As temperatures warm up over the next several days, a rapid melt of the snow pack in the Maitland and Nine Mile River watersheds is expected. The snow pack will be fully depleted by Friday with the exception of portions of the Township of Huron-Kinloss and some woodlots. The snow pack currently has a SWE (snow water equivalent) ranging from approximately 70 mm on the east side of the Maitland watershed to about 96 mm in Huron-Kinloss.
The resulting runoff from the snow melt will create bank-full conditions with flooding in traditional low lying areas.
Based on the current weather forecast and flood modelling, the peak in Harriston and Listowel is expected overnight on Thursday (March 11th) and the peak in Wingham and the remainder of the Maitland watershed is expected to follow on Saturday (March 13th). The peak in the Nine Mile River watershed is expected to occur over the weekend.
Rain is in the forecast for Wednesday and Thursday and this could have a significant impact on runoff amounts. If the rainfall exceeds 20 mm, more significant flooding can be expected. Maitland Conservation staff will be closely monitoring the situation over the next 48 hours and will provide an update if conditions change.
Residents are reminded to use caution near all watercourses. Ice on rivers and ponds will become very unstable today. Slippery streambanks and extremely cold and fast-flowing water will combine to create hazardous conditions.
There is always a risk of bluff erosion along the Lake Huron shoreline but residents should be aware that the approaching rapid thaw will saturate the bluffs and heighten that erosion risk.
This statement will remain in place until 4;00 pm on Monday March 15, 2021. .
Jeff Winzenried, Water Resources Technician
Jayne Thompson, Communications Coordinator
519-335-3557 ext. 226
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.