The prefect of the Ardèche has classified all the watersheds of the rivers of the department as being in crisis, with the exception of the Ardèche and Chassezac rivers in their downstream part. The flow of these two rivers is supported by water releases from the Lozère dams or the Ardèche plateau.
The rains that fell on Sunday did not change the situation
The rains that fell on Sunday did nothing to change the crisis situation that the department of Ardèche is going through. Many rivers experience extremely severe minimum flows. This is for example the case of La Baume in South Ardèche which experiences a flow of 180 liters per second at its confluence with the Ardèche at Ruoms, in other words a trickle of water.
EDF is currently releasing just over one cubic meter per second into the Ardèche via La Fontaulière. 250 liters per second are reserved for drinking water supply and irrigation. The rest is discharged into the river, the flow of which does not exceed two cubic meters per second as far as Ruoms.
After the confluence with the Chassezac, also supported by water releases from the Lozère dams, the flow of the Ardèche increases to 3 cubic meters per second, thus allowing canoeing from Ruoms to Saint-Martin- from Ardèche at the exit of the gorges.
EDF can support the flow of the Ardèche until August 27
Under current conditions, EDF explains that it can thus support the flow of the Ardèche until August 27. EDF must also return water to the Loire, which is also suffering from drought, including at its birth.
From September 1, EDF will be able to draw on the waters of Lake Issarlès, which must be maintained at a high level for tourist reasons until August 31.
In any case, the rivers and their fauna and flora suffer from these extreme conditions due to high temperatures and lack of oxygen. Some fish have been able to do well by taking refuge further downstream where there is still a little flow, explains Floriane Morena, director of the South Ardèche river management union (EPTB).