The Six Mile Creek subwatershed is getting a check up. The Minnehaha Creek Watershed District is doing a diagnostic study of the 27-square-mile drainage area along its southwest border, which should be completed by October.
The area is comprised of a series of lakes and streams that flow 12 miles from Pierson Lake to Halsted Bay. Six of the lakes, as well as Halsted Bay, are considered impaired because of the nutrient content in the water.
The goal of the $151,000 study is to find ways to restore water quality throughout the subwatershed and use that information as the MCWD drafts its next 10-year comprehensive plan.
Studies often look at lakes individually, said Erik Cedarleaf Dahl, planner at MCWD. This study is special in that it looks at the subwatershed as a whole system. The bodies of water are all interconnected, he said.
"This study will give us a comprehensive assessment of the watershed and allow us to plan projects and programs to improve water quality," he said. "It will help guide our next generation comprehensive plan for the Six Mile Creek watershed, as well as prioritize our capital projects and program activities."
It will be looking at every lake, studying the fish and plant communities, as well as taking soil cores from the bottom of the lake. It also will be studying the landscape and the predicted land use around the watershed.
The soil cores will provide an opportunity to look at the history of the lake bed, which Cedarleaf Dahl said will help determine where the extra nutrients came from historically.
Even if they come from water runoff and land use, they may be absorbed into the lake bed and released back into the water and then absorbed back into the soil and so on. It is a cycle that keeps going until it is addressed, he said.
Investigating changes in land use around the area and its effect on the water quality is part of that.
Another portion of the study is working with Peter Sorensen, a professor in the Department of Fisheries, Wildlife and Conservation Biology at the University of Minnesota, on a carp tracking study, said Cedarleaf Dahl.
Sorensen has done other carp studies where he tagged and tracked them to find spawning grounds and winter gathering spots. The information he gathered helped create strategies to control carp in those waters.
The methodology used at Six Mile Creek subwatershed may be similar, but the details are being worked out, as well as the cost, said Cedarleaf Dahl.
Other objectives of the study include finding ways to improve aquatic vegetation and restoring fisheries.
The MCWD is seeking input from residents on priorities about water issues in their area of the subwatershed. People who live on or use a lake know more about it and how it has functioned over time, said Cedarleaf Dahl.
"It is important to have that along with the science," he said.
A community meeting and several technical meetings with different government stakeholders in the area were already held.
Cedarleaf Dahl said those comments will be incorporated into the information presented to the MCWD board in November.