Update on Lake Superior Outflows

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International-Lake-Superior-Board-Of-Control

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 April, effective April 2nd. The outflow is being set to the normal maximum winter flow as prescribed by Plan 2012, the regulation plan for Lake Superior, and is about the same as the March flow.

The April outflow will be released by discharging about 2304 m3/s through the three hydropower plants and passing most of the remaining flow through the control structure at the head of the St. Marys Rapids. The gate setting of the control structure for the month of April will be maintained at the equivalent of one-half gate open (four gates open 20 centimetres (cm) each). The one-half gate equivalent setting is the normal winter maximum, and is typically maintained from December through April. There will be no change to the setting of Gate #1 which supplies water to the channel north of the Fishery Remedial Dike.

The monthly mean water level of Lake Superior in March was 183.42 m. This is 20 cm above the long-term (1918-2014) March average and the highest March level since 1997.

The net water supplies to Lake Superior were above average in March. The level of Lake Superior declined 2 cm last month, which is the average decline in March. The Lake Superior level at the beginning-of-April is 19 cm above average, 18 cm above the level recorded a year ago at this time, and 21 cm above its chart datum level.

The monthly mean water level of Lake Michigan-Huron in March was 176.48 m. This is 19 cm above the long-term (1918-2014) March average, and the highest March level since 1998.

The net water supplies to Lake Michigan-Huron were below average in March. The level of Lake Michigan-Huron declined 1 cm last month, while on average the lake rises 4 cm in March. The level of Lake Michigan-Huron is 17 cm above its long-term average beginning-of-April level, 51 cm higher than it was a year ago, and 48 cm above its chart datum level.

The level of Lake Superior is expected to begin its seasonal rise in April, and the level of Lake Michigan-Huron is expected to continue its seasonal rise.

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@ec.gc.ca

Additional information can also be found at the Board’s homepage: http://ijc.org/en_/ilsbc or Facebook at: https://www.facebook.com/InternationalLakeSuperiorBoardOfControl