Secretariat

The forecast for the Winnipeg River basin is extremely dry for the remainder of May, with no measurable precipitation expected in the next 7 to 10 days. To maintain stable water levels on Lake of the Woods, outflow reductions are required. With active spawning and increased recreation and boating on the Winnipeg River at this time of year, small and staggered outflow reductions will be made to allow for a gradual drop in river levels. Further north in the English River basin, flows are also starting to decline, but Lac Seul will continue refilling over the next week.

The current level of Lake of the Woods is 322.90 m (1059.4 ft), a 65^th percentile level, in the normal range for this time of year. The average lake level increased by 1.5 cm (0.6 in) over the last week and is expected to decrease by up to 1.0 cm (0.4 in) over the next week. Lake of the Woods authorized outflow will be reduced to:

• 575 m³/s on Friday, May 23^rd
• 550 m³/s on Monday, May 26^th
• 525 m³/s on Wednesday, May 28^th
• 500 m³/s on Friday, May 30^th

Each of these outflow reductions will cause levels along the Winnipeg River to decline. By May 30^th, river levels are expected to have decreased by 27 cm (10.6 in) below the Norman Dam, 21 cm (8.3 in) above Kimberley Rapids and 15 cm (6.0 in) at the Dalles. Levels at Minaki will not be affected by these flow changes.

The current level of Lac Seul is 355.37 m (1165.9 ft), a 55^th percentile level, in the normal range for this time of year. The lake level increased by 13.5 cm (5.3 in) over the last week and is expected to increase by 8.5 to 12 cm (3.3 to 4.7 in) over the next week. Lac Seul authorized outflow is 200 m³/s, with no changes scheduled.

The forecast for the next 7 to 10 days is extremely dry, with no rain expected for several days. With water supply to the major lakes declining, Rainy Lake outflow will be reduced this week and consequently, Lake of the Woods outflow reductions will also start tomorrow to maintain stable lake levels.

The current level of Lake of the Woods is 322.91 m (1059.4 ft), a 65^th percentile level, in the normal range for this time of year. The average lake level increased by 3.4 cm (1.3 in) over the last week and is expected to increase by 1.0 to 1.5 cm (0.4 to 0.6 in) over the next week. Lake of the Woods authorized outflow will be reduced to 600 m³/s on Wednesday, May 21^st and to 575 m³/s on Friday, May 23^rd.

Each of these outflow reductions will cause levels along the Winnipeg River to decline. By May 24^th, river levels are expected to have decreased by 21 cm (8.3 in) below the Norman Dam, 16 cm (6.3 in) above Kimberley Rapids and 12 cm (4.7 in) at the Dalles. Levels at Minaki will not be affected by these flow changes.

The current level of Lac Seul is 355.34 m (1165.8 ft), a 55^th percentile level, in the normal range for this time of year. The lake level increased by 14.8 cm (5.8 in) over the last week and is expected to increase by 11 cm (4.3 in) over the next week. Lac Seul authorized outflow is 200 m³/s, with no changes scheduled.

The extremely hot and dry conditions across the Winnipeg River basin this week have allowed for tributary flows to peak and lake level rise to slow on both Lake of the Woods and Lac Seul.

Forest fires have developed near several hydropower dams along the Winnipeg and English Rivers in Ontario and Manitoba, resulting in evacuation of these facilities. Manitoba Hydro has issued a media release related to its facilities at Pointe du Bois and Slave Falls. Ontario Power Generation’s Whitedog and Caribou generating stations have also been evacuated, but remote management of gates at these two facilities is available to adjust flow through the dams.

To provide for stable flows along the Winnipeg and English Rivers while these facilities are evacuated, the LWCB has temporarily paused changes in outflow from Lake of the Woods and Lac Seul dams for the next several days. The Secretariat is in regular contact with OPG and Manitoba Hydro and will reassess conditions over the weekend. 

The current level of Lake of the Woods is 322.89 m (1059.3 ft), a 70^th percentile level, in the normal range for this time of year. The average lake level increased by 6.7 cm (2.6 in) over the last week and is expected to increase by 2.5 to 6.5 cm (1 to 2.5 in) over the next week. Lake of the Woods authorized outflow is 650 m³/s, with no changes scheduled.

The current level of Lac Seul is 355.23 m (1165.4 ft), a 60^th percentile level, in the normal range for this time of year. The lake level increased by 15.7 cm (6.2 in) over the last week and is expected to increase by 15 to 18 cm (6 to 7 in) over the next week. Lac Seul authorized outflow is 200 m³/s, with no changes scheduled.

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The LWCB Basin Data page will not be updated on Monday, May 19^th (Victoria Day in Canada). Daily data updates and publication will resume on Tuesday, May 20^th.

Tributary flows and lake inflows are still high from the precipitation last week. However with dry conditions forecast for the weekend and into next week, flows are expected to peak in the coming days.

