PROVINCE ISSUES MARCH FLOOD OUTLOOK FOR 2017Flood Risk Remains Moderate to Major in West, Eases in Red River Valley
Levels of spring flooding continue to be dependent on future weather conditions, however the risk of overland flooding is slightly reduced since the February outlook while it still remains moderate to major across the province.
The province’s Hydrologic Forecast Centre continues to monitor precipitation, spring melt and inflows from the northern United States and the Souris River basin to the west. At this time, the Souris River basin continues to be of concern while favourable weather conditions have eased expected flows in the Red River Basin. Based on the current outlook, the chance of closing PTH 75 during the spring runoff is low.
The potential for spring runoff is generally normal to above normal throughout all watersheds, with the exception of the Souris River basin which has above normal to well-above normal runoff potential. At this time, it is anticipated the province’s major flood infrastructure, including the Red River Floodway and the Portage Diversion, would be activated under unfavourable weather conditions.
At this time, with unfavourable weather, the outlook suggests:
- watersheds in the southwestern region: major risk;
- Pembina River: moderate to major risk;
- Roseau River: moderate to major risk;
- Assiniboine River: moderate to major risk;
- Eastern region and the Winnipeg River: major risk;
- Interlake region and the Fisher River: moderate risk;
- Red River: moderate risk;
- northern Manitoba/The Pas regions and the Saskatchewan, Carrot and Swan rivers: moderate risk.
At this time, forecasted flood levels for major rivers are as follows:
- the Red River from Emerson to the floodway inlet with normal weather levels would be similar to 2013, with unfavourable weather observed levels would be similar to 2010;
- with the benefit of floodway operations James Avenue 4.6m (15 feet) for favourable weather or 5.5m (18 feet) in unfavourable conditions;
- the Pembina River with normal weather river levels would be similar to 1998, with unfavourable weather levels would be lower than 2011;
- the Roseau River with normal weather river levels would be similar to 2013, with unfavourable weather levels would be similar to 2011;
- the Assiniboine River with normal weather river levels from Shellmouth to Brandon would be similar to 2009 but lower than 2005, levels from Brandon to Portage would be similar to 1995 levels, with unfavourable weather levels from Shellmouth to Brandon would be slightly lower than 1976 or 1995, levels from Brandon to Portage would be less than 2011 or the summer of 2014;
- the Souris River with normal weather river levels at Wawanesa would be similar to 2014 summer levels, with unfavourable weather levels would be lower than 1976 and 2011 levels at Wawanesa; and
- the Fisher River with normal weather river levels would be similar to 2006, with unfavourable weather levels would be lower than 2008.
Dauphin Lake remains a concern at this time. Even with normal future weather conditions, the lake could rise above the flood stage. With unfavourable weather conditions between now and the spring runoff, the lake could rise more than 1.5 ft. above the flood stage.
Following a municipal tour of potentially affected areas throughout southwestern Manitoba, the minister noted the province plans and prepares for flood risk predicted with unfavourable weather conditions and the scenario of highest flood risk.
The province will provide daily flood information to municipalities once runoff commences which they can use to fine tune flood preparations.
More information is available at www.gov.mb.ca/flooding.
Article courtesy of Infrastructure Minister Blaine Pedersen