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2024.09.24 Conditions Update and Outflow Changes

After recent rainfall across the Winnipeg River basin last week, lake levels have increased slightly. The forecast indicates dry conditions for the next week which is expected to lead to decreasing inflows in the southern portion of the basin. In the northern portion of the basin inflows remain higher.

The current level of Lake of the Woods is 322.81 m (1059.1 ft), a 35th percentile level, in the normal range for this time of year. The average lake level remained stable over the last week and over the last week and is expected to remain relatively stable over the next week, increasing or decreasing by 1 cm (less than 0.5 in).

Outages are planned for the Norman Dam and Kenora Powerhouse as indicated in last week’s noticeboard post. Estimated changes in level downstream as a result of the outages can be found at the link above. After the work is completed at the Norman Dam on September 25th, outflow will be restored to 300 m3/s, a 25 m3/s decrease from flows before the outage.

This outflow decrease will mean that levels after the outage will be:

  • 5 cm (2 in) less than before the outage below the Norman Dam
  • 2 cm (1 in) less than before the outage below the Dalles
  • The water level at Minaki will not be impacted by this outflow reduction.

The current level of Lac Seul is 356.37 m (1169.19 ft), a 45th percentile level, within the normal range for this time of year. The average lake level increased by 7 cm (3 in) over the past week and is expected to decrease 2 to 4 cm (1 to 1.5 in). Lac Seul authorized outflow is 300 m3/s. An increase to 350 m3/s is scheduled for Thursday September 26th.


The LWCB Basin Data page will not be updated on Monday, September 30th (Truth and Reconciliation Day, Canada). Daily data updates and publication will resume on Tuesday, October 1st.

2024.09.19 Conditions Update and Notice of Outages at Norman Dam and Kenora Powerhouse

The Winnipeg River Basin has received a significant amount of rain over the past 3 days, following several weeks of relatively dry weather. This rainfall has caused flows in tributaries to increase along with inflow to the main lakes. While some rain is expected today and tomorrow the following week is expected to return to dry weather.

As outflow from most lakes in the basin was low due to the dry weather, this rapid increase in flow has caused levels to climb. This increase will be temporary as dry weather is expected to cause flows to decrease over the coming week.

The current level of Lake of the Woods is 322.83 m (1059.2 ft), a 35th percentile level, in the normal range for this time of year. The average lake level increased by 1 cm (less than 0.5 in) over the last week and is expected to remain relatively stable over the next week, increasing or decreasing by 1 cm (less than 0.5 in) depending on rainfall.

The dam operator is planning work around the Norman Dam and Kenora Powerhouse for September 25th and 26th. This will require no flow through the structures for the duration of the work. The work at the Norman Powerhouse will be completed September 25th from 12:00 to 19:00 CDT. During this outage, outflow from Lake of the Woods will be reduced to 127 m3/s through the Kenora Powerhouse only. The work at the Kenora Powerhouse will be completed September 26th from 9:30 to 12:30 CDT. During this outage, outflow from Lake of the Woods will be 325 m3/s through the Norman Powerhouse only. Once both outages are complete, outflow from Lake of the Woods will be restored to the authorized 325 m3/s with flow through both the Norman Dam and Kenora Powerhouse.

These outages will cause temporary level fluctuations along the Winnipeg River as follows:

Directly downstream of the Norman Dam:

  • On September 25th a large decrease of up to 50 cm (20 in) followed by a similar increase after the outage is completed that day.
  • On September 26th an increase of 15 cm (6 in) followed by a similar decrease after the outage is completed that day.

Directly downstream of the Kenora Powerhouse:

  • On September 25th an increase of 8 cm (4.5 in) followed by a similar decrease after the outage is completed that day.
  • On September 26th a decrease of 8 cm (4.5 in) followed by a similar increase after the outage is completed that day.

Above the Dalles:

  • On September 25th a decrease of 12 cm (5 in) followed by a similar increase after the outage is completed that day.
  • On September 26th no significant level changes are anticipated.

The water level at Minaki will not be affected by these flow changes.

These level changes are estimates based on flow through the structures and actual level changes may vary. For any questions related to these outages, please contact the Secretariat by emailing secretariat@lwcb.ca or calling 1-800-661-5922.

