Lai da Sontga Maria
|Lai da Sontga Maria|
|Data on the structure|
|Lock type:||Arch dam|
|Construction time:||until 1968|
|Height of the barrier structure :||117 m|
|Height above the river bed :||86 m|
|Building volume:||654,000 m³|
|Crown length:||560 m|
|Crown width:||8 m|
|Base width:||21 m|
|Operator:||Kraftwerke Vorderrhein AG, Ovra Electrica Rein Anteriur SA|
|Data on the reservoir|
|Altitude (at congestion destination )|
|Water surface||1.77 km²|
|Storage space||67.3 million km³|
|Design flood :||150 m³ / s|
The Rein da Medel / Reno di Medel is captured in the reservoir with a volume of 67.3 million m³ . In addition to other natural tributaries, there is also an approximately 5500 m long gravity tunnel that feeds water from the Val Uffiern to the east. The filled lake has a length of 3 kilometers and a surface of 177 hectares .
The lake is connected to the Lai da Nalps reservoir to the northwest in a neighboring valley by a pressure tunnel around 8,800 m long . Together with this and the Lai da Curnera further to the west, it forms a water management system connected by pipes with a useful volume of 152 million m³, which is used to generate peak electricity. The three lakes are almost at the same height. Electricity generation is in a cavern lying powerhouse Sedrun the power plants Vorderrhein place and a subsequent power plant level.
The construction of the Gotthard base tunnel for the NEAT in the immediate vicinity of the three reservoirs means that all three dams are monitored with sensors for safety reasons. A simultaneous rupture of all three dams could completely flood the village of Disentis and all the communities below (such as Ilanz , Chur ) due to the tidal waves arriving in the Vorderrheintal almost at the same time .
- See for example the map under  .