UPDATE ON LAKE SUPERIOR OUTFLOWS AND EXPECTED CONDITIONS - FEBRUARY 2016
The International Lake Superior Board of Control, under authority granted to it by the International Joint Commission, has set the Lake Superior outflow to 2400 cubic metres per second (m3/s) (84.8 thousand cubic feet per second (tcfs)) for the month of February, effective February 3rd. The outflow is being set to the normal maximum winter flow prescribed by Lake Superior Regulation Plan 2012, and may at times vary due to weather events and changes in hydrologic and ice conditions.
The February outflow will be released by discharging about 2308 m3/s (81.5 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 for the month of February will be maintained at the equivalent of one-half gate open (four gates open 20 centimetres (cm) (8 inches) 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 a flow of about 15 m3/s (530 ft3/s) to the channel north of the Fishery Remedial Dike.
The net water supplies to Lake Superior were above average in January. The level of Lake Superior fell 6 cm (2 in) last month, while on average the lake falls 7 cm (3 in) in January. The Lake Superior level at the beginning-of-February is 23 cm (9 in) above average, 2 cm (1 in) above the level recorded a year ago at this time, and 32 cm (13 in) above its chart datum level.
The net water supplies to Lake Michigan-Huron were below average in January. The level of Lake Michigan-Huron fell 6 cm (2 in) last month, while on average the lake falls 3 cm (1 in) in January. The level of Lake Michigan-Huron is 27 cm (11 in) above its long-term average beginning-of-February level, 3 cm (2 in) higher than it was a year ago, and 54 cm (21 in) above its chart datum level.
The levels of Lake Superior and Lake Michigan-Huron are both expected to continue their seasonal declines in February.