Sophie Kuijper Dickson, reporter

Funded by the Local Journalism Initiative

The Quebec government has plans to release new permanent flood maps for the province this spring, to replace the interim maps and zoning regulations that were introduced following the floods of 2017 and 2019.
The maps will update which areas are considered to be at risk of flooding, will change how the flood risk information is presented, and will include new regulations to be implemented by municipalities around how land in flood zones can be used.
“Although it is impossible to presume the result for a particular sector, it is expected that in the majority of cases the flood zones will be more extensive following their new delineation,” Josée Guimond, a spokesperson for the province’s environment ministry, wrote in an email to THE EQUITY.
Guimond emphasized that while the maps will likely place new properties within a flood zone, “the mapping simply illustrates the risk of flooding that is already present or will become so due to expected climate changes.”
Kari Richardson is an environmental land use planner with MRC Pontiac. She said the MRC has been involved in a working group that has been giving feedback to the province on how the new flood zones should be drawn.
Richardson confirmed flood zones will be redrawn in some places to include homes that were not previously in flood zones, but that changes will include feedback municipalities offered on the original set of maps that were rolled out after the 2019 flood.
“It’s really going to be helpful for municipalities in their day to day management, including the issuing of building permits and that kind of stuff,” Richardson said.
Flood risk presented differently
Pascale Biron is a hydrologist and professor at Concordia University in Montreal. She has been working with a group that the government has been consulting on the development of its new maps.
Biron explained the updated maps will present flooding data in two new ways.
First, the assessment of risk in each flood zone will be presented differently. Rather than describing a zone’s likelihood of flooding as a one in twenty year or one in one hundred year chance, a framing of flood probability that is often misunderstood, the maps will categorize flood zones as high, medium, or low risk.
Each risk category will be determined by both how often an area floods, and at what depth it usually floods.
Extreme weather events will also be included in the modelling, but coded differently. “So far, in the current flood maps, nobody is talking about the depth. It’s either you’re inside or outside a zone, but you don’t know what will happen if you are indeed flooded,” Biron said.
But the new maps will do this differently.
“They’ll represent not just the probability or likelihood you’ll be flooded, but how much water there will be if you are flooded,” she said.
Each risk zone will be accompanied by its own set of regulations that will determine how the land can or cannot be developed.
“In my opinion the main use [of the maps] is to better plan in the future and stop developing areas where we should just give it back to nature,” Biron said. “If that space is available to be flooded, then less flooding will happen downstream.”
Biron said she imagines the government’s new legislation will distinguish between people who are already living in new flood zones and people with ambitions to build in new flood zones, but said she is not sure of the details.
The municipality of Mansfield-et-Pontefract sits on a piece of land that is hugged by the final bend in the Coulonge River before it flows out into the Ottawa.
The municipality’s mayor, Sandra Armstrong, has lived there her whole life, and so has grown familiar with how and when the community floods in the spring.
She said she does not anticipate the updated maps will present any surprises when it comes to where the new flood zones are drawn.
“There’s flooding every year. We know what sectors will be affected really bad,” Armstrong said.
She is, however, unsure about how the accompanying flood zone regulations will affect land zoning in her municipality.
According to Armstrong, Mansfield now owns 20 waterfront properties that residents sold to Quebec’S Ministry of Public Security following the 2019 floods, that the ministry then sold back to the municipality for a dollar – an effort on the part of the province to move residents away from flood-prone shorelines.
Armstrong explained that holding onto these waterfront lots, which used to be some of the most valued land in town, has been somewhat of a burden for the municipality because it has had to keep them clean while not collecting any tax revenue from them.
“We cannot sell those lots because we don’t know the regulations from the government yet,” Armstrong said.
The release of the maps this spring will be followed by a 45 day consultation period, open to the public, after which a finalized set of maps will be implemented.
Once the maps are made official in the fall of 2024, the MRC will have to integrate the new regulations into its own land use planning framework, which municipalities will then need to implement.