Grande Dixence Technical Documentation Grande Dixence Technical Documentation Contents the Grande Dixence 5 Hydroelectric Complex 6-17

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GRANDE DIXENCE TECHNICAL DOCUMENTATION GRANDE DIXENCE TECHNICAL DOCUMENTATION CONTENTS THE GRANDE DIXENCE 5 HYDROELECTRIC COMPLEX 6-17

GRANDE DIXENCE 8 PANORAMIC VIEW OF THE FACILITIES 10 LONGITUDINAL PROFILE 16

COLLECTING WORK 18-57

Z’MUTT PUMPING STATION 20 STAFEL PUMPING STATION 32 FERPÈCLE PUMPING STATION 40 AROLLA PUMPING STATION 50

STORAGE 58-75

THE GRANDE DIXENCE DAM 60

PRODUCTION 76-99

FIONNAY POWER PLANT 78 NENDAZ POWER PLANT 86 BIEUDRON POWER PLANT 94

INFORMATION 100-104

GRANDE DIXENCE SA PARTNERS 102 GRANDE DIXENCE SA SHAREHOLDING PORTFOLIO 103 CONTACTS 104 THE GRANDE DIXENCE HYDROELECTRIC COMPLEX

Grande Dixence is not only the tallest gravity dam in the world, it is also a masterpiece of technical sophistication and daring devoted entirely to energy. Standing shoulder to shoulder with the highest mountains in Switzerland's Valais region, the structure is the keystone of a vast hydroelectric complex which includes ﬁve pumping stations, over 100 km of headrace tunnels cut into the rock and three power plants. Come and discover the Grande Dixence complex!

The Grande Dixence dam in the Val des Dix (VS) GRANDE DIXENCE Grande Dixence is not only the tallest gravity dam in the world, it is also 9 HYDROELECTRIC COMPLEX a living legend. Level with the highest mountains in the Valais, this structure is a masterpiece in technical skill and audacity channelled into energy. At ﬁrst sight, you will be astounded by the 285 m of concrete towering above you; once you reach the top of the facility, the stunning view of the Lac des Dix and the valley will take your breath away. The top of the dam forms a gigantic panoramic terrace 15 m wide and nearly 700 m long at an altitude of 2,365 m.

Grande Dixence was built in 1961 to replace the ﬁrst Dixence dam, which is now at the bottom of the Lac des Dix. It took over 10 years to build this new structure, which is located in a vast hydroelectric complex completed in 1965. The reservoir holds all the water from a catchment area of 420 km2 half covered by glaciers. It is these 35 glaciers which, via 75 water intakes, 5 pumping stations (Z'Mutt, Stafel, Ferpècle, Arolla and Cleuson) and 100 km of tunnels, feed the Lac des Dix.

The 400 million m3 of water stored behind the Grande Dixence dam represent 20 % of the electricity generated in Switzerland. To make the hydraulic force of the Lac des Dix as proﬁtable as possible, Grande Dixence drives water through its turbines at two levels. The ﬁrst is at an altitude of 1490 m in the Fionnay plant. The second is level with the Rhône, 1000 m lower at the Nendaz plant. To transform this vast quantity of water into electricity and harness this tranquil force into billions of kWh, the Fionnay and Nendaz power stations work in relay.

The tallest gravity dam in the world PANORAMIC VIEW OF THE FACILITIES POINTE DUFOUR 4634 m

GORNERGRAT 3090 m MISCHABELS MATTERHORN 4478 m

MONT COLLON 3637 m MONT-BLANC DE CHEILON 3870 m ROSABLANCHE 3336 m DENT BLANCHE 4357 m

LIFT HEIGHT

SIERRE GRAND COMBIN 4314 m

LE RHÔNE SION CHANDOLINE VISPA LIFT HEIGHT BIEUDRON LA BORGNE ZINAL

NENDAZ LA NAVIZENCE

CLEUSON EVOLÈNE VERBIER

LA DRANSE

GRANDE T FERPÈCLE DIXENCE LIFT HEIGHT SIERRE CAPACITY LAC DE MAUVOISIN

AROLLA ZERM AT LE RHÔNE FIONNAY FERPÈCLE 1896 m STAFEL Z’MUTT LIFT HEIGHT SION CHANDOLINE VISPA POWER BIEUDRON LAC DE MOIRY LA BORGNE ZINAL

NENDAZ LA NAVIZENCE EVOLÈNE CLEUSON HEIGHT CAPACITY VERBIER

LA DRANSE

GRANDE T DIXENCE FERPÈCLE

AROLLA ZERM AT FIONNAY LA NAVIZENCE STAFEL Z’MUTT CATCHMENT AREA HEIGHT

LIFT HEIGHT

LA BORGNE

HEADRACE GALLERY LA PRINTZE

PENSTOCK

DAM

LAKE POWER POWER POWER

LE RHÔNE PRODUCTION PLANT SIERRE SION

PUMPING STATION total power output of 800 Grandethe complexDixence producesa Nendaz, and Fionnay at installations current the With power equivalent to that of a nuclear power station ! the installation is able to provide the network with provide power instantly, on demand. In just 4 minutes, facilities, the main purpose of Cleuson-Dixence is to the complex to 2,000 1,200 plant enables this power output to be increased by 24 LONGITUDINAL PROFILE GRANDE DIXENCEGRANDE HYDROELECTRIC COMPLEX 96 m MW, thereby taking the total power output of LIFT HEIGHT LIFT MW. Like other hydroelectric

MW. The Bieudron power

470 m LIFT HEIGHT LIFT FERPÈCLE 18 LIFT HEIGHT LIFT

96 212 m m certiﬁed by several environmental labels. ment. The energy produced by Grande Dixence is possible impact of its installations on the environ- is constantly optimised and to limit the actual or undertaken to ensure the use of natural resources a policy of sustainable development. This has been natural reserve, it has made ﬁrm commitments to able energy source. The trustee of an exceptional Grande Dixence SA does not stop at using a renew - rage annual consumption of 400,000 households. billion kWh per year, which corresponds to the ave- Cleuson-Dixence facilities reaches approximately 2 The energy produced across all the Grande Dixence-

212 m LIFT HEIGHT LIFT

312 m PRODUCTION STORAGE COLLECTING WORK HEIGHT LIFT HEIGHT LIFT HEIGHT 2240 m 165 m POWER 2364 1883 m

m RHÔNE POWER 1200 MW POWER POWER

1008 m878 m 17 COLLECTING WORK

The conveyance network collects water from a 420 km2 reservoir bordered by the Mischabel, Matterhorn and Mont Gelé mountains, two thirds of which is covered by glaciers. Through 100 kilometres of galleries, including a main tunnel which is 24 kilometres long, at an altitude of 2400 metres in the heart of the mountain, 35 glaciers supply the facility's raw material via 75 water intakes and 5 pumping stations. Together they supply on average 500 million m3 of water every year.

Inlet of the Vouasson tunnel in the Lac des Dix PUMPING STATION Z'MUTT

Set at the foot of the Mattertal, the Z’Mutt pumping station (alt. 1972 m) is the most powerful within the Grande Dixence complex. It is fed by water from the Bis and Schali glaciers which rise above the Visp river, and from the Gorner glacier.

Four pumps with a total power of 88 MW are used at Z'Mutt to pump around 140 million m3 of water every season. This water is pumped to a penstock which carries it to the Trift tunnel (altitude of 2400 metres) in the main collector.

The impact of the concrete on the environment has been kept to a minimum. The only major visible element is the arch dam which crosses the gorge. Apart from the service building, all of the facilities (gravel traps, sand traps and pumping station) are underground.

TECHNICAL SPECIFICATIONS

AFTERBAY RESERVOIR CONSTRUCTION 1961 - 1964 HEIGHT 74 m CREST 144 m THICKNESS AT THE CREST 3 m VOLUME OF CONCRETE 32,000 m3 CAPACITY 800,000 m3 TYPE Arch dam

PUMPING STATION POWER 2 x 30 MW ; 2 x 14 MW FLOW RATE 17.4 m3 / s DISCHARGE HEAD 365 m / 470 m

Z’Mutt afterbay reservoir at the foot of the Matterhorn Z’MUTT PUMPING STATION 23 PLAN OF LOCATION

9 6 95 500 300 621

8 2100 2000

to Mutt 2100 10 7 5

Z’Mutt pumping station

4 2000

1970 13 15

3 1900 1970 17 14 Z’Mutt compensating basin Dam of 800000 m3 capacity 1

1900 Stafelalp Z’Muttbach 21 13 18 2000 12

11 1900

Stafel

Zermatt Z'Mutt arch dam on the edge of the Mattertal 19

1 ARCH DAM 8 BODMEN COMPENSATING CHAMBER, 15 BOTTOM GALLERY 20 3 2100 100 m 2 Z'MUTT COMPENSATING BASIN, CAPACITY APPROX. 2000 m 16 ACCESS TUNNEL TO DAM USEFUL CAPACITY 9 SCHALI-BIS CATCHMENT 17 DAM VALVE CHAMBER APPROX. 800,000 m3 DIVERSION TUNNEL, Q = 8.0 m3 / s 18 CABLES SHAFT 3 FLOATING WATER INTAKE 10 COMPENSATING CHAMBER TUNNEL 19 SUBSTATION 4 2.30 m Ø CATCHMENT AND OVERFLOW PIPE 20 130 kV TRANSMISSION LINE DIVERSION TUNNEL 11 ADMINISTRATION AND 21 ROAD TUNNEL 5 UNDERGROUND PUMPING STATION CONTROL BUILDING 22 HEADRACE TUNNEL TO THE 6 STEEL-LINED DISCHARGE SHAFT 12 ZERMATT - Z'MUTT CABLEWAY MUTT POWER PLANT (EWZ) TO UPPER MAIN TUNNEL (TRIFT) 13 ACCESS TUNNEL Q = 17.4 m3 / s TO PUMPING STATION 7 BIS SHAFT, STEEL-LINED, 1.35 m Ø 14 BRIDGE Z’MUTT PUMPING STATION 25 LONGITUDINAL AND TRANSVERSAL PROFILES OF Z'MUTT CONDUITS AND SHAFTS

637,00 39,00 1 TRIFT TUNNEL Main pressure shaft 2 STEEL-LINED 1.90 m Ø, LINING 1 2400 THICKNESS 14 - 11.5 mm 3 STEEL-LINED 1.80 m Ø, LINING THICKNESS 24 - 14 mm 16,46 4 HIGH-PRESSURE VALVES 2 x 0.80 m Ø 2300 2 x 0.70 m Ø 5 Z'MUTT PUMPING STATION 6 LOW-PRESSURE VALVES 1 x 1.60 m Ø 429,00 2200 2 x 1.20 m Ø 7 2.00 m Ø INLET VALVE 8 STEEL-LINED 2.30 m Ø GRADIENT 2 % 9 STEEL-LINED 2.30 m Ø 2100 GRADIENT 60 % 198,14 25,00 10 FLOATING WATER INTAKE Intake penstock Steel-lined shaft Schali-Bis 11 Z'MUTT COMPENSATING BASIN, USEFUL CAPACITY 2100 2000 APPROX. 800,000 m3 12 1970 12 SCHALI-BIS TUNNEL 377,00 13 BODMEN COMPENSATING CHAMBER 11 10 13 5 USEFUL CAPACITY, 2000 3 1899 APPROX. 2000 m 14 LINED OVER 246.54 m, 1.35 m Ø

6 LINING THICKNESS 9 mm 7 4 GRADIENT ~ 80 % 44,90 105,63 246,54 15 SCHALI-BIS LOW-PRESSURE VALVES 1900 1 x 1.00 m Ø

15 1 x 1.40 m Ø

9 8 3 2 14 50 55 20 20 80 20 20 95 4,00 5,00 2,30 2,80 3,40 2,30 1,35 1,85 1,90 1,80 2,40 2,30 3,80 2,00 30 30 30 30 30 30 1,50 1,50 2,50 1,50 1,50 1,50 50 4,00 50 50 5,00 Z’MUTT PUMPING STATION 2727 HYDRAULIC DIAGRAM

