The dam overflowing should not be a problem—it is foreseen
En las sierras de Málaga, una presa construida hace más de un siglo para domar el río Gaudares se acerca, por primera vez en su historia documentada, al punto de desbordamiento. La presa de Montejaque —diseñada por un ingeniero suizo, levantada sobre caliza porosa que siempre traicionó sus propósitos— nunca fue lo que prometía ser; ahora, paradójicamente, acumula más agua de la que jamás retuvo. Más de 150 vecinos han sido evacuados, pero las autoridades recuerdan que el desbordamiento no es una catástrofe anunciada, sino una posibilidad prevista: el agua encontrará su camino a través de las cuevas del Gato y Hundidero, como el territorio mismo lleva siglos enseñando a quienes saben escucharlo.
- El nivel del embalse se sitúa a solo 30 centímetros del coronamiento, una proximidad sin precedentes para una infraestructura que históricamente nunca logró retener agua de forma estable.
- Más de 150 residentes de Benaoján han sido evacuados preventivamente, y la tensión se extiende a localidades vecinas como Jimera de Líbar, donde la incertidumbre pesa más que cualquier dato técnico.
- La Guardia Civil, la Unidad Militar de Emergencias, geólogos e ingenieros mantienen vigilancia permanente, mientras Endesa —cuya concesión está siendo cancelada— colabora en el seguimiento técnico hora a hora.
- Las autoridades insisten en que un eventual desbordamiento no implica fallo estructural: el agua se canalizaría hacia el sistema de cuevas Gato-Hundidero, que actúa como amortiguador natural antes de alcanzar cualquier núcleo poblado.
- La concesión de Endesa expira pronto y la presa pasará al municipio de Benaoján, consolidando su destino como monumento cultural e industrial más que como infraestructura funcional.
La presa de Montejaque, en la sierra malagueña, se encuentra a treinta centímetros de su coronamiento. Para una infraestructura que nunca logró mantener un nivel estable de agua, esta situación no tiene precedentes. Las autoridades andaluzas han activado el nivel de alerta dos, y el delegado del Gobierno en Andalucía, Pedro Fernández, se desplazó personalmente a la zona junto al alcalde de Benaoján y representantes de distintos organismos para evaluar el estado de la presa.
Más de 150 vecinos de Benaoján han sido evacuados de forma preventiva, con medidas similares en localidades cercanas como Jimera de Líbar. La Guardia Civil y la Unidad Militar de Emergencias mantienen vigilancia ininterrumpida, mientras geólogos e ingenieros analizan el terreno y el caudal acumulado. La delegada del Gobierno en Málaga, Patricia Navarro, ha tratado de tranquilizar a la población: si el agua desborda, no será un fallo estructural. El diseño de la presa contempla esa posibilidad, y el flujo se dirigiría hacia las cuevas del Gato y Hundidero, un sistema kárstico que absorbe y disipa el caudal antes de que llegue a ningún núcleo habitado.
La historia de esta presa explica mucho de lo que ocurre hoy. Construida en 1923 como el primer dique de arco de España, fue levantada en apenas nueve meses por un ingeniero suizo sobre un suelo de caliza porosa que nunca dejó de filtrar el agua. El embalse jamás cumplió su función como central hidroeléctrica: en invierno acumulaba algo de agua, en primavera y verano el nivel bajaba y los agricultores cultivaban el fondo expuesto. Con el tiempo, la presa se convirtió en atracción turística, con rutas de vía ferrata en su cara exterior.
Ahora, la concesión de Endesa está a punto de extinguirse y la infraestructura pasará al municipio de Benaoján. Su futuro parece orientarse hacia la conservación como bien de interés cultural e industrial. Mientras tanto, el agua sigue subiendo, las cuevas esperan, y una presa que nunca fue del todo lo que prometía afronta, quizás, el momento más singular de su centenaria existencia.
The Montejaque dam sits thirty centimeters below the point where water will spill over its crest. This is not a normal state for this particular piece of infrastructure. Authorities in Andalucía have been monitoring it around the clock, watching the water level climb in a way that has not happened before, at least not in any documented memory of the place.
