The remnants of hurricane Beryl have headed to eastern Ontario as well as southern Quebec, after initially arriving in Guelph and southern Ontario on Tuesday.
In a news release on Tuesday, the Grand River Conservation Authority said the remnants of the post-tropical storm were forecast to move through the watershed, seeing 50 to 60 millimetres and some areas getting more than 100 mm.
The GRCA said the weather was forecast to merge with an upper trough that is over central North America right now, creating a highly efficient conveyor belt of moisture into southern Ontario
It will produce significant amounts of localized runoff and cause water levels to rise as a result.
The earliest Atlantic storm to ever reach Category 5 hurricane status roared through the eastern Caribbean last week, killing 11 people.
Residents in the Royal City are encouraged to be careful around all local waterways and keep their children and pets away from all bodies of water.
Grand River said water conditions and forecasts are being closely monitored.
The rain is expected to taper off on Thursday, however, the GRCA said the flood outlook will remain in effect until Friday.