’ve been pretty proactive in the last couple of years in regards to wildfire,” he said.
NorthWestern patrols its lines twice a year, and collaborates with the U.S. Forest Service to identify and prioritize vegetation work in parts of the state with the highest wildfire risk.
But Cashell noted that reducing risk isn’t the same thing as eliminating it. He pointed up to the ash-colored trees dying on the side of Gallatin Canyon.
“The one thing I know for sure just looking at the hillside: If we manage everything near our lines, there’s still hazard out there that we really can’t control,” Cashell said.
Over the last decade, the DNRC has responded to an average of 14 fires a year that were started by power lines, with the vast majority burning less than an acre and occurring on private land.
That’s 14 out of a total of more than 480 fires DNRC tracked. DeGrosky said it’s not just falling trees that cause those power-line fires, though.
“A cross arm breaks, an insulator goes bad, or transformer explodes or catches on fire,” DeGrosky said.
It’s these kinds of infrastructure maintenance issues on the PG&E lines that were reportedly the culprit of the deadly Camp Fire in California, according to DeGrosky.
Although NorthWestern is the biggest utility in the state, there are more than two dozen smaller electric cooperatives in Montana. Brian Plunkett is engineering manager at the Flathead Electric Cooperative, the largest co-op in Montana. He said the group spends $1.5-2 million a year cutting back vegetation from power lines.
“We do spend a lot of resources every year going out and maintaining what we would consider an ample amount of right-of-way clearing,” Plunkett said. “Last year, we did 230 miles. We’ll probably do something very similar this year.”
Plunkett said the California utility PG&E was known for having a “low-maintained system.” The company filed for bankruptcy protection in January, a direct result of anticipated damage claims from the Camp Fire its power lines started in November.
Plunkett said the Flathead Electric Cooperative, or any other power supplier, would have a hard time stopping someone from suing if a fire broke out because of their lines.
“I think you’re always going to have a potential for that,” Plunkett said.
“I don't think anything that we do as a power company is going to, 100% get rid of that type of scenario. But I think what we can do is prove that we are going out and we are using a lot of resources to maintain our right-of-ways, to maintain our system and equipment.”
Plunkett said he hasn’t noticed any changes with Flathead Electric’s liability insurance rates in recent years. According to documents filed with Montanan’s Public Service Commission, NorthWestern’s liability insurer has expressed caution about wildfire risks.
As part of NorthWestern Energy’s current rate case — where regulators are reviewing whether what the utility would like to charge customers is justified — questions came up earlier this year about their liability if their power lines cause a wildfire.
The Montana Public Service Commission specifically asked NorthWestern about the billions of dollars PG&E was found liable for for the fires in California. One rate-case document reads, in part, “The Commission is concerned about how a wildfire involving utility equipment and hazard trees due to pine beetle kill could lead to a similar situation and associated risks to the utility in Montana.”
NorthWestern said wildfire liability insurance coverage has become more expensive and harder to get in the wake of the California fire. The company currently has a liability insurance policy worth $300 million, which includes wildfire coverage.
California’s PG&E utility is facing an estimated $30 billion in liability for two years of wildfires.
If NorthWestern’s cost for liability insurance does go up, and the company wants to pass some of the additional costs on to customers, that issue won’t be decided by regulators during the current case. What the company is currently asking to pass onto customers is just over $3 million annually for hazard tree removal.
NorthWestern has a goal of spending at that level for six years. That doesn’t mean the company would be limited to that spending to cut down hazard trees threatening power lines, but $3 million a year is what the Commission could currently approve for NorthWestern to pass onto customers.
If NorthWestern does spend more on the tree cutting program, or if its cost for liability insurance goes up, and the company wants to pay for either through higher customer utility bills, it would have to get the Commission’s approval in the future.
The Commission is expected to release its decision on NorthWestern’s current rate case before the end of the year.
Get the latest wildfire, fire management and air quality news for Western Montana and the Northern Rockies, on your radio during our morning and evening newscasts, via podcast, or in your inbox each day.