PDF - 9Mo - Grande Dixence SA

GD. P.37Stafelpumping stationAt the foot of the MatterhornWith its cold mineral colours, this is a unique landscape,breathtaking in its beauty and solitude. Standing solidlyat the foot of the renowned north face of the Matterhorn,Stafel is a terminal moraine of the Z’Mutt glacier.The only features betraying the presence of humansare two large sand traps and an afterbay reservoir retainedby an embankment, which supply the pumpingstation. Water from the Z’Mutt glacier is stored here,in this windy, silent place. The water joins that suppliedby the Mischabel, Findelen, Obertheodul and Furggglaciers which cross the dip in the valley via the Stafelsiphon.The pumping station drives the water from the glacierinto the bend of the siphon to force it up to the collectinglevel some 250 m above. Year in year out, Stafelpumps an average of 100 million m 3 of water.N12101121014 9H3 7458611512345678910111213141516ImpoundmentsWater intakeFlood gateTwo sand traps, each 7.5 m 3 /sec.Sand trap flushing tunnelReservoir feed canalWinter headrace canalReservoir drawoff and spillway tunnelSuction conduit, ø 1.80 m, discharge rate 9.9 m 3 /sec.Torrent bedsAqueduct crossing under torrentsRoad130 kV line and switchyardHeliportAfterbay reservoir, useful volume 70,000 m 3Pumping station16111311Cross-section of station3 units each comprising:1 pump delivering 3,3 m 3 /sec.,head 212 m, and 1 synchromotor, 9 MWTotal station discharge rate: 9.9 m 3 /sec.123456789Suction conduit, ø 1.80 m, discharge rate 9.9 m 3 /sec.SwitchgearOverhead travelling craneTransformerHigh-pressure pumpValveMotorDischargeBuried aqueduct32 4 5179680 5 10m