If that of 1940 still lingers in the depths of some memories, the floods have deeply marked the history and landscape of our department. This major risk is the subject of increased vigilance. Vincent Darmuzey, head of the Water and Risk department of the Departmental Directorate of Territories and the Sea (DDTM), is responsible for directing studies relating to flooding: “ We produce very precise modeling maps based on known floods, such as that of 1940 for example. These scenarios allow us to anticipate river overflows, breaches or dike failures. This also allows us to establish an accurate risk diagnosis. »
The elements collected by the DDTM serve as a basis for drafting Flood Risk Prevention Plans, the famous PPRIs which haunt the offices of our municipalities. Often perceived as a major constraint for urban development, these PPRIs, put in place since 1995, are essential to protect populations from a very real risk. Almost the entire Roussillon plain is subject to flooding, yet dozens of municipalities do not yet have a PPRI. Several studies are currently underway downstream of the Agly, from Rivesaltes to the sea, on the Têt downstream of Perpignan and up to Salanque. A public inquiry will be launched in 2025 on the basin of the Basse and Castelnou rivers. Those of Tech and Réart will be the subject of a new update within 2 or 3 years.
« These maps and forecasts are also used by the services of the Regional Directorate for the Environment, Planning and Housing (DREAL) and the Interministerial Service of Defense and Civil Protection of the Prefecture (SIDPC) which is responsible for prevention. and crisis management. Each flood is different but it teaches us something. »
A culture of risk to instill
This is an unfortunate observation, our collective memory is very short. The last two floods, in 1940 and to a lesser extent in 1992, did not slow down urban sprawl. But, even more serious, the vast majority of OP residents do not seem to be aware of the risk, nor of the actions to adopt in the face of floods. In this sense, the Géorisk portal is a very comprehensive free resource that allows you to assess the risk of your home.
Several arrangements are possible to reduce the vulnerability of housing: placing electrical appliances above the flood level, reinstalling cofferdams (the “ tampes » of the houses of our ancestors), install non-return valves on the wastewater network, secure the diesel or gas tanks… Concerning single-storey residences, it is strongly recommended to install a raised floor which can serve as a refuge while waiting for help. There is assistance to make these arrangements if your municipality is located in a risk area.
In the event of flooding, it is important not to travel. Most of the victims of the latest floods are reckless drivers who were swept away by forcing the closed barrier of a ford crossing. It is therefore advisable to stay sheltered, prepare your anti-flood bag and go upstairs.
From aiguat to “Medicane”
This portmanteau word, Medicanecontraction of mediterranean et hurricanewas notably used to describe the floods which hit Libya in 2023. Meteorologically, it is indeed a tropical Mediterranean cyclone which is characterized by torrential rains.
The entire Mediterranean rim has always been subject to brief and intense floods. The rainfall readings of the Saint-Laurent-de-Cerdans schoolteacher in 1940 constitute a record (between 800 and 1,200 mm in 24 hours). With global warming, such a phenomenon could become more extreme. Tropical-type systems that formed a cyclonic eye were first identified in the Mediterranean basin in the 1980s. The increase in average sea temperature increases the risk: the warmer the sea, the more there is of evaporation which supplies energy to the possible cyclone.
The unique relief that makes our Catalan country so beautiful also constitutes an aggravating factor. As the mountains are close to the coast, the watersheds are very short and therefore prone to waterlogging.
