Solutions for adapting to coastal erosion and flooding

Several solutions are possible to counter coastal erosion and flooding. For example, banks in eroding areas can be redeveloped by adding sediment such as sand or pebbles. This method of protection is known as beach nourishment. Nourishment reduces the effect of waves by widening and raising the level of the beach. These actions help protect buildings and infrastructure against coastal erosion and flooding.

We can also map coastlines to determine at-risk areas and locate infrastructure according to the level of risk of coastal erosion or flooding.

Several projects are helping to make Québec more resilient to coastal erosion and flooding. Here are just a few examples.

The town of Percé is particularly vulnerable to bank erosion. A project to rehabilitate the city’s promenade was carried out to protect the banks and infrastructure that had been damaged by major storms. The concrete wall along the bank was removed to create a natural environment less vulnerable to erosion. A beach nourishment with pebbles was carried out, creating a new promenade, as well as providing bank access and recreational facilities. 

The project has also enabled Percé to revitalize its downtown area, and its residents and visitors alike to reclaim the coastline.

A beach nourishment project was carried out to protect buildings and the road from coastal erosion in La Grave, in the Îles-de-la-Madeleine. By 2021, more than 75,000 tons of granular material was spread over a 640-metre extent along the coast. Waves can now break on a gravel slope, protecting buildings from erosion. A historic commercial building was also relocated as it was too close to the water line to be protected by the nourishment.  

The Institut national de la recherche scientifique (INRS) Environmental Hydraulics Laboratory is the only one of its kind in North America. This large laboratory, 120 metres long, 5 metres wide and 5 metres deep, can simulate waves, tides and strong currents. In this way, sustainable approaches to coastal management can be developed to counter the erosion exacerbated by climate change. This research allows, for example, to choose the right materials (pebbles, rocks, etc.) and test nature-based solutions to resist the onslaught of the sea.

To cope with rising water levels and the increased risk of coastal erosion and flooding caused by climate change, the municipality of Sainte-Flavie in the Bas-Saint-Laurent region had to choose a number of preventive adaptation measures based on the risks documented in different areas. In order to protect the safety of its citizens, it was compelled to demolish or protect several residences built along the coast. In addition, in order to protect the heart of the village and preserve its social, economic and cultural vitality, the municipality had to carry out 1.5 kilometres of beach nourishment work.