"I watched my tank of heating oil rise up out of its concrete casing and just float away, like a boat."

Paulette Peythieu has spent a large chunk of her 83 years in the tiny village of Fos on France's mountainous southwestern border with Spain.

But she had never seen anything quite like the floods that, this week, left the hamlet devastated and cut off from the rest of the world.

"You know, I've been wiped out," the 83-year-old confessed on Friday after rescue services and Red Cross volunteers reached the village, three days after the Garonne river was transformed into a raging torrent, wreaking havoc across the Haute Garonne department.

Peythieu, who was born in the village of around 250 habitants, watched the devastation unfold from the first floor of her little house. "You cannot imagine how heartbreaking it was to see that," she said.

The pensioner's entire garden was covered by around 40cm (16 inches) of mud that was compacting hard as the water drained out of it.

On top lay two huge tree trunks, ripped from their roots in a telling indication of the raw power of the torrents that claimed three lives in the region this week.

One of the two bridges in the village was washed away after a loose tree trunk smashed into its central pillar. Weakened, the structure could not resist the tonnes of water sweeping down from mountain tops where unseasonally large deposits of snow had been quickly melted by a sudden spike in temperatures.

In the village's main street, Sebastien Gillet, 30, recounted how he had been forced to rescue his grandmother from her cottage, which was badly damaged by a gas explosion triggered by a leak that was caused by the speed at which the cellar was flooded.

"When the electricity came back on, that must have provided a spark and everything went boom," he said. "The floor on the ground level is wrecked and the windows have all been blown out."

Inspecting the large number of dead tree trunks and branches strewn across the village, a number of residents blamed the build-up of wood debris further upstream for exacerbating the damage.

"You are not allowed to touch anything in the Garonne but you have to be able to cut down dead trees and clear them out. I saw waves pass in front of me after the blockages caused by bits of trees gave way," Michel Berra, a retired teacher who was, like almost everyone else in the village, shovelling mud.

Rescue workers used motorised pumps to clear water from the worst affected properties and Red Cross teams were helping residents with cleaning up.

In the village post office, other volunteers distributed free food supplies provided by a supermarket located just across the nearby border with Spain.

And the local mayor was taking orders for prescription medicines to be collected and delivered by firefighters pending the reopening of the road into the village.