Sainte-Marthe-sur-le-Lac residents remain at risk despite the completion of a new dike, according to local officials.
The warning comes as floodwaters in nearby Gatineau show a notable decline, offering some relief to communities along the Ottawa River.
In Montreal, officials are preparing for a potentially more significant second wave of flooding expected in May, the mayor said.
Authorities continue to urge caution, noting that floodwaters may be contaminated and pose health risks to those returning to affected areas.
So far, 190 residences in Gatineau have already been impacted by the rising waters, with emergency crews working to assess damage and support displaced residents.
While water levels have begun to recede in some zones, officials stress that the situation remains fluid and could change rapidly with additional rainfall or snowmelt.
The ongoing flood response highlights the persistent vulnerability of riverside communities to extreme weather events, even after infrastructure improvements.
