Several areas potentially exposed to landslides in La Baie



Here is how the president of the borough of La Baie, Raynald Simard, spoke this week about the sector overlooking the landslide that occurred on Monday, in the sector of 8e and 9e avenues.

This event is reminiscent of other more tragic dramas that occurred in the region, such as Saint-Jean Vianney in 1971 or the flood of 1996, where a landslide in La Baie on McNicoll Street cost the life of two children.

For his column In the rear view mirror on the show Public placethe journalist Michel Gaudreau was interested in the phenomenon of ground movements and in particular in the mapping of risk areas in Saguenay and the interventions that have been made to stabilize or secure the ground.

In particular, he spoke at length with Denis Coulombe, former director of the urban planning department at the City of La Baie during the flood, as well as with Raynald Simard, who also worked as a building inspector in the urban planning department. at that time.

In the aftermath of the 1996 flood, maps identifying the areas at risk were produced.

Risky places

Such a census is accessible today everywhere in Quebec by a tool called Zone potentially exposed to landslides (ZPEGT), accessible on the Data Quebec site.

It is very obvious, on this map, to see the extent to which the Bay sector has many high-risk areas, including the one where the landslide took place.

On this map, the areas in red show the slopes. Those in pink show the lower and upper slopes. It was in a pink and red zone that Monday’s slide occurred.

The scene of the landslide as it appeared on Thursday, three days after the embankment fell off.

Photo: Courtesy Jonathan Ouellette

This is why at the first signs of a crack on April 26, Saguenay and the Quebec Ministry of Transport as well as a specialized firm, Englobe, had decided to secure the bottom of the embankment and evacuate residents.

The decision was salutary, believes Raynald Simard.

It is clear that it saved the lives of people, the intervention that was made by the City and the decision that was made by our services. Then I can tell you that we were criticized a little in relation to this intervention. People called us cowards and said: “Hey, it’s been like this for 30, 40, 50 years, and then we don’t have a problem with it. But I think today that these people are proud and congratulate the City for having made this intervention, expressed Raynald Simard, who represents District 13, where the landslide occurred on Monday.

A geotechnical study before work

Always relative to the map ZPEGTin a red zone, there is no construction permitted unless an approved geotechnical study and stabilization work is carried out.

Without these, it is not allowed to dig into an embankment to add a shed and enlarge its land.

As for the areas in pink, for example at the top of an embankment, it is necessary to ask for a technical opinion to build a gazebo or a swimming pool at the top of a slope or to build a shed there.

Fences have been installed at the corner of 8th and 9th avenues, in La Baie.

Photo: Radio-Canada / Philippe L’Heureux

Denis Coulombe, as former deputy director of urban planning and then director general of the borough, says he has issued hundreds of technical opinions in recent years.

Councilor Raynald Simard goes in the same direction.

Each intervention that was requested by a citizen or an owner for any intervention on his land, either the development of a swimming pool or the enlargement of a patio, always had to be validated by a geotechnical expertise carried out by a specialized firm. . The permit was conditional on this report and in addition the first request was always paid by the City, continued the president of the borough.

It remains to be seen whether everyone respects the procedure and asks for permits.

Some might want to level a slope or lengthen it and thus put pressure on the slope. Others can cut into the bottom of steep slopes, which is prohibited, to build a shed there, for example. These are very sensitive areas.

A building ended up on its roof when the ground slipped.

Photo: Radio-Canada / Louis Martineau

Each intervention becomes major, we had small training courses offered precisely by specialists in this [qui nous disaient] that even passing the mower on the top of an embankment represents an immense loadrecalled Raynald Simard.

The 1996 flood in memory

According to him, it is difficult to say how many people are delinquent, but he believes that people are still responsible in general and have the flood of 96 in memory.

There’s never been an inventory made of that [des gens délinquants], me in any case to my knowledge, people took these areas seriously. The deluge left terrible scars on the population, compared to the large scree that there had been in the Grande-Baie sector and when these maps were publicized, it was realized that Grande-Baie is not not the only sector that is organized like that, that there are other sectors that could be problematic. I think people took it seriouslychained the one who is at the heart of a second term as a municipal councilor.

Raynald Simard is the councilor for district #13, in La Baie.

Photo: Radio-Canada / Claude Bouchard

Remember that the sector where the landslide occurred had already been the subject of stabilization work in 1991. Houses had been evacuated on the 8e av.

The municipal council of La Baie and its mayor, Claude Richard, had at that time ordered a soil study. It had been produced by the firm Laboratoires SL.

The general manager of this company at that time, Joachim Simard, remembers today that following the study, the embankment had been reinforced from below using reloading.

During the interview this week, he says he found that this embankment withstood the deluge of 1996, but not the rain of last Monday.

The analyzes will dictate the continuation

Ongoing studies will determine who can return to their home and who will have to leave, in which case compensation will be paid.

For those who stay in their home, Denis Coulombe mentioned that they will be able to have papers demonstrating the security of their land, so as not to affect the resale value of their property.

The authorities and the evacuees of La Baie had discussed the financial assistance offered on Thursday.

Photo: Radio-Canada / Louis Martineau

The analyzes will also dictate what type of stabilization work will be required.

But one thing is certain, according to Raynald Simard, it is no longer possible to allow building without worrying about the surrounding environment.



Reference-ici.radio-canada.ca

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