why is work being undertaken at the dam of this Lauragais lake?

See my news
Follow Voix du Midi Lauragais

They are not expected to leave the site until the end of November. Since mid-October – more precisely since Wednesday October 23, 2024 – construction equipment has occupied the access road and the edges of the Thésauque lake dam. This so-called “class C” structure – made up of a dike greater than 5 m and less than 20 m – allows, since the creation of the body of water between the municipalities of Montgeard and Nailloux in 1973, to retain no less than 33 hectares. But present however certain weaknesses.

“Total or partial failures of dams occur regularly. In addition to the risk for populations located downstream, they can cause significant material damage,” says the community of communes Terres du Lauragais. Enough to push the latter – under the authority of the Regional Directorate for the Environment, Planning and Housing (Dreal) – to undertake some work.

Preventive maintenance to ensure public safety

“It’s a kind of preventive maintenance,” explains Nicolas Fédouvice-president of Terres du Lauragais in charge of buildings and green spaces. “If there were to be a crack or a rupture, all the municipalities, up to the Canal du Midi and therefore Gardouch, would be flooded,” he adds.

Then, Thésauque is a very used and frequented lake whose primary vocation, let us remember, is tourism. We are obliged to intervene for the safety of the population.

Regularly, the community of municipalities therefore undertakes – as is currently the case – some maintenance or even rehabilitation work on the dam aimed at “maintaining compliance”. “The last ones were carried out in 2019”, reminds the elected official Voice of Midi Lauragais.

Various repairs and repairs

Requested by Dreal following an inspection carried out in July 2023, the work this time consists of “rehabilitate and strengthen the safety of the dam for better water flow,” informs Terres du Lauragais. “This involves reloading the anti-swelling layer, using pebbles, at the level of the water line and the flood spillway, and adding topsoil in order to consolidate the dike ( approximately 1,000 m³Editor’s note). »

The access path and borders will also be taken over, rehabilitated and replaced. The drain outlet at the foot of the downstream wall will be repaired. “The water is stagnating: the work will therefore be taken up again for improve water flow. This will involve widening and deepening the outlet. » Finally, the intermunicipality plans to secure access to the drain, at the foot of the downstream wall. “The narrow opening prevents safe access to the ladder. It will therefore be necessary to enlarge the opening. » Total cost of the operation? 94 000 € hors taxes (HT). The project, planned for one month, should be completed by the end of November.

Follow all the news from your favorite cities and media by subscribing to Mon Actu.