Across the Winnipeg River basin, tributary flows and lake inflows remain low due to the underlying drought conditions. Precipitation in July was closer to normal for some areas of the basin, notably along a band stretching from Fort Frances, through Dryden and up to Red Lake. Much of this rain was soaked up by the dry ground and did not run off as inflow to the rivers and lakes. With large outflow cuts from Rainy Lake this past week and warm temperatures causing lake water to evaporate, inflow to Lake of the Woods has dropped sharply. An outflow reduction, as described below, is therefore necessary to slow the lake level decline and maintain storage heading into the fall.
The current level of Lake of the Woods is 322.78 m (1059.0 ft), a 15th percentile level for this time of year. The average lake level declined by 3 cm (1 in) over the past week and is expected to remain stable over the next week. Lake of the Woods authorized outflow will decrease to 200 m3/s tomorrow, Friday, August 11.
This outflow reduction will cause the Winnipeg River water level to drop by approximately 9 cm (4 in) below the Norman Dam, 3 cm (1 in) above the Dalles, and will cause no change at Minaki.
The current level of Lac Seul is 356.08 m (1168.2 ft), a 20th percentile level for this time of year. The lake level remained stable over the past week and is expected to increase by 2 to 7 cm (1 to 2.5 in) over the next week. Lac Seul authorized outflow is 100 m3/s with no changes scheduled.