Train services have been disrupted and soldiers are preparing to assist as rivers across France continue to swell following heavy rain.
Meteo France, the national weather agency, said 23 departments remain on orange alert, the second highest level of vigilance, and urged people to limit their journeys and to be on the alert.
The weather has improved in large parts of the country, but more rain is expected on Thursday.
In the south-eastern Paris suburb of Villeneuve-Saint-Georges, which is crossed by both the Seine and its Yerres tributary, local mayor Sylvie Altman said soldiers will be deployed to help evacuate the population.
Police forces and the fire brigade are already on site, patrolling flooded streets on small boats.
Ms Altman told France Info radio that water levels are expected to keep rising until Friday.
“We should get military trucks to help us evacuate and make people move along,” she said.
West of Paris, the Seine River burst its banks in some spots and spread to almost twice its usual breadth between the towns of Saint-Germain-en-Laye and Le Pecq. The area is well downstream from Paris.
Forecasters said the Seine levels should keep rising until the weekend. The river is expected to reach a peak last reached in June 2016, when authorities were forced to close several Parisian monuments including the Louvre museum.
Roads along the shores of the Seine remained closed on Wednesday as well as seven train stations alongside the river.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here