Big Swan Lake vs Little Birch Lake
Water quality, depth, fish species, and recreation comparison.
Little Birch Lake has a higher water quality grade (A, Excellent) than Big Swan Lake (C, Fair). Both are in Todd County, Minnesota.
Both Big Swan Lake and Little Birch 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. Little Birch Lake (A) is materially cleaner than Big Swan Lake (C). A gap that wide is unlikely to close in a single year of remediation work; it reflects multi-decade differences in the lakes themselves.
For a recreational visitor, the wider grade gap is decisive — Little Birch Lake is the better water-quality choice. For a researcher, the gap is the interesting part: what is different about the two watersheds, and which of those differences is mutable?
Big Swan Lake
Moderate clarity, visible to about 8.9 ft.
Little Birch Lake
Good clarity, visible to about 14 ft.
Side-by-Side Metrics
| Metric | Big Swan Lake | Little Birch Lake |
|---|---|---|
| Overall Grade | C (Fair) | A (Excellent) |
| Water Clarity | 8.9 ft | 14 ft |
| Phosphorus | No data | 18 µg/L |
| Chlorophyll-a (Algae) | No data | No data |
| Maximum Depth | 45 ft | 89 ft |
| Surface Area | 946.56 acres | 839.44 acres |
| Public Access | Yes | Yes |
| Fish Species | 1 | 1 |
| Trophic State | mesotrophic | mesotrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Little Birch Lake wins on overall water quality with a Grade A versus Big Swan Lake's Grade C. Water clarity: 14 ft vs 8.9 ft. For fishing diversity, Little Birch Lake also leads with 1 species.