The latest numbers from the Lake Superior Board of Control show that water supply conditions were slightly above average for the month of March.
Additionally, conditions for the Michigan-Huron basin were slightly below average during the same stretch.
Lake Superior remained at its same as February while the seasonal long-term average pattern is for the lake to decline by 1 cm (0.4 in) in March.
Lake Michigan-Huron declined by 1 cm (0.4 in) last month, while the seasonal long-term average pattern is for Lake Michigan-Huron to rise by 5 cm (2.0 in) in March.
At the beginning of April, the lake-wide average water level of Lake Superior was 2 cm (0.8 in) below the seasonal long-term average (1918-2022) and 20 cm (7.9 in) below the level of a year ago while the lake-wide average water level of Lake Michigan-Huron was 3 cm (1.2 in) above the seasonal long-term average (1918-2022) and 7 cm (2.8 in) below the level of a year ago.
The Board expects the total St. Marys River flow in April to be 1,850 m3/s (65,300 cfs).
Hour-to-hour and day-to-day flows may vary depending on hydrologic conditions, as well as variations in flow from the hydropower plants.
The gate setting of the Compensating Works at the head of the St. Marys Rapids will be maintained in April at a setting equivalent to approximately one-half gate fully open (Gates No. 7 through No. 10 open 20 cm (7.9 in)) and Gate No. 1 at its typical setting of 20 cm (7.9 in) open. St. Marys Rapids flow will be approximately 85 m3/s (3,000 cfs) in April.
The MacArthur Lock has been closed for seasonal maintenance and will reopen April 24. The Poe Lock reopened on March 22.
