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.

Recent precipitation has been well above normal across the Winnipeg River watershed. However, due to cold temperatures most of this has been snowfall and there has only been a gradual increase in stream flows in some areas. With temperatures rising and rainfall forecast through the weekend, the LWCB expects basin flow conditions to rapidly change over the next week, leading to quickly rising water levels in many areas. Due to the potential for rapidly changing flow conditions and unstable ice cover, extra caution should be taken when on or near water bodies across the region.

This rain on snow is expected to cause inflow to Lake of the Woods to rise to an extremely high rate, with the latest lake level forecasts showing between 15-30 cm of lake level rise over the next week. Because the lake was drawn down over the winter to create storage room for the spring melt, a 30 cm water level rise will not result in a high lake level. However, such a rapid filling of the lake would leave limited buffer room for wet conditions later in the spring when the region typically sees the wettest weather of the year.

In response, the LWCB is directing larger outflow increases from Lake of the Woods this week and next. The level of the Winnipeg River will rise quickly due to these outflow increases together with local runoff from rain and melting snow. By next week, the Winnipeg River level is expected to be at a high level for the end of April, comparable to a moderately high June level. The higher outflow will help to conserve storage room in the lake, reducing the risk of high levels on Lake of the Woods and along the Winnipeg River should wet conditions continue.

The current level of Lake of the Woods is 322.58 m (1058.3 ft), a 50^th 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 increase by 15-30 cm (6-12 in) over the next week with the rapid rise in inflow.

Lake of the Woods authorized outflow is scheduled to be increased from 575 m³/s to 650 m³/s on Friday, April 22 and from 650 m³/s to 725 m³/s on Monday, April 25. Each of these outflow increases is expected to raise the level of the Winnipeg River as follows:

• Below Norman Dam: 18 cm (7 in)
• Above Kimberley Rapids: 18 cm (7 in)
• Winnipeg River Marina: 15 cm (6 in)
• Near Locke Bay: 15 cm (6 in)
• Above Myrtle Rapids: 15 cm (6 in)
• Above the Dalles: 14 cm (5.5 in)
• Above Throat Rapids: 14 cm (5.5 in)
• Minaki: no change from the first flow increase, 2 cm (1 in) from the second

Additional short-term river level rise is expected due to local runoff from rainfall and snowmelt.

Further outflow increases are likely next week. Details for these outflow changes will be provided on this Notice Board.

The current level of Lac Seul is 354.81m (1164.1 ft), a 45^th percentile level for this time of year. The average lake level rose by 6 cm (2 in) over the past week and is expected to increase by 15-25 cm (6-10 in) over the next week.

Lac Seul authorized outflow is scheduled to be increased from 100 m³/s to 150 m³/s on Friday, April 22.

April continues to see very high precipitation amounts and flows are quickly rising across many areas of the watershed. Cold temperatures over the past week have slowed the spring melt response. However, warmer temperatures with additional rainfall this week will see flows rising much more quickly.

The current level of Lake of the Woods is 322.56 m (1058.3 ft), a 50^th 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 increase by 15-20 cm (6-8 in) over the next week with the rapid rise in inflow.

Lake of the Woods authorized outflow is scheduled to be increased from 500 m³/s to 575 m³/s on Wednesday April 20. The Winnipeg River level immediately below Norman Dam will rise by approximately 18 cm (7 in) as a result of this flow increase. The river level rise will be less with distance downstream of Kenora with no effect expected at Minaki.

An additional outflow increase is likely on Friday, April 22, with further increases to follow next week. Details for these outflow changes will be provided on this Notice Board .

The current level of Lac Seul is 354.79 m (1164.0 ft), a 40^th percentile level for this time of year. The average lake level rose by 6 cm (2 in) over the past week and is expected to increase by 12-22 cm (5-9 in) over the next week.

Lac Seul authorized outflow is 100 m³/s with no changes currently scheduled.

The current level of Lake of the Woods is 322.50 m (1058.1 ft), a 45^th percentile level for this time of year. The average lake level increased by 4.9 cm (1.9 in) over the past week and is expected to increase by 6-13 cm (2.4-5.1 in) over the next week.

Lake of the Woods authorized outflow is 500 m³/s with no changes currently scheduled.

The current level of Lac Seul is 354.76 m (1163.9 ft), a 40^th percentile level for this time of year. The average lake level increased by 4.8 cm (1.9 in) over the past week and is expected to increase 7-13 cm (2.7-5.1 in) over the next week.

Lac Seul authorized outflow is 100 m³/s with no changes currently scheduled.