Lake Superior Levels Near Normal For February

Posted by Mark Mccormick
 February 21, 2011

 Levels still expected to decline

ARTICLE | FEBRUARY 20, 2011 - 6:07PM | ASHLAND CURRENT

This past month the water supply to the Lake Superior basin was near normal, according to the International Lake Superior Board of Control.

However, the water supply to the Lake Michigan-Huron basin was below normal. Lake Superior is currently 24 cm (9 inches) below its chart datum level. The level of Lake Superior is expected to decline in February.

Currently, the Lake Superior level is about 34 cm (13 inches) below its long-term average beginning-of-February level, and is 22 cm (9 inches) lower than the level recorded a year ago. This past month the level of Lake Superior fell 6 cm (2 inches), while on average it falls 7 cm (3 inches) in January.

The level of Lakes Michigan-Huron fell 4 cm (2 inches) during January, while on average it falls 3 cm (1 inch) during January. The level of Lakes Michigan-Huron is now about 49 cm (19 inches) below its long-term average beginning-of-February level, and is 32 cm (13 inches) lower than it was a year ago. Currently Lakes Michigan-Huron is 20 cm (8 inches) below its chart datum level. The level of Lakes Michigan-Huron is expected to remain steady in February.

The International Lake Superior Board of Control, under authority granted to it by the International Joint Commission, has set the Lake Superior outflow to 1,530 cubic meters per second (m3/s) (54.0 thousand cubic feet per second (tcfs)) for the month of February. This is the outflow recommended by the regulation plan for the month of February and a decrease from the January outflow, which was 1,560 m3/s (55.1 tcfs).

The February outflow will be released by discharging about 1,434 m3/s (50.6 tcfs) through three hydropower plants and passing most of the remaining flow through the control structure at the head of the St. Marys rapids.

The Board continues to monitor conditions both on Lake Superior and downstream and will advise the International Joint Commission accordingly on those conditions.

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