Residing Unawares in a Basin-Like Structure: Unintentional Existence in an Enclosed Space

Rewritten Article:

Soaked twice in two years, Haissam Halawi decided to block off the entrance to his garage, situated on a slope, where water had surged into his basement during heavy rains. But his borough denied him a permit for these repairs.

Haissam, a plumber and a father of three, experienced two more floods during the summer of 2024, racking up costs over $100,000 as his insurance only covered part of the damages. Upon learning from a city employee that his home was located in a "bowl zone," where water can accumulate during intense rains, he lamented, "If I'd known, I wouldn't have rented out a third apartment in the basement. And if I could have closed my garage earlier, I wouldn't have been flooded twice more."

Hidden Dangers

Many buildings in Montreal, like Halawi's, are located in "bowl zones," with owners left uninformed. According to the city's own map, 27.5% of Montreal's land lies in areas susceptible to sudden and intense downpours, a risk that intensifies with climate change, as experts warn.

In some neighborhoods, nearly half the properties are affected: 48.3% in Anjou, 46.4% in Verdun, 44.8% in the Southwest, 41.7% in Montreal-Nord. However, this map, published on the city's website without promotion, is difficult to find. One might wonder why residents of these zones, particularly those who've recently experienced floods, weren't directly informed of the recurring risks, enabling them to make necessary repairs.

"We're still developing these tools. The maps still need refinement," responds Maja Vodanovic, responsible for water infrastructure on the executive committee, who notes that other factors, like the urban layout, affect flood vulnerability. Yet, the bowl map is already used in some boroughs to determine the zones where basement development is restricted.

So, is your home situated in a "bowl zone"?

To find out, visit the City of Montreal's website and follow these steps:

Choose the "maps" icon
Uncheck the "heat islands" option
Check the "bowl identification" box
Enter your address in the search tool. You may need to "zoom out" to see the bowl zones around the chosen address. For a better understanding, navigate to the "layers" icon and select the "legend" tab.

Cleared Too Late

On August 9, 2024, many owners learned the hard way that they lived in a "bowl" when storm Debby dumped 154 mm of rain in just 12 hours—more than the average rainfall for an entire summer month in Montreal. Overwhelmed sewage systems could not manage the volume, resulting in flooded basements through doors, windows, and sewer backups.

The Costliest Storm

Debby was the costliest storm for insurance companies in Quebec's history, with 84,000 claims and indemnifications totaling 2.7 billion, according to the Canadian Insurance Bureau (CIB). Many homeowners were hit for the first time, but those with a second claim often lost their flood coverage.

The City of Montreal also received a record number of claims for a single event: 4,479, all denied, as is customary in such circumstances. Claims made to the City might not fully represent the number of affected residents since many choose not to file.

In response, Haissam Halawi, among others, filed a lawsuit against the City, accusing it of negligence in maintaining its sewer network. Since last summer, flood victims have voiced their grievances to the municipal council, complaining about the outdated infrastructure.

M. Vodanovic repeatedly responds with the same statement: expanding the network's capacity would take years, the costs would be astronomical, and floods would still occur during sudden and intense downpours. As a result, she suggests property owners take steps to protect their homes and perhaps abandon their basements.

The City is planning a few retention basins but primarily relies on sponge parks and sponge streets to absorb rainwater during heavy downpours.

Better Informed

Experts argue homeowners won't take precautions without knowing the risks, advocating for improved dissemination of the basin maps and direct communication with each at-risk resident. Ottawa aims to inform 60% of Canadians at risk and have 50% take protective measures by 2025, but we're still far from the target.

"Floods will continue, and probably increase," warns Anabela Bonada, director of the Intact Centre on Climate Adaptation (ICCA) at the University of Waterloo in Ontario. "Municipalities are on the front lines to bear the consequences. They have the responsibility to raise awareness among the population and provide tools to help homeowners protect themselves, as they have the best communication channel."

People must understand the need to take action and stop relying on governmental compensation.

The Montreal Metropolitan Community (CMM) has created a basin map for the 82 municipalities within its territory. Each city has received the map but has yet to make it public.

"We aim to distribute these maps by the end of the year," explains Nicolas Milot, director of ecological transition at the CMM. "We want to better inform citizens about the risks they face, but we need to consider the legal implications of making the maps available."

Several risk factors are highlighted by the CMM and the City of Montreal, such as the topography of the land, the capacity of the sewage system, paved or vegetated surfaces, and neighboring amenities.

A building located in a depression might not necessarily flood, insist municipal officials.

"Garages with entrances on downward slopes are particularly vulnerable," says Jean-Luc Martel, a professor specializing in stormwater management and climate change at the École de technologie supérieure (ETS). "Property owners should be informed to protect themselves."

Those living in basements, often low-income tenants lacking insurance, must also be warned adds Éléne Levasseur, director of research and education at Architecture sans frontières Québec.

"If you live near a river, you're aware of the risks," says Louis Poirier, a researcher in ocean, coastal, and fluvial engineering at the National Research Council of Canada. "But floods caused by rain are difficult to predict, making them more dangerous."

With the collaboration of Jean-Hugues Roy, La Presse

Many buildings in Montreal, like Halawi's garage, are located in "bowl zones," areas prone to flooding during intense rainfall, a risk that intensifies with climate change.
In some neighborhoods, almost half the properties are situated in "bowl zones," including Anjou, Verdun, the Southwest, and Montreal-Nord. Surprisingly, the city's bowl map, available on its website, is hard to find and not promoted to residents.
Expert warnings indicate that as climate change progresses, the frequency of sudden and intense downpours will increase, posing a greater risk to buildings located in bowl zones.
With better understanding of the risks and improved dissemination of the basin maps, homeowners can take more appropriate actions to protect their homes, such as installing water barriers or elevating their basements.
Negligence in informing residents about their potential flood risks and the lack of maintenance in the city's sewer network have led some flood victims, like Haissam Halawi, to file lawsuits against the City of Montreal.