TRAVERSE CITY, MI (AP)-- 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 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.