Record flow conditions are occurring across many areas of the Winnipeg River drainage basin in Ontario, Manitoba and Minnesota following record high precipitation since the start of April. Forecasts indicate that all areas will continue to see exceptionally high flows for the 7-day forecast period. A return to normal flows is unlikely in the coming weeks.

The current level of Lake of the Woods is 323.60 m (1061.7 ft), over 95th percentile level for this time of year. The average lake level rose by 30 cm (12 in) over past week. The lake has risen above the top of the Legislated Operating Range, 323.47 m (1061.25 ft). The International Lake of the Woods Control Board has been activated and will work with the Canadian Lake of the Woods Control Board to approve any actions taken with respect to Lake of the Woods. The dams in Kenora remain fully opened with no changes scheduled.

Inflow to Lake of the Woods remains more than double the maximum outflow that is being released through the fully opened dams in Kenora. Upstream, the dams at Namakan Lake and Rainy Lake continue to be fully opened, with gradually rising outflow. The level at Namakan Lake is higher than the 2014 peak and may exceed all-time records depending on precipitation this month. Rainy Lake is nearing the 2014 peak and continued rise is expected. Outflow reductions from these lakes, therefore, are likely weeks away. With Rainy Lake releasing over 1000 m³/s, inflow to Lake of the Woods will remain very high.

Adding to the flow from Rainy Lake, the tributaries to the Rainy River have peaked again and are slowly dropping. The flow of the Rainy River at Manitou Rapids, approximately halfway between Rainy Lake and Lake of the Woods, is over 1700 m³/s. Total inflow to Lake of the Woods, including the flow out of the Rainy River and all other sources is estimated at over 2500 m³/s, while Lake of the Woods outflow from the fully opened dams in Kenora is estimated at 1250 m³/s and slowly rising with the lake level. As long as outflow is less than inflow, the lake will continue to rise. The level of Lake of the Woods is expected to rise by approximately 15-20 cm (6-8 in) over the next 7 days. Inflow is expected to decrease over this period, but still remain well above the outflow. Continued rise beyond the 7-day forecast window is expected.

As the lake continues to rise, the level of the Winnipeg River between Kenora and Minaki will also rise. The level rise over the next 7 days below Norman Dam and down to Minaki is expected to be 12-16 cm (5-7 in). This estimate is approximate given uncertainty in the extremely high local flows entering the river from tributary areas below Kenora (e.g. Black Sturgeon). The river will continue to gradually rise as long as Lake of the Woods continues to rise.

The current level of Lac Seul is 355.99 m (1167.8 ft), a 90th percentile level for this time of year. Lac Seul inflow is extremely high, resulting in a rise of 68 cm (2.2 ft) over the past week. With the rapid rise in the level of the lake expected to continue, the LWCB has directed the closure of the Root River Diversion (which draws flow out of Lake St. Joseph into Lac Seul), on Thursday, May 19. This will reduce flow into Lac Seul by approximately 90 m³/s. The LWCB has also directed an increase in the outflow from Lac Seul from 415 m³/s to 465 m³/s on Tuesday, May 17, and to 565 m³/s on Thursday, May 19. Additional increases will be evaluated by the LWCB through the week.

The LWCB recognizes that downstream areas along the English River, including Pakwash Lake, Grassy Narrows, and the Winnipeg River in Manitoba are already experiencing extremely high and damaging water levels. However, should extreme inflows to Lac Seul continue through May, the level of Lac Seul will likely reach the top of the legislated flood reserve, requiring much higher outflows to prevent further lake level rise. High outflows from Lac Seul in the near term reduce the risk of extremely high flows in the medium term.

These flow increases from Lac Seul will take some time to work down the English River, with an estimate of about two weeks to reach Nutimik Lake. If there is limited precipitation in the English River basin over the next week, declining flows out of tributaries such as the Wabigoon River may balance the additional flow arriving from Lac Seul to some degree.

The current level of Lake of the Woods is 323.49 m (1061.3 ft), over 95th percentile level for this time of year. The average lake level rose by 27 cm (11 in) over past week. The lake has risen above the top of the Legislated Operating Range, 323.47 m (1061.25 ft). The International Lake of the Woods Control Board has been activated and will work with the Canadian Lake of the Woods Control Board to approve any actions taken with respect to Lake of the Woods. The dams in Kenora remain fully opened with no changes scheduled.

Inflow to Lake of the Woods is more than double the maximum outflow that is being released through the fully opened dams in Kenora. Following a wide convective system that passed through on the evening of May 12, flows are again rising in the Lake of the Woods-Rainy River basin.

