Vegetation and safety near transmission lines

What is integrated
vegetation management?

Integrated vegetation management is a systematic integrated approach to managing vegetation. It applies the right intervention method at the right place and the right time to control vegetation. The activities are integrated because they are all closely linked. In fact, the information recorded at each phase impacts the decisions for the entire process. This integration enables us to make better choices and continuously improve our integrated vegetation management approach.

Hydro-Québec's goal is not to eliminate all of the vegetation but rather only the plants that are incompatible with system reliability. Controlling the vegetation growing in the rights-of-way means planting and maintaining herbaceous plants and shrubs.

The employees that oversee vegetation management include forest industry professionals (forest engineers and technicians, biologists, etc.) and skilled specialized forestry workers hired by the industry's leading companies. Each person has received training in industry techniques and environmental studies.

Planning the annual integrated vegetation management strategy and setting objectives

At this first step, we determine the order in which the interventions will take place during the year based on the regrowth cycles of each right-of-way.

On average, work is carried out every five years. The intervention cycles vary according to local growth conditions and the approach that is selected. The farther north a line is located, the less frequent the clearing operations, since vegetation tends to grow at a slower rate in harsher climates.

Vegetation inventory and identification of sensitive elements in the environment

The vegetation in the rights-of-way is mainly analyzed from aerial photographs and/or field inspections while the work is being done. The list of sensitive elements is updated to ensure that the health and safety risks for the public, the workers and the environment are taken into account.

There are three main intervention methods, which are often used in combination according to what is most appropriate.

Hydro-Québec uses the right method at the right place and the right time.

The choice of method is based on several factors. More information on these factors

  1. Mechanical cutting (using chainsaws, manual or motorized brushcutters and mowers)
    This intervention method relies on common tools.
    More information on mechanical cutting
  2. Selective herbicide application
    This intervention method stops the growth of vegetation that is incompatible with the system.
    More information on selective herbicide application
  3. Land-use development (bicycle paths, reseeding, gardens, etc.)
    This intervention method ensures that communities take full advantage of the rights-of-way.
    More information on land-use development


For mechanical cutting

Whenever possible, Hydro-Québec will contact:

  • The landowners who will be affected;
  • Municipalities (including the RCMs);
  • Outfitters;
  • ZECs.

For herbicide application

At least two weeks before the work is set to start, Hydro-Québec will give notice to:

  • The landowners who will be affected;
  • Municipalities (including the RCMs);
  • Outfitters;
  • ZECs.

When herbicides are spread in rights-of-way, Hydro-Québec will release the following documents under the Pesticide Use Code of the Pesticides Act:

  • Notice to the Ministère du Développement durable de l'Environnement et des Parcs du Québec (MDDEP) at least 21 days prior to the start of the work;
  • Notice to the municipalities and RCMs prior to the start of the work;
  • Notice in a regional media (see example) on the extent of the work that will be carried out at least one week and less than three weeks before the work is set to start.

Example of a published notice

Between (scheduled dates for the job), Hydro-Québec will be carrying out vegetation control work in the transmission line right-of-way that runs through the municipalities of... The aim of right-of-way maintenance is to reduce the risk of power outages and allow fast and safe access to transmission facilities. Such preventive maintenance is conducted in accordance with government standards, in particular the Pesticide Management Code.

The work consists of mechanical cutting in some areas and the application of herbicides in others.

If applicable, the following text will be included:
Since herbicides will be used, it preferable not to consume small fruit that grows in the transmission line right-of-way and not to visit the right-of-way when vegetation control work is being carried out.

Hydro-Québec has a permit issued by the Ministère du Développement durable, de l'Environnement et des Parcs du Québec (permit no. P-55096) to perform this type of work.

For additional information, call Hydro-Québec at
XXX XXX-XXXX or visit our Web site:

Work carried out by skilled employees

For Hydro-Québec, the vegetation management period starts after the snow melts and continues as long as the weather permits or until the snow makes work impossible.

Vegetation management work is carried out by skilled workers hired by independent companies that are certified by Hydro-Québec.

For example, silviculture skills (ex. brush and tree cutting) are an asset for workers who carry out mechanical cutting. Employees who apply herbicides must be certified under the Pesticides Act and the Environment Quality Act.

Quality control

Hydro-Québec oversees the work carried out by the companies and follows up to ensure that quality standards and objectives have been met.

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