Secretariat

Freshet is well underway across the Winnipeg River basin. Tributary flows and lake inflows are rising gradually and there is some moderate rainfall in the forecast early next week. With operators increasing outflow at Rainy Lake, additional outflow increases from Lake of the Woods are required to allow for a gradual refill, while balancing flows downstream on the Winnipeg River.

The current level of Lake of the Woods is 322.56 m (1058.2 ft), a 45^th percentile level, in the normal range for this time of year. The average lake level increased by 8.5 cm (3 in) over the last week and is expected to increase by 6 to 12 cm (2.5 to 4.5 in) over the next week. Lake of the Woods authorized outflow will increase to 375 m³/s on Thursday, April 24^th and to 400 m³/s on Saturday, April 26^th.

As a result of these outflow increases, levels along the Winnipeg River are expected to increase by 11 cm (4.5 in) below the Norman Dam, 8 cm (3 in) above Kimberley Rapids and 5 cm (2 in) at the Dalles. Levels at Minaki will not be affected by these flow changes.

The current level of Lac Seul is 354.70 m (1163.7 ft), a 20^th percentile level, below the normal range for this time of year. The lake level increased by 7 cm (2.5 in) over the last week and is expected to increase by 15 to 25 cm (6 to 10 in) over the next week. Lac Seul authorized outflow is 150 m³/s, with no changes scheduled.

Precipitation over the past week was lower than expected. However, the above-freezing temperatures and mixed precipitation have triggered the start of freshet, and tributary flows and lake inflows are rising gradually. Forecasted warm temperatures and moderate amounts of precipitation for the next week will maintain current inflows.

The current level of Lake of the Woods is 322.46 m (1057.9 ft), a 35^th percentile level, in the normal range for this time of year. The average lake level increased by 3 cm (1 in) over the last week and is expected to increase by 5 to 8 cm (2 to 3 in) over the next week. To continue gradually refilling the lake, Lake of the Woods authorized outflow will increase to 325 m³/s on Thursday, April 17^th and to 350 m³/s on Saturday, April 19^th.

As a result of these outflow increases, levels along the Winnipeg River are expected to increase by 11 cm (4.5 in) below the Norman Dam, 8 cm (3 in) above Kimberley Rapids and 5 cm (2 in) at the Dalles. Levels at Minaki will not be affected by these flow changes.

The current level of Lac Seul is 354.61 m (1163.4 ft), a 20^th percentile level, below the normal range for this time of year. The lake level remained stable over the last week and is expected to increase by 4 to 6 cm (1.5 to 2.5 in) over the next week. To capture snowmelt and start refilling the lake, Lac Seul authorized outflow will decrease to 150 m³/s on Thursday, April 17^th.

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The LWCB Basin Data page will not be updated on Friday, April 18^th (Good Friday, holiday in Canada) or on Monday, April 21^st (Easter Monday). Daily data updates will resume on Tuesday, April 22^nd.

Forecasts are predicting widespread precipitation over the Winnipeg River basin Sunday into Monday. With daytime temperatures well over 10 degrees Celsius, rain is expected at first, followed by a cold front moving in Sunday night and causing the rain to turn to snow or mixed precipitation on Monday. Basin-wide, total precipitation amounts are forecast in the 10 to 40 mm (0.5 to 1.5 in) range, with locally higher amounts up to 75 mm (3.0 in) possible over Lake of the Woods.

The LWCB is anticipating the beginning of spring freshet in the basin over the next week, as tributary flows increase in response to melting snow and precipitation. The Secretariat is closely monitoring conditions, including dam operations in upstream areas as freshet progresses. The Regulation Strategy adopted in March set a Lake of the Woods level target of 322.7 m (1058.7 ft) at the end of May, which is 27 cm (11 in) above the current level. Lake of the Woods outflow will be increased to allow for refill towards this target while balancing gradual level rise along the Winnipeg River.

The current level of Lake of the Woods is 322.43 m (1057.8 ft), a 30^th percentile level, in the normal range for this time of year. The average lake level remained stable over the last week and is expected to increase by 4 to 11 cm (1.5 to 4 in) over the next week. Lake of the Woods authorized outflow will increase to 275 m³/s on Saturday, April 12^th and to 300 m³/s on Monday, April 14^th.

