The current level of Lake of the Woods is 323.49 m (1061.3 ft), over 95th percentile level for this time of year. The average lake level rose by 27 cm (11 in) over past week. The lake has risen above the top of the Legislated Operating Range, 323.47 m (1061.25 ft). The International Lake of the Woods Control Board has been activated and will work with the Canadian Lake of the Woods Control Board to approve any actions taken with respect to Lake of the Woods. The dams in Kenora remain fully opened with no changes scheduled.
Inflow to Lake of the Woods is more than double the maximum outflow that is being released through the fully opened dams in Kenora. Following a wide convective system that passed through on the evening of May 12, flows are again rising in the Lake of the Woods-Rainy River basin.
With less rainfall expected in the near term, the level of the lake is forecast to rise by 20 to 25 cm (8-10 in) over the next 7 days. There is a small chance of higher rainfall which would result in faster lake level rise.
The 2014 peak level for Lake of the Woods was 323.78 m (1062.2 ft). With the expected rise over the next week, Lake of the Woods is likely to be close to this level in 7 days. Continued rise is expected beyond the 7-day forecast window as upstream reservoirs (Namakan and Rainy Lakes) continue to rise and are passing high flows. The LWCB is not able to forecast the level rise beyond the range of reliable precipitation forecasts (5-7 days).
The level of the Winnipeg River level will gradually rise with the with level of Lake of the Woods as the lake provides the pressure to push water through the outlet of the lake in Kenora. The river level is expected to see a rise of roughly 20-25 cm (8-10 in) above today’s level over the next 7 days with continued gradual rise likely beyond the forecast window. The 2014 peak level is expected to be reached near or shortly after the 7-day window. Wet weather could see this occurring earlier. Along the Winnipeg River in Ontario, Whitedog Generating Station operations are not able lower the level of the river due to hydraulic constrictions below Roughrock Lake. Whitedog is passing the water that is received and is not backing up the river.
For both Lake of the Woods and the Winnipeg River, relatively dry weather is needed to see a sharp drop in the flow from the tributaries which are still extremely high. These tributaries, including the Big Fork, Little Fork, Rapid River, Pinewood river and smaller tributaries that flow directly into Lake of the Woods are the earliest opportunity for a drop in inflow to the lake as reductions out of Rainy Lake are unlikely in the coming weeks.
The current level of Lac Seul is 355.74 m (1167.1 ft), an 85th percentile level for this time of year. Inflow to Lac Seul is extremely high, leading to the level of the lake rising by 58 cm (1.9 ft) over the past 7 days. The lake is expected to rise by 48-60 cm (1.6 ft) over the next 7 days.
Lac Seul outflow was increased from 300 to 400 m³/s on Thursday, May 12. The Board is actively examining options for Lac Seul outflow adjustments, balancing the rapid rise in Lac Seul level against the extremely high flow conditions downstream where flooding is already occurring.
Ontario Power Generation has scheduled a reduction to minimum flow in the Root River Diversion from Lake St. Joseph into Lac Seul for next week. More details will be provided at a later date.
Manitoba Hydro has provided the following forecast for the Winnipeg River in the Whiteshell.
The next lake levels forecast will be issued on Monday, May 16.