1 FLOOD REPORT for MANITOBA July 8, 2014 – 09:00 Extremely High

FLOOD REPORT FOR MANITOBA

– July 8, 2014 09:00

Extremely high flows on the upper Assiniboine River and the Qu-Appelle River will result in record high water levels, well above 2011 levels, between Shellmouth Dam and St. Lazare. Officials in this area are advised to undertake necessary flood protection measures.

Environment Canada has issued a strong wind warning for the south basin of Lake Winnipeg for today and tomorrow. Strong winds will also affect Lake Winnipegosis and Lake Manitoba. o Lake Wind-Effect Warnings for Today: A moderate lake wind effect warning for the south basin of Lake Winnipeg and south shorelines of Lake Winnipegosis, and a low lake wind effect warning for the south shorelines of Lake Manitoba.

Flood - Assiniboine River, from Shellmouth Dam to Portage Reservoir Warning*: - All points along the Winnipeg River System, including Nutimik Lake - Souris River ’Appelle River - Qu - Lake St. Martin - Dauphin Lake

Flood - Assiniboine River, from Portage Reservoir to Headingley Watch*: - Red Deer Lake - Lake Manitoba - Lake Winnipeg

High Water - Red River Advisory*: - Saskatchewan River - Swan River - Red Deer River - Streams and drains in the Souris River Basin - Streams and drains in the Parkland region - Streams and drains in the Assiniboine Basin, from Holland upstream

Summary  The Assiniboine River at the Portage Reservoir is forecasted to peak at near 50,000 cfs around noon tomorrow. o As the crest approaches Portage, flows on the Portage Diversion and the lower Assiniboine River will be increased. o The flows on the Assiniboine River downstream of the diversion will gradually be increased to 18,000 cfs by midnight tonight. It will take approximately 24 hours before these flows reach Baie St. Paul and downstream communities. o Flows on the Portage Diversion will increase throughout today and tomorrow as the crest approaches. At the crest, it is expected that flow through the Portage Diversion will reach approximately 32,000 cfs.

 This morning, flow on the Assiniboine River upstream of the Portage Diversion was 41,700 cfs, flow on the Portage Diversion was 25,000 cfs and flow on the Assiniboine River downstream of the diversion was 16,700 cfs. Flow on the lower Assiniboine River is being increased in 500 cfs increments, reaching 18,000 cfs by midnight tonight.

 ’s Hydrologic Forecast Centre reports the Manitoba Infrastructure and Transportation wind forecast for today results in a moderate wind warning for the south shore of Lake Winnipeg and Lake Winnipegosis, and a low wind warning for the south shoreline of Lake Manitoba (see attached map for illustration of forecasted wind effect on lakes). o The winds on Lake Winnipeg could increase water levels by 2-3 feet in the south basin of the lake along with moderate wave action on southern shorelines. o The winds on Lake Winnipegosis could increase water levels by 2-3 feet with moderate wave action on southern shorelines. o The winds on Lake Manitoba could increase water levels by up to one foot in the south basin of the lake along with low wave action on southern shorelines.

 Extremely high flows on the upper Assiniboine River and the Qu-Appelle River will result in record high water levels, well above 2011 levels, between Shellmouth Dam and St. Lazare. Officials in this area are advised to undertake necessary flood protection measures.

 ’Appelle River at Welby, Saskatchewan have increased to record The flows on the Qu high levels, well out of the river bank and above the range of the gauge. The forecasted peak flow at St. Lazare is approximately 25,000 -28,500 cfs on July 14, this flow will result in water levels below the permanent flood protection dikes but approximately one foot higher than 2011 water levels.

 st The Assiniboine River in Brandon at 1 Street dropped to a water level of 1,182.3 feet. The second summer crest on the Assiniboine River at Brandon is expected on July 17- ’s 18 at 31,000-32,000 cfs, slightly below Sunday crest.

 Landowners on the lower Assiniboine River are advised to immediately make necessary preparations for high flows, with forecasted water levels one foot above the 2011 water level (18,000 cfs). The lower Assiniboine River is experiencing a loss of efficiency due to the growth of vegetation on the banks of the river, with field measurements confirming that water levels in 2014 are approximately one foot higher than water levels were at the

same flow in 2011. The projected peak flow of 18,000 cfs on the lower Assiniboine River will reach Baie St. Paul at approximately midnight July 9.

Weather  A mixture of sun and clouds are forecasted with the possibility of localized showers for southern Manitoba. Winds will continue from the northwest at 20-30 km/hour, with gusts of 50 km/hour possible in the Interlake and Winnipeg area. Temperatures will range from ° Celsius 20-23 .

 Mainly sunny conditions are anticipated for southern Manitoba tomorrow with a slight increase in temperatures and more southerly winds. Northwestern Manitoba will also see slightly higher temperatures with sun and cloudy conditions.

