Communities in and around Nith River face possible flooding as warmer temperatures melt existing snow. And rain is forecast for Tuesday, the Grand River Conservation Authority says.

The Nith River saw higher water levels following a thaw on Sunday and moving ice could raise the risk of ice jams in New Hamburg, Plattsville, Ayr and Wolverton.  Officials are not predicting Level One flooding, but say conditions may change. 

Higher water levels and moving river ice resulted in closures to 10th Line Bridge upstream of Belwood Lake northeast of Fergus as well as the St. Jacob's Low Level Bridge on Monday.

Warm weather and rain

Temperatures are expected to reach 2 C on Tuesday with sunny skies in Kitchener-Waterloo, according to Environment Canada. Rain will begin in the evening, with between 15 to 25 mm expected to fall overnight.

Wednesday will reach a balmy 10 C, though the temperature is expected to fall over the course of the day with rain turning to flurries in the evening. The area returns to below-zero temperatures Thursday.

Potential for flooding

Increased water levels in rivers and streams across Grand River watershed are expected to last and could climb higher as a result of this week's weather systems, the GRCA says.

"The combination of snow melt and rainfall could push the stream levels higher resulting in minor flooding in low-lying areas," the conservation authority said in a release. "How much levels rise depends on the amount of rainfall."

Major reservoirs have significant space available and are expected to be able to manage the runoff.

The authority is reminding people to use caution near all waterways as ice is unstable and stream banks remain slippery.