People & environment
A total of 19 buildings within the study perimeter were classified as OMEN. The magnetic field was calculated for all OMENs. In 18 OMENs, the system limit value of 1 microtesla was maintained. In one OMEN, the system limit was exceeded slightly – a dispensation has been granted for this.
The new line routing is used in the entire project perimeter south of the existing building zones and residential areas. By moving the line from the banks of the Rhône and out of the open agricultural land to the wooded hillsides, the potential conflict of the existing 220 kV line from the construction zones in several communities will be resolved. In terms of the landscape, there will be a general improvement over the existing situation.
Due to the bundling with the 132 kV railway power line and the 65 kV line on the same pylons as well as to the higher voltage, however, the pylons will be taller than the existing 220 kV line.
The majority of the pylon sites are located in the forest. Other locations are used intensively for agriculture or include semi-dry meadows and extensively grazed areas.
Along the Ernen – Ulrichen section, the clearing work along the line route was carried out in the spring of 2018. This was necessary to ensure safety on the construction site and safe operation of the line. An approximately 30-metre-wide corridor was cleared over a distance of around 16 kilometres. Trees and shrubs are beginning to grow again in this area. Over time, this will allow the line to blend into the landscape better.
A total forested area of 15,288 m2 had to be cleared to install the line at the pylon locations along the Ernen – Ulrichen section. The temporary clearing of 22,572 m2 is required to provide access to the building sites and pylon locations. Suppression is necessary for an area of 292,471 m2.
After every forest-clearing measure, Swissgrid checks whether additional safety measures are required to protect people and the environment. For example, snow barriers and timber tripods are erected to protect against avalanches. Moreover, Swissgrid also plants young trees in glades along the line route. These kinds of precautions were taken in the municipalities of Ernen, Goms and Obergoms. They guarantee the safety of the roads, which are used year-round, during winter. Besides this, they also support the growth of the forest in the vicinity of the line. The measures allow the forest to fulfil its long-term role of unrestrictedly protecting against avalanches.
In the section stretching from Mörel to Ernen, the forest-clearing activities along the line route are expected to be carried out in the winter of 2021/22. In this section Swissgrid will once again review whether additional protective measures for avalanches and snow slides are necessary. A definitive assessment of the situation and the agreement upon suitable measures is possible only after deforestation.
- Amphibians / reptiles / small mammals / fish
No special habitats such as ponds will be affected by the construction work. No interventions in fishing waters are to be made.
- Wild Game
During construction, care will be taken to ensure that game is not disturbed, particularly during the hunting season. As almost all pylon locations are approached by helicopter, these helicopter operations will disturb the wild game only for a limited time.
No serious conflicts for grouse, golden eagles and migratory birds are to be expected. By moving the lines near Mörel, the potential for conflict for the peregrine falcon has been largely defused. The autumn migration is disturbed to only a small extent, as the line runs parallel to the direction of the valley along the slope.
Vegetation and habitats
The interventions are local and cover small areas; they will not lead to the disappearance of larger habitats.
- During the construction phase: The areas of intervention in the soil include the installation locations, the pylon locations and any temporary roads that are required
- During the operating phase: The interventions remain limited to the pylon locations
The following overhead lines are to be dismantled with the commissioning of the new 380 kV line:
- existing Mörel - Ulrichen 220 kV overhead line of Swissgrid
- 65 kV Ernen – Mörel 1 overhead line of Valgrid SA
- 65 kV Ernen – Mörel 2 overhead line of Valgrid SA
- 65 kV Ernen – Ulrichen overhead line of Valgrid SA
- 65 kV Heiligkreuz – Fiesch overhead line of Gommerkraftwerke AG between Binnegga and Fiesch
The three 65 kV Fiesch – Ernen – Heiligkreuz, Mörel – Ernen and Ernen – Ulrichen overhead lines will be installed underground between the Fiesch power plant, the Ernen power plant and pylon No. 1461.
As the forest cover of the reforestation area will occur naturally, alternative measures were defined in addition to a real substitute:
- Tunetsch cultivated landscape: creating a new wet biotope
- Hockmatte-Schärtegga and Binnachra-Sengg cultivated landscapes: extension of the ecological network, keeping open the in-growth areas
- keeping various dry meadows and pastures open