1
ATerra Park Lake
Polk County, Wisconsin · 7.2 mi from Grays Lake
- +Two grade letters higher (F → A)
- ++9.9 ft water clarity
Cleaner Lakes Than Grays Lake
5 higher-graded lakes within 30 miles, ranked by grade improvement and proximity.
Grays Lake carries a Grade F (Very Poor) water quality score. Within 30 miles, 5 lakes hold a higher grade. Terra Park Lake (Polk County, Grade A, 7.2 mi away) is the closest meaningful upgrade.
2
BDale Maffitt Reservoir
Dallas County, Wisconsin · 8.7 mi from Grays Lake
- +Two grade letters higher (F → B)
- ++8.2 ft water clarity
3
CLake Petocka
Polk County, Wisconsin · 13.9 mi from Grays Lake
- +Two grade letters higher (F → C)
- ++1.7 ft water clarity
4
DThomas Mitchell Lake
Polk County, Wisconsin · 14.2 mi from Grays Lake
- +Higher grade (F → D)
- ++1.7 ft water clarity
5
DEaster Lake
Polk County, Wisconsin · 4.6 mi from Grays Lake
- +Higher grade (F → D)
- ++1.3 ft water clarity
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.