1
ADeep Hole Lake
Oneida County, Wisconsin · 3.7 mi from Thunder Lake
- +Two grade letters higher (C → A)
- ++37.7 ft water clarity
- +Lower phosphorus (10.6 vs 33.1 µg/L)
Cleaner Lakes Than Thunder Lake
3 higher-graded lakes within 30 miles, ranked by grade improvement and proximity.
Thunder Lake carries a Grade C (Fair) water quality score. Within 30 miles, 3 lakes hold a higher grade. Deep Hole Lake (Oneida County, Grade A, 3.7 mi away) is the closest meaningful upgrade.
2
ABass Lake
Oneida County, Wisconsin · 2.2 mi from Thunder Lake
- +Two grade letters higher (C → A)
- ++11.5 ft water clarity
- +Lower phosphorus (21 vs 33.1 µg/L)
3
BLake Thompson
Oneida County, Wisconsin · 3.6 mi from Thunder Lake
- +Higher grade (C → B)
- ++4.9 ft water clarity
- +Lower phosphorus (22.4 vs 33.1 µg/L)
How this list is built
Every lake on LakeQuality has a calculated grade from EPA Water Quality Portal samples — secchi depth, total phosphorus, and chlorophyll-a measured against Metropolitan Council thresholds. To suggest cleaner alternatives, we filter lakes within 30 miles to those with a strictly higher numeric score, then rank by grade improvement with a small proximity tiebreak. Cross-state and limited-data lakes are excluded so the list stays locally relevant.