Lake grades report out

Lake Calhoun has earned an "A" in a recent water quality report. File photo

Lake Calhoun remains at the top of the class in the annual Lake Grades report issued May 26 by Minnehaha Creek Watershed District.

The sparkling crown jewel of the Chain of Lakes kept up its “A” average in the annual report, which grades lakes in the watershed district based on clarity, algae levels and nutrient growth. Lake of the Isles earned a “C,” Cedar Lake earned a “B” and Lake Harriet, typically an “A” lake like Calhoun, slipped in this year’s report to a “B.”

A “C” grade is considered typical for a lake in the seven-county Twin Cities metropolitan area. An “A”-level lake is the best for recreation activities, including swimming, while “B” and “C” lakes are more likely to experience algae growth that may limit their use for recreation.

Other Minneapolis lakes graded in the report include Nokomis (“C”), Harriet (“C”) and Powderhorn (“D”).

The report’s authors caution that the lake grades are just one window into a lake’s overall health. They don’t give the full picture.

That’s an issue the watershed district aims to address when it rolls out its new E-Grade system in 2018. Also known as the Ecosystem Evaluation Program, the E-Grades is intended to offer a much more comprehensive assessment of lakes, wetlands, streams and even groundwater resources throughout the district, adding new measures for flood control, the diversity of plant and animal life and the range of natural habitats supported by each body of water.

The Minnehaha Creek Watershed District collaborates with several organizations and a group of volunteers to sample lakes throughout its 181-square-mile territory. The Minneapolis Park and Recreation Board is responsible for most measurements in Minneapolis.

For more information, or to read the full report, go to