July 2023

Many parts of the basin received some much needed precipitation over the past week. Although this rainfall does help slow or stop the declining flows and levels temporarily, underlying drought conditions persist across the entirety of Winnipeg River basin and sustained precipitation will be needed for a return to normal conditions.

The current level of Lake of the Woods is 322.82 m (1059.1 ft), a 20^th percentile level for this time of year. The average lake level remained stable over the past week and is expected to decline by 1 to 2 cm (0.5 to 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 356.06 m (1168.2 ft), a 20^th percentile level for this time of year. The lake level increased by 4 cm (2 in) over the past week and is expected to increase by 1 to 3 cm (1 in) over the next week. Lac Seul authorized outflow is 100 m³/s with no changes scheduled.

On July 22, Ontario Power Generation notified the LWCB that the repairs at the Ear Falls/Lac Seul Station had been successfully completed and Lac Seul outflow had been restored to the authorized 100 m³/s.

The current level of Lake of the Woods is 322.83 m (1059.1 ft), a 20^th percentile level for this time of year. The average lake level decreased by 3 cm (1 in) over the past week and is expected to remain stable over the next week. Lake of the Woods authorized outflow will decrease to 250 m³/s tomorrow, Friday, July 21. There are no other outflow changes planned for the next few days.

This outflow reduction will cause the Winnipeg River water level to drop by approximately 10 cm (4 in) below the Norman Dam, 4 cm (2 in) above the Dalles, and will cause no change at Minaki.

The current level of Lac Seul is 355.02 m (1168.0 ft), a 25^th percentile level for this time of year. The lake level increased by 6 cm (2 in) over the past week and is expected to remain stable over the next week.

The outage that affected the Ear Falls/Lac Seul Generating Station on July 18 is causing ongoing issues. As such, Lac Seul outflow is being maintained at 140 m³/s to allow for repairs to be made. This slightly higher than authorized outflow will not cause a decline in lake levels and outflow will return to the authorized 100 m³/s as soon as possible. Updates will be posted to this Noticeboard as they are received.

There has been an unplanned outage at the Ontario Power Generation (OPG) Ear Falls and Lac Seul generating stations, and outflow from Lac Seul has been reduced to 0 m³/s since 8am this morning, July 18, 2023. Hydro One and OPG are working to resolve the issue, but the duration of the outage is currently unknown.

The Lake of the Woods Control Board has directed OPG to ensure a minimum of 50 m³/s of outflow (via spill) by the end of the day, if the issue is not resolved by this evening.

Please contact the Lake of the Woods Secretariat at secretariat@lwcb.ca or 1-800-661-5922 if you have any concerns. We will provide another update once the issue is resolved.

Conditions in the Winnipeg River drainage basin over the last month have been abnormally dry and inflows to the Lake of the Woods, Lake St. Joseph and Lac Seul are all at or less than the 5th percentile. Precipitation for the month of June across the basin has been approximately half of the normal amount, and even less around Lac Seul and Lake St. Joseph (see map below). The North American Drought Monitor is also indicating abnormally dry to moderate drought conditions for this area.

The current level of Lake of the Woods is 322.86 m (1059.3 ft), a 20^th percentile level for this time of year. The average lake level decreased by 6 cm (2 in) over the past week and is expected to continue to decrease by approximately another 6 cm over the next week.

In response to these low inflows and to maintain storage over the summer, further outflow reductions are scheduled for next week (similar to this week). Lake of the Woods outflow will be reduced as follows:

• 350 m³/s on Monday, July 17
• 300 m³/s on Wednesday, July 19
• 250 m³/s on Friday, July 21

Each of these outflow reductions will cause the Winnipeg River water level to drop by approximately:

• 11 cm (4 in) below the Norman Dam
• 5 cm (2 in) above the Dalles
• no change at Minaki

The current level of Lac Seul is 355.96 m (1167.8 ft), a 25^th percentile level for this time of year. The lake level increased by 3 cm (1 in) over the past week and is expected to increase by approximately 3 to 5 cm (1 to 2 in) over the next week. Lac Seul authorized outflow is 100 m³/s. There will be a temporary outage at Ear Falls and Manitou Falls generating stations, between July 15 to 17, which will result in a temporary decrease in outflows during this time. At least 50 m³/s outflow will be maintained during this outage, and outflows will be back to the authorized outflow of 100 m³/s on July 17.

The current level of Lake of the Woods is 322.93 m (1059.5 ft), a 25^th percentile level for this time of year. The average lake level decreased by 6 cm (2 in) over the past week and is expected to decrease by 2 to 5 cm (1 to 2 in) over the next week. In response to low inflows and to maintain storage over the summer, a series of outflow reductions is scheduled for next week. Lake of the Woods outflow will be reduced as follows:

• 500 m³/s on Monday, July 10
• 450 m³/s on Wednesday, July 12
• 400 m³/s on Friday, July 14

These outflow reductions are larger than over the last month and as such the level of the Winnipeg River is expected to drop by several inches next week. By dropping flows on the Winnipeg River faster now, storage will be build up on the lake to help provide normal flows on the river for a longer period of time in the case of extended dry conditions. The level of the Winnipeg River will decrease with each outflow reduction by approximately:

• 13 cm (5 in) below the Norman Dam
• 7 cm (3 in) above the Dalles
• no change at Minaki

The current level of Lac Seul is 355.94 m (1167.8 ft), a 25^th percentile level for this time of year. The lake level increased by 3 cm (1 in) over the past week and is expected to increase by approximately 2 to 6 cm (1 to 2 in) over the next week. Lac Seul authorized outflow is 100 m³/s with no changes scheduled.

Over the last week, weather conditions in the Winnipeg River basin have shifted to scattered isolated thunderstorms typical of this time of year. Although these storms produce local high rainfall amounts, the overall state of the basin remains dry and these scattered pulses of precipitation are not affecting tributary flows and lake inflows which remain low and in decline.

To hedge against this dry weather pattern, outflow decreases from Lake of the Woods will be directed to match outflow to inflow, allowing the lake level to stabilize. This will build storage on the lake, ensuring preferred levels and flows can be maintained for the summer months on both Lake of the Woods and the Winnipeg River.

Lake of the Woods authorized outflow will decrease to 550 m³/s on Thursday, July 6. The level of the Winnipeg River is expected to decrease by approximately 14 cm (5.5 in) below the Norman Dam, 8 cm (3 in) above the Dalles and no level impacts are expected at Minaki.

An additional two or three 50 m³/s outflow decreases are tentatively scheduled for the week of July 10 with details to be posted in the next week.

Despite some rain over the last week, inflows continue to remain below normal, and well below the current outflow. As a result, the level of Lake of the Woods will continue to drop over the next few weeks. To maintain preferred summer levels on Lake of the Woods, an outflow decrease is scheduled tomorrow with another planned later this week.

Lake of the Woods authorized outflow will decrease to 600 m³/s on Tuesday July 4. The level of the Winnipeg River is expected to decrease by approximately 14.3 cm (6 in) below the Norman Dam, 8.5 cm (3 in) above the Dalles and no level impacts are expected at Minaki.

Additional outflow decreases will be posted in the next few days.