Dam l'Aigle
| Dam l'Aigle | |||||||||||
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| Coordinates | 45 ° 14 '37 " N , 2 ° 13' 29" E | ||||||||||
| Data on the structure | |||||||||||
| Lock type: | Arch weight wall | ||||||||||
| Construction time: | 1941-1946 | ||||||||||
| Height above valley floor: | 84 m | ||||||||||
| Height above foundation level : | 92 m | ||||||||||
| Crown length: | 289 m | ||||||||||
| Crown width: | 5.5 m | ||||||||||
| Base width: | 47.5 m | ||||||||||
| Power plant output: | 349 MW | ||||||||||
| Data on the reservoir | |||||||||||
| Water surface | 7.50 km² | ||||||||||
| Reservoir length | approx. 25 km | ||||||||||
| Storage space | 220,000,000 m³ | ||||||||||
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The dam l'Aigle is a French dam located on the border of the Corrèze ( Nouvelle-Aquitaine region ) and Cantal ( Auvergne-Rhône-Alpes region ) departments. The structure dams the upper reaches of the Dordogne north of Argentat to form a 26 kilometer long reservoir . The plant was built between 1941 and 1946 and is one of the largest in France with a power plant output of 349 MW.
etymology
According to a local legend, eagles ( French aigle ) once nested in the rocks above the dam .
geography
The dam l'Aigle, French Barrage de l'Aigle (translated dam of the eagle ), is located on the right bank of the Dordogne river in the municipality of Soursac and on the left in the municipality of Chalvignac . The Dordogne forms the border between the Corrèze department (on the right) and the Cantal department (on the left). The closest town is Mauriac 8 kilometers to the east. To Argentat in the southwest it is 28 kilometers (as the crow flies).
The crown of the dam is at an altitude of 344 meters above sea level. The surrounding pen-leveled plateau landscape reaches average heights of 550 to 600 meters. The Dordogne flows at 260 meters above sea level, so it has cut itself 300 meters deep.
geology
The dam l'Aigle is located on the crystalline basement of the French Massif Central . Standing under the dam are very resistant orthogneiss - the Aigle orthogneiss . The Dordogne, which is dammed up to an average width of around 400 meters, cut into gneiss (biotite-sillimanite-gneiss and biotite-sillimanite-cordierite-alkali feldspar-gneiss) and migmatite (migmatite with green cordierite bulbs) to the northeast of the dam , which are from the series of belong to the middle Dordogne . These amphibolite facies metamorphic rocks here predominantly strike southeast (N 135 - subordinate also N 070) and dip at 35 to 65 degrees to the northeast. Most of the stretch lines run southeast-northwest. In the extreme north of the reservoir, the Ussel granite is still touched.
history
The design of the dam goes back to André Coyne and André Decelle, who later became General Director of EDF from 1962 to 1967. The construction work was supervised by the two architects Brochet and Chabbert. Construction began in 1941. The completion of the work was planned for 1942, but the work was delayed in order not to have to hand over the building to the German occupying forces. The dam was therefore only inaugurated on October 15, 1945 after the end of the war. Unit 4 went online on the same day, unit 3 followed in 1947, unit 2 in 1950 and unit 1 not until 1956. In 1982, the dam received an additional unit 6 hundred meters downstream of the dam.
description
The dam dams the course of the Dordogne, into which the Triouzoune flows on the right and the Sumène and Labiou flow on the left.
The dam type of dam is an arched weight wall over which a road runs. The wall forms a vertical cylinder with a 150 meter radius. The two flood overflows , which are provided with a bottleneck, flow into pools which, due to their ski jump profile, direct the water jet more than 50 meters away from the wall. Their flow rate is 4000 cubic meters per second. On the last helical section, the water jet is deflected into an almost vertical plane. This spectacular process enables the greatest possible dispersion of the water masses with a maximum capacity of 3800 cubic meters per second.
The reservoir is 25 km long and has a total capacity of 220 million cubic meters with a surface area of 750 hectares. The pent-up maximum height is 80 m. The dam itself is 95 m high and has a crown length of 289 m. It is 47.5 m thick at its base and then reduces to a 5.5 m thick crown.
The semicircular power plant forms a homogeneous whole with the dam and its two overflows. It is divided into four units, which are equipped with vertically arranged Francis turbines with a nominal output of 54 MW. In 1982 a fifth unit was added with a Francis turbine generating 133 MW. The additional unit designated as G.6 is located in its own building on the right side of the river 100 meters behind the dam and is located in the Corrèze department. The power station's substation is located on the plateau area 500 meters further west near the hamlet of Le Breuil .
The five units have an installed capacity of 349 MW. The dam l'Aigle is the most powerful EDF power plant in the Dordogne catchment area.
In the period from 2006 to 2012, the dam was serviced at a cost of 160 million euros.
literature
- R. Brousse et al .: Mauriac . In: Carte géologique de la France at 1/50 000 . BRGM, 1989.
Individual evidence
- ^ M. Roques (1941): Les schistes cristallins de la partie sud-ouest du Massif central français (doctoral thesis) . Imprimerie nationale, Paris 1941.
