With warm temperatures across the Winnipeg River basin and rainfall forecast for tomorrow, river flows and lake inflows are expected to increase. At Lac Seul, this will mark the beginning of the refill period, with lake levels rising rapidly as the snowpack melts. At Lake of the Woods, small, incremental increases to outflow will begin tomorrow and are likely to continue into next week, as upstream basin inflows are expected to increase. The lake level has been rising steadily, and with ice cover still in place, outflow adjustments are necessary to slow the rise and reduce the risk of damage to docks fixed in the ice.
The current level of Lake of the Woods is 322.54 m (1058.2 ft), a 40th percentile level, within the normal range for this time of year. The average lake level increased by 5 cm (2 in) over the past week and is expected to increase by 6 to 10 cm (2.4 to 4 in) over the next week. Lake of the Woods authorized outflow will increase to 225 m3/s on Friday, April 24th. Additional small outflow increases may be required next week.
This flow increase will cause the level of the Winnipeg River to increase by approximately 4.5 cm (1.8 in) directly downstream of the Norman Dam and by 1.5 cm (0.6 in) above the Dalles. The level at Minaki will not be affected by this flow change.
The current level of Lac Seul is 354.61 m (1163.4 ft), a 15th percentile level, below the normal range for this time of year. The lake level remained stable over the last week and is expected to increase by 18 to 27 cm (7 to 10 in) over the next week. Lac Seul authorized outflow is 150 m3/s, with no changes scheduled.