Winter electricity and additional production
ynergies with the infrastructure of the Grande Dixence have also enabled the Gornerli reservoir to shift a maximum of 650 million kWh of summer electricity into the winter. This is roughly equivalent to the annual production of 180 wind turbines or the consumption of 140,000 Swiss households. The Gornerli therefore makes an important contribution to securing the national power supply in the long term – especially in winter, when Switzerland urgently needs electricity.
The Gornerli increases the total production of the Grande Dixence by approximately 200 million kWh net per year. Part of the previously unused water volumes in the Gornera catchment is stored and also used for power production, in compliance with environmental requirements and compensation measures. The new Gornerli pumping station, which is around 240 metres higher than the current one in Z’Mutt, also saves a large amount of pump energy.
The project will also secure additional income in the form of water taxes and taxes for the commune of Zermatt in particular, but also for the canton of Valais and the other concession communes. Finally, the future co-owners, in particular the current concession communes and the canton, will benefit directly from Grande Dixence’s more efficient existing power plants.
“The Gornerli is a key piece of the puzzle in Switzerland’s energy future.”
Albert Rösti, Federal Councillor and Head of DETEC
FLOOD PROTECTION
Climate change is melting glaciers and causing more heavy precipitation, which increases the risk of flooding.
The Gornerli reservoir plays a key role in flood protection throughout the region as it can absorb and retain the water volumes from heavy precipitation and sudden glacial lake outburst floods. This significantly reduces the risk of flooding and greatly reduces the risk of any consequential damage.
The floods in June 2024 highlighted the urgent need for flood protection. The planned Gornerli retention volume could have prevented both damage events (with the exception of the Triftbach tributary). The Gornerli serves as a retention basin for the Gornera and will be able to retain around half of the inflow into the Matter Vispa in Zermatt in the future. This will significantly reduce the risk of flooding not only in Zermatt but throughout the entire Matter Valley. The project will have a positive impact on flood protection as far as Val d’Hérens and the Rhone Valley.
“The Gornerli improves flood protection in Zermatt but also has a positive effect on the overall flood protection of the Vispa, all the way down to Visp.”
Romy Biner-Hauser, Mayor of Zermatt
WATER SUPPLY
As the water supply is tending to decline (dwindling glaciers), water demand is tending to increase (particularly the communes of Zermatt and Visp), so secure water supply (drinking and process water) will become increasingly important in the future, especially as there will be more periods of drought due to climate change. Possible measures to counteract future water shortages include raising awareness among the general public and industry, optimising existing water supply systems and building new, safe water reservoirs.
There is currently investigations in the Matter Valley region, how to secure the regional water supply in the long term.
“The large capacities of Alpine reservoirs mean they are hugely important for the integrated management of water resources.”
Prof Emmanuel Reynard, Professor of Physical Geography, University of Lausanne