A Superior story
Editor’s note: Today we begin a two-part series on changes occurring in Lake Superior. Our first part highlights rising water levels. On Saturday we will look at temperature changes.
By DAN ROBLEE
HOUGHTON – Lake Superior water levels are up 13 inches from this time last year, and currently stand about seven inches above long-term mean levels. For most, it’s a welcome turnaround from years of low water, but the high water levels have also caused some challenges.
At the Ojibwa Recreation Area marina in Baraga, ramps to many docks were underwater July 6. One dock with its ramp sunk nearly a foot beneath the surface stood empty in an otherwise nearly full marina, while docks with ramps just inches beneath the surface were still in use.
At Markham’s Marina on the Portage Canal, owner Paul Hietala said he had to raise a few docks this year, “but it wasn’t really a big deal.”
Hietala said extremely low water a few years ago had presented a bit more of a challenge, but that too had been manageable, as the marina’s dock slips were situated in fairly deep water. Overall, “it really hasn’t affected us much. … (and) there’s nothing I can do about it,” he said.
A few hundred yards east of the marina, a waterfront fire pit that property owners used regularly last summer was submerged in about six inches of water.
Overall, the high water is “great for commercial shipping, but less great for coastal landowners,” said Guy Meadows, director of the Great Lakes Research Center at Michigan Technological University. He noted the water will rise probably about another inch this summer, following normal patterns.
Earlier this month, Duluth Seaway Port Authority Facilities Manager James Sharrow told the Minneapolis Star Tribune Great Lakes freighters will be able to haul the equivalent of two more full boatloads of cargo this season, in the same number of trips, after being forced to run as much as 10 percent empty in low-water years to navigate shipping channels into some ports.
High water is also a boon to the biology of coastal wetlands, which Meadows said “periodically need a real good flushing” to maintain ecological health.
Meadows said last winter’s massive snowfalls and heavy spring rains have played a role in the higher water, but a decrease in evaporation from the lake has also been significant.
There was 92.2 percent ice cover last winter, which blocked potential evaporation, he said, adding “For the last 12 years, we have not had substantial cover.”
Normally, “we lose an enormous amount of water to evaporation over the winter,” he said. “Something like 10 times as much water flows out of the Great Lakes through evaporation and precipitation than flows out through the St. Lawrence Seaway.”
Colder Lake Superior water temperatures have also decreased evaporation, he noted. Additional effects of the cooler temperatures will be explored in the conclusion of this series.
Meadows said he did not expect the International Lake Superior Board of Control’s decision earlier this month to increase water flow from Lake Superior through the St. Mary’s River to Lake Huron to have a huge effect. That’s partially because evaporation plays a much larger role in water loss, and partly because how much water they release is regulated by a treaty between the U.S. and Canada designed to keep Superior’s levels within a predetermined range.
Lakes Michigan and Huron water levels are still well below long-term means, though they have come up significantly this summer. Still, Meadows said the rise will likely be more noticeable there, where a one-foot rise in water levels will often inundate about 50 feet of gradually sloping beaches.
Lake Superior’s beaches are often steeper. Mark Plichta, who lives at Little Traverse, said he has about 20 to 25 feet less beach this summer, but Brian Donnelly, who has a camp at Little America in Stanton Township, said the high water levels have made almost no difference in the beach width there.
On inland lakes, water levels have fluctuated even more. At Bob DuPont’s home on the south shore of Lake Eva near Tapiola, water levels have come up two-and-a-half to three feet in each of the last two years, after having gradually dropped about eight feet in the years since he bought the property in about 1990.
This spring, he said, heavy runoff left more than a foot of water on top of the lake ice, and over the top of his dock.
When the ice later floated back to the top, it picked up his and neighboring docks with it, then floated them out into the lake in an offshore wind before melting out from underneath.
DuPont said his dock, and all of his neighbors’, except for one probably sunk section, have since been recovered.