Learning from the floods

The successive floods of 2017 and 2019 had the effect of an electric shock that raised awareness of the shortcomings in terms of natural disaster prevention in Quebec. Since then, the mapping of flood-prone areas has been much refined and response plans have been put in place in many municipalities, but there is still a long way to go before Quebec gets out of a crisis management mode rather benefit from sound risk management, say experts.

It is not yesterday that in Quebec, the rivers are unleashed and come out of their beds, causing significant damage. But climate change, which tends to make these phenomena more frequent, requires an in-depth review of the means to be put in place to deal with the jolts of nature.

Has Quebec learned lessons from the 2017 and 2019 floods? “Yes and no,” answers Philippe Gachon, professor in the Department of Geography at UQAM and director general of the Quebec Intersectoral Flood Network.

In the wake of the 2017 floods, which affected several regions, including the Outaouais, the Liberal government implemented the Info-Crue program and undertook a mapping review. The 2019 floods subsequently led the government of the Coalition avenir Québec to establish the Plan to protect the territory against flooding.

These initiatives have given rise to significant progress and the mobilization of scientific resources to open the silos in which they were confined, says Philippe Gachon. But according to him, there is a long way to go from the cut to the lips.

“The problem is complex, but we don’t have an overall vision,” he laments. He cites as an example the unresolved tax issues of municipalities, which derive most of their revenue from property taxes. However, a municipality will not benefit from relocating its citizens living in at-risk areas if it loses tax revenue. Without an overhaul of taxation and compensation programs for lost income, the problem remains, says the expert.

Mr. Gachon also cites the UN’s 2022 Global Assessment Report on Disaster Risk Reduction, which reported an increase in the number of disasters and revealed the authorities’ inability to deal with them. “The lesson that all disasters teach us — and COVID has reminded us of this — is that governments and states spend their time doing crisis management. We don’t anticipate. We are not proactive. »

According to him, to better deal with floods, Quebec should create a true observatory on the risks of flooding with the university network.

Relocate

But, on the ground, how can we better protect territories from flooding? In 2019, Quebec authorized the reconstruction and raising of the Sainte-Marthe-sur-le-Lac dike, which had given way during the flooding. “The dykes are problematic, because one day there will be a really exceptional flood which could either exceed the level of the dike or create breaches,” recalls Pascale Biron, professor in the Department of Geography at the ‘Concordia University. “There, it becomes really catastrophic because it happens very quickly, and people are not at all prepared because they think they are safe. »

In Sainte-Marie de Beauce, repeated flooding prompted the municipality to take drastic measures and move its downtown area. “Offshoring is the measure that best solves long-term problems,” admits Pascale Biron. It may seem expensive to move people, but in the long run, it’s more economical. »

However, it is not realistic to think that it would be possible to systematically rehouse residents living in high-risk areas. Sometimes, only repeated flooding will convince these citizens to consider moving. But even there, the room for maneuver is limited. “There is a fairly short period of time – around two years – after a big event to act. After that, people tend to forget where they sold their property,” said Ms.me Biron.

Different strategies

Municipalities have improved their response plans over the years to better prepare for spring floods. Since the floods of 2017 and 2019, the term “resilience” often comes up in the mouths of elected municipal officials.

The municipalities are also calling for funding of $2 billion over five years for adaptation to climate change. Thursday, before the members of the Union of Quebec Municipalities gathered in Gatineau, Prime Minister François Legault, however, maintained that the government did not have the leeway required to accede to this request.

But how, in the long term, can cities better protect their territory? In this regard, it is necessary to distinguish the episodes of very intense rain from the overflows of the rivers, underlines Pascale Biron.

For example, sewer systems as currently designed overflow quickly when rainfall is intense. In this context, cities must try to divert sewer water with facilities that allow greater soil permeability, such as sidewalk projections or the creation of wetlands.

But these measures have their limits when it comes to overflowing rivers. “Even if we put a park or a wetland around Rigaud, it will not stop the Ottawa River,” notes Mme Biron.

Struggling with repeated flooding, the municipality of Coaticook opted for the construction of a retention basin to better limit the devastating ardor of the Pratt stream downtown.

Professor at the Faculty of Planning at the University of Montreal, Isabelle Thomas talks about other strategies aimed at adapting housing to the environment. She cites New Orleans, where, in the wake of hurricane Katrina, the authorities have set up subsidies to allow the victims to raise their homes, rather than offering them compensation which, in the long run, became very expensive. “It’s called living with water,” she says. In Quebec, there are already flexible tools offered to citizens, but I think we need to go even further and review how we can adapt and support citizens and local players. »

The ecological restoration of the banks seems self-evident, but the relocation of dwellings can become complex. “I think there is progress to be made, such as developing a right of first refusal to allow municipalities that have development projects or the government to buy back land. »

Mme Thomas points out that the buildings that were flooded more than 50% in 2017 and 2019 have already been deconstructed and bought back by the Ministry of Public Security. “So this metamorphosis is already underway. The idea is to think together, collectively, to organize regional development. »

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