Manitoba’s Hydrologic Forecast Centre says there is a high risk of major spring flooding along the Red River main stem. Due to above normal to well above normal winter precipitation to mid-February, the Red’s tributaries, including the Roseau, Rat and Pembina Rivers are at a high risk of moderate to major flooding.
In its first flood outlook of the season, released Friday, the Centre stated with normal weather conditions, levels would be near spring peak levels observed in 2019-20 from Emerson to the Floodway. Unfavourable weather conditions would lead to levels similar to 2009.
Due to the forecasted flows on the Red River, the Floodway is expected to be operated under all weather condition scenarios during the 2022 spring melt.
In its report, the Centre outlined the following factors in determining its forecast:
- Due to normal to below normal summer and fall precipitation, soil moisture at freeze-up is below normal for most Manitoba basins, with the U.S. portion of the Red River basin normal to above normal.
- Winter precipitation has been above normal to well above normal in most Manitoba basins. The United States portion of the Red River basin also received above normal to well above normal precipitation since November 1st. Some areas in the U.S. portion of the Red River basin have received up to 200% of normal precipitation since November 1st
- Snow water equivalent (SWE) estimates obtained from January field measurements indicate that the average water content in the snowpack is in the order of 30 to 80 mm (1.2 to 3.1 inches) in most of the southern Manitoba basins with a few measurements just outside of this range, from 20 to 155 mm (0.8 to 6.1 inches).
- Base flows and levels in most rivers have been declining since the fall of 2021. Base flows and levels are generally near normal in most Manitoba basins.
- The frost depth is variable across the watersheds, but is generally considered to be normal to deeper than normal throughout most of the province due to below normal winter temperatures.
The next flood outlook will be released in late March.