Updated Jul 2026
Michigan Lake Water Quality
Water quality grades for 628 monitored lakes across 71 counties.
Across Michigan, 628 lakes carry an active water-quality grade spread over 71 counties. The underlying measurements come from the Michigan Department of Environment, Great Lakes, and Energy (EGLE), alongside federal programs and volunteer monitoring networks. Roughly 32% of the state's graded lakes carry an A — 202 lakes that earn the top bracket on the combined Secchi/phosphorus/chlorophyll-a rubric. That share is high by national standards and reflects the depth and natural clarity of glacial lakes in the region.
Most Michigan lakes sit in the mesotrophic band — moderate productivity, decent clarity, capable of supporting both warm-water and cool-water fisheries. This is the band where well-managed working lakes tend to land. The cleanest county on average is Presque Isle (grade A); the most-stressed is Berrien. The gap between the top and bottom counties is large enough that "Michigan lake water quality" hides real local variation.
Grade Distribution
How Michigan’s 628 graded lakes break down from A (excellent) to F.
Top-Graded Michigan Lakes
The highest water-quality grades in Michigan — clarity, depth, and A-F grade at a glance.
Windover Lake South Basin; Freeman Township
Clare County, Michigan
See grade for Windover Lake South Basin; Freeman Township →Glen Lake
Leelanau County, Michigan
See grade for Glen Lake →Sanford Lake
Benzie County, Michigan
See grade for Sanford Lake →Camp Lake; Deep Basin; Stambaugh Township
Iron County, Michigan
See grade for Camp Lake; Deep Basin; Stambaugh Township →Moon Lake
Gogebic County, Michigan
See grade for Moon Lake →Squaw Lake
Kalkaska County, Michigan
See grade for Squaw Lake →Moon Lake Central Basin; Watersmeet Township
Gogebic County, Michigan
See grade for Moon Lake Central Basin; Watersmeet Township →Camp Lake
Iron County, Michigan
See grade for Camp Lake →Second Fortune Lake; Crystal Falls Township
Iron County, Michigan
See grade for Second Fortune Lake; Crystal Falls Township →Lake Map
Explore Michigan Lakes
Michigan reports, fishing & travel
Michigan's cleanest and most-polluted lakes, ranked A–F
Fish species and top-graded lakes across Michigan
Species activity outlook by water temperature and season
Where to stay at Michigan's top lakes, each with its grade
Best-graded lakes within 50 miles of Detroit
Best-graded lakes within 50 miles of Grand Rapids
Best-graded lakes within 50 miles of Traverse City
Reservoirs in Michigan
View all 58 reservoirs →58 of 628 Michigan lakes (9%) are man-made reservoirs in the USACE National Inventory of Dams. 22 carry a High or Significant hazard rating. The oldest matched dam dates to 1829.
EPA-Impaired Lakes in Michigan
View all 277 impaired lakes →277 of 628 Michigan lakes (44%) are officially listed as impaired under Clean Water Act §303(d) in the most recent EPA ATTAINS reporting cycle. 241 have an approved Total Maximum Daily Load (TMDL) restoration plan.
Michigan Fishing & Recreation
Licenses, regulations, records, and where to fish across Michigan.
Counties
All 71 Michigan counties, ranked by average lake water quality. Compare them against every county nationwide in the county rankings, browse the full directory of graded lakes, or pick a different state.
Michigan Lake Water Quality Dataset (2026)
Every graded Michigan lake in one spreadsheet — A–F grade, water clarity, phosphorus, chlorophyll-a, trophic state, size, public access, and a link to each lake's report card.
Top 25 Cleanest Lakes
| Rank | Lake | County | Grade | Clarity |
|---|---|---|---|---|
| 1 | Windover Lake South Basin; Freeman Township | Clare | A | 15 ft |
| 2 | Glen Lake | Leelanau | A | 15.5 ft |
| 3 | Sanford Lake | Benzie | A | 15.8 ft |
| 4 | Camp Lake; Deep Basin; Stambaugh Township | Iron | A | 16 ft |
| 5 | Moon Lake | Gogebic | A | 18 ft |
| 6 | Squaw Lake | Kalkaska | A | 16 ft |
| 7 | Moon Lake Central Basin; Watersmeet Township | Gogebic | A | 18 ft |
| 8 | Camp Lake | Iron | A | 16 ft |
| 9 | Second Fortune Lake; Crystal Falls Township | Iron | A | 21.8 ft |
| 10 | Corey Lake | St. Joseph | A | 16 ft |
| 11 | Sunset Lake West Central Basin; Bates Township | Iron | A | 15.5 ft |
| 12 | Windover Lake | Clare | A | 15 ft |
| 13 | Lake Ellen | Iron | A | 18 ft |
| 14 | Corey Lake Southeastern Basin; Fabius Township | St. Joseph | A | 16 ft |
| 15 | Ellen Lake South Central Basin; Mansfield Township | Iron | A | 17 ft |
| 16 | Smoky Lake | Iron | A | 24 ft |
| 17 | Second Lake | Iron | A | 22.5 ft |
| 18 | First Lake | Iron | A | 21 ft |
| 19 | Blue Lake | Iron | A | 20.5 ft |
| 20 | Whitefish Bay Deep Lake | Chippewa | A | 34.4 ft |
| 21 | Little Bass Lake | Lake | A | 18.3 ft |
| 22 | Twin Lake | Kalkaska | A | 23 ft |
| 23 | Little Twin Lake | Kalkaska | A | 20 ft |
| 24 | Indian Lake | Kalkaska | A | 16.5 ft |
| 25 | Chicagon Lake | Iron | A | 20.3 ft |
25 Lakes Needing Attention
Where to stay near Michigan
Top-rated places to stay near Michigan
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Source: EPA National Aquatic Resource Surveys, 2026.