Showers began overnight and the rain will get progressively heavier on Friday with rain continuing into Saturday. CTV is currently forecasting an accumulation of 30 mm of rain in the Montreal area, with more rain further west.

More rain is also expected in the Gatineau and Ottawa valleys, up to 50 mm, which will lead to rising floodwaters in Quebec as water flows downstream.

The already-high water has caused flooding and evacuations in Rigaud, in Trois-Rivieres, in Laval and parts of Montreal.

So far 19 houses have been evacuated on Ile Mercier, an additional dozen on Ile Bizard, and five houses have been evacuated in Pierrefonds.

While water levels in the West Island community rose swiftly Wednesday morning, the amount of water flooding neighbourhoods along the back river dropped slightly Thursday morning but was still enough to cause worry.

The water from the Riviere des Prairies has reached all the way to Pierrefonds Blvd., about 250 metres inland.

Residents, along with the borough mayor, were also upset to learn that earlier this week someone ordered the removal of sandbags that had been prepared and stacked near the river.

Borough Mayor Jim Beis said he would figure out who did that, but only once the current crisis was over.

Meanwhile people are also wondering exactly how the water got so high without warning.

"They weren't monitoring the situation. They're saying it breached around people's homes. Didn't they see some leakage?" said one man.

"It breached and then filled up this whole neighbourhood like a big pool."

Officials are advising people to call 3-1-1 if they need sandbags.

Crews in Pierrefonds, Ile Bizard, Sainte Anne de Bellevue and Ahuntsic Cartierville are reinforcing seawalls and have closed several streets to traffic because of flooding.

People in a zone at risk of flooding should be prepared to leave and pack survival kits including warm clothing, rain gear, identification and medication.

Officials also reminded people to keep propane-fueled generators outside, at least three metres from a house, so as to avoid carbon monoxide poisoning.

Some flood victims can get financial help from the province. A temporary office is set up Thursday in Papineauville, and people can also call the Public Security Ministry. More information is located here.