A strong wind warning continues for the south basin of Lake Winnipeg for today, tonight and Wednesday. The latest marine wind conditions can be viewed at http://weather.gc.ca/marine/anotherArea_e.html?mapID=04&siteID=08600&stationID

Red River  The Red River Floodway continues to operate as per established operating protocols. The water level above the Floodway inlet this morning was at 752.1 feet; the computed natural level is 752.5 feet. Flow in the Floodway channel is approximately 1,430 cfs. Flow upstream of the Floodway inlet is 35,960 cfs. The Red River Floodway is being operated under Rule 1, which means that water levels on the river upstream of the Floodway inlet remain below natural levels.

 Levels in Winnipeg increased slightly to 17.0 feet James Avenue datum, with flows on the Red River at 47,900 cfs. The combined operation of the Portage Diversion and the Red River Floodway is providing a 3.1 foot reduction in water levels at James Avenue. Levels and flows in Winnipeg are forecasted to remain relatively stable over the next few days and then increase to approximately 17.3-17.5 feet James Avenue by July 9-11, due to high flows on the Assiniboine River.

Assiniboine River  The Assiniboine River at the Portage Reservoir is forecasted to peak at near 50,000 cfs around noon tomorrow. o As the crest approaches Portage, flows on the Portage Diversion and the lower Assiniboine River will be increased. o The flows on the Assiniboine River downstream of the diversion will gradually be increased to 18,000 cfs by midnight tonight. It will take approximately 24 hours before these flows reach Baie St. Paul and downstream communities. o Flows on the Portage Diversion will increase throughout today and tomorrow as the crest approaches. At the crest, it is expected that flow through the Portage Diversion will reach approximately 32,000 cfs.

 Overbank flooding is occurring in the Assiniboine River valley in all reaches between the Shellmouth Dam and Brandon. Extremely high flows on the upper Assiniboine River and the Qu-Appelle River will result in record high water levels, well above 2011 levels,

between Shellmouth Dam and St. Lazare. Officials in this area are advised to undertake necessary flood protection measures.

 The water level on the Shellmouth Reservoir has increased to 1,415.7 feet; the summer target level is 1402.5 feet and the crest of the spillway is at 1408.5 feet. Inflows to the reservoir are approximately 18,370 cfs today; outflows from the reservoir are approximately 14,710 cfs. Outflows include 1,110 cfs of conduit flow and 13,600 cfs of spillway flow. The forecast for Shellmouth Dam has been decreased, inflow is forecasted to peak at approximately 18,700 cfs on July 11, the reservoir level is forecasted to peak at approximately 1416.1 feet on July 11, with a peak forecasted outflow of approximately 16,800 cfs on July 11.

 ’Appelle River The flows on the Qu at Welby, Saskatchewan have increased to record high levels, well out of the river bank and above the range of the gauge. The forecasted peak flow at St. Lazare is approximately 25,000 -28,500 cfs on July 14, this flow will result in water levels below the permanent flood protection dikes but approximately one foot higher than 2011 water levels.

 Work to prepare for these high flows is focussed on three fronts: the Portage Diversion; the Assiniboine River downstream of the Portage Diversion; and as a contingency, the Hoop and Holler controlled breach site and the downstream inundation area. o Work on the Portage Diversion is focused on reinforcing the dikes and the drop structures; peak flows in 2011 were approximately 34,000 cfs. o Work on the Assiniboine River downstream of Portage is focused on reinforcing the Assiniboine River dikes and, downstream from Baie St. Paul, assisting with flood protection measures for communities, homes and businesses adjacent to the river; peak flows in 2011 were approximately 18,000 cfs o Work to prepare for a controlled breach at the Hoop and Holler Bend is largely completed, including flood protection of properties in the downstream inundation area. Opening of a controlled breach will be a measure of last resort, used if the Portage Diversion and/or lower Assiniboine River dikes are not able to safely convey the inflows at the Portage Reservoir.

 If a controlled breach at Hoop and Holler Bend is required, up to 5,000 cfs could be released into the La Salle watershed near Elm River, where it would flow overland into the Elm River Channel, and then follow the Elm River Relief Channel, the Scott Coulee, the Scott Drain and the La Salle River downstream of the Elie dam and reservoir. o As the forecasted crest is sharp (i.e. of short duration) if the Hoop and Holler controlled breach is required, water may flow through the breach for only one or two days. o The Hoop and Holler emergency protection efforts are being prioritized in the inundation zone that was affected in 2011.

the growth of vegetation on the banks of the river, with field measurements confirming that water levels in 2014 are approximately one foot higher than water levels were at the same flow in 2011. The projected peak flow of 18,000 cfs on the lower Assiniboine River will reach Baie St. Paul at approximately midnight July 9.

