On a sunny summer day, it’s hard to find a more vibrant spot than Lake Nokomis.
Swimmers take big laps in the open water, sailors and paddleboarders glide along the surface, small children splash in the shallows and anglers cast lines from the docks. Public beaches across the Twin Cities offer affordable recreation to families throughout the region.
They’re also some of the most restored pieces of nature in Minnesota. State and local governments have invested millions into projects seeking to maintain and clean up waters at urban lakes over the past 20 years. Now, scientists at local universities are measuring the results of those efforts, and trying to understand how the public feels about local lakes.
University of St. Thomas biology professor Chip Small and University of Minnesota researcher Becky Forgrave are leading a project tracking water quality and visitors’ perceptions of water quality at urban lakes across the Twin Cities.
“One piece there’s not been much data on is how this investment impacts how people are experiencing water quality,” Small said.
They are collecting data at 17 lakes in the Twin Cities. Students help Small and Forgrave collect weekly water samples measuring levels of phosphorus, E. coli and other variables that affect water quality. The project is also soliciting opinions from guests to gauge their thoughts on the waters they visit.
The survey is advertised on multiple signs posted around each of the 17 lakes. It asks visitors to evaluate the lake’s water quality on a scale of 1 through 10. People can text four numbers that offer an automated questionnaire in different languages: English, Hmong, Spanish and Somali.
The first question, asking for a 1 through 10 grade, is the most important, but the researchers have programmed 11 follow-up questions seeking more detailed assessments about what factors influence perspective on water quality. There are questions about how frequently people visit the lake and why; if the lake seems good for fishing and whether they would eat fish caught there; and if they’ve visited the lake frequently and noticed changes in the water quality.
“People’s opinions can guide research, guide policy, guide management of lakes,” Forgrave said.
Perception doesn’t equal reality
Urban lakes are noticeably cleaner than they used to be, Forgrave said. About 80% of the lakes removed from the state’s impaired water database in the past 20 years are in urban areas, she said.
“It really shows the power of governance, attention and action,” Forgrave said.
But perception doesn’t always match reality, Small said. If the lake appears very green, most people will assume the water quality is low, but that’s not the case.
“In general, perception of water quality is based on clarity,” Small said.
Lola Liu lives in White Bear Lake, but brought her young children to meet friends for a beach day at Lake Nokomis in mid-June. She frequents lake beaches in the summer and generally feels good about the water quality.
“It looks nice and clean,” Liu said.
The week before Liu’s visit, the Minneapolis Park and Recreation Board issued a swim advisory at Lake Nokomis. An early season algae bloom was announced on June 3. Algae blooms are caused by excessive nitrogen and phosphorus and can be exacerbated by warmer temperatures and larger rainfalls caused by climate change.
“Wetter springs and hotter summers are both challenges for more algal blooms,” Forgrave said.
Phosphorus pollution leads to algae blooms, which can lead to fish kills, which can understandably make people feel pretty bad about the quality of their local lake, Small said. That happened on Como Lake in St. Paul in early June.
Algae blooms can cause illness in people who accidentally drink impacted water, and have been known to kill or seriously harm dogs who drink from lakes. The blooms often look like someone spilled green paint into the water, and leave a scummy film over water in impacted areas. The blooms typically give off a swampy odor.
It’s hard for local parks districts to decide when to issue a water quality warning. Often the test results that trigger those warnings are based on samples taken a day or two earlier. Changing weather conditions and rainfall can alleviate the issue by the time signs are posted on local beaches.
Managing the quality of urban lakes is a big challenge, Forgrave said. Lakes aren’t swimming pools. Generally speaking, the larger the lake, the easier it can absorb pollution runoff and changing temperatures. Lake Nokomis is reliably middle of the pack in terms of urban water quality, but smaller bodies like Como Lake in St. Paul can fluctuate easily.
“We should have different expectations for different sizes of lakes,” Small said.
Improving water quality
The ongoing research partnership between the University of Minnesota and St. Thomas is funded by the Minnesota Environment and Natural Resources Trust Fund, a program funded by the state lottery that supports environmental research and natural resources protections. In 2024, Minnesotans voted overwhelmingly to extend the program for another 25 years.
“People want to see that their tax money is improving water quality,” Forgrave said.
Most lake visitors who spoke with Sahan Journal felt good about water quality.
Robert Xiong still takes his sons, ages 14 and 6, fishing at Lake Nokomis. The family lives in Andover now, but called south Minneapolis home for years. They mostly catch bluegills and release them back into the water. He’s always felt good about the lake as a spot to swim or fish with his family.
“We like the lake; we think it’s a good spot to be with kids,” Xiong said.
On the same dock, Jeremy Bucay cast out fishing lines with his friends Mateo and Michael. Normally they swim at Lake Nokomis but enjoy all sorts of recreation there. The water seems clean enough, Bucay said, as his friend reeled in a sunfish.
When he thinks of visiting the lakes, it’s all about swimming, fishing and family, Bucay said.
How to give your thoughts on water quality
- Look out for signs posted around urban lakes you visit, typically placed near beaches and boat launches.
- Text the number affiliated with your language. Each lake has its own set of numbers.
- Answer questions that include 1-10 rankings, yes and no answers, and open-ended responses.
