June 2024

Conditions in the Winnipeg River basin remain very wet. Although there was a dry period following the large rainfall event on June 18^th and 19^th, the magnitude of the event coupled with more recent rain has led to sustained high-normal flows across the basin. The headwaters of the Rainy-Namakan basin received the highest amounts of precipitation, which resulted in local flooding.

More rain is forecast to occur this weekend and into next week which will lead to continued high flows and rising levels across the basin. Inflows to Lake of the Woods and Lac Seul will increase with this upcoming precipitation.

The current level of Lake of the Woods is 323.26 m (1060.6 ft) , a 75^th percentile level, within the normal range for this time of year. The average lake level increased by 7 cm (3 in) over the last week and is expected to increase by 9 to 17 cm (3.5 to 7 in) over the next week, depending on precipitation amounts and upstream flow changes. The current outflow of Lake of the Woods is 1150 m³/s. With more rainfall in the forecast, all logs are being pulled from the Norman Dam, and outflow is expected to be reach 1200 m³/s by Friday, June 28^th. This additional flow is expected to raise the level of the Winnipeg River as follows:

• Below Norman Dam: 14 cm (5.5 in)

• Above Kimberley Rapids: 12 cm (5 in)

• Winnipeg River Marina: 12 cm (5 in)

• Near Locke Bay: 12 cm (5 in)

• Above Myrtle Rapids: 12 cm (5 in)

• Above the Dalles: 12 cm (5 in)

• Above Throat Rapids: 12 cm (5 in)

• Minaki: 9 cm (3.5 in)

The current level of Lac Seul is 356.15 m (1168.5 ft), a 40^th percentile level, within the normal range for this time of year. The average lake level increased by 9 cm (3.5 in) over the past week and is expected to increase by 13 to 19 cm (5 to 7.5 in) over the next week. Lac Seul authorized outflow is 300 m³/s with no changes currently scheduled.

Several lines of severe thunderstorms cross the Winnipeg River basin Tuesday June 18th. Rainfall totals reached up to 100 mm in some locations over the past 24 hours. Most of the basin received at least 30 mm of rain with areas around Rainy Lake and Namakan Lake seeing up to 75 mm. This precipitation has caused tributary flows to begin rising and inflows to the major lakes are expected to increase as a result of these storms.

The current level of Lake of the Woods is 323.18 m (1060.3 ft) , a 60^th percentile level, within the normal range for this time of year. The average lake level increased by 6 cm (2.5 in) over the last week and is expected to increase by 5 to 8 cm (2 to 3 in) over the next week, depending on precipitation amounts and upstream flow changes. The current outflow of Lake of the Woods is 900 m³/s. With a few dry days in the forecast followed by a return of moderate precipitation, inflows are expected to remain high. An outflow increase to 1000 m³/s is scheduled for Thursday June 20^th with another outflow increase to 1100 m³/s tentatively scheduled for Monday June 24^th.

Each of these flow changes will cause a levels along the Winnipeg River to increase by approximately 30 cm, (12 in) directly downstream of the Norman Dam, by 22 cm (8.5 in) above the Dalles, and by 20 cm (8 in) at Minaki.

The current level of Lac Seul is 356.01 m (1168.01 ft), a 45^th percentile level, within the normal range for this time of year. The average lake level increased by 14 cm (5.5 in) over the past week and is expected to increase by 11 to 13 cm (4 to 5 in) over the next week. Lac Seul authorized outflow is 300 m³/s with no changes currently scheduled.

On June 11th, the LWCB visited Lac Seul First Nation, where they met with Chief Clifford Bull and Councillors in Frenchman’s Head. Led by the Chief and other members of the First Nation, the LWCB were treated to an amazing boat tour of Lac Seul, and the opportunity to see many of the historical and significant areas of the First Nation. The boat tour ended on the shores of Manitou Miniss, one of Lac Seul First Nation’s sacred sites, where Mona Gordon, member of Grand Council Treaty #3 Women’s Council, honoured the LWCB by inviting them to participate in the Spring Offering for the Northern Direction.

On June 12th, the LWCB also visited the Wabigoon River hydrometric gauge with members of the Water Survey of Canada Winnipeg Operations Team, who provided a demonstration of a discharge measurement using a remote operated boat. That afternoon, the LWCB held its Regulation Meeting in Dryden, attended by specific interest groups and resource agencies, and adopted its Regulation Strategy for the next few months.

With less rain over the weekend we have seen inflows to Lake of the Woods and Lac Seul stabilize and begin to decline. At this time inflows are still in the high normal range for this time of year. There is still significant precipitation in the forecast this week and as such additional outflow increases from Lake of the Woods will be required.

The current level of Lake of the Woods is 323.15 m (1060.2 ft) , a 60^th percentile level, within the normal range for this time of year. The average lake level increased by 7 cm (3 in) over the last week and is expected to increase by 3 to 11 cm (1 to 4 in) over the next week, depending on precipitation amounts and upstream flow changes. The current outflow of Lake of the Woods is 800 m³/s. With the current precipitation forecast an outflow increase to 850 m³/s is planned for Tuesday June 18^th and an additional increase to 900 m³/s is tentatively scheduled for Thursday June 20^th.

