MANKATO — Homeowners in south-central Minnesota are trying to improve the clarity of lakes in their agricultural region, which have high levels of phosphorus.

Department of Natural Resources Waterville area fisheries supervisor Craig Soupir said elevated trophic state indexes, a measure of general water quality, are commonplace in southern Minnesota.

“We generally have very high phosphorus levels in most lakes in our area,” he said. “Because of that we generally have decent amounts of algae blooms.”

There is no catch-all plan to address water quality in the state’s lakes because each one requires a specific approach tailored to its characteristics.

Lake Crystal resident Mike Roll formed the Crystal Waters Project, a collaboration between farmers, lakefront homeowners and other stakeholders interested in protecting the lake.

“We adopted the philosophy that it’s everybody’s problem,” he said. “Some are more contributors than others, but we all drink the water.”

In 2015, the group helped eliminate 97,000 pounds of carp, an invasive species contributing to poor water quality. They also recently led a shore restoration project.

The Lake Washington Improvement Association began similar initiatives in 2005. Association President Jim Folden said the group’s priority is to promote lake recreation.

The association has worked with the Natural Resources Department in recent years on permitted sprays to reduce invasive weeds. Folden said one of the next steps will be working with landowners to promote healthy lakeshores that limit runoff into the lake.

“That’s going to be our next big push,” Folden said. “We’re going to try see what we can do to get more homeowners on the lake involved.”

Jessica Nelson, watershed outreach and geographic information specialist at Minnesota State University’s Water Resources Center, said ongoing management at southern Minnesota lakes will be what’s needed to improve and maintain their quality.