Record rainfall in Toronto leads to flooding concerns, watershed warning

The Toronto Region Conservation Authority (TRCA) warned people to stay away from the Lower Don River after rising water levels near the Don Valley Parkway and Bayview Avenue due to the heavy rainfall.

Water levels remain dangerously high throughout the city as Toronto saw two-thirds of a month’s rainfall in 18 hours. Pearson Airport saw 31 mm of rainfall on Monday, breaking the previous daily record for June 12 that was set in 1954.

The TRCA had previously issued a flood warning, which has since been downgraded due to improving conditions. A watershed warning remains in place until Tuesday.

“TRCA advises that the weather system that brought significant rainfall to the GTA and TRCA watersheds has now passed. There is minimal rainfall forecasted for at least the next 24 hours,” the conservation authority wrote on Monday night.

TRCA noted that water levels in the Lower Don River are receding, and flooding is not expected in localized watersheds.

“However, watercourses will take time to get back down to normal levels. Therefore, higher than normal water levels and flows can be expected,” TRCA continued.

“Ground conditions are saturated due to an average of 55 mm of rainfall received over the past 24 hours by TRCA watersheds, and some watercourses are still flowing higher than normal.”

CityNews chief meteorologist Natasha Ramsahai said that while Monday was, by far, the most significant in terms of rainfall accumulation, Toronto isn’t out of the woods just yet.

“The same area of low pressure is going to be sitting over the GTA for another two or three days,” Ramsahai said.

TRCA mentioned that all shorelines, rivers and streams within the GTA should be considered dangerous as Monday’s rainfall will result in higher flows and rapidly changing water levels.

Monday broke a daily rainfall record at Toronto Pearson Airport. The most significant June 12 rainfall on record goes back to the 2000s when 53 mm of rain was recorded.