🏗️ 12 Highest Dams in Western Switzerland in 2020
🏗️ The 12 Highest Dams in French-Speaking Switzerland in 2020
- 1 Dams
- 2 Types of dams
- 3 Dams geolocation
- 4 Comparative table of dams
Switzerland, queen of dams
Switzerland has a large number of dams mainly located in the Alps and especially in the canton of Valais. The king of dams is the one of Grande-Dixence because of its height (285 m) and the phenomenal quantity of concrete it contains. It remained for a long time the highest in the world before being surpassed by 3 other dams. In 2018, a Chinese dam, the Jinping I dam with its 305 m is the highest in the world. The dam producing the most electricity is the Trois-Gorges dam, as indicated above.
The use of concrete
The use of concrete allowed dams to rise at the end of the 19th century with, in 1872, the first concrete dam in Europe at Pérolles in the canton of Fribourg. The Hover Dam, along the Colorado River in the United States, was built in the 1930s during the Great Depression and is the first major dam ever built with a height of 220 m. It is remarkably built in only 4 years under much more difficult technological and human conditions than those we could have today. It is currently still in operation and at the same time a tourist attraction with 1 million visitors per year.
Video of the exterior and interior of the Hoover Dam.
How to be sure of the solidity of a dam?
Nowadays, the failure of a dam in Switzerland is a near-zero possibility due to the monitoring and verification technologies in place, and the dam could even be emptied as soon as worrying signals appear, as was the case for the Tseuzier dam in 1978, which was damaged by underground drilling.
In the past, a few disasters have left their mark on people’s minds. A disaster in the United States at the end of the 19th century. Two in Western Europe in the early 1960s and one in China in 1975.
- Johnston USA 1889
- Malpasset France 1959
- Vajont Italy 1963
- Banqiao China 1975
In the United States in 1889, very heavy rains caused the South Fork Dam in Transylvanie on the east coast to overflow and then completely destroy it. This earth and rockfill dam was 22 metres high and had a volume of 18 millions m³. This disaster, known as the “Johnstown Flood”, took the lives of 2200 people.
In Europe, the first disaster (1959 – 423 deaths) was the rupture of the Malpasset dam in France, releasing 50 million m³ of water due to high floods and multiple design failures such as a lack of anchoring in the rock. The second (1963 – 1900 deaths), at the Vajont dam in Italy near Venice, is not due to the failure of the dam but to a huge landslide in the dam’s reservoir that caused 25 million m³ of water to overflow. Fortunately, the dam remains intact after the disaster but is later disused. The danger in the event of an overflow of a reservoir is the erosion of the dam’s foundations by the force of the water, which can quickly cause the dam to rupture.
The rupture of a dam that cost the most lives occurred in 1975 in China with the bursting of the Banqiao dam causing the death of about 25’000 people directly and certainly more than 100’000 as a result of the epidemics and famines that followed and affected more than 10 million people. This disaster was long hidden by the Chinese government.
In the Valais, the threat could come from an earthquake that would cause a dam to break. Estimates have shown that the total rupture of the Grande Dixence would cause a wave 37 metres high in Sion, 2.5 metres in Martigny and another 2 metres in Villeneuve 6 hours later.
When should you visit a swiss dam?
Valais dams should be visited in summer or early autumn as most of them are inaccessible in winter due to the absence of snow removal from the access road or the risk of avalanches. This is particularly the case for the three highest dams in the Valais, the Grande-Dixence, Mauvoisin and Tseuzier dams.
The month of September is on average the month in which the reservoirs are filled to the maximum while the opposite is the month of April in which the reservoir can be filled to only 10% of its capacity. Still in spring, access is not necessarily ideal because of the ever-present snow and the almost empty water reservoir.
Plains dams such as Rossens or Schieffenen have a much less variable filling volume and are of course accessible all year round. Dams mainly produce electricity in winter and early spring while they fill up with water the rest of the year.
