Flood Warning Issued for Mississippi River Watershed

From the Mississippi Valley Conservation Authority

A Flood Warning Statement indicates that flooding is imminent or already occurring in specific watercourses or municipalities. Municipalities and individuals should act to deal with flood conditions. This may include road closures and evacuations.

This Flood Warning is an update to the Flood Watch for the Mississippi River Watershed issued on April 20, 2026.

This update applies to Dalhousie Lake and flood prone areas along the Mississippi River. Upper lakes and major tributaries remain in a flood watch condition, see details below.

Weather forecast

Conditions are expected to stay generally dry this week. Cumulative total rainfall over the next seven days is expected to remain low, with less than 20mm forecasted across the region. Air temperatures for the next two weeks are to remain mild with forecasted daily highs around 10 to 15 °C.

Watershed conditions

Water levels and flows are elevated across the watershed.

Flood warning

The Mississippi River continues to rise as water moves through the system. Dalhousie Lake surpassed the 1:10 year flood threshold (157.50 masl) yesterday and continues to climb towards the 1:25 year flood threshold (157.80 masl) today, with current levels reaching 157.60 masl. The lake is expected to rise an additional 10 cm in the next 24 hours. Water levels and flows are expected to continue rising in the Mississippi River downstream of Dalhousie Lake. Residents in flood prone or low-lying areas historically susceptible to flooding should take the necessary precautions to protect their property.

Flood watch

Upper lakes (Shabomeka, Mazinaw, Little Marble, Marble, Kashwakamak, Big Gull, and Mississagagon) remain in seasonal flood conditions. Water levels have peaked and are expected to begin gradually receding this week with the forecasted break from the rain.

Major tributaries (Clyde River, Fall River, and Indian River) have peaked and levels and flows along these systems are receding towards seasonal levels.

Risks

Rivers and streams are experiencing higher water levels, fast flowing water and slippery or unstable banks. Roads, driveways, and properties in flood-prone areas could be impacted.

Actions

Residents are reminded to stay off all water bodies due to high flows and slippery conditions. Parents are encouraged to remind children about these dangers and provide appropriate supervision.

Residents in flood prone areas are advised to maintain close watch on water levels and flows and take the necessary precautions to protect their property by:

• Ensuring sump pumps are clear, in good working condition and have a backwater valve.
• Having a portable generator and backup pump available.
• Ensuring downspouts are clear and the outlet is at least 3 meters from any structure.
• Removing or securing items that might float away if flows increase.
• Removing valuable items from basements or lower floors that could be subject to flooding.
• Keeping emergency phone numbers handy.
• Familiarizing yourself with your municipality’s emergency preparedness plan – Mississippi Mills Emergency Response Plan.

Duration

This message is in effect until April 28, 2026 or until an update has been issued.

For more information

Daily water levels and flows are available on the MVCA website at www.mvc.on.ca/water-levels. For more information, contact MVCA Water Management at 613-253-0006 ext. 248 or water-management@mvc.on.ca.