Little Birch Lake vs Sauk Lake
Water quality, depth, fish species, and recreation comparison.
Little Birch Lake has a higher water quality grade (A, Excellent) than Sauk Lake (D, Poor). Both are in Minnesota.
Both Little Birch Lake and Sauk 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 Sauk Lake (D). 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?
Little Birch Lake
Good clarity, visible to about 13 ft.
Sauk Lake
Murky, only visible to about 3.9 ft.
Side-by-Side Metrics
| Metric | Little Birch Lake | Sauk Lake |
|---|---|---|
| Overall Grade | A (Excellent) | D (Poor) |
| Water Clarity | 13 ft | 3.9 ft |
| Phosphorus | 19 µg/L | 52 µg/L |
| Chlorophyll-a (Algae) | 3.1 µg/L | 22.3 µg/L |
| Maximum Depth | 89 ft | 61 ft |
| Surface Area | 839 acres | 2,126 acres |
| Public Access | Yes | Yes |
| Fish Species | 20 | 18 |
| Trophic State | mesotrophic | eutrophic |
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 Sauk Lake's Grade D. Water clarity: 13 ft vs 3.9 ft. For fishing diversity, Little Birch Lake also leads with 20 species.
Source: EPA National Aquatic Resource Surveys, 2026.