Mischabels Täschalp Findelen 2550 Furgg Obertheodul 2500 Hohwäng Arb Trift 1 2450 2400 2350 2300 Z’Mutt 3 2250 2 2200 Schali Bis 2150 Stafel 2100 Gorner 2050 2000 1950 1900 Z’Mutt 1850

DIAGRAMMischabel OF ZERMATT Täschalp Findelen VALLEY INSTALLATIONS2550 Furgg Obertheodul 2500 Trift Hohwäng Arb 2450 5 Mischabel Täschalp Findelen 2550 1 MAIN DIVERSION TUNNEL 2400 FREE FLOWING TUNNELS INTAKES Furgg Obertheodul 2500 Trift Hohwäng Arb 2 Z'MUTT SYPHON 2350 PRESSURE SHAFTS PUMPING STATIONS 2450 5 2300 3 GORNER SYPHON 2400 Z’Mutt 2250 2350 5 2200 2300 Schali Bis 2150 Z’Mutt 2250 Stafel 2100 2424,35 5 2200 Gorner 6 2050 Schali Bis 2150 2419,26 2000 Stafel 2100 1950 Gorner 5 2050 1900 2000 2066,28 Z’Mutt 1850 7 5 1950 12 2059,42 1900 Z’Mutt 1850 max. 1971,60

min. 1930,00 8 13 3 5 5 1925,00 4 1900,00 4 4 4 2 2 1902,10 1 1 1900,00 5 5 5 10 5 9 14

DETAILED VIEW OF Z'MUTT PUMPING STATION

1 VERTICAL-SHAFT PUMP 6 TRIFT TUNNEL 12 MAIN PRESSURE SHAFT Q = 5.5 m3 / s, H = 470 m 7 SCHALI-BIS TUNNEL 13 INTAKE PENSTOCK 2 VERTICAL-SHAFT PUMP 8 Z'MUTT COMPENSATING BASIN, 14 DEPARTURE MUTT (EWZ) Q = 3.2 m3 / s, H = 365 m USEFUL CAPACITY 3 PUMP APPROX. 800,000 m3 Q = 2 m3 / s, H = 90-130 m 9 Z'MUTT PUMPING STATION 4 BUTTERFLY VALVES 10 OUTLET 5 SPHERICAL VALVES 11 STEEL-LINED SHAFT SCHALI-BIS

The Matterhorn overlooking the Zermatt hydroelectric facilities — 14 — MW motor against 365 m head, and — 1 — pump discharging 3.2 m 30 — MW motor against 470 m head, and — 1 — pump discharging 5.5 m 10 9 8 7 6 5 4 3 2 1 . B . A SUMMER PUMPING CROSS-SECTION A-A AND OPERATION AND STATION EQUIPMENT INSTALLATION PLANS Z’MUTT PUMPINGZ’MUTT STATION 2 SETS EACH CONSISTING OF : SUPPLY PIPE OIL SUMP STORE BOTTOM TUNNEL ESCAPE TUNNEL DAM ACCESS TUNNEL CABLES TUNNEL MAIN ACCESS TUNNEL RAILS FOR 30 T OVERHEAD CRANE MACHINES HALL 2 SETS EACH CONSISTING OF : 1900,00 1906,30 C 3 3 / s / / s / 10T 14 16 ø 1,35 Q = 8.4 = Q — 1 — pump discharging 2 m 12 11 19 18 17 17.4 m Total discharge of pumps : 3 — MW motor against 90 - 130 m head, and 16 15 14 13 . C BIS SHAFT INLET VALVE TRIFT TRIFT SHAFT AUXILIARIES STANDBY TRANSFORMER 1.20 HIGH-PRESSURE VALVES GALLERY LOW-PRESSURE VALVES GALLERY ACCESS TO VALVES 1 REGULATING SET CONSISTING OF :

m Ø 22,20 3 /s / m VALVE 3 / s ~ 1904,00 80 % GRADIENT, 18 4 30 T 3 / s / 1 1908,30 15T 15 7 17,00 ø 1,20 (including 1 standby unit) rated at 30 MVA 130 / 10 KV 10 SINGLE-PHASE TRANSFORMERS to the Z'Mutt compensating basin. by sets In winter water from the Trift tunnel is used 22 21 0 2 WINTER GENERATION 3 TRANSFORMERS III-IV TRANSFORMERS II TRANSFORMERS I B. acting as turbines and is returned 1920,20 1905,70 1914,50 1900 C B PLAN PLAN OF PUMPING STATION, SECTION C-C LONGITUDINAL SECTION B-B 5 1920,10

16,70 3 1,225 3,45 11,225

22,20 5 3 7

2,50

ø 2,30 7 ø1,60 ø 1,60 ø 1898,60 1904,00 1,60

9,00 10 ø0,50 12,20 ø2,00 14,90 14,90 17 8 6 ø0,60 11 54,50 1 V 13 I I A

A ø1,35 ø1,20 ø 0,70 ,07,20 9,40 1897,40 1900,00 20 9,40 33,00 2

ø1,20 II

II ø1,35 ø1,00 1 50,00 1908,30 7,20 1914,50

III ø1,10 ø1,40 III 8,60

1899,80 1902,10 8,60 ø1,20 14 IV Q =17,4 m IV

9,90 ø1,35 12 30 T 9,90 1902,50 22 3 6,80 19 / sec. 9

B 16,70 29 Z’MUTT PUMPING STATION 31 Z'MUTT DAM 14 1972,00 1971,60 max. 11 1980 left-ﬂank 1970 normal

14 1

12 to the pumping station 1970 9

1960 1944,00 min.

1950 8 13

1940

95.200 1930 1920 7 3 1 6

1910 7 5 3 6 2 1900 1910 1920 4 2 1930 5 3 1940 1904,64 1950 3 4

1960

1970

95.140 SECTION THROUGH AXIS OF DAM

1980

Stafel

1990

15 1 ACCESS TUNNEL 8 DIVERSION TUNNEL 14 REFERENCE CYLINDER

14 Furi 2 VALVES HOUSE 9 2.30 m Ø SUPPLY PIPE 15 ACCESS TUNNEL 2000 10 3 OVERFLOWS TO PUMPING STATION TO THE DAM CREST 4 RESTITUTION SLUICE 10 FURI-STAFEL ROAD TUNNEL

right-ﬂank 20 m 5 BOTTOM SLUICE 11 PENDULUM SUSPENSION CHAMBER 621.000 6 PURGE PIPES FOR BOTTOM SLUICE 12 0.80 - 0.60 m Ø ACCESS SHAFT PLAN OF DAM 7 FLOATING WATER INTAKE 13 0.40 m Ø PENDULUM SHAFT PUMPING STATION STAFEL

Located at the foot of the Matterhorn (alt. 2180 m), the Stafel station pumps 70 million m3 of water every year. It is supplied with water from the Z’Mutt glacier. The station pumps the water up to the collector, which is located 250 metres higher. Two large sand traps and an afterbay reservoir complete the infrastructure.

TECHNICAL SPECIFICATIONS

AFTERBAY RESERVOIR CAPACITY 80,000 m3

PUMPING STATION POWER 3 x 8.8 MW FLOW RATE 9.9 m3 / s DISCHARGE HEAD 212 m TRANSFORMERS 4 x 9.5 MVA (single phase) – 130 / 5 KV

Sand traps for the Stafel pumping station STAFEL PUMPING STATION 35 PLAN OF LOCATION

2280

2260 8.400 61

2240

2200 to the main high-level tunnel (collector) tunnel high-level main the to

1 Compensating basin of 80000 m3 capacity, max. water level 2210 m 8 95.000

9 7 16

11 10 2180 6 15 4 5 12

3 16 11 2 14

1 15 Stafel pumping station

13 1 Z’Muttbach

Stafel afterbay reservoir

1 EMBANKMENTS 9 EMPTYING AND OVERFLOW TUNNEL 15 ACCESS ROAD 1 100 m 2 DAM 10 STILLING BASIN 16 STREAM CONTROL STRUCTURES 3 INTAKE 11 BURIED 1.80 m Ø 4 FORE CANAL PENSTOCK, Q = 9.9 m3 / s 5 2 GRAVEL TRAPS 12 BURIED 2.25 AND 2.45 m Ø SYPHON Q = 2 x7.5 m3 / s PIPE, Q = 21. 3 - 31.2 m3 / s 6 GRAVEL TRAP PURGE TUNNEL 13 SYPHON EMPTYING 7 WINTER SUPPLY CANAL AND PURGING STRUCTURE 8 INTAKE, EMPTYING AND OVERFLOW 14 END OF 130 kV LINE STRUCTURE AND SUBSTATION STAFEL PUMPING STATION 37 LONGITUDINAL AND TRANSVERSAL PROFILES OF CONDUITS

to the Grande Dixence reservoir 1 STRUCTURE AT TRANSITION FROM 4 5 6 ROCK TO MORAINE vers le lac des Dix to the Grande Dixence reservoir 2 PASSAGE UNDER STREAM 2433,964 5 6 4 5 6 2413,91 2415,64 3 SYPHON EMPTYING AND PURGING 2433,96 2433,96 2413,91 2413,91 2415,64 2415,64 ARRANGEMENTS ascending shaft ø2,45 m Stafel pumping station descending shaft ø2,25 m 4 ADIT 5 FURGG TUNNEL branche montante1 ø2,45 m usine de pompage de Stafel branche descendante ø2,25 m 2 2 ascending shaft ø2,45 m1 Stafel pumping station descending shaft ø2,25 m 6 BULKHEAD GATE 2245,20 2214,14 2218,10 1 3 7 EARTHFILL EMBANKMENT 2191,22 2 2 1 1 2175,12 2 2 1 2245,20 2168,12 2245,20 8 STAFEL COMPENSATING BASIN, 2214,14 2218,102214,14 2218,10 3 2191,22 3 3 2175,12 2191,22 USEFUL CAPACITY 80 000 m 2168,12 2168,12 2175,12 9 INTAKE 10 2 GRAVEL TRAPS Q = 2 x7.5 m3 / s

209,980 283,55 220,928 37,955 92,260 134,40 183,25 395,68 73,66 281,79 97,57 10,76 80,346 % 19,035 % 7,12 % 5,432 % 12,739 % 5,21 % 21,293 % 1.00 80 % 20 % 11 MORAINE

209,980 283,55 220,928 37,955 92,260 134,40 183,25 395,68 73,66 281,79 97,57 10,76 209,980 1893,288283,55 220,928 37,955 92,260 134,40 183,25 395,68 12 73,66STEEL LINING281,79 97,57 10,76 80,346 % 19,035 % 7,12 % 5,432 % 80,3412,7396 % % 5,21 % 19,0321,2935 %% 7,12 % 5,4321.00 % 12,739 % 5,21 % 21,29380 % % 20 % 1.00 80 % 20 % 13 REINFORCED GUNITE 1893,288 1893,288 LONGITUDINAL PROFILE OF SYPHON 2,50

12 12 12 13 2,50 2,50 25

25 12 12 12 13

20 12 12 12 13 20 2,10 25 25 25 25 20 20 40 2,10 20 20 2,10 2,90 3,58 3,50 3,20 4,55 ø2,25 m ø2,25 m ø2,45 m ø3,00 m ø3,80 m 40 40 2,90 3,58 3,50 25 3,20 2,90 3,58 3,50 4,55 3,20 75 4,55 ø2,25 ø2,25 m ø2,25 m ø2,45 m ø2,25 m ø2,25 m ø2,45 m 25 ø3,00 m ø3,80 m ø3,00 m ø3,80 m 50

