Flood Bulletin #3

Media Bulletin – Manitoba
April 6, 2011

Weather and Effect on River Conditions

•Very little or no precipitation has been reported in southern Manitoba in the last 24 hours. Flurries are expected in The Pas later this evening.
•The U.S. portion of the Red River watershed is partly cloudy with a chance of rain later today. Potentially significant rainfall is expected this coming weekend in the U.S. portion of the watershed. Predicted amounts of rainfall are not yet available.•Predicted weather over the next few days in Manitoba includes sunny periods with some cloudiness and less than one millimetre (0.04 inches) of precipitation predicted for Thursday. Rain is predicted for Saturday and Sunday in the southern part of Manitoba with a range of precipitation between seven and 10 mm (0.3 to 0.4 in.). Temperatures will gradually rise to an average daily high of 10 C by the weekend for most of southern Manitoba. Temperature forecasts for the next two weeks indicate a very gradual rise in temperature, with temperatures remaining above freezing and slightly higher than the normal.
•Recent mild weather and rains over the past week have resulted in an increase in flow. Overland run-off has started and is causing flooding of agricultural land. Most streams and rivers remain well within their banks, but levels will increase with the gradual rise in temperatures. The rate of water level rise will depend on weather conditions, especially with temperature changes and future precipitation amounts.
•The warming trend has caused ice shifting and the movement of ice in the Red and Assiniboine rivers within the city of Winnipeg. There is open water present in some locations along the Red River in Winnipeg, with long stretches of ice still present. Open water is visible on the Red River south of the East Selkirk Bridge to the Chief Peguis Bridge. An ice jam is stalled just south of the East Selkirk Bridge. Ice is still in place on most parts of the Assiniboine River, with some deterioration closer to the city of Winnipeg.

Red River

•In the U.S. portion of the basin, the Red River between Fargo and Pembina has risen by 0.2 to 0.9 metres (0.5 to three feet) in the last 24 hours. The Red River at Pembina just upstream of Emerson is below the flood stage by approximately 0.3 m (one ft.).
•The main stem of the Red River has risen upstream from Emerson to Morris by approximately
0.6 m (two ft.) since yesterday. North of Morris, readings on the Red River up to the floodway inlet have risen approximately 0.5 m (1.5 ft.).
•Red River tributaries in Manitoba have risen between 0.2 m (0.5 ft.) and 0.6 m (two ft.) in the last 24 hours. The LaSalle and Morris rivers rose by approximately 0.4 m (1.3 ft.), while the Roseau River rose by nearly 0.5 m (1.8 ft.).
•The Red River level at Emerson has increased by more than 0.8 m (2.5 ft.) to a level of 237 m (777.53 ft.) since yesterday. Flows recorded this morning at Emerson are 29,000 cubic feet per second (cfs) and well within riverbanks. The flood stage level at Emerson is 238.7 m (783.2 ft.) and the dike elevation is 242 m (794.0 ft.). Flows at Ste. Agathe are 33,000 cfs compared to 30,000 cfs yesterday.
•The Red River at James Avenue this morning was five m (16.56 ft.), rising 0.5 m (1.5 ft.) since yesterday. Flow at James Avenue is 38,000 cfs. The natural flow into the floodway is 2,800 cfs and water elevation at the floodway is 229.6 m (753.26 ft.), with a rise of 0.6 m (1.9 ft.) from yesterday. The floodway gates have not been operated.
•Flow recorded on the Red River at Selkirk this morning was 44,000 cfs. An ice jam near Selkirk caused a temporary water level rise, but the ice jam effects is lower than in previous years causing minimal flooding.
•Based on predicted peaks on the U.S. portions of the Red River, arrival time of the crest in Winnipeg could be in the last week of April to the first week of May. The crest in Emerson will precede this by one week. The crest magnitude will be calculated as weather and river conditions evolve and will be made available as soon as it is determined. The crest is the highest projected water level, meaning water levels will be high in the days before and following the crest.

Assiniboine River

•The Assiniboine River continues to experience only slight increases and the tributaries are generally seeing no more than a 0.2 m (0.5 ft.) increase since yesterday.
•Miniota has seen a rise of nearly six centimetres (2.4 in.) since yesterday while Headingley increased by three cm (1.2 in.). The flow recorded at Headingley this morning was 2,750 cfs.
•The inflow recorded this morning at Shellmouth reservoir was 400 cfs and outflow was 400 cfs. The reservoir is being maintained at the winter drawdown level of 421.8 m (1,383.83 ft.) until significant snowmelt starts in the watershed.
•Flows in the Portage Diversion are 1,100 cfs in the diversion channel and flows east of Southport are 2,720 cfs.

Pembina River

•The Pembina River has seen only a slight water level rise of less than 10 cm (four in.).
•The Pembina below Pelican Lake outlet experienced minor ice jamming.

Roseau River

•The Roseau River at Dominion City has seen a water level rise of 0.5 m (1.56 ft.) since yesterday.
Saskatchewan River at The Pas

•The Saskatchewan River has seen minimal rises of less than nine cm (3.5 in.) in the last 24 hours.

Souris River

•The Souris River at Souris has risen by three to nine cm (1.2 to 3.5 in.) on the Manitoba side of the border. Flows from U.S. tributaries will be significant due to the high moisture levels in the upper Souris watershed.
•Some locations in the U.S. are at flood or above flood-stage (i.e., Westhope). Levels are expected to remain unchanged over the next five days.

Interlake

•The Fisher River has experienced little change since yesterday but no major river levels have been reported in the last 24 hours.

Other Rivers and Lakes

•Generally minimal changes have occurred in the last 24 hours.
•Lake Winnipegosis is at 254 m (833.3 ft.) water elevation.
•Lake Manitoba is at 247.8 m (812.84 ft.) water elevation.
•Lake St. Martin water levels have risen slightly to 244.7 m (802.77 ft.) due to ice jams restricting flows on the Dauphin River.
•Lake Winnipeg is at 217.8 m (714.47 ft.) water elevation.
River Ice Conditions

•Active snowmelt and river ice break up have started on several locations along the Red and the Assiniboine rivers as average temperatures rise above freezing point. Some of the thin ice has completely melted. This will reduce ice-jam-related flooding. It is hard to predict where ice jams will occur.

Local Flooding Conditions

•Run-off is well underway in drains and other waterways in the Red River basin, and in some locations causing overbank flooding and flooding of agricultural lands.
•Ice jamming, frozen-blocked culverts and resultant overbank flooding is unpredictable and will be monitored closely.

FLOOD PREPARATION AND RESPONSE

•Initial work has started on the ring dikes at Ste. Agathe and St. Adolphe to prepare for partial potential closures that may be required.
•An ice jam on Tourond Creek near Alarie Road, west of PTH 59 near Ste. Agathe caused some overland flooding that went into farm yards, but did not affect homes or buildings. The Manitoba government has on-site equipment breaking up the ice jam.
•Equipment is in place to address a potential ice jam on PTH 9 near the Grassmere drain.
•Work is starting on a temporary dike near Gladstone that will be built with super sandbags.
•Cage (Hesco) barriers are being set up along PTH 5 near Spruce Wood Provincial Park today. The RM of St. Andrews is also installing its own cage barriers today on River Road.
•Work is also underway to establish a dike on a road near the Gardenton Floodway in the Vita area to provide a second line of defense and provide additional protection.
•Approximately 1.3 million sandbags have been produced by provincial sandbag machines.

For more information see www.manitoba.ca/flood.

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