By Jen Neville
The answer to fighting fires that threaten transmission lines begins long before the first spark; it begins with managing the vegetation around the structures and under the lines. This year, vegetation management has already saved transmission lines carrying energy across Arizona to Nevada.
For back-to-back weeks in April, Arizona locals saw three human-caused grassfires spread quickly across the open, arid climate, threatening homes, the desert ecosystem and WAPA’s transmission system between Wickenburg and Tonopah.
“The first wildfire was the Painted Wagon Fire that started on April 9, which scorched 384 acres,” said Vegetation Management and Access Maintenance Manager Steve Narolski. “The second was the Forest Fire which burned about 400 acres and occurred about a week later. The latest was the Patton Fire that has also burned over 400 acres and started April 27.”
The series of wildfires reflects a high fire danger for the season due to increased growth of vegetation from a very wet spring. The second wildfire had concerned both state and federal officials enough to call in aerial retardant drops to arrest further spread.
Yet, WAPA was prepared for this type of event.
“Over the past two years, we’ve been working on the right prescription and contracts to implement integrated vegetation management under our lines across the desert,” said Narolski. “It’s a two-stage approach. First, we reclaim the easement area by clearing out tall-growing vegetation. This leaves only the low, natural vegetation in place. The second step comes the next year when we apply herbicides to keep vegetation at the low growth. The result is reduced impact ecologically, and it saves money compared to mowing it all straight down.”
Along a transmission corridor, vegetation is fuel for fires. “We are working on getting the fuel loading to the point that a ‘cool fire’ could go through without causing flashover from smoking vegetation or heat intensity around structures,” said Narolski. A cool fire burns at a low temperature without threatening the integrity of the steel or wood structure.
Good for environment, customers
The goal of removing fast- or tall-growing vegetation is to allow the fire to pass right under the line without impacting it. This is important because keeping the energy flowing is critical for customers serving towns and cities in Arizona and Southern California, even when there is a fire.
“Our customers were calling during the fire. They are very much invested in the project and want to make sure that the line is in good shape,” Narolski said. “The Salt River Project and Arizona Public Service invest in the vegetation management project, and we need to keep the circuit running.”
During the fire, Narolski served as the incident commander, communicating with dispatch.
“The fact there was no discernable damage to either conductors or steel lattice structure validated that this cost-saving prescription was a success in this ecosystem,” said Narolski. “Our collaborative effort speaks to the mission of providing cost-based, reliable energy that is compliant with environmental laws and works with landowners to manage the local area.”
Energy safety moment
Fast-moving grassfires are dangerous to the public, as well as to the teams fighting them. Add energized lines to the conditions and the complexity of fighting the fire goes up.
“I have fought fires in the past,” Narolski explained. “Fires can get away from you really quick.”
Obviously, safety in these situations is paramount.
“The firefighters on the ground have different levels of expertise, so we encourage them to keep a safe distance from the fire and the energized lines,” he continued. “I always tell them to stay at least 100 feet away to avoid a flashover that could electrocute them. We are always emphasizing safety, and thankfully, no one was injured by these fires.”
WAPA can also use vegetation management to imitate the natural cycle of fires and ecosystem renewal.
“The entire Western U.S. has a fire cycle, and we work to emulate that natural process as much as possible,” he said. “We have to presume that on any given day a fire could happen. If we are keeping the vegetation at low-lying conditions, that is optimal for us and the ecosystem. It puts us in the best position possible to maintain reliability and public safety.”
The foresighted work between functions at WAPA, wise use of customer funds and the partnership with local officials results in successful firefighting both preventatively and in the moment.
Note: Neville is a public affairs specialist.
Vegetation management prevented wildfires from interfering with WAPA's
transmission lines in Arizona. (Photo by Steve Narolski)