HMP&L Pruning of Trees

HMP&L's primary goal is to provide safe, reliable service.  This information is intended to provide a generalized overview of how our utility may use tree maintenance techniques to achieve that goal.

Warning: Do not attempt to prune or remove trees in contact with or near electric lines unless OSHA line clearance certified. Contact HMP&L before planting or pruning a tree near overhead electric wires.

Why do electric utilities prune trees?
SAFETY - Utility vegetation maintenance reduces electric hazard risk to the public by:

• providing separation between wires and vegetation to eliminate potential electrical shock
• reducing potential wildfire hazards from tree/ wire conflicts

RELIABILITY - Trees are among the most common causes of utility service interruptions. Trees that are too close to power lines can interfere with electric service; especially when weather brings lightning, wind, ice, or wet snow. 

How much will be cut from my tree?
Typically, a qualified utility forester or vegetation manager prescribes the amount and type of pruning necessary based on:

• tree growth rate and structure
• wind direction
• tree species: strong or weak wooded
• tree health or vigor
• environmental factors
• water sources
• proximity of tree to wires and line configuration— higher voltage lines require greater clearance

My trees are not even touching the wires, why do they have to be pruned now?
Utility companies are proactive and try to prune trees BEFORE they pose a risk to the power lines. Because trees are dynamic, factors such as swaying in the wind, sagging with ice/snow weight, and uprooting in storms are examples of how problems can develop without warning even if the trees are not in contact with wires at this moment.

What is directional pruning?
Directional pruning removes branches growing toward the power lines while leaving those that are growing away. It is the most appropriate pruning method for utility line clearance. 

How will a tree look after it is directionally pruned?
Trees growing directly under power lines may appear U or V-shaped (crown reduction or through-pruning). Trees growing alongside power lines may appear L- shaped, or one side may be completely removed (side pruning). The tree may often appear misshapen but this pruning is being performed to provide for safety and service reliability, not for aesthetic purposes. In general, trees growing near the power lines will never have the potential to grow with a “natural” shape.

Why won’t the utility put the lines underground?
Undergrounding of lines is very expensive and results in more difficult (and longer) repairs in the event of a power failure. Also, converting an overhead system to underground typically causes substantial damage to existing trees’ root systems.

What do you do if you have a tree or other vegetation that may pose a potential hazard to the power lines?
Please call HMP&L at (270) 631-0660.  HMP&L will inspect the power line to determine if there is a potential hazard.  If a hazard exists, HMP&L will schedule maintenance to remove the hazard.

What do you do if you wish to trim limbs or trees near power lines?
The property owner must contact HMP&L, not less than two business days prior to the maintenance being performed and request the power line to be removed or taken out of service for the maintenance time period.  HMP&L will temporarily disconnect the electric service at the site prior to the maintenance and will return to the site and restore the electrical service following the maintenance.  This service is provided at no charge to HMP&L electric customers during normal business hours.