The network of conduits collects water from a basin measuring 357 km2, two-thirds of which is covered by glaciers, which flow between the Mischabel and Mont Gelé. The raw material for the supply of electricity comes from 35 glaciers, via 75 intakes and 4 pumping stations, and travels through the heart of the mountains along 100 kilometres of tunnels, including a main conduit 24 kilometres long at an altitude of 2400 metres. Taken together, the water from the various sources represents an average volume of 440 million cubic metres.