Parts of Saint John experienced flooding Wednesday night into Thursday morning, resulting in emergency management officials urging residents along the river to be on alert.

Saint John resident Steve Mackin captured a photo of a submerged parking lot at the corner of McAlister and Majors Brook Drive. He took the photo Wednesday just after 7 p.m., and it has since been shared over 2,000 times.

"It's a combination of the water flow down from Forest Hills into that area of the city,” says Mackin. “It just backs up because it just can't handle the sheer volume of water."

Rain pooling over Highway 7 near the Saint John River caused a single-vehicle rollover in Grand-Bay Westfield.

"The driver did lose control and went off the road into the median, and crossed into the other line of traffic,” says Sgt. Greg Oram of Saint John police.

There were no injuries, but police are reminding residents to be mindful.

"Just because the speed limit says on the highway its 100 km/h, you have to drive accordingly to road conditions,” says Oram.

Nova Scotia highways are also more treacherous due to mounting water. A tractor-trailer crashed near the Halifax airport Wednesday, causing slowdowns on Highway 102. The wet roads also made for an even slower commute as students returned to classes.

Some areas along the Bay of Fundy and Atlantic coasts could see up to 70 millimetres of rain before the day is out.

With files from CTV Atlantic’s Mary Cranston.