Manitoba Transportation and Infrastructure’s Hydrologic Forecast Centre has released its March Flood Outlook Report , which indicates a low-to-moderate risk of significant spring flooding across Manitoba basins.
With normal- to below-normal soil moisture at freeze-up and well-below-normal to above-normal winter precipitation for most Manitoba basins, the risk of significant spring flooding is low to moderate for most Manitoba basins. Water levels are expected to remain below dikes and community or individual flood protection levels. However, the risk of flooding could change depending on future weather conditions including rate of snow melt and the timing and amount of snow and rain received between now and the spring runoff.
The spring flooding risk is low for the Red River and tributaries, low to moderate for the Assiniboine River and tributaries and the Interlake region including the Icelandic and Fisher rivers; and generally low for the Souris, Qu’Appelle, Rat, Roseau, Pembina, Saskatchewan and Churchill river basins, and the Whiteshell Lakes region. As in most years, there is a risk of ice jam-related flooding on areas historically susceptible to ice jamming.
Most Manitoba lake levels are normal to below normal and forecasted to remain within their operating range after the spring runoff.
The Red River Floodway is not expected to be operated during this spring flood season based on forecasted conditions. Minimal operation of the Portage Diversion may be necessary under unfavourable weather conditions to control water levels on the lower Assiniboine River. The Shellmouth Reservoir is being operated to reduce the risk of flooding downstream on the Assiniboine River while also providing sufficient storage for water supply and recreation.
This forecast could change depending on weather conditions between now and the spring melt. There is no significant precipitation in the forecast for much of Manitoba over the next seven days. However, the Hydrologic Forecast Centre is monitoring a potential system that could bring up to 25 millimetres of precipitation to the United States’ portion of the Red River Basin.
Gradual run-off has started in some southern Manitoba basins including the Red River Valley. Levels are starting to rise along the main stem of the Red River and residents are cautioned about the impact of rising water levels as well as weak ice on the river. The Hydrologic Forecast Centre will start issuing daily flows and level forecasts once run-off fully begins, which will likely be by the end of March or first week of April.
The Manitoba government, local authorities and First Nations communities are continuing to prepare for spring flooding. This includes reviewing existing emergency plans, sharing information and preparing flood-response resources. Ice cutting and breaking is complete on the Red River and Iceland River. Further work is planned for portions of the Fisher River.
The 2024 spring flood outlook report is available at: https://manitoba.ca/mti/floodinfo/pdf/2024/march_2024_flood_outlook_report.pdf.
(Government of Manitoba news release)
