“A situation close to normal”: the latest hydrological bulletin confirms summer trends

Tournée des sources du Larzac, le 10 septembre 2024. PNRGC

Les rares précipitations mesurées en juillet et en août n’ont pas agi sur la recharge des aquifères, explique le Parc régional des Grands Causses. 

The latest hydrological bulletin from the Grands Causses Regional Natural Park confirms the summer trends. This is a predictable observation after a summer when total rainfall did not exceed 79 mm (Soulobres weather station in Millau). Consequences: the rare rainfall measured in July and August did not affect the recharge of the aquifers.

The period of emptying of the karst reserves, which began in July, continued in August and is expected to continue for a little longer. As a seasonal effect, some aquifers are showing stable indicators, while others are showing a drop in levels.

In the north, on the Causse de Sévérac, at the Ségala and Bastide springs, the flow rates remained close to average throughout the season. In the east, despite a pronounced drop from June, the latest readings measured on the Durzon, the Cernon and the Sorgues also show flow rates close to normal.

Further south, at the source of the Céras in Brusque, after momentary peaks in the spring, flow rates gradually fell from mid-May, reaching levels slightly below average in August. Finally, at the source of the Taurin in the Raspes, the situation is equivalent, with decreasing flow rates and a slightly deficient hydrological balance.

The prefectural decree of August 14, 2024 establishing measures to restrict water use is still in force. It should be relaxed following last week's rainfall that contributed to river flow rates, but without any significant impact on groundwater resources.