For this, he planned to recover the mountain waters in dams and reservoirs and then forward them to the Seuil de Naurouze through channels crossing the Seuil de Graissens. The water from the Sor passing near Revel was the main supply envisaged by Riquet. Other rivers from the Montagne Noire were also part of the system such as the Alzeau, the Laudot, the Rieutort, the Bernassonne, and the Lampy. The Montagne Noire is a region with twice the rainfall of the plain of Lauragais with 1400 millimetres per year at around 500-600 m above sea level. To store the river water he planned to create three basins: the Reservoir of Lampy-Vieux, a hexagonal harbour basin at Naurouze, and the Bassin de Saint-Ferréol with a large earth dam across the mouth of the valley of the Laudot stream.