The motto Minneapolis proclaims to the world is: City of Lakes.
Not City of Six Fortune 500 Headquarters. City of World-Class Arts Institutions. City of Well-Plowed Streets. Or City of Super Bowl LII.
Yet often it feels things like these (while certainly important) dominate our attention and local pride, while the lakes are taken for granted.
For the record, more than 40 Fortune 500 companies are based in New York City, not to mention many of the world’s top museums and performing arts venues. Burlington, Vermont, beats us gloves down when it comes to snow removal (the city plows sidewalks as well as streets). Miami and New Orleans each have hosted 10 Super Bowls.
But no other big American city matches us on lakes. That’s a big reason Minneapolis’ park system has been ranked America’s best for the past five years by the Trust for Public Land. Unlike waterfronts in Chicago or Milwaukee, a surprising number of our lakes evoke a North Woods feel with sky-blue waters ringed by treetops — even if bustling cafes and art hotspots are just a few blocks away.
Folks who’ve never visited MSP are shocked to hear that I swim almost every day throughout the summer in a lake just a few blocks from my home. They look at me as if I’d announced I commute to work in a hot air balloon.
More than a nice amenity, Minneapolis’ lakes are a major asset for ensuring a bright future for the region.
So, how are the lakes?
Well, that depends on whom you talk to.
“The water quality we have here meets all the state standards, yet people still perceive that it’s in trouble,” notes Rachael Crabb, the Park Board’s water resources supervisor.
The Minnehaha Watershed District issues grades for all the lakes in the watershed on water quality. (Wirth and Loring Pond are not rated because they are outside of the Minnehaha Creek watershed; Diamond Lake is classified as a wetland, not lake.) The score of Minneapolis lakes are comparable to those in suburban areas. Here’s the 2016 report card on some of the city’s lakes:
Calhoun/Bde Maka Ska: A
Lake of the Isles: B
Lake Hiawatha: B. Hiawatha’s water quality is vulnerable to runoff from Minnehaha creek and storm sewers after rainfalls, which means the beach is closed more frequently than other lakes.
Lake Nokomis: C. Nokomis gets a C because of growing algae blooms and a high population of carp, which churn up sediment while feeding on the lake bottom.
Powderhorn Lake: D. While significantly clearer than in the past, Powderhorn gets a low mark due to high phosphorus levels when storm water streams in.
Wirth Lake. Wirth Lake “is one of the success stories over the past decade,” according to Crabb. Its water quality was long impaired because of frequent overflows from Bassett Creek, but a new water control system now prevents the creek from backing up into the lake except during the most extreme rainstorms.
Loring Pond. Loring Pond suffers an infestation of cattails and duckweed — the green muck covering much of the pond’s surface in the summertime. Neither is a sign of poor water quality, but duckweed in particular spoils the appeal of this popular park on the edge of downtown.
The Chain of Lakes. The places most people think of when you mention Minneapolis’ lakes all score A or B, meaning they are above average and perfectly healthy for all the activities we love to do in the water. So why are some people skeptical about swimming in the local lakes?
Excessive growth of Eurasian milfoil, abetted by native coontail, make our lakes look like the aquatic equivalent of vacant lots overgrown with brush. This is actually an indicator of increased water clarity, says Rachael Crabb, who nonetheless admits, “These plants are a real problem. … As we clean up the lakes, we see more and taller weeds.”
Even worse, visually, is the filamentous algae (the colloquial term is pond scum) coagulating on the lakes. While not a health risk, it deters some people from playing in the water.
Keeping lakes clean in the middle of a major city is daunting. Lake Calhoun/Bde Maka Ska, for instance, drains 2,992 acres of densely settled human activity, including steady runoff from expansive pavement and intensively fertilized lawns. The overall health of Minneapolis’ lakes stands as a testament to the public agencies and concerned citizens who care about them.
What else is in our lakes?
Here’s a quick guide to pollutants troubling the lakes today, and some to watch for the future.
Phosphorus. This is the biggest culprit in milfoil and algae blooms. Much of the phosphorus in city lakes can be traced back to runoff filled with leaves, grass clippings and lawn fertilizer.
Nitrogen. Another serious side effect of lawn fertilizer, which at high levels can be toxic to fish.
E-coli. A serious health risk at high concentrations, e-coli levels in Minneapolis lakes rise sometimes after heavy rains, when storm water containing pet and bird poop (predominantly geese) washes into the water.
Road and sidewalk salt. Lake lovers are keeping a watchful eye on increasing levels of chloride in the waters, primarily from de-icers spread on roads and sidewalks. The Star Tribune reported that use of road salt has increased 81 percent since 1985.
Zebra mussels. This invasive species has been found in Lake Hiawatha since 2013. In September, a single mussel was found in Lake Harriet. Extensive investigation by divers has turned up no others.
PAHs. Another emerging concern is polycyclic aromatic hydrocarbons (PAH), a carcinogenic chemical found coal tars used as sealants in asphalt roadways, which seeps into waterways.
While it’s good to know that most of our lakes score well on report cards, I’ll explore solutions to these and other challenges facing them in a future commentary. A day at the lake is an essential part of the good life in Minneapolis. And we don’t want be the first generation to tell children our lakes are no longer safe to fish, swim, boat and wade.
Jay Walljasper is a consultant, writer and speaker about how to create strong, bright communities. He is author of “The Great Neighborhood Book” and a senior fellow at New York-based Project for Public Spaces. His website: JayWalljasper.com
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