Wetter than normal summer, lake flooding could be on the way for Manitoba: provincial report
Summer conditions report shows higher risk of lake floods for Manitoba following near-record precipitation
After a spring that brought some of the most severe flooding on record, Manitoba may see a wetter than normal summer and a higher than usual risk of floods for most major lakes in the province this season, a new provincial report says.
The Hydrologic Forecast Centre's 2022 summer conditions report, released Wednesday, says this past spring's Red River flood was the fourth-largest flood ever recorded.
"Unprecedented rains, on top of very saturated soils, resulted in significant and widespread overland flooding across the province," the report says.
From April 1 to June 19, much of the Red River basin got over 330 millimetres of rain — more than double the normal amount during that period, it says.
Record flooding was also seen on the Winnipeg River system, the Whiteshell lakes and the Fisher River, as well as in the Parklands region and along the tributaries of the Red River, the report says.
After that spring of flooding, climate models show the potential for normal to above-normal precipitation for July, August and September, according to the province's report.
Temperatures are forecast to be near normal to warmer than normal for most Manitoba basins, the report says.
The Red and Assiniboine rivers are predicted to remain at normal or above-normal flows throughout the summer and fall until freeze-up, it says.
Flows on the Waterhen, Fairford and Dauphin rivers are expected to remain near normal this summer, while Lake Manitoba, Lake Winnipegosis and Lake St. Martin are expected to be back within their operating ranges, according to the report. Lake Winnipeg is expected to remain above the operating range.
With the exception of Lake Winnipeg, which was expected to continue rising throughout June, most lakes either peaked or were near peak by June 19, but remain above normal seasonal levels, the report says.
That, along with the potential for heavy winds that could cause lake levels to rise significantly, makes the risk of flooding on most major lakes higher than normal this summer.
The report also shows soil moisture in most Manitoba basins are normal to above-normal, with some areas showing soil moisture well above normal.
These wet basin conditions could contribute to increased surface runoff if heavy summer precipitation develops, according to the report.
South of the border, the National Weather Service's outlook is predicting below-normal precipitation and near-normal temperature for the U.S. side of the Red and Souris river basins from July to September, the Hydrologic Forecast Centre's report says.