Significant rainfall expected as post-tropical storm Beryl moves through Grand River watershed

Post-tropical storm Beryl will move through the Grand River watershed Wednesday through to Thursday, and it's expected to bring significant rainfall.

Environment and Climate Change Canada has issued a rainfall warning for the area and says up to 60 mm are possible, with torrential downpours giving rainfall rates of up to 40 mm per hour at times.

The heaviest rain is expected Wednesday.

"Rainfall amounts will likely be highly variable across the region, and some areas may receive in excess of 60 mm. Rain will taper to scattered showers from west to east tonight through early Thursday morning," the warning says.

"Heavy downpours can cause flash floods and water pooling on roads. Localized flooding in low-lying areas is possible."

The Grand River Conservation Authority (GRCA) warns the rain could mean water levels will rise in local rivers, creeks and lakes.

The GRCA said on Tuesday that water levels and flows were at their normal summer levels ahead of the rain.

James Clarke, GRCA's senior communications adviser, said the authority will keep a close eye on the 24 rain gauges throughout the area.

"Any low-lying areas would be monitored closely. Areas with poor drainage would be monitored as well," he told CBC News.

Watch out for river conditions

Clarke said it's important to be safe around water courses, especially now that people are probably using rivers and streams for recreational purposes.

"I know a lot of people go canoeing down the Grand River or rafting down the Grand River, so it's important to watch out for these river conditions beforehand, especially again, this is now summertime, so kids are out of school and could be playing by the river," he said.

"In this situation when there's a flood outlook or more severe weather situations, children and pets should be kept away from water courses."