Tree Trimming
Frequently Asked Questions
Q. Are tree trimming crews working in my neighborhood?
A. Use our Tree Trimming Crew Activity Map to monitor crews while they work in the NES service area.
Q. Why does NES trim trees?
A. We do it to improve power reliability. In June 2005, NES completed its initial three-year tree trimming cycle. As a result, power outages compared to the previous three years were down 19%. Although weather patterns can affect the reliability of our electric system, tree trimming is certainly keeping customers out of the dark.
Q. How are trees trimmed?
A. Our number one goal is to keep trees healthy while making sure they don’t interfere with power lines. We follow the lateral pruning method developed by the International Society of Arboriculture (ISA) and approved by the National Arborist Association, National Arbor Day Foundation, and Metro Tree Ordinance. Lateral pruning makes the overall structure of the tree stronger and more resistant to high winds and heavy ice. Future growth is directed away from power lines. NES no longer "tops" trees, also known as rounding over or shaping. Topping is discouraged by the National Arbor Day Foundation because it makes trees more susceptible to disease and insect problems.
See illustrations of lateral pruning below.
 Before Trimming |
 After Trimming |
The degree to which a tree is trimmed depends on several factors: the tree species, voltage of power lines, and how close branches are to those lines.
| Clearance Regulations | |
High-voltage transmission lines |
15 feet or to the nearest lateral branch |
High-voltage distribution lines |
12 ft. for fast-growing trees, 8 ft. for slow-growing trees or to the nearest lateral branch |
Low-voltage service lines |
1 to 3 feet of clearance |
Q. Will I be notified of tree trimming in my neighborhood?
A. Communication is a crucial element. You will receive a notice in the mail before trimming begins. Work planners will meet with you personally to explain the work that needs to be done. If you can’t be reached, a door hanger will be left at your home explaining what trimming will occur. You are encouraged to call the phone number listed on the door hanger should you have any questions. NES representatives are always happy to meet with any neighborhood group or homeowners' association. Call 615-695-7400 for more information.
Q. Who cleans up the debris after tree trimming?
A. Tree limbs and debris will be picked up by NES contractors within seven working days.
Q. Will NES ever cut down a tree?
A. Occasionally trees near high-voltage lines need to be removed. If a tree is diseased, dying, storm-damaged, or likely to be severely deformed by necessary trimming, NES crews will trim and remove the tree according to specification. Trees near low-voltage service lines that run to individual homes and businesses will not be removed.
Q. Why aren't more lines underground?
A. Burying lines is about five times more expensive than placing them overhead. However, Metro’s Underground Utilities Ordinance requires lines to be buried underground in all new residential developments. Converting overhead lines to underground in existing developments is much more problematic. Older buildings generally run into electrical code problems, and burying transmission lines along the street can be difficult. Underground lines require more space than overhead lines, while right-of-way along roadsides is disappearing.
Learn More: Underground Utilities Ordinance
Q. Where should I plant trees to avoid future problems?
A. Trees grow to varying heights. Before planting, visualize the height and spread of a mature tree in relation to nearby power lines. Also, for your safety, don’t plant trees or large shrubs within 10 feet of a utility pole.
Mature Tree Height
|
Distance from Power Lines
|
25 feet or less |
10 feet |
25 feet to 50 feet |
35 feet |
50 feet or more |
45 feet |
Q. Can NES legally trim trees?
A. According to the Municipal Electric Plant Law of 1935 and the Metro Charter, Appendix III, Article 42, NES has the power to purchase, construct, maintain and improve the electric system and to "do all acts and things necessary and convenient" to carry out the power given. Courts in Tennessee clearly support a public utility's right to trim and remove trees, both within and outside of the right-of-way.
Q. Who can I contact for tree trimming related questions?
A. Call our tree trimming hotline at 615-695-7400.