2024.06.19 Outflow Increases and Level Forecasts
Several lines of severe thunderstorms cross the Winnipeg River basin Tuesday June 18th. Rainfall totals reached up to 100 mm in some locations over the past 24 hours. Most of the basin received at least 30 mm of rain with areas around Rainy Lake and Namakan Lake seeing up to 75 mm. This precipitation has caused tributary flows to begin rising and inflows to the major lakes are expected to increase as a result of these storms.
The current level of Lake of the Woods is 323.18 m (1060.3 ft) , a 60th percentile level, within the normal range for this time of year. The average lake level increased by 6 cm (2.5 in) over the last week and is expected to increase by 5 to 8 cm (2 to 3 in) over the next week, depending on precipitation amounts and upstream flow changes. The current outflow of Lake of the Woods is 900 m3/s. With a few dry days in the forecast followed by a return of moderate precipitation, inflows are expected to remain high. An outflow increase to 1000 m3/s is scheduled for Thursday June 20th with another outflow increase to 1100 m3/s tentatively scheduled for Monday June 24th.
Each of these flow changes will cause a levels along the Winnipeg River to increase by approximately 30 cm, (12 in) directly downstream of the Norman Dam, by 22 cm (8.5 in) above the Dalles, and by 20 cm (8 in) at Minaki.
The current level of Lac Seul is 356.01 m (1168.01 ft), a 45th percentile level, within the normal range for this time of year. The average lake level increased by 14 cm (5.5 in) over the past week and is expected to increase by 11 to 13 cm (4 to 5 in) over the next week. Lac Seul authorized outflow is 300 m3/s with no changes currently scheduled.