|Data on the structure|
|Lock type:||Arch weight wall|
|Construction time:||until 1957|
|Height of the barrier structure :||151 m|
|Height above the river bed :||140 m|
|Building volume:||626,000 m³|
|Crown length:||504 m|
|Data on the reservoir|
|Altitude (at congestion destination )|
|Water surface||1.61 km²|
|Reservoir length||4 km|
|Storage space||101 million m³|
|Catchment area||63.9 km²|
|Design flood :||280 m³ / s|
The Zervreilasee is located in the canton of Graubünden in the municipality of Vals . The name comes from the village of Zervreila , which perished when the lake was dammed in 1957 . Its arch weight wall was built by Motor-Columbus . The reservoir can only be reached from Ilanz through the Valsertal . The last larger town before the reservoir is Vals. The lake is embedded between the Frunthorn (3030 m high), the Fanellhorn (3124 m) and the Zervreilahorn (2898 m).
Above the lake, in the small settlement of Frunt, is the St. Anna chapel .
The municipality of Vals had had a small hydroelectric power station with two turbines and two generators since 1916. Due to inflow problems, only one turbine could mostly be operated. The power station therefore often did not provide enough electricity for the community, and the villagers sat in the dark.
After lengthy and difficult negotiations with large power plants about the use of water in the Grisons valleys, the concession for the new power plant was granted at a community meeting on December 18, 1948. In 1952, Kraftwerke Zervreila AG, Vals, was founded and belonged to Sernf-Niederenbach AG, NOK and the former Motor-Columbus. The power plant was officially inaugurated with a two-day celebration (September 4/5, 1959).
The entire Länta area with the Lampertsch-Alp (1991 m) in the continuation of the valley of the Valser Rhine also belongs to the power plant company, since a second, higher lake was obviously considered in the planning.
The municipality of Vals is getting more and more electricity from the power station. When the license was awarded, it was determined that the municipality can obtain 200 MWh free of charge and up to 800 MWh at a preferential price. In 1960 the purchased energy was only 553 MWh. In 2005, however, the village already consumed several times this amount (17,421 MWh). Since 2003 the community has owned almost 6% of the power plant's share capital.
In 2018, the lake was almost completely emptied as part of a two-year renovation in the area of the pressure pipe. The system also has a new line for flushing out sediments.
Zervreila power plants
Kraftwerke Zervreila AG uses the water power of the 200 km² catchment area in the upper Valsertal and Safiental . The Zervreila reservoir forms the core of the power plants. The Zervreila machine house, built by Iachen Ulrich Könz in 1958, is located at the foot of the dam. It is set up for turbine and pump operation. The water line built into the dam enables the extraction of the below the Kote stored water, which could only be processed by the turbines with insufficient efficiency. The version of the turbine is at , 23.50 m above the subsidence target of the storage basin .
With the compensation basin in front of the dam , the transfer tunnel from the Valsertal to the Safiental can be used as a gravity tunnel . The compensation basin also serves as a pumping basin for transferring water from the Peilertal to the Zervreilasee, with which the reservoir can be completely filled.
The three-stage power plant group has a total output of 232 MW (megawatts):
- Level: Central Zervreila, gross height max. 127 m, installed capacity 20 MW
- Stage: Central Safien, gross height 425 m, installed capacity 86 MW
- 1st stage: Rothenbrunnen headquarters, gross height 673 m, installed capacity 126 MW
- Zervreilasee on schweizersee.ch
- Kraftwerke Zervreila AG
- Jürg Simonett: Zervreila. In: Historical Lexicon of Switzerland .
- Memories of Alois Gartmann, historical photos, paintings
- Peter Rieder: Vals - Enges Tal, Weite Welt . Terra Gruschuna AG, Chur, 2009, ISBN 978-3-7298-1160-7 .
- Project renovation of the ancillary facilities Zervreila dam 2017-2019 (PDF)
- Sigrid Hauser, Helene Binet, Peter Zumthor: Therme Vals . Scheidegger & Spiess, 2007. ISBN 978-3-85881-181-3 .
- Zervreila . (PDF) Swissdams