The current level of Lac Seul is 356.34 m (1169.09 ft), a 40th percentile level, within the normal range for this time of year. The average lake level increased by 3 cm (1 in) over the past week and is expected to increase 1 cm (less than 0.5 in) before decreasing by 1 to 3 cm (less than 0.5 to 1 in) over the next week. Lac Seul authorized outflow is 300 m3/s with no changes scheduled.

2024.09.12 Level Forecast and Outflow Reductions

Conditions have remained very dry over the past week and as a result inflows have continued to decline. The figure below shows the total precipitation over the last 3 days. This dry pattern has persisted since September 6th.

Although there is some potential for rainfall in the forecast, with outflow reductions from Rainy Lake, inflows to Lake of the Woods are expected to continue decreasing, requiring further outflow reductions.

The current level of Lake of the Woods is 322.82 m (1059.1 ft), a 30th percentile level, in the normal range for this time of year. The average lake level decreased by 4 cm (1.5 in) over the last week and is expected to remain relatively stable over the next week, increasing or decreasing by 2 cm (1 in) depending on rainfall. Outflow reductions at Lake of the Woods will continue to slow the rate of level decline. Lake of the Woods authorized outflow will decrease to:

  • 350 m3/s on Thursday, September 12th
  • 325 m3/s on Monday, September 16th
  • 300 m3/s on Wednesday, September 18th

The scheduled outflow reductions will cause levels along the Winnipeg River to decline as follows:

  • Directly downstream of the Norman Dam: approximately 5 cm (2 in) September 12th, 5 cm (2 in) September 16th, and 5 cm (2 in) September 18th for a total drop of 15 cm (6in) total drop by September 18th
  • Above the Dalles: approximately 3 cm (1 in) September 12th, 2 cm (1 in) September 16th and 2 cm (1 in) September 18th for a total drop of 7 cm (3 in) total drop by September 18th
  • The water level at Minaki will not be affected by these flow changes.

The current level of Lac Seul is 356.31 m (1168.99 ft), a 30th percentile level, within the normal range for this time of year. The average lake level declined by 3 cm (1 in) over the past week and is expected to decrease 1 to 5 cm (0.5 to 2 in) over the next week. Lac Seul authorized outflow is 300 m3/s with no changes scheduled.

2024.09.05 Level Forecast and Outflow Reductions

Although the basin is received some rainfall yesterday and more is expected today, dry conditions are expected to return next week and inflow to the major lakes will continue to decline.

The current level of Lake of the Woods is 322.86 m (1059.3 ft), a 35th percentile level, in the normal range for this time of year. The average lake level decreased by 6 cm (2 in) over the last week and is expected to decrease by 2 to 3 cm (0.5 -1 in), over the next week. Outflow reductions at Lake of the Woods will continue to slow the rate of level decline. Lake of the Woods authorized outflow will decrease to:

  • 425 m3/s on Thursday, September 5th
  • 375 m3/s on Monday, September 9th
  • 350 m3/s on Thursday, September 12th

The scheduled outflow reductions will cause levels along the Winnipeg River to decline as follows:

  • Directly downstream of the Norman Dam: approximately 19 cm (7.5 in) September 5th, 12 cm (5 in) September 9th and 5 cm (2 in) September 12th for a total drop of 36 cm (14 in) total drop by September 12th
  • Above the Dalles: approximately 10 cm (4 in) September 5th, 6 cm (2 in) September 9th and 3 cm (1 in) September 12th for a total drop of 19 cm (7.5 in) total drop by September 12th
  • The water level at Minaki will not be affected by these flow changes.

The current level of Lac Seul is 356.34 m (1169.1 ft), a 30th percentile level, within the normal range for this time of year. The average lake level declined by 4 cm (1.5 in) over the past week and is expected to decrease 1 to 2 cm (less than 0.5 in) over the next week. Lac Seul authorized outflow is 350 m3/s and will decrease to 300 m3/s Saturday September 7th.

2024.08.29 Level Forecast and Lake of the Woods Outflow Reductions

Although the basin is receiving some rainfall today, dry conditions are expected to return next week and inflow to the major lakes will continue to decline.

