Flood Report for Manitoba

FLOOD REPORT FOR MANITOBA

July 29, 2014 – 09:00

The wind forecast for today calls for northwest winds on Lake Winnipeg’s south basin resulting in a moderate wind warning.

Flood - Assiniboine River Warning*: - Souris River - Lake Manitoba - Lake St. Martin - Dauphin Lake

Flood Watch*: - Lake Winnipeg

High Water - Plum Creek Advisory*:

Summary  The wind forecast for today and tomorrow calls for mainly northwest and westerly winds, resulting in a moderate wind warning for the south portion of Lake Winnipeg today (see attached map for illustration of forecasted wind effect on Lakes).

 Flow on the Assiniboine River upstream of the Portage Diversion continues to decline. This morning, flow on the Assiniboine River at the Portage Reservoir was 22,680 cfs, flow on the Portage Diversion was 7,870 cfs and flow over the Bascule Gates to the lower Assiniboine River was 14,810 cfs.

 Flows on the Assiniboine River downstream of the Portage Reservoir will be maintained at approximately 15,000 cfs until later this week, at which time the conditions will be re- assessed.

Weather  Southern and northwestern Manitoba will see a mix of sun and clouds today with similar conditions tomorrow, with expected high temperatures of 25 -30° C.  There is the possibility of showers in the Whiteshell area and a similar possibility of showers or thunderstorms in the Dauphin area today.  Environment Canada has issued a strong wind warning for the Lake Winnipeg north basin for today, tonight and Wednesday with winds from the northwest. The latest marine wind conditions can be viewed at: http://weather.gc.ca/marine/region_e.html?mapID=04

Red River  The Red river water level in Winnipeg is 12.1 feet James Avenue datum, with flows at 29,820 cfs. The flows on the Red River and some of its tributaries have increased slightly due to recent precipitation in the U.S.A. and Canada portions of the Red River watershed.

Assiniboine River  Overbank flooding is occurring in the Assiniboine River valley between the Shellmouth Dam and Brandon. The Assiniboine River has crested and is dropping at all points between Shellmouth Dam and Portage la Prairie.

 The water level on the Shellmouth Reservoir declined to 1,411.5 feet; the summer target level is 1402.5 feet and the crest of the spillway is at 1408.5 feet. Shellmouth Dam inflow, reservoir level, and outflow have crested and are declining. Inflows to the reservoir are approximately 3,960 cfs today; outflows from the reservoir are approximately 4,650 cfs. Outflows include 1,065 cfs of conduit flow and 3,585 cfs of spillway flow.

 The flow on the Qu’Appelle River at Welby this morning decreased to 2,700 cfs.

 Flows on the upper Assiniboine River remain high but are declining. This morning, the flow near Russell decreased to 4,420 cfs, The normal flows on the Assiniboine River at Russell in mid-July are 350-400 cfs.

 Flows on the Assiniboine River downstream of the Portage Reservoir will be maintained at approximately 15,000 cfs until later this week, at which time the conditions will be re- assessed.

 The Assiniboine River in Winnipeg will decrease slightly once the reduced flows on the lower Assiniboine River reach the city from the Portage Reservoir. The river will then remain relatively stable until flows from the Portage Reservoir are further decreased.

Souris River  Flows on the Souris River are high and are declining slowly. This morning, the flow at Melita decreased to 2,975 cfs; the flow at Souris decreased to 5,510 cfs, and the flow at Wawanesa decreased to 5,970 cfs. The normal flows on the Souris River in mid-July are approximately 200 cfs.

 Oak Lake and the Plum Lakes are at high levels resulting in high flows on the Plum Creek, which flows into the Souris River at the Town of Souris. Flow on the Plum Creek this morning decreased to 1,515 cfs.

 Whitewater Lake is at a water level of 1633.2 feet. The lake is normally a closed basin with no outflow but the water level is currently high enough to spill naturally into Medora Creek.

Pembina River  Pelican Lake is at 1351.8 feet; all outlet gates on Pelican Lake are closed.

Parkland Region  The gauge on Dauphin Lake is reporting a water level of 859 feet and the lake is expected to decline slowly. Flood stage on Dauphin Lake is 858 feet and the summer target level is 855 feet.

Manitoba Lakes  The Lake Manitoba water level this morning is approximately 814.5 feet. The forecasted peak wind-eliminated water level on Lake Manitoba is 814.8 feet in early August.

 The Fairford River Water Control Structure is being operated for maximum possible discharge; outflow from Lake Manitoba was approximately 14,550 cfs this morning. The estimated natural outflow from Lake Manitoba at the current lake level, if the Fairford River Water Control Structure and associated channel improvements hadn’t been constructed, is approximately 6,750 cfs. The forecasted peak outflow, which will occur when Lake Manitoba reaches its peak water level, is approximately 15,800 cfs.

 Lake Manitoba is currently approximately 1.0 feet below unregulated levels (the levels that would have occurred in the absence of all provincial water control infrastructure) because of the high outflows from the Lake through the Fairford River Water Control Structure.

 The Lake St. Martin gauge is registering a real-time water level reading of 802.9 feet. Outflow from Lake St. Martin through the Dauphin River was 10,960 cfs this morning. Outflow through the Lake St. Martin Emergency Outlet Channel was measured at 3,710 cfs on July 22. The lake is dropping due to the additional outflow through the Lake St. Martin Emergency Outlet Channel.

