Lac de Villefranche-de-Panat

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Lac de Villefranche-de-Panat
Barrage de Villefranche-de-Panat 0616.JPG
From the barrage
Lac de Villefranche-de-Panat NASA.png
Location Aveyron
Coordinates 44°6′25″N 2°41′40″E / 44.10694°N 2.69444°E / 44.10694; 2.69444Coordinates: 44°6′25″N 2°41′40″E / 44.10694°N 2.69444°E / 44.10694; 2.69444
Type reservoir
Primary outflows L'Alrance
Basin countries France
Surface area 1.92 km²
Max. depth 17 m
Surface elevation 727 m

Lac de Villefranche-de-Panat (French pronunciation: ​[lak də vilfʁɑ̃ʃ də pana]) is a lake in Aveyron, France. At an elevation of 727 m, its surface area is 1.92 km².

It lies in the communes of Villefranche-de-Panat and Alrance.


The Lac de Villefranche-de-Panat is part of an electricity generating system where waters falling on the granite plateau of Lévézou that had drained unhindered into the Viaur and the Tarn river were captured and used by the power stations at Alrance and Le Pouget.

Diagram of the linked rivers, reservoirs, dams, pipelines, pumping stations and power stations.

Waters from the Vioulou fell, and waters from the Vaur were pumped into the reservoir at the Lac de Paraloup whence they passed through a 10.8 km steel lined tunnel to the Alrance power station and into the lake. Waters from three streams that fell directly into the Tarn at Le Truel, are pumped directly into the lake. From this lake tunnels were dug to the Lac de Saint-Amans where the waters drop 461m vertically to the power station at Le Pouget on the Tarn.

Alongside the dam

The Dam[edit]

This is a classic gravity type dam of earth lined with concrete.


Height : 43 m
Volume of the earth and concrete dam : 31 500 m³
Width at the base : 29 m
Width at the crest : 2,70 m
Length of the crest : 332 m
Volume of water retained : 10,9 hm³
Evacuation in spate : 48 m³/s
Évacuation method : a overflow channel
Discharge : 11 m³/s
Discharge : 1 butterfly valve

The tunnel leading from Villefranche-de-Panat to the Lac de Saint-Amans is 3.4 m in diameter and 4,690 m long.


The Alrance was dammed between 1948 and 1950.


The lake is used for boating, swimming, and Hydro ULM (microlight sea planes)