Pressure applied by water
In a hydroelectric complex, the pressure generated by the water must be accurately assessed. Here we will calculate the pressure at the bottom of a dam and explain how operates the water hammer.
What is the pressure at the bottom of Lac des Dix, the Grande-Dixence dam?
The simplified formula is as follows: which is the pressure applied to a point on the dam. (pronounced rho) is the density, 1000 kg/m³ for water. g is gravity, 9.81 m/s² and h is the height of the water above the selected pressure point. Let us take a water height of 227 m if the dam is completely filled and we therefore have a pressure of 1000 x 9.81 x 227 = 2’268’700 kg/s²*m. This unit is equal to the Pascal or N/m².
In summary, the force acting on the dam increases with the water level, which explains why the thickness of a dam is greater at its base than at its top. This is particularly striking on a gravity dam such as the Grande Dixence dam, where the thickness varies from 200 m (!) at the base to about 15 metres at the top. It should be noted that the force applied to the dam does not depend on the quantity of water in the reservoir.
The water hammer
Water hammer is a phenomenon of pressure build-up that occurs as a result of a sudden stop in the speed of a liquid when a valve is suddenly closed. In the case of a dam, this phenomenon can cause the failure of the penstock or infrastructure of the downstream power plant. To overcome this problem, an surge chamber is created, which is a vertical well connected to the pipe and which aims to absorb the excess pressure generated by the water hammer. The surge chamber is generally positioned between the inlet gallery that starts from the dam on a gentle slope and the penstock that goes to the power plant on a steep slope.
Is a concrete dam eternal?
No structure is eternal. In this case, there is not enough distance to give a life time since the first major concrete dams were built in the late 1950s. Although they are remarkably resistant, a concrete swelling problem called the “alkali-aggregate reaction” unknown at the construction time affects dams to varying degrees.
To simply explain this reaction, we can say that concrete is a mixture of sand, small stones, cement and water in very precise proportions that hardens some time after this mixture. In the agglomerate thus formed, small spaces are made up of water and air with a high pH which will interact with the silica constituting the sand and the small stones of the concrete by increasing the pressure causing a swelling and then a crack in the structure. This causes an alteration of the mechanical properties of the concrete.
The Salanfe dam in the Valais was particularly affected by this problem, so that work had to be carried out in 2013. These are only used to delay the spread of irreversible swelling in concrete that has been cut vertically over 1 cm wide with a saw. The incisions are gradually closing.
The Sixth Street Viaduct in Los Angeles, built in 1932, was demolished in 2016 due to particularly severe alkali-aggregate reactions that weakened its structure in a sensitive seismic region.
Some particularities of dams in Switzerland and around the world
In Europe and the US
The Vajont dam (261 m) is the highest in Italy, the Tigne dam (160 m), the highest in France and the Lac Oroville dam (231 m) is the highest in the United States. The latter is facing a serious problem in February 2017. Following heavy rains, weirs are used to avoid overflowing, causing erosion damage. The dam is not threatened, but the water may cause one of the damaged weirs to rupture, causing a wave of nearly 10 m. The situation returned to normal a few days later.
The last dam built in Switzerland is the Linthal dam. It was built in 2014 in the canton of Glarus and is the longest in Switzerland with a crown of one kilometre long and the highest in altitude in Switzerland but also in Europe at 2500 m. It is part of the Linthal pumped storage power station, which raises the water from Lake Limmern 630 m below.
In the world
The Three Gorges Dam has the most powerful hydroelectric infrastructure in the world but is not the largest dam in the world, in this case the Tarbella Dam in Pakistan. The latter is mainly composed of earth and rockfill, unlike Trois-Gorges concrete. The Kariba dam on the Zambezi River in Africa has the largest volume of water with 180 billion m³, 4x more than the Three Gorges.
