Condition Reports

River Conditions and Flood Report for Manitoba

April 14, 2008

Riding, Duck and Porcupine Mountains:

Manitoba Water Stewardship reports that warm temperatures and strong melting produced localized flash flooding on some streams in the Duck Mountain area last weekend. Most of the flooding took place on Saturday (a day earlier than expected) and conditions had generally improved by Sunday. Some roads were overtopped on Saturday and a few homes appear to have had water enter their basements. Levels of the Swan River and the Roaring River near Minitonas have risen seven feet since last Friday.

The area affected by localized flooding thus far is between Dauphin and Swan River. The flooding has been mainly due to channels blocked by ice and snow and has subsided rapidly after water has broken through these blockages. Similar problems are likely to develop in the Porcupine Mountain region during the next few days.

Some additional flooding may develop during the next few days due to strong melting in the higher terrain today. Runoff so far is mainly from the lower slopes but runoff from the high ground of the Riding, Duck and Porcupine mountains is expected to begin during the next few days. Any flooding due runoff from the high terrain is likely to be of a minor nature, in part due the fact that the channels are now generally clear of ice and snow.

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.

Red River:

The Red River crested at Emerson on the weekend and is expected to crest in Winnipeg before the end of this week. Crests on the river are unusually low and well below flood stage. A flood sheet showing observed and predicted stages for the Red River is attached. A minor ice jam which had developed at Ste. Agathe broke near noon today. Other minor ice jams may develop but with the river being 3 to 5 metres below floods stage, these ice jams are unlikely to cause any serious concerns. Ice breaking activities from Selkirk to Lake Winnipeg has ceased. Flooding of the Forks walkways in Winnipeg has begun but is expected to end by the weekend.

Assiniboine River:

The crest is presently in the Miniota area and should reach Brandon toward the end of this week and Headingley by the middle of next week. 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. There is a risk of ice jams in the portion from Portage la Prairie to Headingley but associated flooding should minor and even less than that of last spring.

Inflows to Shellmouth Reservoir will be increasing rapidly this week as runoff is now well underway in the upper Assiniboine watershed. The reservoir water level this morning was10 feet below the summer target level and about 15 feet below the spillway elevation. Excessive levels are not anticipated but it is possible that outflows may need to be increased somewhat from the present 300 cubic feet per second.

Other Streams:

Most small streams in south of PTH #1 have crested at much below bankfull levels.

Runoff in the southern Interlake (Icelandic River, Fisher River) and the Westlake region (Whitemud River, Turtle River) is well underway with moderate in-bank flows. Minor localized flooding of a temporary nature may occur due to blockages of drains and ditches but no significant flooding is expected.

Runoff in the Whiteshell area is minimal and as a result there is significant concern about lakes reaching their target levels. Logs are being placed to help capture as much water as possible. Flows in the Pembina River are also unusually low, limiting diversions into Pelican Lake.

Flows in the Souris River are very low with virtually no rise from winter levels.

Hydrologic Forecast Centre
Regulatory and Operational Services,
Manitoba Water Stewardship