It was originally proposed by Chevalier de Clerville and accepted by Pierre Paul Riquet as an integral part of the Canal du Midi.

Riquet needed to provide a sufficient water reservoir to allow the locks to function year round, even in the dry summer season.

When this was deemed to be insufficient, other streams fed into what Riquet called the "rigole de la montagne".

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.

[2] The lake lies in the three communes of Vaudreuille (Haute-Garonne), Les Brunels (Aude) and Sorèze (Tarn).