1,60 25 1,50 25 1,36

1,80 75 ø2,25 75 ø2,25 25 25 1,36 50 1,60 1,50 1,60 1,50 1,80 1,36 1,36 50 4,00 1,80 1,36 1,36 11 7 4,00 4,00 40 12 2177,33 2197,48 2211,50 2203 2210 2213 2211,25 11 11 11 7 7 40 40 12 2177,33 2197,48 2211,50 2203 2210 22132177,33 2211,25 2197,48 2211,50 2203 2210 2213 2211,25 11 12 11 35 4,10 ø2,25 170,875 165,215 35 2,45 4,10 35 ø2,25 4,10 10,092 % 2,221 % ø2,25 ø 1,80 8 10 9 Stafel pumping170,875 station 165,215 170,875 165,215 30 2,45 10,092 % 2,45 2,221 % ø 1,80 10,092 % 2,221 % ø 1,80 8 10 9 8 10 9 usine de pompage de Stafel Stafel pumping station 30

80 40 4,00 40 80 30 2,40 6,40 30 30 80 40 4,00 40 80 80 40 4,00 40 80 2,40 2,40 6,40 6,40 30 30 30 30

LONGITUDINAL PROFILE OF BURIED PIPELINE BETWEEN BASIN AND PUMPING STATION STAFEL PUMPING STATION 39 INSTALLATION PLANS

2158,17 14 14 1 5 4 6,40 6 11,89 6,50 I II III 5 ø1,04 2179,00

10 8 ø0,80

12 7 2175,85 3,13 3,60 12,70 10,00 10,00 6,70 5,05 23,30 39,40 14,80 10,20 6,515 LONGITUDINAL SECTION CROSS-SECTION A-A

Coupe longitudinale A Vue en plan de l’usine Coupe A-A (par l’axe d’une pompe)

23,30 41,00 14,80

11,35

ø1,80

1 MACHINES HALL 13 2 CONTROL ROOM 3 5 kV SWITCHGEAR 2179,14

4 TRANSFORMERS ø1,04 1,04 1,04

2 ø ø 5 PUMPS 11 6 MOTORS ø0,80 3 7 3 0.70 m Ø VALVES 4 2179,00 8 UNTANKING AREA 9 20 kV STANDBY TRANSFORMER I 5 II III 10 6 3,13 8 FOR STATION AUXILIARIES 1 7 10 0.50 m Ø BY-PASS VALVE WITH 0,50 10,00 ENERGY DISSIPATOR 12,70 10,00 6,70 ø0,80 11 0.40 m Ø PENSTOCK

EMPTYING VALVE from Seickren Q max. = 21,3 m3/s 12 to Arben Q max. = 31.2 m3/s 12 2.45 m Ø SYPHON ø2,25 ø2,45 13 AUXILIARIES PLAN OF PUMPING STATION 14 OVERHEAD CRANE 9 A PUMPING STATION FERPÈCLE

Located deep in the Hérens valley (alt. 1896 m), the Ferpècle pumping station collects the water from the Ferpècle and Mont Miné glaciers. Every year, 3 pumps transfer around 60 million m3 of water up the 212-metre gulley to the Arolla pumping station via the Maya reservoir. The total output from the facility is 8.4 m3 / second.

The power station is hidden inside the mountain. Only a dam, two sand traps and a gravel trap are visible. To prevent ﬂoodwater entering the installations, the Ferpècle water intake is equipped with a restrictor on the sand trap.

TECHNICAL SPECIFICATIONS

AFTERBAY RESERVOIR CONSTRUCTION 1962 - 1964 HEIGHT 25.5 m CREST 91 m VOLUME OF CONCRETE 6000 m3 CAPACITY 100,000 m3 SURFACE AREA 1.1 ha TYPE Arch dam

PUMPING STATION POWER 3 x 7.1 MW FLOW RATE 8.4 m3 / s DISCHARGE HEAD 212 m

Ferpècle pumping station water intake FERPÈCLE PUMPING STATION 43 PLAN OF LOCATION 1980 1880 1960 1940 1840 Ferpècle 1920 1820 1900

12 13

10 11

2000

101000

Ferpècle pumping station 14

to Arolla 8 9 1900

6 7 1920 4

5 18 1940 Compensating basin useful capacity 100000m3 max. water level 1894,50 m

1960

Ferpècle afterbay reservoir in the Hérens valley 2 608 400 608

1 WATER INTAKE IN THE RIVER 8 UNDERGROUND PUMPING STATION 14 SERVICE BUILDING

Borgne 1 2 INTAKE, Q = 11 m3 / s 9 INCLINED DELIVERY SHAFT 15 MOURTI DIVERSION PIPE 0,25 m Ø, 100 m 3 2 SAND TRAPS GRADIENT 80 %, 1.55 m Ø, Q = 0.15 m3 / s 4 25.5 m HIGH ARCH DAM Q = 8.4 m3 / s 16 SUBSTATION 5 SPILLWAY TUNNEL, Q = 200 m3 / s 10 BOTTOM STATION GALLERY 17 LES HAUDÈRES-FERPÈCLE 6 DEWATERING AND 11 STATION ACCESS TUNNEL 130 kV LINE OVERFLOW TUNNEL 12 STATION ACCESS BRIDGE 18 POWER STATION WATER INTAKE 7 1.90 m STEEL-LINED SUPPLY 13 ACCESS ROAD TO SERVICE TUNNEL TO PUMPING STATION BUILDING

FERPÈCLE PUMPING STATION 45 LONGITUDINAL AND TRANSVERSAL PROFILES OF CONDUITS

2100 2095,72 9 Arolla 1 TWO 2 x 5.5 m3 / s SAND TRAPS 8 2 POWER STATION WATER INTAKE 3 FERPÈCLE SERVICE BUILDING

4 ACCESS TO LIFT 2000 95,00 ø 1,90 5 FERPÈCLE PUMPING STATION 6 SUPPLY TUNNEL, Q = 8.4 m3 / s 7 7 DELIVERY SHAFT, Q = 8.4 m3 / s 10

8 ADIT 1907,00 12 1871,95 80 % 1896,30 1900 1894,50 2 % 1834,60 1882,00 321,87 80% 9 VEISIVI TUNNEL 3 1875,00 10 WATER INTAKE IN THE RIVER 4 11 PURGE FLUME 1839,70 6 1834,60 1837,78 12 COMPENSATING BASIN, USEFUL 1835,30 53,18 3 5 CAPACITY 100,000 m 1800

13,50 41,48 187,52 78,77 189,22 325,52 ø1,90 ø1,55 ø1,55

1 2

steel lined steel lined 0,65 0,20 0,20 0,20 1,90 2,20 1,90 2,46 ø 1,55 1,95 0,20 ø 0,26 2,50 ø ø1,55 0,11 0,20 0,20 1,60 1,30 0,30 1,60 0,15 1,60 1882,00 ~25’000m3 drain ø 20 cm ø4,10 (use in winter with pack ice) 1,60 1881,00 ~20’000m3 drain ø20 cm 1880,73 3 1880,00 ~16’000m 1 1,33 minimum operational level

0,50 6,00 0,50 6,00 0,50 0,60 0,40 3,06 10 1,90

2,40 0,60 0,60 0,60 0,60 2,40 1877,50 1896,30 5,80

2,15 45 1,10 1,10 4,25 ø2,20 metal element 2,50 5,00 2,50 1875,35 0,40 2,30 2,30 0,20 8,70 50 1,10 60 variable 1,50 30 1,00 1,00 0,60 0,45 5,50 2,93 2,42

surface keying of old concrete 1,90 3,00 3,00 ø2,30 ø

1872,42 1,00 50 20 12 0,70 0,70 moraine

0,20 0,60 0,60 ~2,50 ~3,00 10,00 4,50 3,50 6,50 3,50 ﬁlling with gravel concreted 13,50 lean concrete FERPÈCLE PUMPING STATION 47 INSTALLATION PLANS

7,95 1889,20 administration building 19 1842,60 1885,00 11 1882,00 18 1,20 ø 12 13 1838,70 1834,60 5 3 2 1834,00 1834,60 6 1831,70 6 1830,50

10 14

ø1,30 1,10

1830,50 5,45 5,70 ø B ø1,55 11,15 ø1,10 2,60 1,20 ø CROSS-SECTION B-B 7 ø1,10 B ø1,10 ø1,10

1842,60 8

1,35 9 ø 0,625 11 1838,70 1838,70 15 1838,70 13 I II III 3,80 2 7,10 2 4 4 1834,00 1834,00 1 1834,00 A A 12,35

11,15 10,75

15 1830,50 17 1830,50 9,50 9,50 3 1 5,60 10 4,80 2,85 1829,50 0,40 1827,70 16

1,37 2,45 8,20 8,35 3,00 9,50 9,50 26,25 1,40 11,20 8,05 ø1,20 10,55 14,30 2,80 66,20

LONGITUDINAL SECTION A-A B B ø1,20 ø1,20 66,20

ø1,55

37,60

1 CONTROL ROOM 9 VENTILATION TUNNEL 16 LOW WATER PIT 2 MACHINES HALL 10 SHAFT FOR LIFT TO SERVICE 17 DISTRIBUTOR 3 LOW-PRESSURE VALVES BUILDING AND 130 kV CABLES 18 WORKSHOPS GALLERY – THREE 0,80 m Ø VALVES 11 130 kV CABLES 19 APARTMENT 4 THREE 7800 kVA 12 5 kV BUSBAR GALLERY TRANSFORMERS – 130 / 5 KV 13 25 TON OVERHEAD PLAN VIEW OF PUMPING STATION 5 5 SUPPLY TUNNEL, Q = 8.4 m3 / s TRAVELLING CRANE 6 DELIVERY SHAFT, Q = 8.4 m3 / s 14 THREE 0.625 m Ø 7 SCOUR TUNNEL HIGH-PRESSURE VALVES 8 DEWATERING TUNNEL 15 STORES FERPÈCLE PUMPING STATION 49 FERPÈCLE DAM

A 1895,80 1894,50 1 2 9 9

1890 1880

9 9 9 3 9 9

right bank

1890 1870,00 1900 1867,40 14,60 10,83 10,83 11,40

right bank 1858,00 90,96 left bank A

DOWNSTREAM ELEVATION

5 1,80

A 1895,80 1895,80 1894,50 2 6

2 3 1,80

left bank 3,50 1 1870,00

10% 25,80 A 1895,80 ø0,90 1900 4

to pumping station

7 15,6% Compensating basin useful capacity 10000m3 max. water level 1894,50 m

1858,00 8

40 m

PLAN VIEW OF DAM SECTION A-A

1 ABUTMENT 6 OVERFLOW WEIR 2 PENDULUM OBSERVATION 7 ROADWAY CHAMBER 8 RAMP TO BOTTOM OF BASIN 3 INVERTED PENDULUM SHAFT 9 TRANSVERSAL CONTRACTION 4 WATER INTAKE JOINTS 5 BOTTOM SLUICE PUMPING STATION AROLLA

After the Z’Mutt pumping station, Arolla is the most powerful station at the Grande Dixence site. It receives the water already pumped via Ferpècle, supplementing it with water from the Tsidjiore Nouve and Bertol glaciers. The Arolla facility collects and discharges around 90 million m3 of water every year. Three 16.2 MW dual-inlet pumps each transfer 4.2 m3 of water per second a height of 312 metres.

