Posted on 04/19/2009, 4:00 pm, by mySteinbach

There is a chance of significant rain across southern Manitoba and nearby areas in the United States late Thursday to Saturday.
 
City of Winnipeg:
• The Red River level at James Avenue in Winnipeg this morning was 6.38 metres (20.95 feet), just slightly lower than the 6.4 m (21 ft.) recorded yesterday morning.  The very gradual decline was the result of lowering the floodway control gates.  A gradual decline will continue for the rest of this week.

• The Red River watershed is saturated at this time and, as a result, river levels would quickly respond if significant rainfall were to develop in the coming weeks.  Another crest is quite possible if heavy rain develops during the next three weeks.

• The crest of 6.9 m (22.5 ft.) at James Avenue in Winnipeg was the second highest since major flood control works began operation in 1969.  The crest was 7.5 m (24.5 ft.) in 1997.

Lockport to Breezy Point:
• Levels in this portion will continue to decline very slowly for the rest of this week.  The river level in Selkirk has declined 4.9 centimetres (1.9 inches) since yesterday.
 
Emerson to St. Adolphe:
• Approximately 800 square kilometres of land is now flooded between Emerson and the floodway inlet.

• Levels from Emerson to St. Jean Baptiste declined by about three cm (1.2 in.) during the 24-hour period ending this morning.  A gradual decline will continue this week.

• River levels at Morris and at St. Agathe rose three cm (1.2 in.) since yesterday morning.  No further rise is expected at Morris, but the level at St. Agathe could rise another 4.6 cm (1.8 in.) before the crest occurs tomorrow.

• Levels at St. Adolphe should remain steady for the next few days and then begin a gradual decline.

• Residents and flood fighters in the flooded area are reminded that strong winds and wave action can raise water levels by 0.3 m (one ft.) or more and wave action can erode dikes.  Vigilance with respect to wind is recommended until levels have declined substantially.

• Levels in the United States portion are continuing to decline slowly.

• So far this spring, the Red River has risen 10.4 m (34.2 ft.) at Morris.
 
Floodway Inlet:
• Normal operation of the floodway gates continues with adjustments to maintain water levels south of the inlet at natural levels.

• The water level upstream of the floodway inlet this morning was 233.7 m (766.67 ft.), a decline of 2.4 cm (one in.) since yesterday morning.  The flow into the Red River Floodway this morning was estimated at 42,100 cubic feet per second (cfs) of a total 96,600 cfs upstream of the floodway inlet.
 
Assiniboine River:
• Flow into the Portage Reservoir declined from 16,310 cfs yesterday morning to 15,170 cfs this morning.  A gradual decline is expected to continue for the next five days.  The flow in the Portage Diversion this morning was 14,620 cfs and the flow in the river downstream was 545 cfs.  River flows toward Winnipeg will be increased once levels in the city of Winnipeg are below flood stage.

• Assiniboine River levels from Baie St. Paul to Winnipeg will continue to decline for most of this week.

• Flooding continues along the Assiniboine River from Miniota to Brandon.  The crest appears to have passed Brandon this morning.  Valley flooding should end within a week or so if there is little rain, but it will take additional weeks for water to drain from the valley floor.

• Without the operation of the Shellmouth Dam, levels from Virden to Grand Valley would be at least 0.6 m (two ft.) higher at this time.

• The outflow from Shellmouth Reservoir remains at 50 cfs.  The reservoir water level has risen 21.3 cm (0.7 ft.) since yesterday and stood at 425.6 m (1,396.8 ft.) this morning.  The level is expected to rise to at least 427.2 m (1,401.5 ft.) by the end of April.  The normal summer level is 427.5 m (1,402.5 ft.)
                                                     
Souris River:
• Levels of the Souris River in Manitoba are beginning to rise more rapidly in the Coulter area. Over-bank flows are still limited to the Coulter area but will spread to areas further north by late next week.  A crest exceeding that of 1999 by about 0.3 m (one ft.) is expected at the end of April or in early May.  Some diking is underway in Melita and just south of Souris. Extensive agricultural flooding will occur.
 