On Thursday, Spain's government delegate to Andalucía, Pedro Fernández, traveled to the region to assess the situation himself. He came with the mayor of Benaoján, Guillermo Becerra, security officials, and representatives from various government bodies. What he found was a region operating under emergency alert level two—a status declared by the regional government of Andalucía. The people living nearby are anxious. The water keeps rising. More than 150 residents have been evacuated from Benaoján alone, with additional preventive evacuations in nearby towns like Jimera de Líbar. Fernández acknowledged the uncertainty and distress this has caused.
The Civil Guard and the Military Emergency Unit have established permanent watch over the dam. Endesa, the company that holds the operating rights (though those rights are now being terminated), works alongside government teams on technical monitoring. Geologists are studying the ground around the reservoir. Engineers track water flow constantly, trying to anticipate what comes next. Every hour, new data arrives about how much water has accumulated.
Patricia Navarro, the government delegate for Málaga province, has tried to calm public concern while being honest about the margins. If the water does overflow—when it does, perhaps—this is not a structural failure. It is something the dam was designed to handle. The overflow would not pour directly into populated areas below. Instead, the water would flow into a vast system of caves known as Gato and Hundidero, which sit downstream before any towns. These caves act as a natural buffer, absorbing and dispersing the water, reducing both its volume and its force by the time it emerges. "The dam overflowing should not be a problem," Navarro said. "It is foreseen and does not mean there is any structural fault. We have taken preventive measures so that if this overflow happens, the civilian population affected will be safe."
The dam itself has an unusual history. It was built in 1923 as Spain's first arch dam, designed by a Swiss engineer working for what was then the Hydroelectric Society of the Guadiaro. The company completed it in nine months—remarkably fast for the time. It was meant to hold thirty-three million cubic meters of water, though only thirty million could actually be used. The dam was supposed to generate electricity from the river Gaudares, which flows at about 951 liters per second.
But the dam never worked as intended. The ground beneath it is limestone, porous and thirsty. Water seeps through. The reservoir has never been able to maintain a stable level. In winter, small amounts accumulate. By spring and summer, the water drains away, and farmers in the region continue cultivating the exposed land—which has excellent soil for growing crops. Over time, the dam became more of a tourist attraction than a functioning power plant. People climb its face on via ferrata routes. A few days ago, firefighters had to rescue someone who got stuck on a zip line.
The concession that allowed Endesa to operate the dam is expiring. The infrastructure will soon pass to the municipality of Benaoján. In 2018, the town had to build a connecting road between the two sides of the reservoir—work that should have been Endesa's responsibility. The dam has been designated a site of cultural and industrial interest. The key now is to keep it in a condition that causes no problems upstream or downstream. The water rising to within thirty centimeters of the crest is unprecedented. Authorities say they are ready. The caves below will catch what spills. The people have been moved to safety. And the dam, which never quite managed to be the power source it was built to be, continues to hold its secrets.
Notable Quotes
The dam overflowing should not be a problem, because it is foreseen and does not mean there is any structural fault. We have taken preventive measures so that if this overflow happens, the civilian population affected will be safe.— Patricia Navarro, government delegate for Málaga province
The dam is absolutely monitored, day and night, 24 hours. Every hour we receive data on the water accumulation levels. If the water exits at the crest point, it would flow into an immense cave system that also serves to dissipate that water, so it would emerge in much less quantity and with much less force.— Patricia Navarro, government delegate for Málaga province
The Hearth Conversation Another angle on the story
Why does a dam that's been standing for a century suddenly have this problem now?
The dam was never really stable to begin with. The ground is limestone—it leaks. For a hundred years it's only held water in winter, then drained away. This is the first time it's accumulated this much, this high. Nobody really knows why now.
So it's not broken. It's just full.
Exactly. And that's actually the design working. The overflow is supposed to happen. The caves below are meant to catch it.
Then why evacuate 150 people?
Because you don't take chances with water. Even if the system is designed to handle it, even if engineers say it's safe—you move people first. You ask questions after.
What happens to the dam after this?
It stops being a power plant. It becomes a monument. The company's concession is ending. The town takes over. It's a piece of industrial history now, not infrastructure.
And the caves—they really can absorb all that water?
That's what the engineers say. The system is enormous. The water spreads out, loses force, comes out the other side much weaker. It's nature doing the work.
So this is actually a test of a design that's a hundred years old.
Yes. Built in nine months by a Swiss engineer. Never really worked for electricity. Now we're about to see if it works for what it was always going to do—let water through.