The Bassin de Saint-Ferréol (

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

: ''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 (; , 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 departments. Its highe ...

. 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'ho ...

and accepted by

Pierre Paul Riquet 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. Early life Born as Paul Riquet in Béziers, Hérault, Fran ...

as an integral part of the

Canal du Midi The Canal du Midi (; ) is a long canal in Southern France (). 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 considered one of the g ...

. Riquet needed to provide a sufficient water reservoir to allow the locks 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 The critical feature of the Canal du Midi was to provide sufficient water to ensure that the lock system continued to function, even through the summer months. The first part of this endeavor was the ''rigole de la plaine'' (). It carried water f ...

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 Riquet 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 (; , known as the 'Black Mountain' in English) is a mountain ...

, a fontainier, and

François Andréossy François Andréossy (1633–1688) was a French engineer, cartographer, and a citizen of Narbonne. He was born in Paris on 10 June 1633. After completing his engineering studies in Paris, Andréossy went to Italy in 1660 to study Italian canal ...

, an hydraulics engineer. The lake lies in the three communes of

Vaudreuille Vaudreuille is a commune in the Haute-Garonne department in southwestern France. Population See also *Communes of the Haute-Garonne department The following is a list of the 586 communes in the French department of Haute-Garonne. The ...

(

Haute-Garonne Haute-Garonne (; , ; ''Upper Garonne'') is a department in the southwestern French region of Occitanie. Named after the river Garonne, which flows through the department. Its prefecture and main city is Toulouse, the country's fourth-largest. ...

Les Brunels Les Brunels (; ) is a commune in the Aude department in southern France. Population See also *Communes of the Aude department The following is a list of the 433 Communes of France, communes of the Aude Departments of France, department ...

(

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 " ...

) and

Sorèze Sorèze (; ) is a commune in the Tarn department in southern France. Population 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 in the f ...

( 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