On Saturday 1st March 1930, torrential rain started to fall on already saturated ground in Southwest France. Unseasonably high temperatures brought by southerly winds rapidly melted the thick mantle of snow that had fallen in late winter on the mountains. The River Tarn, fed by its swollen tributaries the Agout and the Tescou, began to rise on Sunday 2nd March, but no alarm was raised.
By the night between the 3rd and 4th March, the Tarn had risen to 12 metres above its normal level in Montauban, and the centre of the town was devastated. The flood put the electricity generating station out of action. Houses on both banks collapsed as the floodwater surged through the darkened streets. Afterwards, it was said that the right bank looked as if it had been bombarded. A thick coating of red mud covered the town.
The result: 25 people killed, 1,092 houses destroyed, 4,200 hectares of streets flooded and 10,000 people homeless. The number of deaths could have been higher had it not been for the bravery of some Montalbanais. A young industrial worker, Adolphe Poult, is reputed to have saved 100 people from drowning by picking them up in his canoe. Exhausted by his efforts, he drowned when his canoe overturned, ironically as the flood was starting to abate.
But worse was to come four hours later downstream in Moissac, just beyond the confluence of the Tarn and the Aveyron. The combined volume of the two swollen rivers shattered the levees and sent a wall of water crashing through the town, sweeping away people and buildings in its wake. In Moissac, 120 people were killed, 1,400 houses were destroyed and nearly 6,000 people became homeless.
Along the Aveyron
Along the lower reaches of the River Aveyron, the low-lying quarters of all the towns and villages suffered flooding and damage from the swirling, mud-laden waters. No doubt the river also carried along trees and other debris that would have aggravated the damage.
At Saint-Antonin, where the River Bonnette joins the Aveyron, the flood started at 13h00 on 2nd March. At Caylus, upstream on the Bonnette, 144 mm of rain had fallen in two days, the equivalent of about six weeks’-worth of rain.
By the following morning, the Aveyron had risen by 11 metres, swamping the bridge at Saint-Antonin. The river continued on its destructive course downstream, hemmed in by the steep gorges, taking the bridge at Cazals with it and causing massive destruction as it spewed out into the plain beyond Montricoux.
The French President Gaston Doumergue toured the worst-affected communes a few days later. According to contemporary reports, “He lost his legendary smile.”
Two questions were raised at the time: how did this catastrophe come about and why was there no warning?
A meteorologist, Maurice Pardé, drew up a detailed report about the origins of the disaster. He concluded that an exceptional set of climatic events, as I indicated in the first paragraph, had combined to cause the rivers to rise so high and so rapidly.
However, he warned that flooding could happen again and that the Tarn is “une des rivières les plus terribles de France.” People had been lulled into a false sense of security because the Tarn had not risen so high since the late 18th century.
Another reason for the lack of an alert was that the waters started to rise on a Sunday. The post and telegraph offices were closed. However, a telephone alert may not have helped. Not many people had a phone in 1930 and lines had been cut by falling trees and landslides caused by the appalling weather.
In addition, although the rain upstream was of almost Biblical proportions, downstream in Montauban and Moissac it was not especially heavy or sustained, so people had no cause for alarm. The rapid rise of the river took many by surprise.
Pardé recommended reforesting the mountain slopes to contain rainwater, constructing a series of dams and reservoirs, building higher embankments and bridges, reinforcing the buildings, putting in place an early warning system and monitoring rainfall more systematically.
In our time here, the Aveyron has flooded at Saint-Antonin, although not with such catastrophic consequences as in 1930. An automatic early warning system exists and some of Pardé’s other suggestions have been carried out. Even so, the practice of building on flood plains continues, and this has had dire consequences in other parts of France in recent years.
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