With less rainfall expected in the near term, the level of the lake is forecast to rise by 20 to 25 cm (8-10 in) over the next 7 days. There is a small chance of higher rainfall which would result in faster lake level rise.

The 2014 peak level for Lake of the Woods was 323.78 m (1062.2 ft). With the expected rise over the next week, Lake of the Woods is likely to be close to this level in 7 days. Continued rise is expected beyond the 7-day forecast window as upstream reservoirs (Namakan and Rainy Lakes) continue to rise and are passing high flows. The LWCB is not able to forecast the level rise beyond the range of reliable precipitation forecasts (5-7 days).

The level of the Winnipeg River level will gradually rise with the with level of Lake of the Woods as the lake provides the pressure to push water through the outlet of the lake in Kenora. The river level is expected to see a rise of roughly 20-25 cm (8-10 in) above today’s level over the next 7 days with continued gradual rise likely beyond the forecast window. The 2014 peak level is expected to be reached near or shortly after the 7-day window. Wet weather could see this occurring earlier. Along the Winnipeg River in Ontario, Whitedog Generating Station operations are not able lower the level of the river due to hydraulic constrictions below Roughrock Lake. Whitedog is passing the water that is received and is not backing up the river.

For both Lake of the Woods and the Winnipeg River, relatively dry weather is needed to see a sharp drop in the flow from the tributaries which are still extremely high. These tributaries, including the Big Fork, Little Fork, Rapid River, Pinewood river and smaller tributaries that flow directly into Lake of the Woods are the earliest opportunity for a drop in inflow to the lake as reductions out of Rainy Lake are unlikely in the coming weeks.

The current level of Lac Seul is 355.74 m (1167.1 ft), an 85th percentile level for this time of year. Inflow to Lac Seul is extremely high, leading to the level of the lake rising by 58 cm (1.9 ft) over the past 7 days. The lake is expected to rise by 48-60 cm (1.6 ft) over the next 7 days.

Lac Seul outflow was increased from 300 to 400 m³/s on Thursday, May 12. The Board is actively examining options for Lac Seul outflow adjustments, balancing the rapid rise in Lac Seul level against the extremely high flow conditions downstream where flooding is already occurring.

Ontario Power Generation has scheduled a reduction to minimum flow in the Root River Diversion from Lake St. Joseph into Lac Seul for next week. More details will be provided at a later date.

Manitoba Hydro has provided the following forecast for the Winnipeg River in the Whiteshell.

The next lake levels forecast will be issued on Monday, May 16.

The current level of Lake of the Woods is 323.40 m (1061.1 ft), over 95th percentile level for this time of year. The average lake level rose by 25 cm (10 in) over past week.

Inflow to Lake of the Woods is more than double the maximum outflow that is being released through the fully opened dams in Kenora. With more rainfall in the near-term forecast, the level of the lake is forecast to rise by 22 to 30 cm (9-12 in) over the next 7 days, depending on the track of convective storms in next system. There is a small chance of much higher rainfall which would result in higher lake level rise and also a small chance of less level rise.

The 2014 peak level for Lake of the Woods was 323.78 m (1062.2 ft). With the expected rise over the next week, Lake of the Woods will be nearing this level. Continued rise is expected beyond the 7-day forecast window and the lake may exceed the 2014 peak level in May if wet weather continues. The LWCB is not able to forecast the level rise beyond the range of precipitation reliable precipitation forecasts (5-7 days). If the weather in the near term is much drier than forecast, a peak below the 2014 high is possible.

The level of the Winnipeg River level will gradually rise with the with level of Lake of the Woods as the lake provides the pressure to push water through the outlet of the lake in Kenora. If the lake reaches the 2014 peak level, the level of the river will as well, roughly 30 cm (1 ft) above today’s levels near Kenora and near Minaki.

The current level of Lac Seul is 355.53 m (1166.4 ft), a 75th percentile level for this time of year. Inflow to Lac Seul is extremely high, leading to the level of the lake rising by 45 cm (1.5 ft) over the past 7 days. The lake is expected to rise by 55-60 cm (2 ft) over the next 7 days.

Lac Seul outflow is scheduled to be increased from 300 to 400 m³/s on Thursday, May 12. Further increases are being planned for the coming week.

Ontario Power Generation has scheduled a reduction to minimum flow in the Root River Diversion from Lake St. Joseph into Lac Seul for next week. More details will be provided at a later date.

Manitoba Hydro has provided the following forecast for the Whiteshell Region as of May 5.

