Calhoun Lake vs Diamond Lake
Water quality, depth, fish species, and recreation comparison.
Calhoun Lake has a higher water quality grade (C, Fair) than Diamond Lake (D, Nutrient-rich). Both are in Kandiyohi County, Minnesota.
Both Calhoun Lake and Diamond Lake sit in Minnesota. A same-state comparison strips out the state-level water-quality regime as a variable: any grade differences here are about the lakes themselves, not the agencies grading them. These two are within a letter of each other on the rubric — Calhoun Lake (C) versus Diamond Lake (D). The deciding factors for a recreational visitor are likely physical (depth, access, fish species) rather than water-quality differences.
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.
Calhoun Lake
Moderate clarity, visible to about 6.9 ft.
Diamond Lake
Murky, only visible to about 5.6 ft.
Side-by-Side Metrics
| Metric | Calhoun Lake | Diamond Lake |
|---|---|---|
| Overall Grade | C (Fair) Better | D (Nutrient-rich) |
| Water Clarity | 6.9 ft Better | 5.6 ft |
| Phosphorus | 24 µg/L Better | 65 µg/L |
| Chlorophyll-a (Algae) | 8.8 µg/L Better | 17.4 µg/L |
| Maximum Depth | 13 ft | 27 ft Better |
| Surface Area | 647 acres | 1,610 acres |
| Public Access | Yes | Yes |
| Fish Species | 15 | 15 |
| Trophic State | eutrophic | eutrophic |
A green ✓ marks the better value for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better). Surface area and trophic state carry no tick — a bigger lake is not a better lake.
Swap a lake
Compare Calhoun Lake or Diamond Lake against a different lake.
Verdict
Calhoun Lake wins on overall water quality with a Grade C versus Diamond Lake's Grade D. Water clarity: 6.9 ft vs 5.6 ft. For fishing diversity, Calhoun Lake also leads with 15 species.
Source: EPA National Aquatic Resource Surveys, 2026.