As a result of these outflow increases, levels along the Winnipeg River are expected to increase by 10 cm (4 in) below the Norman Dam, 7 cm (2.5 in) above Kimberley Rapids and 4 cm (1.5 in) at the Dalles. Levels at Minaki will not be affected by these flow changes.

The current level of Lac Seul is 354.61 m (1163.4 ft), a 20^th percentile level, below the normal range for this time of year. The lake level declined by 5 cm (2 in) over the last week and is expected to remain stable over the next week. Lac Seul authorized outflow is 200 m³/s, with no changes scheduled.

A large portion of the Winnipeg River basin is under a snowfall warning, with heavy and rapidly accumulating snow expected throughout the day and into tomorrow. The highest snowfall amounts of 15 to 20 cm (6 to 8 in) are expected close to the international border. This precipitation is not expected to change the spring outlook for refill of Lake of the Woods. Over the month of March, much of the winter snowpack declined without generating much inflow to the lake, due to sunny and dry conditions. Underlying drought conditions also remain upstream in the Rainy-Namakan basin.

The current level of Lake of the Woods is 322.42 m (1057.8 ft), a 40^th percentile level, in the normal range for this time of year. The average lake level increased by 1 cm (0.5 in) over the last week and is expected to increase by 1 cm (0.5 in) over the next week. Lake of the Woods authorized outflow is 250 m³/s, with no changes scheduled.

The current level of Lac Seul is 354.68 m (1163.6 ft), a 25^th percentile level, in the normal range for this time of year. The lake level declined by 6 cm (2 in) over the last week and is expected to decrease by 3 to 5 cm (1 to 2 in) over the next week. Lac Seul authorized outflow is scheduled to decrease to 200 m³/s on Tuesday, April 8^th.

A low pressure system is expected to travel across the Winnipeg River basin late this evening and into tomorrow. Because temperatures are low, precipitation is expected to fall as snow, with accumulation in the 10 to 20 cm (4 to 8 in) range. There is a chance for freezing rain along the border with Minnesota.

The current level of Lake of the Woods is 322.41 m (1057.8 ft), a 40^th percentile level, in the normal range for this time of year. The average lake level remained stable over the last week and, with the snow and freezing rain coming tomorrow, is expected to increase by 1 to 4 cm (0.5 to 1.5 in) over the next week. Lake of the Woods authorized outflow is 250 m³/s, with no changes scheduled.

The current level of Lac Seul is 354.72 m (1163.8 ft), a 20^th percentile level, below the normal range for this time of year. The lake level declined by 7 cm (2.5 in) over the last week and is expected to decrease by 3 to 5 cm (1 to 2 in) over the next week. Lac Seul authorized outflow will decrease to 250 m³/s today, March 27^th. Due to scheduled maintenance at the Ear Falls dam, Lac Seul outflow will temporarily decrease to 200 m³/s on Monday, March 31^st and Tuesday, April 1^st.

The current level of Lake of the Woods is 322.41 m (1057.8 ft), a 35^th percentile level, in the normal range for this time of year. The average lake level remained stable over the last week and is expected to increase by up to 2 cm (1 in) over the next week. Lake of the Woods authorized outflow is 250 m³/s, with no changes scheduled.

The current level of Lac Seul is 354.78 m (1164.0 ft), a 20^th percentile level, below the normal range for this time of year. The lake level declined by 6 cm (2.5 in) over the last week and is expected to decrease by 6 to 7 cm (2.5 in) over the next week. Lac Seul authorized outflow is 300 m³/s, with no changes scheduled.

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Spring Regulation Strategy

On March 19, the LWCB held its spring Regulation Meeting in Kenora and adopted its Spring Regulation Strategy. The strategy outlines regulation targets for various inflow conditions for the period of March to the end of June, and was developed considering basin conditions, hydrological and meteorological forecasts and the input from various interests concerned with basin management.

Winter 2024-2025 was characterized by differences in snowpack and winter severity between the southern and northern portions of the basin, which is reflected in the lake level targets and outlooks for Lake of the Woods and Lac Seul. There is uncertainty in longterm precipitation forecasts, which indicate equal chances of above or below normal precipitation in early spring, requiring close monitoring of conditions.

