Delavan Lake vs Geneva Lake
Water quality, depth, fish species, and recreation comparison.
Geneva Lake has a higher water quality grade (A, Excellent) than Delavan Lake (C, Fair). Both are in Walworth County, Wisconsin.
Both Delavan Lake and Geneva Lake sit in Wisconsin. 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. The grades are meaningfully apart: Geneva Lake grades a A while Delavan Lake grades a C. 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 — Geneva 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?
Delavan Lake
Moderate clarity, visible to about 8 ft.
Geneva Lake
Crystal clear, you can see 20.2 ft down.
Side-by-Side Metrics
| Metric | Delavan Lake | Geneva Lake |
|---|---|---|
| Overall Grade | C (Fair) | A (Excellent) |
| Water Clarity | 8 ft | 20.2 ft |
| Phosphorus | 49.5 µg/L | 13 µg/L |
| Chlorophyll-a (Algae) | No data | No data |
| Maximum Depth | 52 ft | 135 ft |
| Surface Area | 1.9K acres | 5.4K acres |
| Public Access | Unknown | Unknown |
| Fish Species | 0 | 0 |
| Trophic State | eutrophic | oligotrophic |
Bold value = better for that metric (lower phosphorus / chlorophyll = cleaner; higher Secchi / depth / species count = better).
Verdict
Geneva Lake wins on overall water quality with a Grade A versus Delavan Lake's Grade C. Water clarity: 20.2 ft vs 8 ft. For fishing diversity, Geneva Lake also leads with 0 species.