The view of Winnipeg's Osborne area, from CBC's webcam, is partially obscured by the rain. (CBC)

Heavy rain created havoc Saturday in parts of southern Manitoba, especially in Winnipeg, where the sewer system struggled to keep ahead of the downpour.

Environment Canada warned at midmorning that weather radar showed intense thunderstorms affecting areas north of the Trans-Canada Highway across Manitoba. The storms were moving north and by 9:40 a.m. CT had passed through the Winnipeg area.

While no immediate measurements were available, Environment Canada said the storm could deposit more than 50 millimetres of rain.

In Winnipeg, traffic on Lagimodiere Boulevard, near Warman Road, had to contend with thick sheets of rain and large pools of water Saturday morning. (Megan Benedictson/CBC)

The deluge slowed traffic in some parts of Winnipeg as drivers had to manoeuvre around large pools of water.

In the area of Arlington Street and Notre Dame Avenue, three manhole covers were blown off because of an upsurge from the storm sewer system. A police unit was dispatched to the area.

Police were also looking into problems in Winnipeg's Transcona neighbourhood.

"Apparently in the Transcona area there is quite a bit of standing water," Const. Natalie Aiken said. "The drainage can't keep up with it. So that might be an issue if it doesn't resolve itself there."

In Brandon, there were reports that some trees were knocked down in the north end of the city, and some residents were without power because of the storm.