Deer Lake vs South Twin Lake
Water quality, depth, fish species, and recreation comparison.
Deer Lake and South Twin Lake both received the same overall water quality grade of A (Excellent). Both are in Polk County, Wisconsin.
Deer Lake and South Twin Lake are both in Wisconsin — 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 close: Deer Lake (A) and South Twin Lake (A) are within one letter of each other on the LakeGrade rubric. The per-parameter sub-grades below will show where the small differences actually live.
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.
Deer Lake
Crystal clear, you can see 16 ft down.
South Twin Lake
No clarity data.
Side-by-Side Metrics
| Metric | Deer Lake | South Twin Lake |
|---|---|---|
| Overall Grade | A (Excellent) | A (Excellent) |
| Water Clarity | 16 ft | No data |
| Phosphorus | 16.9 µg/L | 11.7 µg/L |
| Chlorophyll-a (Algae) | No data | No data |
| Maximum Depth | 46 ft | - |
| Surface Area | 786 acres | 639 acres |
| Public Access | Unknown | Unknown |
| Fish Species | 0 | 0 |
| Trophic State | mesotrophic | oligotrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Both lakes earn the same Grade A. The tiebreakers come down to what you want from the lake. Deer Lake matches its peer on species count.