Adopted Strategy

The current level of Lake of the Woods is 323.73 m (1062.1 ft), over 95th percentile level for this time of year. The average lake level declined by 12 cm (4 in) over the past week. Widespread precipitation fell over the past several days, with heaviest amounts over Lake of the Woods and the Big Fork and Little Fork river sub-basins. The recent steady drop in Lake of the Woods level stalled briefly due to this rain, but is expected to resume at a slightly slower rate of 5to 8 cm (2 to 3 in) per week. The dams in Kenora remain fully open.

The Winnipeg River between Kenora and Minaki is expected to gradually fall between 5 to 8 cm (2 to 3 in) over the next week as the Lake of the Woods level falls.

The current level of Lac Seul is 356.62 m (1170.0 ft), an 80th percentile level for this time of year. The level of the main body of Lac Seul declined by 3 cm (1 in) over the past week and is expected to decline by 5 to 8 cm (2 to 3 in) over the next week. Lac Seul authorized outflow is 450 m³/s with no scheduled changes.

Throughout the spring, the Lake of the Woods Control Board has been operating on an emergency basis, with meetings every few days to review the latest basin conditions and forecasts in order to make regulation decisions and provide frequent updates on forecasts to the public. The Board has also been active in briefing First Nations, municipalities and provincial and federal ministries involved in the emergency response to flooding across the basin.

With the return to normal summer levels for Lac Seul and a continued drop of Lake of the Woods expected this month, the Board has resumed normal operations according to an adopted Regulation Strategy. On August 16, the Board held a Regulation Consultation call with invitations to Grand Council Treaty #3 and representatives of Specific Interest Groups and Resource Agencies. Participants received a briefing of current conditions and forecasts and an overview of a draft strategy to operate Lake of the Woods and Lac Seul dams through to the end of October under a range of possible flow conditions. Participants were then given the opportunity to provide feedback on the strategy. The adopted Regulation Strategy is available at https://lwcb.ca/noticeboard/regulation/.

A key focus of the strategy is maintaining maximum outflow from Lake of the Woods until the lake level returns to the legislated operating range, followed by a balanced drawdown of the lake and the Winnipeg River in order to reach normal water levels ahead of freeze-up.

The Lake of the Woods Control Board held a Regulation Meeting on Tuesday, March 8.

Regulation Meetings are held several times a year to review basin conditions and forecasts in order to set a seasonal operational strategy. The Board also considers input from those invited to the meetings, including representatives from First Nations, Specific Interest Groups and Resource Agencies. The seasonal strategy describes how the Board intends to regulate outflows from Lake of the Woods and Lac Seul under a range of potential flow conditions.

The Board adopted a seasonal Regulation Strategy that includes goals for the end of the winter drawdown period (March 31 for Lake of the Woods, April 15 for Lac Seul) and for the refill period until the end of June.

Seasonal conditions examined by the Board included the following, all of which will play a role in the spring regulation of Lake of the Woods, Lac Seul, and the Winnipeg and English Rivers:

• Current Hydrological Conditions

Long-standing drought conditions remain across the Winnipeg River drainage basin, with classifications by Canadian and American agencies ranging from abnormally dry to severe drought. This is an improvement from the summer and early fall of 2021, where drought was severe to exceptional. The improvement is due to late fall rainfall, which has resulted in river flows across most of the drainage basin slowly climbing from very low summer rates to the low end of the normal range for winter.

• Snowpack development

The accumulated snowpack depth is higher than in recent years. Some areas have very high snowpack depth, including around Kenora, Ear Falls, and south of Rainy River in Minnesota. In the upper Rainy-Namakan watershed, the snowpack is on the high end of the normal range for early March. The LWCB expects that the substantial snowpack will resolve the drought conditions.

When considering potential for spring runoff, the water content of the snowpack is more important than the snow depth. Estimates of snow water equivalent, based on a variety of data sources including field measurements, indicate moderately high to high snow water for the start of March. Generally, the snow water at this point of the winter is similar to that seen in 2019 and 2020, and substantially less than in the last year with high spring water levels, 2014. Historic Snow Water Equivalent maps are available at NOAA’s website (select year, and click on Redraw Map).

