Dry conditions over the past week have helped ease flows in the Winnipeg River basin, particularly in the headwaters where tributary flows remain well above normal for this time of year. The dry and warm weather is expected to persist until Sunday, after which a shift in the weather pattern is forecast. A low pressure system will move across the region on Monday, bringing significant moisture in the form of widespread precipitation and embedded thunderstorms. Although the exact track of the system is still uncertain, the rain is expected to linger for a couple days and be heavy at times.
This precipitation will halt the declining flows and cause inflows to the major lakes to increase over the coming week. Although both Lake of the Woods and Lac Seul are still refilling, continued gradual outflow increases are required to slow the rate of lake level rise. The LWCB is monitoring conditions closely and using the adopted Regulation Strategy to guide operations in consideration of the various interests across the basin.
The current level of Lake of the Woods is 322.73 m (1058.8 ft), a 50th percentile level, within the normal range for this time of year. The average lake level increased by 7 cm (2.8 in) over the past week and is expected to increase by 8 to 15 cm (3 to 6 in) over the next week. Lake of the Woods authorized outflow will increase to:
- 475 m3/s on Friday, May 15th
- 550 m3/s on Tuesday, May 19th
Each of these flow increases will cause the level of the Winnipeg River to increase, with a total level rise of approximately 32 cm (13 in) directly downstream of the Norman Dam and 17 cm (7 in) above the Dalles. The level at Minaki will not be affected by this flow change.
The current level of Lac Seul is 355.26 m (1165.5 ft), a 60th percentile level, within the normal range for this time of year. The lake level increased by 23 cm (9 in) over the last week and is expected to increase by 18 to 25 cm (7 to 10 in) over the next week. Lac Seul authorized outflow will increase to:
- 300 m3/s on Friday, May 15th
- 350 m3/s on Tuesday, May 19th
The LWCB Basin Data page will not be updated on Monday, May 18th (Victoria Day in Canada). Daily data updates and publication will resume on Tuesday, May 19th.