EPHRAIM, Wis. -- Like a slowly draining bathtub, this sparkling inlet of Lake Michigan had seen its clear, cool waters recede for years.
Piers that once easily reached the water had gone high and dry. Fishermen did not dare venture into the shallow water looking for smallmouth bass, lest their propellers scrape bottom. And residents of Ephraim, a village on a peninsula that juts into Lake Michigan, were so alarmed that the county paper asked in a headline in April of last year, "Will the Great Lakes Rise Again?"
But after reaching historic lows in 2013, water levels in the Great Lakes are now abruptly on the rise, a development that has startled scientists and thrilled just about everybody with a stake in the waterfront, including owners of beach houses, retailers in tourist areas and dockmasters who run marinas on the lakeshore.
Lakes Michigan, Huron and Superior are at least a foot higher than they were a year ago, and are expected to rise 3 more inches over the next month. Lake Ontario and Lake Erie are 7 to 9 inches higher than a year ago.
In Ephraim, a town on the waters of Green Bay that in summer becomes a pristine playground for sailing, swimming and kayaking, residents have marveled at the lake's comeback, as the water has risen to a level that they had not seen in close to 15 years.
"When the water was going down for years, we all wondered, 'How far is it going to go?'" said Stuart Chomeau, 58, as he peered at his dock, which he said now has close to 30 feet more water under it than it did last year. "This is a welcome change."
Scientists say the reversal of fortunes for the lakes is partly a result of the most bone-chilling winter in memory for many Midwesterners. The thick and long-lasting ice cover on the lakes kept the water colder and slowed evaporation. Heavy snowfall and a rainy spring allowed the lakes to make even more gains.
"We've had a rebound that we haven't seen in many, many years," said Gene Clark, a coastal engineer with the University of Wisconsin Sea Grant Institute in Superior. "We've been historically below average, and now we are finally back to above-average water levels. At this time last year, I was talking to Wisconsin state legislators about what was happening, why the levels were so low and what could the State of Wisconsin do about it. It was very much a crisis."
The International Joint Commission, a group with members from the United States and Canada that advises on water resources, completed a five-year study in April 2013 concluding that water levels in the lakes were likely to drop even farther, in part because of the lack of precipitation in recent years brought on by climate change. The low lake levels in the past decade or more caused a host of frustrating and expensive problems: shoreline erosion, parched wetlands and disruptions to marinas along the Great Lakes. Homeowners on Georgian Bay of Lake Huron complained bitterly that the low water had marred their once-idyllic cottages.
Countless marinas on Lake Superior, Lake Huron and Lake Michigan resorted to dredging their harbors in recent years, a messy and time-consuming process. At the Baileys Harbor marina in Wisconsin, on the shore of Lake Michigan, operators bought their own dredger three years ago, a $60,000 purchase, and have been forced to dredge repeatedly so that boats could maneuver in and out.
"We were getting very worried," said Jim Ahlen, the assistant harbor master. "Boaters were saying they were going to have to find another marina. We're losing customers that way. The charter boats were looking elsewhere. It was tough scratching up here for a lot of years."
This year, Mr. Ahlen said with relief, the marina called off plans to dredge again.
Residents on the lakes are holding their breath with hope that the gains of recent months will not be undone. Climatologists predict that the levels will rise even more in the coming months, following the natural cycle in which levels are at their lowest in late winter, rise throughout the spring and finally hit a peak in late summer.
Drew Gronewold, a hydrologist with the National Oceanic and Atmospheric Administration, said Lake Michigan and Lake Huron had been in a period of persistently low water levels for 15 years, since a rapid decline in the late 1990s. He called the rise from the record lows of December 2012 and January 2013 "remarkable."
But, he added, it is difficult to predict water levels more than six months in advance, because of all the factors like precipitation that can influence them.
"It obviously puts a lot of strain on people," Mr. Gronewold said of the uncertainty and the shifting water levels. "When the water gets very high, we get stressed. We don't like it when houses are falling in the lakes. And when it's very low, ships can't move. But the natural variability of the system is important to the health of the coastal ecosystem."