TECHNICAL SPECIFICATIONS

MAYA AFTERBAY RESERVOIR CAPACITY 17,300 m3

PUMPING STATION POWER 3 x 16.2 MW FLOW RATE 12.6 m3 / s DISCHARGE HEAD 312 m

Lower Bertol water intake AROLLA PUMPING STATION PLAN OF LOCATION

2000 2100 2200 2300 to Arolla to

1 18

Compensating chamber 3 useful capacity 15 000m from Ferpècle max. water level 2084.00 m 7 19 6 3

from Tsidjiore - Nouve

5 4 16 96000

14 8

la Borgne

2 13 Bertol lower from 10 9 12

to the main 10 high-level 11 tunnel (collector) 20

to Bertol 15 17

100 m Arolla pumping station 603600

1 FERPÈCLE SUPPLY TUNNEL, 9 ROCK TO MORAINE TRANSITION 18 AROLLA P4 CABLEWAY GRADIENT 2 ‰, Q = 8.4 m3 / s STRUCTURE (ACCESS TO MAIN UPPER TUNNEL) 2 LOWER BERTOL SUPPLY TUNNEL 10 1.80 m Ø BURIED SUPPLY PIPE 19 AROLLA-BERTOL ROAD Q = 2.0 m3 / s 11 CULVERT UNDER THE BORGNE 20 BRIDGE 3 OVERFLOW SYPHON 12 SUPPLY PIPE DEWATERING AND 4 COMPENSATING CHAMBER SCOUR VALVES DEWATERING AND SCOUR VALVES 13 TSIDJIORE-NOUVE BURIED SUPPLY 5 DEWATERING, SCOUR AND PIPE, Q = 2.0 m3 / s OVERFLOW TUNNEL 14 PIPE DEWATERING 6 ACCESS TUNNEL AND SUPPLY VALVES 7 ACCESS TO VEISIVI TUNNEL 15 1.65 m Ø BURIED DELIVERY PIPE 8 1.80 m Ø STEEL-LINED SHAFT TO 16 130 kV LINE PUMPING STATION, GRADIENT 80 % 17 SUBSTATION

Arolla pumping station machines room AROLLA PUMPING STATION 55 LONGITUDINAL AND TRANSVERSAL PROFILES OF CONDUITS

to the collector 2380,35 quarry-run 1,95

79,97 2300 3,40 0,25

ø0,80 steel lining 2,15 1,60 0,25 drain ø20 cm

from Ferpècle 0,30 0,40 2200 364,03 80% 2,20 0,25 0,60 0,25 1,10 1 2103,42 pumping station 2100 7 12 13 14 2084 2 2009,95 2100 2069 2069,88 2056,22 3 4 1 5 6 8 9 15 10 11 10 20 % 2000 2004,24 2011,96 2000 347,10 128,02 353,04 102,11 80% 80,00 211,35 79,74 57,51 170,00 828,16 348,60 42,7518 115,42 111,02 49,00 78,08 218,20 24,00 63,50 88,50 111,79 42,00 A 790,54

0,400,97 ø1,65 0,97 0,40 1 2 LONGITUDINAL PROFILE OF TSIDJIORE-NOUVE BURIED PIPELINE steel lining steel lining quarry-run steel lining 7 A 0,20 0,20 0,20 ø 2,10 3,80 ø1,65 2,36 ø2,30 ø 1,90 0,11 1,85 0,40 1,65 concrete 2084 r = 1,85 2,56

swinging support 0,30 0,15 0,26 1,60 1,60 0,50 0,502,25 drain ø 20 cm 1,60 0,25

0,50 1,20 3,60 1,20 3,25 6,00 1,00 0,40 0,40 r = 9,70 6,40 r = 9,70

LONGITUDINAL PROFILE OF SUCTION AND DISCHARGE PIPES 13,05

4,55 4,55

useful capacity 15000 m3 max. water level 2084,00 m 4,00 1 %

1,01 4,54 4,54 1,01 1 ROCK TO MORAINE TRANSITION 7 AROLLA COMPENSATING 11 PIPE DEWATERING STRUCTURE CHAMBER MAX. LEVEL 2084 m, AND SCOUR VALVES 9,08

3 2 BURIED DELIVERY PIPE USEFUL CAPACITY 15,000 m 12 FOREBAY COMPENSATING CHAMBER 3 ROAD 8 VEISIVI TUNNEL 13 SAND TRAP, Q = 2.0 m3 / s 4 CULVERT UNDER THE BORGNE 9 AROLLA STATION 14 FORE CANAL 5 SUPPLY PIPE 10 MANHOLE 15 0.80 m Ø BUTTERFLY VALVE 6 LOWER BERTOL WATER INTAKE AROLLA PUMPING STATION 57 INSTALLATION PLANS

7,45 15,10 7,65 57,70 B

2018,20 18 1,00

14 2014,90 12 17 12 2013,50 2012,50 2012,10 16 2 pump 1 aI pump 1 b II III 2010,72 7 2

14,80 2009,62 15,50 4,10 11 9 10 2008,62 2008,00 6

15 8 2004,10 2003,20

12,20 18,90 4,04 4,75 4,50 4,50 CROSS-SECTION B-B 7,85 8,79 15,26 15,00 10,60 76,40

LONGITUDINAL SECTION A-A

B 6

ø 1,65

ø0,90 ø0,90 ø1,30 1 CONTROL ROOM

6,60 2 MACHINES HALL 11 ø1,15 3 TRANSFORMERS 130 / 7,5 KV

1,00 4 SUPPLY PIPE 1,40 3 7 ø0,50 5 FROM TSIDJIORE-NOUVE 10 ø0,50 ø0,70 3

0,70 6 DELIVERY, Q = 12.6 m / s 7,65 ø 7 VALVES CHAMBER 4,20 12,20 A A 8 UNTANKING PIT 9 WORKSHOP 8 9 I 57,70 II III 10 HOSPITAL 1 7,45 6,15 2 ø0,80 ø0,80 ø0,80 ø0,80 11 GARAGES 12 40 TON OVERHEAD 1,00 TRAVELLING CRANE ø0,80 ø0,80 1,20 ø ø1,60 13 STORAGE FOR OIL FROM UNTANKED TRANSFORMERS STORES 14 STORES 12,20 18,90 7,85 4,04 4,75 10,76 4,50 10,50 4,50 10,60 15 HEATING 76,40 16 LIVING ACCOMMODATION PLAN VIEW OF PUMPING STATION 17 CABLES TUNNEL

ø1,80 ø0,80 18 SUBSTATION

4 5 B STORAGE

The water collected by the conveyance network is stored behind the Grande Dixence dam. Grande Dixence has a capacity of 400 million m3. Its 285-metre wall makes it the tallest gravity dam in the world. The structure is made from 6 million m3 of concrete and weighs 15 million tonnes. It is 200 metres wide at the base and 15 metres wide at the crest. The two shores are 700 metres apart at the crest. Inside the wall of the dam, there are 32 kilometres of tunnels and inspection chambers which allow the dam supervisors to continuously inspect the facility.

The top of the dam offers an astounding 360° panorama GRANDE DIXENCE DAM

Towering above the Val des Dix, Grande Dixence The dam is 200 metres wide at its base. As it rises, holds many records. The gravity dam's 285-metre it tapers to a width of 15 metres. A 200-metre deep wall remains the tallest in the world. At around 15 grout curtain surrounds the dam to make the soil million tonnes, it is heavier than the Great Pyramid foundation watertight. It penetrates 100 metres into of Cheops. the valley sides.

To contain the more than 400 million m3 of water The wall itself is made up of 16 m square concrete stored each year, no fewer than 6 million m3 of blocks jointed together so as to ensure maximum concrete were laid between the mountains. The cohesion, strength and impermeability. same amount of concrete could be used to build a 1.5-metre high, 10-centimetre wide wall right around the equator!

TECHNICAL SPECIFICATIONS

GRAVITY DAM CONSTRUCTION 1951 - 1961 COMMISSIONED in 1961 HEIGHT 285 m CREST 15 m wide, 700 m from one side to the other VOLUME OF CONCRETE 5,960,000 m3 LENGTH OF INSPECTION TUNNELS 15,200 m LENGTH OF INJECTION WELLS 14,500 m CAPACITY OF RESERVOIR 400,000,000 m3 SURFACE AREA OF RESERVOIR 4.04 km2 LENGTH OF RESERVOIR 5.3 km LENGTH OF BASE TUNNELS, DRAINAGE TUNNELS AND THALWEG 2160 m

The Grande Dixence dam, the keystone of the hydroelectric complex GRANDE DIXENCE DAM 63 PLAN OF LOCATION

Motôt 2200 2000 1 WATER INTAKE AND 14 HEADRACE TUNNEL FOR WATER 2100 1900 Sion MAIN DISCHARGE INLET FROM VOUASSON 2300 2 GUARD GATE 3.00 m Ø Q = 1.6 m3 / s 2000 3 HEADRACE TUNNEL 15 OPENING IN THE OLD DAM

25 TO THE FIONNAY POWER PLANT 16 TRANSVERSE DAM Le Chennaz Q = 45 m3 / s CONTRACTION JOINTS 4 PRESSURE REDUCING SYSTEMS EVERY 16 m 23 2100 FOR THE OLD 17 OPERATIONS BUILDING (RITZ)

Dixence from Cleuson CHANDOLINE INSTALLATIONS 18 HELIPORT 5 HEADRACE TUNNEL 19 ACCESS TUNNEL TO VALVES AND 12 TO THE CHANDOLINE PRESSURE REDUCING SYSTEMS 6 29 Le Chargeur POWER PLANT (ALPIQ) 20 UNDERGROUND WORKSHOP 3 AND SUBSTATION 65 kV 21 Q = 10.25 m / s 9 17 2200 6 MAIN DISCHARGE INLET 21 CHARGEUR-BLAVA CABLE CAR

3 23 Q = 35 m / s 22 VISITOR PLATFORM 18 20 to Bieudron 8 7 REDUCTION SYSTEM REGULATION 23 MOTÔT-CHARGEUR-BLAVA ROAD to Chandoline Chapelle Q = 75 m3 /s 31 25 103 500 WELL AND INFLOW OF WATER 24 OLD DECOMMISSIONED TUNNELS Q = 10,25 m 19 26 2300 FROM CLEUSON (ALPIQ) 25 OLD DECOMMISSIONED 7 4 8 HEADRACE TUNNEL FOR WATER SERVICE FUNICULARS 3 32 /s 5 FROM CLEUSON 26 MIRADOR 2 Q = 2.7 m3 / s 27 PASTURE TRACKS TO CHEILON left bank right bank 2400 9 SAND TRAP – GRAVEL TRAP 28 MEASUREMENT STATION 8 16 FOR WATER FROM CLEUSON FOR WATER FROM VOUASSON 12 3 22 10 SHIELD FOR DIRECT INTRODUCTION 29 MEASUREMENT STATION 10 3 /s Blava 1 11 FOR WATER FROM CLEUSON 2500 OF WATER FROM CLEUSON

Q = 45 tom Fionnay INTO THE RESERVOIR 30 MEASUREMENT STATION 13 24 (LAKE BELOW 2240.50) FOR WATER FROM CHENNAZ 28 11 INLET STRUCTURE 31 HEADRACE TUNNEL TO THE 24 minimum level 2215 maximum level 2364 FOR BOTTOM OUTLET BIEUDRON POWER PLANT 103 000 VALVES CHAMBER AND BOTTOM Q = 75 m3 / s 3 /s 12

30 24 from Vouasson OUTLET TUNNEL 32 VALVE CHAMBER Q = 1,6 m Q = 10 m3 / s CLEUSON-DIXENCE 14 First Dixence dam 13 HEADRACE TUNNEL FOR WATER 15 2364,00 FROM CHENNAZ 13 27 3 000 Q = 1.5 m / s

2300 2200 2300 2364,00 2200 597 GRANDE DIXENCE DAM 65 FALL OUTLETS AND MAIN DISCHARGE INLET

3 / s 13

Q = 35 m B 22 Bieudron Q = 75 m3 / s 15 14 48,09 10 11 12 9 289,20 23

7 1,60 103400 Chandoline p = 2 33,18 8 22,80 ø 22,30 2,25 m Q = 10,25 m 3,00 6 100 % 14,75 p = 5 C 38,25 27,42 5 B 4 C 199,92

