Manitoba has released its flood risk forecasting for the spring and the news is not good. Red River Valley is at a high risk to flood with both the Red River Floodway and thePortage Diversion expected to be pressed into service.
March is still a crucial month in terms of snowmelt and conditions so information is still being collected from both Saskatchewan and the U.S.
With normal weather conditions, levels on the Red River south of the floodway are expected to be near 2011 levels. Unfavourable weather conditions, including late season snow, spring rains and a more rapid snowmelt, would bring Red River levels comparable to the 2009 levels, which saw extended road closures of PTH 75 and other roads, and evacuations in some areas. Water levels will be below the flood protection levels of community and individual dikes. However, partial closure of some community dikes may be required to maintain local access.
Flows on the Assiniboine and Souris rivers are also expected to be high. However, peak water levels will be below flood protection levels. Flows may produce some flooding of farmland and low-lying areas. The Shellmouth Dam will be operated to store a portion of the spring run-off, thereby reducing downstream river flows.
Manitoba’s major lakes are expected to remain within their respective operating ranges. There is a low risk of overland flooding in the Interlake, upper Assiniboine and Whiteshell lakes areas. The Saskatchewan River and Carrot River in northern Manitoba are at moderate risk of overland flooding.
Based on long-term weather forecasts, below-normal temperatures are expected in March and April, further delaying snowmelt, with the risk of spring rains occurring at the same time. Manitoba Infrastructure is collecting ice thickness samples across Manitoba basins. Ice is expected to be thicker than normal, which would increase the risk of ice-jam flooding.
The province will also be providing more detailed information to municipal officials. Further outlooks will be issued as updated forecast data becomes available. More information about flooding and how to prepare for an emergency situation is available atwww.gov.mb.ca/flooding.
PHOTO CREDIT - mhs.mb.ca