Condition Reports

River Conditions and Flood Report for Manitoba

April 15, 2008

Riding, Duck and Porcupine Mountains:

Manitoba Water Stewardship reports that most streams in the Duck and Porcupine Mountain have crested and are now below flood stage. Very warm temperatures with highs near 20 C during the past few days have melted most of the snow in the lowland area and have initiated runoff from the high ground. The quick runoff from lowland areas produced localized flash flooding on some streams in the Duck Mountain area last Saturday and in the Porcupine Mountain area yesterday. Most of this brief flooding was due to drains blocked by snow and ice. Levels declined to below flood stage as soon as the channels cleared. There was very little ice jamming and none is expected.

Runoff from the high terrain is now well underway due the strong melting during the past few days. While this will maintain high flows on many streams in the area, overbank flows are unlikely due to the channels now being clear of snow and ice.

Red Deer River, Carrot River, Saskatchewan River:

Moderate flows are expected to develop later this week and next week as runoff gets fully underway. Only localized minor flooding is expected based on normal weather conditions from now on. Peak flows and levels will be well below those of the past two years.

Red River:

The crest of the Red River is presently in the Winnipeg area where a crest of 11.5 feet is expected today. A flood sheet showing observed and predicted stages for the Red River is attached. There is no stationary ice remaining in areas from Emerson to Selkirk. Crests from Selkirk to Breezy Point are expected during the next few days and while some ice jamming is still possible, flooding is very unlikely. Runoff from recent snowstorms in the United States is minimal and will not produce a second crest in Manitoba. This is the lowest runoff event on the Red River since 2003.

Assiniboine River:

Heavy runoff from the headwaters of Birdtail Creek and the Little Saskatchewan River due to recent rapid melting will result in a second crest at Miniota during the next few days. The crest is expected at Brandon on April 22 and at Portage la Prairie on April 24, although much will depend on when the ice moves. Crests from Baie St. Paul to Headingley may occur later this week due to ice moving out. A flood sheet showing observed and predicted peak stages is attached. Flooding is not expected on the Assiniboine River. Peak stages will be well below flood stage unless ice jams develop.

The inflow to Shellmouth Reservoir is now increasing rapidly as recent high temperatures have melted most of the snow in the watershed upstream of the reservoir. Rises of a foot per day are expected to develop in the next few days. Excessive reservoir levels are not anticipated but it is possible that outflows may need to be increased beyond the present 300 cubic feet per second. This situation is being monitored closely and the Regulation Liaison Committee will be consulted regarding possible changes in outflow.  

Other Streams:

Most streams south of PTH #1 have crested at much below average spring levels. Flooding is not expected in the Interlake or Westlake regions.

Weather:

Environment Canada is predicting light scattered showers during the next few days with cooler temperatures. This will have no significant effect on runoff and river levels. No precipitation expected from Thursday to Saturday when milder temperatures are likely to return.

Hydrologic Forecast Centre
Regulatory and Operational Services,
Manitoba Water Stewardship