3 17 / s

6,50 A Fionnay Q = 45 m

26,70 3 2 24 1 7,50 p = 1,92 596800 100 m A

PLAN OF LOCATION 0,50 0,50

gunited 1/2 profile concreted1/2 profile 3,75 8,50 3,75 4,25 1,50 0,50 7,00 4,25 r = 4,85 2 ,14 400 million m3 of water, ready to drive the turbines 0,85

6,00 0,05 0,30 ø 3,50

0,50 r = 2,25 ø 2,50 ø 2,50 0,70 8,20 11,84 r = 2,00 4,40 4,00 4,57 ø 3,50 0,60 1,70 0,32 3,75 2162,26 0 ,10 0,40

0,40 ø 3,00 0,50 1 WATER INTAKE AND MAIN 9 2 MAIN DISCHARGE VALVES, 17 DECOMMISSIONED transversal joint 46 joint transversal 48 joint transversal 16,00 0,50 2,80 DISCHARGE INLET 0.75 x 1.4 0 m TUNNEL SECTION 2,80 1,00 1,70 2,80 0,50 0,60 2 UPSTREAM FACE OF DAM 10 BULKHEAD GATE, 1.40 x 1.00 m 18 2 BULKHEAD GATES, 3.00 x 2.00 m 3 REMOVABLE SHIELD FOR INFLOW 11 REDUCTION SYSTEM REGULATION 19 VALVES CONTROL ROOM OF WATER FROM CLEUSON WELL AND INFLOW OF WATER 2 0 VALVE CHAMBER INTO THE RESERVOIR FROM CLEUSON (ALPIQ) 21 AXIS OF DAM 6 1 19 2162,26 (LAKE BELOW 2240.50) 12 PLUG AND WATERTIGHT DOOR 22 CHARGEUR-TRACOUET 2170,00 13 20 4 CLEUSON TUNNEL (ALPIQ) 13 MAIN DISCHARGE TUNNEL HEADRACE TUNNEL 2163,92 ø 2,50 15,00 5 DIX-BAGNES TUNNEL 14 INFLOW OF WATER 2 3 CLEUSON-DIXENCE BUTTERFLY 18 6 GUARD GATE, 3.00 m Ø FROM CLEUSON (ALPIQ) VALVE CHAMBER, 3.30 m Ø

2 227,34 38,25 47,93 3,00 7 BUTTERFLY VALVE, 1.40 m Ø 15 ACCESS TUNNEL 2 4 BIEUDRON WATER INTAKE 8 2 PRESSURE REDUCING SYSTEMS, 16 WORKSHOP, UNDERGROUND

13,10 26,70 6,50 LONGITUDINAL PROFILE A-A 3.00 m Ø, LENGTH 18.00 m STORE AND SUBSTATION 65 kV

21 GRANDE DIXENCE DAM 67 FALL OUTLETS AND MAIN DISCHARGE INLET

steel lining

variable variable dam monorail 0,20 9,70 ø 0,15 r = 1,00 r 1 0,20 12 2,00 0,20 15

0,30 11

5,90 2,00 0,30 r = 1,40 r r = 1,40 r 2,00 from Cleuson

2 3 1,80 r = 2,00 2,30 ø1,80 2,20 2,00 4,40 ø 5,30 2243,25 ø1,80 2,00 3,10 3,10 2,50 3,10 1,80 0,30 0,30

2,40 2160,43 0,20 1,90 1,90

0,30 r = 1,10 11% = p 0,15 0,20 steel lining 14 0,40 0,40 0,40 2248,50 4,00 0,40 0,25 2,00 0,25 10 13

1,40 2157,49 0,50 2,50 0,50 0,50 0,50 1,70 2,00 1,70 1,70 2,20 9 1,94 0,75 D 11 D 2,50 8 9 23,90

2227,00 1,00 5,90 6,00

2157,49 ø9,70 3 1 10

2162,70 HORIZONTAL CROSS-SECTION D-D ø3,50 ø1,80 ø1,80 2 7 2156,96 5 6 4 Q = 35 m3/s 20 2158,39 2162,20 2174,32 1,60 16,77 18 3 17 5 22,30 p = 18,3% 29,03 2162,70 19 ø3,50 1,40 ø 1,80 ø 2,00 ø 100% 2157,74 LONGITUDINAL PROFILE B-B, REFERS TO PLAN OF LOCATION P.64 16 ø3,00

22,30 p = 18,3% 22,50 11,00 18,00 7,80 260,43 16,57 12,20 4,00 LONGITUDINAL PROFILE C-C, REFERS TO PLAN OF LOCATION P.64

1 MAIN DISCHARGE INLET 8 AFTERBAY CHAMBER WITH SPIRAL 13 SERVICE WALKWAY VALVES CHAMBER RAMP FOR DIRECT INFLOW 14 BYPASS VALVE 2 VENT PIPE OF WATER FROM CLEUSON INTO 15 THRESHOLD SPILLWAY 3 DIX-BAGNES TUNNEL THE PRESSURE REDUCING 16 BUTTERFLY VALVE, Ø 1.40 m 4 2 SLIDE VALVES, 1.40 x 0.75 m SYSTEM REGULATION SHAFT 17 NEEDLE VALVE 5 REDUCING SYSTEM I 9 ACCESS TUNNEL 18 VALVE CHAMBER 6 REDUCING SYSTEM II 10 REGULATION SHAFT, Ø 1.80 m 19 BULKHEAD GATE, 1.40 x 1.00 m 7 MAIN DISCHARGE INLET 11 INFLOW OF WATER FROM CLEUSON 2 0 TUNNEL TO CHANDOLINE Q = 35 m3 / s 12 SPIRAL RAMP

GRANDE DIXENCE DAM DEVELOPED LONGITUDINAL CROSS-SECTION OF THE DAM

left bank 1 right bank 2

87,00 m 96,00 m 384,00 m 128,00 m 85 83 86 84 82 80 78 76 74 72 70 68 66 64 62 60 58 56 54 52 50 48 46 44 42 40 38 36 34 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 2365,00

6 16 16 16

ø 1,90 ø 1,90 2300 2300

2242,10 2242,80 3 4 15 5 2215 2200 max. 285,00 m max. 285,00 6 ø 1,90 2,50 9 16

2,50 10 7 2159,00

8 16 11 2155,70 12 13 2100 11 2100 thalweg tunnel 2080,00 2075,55 2075,00 14 2075,10 300,00 m

2000 2000 grout curtain

1900 1900

1 DEVELOPED LENGTH 7 WATER INTAKE AND MAIN 11 COOLING AND INJECTION SHAFT, APPROX. 695 m DISCHARGE INLET 1.90 m Ø 2 DIRECTION CHANGE PLAN VIEW (AXIS ALTITUDE 2163.93) 12 GROUND PROFILE AT THE AXIS 3 MAIN ACCESS 8 INLET STRUCTURE OF THE BOTTOM TUNNEL TO THE BOTTOM TUNNEL FOR BOTTOM OUTLET 13 GROUND PROFILE 4 OLD CLEUSON TUNNEL CLOSED 9 BOTTOM TUNNEL AT THE UPSTREAM FACE BY A CONCRETE PLUG HEIGHT 3.50 m, WIDTH 2.50 m 14 GROUT CURTAIN DRILLING 5 MINIMUM LEVEL 2215.00 10 LONGITUDINAL INSPECTION TUNNEL AND INJECTION TUNNEL 6 1.50 m Ø SHIELD FOR DIRECT INFLOW HEIGHT 2.50 m, WIDTH 1.50 m, 15 CLEUSON-DIXENCE OF WATER FROM CLEUSON (ALPIQ) DISTANCE BETWEEN TUNNELS 16 m WATER INTAKE INTO THE RESERVOIR

Grande Dixence and the ﬁrst Dixence dam (left) which is usually submerged under the Lac des Dix GRANDE DIXENCE DAM 71 TYPICAL PROFILE AND DETAILS OF THE DAM

15,00 16,30

2363,96 0,50 2,55 1,30 8,45 3,00 0,50 1 INSPECTION SHAFT INJECTION AND SEALING 2365 2 SEAL INSPECTION OF THE TRANSVERSE JOINTS 29,7 % 0,5 % 2365,00 1,20 2350 0,5 % 1,20 1,00 0,33 0,5 % 3 INSPECTION TUNNEL 16 SAMPLING COLLECTOR 2364,00 1,00 7,10

1,00 1,00 2,00 3,80 0,30 1,90 0,30 A4 2334,28 2364,00 4 THALWEG TUNNEL 17 COLLECTOR RETURN PIPE 0,35 f 29,7 % 0,15 32 0,10 0,10 2327,60 0,35 5 DRAINAGE TUNNEL 18 PIPE FOR CLEANING THE COLLECTOR 0,30 0,40 68 % joint 0,30 0,60 0,60 15,00 6 DRILLING AND DURING CONCRETING A3 31 33 23 INJECTION TUNNEL 19 STEEL TUBE INJECTION RAIL 2300 2302,00 2300,00 0,45 0,40 34 7 LOW-LEVEL TUNNEL 20 - 22 mm Ø 24,60 1,90 36 8 MINIMUM RESERVOIR DIMENSION 20 LAYERS OF CONCRETE 81 % A2 B3 9 WATER INTAKE AND MAIN HEIGHT: 3.20 m (5 x 0.64 m) 2263,60 2261,60 CREST OF THE DAM DETAIL OF UPSTREAM DISCHARGE INLET 21 INJECTION PIPES 1 2250 3 B2 SEAL, HORIZONTAL CROSS-SECTION 10 BOTTOM OUTLET DISTANCE 3.00 m

36,40 29,00 34,80 3,80 11 BOTTOM OUTLET 22 LONGITUDINAL JOINT 2234,69 10 % VALVES CHAMBER C3 16 17 3,00 18 23 INJECTION STOP PLATE 15 A 2216,80 2,50 4,95 2216,40 3 12 GROUT CURTAINS THICKNESS 1.5 mm 16,00 19 max. 285,00 m max. 285,00

3,80 21,40 38,60 3,80 13 AXIS OF THE DAM 24 COLLECTOR (CASED CHANNEL) 2 A

2200 3,80 1,90 3,20

16,00 20 16,00 14 BOTTOM OUTLET TUNNEL 25 TENON C2 16,00

2184,40 E 3,20 21 7,20 1,05 7,10 1,90 2,90 34 15 KEYING SPACE 26 THEORETICAL JOINT PLANE

2181,20 81 % 8 A1 B1 2172,00 27 CONCRETING LIMIT 2170 35 23 22 2,50 ø2,50 13,40 25,20 12,60 28,20 9 28 CHANNEL PROTECTION PANEL

2,90 1,90 3,80 1,50 var. 0,30 10 10,20 1,50 1,90 1,50 0,30 2,50 C1 J2 29 CONCRETE-CASED CHANNEL 1,90

2155,70 2,50 2146,40 joint A-B H 2139,80 30 8 HOLE, 5 mm Ø 2137 2,90 1,90 1,50 1,50 2133,20 DETAIL OF AN INJECTION PANEL

joint B-C G 31 1.5 mm THICK V-SHAPED 1,90 40,20 34,80 6,90 37,80 32,20 1,90 F 2,30 COPPER SHEET SEAL

f 3 % 2110,00 0,15 0,15 5 32 CONCRETE WITH A GRAIN

1,05 9,00 1,50 5 23 2100 4 SIZE OF 0 - 40 mm 8,30 3,50 7 0,30 2,50 0,10 24 0,35 33 Z-SHAPED COPPER SHEET ø0,60 28 0,30 ~2075.00 34 INJECTION SHAFT, 1.90 m Ø 6 11 17 25 0,65 35 HORIZONTAL TUNNELS EVERY 16 m 12 14 201,20 26 36 UPSTREAM FACE OF DAM 27 0,30 13 0,15

DETAIL OF COLLECTOR, CROSS-SECTION A-A TYPICAL CROSS-SECTION OF A JOINT

normal type plan view 1,801,80 1,501,50 160 mm 0,15 20 mm shaft access tunnel 50 mm 20 mm 20 mm 50 mm r = 0,55 0,35 r = 0,35 B r = 0,875 ø 20 mm 29 r = 1,95 21 0,15 2,40 2,40 1,90 2,00 2,00 2,50 0,80 0,10 0,40 0 ,10 0,40 0,40 0 ,10 0,40 0,600,60 r r= =0,20 0,20 0,700,70 40 mm inspection shaft escalierstairs 0,30 0,30 0,46 1,05 19 21 19 30 29 3 1 2 44 55 possible variable ﬂoor variable B

1,50 1,90 variable variable DETAIL OF AN INJECTION PIPE, CROSS-SECTION B-B GRANDE DIXENCE DAM 73 CALCULATED CONSTRAINTS AND EFFECTIVE METERING

2 2 2

15 2365 20 25 35 40 45 LOAD SCENARIO

10 kg/cm 30 kg/cm 50 kg/cm 2350 – Ordinary load scenario: lake empty 140 or full, safety coefﬁcient varying

55 between 2.55 and 3.80 (on cyl.) based on dispersions obtained for the 140 250 results of the concrete tests. 2300 ---- Exceptional load scenario: lake empty or full and earthquake, 140 140 200 30 250 safety coefﬁcient 2.25 (on cyl.)

