Green Lake vs Little Green Lake
Water quality, depth, fish species, and recreation comparison.
Green Lake has a higher water quality grade (A, Excellent) than Little Green Lake (D, Poor). Both are in Green Lake County, Wisconsin.
Green Lake and Little Green 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. Green Lake (A) is materially cleaner than Little Green 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 — Green 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?
Green Lake
Good clarity, visible to about 13.5 ft.
Little Green Lake
Very murky, less than 3.2 ft of visibility.
Side-by-Side Metrics
| Metric | Green Lake | Little Green Lake |
|---|---|---|
| Overall Grade | A (Excellent) | D (Poor) |
| Water Clarity | 13.5 ft | 3.2 ft |
| Phosphorus | 38.1 µg/L | 92.8 µg/L |
| Chlorophyll-a (Algae) | 4.4 µg/L | No data |
| Maximum Depth | 236 ft | 28 ft |
| Surface Area | 7,920 acres | 462 acres |
| Public Access | Yes | Yes |
| Fish Species | 7 | 5 |
| Trophic State | mesotrophic | eutrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Green Lake wins on overall water quality with a Grade A versus Little Green Lake's Grade D. Water clarity: 13.5 ft vs 3.2 ft. For fishing diversity, Green Lake also leads with 7 species.
Source: EPA National Aquatic Resource Surveys, 2026.