Pembina River:
• Serious flooding of the entire Pembina Valley continues.

• The crest passed La Rivière yesterday and was at Windygates this morning.  Sandbagging efforts at Holiday Mountain Resort have been successful although some leakage through the dike raised some concerns overnight.

• The river is still flowing over PTH 34 near Swan Lake but the depth of overflow was not known as of this morning.

• Crests from Rock Lake to La Rivière have been similar to those of 1974 which was among the largest floods in recent decades.

• An estimated peak discharge of 16,000 cfs occurred at Windygates this morning, exceeding the extreme crest of 2006 at this location.

• Rock Lake has declined 12.2 cm (4.8 in.) since yesterday and was at 407.8 m (1,337.9 ft.) this morning.  The crest two days ago was among the highest on record.

• The level of Pelican Lake was 412.4 m (1,353.0 ft.) yesterday and has declined in recent days due to operation of the outlet control works.

• The U.S. National Weather Service is predicting another significant crest at Walhalla tomorrow based on the crest now near Windygates.  However it expects only a minor rise of three cm (1.2 in.) to 6.6 m (21.6 ft.) at Neche on April 22 to 23 which is six cm (2.4 in.) higher than that of 2006.  Based on this forecast there would be little boundary overflow unless strong south winds develop during the next 10 days or so.

• Manitoba Water Stewardship and Manitoba Infrastructure and Transportation staff are closely monitoring possible overflows at the international border.  Actions have been taken to protect Gretna and Halbstadt from possible flooding due to overflows.
 
Other Rivers:
• The Fisher River crested at Koostatak this morning.  Both the Fisher River and the Icelandic River have now crested but levels remain high and flooding continues at the Peguis First Nation.

• Extensive overland flooding continues in the Interlake region with many roads overtopped or washed out. If the weather is favourable, conditions will begin to improve later this week but some flooding will continue for several weeks.

• All tributaries of the Red River had crested as of this morning.

• The flood potential for the Westlake area is quite low.  Minor localized flooding may occur late next week.

• The flood potential remains low from Swan River to The Pas.
 
Overland Flooding

• Overland flooding continues in many portions of southern Manitoba, especially in the Red River Valley and the Interlake and, although this will continue through the coming weekend, it should generally start to subside.  Flooding could quickly increase if significant rainfall were to develop. Residents in low-lying areas are advised to take precautions against possible sudden rises.

• Further details are provided below and specific forecasted crest stages are shown on the daily flood sheets issued by Manitoba Water Stewardship.
 
Flood Response

• The RM of Pembina has declared a local state of emergency to deal with flooding caused by the Pembina River, particularly around La Rivière and the Holiday Mountain Resort. Sandbag dikes have been built around low-lying areas.

• Work is continuing to construct a 750 m dike along PTH 3 at Melita and to augment the town’s earth dike by the end of the week.

• All ring dike closures in the Red River Valley are in place and are being monitored.

• Significant overland flooding is still occurring in the Interlake.  The damage to provincial drains and roads is being assessed.

• So far, the total number of registered evacuees is 2,216. Approximately 950 people have registered with the Red Cross.  Indian and Northern Affairs Canada reports 1,266 First Nations people have registered with Manitoba Association of Native Firefighters.  This number does not include people who have self-evacuated and not registered.
 
Well Water Caution – Province Will Cover Costs of Testing

Residents in areas affected by flooding who are using well water are advised to boil all well water before consuming it or use a safe alternative such as bottled water until test results confirm the bacterial safety of the water.  Well-water sampling should occur after flooding has subsided.  The province normally covers 70 per cent of such bacterial water testing but, under the current circumstances, the well owners’ 30 per cent share is being waived for the flooded areas for a period of up to three months after flood waters recede.