The LWCB held a public webinar on May 10 to review the high flow conditions across the Winnipeg River drainage basin. A recording of the presentation will be posted for limited period on YouTube.

Key points from the Webinar are as follows:

1. A moderately high snowpack by end March in the Rainy-Namakan sub-basin and most of the Lake of the Woods sub-basin, with higher amounts near Kenora. Snowpack for this region was similar to 2019, and much less than 2014, the last year with high water in spring.

2. Precipitation in April set new records for all regions of the Winnipeg River basin except Lac La Croix (3rd highest) and Rainy-Namakan (tied with 2001 for record). April 1-May 9 precipitation was near double the total precipitation from December 1-March 31 for Lac Seul, Rainy-Namakan and Lake of the Woods sub-basins, and 300-500% of normal for April, with the highest amounts to the northwest.

3. Much of the precipitation in early April added to the water in the snowpack and temperatures mid-month fell well below normal. The spring melt was delayed, as three consecutive weeks saw large Colorado Lows pass through. As temperatures warmed at the end of the month, rain on snow caused a rapid rise in flows in the Lake of the Woods-Rainy River basin. This rise started in early May in the English River basin.

4. The rain-on-snow occurred while the ground was still frozen, resulting in rapid runoff to tributaries and eventually to the major rivers and lakes. Record flows for early May developed in all regions, with some rivers seeing all-time records broken (e.g. Wabigoon River, Vermilion River). Record inflows for this time of year are occurring in each of the major lakes (Lac Seul, Namakan Lake, Rainy Lake and Lake of the Woods). In many areas the major tributaries continue to rise, exceptions being the Big Fork and Little Fork Rivers that feed into Rainy River, and Vermilion River that flows to Namakan Lake. Dams at Namakan Lake and Rainy Lake have been fully opened and will not be closed until these lakes return to the regulated level ranges set by the International Joint Commission, which will likely take weeks. Outflow from Rainy Lake will, therefore, provide high flow input to the Rainy River and Lake of the Woods for weeks.

5. Compared to spring high water events in recent memory (2001, 2002, 2014) which peaked in June or July, this event is occurring earlier. This is cause for concern because May and June are typically the wettest months of the year, and there is little removal of water through evaporation or plant take-up compared with June or July.

6. The LWCB expects that weeks of high water will be ahead for all regions of the Winnipeg River watershed. How long this lasts depends on how much rain falls in the coming weeks. There are no additional actions that can be taken at dams to limit water level rise in the Lake of the Woods-Winnipeg River system now that the dams in Kenora are fully opened. Along the Winnipeg River in Ontario, Whitedog Generating Station operations are not able lower the level of the river due to hydraulic constrictions below Roughrock Lake. Whitedog is passing the water that is received and is not backing up the river.

Because rainfall cannot be accurately forecast beyond 5-7 days, it is not possible for the LWCB to provide an estimate as to when any region of the basin will see water levels stop rising or return to normal. Both Lake of the Woods and the Winnipeg River will continue to rise as long as the flow into Lake of the Woods is greater than the flow going out of the fully opened dams in Kenora. The Winnipeg River in Manitoba is likely to reach extremely high levels with high flows from both the English River and Winnipeg River in Ontario flowing into the Whiteshell.

7. Water levels across the region could reach 2014 peaks or higher. There is no upper limit for flows, which are entirely dependent on rainfall across the basin in the coming weeks. Residents and communities in areas that experienced high water impacts in 2014 should make preparations accordingly.

The LWCB will post 7-day lake level forecasts for Lake of the Woods and Lac Seul on Mondays, Wednesdays and Fridays through the high water period. Forecasts will be posted on this Notice Board.

Extremely high Rainy River flows into Lake of the Woods are expected to continue with the full opening of the Rainy Lake dam and record flows for this time of year out of the Fork Rivers in Minnesota. Lake of the Woods is expected to continue to rise beyond the top of the legislated operating range, 323.47 m (1061.25 ft). Wet weather could result in the levels of Lake of the Woods and of the Winnipeg River continuing to rise quickly in May.

Norman Dam to be Fully Opened May 7

The current level of Lake of the Woods is 323.16 m (1060.2 ft), over 95th percentile for the first week of May. The average lake level rose by 31 cm (12 in) over the past week and is expected to rise by 25-32 cm (10-13 inches) over the next week.

