1
AMl-Thains Lake
Mille Lacs County, Minnesota · 16.3 mi from Ann Lake
- +Two grade letters higher (D → A)
- ++14.1 ft water clarity
- +Lower phosphorus (26 vs 78.5 µg/L)
Cleaner Lakes Than Ann Lake
2 higher-graded lakes within 30 miles, ranked by grade improvement and proximity.
Ann Lake carries a Grade D (Poor) water quality score. Within 30 miles, 2 lakes hold a higher grade. Ml-Thains Lake (Mille Lacs County, Grade A, 16.3 mi away) is the closest meaningful upgrade.
2
CLory Lake
Isanti County, Minnesota · 13.5 mi from Ann Lake
- +Higher grade (D → C)
- ++4 ft water clarity
- +Lower phosphorus (41 vs 78.5 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.