According to the Congressional Research Service, an average of 7.1 million acres have been burned by wildfires each year since 2000. After more than 10 million acres were burned by wildfires in 2020, multiple industries are working to reduce their devastating effects. Electrical transmission lines are periodically responsible for wildfires, making the review of outdated utility vegetation management strategies an important step toward preventing tall-growing vegetation from making contact with essential components.
While some industry professionals have proposed burying power lines, that effort would take billions of dollars and years to complete. Instead of overhauling current infrastructure to enhance electrical transmission safety, utility companies have access to a more cost-effective and environmentally friendly solution: selective herbicides.
Wildfire Preventive Methods
In the past, utility vegetation management programs relied on mechanized mowing to control various forms of tall-growing vegetation. While mowing can be effective in providing short-term relief, it also strengthens the development of incompatible plant species and devastates biodiverse habitat. Selective herbicide treatments can be applied to targeted vegetation as part of an Integrated Vegetation Management (IVM) program and reduce mowing requirements as well as long-term maintenance costs.
Using selective herbicide treatments to establish fuel breaks throughout utility rights-of-way can help stifle the cause and spread of wildfires. Starting in the wire zone, which is represented by all land below wires and conductors as well as 10 feet beyond their outer edge, vegetation managers can work to control trees and tall-growing vegetation to promote the development of low-growing plant communities that consist of grasses, herbs and small shrubs. This greatly reduces the risk of power line interference while establishing natural fuel breaks that can slow the spread of wildfires.
Scott Flynn, PhD, zonal biology leader and field scientist with Corteva Agriscience, details the environmental and economic impact of this approach.
“The proper use of herbicides is proven to prevent the development of incompatible vegetation without disturbing desirable plant communities,” Flynn says. “Mowing not only damages native plants, but also stimulates regrowth and supports the spread of viable seeds. This doesn’t just increase re-treatment requirements and maintenance costs, it can create more work and greater fire hazards over time.”
Using selective herbicides can enhance mowing results and effectively control incompatible plant species throughout the wire zone by interfering with their essential plant processes. This supports the development of desirable low-growing plant communities that create a natural barrier against the future development of targeted vegetation. But keeping the wire zone clear of trees and other tall-growing plants doesn’t just prevent vegetation from growing or falling into power lines, it also reduces the amount of flammable debris that can fuel wildfires.
Slowing the Spread
In addition to downed power lines, cigarettes, automotive accidents, lightning and acts of arson can ignite fires that are capable of spreading quickly. Heat, low humidity and high winds can also create volatile conditions for blazes to spread. And while vegetation managers are unable to control the weather, they do have the ability to eliminate a primary fuel source for wildfires: dry vegetation.
Similar to fuel break establishment within the wire zone, vegetation managers can use IVM strategies to convert the border zone, which consists of all land within 10 feet of a right-of-way (ROW), to include low-growing grasses and forbs. As fuel breaks established in this area can inhibit flames from spreading, firefighters can suppress the flames more safely and effectively.
“Since many perennial grasses or forbs do not significantly contribute to a fire’s intensity, their presence provides a landscape of fire-resistant plant species that help to disrupt the spread of wildfires,” Flynn explains.
For border zones with increased tree densities, an IVM-based strategy can be used to eliminate the tallest and most flammable plant species. Similar approaches can also be used to provide ample spacing between less-flammable tree species, creating a natural ventilation system for the heat of wildfires to escape. This also provides low-growing vegetation a chance to thrive, which helps to enhance the strength of fuel breaks throughout ROW corridors.
Supporting the development of native plant communities throughout each right-of-way is an industry best practice and should be a goal for all utility vegetation management programs. There may even be areas in which total vegetation control is required to keep wildfires from spreading to nearby buildings, structures or surrounding communities. Whereas fuel break establishment can slow the spread of wildfires, firebreaks work to stop flames in their tracks.
Generally free of flammable vegetation, canyons and bodies of water are examples of areas where firebreaks occur naturally. Comparatively, a variety of plant species can run rampant throughout utility-managed lands like substations or right-of-way corridors when they aren’t controlled effectively. However, by using a tank-mix partner like Cleantraxx® herbicide, utility vegetation managers can achieve total vegetation control on these sites to successfully eliminate fuel for wildfires and effectively prevent their spread.
Improving Safety and Budget Management
Using selective herbicide applications as part of an IVM-based strategy can support low-growing plant communities that enhance the development of wildlife habitat, reduce the impact of wildfires and prevent the future development of incompatible plant species. As incompatible vegetation is replaced by low-growing plant communities, reduced treatment requirements lead to lower maintenance costs over time, which in turn enhances budget flexibility for utility vegetation management programs.
It only takes a single ember to ignite and destroy thousands of acres. But the effective control of incompatible plant species that cause wildfires and fuel their spread can allow utility companies to safeguard the communities in which they serve. To learn more about the economic and environmental benefits IVM strategies can provide to utility vegetation management teams, contact your territory manager from Corteva Agriscience or visit VegetationMgmt.com.
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