The Maitland Valley Conservation Authority is issuing a Watershed Conditions Statement – Flood Outlook for all municipalities within the Maitland Valley and Nine Mile River watersheds.
Thunderstorms over the past 24 hours have brought approximately 30 mm of rainfall to southern portions of the watershed and between 40 – 55 mm to northern areas, including the Nine Mile watershed. Headwater tributaries – including the North Maitland River (Harriston to Wingham) and Nine Mile River (Lucknow) – have shown the strongest response and are expected to reach peak levels tomorrow morning. Presently, these watercourses are expected to approach or exceed bankfull levels but significant flooding is not anticipated.
Weather forecasts indicate an additional 30 – 40 mm of rainfall is possible over the next five days, with rainfall expected Thursday, April 2nd and Saturday, April 4th, along with the potential for locally higher amounts associated with thunderstorms. Saturated ground conditions will promote rapid runoff and quick responses in local watercourses. While widespread flooding is not currently anticipated, localized flooding will be possible over the next several days, particularly in areas that receive more intense or prolonged rainfall.
Municipal officials are advised to monitor drainage systems and low-lying infrastructure. Residents are reminded to exercise caution near all watercourses, as banks may be slippery and water levels and flows can change quickly. Water levels are already elevated in some areas, and all watercourses are expected to respond rapidly to additional rainfall through the remainder of the week.
MVCA staff will continue to monitor watershed conditions and weather forecasts and will provide updates as required.
This message is in effect until 10:00 a.m. on Tuesday, April 7, 2025.
Contact:
Jeff Winzenried, Flood Forecasting Supervisor
jwinzenried@mvca.on.ca
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.