The woman was identified as 30-year-old Maria Pantazopoulos from Laval.
According to Ronald McInnis, spokesman for the Quebec provincial police, Pantazopoulos was standing in about 15 to 30 centimetres of water while a photographer was taking her picture.
McInnis said her dress got heavy from soaking up water and the woman asked for help getting out of the river.
The photographer and his assistant were unable to lift her out. That's when the woman was swept away by harsh currents and taken under water.
Quebec provincial police found her nearly four hours after the incident, at around 6 p.m. ET, with the help of a local diver who found her in a deep water basin.
The woman had been married June 9 but had wanted more photos of herself in her wedding dress at the river.
Authorities say the current is very strong, leaving little chance of survival.
McInnis said the 30-year-old newlywed may have been doing a "trash the dress" photo shoot, a trend in photography that puts well-dressed people in environments where they seem slightly out of place.
This trend is often seen in destination weddings when brides challenge beach waves while wearing a wedding dress.
Pantazopoulos' family members have declined to speak to the media.Suggest a correction