Great Lakes on a record-breaking water-level rebound

After a record low point in January 2013, Lakes Michigan and Huron have gone on a record-breaking rebound.

Connected Michigan and Huron, as well as Lake Superior, saw dramatic water level recovery from January 2013 to this November. Going back to the mid-1800s, there has never been a faster recovery over a 23-month period, beginning in January, said Andrew Gronewold, a hydrologist with the Great Lakes Environmental Research Laboratory in Ann Arbor.

Lakes Michigan and Huron have recovered 3.2 feet since January 2013; Lake Superior 2.3 feet, Gronewold said. All of the Great Lakes, except heavily regulated Lake Ontario, are higher this November than they were at this time last year. And all but Ontario are above their long-term average depths. It's the first time since the late 1990s that both Michigan-Huron and Superior were above their averages at the same time, he said.

"This surge has brought to an end a period where we were below historic averages for about 15 years," Gronewold said.

It's continued good news for lakefront property owners who struggled with useless, high-and-dry docks and community marinas that required expensive dredging just three years ago. Deeper lakes also allow heavier loads for Great Lakes freighters and the minerals and other products they move.

The fast turnaround has to do with the water sources replenishing the lakes, Gronewold said.

"We've had above-average precipitation and above average runoff, particularly in the springs of 2013 and 2014," he said.

The Great Lakes typically reach their peak depth around July, then begin a decline that continues until the following spring. That makes what's going on this winter very unusual, said Keith Kompoltowicz, chief of watershed hydrology for the U.S. Army Corps of Engineers' Detroit office.

"From summer high to winter low, it's right around a foot drop typically," he said. "And we haven't really seen any decline yet. It's a very rare feat on Michigan-Huron."

The Army Corps forecasts a lake level drop of only a few inches over this winter, before levels start to rise again next spring, he said.

The forecast for the lakes through next May calls for:

■ Lakes Michigan and Huron to be 15-21 inches higher than last year; and about 7 inches above their long-term average.

■ Lake Superior to remain 9-10 inches over a year ago; and from 6-9 inches above average.

■ Lake Erie to be 5-11 inches deeper than last year; and 6-8 inches above average.

■ Lake Ontario about 2-5 inches below last year; and near its long-term average.

■ Lake St. Clair — which is measured along with the Great Lakes because it is a feeder lake — to be 7-18 inches higher than last year; and 7-11 inches above average.

While the continuing trend for Great Lakes water levels is positive, things can change relatively quickly, Gronewold said. Forecasts farther out than six months are difficult to rely upon, he said.

"With the Arctic, polar vortex last winter, hardly anybody was predicting that kind of ice cover and water temperatures," he said.

Contact Keith Matheny: 313-222-5021 or kmatheny@freepress.com