1
ALittle Long Lake
Hennepin County, Minnesota · 4.7 mi from Oak Lake
- +Two grade letters higher (C → A)
- ++14.5 ft water clarity
- +Lower phosphorus (21.3 vs 42.5 µg/L)
Cleaner Lakes Than Oak Lake
2 higher-graded lakes within 30 miles, ranked by grade improvement and proximity.
Oak Lake carries a Grade C (Fair) water quality score. Within 30 miles, 2 lakes hold a higher grade. Little Long Lake (Hennepin County, Grade A, 4.7 mi away) is the closest meaningful upgrade.
2
CWaconia Lake
Carver County, Minnesota · 6.3 mi from Oak Lake
- +Higher overall water quality score
- ++2.8 ft water clarity
- +Lower phosphorus (30 vs 42.5 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.