L’Aiguat
There’s a Catalan proverb: “Quan arriba l’aiguat, hi ha pas res de salvat”. When the aiguat comes, nothing is saved.
AIGUAT (prounounced aïgooat) is a Catalan word with no single word equivalent in English or French meaning exceptional rainfall and flooding combined.”
Autumn storms in the P-O
The P-O might not suffer terrifying hurricanes, like those in the USA and Caribbean, but its weather can still be dramatic, frightening and destructive.
Like other Mediterranean regions, our long dry summers are usually followed by a wet autumn.
When warm, humid air from the Mediterranean meets colder air higher up in the atmosphere, very unstable clouds can develop and deliver on average 30%-40% of our annual rainfall in just three months (September, October, November).
The real problem comes when there’s little wind to move those clouds on. Things start to get hairy when 200mm or more falls over a 24-hour period – something that happens once every 5-10 years in the P-O, according to Metéo France. Much more than this, and catastrophic floods can result.
The great floods of the Tech
Records of the River Tech’s regular floods date back to 1421. Over the centuries, many have been especially bad. In 1876, for example, between 17th and 20th October, houses were demolished, railway bridges destroyed, road bridges badly damaged, and two people drowned.
Sixty-four years later – bizarrely, over exactly the same period – the region experienced the most devastating and record-breaking aiguat of them all.
The aiguat of 1940
It was 1940. Over five days, from 16th October, nearly 2,000mm of rain fell in parts of the Canigou massif. On 17th October alone, 840mm was officially recorded in 24 hours at La Llau – already an extraordinary figure – although the rain gauge overflowed four times and the true total may have been closer to 1,000mm.
Witnesses said the Têt and Tech ran brown, black, sometimes reddish. Added to this, the smell of sulphur made some people think the water came from hell. On October 17th l’Indépendant ran the headline (referring to Vernet-les-Bains): “Hier Paradis des Pyrénées, évoque aujourd’hui un chaptire de l’enfer de Danté”. Paradise in the Pyrenees yesterday, Dante’s Inferno today.
Vernet was on Canigou’s north side, but the Tech valley on the south side fared worse. Hardest hit were Amélie-les-Bains (58 buildings flooded, 40 houses destroyed and 23 people dead), Prats-de-Mollo, Banat and Arles-sur-Tech. Roads were impassable, buried under 1m of rocks and stones.
The village of Le Tech was also devastated. The church of Notre-Dame-de-l’Assomption, the mairie and the school were swept away, along with the home of the teachers. Thirteen people were reported missing. The church was subsequently rebuilt higher up the village.
At Prats-de-Mollo, the disaster was compounded by a huge landslide at l’Avellanosa. Around two million cubic metres of earth and rock slid into the Tech, creating a temporary natural dam. When it eventually gave way, it sent a wave estimated at around five metres high down the valley. Remarkably, the scar of this enormous landslide can still be seen today before you reach Prats-de-Mollo.
Down on the plain, thousands of hectares of fields, orchards and vineyards were drowned under 1-1.5m of water. At Elne a railway bridge was destroyed. Here, the Tech, at its peak, was estimated to be flowing at 3,500 cubic metres per second!
Further downstream, the railway bridge over the Tech between Elne and Palau-del-Vidre was destroyed. A locomotive sent out during the night to inspect the damage disappeared when it reached the missing bridge, taking five railway workers with it.
We can only guess the devastation caused to plant and animal life. Over ten thousand trees alone were uprooted.
The total human death toll in the P-O was 48 – all in the Tech Valley – and hundreds lost their homes. Spare a thought for those across the border, though. In Catalonia, 320 died and thousands were left homeless.
The aftermath
It’s said there was the smell of death in valleys once rich and prosperous. After the waters receded, in places like St-Laurent de Cerdagne, which had experienced the highest rainfall, you could stand next to telegraph poles and touch the top, or sit on the edge of house roofs, with your feet touching the ground.
This was wartime, and the scene and response to it resembled the aftermath of a bombing raid. Many flood defences were put in place after that. At some point in the future they are likely to face another serious test. But these days there are more stringent warning, safety measures and evacuation procedures in place too.
The 2011 aiguat in the Vallée Heureuse
Destruction can be very localised, according to where the rainfall is most intense. The most damaging localised aiguat in recent years came in 2011, from a small river that rises in the Albères and runs through Sorède. This amazing video, compiled by Denis Spiral, shows the Vallée Heureuse like you’ve never seen it before.
At least six streams course down the flanks of Pic Néoulous and feed into the River Tassio, which in turn flows down the Vallée Heureuse, across two dams, and through Sorède.
By November 21st that year, four days of steady rain had already left the ground saturated, when a massive storm kicked off with a bone-rattling thunderclap at 9.30am, directly above Néoulous. For the next seven hours the rain was torrential, relentless.
The Tassio quickly turned into a raging brown torrent and by lunchtime had cut the valley off from the village. A swirling mass of boulders, stones and tree trunks gradually blocked a bend in the river until finally something gave way and debris-filled water surged, tsunami-like, down the valley, taking everything in its path, including parts of roads, bridge railings and a 100-year-old concrete footbridge.
It blew in the windows of a ground floor bedroom, swept away a garage, filled swimming pools with silt and rocks. Luckily, no one was injured, despite some people watching from positions dangerously close to this terrifying natural event – this aiguat.
Risks at the coast
There can be risks at the coast as well. Although the Med isn’t tidal, gales or a drop in atmospheric pressure can cause sea levels to rise in spectacular fashion.
When the skies clear
With the return of benign, clear skies, the violence of autumn storms can be hard to imagine if not experienced first hand. Winters can be dry by comparison. Come December, if there’s a cold snap, any rain turns to snow on the high slopes – often the first to stick on Canigou. But the weather changes fast here and you can never be sure when or where the aiguat may strike next.
Lesley McLaren is one of the “Warblers”. If you’d like to learn more about the natural world in this region, why not visit the Warblers’ Mediterranean Pyrenees website. Photos by the “Warblers” unless otherwise stated.
What an interesting article. Well done on the research.
I have been here long enough to have experienced 3 extremely wet autumns and seen the resulting danger and destruction.
Some of the remedial construction work since may have helped enough for me to hope for more rain to come soon – or perhaps I shouldn’t?