The Ardeche river and its main the Chassezac are capable of spectacular floods due to their volume and the rapid rise of their waters. These generally happen in spring as a result of the melting of the snow (but this situation is getting rarer, as the snow), and in autumn following the equinox around 20 September.
     The natural flow of the Ardeche in spring and autumn means a water level allowing a pleasant descent of the Gorges.
     However, in summer the level is low, but hydroelectric dams help maintain the Ardeche at a navigable level throughout the year.