International Lake Superior Board of Control

As of Friday, August 5, the St. Marys Rapids flow is expected to be approximately 923 cubic meters per second (m3/s) (32.6 thousand cubic feet per second (tcfs)). At these flows, some flooding of low-lying areas including recreation trails on Whitefish Island is expected, and everyone is encouraged to use extreme caution.

Anglers and other users of the St. Marys Rapids, please be advised that the St. Marys Rapids flows and water levels will increase in July. As of Wednesday July 6, the St. Marys Rapids flow is expected to be approximately 786 cubic meters per second (m 3 /s) (27.8 thousand cubic feet per second (tcfs)). At these flows, some flooding of low-lying areas including recreation trails on Whitefish Island is expected, and everyone is encouraged to use extreme caution.

Anglers and other users of the St. Marys Rapids, please be advised of the increased flows and water levels that will be experienced in the Rapids in June. After the Compensating Works gate movements scheduled for Monday June 6, the St. Marys Rapids flow is expected to be approximately 720 cubic meters per second (m3/s) (25.4 thousand cubic feet per second (tcfs)) which is the highest flow in the Rapids since 2019. At these flows, some flooding of low-lying areas of Whitefish Island is expected as additional gates are opened and flows increase. As a result, some recreational trails and features in these areas will likely be flooded, and users are encouraged to use extreme caution.

Anglers and other users of the St. Marys Rapids are advised that on Wednesday morning, May 11, 2022, Gates #9 through #12 will be raised from their current position to a setting of 33 cm (13 in) open for the remainder of the month. Gates #7 and #8 will remain at their current setting of 20 cm (8 in). There will be no change to the setting of Gate #1, which supplies a flow of about 15 m3/s to the channel north of the Fishery Remedial Dike. These gate movements will result in an increase in the flow through the St. Marys Rapids from approximately 85 m3/s (3,000 cfs) to approximately 156 m3/s (5,500 cfs).

Outflows from Lake Superior and into Lake Michigan-Huron continue to be set in consideration of water levels upstream and downstream. The Board expects the total outflow to be 1,910 m3/s (67 tcfs) in May, which is as prescribed by Lake Superior Regulation Plan 2012. The gate setting at the Compensating Works will be maintained at the setting equivalent to one-half gate open (Gates #7 through #10 partially open 20 cm (7.9 in)). There will be no change to the setting of Gate #1, which supplies a flow of about 15 m3/s to the channel north of the Fishery Remedial Dike.

Lake Superior water levels remain below the seasonal long-term average while Lake Michigan-Huron water levels remain above the seasonal long-term average. Lake Superior outflows continue to be set in consideration of water levels upstream and downstream.

Lake Superior and Lake Michigan-Huron water levels are near their seasonal low point and depending on weather and water supply conditions could begin their seasonal spring rise over the coming weeks. The gate setting at the Compensating Works will be maintained at the setting equivalent to one-half gate open (Gates #7 through #10 partially open 20 cm (7.9 in)). There will be no change to the setting of Gate #1, which supplies a flow of about 15 m3 /s to the channel north of the Fishery Remedial Dike.

Weather and water supplies to Lakes Superior and Michigan-Huron were much drier than average in January. Lake Superior water levels remain below the seasonal long-term average while Lake Michigan-Huron water levels remain above the seasonal long-term average.

The Board expects the total outflow to be 1,730 m3/s (61.1 tcfs) in January, which is as prescribed by Lake Superior Regulation Plan 2012. The gate setting at the Compensating Works will be maintained at the setting equivalent to one half gate open (Gates #7 through #10 partially open 20 cm (7.9 in)). There will be no change to the setting of Gate #1, which supplies a flow of about 15 m3/s to the channel north of the Fishery Remedial Dike.