The current level of Lake of the Woods is 322.82 m (1059.1 ft), a 70^th percentile level, in the normal range for this time of year. The average lake level increased by 13.6 cm (5.4 in) over the last week and is expected to increase by 8 to 11 cm (3 to 4.3 in) over the next week. Lake of the Woods authorized outflow will increase to 600 m³/s today, May 8^th. There is a tentative outflow increase to 650 m³/s scheduled for Tuesday, May 13^th, to be confirmed on Monday.

As a result of these outflow increases, levels along the Winnipeg River are expected to increase by 28 cm (11 in) below the Norman Dam, 22 cm (8.6 in) above Kimberley Rapids and 16 cm (6.3 in) at the Dalles. Levels at Minaki will not be affected by these flow changes.

The current level of Lac Seul is 355.07 m (1164.9 ft), a 55^th percentile level, in the normal range for this time of year. The lake level increased by 17.6 cm (7 in) over the last week and is expected to increase by 13 to 14.5 cm (5 to 6 in) over the next week. Lac Seul authorized outflow is 200 m³/s, with no changes scheduled.

The Winnipeg River basin received above normal rainfall over the last week, with the highest amounts in the 50 to 75 mm (2 to 3 in) range over Lake of the Woods and the Rainy-Namakan basin (see map below). For comparison, average rainfall in the last quarter of April is 10 mm (0.4 in). Some additional bands of rain are forecast today and tomorrow, after which the remainder of the forecast shows warm and dry conditions through the first week of May.

Tributary flows and lake inflows have risen to the top of the normal range and in some locations are peaking well above normal, at 90^th percentile for this time of year. The LWCB is referring to its Regulation Strategy and using the guidelines for moderate inflow conditions to manage lake levels and flows. At Lake of the Woods, the lake level is rising quickly and will hit the preferred end-of-May level of 322.7 m (1058.7 ft) in the next few days. To slow lake level rise, the Board has scheduled staggered outflow increases over the next week, considering the need to balance rising levels downstream on the Winnipeg River. At Lac Seul, refill is on track to meet preferred mid-May lake levels for fisheries.

The current level of Lake of the Woods is 322.68 m (1058.6 ft), a 50^th percentile level, in the normal range for this time of year. The average lake level increased by 12.0 cm (4.7 in) over the last week and is expected to increase by 6 to 8 cm (2.4 to 3 in) over the next week. Lake of the Woods authorized outflow will increase as follows:

• to 500 m³/s on Thursday, May 1^st
• to 550 m³/s on Tuesday, May 6^th
• to 600 m³/s on Thursday, May 8^th

Each of these outflow increases will cause levels along the Winnipeg River to rise. By March 9^th, river levels are expected to have increased by 40 cm (15.7 in) below the Norman Dam, 30 cm (11.8 in) above Kimberley Rapids and 22 cm (8.7 in) at the Dalles. Levels at Minaki will not be affected by these flow changes.

The current level of Lac Seul is 354.89 m (1164.3 ft), a 45^th percentile level, in the normal range for this time of year. The lake level increased by 19.7 cm (7.8 in) over the last week and is expected to increase by 17 to 23 cm (6.7 to 9 in) over the next week. Lac Seul authorized outflow will increase to 200 m³/s on Thursday, May 1^st.

Environment Canada has issued a rainfall warning for a large part of the Winnipeg River basin with 20 to 40 mm (0.75 to 1.5 in) of rain expected today. The Ontario Ministry of Natural Resources (MNR) has also issued a flood watch for the Dryden Fort Frances Atikokan District, noting that there is a potential for flooding in low-lying areas. There is no current flood risk, however, for Lake of the Woods, Lac Seul or the Winnipeg or English Rivers.

The current level of Lake of the Woods is 322.60 m (1058.4 ft), a 45^th percentile level, in the normal range for this time of year. The average lake level increased by 8.3 cm (3.3 in) over the last week and is expected to increase by 11 to 16 cm (4.3 to 6.3 in) over the next week.

With rising Rainy River flows, the LWCB is directing increases in Lake of the Woods outflow to slow the rate of lake level rise. A first outflow increase to 450 m³/s is scheduled for Tuesday, April 29^th. A second increase is tentatively planned for later in the week. Details will be posted on this Notice Board, following analysis of this rain event.

Water levels and flows along the Winnipeg River may begin to rise with the rain today, without Lake of the Woods outflow increases. Tomorrow’s Lake of the Woods outflow increase will cause levels along the Winnipeg River to increase by an additional 12 cm (4.7 in) below the Norman Dam, 9 cm (3.5 in) above Kimberley Rapids and 6 cm (2.4 in) at the Dalles. Levels at Minaki will not be affected by these flow changes.

The current level of Lac Seul is 354.79 m (1164.0 ft), a 30^th percentile level, below the normal range for this time of year. The lake level increased by 14 cm (5.5 in) over the last 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 150 m³/s, with no changes scheduled.

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.