The Atlantropa project
The Atlantropa project is one of the most colossal construction projects ever imagined. It is a gigantic dam 35 kilometres long designed by the German engineer Herman Sörgel in 1928 at the level of the Strait of Gibraltar separating the Atlantic Ocean and the Mediterranean Sea. The dam would have reduced water supply in the Mediterranean and thus created a difference in level allowing underground plants to produce huge amounts of electricity. The water level was expected to decrease by almost one metre per year to 100 metres for the sea part between Sicily and Gibraltar and 200 metres between Sicily and the eastern part. The 2 parts of the sea being separated by a dam between Sicily and Africa. Another dam was to be built at the Dardanelles to separate the Black Sea from the Mediterranean Sea. According to Sörgel, new land has emerged from the water, making it possible to have additional cultivable and habitable areas. For example, the Adriatic Sea would have almost disappeared.
Unfortunately, the project is not ecologically acceptable, which was not part of the considerations at the beginning of the 20th century. For example, the drop in the level of the Mediterranean Sea would have discovered new lands but they would have been difficult to cultivate because of the salinity of the soil. The salt concentration of the water is reported to have increased, causing disturbances to aquatic fauna and flora. Other problems would have arisen, such as access to coastal cities that would no longer have a port. More generally, the drop in water level would have had repercussions on the climate around the Mediterranean.
A travelling exhibition presented the Atlantropa project to the population in the 1930s, mainly in Germany. Sörgel was invited to the universal exhibitions in Barcelona in 1929 and New York in 1939. He even continued to promote it after the Second World War and died hit by a car on his way to one of his own meetings.
Un reportage vidéo sur le projet Atlantropa
Types of dams
The types of dams in Switzerland are as follows:
- Arch Dams
- Gravity Dams
- Buttress Dams
- Embankment Dams
Examples: Mauvoisin, Emosson, Tseuzier, Hongrin, Moiry, Toules, Rossens, Schiffenen and Montsalvens dams. Highest in Switzerland: Mauvoisin, 250 m.
This type of elegant dam allows part of the water pressure to rest on the rock faces. It is less concrete consuming and requires a relatively small distance between the walls.
The first arch-type dam in Europe is built in the middle of the 19th century by the father of the famous writer Emile Zola in the south of France. It is made of masonry.
Some dams such as the Hongrin dam have a double vault, the 2 vaults are separated by a rocky anchor. This dam is visible from the Rochers de Naye at the level of the Jardin Alpin La Rambertia.
Example: Grande-Dixence and Salanfe dams. Highest in Switzerland, Grande-Dixence, 285 m.
The dam alone supports the weight of the dam, which is triangular in shape in cross-section perpendicular to the crown of the dam. It requires a large quantity of concrete.
Little used in Switzerland, dam allowing large widths while saving concrete because the buttresses of the dam are arch-shaped. The two dams of this type in Switzerland are:
- Lucendro in Canton Ticino at 73 m high.
- Cleuson in Valais at 87 m high.
The Cleuson dam has the particularity of being of the buttress type despite its appearance which reminds us of the gravity type. This is because the spaces between the buttresses are filled with concrete to increase its strength in 1950, not to fight against water pressure, but to improve its resistance in the event of bombardment. The end of construction took place a few years after the end of the Second World War and images of the destruction of some dams during the war, particularly in Germany, are still very much in evidence at that time.
The Cleuson dam.
The Möhne dam near Dortmund was bombed by the Royal Air Force in 1943 during Operation Chastise. The picture was taken from an English plane. New bombs called “bouncing bombs” must be invented to destroy the dams and pass over the anti-torpedo protection nets. Source Wikimedia Commons.
Example: Mattmark. Highest in Switzerland, Göscheneralp, 155 m.
Barrage constitué d’enrochement ou de terre avec un noyau étanche en béton ou argile. Beaucoup plus large et limité en hauteur que les barrages en béton.