Lake of the Woods

Winter baseflows in tributaries of the Lake of the Woods and Rainy-Namakan basins were low due to underlying drought conditions. Snowpack was also below average around Lake of the Woods and along the Rainy River. These factors point towards the potential for average to below normal spring inflow driven by baseflow and snow melt. While balancing the risk of above normal spring rainfall, the regulation strategy targets a normal lake level for the end of March. Conditions will be monitored throughout the spring so that outflow can be adjusted to ensure refill and rising lake levels, while considering downstream impacts.

Lac Seul

In the English River basin, snowpack was close to normal and tributary baseflows were also in the normal range.  These factors point towards spring inflows that will be sufficient to support refill if normal spring precipitation develops. The regulation strategy targets a normal and slightly broader range of lake levels for mid-April, taking into consideration uncertainty in longterm precipitation forecasts. Adjustments to outflow will be made to first target a level that is suitable for the start of the refill period and then to ensure gradual refill, while considering downstream impacts.

Over the last week, many parts of the basin experienced a first taste of spring when warm daytime temperatures coupled with sunny days. This weekend, a system is forecast to bring rain to the basin, further melting the snowpack. Although there is still some uncertainty as to how much runoff the rain will generate, inflow to the major lakes is expected to increase over the next week. Depending on how quickly flows increase on the Rainy River, gradual outflow increases at Lake of the Woods may be required next week. Notice of these changes will be provided as soon as possible.

The current level of Lake of the Woods is 322.42 m (1057.8 ft), a 25^th percentile level, in the normal range for this time of year. The average lake level declined by 1.5 cm (0.5 in) over the last week and is expected to increase by 2.5 to 6 cm (1 to 2.5 in) over the next week. Lake of the Woods authorized outflow is 250 m³/s, with no changes scheduled.

The current level of Lac Seul is 354.85 m (1164.2 ft), a 20^th percentile level, below the normal range for this time of year. The lake level declined by 7 cm (2.5 in) over the last week and is expected to decrease by 2.5 to 6 cm (1 to 2.5 in) over the next week. Lac Seul authorized outflow is 300 m³/s, with no changes scheduled.

The current level of Lake of the Woods is 322.44 m (1057.85 ft), a 20^th percentile level, below the normal range for this time of year. The average lake level declined by 2 cm (1 in) over the last week and is expected to decline by 1 cm (0.5 in) over the next week. Lake of the Woods authorized outflow is 250 m³/s, with no changes scheduled.

On March 1^st, the level of Lac Seul was 354.97 m (1164.6 ft) within the target range of the Regulation Strategy adopted last October. The current level of Lac Seul is 354.93 m (1164.4 ft), a 20^th percentile level, below the normal range for this time of year. The lake level declined by 6 cm (2.5 in) over the last week and is expected to decrease by 5 to 6 cm (2 to 2.5 in) over the next week. Lac Seul authorized outflow is 300 m³/s, with no changes scheduled.

Over the last week, southern portions of the Winnipeg River basin received some rain and daytime temperatures were above freezing. This caused the snowpack to compact and become wetter. Conditions are however expected to change with an Alberta clipper forecast to cross the basin this evening and into Friday. Environment Canada has issued snowfall warnings, predicting rapid snow accumulation in the range of 15 to 25 cm (6 to 10 in). The return of colder temperatures is also forecast for this weekend.

The current level of Lake of the Woods is 322.45 m (1057.9 ft), a 20^th percentile level, below the normal range for this time of year. The average lake level declined by 1.5 cm (1 in) over the last week and is expected to change little over the next week. Lake of the Woods authorized outflow remains 250 m³/s, with no changes scheduled.

The current level of Lac Seul is 354.94 m (1164.6 ft), a 20^th percentile level, below the normal range for this time of year. The lake level declined by 7.5 cm (3 in) over the last week and is expected to decrease by 5.5 cm to 7 cm (2 to 2.5 in) over the next week. Lac Seul authorized outflow is 300 m³/s, with no changes scheduled.

The current level of Lac Seul is 355.02 m (1164.7 ft), a 20^th percentile level, below the normal range for this time of year. The lake level declined by 8 cm (3 in) over the last week and is expected to decrease by 7 to 9 cm (2.5 to 3.5 in) over the next week. Lac Seul authorized outflow was reduced to 300 m³/s today, February 25^th. Outflow is expected to continue gradually declining as the lake level drops.