200 40 60 –-– Constraint concentrations at end of footings: lake empty or full 2250 140 and earthquake, safety coefﬁcient 140 1.75 (on cyl.) 200 250

220 140 200 250

50 60

2 140 220 200 180 200 2200 65 kg/cm 160 140 140 250 150

70 80

200 160 165 250 220 185 160 200 195 160 200 150 2150 185 200 250 180 300 205 300 160 195 160 250 180 170 210 170 160 200 270 240 190 185 160 170 300 250 190 200 180 200 CONCRETE METERING 195 215 90 100 215 165 110 120 250 245 225 205 130 140 150 270 180 195 165 170 180 190 275 250 250 Metering indicated in kg of normal Portland 285 260 200 170 210 215 190 270 100 110 kg/cm 205 170 40 kg/cm 50 60 70 80 90 295 270 240 185 3 3 2100 cement per m of ﬁnished concrete (kg / m ) 210 250 45 kg/cm 200 250 2 2 300 50 220 60 55 2 3 200 65 140 kg / m 280 70 kg/cm from 141 to 160 kg / m3

2 from 161 to 180 kg / m3 from 181 to 200 kg / m3 from 201 to 220 kg / m3 from 221 to 240 kg / m3 from 241 to 260 kg / m3 from 261 to 280 kg / m3 from 281 to 300 kg / m3

The Val des Dix, upstream of the dam GRANDE DIXENCE DAM WATER INTAKE AND MAIN 75 BOTTOM OUTLET DISCHARGE INLET

7,50 8,67 1,70 14 11 23,00 6,10 2177,50 3

1 2,50

2,80 2 2155,70 0,90 6 13 8 4 1,901,50 3,00 2,00

5,40 1,80 1,20 0,40 0,30 2173,97 2173,41 0,50 12 1 5

2137,00 2,83 2,40 0,40

2,45 2,00 0,40

0,65 2,00 B B 2,70 ø0,25 1,80 1 2169,21 0,50 0,41 4,10 0,65 4,00 ø 0,60 0,40 3,12 8 7 6 13 ø0,25 0,50 2,43 31,00 2,00 2,00 2167,01 0,40 0,30 ø0,25 1,70 3,12 A 0,80 15,04

5,00 2,94 5,30 4,20 0,50 7,50 2163,93 9 2163,84 2137,00 0,65 1,80 5 7 3,00 3,12 ø3,50 1,80 A A 0,90 3 3,36 4 12 ø0,25 2,50 3,00 2,83 2158,93 10 11 1,90 1,10 HORIZONTAL CROSS-SECTION A-A 4,50 8,60 10 11 32,70 10,75 5,00 cast in concrete 2,15 LONGITUDINAL CROSS-SECTION B-B steel 2 lined 2,00 f = 3%

15 16 1,05

53,25 0,60 30,00 2 19 1,20 1 0,80 2,70

23,00 8,50 3,75 1,25 3 2,40

4 2,60 4 1,90 4,25

2 2091,25 2089,50 8,50

3,50 2090,20 8 2075,98 B ø2,50 B 2088,77 5

17,60 18 12,20

0,75 7,50 9 10 2,50 17 2,90 2,00 2,00 0,40 5,40 0,50 0,80 0,50 4,25 1,20 ø2,50 2077,40

5 ø3,50

1,10 7 2081,15 2,60 2,00 14 1,40

3,75 13 0,60 2,00 6 2,45 5,75 % 2,70 5 % 2,65 2,95 10 20

0,30 A 5,60 28,65 9,00 1,50 11,36 18,44 8 1,05 1,20 29,80 3,70 2,00 HORIZONTAL CROSS-SECTION A-A

LONGITUDINAL CROSS-SECTION B-B

1 GRIDS 8 BYPASS 0.25 m Ø 16 UPSTREAM FACE 2 BULKHEAD GATE CONTROL 9 2.00 x 3.00 m BULKHEAD GATE 17 CONCRETE TRAINING WALLS 1 INLET STRUCTURE 8 BOTTOM OUTLET EVACUATION CHAMBER 10 SEAL INSPECTION SHAFT 18 AXIS OF BLOCK XXIV FOR BOTTOM OUTLET TUNNEL LENGTH APPROX. 505 m 3 HORIZONTAL INSPECTION TUNNEL 11 INSPECTION CHAMBER 19 TRANSVERSE JOINT NO 48 2 PROVISIONAL INLETS 9 GABIONS 4 ACCESS TUNNEL 12 DRAIN 0.25 m Ø 2 0 TRANSVERSE JOINT NO 46 3 BOTTOM TUNNEL 10 AXIS OF DAM 5 BYPASS VALVE ACCESS SHAFT 13 VENT 0.25 m Ø 4 THALWEG TUNNEL 11 UPSTREAM FACE OF DAM 6 BYPASS VALVE, 0.25 m Ø 14 LONGITUDINAL JOINT 5 VALVES CHAMBER ACCESS SHAFT 12 CONDUIT, Ø 0.60 m 7 SEALED CASING 15 AXIS OF THE DAM 6 VALVES CHAMBER 13 SHIELDED AIRLOCK 7 VENT PRODUCTION

The water stored behind the Grande Dixence dam is transferred as required to the three surrounding underground power plants: Fionnay, Nendaz and Bieudron. These power plants represent a total of 2000 MW and produce around 2 billion kWh every year. Once it has passed through the turbines, the water is returned to the Rhône.

Pelton turbine wheel POWER PLANT FIONNAY

The water held behind the Grande Dixence dam is transformed into electricity in two stages. The ﬁrst stage takes place at the Fionnay underground power plant. An underground and gently sloping tunnel stretching over nine kilometres had to be constructed to carry the water to the turbines.

The surge chamber, which is located at Louvie in the Val de Bagnes, becomes a penstock which descends 800 metres at a gradient of 73 %. The penstock runs to the distributor at the Fionnay facility, a vast cavern hollowed out of the rock.

TECHNICAL SPECIFICATIONS

AFTERBAY RESERVOIR CAPACITY 166,000 m3

POWER PLANT NUMBER OF TURBINES 6 x 2 Pelton INSTALLED POWER CAPACITY 290 MW FLOW RATE 45 m3 / s max. MAX. DROP HEIGHT 873.8 m MIN. DROP HEIGHT 679.8 m TRANSFORMERS 9 x 40 MVA (single phase) – 220 / 15 KV

Fionnay afterbay reservoir (right: Grande Dixence reservoir; left: Mauvoisin reservoir) FIONNAY POWER PLANT 81 PLAN OF LOCATION

1 LOUVIE STEEL-LINED SHAFT 15 FMM TAILPOND DISCHARGE TUNNEL 3 TO 2.80 m Ø, Q = 45 m3 / s 16 DEWATERING STRUCTURE 2 VALVES CHAMBER WITH PUMP 3 MACHINES HALL 17 CHAMPSEC POWER PLANT INTAKE 4 TRANSFORMERS AND HIGH 18 SUPPLY TUNNEL TO CHAMPSEC Fionnay VOLTAGE SWITCHGEAR CHAMBERS POWER PLANT (FMM) 5 SURFACE SERVICE BUILDING 19 ORIGINAL RIVER BED IN TAILPOND La Dranse 1500 6 ACCESS TUNNEL AND TAILRACE 20 ACCOMMODATION FOR PERSONNEL 1490 20 1540 24 TUNNEL ONE ABOVE THE OTHER 21 WINTER ACCESS TUNNEL 1486 7 TAILRACE TUNNEL TO PLANT 1480 1460 8 TAILRACE TUNNEL OVERFLOW 22 CABLEWAY TO LOUVIE SHAFT

1420 27 SYPHON AND OUTLET SHAFT SHUT-OFF VALVE 21 26 Lourtier 9 TAILRACE TUNNEL OUTLET INTO 23 AVALANCHE PROTECTIONS 14 1486 1400 TAILPOND AND NENDAZ POWER 24 FIONNAY-CHAMOSON 220 kV LINE 12 11 13 17 PLANT INTAKE 25 FIONNAY-LOURTIER ROAD 16 19 embankment 25 9 10 NENDAZ TUNNEL SHUT-OFF 26 GD TAILPOND, 15 10 La Dranse VALVE 3.00 m Ø LIVE CAPACITY : 166,000 m3 ; 7 23 11 11 4.10 m Ø VERTICAL SHAFT AND MAXIMUM LEVEL 1486,00 SUPPLY TUNNEL TO NENDAZ 27 FMM TAILPOND 21 1420 8 POWER PLANT. Q = 45 m3 / s 1440 23 12 TAILPOND DIVERSION, DISCHARGE

5 1460 AND OVERFLOW STRUCTURE 6 1480 13 OUTLET TUNNEL 18 8 1500 4 FROM STRUCTURE 12 14 EXCHANGE TUNNEL BETWEEN 1520 3 FORCES MOTRICES DE MAUVOISIN 11 2 1540 (FMM) AND GRANDE DIXENCE (GD) 22 Fionnay power plant

1 18

98 450

to Nendaz

100 m from Louvie 589 250 589 FIONNAY POWER PLANT 83 3939 3838 3737 4949 4444 44 3333 INSTALLATIONS PLANS 133,92133,92 22,9022,90 110,32110,32 0,700,70

1503,351503,35

1498,051498,05 II II II IVIV VV VIVI 1498,901498,90 1494,351494,35 1490,651490,65

1486,001486,00 1481,701481,70

9,959,95 5,555,55 9,959,95 2,91 2,91 5,15 5,15 1,28 1,28 2,64 2,64 2,64 2,64 20,7220,72 0,88 0,88 15,5015,50 15,5015,50 15,5015,50 12,10 12,10 15,5015,50 15,50 15,50 3030 2626 2525 3636 2424 3131 4040 3434 3535

