Line Clearance FAQs Frequently Asked Questions
How can trees affect my power?
Trees can affect power in a number of different ways. Service reliability can be affected by trees, either at the precise location where a tree may contact a line, at other locations on that line or at other locations on the interconnected electric grid. Fallen trees can interrupt power to many customers. In a worst case scenario, a tree can tear down the entire line and break the poles that hold the line in place.
It’s not necessary for a tree to tear down a line to disrupt power. A tree or even a limb can fall across two of the distribution wires on the pole and create a path for the electricity to flow. When this happens, protective equipment will generally de-energize the line. Electrical blinks and flickers may be experienced if intermittent, short duration contacts are made with the line. The blinks and flickers may be caused by high growing brush or vines as well as trees. Trees along transmission systems only need to grow or become close to power lines in order to cause interruptions or outages, therefore, even greater efforts are made along the transmission system. If you have concerns about trees or vines growing near power lines, please contact Duke Energy. A customer service representative will be happy to assist you.
Are there safety issues surrounding trees and power lines?
Serious injuries or death can occur if energized lines are touched. Trees and tree limbs can tear down power lines. When trees grow close to and into the lines, there is a possibility of someone climbing a tree and making contact with an energized line. The lines are just as dangerous if touched by someone climbing in a tree as they would be if touched by someone standing on the ground. Transmission lines even have the potential of electrocuting persons on the ground near a tree, if the tree makes contact with a transmission line.
My trees haven’t caused any power outages. Why are you cutting or pruning them?
To provide safe and reliable service, Duke Energy must remove brush and trim trees along the power lines. These practices and techniques are approved by nationally recognized arborists. We have an obligation to provide safe, reliable electricity. Our ability to provide reliable electric service is influenced by the maintenance of trees and brush around power lines.
The development of an Integrated Vegetation Management Program allows us to evaluate power line areas and determine the best method for maintaining reliable service from the poles and lines. The objective of the Integrated Vegetation Management Program is to maintain the lines, before the trees and brush are close enough to cause outages, in a manner that is consistent with good arboricultural practices. It is also our responsibility to maintain the safest working environment possible for our linemen and tree workers. Pruning limbs before they reach or come close to the energized wires allows for this to happen.
When tree workers are clearing the lines in an area, keep in mind they are helping us provide you with safe, reliable power in a way that minimizes any adverse effects to the health of your trees.
How does Duke Energy decide when to prune, or is this just a random selection?
We have a routine maintenance program for trees and brush growth around power lines. In cases where tree conditions are worse, one line may be maintained more often than another. If a particular line is not currently scheduled for maintenance, but begins to show an unacceptable number of tree related outages, it might be maintained sooner than originally anticipated.
Are trees trimmed or removed for the installation of new electric lines?
We evaluate the best line routes with the least impact to the environment. Typically, in this part of the country, any route that is chosen involves a conflict with trees. We prune and cut down the necessary trees and vegetation in order to properly install and maintain poles and lines.
Does Duke Energy trim or remove trees other than those near power lines?
We are only involved with the maintenance and removal of trees and other vegetation that might endanger the safe and reliable operation of poles and lines for the delivery of electricity.
When is the best time to prune trees?
Most professionals recommend tree pruning during the winter time when the trees are not growing. Most professionals also advise that if you are not severely pruning a tree, it can be pruned any time of year. Certified arborists recommend that it is more important to make the proper cuts and follow sound arboricultural practices than to limit pruning to just a certain time of year.
How much will be cut from my trees?
Each tree is different and must be considered individually. Species growth habit (rate, size, shape, etc) and the trees position in relation to the power line needs to be taken into consideration prior to trimming. The current condition of the tree or individual limbs is also assessed before trees are trimmed. On occasion structural defects are found and need to be corrected in order to protect the line. Trees with trunks close to the power lines require much heavier pruning than trees located farther from the line. Some techniques that are appropriate on most deciduous trees cannot be used on some coniferous (cone-bearing) species.
When pruning operations are performed, our trimming experts make every attempt to trim sufficient clearance so that the tree will remain safe until we return on our next routine maintenance cycle.
Does Duke Energy “round-over” and/or “shape” trees?
We do not “round” trees over because it’s not good for the health of your trees. We subscribe to a method of pruning called lateral and directional pruning. These methods are endorsed by many in the tree-care industry as being the best pruning technique for the health of the tree.
The basis for lateral pruning is that each limb removed from a tree is removed either where it joins another limb or at the trunk. This procedure is different than the philosophy of “rounding” trees over in which limbs are cut at arbitrary points normally leaving unhealthy “stub” cuts. Directional pruning involves cutting a limb back to another limb (or lateral) so that future growth of the resulting limb is directed away from the power lines. With directional pruning techniques, tree growth causes minimal impact to public safety and electrical service.