Outflow from Lake of the Woods is scheduled to be increased to 1125 m³/s on May 5 (see details below). The LWCB has directed the full opening of the Norman Dam on Saturday, May 7, which is expected to increase outflow to 1250 m³/s. This additional flow is expected to raise the level of the Winnipeg River as follows:

Below Norman Dam: 35 cm (14 in)
Above Kimberley Rapids: 30 cm (12 in)
Winnipeg River Marina: 31 cm (12 in)
Near Locke Bay: 30 cm (12 in)
Above Myrtle Rapids: 30 cm (12 in)
Above the Dalles: 30 cm (12 in)
Above Throat Rapids: 30 cm (12 in)
Minaki: 22 cm (9 in)

Lake of the Woods and the Winnipeg River will continue to rise until inflow is in balance with the outflow. Levels will not decline until outflow is greater than the inflow.

Lac Seul and English River Flows Rising Quickly

Flows in the English River and Lac Seul are expected to rise quickly over the next week with rapid melting of the heavy snowpack. Tributaries will likely see very rapid rise in level and flows.

The current level of Lac Seul is 355.06 m (1164.9 ft), a 55th percentile level for this time of year. The lake level rose by 14 cm (6 in) over the past week, and is expected to rise by 20-30 cm (8-12 in) over the next week. Lac Seul authorized outflow is scheduled to be increased from 330 m³/s to 400 m³/s on Friday, May 6.

Virtual Public Information Session May 10

The Lake of the Woods Control Board will host a virtual Public Information Webinar from 7:00-8:00 p.m. CT on Tuesday May 10. The Webinar will cover the latest conditions and forecasts and participants will be able to submit questions to the Board. Please email secretariat@lwcb.ca for access details.

The Lake of the Woods Control Board met on May 2 to review current conditions and water level projections for Lake of the Woods. Inflow to Lake of the Woods is expected to continue to be well above the maximum outflow rate from the lake for the 7-day forecast period. Based on this projection, the lake is expected to rise towards the top of the legislated operating range by mid-May. The Board is directing the full opening of the Norman Dam by May 7 in response.

The current level of Lake of the Woods is 323.09 m (1060.0 ft), over 95th percentile for the first week of May. The average lake level rose by 30 cm over the past week and is expected to rise by 15-20 cm (6-8 inches) over the next week.

Lake of the Woods outflow is scheduled to be increased from 1025 to 1125 m³/s on Thursday, May 5. The Winnipeg River is expected to rise as follows as a result of this outflow increase:

Below Norman Dam: 30 cm (12 in)
Above Kimberley Rapids: 24 cm (10 in)
Winnipeg River Marina: 24 cm (10 in)
Near Locke Bay: 24 cm (10 in)
Above Myrtle Rapids: 24 cm (10 in)
Above the Dalles: 24 cm (10 in)
Above Throat Rapids: 24 cm (10 in)
Minaki: 18 cm (7 in)

Outflow will be increased again on Saturday, May 7, with the full opening of the Norman Dam. Details of the expected flow change and river level rise will be provided later in the week.

Flows in the English River and Lac Seul are expected to rise quickly over the next week with rapid melting of the heavy snowpack. Tributaries will likely see very rapid rise in level and flows.

The current level of Lac Seul is 355.0 m (1165.7 ft), a 55th percentile level for this time of year. The lake level rose by 10 cm (4 in) over the past week, and is expected to rise by 10-15 cm (4-6 in) over the next week.

Lac Seul authorized outflow is scheduled to be increased from 225 to 330 m³/s on Wednesday, May 4. A further increase is planned for later in the week, details for which will be provided on this Notice Board.

With additional rainfall from another Colorado Low this weekend, the next outflow increase from Lake of the Woods has been scheduled for Sunday, May 1. Lake of the Woods outflow will be increased from 925 m³/s to 1025 m³/s. The Winnipeg River is expected to rise as follows in response to the outflow increase, with additional temporary rise likely due to local runoff and rainfall:

Below Norman Dam: 30 cm (12 in)
Above Kimberley Rapids: 24 cm (10 in)
Winnipeg River Marina: 24 cm (10 in)
Near Locke Bay: 23 cm (9 in)
Above Myrtle Rapids: 22 cm (9 in)
Above the Dalles: 22 cm (9 in)
Above Throat Rapids: 23 cm (9 in)
Minaki: 19 cm (8 in)

With Sunday’s increase, outflow is estimated to be at 92% of maximum capacity. Maximum outflow capacity is limited by the lake level, which provides the pressure to push water out of the lake and past Norman Dam. As the lake continues to rise, outflow will also gradually rise as will the level of the Winnipeg River.

The LWCB will meet again on Monday, May 2 to review the latest conditions and forecasts and evaluate further outflow increases.

