Hautes-Laurentides | The Morier dike is holding up

The Morier dike, whose anticipated rupture forced the preventive evacuation of hundreds of people in the Hautes-Laurentides last winter, is holding up. Work carried out since December has made it possible to stabilize the water level in the dike, the government has just announced.

In a press release, the Ministry of the Environment, the Fight against Climate Change, Wildlife and Parks (MELCCFP) confirmed on Monday that the work carried out on the Morier dike “was successfully carried out”.

More precisely, adds the ministry, the work “had beneficial effects on the level of the water table in the area and, consequently, on the water level in the dike”. “Weekly monitoring carried out since the work was carried out confirms its effectiveness,” the authorities persist.

Last December, some 1,900 people had to be evacuated in the Hautes-Laurentides due to the possible rupture of the Morier dike.

Civil security had notably demanded the evacuation of the municipalities of Lac-des-Écorces and Chute-Saint-Philippe following the discovery, a few days earlier, of accumulations of water downstream of the structure. At that time, the last assessment of the dike was in 2019.

Earlier than expected

All this happened on December 3, just three weeks before Christmas, and forced the closure of several schools. Three days later, the Ministry of the Environment warned the evacuees that they would have to wait until at least December 17 before knowing whether they could return to their homes. They were finally allowed to do so three days earlier, on December 14, due to stabilization work going well.

Since December, a drainage trench at the downstream foot of the dike, in the area deemed “critical”, has been constructed. Wider security work was also carried out. According to the ministry, the final analyzes “confirm that the usual management of the Kiamika reservoir is safe.”

The infrastructure will therefore be monitored “in accordance with the parameters defined in its water management plan”, both for the spring flood period and for the summer period. In other words, “no additional constraints” will be imposed until further notice and the spring flood will be managed normally.

First built in 1954, the Morier dike is an earthen retaining structure 15.55 meters high and 678 meters long. It has a retention capacity of 382,000,000 cubic meters.

Several other dams have already failed in recent months in Quebec, causing flooding. This was the case in Sainte-Émélie-de-l’Énergie and Chertsey, in Lanaudière, during the spring floods of 2023. In Baie-Saint-Paul, last May, victims also saw their homes flooded in less than twenty minutes with the rupture of a protective dike in the city center.

With Vincent Larin, La Presse