American Transmission Co. projects

Project website for a Wisconsin-based company that owns and operates the high-voltage electric transmission system that powers communities in portions of the Upper Midwest.

Trees and vegetation: Managing utility corridors

For safety and reliability reasons, Wisconsin law requires ATC to eliminate natural hazards – such as trees and other vegetation – that can interfere with high-voltage power lines. Trees can cause interruptions in electric service if they grow into or fall on the lines. In fact, the 2003 eastern U.S. blackout was initially caused by power line contact with overgrown trees. Therefore, utility corridors must be clear of trees and brush to help ensure reliable operation and access to facilities for maintenance or repair.

Utility corridor maintenance is conducted regularly

Utility corridor maintenance is conducted regularly according to the easements rights for a particular property or parcel. Trees and brush outside the edge of the corridor may remain, but any vegetation within the corridor and where easements rights allow, may be cleared during regular maintenance activities. Beyond the edges of the corridor, large trees that are weak, diseased or leaning and that pose a threat to electric lines and structures, are removed or pruned to reduce the risk to the lines. With landowner consent, vegetation that is likely to re-sprout after cutting may be chemically treated to inhibit further re-growth. ATC uses only qualified applicators using low-toxicity U.S. EPA registered herbicides.

Invasive species are removed

While not directly interfering with our high-voltage power lines, the dense growth of invasive plants severely limits our access to our equipment. By clearing this vegetation, we are better able to inspect and maintain our facilities and expose fast-growing tall trees that may be hidden from site. The practice of removing invasive plants is consistent with the Wisconsin Department of Natural Resources initiative to remove invasive plants. The most common invasive plants found along our utility corridors are predominately a combination of buckthorn and exotic honeysuckles. Both of these plants are considered invasive and they tend to choke out plants that are native to Wisconsin because of their longer growing seasons and the drain on soil nutrients and water. Removing these invasive plant species from utility corridors allows low-growing native vegetation in the area to quickly re-establish in and improves biodiversity in the area. Protecting native vegetation from invasive species provides better habitat for birds and other animals and improves the ecological balance in the vicinity of the utility corridor.

We will review your landscape plans

ATC strongly discourages planting anything in a utility corridor regardless of the size. If you have an easement with ATC and have questions about planting near the edge of the corridor, please talk with us first so that we can advise you on appropriate plant species or easement rights. Ultimately, the easement agreement and ATC govern what trees and vegetation, if any, are suitable in and around the utility corridor. For a review of your plans, contact our Real Estate Department, 866-899-3204.

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