If one of your local tree companies has Certified Arborists on staff, ask them about healthy pruning techniques for trees.
When is it necessary to remove trees instead of pruning them away from the power lines?
Normally, when trees are dead or unhealthy, we will discuss with you the possibility of removing the tree(s). A tree may have a decayed portion of the trunk; the entire tree may be dead or in the process of dying which might cause it to break or fall. It may have soil that is severely eroded away from the root system such that it is more likely to fall. Sometimes large growing trees are so close to the lines, and will have to be pruned so severely, that it becomes necessary to take the tree(s) down.
Are the tree trimmers trained and professional?
It is important that each tree professional working for Duke Energy be trained in proper techniques and safety. Extensive training is provided by the contractors. We also have certified arborists on our staff who oversee all facets of our vegetation management programs.
How do you decide whether to use herbicides on trees or just prune them?
In Ohio, Kentucky and Indiana, herbicide treatments are performed on vegetation when it is still very small, such as after the rights of way has been mowed and the root systems of the brush have had a chance to regrow. A follow-up treatment is applied in order to control any of the brush that might have been missed on the initial treatment. This will allow the compatible vegetation to effectively grow in the rights of way. By encouraging this compatible vegetation, Duke Energy can actually decrease the extent of vegetation removal that may normally be required in future years.
Herbicide treatments are selectively applied across the width of the rights of way. Tree pruning occurs on trees along the sides. Any mature trees found within the rights of way are also either removed or pruned.
Are all power lines the same?
No. There are two different kinds of power lines –transmission lines and distribution lines. Each type has their own line clearing standards that must be followed by residents and Duke Energy.
What is the difference between a transmission line and a distribution line?
Transmission lines are high capacity power lines that bring electricity from a generating station into the community.
- Carry 69,000 volts to 345,000 volts
Distribution lines carry power from local substations to homes and businesses.
- Carry 4,500 volts to 34,500 volts
How much clearance is needed around the distribution lines?
There are three types of distribution lines. They require different clearances:
- Single-phase line
- 10 feet on each side and under the power line
- Remove overhanging live branches to minimum 15 foot height clearance and all dead and structurally weak overhanging branches
- Two and three-phase line
- 10 feet on each side and under the nearest power line
- Remove unsuitable overhanging and/or invading limbs/branches above the power line
Will I be notified before a tree crew comes to cut trees on my property?
Door hangers identifying the work to be performed on distribution lines in the area are left on each customer’s door at least three days before the crews arrive for scheduled line pruning in the area. This process applies to the routine maintenance work that is pre-planned and scheduled. In emergency situations or in follow-ups related to outages that cannot be planned ahead of time, we are unable to give prior notification. The tree worker is also instructed to give the customer a courtesy knock once they arrive on your property prior to beginning the work.
How often does Duke Energy trim trees in my area?
We employ a systematic approach to maintaining more than 26,700 miles of overhead distribution lines in Ohio, Kentucky and Indiana. The condition of vegetation (trees and brush) around the power lines dictates our need to manage the growth. Depending on the conditions on a given line, our maintenance schedule may vary from four to six years.
What types of trees and/or plants should be planted near transformers and distribution power lines?
Before you plant a tree or shrub, make sure the location is out of the way of overhead and underground power lines and other utilities. For help locating underground lines in your area, dial 811.
Kentucky, Ohio and Indiana
Anyone working or lifting within 10 feet of overhead power lines or poles is required to contact the appropriate electric utility. We recommend that you be safe and take the same precautions if the tree or limbs are within 10’ of energized wires. To request assistance please call 1-800-521-2232.
To report a power outage using our automated reporting system, call our call center at 513-421-9500 or 1-800-634-4300.
Selecting Trees for Distribution Rights of Way
When selecting a tree or shrub to plant, it is just as important to consider what you plant as it is where you plant. The right tree or shrub, planted in the right place, can give you years of beauty and value without the potential dangers of getting too close to power lines.
Tree placement in relation to overhead power lines is critical in order to preserve the natural size, shape and overall integrity of the tree and protect the intent for which it was planted. Utility line clearance (tree trimming) does not take into consideration the aesthetics sought by the design objective; however, it is necessary to maintain safe, reliable service.
To help you decide which tree is right for your yard, here are a few suggestions.
