Johnson Lake vs Shallow Lake
Water quality, depth, fish species, and recreation comparison.
Johnson Lake and Shallow Lake both received the same overall water quality grade of A (Excellent). Both are in Itasca County, Minnesota.
Johnson Lake and Shallow Lake are both in Minnesota — a same-state head-to-head where the comparison comes down to lake-specific differences in depth, watershed, and monitoring history rather than the broader state-level water-quality regime. The grades are close: Johnson Lake (A) and Shallow Lake (A) are within one letter of each other on the LakeGrade rubric. The per-parameter sub-grades below will show where the small differences actually live.
With grades this close, the choice between the two lakes turns on non-water-quality factors: depth, fish species, public access, distance from home. The per-lake pages below cover all of those.
Johnson Lake
Crystal clear, you can see 15.7 ft down.
Shallow Lake
Crystal clear, you can see 16.4 ft down.
Side-by-Side Metrics
| Metric | Johnson Lake | Shallow Lake |
|---|---|---|
| Overall Grade | A (Excellent) | A (Excellent) |
| Water Clarity | 15.7 ft | 16.4 ft |
| Phosphorus | 9.5 µg/L | 9 µg/L |
| Chlorophyll-a (Algae) | 2.7 µg/L | 3.2 µg/L |
| Maximum Depth | 88 ft | 85 ft |
| Surface Area | 434 acres | 539 acres |
| Public Access | Yes | Yes |
| Fish Species | 11 | 12 |
| Trophic State | oligotrophic | oligotrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Both lakes earn the same Grade A. The tiebreakers come down to clarity (Johnson Lake: 15.7 ft, Shallow Lake: 16.4 ft) and what you want from the lake. Johnson Lake has fewer fish species than Shallow Lake.
Source: EPA National Aquatic Resource Surveys, 2026.