The International Lake Superior Board of Control, under authority granted to it by the International Joint Commission (IJC), has set the Lake Superior outflow to 2400 cubic metres per second (m3/s) for the month of May, effective May 2nd. The outflow is as prescribed by Lake Superior Regulation Plan 2012.
The May outflow of 2400 m3/s is expected to exceed the combined capacities of the hydropower plants on the St. Marys River, which will be approximately 1940 m3/s in May, and the excess flow will be released through the control structure at the head of the St. Marys Rapids.
The gate setting of the control structure will be increased on Wednesday, May 11th, from the current setting equivalent to approximately one gate open to a setting equivalent to approximately three gates open. This will be achieved by partially opening each of Gates #2 to #13 and #15 to a setting of 53 cm open. Anglers need to be cautious of the changing flows and water levels in the rapids on May 11th and the higher flows and levels that will be experienced in the rapids in May. 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. Gate #14 will remain closed to allow water level measurements to be collected, and Gate #16 will be set to 5 cm open to facilitate sea lamprey trapping.
The net water supplies to Lake Superior were below average in April. The level of Lake Superior rose 2 cm last month, while on average the lake rises 7 cm in April. The Lake Superior level at the beginning-of-May is 20 cm above average, 2 cm above the level recorded a year ago at this time, and 30 cm above its chart datum level.
The net water supplies to Lake Michigan-Huron were below average in April. The level of Lake Michigan-Huron rose 7 cm last month, while on average the lake rises 11 cm in April. The level of Lake Michigan-Huron is 37 cm above its long-term average beginning-of-May level, 23 cm higher than it was a year ago, and 79 cm above its chart datum level.
The levels of Lake Superior and Lake Michigan-Huron are both expected to continue their seasonal rise in May.
Mr. Jaymie Gadal is the Board Member for Canada. Brigadier General Richard Kaiser is the U.S. Board Member.
For further information, please contact Mr. Jacob Bruxer, Canadian Regulation Representative, International Lake Superior Board of Control, by phone at (613) 938-5862 or by e-mail at Jacob.Bruxer@canada.ca
Additional information can also be found at the Board’s homepage: http://ijc.org/en_/ilsbc
Or on Facebook at: https://www.facebook.com/InternationalLakeSuperiorBoardOfControl