Lemieux’s origins can be traced back to the mid 1850s when it started as a service centre for the local lumber industry and then as a farming hamlet. On the surface, the new town was a thriving area, but beneath lay what would eventually be its downfall.
The newly minted town was built on sensitive marine silts and clays, called Leda clay, laid down during the Champlain Sea around 10,000 years ago. On May 4, 1971, the unique soil gave way in nearby St. Jean Vianny, and a deadly landslide took 31 lives and 40 homes. After the catastrophe, the Geological Survey of Canada tested the soil in the region along the South Nation River and determined the small town of Lemieux, comprised of 28 homes and a local Parish, was in danger of experiencing the same type of slide.
In 1989, the South Nation Conservation Authority strongly recommended that Lemieux be relocated. Heeding the warning, the government relocated the residents – many who’d been there for generations – and bulldozed the buildings. The last building to be dismantled was the local church, the Parish of St. Joseph de Lemieux.
On June 20, 1993, two years after the town was officially abandoned, a low-angle slope failure occurred due to excessive rain. This resulted in a massive retrogressive landslide covering 17 hectares that swallowed the town’s former main street, creating a new bay on the South Nation River and dumping around 2.8 million cubic metres of debris into the Valley.
Since then the landscape of the scar has changed considerably, owing to the unstable erosion of the soil. In memorial, government officials erected a plaque at the location of Lemieux’s main street, now standing guard where a town used to be.