Big Lake vs Thomson Reservoir
Water quality, depth, fish species, and recreation comparison.
Big Lake has a higher water quality grade (A, Excellent) than Thomson Reservoir (F, Very Poor). Both are in Carlton County, Minnesota.
A
Big Lake
Carlton County, Minnesota
Good clarity, visible to about 11.8 ft.
F
Thomson Reservoir
Carlton County, Minnesota
Very murky, less than 3 ft of visibility.
Side-by-Side Metrics
| Metric | Big Lake | Thomson Reservoir |
|---|---|---|
| Overall Grade | A (Excellent) | F (Very Poor) |
| Water Clarity | 11.8 ft | 3 ft |
| Phosphorus | 12 µg/L | No data |
| Chlorophyll-a (Algae) | 3.1 µg/L | No data |
| Maximum Depth | 25 ft | 22 ft |
| Surface Area | 526.42 acres | 389.96 acres |
| Public Access | Yes | No |
| Fish Species | 9 | 10 |
| Trophic State | mesotrophic | eutrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Big Lake wins on overall water quality with a Grade A versus Thomson Reservoir's Grade F. Water clarity: 11.8 ft vs 3 ft. For more fish-species variety, Thomson Reservoir edges ahead with 10 documented species.