For safety and reliability reasons, federal regulations require ATC to eliminate natural hazards - such as trees and other vegetation - that can interfere with electric transmission lines. Trees can cause interruptions in electric service if they grow into or fall on the lines. Since 1996 tree and power line conflicts have been implicated as the cause of three large-scale electric grid failures in the U. S. and Canada, including the massive August 14, 2003, blackout that affected 50 million people.  As a result, federal regulations on tree-clearing have become more stringent.

Answer your questions:  Tree and vegetation clearing

A transmission line right-of-way typically includes land directly beneath the wires (wire zone) and land between the wire zone and the edge of the right-of-way (border zone). All vegetation within the wire zone will be cleared regardless of height, and trees, tall-growing vegetation and woody brush and invasive species will be cleared from the border zone. While many property owners will use the easement area for gardens, prairie plantings, wild flowers, along with other non-vegetation uses, anything in the easement is subject to removal should conditions or circumstances relating to the operation of our facilities warrant it.  

Beyond the edges of the right-of-way, large trees that are dead, dying, diseased or leaning that pose a threat to transmission lines and structures are removed or pruned.  With landowner consent, vegetation that is likely to re-sprout after cutting may be chemically treated to inhibit re-growth. Only certified and licensed applicators conduct this work in accordance with herbicide labels and all state, local and federal regulations.

Woody invasive species are removed

The dense growth of invasive woody plants can impede access to our equipment. By clearing invasive vegetation, we are better able to inspect and maintain our facilities and expose fast-growing trees that may be hidden from sight. This practice is consistent with the Wisconsin Department of Natural Resources initiative to remove invasive plants. Invasive plants found along our rights-of-way are predominantly a combination of buckthorn and exotic honeysuckles. They are considered invasive because they have longer growing seasons and drain soil nutrients and water, which enables them to choke out native plants. Removing them from transmission corridors allows low-growing native vegetation in the area to quickly re-establish and improves biodiversity along the right-of-way.

We regularly inspect our facilities
The vegetation maintenance cycle is typically five years. However, all of our facilities are inspected on an annual basis either on foot or by helicopter to identify any necessary repairs, deterioration or vegetation threats to our facilities that must be addressed prior to the next scheduled maintenance cycle.

We discuss maintenance work with landowners
We know property owners near our facilities will have questions about vegetation removal and it is our goal to provide opportunities to discuss our plans before our forestry contractors arrive for scheduled work. In general, we will notify landowners in advance and provide a description of our plans, the reason for the work, timeframe and contact information for a designated ATC representative. We aim to provide ample time for the property owner to identify and make arrangements to relocate trees or bushes, if they can be moved safely.

For more information contact: Waunell Trepanier-Friese, ATC coordinator of Transmission Vegetation Management at 1-866-899-3204.