The clean up operation was underway in the Aude department on Tuesday a day after flood waters claimed the lives of at least 11 people.
With three people still reported missing the death toll could rise to 14.
Schools remained closed across the department, which was still on red alert – the highest weather warning – with several parts of the department still considered dangerous due to the flood waters.
The department will remain on red alert until Wednesday when it is hoped the flood waters will have sufficiently receded.
Red alert means the public are advised to avoid travelling and take extreme precaution. Authorities in the Aude warned motorists not to risk driving on submerged roads and told people to avoid drinking tap water.
Vigicrues, the government organisation that monitors floods said it was still possible rivers could burst their banks and that road and rail travel could be complicated given the number of roads blocked.
Some 1,500 homes remained without power on Tuesday morning while on Monday evening some 10,000 homes were without drinking water.
The Red Cross has launched an appeal for donations to help them deal with the “considerable damage”.
“From the very beginning, the teams of the Aude Red Cross and neighboring departments have mobilized to ensure their missions of support to the local population,” a statement from the Red Cross said.
The town of Trebes (see below) was hit particularly hard by the floods overnight on Sunday with at least six residents known to have died.
The town was also hit by tragedy in March when a jihadist went on a murderous rampage that included shooting dead two people at a supermarket in Trebes before being killed by police.
Reports in France said one woman who lost her husband in the terror attack also lost both her parents in the weekend's floods.
As well as the six victims in Trebes, two people died in the village of Villegailhenc, one in Villardonnel, one in Vallalier and one in Carcassonne.
Residents in the region have expressed anger over what they see as a failure on the part of local authorities and police to warn people as the flood waters were rising on Sunday night.
The Aude department was only placed on red alert (Vigiliance Rouge) at 6am on Monday morning when the heaviest rains had already passed and rivers had burst heir banks.
One resident of Trebes, whose house was flooded, showed his anger during a visit by Prime Minister Edouard Philippe on Monday evening asking why weren't people warned in advance.
“There was a moment when you have to say 'OK this could be dangerous',” he said.
“Can no one keep an eye on the River Aude and send the firefighters into the street to tell people 'Get out of your homes, we are evacuating you'?. Could no one do that?”
The mayor Trebes Eric Ménassi responded: “The tragedy that we have been through was impossible to predict and overwhelming.”
“We were on the ground with my team since midnight. The heavy rain came at around 2am in a way that as sudden and extreme.”
PM Philippe said the extreme weather was “unpredictable” and said all the local services were mobilised to deal with the tragedy.
The storms were triggered when a front of warm and humid air from the Mediterranean Sea slammed into colder air around the Massif Central mountain range, inundating an area from the eastern Pyrenees to Aveyron further north.
This well-known weather pattern occurs three to six times a year in the region and nearly always triggers flash flooding.
But the French weather forecasting service, Meteo France, suggested these episodes had recently become more frequent and more severe.