North Dakota vs Minnesota, Lake Water Quality Comparison
A data-driven comparison of lake water quality between North Dakota and Minnesota, built from EPA Water Quality Portal monitoring data.
| North Dakota | Minnesota | |
|---|---|---|
| Total Lakes | 149 | 2,394 |
| Average Grade | C | C |
| Average Score | 1.77 | 2.48 |
| Grade A Lakes | 3 | 699 |
| Grade B Lakes | 16 | 45 |
| Grade C Lakes | 39 | 325 |
| Grade D Lakes | 23 | 231 |
| Grade F Lakes | 10 | 237 |
| Oligotrophic (Cleanest) | 1 | 232 |
| Eutrophic (High Nutrient) | 55 | 586 |
| Fish Species Documented | 0 | 72 |
| Lakes with Fish Data | 0 | 1,623 |
| Lakes with Invasives | 8 | 791 |
| Average Depth (ft) | - | 43 ft |
| Lakes with Depth Data | 0 | 1,842 |
| Improving Trend | 21 | 741 |
| Declining Trend | 32 | 845 |
| Ice Data Available | 0 | 1,054 |
Analysis
North Dakota has 149 graded lakes averaging a C (score 1.77), while Minnesota has 2,394 graded lakes averaging a C (score 2.48). On average water quality, Minnesota comes out ahead.North Dakota counts 3 Grade A lakes and 1 oligotrophic (clearest-class) lakes, against 699 and 232 for Minnesota.
Long-term monitoring shows 21 improving and 32 declining lakes in North Dakota, versus 741 improving and 845 declining in Minnesota. Dataset coverage varies by state: North Dakota 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 North Dakota or Minnesota have cleaner lakes?
North Dakota has an average lake grade of C (score 1.77) while Minnesota averages C (score 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 graded lakes?
North Dakota has 149 graded lakes while Minnesota has 2,394. Counts reflect lakes with enough EPA Water Quality Portal monitoring data to grade, not the total number of lakes in each state.