Flood waters are continuing to threaten hundreds of homes in the Montreal-area town of Rigaud.

Mayor Hans Gruenwald Jr. says about 400 residences could be affected by the surging water levels.

Gruenwald says river levels have risen by eight centimetres in the past two weeks and are expected to climb another five to seven centimetres today.

He says that means water could start entering homes through basement windows.

Thirty-one families have had to evacuate their homes and are being helped by family, friends and the Red Cross.

Flooding is also affecting homes in the borough of Pierrefonds-Roxboro on the western part of the island of Montreal.

Gruenwald said he is very concerned with the situation in his community.

"We are preoccupied with this high level, not just because of the level of the water," he said Wednesday. "We are preoccupied because, at that level, if we start having strong wind, either east wind or west wind, it will cause an enormous amount of damage."

The Red Cross has helped people in 31 Rigaud residences evacuate and the mayor urged others to follow suit.

"If anything happens and we need to give this service to evacuate them under emergency status at 2 o'clock in the morning with three feet of water in the street, it's not going to be very funny," Gruenwald said.

"This is not July, this is not August, when the water is nice and warm. This is serious business, very serious business."