Officials say a 70-year-old German man who was helping to supervise children at one of the summer camps hit by the floods is missing.
Heavy rainfall is now threatening several French regions with flooding, including the French capital and outlying areas as the River Seine is forecast to reach or surpass the level that incurred serious damage in June 2016.
French Prime Minister Manuel Valls said that the full cost of week-long floods is still unclear and pledged a special fund for those worst-hit.
Red flood alerts were eased on Sunday as clean-up operations began in parts of north and central France with damage to rail network described as 'catastrophic'.
Several towns were under water Thursday, while Paris museums and a metro line were forced to close as forecasts were for continuing rain this weekend.
The floods have hit towns and villages from the north-central loiret region to the Channel coast, while in Paris the river Seine has spilled over its banks.
President announces state of 'natural disaster' in region, forecasters face criticism over weather alerts, police arrest 9 people for looting.
President François Hollande visited the region and expressed the 'solidarity of the nation' to those affected by the flooding tragedy.
Death toll could rise to 19 after violent storms sent water cascading through Antibes, Cannes and Nice.
Days of heavy rainfall followed by violent storms have caused flash flooding, with the southern Var département (county) hit worst.
The victims include a mother and child who died after their car was swept off a bridge amid flash flooding caused by exceptional rainfall.
About 300 people had to be winched to safety as for the third time in a month heavy rain caused havoc in the southern French city.
People forced to sleep in railway stations, airports and schools after up to 30cm of rain drenched much of the south of France.
The victims were on a campsite hit by a two-metre high wall of water caused by heavy storms in the Languedoc-Roussillon region.