Condition Reports

Updated Report on Runoff and River Conditions

April 10, 2008

Levels of most rivers in southern Manitoba continue to rise slowly. The runoff is well below average as expected. Flows on many streams will be insufficient to move the ice, which will gradually weaken and dissipate in the weeks ahead.

Updated levels and crest forecasts for the Red River and the Assiniboine River are shown on the attached sheets. Levels are rising at a rate of less than 1.5 feet per day at most locations. Predicted peak stages are well below bankfull for both rivers.

Weather:

Little of no precipitation is expected over southern Manitoba during the next five days. Strong warming with highs of 15-20 C is expected early next week. A storm moving across Nebraska is expected to produce blizzard conditions in South Dakota and is forecast to produce up to six inches of wet snow in the Fargo area. Only a minor amount of snow is expected at Grand Forks and no snow is expected from Drayton northward.   

Red River:

Crests for the Red River remain somewhat uncertain as the amount of runoff from last weekend’s snowfall in the Fargo area is not yet clear. Another snowstorm is expected in the Fargo area tonight through early Saturday, with up to six inches of wet snow being predicted. Despite this, it is unlikely that the predicted peak stages in the Manitoba portion will be exceeded. Serious ice jamming appears unlikely due to low river flows and ice breaking activities.

Assiniboine River:

Runoff is well underway in the Assiniboine River watershed downstream of St. Lazare but is only beginning in areas further upstream. It is expected that inflows to Shellmouth Reservoir will increase significantly over the weekend and reservoir levels will begin to rise as warmer weather develops. The outflow from Shellmouth Reservoir was decreased from 600 to 300 cubic feet per second today due to reported heavy snowpack losses in the Whitesand portion of the watershed in Saskatchewan. The Shellmouth Reservoir water level as of this morning was 1393.2 feet, which is somewhat higher than the average level prior to spring runoff. Flooding is not expected along the Assiniboine River this spring unless heavy spring rain develops.

Other Streams:

A minor runoff is underway in most watersheds in southern Manitoba. Peak flows will be much below average and are likely to occur next week or earlier. A moderate runoff is expected in portions of the southern Interlake and Westlake regions where heavy snow fell in late March., but flooding is unlikely even in these areas. Minor localized flooding may occur on streams flowing off the Riding, Duck and Porcupine Mountains next week if high temperatures develop as predicted.

Hydrologic Forecast Centre
Regulatory and Operational Services,
Manitoba Water Stewardship