Flood warnings expanded for Grand River watershed ahead of more heavy rain

With more rain on the way, CTV’s Karis Mapp explains what we can expect as water levels rise.

The Grand River Conservation Authority (GRCA) issued new flood warnings Tuesday for Cambridge and Six Nations as river levels continue to rise across the watershed.

It has also upgraded an existing alert for West Montrose, while warnings remain in place for St. Jacobs, Conestogo, New Hamburg, Ayr, Drayton, Grand Valley, Brant County and Drayton, as well as a flood watch for the remainder of the Grand River watershed.

• MORE: Flooding issues in Ayr, Ont.

“Warm weather and rain over the past four days have melted the snowpack and have led to ice jams and flooding,” Tuesday’s updated advisory read, in part. “While the risk of ice jams is believed to be past, river flows remain extremely high.”

The message coincided with a special weather statement from Environment Canada, warning that between 20 and 40 mm of rain could fall on Tuesday and continuing into Wednesday.

“Thunderstorms may result in locally higher rainfall amounts. River levels are elevated and additional runoff from rainfall will cause river flows to increase further,” the alert said.

In Cambridge, the GRCA said flows in the lower Speed River are expected to increase late Tuesday morning, leading to flooding in low-lying areas.

Rising river levels along the lower Grand River could also cause flooding in Six Nations.

Meanwhile, in West Montrose, river flows are forecast to reach the Flood Warning Zone 3 by midday Tuesday.