Ice jam poses flood threat for Ontario's St. Clair River communities

Ontario communities along the St. Clair River are closely monitoring an ice blockage that could create flooding and shoreline erosion.

The Canadian and American coast guards are working feverishly to unclog an ice blockage on the St. Clair River.

The ice jam has caused flooding on the American side, while coastal communities along the Ontario portion are on high alert for potential flooding and shoreline erosion, due to impacts from ice jams and strong, changing winds.

Ice-breaking vessels from the U.S. Coast Guard have been active in the Algonac, Mich. region to help break up the ice. Meanwhile, the Canadian Coast Guard are operating ships in the lower portion of the St. Clair River and between Russell Island and Marine City, respectively.

Although winds have subsided and water levels have fallen, long-range wind forecasts show the potential for flood conditions this week, according to the St. Clair Region Conservation Authority in its Feb. 8 flood watch bulletin.

St.Clair River ice jam/Mark Robinson

U.S. Coast Guard ice-breaking vessel tries to unclog the blockage that has caused flooding for some coastal communities along St. Clair River. Photo: Mark Robinson.

The ice that has already built up on the river, along with increasing wind gusts of 50-60 km/h expected Thursday and up to 70 km/h Friday, could increase water levels.

Content continues below

"Residents are reminded to avoid shorelines, watercourses and flooded areas due to dangerous ice conditions, slippery banks and cold, swift moving water. Children and pets should be kept away from the water," the conservation authority said in the bulletin.

The ice jam has resulted in significant flooding around Marine City and East China Township in Michigan, with the National Oceanic and Atmospheric Administration (NOAA) indicating that water levels rose at least 45 centimetres in a single day in Algonac.

Weather Network meteorologist and Storm Hunter Mark Robinson visited the scenes along the St. Clair River, including near Port Lambton, Ont. He noted the recent bitter cold temperatures are going to present a challenge to the ice breakers.

"The ice breakers have been going up and down, up and down, opening up the channel, allowing water to flow through. But the big issue that we're having now is that... this ice jam is locking into place because of the extreme cold temperatures that we're getting now, " said Robinson.

"That means if we get anymore breakup of ice off of Lake Huron, coming down into the St. Clair River, it's going to slam into the jam that's already here."

St. Clair River ice jam/Mark Robinson

St. Clair River ice blockage. Photo: Mark Robinson.

Content continues below

WATCH: ICEBREAKERS BATTLE THE COLD TO KEEP ICE JAMS FROM WORSENING

The flood watch remains in effect until Thursday, Feb. 11, unless earlier revisions are posted.