The following small-growing trees (no larger than 15 feet) are adaptable to the region and can be planted directly underneath distribution power lines without the need to prune for the electric line:
- ‘Durand Dwarf’ Amur Maple
- Red Jewel Crabapple (not all crabs work; consult your local nursery)
- Kousa Dogwood
- Dwarf Red Buckeye
- Star Magnolia
The following medium-sized trees (maturing to 25 to 40 feet) can be planted at least 30 feet from distribution power lines:
- Hedge Maple
- Eastern Redbud
- Flowering Dogwood
- Eastern Hop Hornbeam
Be careful as you plan to visualize the tree at its full size. Large trees, such as oaks, often spread out considerably as they grow. Plant large-growing species (maturing to 40 feet or more) at least 40 feet from distribution power lines to avoid future pruning:
- Scarlet Oak
- Red Oak
- White Oak
- Sugar Maple
- Red Maple
- Honey Locust
- Linden or Basswood
Selecting and positioning shrubs is not nearly as difficult as planning for trees. In most cases, shrubs will never grow to affect power lines.
However, we need to keep as much open space as possible around pad-mounted transformers (the rectangular green boxes located near property lines). That’s why we encourage you not to plant any type of vegetation other than turf type grasses within ten feet of the opening side of the box (where the padlock is located). This open space is needed so we can get inside to perform repairs and maintenance.
Who trims tree limbs that interfere with the light levels or pattern of light from streetlights?
Over the course of time, tree growth may begin to interfere with your desired light pattern. It’s your responsibility to maintain (or have maintained) the growth of any trees interfering with the lighting pattern. During our routine circuit pruning cycle, Duke Energy will address any vegetation that may damage the actual light fixture or the conductors feeding it.
Is there a charge for trimming trees on my property?
Tree trimming is a part of our responsibility to ensure safe, reliable electric service to you. The cost of managing the natural growth around power lines is a part of the rates approved by the utility commissions in Indiana, Ohio and Kentucky.
When do I need to contact Duke Energy about working around power lines (landscaping, house painting, etc.)?
Call 1-800-521-2232 for assistance. A job ticket will be generated and you should have a response with possible options within 2 weeks.
For assistance in locating and marking underground utility lines, Dial 811 and they will assist you.
Does Duke Energy provide help to a property owner to trim or remove trees away from distribution power lines?
Pruning vegetation around power lines is an extremely hazardous job. Duke Energy discourages you from undertaking any pruning activities close to electrical equipment. If you are concerned about the growth of trees or other vegetation on or near the service lines around your house, we encourage you to contact Duke Energy, and a representative will be glad to assess the situation.
Is Duke Energy responsible for cleanup after pruning trees around distribution lines?
The majority of our pruning and cutting occurs during routine line maintenance cycles. In the region, our policy is to dispose of any small limbs and brush in maintained settings. The larger pieces of wood are cut into manageable lengths for your use. In non-maintained sites, pruned vegetation and wood is left in place. This material will bio-degrade into its natural components. When an “Act of God” (such as lightning, ice storms, high winds, hurricanes, tornadoes) cause trees or other vegetation to fall across power lines and thus create power outages, we cut the trees and brush so poles and lines can be replaced and re-energized. Disposal of any wood, limbs or debris resulting from this type of emergency operation is the responsibility of the property owner.
Transmission Line Clearing Guidelines
What are the transmission line clearance guidelines?
Our transmission line clearance guidelines can be found here. (pdf, 106 KB)
Will Duke Energy remove wood and debris from my property?
In a maintained area of your property, Duke Energy will remove wood and debris at the owner’s request.
Will I be notified before a tree crew comes to cut trees in my yard/neighborhood?
Letters or door hangers will be used to notify customers of a bulk transmission line clearance project in their community at least two weeks prior to the start of the project.
Why is the tree trimming and removal around and under the large steel transmission towers and power lines more aggressive now?
Bulk transmission lines are high capacity power lines (>200,000 volts) that interconnect regionally and nationally to provide enhanced reliability. They are the backbone of our electrical system.
After the 2003 Northeast Blackout that left 50 million people without electric service, the Federal Energy Regulatory Commission required standards in 2007 to enhance the reliability of the transmission grid. These standards require utility companies to develop line clearance programs to protect the bulk transmission lines and include substantial penalties for noncompliance.
What factors impact the amount of clearance required to protect a power line and transmission tower?
- Size of the power line
- Amount of electricity flowing on the line
- Outside temperature
- Length of the power line span
- Weather conditions
How often do you clear the zones around the high-voltage transmission lines?
Duke Energy’s bulk transmission line clearance program is on a six year cycle. However, we also patrol the lines between cycles and remove or prune trees and vegetation that grow within 20 feet of the power line under maximum load conditions.
How can I find out more information about Duke Energy’s line clearance program, get a recommended list of trees and shrubs or schedule an appointment with a forester?
Call 1-800-521-2232 for assistance. You can view the list of approved vegetation species for transmission lines by clicking here. (pdf, 84 KB)