Manitoba is facing a low to moderate risk of significant flooding in most basins this spring.
Released last week by the province’s Hydrological Forecast Centre, the February Flood Outlook Report suggests a moderate risk of significant flooding along the Red, Assiniboine and Pembina rivers, based on current conditions. A moderate risk of flooding also exists in the Interlake region, including the Fisher and Icelandic rivers.
On the other hand, the risk of spring flooding is considered low along several other rivers, including the Roseau, Rat, Saskatchewan, and Churchill rivers. Water levels are expected to remain below community flood protection levels, the report said, adding the risk of flooding is low for most Manitoba lakes throughout the spring period. Most lakes are expected to be within the desired operating ranges after the spring runoff.
The low to moderate flood risk is based on near normal to below normal soil moisture at freeze-up and normal to well above normal winter precipitation for most Manitoba basins. Portions of the Red River basin in Manitoba and the US are an exception, with above to well above normal soil moisture.
Soil frost depth across most of Manitoba is deeper than normal this winter, the report said. Generally, when frost is deeper than normal, it takes longer to thaw, reducing the soil’s ability to absorb water and leading to increased surface runoff.
The report warned the spring flood risk is still largely dependent on weather conditions from now until the spring melt, and throughout the spring. To that end, the long-term precipitation outlook issued in February by the International Research Institute (IRI) at the Columbia Climate School showed no clear signal for the March-May period.
The next Manitoba flood outlook will be released in late March.
