Flood Report for Manitoba
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FLOOD REPORT FOR MANITOBA June 30, 2014 A wind warning is in effect for Lake Manitoba, Lake Winnipeg, Lake Winnipegosis and Lake of the Woods. Significant overland flooding is occurring in the Parklands region and Southwest region of Manitoba. Flood Warning*: - Assiniboine River, from Shellmouth Dam to Brandon (due to high flows) - All points along the Winnipeg River System, including Nutimik Lake - Lake St. Martin - Dauphin Lake - Qu’Appelle River - Vermillion River Near Dauphin - Wilson River Near Dauphin - Valley River Near Dauphin - Medora Creek near Napinka - Gainsborough Creek Near Lyleton - Gopher Creek Near Virden - Roaring River at Minitonis - McKinnon Creek Near McCreary - Scissor Creek Near McCauley - Little Souris River Near Brandon - Epinette Creek Near Carberry - Graham Creek Near Melita - Little Saskatchewan River Near Rivers Flood Watch*: - Lake Manitoba - Lake Winnipeg High Water - All points along the Red River Advisory*: - All points along the Saskatchewan River - All points along the Souris River Summary Environment Canada has issued a wind warning for Lake Manitoba, the north and south basins of Lake Winnipeg, Lake Winnipegosis, and Lake of the Woods. o On Lake Manitoba, west winds will become northerly on Tuesday morning gusting 23-50 km/h. o On Lake Winnipeg (south basin), west winds will become northerly gusting at 30 – 55 km/h; on the north basin winds will become northerly with similar wind speeds. o On Lake Winnipegosis winds will increase from a northerly and northwest direction at 26-53 km/h. o On Lake of the Woods winds will be up to 55 km/h from the west then southwest. For more information: http://weather.gc.ca/marine/region_e.html?mapID=04 Manitoba Infrastructure and Transportation’s Hydrologic Forecast Centre reports lake wind forecast for tomorrow suggests a high to severe wind warning for Lake Manitoba and the southern basin of Lake Winnipeg, southern shoreline of Lake Winnipegosis . The winds could increase water levels and result in significant wave action on southern and south eastern and southwestern shorelines (with water levels that could rise 3-5 feet) . Weather The storm system over the weekend brought significant amounts of rainfall to parts of western Manitoba, with some locations reporting well over 100 mm. Yesterday Brandon received approximately 45 mm; Dauphin 17 mm, and Melita 30 mm. Winnipeg received 11 mm, and Gimli received 22 mm. Rainfall for today is expected to be lighter as the low pressure system moves north and eastward. Amounts today generally will be 10-15 mm in the Brandon, Dauphin area with similar amounts in the Whiteshell. The Interlake is expected to receive lesser amounts with Gimli forecasted to receive 5-10 mm with possible additional showers in the evening and overnight. Red River The Red River will operate under Rule 1 starting on July 1st at 9:00 AM; a safety river boom will be installed on the river today. The Floodway will operate so that river water levels upstream of the floodway inlet remain below natural. The Red River is rising at all points in Manitoba. The Red River at James Avenue in downtown Winnipeg is at 17 feet today and is forecasted to go up to 17.4 feet to 17.7 feet in the next week. The river is forecasted to stay above 14 feet until mid July. There is the potential that the Red River Floodway could be operated under Rule 4 in the future, to reduce the risk of basement flooding damages within Winnipeg, depending on weather conditions. The current forecasted weather for the next five days indicates favourable weather, without the potential for intense rainfalls that can result in basement flooding. 2 Assiniboine River There is overbank flooding in the Assiniboine River valley in all reaches between Shellmouth Dam and Brandon. The water level on the Shellmouth Reservoir has increased to 1,410.9 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 6,280 cfs today; outflows from the reservoir are approximately 3,720 cfs. Outflows include 1,060 cfs of conduit flow and 2,660 cfs of spillway flow. The forecasted inflows, outflows and reservoir levels are being re- evaluated because of the rising inflows from the upper Assiniboine River watershed. The Portage Diversion is in operation. Flow on the Assiniboine River upstream of the Portage Diversion is 12,000 cfs. The Portage Diversion is diverting 1,780 cfs. Parkland Region Flows on many of the rivers and streams in the Parkland Region reached record levels due to the weekend precipitation event. Most have crested or are near crest at the gauging stations. Flows on tributaries to Dauphin Lake are increasing due to the recent precipitation. Dauphin Lake is currently at 858.6 feet. The forecasted peak water level on Dauphin Lake is 860.0 – 860.4 feet, due to the effects of the recent precipitation event. The 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 was at approximately 813.9 feet at the Steeprock gauge, while the water level at the Westbourne gauge was 812.8 feet. These levels are very affected by the recent strong winds. The forecasted peak level is being re-evaluated, to account for the effects of the recent precipitation event. Lake Manitoba is currently approximately 1.8 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 actual outflows have been higher than what the natural outflows would have been for all of 2014, and also in previous years. The Fairford River Water Control Structure is being operated for maximum possible discharge; outflow from Lake Manitoba is approximately 13,830 cfs. 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 4,500 cfs. The Lake St. Martin gauge is registering a real-time water level reading of 803.3 feet, which is somewhat effected by the recent wind event. The forecasted peak lake level is being re-evaluated to account for the effects of the recent precipitation event. 3 Work to initiate the re-opening of the Lake St. Martin Emergency Outlet Channel will begin July 2. Operation of the Lake St. Martin Emergency Channel will increase outflow from Lake St. Martin, directly lowering levels, and 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 initial discharge through the Lake St. Martin Emergency Outlet Channel will be approximately 5,600 cfs. The channel is expected to stay open until the spring of 2015, and will help bring the Lake St. Martin water level below 801 feet by October 31, 2014. Lake Winnipeg is at 715.6 feet, and Manitoba Hydro`s latest forecasts are that it will rise to 716.1 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. Nutimik Lake, which is part of the Winnipeg River system, is at 908.4 feet, a record high level on the lake. The Lake of the Woods Control Board has indicated that Nutimik Lake could rise by an additional foot by mid-July, depending on weather conditions. Dorothy and Eleanor Lakes, which are downstream from Nutimik Lake, are also experiencing high water levels and some overland flooding. Some boat houses are being flooded and some sandbagging is underway. The Pas and Northern Manitoba The flow on the Saskatchewan River at The Pas today is 63,380 cfs. The forecast for the Saskatchewan River is being re-evaluated to take into account the recent precipitation amounts, and a new forecast will be provided shortly. The flow on the Carrot River at Turnberry in Saskatchewan increased by 910 cfs, and the water level rose by over 2 ft. Forecasted peak water levels within Manitoba will be provided shortly. Cormorant Lake is at 844.6 feet this morning. The forecasted peak is currently being re- evaluated. *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. 4 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. 5 Manitoba Lake Wind Effect Forecast for July 1, 2014 833.405 Wind Effect Alert Categories Crest level increase will be greater than 5 feet; Severe Wave action will be very significant and forceful. Ü Crest level increase will be between 3 and 5 feet; High Lake Wave action will be significant. Winnipegosis Crest level increase will be between 2 and 3 feet; 803.33 Moderate-High Winnipegosis Wave action will be considerable.