The current level of Lake of the Woods is 322.92 m (1059.5 ft), an 45th percentile level, in the normal range for this time of year. The average lake level decreased by 8 cm (3 in) over the last week and is expected to decrease by 3 to 6 cm (1 to 2 in), over the next week. Outflow reductions at Lake of the Woods will continue to slow the rate of level decline. Lake of the Woods authorized outflow will decrease to:

  • 575 m3/s on Friday, August 30th
  • 500 m3/s on Tuesday, September 3rd
  • 425 m3/s on Thursday, September 5th

The scheduled outflow reductions will cause levels along the Winnipeg River to decline as follows:

  • Directly downstream of the Norman Dam: approximately 19 cm (7.5 in) with each outflow reduction, 40 cm (16 in) total drop by September 5th
  • Above the Dalles: approximately 10 cm (4 in) with each outflow reduction, 21 cm (8.5 in) total drop by September 5th
  • The water level at Minaki will not be affected by these flow changes.

The current level of Lac Seul is 356.38 m (1169.2 ft), a 30th percentile level, within the normal range for this time of year. The average lake level declined by 2.5 cm (1 in) over the past week and is expected to remain stable over the next week. Lac Seul authorized outflow is 350 m3/s with no changes scheduled.


The LWCB Basin Data page will not be updated on Monday, September 2nd (Labour Day). Daily data updates and publication will resume on Tuesday, September 3rd.

2024.08.22 Level Forecast and Lake of the Woods Outflow Reductions

The current level of Lake of the Woods is 323.00 m (1059.7 ft), an 50th percentile level, in the normal range for this time of year. The average lake level decreased by 8 cm (3 in) over the last week and is expected to decrease by 2 to 5 cm (0.5 to 2 in), over the next week. 

The basin received almost no precipitation over the past week, and only moderate amounts of rainfall are expected over the next week. Therefore, additional outflow reductions are required to continue to slow the rate of level decline on Lake of the Woods. Authorized outflow will decrease to:

  • 725 m3/s on Friday, August 23rd
  • 675 m3/s on Monday, August 26th
  • 625 m3/s on Wednesday, August 28th
  • 575 m3/s on Friday, August 30th

The scheduled outflow reductions will cause levels along the Winnipeg River to decline as follows:

  • Directly downstream of the Norman Dam: approximately 14 cm (5.5 in) with each outflow reduction, 43 cm (17 in) total drop by August 30th
  • Above the Dalles: approximately 9 cm (3.5 in) with each outflow reduction, 27 cm (10.5 in) total drop by August 30th
  • Minaki: Once Lake of the Woods outflow falls below 700 m3/s, the level at Minaki will once again be managed by the Whitedog Dam forebay elevation. The water level will drop approximately 13 cm (5 in) before stabilizing at or below 316.09 m (1037.0 ft) early next week.

The current level of Lac Seul is 356.41 m (1169.3 ft), a 35th percentile level, within the normal range for this time of year. The average lake level declined by 0.5 cm (0.5 in) over the past week and is expected to remain stable over the next week. Lac Seul authorized outflow is 350 m3/s with no changes scheduled.

2024.08.15 Level Forecast and Lake of the Woods Outflow Reductions

Inflow to Lake of the Woods has dropped extremely quickly, going from 80th to 40th percentile over the last week. The lake level has also declined rapidly coming down as much as 13 cm (5 in) over the last week and now sitting in the normal range. Weather forecasts for the Winnipeg River basin are hot and relatively dry for the next week. Therefore, to slow Lake of the Woods level decline, and balance outflow with inflow, additional outflow reductions are required next week.

The current level of Lake of the Woods is 323.08 m (1059.9 ft), an 55th percentile level, in the normal range for this time of year. The average lake level decreased by 12 cm (4.5 in) over the last week and is expected to decrease by 4 to 7 cm (1.5 to 2.5 in), over the next week. Lake of the Woods authorized outflow will decrease to:

  • 875 m3/s on Friday, August 16th
  • 825 m3/s on Monday, August 19th
  • 775 m3/s on Wednesday, August 21st
  • 725 m3/s on Friday, August 23rd

The scheduled outflow reductions will cause levels along the Winnipeg River to decline as follows:

  • Directly downstream of the Norman Dam: 15 cm (6 in) with each outflow reduction, 74 cm (29 in) total drop by August 23rd
  • Above the Dalles: 11 cm (4 in) with each outflow reduction, 51 cm (20 in) total drop by August 23rd
  • Minaki: 10 cm (4 in) with each outflow reduction, 50 cm (19.5 in) total drop by August 23rd

The current level of Lac Seul is 356.41 m (1169.3 ft), a 35th percentile level, within the normal range for this time of year. The average lake level increased by 2 cm (1 in) over the past week and is expected to remain stable over the next week. Lac Seul authorized outflow is 350 m3/s with no changes scheduled.

