Walworth County Lake Quality
Wisconsin, 34 lakes, average grade B (Good)
There are 34 graded lakes in Walworth County. The mix is varied enough that the county-level average tells you the broad strokes, not the choose-this-cabin specifics. With an average grade of B, Walworth County sits comfortably above the Wisconsin median.
Many of the county's lakes are deep glacial basins — over 50 feet at their deepest point — which gives them thermal stratification and a buffer against summer warming. Geneva Lake (grade A) is the cleanest in the county.
Quick Answers for Walworth County
Planning a trip? Check special fishing regulations for Geneva Lake, whether the fish are safe to eat, and the best times to fish — or browse the full Wisconsin regulations index.
DNR Reports (2)
Wisconsin DNR Fisheries Survey resources for lakes in Walworth County. browse all reports →
- 2023Lauderdale Lakes Chain comprehensive survey, 2023Comprehensive Survey · WI DNR · 2023 (PDF)
- 2021Turtle Lake spring shocking survey, 2017, 2021Spring Shocking Survey · WI DNR · 2021 (PDF)
All Lakes in Walworth County
| Rank | Lake | Grade | Clarity | Max Depth | Phosphorus |
|---|---|---|---|---|---|
| 1 | Geneva Lake | A | 19 ft | 135 ft | 13 µg/L |
| 2 | Pleasant Lake | A | 44.3 ft | 29 ft | 15.1 µg/L |
| 3 | Green Lake | A | 42.7 ft | 57 ft | 10.5 µg/L |
| 4 | Booth Lake | A | 25.4 ft | 24 ft | 16.4 µg/L |
| 5 | Turtle Lake | A | 36.1 ft | 30 ft | 14.5 µg/L |
| 6 | Pickerel Lake | A | 27.9 ft | 31 ft | - |
| 7 | Middle Lake | A | 34.5 ft | 40 ft | 12.3 µg/L |
| 8 | Lake Beulah | A | 32.8 ft | 58 ft | 13.4 µg/L |
| 9 | Mill Lake | A | 24.6 ft | 40 ft | 15.3 µg/L |
| 10 | Geneva Lake | A | 20.7 ft | 135 ft | 13.4 µg/L |
| 11 | Army Lake | A | 26.9 ft | 17 ft | 11.2 µg/L |
| 12 | Lake Wandawega | A | 19.7 ft | - | - |
| 13 | Peters Lake | A | 18.3 ft | - | 19.6 µg/L |
| 14 | Swan Lake | A | 22.1 ft | - | - |
| 15 | Geneva Lake Site B | A | 24.1 ft | 135 ft | 12.9 µg/L |
| 16 | Swift Lake | A | 19.7 ft | - | - |
| 17 | Lake Beulah Station 2 | A | 10.8 ft | 58 ft | 16.5 µg/L |
| 18 | Lake Beulah | A | 11 ft | 58 ft | 13 µg/L |
| 19 | Whitewater Lake | B | 13.1 ft | 35 ft | 26.2 µg/L |
| 20 | Delavan Lake | B | 24.8 ft | 52 ft | 49.5 µg/L |
| 21 | North Lake | B | 11.5 ft | 11 ft | - |
| 22 | Delavan Lake | B | - | 52 ft | 25.9 µg/L |
| 23 | Delavan Lake | B | 9 ft | 52 ft | 27 µg/L |
| 24 | Delavan Lake | B | 9.3 ft | 52 ft | 26.5 µg/L |
| 25 | Delavan Lake | C | 10 ft | 52 ft | 73 µg/L |
| 26 | Silver Lake | C | 9.8 ft | - | - |
| 27 | Lake Ivanhoe | C | 8.2 ft | 10 ft | - |
| 28 | Lake Lorraine | C | - | 8 ft | 54.1 µg/L |
| 29 | Potter Lake | C | - | 26 ft | 35 µg/L |
| 30 | Potter Lake | C | 3.9 ft | 26 ft | 35 µg/L |
| 31 | Rice Lake | C | 6.2 ft | 10 ft | 57.2 µg/L |
| 32 | Honey Lake | D | 8.2 ft | 6 ft | 99 µg/L |
| 33 | Comus Lake | D | 4.9 ft | 6 ft | 193 µg/L |
| 34 | Outlet To Lake Geneva | F | - | 135 ft | 462 µg/L |
Source: EPA National Aquatic Resource Surveys, 2026.