Lake 37 vs Lake St. Louis by Dam
Water quality, depth, fish species, and recreation comparison.
Lake 37 has a higher water quality grade (B, Good) than Lake St. Louis by Dam (F, Very Poor). Both are in St. Charles County, Wisconsin.
Lake 37 and Lake St. Louis by Dam are both in Missouri — 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: Lake 37 grades a B while Lake St. Louis by Dam 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 — Lake 37 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?
Lake 37
Murky, only visible to about 4 ft.
Lake St. Louis by Dam
Very murky, less than 2.3 ft of visibility.
Side-by-Side Metrics
| Metric | Lake 37 | Lake St. Louis by Dam |
|---|---|---|
| Overall Grade | B (Good) | F (Very Poor) |
| Water Clarity | 4 ft | 2.3 ft |
| Phosphorus | 16 µg/L | 74.8 µg/L |
| Chlorophyll-a (Algae) | 7.2 µg/L | 32.2 µg/L |
| Maximum Depth | - | - |
| Surface Area | 30 acres | 563 acres |
| Public Access | Unknown | Unknown |
| Fish Species | 0 | 0 |
| Trophic State | eutrophic | eutrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Lake 37 wins on overall water quality with a Grade B versus Lake St. Louis by Dam's Grade F. Water clarity: 4 ft vs 2.3 ft. For fishing diversity, Lake 37 also leads with 0 species.