Water levels could worsen between here and Quebec City
There are still too many factors in play to predict when most of the flood water will recede in the greater Montreal area, but as it starts heading downstream, flooding could worsen in towns along the St. Lawrence River between Montreal and Quebec City.
Water levels along the Ottawa River, Rivière des Mille Îles and Rivière des Prairies either peaked Sunday or Monday, depending on the area, said Hydro Météo hydrologist Annie Lagadec on Wednesday. But it’s the towns along the St. Lawrence River that could now feel the effects as the water flows downstream.
Fisheries and Oceans Canada is predicting water levels in Lac StPierre, located about 60 kilometres northeast of Montreal, to increase by 15 centimetres by Friday.
“That may not seem like a lot, but the water levels in the lake are already 1.8 metres higher than usual,” said Denis Lefaivre, a research scientist with the department.
Communities around Lac StPierre have already been fighting off flooding brought on by high tides. The municipality of Yamachiche, located on the northern side of the lake, declared a state of emergency on Wednesday.
It’s only after passing the Quebec City region — where the St. Lawrence River widens enough to handle the increase in water — that the flow shouldn’t necessarily cause more flooding along its way, Lagadec said.
Strong winds and rising tides in Eastern Quebec are also slowing down the water’s natural path toward the Atlantic Ocean, delaying the decrease in water levels in certain areas.
Ultimately, Lagadec explained, exactly how fast the water recedes in some of the flooded areas also depends on how much rain falls across Quebec in coming days.
There are only minor rainfalls predicted for Thursday and Friday, but significant rain is expected for this weekend.
According to Environment Canada meteorologist Michelle Fleury, two low-pressure systems taking shape over Colorado and west of Lake Superior could merge over Quebec this weekend.
Montreal is expected to receive between 10 and 20 millimetres — “not alarming amounts,” Fleury said — during the weekend, while Eastern Quebec is expected to be hit with more than 20 millimetres.
“The amounts we’re expecting shouldn’t cause any more flooding,” Fleury said. “But they could slow down the rate at which the water levels decrease.”
The rain is expected to subside come Monday, Fleury added, and much-needed sunshine could be seen by mid-next week.