As the winter snows began to melt in April 2022, multiple severe landslides occurred throughout the extensive Saguenay region, creating significant public security risks. The City of Saguenay tasked Englobe with conducting a thorough analysis of multiple embankments to identify potential landslide risks. We detected major cracks in a La Baie embankment, worsened by heavy rains comparable to those during the Saint-Jean-Vianney disaster, and an initial preventive evacuation of 6 homes was conducted.
Next, an investigation jointly led by Englobe, the City of Saguenay and the Quebec Minister of Transportation and Sustainable Mobility’s (MTMD) Geotechnics and Geology Department (DGG) was launched. Our worst fears were confirmed when on June 13, a landslide did occur and a regional state of emergency was declared. From this moment, Englobe, thanks to its expertise and the quality and dedication of its professionals, played a crucial role in the outcome.
In a world of growing technical hyper-specialization, Englobe broke new ground by acting as an agile and flexible integrator, capably managing both the human and technical aspects of an uncertain and complex situation from end to end while restoring residents’ peace of mind and enabling them to begin healing their community.
Putting people first
In this time of crisis, our top priority was to protect the lives and human dignity of those impacted by the disaster. The early preventive evacuations carried out in April saved the lives of the residents of the home destroyed in the June 13 landslide. Our geotechnical analyses identified the soil’s clay-rich composition as well as the retrogressive nature of the landslide, which could potentially lead to further landslides in the form of deadly mudflows.
We significantly expanded the risk zone and oversaw a total emergency evacuation of 83 homes, potentially saving 230 residents. By eliminating considerable weight, this process also served to further stabilize the unpredictable clay soil, which had been weakened by heavy seasonal rains. Our supervision of the stabilization work in the risk zone enabled the securing of municipal buildings, pharmacies, banks, supermarkets and a water purification plant, thereby preserving local jobs, access to essential services and, above all, residents’ day-to-day lives.
The disaster’s high media profile, the state of emergency declared in the municipality and the region’s history with this type of crisis severely tested the residents' resilience. Given Englobe’s proximity to the community, we played a reassuring and humanizing technical role. We intervened on over 50 sensitive sites presenting similar risks during the same period, managed citizen concerns, took part in the evacuation and eventual destruction processes at the seven at-risk residences, helped remove affected citizens' property, and mobilized all required human and material resources.
Once the Minister of Public Safety (MSP) declared the regional state of emergency, we had to manage a chaotic social environment, marked by public anxiety, by rapidly mapping and operationalizing critical initiatives within a detailed, workable project. Supporting and collaborating closely with experts from the City of Saguenay, the MSP and the MTMD, we immediately mobilized a province-wide multidisciplinary team, and structured their work in accordance with precise project stages subject to established contractual standards.
Working with municipal and provincial stakeholders proved challenging, requiring us to navigate varying process velocities and complex administrative structures to obtain the various project requirements in a timely way. By creating a robust operational chain, we provided swift, priority access to the decision-makers and resources needed to complete the project. According to David Boily, Director Engineering - Civil Infrastructures “with the sheer number of people involved, the tight deadlines we had to meet, and the seriousness of the situation, it was essential to facilitate access to the human and material resources needed to bring the project to fruition”.
Worsening weather conditions also complicated our mandate. The onset of ground frost, heavy snowfall, and rapid snowmelt created ideal conditions for additional potential landslides on a regional scale. As the entire, vast Saguenay region was under the same state of emergency, we were also required to simultaneously manage similar events with extreme efficiency and within very tight deadlines.
Moreover, we wanted to minimize the likelihood of media noise and leaks in this extremely high-profile situation. As a result, we centralized and streamlined information into a weekly compendium, while ensuring the interventions carried out by municipal officials operating in the purpose-built crisis cell were technically and administratively correct.
Restoring the land and local dignity
As the landslide had seriously damaged a significant area within the La Baie region, restoring its dignity and beauty was essential. Initially, we employed the conventional method of using rock to stabilize the soil. Leveraging our expertise in phythotechnology, we enhanced this technique by integrating vegetation concepts. This method was doubly successful as it not only improved and embellished the environment with added finesse but was also ideally adapted to the soil's uniquely clay-heavy composition. In fact, the transplanted plant species’ root systems not only helped restore and strengthen the damaged embankment, but also serve to accelerate soil draining during heavy rainfall, thus reducing the risk of clay liquefaction which can generate dangerous mudflows. In this way, we ensured the sustainability of the damaged soil while efficiently preventing similar disasters in the future.
We also wanted to thoroughly study the local ecosystem and understand its composition in order to accurately restore it to its original state. Following analysis, we opted to use locally sourced native species such as white spruce, balsam fir, jack pine, ninebark, and dogwood. By combining civil engineering and agronomy, we successfully rehabilitated the damaged environment, restoring its safety, dignity and original panache in a way that removed any trace of the disaster, at minimum cost to the environment and the collective psyche.