Vegetation Management

Bucket truck trimming treesBecause keeping the lights on is our primary goal, we clear the trees that could grow into the overhead power lines that deliver electricity to you and your neighbors. Trees that grow under the power lines are the greatest threat to reliable electric service. We require a minimum of 10 feet of clearance from our facilities.

A large tree crown can spread 50 to 60 feet, so if it is growing directly under the line, there is going to be a significant aesthetic impact to the appearance of that tree. That is why it is so important that people not plant large trees near electric lines, as they will never be allowed to reach their full potential. In fact, most cities have ordinances which prevent the planting of large trees near power lines or in a utility easement.

The following information is intended as a guide for use when performing vegetation management services. Vegetation management includes the services of distribution and transmission line clearance, overhead safety inspection program and landscape maintenance. Regardless of the service performed, every work site has its own safety and work requirements.

Note: This information addresses procedures for Holy Cross Energy operating employees and is not intended for use as personal safety guidelines. Contractors are responsible for developing and following their own safety procedures.

Contractors who are performing vegetation management services are required to have a copy of this information with them in the field. Those performing line clearance activity are also required to have the book "Best Management Practices (BMP) - Utility Pruning of Trees" by the International Society of Arboriculture on each truck or work location at all times. Contractors are required to supply their own copy of this publication.

**This information supersedes all previous manuals and guidelines for line clearance and vegetation management work for Holy Cross Energy.

Tree Planting Tips
While landscaping can be used to create an area of beauty and enjoyment, it can also help conserve energy.

  • Evergreens can serve as windbreaks and should be planted on the west or north side of your house at least 50 feet away.
  • Deciduous trees (trees that drop their leaves in the fall) should be planted on the south and/or west side of your house. They can provide cooling shade in the summer and allow warm sunlight through in the winter.
  • Trees vary in their mature heights. Planting the right trees in the right place will enhance property value and prevent costly damage or maintenance to your home. Low growing trees will not reach electric lines and will not cause power outage.
  • See more tips on planting the right tree in the right place
  • Tree Care Tips & Techniques

Tree Safety

  • Remember that electric utility lines carry voltages that are many times greater than the standard household voltage. Both primary and secondary lines have the potential to kill or severely injure people who make contact with them, either directly or indirectly. This means that although you are not touching the power line, if something near you touches it, you could be electrocuted.
  • Members of the public should never attempt to clear trees from around power lines.

Frequently Asked Questions

  • How much will they cut from my tree?           
    • Typically, the amount and type of pruning that is necessary is based on:
      • Tree species
      • Growth rates (how fast the branches grow back)
      • Wood strength (the chance of the branch breaking under the load of strong wind, snow or ice) -Conductivity (how well the wood can conduct electricity)
      • Branch size (Larger-diameter branches coming in contact with conductors by failure or deflection create the greatest risk for tree-related interruptions)
      • Voltage conducted by the line and the line's construction (the higher the voltage, the greater the clearance required)
      • Framing and spacing between phases of multi-phase lines (compact design and multi-phase lines pose higher risk to tree-related interruptions)
      • Location of a tree in relationship to protective devices and critical customers on the circuit (hospitals, etc)
      • Location of a tree in regards to general public safety (existence of tree houses, public places, climb ability of tree etc)
      • Risk of wildfire ignition
  • Which pruning guidelines does Holy Cross Energy follow?
    • Holy Cross Energy follows the American National Standard Institute (ANSI) A-300 Part 1: Tree, Shrub, and Other Woody Plant Maintenance - Standard Practices, Pruning. These guidelines are followed to remove or shorten dangerous limbs, such as those overhanging wires that have a high potential for breaking or bending into Holy Cross Energy conductors due to ice, snow or wind loading.
  • Why not put the utility lines underground?
    • Installing utility lines underground comes with a very high price tag, coupled with more difficult (and longer) repairs in the event of a power failure. Also, converting an overhead system to underground may do more damage to the root systems of existing trees.

While we attempt to preserve the aesthetic value of trees and vegetation in and around our facilities (ex. meters, poles, etc.), during outage situations our primary concerns are reducing fire and electrocution hazards, and providing personal and public safety from falling branches and tree failure. Following these events, some trees may require additional pruning to meet industry standards.

 

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