Below are estimates from 2022, 2020, and 2014.

• Winter Temperatures

Colder winters generally correspond to later thawing of the ground in the spring. Runoff from snowmelt and rainfall cannot be absorbed in frozen ground, and will instead flow to wetlands, streams, rivers and lakes. Early spring rainfall before the ground has thawed can, therefore, lead to rapid rise in streamflows.

This winter has been colder than normal. Heating Degree Days are a simple measure of accumulated cold through the winter that can be useful in understanding the severity of the winter. Heating degree days from December 1 in Kenora are 85th percentile for data back to 1967. This is the coldest since 2014, though only slightly greater than 2018. However, anecdotal reports that early season snow has provided an insulating layer to the ground, thereby limiting frost depth, are consistent with limited frost depth measurements.

• Spring outlook

Seasonal forecasts from Canadian and American weather agencies indicate an equal likelihood of above or below normal precipitation through May, with the American seasonal forecast suggesting a warmer spring is more likely.

---

How quickly flows rise across the basin will be determined by the weather conditions, including temperature, wind and, most importantly, rainfall. While there is substantial snow in the basin, a dry spring may still result in lower water levels for the summer, whereas a wet spring could see high flows develop. The amount of rain and its timing relative to the melting snow and thawing ground, will be the most important factors in how the spring flows develop.

The Board will closely monitor the development of the spring melt as it continues to direct drawdown of the lakes in March. Once the spring melt is underway, the Board will follow the newly adopted strategy to balance rising lake and river levels to try balance objectives such as fisheries, wild rice, navigation and risk of high water.

The Lake of the Woods Control Board held a Regulation Meeting on October 29th. The goal of the meeting was to discuss and adopt a strategy to guide Lake of the Woods and Lac Seul flow operations from now until the end of March. Invitations to participate in the discussion were sent to representatives of First Nations, Specific Interest Groups, and advisors from Resource Agencies as described on the Board Description page.

The focus of the discussion was the ongoing drought conditions and the low flows across the basin. For much of the year, the LWCB has regulated to hold back water in Lac Seul and Lake of the Woods given the extremely dry conditions. This stored water is essential to supply the English and Winnipeg Rivers through the winter when tributary flows are typically lowest. Flow requirements for hydropower in Ontario and Manitoba become a key consideration in the core winter period when energy demand for heating is at its highest. Maintaining a base flow to protect residential water lines along these rivers is also important. Other considerations include the rate of drawdown of Lac Seul and Lake of the Woods over the winter period, as this affects fall spawning success and has the potential to cause ice damage to shoreline structures such as docks. Finally, preliminary targets for the lake levels at the end of the winter were considered with a focus on risk of continued drought conditions in the spring of 2022.

The adopted strategy aims to maintain the current stable, low flows out of Lac Seul and Lake of the Woods for the remainder of fall until freeze-up, continuing to store water for release over the winter period. The LWCB will monitor the progress of freeze-up and lake and river ice development, and will look to increase outflow from these lakes to meet the core winter flow requirements for the English and Winnipeg Rivers ahead of significant ice build-up. The timing of outflow increases will depend on the temperature over the coming weeks and will be updated on this Notice Board.

The LWCB will meet to review the early winter conditions and assess the snowpack and winter severity in January. Based on this, it will target changes, if necessary, to the core winter flow rates before the next LWCB Regulation Meeting scheduled for early March. At that meeting, the strategy for the end of winter and early spring will be adopted.

The current level of Lake of the Woods is 322.51 m (1058.1 ft), a 5th percentile level for this time of year. The average lake level changed little over the past week and is expected to decline by 2-3 cm (1 in) over the next week with continued dry weather. Lake of the Woods authorized outflow is 90 m³/s with no changes scheduled.

The current level of Lac Seul is 355.83 m (1167.4 ft), a 10th percentile level for this time of year. The average lake level rose by 2 cm (1 in), and is expected to rise by a similar amount over the next week. Lac Seul authorized outflow is 75 m³/s with no changes scheduled.