The Bassin de Saint-Ferréol (

Languedocien Languedocien (French name, ), Languedocian or Lengadocian (), is an Occitan dialect spoken in rural parts of southern France such as Languedoc, Rouergue, Quercy, Agenais and Southern Périgord. It is sometimes also called Languedocien-Guyennai ...

: ''Lac de Sant Ferriòl'') was created as the result of a large earth dam across the mouth of the valley of Laudot stream at St. Ferréol in the

Montagne Noire The Montagne Noire ( oc, Montanha Negra, known as the 'Black Mountain' in English) is a mountain range in central southern France. It is located at the southwestern end of the Massif Central at the juncture of the Tarn, Hérault and Aude departm ...

. It was originally proposed by

Chevalier de Clerville Chevalier may refer to: Honours Belgium * a rank in the Belgian Order of the Crown * a rank in the Belgian Order of Leopold * a rank in the Belgian Order of Leopold II * a title in the Belgian nobility France * a rank in the French Legion d'h ...

and accepted by

Pierre Paul Riquet Stele in Toulouse Cathedral Pierre-Paul Riquet, Baron de Bonrepos (29 June 1609 (some sources say 1604) – 4 October 1680) was the engineer and canal-builder responsible for the construction of the Canal du Midi. Background Paul Riquet was bo ...

as an integral part of the

Canal du Midi The Canal du Midi (; ) is a long canal in Southern France (french: le Midi). Originally named the ''Canal royal en Languedoc'' (Royal Canal in Languedoc) and renamed by French revolutionaries to ''Canal du Midi'' in 1789, the canal is considere ...

Riquet Riquet is a given name. Notable people with the name include: *Dominique Riquet (born 1946), French surgeon and politician of the Radical Party and MEP *François-Joseph-Philippe de Riquet (1771–1843), comte de Caraman was the 16th Prince de Chi ...

needed to provide a sufficient water reservoir to allow the

locks Lock(s) may refer to: Common meanings *Lock and key, a mechanical device used to secure items of importance *Lock (water navigation), a device for boats to transit between different levels of water, as in a canal Arts and entertainment * ''Lock ...

to function year round, even in the dry summer season. The dam was begun on 15 April 1667 and was completed in four years. It was the first dam built specifically to supply water to a navigable canal and was by far the greatest single work of civil engineering undertaken during the building of the

. The dam has a crest length of , a maximum height of , and a base thickness of more than . Water may be drawn from the reservoir via a stone vaulted tunnel that penetrates the base of the dam. Silt can be removed from the floor of the reservoir through the tunnel. When filled to capacity, the reservoir contains some of water. Originally, the basin was to be fed by only the River Laudot. When this was deemed to be insufficient, other streams fed into what Riquet called the " rigole de la montagne". Rigole is a diversionary channel. This stream would have included contributions from the River Alzau, River Vernassone, River Lampillon, River Lampy, and River Rieutort. The stream passed through the long, diameter Cammazes Tunnel on its way to the basin. The tunnel was built by the military engineer Marshall Sebastien Vauban in 1686–87. The entrance of the Laudot into the basin is split so that one portion goes into the basin and the other portion diverts around the basin and returns to the Laudot downstream of the dam. The waters released from the dam follow the downstream route of the Laudot until they join with the rigole de la plaine at Les Thoumazes. The waters continue to the

Bassin de Naurouze The Bassin de Naurouze is an octagonal holding tank, created during the building of the Canal du Midi as designed and built by Pierre-Paul Riquet. It was abandoned a few years after construction of the canal because of its recurrent silting proble ...

before entering the canal itself. Though

took credit for the water supply provided by the basin, much of the knowledge required was provided by

Pierre Campmas Pierre Campmas, of Revel, assisted Pierre-Paul Riquet in his earliest design of the Canal du Midi. He helped Riquet confirm that the valleys of the Montagne Noire The Montagne Noire ( oc, Montanha Negra, known as the 'Black Mountain' in English ...

, a fontainier, and François Andréossy, an hydraulics engineer. The lake lies in the three communes of Vaudreuille (

Haute-Garonne Haute-Garonne (; oc, Nauta Garona, ; en, Upper Garonne) is a department in the Occitanie region of Southwestern France. Named after the river Garonne, which flows through the department. Its prefecture and main city is Toulouse, the country's ...

), Les Brunels (

Aude Aude (; ) is a Departments of France, department in Southern France, located in the Occitania (administrative region), Occitanie Regions of France, region and named after the river Aude (river), Aude. The departmental council also calls it "Ca ...

) and

Sorèze Sorèze (; oc, Sorese ca, Sorese) is a commune in the Tarn department in southern France. See also * Communes of the Tarn department The following is a list of the 314 communes of the Tarn department of France. The communes cooperate i ...

( Tarn).

References

Gallery

Image:Lac St-Fereol 01.JPG, Release of dam water from Lake St. Ferréol. Image:Canal du Midi St Ferreol Dam.JPG, St. Ferréol Dam cross section. {{DEFAULTSORT:Bassin De Saint Ferreol Lakes of Aude Lakes of Haute-Garonne Lakes of Tarn (department) Canal du Midi Reservoirs in France