The spring freshet is underway for many areas of the Winnipeg River drainage basin. Precipitation over the past few days has added to the water content of the snowpack and resulted in a slow rise in flows in many tributaries.
The LWCB is regulating outflows from Lac Seul and Lake of the Woods to begin refill of these lakes according to its recently adopted Regulation Strategy. The rate of lake level rise and the associated changes in outflow from these lakes will depend largely on the precipitation received over the coming weeks.
The current level of Lake of the Woods is 322.44 m (1057.9 ft), a 35th percentile level for this time of year. The average lake level was stable over the past week and is expected to rise by 3-6 cm (1-2 in) over the next week. Meteorological forecasts indicate the potential for above-normal April precipitation from April 13-14. If this develops, the lake will rise at a faster rate.
Lake of the Woods authorized outflow is scheduled to be increased from 450 m³/s to 475 m³/s on Friday, April 8 and to 500 m³/s on Monday, April 11. The level of the Winnipeg River immediately below Norman Dam is expected to rise by 6 cm (2 in) as a result of each of these flow increases, while the river level at Minaki will not be affected. Additional flow increases next week are likely if precipitation forecasts are accurate.
The current level of Lac Seul is 354.70 m (1163.7 ft), a 40th percentile level for this time of year. The average lake level rose by 1 cm (1/2 in) the past week and is expected to rise by 5-8 cm (2-3 in) over the next week.
Lac Seul authorized outflow was reduced from 125 m³/s to 100 m³/s on Tuesday, April 5. No flow changes are currently scheduled.