Two Canadian provinces, Quebec and Manitoba, are facing flood emergencies.
At least 700 military personnel are in south-eastern Quebec to provide assistance with evacuations, sandbagging, and finding shelters for people forced from their homes.
The Richelieu River has reached record high levels and burst its banks in several places.
At least 3,000 homes have been affected with a third of them evacuated.
Farms and roads in the region have been washed out after the melting of an unusually heavy snowpack, combined with a week of rain.
Meanwhile in Manitoba, officials are scrambling to raise several dykes after learning that an unreliable water gauge was reading low.
The Assiniboine River is expected to rise by more than 30 centimetres in the next few days; rain is also forecast for the region.