The Ganaraska Region Conservation Authority advises that a strong low pressure system will bring heavy rainfall beginning on Sunday evening with total accumulations of 40 to 50 mm by the time it moves out on Tuesday morning.
Local rivers and creeks are currently flowing at normal baseflow levels for May and so flooding is not expected with this amount of rainfall. However, the extra runoff will cause faster currents and higher water levels following the rainfall.
Strong and gusty winds from the east are also forecast on Monday when the worst of the rain is expected. This may lead to wave action and increased erosion along the Lake Ontario shoreline while its water level will continue to rise with the added runoff. The Flood Watch for Lake Ontario remains in effect at this time and will be updated on or before June 1st.
During this late spring storm, water levels will be on the rise and the water temperature will still be cold. As a result, local streams and rivers may become dangerous, especially in the vicinity of culverts and bridges. Children should be warned to stay away from all watercourses and shorelines.
This Watershed Conditions Statement will be in effect through Tuesday, May 19th, 2020. Conservation Authority staff will continue to monitor watershed conditions and provide updates as necessary. Should you have any questions or wish to report flooding, please contact the following GRCA staff at 905-885-8173.