The objective of the Forestville Transmission Line project in Forestville, Québec, commissioned by Hydro-Québec, was to modernize and secure the regional electrical grid. The previous infrastructure, which consisted primarily of wooden poles, had become unstable due to environmental degradation and damage from wildlife. In addition, the location of the project, passing through urban zones, posed risks related to public safety and maintenance efficiency. CIMA+ played a central role in designing and implementing this new transmission line, which was executed in two phases. One phase addressed erosion-prone segments along the St. Lawrence River, while the other phase rerouted the line outside of the urban core in order to minimize disruption.
One key innovation was the deployment of a support system consisting entirely of steel, which was the first of its kind in Québec. Steel poles increase structural resilience, extend the life of the infrastructure by a century and reduce long-term maintenance needs. CIMA+ also led the complex integration of geotechnical and environmental assessments, route adaptation based on community feedback and technical compliance with Forestville Airport regulations.
Pioneering long-term reliability through the innovative use of materials
The Forestville project introduced Québec’s first transmission line fully supported by a new generation of steel poles. Designed collaboratively by Hydro-Québec and CIMA+, these structures replaced deteriorating wooden poles, and can span up to 120 metres, thereby reducing the total number of supports required. The steel can also withstand harsh weather and damage from local wildlife.
The new poles were designed to be compatible with the same equipment that was used for the wooden poles, both in terms of construction and maintenance, with particular attention paid to limiting the weight and diameter. They have been rigorously tested for load resistance and for adaptability to various types of soil. The 100-year lifespan and compatibility with existing equipment will reduce maintenance while enhancing safety and long-term network resilience, thus setting a new standard for sustainable, high-performance energy infrastructure.
Managing topographical and regulatory constraints
The complexity of the route and the imposed environmental and logistical constraints presented major challenges in connection with the project. The 13-km route was defined based on topography, environmental management, technical feasibility, private-land limitations and the City’s development plans. In-depth studies of soils, existing infrastructure and impacts on stakeholders were also carried out. The line crosses both urban and rural areas, where adjustments were necessary, notably in order to comply with Forestville Airport standards, avoid interference with aircraft approach routes and allow for future Airport expansion.
Improving infrastructure with minimal environmental disruption
The route of the new line was optimized to limit impacts on sensitive ecosystems. Geotechnical studies made it possible to adapt anchors and foundations to different ground conditions (rock, wetlands and soft soils), leading to the preservation of a large part of the forest cover and agricultural land. Watercourses and wetlands were identified ahead of time in order to avoid crossings, and mitigation measures were implemented wherever bypassing them was impossible. These measures included the addition of organic structural supports to solidify eroding embankments for ease of passage, the tracking of construction equipment and strict control of site machinery traffic. All movement of equipment and supplies was rigorously planned with a view to reducing pressure on the ground and limiting disturbance of fragile soils.
Gaining stakeholder support
A carefully planned public consultation process made it possible to address the concerns of a wide range of stakeholders. Following the consultations, the initial route was modified to avoid active agricultural zones and maintain local economic activities. Other adjustments were made to preserve ski trails and recreational areas, favouring passage over public land and existing rights-of-way, which reduced the need to remove trees. The location of poles was also adjusted in order to reduce the visual footprint and to avoid disturbing landscape views for nearby residents.
A model for new energy infrastructure that adds to the local economy
The project not only succeeded in preserving sensitive natural areas and minimizing tree loss, but also delivered economic benefits by engaging local contractors and enhancing the reliability of power transmission for residents and businesses. This initiative was delivered on time and on budget, with no service interruptions, and constitutes a replicable model for resilient energy infrastructure across Canada.