Haute Garonne. Water withdrawal restrictions in the department
The third water committee of the year in Haute-Garonne met on July 7, 2022 to take stock of the hydrological situation in the department.
During this meeting, the need to be vigilant and economical in the use of water was recalled, as well as the risk of severe low water levels in view of climatic consumption. With the arrival of a heat wave episode, Étienne Guyot, prefect of Haute-Garonne decided to introduce measures to restrict water withdrawals.
A significant drying up of rivers under the effect of the heat and the importance of withdrawals
Following stormy showers in the department in the second half of June, the flows of all the rivers at the beginning of July were above the minimum flows expected. As a reminder, destocking from the reservoirs had started early this year to compensate for agricultural levies.
However, with the very high temperatures and significant withdrawals, particularly for irrigation (estimated at 30 m³/s on the Garonne), the flows have already dropped sharply and early on the main rivers in the department. The strong replenishments initiated from the reservoirs make it possible to partially limit the drying up of these.
Despite very significant destocking from the hydroelectric reservoirs of the Ariège (representing a third of the water of the Garonne in Toulouse) for the low water level support of the Garonne, the flow of the Garonne downstream (at Lamagistère) is particularly low.
The forecasts of Météo France announce a scorching weather and without rain for at least another ten days. These therefore lead to great vigilance on the situation which is currently particularly tense with an early and intense low water level.
Consequently, the restrictions on withdrawals are reinforced on the small non-replenished and non-instrumented rivers of the department, with a total ban from July 16, 2022:
· small non-replenished and non-instrumented rivers are in total prohibition on the whole of the department at 100%,
· Tescou is in total prohibition of sampling;
· the rivers connected to the Neste canal and to the branch canals are on the alert. This does not imply restrictions but a strong incentive for all users to save water.
Writing