Help Protect Our Lakes

The city lakes are Minneapolis’s family jewels. Few people in other places enjoy such natural wonders to wade, paddle, sail, fish, swim, stroll, bike, skate, ski, sunbathe, picnic, and experience nature in the midst of a bustling city. 

We all owe a debt of gratitude to the civic leaders who donated land around the lakes to the new park district in the 1880s rather than develop it as lucrative real estate. This treasure has been handed down from generation to generation to all residents of the city.

Like any inheritance, however, these lakes must be vigilantly sustained so that our children and grandchildren may also enjoy them. Each generation must wage its own campaign to protect clean water and scenic views from the side effects of surrounding development. As Minneapolis’s population swelled from 46,000 to over 400,000 in the past 140 years, a host of problems have arisen that threaten Minneapolis’s greatest asset.

Most of these problems stem from the fact that storm sewers draining large swaths of sometimes dirty urban activity flow directly into our lakes—including roadways and parking lots, which do not absorb wastewater, and lawns doused with chemicals. 

Here’s a more detailed look at state of Minneapolis’s lakes.

A looming concern on the horizon is the effects of climate disruption, which scientific researchers predict will intensify challenges our lakes already face. Greater rainfall is predicted, which will increase the volume of polluted run-off streaming into the lakes, according to according the MN DNR climatology office. Indeed, 2013-2018 was the wettest six-year period since weather record-keeping began in the 1870s. The 30-inch increase in precipitation in those six years equaled an extra year’s worth of rain and snow.

The fight to limit damage from invasive species will become even more difficult as new plants and animals move into the region as their natural habitat migrates northward.

Today’s Major Problems

Right now, the biggest issues affecting the city lakes include:

Phosphorous—a major cause of algae blooms, including filamentous algae (also known as pond scum) which  gunks up and stinks up the lakes in early summer.

Nitrogen—a contributing factor to milfoil growth and algae blooms, which is found in lawn fertilizer. It is toxic to fish at high concentrations.

Road & Sidewalk Salt—a threat to all aquatic life in our lakes that  is being used in increasing quantities.

PAH—a carcinogenic material found in the coal tars used in asphalt road sealants, which stormwater deposits into  the lakes.

E-coli—an occasional short-term problem when heavy rains flush pet  and goose poop into lakes, leading to closed beaches.

Protecting Minneapolis’s waters grew tougher throughout the 20th century as wetlands bordering the lakes —nature’s own water purifier—were systematically destroyed. Since the mid-1990s, a number of wetlands have been re-created and more than a hundred grit chambers installed to filter out contaminants before they reach the lakes.

Identifying more strategic spots for wetlands and grit chambers as well as maintaining existing ones is part of the solution to protecting our lakes, noted Minneapolis Foundation president RT Rybak at special meeting of donors focused on the lakes held in 2017. Here are some other ideas that have been proposed by Park Board staff, environmental experts, Minneapolis Foundation donors, and other citizens.

“The whole idea is to keep stuff out of the lakes in the first place,” explains Debra Pilger, Director of Environmental Management for the Minneapolis Parks & Recreation Board. She points to stricter water quality regulations in Minneapolis restricting coal tars used in sealants and phosphorous in lawn fertilizers as important contributions to clean lakes.

Managing Milfoil

Most people pinpoint invasive Eurasian milfoil as one of the biggest problems for Minneapolis’ lakes. Although it doesn’t diminish the water quality, it crowds out native species, interferes with swimming and boating and makes the lakes look unappealing.

Some suburban and rural Minnesota communities use chemicals to manage milfoil, but the health and ecological consequences make it an unattractive option to most city residents. Another drawback of that strategy is that milfoil can develop resistance to the poisons used, creating a strain of super-milfoil that is almost impossible to eradicate.

For now, mowing the milfoil is the chief method of management. But DNR regulations limit how much mowing can be done. 

Reducing the amount of phosphorous and nitrogen entering the water is the surest way to protect our lakes, stresses Pilger. While phosphorous is restricted in fertilizer sold in Minneapolis, it still enters the lake via grass clippings, soil, leaves and city water used for lawn irrigation. (Phosphorous is added to Minneapolis city water to prevent corrosion of older lead water pipes.) More regular street sweeping also would improve water quality. 

The University of Minnesota is experimenting with new varieties of lower-maintenance grass for lawns—which require less fertilizer, mowing, and watering. That also means less run-off laced with phosphorous and nitrogen headed for the lakes. Familiar Kentucky bluegrass, which guzzles water and is vulnerable to our native weeds, can be replaced with grasses from the hardy Fine Fescue family—which looks like your usual lawn but will save time and money as well as the lake. 

Many Minnesotans overwater their grass, especially if they have a sprinkler system running on an automatic timer,  notes Sam Bauer, a local lawn consultant. Let the weather be your lawn watering guide, he advises, rather than the “set it and forget it” button on your irrigation system.

Other Tips for Becoming a Lake Steward

  • Minimize the amount of runoff flowing off your property with rain gardens (designed to absorb more rainfall), rain barrels (which can be used for phosphorous-free watering) and planting native species and other lake-friendly landscaping. The nonprofit organization Metro Blooms has helped residents create more than 1000 rain gardens around the Twin Cities in recent years.
  • Promptly pick up pet poop, rather than letting it seep into the ground and eventually down the storm drain and into your nearest lake. 
  • Be smart about applying salt to sidewalks and driveways. Shovel snow and scrape ice before applying salt to sidewalks and driveways, advises Rachael C. Crabb, Water Resources Supervisor of the Minneapolis  Parks & Recreation Board. Also, use more grit and less salt—a 12-ounce coffee mug provides enough salt for 250-square feet of pavement. And keep in mind that traditional salt does not effectively melt snow in very cold temperatures. While many city and county governments are cutting back on salt use, commercial firms are reluctant to follow suit due to fear of liability lawsuits. Many lake advocates are supporting legislation that limits liability exposure for commercial firms and property owners who are certified after being trained in the “Smart Salting” program created by the Minnesota Pollution Control Agency.
  • Monitor your neighborhood sewer grate, picking up leaves and other organic matter as well as garbage that will wind up in the lake. Join the City of Minneapolis’s adopt-a-drain program.
  • Become a Master Water Steward through a program developed by the Freshwater Society—and share your wisdom with friends and neighbors.
  • Join with your neighbors to brainstorm inventive ideas for involving more people in protecting our lakes.  Here are a few ideas that arose during a meeting of Minneapolis Foundation donors:
  • Start a Lakekeepers Movement, rallying supporters with the message “We all have waterfront property in Minneapolis.” Protecting and preserving our lakes calls for an education, organizing and demonstration campaigns. Many people still don’t understand the connection between what happens on their lawn and what happens to the lake. This work could begin with a task force or block clubs going door-to-door informing neighbors about the impact of lawn chemicals and the importance of clearing sewer grates. Groups of neighbors could be mobilized to sweep the streets free of leaves and trash in between scheduled city sweepings. The aspiration would be to change people’s cultural attitudes to the point where lake-friendly lawns and rain gardens elicit more admiration than a lush expanse of alien Kentucky bluegrass. Home tours could be organized to show off how easy and beautiful it is to protect the lakes.
  • Publicize a Water Quality Scorecard. Using data from the park board and grades from the Lake Minnehaha Watershed district, create an easy-to-understand measure for charting progress or decline on key problems in the lakes.
  • Put Kids to Work. Create summer jobs for low-income youth as beachkeepers and milfoil exterminators. A corps of kids could be hired to take care of the beaches or trained as scuba divers to weed out milfoil and other invasive plants from the lake bottom.