A moisture-laden low pressure system that began moving slowly through the Great Lakes region yesterday will continue to bring significant and widespread rainfall to Southern Ontario through Thursday. As of this Wednesday morning, 25 to 40 mm of rain has fallen throughout the Maitland and Nine Mile watersheds. Current weather forecasts are showing rainfall to persist over the next 24 hours, bringing additional amounts of 40 to 50 mm of rain. Localized areas may be higher due to thunderstorm activity.
River levels are expected to reach or slightly exceed bankfull conditions, with flooding limited to traditional flood-prone areas. Significant flooding is not expected at this time. Peak levels are expected Thursday morning in the headwater regions (Listowel, Harriston, Lucknow), with larger watercourses peaking on the weekend. Municipal staff should monitor local problem areas and be prepared for the closures of low lying roads.
Residents are reminded to stay away from rivers, ditches, and streams. River banks will be saturated and slippery and flows will be very fast over the next several days.
Maitland Conservation staff will continue to monitor the forecast and an update on watershed conditions will be provided if warranted. This message will remain in effect until 10:00 a.m. on Monday September 27, 2021.
Steve Jackson, Flood & Erosion Safety Services Coordinator
Jayne Thompson, Communications Coordinator
519-335-3557 ext. 226 Cell: 519-357-6670
Types of Flood Messages:
Watershed Conditions Statement – Water Safety – General watershed conditions are being assessed for high runoff potential that could lead to flooding, and to remind the public of general river safety issues.
Watershed Conditions Statement – Flood Outlook – Early notice of the potential for flooding based on weather forecasts calling for heavy rain, snow melt, high wind or other conditions that could lead to high runoff, cause ice jams, lakeshore flooding or erosion.
Flood Watch – Flooding is possible in specific watercourses or municipalities. Municipalities, emergency services and individual landowners in flood-prone areas should prepare.
Flood Warning – Flooding is imminent or already occurring in specific watercourses or municipalities. Municipalities and individuals should take action to deal with flood conditions. This may include road closures and evacuations.