Some West Island residents on floodwatch

The small island of Ile-Mercier is home to only a few dozen residents, but each and every one of them is bracing for worst flooding in nearly two decades.

Right now the problem is the bridge that connects the island to Ile-Bizard, the rising Riviere des Prairies has started to slowly cover the low bridge in water.

The entire roadway could be submerged in the next few days.

The bridge is the only way on or off the island, so firefighters are keeping a close watch and are ready to order an evacuation if need be.

"If something happens on the island and we cannot go through the bridge we're in trouble, so they want to be sure that if ever the water level goes up too much on the small bridge they will think about the possibility of asking people to come out of the island," Normand Marinacci, mayor of the Ile Bizard Ste. Genevieve borough, told CTV Montreal.

Should the order be given, emergency housing has been setup.

"It's at the arena, it's open, and it's available if ever they have to leave their home. But there's no decision taken yet if they will have to leave their home," Marinacci said.

Marinacci added the water appears to have already made its way to some homes, and with more rain in the forecast it's likely going to get worse.

Sandbags have been deployed around the bridge to keep the river at bay for as long as possible.

The last flood that forced residents from their homes was in 1998.