Comparative table of dams
Among all the dams in French-speaking Switzerland, the 12 highest were visited by La Torpille. In the table, the Three Gorges Dam in China is added for comparison purposes, it is the facility that produces the most energy in the world, all energies combined. To see the entire contents of the table drag the mouse on the right.
|Barrages||Grande-Dixence||Mauvoisin||Emosson||Tseuzier||Moiry||Hongrin||Cleuson ||Toules||Rossens||Montsalvens||Salanfe||Schiffenen||Trois-Gorges (Chine)|
|Link to attraction||Link||Link||Link||Link||Link||Link||Link||Link||Link||Link||Link||Link|
|Commissioning date [year]||1961||1958||1975||1957||1958||1971||1951||1964||1948||1920||1950||1964||2006-2009|
|123 (North) 95 (South)|
|Length [m]||748||520||555||256||610||325 (Nord)|
|Base thickness [m]||195||53.2||45||26||34||22?||80||20.5||28||22||40||14||115|
|Crown thickness [m]||15||12||8||7||7||3?||3.5 à 5||4.5||5||3?||5||7||40|
|Crown altitude [m]||2364||1971||1931||1777||2250||1255||2187||1811||670||802||1925||534||229|
|Crowning open to cars||No||No||No||No||No||No||No||No||Yes||Yes||No||Yes||No|
|Flood evacuator [m3/s]||?||107||60||36||62||100||145||355||430||12.2||1000|
|Reservoir volume [Mm3]||400||211||227||50||77||52||20||20||220||12.6||40||58.6||45'300|
|Reservoir area [km2]||4.04||2.08||3.27||0.85||1.3||1.6||0.5||0.60||9.6||0.74||1.85||4.25||1544|
|Reservoir length [km]||5||5||5||1.3||2.4||2.7||1.4||1.5||13.5||1.7||1.8||12.5||600|
|Concrete volume [1000*m3]||6'000||2'000||1'100||300||814||228 (North)|
|Max distortion [cm]||11||7||9||7||6||2.4||7.5||3.2|
|Galleries in dam [km]||32|
|Total water catchment area [km2]||420 (46 direct whatershed)||167 (198 with watershed after dam)||175 (34 direct whatershed)||18.7||MOTTEC|
29 Moiry dam
36 Tourtemagne dam
87: Navisence in Mottec
19: Torrent du Moulin
66: Navisence à Vissoie
45 East and West adductions
45 Hongrin et Petit-Hongrin
|23 (16 direct whatershed and 7 Tortin water collector)||78 (110 Orsière central)||954||173||31|
(Salanfe 18, Saufla: 13)
|Collectors [km]||100||About 13 (7.5 + 5.5)||47||20.8||2||5?||0||0||4||0|
|Lake name||Lac des Dix||Mauvoisin lake||Emosson lake||Tseuzier lake||Moiry lake||Hongrin lake||Cleuson lake||Toules lake||Gruyère lake||Montsalvens lake||Salanfe lake||Schiffenen lake||Trois-Gorges lake|
|Distance/Time around the Lake||Not possible because of east side||12km / 7h||?||4.7km / 1h10m||7.5km / 2h20||22.5km / 5h30||4km / 1h15||12.5km / 4h30||50km/14h35||10km / 2h45m||7km / 1h45m|
|River||Dixence||Dranse de Bagnes||Barberine||Lienne||Gougra||Hongrin||Printse||Dranse d'Entremont||Sarine||Jogne||Salanfe||Sarine||Yangtze|
|Remaining river downstream||❌||❌||❌||❌||❌||Yes||❌||❌||Yes||Yes||❌||Yes||Yes|
|Company name||Grande Dixence SA ou|
de Mauvoisin SA
|Electricité Emosson SA / CFF||Electricité de la Lienne SA||Forces Motrices de la Gougra SA||Forces Motrices Hongrin-Léman SA||Energie de l'Ouest Suisse (EOS)||Forces Motrices du Grand-St-Bernard||Groupe E||Groupe E||Salanfe SA||Groupe E||China Yangtze Power|
|Can be visited||Yes 15 francs||On reservation|
Free of charge
|No||On reservation||On reservation|
Free of charge?