 Operation of the Lake St. Martin Emergency Outlet Channel increases total outflow from Lake St. Martin, directly lowering levels, and will allow the Fairford River Water Control Structure to remain at maximum discharge through the winter, thus allowing for higher outflows from Lake Manitoba. The Lake St. Martin Emergency Outlet Channel is expected to stay open until the spring of 2015 and will help bring the Lake St. Martin water level to approximately 802 feet by mid-November, 2014.

 The latest forecast indicates that the lake will rise to 716.4 feet by late July. The lake is not expected to drop below 715 feet until mid-October. The water level regulation range for Lake Winnipeg is between 711 and 715 feet. Manitoba Hydro is operating its structures at the outlet of Lake Winnipeg to allow for maximum possible outflow from the lake and forecasts that the maximum outflow from Lake Winnipeg will be approximately 170,000 cfs when the lake reaches its peak level.



Eastern Region  Flows on the Winnipeg River system remain high; however, water levels have stabilized and are declining throughout the basin. Nutimik Lake is down 0.1 feet to 907.0 feet.

 Natalie Lake, the forebay at Seven Sisters, was being held below its operating range at 896 feet, the lake has now been returned to its normal high-water operating range of 896.5 feet. This will result in a slight rise in water levels in some of the upstream lakes; no impact is expected at Nutimik Lake.

 Manitoba Hydro’s latest forecast from July 25, is that the lakes on the Winnipeg River will change by the following amounts by August 9, 2014: o Nutimik Lake will drop by 0.5 feet. o Dorothy Lake will rise by 0.2 feet by July 29, and then drop by 0.2 feet (no net change) o Margaret/Eleanor Lake will rise by 0.3 feet by July 29, and then drop by 0.2 feet (net rise of 0.1 feet). o Sylvia Lake will rise by 0.4 feet by July 29, and then drop by 0.1 feet (net rise of 0.3 feet)

 Many other lakes in Whiteshell Provincial Park, such as Falcon, West Hawk, and Caddy, are higher than the desirable range but below the peak water level experienced earlier this spring. Where water control structures are present, they are being operated to provide maximum flood relief.

 Water level information for the lakes in the Whiteshell Provincial Park is available at: http://www.gov.mb.ca/mit/floodinfo/floodoutlook/forecast_centre/lakes/lake_levels/2010/whiteshell_lakes_2012-2014.pdf

The Pas and Northern Manitoba  The Saskatchewan River at The Pas is declining slowly. This morning, the river was at a water level of 853.0 feet and a flow of 57,440 cfs.

 The flow on the Carrot River at Turnberry continues to decline, with a flow of 4,075 cfs. The Carrot River near The Pas dropped to 854.7 feet today.

*Definitions Flood Warning: A flood warning is issued when river or lake levels are exceeding or are expected to be exceeding flood stage within the next 24 hours.

Flood Watch: A flood watch is issued when river or lake levels are approaching and likely to reach flood stage, but likely not within the next 24 hours.

High Water Advisory: A high water advisory is issued when a heavy storm or high flows are expected and may cause water levels to rise, but not necessarily reach flood stage. A high water advisory can be an early indicator for conditions that may develop into a flood watch or flood warning.

Manitoba Lake Wind Effect Forecast for July 29 PM, 2014

834.1 Ü Lake Winnipegosis

Winnipegosis Lake St. P! Martin 802.94

Dauphin Steep Lake Rock P! P!

858.96 Dauphin Lake P!Ochre Beach

Lake Winnipeg 716.39

Lundar Victoria Beach Beach Lake P! P! Manitoba Gimli P! Sandy Bay P! 814.59 Twin Lakes Beach P! Lynchs Point P! Oak Lake Beach Sifton !P Oak Lake 1411.53

1:220,000 1:1,400,000

Site Measured Level (ft) Date Time Wind Effect Alert Categories St. Ambroise 814.68 2014-07-28 11:00am Crest level increase will be greater than 5 feet; Twin Lakes 814.59 2014-07-28 11:50am Severe Wave action will be very significant and forceful. Lake Francis 814.03 2014-07-28 12:00pm Crest level increase will be between 3 and 5 feet; Lundar Beach 815.08 2014-07-28 1:00pm High Vogar 814.84 2014-07-28 3:05pm Wave action will be significant. Skunk Bay 814.50 2014-07-28 2:25pm Crest level increase will be between 2 and 3 feet; Dog Lake 815.31 2014-07-28 2:45pm Moderate-High Wave action will be considerable. Narrows 814.49 2014-07-28 2:15pm Crest level increase will be between 1 and 2 feet; Dolly Bay 814.48 2014-07-28 1:45pm Moderate Wave action will be moderate. Silver Bay 814.62 2014-07-28 11:35am Crest level increase will be less than 1 foot; Watchorn 814.63 2014-07-28 11:15am Low Daytons Bay 814.52 2014-07-28 0.4375 Wave action will be low. Fairford 814.01 2014-07-28 6:55am Wind set-up and wave action are predicted Davis Point 814.20 2014-07-28 9:05am No Alert to be light. Hillyer Rd 814.20 2014-07-28 8:45am Wind effect data not available. Peonan Point 813.94 2014-07-28 8:20am No Data

Note: All water levels labeled within the lakes are current wind eliminated lake levels provided in feet Hydrologic Forecasting and Water Management Manitoba Infrastructure & Transportation Manitoba Lake Wind Effect Forecast for July 30 AM, 2014