Tree and Vegetation Specifications

Trees are a beautiful part of our communities, but when they grow too close to power lines or equipment, they can create serious hazards. That’s why Central Lincoln actively manages trees and vegetation across our 700-square-mile service area.

By trimming or removing trees near power lines, we help:

  • Keep the public and our crews safe
  • Reduce the risk of power outages
  • Prevent wildfires
  • Improve response time during storms and emergencies

We appreciate your help in keeping power reliable for everyone. When planting near power lines, please choose the right tree for the right place, and avoid fast-growing shrubs or vines that may interfere with equipment.

How We Maintain Safe Clearances

We follow safety standards and best practices to manage trees and brush near our infrastructure. Here’s how we manage vegetation based on proximity to power lines and equipment.

How We Measure Tree Size

Diameter at breast height (DBH) is the standard way to measure a tree’s thickness: it’s the diameter 4.5 feet above the ground on the uphill side of the tree. If the trunk forks below 4.5 feet, each stem is measured and treated separately. If there’s swelling or irregularity at 4.5 feet, the measurement is taken just below that point.

Within 10 Feet of Poles or Power Lines

  • Brush and Small Trees: Woody plants under 6 feet tall and less than 6 inches DBH may be removed, mowed, or treated with herbicide.
  • Tree Removal: Trees up to 16 inches DBH will be removed if they interfere with power lines.
  • Dying or Hazardous Trees: Dead, dying, or unstable trees may be removed at Central Lincoln’s discretion to prevent future issues.
  • Herbicide Use: Herbicides may be used in accordance with the manufacturer’s label.

Beyond 10 Feet but Still Near Conductors:

  • Trimming: We trim or remove branches and saplings that could grow into power lines.
  • Large Trees: Trees over 16 inches DBH may have their tops reduced (crown reduction) to maintain at least 10 feet of clearance.
  • Fast-Growing Species: Certain fast-growing trees that quickly become hazards will be removed.

Up to 30 Feet Above the Lines:

  • High Branches: Limbs that overhang power lines—up to 30 feet above—may be trimmed to prevent damage or outages, even if the wood is well-established.

Other Equipment and Lines

  • Secondary Lines: Vegetation around these lines will only be trimmed if the service line is pushed out of position or is rubbing against trees. A 6-foot clearance is recommended. Removals must be approved by Central Lincoln.
  • Line Drops for Customer Work: In some cases, Central Lincoln may temporarily drop service lines to allow you or your contractor to safely perform work. Please contact us in advance.
  • All Poles and Guy Wires: Trees and vegetation will be removed to create 6 feet of clearance for the line crew’s climbing space and safety.
  • Poles Marked for Replacement: A minimum 6-foot clearance from vegetation is required around these poles as well.

Our Routine Maintenance Cycle

We aim to inspect and maintain vegetation clearances on a 5-year rotation. While we do our best to accommodate customer requests, those requests may need to align with scheduled maintenance in your area.

Storm Debris and Emergency Restoration

  • Storm Debris and Emergency Restoration: Cleaning up debris left by storms or emergency restoration work is the responsibility of the property owner.
  • Dead or Hazardous Trees (often referred to as Danger Trees): Central Lincoln will assist in determining the best course of action for tree removal. If Central Lincoln removes the tree, debris will not be hauled away. Once the site is safe, customers may need to hire a private contractor to complete cleanup or additional work.

Access for Central Lincoln Trucks and Equipment

To safely reach power lines and equipment, our crews need clear access paths. Please maintain:

  • 14 feet of overhead clearance for tall trucks and equipment
  • 8 feet of side clearance so vehicles can pass through safely

Maintaining this clearance helps our crews reach equipment quickly during maintenance and outages.

In addition, please keep padmount transformers (the large green boxes often found in neighborhoods) accessible at all times.

  • Leave at least 10 feet of clear space in front of the doors
  • Maintain 3 feet of clearance on all other sides.

Avoid placing fences, walls, sheds, shrubs, or trees within these distances, as obstructions can slow power restoration and create safety hazards for crews.

Illustration showing safe vegetation clearances around power lines. A utility pole with a transformer stands between a house and a tall evergreen. Arrows show 30 feet of clearance above the pole, 10 feet of clearance on each side of the conductors, and 6–10 feet of space around the base. A legend explains vegetation guidelines: trees under 6 inches DBH should be mowed or removed, 6–12 inches DBH removed, over 12 inches DBH side trimmed to maintain 10 feet of clearance or removed if not possible, and hazard trees removed.
Clearances shown reflect Central Lincoln’s minimum vegetation guidelines for distribution lines.
Illustration showing safe clearance around an energized padmount transformer. A worker kneels using an insulated tool to access the transformer doors. Arrows indicate required clearances: 10 feet in front of the doors and 3 feet from each side. Surrounding shrubs demonstrate why vegetation and obstructions should not be placed too close.
Maintain 10 feet of clearance in front and 3 feet on the sides of padmount transformers to help crews safely restore power.