Michigan vs Wisconsin, Lake Water Quality Comparison
A data-driven comparison of lake water quality between Michigan and Wisconsin, built from EPA Water Quality Portal monitoring data.
| Michigan | Wisconsin | |
|---|---|---|
| Total Lakes | 646 | 1,428 |
| Average Score | 3.31 | 2.58 |
| Oligotrophic (Cleanest) | 51 | 132 |
| Eutrophic (High Nutrient) | 36 | 275 |
| Fish Species Documented | 97 | 9 |
| Lakes with Fish Data | 340 | 1,177 |
| Lakes with Invasives | 9 | 914 |
| Average Depth (ft) | - | 34 ft |
| Lakes with Depth Data | 0 | 1,199 |
| Improving Trend | 337 | 532 |
| Declining Trend | 125 | 374 |
Analysis
Michigan has 646 lakes with nutrient and algae readings, against 1,428 in Wisconsin. On average water quality, Michigan comes out ahead.Michigan counts 51 oligotrophic lakes, the clearest trophic class, against 132 in Wisconsin.
Long-term monitoring shows 337 improving and 125 declining lakes in Michigan, versus 532 improving and 374 declining in Wisconsin. Dataset coverage varies by state: Michigan has maximum-depth data for 0 lakes and documented fish species on 340, compared with 1,199 and 1,177 for Wisconsin. Where a figure is zero, that state dataset has not yet been ingested — grades there rest on EPA clarity and nutrient measurements alone.
Frequently Asked Questions
Does Michigan or Wisconsin have cleaner lakes?
Michigan lakes average a composite water-quality score of 3.31; Wisconsin lakes average 2.58. Michigan has the better average water quality. Grades are computed from EPA Water Quality Portal clarity and nutrient measurements.
Which state has more measured lakes?
Michigan has 646 measured lakes while Wisconsin has 1,428. Counts reflect lakes with enough EPA Water Quality Portal monitoring data to reae, not the total number of lakes in each state.