Historic rainfall hits Montreal in remnants of tropical storm Debby

Cleanup begins after major Montreal storm Residents in Montreal's West Island have begun clean up after a major rain storm hit the region on Aug. 9, 2024.

Communities across Quebec began taking stock of the damage on Saturday a day after the remnants of Hurricane Debby knocked out power to hundreds of residents and pummeled several parts of the province with record-breaking rainfalls.

The historic deluge that brought more than 140 millimetres of rain to the Island of Montreal washed out roads and flooded basements across Quebec. And provincial police in the Mauricie region said they're now searching for an 80-year-old pedestrian they fear was swept into the Batiscan River late on Friday after a nearby roadway collapsed.

Emergency services were called to the scene in the municipality of Notre-Dame-de-Montauban at around 11:30 p.m., but the area is currently inaccessible and dangerous, making it more difficult for police to conduct their search.

"Since it's impossible for police officers to search the riverbanks, drones are used to detect any element that would enable us to locate the missing individual," said Police spokesperson Camille Savoie.

Environment Canada Meteorologist Gregory Yang said the worst of the storm has passed, with remnants currently lingering over Anticosti Island in the province's Cote-Nord region and tracking eastward. Only 10 to 15 millimetres of rain are expected.

Yang described the rainfall as historic, not just for Montreal but likely for nearby regions like the Laurentians.

"It's very significant," he said.

Up to 173 mm of rain drenched the western tip of Montreal island on Friday, while 145 mm fell on the downtown area. Both totals shattered the previous single-day record of 102.8 mm recorded in the Montreal area in November 1996. Friday's rainfall also far exceeded the average quantity of rain for the entire month of August, which is 94.1 mm.

But other parts of the province saw even greater levels of precipitation. The municipality of Lanoraie in the Lanaudiere region of the province was lashed with 221 mm.

Quebec's Transport Ministry released a statement on Saturday saying the storm caused major damage to several roadways, with the Lanaudiere and Mauricie regions hardest hit.

A statement from the City of Ottawa also said some roads in the West Carleton and Kanata neighbourhoods were badly damaged.

The storm plunged hundreds of thousands of Quebec residents into darkness, and work was still underway to restore power. Just over 70,000 customers were without electricity as of 2 p.m. Saturday, down from the roughly 550,000 customers affected on Friday evening.

Outside Quebec, Fredericton was hit with 57.8 mm of rain when the storm moved east to New Brunswick, and more precipitation is in the forecast. Yang said the city could expect some showers on Saturday afternoon, but nothing as dramatic as what Quebec experienced.

Several municipalities in Ontario also saw their share of rain during Friday's storm. Summerstown received 117.9 mm of rain, while Kinburn, Cornwall and Ottawa each recorded 115.8, 95 and 74.7 mm respectively.

This report by The Canadian Press was first published Aug. 10, 2024.