LONGITUDINAL SECTION C-C

3232 16 16 15 15 AA 1 CONTROL ROOM FOR SETS I AND II 2 9 TAILRACE TUNNEL 1919 1717 18 18 21 21 2 CONTROL ROOM FOR SETS III AND IV 30 SYPHON BANK (TAILRACE 22,3022,30 3 CONTROL ROOM FOR SETS V AND VI TUNNEL OVERFLOW) 4 MACHINES HALL 31 CHAMPSEC TUNNEL 8,00 8,00 5 VALVES GALLERY 32 OVERFLOW OUTLET TUNNEL 11,0011,00 20,0020,00 20,0020,00 11,0011,00 6 2 x 0.80 m Ø SPHERICAL VALVES 33 2 x 70 TON OVERHEAD 18,30 18,30 9,50 9,50 7 10 x 0.65 m Ø SPHERICAL VALVES TRAVELLING CRANES 2020 8 STEEL-LINED DOOR 3 4 TURBINES PIT 5,50 5,50 5,40 5,40 6,40 6,40 2323 6,00 6,00 9 ACCESS TUNNEL TO 35 GENERATOR PIT 10,2010,20 2222 STEEL-LINED SHAFT 36 COOLING WATER PUMPS 8,40 8,40 2626 2525 2424 10 LOUVIE-FIONNAY SHAFT, 37 DISTRIBUTION ROOM 3030 20,6020,60 8,408,40 19,7519,75 5,605,60 25,4025,40 5,605,60 25,4025,40 5,605,60 17,5717,57 STEEL-LINED 3.00 TO 2.80 m Ø 38 CONTROL ROOM 22,60 22,60 133,92133,92 3131 4,4,2424 BB 1414 14,70 14,70 11 DISTRIBUTOR 39 LIFT EQUIPMENT 40 STORE FOR HEAVY COMPONENTS 12 WALKWAY 2727 20,7220,72 II 15,5015,50IIII 15,50 15,50 IIIIII 15,5015,50 IVIV 15,5015,50 VV 15,5015,50VIVI 12,10 12,10

13 AUXILIARY SET 44 GENERATOR 2828 5,85 5,85 CC

CC 10,50 10,50 98,00 98,00

14 15 kV SWITCHGEAR 4 9 TURBINES 14,80 14,80 44 17,20 17,20 15 TRANSFORMERS CHAMBER 5,55 5,55 5,55 5,55 5,55 5,55

5,50 5,50 9,959,95 9,959,95

16 220 kV SWITCHGEAR 2929

17 SERVICE BLOCK 3,61 3,61 BB 11,19 11,19 18 WORKSHOP

19 HEATING 5,60 5,60 4,404,40 2 0 UNTANKING CHAMBER 8,108,10 4,524,52 21 ACCESS TUNNEL 106,30106,30 2,522,52 1,501,50 8,108,10 ø0,25ø0,25 17,21 17,21 22 PLANT SERVICES ø0,80ø0,80 110,32110,32 2 3 FIREFIGHTING EQUIPMENT 2 4 PLANT SERVICES CONTROL ROOM 0,44 0,44 1,45 1,45 1,00 1,00 ø ø ø1,85 ø1,85 ø2,16 ø2,16 ø ø ø2,43 ø2,43 ø2,68 ø2,68 ø2,56 ø2,56 ø2,30 ø2,30 25 BATTERIES ø2,80 ø2,80 2 6 RECEPTION ROOM 1010 99 1111 88 6 6 5 5 6 6 1 1 7 7 1212 4 4 22 77 4949 4444 3 3 1313 2 7 INFIRMERY AA 2 8 MAIN ACCESS TUNNEL HORIZONTAL SECTION FIONNAY POWER PLANT 85 INSTALLATIONS PLANS

5 41 3 43 33 49 14 15 16

1505,90 1503,35

1498,60 14,80 1494,90 5,20 4 5,85 ø 0,80 1490

8,20 5,00 17, 21 5,60 11,99 15,40 16,10 31,70 98,00

11 6 7 29 34 42

TRANSVERSE CROSS-SECTION A-A, REFERS TO THE HORIZONTAL CROSS-SECTION P.83

1498,90 14,80 4 5,85 44 1490,65 1491,32 46 1487,30 1486,00 5,50 48 1481,70 47 17,20

TRANSVERSE CROSS-SECTION B-B, REFERS TO THE HORIZONTAL CROSS-SECTION P.83

3 CONTROL ROOM FOR SETS V AND VI 3 4 TURBINES PIT 4 MACHINES HALL 41 25 TON OVERHEAD 5 VALVES GALLERY TRAVELLING CRANE 6 2 x 0.80 m Ø SPHERICAL VALVES 42 VENTILATION TUNNEL 7 10 x 0.65 m Ø SPHERICAL VALVES 43 NOZZLE 11 DISTRIBUTOR 44 GENERATOR 14 15 kV SWITCHGEAR 45 GOVERNOR 15 TRANSFORMERS CHAMBER 46 SERVICE GALLERY 16 220 kV SWITCHGEAR 47 DRAINAGE GALLERY AND 2 9 TAILRACE TUNNEL COOLING WATER PIPES 33 2 x 70 TON OVERHEAD 48 COOLING PIPES TRAVELLING CRANES 4 9 TURBINES

Valves chamber, Fionnay power plant POWER PLANT NENDAZ

After passing through the turbines at Fionnay, the water from Grande Dixence is transferred to the Nendaz power plant. It enters a pressure tunnel which leads to the Péroua surge chamber 1000 metres above the power plant. The tunnel linking Fionnay and Nendaz is 16kilometres long. At its end is a penstock.

Deep in the mountain between Aproz and Riddes, the Nendaz power station is – after the Bieudron plant – the largest hydroelectric power plant in operation in Switzerland. It operates on the cascade principle with the Fionnay power station, which means its capacity and output are regulated by the latter.

TECHNICAL SPECIFICATIONS

POWER PLANT NUMBER OF TURBINES 6 x 2 Pelton INSTALLED POWER CAPACITY 390 MW FLOW RATE 45 m3 / s max. MAX. DROP HEIGHT 1007.8 m MIN. DROP HEIGHT 1001.8 m TRANSFORMERS 6 x 80 MVA (three-phase) – 220 / 13 KV

Machines room, Nendaz power plant NENDAZ POWER PLANT 89 PLAN OF LOCATION

Fionnay

520 500 490

1 Riddes 585 200 585 114 500 2 12

3 4

Nendaz power plant 4 8 13 11 5 6 Riddes

Rhône 9

480

7 Aproz

Riddes

Valves chamber, Nendaz power plant

Chamoson substation Chamoson Romanel 410/230 kV substation 230 kV 1 NENDAZ SHAFT, STEEL-LINED, 10 SERVICE BUILDING, WORKSHOP, Chamoson 2.90 m Ø, Q = 45 m3 / s UNTANKING ROOM AND ENTRANCE 2 VALVES GALLERY TO PLANT 3 MACHINES HALL 11 GARAGES 4 TAILRACE CANAL 12 MAIN STORE AND VEHICLES Mörel 5 TAILRACE CANAL BULKHEAD GATE WORKSHOP 6 220 kV CABLES TUNNEL 13 PROTECTIVE FILL

Sanetsch 100 m Chandoline FOR SETS I TO III 14 SUBSTATION SERVICE BUILDING 7 CABLES BRIDGE FOR SETS I TO III WITH CONTROL ROOM 8 PLANT ACCESS TUNNEL AND CABLES ROUTE FOR SETS IV TO VI 9 BRIDGE OVER RHÔNE AND CABLES ROUTE FOR SETS IV TO VI NENDAZ POWER PLANT 91 OVERALL LONGITUDINAL PROFILE AND TRANSVERSE PROFILE

RosablancheRosablanche

Mont-GeléMont-Gelé

33 11 99 88 55 supplysupply tunnel tunnel Q Q = = 45m 45m/s/s 2525 2323 1919 2020 1717 1313 1212 1111 1010 77 66 42,1942,19 44 33 22 2727 2626 2424 2222 2121 1818 1616 1515 1414 2364,002364,00 2377,442377,44 2364,002364,00 2301,002301,00 2266,072266,07 400,00400,00 pp 1,92 1,92‰‰ 2163,922163,92 2146,272146,27

207,96 207,96 7993,047993,04 356,44356,44 73%73% supplysupply tunnel tunnel Q Q = = 45m 45m33/s/s 8557,448557,44 126,15 126,15 226,33 226,33 610,00610,00 2590,60 2590,60 823,65 823,65 1111 870,00 870,00

1504,001504,00 1486,001486,00 1490,191490,19 1112,731112,73 873,80 873,80 1450,001450,00 1466,951466,95 1406,511406,51 1424,021424,02 366,69366,69 898,73898,73 3196,703196,70 1311,261311,26 7315,357315,35 4423,624423,62 848,54848,54 1616 246,93 246,93 1036,021036,02 881,44881,44 165,76 165,76

76%76%

650,00650,00 1007,80 1007,80

476,50476,50 Rhône Rhône 647,94647,94 478,20478,20 478,20478,20 758,33758,33 NendazNendaz power power plant plant FionnayFionnay power power plant plant GrandeGrande Dixence Dixence dam dam

515,88515,88 steelsteel lining lining 16 16 - - 22 22 mm mm thick thick steelsteel lining lining 24 24 - - 38 38 mm mm thick thick 1616 - - 33 33 mm mm thick thick steelsteel lining lining 10 10 - - 14 14 mm mm thick thick steelsteel lining lining linerliner normalnormal cross cross section section reinforcedreinforced cross cross section section steelsteel lining lining 15 15 - - 34 34 mm mm thick thick steelsteel lining lining 14 14 mm mm thick thick gunited gunited 1/2 1/2 profile profile concretedconcreted 1/2 1/2 profile profile 66 mm mm thick thick stiffenningstiffenning 1st1st stage stage 0,300,30 1st1st stage stage concrete concrete 0,90 0,90 0,63 0,63 concreteconcrete outerouter 0,050,05 0,30 0,30 0,35 0,35 concreteconcrete 0,250,25 2nd2nd stage stage concrete concrete 2nd2nd stage stage 2,252,25 0,300,30 innerinner concreteconcrete 0,800,80 0,200,20 2,002,00 4,40 4,40

concreteconcrete 3,85 3,85 4,90 4,90 ø3,60 ø3,60 4,80 4,80

draindrain ø 3,50 ø 3,50 4,12 4,12 4,57 4,57 ø3,10 ø3,10

ø 2,90 ø 2,90 0,600,60 variable variable

draindrain 2,00 2,00 ø2,80 - 3,00 - ø2,80 3,00 - ø2,80 0,30 0,30 0,44 0,44 0,87 0,87 0,90 0,90 variablevariable

ø3,50ø3,50 0,25 0,25 0,350,35 øø 2,90 2,90 0,350,35 0,550,55 øø 2,90 2,90 0,550,55 0,300,30 ø3,60ø3,60 0,300,30 ø4,20ø4,20 ø2,80ø2,80 - - 3,00 3,00 0,370,37 0,370,37 0,15 0,15 3,603,60 4,004,00 4,204,20 4,204,20 0,75 0,75 ø4,55ø4,55 øø 4,30 4,30 3,403,40 4,254,25 4,604,60 7,607,60