2024.08.13 Lake of the Woods Outflow Reductions

The current level of Lake of the Woods is 323.11 m (1060.1 ft), a 55th percentile level, in the normal range for this time of year. The average lake level decreased by 13 cm (4 in) over the last week and is expected to decrease by 6 to 10 cm (2 to 4 in), over the next week.

Over the last week, dam operators did no accurately estimate outflow at the outlet of Lake of the Woods. As a result, additional outflow reductions are required to achieved an authorized outflow of 875 m3/s by Saturday, August 17th as planned. Lake of the Woods outflow will decrease by approximately:

  • 100 m3/s on Wednesday, August 14th
  • 93 m3/s on Friday, August 16th

If conditions remain dry, similar outflow reductions will be required the following week to slow the rate of lake level decline. The scheduled outflow reductions will cause levels along the Winnipeg River to decline as follows:

  • Directly downstream of the Norman Dam: 30 cm (12 in) with each outflow reduction, 53 cm (21 in) total drop by August 17th
  • Above the Dalles: 23 cm (9 in) with each outflow reduction, 40 cm (16 in) total drop by August 17th
  • Minaki: 20 cm (8 in) with each outflow reduction, 34 cm (13 in) total drop by August 17th

2024.08.08 Level Forecast and Lake of the Woods Outflow Reductions

The northern portions of the Winnipeg River basin are receiving moderate precipitation this week which will help maintain levels and flows. In the southern half of the basin, precipitation has been low and forecasts for next week are very dry. Inflow to Lake of the Woods is therefore declining rapidly and the lake level has also started to drop. To maintain a gradual decline in lake level, outflow reductions at Lake of the Woods are required, as long as conditions remain dry.

The current level of Lake of the Woods is 323.20 m (1060.4 ft), an 80th percentile level, above the normal range for this time of year. The average lake level decreased by 8 cm (3 in) over the last week and is expected to decrease by 6 to 10 cm (2 to 4 in), over the next week. Lake of the Woods authorized outflow will decrease to:

  • 975 m3/s on Thursday, August 8th
  • 925 m3/s on Monday, August 12th
  • 875 m3/s on Thursday, August 15th

If conditions remain dry, similar outflow reductions will be required the following week to slow the rate of lake level decline. The scheduled outflow reductions will cause levels along the Winnipeg River to decline as follows:

  • Directly downstream of the Norman Dam: 15 cm (6 in) with each outflow reduction, 52 cm (20 in) total drop by August 16th
  • Above the Dalles: 11 cm (4 in) with each outflow reduction, 38 cm (15 in) total drop by August 16th
  • Minaki: 10 cm (4 in) with each outflow reduction, 33 cm (13 in) total drop by August 16th

The current level of Lac Seul is 356.36 m (1169.2 ft), a 30th percentile level, within the normal range for this time of year. The average lake level decreased by 2 cm (1 in) over the past week and is expected to decrease by 2 to 4 cm (0.5 to 1.5 in) over the next week. Lac Seul authorized outflow is 350 m3/s with no changes scheduled.

2024.08.06 Lake of the Woods Outflow Reduction

Levels have been steadily declining on Lake of the Woods for more than a week and are expected to continue declining with decreasing flows on the Rainy River upstream. The current level of Lake of the Woods is 323.24 m (1060.5 ft), an 85th percentile level, above the normal range for this time of year. The average lake level decreased by 6 cm (2 in) over the last week and is expected to decrease by 3 to 6 cm (1 to 2 in), over the next week. Lake of the Woods authorized outflow will decrease to 975 m3/s on Thursday, August 8th. Depending on precipitation, additional outflow reductions may be required next week.  

This outflow reduction will cause levels along the Winnipeg River to decline by approximately 22 cm (8.5 in) directly downstream of the Norman Dam, 17 cm (6.5 in) above the Dalles and 14 cm (5.5 in) at Minaki.

Inflows and levels at Lac Seul are expected to remain stable over the next week. No outflow changes are planned with authorized outflow remaining at 350 m3/s.