Researchers say agriculture is killing Lake Pepin. Can a national treasure be saved before it’s too late?
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Nineteen years ago, Michael McKay purchased a house in Wacouta Township, a few miles south of Red Wing, along the northwestern shore of Lake Pepin. A Minneapolis native, McKay had come to the area for work, but it wasn’t long before the city guy fell under the big lake’s spell.
Later, when a new job materialized in the Twin Cities, McKay chose a 90-minute commute to Shoreview rather than relinquish his idyll. “There was no way in hell I was going to move back,” he says. Instead of relocating his family, he remodeled his rambler, replacing every window in the house just so he could soak up the commanding views.
Standing on a ridge in his backyard, McKay, a fit-looking 59-year-old with silvering hair, surveys the head of the lake. At 30 miles long and three miles wide, Pepin is the largest lake on the Mississippi River and its scenery befits that distinction. McKay is quick to note the bald eagle circling overhead. Eagles are ubiquitous on Pepin. It’s a source of pride among locals (many of whom remember when the birds were scarce), and a selling point for the local tourism industry. The eagle population got a boost from the Prairie Island Nuclear Generating Plant, which discharges warm water into the Mississippi River at Red Wing. Even in January, the north end of Pepin, where the river enters the lake, is ice-free, allowing over-wintering eagles to fatten on fish.
McKay contemplates this interplay between man and the natural world. “It’s almost like the lake is one big living organism,” he muses.
A few years ago, however, McKay and his neighbors along Wacouta Bay began to notice signs that the “organism” was ailing. Some parts of Pepin seemed to be growing shallower, McKay says. It became difficult to cross the lake to favorite haunts on the Wisconsin side, even in a low-draft fishing boat or water scooter. A few river towns gave up dredging, making it difficult for locals to reach navigable parts of the lake.
Near the Mississippi inlet, McKay noticed, unfamiliar sand bars had emerged. Riparian vegetation had begun to spread, and new islands and peninsulas were forming. Examining aerial photographs, he noticed how the land mass around Wacouta Bay had expanded over the decades.
“You can see what’s happening,” McKay says flatly. “The lake is filling up.”
Mckay does not self-identify as an environmentalist. He has no background in water issues or conservation, and his current job, as general manager at the St. James Hotel in Red Wing, keeps him plenty busy. But last year, McKay and some of his neighbors from Wacouta Bay joined other Lake Pepin lovers from Minnesota and Wisconsin to form the Lake Pepin Legacy Alliance, a nonprofit citizens group urging stricter controls on erosion, the cause of the crisis. McKay was worried enough about the changes in Pepin that he decided not only to sign on with the group, but to serve as its executive director.
As part of that job, McKay has immersed himself in tracking the multi-agency governmental effort to address the problem. He has attended countless conferences (and hosted some) and pored over reams of Lake Pepin–related research (the subject of the biggest water-pollution study in state history).
The experience was an eye opener in the real-world convergence of science and public policy: “We wanted to find out what the hell was happening,” McKay says, a touch exasperated. “And we were shocked when we found out all the information that is out there—all that is known—and yet there’s no action.”
Indeed, the prognosis for Lake Pepin is grim. Using core samples extracted from the bottom of the lake, researchers have calculated the contemporary and historical volumes of sedimentation, the term for the in-filling caused by silt, clay, and other solids that are deposited in the lake by the Mississippi River. At the current rate, according to these estimates, the upper third of Pepin will mostly vanish within a century. Within 340 years, all of Pepin will be transformed into a muddy channel. Much of the life will be choked from the lake, experts say, because sunlight won’t penetrate the murky waters. Lacking healthy aquatic vegetation, what’s left of the lake will be largely bereft of fish, waterfowl, and, perhaps, even those iconic eagles. And without those treasures, tourism in the area could plunge.
The scenario is mind-boggling but, then again, so is the amount of muck flowing into Pepin. Imagine a dump truck emptying a 12-cubic-yard load into the lake every eight minutes, every hour, every day of the year, says Norman Senjem, the Mississippi River Basin coordinator for the Minnesota Pollution Control Agency. Or, if you prefer, picture a square city block, and then conjure a pile the height of the 32-story Foshay Tower. That’s how much sediment washes into Lake Pepin annually.
Senjem and the MPCA want to slow that landslide. The agency hopes to reduce the flow of suspended solids into Pepin by 50 percent. According to agency scientists, such a reduction would promote the growth of wild celery, an aquatic plant species that provides essential forage for waterfowl and ideal cover for fish.
This isn’t the first time Lake Pepin has been threatened. Historian John Anfinson, author of The River We Have Wrought, points out that the city of St. Paul disposed of its garbage directly in the river until the late 1800s. The waste stream included vast quantities of horse manure, manufacturing detritus, and untreated human sewage, all of which flowed to Pepin. In one report, Anfinson says, the Corps of Engineers characterized most of the sandbars between the Twin Cities and Wabasha as consisting of a 50-50 mix of garbage and sawdust.
Anfinson says the environmental nadir for Pepin came in the 1920s and ’30s, with most of the pollution coming from the growing cities of Minneapolis and St. Paul. “It was appalling,” he says. “By the 1920s, there were sewage mats that would cover half the river between St. Paul and Hastings.” In times of low water flow, stretches of the Mississippi boasted a frightful ratio: one gallon of sewage to every 5.8 gallons of water.
Ironically, relief came to the river as a result of a very unnatural alteration of the river: the construction of Lock and Dam 2 at Hastings in 1930. The new structure effectively transformed a large stretch of the Mississippi into a sewage pond. Trash that once flowed unimpeded into Pepin started to back up, creating a repulsive stench along the river corridor. This olfactory outrage sparked calls for action, and, in 1938, the Twin Cities sewage treatment plant, just south of downtown St. Paul, near Pig’s Eye Lake, was completed. It was a key triumph in the modern environmental history of the upper Mississippi—in Anfinson’s view, on par with the passage of the Clean Water Act in the 1970s. The Mississippi was once again transformed. Pepin’s fisheries, which were on the verge of collapse in 1929 due to low oxygen and industrial pollutants, recovered. An environmental apocalypse was forestalled.
Today, the minnesota river is the principle source of the sediment flowing into Lake Pepin, according to the MPCA and a host of researchers. Remember that Foshay Tower analogy? The Minnesota accounts for the first 24 stories of that sediment skyscraper. “The Minnesota River is the big lion,” Senjem says. “Everything else is kind of dwarfed.”