Free of charge
Free of charge
Free of charge
|Central 1 [MW]||CHANDOLINE - 150|
|FIONNAY - 138|
Outdoor - 160
|CHAMARIN - 0.9|
|MOTTEC - 69|
|VEYTAUX I - 240|
|PALLAZUIT - 36|
|PIED DE BARRAGE 2 - 1.7|
|ELECTROBROC - 25|
|MIEVILLE - 70 Outdoor||PIED DE BARRAGE 1 - 70|
|RIVE GAUCHE - 9800
|Turbine||x? Pelton||3 Francis||2 vertical Pelton with 5 injectors of 80MW||1 Pelton||6 Pelton ( 3 alternators)||4 Pelton (2 alternators)||1 Pelton ?||1 Francis 1.7 MW||5x Francis||2 vertical Pelton 35MW||2x Kaplan||14x Francis 700MW|
|Flow rate [m3/s]||Stopped in 2013||3x 11.5||29m3/s||0.45||3x 4||4x 8||10||2||26||7.2||135|
|Pipe length [km]||Supply tunnel: 4.7|
Shielded penstock: 0.6 ?
|Supply tunnel: 9.8 + 0.27|
Shielded penstock: 0.92
|environ 3.5||Supply tunnel: 3.4|
Shielded penstock: 1
|Supply tunnel: 7.98|
Shielded penstock: 1.22
|Supply tunnel: 5.5|
Shielded penstock: 0.6
|Drop height [m]||1800||400||626||388||685||883||480||67||100 variable||1472 variable||45||90|
|Water intake||Dam||Dam||Bassin de compensation de Châtelard||Dam||Moiry and Tourtemagne dams||Dam||Dam||Dam||Dam||Dam||Dam||Dam|
|Flow||Rhône||Fionnay I tailpond||Rhône||Bisse d'Ayent||Mottec tailpond||Lake of Geneva||Tailpond||Sarine||Sarine||Rhône||Sarine||Yangtze|
|Year of commissioning||1934 (Dixence)|
1958 (Grande Dixence)
|Central 2 [MW]||FIONNAY - 290|
|RIDDES/ECONE - 225|
|VALLORCINE - 242|
|CROIX - 66|
|VISSOIE - 45|
|VEYTAUX II - 240|
|ORSIERE- 24||HAUTERIVE - 70|
|PIED DE BARRAGE - 0.18|
|PIED DE BARRAGE 2 - 2.5 Outdoor||RIVE DROITE - 8400
|Pipe length [km]||9||Supply tunnel: 15|
Shielded penstock: 2.45
|Supply tunnel: 1 + 0.5|
Shielded penstock: 1.1
[Shielded penstock: 0.5/1.89]
|Supply tunnel: 3.2|
Shielded penstock: 1.4
|Supply tunnel: 6.9|
Shielded penstock: 0.9
|Supply tunnel: 7.98|
Shielded penstock: 1.22
|Supply tunnel: 5.6|
Shielded penstock: 0.7
|Turbine||12 horizontal Pelton (6 alternators)||10 Pelton (5 alternators) ?||3 vertical Pelton with 5 injectors de 64MW|
[1 Francis 50MW]
|2 horizontal Pelton of 33MW||6 Pelton (3 alternators)||2 Pelton||4 vertical Pelton with 2 injectors ?||4x Francis||1x Diagonal||1x Francis||12x Francis 700MW|
|Flow rate [m3/s]||45||10x 2.8||29|
|9||3x 4||2x 16||8||75||0.5||5|
|Drop height [m]||800||1000||750|
|855||342||883||387||75 à 110||45||48||90|
|Dam||Mottec tailpond and Navisence river||Barrage||Palazuit tailpond||Dam||Dam||Dam||Dam|
|Flow||Fionnay II (166'000 m3) tailpond||Rhône||Châtelard-Frontière|
|Croix tailpond||Vissoie tailpond||Lac Léman||Dranse d'Entremont||Sarine||Jogne||Sarine||Yangtze|
