2026.05.04 Outflow Increases for Lake of the Woods and Lac Seul
The spring freshet is in full swing across the Winnipeg River basin. Areas to the east, which saw exceptionally high rainfall at the end of April, continue to see rising flows in tributary rivers and inflows to major lakes.
In the Lac Seul sub-basin, flows have risen sharply to high seasonal levels in the east of the basin, including into Lake St. Joseph and in the natural tributaries to Lac Seul east of Sioux Lookout (Sturgeon River, English River). Lac Seul level is projected to rise above the minimum fisheries target for May 15 with this strong freshet response.
Lac Seul authorized outflow will be increased from 100 to 175 m³/s on Tuesday, May 5.
In the Lake of the Woods sub-basin, rainfall at the end of April was heaviest in the eastern headwater regions in Minnesota and Ontario. Flows measured in the major tributaries from these headwaters (Namakan River at the outlet of Lac la Croix and Seine River, respectively), are exceptionally high for early May. Flows in Turtle River in Ontario, another important tributary draining the north of the Rainy basin into Rainy Lake is moderately high. Dam operators at Namakan Lake and Rainy Lake are increasing outflows as this water makes it way through the system, which will result in rising inflows to Lake of the Woods over the next week.
In keeping with the LWCB’s adopted spring Regulation Strategy, Lake of the Woods authorized outflow will be increased from 225 to 275 m³/s on Tuesday, May 5 and from 275 m³/s to 325 m³/s on Friday, May 8. The Winnipeg River level below Norman Dam is expected to rise by 10 cm (4 inches) following each of these outflow increases. The Winnipeg River level at Minaki will not be affected by these flow changes.