Data on pumping stations Pumping station Z’Mutt Stafel Ferpècle Arolla Power 88MW 26.4MW 21.3MW 48.6MW Flow rate 17.4m3/sec 9.9m3/sec 8.4m3/sec 12.6m3/sec Capacity of balancing reservoir 840,000m3 70,000m3 100,000m3 17,300m3 Lift heights 470m and 365m 212m 212m 312m Altitude 1972m 2180m 1896m 2009m