Report Outlines Michigan's Lake Water Quality

The Michigan Department of Environmental Quality and the U.S. Geological Survey late last month announced the release of a summary report of ambient water quality characteristics of Michigan's inland lakes with public access.

The "State and Regional Water-Quality Characteristics and Trophic Conditions of Michigan's Inland Lakes, 2001-2005" report was prepared by USGS and Michigan Water Science Center, in cooperation with DEQ.

The report summarizes the results of the first five years of Michigan's Lake Water Quality Assessment monitoring project under a joint funding agreement supported with Clean Michigan Initiative funding. The 10-year LWQA monitoring project, which will be completed in 2011, is a component of the DEQ's surface water monitoring strategy.

During 2001-2005, 433 lake basins from 364 inland lakes with public access were monitored for baseline water quality conditions and trophic status, an indicator of primary biological productivity. Trophic evaluations based on the data collected for these lakes indicate nearly three-quarters are either mesotrophic or oligotrophic, which are typically perceived as very good to high quality lakes, and 22 percent are eutrophic. Only four percent of the lakes were classified as hypereutrophic, which is perceived as lower quality by most lake users. Although the distribution of lakes in Michigan is not uniform, the highest percentage of oligotrophic lakes are in the Northern Lakes and Forests or North Central Hardwoods Omernik Level III Ecoregions located in northern Michigan.

The report is available online at or by contacting Lori Fuller at