The Mequinensa dam (Baix Cinca), on the border between Catalonia and Aragon, is a key strategic infrastructure, with the capacity to regulate the flow of the Ebro river in its final section, up to the mouth, in the Ebro delta, and laminar large avenues of water to avoid flooding. The structure is periodically reviewed with state-of-the-art technology to ensure its safety.
The largest reservoir in the Ebro river basin, inaugurated 60 years ago, presented its first emergency plan yesterday, with the assistance of mayors and heads of the competent administrations. Until now, the law did not oblige dams to have evacuation plans and systems. Mequinensa is the first Catalan swamp that has done its homework.
Without the desire to cause alarm, but with the aim that the residents of the ten nearest municipalities know what to do in a hypothetical emergency situation. Endesa, owner of the Mequinensa dam and hydroelectric power station, yesterday organized the first day of dissemination of the plan together with Civil Protection officials from the Generalitat and the Government of Aragon. It has started with the Aragonese municipality of Mequinensa.
The most extreme case, with foreseeable catastrophic consequences, is the breaking of the dam in the swamp. The enormous avenue of water generated would affect ten municipal terms between the two communities, six of them in Catalonia: Granja d'Escarp, Massalcoreig, Almatret, La Pobla de Massaluca, Riba-roja d'Ebre and Seròs. This would require a rapid evacuation of the population and to move it to the highest points of the urban centers.
The sirens sounded yesterday morning for the first time at the highest part of the Mequinensa dam, right where the emergency room has been installed. From here, with redundant communication systems, the first alert would be sent to the affected municipalities and the sirens would be activated in the worst case scenario. The three Catalan towns most affected (La Granja d'Escarp, Massalcoreig and Almatret) would have half an hour to react, while the rest would have a margin of two hours.
The breaking of the dam is the most extreme situation, highly improbable, but a reservoir like Mequinensa must anticipate other emergency situations. One of the scenarios that must be taken into account by the Civil Protection teams and the owners of the marsh itself is a large flood of water in the Ebro, upstream, that overflows the capacity of the dam. In this case, the swamp would have to drain enormous volumes, which would cause flooding in the municipalities located downstream, first in the areas closest to the river, in the Catalan section of the Ebro.
The climate emergency, with episodes of torrential rain increasingly likely, forces those responsible for emergency plans to foresee new scenarios. "The climate emergency means that we have to update the models and forecasts every five years", explains Francisco José Conesa, head of dams at Endesa.
"For natural phenomena, such as torrential rains and large floods, we have to foresee the affected areas and the way to warn and evacuate the population", highlights Álvaro González, head of the Directorate's Implementation Service General of Civil Protection.
