The Grand River Conservation Authority has issued a flood watch for the entire watershed with warm temperatures and rainfall expected this week.
The organization said significant snowmelt is expected with increased runoff into local waterways.
“Flows in local waterways throughout the Grand River watershed are expected to begin increasing on Wednesday and remain elevated into early next week,” the conservation authority said in its flood watch message.
“Runoff from this event will result in flooding in low-lying areas typically prone to spring flooding.”
The Grand River, which flows through Waterloo Region, Brantford and Caledonia, has southern Ontario’s largest watershed that reaches into Guelph via the Speed and Eramosa rivers.
The conservation authority added that ice on local waterways is extremely unstable and will break up and shift, increasing the risk of flooding in areas prone to ice jams.
Ice fishing has been halted for the season at all conservation areas.
“The public is reminded to exercise extreme caution around all water bodies,” the conservation authority said.
“Banks adjacent to rivers and creeks are very slippery at this time and, when combined with cold, fast-moving water, pose a serious hazard.”
The temperature is expected to continue to increase until the middle of this week before returning to more seasonal conditions over the weekend.
There is also a chance of 10 to 15 millimetres of rainfall this week.