Big Swan Lake vs Francis Lake
Water quality, depth, fish species, and recreation comparison.
Francis Lake has a higher water quality grade (C, Fair) than Big Swan Lake (F, Very Poor). Both are in Meeker County, Minnesota.
Big Swan Lake and Francis 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 meaningfully apart: Francis Lake grades a C while Big Swan Lake grades a F. That two-letter spread reflects real underlying differences — different watershed inputs, different depth profiles, or different monitoring rigor.
For a recreational visitor, the wider grade gap is decisive — Francis 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
Very murky, less than 2.6 ft of visibility.
Francis Lake
Murky, only visible to about 6.5 ft.
Side-by-Side Metrics
| Metric | Big Swan Lake | Francis Lake |
|---|---|---|
| Overall Grade | F (Very Poor) | C (Fair) |
| Water Clarity | 2.6 ft | 6.5 ft |
| Phosphorus | 86.5 µg/L | 23 µg/L |
| Chlorophyll-a (Algae) | 61.3 µg/L | 8.9 µg/L |
| Maximum Depth | 32 ft | 17 ft |
| Surface Area | 684 acres | 1,053 acres |
| Public Access | Yes | Yes |
| Fish Species | 23 | 14 |
| Trophic State | eutrophic | eutrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Francis Lake wins on overall water quality with a Grade C versus Big Swan Lake's Grade F. Water clarity: 6.5 ft vs 2.6 ft. For more fish-species variety, Big Swan Lake edges ahead with 23 documented species.
Source: EPA National Aquatic Resource Surveys, 2026.