The current level of Lake of the Woods is 322.47 m (1058.10ft), less than a 5th percentile level for this time of year. The average lake level fell by 2 cm (1 in) over the past week and is expected to fall by as much as 3 cm (1 in) over the next week.
Lake of the Woods authorized outflow will be reduced from 100 to 90 m3/s on Friday October 1st. The level of the Winnipeg River immediately below the Norman Dam is expected to drop by 1-2 cm (1 in) in response. The level at Minaki will not be affected by this flow change.
The current level of Lac Seul is 355.64 m (1166.8 ft), less than a 5th percentile level for this time of year. The average lake level rose by 2 cm (1 in) over the past week and is expected to rise by 2 to 6 cm (1 to 3 in) over the next week.
Lac Seul authorized outflow is 75 m3/s and no outflow changes are currently scheduled.
The past week saw some much needed precipitation in a large portion of the Winnipeg River basin. According to the U.S. Drought Monitor, drought categories for some Minnesota portions of the basin improved from Exceptional to Extreme Drought or from Extreme to Severe Drought.
However, due to the widespread drought conditions, little of this rainfall has reached streams and larger tributaries in the basin. Substantial rainfall is still needed to resolve the underlying drought conditions in the landscape and return flows to normal.
Water levels in key reservoirs upstream of Lake of the Woods, Rainy Lake and Namakan Lake, rose modestly but remain below regulatory targets set by the International Joint Commission. As a result, there has been no increase in the very low seasonal outflows from the dams at these lakes.
Flows in the Rainy River and its main tributaries, the Big Fork River and Little Fork River, saw very small responses to the rainfall. Inflow to Lake of the Woods has not increased significantly as a result.
Rainy River from International Falls, MN. Sep 22, 2021. Photo: Lee Grim
The current level of Lake of the Woods is 322.50 m (1058.1 ft), a 5th percentile level for this time of year. The lake level declined by 1 cm (1/2 in) over the past week and is expected to decline by 1-3 cm over the next week with forecasted dry weather. Lake of the Woods authorized outflow is 100 m³/s, with no outflow changes currently scheduled.
In the English River basin, the rainfall led to a greater rise in tributary flows in some areas, for example near Sioux Lookout and the Chukuni River where flows are now in the normal range for late September. Other tributaries remain well below normal, as does the level of Lac Seul and the mainstem of the English River as measured at Grassy Narrows.
The current level of Lac Seul is 355.62 m (1166.7 ft), less than 5th percentile for this time of year. The lake level rose by 6 cm (2 in) over the past week and is expected to rise by 1-3 cm (1 in) over the next week. Lac Seul authorized outflow is 75 m³/s with no changes currently scheduled. A planned regional power outage scheduled by Hydro One will result in fluctuations in outflow from Lac Seul on September 26 and 27, varying between 39 and 107 m³/s before returning to the authorized 75 m³/s.
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 fall by 1 to 2 cm (1 in) over the next week.
Lake of the Woods authorized outflow is 100 m3/s and no outflow changes are currently scheduled. Average inflow over the next week is estimated to be approximately 65 m3/s.
The current level of Lac Seul is 355.57 m (1166.6 ft), a 5th percentile level for this time of year. The average lake level rose by 2 cm (1 in) over the past week and is expected to rise by 2 to 5 cm (1 to 2 in) over the next week.
Lac Seul authorized outflow is 75 m3/s and no outflow changes are currently scheduled. Average inflow over the next week is estimated to be approximately 150 m3/s.
On Wednesday September 8, the Board held a Regulation Consultation call to review the current strategy and basin conditions. Based on the discussion, the Board determined that the current strategy adequately addressed the on-going drought conditions and a new strategy would be adopted at the next Regulation meeting, scheduled for the end of October.
Manitoba Hydro provided the following forecast on September 9 for lake levels along the Winnipeg River in the Whiteshell. For questions related to water levels in this area, please contact Manitoba Hydro.
* Note: average is based on limited historic data.
The Winnipeg River receives most of its water from Ontario’s Lake of the Woods and Lac Seul, these flows are regulated by the LWCB. Manitoba Hydro models the expected rise and fall for lakes on the Winnipeg River downstream of Slave Falls Generating Station based on flows set by the LWCB, unregulated tributaries, and expected precipitation.
Please note:
Operations of Caribou Falls Generating Station in Ontario and local precipitation may cause daily fluctuations in levels.
Manitoba Hydro’s generating stations on the Winnipeg River pass on all the water received from upstream – generally referred to as “run of river”.
This weekly forecast will be provided during the open water season.
The current level of Lake of the Woods is 322.51 m (1058.1 ft), a 10th percentile level for this time of year. The average lake level changed little over the past week and is expected to fall by 1 to 3 cm (1 in) over the next week.
Lake of the Woods authorized outflow will be reduced from 120 to 100 m3/s on Thursday September 2. The level of the Winnipeg River immediately below the Norman Dam is expected to drop by 3 cm (1 in) in response. Areas farther downstream will observe a smaller level change. The level at Minaki will not be affected by this flow change.
The current level of Lac Seul is 355.55 m (1166.5 ft), a 5th percentile level for this time of year. The average lake level rose by 2 cm (1 in) over the past week and is expected to rise by 1 to 3 cm (1 to 2 in) over the next week.
