The update of maps of flood-prone areas in the Quebec City region has entered the municipal consultation stage. Authorities have divided waterways into two groups: draft maps for the first were sent to municipalities on September 25, and for the second they will be sent on November 15. The final deadlines for preparing the documents have already been set, but the date of their official approval by the provincial government is still unknown.
In brief
- September 25, 2026 municipalities received draft maps for the first group of rivers and waterways.
- November 15, 2026 the materials for the second group are planned to be delivered.
- There are 90 days for comments and recommendations from the moment the maps are received.
- Final documents for the first group will be sent to the government on March 31, 2027, and for the second on May 31, 2027.
- Gazette officielle du Québec.
How will the consultations take place?
The Quebec City metropolitan community (CMQuébec) divided waterways into two groups in order to review the proposed flood-zone boundaries together with municipalities and regional county municipalities (MRCs).
After receiving the drafts, local authorities have 90 days to submit comments and recommendations. According to CMQuébec’s Director of Land-Use Planning, Antoine Veril, this is not about a radical overhaul of the maps. The goal is to take into account specific information that may not have been included in the initial models.
For example, a municipality may report a location where a river overflows its banks even though such an area is not shown on the map. Another reason for an adjustment is recently completed public works that changed the capacity of a culvert under a road.
Such information will allow specialists to make final refinements before the documents are sent to the government.
When will the maps be sent to the government?
The schedule depends on which group a particular waterway belongs to.
- First group: the final maps must be submitted to Quebec’s Ministry of the Environment, the Fight Against Climate Change, Wildlife and Parks (MELCCFP) on March 31, 2027.
- Second group: submission is scheduled for May 31, 2027.
After the documents are received by the ministry, they will be ready for review for approval by a decree of the Conseil des ministres. The new maps must then be published in Quebec’s official government publication, the Gazette officielle du Québec.
However, the specific date for adopting the decree has not yet been set. CMQuébec emphasizes that the timeline for approval falls under the authority of the Minister of the Environment. The regional organization cannot determine on its own when the government will complete this procedure.
Thus, completing the preparation of the maps in spring 2027 does not mean that residents will gain access to them at that same time.
What is happening with the modeling of the St. Lawrence River?
In parallel, CMQuébec has begun modeling hydrological processes on the St. Lawrence River.
As far back as two years ago, the organization asked the Quebec government to allocate funding and provide a mandate to study the river’s dynamics. The need for this work is linked, among other things, to risks driven by climate change.
For now, however, it is premature to talk about preparing flood-zone maps for the St. Lawrence. At this stage, the organization is working on modeling, and no specific timeline for the appearance of the corresponding maps has been determined.
Why does this matter for residents?
The updated maps may matter to property owners, homebuyers, developers, and municipal authorities. They help identify areas at risk of flooding and take these risks into account when planning construction and infrastructure development.
At the same time, until the documents are officially approved, the final boundaries of flood zones remain unknown. Municipal consultations give local authorities an opportunity to report actual on-the-ground conditions and obtain the necessary technical refinements.
What happens next?
In the coming months, municipalities will continue reviewing the proposed maps and submitting their comments. CMQuébec will then prepare the final versions for submission to MELCCFP in March and May 2027.
After that, the timeline for official approval will depend on the decision of the Quebec government.
The main uncertainty lies not only in which areas will end up in the new flood zones, but also in when residents will be able to review the final maps. For now, the schedule for preparing the documents has been set, while the date they take effect remains open.
