Human beings have the annoying tendency to want to tame the elements, but this practice is not necessarily a beneficial strategy, because sooner or later, nature is likely to prevail. It is in this spirit that the concept of “space of freedom” of watercourses, born in Europe, is gaining ground in Quebec in order to limit the impacts of flooding.
A professor in the Department of Geography at Concordia University, Pascale Biron has refined, with the collaboration of colleagues, the concept of the free space of rivers, inspired by European programs such as “Room for the River”, in the Bas, in order to adapt it to the province of Quebec.
This concept is based on the fact that watercourses are dynamic and that their course evolves over time according to erosion and overflow. “A river is not static. Instead of constantly fighting against nature, you have to agree to work with it,” explains Pascale Biron.
“Green genius”
These spaces of freedom aim to give back to the rivers the place to overflow when, inevitably, they come out of their bed, even if there is redevelopment of its banks and relocation of existing dwellings.
Thus, rather than trying to constrain the river with the help of infrastructure, riprap and low walls, we must resort to “greener engineering”, such as the rehabilitation of wetlands, she says. With the help of colleagues, she has thus developed tools to facilitate the mapping of these areas of freedom and try to predict the evolution of the river over several decades.
This concept is gaining followers. The MRC of Coaticook and Saint-André-d’Argenteuil have notably adhered to it.
“We would now like it to pass within the legal normative framework”, indicates Mme Biron, who notes a growing interest in this concept, which is now part of research projects carried out with the Ministry of the Environment, the Fight against Climate Change, Wildlife and Parks.
Pitfalls
“We fought for a long time against the mobility of the Coaticook River to stabilize it and control erosion,” admits Marie-Claude Bernard, development coordinator at the MRC de Coaticook, who is working on a open spaces for the Coaticook River. “We wanted to control the damage, but we realized that sometimes erosion is not necessarily harmful and allows the river to function better. »
But the project is complex. “In the field, we encounter several regulatory, financial or governance pitfalls, depending on the different ministries,” said Ms.me Bernard.
It requires the support of local residents, who, for the most part, are agricultural producers, she says. Agricultural uses could be granted elsewhere on the territory, and in this case, the operation could require the offer of compensation or tax advantages to the farmers affected, she underlines.
Over a 50-year horizon, the Coaticook River’s “mobility zone” covers an area of 469 hectares, says Ms.me Bernard.