Dam threat could turn Quebec floods into once a millennial event

Published: April 27, 2019

Updated: June 3, 2019

Author: Luke Jones



What started as a severe but not abnormal spring thaw flood in Quebec has escalated to not only a once a generation event but a one-in-a-thousand-year catastrophe. Public security officials in the province have issued a mandatory evacuation of an area on the Rouge River near Montreal because a hydro dam is threatening to fall.

Simon Racicot, director of production and maintenance with Hydro-Quebec, said the game was only built to withstand a millennial flood. If the dam does break, the situation would suggest the current floods in Quebec are a once in a thousand-year event. The dam was constructed in 1942 and stretched across 60 meters and is 19 metres tall, built to hold back 4 million cubic metres of water.

“That means a flood that happens every 1,000 years,” he said.

“We are confident that the structure is solid,” Racicot said. “But the protocols force us to warn people of the danger. We are entering into an unknown zone right now – completely unknown.”

Public Security Minister Genevieve Guilbault said hydro utility in Quebec thinks the dam will withstand the water pressure and remain structurally sound. However, he says continued bad weather means the situation is fluid.

“But we are expecting more rain over the coming hours and days, so the water levels of the Rouge River can rise,” she said in Montreal.

Luckily the affected region is in a rural location, although Guilbault confirmed 23 homes and 38 cottages are located in the evacuation zone. Police in Quebec say they are aiding in the evacuation of 250 people in the area.

If the dam does rupture, Hydro-Quebec has ensured communities further downstream will be mostly untouched as waterfall will be minimal by time Rouge River meets the Ottawa River.