On Wednesday, November 13, the Municipality of Les Coteaux invited residents of the Delisle River to an information session on its Interim Control By-law applicable to the banks of the Delisle River. The meeting took place at 21 rue Prieur and was attended by some forty citizens and various stakeholders.

In July 2023, a portion of rue Lippé in front of civic address 8 collapsed. Fortunately, no one was injured, but the street is still inaccessible in this sector almost a year and a half later. Many local residents are worried and concerned about the situation. Faced with this natural hazard, the Municipalité des Coteaux had no choice but to take action and adopt By-law 303 to limit work in the Rivière Delisle area.

The evening was punctuated by speeches from Mayor Sylvain Brazeau, General Manager Paméla Nantel and Assistant General Manager Audrey Caza. Sébastien Demers, Director of Urban Planning for the Municipalité des Coteaux, was also present. Experts familiar with the watercourse were also on hand to answer questions. They were Émile Farrell-Dessureault, Environment and Climate Transition Professional, Engineering, Infrastructure and Adaptation to Climate Change at the Fédération québécoise des municipalités; Michael Laverdière, Municipal Engineer, Engineering, Infrastructure and Adaptation to Climate Change at the Fédération québécoise des municipalités; and Dario Fernando Soto, Engineer, Team Leader - Geotechnics at Solamtech inc.

"The Delisle River area has been struggling with soil movement for a long time. It started back in the days of Coteau-Station, before the merger. However, over the past year or so, the problem has accelerated, which is why the municipality has had to take action and take precautions. That's why we have adopted By-law 303, which aims to regulate interventions and construction near the Delisle River", declared Mayor Sylvain Brazeau from the outset of the meeting.

Expertise sought from the Fédération québécoise des municipalités

Since it does not have in-house engineering expertise, the Municipality of Les Coteaux had to turn to the Fédération québécoise des municipalités for expert advice and support in this matter.

"Bylaw 303 is designed to protect residences located along the Delisle River and to limit the work that can be carried out there. It provides a framework for work on main buildings, accessory buildings and swimming pools, infrastructures, earthworks and miscellaneous work, subdivisions, sensitive uses and protective work to be carried out in these zones. The regulations define the risks and setbacks to be respected for each type of work to be carried out. In some cases, geotechnical expertise is required. These have been classified into four categories, and are intended to ensure that the planned intervention is not likely to be affected by a landslide, to reduce site stability or trigger a landslide, or that the subdivision is safe for future construction or use, or that landslide protection work is carried out in accordance with the best practices", said Mr. Demers.

For most projects, the setback is set at 40 metres. In some cases, it can be reduced to 20 metres, depending on the work to be carried out and the terrain where it will be carried out. For example, on a cantilevered lot, the setback is 20 metres. For tree felling, the setback must be 10 metres.

How was the setback, which many residents feel is excessive, determined? "From various analyses carried out over the past few months. Another process, a photogrammetric study, is currently underway and should enable us to adjust the setback if necessary. Using aerial photos taken in the past and superimposed on one another, this study enables us to estimate the recession of the Delisle River over the past 30 or 40 years. This will not only confirm the data obtained during the initial analyses, but also give us a good overview of the actual situation and a good picture of reality. We'll be able to foresee the river's future movements in the years and decades to come. The setback margin could therefore be modified as a result of this process," explained Mr. Laverdière.

Steps begun in 2023

In July 2023, the Municipality of Les Coteaux began work on the Rue Lippé project, following the collapse of the road. After an initial visit to the site, the municipal administration turned to the FMQ for assistance, particularly in terms of engineering.

It then applied for financial assistance from the Quebec government's Flood Resilience and Adaptation Program . At the same time, it applied to the Ministère de l'Environnement for a grant under the Programme de restauration et de création de milieux humides et hydriques (program for the restoration and creation of wetlands and hydric environments) in connection with the construction of a bypass road in the rue Lippé sector.

A grant application has also been submitted to the Ministère des Transports to finance part of the cost of building the bypass. As the budget for 2024 has been exhausted, the Municipality will submit a new application in 2025.

"The application was turned down because the program's budget had been exhausted. Our file was not sufficiently advanced to obtain funding at this stage of the project. The file is complex and we have to complete several stages, including geotechnical and hydraulic studies. This is a requirement of the Ministère de la Sécurité publique. We have mandated the firm Solmatech to do this. Quarterly visits, i.e. every three months, must also be made to the site to measure soil movements. The same company has been given this mandate, and must visit the site in spring, summer, autumn and winter. A report must be produced after each visit and forwarded to the appropriate authorities," says Ms. Caza.

Alongside these operations, the Municipality has also taken steps to acquire lots owned by citizens and VIA Rail, with a view to building a bypass in the coming years. On November 21, 2023, elected officials approved a resolution to create the future Rue Rémillard, which will serve as a bypass. Since then, several rights of first refusal have been filed for lots on Doucet, Bray and Lefebvre streets. Discussions are underway with Canadian National to acquire parcels belonging to them.

Shoreline characterization studies and a report containing scenarios and their costs were also drawn up in accordance with the requirements of the Ministry of Public Safety, and forwarded to them. "The MSP asked us to find alternative solutions and define their cost for the eastern and western sectors of the Delisle River. This is what we have done in the document. The MSP will then decide whether we can obtain a subsidy that could cover up to 85% of the investments to be made, depending on the scenario chosen," continued Ms. Caza.

Once it has received the MSP's response, the Municipality of Les Coteaux can go ahead with the engineering tendering process to implement the solution. “We could go ahead with a riprap operation or a bypass road," she says.

What about the collapsed portion of rue Lippé? "The plans and specifications will take several months to draw up, and the documents will have to be approved by the Ministère de la Sécurité publique and the Ministère des Transports. So we don't know exactly when we'll be able to go ahead with the reconstruction. This is a long-term project involving several government bodies. The municipality is continuing to take steps upstream to accelerate the file and be ready when we get a positive response,” she admitted.

Mayor Sylvain Brazeau agrees. "The municipal council is very sensitive to this issue and understands citizens' concerns. We're doing everything we can to get things moving quickly. We're looking into the possibility of setting up a financial assistance program to cover the cost of geotechnical studies required of citizens for certain types of work to be carried out on their properties. Details should be unveiled by the end of 2024."

Interested citizens can consult By-law 303 on the Municipalité des Coteaux website or via this link. If you have any questions, please contact Sébastien Demers, Director of Land Use Planning and Environment, at 450 267-3531, ext. 224.