The Hydrologic Forecast Centre of Manitoba Infrastructure and Transportation has released the 2015 Fall Conditions Report on soil moisture levels at freeze-up, which at this time suggests high levels in the western areas of the province while the Red River Valley is about average.
The Hydrologic Forecast Centre is gathering information now that will form the flood forecasts in the first few months of 2016.
The 2015 Fall Conditions Report notes flood forecasters look at six primary factors when assessing long-term prospects for potential floods or droughts in the spring and summer. One of the factors is the amount of moisture in the soil before freeze-up, accumulated over the summer and fall.
The report also notes:
- most river basins in Manitoba, the Red, Assiniboine, Qu’Appelle and Souris river watersheds, received normal to above normal precipitation between April and November;
- the upstream watershed of the Saskatchewan River received normal precipitation between April and November while downstream received above normal precipitation;
- precipitation in September, October and November was above normal to well above normal throughout the watersheds of the Saskatchewan, Assiniboine, Qu’Appelle and the Souris river basins, with a higher risk of spring flooding within these river basins if future precipitation is normal to above normal and fast snowmelt occurs;
- soil moisture in the Saskatchewan, Assiniboine, Qu’Appelle and Souris river basins is slightly greater than the soil moisture observed in the fall of 2014, which led to above average run-off in spring of 2015;
- the Red River basin has a mixed soil moisture pattern with the Manitoba portion of the basin having above normal soil moisture and the United States portion of it with normal to below normal soil moisture;
- the Whiteshell Lakes area, including the Lake of the Woods area, has near normal soil moisture conditions;
- current lake levels indicate that most lakes, including Lake Manitoba, are within desirable ranges for this time of the year;
- the Saskatchewan, Assiniboine, Qu’Appelle and Souris Rivers currently have base flows that are considered well-above normal;
- the Red River base flow is also above normal for this time of year with above normal base flows and levels representing a higher potential for spring flooding; and
- Environment Canada’s latest long-term precipitation forecast indicates precipitation will be above normal for parts of the Souris River basin and northern Manitoba and will be near normal for the rest of the province, and the Hydrologic Forecast Center will regularly monitor the winter precipitation patterns throughout these basins.
As spring approaches, the province will assess the flood potential and prepare as required. This will include working with municipal emergency management teams to review existing emergency response plans and sharing information through conference calls and flood-preparedness meetings.
The first flood outlook is expected to be available towards the end of February. The 2015 Fall Conditions Report is available at www.gov.mb.ca/flooding.
