Manitoba Water Stewardship's Hydrologic Forecast Centre has issued a high water advisory for the Assiniboine River and its tributaries, from the Shellmouth/Russell area to Headingley, as a result of ice jams.
Shellmouth Dam (above) in more normal times. Also see photo (below) just below the dam. Pics by l.p.
· The Assiniboine tributaries and the main river remain well within their banks at most locations. However, due to the recent heavy snow followed by a sudden drop in temperatures, ice jams and flooding are occurring at various locations downstream of the Shellmouth Reservoir, Miniota and in the Brandon area. · This local ice-jam flooding is expected to continue at locations on the main river and some larger tributaries like the Souris and the Little Saskatchewan rivers until the freezing process stabilizes in the next two weeks.
· Communities in the Assiniboine Valley, especially in low-lying areas such as Russell, St. Lazare, Miniota and Brandon, should be aware that ice-related flooding could occur.
· The Shellmouth Reservoir has been declining since late September when the outflow was 3,360 cubic feet per second (cfs). Today the flow is 1,600 cfs and the level of the reservoir is 428 metres (1,404.22 feet). The inflow into the reservoir is 1,570 cfs. The outflow will be kept constant at 1,600 cfs for the next few weeks to ensure the reservoir is at an acceptable level before next spring.
· Manitoba Water Stewardship is closely monitoring river and lake level conditions.
Weather - The weather forecast calls for clear periods for southern Manitoba and temperatures remaining in the -10 to -20 C range for the next five days. This should help reduce ice jams and related flooding.