INTERNATIONAL LAKE SUPERIOR BOARD OF CONTROL
Update on Lake Superior outflow
The International Lake Superior Board of Control, under authority granted to it by the International Joint Commission, has set the Lake Superior outflow to 1,650 cubic meters per second m3/s (58.3 thousand cubic feet per second (tcfs)) for the month of June, effective June 1, 2012.
This is an increase from the May outflow, which was 1560 m3/s.
This outflow includes 1,560 m3/s as prescribed by Plan 1977-A and approximately 90 m3/s additional allocation to the Canadian hydropower facility to facilitate sea lamprey trapping tests.
The June outflow will be released by discharging about 1,548 m3/s (54.7 tcfs) 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 will be maintained at the existing setting equivalent to one-half gate open (four gates open 20 centimeters (cm), or about 8 inches each).
There will be no change to the setting of Gate No. 1 that supplies the Fishery Remedial Works.
This past month the water supplies to the lakes Superior and Michigan-Huron basins were below normal.
Lake Superior is currently 8 cm (3 inches) below chart datum level.
The level of Lake Superior is expected to rise in June.
Currently, the Lake Superior level is about 29 cm (11 inches) below its long-term average beginning-of-June level, and is 2 cm (1 inch) higher than the level recorded a year ago.
This past month the level of Lake Superior rose 11 cm (4 inches), while on average it rises 8 cm (3 inches) in May.
The level of Lakes Michigan-Huron rose 4 cm (2 inches) this May, while on average it rises 8 cm (3 inches) in May.
The level of Lakes Michigan- Huron is now about 41 cm (16 inches) below its long-term average beginning-of-June level, and is 12 cm (5 inch) lower than it was a year ago.
Currently Lakes Michigan-Huron is 6 cm (2 inches) above its chart datum level.
The level of Lakes Michigan-Huron is expected to rise in June.
The board continues to monitor conditions both on Lake Superior and downstream and will advise the International Joint Commission accordingly on those conditions.
BG Margaret Burcham is the United States board member.
Mr. David Fay is the Board Member for Canada.