Iowa vs Minnesota, Lake Water Quality Comparison
A data-driven comparison of lake water quality between Iowa and Minnesota, built from EPA Water Quality Portal monitoring data.
| Iowa | Minnesota | |
|---|---|---|
| Total Lakes | 209 | 2,394 |
| Average Score | 0.85 | 2.48 |
| Oligotrophic (Cleanest) | 0 | 232 |
| Eutrophic (High Nutrient) | 54 | 586 |
| Fish Species Documented | 0 | 72 |
| Lakes with Fish Data | 0 | 1,623 |
| Lakes with Invasives | 3 | 791 |
| Average Depth (ft) | - | 43 ft |
| Lakes with Depth Data | 0 | 1,842 |
| Improving Trend | 95 | 741 |
| Declining Trend | 82 | 845 |
| Ice Data Available | 0 | 1,054 |
Analysis
Iowa has 209 lakes with nutrient and algae readings, against 2,394 in Minnesota. On average water quality, Minnesota comes out ahead.Iowa counts 0 oligotrophic lakes, the clearest trophic class, against 232 in Minnesota.
Long-term monitoring shows 95 improving and 82 declining lakes in Iowa, versus 741 improving and 845 declining in Minnesota. Dataset coverage varies by state: Iowa has maximum-depth data for 0 lakes and documented fish species on 0, compared with 1,842 and 1,623 for Minnesota. 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 Iowa or Minnesota have cleaner lakes?
Iowa lakes average a composite water-quality score of 0.85; Minnesota lakes average 2.48. Minnesota has the better average water quality. Grades are computed from EPA Water Quality Portal clarity and nutrient measurements.
Which state has more measured lakes?
Iowa has 209 measured lakes while Minnesota has 2,394. Counts reflect lakes with enough EPA Water Quality Portal monitoring data to reae, not the total number of lakes in each state.