In addition to these inspections, there are 16 high-precision measuring devices that provide real-time information and automatically register any changes. All the key measurement data is continually transmitted to the operations centre in the nearby town of Sion.
The dam is monitored using a wide range of measuring equipment:
- 7 conventional pendulums (a weighted wire suspended in the topmost gallery and held taut at the bottom of the shaft by a 150 kg weight) with 26 points for taking readings, enabling upstream-downstream and left bank-right bank displacement to be measured*
- 3 inverted pendulums to monitor displacements of the foundations of the dam
- 3 rockmeters to measure any settlement or lifting of the foundations of the dam
- 16 manometers for pressure readings with measurement of infiltration rates
- 3 vacuum meters upstream of the drainage tunnel
- 3 water level indicators at the base of the structure and in the lower tunnel to measure water infiltration*
- 8 piezometer tubes that measure the water pressure and water level
- 1 geodesic measurement network
*measurements transmitted to the operations centre in Sion
