Posted at 9:43 p.m.
The man in his forties had thrown himself into the water from a platform, said Sergeant Stéphane Tremblay, spokesman for the Sûreté du Québec.
He was recovered unconscious, and resuscitation maneuvers were carried out until the arrival of the emergency services, around 4 p.m. Transported to a hospital, the man is still in critical condition.
As it is a potential drowning, a forensic identification team was called to the scene to investigate. The scene had been released on Saturday evening.