April 2023

The current level of Lake of the Woods is 322.68 m (1058.7 ft), a 60^th percentile level for this time of year. The average lake level increased by 12 cm (4 in) over the past week and is expected to increase by 5 to 7 cm (2 in) over the next week. Lake of the Woods authorized outflow was increased to 675 m³/s today and currently, there are no additional increases scheduled.

The current level of Lac Seul is 354.89 m (1164.3 ft), a 50^th percentile level for this time of year. The lake level increased by 5 cm (2 in) over the past week and is expected to increase by 7 to 10 cm (2.5 to 4 in) over the next week. Lac Seul authorized outflow is 100 m³/s with no changes scheduled.

Inflow to Lake of the Woods remains high and as a result, the level of Lake of the Woods increased by 15 cm (5 in) over the last week. With some precipitation in the forecast, another outflow increase is scheduled this week to slow the rate of level rise.

Lake of the Woods authorized outflow will increase to 675 m³/s on Thursday, April 27. This flow change will cause levels along the Winnipeg River to increase by 14 cm (5 in) directly below the Norman Dam and by 9 cm (4 in) above the Dalles. The level at Minaki will not be affected.

A precipitation system will impact southern portions of the Winnipeg River basin this Friday, April 21. Snow is expected, with amounts ranging from 10 to 15 cm (4 to 6 in) and in some locations as high as 25 cm (10 in). This precipitation will, in the short term, cause increased flows and levels in the rivers and lakes. In the long-term, this added snowpack will increase the snow water content and as it melts will cause river flows and lake inflows to remain at above normal levels. Additional larger outflow increases are scheduled at Lake of the Woods to help slow the rate of level rise. The ice cover is no longer in place on the Winnipeg River, minimizing the impact of river level rise due to these outflow increases.

The current level of Lake of the Woods is 322.57 m (1058.3 ft), a 50^th percentile level for this time of year. The average lake level increased by 14 cm (5 in) over the past week and is expected to increase by 13 to 16 cm (5 to 6 in) over the next week. Lake of the Woods authorized outflow will increase to 575 m³/s on Friday, April 21 (slightly higher than planned) and again to 625 m³/s on Monday, April 24.

Each of these outflow changes will cause levels along the Winnipeg River to increase by 14 cm (5 in) directly below the Norman Dam and by 8 cm (3 in) above the Dalles for a total rise of 28 cm (11 in) and 16 cm (6 in) respectively at each location. These flow changes will not affect the level at Minaki.

Less precipitation is forecast to impact the English River basin on April 21st. In this basin, freshet is slow to begin and river flows and lake inflows are at low-normal conditions. As such, an outflow reduction was scheduled at Lac Seul to allow for the lake level to start rising gradually in anticipation of higher spring inflows.

The current level of Lac Seul is 354.84 m (1164.2 ft), a 50^th percentile level for this time of year. The lake level increased by 3 cm (1 in) over the past week and is expected to increase by 6 to 8 cm (2 to 3 in) over the next week. Lac Seul authorized outflow was reduced to 100 m³/s on April 20.

Inflow to Lake of the Woods continues to rise and is expected to remain high over the next week. Another round of precipitation is forecast to impact the southern portion of the Winnpeg River basin at the end of the week and flows on the Rainy River are expected to increase.

To slow the rate of level rise on Lake of the Woods and achieve a gradual refill of the lake, staged outflow increases will continue with increases of 25 m³/s per day to minimize impacts downstream on the Winnipeg River. Authorized outflow will increase to 500 m³/s on April 19, to 525 m³/s on April 20 and to 550 m³/s on April 21.

Each of these outflow changes will cause levels along the Winnipeg River to increase by 6 cm (2 in) directly below the Norman Dam and by 3 cm (1 in) above the Dalles for a total rise of 20 cm (8 in) and 11 cm (4 in) respectively at each location by Friday. These flow changes will not affect the level at Minaki.

Inflow to Lake of the Woods increased over the weekend due to precipitation and increased flows from the Rainy River. As a result, the level of Lake of the Woods increased by 7 cm (2.5 in) over the last three days.

To slow the rate of level rise and achieve a gradual refill of the lake, staged outflow increases are planned this week starting with an increase to 450 m³/s today, April 17, and another increase to 475 m³/s tomorrow, April 18. Each of these outflow changes will cause levels along the Winnipeg River to increase by 6 cm (2 in) directly below the Norman Dam and by 3 cm (1 in) above the Dalles. These flow changes will not affect the level at Minaki.

As inflow stabilizes and the accuracy of this week’s precipitation forecast improves, the need for additional outflow increases will be assessed.

A low pressure system will impact the Winnipeg River basin this Friday, April 14 and into Saturday, April 15. The heaviest precipitation is expected to occur over the Northern half of the basin, resulting in additional snow or freezing rain on top of the current snowpack. Warmer temperatures during the day, and on Saturday, will result in moderate amounts of rain basin wide.

This event will accelerate the freshet that has already begun with snow melting rapidly over the last week due to the warm and sunny conditions. Runoff from the precipitation is expected to cause river flows and lake inflows to increase temporarily. Lake levels are expected to start increasing gradually starting the refill period.

The current level of Lake of the Woods is 322.43 m (1057.8 ft), a 30^th percentile level for this time of year. The average lake level remained stable over the past week and is expected to increase by 2 to 6 cm (1 to 2 in) over the next week. Lake of the Woods authorized outflow is 425 m³/s with no changes scheduled.

The current level of Lac Seul is 354.81 m (1164.1 ft), a 50^th percentile level for this time of year. The lake level changed little over the past week and is expected to increase by 3 to 8 cm (2 to 3 in) over the next week. Lac Seul authorized outflow is 150 m³/s with no changes scheduled.

Due to a power outage in the National Capital region, the Basin Data page could not be updated today. It will also not be updated over the Easter long weekend. Daily data updates will resume on Tuesday, April 11.

Flow and level data is available at the source websites:

• Water Survey of Canada
• United States Geological Survey

The following level forecast was produced on April 5:

The current level of Lake of the Woods is 322.42 m (1057.8 ft), a 35^th percentile level for this time of year. The average lake level declined by 1 cm (0.5 in) over the past week and is expected to decline by up to 2 cm (1 in) over the next week. Lake of the Woods authorized outflow is 425 m³/s with no changes scheduled.

The current level of Lac Seul is 354.80 m (1164.0 ft), a 45^th percentile level for this time of year. The lake level declined by 2 cm (1 in) over the past week and is expected to remain stable over the next week. Lac Seul authorized outflow is 150 m³/s with no changes scheduled.

The LWCB has published an updated version of its “Before You Build” page. This document provides guidance on hazard land levels for construction of docks, boathouses and cottages and has been updated to reflect the high water levels of 2022.

New hazard land levels have been established for:

• Winnipeg River in Manitoba – Nutimik Lake
• English River – Below Ear Falls/Pakwash Lake

Statistics and reference water levels have also been updated to reflect more recent data.

For questions or comments, please email secretariat@lwcb.ca