1 1.80 m Ø BIFURCATION FOR 5 LOUVIE SURGE CHAMBER 70 % 9 2 x 2,82 m Ø SLIDE GATES 16 ISÉRABLES ADIT B) 22 2.90 m Ø VERTICAL 26 WALKWAY AND BRIDGE CHANDOLINE (ALPIQ) SLOPE, 13 - 23 mm THICK STEEL 10 FIONNAY TAILPOND LENGTH 512.47 m STEEL-LINED SHAFT FOR 220 kV CABLES Q = 10.25 m3 / s LINING TO ELEVATION 2301 m CAPACITY 166,000 m3 17 PÉROUA SURGE CHAMBER, 23 2.90 m Ø INCLINED STEEL-LINED 27 220 kV SUBSTATION AND MAIN DISCHARGE 6 3.00 m Ø BUTTERFLY VALVE 11 3.00 m Ø BUTTERFLY VALVE FROM STEEL-LINED TO ELEVATION SHAFT, LINING THICKNESS Q = 35.00 m3 / s 7 STEEL-LINED SHAFT VARYING 8 - 12 mm THICK STEEL LINING 1450,00 m 16 - 22 mm, BANDED 2 2 x 2.00 x 3.00 m FROM 3 TO 2.80 m Ø, SLOPE 73 % IN LINED ZONE 18 VALVE CHAMBER 24 NENDAZ POWER PLANT, BULKHEAD GATES 8 FIONNAY POWER PLANT, 12 4.10 m Ø VERTICAL SHAFT 19 3.00 m Ø BUTTERFLY VALVE MAXIMUM GROSS HEAD: 1007.8 m, 3 3.00 m Ø BUTTERFLY VALVE MAXIMUM GROS HEAD : 873.8 m, 13 SARREYER ADIT, LENGTH 1219.97 m 20 3.10 m Ø PENSTOCK MAXIMUM DISCHARGE: 45.0 m3 / s, 4 MAXIMUM STATIC HEAD 873.8 m MAXIMUM DISCHARGE : 45.0 m3 / s, 14 ISÉRABLE ADIT A) LENGTH 1121.19 m 21 ANCHOR BLOCKS INSTALLED CAPACITY: 390 MW INSTALLED CAPACITY: 290 MW 15 FARA INTAKE, Q = 1.00 m3 / s 25 TAILRACE CANAL NENDAZ POWER PLANT 93 INSTALLATIONS PLANS

20 28 29 134,00 38 494,00 495,15 17 37 494,00 491,20 18 12,20 487 11 485,95 12,80 9,80 4,55 0,80 36 482,80 8,10 10,97 I 18,90 II 18,90 III3 IV26 V18,90 VI 28,52 5,00 3 6,40 479,00 479,45 1 479,00 0,70 478,20 474,10 2,10 476,00 0,50 7,65 34 473,50 474,10 471,60 471,35 472,00 9,45 9,45 9,45 9,45 22 23 24 25 27 30 31 32 12 0,95 0,95 0,95 0,95 0,60 0,60 0,60 max 31,44 min 14,65 23,20 2,10 0,60 2,69 2,69 2,69 2,69 LONGITUDINAL SECTION B-B 4,85 5,55 4,85 15 35 33 27 22

TRANSVERSE CROSS-SECTION A-A, REFERS TO THE HORIZONTAL CROSS-SECTION P.93

A from Fionnay

ø2,80

ø2,68

ø2,56

ø2,43

ø2,28

ø2,14

ø1,98

ø1,81

ø1,62

ø1,40

ø0,80 ø0,80 ø1,15

ø1,00 21 20 19 18 17 4,20 15,60 9,45 9,45 16 2,50 0,60 9,45 9,45 5,00 15 5,00 0,60

2,502,40 9,45 9,45 13,50 3 9,45 9,45 2,50 4,00 14

1 CONTROL ROOM FOR SETS I TO III 17 VALVES GALLERY AND TAILRACE 32 AERATION 24,05 12 2 CONTROL ROOM FOR SETS IV TO VI TUNNEL ONE ABOVE THE OTHER 33 GOVERNORS 1,70 B I II III IV V VI 13 3 MACHINES HALL 18 0.65 m Ø SPHERICAL VALVE 3 4 SERVICE GALLERY B 1,25 9,80 0,60 4 STEEL-LINED DOOR 19 COOLING PUMPS ROOM 35 TRAINING WALLS E4,55 5 SECONDARY ACCESS TUNNEL 2 0 VERTICAL SHAFT 36 AIR CONDITIONING

1,40

6 220 kV CABLES TUNNEL FOR COOLING PIPES 37 220 kV CABLES TUNNEL 8,40 2,80 8,55 10,30 8,55 9,00 8,55 1,40 0,35 FOR SETS I TO III 21 1000 m3 COOLING WATER RESERVOIR. FOR SETS I TO III 22 4 5 1 6 2 7 7 8 9 10 11 9,35 10,97 18,90 18,90 18,90 18,90 18,90 28,52 7 80 MVA THREE-PHASE FLOOT AT ELEVATION 495.00 m A 134,00 TRANSFORMERS 22 COOLING PIPES GALLERY 8 PLANT SERVICES CONTROL ROOM 2 3 TRANSFORMERS OIL PITS HORIZONTAL SECTION 9 PLANT SERVICES TRANSFORMERS 2 4 GENERATOR 10 HYDRAULIC ROOM 25 GENERATOR PIT 11 220 kV CABLES TUNNEL 2 6 TURBINES FOR SETS V TO VI 2 7 TURBINES PIT 12 MAIN ACCESS TUNNEL 2 8 TRAVELLING CRANE TRACK 13 ERECTION BAY 2 9 2 x 80 TON OVERHEAD 14 HOUSE SETS TRAVELLING CRANES 15 TAILRACE TUNNEL 30 VENTILATION ROOM 16 ACCESS TO STEEL-LINED SHAFT 31 STORE FOR HEAVY COMPONENTS POWER PLANT BIEUDRON

The Bieudron facility is Switzerland's most powerful hydroelectric power plant. The underground power station, which is adjacent to the Nendaz power plant, was built between 1993 and 1998 to more than double the power capacity of the Grande Dixence complex. It can inject as much power as a nuclear power station into the grid in just a few minutes! The Bieudron power plant holds three world records: the drop height (1883 m), the power per Pelton turbine (3 x 423 MW) and the power per generator pole (35.7 MVA).

TECHNICAL SPECIFICATIONS POWER PLANT NUMBER OF TURBINES 3 Pelton INSTALLED POWER CAPACITY 3 x 423 MW POWER PER GENERATOR POLE 3 x 35.7 MVA FLOW RATE 75 m3 / s max. MAX. DROP HEIGHT 1883 m TRANSFORMERS 3 x 465 MVA (three-phase) – 410 / 21 KV

FOR MORE INFORMATION ON THE BIEUDRON POWER STATION: CLEUSON - DIXENCE DISCOVER A HYDROELECTRIC FACILITY UNIQUE IN THE WORLD Technical brochure, 44 pp.

Machines room, Bieudron power plant BIEUDRON POWER PLANT 97 PLAN OF LOCATION INSTALLATIONS PLAN

2 3

11 1 13 Chamoson switching Chamoson switching 18 station 410/230 kV 19 10 station 230 kV

5 12

11 Bieudron power plant 6 9 1200 MW Rhône Aproz 6 km 16 10 17 9 14 7 7 14 Riddes 2 km 6 8 5 Nendaz power plant 14 15

390 MW 14 4 8 TURBINE-GENERATOR UNIT

3 1

114 500

1 NENDAZ PLANT,200 585 390 MW 10 410 kV CABLES TUNNEL 17 ACCESS TUNNELS 1 GENERATOR SHAFT 8 RACK AND PLATFORM 2 PENSTOCK INLET, 75 m3/s AND ACCESS TO TRANSFORMERS 18 COMMAND AND CONTROL SYSTEM 2 EXCITER 9 INJECTOR 3 DISTRIBUTOR, 3 x 25 m3/s 11 RESTITUTION WORK FOR SWITCHING STATION 3 ROTOR – COOLING WATER 10 BUSBARS 4 SPHERICAL VALVES CHAMBER TO THE RIVER RHÔNE 19 AUTO-TRANSFORMER 4 ROTOR 11 COMBINED TRUST AND 5 BIEUDRON MACHINES ROOM 12 CABLES GATEWAY (600 MVA / 230 / 410 kV) 5 STATOR BEARING SUPPORT 6 BAR TUNNELS 13 CHAMOSON SWITCHING STATION 6 TURBINE GUIDE BEARING 7 TRANSFORMER CELLS (410 / 230 kV) 7 PELTON TURBINE 8 COOLING WATER RESERVOIR, 14 CONNECTING TUNNELS CAPACITY 21,000 m3 15 EMERGENCY TUNNEL 9 TAILRACE TUNNEL 16 VENTILATION TUNNELS BIEUDRON POWER PLANT 99 INSTALLATIONS PLANS

103 m

25 m 25 m

1 EXCITER 2 GENERATOR 3 PELTON TURBINE AND INJECTOR 4 RACK AND PLATFORM Unit 1Unit 2Unit 3 5 BUSBARS 1

Assembly 39 m 5 site 2

25 m 43 m 46 m

3 1 DISTRIBUTOR 2 VALVES CHAMBER 4 5 3 250 TONS OVERHEAD CRANE

5 4 MACHINES ROOM 5 TUNNEL FOR LOW AND MEDIUM VOLTAGE CABLES 10 6 LOW WATER TUNNEL 2 7 BAR TUNNEL 8 FLAP GATE 1 7 9 TAILWATER BRANCH 11 10 TRANSFORMER CELLS 8 9 11 TAILRACE

6 INFORMATION

For many years, Grande Dixence SA has welcomed visitors to its dam, as well as its pumping and power stations. The Grande Dixence dam is open to visitors from mid-June to the end of September. Four guided tours inside the wall take place every day. The pumping and power stations on the Grande Dixence complex can be visited on every working day of the year (for more information, visit www.grande-dixence.ch).

The crest of the Grande Dixence dam is the starting point for many a beautiful mountain walk GRANDE DIXENCE SA PARTNERS GRANDE DIXENCE SA 103 SHAREHOLDING PORTFOLIO

The energy produced by Grande Dixence SA is supplied in its entirety – Elektrizitätswerk Zermatt AG (EWZ), industrial services for the municipality of Zermatt, with 45 % of to the four partner companies which have the share capital of the the share capital held since November 2001. This partnership has allowed EWZ and Grande Dixence SA company (300 million CHF), i.e. : to develop synergies to exploit and process the water in the Zermatt basin.

6 0 % – HYDRO Exploitation SA, created in June 2002 jointly by EOS Holding and FMV SA, to manage ALPIQ SUISSE SA, LAUSANNE their installations. Grande Dixence SA holds 35 % of the share capital. Established in 2003, HYDRO Exploitation SA was one of the ﬁ rst companies to focus entirely on the use of hydroelectric energy. Primarily designed for its shareholders, the company's services could also be offered to the owners of other hydraulic facilities in Valais or elsewhere.

1 3 1 / 3 % – Cleuson-Dixence, an ordinary partnership created jointly with EOS in 1992 to increase the capacity AXPO POWER AG, BADEN for electricity production. Grande Dixence SA's holding is 15/22.

— Forces Motrices de la Borgne SA (FMdB), with 29 % of the share capital since January 2009. FmdB owns the Bramois development, located downstream of the Grande Dixence installations, and uses the waters of the Borgne river. FmdB's other shareholders are the communes of Hérémence, St-Martin, 1 3 1 / 3 % Vex, Mont-Noble and Sion (51%) and the company FMV SA (20 %). BKW ENERGIE AG, BERNE

1 3 1 / 3 % IWB INDUSTRIELLE WERKE BASEL, BÂLE CONTACT INFORMATION

Grande Dixence SA, Sion +41 27 328 43 11 www.grande-dixence.ch

FOR MORE INFORMATION:

Grande Dixence - a legend in the heart of the Alps

GRANDE DIXENCE, A LEGEND IN THE HEART OF THE ALPS General brochure, 72 pp, A4

CLEUSON - DIXENCE GRANDE DIXENCE SENTIER DES BOUQUETINS INTRODUCING A HYDROELECTRIC COMPLEX EXPERIENCE THE ENERGY AT THE IBEX TRAIL UNIQUE IN THE WORLD THE HEART OF THE ALPS

CLEUSON - DIXENCE GRANDE DIXENCE EDUCATIONAL ROUTE INTRODUCING A HYDROELECTRIC EXPERIENCE THE ENERGY THE IBEX TRAIL COMPLEX UNIQUE IN THE WORL AT THE HEART OF THE ALPS Discovery brochure, 86 pp, A5 Technical brochure, 44 pp, A5 General brochure, 52 pp, A5