The municipality of L’Islet experienced two significant coastal flooding events in 2020. On both occasions, private residences, heritage buildings, the natural shoreline and seasonal recreational facilities, such as campgrounds, were impacted. Prior to these flooding events, the community was also negatively affected, although to a lesser degree, by extended heat waves, lack of summer precipitation and associated drought-like conditions. Such droughts, as elsewhere in southern Quebec, raised concerns about water shortages for both domestic and agricultural uses in L’Islet. The summers between 2015 and 2017 were the hottest on record in the area.
The municipality of L’Islet collaborated with a citizen environmental committee, the ROBVQ (Regroupement des organismes de bassins versants du Quebec) and Le Groupe Conseil Carbone (CCG), a climate change consulting firm, to develop its vulnerability and risk assessment and adaptation plan. Historical climate hazards were investigated in order to evaluate the current and future effects of climate change on the municipality. Social, economic and environmental aspects were also considered in the evaluation of vulnerabilities and risks.
For the vulnerability and risk assessment, the municipality consulted with citizens to assess climate-related vulnerabilities and risks on soil use, water courses and municipal infrastructure in order to establish a “collective memory.” The goal was to use this citizen input to provide contextual insights on climate information.
Numerous physical, natural and socio-economic systems were identified as being vulnerable to climate related events within the municipality of L’Islet. The climate-related events examined included flooding, intense storms, damaging waves on the St. Lawrence River, heat waves, and drought. The resulting vulnerabilities included:
- Unstable and aging retaining walls on private and municipal property along the St. Lawrence River susceptible to shoreline erosion from high waves, high tides and seasonal flooding.
- Heritage buildings (e.g. churches, graveyard, several schools), including residences prone to flooding damage and a loss in heritage sites, which could negatively impact the region’s tourism.
- L’Islet’s aging population and agricultural labour force who are particularly exposed to extreme heat events.
- Migratory birds and other species affected by flooding, drought and intense storms, which could also affect nature-based tourism.
- Biodiversity loss, including possible loss of native species and an increase in invasive species and insect pests.
- The quantity and quality of drinking water from private wells and municipal sources being vulnerable to flooding events and subsequent runoff.
- Agricultural lands being susceptible to summer droughts and resulting crop loss.
A total of 29 social, economic and environmental risks were then identified, with the highest ranked risks being declines in agricultural crop yield, plant biodiversity reduction and damage, water contamination, increased need for building and shoreline maintenance, and damage to heritage buildings. Also highly ranked were an increase in the number of very hot days associated with heat exhaustion, heat stroke for exterior workers, accelerated shore erosion, and an increase in damaging coastal flooding events.