Condition Reports

Report on River Conditions for Manitoba

April 17, 2008

Weather:

A slow moving storm is expected to bring heavy snow to eastern Saskatchewan and a mixture of rain and snow to western Manitoba from Saturday to Monday according to the Environment Canada forecast. Little precipitation is expected in the eastern half of Manitoba.

Red River:

Levels are declining at all points in Manitoba. Officials from the Selkirk area and north report that ice has now pushed into Netley Lake. This means that the threat of ice jamming on the Red River has ended.

The river level in downtown Winnipeg was 10.4 feet this morning and should decline below the Forks walkway level of 9 feet this Saturday.

Assiniboine River:

The Assiniboine River crest is still in the Miniota area due to heavy runoff from Birdtail Creek resulting from the rapid melt in the high ground last weekend. The flow crest is expected at Brandon next Tuesday but the peaks stage could occur earlier depending on when the ice moves out. Crests from Portage La Prairie to Lido Plage are likely to occur during the next few days when the remaining ice moves out. Peaks stages will be lower than in recent years and flooding is not anticipated along the entire length of the river unless heavy precipitation develops during the next few weeks. Operation of the Portage Diversion is unlikely but it will be operated temporarily if high ice flows develop in the area.

The Shellmouth Reservoir water level has been rising at a rate of about 0.8 feet per day and this is likely to continue through the weekend. The level this morning was 1395.8 feet. It is anticipated that the level will rise to somewhat above the summer target level without a significant increase in the outflow, unless heavy precipitation develops during the next few weeks. A slow moving storm could bring up to 50 mm of precipitation to the Saskatchewan portion of the watershed draining into Shellmouth Reservoir from Saturday to Monday. At the present time Environment Canada is predicting that most of this will fall as snow. If tomorrow’s weather forecast still calls for heavy precipitation, outflows from the reservoir may need to be increased. An updated inflow forecast based on the predicted precipitation and a recommended outflow setting will be presented to the Regulation Liaison Committee tomorrow.   

Interlake Region:

Levels of the Fisher River crested at the Peguis Townsite overnight. The level had risen to 737 feet which is close to flood stage for some low-lying homes in the Reserve. Levels are declining at all points upstream and should continue to decline at the Townsite. Minor brief flooding could occur at points further north to Koostatak if ice jams develop.

Levels on the Icelandic River will be fairly high for the next few days but significant flooding is unlikely.

Riding, Duck and Porcupine Mountain areas:

Levels continue to decline and all streams are within their banks. It is unlikely that the storm expected on the weekend will cause significant rises in streams in this region.

The Pas area:

Runoff is underway but crest will be delayed by anticipated very cool weather next week. The Saskatchewan Watershed Authority indicates that peak flows in the headwaters of the Red Deer River and the Carrot River are one-half to two thirds the magnitude of last years crests. These rivers are expected to remain within their banks in Manitoba unless heavy precipitation develops during the next few weeks. Also inflows to Tobin Reservoir are expected to be about half the magnitude of last spring, and therefore flooding is not anticipated in the vicinity of The Pas.

Hydrologic Forecast Centre
Regulatory and Operational Services,
Manitoba Water Stewardship