Scientists say the longest period on record of abnormally low Great Lakes water levels has ended, but it's uncertain whether the recovery is temporary or the beginning of a new long-term trend.
The slump began in the late 1990s. It continued for 15 years, culminating early last year when Lake Michigan and Lake Huron set low-water records. Since then, levels have sharply rebounded.
In September, the levels of all five of the Great Lakes were above average for the first time since the drop-off began, said Drew Gronewold of the NOAA Great Lakes Environmental Research Laboratory in Ann Arbor.
Between January 2013 and this November, Lake Superior rose 2.3 feet, while Lakes Michigan and Huron rose 3.2 feet.
Gronewold and Keith Kompoltowicz (kom-POL'-to-witz) of the U.S. Army Corps of Engineers said the recovery is due primarily to heavy rain and snowfall in the region over the past two years.
They predict that levels will remain above normal for the next six months on all the Great Lakes except Lake Ontario, which may be a couple of inches below normal.
Beyond that, "it becomes difficult for us to predict whether or not water levels might drop again, stay at this level or go higher," Gronewold said.
The recovery is good news for commercial shippers, recreational boaters and others who have had to worry about running around in harbors and shallow channels. But Kompoltowicz says some owners of shoreline property are concerned about erosion.
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