Each of these flow changes will cause a levels along the Winnipeg River to increase by approximately 15 cm, (6 in) directly downstream of the Norman Dam, by 10 cm (4 in) above the Dalles, and by 10 cm (4 in) at Minaki.

The current level of Lac Seul is 355.97 m (1167.9 ft), a 45^th percentile level, within the normal range for this time of year. The average lake level increased by 15 cm (6 in) over the past week and is expected to increase by 12 to 20 cm (5 to 8 in) over the next week. Lac Seul authorized outflow is 300 m³/s with no changes currently scheduled.

Over the past week, the Winnipeg River basin received some pockets of moderate rainfall which contributed to lake inflows and delayed their decline. As a result, inflows to Lac Seul and Lake of the Woods remain in the high normal range for this time of year. Forecasts are indicating a drier period through the weekend, followed by a large rainfall system expected to move through the basin early next week. Rainfall amounts associated with this system are currently uncertain, however outflow increases at Lake of the Woods next week are possible if the precipitation in the forecast materializes.

The current level of Lake of the Woods is 323.12 m (1060.1 ft) , a 60^th percentile level, within the normal range for this time of year. The average lake level increased by 6 cm (2.5 in) over the last week and is expected to increase by 3 to 8 cm (1 to 3 in) over the next week, depending on precipitation amounts and upstream flow changes. The current outflow of Lake of the Woods is 800 m³/s. With the current precipitation forecast an outflow increase to 850 m³/s is tentatively scheduled for Tuesday June 18^th.

The current level of Lac Seul is 355.91 m (1167.68 ft), a 45^th percentile level, within the normal range for this time of year. The average lake level increased by 17 cm (7 in) over the past week and is expected to increase by 8 to 14 cm (3 to 5.5 in) over the next week. Lac Seul authorized outflow is 300 m³/s with no additional outflow increases currently planned.

If you have any questions, comments or observations, please contact the Secretariat at secretariat@lwcb.ca or by calling 1-800-661-5922. This Noticeboard will be updated regularly as conditions develop.

For more information on Namakan and Rainy Lakes, visit the Water Level Notices page of the International Rainy-Lake of the Woods Watershed Board.

Over the past week the Winnipeg River basin received above normal rainfall and this has caused inflows to both Lake of the Woods and Lac Seul to remain stable and in the high-normal range for this time of year. Lake of the Woods inflow is around 1,700 m³/s (80th percentile) and Lac Seul inflow is around 1,100 m³/s (70th percentile). These inflows have resulted in the continued rise of lake levels, but lake levels and outflows are still within the normal range on both Lake of the Woods and Lac Seul. At Lac Seul, the lake continues to refill with outflows remaining in the normal range.

At Lake of the Woods the current lake level of 323.06 m (1059.91 ft) is 6 cm ( 2 in) above the normal summer level of 323.0 m (1059.7 ft) and 1.06 m (3.47 ft) below the peak level in 2022 of 324.12 m (1063.39 ft). Lake of the Woods outflow is currently 800 m³/s. Lake levels and outflows are being managed in accordance with the regulation strategy adopted in March, taking all interests into consideration both upstream on the lake and downstream on the Winnipeg River. In particular, this consideration from the high inflow scenario applies at this time:

“Avoid outflow above 800 to 900 m³/s if the lake level (or projected level) will remain
below 323.20 m (1060.4 ft) in June. A flow of 900 m³/s on the Winnipeg River would
cause the level below the Norman Dam to rise 1.4 m (4.6 ft) above normal, whereas a
lake level of 323.2 m (1060.4 ft) is only 15 cm (6 in) above median at the end of June.”

Weather forecasts and inflow predictions indicate that the level of Lake of the Woods is not expected to increase above 323.2 m (1060.4 ft) within the next 10 days. Therefore, no additional outflow increases are scheduled at this time. The Secretariat will continue to monitor conditions in the event that inflows remain higher than forecasted.

The current level of Lake of the Woods is 323.06 m (1059.91 ft) , a 60^th percentile level, within the normal range for this time of year. The average lake level increased by 13 cm (5 in) over the last week and is expected to increase by 6 to 9 cm (2 to 3.5 in) over the next week, depending on precipitation amounts and upstream flow changes. The current outflow of Lake of the Woods is 800 m³/s. With inflows forecasted to decline with dry weather, no outflow changes are currently planned.

The current level of Lac Seul is 355.72 m (1167.1 ft), a 45^th percentile level, within the normal range for this time of year. The average lake level increased by 17 cm (7 in) over the past week and is expected to increase by 12 to 15 cm (5 to 6 in) over the next week. Lac Seul authorized outflow is 300 m³/s with no additional outflow increases currently planned.

If you have any questions, comments or observations, please contact the Secretariat at secretariat@lwcb.ca or by calling 1-800-661-5922. This Noticeboard will be updated regularly as conditions develop.

For more information on Namakan and Rainy Lakes, visit the Water Level Notices page of the International Rainy-Lake of the Woods Watershed Board.