The Upper Great Lakes continued their meteoric 2014 rise in August, with Lake Superior’s monthly water level the highest in 17 years and lakes Michigan and Huron reaching the highest August level since 1998.
Lake Superior rose 0.4 inches in August, the usual increase for the month, and sits at 6 inches above average for Sept. 1, and 8 inches above the level at this time last year, according to the International Lake Superior Board of Control.
Lakes Huron and Michigan saw an even faster rise - up 2 inches in August, a month the lakes usually go down 2 inches. The two lakes now sit just 1 inch below their long-term Sept. 1 average, and a full 17 inches above the Sept. 1 level one year ago.
Water supply for lakes Superior, Michigan and Huron were above normal, with continued increased rain, reduced evaporation and more stream inflow.
The upper lakes have been on an upward trajectory now for more than a year, easing concerns over below normal water levels that had lingered for a decade or so.
The level of the lakes is considered important for shipping as well as recreational boating, which have been plagued in recent years by unusually low water levels. Unusually high levels can be a problem as well, especially for increased erosion.
Lake Superior generally rises from April to August, before a seasonal decline from September to March.
