Flows in the eastern headwaters of the basin continue to rise and are now well above normal for early May. Dry weather over the past few days has provided some relief, and water levels in the upper tributaries are expected to peak over the weekend. As this large volume of water moves through the system, inflows to the major downstream lakes continue to increase.
At Lac Seul, refill is progressing rapidly, with lake levels now within the normal range. At Lake of the Woods, inflows are expected to rise gradually throughout the week. While local inflows are declining due to dry conditions, operators at Rainy Lake are making significant outflow increases to pass water arriving from the headwaters. To manage Lake of the Woods level rise, additional staggered outflow increases are required.
The current level of Lake of the Woods is 322.66 m (1058.6 ft), a 45th percentile level, within the normal range for this time of year. The average lake level increased by 6.5 cm (2.6 in) over the past week and is expected to increase by 4 to 5 cm (1.5 to 2 in) over the next week. Lake of the Woods authorized outflow will increase to:
- 325 m3/s on Friday, May 8th
- 375 m3/s on Sunday, May 10th
- 425 m3/s on Tuesday, May 12th
Each of these flow increases will cause the level of the Winnipeg River to increase, with a total level rise of approximately 33 cm (13 in) directly downstream of the Norman Dam and 15 cm (6 in) above the Dalles. The level at Minaki will not be affected by this flow change.
The current level of Lac Seul is 355.03 m (1164.8 ft), a 50th percentile level, within the normal range for this time of year. The lake level increased 25 cm (10 in) over the last week and is expected to increase by 18 to 22 cm (7 to 8.5 in) over the next week. Lac Seul authorized outflow is 175 m3/s. An update on the next outflow increase will be provided early next week.