The 2023 Cooperative Lakes Monitoring Program report is here and you can view it by clicking on the link above. The Lake Health Committee has included the different tests, their meanings, and our understanding of the data.

Secchi Disk Transparency (Water Clarity). Since 1976 the water clarity on Rose Lake has stayed at an average depth of 10 - 11 feet and is holding steady. We are slightly below average with other lakes in Michigan. This number is produced by taking the average of when the disk disappears and reappears in the water.

Chlorophyll-a, the green pigment in plants, absorbs sunlight and servers as the oxygen production site. This is also a measure of algae. Algae is the most common reason for low water quality readings. Although our Chlorophyll-a numbers are trending downward, this test started only two years ago. We will need further data to see any relevant trends. Our Chlorophyll-a readings are lower than most inland Michigan lakes.

Spring/Summer Phosphorus promotes excessive aquatic plant growth. Phosphorus originates from a variety of sources, many of which are related to human activities. Major sources include human and animal wastes, soil erosion, detergents, septic systems and runoff from farmlands and/or lawns. For the past two years, the spring/summer phosphorus numbers are decreasing but with only two years data, we will continue to assess long term trends.

Dissolved Oxygen is undoubtedly the most important of the gases, since most aquatic organisms need it to survive. The ability of oxygen and other gases to be present depends on water temperature. The colder the water, the more gases it can hold. Boiling water removes all gases. As you can see in the report, our lake runs out of oxygen at the bottom by late summer as the temperatures in the water rise.

Trophic Status of a lake is the nutrient level measurement from the beginning, middle and end of its life span. Yes, lakes could and have had endings. Our nutrient level has improved since testing began in 1976. Rose Lake’s average trophic status is: 39 and that number puts her in the early middle age of her life span.

We thank you for taking a moment to view this important information about Rose Lake/Lake of the Woods water quality. Since the Lake Health committee was formed three years ago, we are well on our way to making a positive impact on the health of the lake. Thank you to everyone involved for your hard work, dedication, and support.