Federal scientists said Wednesday they are fairly confident the 15-year era of low Great Lakes water levels is over.

The changes mean a return to normalcy for cargo shipping, recreational boating, and fewer costs associated with those sectors of the economy. The rising water levels also bring the prospect of more erosion, less beachfront property, and more skirmishes over private property rights.

Drew Gronewold, hydrologist for the National Oceanic and Atmospheric Administration’s Great Lakes Environmental Research Laboratory in Ann Arbor, said the recovery for Lake Superior is the most rapid on record and the fastest since the 1950s for Lakes Michigan-Huron.

The semiannual forecast he and others released during a conference call with Great Lakes writers calls for more steady rises through May. They said they can only predict six months into the future and recognize the instability of climate change can be a real wild card, though.

During the call, scientists said they expect the upcoming winter to cast a more familiar spell on the Great Lakes region — cold, but not nearly as bone-chillingly frigid or snowy as last winter, with temperatures and precipitation that will be more typical because of a 65 percent chance of an El Nino weather pattern forming.

“This winter will not be like last winter,” James Noel, service coordination hydrologist for NOAA’s Ohio River Forecasting Center, said. “It will be much closer to normal.”

Even this fall, there has been a “very unusual” steady increase in Lake Superior and Lakes Michigan-Ontario water levels. Autumn is a time when lake levels typically start to recede because of how differences between air and water temperatures accelerate an evaporation process that continues until the lakes freeze.

Those lakes, which flow southward, are the driving forces behind Lake Erie’s average water level, which was 7 inches greater in November than it was that same month in 2013 and 6 inches above its long-term average. Scientists expect it will be 5 to 11 inches above its average May, 2014, level by next May, and continue to be 6 inches above its long-term average, Keith Kompoltowicz, U.S. Army Corps of Engineers watershed hydrology chief in Detroit, said.

Though they shied away from policy implications in other areas, scientists said during their briefing that the Great Lakes shipping industry welcomed a return to normal water levels this year because of how much more expensive it was carrying lighter loads for 15 years. Every inch of water lost costs the region millions of dollars in delayed shipping and extra trips.

Marinas won’t be under as much pressure to dredge with stabilized water levels. Scholars of water law, including those who have spoken at the University of Toledo in recent years, have said a couple inches more water can intensify battles over shoreline development and property rights, especially when higher water reduces the amount of beachfront property.

At last month’s annual Great Lakes water law symposium at UT, one panel focused on a national debate over coastal wetlands. Two U.S. Supreme Court rulings have failed to resolve which connecting ditches and streams are protected by U.S. Environmental Protection Agency rules. Scientists agreed there likely will be wetter marshes if there are higher lake levels, but they declined to speculate how they could affect the national wetlands debate.

For the most part, scientists who presented the hydrology data seemed impressed by the region’s rapid recovery in water levels, though a bit perplexed by how quickly it occurred, given how some trends take years to reverse.

This November’s mean for Lake Superior was the highest since 1997, Mr. Kompoltowicz said.

But Mr. Noel cautioned of greater variability in precipitation with a warming climate system, from storm surges to droughts.

“It is really a challenging question,” Mr. Gronewold said of long-term modeling for Great Lakes water levels under various climate scenarios.

Contact Tom Henry at: thenry@theblade.com, 419-724-6079, or via Twitter @ecowriterohio.

First Published December 11, 2014, 5:14 a.m.