The flow will increase to about 720 cubic meters per second, or 25.4 thousand cubic feet per second.
Fishermen and people using St. John’s rapids are warned. Marys that the area will have the highest flow since 2019 after June 6th.
The compensatory movements of the works door are scheduled for June 6 and will increase the flow to approximately 720 cubic meters per second, or 25.4 thousand cubic feet per second.
Below is more detailed information on the change in the publication of the Lake Superior International Control Board.
Fishermen and other users of the St. Marys, please note the increase in flows and water levels that will be experienced in the rapids in June. Following the movements of the Compensation Works Gate scheduled for Monday, June 6, the flow of St. John’s rapids is expected. Marys is approximately 720 cubic meters per second (m3 / s) (25.4 thousand cubic feet per second (tcfs)), which is the highest flow rate of the Rapids since 2019.
With these flows, some flooding is expected from the lowlands of Whitefish Island as additional gates open and flows increase. As a result, some trails and recreational features in these areas are likely to be flooded and users are advised to exercise extreme caution.
Lake Superior’s water level rose significantly in May after another month of significantly wetter-than-average conditions in the basin. Lake Superior rose 22 cm (8.7 inches) last month, while on average the lake rose 10 cm (3.9 inches) in May. Water supplies were closer to average in the Michigan-Huron Lake Basin. Lake Michigan-Huron rose 8 cm (3.2 inches) last month, which is the long-term seasonal average for this month. Outflows from Lake Superior and Lake Michigan-Huron continue to be established taking into account water levels upstream and downstream.
The Board expects the total outflow to be 2,470 m3 / s (87.2 tcfs) in June, as set out in the 2012 Lake Superior Regulation Plan. As a result of this increase in total outflow, combined with ongoing repairs to the Canadian hydroelectric plant, the door configuration at the Compensation Works will be increased to the equivalent of approximately five fully open doors on Monday, June 6th. This will be achieved by raising doors # 7 to # 12 to a 162 cm (64 inch) open position. Door no. 16 will open at a position of 5 cm (2 inches) to improve the efficiency of the annual sea lamprey catch conducted by the U.S. Fish and Wildlife Service. There will be no change in the configuration of gate # 1, which supplies a flow of about 15 m3 / s to the canal north of the Fishing Repair Dock.
In early June, Lake Superior’s water level is 12 cm (4.7 inches) above the long-term seasonal average (1918-2021) and 2 cm (0.8 inches) above level from a year ago. In early June, the level of Lake Michigan-Huron across the lake is 27 cm (10.6 inches) above average, 14 cm (5.5 inches) below the level of a year ago.
Depending on weather and water supply conditions during the following month, Lake Superior may increase by up to 15 cm (5.9 inches) and Lake Michigan-Huron water levels may increase by up to 12 cm (4 inches). , 7 inches) in June.