Back to Tree Trimming

Why We Trim Trees

Trimming trees and managing right-of-way vegetation can prevent many - but not all - outages that are caused when trees adjoining Ameren’s easements fall onto power lines.


Fallen trees and branches are a primary cause of electric power outages.To minimize the likelihood of safety hazards and power outages, trees and vegetation must be kept clear of electric power lines. 

  • Ameren Illinois trims trees only in right-of-way and easements. Trees near the electric line that runs from the main power line to a home - called a service drop - are the property owner’s responsibility.  
  • Usually, when homes are built an easement is granted at the time of development that allows utilities the ability to access and maintain their equipment. Ameren Illinois may therefore hold easement rights on the land on which power lines and poles are located. Ameren Illinois requests landowners not to encroach on the easements with trees or buildings that may disrupt the operation of the lines. 
  • If you are concerned about tree growth near your service drop, please call 800.755.5000 to request and schedule an appointment to have your service drop disconnected in order to have the trees near this line trimmed safely. We recommend that you hire a professional tree service to do this trimming. 
  • In some cases, Ameren Illinois may have to remove trees that we deem a high risk to electrical service or to the general public. Fast growing trees under power lines can interfere with electrical service and cause power outages. A contractor from Ameren Illinois will notify the homeowner regarding the need for removal.


Ameren Illinois contracts with more than 300 tree-trimming crews who work year round on Ameren Illinois easements. In determining our maintenance cycle, we consider our objective of providing safe, reliable service, as well as the costs involved. The costs of maintaining the electrical system, including tree-trimming costs, are recovered in our rates. It’s a balance of providing you a safe, dependable electrical system while keeping costs within reason.
Faster growing trees will require more clearance than slower growing trees. Smaller, slower growing trees will require less trimming and are more suitable to be planted closer to electric lines. Ameren Illinois takes into consideration what type of species the tree is, how fast the tree will grow, how close it is to the electric lines, and the type of voltage running through those lines. The required distance between vegetation and power lines varies from line to line depending on the voltage, local ordinances, tree characteristics and the tree owner.
The directional pruning method we use is endorsed by the International Society of Arboriculture. Directional pruning, also known as “lateral trimming,” removes only those branches that conflict with power lines. Rather than cutting limbs back to unsightly and unnatural stubs, branches are pruned back to the center of the trunk where trees normally shed them. Future tree growth is directed away from the power lines. 

Directionally pruned trees are less susceptible to disease and insects, and the overall structure of the tree is stronger and more resistant to high winds and ice. Although the shape has been altered, it is recommended over topping or rounding of trees, which tends to promote quick re-growth of small, weakly attached shoots. 

We work to provide you with safe, reliable power, and we have a responsibility to do that in an environmentally sound way
Never attempt to prune trees near power lines yourself. Only qualified line clearance tree contractors are allowed to work within a minimum of 10 feet of high voltage lines. . 

Service drops - the lines that deliver electricity from Ameren Illinois power poles to the customer's meters - are relatively low voltage (typically 120/240) and are not normally pruned by Ameren Illinois' contractors. Trees near this line are the property owner's responsibility.
First, understand that our tree trimming service is an integral part of our goal to provide you with safe, reliable electric service. 

Second, try to keep an open mind when our line clearance crews explain why trimming is occurring. 

Third, by allowing our contractor to use the proper trimming techniques your trees remain healthy, and the regrowth from the tree will tend to interfere less with power lines. 

Finally, if you are planting new trees, remember to plant the right tree in the right place. See our Tree Planting Tips for more information
We cannot recommend a particular company, but we do encourage homeowners to make sure the company they choose has a qualified arborist on staff, is insured for personal property, liability and workman’s compensation, and is affiliated with an arboricultural organization.
If you live in Ameren Illinois' service area, you may have received a postcard about tree trimming in your area. You do not need to respond to the notice, but if you have any questions or concerns about the tree trimming work, please call 800.755.5000.
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