Flows in many areas of the Rainy-Lake of the Woods basin remain exceptionally high for the end of April. However, some major rivers, including the Big Fork and Little For Rivers in Minnesota and Rainy River, have crested and are declining. With dry weather, flows are expected to continue to decline but will still be very high. Wet weather could stall the drop in flows or have them climbing again. Most current weather forecasts indicate limited rainfall for the next week.

The current level of Lake of the Woods is 322.85 m (1059.2 ft), a 75th percentile level for this time of year. The average lake level rose by 25 cm (10 in) over the past week and is projected rise 15-25 cm (6-10 in) over the next week. This projection is based on current 7-day precipitation forecasts and expected outflow adjustments from Rainy Lake. Higher rainfall totals or higher outflows could see greater rise in the lake level.

The LWCB met this week to review the extreme conditions and evaluate further outflow increases from Lake of the Woods. It has directed a further outflow increase tomorrow and will reassess the need for additional increases on Monday, May 2.

Lake of the Woods outflow is scheduled to be increased on Friday, April 29 from 825 m³/s to 925 m³/s. The level of the Winnipeg River is expected to rise as follows as a result of this outflow increase:

Below Norman Dam: 30 cm (12 in)
Above Kimberley Rapids: 24 cm (10 in)
Winnipeg River Marina: 23 cm (9 in)
Near Locke Bay: 23 cm (9 in)
Above Myrtle Rapids: 22 cm (9 in)
Above the Dalles: 21 cm (8 in)
Above Throat Rapids: 22 cm (9 in)
Minaki: 20 cm (8 in)

The current level of Lac Seul is 354.91 m (1164.4 ft), a 55th percentile level for this time of year. The average lake level rose by 10 cm (4 in) over the past week and is expected to rise by 6-10 cm (2-4 in) over the next week. Lac Seul authorized outflow is scheduled to be increased from 150 to 225 m³/s on Friday, April 29.

Rainfall totals from last weekend’s Colorado Low were very high for this time of year, with the highest amounts around Rainy Lake. This is the sixth straight quarter-month period with well-above normal precipitation in the Rainy-Namakan and Lake of the Woods local sub-basins, making this April one of the wettest on record. With the most recent rainfall coming on snow and frozen ground, the rise in flows in tributaries across the region has been rapid.

The LWCB was informed that outflow from the Rainy Lake dam at Fort Frances-International Falls into the Rainy River is being maximized in response to the heavy rainfall in that area and rapidly rising Rainy Lake. Tributaries to the Rainy River, including the Big Fork River, Little Fork River, Rapid River, La Vallee River and Pinewood River are near to or have broken record high levels for April. The combination of very high flows out of Rainy Lake and from these tributaries has inflow to Lake of the Woods from the Rainy River at an extremely high rate. Additional runoff from around the lake is also contributing to a rapid rise in the lake level.

Most of the tributaries to Rainy River have either crested or appear to close to cresting for now, with several days of dry weather in the forecast. However, inflow to Lake of the Woods will remain very high and the lake will continue to rise quickly as a result.

The current level of Lake of the Woods is 322.77 m (1058.7 ft), a 70th percentile level for this time of year. The average lake level rose by 18 cm (7 in) over the past week and is projected rise 25-35 cm (10-14 in) over the next week. This projection is based on current 7-day precipitation forecasts and expected outflow adjustments from Rainy Lake. Higher rainfall totals or higher outflows could see greater rise in the lake level.

Lake of the Woods outflow was increased from 650 to 725 m³/s on Monday, April 25. Outflow is scheduled to be increased from 725 m³/s to 825 m³/s on Wednesday, April 27. The Winnipeg River is expected to rise as follows in response to this outflow increase, with additional rise possible from local runoff:

• Below Norman Dam : 30 cm (12 in)
• Above Kimberley Rapids : 24 cm (10 in)
• Winnipeg River Marina: 21 cm (8 in)
• Near Locke Bay: 21 cm (8 in)
• Above Myrtle Rapids: 21 cm (8 in)
• Above the Dalles: 20 cm (8 in)
• Above Throat Rapids: 21 cm (8 in)
• Minaki: 21 cm (8 in)

Further increases in outflow will follow in the coming days and will be posted on this Notice Board.

The current level of Lac Seul is 354.90 m (1164.4 ft), a 50th percentile level for this time of year. The average lake level rose by 9 cm (4 in) over the past week and is expected to rise by 2-7 cm (1-3 in) over the next week. Lac Seul authorized outflow is 150 m³/s. An outflow increase is being planned for Friday, April 29. Details will be provided on this Notice Board.