Montréal, May 10, 2017
Québec–New Hampshire interconnection: Comparative route analysis – Overhead remains best compromise for sustainable development
Hydro-Québec has published its analysis of the undergrounding scenario for the southern portion of the Quebec-New Hampshire interconnection line under the roads that run through Fôret Hereford. Our team of engineers and environmental experts compared this route, proposed by Forêt Hereford Inc. (FHI), to the underground and overhead routes previously assessed by Hydro-Québec during its draft-design studies. The route proposed by FHI would:
- Require work to excavate a trench and to underground the cables. This work, spread over two years, would have a potentially negative environmental impact on wetlands and streams.
- Rely on the construction of overhead-underground structures on private land outside of the forest. These structures would have to remain accessible at all times.
- Call for restricting the movement of local residents during construction and also during maintenance operations, once the line has been commissioned.
Undergrounding: Less visible, but not without impact
An underground transmission line, regardless of whether it runs under forest roads or under roads in neighboring communities, has an undeniable advantage: It is not visible. However, after thoroughly analyzing all aspects of these scenarios and comparing them to the selected route, Hydro-Québec has found that overheading remains the option with the least impact on the environment and on local populations. It minimizes impact on streams and wetlands, while causing the least disturbance to the community and its socio-economic activities. In addition, the overhead line is more advantageous in financial terms, as its lifespan is twice as long.
An extra cost of about $60M
The route proposed by FHI would cost about $60 million more than an overhead line, and last half as long. When compared to the underground route running along public roadways that Hydro-Québec had already considered, FHI’s proposed route would cost $5 million less. However, this estimate relies on the bedrock not posing any particular challenges, a situation that seems unlikely in an area this close to a mountain. Bedrock work often requires dynamiting, which would naturally drive up the costs.
Route selected: The result of a thorough consultation process
To enhance acceptance of projects, Hydro-Québec encourages communities to participate in planning them. As part of the Québec-New Hampshire interconnection project, Hydro-Québec carried out an open public participation process, during which elected representatives, local authorities and residents were consulted. This exercice, coupled with Hydro-Québec’s comprehensive analyses, led to the choice of an overhead line routed west of Mont Hereford. Hydro-Québec also commits to take a number of mitigation and compensation measures, which were established in collaboration with the Information and discussion panel – Mont Hereford area.
To view the report [in French only]: http://www.hydroquebec.com/data/projet-interconnexion-quebec-new-hampshire/pdf/analyse-comparative-traces-aerien-souterrains-mai-2017.pdf (This hyperlink will open a new window)