|Year of commissioning||1958||1973||1958||2017||?||1948 (1902)||2013||1964|
|Central 3 [MW]||NENDAZ - 430|
|CHANRION - 28|
|CFF CHATELARD I et II - 110MW - Underground||SAINT-LEONARD - 34|
|NAVIZENCE - 70|
|SEMBRANCHER||PIED DE BARRAGE 1 - 0.6 Outdoor||CENTRALE 3 - 4300
|Prise d'eau||Fionnay II tailpond||Breney (before dam) tailpond||Dam||Croix tailpond||Vissoie tailpond and Navisence river||Dam||Dam|
|Turbine||12 horizontal Pelton (6 alternators)||1 pelton with 2 injectors?||3 horizontal Pelton with 1 injector 11MW (I)|
2 horizontal Pelton with 2 injecteurs 40MW (II)
|2 Francis 17 MW||6 Pelton (3 alternators)||1 Francis||6x Francis 700W
2x Francis 50W
|Flow rate [m3/s]||45||2x 5||16||10.5||3x 4||1|
|Pipe length [km]||16||Supply tunnel: 4.1|
Shielded penstock: 0.9
|Supply tunnel: 8.5|
Shielded penstock: 1.1
|Drop height [m]||1000||350||804||420||695||67||90|
|Flow||Rhône||Mauvoisin dam||Châtelard tailpond||Rhône||Rhône||Sarine||Yangtze|
|Year of commissioning||1958||1925 (I) /1972 (II)||1908 (2014)||1976|
|Central 4 [MW]||BIEUDRON/RIDDES - 1200|
|CHAMPSEC - 5|
|CFF VERNAYAZ - 107 Outdoor||MARTIGNY-BOURG|
|Turbine||3x vertical Pelton turbine with 5 injecteurs||2 Pelton turbines||3 Pelton with 2 injectors |
|Flow rate [m3/s]||75||1.2||17|
|Pipe length [m]||Supply tunnel: 15.8|
Shielded penstock: 4.3
|Drop height [m]||1900||550||645|
|Water intake||Dam||Les Creux tailpond||Châtelard tailpond|
|Flow||Rhône||Dranse de Bagnes||Rhône|
|Year of commissioning||1998||1928|
|Pumping station||Zmutt - 470m-86MW-17m3/s||Vallorcine power plant|
2x 9m3/s, 800m, 120 GWh/an
vers barrage Emosson
|Mottec: pump: 23MW||Veytaux I|
4 pumps, 32 m3/s
|4 pumps of 1MW and 0.5 m3/s||Clusanfe|
|Stafel - 212m-26MW-9m3/s||Châtelard II power plant|
31 MW, 4 m3/s, 800m
to Emosson dam
|Gietroz du Fond|
|Ferpecle - 212m (via Arolla) -21MW-8m3/s|
|Arolla - 312m-48MW-12m3/s|
|Cleuson dam - 165m|
|Pumped storage [MW]||In construction 2018|
Nant de Drance 900
6 Francis 150 MW
|Total Production [GWh/year]||2800 (2015)||700||1100|
(800 ESA + 300 CFF)
(Palazuit 100 + 130 Orsière)
|Total power [MW]||2700 (2015)||400||637|
(410 ESA + 217 CFF)
(36 + 24)
|Accumulated energy [GWh]||660||100|
|Drama/problem [year]||1999||1818 (before dam construction)||1978|
|Details||Pipe Break||Gietroz galcier||Major cracks in the dam||"Cancer" du béton|
|Records||Highest weight dam in the world|
World's most powerful pelton turbine
|Highest arch dam in Europe||Oldest horizontal and vertical arch dam in Europe||Most powerful dam in the world|