Since the beginning of January, temperatures across the Winnipeg River basin have plunged and the region is experiencing its coldest weather since the start of winter. December was much warmer than average, with much less precipitation than average. With very little snowpack accumulated, many areas of the basin are classified as being abnormally dry or in a moderate to severe drought on the Canadian and U.S. Drought Monitors. In northern Minnesota, where a large part of the inflow to Lake of the Woods is generated, snow depth is less than 2 inches and ranks lowest compared to average snow depth at this time of year.
Although there is a lack of snow, the southern portion of the Winnipeg River basin, around Namakan and Rainy Lakes, was impacted by a series of weather systems in late December. These systems brought rain, resulting in a rise in flows in the rivers and inflows to the lakes. A series of outflow increases at both Namakan and Rainy Lakes was required to maintain the lake levels within their Rule Curves. Inflows to Lake of the Woods also increased in the second half of December. The lake level is no longer declining and sits at a 30th percentile level for this time of year.
In order to ensure continuous drawdown of the lake and to target spring levels as set out in the Regulation Strategy, a small outflow increase from Lake of the Woods is required.
The current level of Lake of the Woods is 322.59 m (1058.4 ft), a 30th percentile level for this time of year. The average lake level declined by less than 1 cm (0.5 in) over the past week and is expected to decline by 1 to 2 cm (0.5 in) over the next week. Lake of the Woods authorized outflow will increase to 325 m3/s on Monday, January 15.
This flow increase will cause levels on the Winnipeg River to rise by approximately 5 cm (2 in) downstream of the Norman Dam, 2 cm (1 in) at the Dalles and will cause very little level change at Minaki. Please be cautious when on or near the ice as flow and level changes can affect ice conditions.
The current level of Lac Seul is 355.35 m (1166.8 ft), a 15th percentile level for this time of year. The lake level declined by 9 cm (3 in) over the past week and is expected to decline by 9 to 11 cm (3 to 4 in) over the next week. Lac Seul authorized outflow is 325 m3/s with no changes scheduled.
Special Notice for Winnipeg River Directly Downstream of Dams in Kenora:
On January 10, H2O Power performed a flow switch at the Norman Dam and Kenora Powerhouse. While maintaining the Lake of the Woods authorized outflow of 300 m3/s (which is computed as the total outflow from these two dams), the outflow from the Norman Dam was increased by approximately 44 m3/s and the outflow from the Kenora Powerhouse was decreased by 44 m3/s. This was done to provide maintenance on the generators at the Kenora Powerhouse. These changes resulted in immediate water level changes directly downstream of the dams. This flow switch was not authorized by the Lake of the Woods Control Board (LWCB). It is the LWCB’s preference to limit winter flow changes and to provide notice to residents of any notable water level changes and any potential impacts to ice conditions.