How To Properly Manage Vegetation Around Power Lines

For electric utilities, vegetation management is arguably the most important factor in system reliability and outage management. Trees and brush can fall on power lines, blow into transformers, block access to equipment and even create fire hazards. With increasing public pressure and regulations, it’s more important than ever to manage vegetation around power lines.

Why is Utility Vegetation Management Important?

Most electrical customers probably never realize how crucial Industrial Vegetation Management is to keep their lives going as usual. Utility lines run across long distances where land and living things constantly change and weather takes its toll. Without management, critical utilities would be damaged or destroyed. In some regions from one quarter to one half of all outages can be ascribed to vegetation.


Threats exist year-round, from forest fires to hurricane force winds to ice storms. Several major storms and blackouts of the past two decades have increased awareness as well as regulatory scrutiny of the nation’s power grid. Federal and state agencies have been proactive in attempting to improve electric utility reliability performance.

What is a Utility Forest?

The population of trees that surround a system of power lines is known as a utility forest. It can be enormous and must be monitored and maintained continuously. Over time, trees and plants grow at different rates according to conditions, shift position and eventually, tower above power lines. 


Even in the absence of inclement weather, trees can fall or lose branches due to disease, insects or old age. Invasive species bring another complication to the utility forest. Simply keeping track of all potential issues is full-time work.

Danger Trees and Hazard Trees

Trees with the potential to cause problems for utilities can be classified as “danger trees” or “hazard trees.” Both relate to the trees’ potential to come in contact with power lines. A hazard tree is a specific type of danger tree that poses a greater likelihood of causing problems. Understanding each of these situations, knowing how to spot them, and responding promptly can help prevent power outages, fires, and injuries.

Elements of a Proper Utility Vegetation Management Plan

A utility forest requires specialized, ongoing monitoring for risks. The best approach for a utility company is to follow a continuous, integrated UVM plan. Professional arborists can monitor for potential problems and recommend when to remove or prune trees, or manage vegetation using herbicides.


An effective UVM plan succeeds by doing the following:


Emphasizing Preventative Maintenance

A proactive approach means controlling plant growth and removing threats before a problem arises, saving money and labor in the long run.


Understanding the Requirements

Power line clearance requirements are different for transmission and distribution lines, due to their difference in voltage. Other components of the electrical grid carry their own level of risk and therefore different requirements.  


Knowing What Vegetation to Keep and What to Remove

Certain vegetation can help inhibit the growth of taller or harder-to-control vegetation. Rather than clearing all plants, a strategic approach includes selectively removing unwanted vegetation and promoting the growth of desirable vegetation.


Choosing the Best Tactics for the Situation

Not all vegetation can or should be cleared using the same means. Professional vegetation managers may approach different areas manually, by mowing, pruning shrubs, and removing trees, or by treating them with herbicides. Herbicides can be applied using a pre-emergent strategy or after a species is established.


Promptly Identifying Danger or Hazard Trees

The threat of danger and hazard trees can be mitigated by identifying them early. A skilled arborist will look for fungal activity, root damage, weakly attached branches, and unnatural leaning of the tree, and other signs that a tree poses a threat to power lines.


Investing Wisely in UVM Services

Successful UVM programs require consistency over time, and that means committing to funding them. By analyzing the potential costs of power outages, lost public trust, regulatory penalties and even lawsuits, electric utilities can choose how to prioritize UVM services in their budgets.

Posted: 7/27/2020 3:54:48 PM by Global Administrator