Vegetation Management, Tree Trimming & Removal

Living in Harmony with Vegetation and Power Lines

If you notice a tree that is interfering with our powerlines or poses a hazard, please call our Customer Service Department in Fort Erie at 905-871-0330 or in Port Colborne at 905-835-0051 as soon as possible.

For your safety DO NOT attempt to prune or cut down a tree near powerlines.

Canadian Niagara Power Inc. (CNPI) is responsible to maintain tree clearance around all its transmission and distribution lines that are located on the public road allowance and easements.  CNPI’s Integrated Vegetation Management Program has been developed to manage vegetation in proximity to electrical equipment on a regular schedule to:

  1. Ensure Public Safety
  2. Reliability of Electric Service

Canadian Niagara Power Inc. (CNPI) Vegetation Management Program is in place to ensure objectives are set, compatible/incompatible vegetation is identified, control methods are evaluated, implemented, monitored and assessed. Currently CNPI’s vegetation management program identifies tree pruning cycles for both transmission and distribution systems.

Transmission System Vegetation Management Program

CNPI’s transmission system is specified into 3 zones, one zone is completed each year, the zones re on a 3-year rotation.  (Figure 1).

115kV Tree Trimming
Figure 1 – CNPI Transmission Zone Map

The Minimum Vegetation Clearance Distance (MVCD) is the minimum distance that must be maintained at all times between vegetation and the power line (conductor) to prevent a flashover. (Table 1.1) (Figure 2)

Table 1.1 Minimum Vegetation Clearance Distance (1000ft to 2000ft)
Table 1.1 Minimum Vegetation Clearance Distance (1000ft to 2000ft)
Vegetation Management Clear Zone Requirements
Figure 2 – Clear Zone Requirements

The minimum vegetation clearance distances (MVCD) must be maintained between vegetation and the conductor in order to remain compliant with regulations (NERC FAC-003-3).  In the example below, MVCD must be maintained between the maximum sag of the conductor and the top of the tree, by ensuring timely removal of the tree. (Figure 3)

Figure 3 - The minimum vegetation clearance distances (MVCD) that must be maintained between vegetation and the conductor.
Figure 3 - The minimum vegetation clearance distances (MVCD) that must be maintained between vegetation and the conductor.

Distribution System Vegetation Management Program

CNPI is responsible to maintain tree clearance around all its distribution lines that are located on the public road allowance and easements. CNPI’s Distribution Vegetation Management Program identifies various cycles and zones to be completed each year. Fort Erie and Port Colborne service territories consist of 3 Zones which are rotated annually. (Figure 4, 5)

Fort Erie Vegetation Management Program
Figure 4 - Vegetation Management Plan, Town of Fort Erie
Port Colborne Vegetation Management Program
Figure 5 – Vegetation Management Plan, City of Port Colborne

CNPI will trim or remove trees that interfere with or have a potential for interfering with existing CNPI lines, or that obstruct the route of new lines as well as all service wires (wires that run from CNPI poles to the customer's house or building), yard light wires will be trimmed.

CNPI adheres to the American National Standards Institute (ANSI) A300, Standard Practices for Trees, Shrubs and Other Woody Plant Maintenance. This standard requires tree-trimmers to cut branches back to the "parent limb." This practice allows the pruning cuts to "heal" more rapidly, reducing the chances of insect and disease damage, and promotes a healthier regrowth of branches that are directed away from the power lines.

Directional pruning techniques, which allow the tree to be pruned according to accepted standards while helping to prevent the branch from growing back into the power lines, is often used when pruning trees.

Pruning considerations include: species of tree, growth and regrowth rates, location of trees in proximity to power lines, voltage of power lines, type of power-line construction, length of pruning cycle, natural tree shape and branching pattern, general tree condition, appearance after pruning and tree-owner input.

Below are illustrations of the types of trimming that CNPI performs. The style used depends on how the tree is placed in relation to the power line, the type of tree that is being trimmed, and the considerations mentioned above. (Figure 6 and Table 1.2)

Figure 6 - Types of Trimming around Distribution Lines
Tree Trimming - V
Tree Trimming - C
Table 1.2 Minimum Vegetation Clearance Distance Distribution
Table 1.2 Minimum Vegetation Clearance Distance Distribution

Per the Ontario Electricity Act, Section 40 (4), where necessary, CNPI will perform trimming of customer owned trees and vegetation to maintain clearance from the distribution lines, however, overall responsibility for the tree removal of dead trees remains with the property owner.

Underground Equipment

Customers are to keep shrubs and structures a minimum of 3 metres away from the front, or door side, and minimum of 2 metres away from all other sides of pad mount transformers and switchgear. (Figure 7)

Clearances to Underground Equipment
Figure 7 - Underground Equipment Clearance

To maintain the reliability, integrity and efficiency of the distribution system, CNPI has the right to have unobstructed access to CNPI electrical distribution equipment, including but not limited to padmount transformers and switchgear, on private and public property at all times for inspection, repairs, maintenance, etc.

Should CNPI be unable to access, operate, maintain, respond to emergency, construct new, or for any other reason deemed necessary as a result of obstruction(s), CNPI will take every necessary action to remove the obstruction(s). CNPI will not be responsible for any remediation resulting from these actions.