A red alert for flooding in Finistère has been extended until tomorrow morning after high tides saw many streets in coastal and riverside towns flooded.
Météo France issued the red alert yesterday while much of the rest of Brittany was on orange alert along with Loire-Atlantique.
Residents in Quimperlé, Finistère, had been sand-bagging their homes to try to limit the damage but high tides early this morning saw floods washing through the town's streets, with around 50 homes and businesses affected.
More high tides are due this afternoon and tomorrow morning and authorities fear more flooding, with the rivers Oust, Blavet and Vilaine in danger of breaking their banks.
Anyone planning to use cross-Channel ferries should contact their company. Brittany Ferries has already cancelled some Plymouth-Roscoff crossings and today's 18.30 Cherbourg-Poole service has been put back to 20.30. The Portsmouth-Caen sailing on Monday is being diverted to Cherbourg due to port maintenance.
The new warning comes 10 days after the north of France was lashed by the Christmas storm and follows three days of heavy rain and violent winds.
Finistère, Morbihan and Ille-et-Vilaine had already been on orange alert but forecasters stepped up the warning for Finistère, saying the storms had left rivers very full and the winds were driving high seas. There was a very strong danger of people on the coast being swept away.
Météo France said water courses in southern Brittany were at danger levels and said there was a particular danger along the river Laïta in Quimperlé, which had been nearly two metres above its normal level
It had already burst its banks and flooded the quaysides in under 30 minutes. Police and fire crews had to act to move back hordes of sightseers who were in danger from waves swollen by the high tide.
On Wednesday a woman was killed when the winds blew a tree on to her car at Questembert.
At Trinité-sur-Mer in Morbihan a car was swept away by waves hitting the quayside. See a video on the BFMTV website