 This morning, flow on the Assiniboine River upstream of the Portage Diversion was 41,700 cfs, flow on the Portage Diversion was 25,000 cfs and flow on the Assiniboine River downstream of the diversion was 16,700 cfs. flow on the lower Assiniboine River is being increased in 500 cfs increments, reaching 18,000 cfs by midnight tonight.

Souris River  The Souris River and some of the larger tributaries, such as Pipestone Creek, have crested but continue to experience high flows.

 The Souris River has crested at Melita, Souris and is declining. The Souris River at Wawanesa remains near crest with a flow of 16,400 cfs and a water level of 1,155.3 feet.

 Whitewater Lake is at a historic high of 1633.5 feet. The lake is high enough to spill naturally into the Medora Creek and it has been reported that a nearby road was overtopped, resulting in flooding of additional agricultural land.

Parkland Region  Flows on some streams in the Parkland Region remain high but are dropping quickly across the region.

 Flows on tributaries to Dauphin Lake remain high. The water level gauge on Dauphin Lake is reporting a water level of 859.5 feet but the water level on the lake is affected by wind. The forecasted peak water level on Dauphin Lake is 860.0-860.4 feet. Flood stage on Dauphin Lake is 858 feet and the summer target level is 855 feet. The peak water level in 2011 was 861.14 feet.

Manitoba Lakes  The Lake Manitoba water level this morning was at approximately 813.8 feet at the Steeprock gauge, while the water level at the Westbourne gauge was 814.2 feet. These water levels are affected by winds on the lake. The forecasted peak water level on Lake Manitoba is 814.6 feet in early August.

 The Fairford River Water Control Structure is being operated for maximum possible discharge; outflow from Lake Manitoba is approximately 13,220 cfs. The outflow is stable but north winds are forcing water to the south, decreasing the water level near the Lake Manitoba outlet, thereby decreasing outflow. The estimated natural outflow from Lake Manitoba at the current lake level, if the Fairford River Water Control Structure and ’t been constructed, is approximately 5, associated channel improvements hadn 500 cfs.

 Lake Manitoba is currently approximately 1.4 feet below unregulated levels (the levels that would have occurred in the absence of all provincial water control infrastructure)

because of the high outflows out of the Lake through the Fairford River Water Control Structure.

 The water level on Lake St. Martin is at 803.6 feet. Flow through the Lake St. Martin Emergency Outlet Channel on Sunday was measured at approximately 4,600 cfs. Some additional work remains to fully open the channel.

 Operation of the Lake St. Martin Emergency Outlet Channel will increase total outflow from Lake St. Martin, directly lowering levels, and will allow the Fairford River Water Control Structure to remain at maximum discharge longer, thus allowing for higher outflows from Lake Manitoba later in the year. 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 near 801 feet by late November, 2014.

 The water level on Lake Winnipeg is wind-affected, Manitoba Hydro`s latest forecast indicates that the lake will rise to 716.6 feet by late July. 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.

Eastern Region  The Winnipeg River system is experiencing very high flows due to significantly higher than normal precipitation in eastern Manitoba and northern-western Ontario. On July 3, 2014 the inflow to Pointe Du Bois was 91,100 cfs and the most recent forecast is for inflow to rise to 98,200 cfs by July 22, 2014, based on expected precipitation.

 ’s latest Downstream, Manitoba Hydro forecast from July 6, is that the lakes on the Winnipeg River could rise by the following amounts by July 18, 2014: o Nutimik Lake is at 908.2 feet today, and is forecasted to increase by 0.55 feet. o Dorothy Lake is forecasted to increase by 0.45 feet. o Margaret/Eleanor Lake is forecasted to increase by 0.35 feet. o Sylvia Lake is forecasted to increase by 0.2 feet.

 Natalie Lake, at Seven Sisters is being maintained at 896 feet to provide further relief from high water conditions upstream. This is a foot lower than normal high water operating procedures and 3.5 ft lower than normal water operating procedures.

 Manitoba Hydro reports that water levels at Lac du Bonnet will be managed between 835.3 and 836 feet, measured at the forebay of McArthur Falls. Water levels around 835.3 feet will be maintained over the next week or two.

 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 flow on the Saskatchewan River at The Pas today is 68,850 cfs and the water level is at 854.9 feet. The peak on the Saskatchewan River is forecasted at approximately 70,600 cfs, or a water level of 855.3 feet, from July 10-12.

 The flow on the Carrot River at Turnberry is at 4,040 cfs, and the water level increased by 0.4 feet. The Carrot River near The Pas is at 856.3 feet today, and is forecasted to peak at 856.8 feet by next week.

 Water levels on Red Deer Lake were reported at 863.4 feet yesterday, data for today was not available. Flood stage on the lake is 864.5 feet. The lake is projected to peak at a wind-eliminated water level of 864-864.25 feet between July 10 and 15.

 Cormorant Lake is at 844.6 feet this morning; the lake is forecasted to rise to 844.8- 845.2 feet in the next two weeks.

*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.